Logic Algebra (Second Edition)

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Charles K. Unusually, he shared the Prize with two other physicists who had pursued unrelated work. He also served as Vice Chancellor of the university for a decade. Today, he lives in retirement. Kao began his experiments with fiber optics in the s with strands of glass fibers thinner than a human hair and cheaper to produce than fishing line, which transmitted nearly limitless amounts of digitized data via pulses of laser light. Today, fiber optic cables make up the main infrastructure of modern telecommunications systems, including both telephony and data transmission.

Thus, the Internet depends directly upon Kao's work. The Academy is a non-profit, bilingual, private independent school for grades one through 12, and is an inquiry-based learning environment. Web resource: Charles K. Kao's NobelPrize. Martin Karplus. In , Karplus received the Nobel Prize in Chemistry, along with Michael Levitt and Arieh Warshel, for developing multi-scale models for complex chemical systems.

Their contribution was ground-breaking, because they managed to make Newton's classical physics work side-by-side with quantum mechanics. This approach makes possible computer simulations that are so realistic they closely resemble the outcome of traditional laboratory experiments. He has made many contributions to physical chemistry, quantum chemistry, and molecular dynamics.

The Karplus equation, which describes the correlation between coupling constants and dihedral angles in protein nuclear magnetic resonance spectroscopy, is named after him. Karplus, who was born in Austria, has also made numerous contributions to the field of theoretical chemistry through textbooks, such as Proteins: A Theoretical Perspective of Dynamics , Structure and Thermodynamics , and Atoms and Molecules: An Introduction for Students of Physical Chemistry. His current research interests are concerned with the physical properties of molecules of biological interest.

Web resource: Martin Karplus's Home Page. Donald Knuth. Donald Knuth is a mathematician and computer scientist. He is the author of the multi-volume work, The Art of Computer Programming , which is the "bible" of the field of computer programming. As of , the first three volumes and part one of volume four of this magnum opus had been published.

Knuth was elected to the U. National Academy of Sciences in , and in , he was elected as a foreign member of the Royal Society of London. In , he was elected as a Fellow of the Society for Industrial and Applied Mathematics, and in , he became a fellow of the American Mathematical Society. Web resource: Donald Knuth's Home Page. Robert J. Marks II. Previously, he was on the faculty of the University of Washington for 25 years. He is a pioneer in the field of computational intelligence which includes neural networks, fuzzy sets, and evolutionary computing , and was the first president of the Institute of Electrical and Electronics Engineers IEEE Neural Networks Council.

He has over peer-reviewed journal publications. He is also a proponent of intelligent design, holding that certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection. Marks has made important technical contributions across widely diverse areas, such as the spacing of radium inserts to treat prostate cancer, signal display, remote sensing, optical image sampling, optical computers, and the use of fuzzy logic to control the electrical grid how electricity is delivered today depends crucially on the work of Marks.

He has served as a consultant to companies such as Microsoft and Boeing corporation. He is a fellow of the IEEE. In , Marks founded the Evolutionary Informatics Lab at Baylor to study the information-theoretic underpinnings of intelligent design. The research of that lab has produced a steady stream of peer-reviewed engineering publications that are influencing many in the engineering community to accept intelligent design, controversial though it remains, as a legitimate scientific theory. Web resource: Robert J. Marks II's Home Page.

Craig C. Mello is a biologist and professor of molecular medicine at the University of Massachusetts. Mello is involved in several RNAi-based biotechnological companies. He co-founded the scientific advisory board member of RXi Pharmaceuticals, which is now Galena Biopharma. He serves on the Technology Advisory Board of Monsanto, formerly Biologics, a company focused on development of RNAi products for honeybee health and various veterinary and agricultural applications.

Mello has earned numerous other notable awards and honors besides the Nobel Prize, including the Hope Funds Award of Excellence in Basic Research in , the Massry Prize in , and election to the National Academy of Sciences in Web resource: Craig C. Mello's Home Page. Luc Montagnier. In , Montagnier was awarded the Nobel Prize for Physiology or Medicine for his discovery of the human immunodeficiency virus.

In , Montagnier led the team which first isolated the Human Immunodeficiency Virus HIV , a new type of retrovirus previously unrecognized in humans, and brought the first evidence that this virus was the causative agent of AIDS. Montagnier has also conducted research, along with colleagues, that has indicated that electromagnetic signals emitted by medicines can remain in water and have dramatic biological effects. Montagnier, a native of France, has been honored worldwide with many awards, including the Grand Officer of the Legion of Honour in , the induction to the National Inventor Hall of Fame in , and the Lasker Prize in Medicine in , among numerous other awards.

