Biocatalysis: applications and potentials for the chemical industry.

PubMed

Thomas, Stuart M; DiCosimo, Robert; Nagarajan, Vasantha

2002-06-01

The chemical industry is exploring the use of renewable feed stocks to improve sustainability, prompting the exploration of bioprocesses for the production of chemicals. Attractive features of biological systems include versatility, substrate selectivity, regioselectivity, chemoselectivity, enantioselectivity and catalysis at ambient temperatures and pressures. However, a challenge facing bioprocesses is cost competitiveness with chemical processes because capital assets associated with the existing commercial processes are high. The chemical industry will probably use biotechnology with existing feed stocks and processes to extract higher values from feed stocks, process by-products and waste streams. In this decade, bioprocesses that offer either a process or a product advantage over traditional chemical routes will become more widely used.

IMPROVING THE ENVIRONMENTAL PERFORMANCE OF CHEMICAL PROCESSES THROUGH THE USE OF INFORMATION TECHNOLOGY

EPA Science Inventory

Efforts are currently underway at the USEPA to develop information technology applications to improve the environmental performance of the chemical process industry. These efforts include the use of genetic algorithms to optimize different process options for minimal environmenta...

Control in the Chemical Industry

ERIC Educational Resources Information Center

Jones, R. G.

1974-01-01

Discusses various control techniques used in chemical processes, including measuring devices, controller functions, control valves, and feedforward and feedback actions. Applications of control to a real chemical plant are exemplified. (CC)

40 CFR 430.32 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2010 CFR

2010-07-01

... semi-chemical (cross recovery) process] Pollutant or pollutant property Kg/kkg (or pounds per 1,000 lb... for unbleached kraft facilities where pulp and paper are produced using a combined unbleached kraft and semi-chemical process, wherein the spent semi-chemical cooking liquor is burned within the...

40 CFR 430.32 - Effluent limitations representing the degree of effluent reduction attainable by the application...

Code of Federal Regulations, 2011 CFR

2011-07-01

... semi-chemical (cross recovery) process] Pollutant or pollutant property Kg/kkg (or pounds per 1,000 lb... for unbleached kraft facilities where pulp and paper are produced using a combined unbleached kraft and semi-chemical process, wherein the spent semi-chemical cooking liquor is burned within the...

Chemical processing of glasses

NASA Astrophysics Data System (ADS)

Laine, Richard M.

1990-11-01

The development of chemical processing methods for the fabrication of glass and ceramic shapes for photonic applications is frequently Edisonian in nature. In part, this is because the numerous variables that must be optimized to obtain a given material with a specific shape and particular properties cannot be readily defined based on fundamental principles. In part, the problems arise because the basic chemistry of common chemical processing systems has not been fully delineated. The prupose of this paper is to provide an overview of the basic chemical problems associated with chemical processing. The emphasis will be on sol-gel processing, a major subset pf chemical processing. Two alternate approaches to chemical processing of glasses are also briefly discussed. One approach concerns the use of bimetallic alkoxide oligomers and polymers as potential precursors to mulimetallic glasses. The second approach describes the utility of metal carboxylate precursors to multimetallic glasses.

Xylitol: a review on bioproduction, application, health benefits, and related safety issues.

PubMed

Ur-Rehman, Salim; Mushtaq, Zarina; Zahoor, Tahir; Jamil, Amir; Murtaza, Mian Anjum

