bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrafine Metal Particles in Porous and Dense Silica Gels
Authors: Pope Edward J.A. , Mackenzie J.D. 
Published: August 2016

The present trend of developing electronic devices with increasingly fine dimensions borders on a number of fundamental scientific questions about the very nature of how materials at ultrafine dimensions behave. This article addresses some of these questions. The fabrication of discrete metallic phases in porous and nonporous glassy matrices presents a number of exciting device possibilities. Methods of fabricating ultrafine metallic phases in silica via the sol-gel route are presented.In attempting to fabricate materials with ultrafine physical dimensions for a wide variety of applications, several fundamental questions arise about the nature of materials behavior. For example, how many metal atoms are necessary to form a cluster exhibiting “metallic“ properties? Moreover, does the number of atoms necessary depend upon which metallic property is examined? This question has been partly addressed by D.C. Johnson and co-workers with regard to magnetism in osmium clusters. Their results show a threefold increase in magnetic susceptibility between clusters containing 3–10 osmium atoms.Another important question, especially when considering device applications, is how the relative contributions of surface and bulk thermodynamics affect such properties as phase transformations. In addition, ultrafine phase dimensions interact with the fundamental unit lengths of a wide range of processes, including the wavelength of visible light, the mean free path lengths of conduction processes, the wavelengths of phonon vibrations, etc. How do these interactions affect optical, thermal, and electronic properties?Fabrication of ultrafine metallic particles in porous and nonporous matrices may lead to many possible device applications including heterogeneous catalysts, nonlinear optic devices, highvoltage switching devices based on interparticle tunneling, and perhaps even new types of charge storage devices (capacitors).
Continuum Modeling
Authors: Davison Lee 
Published: August 2016

Common experience with the thermomechanical properties and behavior of matter is usually at the continuum level, i.e., observations concern such phenomena as elastic and inelastic deformation of solids, flow of fluids, and conduction of heat. Continuum descriptions of these phenomena are expressed in terms of partial differential equations representing the principles of balance of mass, momentum, and energy. Since the basic principles apply to all materials, it is apparent that they alone will not suffice for solving specific problems. The peculiarities of individual materials are expressed in terms of constitutive equations, of which Hooke's law of elasticity and Newton's law of viscosity are examples. For the most part, “continuum modeling” refers to the process of devising constitutive equations. This work requires exercise of physical insight at both the macroscopic and microscopic levels, consideration of experimental observations, and application of formal mathematical principles.Much of materials science is devoted to development and application of materials that have been selected for, or designed to have, useful properties different from those of existing materials. Many materials are of interest precisely because they have unusual properties. For example, paints and other coatings are often designed to flow easily when spread, but resist running afterward. Much work is devoted to analyzing manufacturing processes, whether they be processing of foodstuffs, forging metals, drawing films and fibers, or curing polymers. Properties and physical states of materials that are important during manufacture are often very different from those desired under service conditions.
Up Close: Johns Hopkins Center for Nondestructive Evaluation
Authors: Millberg L.S. 
Published: August 2016

Nondestructive evaluation has historically been used almost exclusively for detecting macroscopic defects after materials have been made or put into service. However, the role of NDE is now changing to include in-process control in an effort to increase yields and performance of materials. This includes materials stability during transport, storage, and fabrication, as well as degradation behavior during in-service life. The NDE community has implied that applying NDE in these ways is crucial to solving the economic problems of U.S. manufacturing industries. So called “intelligent manufacturing” is impossible without integrating modern NDE techniques into the production of today's advanced materials.The Johns Hopkins University Center for Nondestructive Evaluation (CNDE) was established in 1984 as an interdisciplinary center for research and instruction, drawing on the resources and talent of the School of Engineering, Applied Physics Laboratory, School of Medicine, and School of Arts and Sciences. Currently 31 faculty or senior staff work with the Center. The techniques being developed are aimed at reliable in-process control of materials and processes. Another important purpose is the education of talented students who will enter the NDE field; 150 students are associated with the Center, a third of whom are graduate students. The CNDE also provides both research collaborators and industrial sponsors with access to all NDE research and instruction at Johns Hopkins University. Twenty-six research institutions have formal cooperative research programs and 19 organizations are corporate sponsors (see Figure 1).
Ceramics
Authors: Eagan Robert J. 
Published: August 2016

