bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Modification by Ordered Monolayers: New Ways of Protecting Materials Against Corrosion
Authors: Rohwerder M. , Stratmann M. 
Published: August 2016

Metal/polymer composites are used in numerous technical applications. For example, polymer coatings on metal surfaces are used for corrosion protection, metal films on polymers inhibit static buildup, and polymers between two metals can serve as a “glue” for connecting materials that cannot be welded. Polymer/metal composites also play an important role in modern electronics. In condensers, polymers serve as insulating layers between metallic leads and are used to encapsulate entire electronic circuits. In all circumstances, interfaces are formed between the two different materials, and since the chemistry and structure change abruptly, interfacial failure is frequently observed.The cause of failure may just be mechanical (e.g., shrinkage of the polymer during curing), or the interface stability may be degraded by attack of aggressive species, resulting in delamination. More specifically, loss of adhesion is directly caused by interfacial electrochemical reactions that nucleate at a defect and progress into intact regions of the interface. This occurs for encapsulated electronic parts in humid atmospheres as well as for lacquers on automotive parts.Thus the investigation of corrosion reactions at a buried interface is an important area of research, but it is made very difficult by the fact that most electrochemical methods do not give information on localized reaction kinetics at a buried (metal/polymer) interface. This situation has changed with the invention and development of the scanning Kelvin probe (SKP). This method allows, for the first time, local analysis of reactions occurring at a buried metal/polymer interface. Based on the results obtained with the SKP, a detailed reaction model for the delamination process has been developed. This understanding has led to the development of new approaches that protect the interface from delamination. The idea is to chemically modify the interface using Afunctional molecules that promote adhesion between metal and polymer surfaces.
Diagnosing Engineering Problems with Neutrons
Authors: Withers P.J. , Holden T.M. 
Published: August 2016

In the past, many unexpected failures of components were due to poor quality control or a failure to calculate—or to miscalculate—the stresses or fatigue stresses a component would experience in service. Today, improved manufacturing, fracture mechanics, and computational finite element methods combine to provide a solid framework for reducing safety factors, enabling leaner design. In this context, residual stress—that is, stress that equilibrates within the structure and is always present at some level due to manufacturing—presents a real problem. It is difficult to predict and as hard to measure. If unaccounted for in design, these stresses can superimpose upon in-service stresses to result in unexpected failures.Neutron diffraction is one of the few methods able to provide maps of residual stress distributions deep within crystalline materials and engineering components. Neutron strain scanning, as the technique is called, is becoming an increasingly important tool for the materials scientist and engineer alike. Point, line-scan, area-scan, and full three-dimensional (3D) maps are being used to design new materials, optimize engineering processes, validate finite element modeis, predict component life, and diagnose engineering failures.
Superconductivity at High Temperatures Without Copper: Ba1-xKxBiO3
Authors: Cava R.J. , Batlogg B. 
Published: August 2016

Before the pioneering work of Bednorz and Müller in finding superconductivity near 30 K in lanthanum-barium-copper oxide,. oxide superconductors were well known, but perhaps not fully appreciated. Most anomalous among those superconductors was the perovskite structure material BaPb0.75Bi0.25O3, with a superconducting transition temperature (Tc) of 12 K2 and a surprisingly low density of states at the Fermi level. The increases in Tc for copper-oxide-based materials continue to generate worldwide excitement, but from both a chemical and theoretical point of view, high Tc superconductivity observed in a noncopper containing material is also of considerable interest.Recently we found that the simple cubic perovskite compound Ba0.6K0.4BiO3 displays a superconducting transition temperature near 30K—a Tc considerably higher than that of conventional superconductors and surpassed only by copper containing compounds. This material is in stark contrast to the now well-known copper oxides for two reasons: (1) superconductivity occurs within the framework of a three dimensionally connected bismuth-oxygen array (and not a 2-d array as in the Cu-O based compounds) and: (2) there are no magnetic fluctuations present in the chemical system, either in the superconductor itself or in the nonsuperconducting end member compound, eliminating the possibility that the high Tc might be caused by magnetic interactions. The parent compound BaBiO3 is, however, of considerable interest due to the presence of a structurally frozen charge disproportionation of the bismuth atoms, considered by many to be the electronic equivalent of the antiferromagnetism observed in the nonsuperconducting cuprate host compounds.The ideal undistorted perovskite ABO3 structure consists of a regular array of equally dimensioned BO6 octahedra sharing all corner oxygens with neighboring equivalent octahedra, with 180° B-O-B angles.
High Tc Superconducting Thin Films
Authors: Laibowitz Robert B. 
Published: August 2016

