bluuebunny/crossref_metadata_2025 huggingface dataset:
Electromechanical measurements of electric field-induced displacements of fibers
Authors: Vyshatko Nikolai P. , Vilarinho Paula M. , Kholkin Andrei L.
Published: January 2008

In this paper we report on a development of a new method for measurements of electric field-induced displacements in a cylindrical geometry (optical fiber with the deposited piezoelectric film). The measurement setup is based on a commercially available Fotonic Sensor MTI 2000 (MTI Inc.). Major disadvantages of measurement by standard techniques (e.g., interferometry) such as low reflectivity, high roughness of the coating resulting in poor fringe quality, and big displacement range are successfully avoided using a special configuration of an optical probe and a sample. The method allows performing investigations of electromechanically induced vibrations in a broad frequency range (from 0 up to 150kHz) and various combinations of ac and dc voltages. The capabilities of the proposed method are validated by strain measurements of an optical fiber cantilever beam covered by Pb(Zr,Ti)O3 thick film.
Why Do Stars Emit X Rays?
Authors: Parker Eugene N.
Published: January 2008

The Sun was the first observed x-ray star. In 1948 rocket-borne instruments, carried out of the terrestrial atmosphere for only a few minutes at a time, detected solar x rays. Then in April 1960 instruments recorded the first x-ray photograph of the Sun.
AIP in 1986: An Annual Report
Authors: Koch H. William
Published: January 2008

As in the past five years, this annual report of the American Institute of Physics is organized into sections describing output products and services produced by AIP.
Yields of US and Soviet Nuclear Tests
Authors: Evernden Jack F. , Marsh Gerald E.
Published: January 2008

The likelihood that the United States will negotiate a comprehensive or lowthreshold test ban treaty with the Soviet Union in the relatively near future depends not only on the ability of the US to monitor such an agreement but also on US perception of past Soviet compliance with treaties that limit nuclear testing. Of particular importance is the 1974 Threshold Test Ban Treaty, which prohibits tests of nuclear weapons exceeding 150 kilotons in yield. This treaty is unratified, but both the United States and the Soviet Union have avowed their compliance since 1976, when the treaty was scheduled to go into effect. (For an annotated list of treaties, see Herbert York's article in PHYSICS TODAY, March 1983, page 24.)
Debate on APS Directed-Energy Weapons Study
Authors: Canavan Gregory H. , Bloembergen Nicolaas , Patel C. Kumar N.
Published: January 2008

In April, The American Physical Society issued a 424-page report saying that “even in the best of circumstances, a decade or more of intensive research would be required to provide the technical knowledge needed for an informed decision about the potential effectiveness and survivability of directed-energy weapon systems.” (See PHYSICS TODAY, May 1987, page S1.) In May, Los Alamos National Laboratory published a 70-page paper by Gregory Canavan that is optimistic about a directed-energy weapons system and critical of the APS study. (See PHYSICS TODAY, June, page 43.) In this debate Canavan criticizes the APS study on ten technical issues, and Nicolaas Bloembergen and Kumar Patel, the cochairmen of the APS study group, respond point by point.
Observational Neutrino Astrophysics
Authors: Koshiba Masa-Toshi
Published: January 2008

Neutrinos have been an important feature of theories of stellar processes for many decades. As a star forms from interstellar matter, its temperature gradually increases because of its gravitational contraction. However, this thermal energy is not sufficient to make it shine for long. We believe that the primary energy source of the Sun, and of stars in general, is a series of nuclear fusion reactions, occurring deep inside the star, in which energy is released as four protons are converted into a helium nucleus. In the process, two protons are converted into neutrons by each emitting a positron and an electron neutrino. Thus a star must emit electron neutrinos constantly.
Ultrafine Particles
Authors: Hayashi Chikara
Published: January 2008

Scientists have been dealing with particles with diameters in the range 1–100 nm, albeit in dispersed systems, since the founding of colloid chemistry in the 1860s. However, it is only in the last 25 years that we have been able to study individual particles of this size. The result has been the discovery that these “ultrafine” particles have properties not displayed by larger or smaller collections of atoms or molecules, properties that suggest many scientific and technological applications.
Graphite Intercalation Compounds
Authors: Kamimura Hiroshi
Published: January 2008

Graphite intercalation compounds are synthetic metals formed by inserting layers of atoms or molecules of a guest chemical species between the layers of carbon atoms that make up graphite. Because carbon occupies a middle position in the order of electronegativity of the elements in the periodic table, graphite welcomes many chemicals as guests, or intercalants, making it possible to produce hundreds of metallic materials. (See figure 1.)
Novel Magnetic Properties of Solid Helium-3
Authors: Cross Michael C. , Osheroff Douglas D.
Published: January 2008

