bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rice Husk Ash as a Renewable Source for the Production of Value Added Silica Gel and its Application: An Overview
Authors: Prasad Ram , Pandey Monika 
Published: October 2012

In recent years, silica gels have developed a lot of interest due to their extraordinary properties and their existing and potential applications in science and technology. Silica gel has a wide range of applications such as a desiccant, as a preservation tool to control humidity, as an adsorbent, as a catalyst and as a cata-lyst support. Silica gel is a rigid three-dimensional network of colloidal silica, and is classified as: aqua-gel, alco-gel, xero-gel and aero-gel. Out of all known solid porous materials, aero-gels are particularly known for their high specific surface area, high porosity, low bulk density, high thermal insulation value, ultra low dielectric constant and low index of refraction. Because of these extraordinary properties silica aero-gel has many commercial applications such as thermal window insulation, acoustic barriers, super-capacitors and catalytic supports. However, monolithic silica aero-gel has been used extensively in high energy physics in Cherenkov radiation detectors and in shock wave studies at high pressures, inertial confinement fusion (ICF) radio-luminescent and micrometeorites. Silica gel can be prepared by using various sol gel precursors but the rice husk (RH) is considered as the cheapest source for silica gel production. Rice husk is a waste product abundantly available in rice producing countries during milling of rice. This review article aims at summarizing the developments carried out so far in synthesis, properties, characterization and method of determination of silica, silica gel, silica aero-gel and silica xero-gel. The effect of synthesis parameters such as pH, temperature of burning the rice husk, acid leaching prior to formation of rice husk ash (RHA) on the properties of final product are also described. The attention is also paid on the application of RH, RHA, sil-ica, silica aero-gel and silica xero-gel. Development of economically viable processes for getting rice husk silica with specific properties assumes importance at this juncture. © 2012 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Ceria-Based Mixed Oxide Supported Nano-Gold as an Efficient and Durable Heterogeneous Catalyst for Oxidative Dehydrogenation of Amines to Imines Using Molecular Oxygen
Authors: Dar Bashir Ahmad , Sharma Meena , Singh Baldev 
Published: October 2012

The present work is intended to determine the catalytic activity of Mixed Oxide supported gold for aerobic oxidative dehydrogenation of amines to imines using Ceria as a main constituent of the each support. The model catalysts Au/CeO2:TiO2 Au/CeO2:SiO2, Au/CeO2:ZrO2 and Au/CeO2:Al2Os were prepared by deposition co-precipitation method and deposition of gold was determined by EDEX analysis. The supported nano-gold catalyzes the dehydrogenation of secondary amines to imines without loss of activity. On recycling good amount of product yield is obtained. Oxidation of secondary amines to imines is carried at 100˚C and almost 90 % conversion was obtained with >99% selectivity. © 2012 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Short Review: Cu Catalyst for Autothermal Reforming Methanol for Hydrogen Production
Authors: Wu Ho-Shing , Lesmana Donny 
Published: October 2012

Hydrogen is a promising alternative energy sources, hydrogen can be used in fuel cell applications to pro-ducing electrical energy and water as byproduct. Therefore, fuel cell is a simple application and environ-mentally friendly oriented technology. Recent years various methods have been conducted to produce hy-drogen. Those methods are derived from various sources such as methanol, ethanol, gasoline, hydrocarbons. This article presents a brief review a parameter process of that affects in autothermal reforming methanol use Cu-based catalysts for production of hydrogen. © 2012 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
De-oxygenation of CO2 by using Hydrogen, Carbon and Methane over Alumina-Supported Catalysts
Authors: Raskar R. Y. , Kale K. B. , Gaikwad A. G. 
Published: October 2012

