वर्ष 2005 में भारत सरकार के वाणिज्य मंत्रालय ने अंतरराष्ट्रीय स्तर पर प्रतिस्पर्धात्मक वातावरण उपलब्ध कराने तथा निर्यात के लिए बाधा मुक्त वातावरण तैयार करने के उद्देश्य से विशेष आर्थिक जोन (एसईजैड) अधिनियम लागू किया। एसईजैड को 'विशिष्ट रूप से निर्धारित शुल्क मुक्त वातावरण और व्यापार संबंधी कार्यों व शुल्कों और टैरिफ के उद्देश्य से विदेशी सीमा (सीमा शुल्क क्षेत्र से परे)' माना गया है। एसईजैड अधिनियम 2005 और इससे संबंधित एसईजैड नियमावली 10 फरवरी 2006 को प्रभावी हुए। इससे क्रियाकलापों को बहुत अधिक सरल बनाया गया तथा केंद्र व राज्य सरकारों से संबंधित मामलों में एकल खिड़की क्लीयरेंस नीति के रूप में निर्धारित किया गया। यह योजना बड़े उद्योगों के लिए बहुत आदर्श है तथा इसका भावी निर्यात एवं रोजगार पर बहुत अनुकूल प्रभाव पड़ेग।
एसईजैड योजना में एसईजैड इकाइयों को प्रत्यक्ष करों के संदर्भ में वही लाभ दिए गए हैं जो एसटीपीआई के अंतर्गत दिए गए हैं, केवल परिचालन संबंधी विवरण में थोड़े बहुत अंतर हैं। परन्तु आय कर के संबंध में अंतर उल्लेखनीय है। एसईजैड योजना के अंतर्गत आय कर में छूट को उत्पाद का निर्यात आरंभ होने की तिथि से 15 वर्ष की अवधि के दौरान धीरे-धीरे कम किया जाता है। उत्पाद का विनिर्माण आरंभ होने के 5 वर्षों तक निर्यात लाभों को आय कर में 100 प्रतिशत छूट प्राप्त है, अगले 5 वर्षां तक यह छूट 50 प्रतिशत है जबकि और अगले 5 वर्षों तक यह 50 प्रतिशत है, बशर्ते कि लाभों को विशेष आरक्षित राशि में हस्तांतरित किया जाए।
एसईजैड नीति का उद्देश्य प्रतिस्पर्धा का सृजन, विश्व स्तर की अवसंरचना उपलब्ध कराते हुए सुविधाजनक एवं समेकित क्षेत्रों की स्थापना करना और वैश्विक स्तर के व्यापार के लिए उपयुक्तत सेवाएं प्रदान करना है। एसईजैड अधिनियम 2005 निर्यात प्रवर्धन एवं संबंधित बुनियादी ढांचे के सृजन में राज्य सरकारों को प्रमुख सुविधाएं उलपब्ध कराता है। एसईजैड योजना की कुछ प्रमुख विशेषताएं इस प्रकार हैं -
बाधा रहित विनिर्माण एवं निर्यात के उद्देश्य से किए जाने वाले व्यापार के लिए विशेष आर्थिक जोन (एसईजैड) गठित किए गए हैं।
घरेलू टैरिफ क्षेत्र (डीटीए) से एसईजैड को होने वाली बिक्री को भौतिक निर्यात माना जाता है। इससे घरेलू आपूर्तिकर्ताओं को ड्राबैक/डीईबीपी लाभ प्राप्त होते हैं, केंद्रीय बिक्री कर में छूट मिलती है और सेवा कर में भी छूट प्राप्त होती है।
एसईजैड इकाइयों को 5 वर्षों तक आय कर में शत-प्रतिशत, उसके 5 वर्ष बाद 50 प्रतिशत और उसके पश्चात 5 वर्षों तक प्राप्त किए गए लाभों पर 50 प्रतिशत की छूट प्राप्त होती है।
यह योजना, जो बड़े उद्योगों के लिए बहुत उपयुक्त है, ने भावी निर्यात एवं रोजगार पर उल्लेखनीय प्रभाव डाला है।
Thursday, March 8, 2012
साफ्टवेयर प्रौद्योगिकी पार्क
देश से साफ्टवेयर निर्यात को बढ़ावा देने के लिए 1991 में सूचना प्रौद्योगिकी विभाग के अंतर्गत स्वायतशासी सोसायटी के रूप में, भारत में, साफ्टवेयर प्रौद्योगिकी पार्क स्थापित किए गए। एसटीपीआई द्वारा साफ्टवेयर निर्यात समुदाय को प्रदान की गई सेवाएं सांविधिक स्वकरूप की रही हैं और इनमें अनिवार्य सेवाओं के अलावा डेटा कम्युनिकेशन सर्वर, इनक्यूबेशन सुविधाएं, प्रशिक्षण और मूल्यवर्धित सेवाएं सम्मिलित हैं। एसटीपीआई ने एसएमई पर विशेष बल देते हुए यूनिटों को आरंभ करने में सॉफ्टवेयर निर्यात के संवर्धन के संदर्भ में प्रमुख विकासात्मक भूमिका अदा की है। एसटीपी योजना साफ्टवेयर उद्योग के संवर्धन के संदर्भ में अत्यधिक सफल सिद्ध हुई है। पिछले कुछ वर्षों में एसटीपी इकाइयों द्वारा किया गया निर्यात कई गुना बढ़ गया है। आज अर्थात 2008-09 के दौरान एसटीपीआई की पंजीकृत यूनिट द्वारा किया गया निर्यात भारतीय रुपये में 215571 करोड़ है जो हमारे देश के कुल सॉफ्टवेयर निर्यात का लगभग 90 प्रतिशत है।
एसटीपीआई योजना की पहचान सूचना प्रौद्योगिकी तथा आईटीईएस निर्यात के संवर्धन हेतु एक सर्वाधिक प्रभावकारी योजना के रूप में की गई है। कार्यक्रम के आरंभ होने से अब तक जो 51 एसटीपीआई केंद्र स्थापित किए गए हैं उनसे सूचना प्रौद्योगिकी एवं आईटीईएस निर्यात को बहुत बढ़ावा मिला है। पूंजीगत साजो-सामान के लिए सीमा शुल्क में उपलब्ध छूट (कुछ अपवादों को छोड़कर) के अलावा सेवा कर, सीमा शुल्क एवं केंंदीय बिक्री कर की अदायगी में भी छूट दी गई है। तथापि, निर्यात से प्राप्त होने वाले लाभ पर आय कर में शत-प्रतिशत की छूट सर्वाधिक महत्वपूर्ण प्रोत्साहन है, जिसे 31 मार्च 2011 तक बढ़ा दिया गया है। इस योजना की शक्ति मुख्यत: इस तथ्य पर निर्भर है कि यह वास्तव में एक ऐसी वास्तविक योजना है जिससे सॉफ्टवेयर कंपनियों को सर्वाधिक सुविधाजनक एवं सबसे सस्ते स्थानों पर अपने क्रियाकलाप चलाने में सुगमता होती है और वे अपने निवेश को भली प्रकार सुनियोजित कर सकते हैं तथा इस व्यापार में आवश्यकता के अनुसार धन निवेश कर सकते हैं। एसटीपी योजना एक पूर्णत: भारतीय योजना है जिसके केंद्र पूरे भारत में फैले हुए हैं और एसटीपी योजना के अंतर्गत 8000 से अधिक इकाइयां पंजीकृत हैं।
एसटीपी योजना के लाभ
एसटीपी योजना के अंतर्गत निम्नलिखित लाभ उपलब्ध हैं :
आय कर अधिनियम की धारा 10क और 10ख के अंतर्गत 31.3.2011 तक आय कर में लाभ
घरेलू खरीद पर केंद्रीय उत्पाद शुल्क में छूट.
फार्म C पर घरेलू खरीद किए जाने पर केंद्रीय बिक्री कर की प्रतिपूर्ति
सैकंड हैंड या पुराने उपकरणों सहित सभी संबंधित उपकरणों/माल का आयात किया जा सकता है (प्रतिबंधित मदों को छोड़कर)
उपकरणों को उधार/पट्टे पर भी आयात किया जा सकता है।
स्वचालित रूट से 100 प्रतिशत एफडीआई की अनुमति है।
स्वीाकृत निर्यात के एफओबी मान के 50 प्रतिशत तक डीटीए की बिक्री की जा सकती है।
कुछ शर्तों सहित आयात किए गए कम्प्यूटरों का अनुप्रयोग प्रशिक्षण के लिए भी किया जा सकता है।
कम्प्यूटरों पर पांच वर्ष या इससे अधिक समय के बाद शत-प्रतिशत मूल्य ह्रास की अनुमति है।
कम्प्यूटरों को उपयोग के 2 वर्ष के पश्चात बिना किसी शुल्क की अदायगी के मान्यता प्राप्त गैर-वाणिज्यिक शैक्षणिक संस्थाओं/अस्पतालों को दान किया जा सकता है।
निर्यात से प्राप्त होने वाली राशि 12 महीनों के अंदर वसूली जा सकती है।
इकाइयों को निर्यात से हुई शत-प्रतिशत आय को ईईएफसी खाते में रखने की अनुमति दी गई है।
एसटीपीआई योजना की पहचान सूचना प्रौद्योगिकी तथा आईटीईएस निर्यात के संवर्धन हेतु एक सर्वाधिक प्रभावकारी योजना के रूप में की गई है। कार्यक्रम के आरंभ होने से अब तक जो 51 एसटीपीआई केंद्र स्थापित किए गए हैं उनसे सूचना प्रौद्योगिकी एवं आईटीईएस निर्यात को बहुत बढ़ावा मिला है। पूंजीगत साजो-सामान के लिए सीमा शुल्क में उपलब्ध छूट (कुछ अपवादों को छोड़कर) के अलावा सेवा कर, सीमा शुल्क एवं केंंदीय बिक्री कर की अदायगी में भी छूट दी गई है। तथापि, निर्यात से प्राप्त होने वाले लाभ पर आय कर में शत-प्रतिशत की छूट सर्वाधिक महत्वपूर्ण प्रोत्साहन है, जिसे 31 मार्च 2011 तक बढ़ा दिया गया है। इस योजना की शक्ति मुख्यत: इस तथ्य पर निर्भर है कि यह वास्तव में एक ऐसी वास्तविक योजना है जिससे सॉफ्टवेयर कंपनियों को सर्वाधिक सुविधाजनक एवं सबसे सस्ते स्थानों पर अपने क्रियाकलाप चलाने में सुगमता होती है और वे अपने निवेश को भली प्रकार सुनियोजित कर सकते हैं तथा इस व्यापार में आवश्यकता के अनुसार धन निवेश कर सकते हैं। एसटीपी योजना एक पूर्णत: भारतीय योजना है जिसके केंद्र पूरे भारत में फैले हुए हैं और एसटीपी योजना के अंतर्गत 8000 से अधिक इकाइयां पंजीकृत हैं।
एसटीपी योजना के लाभ
एसटीपी योजना के अंतर्गत निम्नलिखित लाभ उपलब्ध हैं :
आय कर अधिनियम की धारा 10क और 10ख के अंतर्गत 31.3.2011 तक आय कर में लाभ
घरेलू खरीद पर केंद्रीय उत्पाद शुल्क में छूट.