Nuclear magnetic ordering in solid helium-3 provides the ultralow-temperature physicist with a unique opportunity to study cooperative magnetic phenomena in a quantum spin system. There are two known—and very different— magnetic phases of low-density solid He3, and at higher densities ferromagnetism may exist. with ordering temperatures at low densities near 1 mK, these systems are easily accessible with modern demagnetization cryostats. Over the next few years experimental and theoretical studies of these systems will advance considerably our understanding of nuclear magnetism.
Vortices in Rotating Superfluid He3
Authors: Hakonen Pertti , Lounasmaa Olli V.
Published: January 2008

For about a century now, physicists have been working hard to extend the temperature range accessible to experimental investigations closer and closer to absolute zero. This endeavor has been amply rewarded by new and fundamentally important discoveries.
The Coupled Cluster Method
Authors: Bishop Raymond F. , Kümmel Hermann G.
Published: January 2008

Liquids and solids, atoms and molecules, nuclei—all these clearly are interacting many-body systems. Even a nucleon may be regarded as a manyparticle system, not just because it is now known to consist of three quarks interacting via gluons, but because of the possibility in quantum field theory of virtual excitation of many particles from the vacuum. in the table page 56 we list some of the many-particle systems we encounter in the physical world at length scales that range from a few centimeters to a few fermis. Many of these systems exhibit phenomena—superconductivity in solids and fission in nuclei, for example—whose understanding does not follow immediately from knowledge of the constituents of the system and the interactions among the constituents, but requires new concepts and ideas. Many-body physics is the branch of theoretical physics that studies the new phenomena or “emergent properties” that arise from interactions among “elementary” constituents of a many-particle system and provides means and methods for carrying out precise calculations of such characteristic properties of these systems as may be compared with experimental results to verify hypotheses about the nature of the constituents and their interactions.
The Impact of Special Relativity on Theoretical Physics
Authors: Jackson J. David
Published: January 2008

As one of my colleagues put it, “Asking about the impact of special relativity on theoretical physics is like asking about the impact of Shakespeare on the English language.” An impossibly large, even senseless, task. Special relativity is a fact of life, part and parcel of the way nature is. If its impact on everyday life is slight, its impact on physicists' thinking is profound. Space and universal, inexorable time were rudely united into space-time by Albert Einstein's discovery of special relativity. Explorations of the properties of space-time, of the covariance of physical laws, and of the physical invariants of nature, together with quantum mechanics, led to the formulation of relativistic quantum field theories. The external symmetries of space-time were augmented by abstract spaces for internal symmetries corresponding to invariant (conserved) quantities such as isospin, strangeness and charm. The whole worldview of modern theoretical physics can be traced back to the fundamental postulate or idea that physical phenomena do not change just because you happen to be moving by, instead of standing still, when observing them. Rotations and other transformations in internal spaces have replaced “moving by,” but the idea is the same.
Einstein and Ether Drift Experiments
Authors: Stachel John
Published: January 2008

Volume 1 of The Collected Papers of Albert Einstein, to be published on 22 May, contains a number of previously unpublished lecture notes, examination papers and letters by Einstein. Among the most notable new items are 42 letters written between 1898 and 1902 to his fiancée Mileva Marić, whom he met while they were fellow students of physics at the Swiss Polytechnical School in Zurich, which both entered in 1896.
Grappling with Complexity
Authors: Zabusky Norman J.
Published: January 2008

We are in the midst of a computational revolution that will change science and society as dramatically as the agricultural and industrial revolutions did. The discipline of computational science is significantly affecting the way we do hard and soft science. The articles in this special issue of PHYSICS TODAY demonstrate the vital growth of the infant computational physics. Supercomputers with ultrafast, interactive visualization peripherals have come of age and provide a mode of working that is coequal with laboratory experiments and observations and with theory and analysis. We can now grapple with nonlinear and complexly intercoupled phenomena in a relatively short time and provide insight for quantitative understanding and better prediction. In the hands of enthusiastic and mature investigators, intractable problems will recede on a quickened time scale in this computationally synergized environment.1
Exploiting Highly Concurrent Computers for Physics
Authors: Bowler Ken C. , Bruce Alastair D. , Kenway Richard D. , Pawley G. Stuart , Wallace David J.
Published: January 2008

Computational physics—that is, the use of computers to solve problems by simulating theoretical models—is part of a new methodology that has taken its place alongside theory and experiment during the last 50 years or so. Computer simulations permit one to study microscopic properties and their macroscopic consequences in a host of problems that may be inaccessible to direct experimental study or too complex for theoretical analysis. Thus computers have become laboratories for experimenting with theories. The growth of computational physics has been fueled by the explosion in the availability of relatively cheap and powerful computers—and, for just that reason, the field is utterly dependent for its good health on continued advances in computer technology.
Molecular Dynamics Simulations of Proteins
Authors: Karplus Martin
Published: January 2008

Simulations have brought about a conceptual change in our understanding of biomolecules. Instead of viewing protein functions such as enzymatic catalysis only in terms of the structural data provided by high-resolution x-ray crystallography, one now recognizes the important role of the internal atomic motions. The average atomic positions corresponding to the x-ray structure still allow discussion of many aspects of biomolecular function in the language of structural chemistry; however, the recognition of the importance of fluctuations opens the way for more sophisticated and accurate interpretations of biomolecular properties.
The Physics of Aerobatic Flight
Authors: O'Dell C. R.
Published: January 2008