2015-01-01

Xylitol is a pentahydroxy sugar-alcohol which exists in a very low quantity in fruits and vegetables (plums, strawberries, cauliflower, and pumpkin). On commercial scale, xylitol can be produced by chemical and biotechnological processes. Chemical production is costly and extensive in purification steps. However, biotechnological method utilizes agricultural and forestry wastes which offer the possibilities of economic production of xylitol by reducing required energy. The precursor xylose is produced from agricultural biomass by chemical and enzymatic hydrolysis and can be converted to xylitol primarily by yeast strain. Hydrolysis under acidic condition is the more commonly used practice influenced by various process parameters. Various fermentation process inhibitors are produced during chemical hydrolysis that reduce xylitol production, a detoxification step is, therefore, necessary. Biotechnological xylitol production is an integral process of microbial species belonging to Candida genus which is influenced by various process parameters such as pH, temperature, time, nitrogen source, and yeast extract level. Xylitol has application and potential for food and pharmaceutical industries. It is a functional sweetener as it has prebiotic effects which can reduce blood glucose, triglyceride, and cholesterol level. This review describes recent research developments related to bioproduction of xylitol from agricultural wastes, application, health, and safety issues.

Fish protein hydrolysates: application in deep-fried food and food safety analysis.

PubMed

He, Shan; Franco, Christopher; Zhang, Wei

2015-01-01

Four different processes (enzymatic, microwave-intensified enzymatic, chemical, and microwave-intensified chemical) were used to produce fish protein hydrolysates (FPH) from Yellowtail Kingfish for food applications. In this study, the production yield and oil-binding capacity of FPH produced from different processes were evaluated. Microwave intensification significantly increased the production yields of enzymatic process from 42% to 63%. It also increased the production yields of chemical process from 87% to 98%. The chemical process and microwave-intensified chemical process produced the FPH with low oil-binding capacity (8.66 g oil/g FPH and 6.25 g oil/g FPH), whereas the microwave-intensified enzymatic process produced FPH with the highest oil-binding capacity (16.4 g oil/g FPH). The FPH from the 4 processes were applied in the formulation of deep-fried battered fish and deep-fried fish cakes. The fat uptake of deep-fried battered fish can be reduced significantly from about 7% to about 4.5% by replacing 1% (w/w) batter powder with FPH, and the fat uptake of deep-fried fish cakes can be significantly reduced from about 11% to about 1% by replacing 1% (w/w) fish mince with FPH. Food safety tests of the FPH produced by these processes demonstrated that the maximum proportion of FPH that can be safely used in food formulation is 10%, due to its high content of histamine. This study demonstrates the value of FPH to the food industry and bridges the theoretical studies with the commercial applications of FPH. © 2015 Institute of Food Technologists®

Ultrasound‐assisted emerging technologies for chemical processes

PubMed Central

Geertman, Rob; Wierschem, Matthias; Skiborowski, Mirko; Gielen, Bjorn; Jordens, Jeroen; John, Jinu J; Van Gerven, Tom

2018-01-01

Abstract The chemical industry has witnessed many important developments during past decades largely enabled by process intensification techniques. Some of them are already proven at commercial scale (e.g. reactive distillation) while others (e.g. ultrasound‐assisted extraction/crystallization/reaction) are on their way to becoming the next‐generation technologies. This article focuses on the advances of ultrasound (US)‐assisted technologies that could lead in the near future to significant improvements in commercial activities. The aim is to provide an authoritative discussion on US‐assisted technologies that are currently emerging from the research environment into the chemical industry, as well as give an overview of the current state‐of‐the‐art applications of US in chemical processing (e.g. enzymatic reactive distillation, crystallization of API). Sufficient information is included to allow the assessment of US‐assisted technologies and the challenges for implementation, as well as their potential for commercial applications. © 2017 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:29780194

40 CFR 63.100 - Applicability and designation of source.

Code of Federal Regulations, 2010 CFR

2010-07-01

... manufacturing process unit has two or more products that have the same maximum annual design capacity on a mass... subject to this subpart. (3) For chemical manufacturing process units that are designed and operated as... chemical manufacturing process units that are designed and operated as flexible operation units shall be...

