bluuebunny/crossref_metadata_2025_split huggingface dataset:
Processes and Performance in Renaissance Painting
Authors: Alexander Ingrid C. 
Published: August 2016

During the greater part of the 15th century, the Burgundian princes created a stable, unified center for industry and the flourishing of the arts in the Netherlands. Philip the Good became one of the most powerful and wealthy princes of the House of Burgundy in the period. Under his rule, the Netherlands became an important center for commerce. The port of Bruges, and later Antwerp, offered easy access to the important trade routes. The German merchants of the Hansa towns of Bremen, Danzig, Lübeck, and Hamburg and ships from England and the Baltic regions brought wares to be bought and sold in Flemish towns. The routes along the Atlantic and Mediterranean provided direct lines of communication between Italian merchants from Venice, Genoa, Florence, and Bruges.The Netherlands soon became a center of a large part of the business activity in Europe and its prosperity grew. The concentration of trade, the presence of numerous banks, and the commission they charged contributed to the wealth of its bourgeois merchants and financiers. They soon became as rich and sometimes richer than the Burgundian princes. Thus they had the means to become important patrons of the arts so as to display their wealth. The acquisition of rare and exotic goods became an essential part of a society where exhibiting one's wealth was admired.Flemish artists' corporations were well organized, not unlike modern businesses. They were well-known locally and abroad and had significant influence on the art of the period. Works of art were created in workshops where a long apprenticeship afforded the artists guidance and expert training in their craft. High standards which contributed to the good reputation of the art of Flanders, were maintained by setting the quality of the materials and establishing the techniques used. The painters' guild controlled the production of paintings and took measures to control the supply of materials to keep down prices and to control competition. Also, contracts between artist and patron would sometimes stipulate the type of materials to be used.
Up Close: Materials Science in Spain—Its Dynamic Growth
Authors: Ortiz C. , Gonzalez D. 
Published: August 2016

The year 1992 is very special for Spain: 500 years have passed since the discovery of the American continent. That discovery helped make Spain the most powerful country in the world in the 16th century. In time, though, Spain lost its influence to England, and materials processing played a surprising role in this transfer. It has been shown that one of the main reasons Spain's “Invincible Armada” was defeated by the English Navy was that the Spanish ships used faulty cannon balls. The balls were of such poor quality that, once fired, they disintegrated before they could damage enemy warships. Faulty material technology—low compactness or degree of sintering—caused the disintegration.As we approach the 21st century, the Spanish scientific community has reached a high level of expertise in materials science. A decade ago, Spain's R&D activities were poorly funded and research was carried out without the necessary infrastructure. In 1986, the government established a national R&D strategy which included a dedicated Program for New Materials. In addition, the Regional Communities (Autonomias) have reinforced these nationally planned and funded R&D activities. And as a member of the European Community (EC), Spain has also begun integration into European R&D. After three years, Spanish scientists are already achieving success in the Brite/Euram Program at a level comparable to more scientifically and technologically advanced countries. Figure 1 shows the Spanish government's total R&D budget in materials science from 1985 to 1991, and additions from the EC since 1989. Clearly, financial support for materials science has increased dramatically in the last few years.
Theory and Practice in the Prediction of New Materials
Authors: Rabe K.M. 
Published: August 2016

The prediction of new materials is, in theory, a completely straightforward problem. The fundamental equations of quantum mechanics for solids are well-established and can be numerically solved, at least approximately, by powerful first-principles methods developed over the last decade. It remains, then, only to examine the solutions to find those systems that will exhibit the properties desired.The number of possibilities to be considered and sorted is many orders of magnitude larger than can be managed in a case-by-case first-principles analysis. Therefore, in practice, the approach to theoretical prediction of new materials is to establish easy-to-apply rules for screening large numbers of candidate stoichiometrics (which might or might not be known compounds). These rules are based on physical understanding of the occurrence of the structure or property, inference from known examples, and general principles governing chemical trends in the structure and stability of known compounds. Data from the scientific literature on the occurrence and structure of crystalline compounds are now organized into a number of crystallographic databases, providing a unique opportunity to investigate, from a global perspective, the factors that influence structure and stability. To display, access, and extract general principles from this enormous amount of information, a graphical method such as the “quantum diagram” method is essential, and can be thought of as providing a convenient “roadmap” for navigation around the database. Useful conclusions about individual compounds or small sets of compounds can also be drawn from this type of analysis. These conclusions form the basis for rules for predicting new representatives that direct attention to special regions on the roadmap, as illustrated on the cover of this issue. Systems that satisfy these rules are the most likely to reward experimental investigation.
Computational Materials Science of Cement-Based Materials
Authors: Garboczi E.J. , Bentz D.P. 
Published: August 2016