The modern aerobatic aircraft represents a very advanced state of specialization that has resulted from an evolutionary path rather different from that of commercial or military aircraft. The construction of any aircraft is a series of compromises, the designer not being able to add much in one performance area without detracting from another. Over the last 30 years there have been enormous improvements in the design and performance characteristics of sport aircraft. Perhaps surprisingly, most of these developments have been made by custom builders, rather than large aviation manufacturers.
A Numerical Laboratory
Authors: Winkler Karl-Heinz A. , Chalmers Jay W. , Hodson Stephen W. , Woodward Paul R. , Zabusky Norman J.
Published: January 2008

In a series of talks in 1946, John von Neumann envisioned the use of high-speed computers to generate solutions to nonlinear problems, particularly in fluid dynamics. He pointed out that scientists were conducting expensive and difficult experiments to observe physical behavior even when the underlying principles and governing equations were known. “The purpose of the experiment is not to verify a proposed theory but to replace a computation from an unquestioned theory by direct measurements,” he wrote. “Thus wind tunnels are used at present, at least in large part, as computing devices of the so-called analogy type to integrate the nonlinear partial differential equations of fluid dynamics.”
Science Museums as Environments for Learning
Authors: Semper Robert J.
Published: January 2008

A science museum is created by its contents and the activities relating to them. These contents may be historical artifacts, such as a steam engine, or exhibits of natural phenomena, scientific ideas or technological inventions. A museum is an educational county fair, a serious and exciting learning environment where the relationships between one exhibit and the next, and among the exhibits, the visitors and the space as a whole are important. This location-and-object specific attribute sets museums apart from other communications media such as television, books and periodicals.
Anticipations of the Geometric Phase
Authors: Berry Michael
Published: January 2008

In science we like to emphasize the novelty and originality of our ideas. This is harmless enough, provided it does not blind us to the fact that concepts rarely arise out of nowhere. There is always a historical context, in which isolated precursors of the idea have already appeared. What we call “discovery” sometimes looks, in retrospect, more like emergence into the air from subterranean intellectual currents.
The Physics of Metal Clusters
Authors: Cohen Marvin L. , Knight Walter D.
Published: January 2008

Scientists often set the stage for their most productive advances by first developing simple models, even when sophisticated first-principles tools are available. These models usually originate from the necessity to explain experimental observations. If the models are robust, then a variety of data fall into place, and successful predictions are made. If a model is “correct,” it is eventually found to be consistent with or derivable from fundamental theory. The Bohr model for atoms is a prime example. Ernest Rutherford's experiments showed that J. J. Thomson's “plum pudding” model of an atom, consisting of a positive spherical “pudding” embedded with negative electron “plums,” had to be replaced by Rutherford's nuclear picture, and subsequent optical data led to the Bohr model. Eventually quantum theory confirmed that the Bohr model is an excellent rudimentary representation for an atom. Although it has been superseded by more elaborate quantum theoretical approaches, this model is still taught to students of atomic physics because of the physical insight one gains by using the Bohr picture of an atom.
Superconductor Images of Electron Devide Physics
Authors: Hess Karl
Published: January 2008

A deep, quantitative understanding of the behavior of electronic devices is necessary to ensure that the circuits made by integrating those devices will have the desired characteristics. Such understanding of the device behavior has become all the more important as the devices have become smaller and many more of them are packed in smaller chips at ever higher densities. Supercomputers have been increasingly used to simulate small devices in recent years. There are several reasons for this development. First, boundary conditions become important as the device size decreases, and this makes the task of simulating the devices more complex. Second, several characteristic quantities that determine the behavior of a device, such as carrier concentration and velocity, do not vary gradually. Third and most important, boundary conditions generally lead to the quantization of physical quantities, and many novel quantization effects become significant and observable in nanometer structures.
Quantum Electron Devices
Authors: Capasso Federico , Datta Supriyo
Published: January 2008

Much of our understanding of electron transport in solids is based on the semiclassical picture that views electrons as particles obeying Newtonian mechanics in an external field and occasionally scattered by phonons and impurities. Quantum effects such as size quantization and tunneling, however, cannot be understood within this conceptual framework.
Dynamical Perturbations to the Ozone Layer
Authors: Salby Murry L. , Garcia Rolando R.
Published: January 2008

Several years ago spectrophotometer measurements revealed substantial depletions of atmospheric ozone over Antarctica, reviving concerns over damage to Earth's ozone layer by human activities. These ground-based observations were subsequently verified in global ozone data that had been collected by satellite for years. The sizable ozone depletions over Antarctica are now believed to arise from complex chlorine chemistry, stimulated ultimately by the emission of man-made chlorofluorocarbons into the atmosphere.
Gender and Science: Women in American Astronomy, 1859–1940
Authors: Lankford John , Slavings Rickey L.
Published: January 2008