Until the 1980s, most people thought of ceramics as artware and artifacts. The recent development of advanced ceramics for high performance thermal insulation (space shuttle tiles), high temperature structures (heat engines), and electronics (superconductors) has dramatically changed perceptions about the utility of ceramics.High technology ceramics are related to “traditional” ceramics only to the extent that they are inorganic, nonmetallic materials. Traditional ceramics are derived from minerals. For example, dinnerware and bricks consist mostly of clay, while sand is the major ingredient in flat glass and containers. Abundant raw materials, simple processing, adequate performance at low cost, and technological evolution have kept these industries viable for several thousand years.But, for demanding electronic or structural applications, synthesizing ceramics from minerals is often unacceptable. The chemical variability of mineral deposits, the difficulty of obtaining a homogeneous mixture of powders, and the problems of consolidating the powders into a uniform ceramic with desirable grain morphology, chemistry and grain boundary phases have stimulated the development of chemically derived ceramic precursors.
The Use of Exothermic Reactions in the Synthesis and Densification of Ceramic Materials
Authors: Holt J.B. 
Published: August 2016

This article will provide information about chemical processes which rely on the heat evolved during reaction to synthesize and, in some cases, to simultaneously density single-phase or composite ceramic materials. Although the basic concept underlying these processes is simple, the high temperature reactions are complex and require careful study with individual systems before their potential as fabrication processes can be fully realized.Many reactions between solids involving elements and/or compounds, or between solids and gases are highly exothermic. Listed in Table I is a selected group of typical chemical reactions accompanied by their calculated adiabatic temperatures. As a general rule any reaction with an adiabatic temperature ~2000°C or over can be reacted under combustion conditions. For example, suppose that a cold-pressed cylindrical compact of titanium and boron powder (Eq. 1) is ignited at the top surface with a convenient source of heat such as a laser. From the igniting surface a combustion wave rapidly self-propagates down the compact, transforming the reactants into the TiB2 product. Figure 1 shows a Ti and C powder compact where the combustion wave has progressed about halfway down the compact.
Pattern Formation in Materials Science
Authors: Gollub J.P. , Sander L.M. 
Published: August 2016

The growth of materials at interfaces frequently leads to patterns with length scales that can be much larger than atomic sizes. Patterns resulting from morphological instabilities occur during crystal growth and are responsible for the intricate shapes of snowflakes, dendritic crystals, and the like. They also occur during the electrochemical deposition of metals on surfaces, and during the growth of thin films by vapor deposition. Our purpose is to point out some particularly interesting connections that have come to be appreciated during the past five years between different types of pattern-forming phenomena, and to summarize some recent theoretical approaches to understanding them.The phenomenon of dendritic crystal growth, though studied for many years, is still a great challenge. As an example, we show the development of a needle crystal of ammonium bromide (NH4Br) from supersaturated aqueous solution in Figure 1. The contours are cross sections of the interface at 20-second intervals, obtained by digital image analysis. One can see that an approximately parabolic tip translates at constant speed, and that the needle crystal is apparently unstable to the development of a train of sidebranches that propagate outward from the main stem but do not move forward with the tip.
Phosphate Glasses
Authors: Sales Brian C. 
Published: August 2016

Until recently, phosphate glasses were regarded as somewhat of a scientific curiosity—materials limited in technological application but nevertheless exhibiting interesting fundamental properties. Although the basic properties of many phosphate glasses have been studied on a laboratory scale during the past 50 years, very few of these materials proved to be of commercial interest. This lack of extensive practical application was primarily related to their poor chemical durability and a tendency to crystallize during processing.The pace of modern technological development continues to result in an increased demand for new materials with specific characteristics, and this demand has led to renewed interest in a number of previously neglected materials—including phosphate glasses. The combined physical and chemical characteristics of phosphate glasses make them relatively unique among the families of inorganic glasses. These characteristics include: large thermal expansion coefficients, low preparation and softening temperatures, low melt viscosities, chemical compatibility with living bone, and a polymeric structure similar to that in organic polymers. Most recent research on phosphate glasses has emphasized one or more of these characteristics.The major scientific questions pertinent to technological applications of phosphate glasses are related to utilizing the desirable characteristics of these materials while maximizing their corrosion resistance and thermal stability. In order to tailor a phosphate glass for a particular application, the corrosion mechanism of the glass must often be understood in detail, along with the relationship between the microscopic structure of the glass and its macroscopic properties.
The Importance of Accreditation in Materials Education
Authors: Mikkola D.E. 
Published: August 2016