Cement-based materials are random composite materials over many length scales. In common with any random material, the two main problems that must be solved to obtain quantitative theoretical understanding of microstructure-property relationships are: (1) what actually is the microstructure, and (2) given enough knowledge of a micro-structure, how can properties be calculated?In the past few decades, physicists and chemists have studied microstructure/property relationships for atomically disordered materials like semiconductor and metallic glasses, while mechanical engineers have done the same for continuum problems of macroscopic inclusions of one material distributed in a matrix of a second material. With the large memories and fast computational speeds of late 20th-century computers, it is now possible to attack problems that lie between these two extremes, namely random grain problems like those of cement-based and ceramic materials. For these kinds of materials, the important randomness for most problems is at the grain or particle level, not the atomic level, and is complicated by the fact that their microstructure changes markedly on time scales of hours and days, either due to sintering (ceramics), or hydration reactions (cement-based materials). The following sections of this paper describe how microstructures are simulated and properties like electrical conductivity and elastic moduli are computed-mostly for cement-based materials, but with some mention of parallel work on ceramic materials.
From Wood Mechanical Measurements to Composite Materials for Musical Instruments: New Technology for Instrument Makers
Authors: Besnainou Charles 
Published: August 2016

Several authors have conducted research to characterize the woods used for musical instruments. The principle of such studies is that acoustical qualities of musical instruments are linked to modal properties of the resonator, especially to the soundboard. Therefore, by knowing the mechanical parameters of materials, it is easy to deduce the frequencies of the eigen modes of a vibrating structure. Equation 1 requires only the geometrical dimension of a plate, the density, and Young's modulus to define a material:where l is length, b is width, d is thickness, E is Young's modulus, I (= bd3/12) is inertial momentum, ρ is density, n is partial number, and fn, is frequency mode(n).But, how do we choose the values of each parameter, since woods are variable materials with a large distribution of values-for samples coming from the same tree?
Bass Handbells of Aluminum
Authors: Rossing Thomas D. , Gangadharan Deepak , Mansell Edward R. , Malta Jacob H. 
Published: August 2016

Handbells have become very popular musical instruments, especially in schools and churches; about 40,000 hand-bell choirs have been reported in the United States alone. Tuned handbells are generally made of cast bronze, which has been the traditional bell material for many centuries.Demand for handbells of lower and lower pitches has led to the development of bass bells as low as G0 (fundamental frequency of 24.5 Hz). Unfortunately, these large bass bells radiate inefficiently, especially the bells made of bronze. This is because the speed of bending waves in these bells is considerably lower than the speed of sound in air, a condition known as “being below the coincidence frequency.”In order to obtain a higher radiation efficiency and thereby enhance the sound of bass bells, the Malmark Company has created a new bell design using aluminum rather than bronze. These bells are larger in diameter, and they have lower coincidence frequencies, both of which lead to more efficient radiation of bass notes. In addition, they are considerably lighter in weight, and thus are much more easily handled by bell ringers.In this article, the acoustical properties of two G1 handbells, one of aluminum and one of bronze, are compared. The aluminum handbell has a diameter of 48.5 cm, a height of 34 cm, and a wall thickness from 4 to 5 mm. The bronze bell has a diameter of 38.5 cm, a height of 28.5 cm, and a wall thickness from 3 to 4 mm.
Absolute Magnetometry Using Electron Holography: Magnetic Superlattices and Small Particles
Authors: Mankos Marian , Cowley J.M. , Scheinfein M.R. 
Published: August 2016

Synthesized magnetic structures are of interest due to their unique and unusual properties, which are governed by their micromagnetic structure. For example, giant-magnetoresistance (GMR) multilayer structures composed of magnetic layers separated by nonmagnetic spacers, and granular GMR films composed of magnetic and nonmagnetic metals exhibit phenomena whose interpretation requires knowledge of both the physical and micromagnetic structure at nanometer-length scales. Techniques for magnetic-microstructure imaging are based on the interaction between a probe and either the magnetic microstructure itself (magnetization) or a physical quantity related to the magnetization distribution (e.g., magnetostriction, magnetic induction). Transmission methods are sensitive to bulk magnetic microstructure averaged along the direction of the incident probe; surface structure is lost. Reflection techniques interact with the near-surface region and no information is obtained about the bulk structure aside from those properties that can be inferred from appropriate boundary conditions.Electron-optical methods represent the widest class of high-spatial-resolution, magnetic-domain imaging techniques. The most advanced techniques provide the highest contrast, sensitivity, and point resolution (1 nm). Electron holography offers quantitative micromagnetic information at high spatial resolution, a feature missing in most magnetic-imaging techniques. Quantitative information can be extracted from the absolutely calibrated electron wavelength and a knowledge of electron phase shifts in electromagnetic fields. High sensitivity, nanometer spatial resolution, and absolute calibration make electron holography a powerful tool for examining magnetic microstructure. In electron holography, both the amplitude and phase of the transmitted electron waves can be recovered in contrast to conventional electron microscopy where only the intensity is available. The phase, containing information about the local distribution of electromagnetic fields, can be retrieved from an electron hologram.
Solution Deposition of Ferroelectric Thin Films
Authors: Tuttle B.A. , Schwartz R.W. 
Published: August 2016