The de-oxygenation of CO2 was explored by using hydrogen, methane, carbon etc., over alumina supported catalysts. The alumina-supported ruthenium, rhodium, platinum, molybdenum, vanadium and magnesium catalysts were first reduced in hydrogen atmosphere and then used for the de-oxygenation of CO2. Furthermore, experimental variables for the de-oxygenation of CO2 were temperature (range 50 to 650 oC), H2/CO2 mole ratios (1.0 to 5), and catalyst loading (0.5 to 10 wt %). During the de-oxygenation of CO2 with H2 or CH4 or carbon, conversion of CO2, selectivity to CO and CH4 were estimated. Moreover, 25.4 % conversion of CO2 by hydrogen was observed over 1 wt% Pt/Al2O3 catalyst at 650 oC with 33.8 % selectivity to CH4. However, 8.1 to 13.9 % conversion of CO2 was observed over 1 wt% Pt/Al2O3 catalyst at 550 oC in the presence of both H2 and CH4. Moreover, 42.8 to 79.4 % CH4 was converted with 9 to 23.1 % selectivity to CO. It was observed that the de-oxygenation of CO2 by hydrogen, carbon and methane produced carbon, CO and CH4. © 2012 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
Synthesis of Fluorite (CaF2) Crystal from Gypsum Waste of Phosphoric Acid Factory in Silica Gel
Authors: Khunur Mohammad Misbah , Risdianto Andri , Mutrofin Siti , Prananto Yuniar Ponco 
Published: October 2012

This paper report the synthesis and characterization of fluorite single crystal prepared from gypsum waste of phosphoric acid production in silica gel. Instead of its high calcium, gypsum was used to recycle the waste which was massively produces in the phosphoric acid production. The gypsum waste, the raw material of CaCl2 supernatant, was dissolved in concentrated HCl and then precipitated as calcium oxalate (CaC2O4) by addition of ammonium oxalate. The CaCl2 was obtained by dissolving the CaC2O4 with HCl 3M. The crystals were grown at room temperature in silica gel and characterized by AAS, FTIR and powder XRD. The optimum crystal growth condition, which is pH of gel, CaCl2 concentration and growth time, were investigated. The result shows that at optimum condition of pH 5.80, CaCl2 concentrations of 1.2 M, and growth time of 144 hours, colorless crystals with the longest size of 3 mm, were obtained (72.57%). Characterization of the synthesized crystal by AAS indicates that the obtained crystal has high purity. Meanwhile, analysis by FTIR spectra shows a Ca–F peak at 775 cm-1, and powder-XRD analysis confirms that the obtained crystal was fluorite (CaF2). © 2012 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)
General Vacuum Techniques
Authors: Peacock Neil T. 
Published: October 2012

AbstractThis article reviews the procedures and equipment used to maintain a vacuum system at pressures in the range from 10−3to 10−11 torr. Equipment covered includes pumps, flanges, and sealing. Common pump types are covered, including details of their principles and technique of operation, as well as their recommended uses. Total and partial pressure gauges used in this range are also described. Common materials for vacuum systems and their properties are summarized along with fabrication methods. Leak detection methods and techniques are presented.
Simulation of Chemical Vapor Deposition Processes
Authors: Kleijn Chris R. , Cavallotti Carlo 
Published: October 2012

AbstractChemical vapor deposition (CVD) is probably the most used technology for the growth of high quality thin solid films. It is in fact widely used in the electronic and optoelectronic industry to deposit semiconducting, conducting, and insulating films as well as in the mechanical industry to grow anticorrosion and antiwear coatings on tools and equipment. The success of CVD is determined by its capability to couple reasonably high deposition rates while maintaining high‐level structural and morphological properties of the grown material. The success of CVD processes as well as the continuous increase of deposition rates and of the range of materials that can be grown through this technique relies in part on the availability of powerful modeling tools that simulate the growth process. In the present article, the status of the art of modeling CVD processes is reviewed. Particular emphasis is placed on the multiscale nature of this theoretical field, which encompasses phenomena with characteristic length scales that go from 10–10 to 100 m. In this light, advantages and disadvantages related to the use of modeling tools apt to treat specific length and time scales phenomena relevant to CVD are reviewed and discussed.
Principles and Practices of Thermal Analysis and Calorimetry
Authors: Hill John 
Published: October 2012