The strength, vitality, and development of the materials professions are determined largely by the quality of education of their new members. While this truism applies to any profession, it is critically important that it be recognized in a rapidly changing and evolving area such as the materials field, which includes activities in materials engineering, ceramic engineering, polymer engineering, and metallurgical engineering. The recent development of tools and techniques that allow relating details of atomic and electronic structure to material properties, the discovery of new classes of materials, many of which are complex integrations of metals, ceramics, and/or polymers, along with the rich diversity of new processing methods that yields improved properties and new materials concepts, are examples that emphasize the dynamic and exciting nature of the field.The primary responsibility for monitoring, evaluating, and certifying the quality of engineering and engineering-related education in colleges and universities in the United States lies with ABET, the Accreditation Board for Engineering and Technology. (For a discussion of accreditation in chemistry, see “Chemistry Education Programs Relevant to Materials Science” by P. Lykos in this issue.) ABET, working with the engineering professional societies, develops accreditation policies and criteria and conducts a comprehensive program of evaluation of first professional engineering degree programs. Programs meeting the prescribed criteria are granted accredited status.
The Metamict State
Authors: Ewing R.C. , Chakoumakos B.C. , Lumpkin G.R. , Murakami T. 
Published: August 2016

Recently, the words “metamict” or “metamictization” have been increasingly used instead of “amorphous” or “amorphization” in acknowledgment of the fact that the first recognized example of the transition from the crystalline to the aperiodic state was in natural materials—minerals. The term (originally “metamikte” from Greek for “mix otherwise” because of their complex compositions) was first defined by Broegger in a Danish encyclopedia as one of three classes of amorphous substances: porodine (= colloidal), hyaline, and metamikte. Minerals considered to be metamict were judged amorphous because of their conchoidal fracture and isotropic optical properties; however, well-developed crystal faces evidenced the prior crystalline state.Hamberg was the first to suggest that metamictization is a radiation-induced, periodic-to-aperiodic phase transition caused by alpha particles which originate from constituent radionuclides in the uranium and thorium decay series. Rinne and Vegard confirmed by x-ray diffraction studies that metamict minerals were either amorphous or finely crystalline. Later work supported the idea of a radiation-induced transformation. The work of Stackelberg and Rottenbach established that the decrease in density, refractive indices, and birefringence correlated with the breakdown of the structure with increasing alpha-decay dose. Stackelberg and Rottenback tried to test this hypothesis directly by bombarding a thin slab of zircon with alpha particles. The results were inconclusive because the slab fractured, but this must have been one of the first experiments in which an “ion beam” was used to “modify” a material.
Intercalation In Layered Materials
Authors: Dresselhaus M.S. 
Published: August 2016

There is great current interest in layered anisotropic materials. Much of the interesi relates to the possibility of an approximate decoupling of 3-dimensional (3D) behavioi into ID properties perpendicular to the layer planes and 2D properties associated with the layer planes. Since this decoupling in layered materials is enhanced by intercalation, much attention has been given to intercalation compounds in recenl years as a means to study interesting questions of low dimensional physics. Since many deliberately structured materials also are prepared in layered sequences, there are many close connections between the properties of intercalated layered materials and deliberately structured materials. This article will focus on several important connections between intercalated layered materials and multilayered superlattice structures prepared by molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD).Interest in intercalation compounds has led to three lively MRS symposia on this topic (Fall 1982, Fall 1984, Fall 1986) and a number of summer schools and workshops, one of which was held in July 1986 at Erice, Sicily, under the auspices of NATO and the European Physical Society. The published lecture notes1 from this summer school provide a useful introduction and reference for students and others interested in this field.
Ion Beam Mixing: Amorphous, Crystalline, and Quasicrystalline Phases
Authors: Lilienfeld D.A. , Hung L.S. , Mayer J.W. 
Published: August 2016

In the last quarter of a century, modification of the near-surface region of materials has become of major technological importance. The principal surface modification technique utilized in integrated circuit technology is ion implantation, a technique which has more recently been applied in the metal-processing industry as well. The very high doses required for applications such as increasing the hardness of steel or forming buried oxide layers in silicon have pushed ion implantation to its limits. Ion beam mixing, the intermixing of surface layers by the penetration of energetic ions through them, was developed to overcome these limits. Additionally, ion beam mixing has been able to produce new phases, amorphous and crystalline, which have technologically and scientifically interesting properties.Ion beam mixing was studied extensively in silicide forming systems, due partly to applications to electrical contacts for silicon devices. In intermetallic alloy systems, research has concentrated on determining the interplay between the formation of amorphous and crystalline structures and that between equilibrium and metastable phases. Although over 50 alloy systems have been studied, this article will concentrate on the Al-based alloys. These alloys, particularly the near-noble-metal alloys, demonstrate nearly all the features associated with ion-induced phase formation. Further, Al-rich refractory metal alloys form quasicrystalline icosahe-dral alloys. Ion-beam mixing results parallel those of splat-quenching, the technique first used to produce the fivefold symmetric structure.
Ion-Beam-Assisted Deposition and Synthesis
Authors: Rossnagel S.M. , Cuomo J.J. 
Published: August 2016