While high Tc superconductivity was first discovered in bulk material, it was apparent that thin films of these materials, particularly the compound YBa2Cu3O7-δ, would be of great interest to both science and technology. In this sense the development of these materials parallels a similar history in the low Tc materials. Initially, most of the low Tc materials of interest were single element metals such as Nb, Pb and Al in bulk form. Later work, mostly in magnets, led to the development of compounds or alloys of such metals as Nb-Sn, Nb-Ti, and many others. However, many physical and technological investigations required thin films with thicknesses in the range of 0.1-10μm. Microwave, infrared, and critical current studies are examples of some of the scientific uses of thin films. A few examples of the applications would include josephson junction-based digital computer circuits, SQUID (Superconducting Quantum Interference Devices), transmission lines, and interconnects and rf mixers. These studies are also of great interest in the high Tc materials. It is readily apparent that scientific and technological developments in superconductivity are closely interwoven.The high level of interest in thin films can be appreciated by observing that it was barely a few months after the announcement of superconductivity above 77 K that the first films of these complex, multi-element materials, superconducting at about 86 K were announced. These early efforts at thin film fabrication were generally accomplished using multi-element deposition techniques but subsequent development has seen many varieties of film fabrication techniques used quite successfully to fabricate high-quality films.
Up Close: Materials Science at Argonne National Laboratory
Authors: Fradin Frank 
Published: August 2016

Basic and applied materials research at Argonne National Laboratory (ANL) is conducted by the Materials Science Division (MSD) and the Materials and Components Technology Division (MCT). Of the $30 million annual budget, $23 million comes from the U.S. Department of Energy (DOE) that funds Basic Energy Sciences (BES)-Materials Sciences, Reactor Development, Fusion Energy, Fossil Energy, and Conservation Technology. Another $5 million of the $30 million budget comes from the Nuclear Regulatory Commission and the remaining $2 million is from the Department of Defense.Representative projects in fission energy include fuel element behavior in the Advanced Breeder Reactor, fuel development for the Integral Fast Reactor, and supporting research in aqueous corrosion and in phase stability.Materials research for fusion environments includes containment materials, liquid metal compatibility, vanadium alloy development, defect production processes, radiation-induced segregation, sputtering of self-replenishing low atomic number coatings, and ultrahigh field superconductors.
Maintaining Technological Leadership in a World Economy—1988 MRS Fall Meeting Plenary Address
Authors: Thurow Lester C. 
Published: August 2016

If you are an economist in this day and age, and especially if you are an economist at MIT, you often get asked “Is economics really a science?”I used to give a very complicated answer to that question, but recently I discovered a much simpler one: When the Discovery went up, the Space Administration announced that the success of the Discovery was entirely due to the scientific achievement of economists because in shifting from the Challenger to the Discovery the Space Aclrninistration had to do a lot of experiments, and they had to replace rats with economists in all these experiments. They announced three reasons for replacing rats with economists: First, there were now more economists and they were cheaper; second, you sometimes emotionally get attached to the rats; and third, there are some things that rats just won't do.The serious answer to that question, however, is that economics is much like geology. Geologists understand earthquakes and volcanoes perfectly—it's plate tectonics. But if you ask a geologist, “Tell me the precise timing and the precise magnitude of the next earthquake in Los Angeles,” you are in trouble.The problem is that people like to ask economists that question: “Give me the precise timing and the precise magnitude of some event.” And economists have a character weakness. They tend to answer those kinds of questions. And those kinds of questions simply can't be answered.
Up Close: Center for Micro-Engineered Ceramics at the University of New Mexico
Authors: Kodas Toivo 
Published: August 2016

The Center for Micro-Engineered Ceramics (CMEC) recently established at the University of New Mexico is a National Science Foundation Industry/University Cooperative Research Center. It is supported by the National Science Foundation, Los Alamos and Sandia National Laboratories, New Mexico Research and Development Institute, and the ceramics industry.The CMEC is unique in that it combines the resources of two universities (University of New Mexico and New Mexico Institute of Mining and Technology) and two national laboratories to attack ceramics-related basic research problems of industrial significance. An essential part of the effort is the strong interplay between the basic scientific disciplines, particularly physics and chemistry, along with engineering; the work is interdisciplinary with members from chemical engineering, mechanical engineering, chemistry, physics, and geology.The goals of the CMEC are to1. Aggressively attack ceramics-related basic research problems using university/national laboratory/industry collaborations;2. Transfer technology between the universities, national laboratories, and industry; and3. Train a new generation of ceramic scientists and engineers at both the undergraduate and graduate levels.At present, the areas of major interest are novel powder synthesis and processing schemes for controlled morphology powder compacts, and coatings and porous films. In addition, both laboratories and universities have programs on ceramic superconductors.
Point Defects in Materials Part II: Applications to Different Materials Problems
Authors: Seidman David , Shi Donglu 
Published: August 2016