AbstractThis article presents a brief introduction to thermal analysis and calorimetry with emphasis on the application of the associated thermoanalytical techniques to the characterization of a wide range of materials over wide temperature ranges. The currently accepted nomenclature for these techniques is given together with the reference materials recommended for calibration. Also, the thermodynamic principles on which these techniques are based are summarized and the major recent literature on thermal analysis and calorimetry is listed together with some relevant internet websites. Essentially, this article constitutes a useful working handbook of thermal analysis and calorimetry.
Differential Scanning Calorimetry and Differential Thermal Analysis
Authors: Schick Christoph , Lexa Dusan , Leibowitz Leonard 
Published: October 2012

Abstract
Differential scanning calorimetry (DSC) and differential thermal analysis (DTA) are effective analytical tools to characterize melting, crystallization, and mesomorphic transitions and to determine the corresponding enthalpy and entropy changes. The glass transition and other effects that show either changes in heat capacity or a latent heat are accessible too. The advantage of DSC and DTA compared to other calorimetric techniques lies in the broad dynamic range regarding heating and cooling rates, including isothermal and temperature‐modulated operation. The broad dynamic range is especially of interest because many materials are commonly used or produced on far from equilibrium routes and transitions are strongly time (rate) dependent.
Generation and Measurement of Magnetic Fields
Authors: Mielke Charles H. , Schneider‐Muntau Hans J. , Coey J. M. D. , Kuhns Phil , Rubin Larry , Schott Chistian 
Published: October 2012

AbstractIn basic science areas, such as semiconductor physics, superconductivity, structural biology, and chemistry, magnetic fields are used as a powerful tool for analysis of matter because they can change the physical state of a system. In the presence of a magnetic field, the angular momenta (spins), the orbital motion of charged particles, and therefore the energy of the investigated physical system, are altered.Wemust realize, however, that the size of the induced effects are very modest compared to other physical quantities. One Bohr magneton (typical range of atomic magnetic moments) in a magnetic field of 10 tesla (T) (a 10 T field is ∼200,000 times the strength of the earth's magnetic field) has an energy of 0.58 meV, corresponding to a temperature of 6.7 K, a small value in comparison to room temperature. On the other hand, the generation of a magnetic field of 10Talready requires a noticeable engineering effort, with continuous fields of 50 T being the upper limit of what can be achieved today. Pulsed magnetic fields can be generated up to 100 T for durations in the millisecond range, and up to 1000 T on the microsecond time scale. Therefore, experiments must be chosen judiciously. Very often, a low‐noise sample environment, such as low mechanical vibrations, small field fluctuations (in the case of dc fields), and low temperatures are decisive to the success of scientific measurements in magnetic fields.
Scanning Electron Microscopy
Authors: Leonard Donovan N. , Chandler Gary W. , Seraphin Supapan 
Published: October 2012