Application of hydrometallurgy techniques in quartz processing and purification: a review

NASA Astrophysics Data System (ADS)

Lin, Min; Lei, Shaomin; Pei, Zhenyu; Liu, Yuanyuan; Xia, Zhangjie; Xie, Feixiang

2018-04-01

Although there have been numerous studies on separation and purification of metallic minerals by hydrometallurgy techniques, applications of the chemical techniques in separation and purification of non-metallic minerals are rarely reported. This paper reviews disparate areas of study into processing and purification of quartz (typical non-metallic ore) in an attempt to summarize current work, as well as to suggest potential for future consolidation in the field. The review encompasses chemical techniques of the quartz processing including situations, progresses, leaching mechanism, scopes of application, advantages and drawbacks of micro-bioleaching, high temperature leaching, high temperature pressure leaching and catalyzed high temperature pressure leaching. Traditional leaching techniques including micro-bioleaching and high temperature leaching are unequal to demand of modern glass industry for quality of quartz concentrate because the quartz products has to be further processed. High temperature pressure leaching and catalyzed high temperature pressure leaching provide new ways to produce high-grade quartz sand with only one process and lower acid consumption. Furthermore, the catalyzed high temperature pressure leaching realizes effective purification of quartz with extremely low acid consumption (no using HF or any fluoride). It is proposed that, by integrating the different chemical processes of quartz processing and expounding leaching mechanisms and scopes of application, the research field as a monopolized industry would benefit.

Two new advanced forms of spectrometry for space and commercial applications

NASA Technical Reports Server (NTRS)

Schlager, Kenneth J.

1991-01-01

Reagentless ultraviolet absorption spectrometry (UVAS) and Liquid Atomic Emission Spectrometry (LAES) represent new forms of spectrometry with extensive potential in both space and commercial applications. Originally developed under KSC sponsorship for monitoring nutrient solutions for the Controlled Ecological Life Support System (CELSS), both UVAS and LAES have extensive analytical capabilities for both organic and inorganic chemical compounds. Both forms of instrumentation involve the use of remote fiber optic probes and real-time measurements for on-line process monitoring. Commercial applications exist primarily in environmental analysis and for process control in the chemical, pulp and paper, food processing, metal plating, and water/wastewater treatment industries.

Modeling microbiological and chemical processes in municipal solid waste bioreactor, Part II: Application of numerical model BIOKEMOD-3P.

PubMed

Gawande, Nitin A; Reinhart, Debra R; Yeh, Gour-Tsyh

2010-02-01

Biodegradation process modeling of municipal solid waste (MSW) bioreactor landfills requires the knowledge of various process reactions and corresponding kinetic parameters. Mechanistic models available to date are able to simulate biodegradation processes with the help of pre-defined species and reactions. Some of these models consider the effect of critical parameters such as moisture content, pH, and temperature. Biomass concentration is a vital parameter for any biomass growth model and often not compared with field and laboratory results. A more complex biodegradation model includes a large number of chemical and microbiological species. Increasing the number of species and user defined process reactions in the simulation requires a robust numerical tool. A generalized microbiological and chemical model, BIOKEMOD-3P, was developed to simulate biodegradation processes in three-phases (Gawande et al. 2009). This paper presents the application of this model to simulate laboratory-scale MSW bioreactors under anaerobic conditions. BIOKEMOD-3P was able to closely simulate the experimental data. The results from this study may help in application of this model to full-scale landfill operation.

Discussion on the Development of Green Chemistry and Chemical Engineering

NASA Astrophysics Data System (ADS)

Zhang, Yunshen

2017-11-01

Chemical industry plays a vital role in the development process of national economy. However, in view of the special nature of the chemical industry, a large number of poisonous and harmful substances pose a great threat to the ecological environment and human health in the entire process of raw material acquisition, production, transportation, product manufacturing, and the final practical application. Therefore, it is a general trend to promote the development of chemistry and chemical engineering towards a greener environment. This article will focus on some basic problems occurred in the development process of green chemistry and chemical engineering.