This issue of the MRS Bulletin follows up on the November issue's five articles on point defect phenomena in a wide range of materials with five more articles on point defects. The present articles emphasize the behavior of different phenomena in various materials—nonstoichiometric metal oxides, intermetallic compounds, type II superconductors and semiconductors—in terms of fundamental properties of point defects. Again, point defects is the unifying theme but the emphasis shifts to material behavior.This issue begins with Marshall Stoneham's article on the roles theory plays in predicting and understanding material behavior in terms of point defects in the different classes of materials. The following article by Rüdiger Dieckmann discusses the relationships between point defect concentrations in nonstoichiometric metal oxides and diffusion, i.e., mass transport. Next, Georges Martin and Pascal Bellon review their new approach for analyzing the role played by antisite defects in nonequilibrium phase transitions in intermetallic compounds. Then, Donglu Shi focuses on the effect of point, line, and planar defects on three major properties of type II superconductors—the critical transition temperature, the upper critical magnetic field, and the critical current density. Finally, Lionel Kimerling shows how defect engineering is used to achieve a high degree of complexity in product fabrication and greater sophistication in product performance; he illustrates what he means by defect engineering with examples from basic processes used in electronic materials processing.
Vacancies and Self-Interstitials
Authors: Huntington H.B. 
Published: August 2016

This article aims to review in rather cursory fashion the ways the concepts of lattice defects have contributed at an early stage to our understanding of solid-state kinetics in metals and insulators.The importance of point defects in solid-state kinetics was just beginning to be widely recognized in the late 1930s. The crucial experiments of Kirkendall and others were still to come. Many of the leaders in the field of metallurgy believed almost tacitly that diffusion in substitutional alloys occurred by direct interchange or perhaps a ring mechanism.For the ionic salts, however, basic calculations were further advanced, and it was possible to figure quite confidently the role of Schottky and Frenkel defects in facilitating atom movements. In their seminal paper, Mott and Littleton made specific calculations as to the energies involved in diffusion by the various mechanisms and hence to the relative importance of these mechanisms in the kinetics of these materials. They began by taking over the Born-Mayer short-range formula for ionic repulsion. Next they treated in detail the polarization response of the salt to an extra charge in the lattice, whether interstitial or vacancy. This polarization included the individual polarizabilities of the ions and, for the static case, the ion displacements. Application of this analysis gave good quantitative results for the activation energies to be expected for diffusion and ionic conductivity. For the alkali halides it was made clear that the Schottky defect would dominate and that Frenkel defects would be few.
Biomedical Materials
Authors: Barenberg S.A. , Mueller E.P. 
Published: August 2016

Biomedical materials is an embryonic interdisciplinary science whose practitioners are scientists, engineers, biochemists, and clinicians who use synthetic polymers, metals, ceramics, inorganic, and natural polymers to fabricate artificial organs, medical devices, drug delivery systems, prosthetics, and packaging systems.The intent of this special issue of the MRS Bulletin is to provide readers with insight into current biomaterials research and product development. This issue is not meant to be either conclusive or definitive, but rather a “sound bite” of the field.For further information, please feel free to contact either the individual authors or the editors of this issue.
Drug Delivery Systems
Authors: Langer Robert 
Published: August 2016

For many years, drug delivery systems were composed of simple pills, eyedrops, ointments, or intravenous solutions. Recently, materials have begun to play a major role in improving drug delivery. Drugs are now chemically attached to polymers, entrapped in small vesicles that are injected into the bloodstream, or put in pumps or polymeric materials that are placed in the body. These new materials-based systems are beginning to change the way drugs can be administered and, in so doing, have improved human health. This article provides a brief review of the major classes of drug delivery systems; a recent paper discusses these issues in detail.Chemically attaching a drug to a polymer may alter such properties as its distribution in the body, rate of appearance in certain tissues, solubility, or antigenicity. For example, drugs have been linked to soluble macromolecules such as proteins, polysaccharides, or synthetic polymers via degradable linkages. This alters the drug's size and other properties, resulting in a different bodily drug distribution pattern. One example involves coupling the antitumor agent neocarzinostatin to styrene-maleic acid copolymers. When this complex was injected intra-arterially in patients with liver cancer, tumor size decreased significantly. In animals, the antitumor agent, doxorubicin, bound to N(2-hydroxypropyl) methacrylamide copolymers reduced toxicity. The plasma half-life and the drug levels in the tumor increased while the concentrations in the rest of the body decreased.
Effective Technology Transfer Through Active Licensing
Authors: Levy Nelson L. , Coles Eric 
Published: August 2016