Historically, the division of labor within American astronomy was gender specific. Although the field took in large numbers of women, gender dictated who collected data, who reduced it, who analyzed it and who published the results. The assignment of roles reflected the perceptions male astronomers had of females, and those perceptions in turn mirrored the values of American culture.
The Hubble Space Telescope Observatory
Authors: O'Dell C. R.
Published: January 2008

No other astronomy project has taken so long to develop, proven so technologically challenging or cost so much as the Hubble Space Telescope. At a development cost of about $1.5 billion, the HST is big science by the standards of modern physics. Soon after the HST is launched on 12 April, the physics community will determine if the resources and professional efforts that have gone into the HST will produce the promised scientific returns that drew hundreds of the best scientists from the US and Europe into the project.
Edwin P. Hubble and the Transformation of Cosmology
Authors: Smith Robert W.
Published: January 2008

In the first three decades of this century the modern science of cosmology was forged from general relativity theory and new observing methods and instruments, particularly large optical telescopes perched thousands of feet above sea level in California and Arizona. These radical changes in the theoretical and observational tools used by astronomers, physicists and mathematicians accompanied revolutionary changes in cosmology itself. The new cosmology of the early 1930s included two key cognitive features absent from the cosmology of the turn of the century: first, the existence of galaxies outside our own stellar system that are visible in Earth-based telescopes, and second, that these galaxies evince the expansion of the universe.
The Khrushchev Détente and Emerging Internationalism in Particle Physics
Authors: Marshak Robert E.
Published: January 2008

Mikhail Gorbachev's program of glasnost and perestroika—now in its fifth year—has wrought striking changes inside the Soviet Union, and even more spectacular metamorphoses outside its borders. Among the positive repercussions of the Gorbachev program on the international scene, we have seen major improvements in international scientific cooperation. In particle physics the improvement during the years of the Gorbachev détente appears less dramatic than it does in space science, for example. But that's largely because the opportunity to solidify East-West cooperation in particle physics had been seized much earlier—during the Khrushchev détente of 1956–60, a time when this field, with its large and expensive accelerators, stood alone as the epitome of “big science.”
Atomic Force Microscopy
Authors: Rugar Daniel , Hansma Paul
Published: January 2008

In 1986 Gerd Binnig and Heinrich Rohrer shared the Nobel Prize in Physics for inventing the scanning tunneling microscope and discovering that it can image individual surface atoms with unprecedented resolution. The success of the scanning tunneling microscope has led to the invention of a host of other “scanning probe” microscopes, which rely on mechanically scanning a sharp tip over a sample surface. The atomic force microscope is one of the most successful of these new devices.
New Mechanisms for Laser Cooling
Authors: Cohen-Tannoudji Claude N. , Phillips William D.
Published: January 2008

When an atom or a molecule interacts with a light beam, the light emitted or absorbed carries valuable information about the atomic or molecular structure. This phenomenon underlies the whole field of spectroscopy. But the interaction of a photon with an atom can be used to manipulate the atom as well as to probe its structure. For example, in an approach called optical pumping, invented by Alfred Kastler, one can use the resonant exchange of angular momentum between atoms and polarized photons to align or orient the spins of atoms or to put them in nonequilibrium situations. In his original 1950 paper Kastler also proposed using optical pumping to cool and to heat the internal degrees of freedom, calling the phenomena the “effet luminofrigorique” and the “effet luminocalorique.” Another famous example of the use of photon-atom interaction to control atoms is laser cooling. This technique relies on resonant exchange of linear momentum between photons and atoms to control their external degrees of freedom and thus to reduce their kinetic energy. Laser cooling was suggested independently by Theodor Hänsch and Arthur Schawlow for neutral atoms and by David Wineland and Hans Dehmelt for trapped ions. In an article written three years ago for PHYSICS TODAY (June 1987, page 34), Wineland and Wayne Itano presented the principle of laser cooling and the potential applications of cold atoms to fields of physics such as ultrahigh resolution spectroscopy, atomic clocks, collisions, surface physics and collective quantum effects. At that time laser cooling had brought temperatures down to a few hundred microkelvin, but unexpected improvements during the last three years have dramatically lowered those temperatures to only a few microkelvin. We now feel we understand the new physical mechanisms responsible for these very low temperatures.
Science on the Air: NSF's Role
Authors: Tressel George
Published: January 2008

In 1976 I wrote a very intemperate letter to the director of the National Science Foundation, H. Guyford Stever. While I didn't keep a copy, it went something like this: Recently, Science printed an account of your speech on the public understanding of science. With all due respect, the National Science Foundation does not know the meaning of those words.
Selling Science
Authors: Nelkin Dorothy
Published: January 2008