40 CFR 65.85 - Procedures.

Code of Federal Regulations, 2014 CFR

2014-07-01

... permit limit applicable to the process vent. (4) Design analysis based on accepted chemical engineering principles, measurable process parameters, or physical or chemical laws or properties. (5) All data... tested for vapor tightness. (b) Engineering assessment. Engineering assessment to determine if a vent...

40 CFR 65.85 - Procedures.

Code of Federal Regulations, 2012 CFR

2012-07-01

... permit limit applicable to the process vent. (4) Design analysis based on accepted chemical engineering principles, measurable process parameters, or physical or chemical laws or properties. (5) All data... tested for vapor tightness. (b) Engineering assessment. Engineering assessment to determine if a vent...

40 CFR 65.85 - Procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... permit limit applicable to the process vent. (4) Design analysis based on accepted chemical engineering principles, measurable process parameters, or physical or chemical laws or properties. (5) All data... tested for vapor tightness. (b) Engineering assessment. Engineering assessment to determine if a vent...

40 CFR 65.85 - Procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... permit limit applicable to the process vent. (4) Design analysis based on accepted chemical engineering principles, measurable process parameters, or physical or chemical laws or properties. (5) All data... tested for vapor tightness. (b) Engineering assessment. Engineering assessment to determine if a vent...

40 CFR 65.85 - Procedures.

Code of Federal Regulations, 2013 CFR

2013-07-01

... permit limit applicable to the process vent. (4) Design analysis based on accepted chemical engineering principles, measurable process parameters, or physical or chemical laws or properties. (5) All data... tested for vapor tightness. (b) Engineering assessment. Engineering assessment to determine if a vent...

APPLICATIONS ANALYSIS REPORT: SITE PROGRAM DEMONSTRATION TEST SOLIDITECH, INC. SOLIDIFICATION/ STABILIZATION PROCESS

EPA Science Inventory

This Applications Analysis Report evaluates the Soliditech, Inc., solidification/ stabilization process for the on-site treatment of waste materials. The Soliditech process mixes and chemically treats waste material with Urrichem (a proprietary reagent), additives, pozzolanic mat...

Recent Developments in the Application of Biologically Inspired Computation to Chemical Sensing

NASA Astrophysics Data System (ADS)

Marco, S.; Gutierrez-Gálvez, A.

2009-05-01

Biological olfaction outperforms chemical instrumentation in specificity, response time, detection limit, coding capacity, time stability, robustness, size, power consumption, and portability. This biological function provides outstanding performance due, to a large extent, to the unique architecture of the olfactory pathway, which combines a high degree of redundancy, an efficient combinatorial coding along with unmatched chemical information processing mechanisms. The last decade has witnessed important advances in the understanding of the computational primitives underlying the functioning of the olfactory system. In this work, the state of the art concerning biologically inspired computation for chemical sensing will be reviewed. Instead of reviewing the whole body of computational neuroscience of olfaction, we restrict this review to the application of models to the processing of real chemical sensor data.

Low-Temperature Plasma Functionalization of Carbon Nanotubes

NASA Technical Reports Server (NTRS)

Khare, Bishun; Meyyappan, M.

2004-01-01

A low-temperature plasma process has been devised for attaching specified molecular groups to carbon nanotubes in order to impart desired chemical and/or physical properties to the nanotubes for specific applications. Unlike carbon-nanotube- functionalization processes reported heretofore, this process does not involve the use of wet chemicals, does not involve exposure of the nanotubes to high temperatures, and generates very little chemical residue. In addition, this process can be carried out in a relatively simple apparatus and can readily be scaled up to mass production.

Current status and future perspectives of electron interactions with molecules, clusters, surfaces, and interfaces [Workshop on Fundamental challenges in electron-driven chemistry; Workshop on Electron-driven processes: Scientific challenges and technological opportunities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Becker, Kurt H.; McCurdy, C. William; Orlando, Thomas M.