Montagnier is the author or co-author of scientific publications and of more than patents. His current studies aim at the diagnosis and treatment of microbial, viral, and epigenetic factors associated with cancers, neurodegenerative, and articular diseases, using innovative technologies. Gordon Moore. Gordon Moore is the co-founder and Chairman Emeritus of Intel Corporation and the author of Moore's Law, which is the observation that over the history of computing hardware, the number of transistors on integrated circuits doubles approximately every two years.

Moore received his PhD from in chemistry, with a minor in physics, from the California Institute of Technology. Moore was named Chairman Emeritus of Intel Corporation in The Foundation is privately endowed, and holds a portfolio of high-risk, high-tech, large-scale initiatives in the areas of fundamental science, medicine, and the environment. In , he was inducted as a Fellow of the Computer History Museum. Web resource: Gordon and Betty Moore Foundation. Kary B. Mullis is a biochemist who won the Nobel Prize in Chemistry in , along with Michael Smith, for automation of a chemical process known as the polymerase chain reaction PCR.

The new technique has had far-reaching applications in medicine, genetics, biotechnology, and forensics. PCR, because of its ability to extract DNA from fossils, is also the basis of the new scientific discipline of paleobiology. During his seven years there, he conducted research on oligonucleotide synthesis and invented his new PCR technique. Mullis's process made it possible to make multiple copies of DNA in a relatively short time, which led to an explosion of research activity and ushered in the modern age of recombinant DNA technology.

In , Mullis began consulting on nucleic acid chemistry for more than a dozen corporations, including Cytometrics, Eastman Kodak, and Specialty Laboratories. Mullis has received numerous awards, including the Ronald H. He was also inducted into the National Inventors Hall of Fame in Mullis also holds several patents.

His latest one involves a revolutionary technique for instantly mobilizing the immune system to neutralize invading pathogens and toxins. Web resource: Kary B. Mullis's Home Page. Lewis, for her research on the genetic control of embryonic development. Seiji Ogawa. Ogawa won the Japan Prize in for his contribution to functional magnetic resonance imaging fMRI technology, which is used to visualize the regions in the living human brain activated by thought, voluntary movements, and other responses to external stimulation.

The technique does this indirectly by measuring increases in the presence of oxygen, as a proxy for increased blood flow, in the affected brain regions. More recently, the technique has been moving toward higher brain functions , such as cognition. One of the most revolutionary investigative techniques in the recent history of biomedical science, fMRI has become an essential tool for the modern investigation of brain functioning.

Ogawa earned his PhD in chemistry from Stanford University after being trained as an applied physicist in his native Japan. Web resource: Seiji Ogawa's Home Page. Jeremiah P. Ostriker is an astrophysicist and Professor of Astronomy at Columbia University. He is best known for his research in the areas of dark matter and dark energy, the Warm-Hot Intergalactic Medium WHIM , galaxy formation and black hole growth, and the interaction between quasars and their surroundings. Ostriker earned his PhD in astrophysics from the University of Chicago and conducted his postdoctoral fellowship at the University of Cambridge.

On June 20, , Ostriker was given the White House Champions of Change Award for his role in initiating the Sloan Digital Sky Survey project, which makes all of its astronomical data sets available publicly on the Internet. Ostriker has authored or co-authored more than scientific publications. His current work in theoretical astrophysics is in those areas of cosmology that can be best approached by large-scale numerical calculations. Web resource: Jeremiah P. Ostriker's Home Page. Roger Penrose. Roger Penrose is a mathematician and mathematical physicist.

Penrose shared the Wolf Foundation Prize for Physics in with Stephen Hawking 20 on our list for his contribution to our understanding of the universe. He is best known for his work in general relativity and cosmology. Penrose, who earned his PhD at Cambridge University, did important early work in pure mathematics on the problem of tiling filling a plane with various shapes, leaving no gaps.

He also popularized the Penrose triangle, the Penrose stairs, and other similar paradoxical structures, which he called "impossibility in its purest form. Escher, whose earlier depictions of impossible objects partly inspired them. Penrose also invented twistor theory, which is a novel way to look at the structure of spacetime, leading us to a deeper understanding of the nature of gravity.

Along with the Wolf Foundation Prize for Physics, Penrose has received numerous other awards, including the De Morgan Medal for his wide and original contributions to mathematical physics in , the Naylor Prize of the London Mathematical Society in , and the Eddington Medal of the Royal Astronomical Society in Penrose has stated his belief that there are some facets of human thinking that can never be emulated by a machine.