In 1987, scientists at the spring meeting of The American Physical Society announced the development of new, hightemperature superconducting materials. The session, which had been widely publicized through early preprints and press releases, was attended by 3500 physicists and hundreds of reporters. Bertram Batlogg from the Bell Laboratories solid-state research team proclaimed, “Our life has changed.” An ecstatic press headlined Batlogg's comment, and underneath heralded “breathtaking advances,” “stunning possibilities” and “revolution.” Journalists reported “gasps” from scientists; high-Tc superconductivity was “a quantum leap in technology,” a “new frontier.” News articles anticipated new transportation (levitated trains), new power systems (cheap energy) and the creation of an “Oxide Valley” comparable to California's Silicon Valley.
Hole-Burning Spectroscopy of Glasses
Authors: Haarer Dietrich , Silbey Robert
Published: January 2008

The history of man-made glass dates back to ancient Egypt, where the first glass containers were created around 1500 BC. Later, in classical Rome, glass objects of unparalleled beauty were made. Glassy materials and the artifacts and objects made from them have fascinated mankind since those early times.
Precursor of Perestroika
Authors: Fainberg Vladimir Ya.
Published: January 2008

A little time has now passed since the death of Andrei Dmitrievich Sakharov. Many articles and papers have been published reflecting on this tragic event from various points of view, but time alone will reveal the depth of the loss suffered by our country and humanity and the grief felt by all people of discernment. It will be some time before we cease to feel our bereavement at the crumbling of the foothold that supported us in hard times, in our hour of need.
Scientist, Thinker, Humanist
Authors: Goldanskii Vitalii I.
Published: January 2008

I cannot say that I knew Andrei Dmitrievich Sakharov well, so this will be a view of him from off to the side, so to speak. It was 1950, in Dubna, when I first saw Sakharov. I was working at the first of the Dubna accelerators at the time. One day, while a management team headed by Igor V. Kurchatov was visiting the place to get a look at the experimental results, a very quiet and shy young man caught my attention. When I asked some acquaintances who he was, I was told, “Sakharov, candidate in sciences from the Lebedev Physics Institute.” I was advised to remember his name, since even at the time a very bright future was seen for him.
Sakharov in His Own Words
Authors: Eisenhower Susan , Sagdeev Roald Z.
Published: January 2008

Few people in this century have been so esteemed for their original thought, humanitarian commitment and moral courage as Andrei Sakharov. His extraordinary personal qualities continue to serve as inspiration to many millions of people throughout the world. Within the Soviet Union, particularly, Sakharov's voice is greatly missed.
Supernovae
Authors: Bethe Hans A.
Published: January 2008

Supernovae are spectacular events. The recent one, SN1987A, emitted light at a rate 100 million times that of the Sun—and it was one of the fainter supernovae. Unfortunately, supernovae are very rare. The last one seen in our galaxy was Kepler's in 1604.
The Physics of J. Willard Gibbs in his Time
Authors: Klein Martin J.
Published: January 2008

Who was the “Mr. Josiah Willard Gibbs of New Haven” who was appointed professor of mathematical physics by the Yale Corporation on 13 July 1871? He was born on 11 February 1839, the only son and the fourth of the five children of Mary Anna Van Cleve Gibbs and Josiah Willard Gibbs the elder, a distinguished philologist and professor of sacred literature at Yale. Although the elder Gibbs worked in a field of learning very different from his son's, there were common features in their approaches. What was said of the father could well have been said of the son: “Mr. Gibbs loved system, and was never satisfied until he had cast his material into the proper form. His essays on special topics are marked by the nicest logical arrangement.”
Special Issue: Dynamics of Molecular Systems
Authors: Drake J. M. , Klafter J.
Published: January 2008

The development of ultrashort light pulses during the last decade has opened the way to the direct probing of the fundamental dynamic processes of molecular systems. Coupled with the huge strides made in handling complex, many-body systems by computer simulation and the continued development of molecular theories, the availability of these ultrashort lased pulses has allowed our understanding of reaction dynamics and their subtleties to flourish. Our goal is to achieve a high level of predictability concerning the dynamic behavior of molecular systems in a broad range of disordered environments. However, the individual approaches to this goal—that is, the ways in which the fundamental scientific issues of molecular dynamics are studied—have varied.
Condensed Matter Physics in a Market Economy
Authors: Rowell John M.
Published: January 2008

In 1991 I attended my 30th consecutive March meeting of The American Physical Society, held in Cincinnati. This anniversary made me reflect on the changes I have seen in the field since I listened to my first ten-minute talk in Baltimore in 1962. I believe it was obvious to many in Cincinnati that there is a malaise affecting our field that was not present 30 or even 10 years ago. By “our field,” I mean what is variously called solid-state physics, condensed matter physics, materials physics and materials science.
Superconductivity in Doped Fullerenes
Authors: Hebard Arthur F.
Published: January 2008

Carbon 60 is a fascinating and arrestingly beautiful molecule. With 12 pentagonal and 20 hexagonal faces symmetrically arrayed in a soccer-ball-like structure that belongs to the icosahedral point group Ih, its high symmetry alone invites special attention. The publication in September 1990 of a simple technique for manufacturing and concentrating macroscopic amounts of this new form of carbon (see Donald R. Huffman's article in PHYSICS TODAY, November 1991, page 22) announced to the scientific community that enabling technology had arrived. Macroscopic amounts of C60 (and the higher fullerenes, such as C70 and C84) can now be made with anapparatus as simple as an arc furnace powered with an arc welding supply. Accordingly, chemists, physicists and materials scientists have joined forces in an explosion of effort to explore the properties of this unusual molecular building block.
Color Perception
Authors: Robertson Alan R.
Published: January 2008