2000-09-01

This report is based largely on presentations and discussions at two workshops and contributions from workshop participants. The workshop on Fundamental Challenges in Electron-Driven Chemistry was held in Berkeley, October 9-10, 1998, and addressed questions regarding theory, computation, and simulation. The workshop on Electron-Driven Processes: Scientific Challenges and Technological Opportunities was held at Stevens Institute of Technology, March 16-17, 2000, and focused largely on experiments. Electron-molecule and electron-atom collisions initiate and drive almost all the relevant chemical processes associated with radiation chemistry, environmental chemistry, stability of waste repositories, plasma-enhanced chemical vapor deposition, plasma processing of materials for microelectronic devices andmore » other applications, and novel light sources for research purposes (e.g. excimer lamps in the extreme ultraviolet) and in everyday lighting applications. The life sciences are a rapidly advancing field where the important role of electron-driven processes is only now beginning to be recognized. Many of the applications of electron-initiated chemical processes require results in the near term. A large-scale, multidisciplinary and collaborative effort should be mounted to solve these problems in a timely way so that their solution will have the needed impact on the urgent questions of understanding the physico-chemical processes initiated and driven by electron interactions.« less

Quantum chemical methods for the investigation of photoinitiated processes in biological systems: theory and applications.

PubMed

Dreuw, Andreas

2006-11-13

With the advent of modern computers and advances in the development of efficient quantum chemical computer codes, the meaningful computation of large molecular systems at a quantum mechanical level became feasible. Recent experimental effort to understand photoinitiated processes in biological systems, for instance photosynthesis or vision, at a molecular level also triggered theoretical investigations in this field. In this Minireview, standard quantum chemical methods are presented that are applicable and recently used for the calculation of excited states of photoinitiated processes in biological molecular systems. These methods comprise configuration interaction singles, the complete active space self-consistent field method, and time-dependent density functional theory and its variants. Semiempirical approaches are also covered. Their basic theoretical concepts and mathematical equations are briefly outlined, and their properties and limitations are discussed. Recent successful applications of the methods to photoinitiated processes in biological systems are described and theoretical tools for the analysis of excited states are presented.

Flow chemistry using milli- and microstructured reactors-from conventional to novel process windows.

PubMed

Illg, Tobias; Löb, Patrick; Hessel, Volker

2010-06-01

The terminology Novel Process Window unites different methods to improve existing processes by applying unconventional and harsh process conditions like: process routes at much elevated pressure, much elevated temperature, or processing in a thermal runaway regime to achieve a significant impact on process performance. This paper is a review of parts of IMM's works in particular the applicability of above mentioned Novel Process Windows on selected chemical reactions. First, general characteristics of microreactors are discussed like excellent mass and heat transfer and improved mixing quality. Different types of reactions are presented in which the use of microstructured devices led to an increased process performance by applying Novel Process Windows. These examples were chosen to demonstrate how chemical reactions can benefit from the use of milli- and microstructured devices and how existing protocols can be changed toward process conditions hitherto not applicable in standard laboratory equipment. The used milli- and microstructured reactors can also offer advantages in other areas, for example, high-throughput screening of catalysts and better control of size distribution in a particle synthesis process by improved mixing, etc. The chemical industry is under continuous improvement. So, a lot of research is being done to synthesize high value chemicals, to optimize existing processes in view of process safety and energy consumption and to search for new routes to produce such chemicals. Leitmotifs of such undertakings are often sustainable development(1) and Green Chemistry(2).

27 CFR 24.250 - Application for use of new treating material or process.

Code of Federal Regulations, 2011 CFR

2011-04-01

... from the testing program conducted by the chemical manufacturer demonstrating the function of the material or process; (7) A list of all chemicals used in compounding the treating material and the quantity... manufacturer or supplier of the treating material or process may be forwarded by the manufacturer or supplier...