फार्म C पर घरेलू खरीद किए जाने पर केंद्रीय बिक्री कर की प्रतिपूर्ति
सैकंड हैंड या पुराने उपकरणों सहित सभी संबंधित उपकरणों/माल का आयात किया जा सकता है (प्रतिबंधित मदों को छोड़कर)
उपकरणों को उधार/पट्टे पर भी आयात किया जा सकता है।
स्वचालित रूट से 100 प्रतिशत एफडीआई की अनुमति है।
स्वीाकृत निर्यात के एफओबी मान के 50 प्रतिशत तक डीटीए की बिक्री की जा सकती है।
कुछ शर्तों सहित आयात किए गए कम्प्यूटरों का अनुप्रयोग प्रशिक्षण के लिए भी किया जा सकता है।
कम्प्यूटरों पर पांच वर्ष या इससे अधिक समय के बाद शत-प्रतिशत मूल्य ह्रास की अनुमति है।
कम्प्यूटरों को उपयोग के 2 वर्ष के पश्चात बिना किसी शुल्क की अदायगी के मान्यता प्राप्त गैर-वाणिज्यिक शैक्षणिक संस्थाओं/अस्पतालों को दान किया जा सकता है।
निर्यात से प्राप्त होने वाली राशि 12 महीनों के अंदर वसूली जा सकती है।
इकाइयों को निर्यात से हुई शत-प्रतिशत आय को ईईएफसी खाते में रखने की अनुमति दी गई है।
Disadvantages of Global Warming
Ocean circulation disrupted, disrupting and having unknown effects on world climate.
Higher sea level leading to flooding of low-lying lands and deaths and disease from flood and evacuation.
Deserts get drier leaving to increased desertification.
Changes to agricultural production that can lead to food shortages.
Water shortages in already water-scarce areas.
Starvation, malnutrition, and increased deaths due to food and crop shortages.
More extreme weather and an increased frequency of severe and catastrophic storms.
Increased disease in humans and animals.
Increased deaths from heat waves.
Extinction of additional species of animals and plants.
Loss of animal and plant habitats.
Increased emigration of those from poorer or low-lying countries to wealthier or higher countries seeking better (or non-deadly) conditions.
Additional use of energy resources for cooling needs.
Increased air pollution.
Increased allergy and asthma rates due to earlier blooming of plants.
Melt of permafrost leads to destruction of structures, landslides, and avalanches.
Permanent loss of glaciers and ice sheets.
Cultural or heritage sites destroyed faster due to increased extremes.
Increased acidity of rainfall.
Earlier drying of forests leading to increased forest fires in size and intensity.
Increased cost of insurance as insurers pay out more claims resulting from increasingly large disasters.
Higher sea level leading to flooding of low-lying lands and deaths and disease from flood and evacuation.
Deserts get drier leaving to increased desertification.
Changes to agricultural production that can lead to food shortages.
Water shortages in already water-scarce areas.
Starvation, malnutrition, and increased deaths due to food and crop shortages.
More extreme weather and an increased frequency of severe and catastrophic storms.
Increased disease in humans and animals.
Increased deaths from heat waves.
Extinction of additional species of animals and plants.
Loss of animal and plant habitats.
Increased emigration of those from poorer or low-lying countries to wealthier or higher countries seeking better (or non-deadly) conditions.
Additional use of energy resources for cooling needs.
Increased air pollution.
Increased allergy and asthma rates due to earlier blooming of plants.
Melt of permafrost leads to destruction of structures, landslides, and avalanches.
Permanent loss of glaciers and ice sheets.
Cultural or heritage sites destroyed faster due to increased extremes.
Increased acidity of rainfall.
Earlier drying of forests leading to increased forest fires in size and intensity.
Increased cost of insurance as insurers pay out more claims resulting from increasingly large disasters.
Applications of Nanotechnology
Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometres. Quantum mechanical effects are important at this quantum-realm scale.
The biological and medical research communities have exploited the unique properties of nanomaterials for various applications (e.g., contrast agents for cell imaging and therapeutics for treating cancer). Terms such as biomedical nanotechnology, nanobiotechnology, and nanomedicine are used to describe this hybrid field. Functionalities can be added to nanomaterials by interfacing them with biological molecules or structures. The size of nanomaterials is similar to that of most biological molecules and structures; therefore, nanomaterials can be useful for both in vivo and in vitro biomedical research and applications. Thus far, the integration of nanomaterials with biology has led to the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications, and drug delivery vehicles.
Nanotechnology-on-a-chip is one more dimension of lab-on-a-chip technology. Magnetic nanoparticles, bound to a suitable antibody, are used to label specific molecules, structures or microorganisms. Gold nanoparticles tagged with short segments of DNA can be used for detection of genetic sequence in a sample. Multicolor optical coding for biological assays has been achieved by embedding different-sized quantum dots into polymeric microbeads. Nanopore technology for analysis of nucleic acids converts strings of nucleotides directly into electronic signatures.
Nanotechnology has been a boon for the medical field by delivering drugs to specific cells using nanoparticles. The overall drug consumption and side-effects can be lowered significantly by depositing the active agent in the morbid region only and in no higher dose than needed. This highly selective approach reduces costs and human suffering. An example can be found in dendrimers and nanoporous materials. Another example is to use block co-polymers, which form micelles for drug encapsulation.
Nanotechnology can help reproduce or repair damaged tissue. “Tissue engineering” makes use of artificially stimulated cell proliferation by using suitable nanomaterial-based scaffolds and growth factors. For example, bones can be regrown on carbon nanotube scaffolds. Tissue engineering might replace today's conventional treatments like organ transplants or artificial implants. Advanced forms of tissue engineering may lead to life extension.
A strong influence of photochemistry on waste-water treatment, air purification and energy storage devices is to be expected. Mechanical or chemical methods can be used for effective filtration techniques. One class of filtration techniques is based on the use of membranes with suitable hole sizes, whereby the liquid is pressed through the membrane. Nanoporous membranes are suitable for a mechanical filtration with extremely small pores smaller than 10 nm (“nanofiltration”) and may be composed of nanotubes. Nanofiltration is mainly used for the removal of ions or the separation of different fluids. On a larger scale, the membrane filtration technique is named ultrafiltration, which works down to between 10 and 100 nm. One important field of application for ultrafiltration is medical purposes as can be found in renal dialysis. Magnetic nanoparticles offer an effective and reliable method to remove heavy metal contaminants from waste water by making use of magnetic separation techniques. Using nanoscale particles increases the efficiency to absorb the contaminants and is comparatively inexpensive compared to traditional precipitation and filtration methods.
A reduction of energy consumption can be reached by better insulation systems, by the use of more efficient lighting or combustion systems, and by use of lighter and stronger materials in the transportation sector. Currently used light bulbs only convert approximately 5% of the electrical energy into light. Nanotechnological approaches like light-emitting diodes (LEDs) or quantum caged atoms (QCAs) could lead to a strong reduction of energy consumption for illumination.
Today's best solar cells have layers of several different semiconductors stacked together to absorb light at different energies but they still only manage to use 40 percent of the Sun's energy. Commercially available solar cells have much lower efficiencies (15-20%). Nanotechnology could help increase the efficiency of light conversion by using nanostructures with a continuum of bandgaps.
The degree of efficiency of the internal combustion engine is about 30-40% at present. Nanotechnology could improve combustion by designing specific catalysts with maximized surface area. In 2005, scientists at the University of Toronto developed a spray-on nanoparticle substance that, when applied to a surface, instantly transforms it into a solar collector.
Current high-technology production processes are based on traditional top down strategies, where nanotechnology has already been introduced silently. The critical length scale of integrated circuits is already at the nanoscale (50 nm and below) regarding the gate length of transistors in CPUs or DRAM devices.
Electronic memory designs in the past have largely relied on the formation of transistors. However, research into crossbar switch based electronics have offered an alternative using reconfigurable interconnections between vertical and horizontal wiring arrays to create ultra high density memories. Two leaders in this area are Nantero which has developed a carbon nanotube based crossbar memory called Nano-RAM and Hewlett-Packard which has proposed the use of memristor material as a future replacement of Flash memory.
The production of displays with low energy consumption could be accomplished using carbon nanotubes (CNT). Carbon nanotubes are electrically conductive and due to their small diameter of several nanometers, they can be used as field emitters with extremely high efficiency for field emission displays (FED). The principle of operation resembles that of the cathode ray tube, but on a much smaller length scale.
Entirely new approaches for computing exploit the laws of quantum mechanics for novel quantum computers, which enable the use of fast quantum algorithms. The Quantum computer has quantum bit memory space termed "Qubit" for several computations at the same time. This facility may improve the performance of the older systems.
Lighter and stronger materials will be of immense use to aircraft manufacturers, leading to increased performance. Spacecraft will also benefit, where weight is a major factor. Nanotechnology would help to reduce the size of equipment and thereby decrease fuel-consumption required to get it airborne.
Hang gliders may be able to halve their weight while increasing their strength and toughness through the use of nanotech materials. Nanotech is lowering the mass of supercapacitors that will increasingly be used to give power to assistive electrical motors for launching hang gliders off flatland to thermal-chasing altitudes.
Chemical catalysis benefits especially from nanoparticles, due to the extremely large surface to volume ratio. The application potential of nanoparticles in catalysis ranges from fuel cell to catalytic converters and photocatalytic devices. Catalysis is also important for the production of chemicals.