To understand the physics of color, one must first understand the basics of color perception. Color is, first and foremost, a perception. Even though the stimulus that enters our eyes and produces the perception can be described and measured in physical terms, the actual color that we perceive is the result of a complex series of processes in the human visual system. Isaac Newton expressed this clearly in his famous treatise Opticks when he said:
From Photons to Bits
Authors: Khosla Rajinder P.
Published: January 2008

There are many ways to record optical images. One might describe Paleolithic cave paintings as the earliest imaging technology. As significant as they probably were to those who made and lived with them, these depictions were limited by the artist's skill and time, and only persons who entered the cave could benefit from them. It was not until the coming of the printing press that a particular image could be made available to a wide audience. But even then one was still dependent on the artistic skill and subjective vision of the individual artist.
Digital Color Printing
Authors: Starkweather Gory K.
Published: January 2008

Color printing is a modern technological wonder that appeals to an impressive sensory ability: human vision. Colorful images influence what we buy, how we dress and the decisions we make on a host of other life-style issues. Digital color printing provides ease of control and the potential for repeatable, WYSIWYG—"what you see is what you get"—printing. Analog color printing does not permit a comparable level of editing and control, and only in the hands of craftspeople does it provide repeatable results. Digital color printing transfers image control from the chemical tank to the computer. (See figure 1.) Furthermore, personal computers have increased so much in speed, memory and computing power that processing requirements deemed virtually impossible to satisfy only ten years ago are now met routinely. The emergence of digital (or electronic) photography will bring new and exciting capabilities to users and allow us to optimize the preparation of information.
Roundtable: Science Under Stress
Authors: Lubkin Gloria
Published: January 2008

Lubkin: Because the sponsor of this discussion is PHYSICS TODAY, we would like to concentrate on physics. But you needn't limit yourselves to physics, since many of the issues obviously transcend our own field. Many physicists—and scientists in general—have been complaining, even before the country fell into economic recession, that funding for research is inadequate, that their subfield is hurting everywhere, at universities, national laboratories and industrial companies. With the issue of funding so pervasive, I'd like to start by asking whether budgets for physics research are considered adequate today and whether physicists are realistic about this, given the state of the economy and the demands on the government.
Electronic Sputtering: From Atomic Physics to Continuum Mechanics
Authors: Johnson Robert E. , Sundqvist Bo U. R.
Published: January 2008

The surprising fact that even very complex molecules can be ejected intact into the vapor phase when a material is electronically excited by incident particles provides a new probe of the behavior of condensed matter at high excitation densities. The physics of the conversion of the electronic excitation energy into mechanical and chemical energy links atomic physics in a solid at low excitation densities to nanometer-scale continuum mechanics at high excitation densities
Acoustics of Drums
Authors: Rossing Thomas D.
Published: January 2008

Drums have played an important role in nearly all musical cultures. They have been used to transmit messages, convey the time of day, send soldiers into battle and warn of impending disaster. Although drums have been constructed of wood, stone and metal, the most familiar type of drum consists of a membrane of animal skin or synthetic material stretched over some type of air enclosure.
Special Issue: John Bardeen
Authors: Lubkin Gloria B.
Published: January 2008

When John Bardeen was awarded a second Noble Prize in Physics, the only person ever to win two Nobels in the same field, he got a telagram from leo Kadanoff saying: “Keep up the good work. Win three times and you get to keep the Kind.”
Recollections From The Early Years of Solid-State Physics
Authors: Herring Conyers
Published: January 2008

Bardeen's devotion to solid-state physics began in the mid-1930s, when he was a graduate student and the field was young. By 1951 he had helped to discover the transistor and had set the stage for his later studies of superconductivity.
John Bardeen and the Point-Contact Transistor
Authors: Holonyak Nick
Published: January 2008

To this day it is not well understood that the bipolar transistor began with John Bardeen and Walter H. Brattain's point-contact transistor. The invention of the point-contact transistor was a momentous event, not only in itself but even more because of the unimaginable revolution in electronics that followed. This revolution, which continues unabated, had a beginning: Bardeen's recognition of minority-carrier injection—that is, his realization that an applied voltage causes valence band holes from the surface region of an n-type semiconductor material near a metal contact to be injected into the bulk of the material. This realization made the semiconductor suddenly important and no longer just an interesting material to study.
Progress Toward a Tokamak Fusion Reactor
Authors: Geoffrey Cordey J. , Goldsron Robert J. , Parker Ronald R.
Published: January 2008