The National Science Foundation has estimated that 28% of the information processing products, 37% of the pharmaceutical processes, and 44% of the pharmaceuticals on the market today derive directly from university research. Single companies create annual research budgets in the hundreds of millions of dollars by allocating to research 2–10% of their revenues, a percentage identical to the typical royalty rate. Yet none of our great research institutions receives royalty income in excess of $15 million, and most receive under $1 million. Certainly, our universities and their faculty could enjoy greater benefit from the transfer of their technology to the private sector. Such expectations account for the explosive growth of university technology transfer programs.We would define the mission of technology transfer as (1) to bring university inventions into public use with maximum integrity, effectiveness, and speed, and (2) to maximize the financial return to the university and the inventor. This article will describe “active licensing,” an approach to technology transfer that we have found to be more effective and that we feel is more rational than the paradigms in use at most institutions.Figure 1 presents the commercial value of technology as a function of incremental time and cost investment in development of the technology.
Materials Rheology: An Overview
Authors: Kurtz Stuart J. 
Published: August 2016

My fellow authors and I have assembled a series of articles on using rheology to understand the structure and processing of a wide range of materials. We approach this task by presenting an introduction to the concepts of rheology and some illustrative applications, followed by a description of linear vis-coelasticity and a description of the rheological behavior of elastic fluids. These concepts and related tools are then used to describe molten polymers, colloidal suspensions, latex systems, electrorheological fluids, and gels. In each of these areas, we show how rheology provides insights into the structure of materials and the type of information required to process them. We also show that the rheological approach spans macroscopic and microscopic domains. These aspects of rheology are of value to materials scientists and engineers. We hope these examples will clarify the relevance of rheology to materials.If we are successful in this presentation, you will obtain a flavor of the process of rheological studies. While reading through these articles, look for the interplay of the concepts of molecular or domain structures and the flow and deformation of the bulk materials. These articles may even inspire you to examine the role that rheology may play in your own studies.
Mechanical Response of Linear Viscoelastic Solids
Authors: Wineman Alan 
Published: August 2016

The word “viscoelastic” is used to describe the mechanical response of materials exhibiting both the springiness associated with elastic solids and viscous flow characteristics associated with fluids. A familiar example of a material called viscoelastic is Silly PuttyTM. If a blob of Silly Putty is rolled into a ball and then dropped onto a hard surface, it will bounce like an elastic ball. If the ball is placed on a hard surface, its own weight will cause it to flow into a puddle. This behavior indicates that time is an intrinsic parameter in discussing viscoelastic response of materials. The elastic response is associated with a contact force of very short duration. The flow into a puddle occurs when forces act for a long period of time.Viscoelastic response occurs in materials such as soils, concrete, cartilage, biological tissue, and polymers. Soils and cartilage can be thought of as porous solids filled with fluid. Viscous response is due to the flow of the fluid in the pores; elastic response is due to the distortion of the porous solid.
Rheology of Molten Polymers
Authors: Dealy John M. 
Published: August 2016

The term “polymeric liquids” is used to describe both solutions of polymers and molten polymers. All polymeric liquids exhibit non-Newtonian flow behavior, including a shear stress-dependent viscosity and elasticity. However, concentrated solutions and melts of polymers whose molecular weights exceed a certain critical value (the “critical molecular weight for entanglement,” Mc) exhibit quite remarkable deviations from classical fluid behavior, especially marked elasticity. Among the remarkable rheological phenomena exhibited by these materials are elastic recoil and flow-induced an-isotropy. Indeed, in certain situations, such materials can exhibit elastic effects that are almost indistinguishable from those exhibited by cross-linked rubbers. This behavior is important, because most commercial “thermoplastics,” such as polyethylene and polystyrene, have high molecular weights (M > Mc) and are processed in the molten state.A given generic polymer, polyethylene for example, can exhibit a wide range of properties depending on the molecular weight distribution. Another important aspect of molecular structure is branching. For many monomers (the molecular building blocks that make a polymer molecule), two types of polymer structure are possible, linear and branched. For example, ethylene can be polymerized in two ways to form either linear polyethylene or branched polyethylene. Branching enhances the non-Newtonian and elastic aspects of the melt flow behavior. Yet another possible aspect of polymer molecular structure is the presence of a comonomer.