Solution deposition has been used by almost every electroceramic research-and-development organization throughout the world to evaluate thin films. Ferrite, high-temperature-superconductor, dielectric, and antireflection coatings are among the electroceramics for which solution deposition has had a significant impact. Lithium niobate, lithium tantalate, potassium niobate, lead scandium tantalate, lead magnesium niobate, and bismuth strontium tantalate are among the ferroelectric thin films processed by solution deposition. However, lead zir-conate titanate (PZT) thin films have received the most intensive study and will be emphasized in this article.Solution deposition facilitates stoichiometric control of complex mixed oxides better than other techniques such as sputter deposition and metalorganic chemical vapor deposition (MOCVD). Solution deposition is a fast, cost-efficient method to survey extensive ranges of film composition. Further it is a process compatible with many semiconductor-fabrication technologies, and it may be the deposition method of choice for applications that do not require conformal depositions and that have device dimensions of 2 μm or greater. Specific applications for which solution deposition is commercially viable include decoupling capacitors, uncooled pyroelectric infrared detectors, piezoelectric micromotors, and chemical microsensors based on surface-acoustic-wave technology. Reviews of some of the more fundamental aspects of solution-deposition processing may be found in the scientific literature.
Pair Potentials in Atomistic Computer Simulations
Authors: Vitek V. 
Published: August 2016

Computer modeling of crystal defects ranges at present from generic empirical investigations to first-principle quantum-mechanical calculations (see, for example, References 1–4). Descriptions of atomic interactions in terms of pair potentials dominated such studies until the early 1980s, and many fundamental features of lattice defects and interfaces were revealed in these calculations. The generic results of these studies withstood the test of time, and calculations employing more sophisticated schemes usually confirmed their validity. An early example goes back to the late 1950s when Vineyard and co-workers pioneered the very first computer simulations in their studies of radiation damage. Empirical pair potentials were used in these investigations in which many fundamental, generic aspects of the effect of irradiation of crystalline materials by energetic particles were discovered.Such simple treatments of atomic interactions may appear totally inadequate from the point of view of pure physics. However, it must be recognized that the purpose of the majority of atomistic studies of lattice defects has been to elucidate atomic structure and atomic-level properties in materials with given: (a) crystal structure, (b) elastic properties and possibly phonon spectra, (c) values of certain material parameters such as vacancy formation energies and stacking fault energies, and (d) in alloys, alloying and ordering energies, and possibly antiphase boundary energies. This is in contrast with ab initio studies, the objective of which is to determine all these properties from first principles. These goals of atomistic studies are, of course, the same for all semi-empirical approaches discussed in this collection of articles. In general, the validity of the structural features of lattice defects found in calculations using empirical schemes is best guaranteed if they can be related to fitted material properties and are not sensitively dependent on the deails of the fittings and functional forms employed.
Tight-Binding Theory and Computational Materials Synthesis
Authors: Sutton A.P. , Godwin P.D. , Horsfield A.P. 
Published: August 2016

At the heart of any atomistic simulation is a description of the atomic interactions. A whole hierarchy of models of atomic interactions has been developed over the last twenty years or so, ranging from ab initio density-functional techniques, to simple empirical potentials such as the embedded-atom method and Finnis-Sinclair potentials in metals, valence force fields in covalently bonded materials, and the somewhat older shell model in ionic systems. Between the ab initio formulations and empirical potentials lies the tight-binding approximation: It involves the solution of equations that take into account the electronic structure of the system, but at a small fraction of the cost of an ab initio simulation, because those equations contain simplifying approximations and parameters that are usually fitted empirically.Tight binding may be characterized as the simplest formulation of atomic interactions that incorporates the quantum-mechanical nature of bonding. The particular features that it captures are as follows: (1) the strength of a bond being dependent not only on the interatomic separation but also on the angles it forms with respect to other bonds, which arises fundamentally from the spatially directed characters of p and d atomic orbitals, (2) the filling of bonding (and possibly antibonding) states with electrons, which controls the bond strengths, and (3) changes in the energy distribution of bonding and antibonding states as a result of atomic displacements. These features enable one to obtain considerable improvements in accuracy compared to the simple “glue models” of bonding since use is made of the physics and chemistry of bonding.
New Carbohydrate-Based Polymeric Materials
Authors: Callstrom Matthew R. , Bednarski Mark D. 
Published: August 2016