27 CFR 24.250 - Application for use of new treating material or process.

Code of Federal Regulations, 2012 CFR

2012-04-01

... from the testing program conducted by the chemical manufacturer demonstrating the function of the material or process; (7) A list of all chemicals used in compounding the treating material and the quantity... manufacturer or supplier of the treating material or process may be forwarded by the manufacturer or supplier...

27 CFR 24.250 - Application for use of new treating material or process.

Code of Federal Regulations, 2013 CFR

2013-04-01

... from the testing program conducted by the chemical manufacturer demonstrating the function of the material or process; (7) A list of all chemicals used in compounding the treating material and the quantity... manufacturer or supplier of the treating material or process may be forwarded by the manufacturer or supplier...

27 CFR 24.250 - Application for use of new treating material or process.

Code of Federal Regulations, 2014 CFR

2014-04-01

... from the testing program conducted by the chemical manufacturer demonstrating the function of the material or process; (7) A list of all chemicals used in compounding the treating material and the quantity... manufacturer or supplier of the treating material or process may be forwarded by the manufacturer or supplier...

On Exact and Inexact Differentials and Applications

ERIC Educational Resources Information Center

Cortez, L. A. B.; de Oliveira, E. Capelas

2017-01-01

Considering the important role played by mathematical derivatives in the study of physical-chemical processes, this paper discusses the different possibilities and formulations of this concept and its application. In particular, in Chemical Thermodynamics, we study exact differentials associated with the so-called state functions and inexact…

40 CFR 63.1104 - Process vents from continuous unit operations: applicability assessment procedures and methods.

Code of Federal Regulations, 2014 CFR

2014-07-01

... permit limit applicable to the process vent. (iv) Design analysis based on accepted chemical engineering... rates, halogenated process vent determinations, process vent TRE index values, and engineering... corrected to 2.3 percent moisture; or (2) The engineering assessment procedures in paragraph (k) of this...

40 CFR 63.1104 - Process vents from continuous unit operations: applicability assessment procedures and methods.

Code of Federal Regulations, 2013 CFR

2013-07-01

... permit limit applicable to the process vent. (iv) Design analysis based on accepted chemical engineering... rates, halogenated process vent determinations, process vent TRE index values, and engineering... corrected to 2.3 percent moisture; or (2) The engineering assessment procedures in paragraph (k) of this...

40 CFR 63.1104 - Process vents from continuous unit operations: applicability assessment procedures and methods.

Code of Federal Regulations, 2011 CFR

2011-07-01

... permit limit applicable to the process vent. (iv) Design analysis based on accepted chemical engineering... rates, halogenated process vent determinations, process vent TRE index values, and engineering... corrected to 2.3 percent moisture; or (2) The engineering assessment procedures in paragraph (k) of this...

40 CFR 63.1104 - Process vents from continuous unit operations: applicability assessment procedures and methods.

Code of Federal Regulations, 2012 CFR

2012-07-01

... permit limit applicable to the process vent. (iv) Design analysis based on accepted chemical engineering... rates, halogenated process vent determinations, process vent TRE index values, and engineering... corrected to 2.3 percent moisture; or (2) The engineering assessment procedures in paragraph (k) of this...

Chemically Patterned Inverse Opal Created by a Selective Photolysis Modification Process.

PubMed

Tian, Tian; Gao, Ning; Gu, Chen; Li, Jian; Wang, Hui; Lan, Yue; Yin, Xianpeng; Li, Guangtao

2015-09-02

Anisotropic photonic crystal materials have long been pursued for their broad applications. A novel method for creating chemically patterned inverse opals is proposed here. The patterning technique is based on selective photolysis of a photolabile polymer together with postmodification on released amine groups. The patterning method allows regioselective modification within an inverse opal structure, taking advantage of selective chemical reaction. Moreover, combined with the unique signal self-reporting feature of the photonic crystal, the fabricated structure is capable of various applications, including gradient photonic bandgap and dynamic chemical patterns. The proposed method provides the ability to extend the structural and chemical complexity of the photonic crystal, as well as its potential applications.