The synthesis provides novel materials with tailored features and chemical properties: for example, nanoparticles with a distinct chemical surrounding (ligands), or specific optical properties. In this sense, chemistry is indeed a basic nanoscience. In a short-term perspective, chemistry will provide novel “nanomaterials” and in the long run, superior processes such as “self-assembly” will enable energy and time preserving strategies. In a sense, all chemical synthesis can be understood in terms of nanotechnology, because of its ability to manufacture certain molecules. Thus, chemistry forms a base for nanotechnology providing tailor-made molecules, polymers, etcetera, as well as clusters and nanoparticles.
Nanotechnology has the potential to make construction faster, cheaper, safer, and more varied. Automation of nanotechnology construction can allow for the creation of structures from advanced homes to massive skyscrapers much more quickly and at much lower cost. In the near future Nanotechnology can be used to sense cracks in foundations of architecture and can send nanobots to repair them.
Nanotechnology is one of the most active research areas that encompass a number of disciplines Such as electronics, bio-mechanics and coatings including civil engineering and construction materials.
The use of nanotechnology in construction involves the development of new concept and understanding of the hydration of cement particles and the use of nano-size ingredients such as alumina and silica and other nanoparticles. The manufactures also investigating the methods of manufacturing of nano-cement. If cement with nano-size particles can be manufactured and processed, it will open up a large number of opportunities in the fields of ceramics, high strength composites and electronic applications. Since at the nanoscale the properties of the material are different from that of their bulk counter parts. When materials becomes nano-sized, the proportion of atoms on the surface increases relative to those inside and this leads to novel properties. Some applications of nanotechnology in construction are describe below.
Steel has been widely available material and has a major role in the construction industry. The use of nanotechnology in steel helps to improve the properties of steel. The fatigue, which led to the structural failure of steel due to cyclic loading, such as in bridges or towers.The current steel designs are based on the reduction in the allowable stress, service life or regular inspection regime. This has a significant impact on the life-cycle costs of structures and limits the effective use of resources.The Stress risers are responsible for initiating cracks from which fatigue failure results .The addition of copper nanoparticles reduces the surface un-evenness of steel which then limits the number of stress risers and hence fatigue cracking. Advancements in this technology using nanoparticles would lead to increased safety, less need for regular inspection regime and more efficient materials free from fatigue issues for construction.
The nano-size steel produce stronger steel cables which can be in bridge construction. Also these stronger cable material would reduce the costs and period of construction, especially in suspension bridges as the cables are run from end to end of the span. This would require high strength joints which leads to the need for high strength bolts. The capacity of high strength bolts is obtained through quenching and tempering. The microstructures of such products consist of tempered martensite. When the tensile strength of tempered martensite steel exceeds 1,200 MPa even a very small amount of hydrogen embrittles the grain boundaries and the steel material may fail during use. This phenomenon, which is known as delayed fracture, which hindered the strengthening of steel bolts and their highest strength is limited to only around 1,000 to 1,200 MPa.
Glass is also an important material in construction. Research is being carried out on the application of nanotechnology to glass. Titanium dioxide (TiO2) nanoparticles are used to coat glazing since it has sterilizing and anti-fouling properties. The particles catalyze powerful reactions which break down organic pollutants, volatile organic compounds and bacterial membranes. The TiO2 is hydrophilic (attraction to water) which can attract rain drops which then wash off the dirt particles. Thus the introduction of nanotechnology in the Glass industry, incorporates the self cleaning property of glass.
Fire-protective glass is another application of nanotechnology. This is achieved by using a clear intumescent layer sandwiched between glass panels (an interlayer) formed of silica nanoparticles (SiO2) which turns into a rigid and opaque fire shield when heated. Most of glass in construction is on the exterior surface of buildings. So the light and heat entering the building through glass has to be prevented. The nanotechnology can provide a better solution to block light and heat coming through windows.
Coatings is an important area in construction coatings are extensively use to paint the walls, doors, and windows. Coatings should provide a protective layer which is bound to the base material to produce a surface of the desired protective or functional properties. The coatings should have self healing capabilities through a process of “self-assembly.” Nanotechnology is being applied to paints to obtained the coatings having self healing capabilities and corrosion protection under insulation. Since these coatings are hydrophobic and repels water from the metal pipe and can also protect metal from salt water attack.Nanoparticle based systems can provide better adhesion and transparency. The TiO2 coating captures and breaks down organic and inorganic air pollutants by a photocatalytic process, which leads to putting roads to good environmental use.
Fire resistance of steel structures is often provided by a coating produced by a spray-on-cementitious process.The nano-cement has the potential to create a new paradigm in this area of application because the resulting material can be used as a tough, durable, high temperature coating. It provides a good method of increasing fire resistance and this is a cheaper option than conventional insulation.
Nanotechnology is already impacting the field of consumer goods, providing products with novel functions ranging from easy-to-clean to scratch-resistant. Modern textiles are wrinkle-resistant and stain-repellent; in the mid-term clothes will become “smart”, through embedded “wearable electronics”. Already in use are different nanoparticle improved products. Especially in the field of cosmetics, such novel products have a promising potential.
Complex set of engineering and scientific challenges in the food and bioprocessing industry for manufacturing high quality and safe food through efficient and sustainable means can be solved through nanotechnology. Bacteria identification and food quality monitoring using biosensors; intelligent, active, and smart food packaging systems; nanoencapsulation of bioactive food compounds are few examples of emerging applications of nanotechnology for the food industry. Nanotechnology can be applied in the production, processing, safety and packaging of food. A nanocomposite coating process could improve food packaging by placing anti-microbial agents directly on the surface of the coated film. Nanocomposites could increase or decrease gas permeability of different fillers as is needed for different products. They can also improve the mechanical and heat-resistance properties and lower the oxygen transmission rate. Research is being performed to apply nanotechnology to the detection of chemical and biological substances for sensanges in foods.
The most prominent application of nanotechnology in the household is self-cleaning or “easy-to-clean” surfaces on ceramics or glasses. Nano ceramic particles have improved the smoothness and heat resistance of common household equipment such as the flat iron.
The first sunglasses using protective and anti-reflective ultrathin polymer coatings are on the market. For optics, nanotechnology also offers scratch resistant surface coatings based on nanocomposites. Nano-optics could allow for an increase in precision of pupil repair and other types of laser eye surgery.
The use of engineered nanofibers already makes clothes water- and stain-repellent or wrinkle-free. Textiles with a nanotechnological finish can be washed less frequently and at lower temperatures. Nanotechnology has been used to integrate tiny carbon particles membrane and guarantee full-surface protection from electrostatic charges for the wearer.
One field of application is in sunscreens. The traditional chemical UV protection approach suffers from its poor long-term stability. A sunscreen based on mineral nanoparticles such as titanium dioxide offer several advantages. Titanium oxide nanoparticles have a comparable UV protection property as the bulk material, but lose the cosmetically undesirable whitening as the particle size is decreased.
Applications of nanotechnology have the potential to change the entire agriculture sector and food industry chain from production to conservation, processing, packaging, transportation, and even waste treatment. NanoScience concepts and nanotechnology applications have the potential to redesign the production cycle, restructure the processing and conservation processes and redefine the food habits of the people.
Major challenges related to agriculture like low productivity in cultivable areas, large uncultivable areas, shrinkage of cultivable lands, wastage of inputs like water, fertilizers, pesticides, wastage of products and of course Food security for growing numbers can be addressed through various applications of nanotechnology.
The biological and medical research communities have exploited the unique properties of nanomaterials for various applications (e.g., contrast agents for cell imaging and therapeutics for treating cancer). Terms such as biomedical nanotechnology, nanobiotechnology, and nanomedicine are used to describe this hybrid field. Functionalities can be added to nanomaterials by interfacing them with biological molecules or structures. The size of nanomaterials is similar to that of most biological molecules and structures; therefore, nanomaterials can be useful for both in vivo and in vitro biomedical research and applications. Thus far, the integration of nanomaterials with biology has led to the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications, and drug delivery vehicles.
Nanotechnology-on-a-chip is one more dimension of lab-on-a-chip technology. Magnetic nanoparticles, bound to a suitable antibody, are used to label specific molecules, structures or microorganisms. Gold nanoparticles tagged with short segments of DNA can be used for detection of genetic sequence in a sample. Multicolor optical coding for biological assays has been achieved by embedding different-sized quantum dots into polymeric microbeads. Nanopore technology for analysis of nucleic acids converts strings of nucleotides directly into electronic signatures.
Nanotechnology has been a boon for the medical field by delivering drugs to specific cells using nanoparticles. The overall drug consumption and side-effects can be lowered significantly by depositing the active agent in the morbid region only and in no higher dose than needed. This highly selective approach reduces costs and human suffering. An example can be found in dendrimers and nanoporous materials. Another example is to use block co-polymers, which form micelles for drug encapsulation.
Nanotechnology can help reproduce or repair damaged tissue. “Tissue engineering” makes use of artificially stimulated cell proliferation by using suitable nanomaterial-based scaffolds and growth factors. For example, bones can be regrown on carbon nanotube scaffolds. Tissue engineering might replace today's conventional treatments like organ transplants or artificial implants. Advanced forms of tissue engineering may lead to life extension.
A strong influence of photochemistry on waste-water treatment, air purification and energy storage devices is to be expected. Mechanical or chemical methods can be used for effective filtration techniques. One class of filtration techniques is based on the use of membranes with suitable hole sizes, whereby the liquid is pressed through the membrane. Nanoporous membranes are suitable for a mechanical filtration with extremely small pores smaller than 10 nm (“nanofiltration”) and may be composed of nanotubes. Nanofiltration is mainly used for the removal of ions or the separation of different fluids. On a larger scale, the membrane filtration technique is named ultrafiltration, which works down to between 10 and 100 nm. One important field of application for ultrafiltration is medical purposes as can be found in renal dialysis. Magnetic nanoparticles offer an effective and reliable method to remove heavy metal contaminants from waste water by making use of magnetic separation techniques. Using nanoscale particles increases the efficiency to absorb the contaminants and is comparatively inexpensive compared to traditional precipitation and filtration methods.
A reduction of energy consumption can be reached by better insulation systems, by the use of more efficient lighting or combustion systems, and by use of lighter and stronger materials in the transportation sector. Currently used light bulbs only convert approximately 5% of the electrical energy into light. Nanotechnological approaches like light-emitting diodes (LEDs) or quantum caged atoms (QCAs) could lead to a strong reduction of energy consumption for illumination.