Concurrent energetic particle bombardment during film deposition can strongly modify the structural and chemical properties of the resulting thin film. The interest in this technique, ion-assisted deposition, comes about because it can be used to produce thin films with properties not achievable by conventional deposition. Bombardment by low energy ions occurs during almost all plasma-based thin film deposition techniques. Bombardment of a growing film, particularly by accelerated ions, can also be combined with non-plasma-based deposition techniques, such as evaporation, to simulate some of the effects observed with sputtering. The bombarding particle flux is usually controllable so that the arrival rate, energy, and species can be independently varied from the depositing flux. Thus, a basic aspect of ion-beam-based deposition techniques is the “control” often absent in plasma-based techniques. In plasmas, the voltage, current, and pressure are all interdependent. The energetic bombardment at the substrate-film interface depends on the various properties of the plasma, as does the deposition rate. It is often difficult, or even impossible, to decouple these processes. With ion-beam-based deposition techniques, the ion bombardment is essentially independent of the deposition process, and both can be more easily controlled.The incident energetic particle contributes some of its energy or momentum to irreversibly change the dynamics of the film surface. The incident particle may also be incorporated into the growing film, changing the film's chemical nature. The changes induced by particle bombardment during deposition are often not characteristic of equilibrium thermodynamics because the incident particle's energy is often many times the local adsorption or binding energy.
Natural Language Processing Techniques on Oil and Gas Drilling Data
Authors: Antoniak M. , Dalgliesh J. , Verkruyse M. , Lo J. 
Published: August 2016

Abstract
Recent advances in search, machine learning, and natural language processing have made it possible to extract structured information from free text, providing a new and largely untapped source of insights for well and reservoir planning. However, there are major challenges involved in applying these techniques to data that is messy and/or lacking a labeled training set; we cover some of the methods in which these problems can be overcome. We present a method to compare the distribution of hypothesized and realized risks to oil wells described in two datasets that contain free-text descriptions of risks. We treat one dataset as a training set for a logistic regression classifier, and then use this classifier to label in the events in the other, out-of-domain dataset. To adjust for differences between the datasets, we rebalance the training set and supplement it with labeled instances automatically extracted from the test set. These simple domain adaptation techniques allow us to achieve an average F1 score of 0.84 on the out-of-domain test set.
Drawdown Control: A Platform for Safeguarding and Optimising Production
Authors: Calvert Patrick 
Published: August 2016

Abstract
Since the inception of Intelligent Energy over a decade ago, there has been a gradual transition from the collection and visualization of large data sets through to the intelligent analysis and interpretation of data. A recent drive towards automation has evolved from the desire to streamline ongoing activities, reduce exposure to human error and continuously position operations at the optimum operating point.
Attempts to automate the optimization process, whether through closed loop optimization or multi-variable control, have largely focused on the facilities. This approach has merit when production is on plateau, as the rates will typically be constrained by the processing capacity of the facilities. As production declines, the handling capacity of the facilities becomes less of a burden and the deliverability of the well stock gains prominence. Productivity is now constrained by well uptime along with the health of the completion.
Adequate control of the drawdown can have a positive impact on both the health of the completion and on the uptime of the well. For weak wells, the well must be beaned up at a certain rate to prevent liquid loading. Control of the drawdown is therefore paramount in ensuring a successful restart. For wells that cut water or free gas and transect multiple reservoir layers, the drawdown will drive coning and promote cross flow. As both are detrimental to production, overall productivity is driven by the ability to control and optimise the drawdown. Finally, if the rock is poorly consolidated, rapid fluctuations in the drawdown can have a detrimental impact on the rate of sand production, screen erosion and skin growth.
Within this paper, the value of controlling the drawdown will be presented along with a control solution that has proved effective at controlling the drawdown during start-up, continuous production and ramp down to within 5 psi.