Abstract
The scanning electron microscope (SEM) is one of the most widely used instruments in materials research laboratories and is common in various forms in fabrication plants. Scanning electron microscopy is central to microstructural analysis and therefore important to any investigation relating to the processing, properties, and behavior of materials that involves their microstructure. The SEM provides information relating to topographical features, morphology, phase distribution, compositional differences, crystal structure, crystal orientation, and the presence and location of electrical defects. The SEM is also capable of determining elemental composition of microvolumes with the addition of an x‐ray or electron spectrometer and phase identification through analysis of electron diffraction patterns. The strength of the SEM lies in its inherent versatility due to the multiple signals generated, simple image formation process, wide magnification range, and excellent depth of field.
Lenses in the SEM are not a part of the image formation system but are used to demagnify and focus the electron beam onto the sample surface. This gives rise to two of the major benefits of the SEM: range of magnification and depth of field in the image. Depth of field is that property of SEM images where surfaces at different distances from the lens appear in focus, giving the image three‐dimensional information. The SEM has more than 300 times the depth of field of the light microscope. Another important advantage of the SEM over the optical microscope is its high resolution. Subnanometer resolution at low beam energies (e.g., 1 kV) is now achievable from an SEM with a field emission (FE) electron gun. Magnification is a function of the scanning system rather than the lenses, and therefore a surface in focus can be imaged at a wide range of magnifications. The higher magnifications of the SEM are rivaled only by the transmission electron microscope (TEM), which requires the electrons to penetrate through the entire thickness of the sample. As a consequence, TEM sample preparation of bulk materials is tedious and time‐consuming, compared to the ease of SEM sample preparation, and may damage the microstructure. The information content of the SEM and TEM images is different, with the TEM image showing the internal structure of the material.
Due to these unique features, SEM images frequently appear not only in the scientific literature but also in the daily newspapers and popular magazines. The SEM is relatively easy to operate and affordable and allows for multiple operation modes, corresponding to the collection of different signals. This chapter reviews the SEM instrumentation and principles, its capabilities and applications, and recent trends and developments.
Ion Beam Methods, Introduction
Authors: Jeynes Chris 
Published: October 2012

Abstract
Ion beam techniques are used with ion energies from eV to many MeV and a very wide range of ion species to characterize materials at length scales from sub‐nm to sub‐mm and in a wide variety of different ways. Many of these techniques are non‐destructive.
Atomic concentration can be determined from matrix elements (the stoichiometry) to minor and trace elements (at ng/g sensitivity and better), in one dimension (depth profiles), two dimensions (elemental maps), and three dimensions with full tomography being feasible. There is sensitivity to the whole Periodic Table one way or another, with nuclear techniques for isotopic sensitivity, and high resolution mass spectrometry for obtaining isotopic ratios at ultra‐high sensitivities of 1e14 and better.
Other techniques include ultra‐high resolution microscopy, characterization of semiconductor device defects at high spacial resolution, and the investigation of damage processes in the nuclear irradiation of materials.
Ion beam methods for thin film materials have major application areas from archaeology to zoology (including materials science, geology, cultural heritage, electronics and many others).
Neutron Techniques, Introduction
Authors: Goldman Alan I. 
Published: October 2012

Abstract

This chapter explores the wide range of applications of elastic and inelastic neutron scattering to the study of materials. Neutron scattering provides information complementary to several other techniques found in these volumes. Perhaps most closely related are the electron scattering methods described in Chapter
Electron Techniques
and x‐ray scattering methods described in Chapter
X‐Ray Techniques
. The utility of all these scattering methods in investigations of atomic scale structure arises from the close match of the wavelength of these probes to typical interatomic distances (a few angstroms). The differences between these techniques are discussed.
Neutron Powder Diffraction
Authors: Vogt Thomas 
Published: October 2012

AbstractThe first powder diffraction studies on simple materials such as iron metal using x‐rays were done independently by Debye and Scherrer in Germany and by Hull in the United States. For a long time x‐ray powder diffraction was primarily used for qualitative purposes such as phase identification and the assessment of crystalline quality. The earliest structure determinations using only x‐ray powder diffraction data were done by Zachariasen in 1949, who solved the structures of α‐ and β‐UF5 by an intuitive trial‐and‐error approach. An important subsequent step was taken when Zachariasen and Ellinger solved the monoclinic structure of β‐plutonium using manual direct‐method procedures. The use of neutrons to determine structures using powder diffraction has advanced significantly over the past 60 years. Neutron powder diffraction is complementary to both x‐ray and electron powder diffraction. The greater penetration depth of neutrons, due to the fact that the neutron‐nucleus interaction is a point scattering process implying no variation of the nuclear scattering length with the scattering angle, the independence of the scattering cross‐section from the atomic number (Z) of an element, and therefore the stronger interaction of neutrons with “light” elements such as oxygen and hydrogen, and its isotope specificity as well as its interaction with unpaired electrons (“magnetic scattering”) make neutrons a unique and indispensable probe for structural condensed matter physics and chemistry.
Dynamic Light Scattering
Authors: Sidebottom David 
Published: October 2012