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He maintains that his work explains what physics and mathematics can tell us about how the mind works, what they can't, and what we need to know to understand the physical processes underlying our conscious experience. Web resource: Roger Penrose Home Page. Stanley B. In , he won the Nobel Prize in Physiology or Medicine.

Prusiner demonstrated that prions may be formed when a normal, benign cellular protein acquires an altered shape. His concept of infectious proteins, as well as his proposal of multiple biologically active shapes or conformations for a single protein, were considered heretical at the time, but are now widely though not universally acceptedIn humans, prions are now believed to cause such neurodegenerative diseases as Creutzfeld-Jakob Disease and kuru. Prusiner conducted his medical school training at the University of Pennsylvania and his postgraduate clinical training at the University of California, San Francisco.

Web resource: Stanley B. Prusiner's Home Page. Henry F. Schaefer III.

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Schaefer received his PhD from Stanford University and is known for inventing the field of computational quantum chemistry, developing it into a reliable quantitative discipline in chemistry. Using supercomputers and simulations rather than actual chemical substances, his lab uncovers chemical structures by crunching numbers. His theoretical research has been directed at one of the most challenging problems in molecular quantum mechanics, the problem of electron correlation in molecules. Schaefer is the author of more than 1, scientific publications, the majority appearing in the Journal of Chemical Physics and the Journal of the American Chemical Society.

Some of his research challenges the work of Nobel Prize winner Gerhard Herzberg regarding the geometry of triplet methylene. Web resource: Henry F. Thomas C. He is best known for his work in the area of synaptic transmission, which is the process by which signaling chemicals known as neurotransmitters are released by one neuron and bind to and activate the receptors of another neuron. During his postdoctoral training, he worked on describing the role of the LDL receptor in cholesterol metabolism, for which Michael S. Brown and Joseph L. Goldstein were awarded the Nobel Prize in Physiology or Medicine in Sterols are a major class of biomolecule and critical for life.

This discovery led to the development of statin-derived cholesterol medications such as atorvastatin Lipitor , which is today a top-selling branded pharmaceutical drug. Web resource: Thomas C. Jack W. Szostak is a biologist and a professor of genetics at Harvard Medical School. Greider , for discovering the details of telomere function. During the s, Szostak and his colleagues demonstrated in a series of experiments that telomeresregions of repetitive nucleotide sequences located at each end of a chromosome moleculeprotect the ends of chromosomes from deterioration and from fusion with neighboring chromosomes.

Szostak earned his PhD in biochemistry at Cornell University. He has made many contributions to the field of genetics. He is credited with the construction of the world's first yeast artificial chromosome. In addition to winning the Nobel Prize, Szostak has also won the Dr. The Szostak Lab is currently researching the origin of lifethe chemical and physical processes that facilitated the transition from chemical evolution to biological evolution on the early earth.

As a way of exploring these processes, his laboratory is trying to build a synthetic cellular system that undergoes Darwinian evolution. Web resource: Jack W. Szostak's Home Page. James M. Tour is a synthetic organic chemist, specializing in nanotechnology and serves as the T. Tour earned his PhD in synthetic organic and organometallic chemistry from Purdue University, and conducted his postdoctoral training in synthetic organic chemistry at the University of Wisconsin and Stanford University. Tour was ranked one of the top 10 chemists in the world over the past decade by Thomson Reuters in He is best known for his work in molecular electronics and molecular switching molecules.

Tour holds more than 60 United States patents, plus many non-US patents. Tour's most important contributions have been in molecular electronics, which involves nanoscale electronic devices utilizing molecular switiching molecules. His team at Rice has constructed many different kinds of nanoscale elecro-mechanical systems. One of the best know of these is the "nonocar," a nanoscale "automobile. Tour has over research publications and is active in consulting on several national defense-related topics, in addition to numerous other professional committees and panels. The Houston Chronicle reports that Tour wakes up at am every morning to study the Bible for two hours.

Web resource: James M. Tour's Home Page. Charles H. Townes is a physicist who taught at several universities, including the University of Tokyo, the University of Paris, the University of California, and Columbia University, among others. He won the Nobel Prize in Physics in , along with Nikolay Basov and Alexander Prokhorov, for fundamental work in the quantum electronics of oscillators and amplifiers. Their work opened up the whole field of modern lasers. Townes received the PhD degree from California Institute of Technology with a thesis on isotope separation and nuclear spins.

During World War II, he worked on designing radar systems and he holds a number of patents in that area. From there, he began to apply the microwave technique of wartime radar research to spectroscopy, providing a powerful tool for the study of the structure of atoms and molecules, as well as a potential new way of controlling electromagnetic waves. Web resource: Charles H. Townes's NobelPrize. Harold E. Varmus is a biologist and the current Director of the National Cancer Institute.