Today's best solar cells have layers of several different semiconductors stacked together to absorb light at different energies but they still only manage to use 40 percent of the Sun's energy. Commercially available solar cells have much lower efficiencies (15-20%). Nanotechnology could help increase the efficiency of light conversion by using nanostructures with a continuum of bandgaps.
The degree of efficiency of the internal combustion engine is about 30-40% at present. Nanotechnology could improve combustion by designing specific catalysts with maximized surface area. In 2005, scientists at the University of Toronto developed a spray-on nanoparticle substance that, when applied to a surface, instantly transforms it into a solar collector.
Current high-technology production processes are based on traditional top down strategies, where nanotechnology has already been introduced silently. The critical length scale of integrated circuits is already at the nanoscale (50 nm and below) regarding the gate length of transistors in CPUs or DRAM devices.
Electronic memory designs in the past have largely relied on the formation of transistors. However, research into crossbar switch based electronics have offered an alternative using reconfigurable interconnections between vertical and horizontal wiring arrays to create ultra high density memories. Two leaders in this area are Nantero which has developed a carbon nanotube based crossbar memory called Nano-RAM and Hewlett-Packard which has proposed the use of memristor material as a future replacement of Flash memory.
The production of displays with low energy consumption could be accomplished using carbon nanotubes (CNT). Carbon nanotubes are electrically conductive and due to their small diameter of several nanometers, they can be used as field emitters with extremely high efficiency for field emission displays (FED). The principle of operation resembles that of the cathode ray tube, but on a much smaller length scale.
Entirely new approaches for computing exploit the laws of quantum mechanics for novel quantum computers, which enable the use of fast quantum algorithms. The Quantum computer has quantum bit memory space termed "Qubit" for several computations at the same time. This facility may improve the performance of the older systems.
Lighter and stronger materials will be of immense use to aircraft manufacturers, leading to increased performance. Spacecraft will also benefit, where weight is a major factor. Nanotechnology would help to reduce the size of equipment and thereby decrease fuel-consumption required to get it airborne.
Hang gliders may be able to halve their weight while increasing their strength and toughness through the use of nanotech materials. Nanotech is lowering the mass of supercapacitors that will increasingly be used to give power to assistive electrical motors for launching hang gliders off flatland to thermal-chasing altitudes.
Chemical catalysis benefits especially from nanoparticles, due to the extremely large surface to volume ratio. The application potential of nanoparticles in catalysis ranges from fuel cell to catalytic converters and photocatalytic devices. Catalysis is also important for the production of chemicals.
The synthesis provides novel materials with tailored features and chemical properties: for example, nanoparticles with a distinct chemical surrounding (ligands), or specific optical properties. In this sense, chemistry is indeed a basic nanoscience. In a short-term perspective, chemistry will provide novel “nanomaterials” and in the long run, superior processes such as “self-assembly” will enable energy and time preserving strategies. In a sense, all chemical synthesis can be understood in terms of nanotechnology, because of its ability to manufacture certain molecules. Thus, chemistry forms a base for nanotechnology providing tailor-made molecules, polymers, etcetera, as well as clusters and nanoparticles.
Nanotechnology has the potential to make construction faster, cheaper, safer, and more varied. Automation of nanotechnology construction can allow for the creation of structures from advanced homes to massive skyscrapers much more quickly and at much lower cost. In the near future Nanotechnology can be used to sense cracks in foundations of architecture and can send nanobots to repair them.
Nanotechnology is one of the most active research areas that encompass a number of disciplines Such as electronics, bio-mechanics and coatings including civil engineering and construction materials.
The use of nanotechnology in construction involves the development of new concept and understanding of the hydration of cement particles and the use of nano-size ingredients such as alumina and silica and other nanoparticles. The manufactures also investigating the methods of manufacturing of nano-cement. If cement with nano-size particles can be manufactured and processed, it will open up a large number of opportunities in the fields of ceramics, high strength composites and electronic applications. Since at the nanoscale the properties of the material are different from that of their bulk counter parts. When materials becomes nano-sized, the proportion of atoms on the surface increases relative to those inside and this leads to novel properties. Some applications of nanotechnology in construction are describe below.
Steel has been widely available material and has a major role in the construction industry. The use of nanotechnology in steel helps to improve the properties of steel. The fatigue, which led to the structural failure of steel due to cyclic loading, such as in bridges or towers.The current steel designs are based on the reduction in the allowable stress, service life or regular inspection regime. This has a significant impact on the life-cycle costs of structures and limits the effective use of resources.The Stress risers are responsible for initiating cracks from which fatigue failure results .The addition of copper nanoparticles reduces the surface un-evenness of steel which then limits the number of stress risers and hence fatigue cracking. Advancements in this technology using nanoparticles would lead to increased safety, less need for regular inspection regime and more efficient materials free from fatigue issues for construction.
The nano-size steel produce stronger steel cables which can be in bridge construction. Also these stronger cable material would reduce the costs and period of construction, especially in suspension bridges as the cables are run from end to end of the span. This would require high strength joints which leads to the need for high strength bolts. The capacity of high strength bolts is obtained through quenching and tempering. The microstructures of such products consist of tempered martensite. When the tensile strength of tempered martensite steel exceeds 1,200 MPa even a very small amount of hydrogen embrittles the grain boundaries and the steel material may fail during use. This phenomenon, which is known as delayed fracture, which hindered the strengthening of steel bolts and their highest strength is limited to only around 1,000 to 1,200 MPa.
Glass is also an important material in construction. Research is being carried out on the application of nanotechnology to glass. Titanium dioxide (TiO2) nanoparticles are used to coat glazing since it has sterilizing and anti-fouling properties. The particles catalyze powerful reactions which break down organic pollutants, volatile organic compounds and bacterial membranes. The TiO2 is hydrophilic (attraction to water) which can attract rain drops which then wash off the dirt particles. Thus the introduction of nanotechnology in the Glass industry, incorporates the self cleaning property of glass.
Fire-protective glass is another application of nanotechnology. This is achieved by using a clear intumescent layer sandwiched between glass panels (an interlayer) formed of silica nanoparticles (SiO2) which turns into a rigid and opaque fire shield when heated. Most of glass in construction is on the exterior surface of buildings. So the light and heat entering the building through glass has to be prevented. The nanotechnology can provide a better solution to block light and heat coming through windows.
Coatings is an important area in construction coatings are extensively use to paint the walls, doors, and windows. Coatings should provide a protective layer which is bound to the base material to produce a surface of the desired protective or functional properties. The coatings should have self healing capabilities through a process of “self-assembly.” Nanotechnology is being applied to paints to obtained the coatings having self healing capabilities and corrosion protection under insulation. Since these coatings are hydrophobic and repels water from the metal pipe and can also protect metal from salt water attack.Nanoparticle based systems can provide better adhesion and transparency. The TiO2 coating captures and breaks down organic and inorganic air pollutants by a photocatalytic process, which leads to putting roads to good environmental use.
Fire resistance of steel structures is often provided by a coating produced by a spray-on-cementitious process.The nano-cement has the potential to create a new paradigm in this area of application because the resulting material can be used as a tough, durable, high temperature coating. It provides a good method of increasing fire resistance and this is a cheaper option than conventional insulation.
Nanotechnology is already impacting the field of consumer goods, providing products with novel functions ranging from easy-to-clean to scratch-resistant. Modern textiles are wrinkle-resistant and stain-repellent; in the mid-term clothes will become “smart”, through embedded “wearable electronics”. Already in use are different nanoparticle improved products. Especially in the field of cosmetics, such novel products have a promising potential.
Complex set of engineering and scientific challenges in the food and bioprocessing industry for manufacturing high quality and safe food through efficient and sustainable means can be solved through nanotechnology. Bacteria identification and food quality monitoring using biosensors; intelligent, active, and smart food packaging systems; nanoencapsulation of bioactive food compounds are few examples of emerging applications of nanotechnology for the food industry. Nanotechnology can be applied in the production, processing, safety and packaging of food. A nanocomposite coating process could improve food packaging by placing anti-microbial agents directly on the surface of the coated film. Nanocomposites could increase or decrease gas permeability of different fillers as is needed for different products. They can also improve the mechanical and heat-resistance properties and lower the oxygen transmission rate. Research is being performed to apply nanotechnology to the detection of chemical and biological substances for sensanges in foods.
The most prominent application of nanotechnology in the household is self-cleaning or “easy-to-clean” surfaces on ceramics or glasses. Nano ceramic particles have improved the smoothness and heat resistance of common household equipment such as the flat iron.
The first sunglasses using protective and anti-reflective ultrathin polymer coatings are on the market. For optics, nanotechnology also offers scratch resistant surface coatings based on nanocomposites. Nano-optics could allow for an increase in precision of pupil repair and other types of laser eye surgery.
The use of engineered nanofibers already makes clothes water- and stain-repellent or wrinkle-free. Textiles with a nanotechnological finish can be washed less frequently and at lower temperatures. Nanotechnology has been used to integrate tiny carbon particles membrane and guarantee full-surface protection from electrostatic charges for the wearer.
One field of application is in sunscreens. The traditional chemical UV protection approach suffers from its poor long-term stability. A sunscreen based on mineral nanoparticles such as titanium dioxide offer several advantages. Titanium oxide nanoparticles have a comparable UV protection property as the bulk material, but lose the cosmetically undesirable whitening as the particle size is decreased.
Applications of nanotechnology have the potential to change the entire agriculture sector and food industry chain from production to conservation, processing, packaging, transportation, and even waste treatment. NanoScience concepts and nanotechnology applications have the potential to redesign the production cycle, restructure the processing and conservation processes and redefine the food habits of the people.
Major challenges related to agriculture like low productivity in cultivable areas, large uncultivable areas, shrinkage of cultivable lands, wastage of inputs like water, fertilizers, pesticides, wastage of products and of course Food security for growing numbers can be addressed through various applications of nanotechnology.
Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometres. Quantum mechanical effects are important at this quantum-realm scale.
The biological and medical research communities have exploited the unique properties of nanomaterials for various applications (e.g., contrast agents for cell imaging and therapeutics for treating cancer). Terms such as biomedical nanotechnology, nanobiotechnology, and nanomedicine are used to describe this hybrid field. Functionalities can be added to nanomaterials by interfacing them with biological molecules or structures. The size of nanomaterials is similar to that of most biological molecules and structures; therefore, nanomaterials can be useful for both in vivo and in vitro biomedical research and applications. Thus far, the integration of nanomaterials with biology has led to the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications, and drug delivery vehicles.