Technology Prospecting on Enzymes: Application, Marketing and Engineering

PubMed Central

Li, Shuang; Yang, Xiaofeng; Yang, Shuai; Zhu, Muzi; Wang, Xiaoning

2012-01-01

Enzymes are protein molecules functioning as specialized catalysts for chemical reactions. They have contributed greatly to the traditional and modern chemical industry by improving existing processes. In this article, we first give a survey of representative industrial applications of enzymes, focusing on the technical applications, feed industry, food processing and cosmetic products. The recent important developments and applications of enzymes in industry are reviewed. Then large efforts are dedicated to the worldwide enzyme market from the demand and production perspectives. Special attention is laid on the Chinese enzyme market. Although enzyme applications are being developed in full swing, breakthroughs are needed to overcome their weaknesses in maintaining activities during the catalytic processes. Strategies of metagomic analysis, cell surface display technology and cell-free system might give valuable solutions in novel enzyme exploiting and enzyme engineering. PMID:24688658

Enzyme-based solutions for textile processing and dye contaminant biodegradation-a review.

PubMed

Chatha, Shahzad Ali Shahid; Asgher, Muhammad; Iqbal, Hafiz M N

2017-06-01

The textile industry, as recognized conformist and stake industry in the world's economy, is facing serious environmental challenges. In numerous industries, in practice, various chemical-based processes from initial sizing to final washing are fascinating harsh environment concerns. Some of these chemicals are corrosive to equipment and cause serious damage itself. Therefore, in the twenty-first century, chemical and allied industries quest a paradigm transition from traditional chemical-based concepts to a greener, sustainable, and environmentally friendlier catalytic alternative, both at the laboratory and industrial scales. Bio-based catalysis offers numerous benefits in the context of biotechnological industry and environmental applications. In recent years, bio-based processing has received particular interest among the scientist for inter- and multi-disciplinary investigations in the areas of natural and engineering sciences for the application in biotechnology sector at large and textile industries in particular. Different enzymatic processes such as chemical substitution have been developed or in the process of development for various textile wet processes. In this context, the present review article summarizes current developments and highlights those areas where environment-friendly enzymatic textile processing might play an increasingly important role in the textile industry. In the first part of the review, a special focus has been given to a comparative discussion of the chemical-based "classical/conventional" treatments and the modern enzyme-based treatment processes. Some relevant information is also reported to identify the major research gaps to be worked out in future.

Process for derivatizing carbon nanotubes with diazonium species

NASA Technical Reports Server (NTRS)

Tour, James M. (Inventor); Bahr, Jeffrey L. (Inventor); Yang, Jiping (Inventor)

2007-01-01

The invention incorporates new processes for the chemical modification of carbon nanotubes. Such processes involve the derivatization of multi- and single-wall carbon nanotubes, including small diameter (ca. 0.7 nm) single-wall carbon nanotubes, with diazonium species. The method allows the chemical attachment of a variety of organic compounds to the side and ends of carbon nanotubes. These chemically modified nanotubes have applications in polymer composite materials, molecular electronic applications and sensor devices. The methods of derivatization include electrochemical induced reactions thermally induced reactions (via in-situ generation of diazonium compounds or pre-formed diazonium compounds), and photochemically induced reactions. The derivatization causes significant changes in the spectroscopic properties of the nanotubes. The estimated degree of functionality is ca. 1 out of every 20 to 30 carbons in a nanotube bearing a functionality moiety. Such electrochemical reduction processes can be adapted to apply site-selective chemical functionalization of nanotubes. Moreover, when modified with suitable chemical groups, the derivatized nanotubes are chemically compatible with a polymer matrix, allowing transfer of the properties of the nanotubes (such as, mechanical strength or electrical conductivity) to the properties of the composite material as a whole. Furthermore, when modified with suitable chemical groups, the groups can be polymerized to form a polymer that includes carbon nanotubes ##STR00001##.