Nearly 90% of the world's energy needs are today supplied by fossil fuels. Long-term reliance on fossil-fuel energy sources, however, is acknowledged to be a dangerous strategy—despite the large reserves of coal available in the US and elsewhere. Use of fossil fuels exacerbates pollution and acid rain and heightens the risk of global warming by adding CO2 to the atmosphere. Society will be served best if energy production in the next century uses environmentally attractive methods that do not involve the combustion of fossil fuels. (See the article by John H. Gibbons and Peter D. Blair in PHYSICS TODAY, July 1991, page 22.) The long time required to develop and implement new large-scale energy technologies—on the order of decades—underscores the urgency of the need to accelerate development of alternative energy sources.
Semiconductor Quantum Heterostructures
Authors: Chang Leroy L. , Esaki Leo
Published: January 2008

Junctions between dissimilar semiconductors have long attracted the attention of researchers in solid-state physics and electronics. The additional degree of freedom provided by the two materials in the semiconductor heterojunction offers opportunities to pursue new phenomena and applications not possible with homogeneous media. A notable example is the heterojunction injection laser, which, because of its ability to operate continuously at room temperature, has had a great technological impact in areas ranging from optical communications to the compact-disc player.
Biological and Synthetic Hierarchical Composites
Authors: Baer Eric , Hiltner Anne , Morgan Roger J.
Published: January 2008

Many advanced composites can best be described hierarchically. In particular, the biological composites that occur in organisms are generally seen to be organized on discrete scale levels ranging from the molecular to the macroscopic. At each level the components are held together by specific interactions and organized in a way that is optimized for the ultimate function and performance of the overall system. Biological composites typically consist of fibers made from long macromolecules, organized into different structures. One can learn much from biological composites by considering the relationship between their structures and their properties. Whether natural or synthetic, for a composite system to function efficiently its components must be assembled into a specific architecture that gives the required spectrum of properties.
John Bardeen and the Theory of Superconductivity
Authors: Schrieffer J. Robert
Published: January 2008

When one speaks with John Bardeen's friends about him, one frequently hears words such as brilliant, quiet, persistent, generous, visionary, athletic, kind, thoughtful and remarkable. It is my good fortune to have the chance to recount some incidents from his life that are connected with the theory of superconductivity. This article draws on my personal memories; his many other friends and colleagues will set down their own recollections elsewhere.
Sos! Save Our Science!
Authors: Sagdeev Roald Z.
Published: January 2008

The brains of science are rarely spared in political revolutions. Even if no scientist is beheaded by guillotine, as Antoine Lavoisier was during the French Revolution, the upheaval throws many other obstacles in the way of the scientific community's surviving without substantial losses. In 1917–20, at the peak of economic chaos and civil war in Russia, the scientific intelligentsia was indeed an endangered species, not only because of the blood being spilled everywhere but also because of the revolution's simple economic impact: The country was in ruins. At that historical moment the author Maksim Gorky, who played a positive role in the early years of the Bolshevik regime, persuaded Lenin to adopt extraordinary measures to rescue the very small group of intellectuals—scientists as well as writers and artists. As a result of this pressure, Lenin agreed to establish special food rations for the intelligentsia, in Petrograd (now St. Petersburg) in particular.
Metallic Magnetic Superlattices
Authors: Falicov L. M.
Published: January 2008

Artificially made, ordered material systems are a pillar of late-20th-century advanced technology. In principle, metallic magnetic superlattices—also called magnetic multilayers—should exhibit more new and interesting physical effects than any other artificially made material system. This gives them the potential for many technological advances in information storage and retrieval and in the synthesis of new magnets for a variety of applications.
Transgenic expression ofHelicobacter pyloriCagA induces gastrointestinal and hematopoietic neoplasms in mouse
Authors: Ohnishi Naomi , Yuasa Hitomi , Tanaka Shinya , Sawa Hirofumi , Miura Motohiro , Matsui Atsushi , Higashi Hideaki , Musashi Manabu , Iwabuchi Kazuya , Suzuki Misao , Yamada Gen , Azuma Takeshi , Hatakeyama Masanori
Published: January 2008

Infection withcagA-positiveHelicobacter pyloriis associated with gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma of B cell origin. ThecagA-encoded CagA protein is delivered into gastric epithelial cells via the bacterial type IV secretion system and, upon tyrosine phosphorylation by Src family kinases, specifically binds to and aberrantly activates SHP-2 tyrosine phosphatase, a bona fide oncoprotein in human malignancies. CagA also elicits junctional and polarity defects in epithelial cells by interacting with and inhibiting partitioning-defective 1 (PAR1)/microtubule affinity-regulating kinase (MARK) independently of CagA tyrosine phosphorylation. Despite these CagA activities that contribute to neoplastic transformation, a causal link between CagA andin vivooncogenesis remains unknown. Here, we generated transgenic mice expressing wild-type or phosphorylation-resistant CagA throughout the body or predominantly in the stomach. Wild-type CagA transgenic mice showed gastric epithelial hyperplasia and some of the mice developed gastric polyps and adenocarcinomas of the stomach and small intestine. Systemic expression of wild-type CagA further induced leukocytosis with IL-3/GM-CSF hypersensitivity and some mice developed myeloid leukemias and B cell lymphomas, the hematological malignancies also caused by gain-of-function SHP-2 mutations. Such pathological abnormalities were not observed in transgenic mice expressing phosphorylation-resistant CagA. These results provide first direct evidence for the role of CagA as a bacterium-derived oncoprotein (bacterial oncoprotein) that acts in mammals and further indicate the importance of CagA tyrosine phosphorylation, which enables CagA to deregulate SHP-2, in the development ofH. pylori-associated neoplasms.
Studies on high electronic energy deposition in transparent conducting indium tin oxide thin films
Authors: Deshpande N G , Gudage Y G , Ghosh A , Vyas J C , Singh F , Tripathi A , Sharma Ramphal
Published: January 2008