Nanotechnology-on-a-chip is one more dimension of lab-on-a-chip technology. Magnetic nanoparticles, bound to a suitable antibody, are used to label specific molecules, structures or microorganisms. Gold nanoparticles tagged with short segments of DNA can be used for detection of genetic sequence in a sample. Multicolor optical coding for biological assays has been achieved by embedding different-sized quantum dots into polymeric microbeads. Nanopore technology for analysis of nucleic acids converts strings of nucleotides directly into electronic signatures.
Nanotechnology has been a boon for the medical field by delivering drugs to specific cells using nanoparticles. The overall drug consumption and side-effects can be lowered significantly by depositing the active agent in the morbid region only and in no higher dose than needed. This highly selective approach reduces costs and human suffering. An example can be found in dendrimers and nanoporous materials. Another example is to use block co-polymers, which form micelles for drug encapsulation.
Nanotechnology can help reproduce or repair damaged tissue. “Tissue engineering” makes use of artificially stimulated cell proliferation by using suitable nanomaterial-based scaffolds and growth factors. For example, bones can be regrown on carbon nanotube scaffolds. Tissue engineering might replace today's conventional treatments like organ transplants or artificial implants. Advanced forms of tissue engineering may lead to life extension.
A strong influence of photochemistry on waste-water treatment, air purification and energy storage devices is to be expected. Mechanical or chemical methods can be used for effective filtration techniques. One class of filtration techniques is based on the use of membranes with suitable hole sizes, whereby the liquid is pressed through the membrane. Nanoporous membranes are suitable for a mechanical filtration with extremely small pores smaller than 10 nm (“nanofiltration”) and may be composed of nanotubes. Nanofiltration is mainly used for the removal of ions or the separation of different fluids. On a larger scale, the membrane filtration technique is named ultrafiltration, which works down to between 10 and 100 nm. One important field of application for ultrafiltration is medical purposes as can be found in renal dialysis. Magnetic nanoparticles offer an effective and reliable method to remove heavy metal contaminants from waste water by making use of magnetic separation techniques. Using nanoscale particles increases the efficiency to absorb the contaminants and is comparatively inexpensive compared to traditional precipitation and filtration methods.
A reduction of energy consumption can be reached by better insulation systems, by the use of more efficient lighting or combustion systems, and by use of lighter and stronger materials in the transportation sector. Currently used light bulbs only convert approximately 5% of the electrical energy into light. Nanotechnological approaches like light-emitting diodes (LEDs) or quantum caged atoms (QCAs) could lead to a strong reduction of energy consumption for illumination.
Today's best solar cells have layers of several different semiconductors stacked together to absorb light at different energies but they still only manage to use 40 percent of the Sun's energy. Commercially available solar cells have much lower efficiencies (15-20%). Nanotechnology could help increase the efficiency of light conversion by using nanostructures with a continuum of bandgaps.
The degree of efficiency of the internal combustion engine is about 30-40% at present. Nanotechnology could improve combustion by designing specific catalysts with maximized surface area. In 2005, scientists at the University of Toronto developed a spray-on nanoparticle substance that, when applied to a surface, instantly transforms it into a solar collector.
Current high-technology production processes are based on traditional top down strategies, where nanotechnology has already been introduced silently. The critical length scale of integrated circuits is already at the nanoscale (50 nm and below) regarding the gate length of transistors in CPUs or DRAM devices.
Electronic memory designs in the past have largely relied on the formation of transistors. However, research into crossbar switch based electronics have offered an alternative using reconfigurable interconnections between vertical and horizontal wiring arrays to create ultra high density memories. Two leaders in this area are Nantero which has developed a carbon nanotube based crossbar memory called Nano-RAM and Hewlett-Packard which has proposed the use of memristor material as a future replacement of Flash memory.
The production of displays with low energy consumption could be accomplished using carbon nanotubes (CNT). Carbon nanotubes are electrically conductive and due to their small diameter of several nanometers, they can be used as field emitters with extremely high efficiency for field emission displays (FED). The principle of operation resembles that of the cathode ray tube, but on a much smaller length scale.
Entirely new approaches for computing exploit the laws of quantum mechanics for novel quantum computers, which enable the use of fast quantum algorithms. The Quantum computer has quantum bit memory space termed "Qubit" for several computations at the same time. This facility may improve the performance of the older systems.
Lighter and stronger materials will be of immense use to aircraft manufacturers, leading to increased performance. Spacecraft will also benefit, where weight is a major factor. Nanotechnology would help to reduce the size of equipment and thereby decrease fuel-consumption required to get it airborne.
Hang gliders may be able to halve their weight while increasing their strength and toughness through the use of nanotech materials. Nanotech is lowering the mass of supercapacitors that will increasingly be used to give power to assistive electrical motors for launching hang gliders off flatland to thermal-chasing altitudes.
Chemical catalysis benefits especially from nanoparticles, due to the extremely large surface to volume ratio. The application potential of nanoparticles in catalysis ranges from fuel cell to catalytic converters and photocatalytic devices. Catalysis is also important for the production of chemicals.
The synthesis provides novel materials with tailored features and chemical properties: for example, nanoparticles with a distinct chemical surrounding (ligands), or specific optical properties. In this sense, chemistry is indeed a basic nanoscience. In a short-term perspective, chemistry will provide novel “nanomaterials” and in the long run, superior processes such as “self-assembly” will enable energy and time preserving strategies. In a sense, all chemical synthesis can be understood in terms of nanotechnology, because of its ability to manufacture certain molecules. Thus, chemistry forms a base for nanotechnology providing tailor-made molecules, polymers, etcetera, as well as clusters and nanoparticles.
Nanotechnology has the potential to make construction faster, cheaper, safer, and more varied. Automation of nanotechnology construction can allow for the creation of structures from advanced homes to massive skyscrapers much more quickly and at much lower cost. In the near future Nanotechnology can be used to sense cracks in foundations of architecture and can send nanobots to repair them.
Nanotechnology is one of the most active research areas that encompass a number of disciplines Such as electronics, bio-mechanics and coatings including civil engineering and construction materials.
The use of nanotechnology in construction involves the development of new concept and understanding of the hydration of cement particles and the use of nano-size ingredients such as alumina and silica and other nanoparticles. The manufactures also investigating the methods of manufacturing of nano-cement. If cement with nano-size particles can be manufactured and processed, it will open up a large number of opportunities in the fields of ceramics, high strength composites and electronic applications. Since at the nanoscale the properties of the material are different from that of their bulk counter parts. When materials becomes nano-sized, the proportion of atoms on the surface increases relative to those inside and this leads to novel properties. Some applications of nanotechnology in construction are describe below.
Steel has been widely available material and has a major role in the construction industry. The use of nanotechnology in steel helps to improve the properties of steel. The fatigue, which led to the structural failure of steel due to cyclic loading, such as in bridges or towers.The current steel designs are based on the reduction in the allowable stress, service life or regular inspection regime. This has a significant impact on the life-cycle costs of structures and limits the effective use of resources.The Stress risers are responsible for initiating cracks from which fatigue failure results .The addition of copper nanoparticles reduces the surface un-evenness of steel which then limits the number of stress risers and hence fatigue cracking. Advancements in this technology using nanoparticles would lead to increased safety, less need for regular inspection regime and more efficient materials free from fatigue issues for construction.
The nano-size steel produce stronger steel cables which can be in bridge construction. Also these stronger cable material would reduce the costs and period of construction, especially in suspension bridges as the cables are run from end to end of the span. This would require high strength joints which leads to the need for high strength bolts. The capacity of high strength bolts is obtained through quenching and tempering. The microstructures of such products consist of tempered martensite. When the tensile strength of tempered martensite steel exceeds 1,200 MPa even a very small amount of hydrogen embrittles the grain boundaries and the steel material may fail during use. This phenomenon, which is known as delayed fracture, which hindered the strengthening of steel bolts and their highest strength is limited to only around 1,000 to 1,200 MPa.
Glass is also an important material in construction. Research is being carried out on the application of nanotechnology to glass. Titanium dioxide (TiO2) nanoparticles are used to coat glazing since it has sterilizing and anti-fouling properties. The particles catalyze powerful reactions which break down organic pollutants, volatile organic compounds and bacterial membranes. The TiO2 is hydrophilic (attraction to water) which can attract rain drops which then wash off the dirt particles. Thus the introduction of nanotechnology in the Glass industry, incorporates the self cleaning property of glass.
Fire-protective glass is another application of nanotechnology. This is achieved by using a clear intumescent layer sandwiched between glass panels (an interlayer) formed of silica nanoparticles (SiO2) which turns into a rigid and opaque fire shield when heated. Most of glass in construction is on the exterior surface of buildings. So the light and heat entering the building through glass has to be prevented. The nanotechnology can provide a better solution to block light and heat coming through windows.
Coatings is an important area in construction coatings are extensively use to paint the walls, doors, and windows. Coatings should provide a protective layer which is bound to the base material to produce a surface of the desired protective or functional properties. The coatings should have self healing capabilities through a process of “self-assembly.” Nanotechnology is being applied to paints to obtained the coatings having self healing capabilities and corrosion protection under insulation. Since these coatings are hydrophobic and repels water from the metal pipe and can also protect metal from salt water attack.Nanoparticle based systems can provide better adhesion and transparency. The TiO2 coating captures and breaks down organic and inorganic air pollutants by a photocatalytic process, which leads to putting roads to good environmental use.
Fire resistance of steel structures is often provided by a coating produced by a spray-on-cementitious process.The nano-cement has the potential to create a new paradigm in this area of application because the resulting material can be used as a tough, durable, high temperature coating. It provides a good method of increasing fire resistance and this is a cheaper option than conventional insulation.
Nanotechnology is already impacting the field of consumer goods, providing products with novel functions ranging from easy-to-clean to scratch-resistant. Modern textiles are wrinkle-resistant and stain-repellent; in the mid-term clothes will become “smart”, through embedded “wearable electronics”. Already in use are different nanoparticle improved products. Especially in the field of cosmetics, such novel products have a promising potential.