Michael Bishop, for their discovery of the cellular origin of retroviral oncogenes. Most of Varmus's scientific research was conducted at the University of California-San Francisco's Medical School, where he and his colleagues studied the cellular origins of oncogenes in a chicken retrovirus. Their discoveries led to the isolation of many cellular genes that normally control growth and development and are frequently mutated in human cancer.

Varmus is also widely known for his research on the replication cycles of retroviruses and of the hepatitis B family of viruses, as well as on the functions of genes implicated in cancer and the development of mouse models of human cancer. He has authored over scientific papers and five books, including The Art and Politics of Science.

Web resource: Harold E. Varmus's Home Page. Craig Venter. Craig Venter is a biologist and entrepreneur. Venter founded Celera Genomics, a private research group, to carry out his sequencing of the human genome, in direct competition with the government effort at the NIH to accomplish that result. JCVI is home to more than scientists and other staff, has more than , square feet of laboratory space, and is the world leader in genomic research. In , he joined the National Institutes of Health. The HGP was an international scientific research project whose aim was to identify and map the entire sequence of DNA base pairs that make up the human genome.

The HGP also attempted to identify and map the various biological functions for which the human genotype is responsible. It remains the largest collaborative biological project in history. Venter's JCVI is also committed to science education, offering programs in science, math, and technology for students of all ages. Venter was awarded the Dickson Prize in , the National Medal of Science in , and the Kistler Prize in , among other honors and awards.

Web resource: The J. Craig Venter Institute. James D. Watson greatly expanded the CSHL's level of funding and research, making it into a world-leading research center in molecular biology. Later, he shifted the laboratory's research emphasis to the study of cancer. Watson received his PhD from Indiana University, and a little over a decade later received the Nobel Prize in Physiology and Medicine, which he shared with Francis Crick and Maurice Wilkins, for their discovery of the molecular structure of desoxyribonucleic acid DNA and its significance for information transfer in living systems.

Watson taught at Harvard University for many years, where he received a series of academic promotions from assistant professor to associate professor to full professor of biology.


Web resource: James D. Watson's Home Page. Steven Weinberg. He won the Nobel Prize in Physics in , along with Sheldon Lee Glashow and Abdus Salam, for their contributions to a unified theory of the weak and electromagnetic interactions between elementary particles. Their work, which involved the prediction of the weak neutral current interactions W and Z bosons , which were later experimentally confirmedachieved the unification of two of the four fundamental forces of nature. Weinberg earned his PhD from Princeton University, and then conducted his postdoctoral work at Columbia University and the University of California, Berkeley, where he was later promoted to the faculty.

Weinberg has conducted pioneering researched in many areas of physics, including quantum field theory, gravitational theory, supersymmetry, superstrings, and cosmology. Weinberg's influence and importance are confirmed by the fact that he is frequently among the top scientists with the highest research effect indices, such as the h-index and the creativity index.

Weinberg is also well-known for his outspoken negative opinions on religion. Weinberg has a large number of awards to his name, including the National Medal of Honor in , the Benjamin Franklin Medal for Distinguished Achievements in Sciences from the American Philosophical Society in , and the James Joyce Award in , among many others.

Web resource: Steven Weinberg's Home Page. George M. Whitesides is a Professor of Chemistry at Harvard University. He is known for his work in a very wide variety of areas of chemistry, notably NMR spectroscopy, organometallic chemistry, soft lithography, micro-fabrication, microfluidics, nanotechnology, molecular self-assembly and self-organization, and research into the origin of life.

Whitesides earned a PhD in chemistry from the California Institute of Technology, where his graduate work focused on the use of NMR spectroscopy in organic chemistry. He is the author of more than 1, scientific articles and is listed as an inventor on more than 50 patents. Whitesides has one of the highest Hirsch index rating of all living chemists, which measures both the productivity and impact of the published work of a scientist or scholar. Whitesides's current research interests continue to span a very wide array of fields, from cell-surface biochemistry to science for developing economies.

Web resource: George M. Whitesides's Home Page. Edward O. Wilson is a biologist and naturalist. His specialty is myrmecologythe study of antson which he is considered to be the world's leading authority. Upon his retirement in , he assumed the titles of Professor Emeritus and Honorary Curator in Entomology. Wilson is also famous for his many popular books on evolutionary biology, for his advocacy of environmental causes specially preserving biodiversity , and for his efforts to advance the secular humanist worldview. He is a Fellow of the Committee for Skeptical Inquiry.