Abstract
Dynamic light scattering is commonly used to monitor the diffusion of small particles in either liquids or aerosols and can be used to evaluate the particle size and distribution of these diffusing particles. However, it is also used to probe the slow dynamics of density fluctuations that are inherent in certain fluids. This includes measures of the diverging correlation length near the critical point of liquid mixtures that exhibit a miscible‐immiscible phase transition and measurements of the tremendously lethargic viscoelastic dynamics seen in supercooled liquids near the glass transition. In this article, the dynamic light scattering technique of photon correlation spectroscopy is described in sufficient detail for a novice to appreciate and likely execute. The theoretical framework for the technique is developed at an introductory level and the relationships between measured intensity‐intensity autocorrelation functions and their corresponding dynamic structure factors are presented. A distinction is drawn between homodyne and heterodyne experiments and the relative merits of each are illustrated by examples. Details of the experimental set up are also reviewed and some of the most common pitfalls and artifacts are discussed.
Measuring the Electronic Properties of Materials at the Nanoscale
Authors: Lauhon Lincoln J. 
Published: October 2012

Abstract
The general objective of electronic property measurements is to relate extrinsic characteristics of devices or test structures to the intrinsic properties of materials. When there are significant nanoscale inhomogeneities in macroscale materials, or the materials themselves are nanoscale, the measurement of electronic properties at high spatial resolution may be essential to the fundamental understanding of structure–property relationships. This chapter is intended to serve as a framework for the consideration of measuring the electronic properties of materials at the nanoscale, and as a guide to the use of other articles in this volume. Background is provided on general principles of nanoscale measurement, approaches to nanofabrication that enable investigation of nanoscale and nanostructured materials, and distinct regimes of transport that inform the interpretation of electrical measurements. Specific techniques that exploit local probe–sample interactions are introduced according to their principles of operation, to either locally measure characteristics of a material or to generate a local perturbation material that is detected remotely. This framework is used to organize the chapter in terms operational mechanisms of techniques, rather than outcomes of measurement. Noncontact measurements that generate knowledge of local electronic properties are also examined. The chapter is not strictly limited to techniques that provide nanoscale resolution, but rather techniques that resolve electronic properties on length scales over which said properties may vary. The chapter focuses on generally accessible measurements of practical importance to understanding and optimizing the properties of materials with readily envisioned applications.
Super‐Resolution Optical Microscopy
Authors: Han Jason J. , Shreve Andrew P. , Werner James H. 
Published: October 2012

Abstract
Far‐field super‐resolution optical microscopy is a young and rapidly developing technology that enables optical imaging with unprecedented sub‐diffraction‐limited spatial resolution. These imaging methods have been developed primarily within the context of biological imaging, but show great potential as a new and complementary tool for characterization of nanostructural material features traditionally inaccessible by conventional optical imaging methods. In this article, we introduce the working principles of super resolution optical microscopy, suggest specific materials that should be good candidates for these new techniques, and discuss practical aspects that should be considered for its implementation for materials characterization.
Reflection High‐Energy Electron Diffraction
Authors: Hasegawa Shuji 
Published: October 2012

Abstract
The fundamentals, experimental techniques, and practical aspects of reflection high‐energy electron diffraction (RHEED) are described with some examples of observations. Actual samples that we deal with in experiments are in many cases far from ideal ones; the surfaces are not perfectly single‐crystalline with infinitely large domains, or not atomically flat. The RHEED patterns are then modified from the theoretical ones for ideal samples. Inversely, from such modifications in the patterns, we can obtain various kinds of information on the atomic structures of surfaces and thin films. Examples of RHEED analyses presented here include monitoring structural phase transitions and epitaxial growth of atomic layers. RHEED has advantages in observing such dynamical phenomena of structure changes.