Complex set of engineering and scientific challenges in the food and bioprocessing industry for manufacturing high quality and safe food through efficient and sustainable means can be solved through nanotechnology. Bacteria identification and food quality monitoring using biosensors; intelligent, active, and smart food packaging systems; nanoencapsulation of bioactive food compounds are few examples of emerging applications of nanotechnology for the food industry. Nanotechnology can be applied in the production, processing, safety and packaging of food. A nanocomposite coating process could improve food packaging by placing anti-microbial agents directly on the surface of the coated film. Nanocomposites could increase or decrease gas permeability of different fillers as is needed for different products. They can also improve the mechanical and heat-resistance properties and lower the oxygen transmission rate. Research is being performed to apply nanotechnology to the detection of chemical and biological substances for sensanges in foods.
The most prominent application of nanotechnology in the household is self-cleaning or “easy-to-clean” surfaces on ceramics or glasses. Nano ceramic particles have improved the smoothness and heat resistance of common household equipment such as the flat iron.
The biological and medical research communities have exploited the unique properties of nanomaterials for various applications (e.g., contrast agents for cell imaging and therapeutics for treating cancer). Terms such as biomedical nanotechnology, nanobiotechnology, and nanomedicine are used to describe this hybrid field. Functionalities can be added to nanomaterials by interfacing them with biological molecules or structures. The size of nanomaterials is similar to that of most biological molecules and structures; therefore, nanomaterials can be useful for both in vivo and in vitro biomedical research and applications. Thus far, the integration of nanomaterials with biology has led to the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications, and drug delivery vehicles.
Nanotechnology-on-a-chip is one more dimension of lab-on-a-chip technology. Magnetic nanoparticles, bound to a suitable antibody, are used to label specific molecules, structures or microorganisms. Gold nanoparticles tagged with short segments of DNA can be used for detection of genetic sequence in a sample. Multicolor optical coding for biological assays has been achieved by embedding different-sized quantum dots into polymeric microbeads. Nanopore technology for analysis of nucleic acids converts strings of nucleotides directly into electronic signatures.
Nanotechnology has been a boon for the medical field by delivering drugs to specific cells using nanoparticles. The overall drug consumption and side-effects can be lowered significantly by depositing the active agent in the morbid region only and in no higher dose than needed. This highly selective approach reduces costs and human suffering. An example can be found in dendrimers and nanoporous materials. Another example is to use block co-polymers, which form micelles for drug encapsulation.
Nanotechnology can help reproduce or repair damaged tissue. “Tissue engineering” makes use of artificially stimulated cell proliferation by using suitable nanomaterial-based scaffolds and growth factors. For example, bones can be regrown on carbon nanotube scaffolds. Tissue engineering might replace today's conventional treatments like organ transplants or artificial implants. Advanced forms of tissue engineering may lead to life extension.
A strong influence of photochemistry on waste-water treatment, air purification and energy storage devices is to be expected. Mechanical or chemical methods can be used for effective filtration techniques. One class of filtration techniques is based on the use of membranes with suitable hole sizes, whereby the liquid is pressed through the membrane. Nanoporous membranes are suitable for a mechanical filtration with extremely small pores smaller than 10 nm (“nanofiltration”) and may be composed of nanotubes. Nanofiltration is mainly used for the removal of ions or the separation of different fluids. On a larger scale, the membrane filtration technique is named ultrafiltration, which works down to between 10 and 100 nm. One important field of application for ultrafiltration is medical purposes as can be found in renal dialysis. Magnetic nanoparticles offer an effective and reliable method to remove heavy metal contaminants from waste water by making use of magnetic separation techniques. Using nanoscale particles increases the efficiency to absorb the contaminants and is comparatively inexpensive compared to traditional precipitation and filtration methods.
A reduction of energy consumption can be reached by better insulation systems, by the use of more efficient lighting or combustion systems, and by use of lighter and stronger materials in the transportation sector. Currently used light bulbs only convert approximately 5% of the electrical energy into light. Nanotechnological approaches like light-emitting diodes (LEDs) or quantum caged atoms (QCAs) could lead to a strong reduction of energy consumption for illumination.
Today's best solar cells have layers of several different semiconductors stacked together to absorb light at different energies but they still only manage to use 40 percent of the Sun's energy. Commercially available solar cells have much lower efficiencies (15-20%). Nanotechnology could help increase the efficiency of light conversion by using nanostructures with a continuum of bandgaps.
The degree of efficiency of the internal combustion engine is about 30-40% at present. Nanotechnology could improve combustion by designing specific catalysts with maximized surface area. In 2005, scientists at the University of Toronto developed a spray-on nanoparticle substance that, when applied to a surface, instantly transforms it into a solar collector.
Current high-technology production processes are based on traditional top down strategies, where nanotechnology has already been introduced silently. The critical length scale of integrated circuits is already at the nanoscale (50 nm and below) regarding the gate length of transistors in CPUs or DRAM devices.
Electronic memory designs in the past have largely relied on the formation of transistors. However, research into crossbar switch based electronics have offered an alternative using reconfigurable interconnections between vertical and horizontal wiring arrays to create ultra high density memories. Two leaders in this area are Nantero which has developed a carbon nanotube based crossbar memory called Nano-RAM and Hewlett-Packard which has proposed the use of memristor material as a future replacement of Flash memory.
The production of displays with low energy consumption could be accomplished using carbon nanotubes (CNT). Carbon nanotubes are electrically conductive and due to their small diameter of several nanometers, they can be used as field emitters with extremely high efficiency for field emission displays (FED). The principle of operation resembles that of the cathode ray tube, but on a much smaller length scale.
Entirely new approaches for computing exploit the laws of quantum mechanics for novel quantum computers, which enable the use of fast quantum algorithms. The Quantum computer has quantum bit memory space termed "Qubit" for several computations at the same time. This facility may improve the performance of the older systems.
Lighter and stronger materials will be of immense use to aircraft manufacturers, leading to increased performance. Spacecraft will also benefit, where weight is a major factor. Nanotechnology would help to reduce the size of equipment and thereby decrease fuel-consumption required to get it airborne.
Hang gliders may be able to halve their weight while increasing their strength and toughness through the use of nanotech materials. Nanotech is lowering the mass of supercapacitors that will increasingly be used to give power to assistive electrical motors for launching hang gliders off flatland to thermal-chasing altitudes.
Chemical catalysis benefits especially from nanoparticles, due to the extremely large surface to volume ratio. The application potential of nanoparticles in catalysis ranges from fuel cell to catalytic converters and photocatalytic devices. Catalysis is also important for the production of chemicals.
The synthesis provides novel materials with tailored features and chemical properties: for example, nanoparticles with a distinct chemical surrounding (ligands), or specific optical properties. In this sense, chemistry is indeed a basic nanoscience. In a short-term perspective, chemistry will provide novel “nanomaterials” and in the long run, superior processes such as “self-assembly” will enable energy and time preserving strategies. In a sense, all chemical synthesis can be understood in terms of nanotechnology, because of its ability to manufacture certain molecules. Thus, chemistry forms a base for nanotechnology providing tailor-made molecules, polymers, etcetera, as well as clusters and nanoparticles.
Nanotechnology has the potential to make construction faster, cheaper, safer, and more varied. Automation of nanotechnology construction can allow for the creation of structures from advanced homes to massive skyscrapers much more quickly and at much lower cost. In the near future Nanotechnology can be used to sense cracks in foundations of architecture and can send nanobots to repair them.
Nanotechnology is one of the most active research areas that encompass a number of disciplines Such as electronics, bio-mechanics and coatings including civil engineering and construction materials.
The use of nanotechnology in construction involves the development of new concept and understanding of the hydration of cement particles and the use of nano-size ingredients such as alumina and silica and other nanoparticles. The manufactures also investigating the methods of manufacturing of nano-cement. If cement with nano-size particles can be manufactured and processed, it will open up a large number of opportunities in the fields of ceramics, high strength composites and electronic applications. Since at the nanoscale the properties of the material are different from that of their bulk counter parts. When materials becomes nano-sized, the proportion of atoms on the surface increases relative to those inside and this leads to novel properties. Some applications of nanotechnology in construction are describe below.
Steel has been widely available material and has a major role in the construction industry. The use of nanotechnology in steel helps to improve the properties of steel. The fatigue, which led to the structural failure of steel due to cyclic loading, such as in bridges or towers.The current steel designs are based on the reduction in the allowable stress, service life or regular inspection regime. This has a significant impact on the life-cycle costs of structures and limits the effective use of resources.The Stress risers are responsible for initiating cracks from which fatigue failure results .The addition of copper nanoparticles reduces the surface un-evenness of steel which then limits the number of stress risers and hence fatigue cracking. Advancements in this technology using nanoparticles would lead to increased safety, less need for regular inspection regime and more efficient materials free from fatigue issues for construction.
The nano-size steel produce stronger steel cables which can be in bridge construction. Also these stronger cable material would reduce the costs and period of construction, especially in suspension bridges as the cables are run from end to end of the span. This would require high strength joints which leads to the need for high strength bolts. The capacity of high strength bolts is obtained through quenching and tempering. The microstructures of such products consist of tempered martensite. When the tensile strength of tempered martensite steel exceeds 1,200 MPa even a very small amount of hydrogen embrittles the grain boundaries and the steel material may fail during use. This phenomenon, which is known as delayed fracture, which hindered the strengthening of steel bolts and their highest strength is limited to only around 1,000 to 1,200 MPa.
Glass is also an important material in construction. Research is being carried out on the application of nanotechnology to glass. Titanium dioxide (TiO2) nanoparticles are used to coat glazing since it has sterilizing and anti-fouling properties. The particles catalyze powerful reactions which break down organic pollutants, volatile organic compounds and bacterial membranes. The TiO2 is hydrophilic (attraction to water) which can attract rain drops which then wash off the dirt particles. Thus the introduction of nanotechnology in the Glass industry, incorporates the self cleaning property of glass.
Fire-protective glass is another application of nanotechnology. This is achieved by using a clear intumescent layer sandwiched between glass panels (an interlayer) formed of silica nanoparticles (SiO2) which turns into a rigid and opaque fire shield when heated. Most of glass in construction is on the exterior surface of buildings. So the light and heat entering the building through glass has to be prevented. The nanotechnology can provide a better solution to block light and heat coming through windows.