Wilson first tried to enlist in the United States Army, but he failed his Army medical examination due to his impaired eyesight. He completed his undergraduate education and later completed his PhD in biology at Harvard University. In addition to his work in myrmecology, Wilson has also authored a number of best-selling popular works on various aspects of biology and the philosophy of science, including On Human Nature , Biophilia and Consilience: The Unity of Knowledge.

The latter was another controversial work which argued that the natural sciences are destined to replace the social sciences and even the humanities. Wilson, who was raised in Alabama as a Southern Baptist, adheres to the philosophy of scientific humanism, which he sees as "the only worldview compatible with science's growing knowledge of the real world and the laws of nature.

Wilson has long taken a special interest in preserving endangered species. In , he assisted in establishing a nonprofit, the E. Wilson Biodiversity Foundation, devoted to achieving this goal. Web resource: The E. Wilson Biodiversity Foundation. Edward Witten. Edward Witten is a theoretical physicist and professor of mathematical physics at the Institute for Advanced Study in Princeton.

In , Time magazine stated that Witten was widely thought to be the world's greatest living theoretical physicist. Witten earned his PhD in physics from Princeton University, but initially enrolled in applied mathematics. Witten then held a junior fellowship at Harvard University, and a few years later a MacArthur Foundation fellowship. Witten coined the term "topological quantum field theory" to denote a physical theory in which the expected values of observable quantities encode information about the topology of spacetime.

He also discovered that Chern-Simons theory could provide a framework for understanding the mathematical theory of knots and 3-manifolds. Witten is best known for his fundamental mathematical insights into string theory. His finding that various string theories can be mapped onto one another by certain rules, called dualities, led to a flurry of work now known as the "second superstring revolution. Web resource: Edward Witten's Home Page. Shinya Yamanaka. Shinya Yamanaka is a physician and researcher who studies adult stem cells. Yamanaka was awarded the Nobel Prize for Physiology or Medicine, along with John Gurdon, for their discovery that mature adult somatic cells can be converted into stem cells with regenerative properties pluripotency similar to those of embryonic stem cells.

He was an associate professor when he began the research that led him to the Nobel Prize. In addition to his present academic positions mentioned above, he also currently serves as President of the International Society for Stem Cell Research. Governments moved to promote and fund research into nanotechnology, such as in the U. By the mids new and serious scientific attention began to flourish.

Recent advances in vacuum sciences and applications

Projects emerged to produce nanotechnology roadmaps [19] [20] which center on atomically precise manipulation of matter and discuss existing and projected capabilities, goals, and applications. Nanotechnology is the engineering of functional systems at the molecular scale. This covers both current work and concepts that are more advanced. In its original sense, nanotechnology refers to the projected ability to construct items from the bottom up, using techniques and tools being developed today to make complete, high performance products. By comparison, typical carbon-carbon bond lengths , or the spacing between these atoms in a molecule , are in the range 0.

By convention, nanotechnology is taken as the scale range 1 to nm following the definition used by the National Nanotechnology Initiative in the US.

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  4. The lower limit is set by the size of atoms hydrogen has the smallest atoms, which are approximately a quarter of a nm kinetic diameter since nanotechnology must build its devices from atoms and molecules. The upper limit is more or less arbitrary but is around the size below which phenomena not observed in larger structures start to become apparent and can be made use of in the nano device. To put that scale in another context, the comparative size of a nanometer to a meter is the same as that of a marble to the size of the earth.

    Two main approaches are used in nanotechnology. In the "bottom-up" approach, materials and devices are built from molecular components which assemble themselves chemically by principles of molecular recognition. Areas of physics such as nanoelectronics , nanomechanics , nanophotonics and nanoionics have evolved during the last few decades to provide a basic scientific foundation of nanotechnology.

    Several phenomena become pronounced as the size of the system decreases. These include statistical mechanical effects, as well as quantum mechanical effects, for example the " quantum size effect" where the electronic properties of solids are altered with great reductions in particle size. This effect does not come into play by going from macro to micro dimensions. However, quantum effects can become significant when the nanometer size range is reached, typically at distances of nanometers or less, the so-called quantum realm.

    Additionally, a number of physical mechanical, electrical, optical, etc. One example is the increase in surface area to volume ratio altering mechanical, thermal and catalytic properties of materials. Diffusion and reactions at nanoscale, nanostructures materials and nanodevices with fast ion transport are generally referred to nanoionics. Mechanical properties of nanosystems are of interest in the nanomechanics research. The catalytic activity of nanomaterials also opens potential risks in their interaction with biomaterials. Materials reduced to the nanoscale can show different properties compared to what they exhibit on a macroscale, enabling unique applications.