The total world production of water-soluble polymers is estimated to be greater than five million tons per year. Water-soluble polymers are most conveniently described according to their origin in three classes (see Structures 1-6):∎ Natural polymers, including starch (1) and cellulose (2);∎ chemically modified natural polymers, including, for example, hydroxyethyl starch (3) and cellulose acetate (4); and∎ synthetic polymers, the most important of which are polyacrylamide (5) and polyvinyl alcohol (6), (commonly composed of both alcohol and acetate groups as shown). The widespread use of these materials is due to both their availability and the range of useful physical properties found in the various natural and chemically modified natural polymers.Of the commercial water-soluble polymers, approximately 50–80% are based on natural polysaccharide materials. One of the primary reasons that these materials find such widespread use is the dramatic response of their properties to changes in their functionality and stereochemistry: chemical modification or the combination of polysaccharides with other polymeric materials has yielded materials whose applications range from explosives to food additives. Although efforts directed at controlling the properties of polysaccharides has resulted in a wide variety of useful materials, we felt control of the composition of carbohydrate-based polymers at the molecular level would provide materials with properties superior to those derived from natural and chemically modified polysaccharide materials.Our approach for the preparation of new carbohydrate-based materials is to use the carbohydrate as a template for the introduction of desired functionality with complete regiochemical and stereochemical control by both chemical and enzymatic methods (Scheme I).
Simulations of Nanometer-Thick Lubricating Films
Authors: Robbins Mark O. , Thompson Peter A. , Grest Gary S. 
Published: August 2016

Hydrodynamics and elastohydrodynamics have been successful in describing lubrication by micron-thick films. However, these continuum theories begin to break down as film thicknesses become comparable to molecular dimensions. An increasing number of applications require an understanding of lubricants in such severely confined geometries. Examples include lubrication of nanoscale bearings in micromachinery or high-density magnetic disk drives, as well as asperity interactions in macroscopic bearings that operate in the mixed lubrication regime.Development of new experimental and theoretical techniques for studying thin lubricant films has paralleled the growing interest in their properties. The surface force apparatus (SFA) allows normal and shear forces to be measured between atomically flat solid surfaces while their separation is determined to within 0.1 nm using interferometry or capacitance. The contact area in the SFA is typically 100 μm across, much larger than the separation between solid walls. The atomic force microscope (AFM) can be used to explore friction in lubricated contacts whose diameter is comparable to the separation (5 nm). This allows spatial resolution of the frictional force on a molecular scale. Quartz-crystal oscillators have been used to determine the frictional forces between a surface and an adsorbed film of one or more monolayers. Theoretical advances have been aided by the advent of supercomputers that allow thin films to be simulated at the molecular level using molecular dynamics. These new experimental and theoretical techniques reveal a sequence of dramatic changes in the static and dynamic properties of fluid films as their thickness approaches molecular scales.
Copper Etching: New Chemical Approaches
Authors: Hampden-Smith Mark J. , Kodas Toivo T. 
Published: August 2016

There is a tremendous demand for improved performance and speed in consumer electronics that is likely to continue as new applications and developments occur. This demand necessitates a reduction in the critical dimensions and an increase in the density of devices in microelectronic circuits. As a result, new materials must be considered for integration into microelectronics technology. In particular, the metal wiring or interconnects that connect different components in silicon-based semiconductor devices is a subject of great interest. As the dimensions of transistors shrink below the 0.5 μm level, their speed will become limited by the delays in the existing interconnect material, Al-Si-Cu alloy (p ~ 3 μΩ cm). Therefore, to avoid problems associated with RC (“resistance/capacitance”) time delays and voltage drops, it will be necessary to construct interconnections of materials that possess lower resistivities, resistance to electromigration and hillock formation, and resistance to diffusion into other materials (see Table I).A number of materials are possible candidates to replace the Al-Si-Cu alloy, including W, Ag, Au, and Cu. Tungsten has excellent resistance to electromigration and hillock formation, but has higher resistivity compared with the Al-Si-Cu alloy. Thus, applications of W are likely to be found where short interconnection distances are necessary. Silver has the lowest resistivity of all metals, but is easily corroded and diffuses rapidly into many materials used in semiconductor devices. However, some specific applications for silver are viable, such as the formation of contacts on ceramic superconductors. Gold has a lower resistivity than the Al-Si-Cu alloy and is inert to chemical corrosion. As a result Au is used where device reliability is the primary concern-for example, for wiring in GaAs-based semiconductors and electrical contacts in packaging.