Coatings is an important area in construction coatings are extensively use to paint the walls, doors, and windows. Coatings should provide a protective layer which is bound to the base material to produce a surface of the desired protective or functional properties. The coatings should have self healing capabilities through a process of “self-assembly.” Nanotechnology is being applied to paints to obtained the coatings having self healing capabilities and corrosion protection under insulation. Since these coatings are hydrophobic and repels water from the metal pipe and can also protect metal from salt water attack.Nanoparticle based systems can provide better adhesion and transparency. The TiO2 coating captures and breaks down organic and inorganic air pollutants by a photocatalytic process, which leads to putting roads to good environmental use.
Fire resistance of steel structures is often provided by a coating produced by a spray-on-cementitious process.The nano-cement has the potential to create a new paradigm in this area of application because the resulting material can be used as a tough, durable, high temperature coating. It provides a good method of increasing fire resistance and this is a cheaper option than conventional insulation.
Nanotechnology is already impacting the field of consumer goods, providing products with novel functions ranging from easy-to-clean to scratch-resistant. Modern textiles are wrinkle-resistant and stain-repellent; in the mid-term clothes will become “smart”, through embedded “wearable electronics”. Already in use are different nanoparticle improved products. Especially in the field of cosmetics, such novel products have a promising potential.
Complex set of engineering and scientific challenges in the food and bioprocessing industry for manufacturing high quality and safe food through efficient and sustainable means can be solved through nanotechnology. Bacteria identification and food quality monitoring using biosensors; intelligent, active, and smart food packaging systems; nanoencapsulation of bioactive food compounds are few examples of emerging applications of nanotechnology for the food industry. Nanotechnology can be applied in the production, processing, safety and packaging of food. A nanocomposite coating process could improve food packaging by placing anti-microbial agents directly on the surface of the coated film. Nanocomposites could increase or decrease gas permeability of different fillers as is needed for different products. They can also improve the mechanical and heat-resistance properties and lower the oxygen transmission rate. Research is being performed to apply nanotechnology to the detection of chemical and biological substances for sensanges in foods.
The most prominent application of nanotechnology in the household is self-cleaning or “easy-to-clean” surfaces on ceramics or glasses. Nano ceramic particles have improved the smoothness and heat resistance of common household equipment such as the flat iron.
Wednesday, March 7, 2012
Earth's outer surface is divided into several rigid segments, or tectonic plates, that migrate across the surface over periods of many millions of years.
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. It is sometimes referred to as the world, the Blue Planet, or by its Latin name, Terra.
Earth formed approximately 4.54 billion years ago by accretion from the solar nebula, and life appeared on its surface within one billion years. The planet is home to millions of species, including humans. Earth's biosphere has significantly altered the atmosphere and other abiotic conditions on the planet, enabling the proliferation of aerobic organisms as well as the formation of the ozone layer which, together with Earth's magnetic field, blocks harmful solar radiation, permitting life on land. The physical properties of the Earth, as well as its geological history and orbit, have allowed life to persist during this period. The planet is expected to continue supporting life for another 500 million to 2.3 billion years.
Earth's outer surface is divided into several rigid segments, or tectonic plates, that migrate across the surface over periods of many millions of years. About 71% of the surface is covered by salt water oceans, with the remainder consisting of continents and islands which together have many lakes and other sources of water that contribute to the hydrosphere. Earth's poles are mostly covered with solid ice (Antarctic ice sheet) or sea ice (Arctic ice cap). The planet's interior remains active, with a thick layer of relatively solid mantle, a liquid outer core that generates a magnetic field, and a solid iron inner core.
Earth interacts with other objects in space, especially the Sun and the Moon. At present, Earth orbits the Sun once every 366.26 times it rotates about its own axis, which is equal to 365.26 solar days, or one sidereal year.The Earth's axis of rotation is tilted 23.4° away from the perpendicular of its orbital plane, producing seasonal variations on the planet's surface with a period of one tropical year (365.24 solar days). Earth's only known natural satellite, the Moon, which began orbiting it about 4.53 billion years ago, provides ocean tides, stabilizes the axial tilt, and gradually slows the planet's rotation. Between approximately 3.8 billion and 4.1 billion years ago, numerous asteroid impacts during the Late Heavy Bombardment caused significant changes to the greater surface environment.
Both the mineral resources of the planet and the products of the biosphere contribute resources that are used to support a global human population. These inhabitants are grouped into about 200 independent sovereign states (193 United Nations recognized sovereign states), which interact through diplomacy, travel, trade, and military action. Human cultures have developed many views of the planet, including personification as a deity, a belief in a flat Earth or in the Earth as the center of the universe, and a modern perspective of the world as an integrated environment that requires stewardship.
Earth formed approximately 4.54 billion years ago by accretion from the solar nebula, and life appeared on its surface within one billion years. The planet is home to millions of species, including humans. Earth's biosphere has significantly altered the atmosphere and other abiotic conditions on the planet, enabling the proliferation of aerobic organisms as well as the formation of the ozone layer which, together with Earth's magnetic field, blocks harmful solar radiation, permitting life on land. The physical properties of the Earth, as well as its geological history and orbit, have allowed life to persist during this period. The planet is expected to continue supporting life for another 500 million to 2.3 billion years.
Earth's outer surface is divided into several rigid segments, or tectonic plates, that migrate across the surface over periods of many millions of years. About 71% of the surface is covered by salt water oceans, with the remainder consisting of continents and islands which together have many lakes and other sources of water that contribute to the hydrosphere. Earth's poles are mostly covered with solid ice (Antarctic ice sheet) or sea ice (Arctic ice cap). The planet's interior remains active, with a thick layer of relatively solid mantle, a liquid outer core that generates a magnetic field, and a solid iron inner core.
Earth interacts with other objects in space, especially the Sun and the Moon. At present, Earth orbits the Sun once every 366.26 times it rotates about its own axis, which is equal to 365.26 solar days, or one sidereal year.The Earth's axis of rotation is tilted 23.4° away from the perpendicular of its orbital plane, producing seasonal variations on the planet's surface with a period of one tropical year (365.24 solar days). Earth's only known natural satellite, the Moon, which began orbiting it about 4.53 billion years ago, provides ocean tides, stabilizes the axial tilt, and gradually slows the planet's rotation. Between approximately 3.8 billion and 4.1 billion years ago, numerous asteroid impacts during the Late Heavy Bombardment caused significant changes to the greater surface environment.
Both the mineral resources of the planet and the products of the biosphere contribute resources that are used to support a global human population. These inhabitants are grouped into about 200 independent sovereign states (193 United Nations recognized sovereign states), which interact through diplomacy, travel, trade, and military action. Human cultures have developed many views of the planet, including personification as a deity, a belief in a flat Earth or in the Earth as the center of the universe, and a modern perspective of the world as an integrated environment that requires stewardship.
Mercury
The innermost planet in the Solar System is a dense, heavily cratered world that takes about 59 Earth days to fully rotate on its own axis as it travels on its 88-day journey around the Sun.
It is possible to see Mercury from the Earth without a telescope or binoculars though its closeness to the Sun's bright light can make it difficult to spot.
Photographed and studied at close range by the Mariner 10 and Messenger probes, Mercury is blasted by solar radiation and is not thought to be a likely place for life to flourish.
Find out more about the other planets in the Solar System
It is possible to see Mercury from the Earth without a telescope or binoculars though its closeness to the Sun's bright light can make it difficult to spot.
Photographed and studied at close range by the Mariner 10 and Messenger probes, Mercury is blasted by solar radiation and is not thought to be a likely place for life to flourish.
Find out more about the other planets in the Solar System
Cyclone Elita
Tropical cyclone Elita formed just off the west coast of the island of Madagascar in the Mozambique Channel on 26 January 2004 as a minimal tropical storm with winds estimated at around 40 mph by the Joint Typhoon Warning Center. Elita then slowly meandered towards the northeast along the coastline of Madagascar before turning southeast and coming ashore on the 29th near the coastal town of Mahajanga on the northwestern coast of Madagascar. One person was reported killed by the storm and numerous houses and buildings were destroyed in the town.
Cyclone Elita was an unusual tropical cyclone that made landfall on Madagascar three times. Elita developed in the Mozambique Channel on January 24, 2004. It strengthened to become a tropical cyclone before striking northwestern Madagascar on January 28. Elita weakened to tropical depression status while crossing the island, and after exiting into the southwest Indian Ocean it turned to the west and moved ashore for a second time on January 31 in eastern Madagascar. After crossing the island, the cyclone intensified again after reaching the Mozambique Channel, and Elita turned to the southeast to make its final landfall on February 3 along southwestern Madagascar. Elita dropped heavy rainfall of over 200 mm (8 inches), which damaged or destroyed thousands of houses in Madagascar. Over 50,000 people were left homeless, primarily in Mahajanga and Toliara provinces. Flooding from the storm damaged or destroyed more than 450 km2 (170 sq mi) of agricultural land, including important crops for food. Across the island, the cyclone caused at least 33 deaths. Elsewhere, the cyclone brought rainfall and damage to Mozambique and Malawi, while its outer circulation produced rough seas and strong winds in Seychelles, Mauritius, and Réunion.
Cyclone Elita was an unusual tropical cyclone that made landfall on Madagascar three times. Elita developed in the Mozambique Channel on January 24, 2004. It strengthened to become a tropical cyclone before striking northwestern Madagascar on January 28. Elita weakened to tropical depression status while crossing the island, and after exiting into the southwest Indian Ocean it turned to the west and moved ashore for a second time on January 31 in eastern Madagascar. After crossing the island, the cyclone intensified again after reaching the Mozambique Channel, and Elita turned to the southeast to make its final landfall on February 3 along southwestern Madagascar. Elita dropped heavy rainfall of over 200 mm (8 inches), which damaged or destroyed thousands of houses in Madagascar. Over 50,000 people were left homeless, primarily in Mahajanga and Toliara provinces. Flooding from the storm damaged or destroyed more than 450 km2 (170 sq mi) of agricultural land, including important crops for food. Across the island, the cyclone caused at least 33 deaths. Elsewhere, the cyclone brought rainfall and damage to Mozambique and Malawi, while its outer circulation produced rough seas and strong winds in Seychelles, Mauritius, and Réunion.
Intelsat
In 1965, Intelsat established the first commercial global satellite communications system. For the first time, people, businesses and governments could communicate instantly, reliably and simultaneously from all corners of the globe. NASA put a man on the moon--and the world watched it happen via Intelsat.
With major milestones such as our 2001 privatization and 2006 acquisition of PanAmSat, Intelsat and our culture of leadership and technical excellence has established satellite communications as an essential element of the global telecommunications infrastructure.