    For instance, opaque substances can become transparent copper ; stable materials can turn combustible aluminium ; insoluble materials may become soluble gold. A material such as gold, which is chemically inert at normal scales, can serve as a potent chemical catalyst at nanoscales. Much of the fascination with nanotechnology stems from these quantum and surface phenomena that matter exhibits at the nanoscale.

    Modern synthetic chemistry has reached the point where it is possible to prepare small molecules to almost any structure. These methods are used today to manufacture a wide variety of useful chemicals such as pharmaceuticals or commercial polymers. This ability raises the question of extending this kind of control to the next-larger level, seeking methods to assemble these single molecules into supramolecular assemblies consisting of many molecules arranged in a well defined manner.

    The concept of molecular recognition is especially important: molecules can be designed so that a specific configuration or arrangement is favored due to non-covalent intermolecular forces. The Watson—Crick basepairing rules are a direct result of this, as is the specificity of an enzyme being targeted to a single substrate , or the specific folding of the protein itself. Thus, two or more components can be designed to be complementary and mutually attractive so that they make a more complex and useful whole.

    Such bottom-up approaches should be capable of producing devices in parallel and be much cheaper than top-down methods, but could potentially be overwhelmed as the size and complexity of the desired assembly increases. Most useful structures require complex and thermodynamically unlikely arrangements of atoms. Nevertheless, there are many examples of self-assembly based on molecular recognition in biology , most notably Watson—Crick basepairing and enzyme-substrate interactions.

    The challenge for nanotechnology is whether these principles can be used to engineer new constructs in addition to natural ones. Molecular nanotechnology, sometimes called molecular manufacturing, describes engineered nanosystems nanoscale machines operating on the molecular scale. Molecular nanotechnology is especially associated with the molecular assembler , a machine that can produce a desired structure or device atom-by-atom using the principles of mechanosynthesis.

    Manufacturing in the context of productive nanosystems is not related to, and should be clearly distinguished from, the conventional technologies used to manufacture nanomaterials such as carbon nanotubes and nanoparticles. When the term "nanotechnology" was independently coined and popularized by Eric Drexler who at the time was unaware of an earlier usage by Norio Taniguchi it referred to a future manufacturing technology based on molecular machine systems.

    The premise was that molecular scale biological analogies of traditional machine components demonstrated molecular machines were possible: by the countless examples found in biology, it is known that sophisticated, stochastically optimised biological machines can be produced. It is hoped that developments in nanotechnology will make possible their construction by some other means, perhaps using biomimetic principles.

    However, Drexler and other researchers [27] have proposed that advanced nanotechnology, although perhaps initially implemented by biomimetic means, ultimately could be based on mechanical engineering principles, namely, a manufacturing technology based on the mechanical functionality of these components such as gears, bearings, motors, and structural members that would enable programmable, positional assembly to atomic specification.

    In general it is very difficult to assemble devices on the atomic scale, as one has to position atoms on other atoms of comparable size and stickiness. Another view, put forth by Carlo Montemagno , [29] is that future nanosystems will be hybrids of silicon technology and biological molecular machines. Richard Smalley argued that mechanosynthesis are impossible due to the difficulties in mechanically manipulating individual molecules. Leaders in research on non-biological molecular machines are Dr. An experiment indicating that positional molecular assembly is possible was performed by Ho and Lee at Cornell University in They used a scanning tunneling microscope to move an individual carbon monoxide molecule CO to an individual iron atom Fe sitting on a flat silver crystal, and chemically bound the CO to the Fe by applying a voltage.

    The nanomaterials field includes subfields which develop or study materials having unique properties arising from their nanoscale dimensions. These seek to develop components of a desired functionality without regard to how they might be assembled. These subfields seek to anticipate what inventions nanotechnology might yield, or attempt to propose an agenda along which inquiry might progress.

    These often take a big-picture view of nanotechnology, with more emphasis on its societal implications than the details of how such inventions could actually be created.

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    Nanomaterials can be classified in 0D, 1D, 2D and 3D nanomaterials. The dimensionality play a major role in determining the characteristic of nanomaterials including physical , chemical and biological characteristics. With the decrease in dimensionality, an increase in surface-to-volume ratio is observed. This indicate that smaller dimensional nanomaterials have higher surface area compared to 3D nanomaterials.

    Recently, two dimensional 2D nanomaterials are extensively investigated for electronic , biomedical , drug delivery and biosensor applications. There are several important modern developments. There are other types of scanning probe microscopy. Although conceptually similar to the scanning confocal microscope developed by Marvin Minsky in and the scanning acoustic microscope SAM developed by Calvin Quate and coworkers in the s, newer scanning probe microscopes have much higher resolution, since they are not limited by the wavelength of sound or light.