We have examined the effect of swift heavy ions using 100 MeV Au8+ions on the electrical properties of transparent, conducting indium tin oxide polycrystalline films with resistivity of 0.58 × 10−4 Ω cm and optical transmission greater than 78% (pristine). We report on the modifications occurring after high electronic energy deposition. With the increase in fluency, x-ray line intensity of the peaks corresponding to the planes (1 1 0), (4 0 0), (4 4 1) increased, while (3 3 1) remained constant. Surface morphological studies showed a pomegranate structure of pristine samples, which was highly disturbed with a high dose of irradiation. For the high dose, there was a formation of small spherical domes uniformly distributed over the entire surface. The transmittance was seen to be decreasing with the increase in ion fluency. At higher doses, the resistivity and photoluminescence intensity was seen to be decreased. In addition, the carrier concentration was seen to be increased, which was in accordance with the decrease in resistivity. The observed modifications after high electronic energy deposition in these films may lead to fruitful device applications.
Genomic Analysis Highlights the Role of the JAK‐STAT Signaling in the Anti‐Proliferative Effects of Dietary Flavonoid—‘Ashwagandha’ in Prostate Cancer Cells
Authors: Aalinkeel Ravikumar , Hu Zihua , Nair Bindukumar B. , Sykes Donald E. , Reynolds Jessica L. , Mahajan Supriya D. , Schwartz Stanley A.
Published: January 2008

Phytochemicals are dietary phytoestrogens that may play a role in prostate cancer prevention. Forty percent of Americans use complementary and alternative medicines (CAM) for disease prevention and therapy. Ashwagandha (Withania somnifera) contains flavonoids and active ingredients like alkaloids and steroidal lactones which are called ‘Withanolides’. We hypothesize that the immunomodulatory and anti‐inflammatory properties of Ashwagandha might contribute to its overall effectiveness as an anti‐carcinogenic agent. The goal of our study was gain insight into the general biological and molecular functions and immunomodulatory processes that are altered as a result of Ashwagandha treatment in prostate cancer cells, and to identify the key signaling mechanisms that are involved in the regulation of these physiological effects using genomic microarray analysis in conjunction with quantitative real‐time PCR and western blot analysis. Ashwagandha treatment significantly downregulated the gene and protein expression of proinflammatory cytokines IL‐6, IL‐1β, chemokine IL‐8, Hsp70 and STAT‐2, while a reciprocal upregulation was observed in gene and protein expression of p38 MAPK, PI3K, caspase 6, Cyclin D and c‐myc. Furthermore, Ashwagandha treatment significantly modulated the JAK‐STAT pathway which regulates both the apoptosis process as well as the MAP kinase signaling. These studies outline several functionally important classes of genes, which are associated with immune response, signal transduction, cell signaling, transcriptional regulation, apoptosis and cell cycle regulation and provide insight into the molecular signaling mechanisms that are modulated by Ashwagandha, thereby highlighting the use of this bioflavanoid as effective chemopreventive agent relevant to prostate cancer progression.
The new covenant of employability
Authors: Clarke Marilyn , Patrickson Margaret
Published: January 2008

Purpose

Changing career patterns and the erosion of job security have led to a growing emphasis on employability as a basis for career and employment success. The written and psychological contracts between employer and employer have become more transactional and less relational, and loyalty is no longer a guarantee of ongoing employment. Individuals are thus expected to take primary responsibility for their own employability rather than relying on the organisation to direct and maintain their careers. The purpose of this paper is to identify and examine the assumptions underpinning the concept of employability and evaluate the extent to which employability has been adopted as a new covenant in the employment relationship.

Design/methodology/approach

Through a review of relevant literature the paper discusses current research on careers and employability and examines the available evidence regarding its adoption as a basis for contemporary employment relationships.

Findings

The paper finds that the transfer of responsibility for employability from organisation to individual has not been widespread. There is still an expectation that organisations will manage careers through job‐specific training and development. Employability has primarily benefited employees with highly developed or high‐demand skills. Employability is not a guarantee of finding suitable employment.

Practical implications

Employers can assist their employees by clarifying changes to the psychological contract, highlighting the benefits of career self‐management, and providing training and development in generic employability skills.

Originality/value

The paper questions underlying assumptions about employability and explores issues of relevance to human resource managers, policy‐makers, employers and employees.