International Telecommunications Satellite Organization (INTELSAT), it was—from 1964 to 2001—an intergovernmental consortium owning and managing a constellation of communications satellites providing international broadcast services.
With major milestones such as our 2001 privatization and 2006 acquisition of PanAmSat, Intelsat and our culture of leadership and technical excellence has established satellite communications as an essential element of the global telecommunications infrastructure.
International Telecommunications Satellite Organization (INTELSAT), it was—from 1964 to 2001—an intergovernmental consortium owning and managing a constellation of communications satellites providing international broadcast services.
Tuesday, March 6, 2012
Code Division Multiple Access.
CDMA stands for Code Division Multiple Access. It is a technique used for digital communication, and wireless technology in particular, that involves multiplexing. Whereas conventional communication systems use constant frequencies, CDMA uses multiple access, or multiplexing. Accomplished through the specific type known as spread spectrum in this case, multiplexing uses varied frequencies to transmit audio signals. This, coupled with code division, which requires a certain code to send and receive the frequency, further protects CDMA communications from interference.
Radio systems, one of the earliest forms of telecommunication, required users to communicate on distinct frequencies. Frequency Division Multiple Access (FDMA), one form of early wireless communication, only allowed users to operate on a single frequency. When tuning in to a radio to get sound, for instance, the listener must select one frequency or another, and must tune the frequency to filter out noise in the spectrum. Another form of early radio communication was Time Division Multiple Access (TDMA). In this case, users could not share a frequency, and each user had to coordinate his or her turn on that frequency in order to communicate.
Both FDMA and TDMA posed restrictions for early users, particularly the military. As early as World War II, militaries recognized the high value in using wireless technology to communicate across vast distances. Military communication units did not always have the time to wait their turn to transmit sound, or to find the right frequency.
Some telecommunication systems allowed military communication units to transmit sound into the same spectrum their adversaries used. Military signals needed a unique identification through a distinct code to avoid interference from enemy communication. The receiver of that message on the other end could then retrieve the message based on its unique code in the spectrum.
Just as the radio moved from military use to commercial use, so too was the case with the wireless technology. CDMA became the early choice for personal communication because it could allow multiple users to communicate within the spectrum, avoiding interference or blocking among users. In 1999, CDMA became the standard technology for the telecommunications industry for its growing wireless systems. Since there are large numbers of users in the system communicating at the same time, code division ensures that each user’s signal remains separate in the spectrum.
Radio systems, one of the earliest forms of telecommunication, required users to communicate on distinct frequencies. Frequency Division Multiple Access (FDMA), one form of early wireless communication, only allowed users to operate on a single frequency. When tuning in to a radio to get sound, for instance, the listener must select one frequency or another, and must tune the frequency to filter out noise in the spectrum. Another form of early radio communication was Time Division Multiple Access (TDMA). In this case, users could not share a frequency, and each user had to coordinate his or her turn on that frequency in order to communicate.
Both FDMA and TDMA posed restrictions for early users, particularly the military. As early as World War II, militaries recognized the high value in using wireless technology to communicate across vast distances. Military communication units did not always have the time to wait their turn to transmit sound, or to find the right frequency.
Some telecommunication systems allowed military communication units to transmit sound into the same spectrum their adversaries used. Military signals needed a unique identification through a distinct code to avoid interference from enemy communication. The receiver of that message on the other end could then retrieve the message based on its unique code in the spectrum.
Just as the radio moved from military use to commercial use, so too was the case with the wireless technology. CDMA became the early choice for personal communication because it could allow multiple users to communicate within the spectrum, avoiding interference or blocking among users. In 1999, CDMA became the standard technology for the telecommunications industry for its growing wireless systems. Since there are large numbers of users in the system communicating at the same time, code division ensures that each user’s signal remains separate in the spectrum.
Digital Versatile Disc — Read Only Memory
A Digital Versatile Disc — Read Only Memory, or DVD-ROM, is a media storage disk that closely resembles a CD or compact disk. The major difference is that the DVD-ROM is formatted to hold far more data. A CD commonly has a capacity of 650 megabytes, while the smallest capacity DVD can store about seven times more data, or 4.38 gigabytes (GB).
There are various kinds of DVDs, but the DVD-ROM refers to a read-only disc, or a disc that cannot be written over. If you purchase a DVD movie from the local video store, you have a good example of a DVD-ROM. Blank DVDs with designations like "DVD-R" and "DVD+R" are formatted, recordable DVDs. The —R and +R refer to competing format standards, but both will record movies, audio or other data.
A DVD-ROM encodes data in the form of a spiraling trail of pits and lands separated by mere nanometers. The trail starts at the center of the DVD-ROM and winds around countless times until it reaches the outer edge. In the case of a double layer disk, the trail continues on a second layer of material. If the disc is also double-sided, the trail of pits and lands extends to side two.
A laser beam in the DVD player tracks the beam as the disc spins, while a special device reads the intensity of the reflection as it bounces off the pits and lands. The reflective variance gets translated to bits of data which form bytes. Hence, DVDs, including the DVD-ROM, can vary in capacity as follows:
Single-sided single-layer disc — 4.38 GB
Single-sided double-layer disc — 7.95 GB
Double-sided single-layer disc — 8.75 GB
Double-sided double-layer disc — 15.9 GB
The DVD-ROM has replaced the videocassette, being far more efficient and superior in all respects. For one, a DVD-ROM stores data in digital form, while the videocassette uses less precise analog technology. A DVD-ROM, under normal conditions, remains error free and consistent, regardless of the amount of times it is viewed, while a video cassette stretches with wear and eventually needs replacement. The DVD-ROM can also hold more information in a higher format, and one can skip to specific scenes without the need for fast-forwarding or rewinding. Finally, the DVD-ROM is much more compact and easier to store, and DVD players can double as CD players.
If purchasing a DVD player, be sure to get one that can play all DVD-ROM formats, including double-sided, double-layered discs. For home theater systems look for models equipped with a 192 kilohertz (kHz), 24-bit digital/analog converter (DAC) for true Dolby theater quality. By comparison, standard DVD players use 96 kHz, 24-bit DACs. This is still a big improvement over CDs, however, which use 44.1 kHz, 16-bit sampling to produce audio. For this reason, people are moving towards DVDs to store music. An audio DVD can hold just over an hour of multi-channel music at 192 kHz, the highest bit rate; about two hours at 96 kHz; and close to seven hours at the standard CD sampling rate of 44.1 kHz.
While cassettes, videocassettes and laser diskc have become legacy technologies, the DVD-ROM appears to be here to stay. Recordable DVDs are available wherever music and movies are sold, including department stores, office supply chains and discount marts.
There are various kinds of DVDs, but the DVD-ROM refers to a read-only disc, or a disc that cannot be written over. If you purchase a DVD movie from the local video store, you have a good example of a DVD-ROM. Blank DVDs with designations like "DVD-R" and "DVD+R" are formatted, recordable DVDs. The —R and +R refer to competing format standards, but both will record movies, audio or other data.
A DVD-ROM encodes data in the form of a spiraling trail of pits and lands separated by mere nanometers. The trail starts at the center of the DVD-ROM and winds around countless times until it reaches the outer edge. In the case of a double layer disk, the trail continues on a second layer of material. If the disc is also double-sided, the trail of pits and lands extends to side two.
A laser beam in the DVD player tracks the beam as the disc spins, while a special device reads the intensity of the reflection as it bounces off the pits and lands. The reflective variance gets translated to bits of data which form bytes. Hence, DVDs, including the DVD-ROM, can vary in capacity as follows:
Single-sided single-layer disc — 4.38 GB
Single-sided double-layer disc — 7.95 GB
Double-sided single-layer disc — 8.75 GB
Double-sided double-layer disc — 15.9 GB
The DVD-ROM has replaced the videocassette, being far more efficient and superior in all respects. For one, a DVD-ROM stores data in digital form, while the videocassette uses less precise analog technology. A DVD-ROM, under normal conditions, remains error free and consistent, regardless of the amount of times it is viewed, while a video cassette stretches with wear and eventually needs replacement. The DVD-ROM can also hold more information in a higher format, and one can skip to specific scenes without the need for fast-forwarding or rewinding. Finally, the DVD-ROM is much more compact and easier to store, and DVD players can double as CD players.
If purchasing a DVD player, be sure to get one that can play all DVD-ROM formats, including double-sided, double-layered discs. For home theater systems look for models equipped with a 192 kilohertz (kHz), 24-bit digital/analog converter (DAC) for true Dolby theater quality. By comparison, standard DVD players use 96 kHz, 24-bit DACs. This is still a big improvement over CDs, however, which use 44.1 kHz, 16-bit sampling to produce audio. For this reason, people are moving towards DVDs to store music. An audio DVD can hold just over an hour of multi-channel music at 192 kHz, the highest bit rate; about two hours at 96 kHz; and close to seven hours at the standard CD sampling rate of 44.1 kHz.
While cassettes, videocassettes and laser diskc have become legacy technologies, the DVD-ROM appears to be here to stay. Recordable DVDs are available wherever music and movies are sold, including department stores, office supply chains and discount marts.
TFT monitor
A TFT monitor uses thin-film transistor technology for the ultimate LCD display. LCD monitors, also called flat panel displays, are replacing the old style cathode ray tubes (CRTs) as the displays of choice. Nearly all LCD monitors today use TFT technology.
The benefit of a TFT monitor is a separate, tiny transistor for each pixel on the display. Because each transistor is so small, the amount of charge needed to control it is also small. This allows for very fast re-drawing of the display, as the image is re-painted or refreshed several times per second.
Prior to TFT, passive matrix LCD displays could not keep up with fast moving images. A mouse dragged across the screen, for example, from point A to point B, would disappear between the two points. A TFT monitor can track the mouse, resulting in a display that can be used for video, gaming and all forms of multimedia.
The benefit of a TFT monitor is a separate, tiny transistor for each pixel on the display. Because each transistor is so small, the amount of charge needed to control it is also small. This allows for very fast re-drawing of the display, as the image is re-painted or refreshed several times per second.
Prior to TFT, passive matrix LCD displays could not keep up with fast moving images. A mouse dragged across the screen, for example, from point A to point B, would disappear between the two points. A TFT monitor can track the mouse, resulting in a display that can be used for video, gaming and all forms of multimedia.
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