    The tip of a scanning probe can also be used to manipulate nanostructures a process called positional assembly. Feature-oriented scanning methodology may be a promising way to implement these nanomanipulations in automatic mode. Various techniques of nanolithography such as optical lithography , X-ray lithography , dip pen nanolithography, electron beam lithography or nanoimprint lithography were also developed.

    Lithography is a top-down fabrication technique where a bulk material is reduced in size to nanoscale pattern. Another group of nanotechnological techniques include those used for fabrication of nanotubes and nanowires , those used in semiconductor fabrication such as deep ultraviolet lithography, electron beam lithography, focused ion beam machining, nanoimprint lithography, atomic layer deposition, and molecular vapor deposition, and further including molecular self-assembly techniques such as those employing di-block copolymers.

    The precursors of these techniques preceded the nanotech era, and are extensions in the development of scientific advancements rather than techniques which were devised with the sole purpose of creating nanotechnology and which were results of nanotechnology research. The top-down approach anticipates nanodevices that must be built piece by piece in stages, much as manufactured items are made. Scanning probe microscopy is an important technique both for characterization and synthesis of nanomaterials. Atomic force microscopes and scanning tunneling microscopes can be used to look at surfaces and to move atoms around.

    By designing different tips for these microscopes, they can be used for carving out structures on surfaces and to help guide self-assembling structures. By using, for example, feature-oriented scanning approach, atoms or molecules can be moved around on a surface with scanning probe microscopy techniques. In contrast, bottom-up techniques build or grow larger structures atom by atom or molecule by molecule. These techniques include chemical synthesis, self-assembly and positional assembly. Dual polarisation interferometry is one tool suitable for characterisation of self assembled thin films.

    Another variation of the bottom-up approach is molecular beam epitaxy or MBE. Alfred Y. Cho, and Art C. Gossard developed and implemented MBE as a research tool in the late s and s. Samples made by MBE were key to the discovery of the fractional quantum Hall effect for which the Nobel Prize in Physics was awarded.

    MBE allows scientists to lay down atomically precise layers of atoms and, in the process, build up complex structures. Important for research on semiconductors, MBE is also widely used to make samples and devices for the newly emerging field of spintronics. However, new therapeutic products, based on responsive nanomaterials, such as the ultradeformable, stress-sensitive Transfersome vesicles, are under development and already approved for human use in some countries.

    As of August 21, , the Project on Emerging Nanotechnologies estimates that over manufacturer-identified nanotech products are publicly available, with new ones hitting the market at a pace of 3—4 per week. Most applications are limited to the use of "first generation" passive nanomaterials which includes titanium dioxide in sunscreen, cosmetics, surface coatings, [55] and some food products; Carbon allotropes used to produce gecko tape ; silver in food packaging, clothing, disinfectants and household appliances; zinc oxide in sunscreens and cosmetics, surface coatings, paints and outdoor furniture varnishes; and cerium oxide as a fuel catalyst.

    Further applications allow tennis balls to last longer, golf balls to fly straighter, and even bowling balls to become more durable and have a harder surface. Trousers and socks have been infused with nanotechnology so that they will last longer and keep people cool in the summer. Bandages are being infused with silver nanoparticles to heal cuts faster. Nanotechnology may have the ability to make existing medical applications cheaper and easier to use in places like the general practitioner 's office and at home.

    Scientists are now turning to nanotechnology in an attempt to develop diesel engines with cleaner exhaust fumes. Platinum is currently used as the diesel engine catalyst in these engines. The catalyst is what cleans the exhaust fume particles. First a reduction catalyst is employed to take nitrogen atoms from NOx molecules in order to free oxygen.

    Next the oxidation catalyst oxidizes the hydrocarbons and carbon monoxide to form carbon dioxide and water. Danish company InnovationsFonden invested DKK 15 million in a search for new catalyst substitutes using nanotechnology. The goal of the project, launched in the autumn of , is to maximize surface area and minimize the amount of material required. Objects tend to minimize their surface energy; two drops of water, for example, will join to form one drop and decrease surface area. If the catalyst's surface area that is exposed to the exhaust fumes is maximized, efficiency of the catalyst is maximized.

    The team working on this project aims to create nanoparticles that will not merge. Every time the surface is optimized, material is saved. Thus, creating these nanoparticles will increase the effectiveness of the resulting diesel engine catalyst—in turn leading to cleaner exhaust fumes—and will decrease cost. Nanotechnology also has a prominent role in the fast developing field of Tissue Engineering. When designing scaffolds, researchers attempt to mimic the nanoscale features of a cell 's microenvironment to direct its differentiation down a suitable lineage.

    Researchers have successfully used DNA origami -based nanobots capable of carrying out logic functions to achieve targeted drug delivery in cockroaches. It is said that the computational power of these nanobots can be scaled up to that of a Commodore An area of concern is the effect that industrial-scale manufacturing and use of nanomaterials would have on human health and the environment, as suggested by nanotoxicology research. For these reasons, some groups advocate that nanotechnology be regulated by governments.

    Advances in Surface Science, Volume 38

    Others counter that overregulation would stifle scientific research and the development of beneficial innovations. Public health research agencies, such as the National Institute for Occupational Safety and Health are actively conducting research on potential health effects stemming from exposures to nanoparticles. Some nanoparticle products may have unintended consequences. Researchers have discovered that bacteriostatic silver nanoparticles used in socks to reduce foot odor are being released in the wash.

    Public deliberations on risk perception in the US and UK carried out by the Center for Nanotechnology in Society found that participants were more positive about nanotechnologies for energy applications than for health applications, with health applications raising moral and ethical dilemmas such as cost and availability. Experts, including director of the Woodrow Wilson Center's Project on Emerging Nanotechnologies David Rejeski, have testified [72] that successful commercialization depends on adequate oversight, risk research strategy, and public engagement.

    Berkeley, California is currently the only city in the United States to regulate nanotechnology; [73] Cambridge, Massachusetts in considered enacting a similar law, [74] but ultimately rejected it. Over the next several decades, applications of nanotechnology will likely include much higher-capacity computers, active materials of various kinds, and cellular-scale biomedical devices.

    Nanofibers are used in several areas and in different products, in everything from aircraft wings to tennis rackets. Inhaling airborne nanoparticles and nanofibers may lead to a number of pulmonary diseases , e. A two-year study at UCLA's School of Public Health found lab mice consuming nano-titanium dioxide showed DNA and chromosome damage to a degree "linked to all the big killers of man, namely cancer, heart disease, neurological disease and aging".

    A major study published more recently in Nature Nanotechnology suggests some forms of carbon nanotubes — a poster child for the "nanotechnology revolution" — could be as harmful as asbestos if inhaled in sufficient quantities. Anthony Seaton of the Institute of Occupational Medicine in Edinburgh, Scotland, who contributed to the article on carbon nanotubes said "We know that some of them probably have the potential to cause mesothelioma.

    So those sorts of materials need to be handled very carefully. Calls for tighter regulation of nanotechnology have occurred alongside a growing debate related to the human health and safety risks of nanotechnology. Some regulatory agencies currently cover some nanotechnology products and processes to varying degrees — by "bolting on" nanotechnology to existing regulations — there are clear gaps in these regimes.

    Stakeholders concerned by the lack of a regulatory framework to assess and control risks associated with the release of nanoparticles and nanotubes have drawn parallels with bovine spongiform encephalopathy "mad cow" disease , thalidomide , genetically modified food, [91] nuclear energy, reproductive technologies, biotechnology, and asbestosis. Andrew Maynard, chief science advisor to the Woodrow Wilson Center's Project on Emerging Nanotechnologies, concludes that there is insufficient funding for human health and safety research, and as a result there is currently limited understanding of the human health and safety risks associated with nanotechnology.

    The Royal Society report [15] identified a risk of nanoparticles or nanotubes being released during disposal, destruction and recycling, and recommended that "manufacturers of products that fall under extended producer responsibility regimes such as end-of-life regulations publish procedures outlining how these materials will be managed to minimize possible human and environmental exposure" p.

    The Center for Nanotechnology in Society has found that people respond to nanotechnologies differently, depending on application — with participants in public deliberations more positive about nanotechnologies for energy than health applications — suggesting that any public calls for nano regulations may differ by technology sector. From Wikipedia, the free encyclopedia. For the materials science journal, see Nanotechnology journal. For other uses of "Nanotech", see Nanotech disambiguation. Main article: History of nanotechnology. Main article: Nanomaterials. Main article: Molecular self-assembly.

    Main article: Molecular nanotechnology. Play media. Main article: List of nanotechnology applications. Main article: Implications of nanotechnology. Main articles: Health and safety hazards of nanomaterials and Pollution from nanomaterials. Main article: Regulation of nanotechnology.

    Technology portal. Main article: Outline of nanotechnology. Eric Nanosystems: Molecular Machinery, Manufacturing, and Computation. Bibcode : Cmplx.. Journal of Cutaneous and Aesthetic Surgery. Bibcode : NatSR A New Kind of Science. Wolfram Media, Inc. Archived from the original on 5 June Retrieved 12 May Bibcode : Natur. Smalley ".

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