Application of Electro Chemical Machining for materials used in extreme conditions

NASA Astrophysics Data System (ADS)

Pandilov, Z.

2018-03-01

Electro-Chemical Machining (ECM) is the generic term for a variety of electrochemical processes. ECM is used to machine work pieces from metal and metal alloys irrespective of their hardness, strength or thermal properties, through the anodic dissolution, in aerospace, automotive, construction, medical equipment, micro-systems and power supply industries. The Electro Chemical Machining is extremely suitable for machining of materials used in extreme conditions. General overview of the Electro-Chemical Machining and its application for different materials used in extreme conditions is presented.

Teaching the Concept of Gibbs Energy Minimization through Its Application to Phase-Equilibrium Calculation

ERIC Educational Resources Information Center

Privat, Romain; Jaubert, Jean-Noe¨l; Berger, Etienne; Coniglio, Lucie; Lemaitre, Ce´cile; Meimaroglou, Dimitrios; Warth, Vale´rie

2016-01-01

Robust and fast methods for chemical or multiphase equilibrium calculation are routinely needed by chemical-process engineers working on sizing or simulation aspects. Yet, while industrial applications essentially require calculation tools capable of discriminating between stable and nonstable states and converging to nontrivial solutions,…

Sonochemistry in environmental remediation. 1. Combinative and hybrid sonophotochemical oxidation processes for the treatment of pollutants in water.

PubMed

Adewuyi, Yusuf G

2005-05-15

Sonoprocessing is the utilization of sonic and ultrasonic waves in chemical synthesis and processes. It is a new and rapidly growing research field with broad applications in environmental engineering, green chemical synthesis, and processing. The application of this environmentally benign technique in environmental remediation is currently under active research and development. Sonochemical oxidation is effective in treating toxic effluents and reducing toxicity. However, the ultrasonic treatment is highly energy intensive since sonication is relatively inefficient with respect to total input energy and is therefore not economically attractive or feasible alone. Hence, sonochemistry has not yet received much attention as an alternative for industrial and large-scale chemical and environmental processes. One of the most interesting topics in the recent advances in sonochemistry is the possibility of double or more excitations with ultrasound and other types of energy. The coupling of ultrasound with other free energy sources (i.e., UV) or chemical oxidation utilizing H2O2, O3, or ferrous ion presents interesting and attractive approaches. Therefore, many recent efforts have been devoted to improving the efficiency of sonochemical reactions by exploiting the advantages of combinative or hybrid processes involving the simultaneous or sequential use of ultrasonic irradiation and other advanced oxidation processes, electrochemical processes, and biological treatment. This paper provides a critical review of the applications of ultrasound in environmental remediation, focusing on recent developments and unifying analysis of combinative or hybrid systems, namely, sonophotochemical oxidation processes.

Contamination and changes of food factors during processing with modeling applications-safety related issues

USDA-ARS?s Scientific Manuscript database

Chemical and microbiological contamination of food during processing and preservation can result in foodborne illness outbreaks and food poisoning. Chemical contaminations can occur through exposure of foods to illegal additives, pesticides and fertilizer residues, toxic compounds formed by microbes...

Recent Development in Optical Chemical Sensors Coupling with Flow Injection Analysis

PubMed Central

Ojeda, Catalina Bosch; Rojas, Fuensanta Sánchez

2006-01-01

Optical techniques for chemical analysis are well established and sensors based on these techniques are now attracting considerable attention because of their importance in applications such as environmental monitoring, biomedical sensing, and industrial process control. On the other hand, flow injection analysis (FIA) is advisable for the rapid analysis of microliter volume samples and can be interfaced directly to the chemical process. The FIA has become a widespread automatic analytical method for more reasons; mainly due to the simplicity and low cost of the setups, their versatility, and ease of assembling. In this paper, an overview of flow injection determinations by using optical chemical sensors is provided, and instrumentation, sensor design, and applications are discussed. This work summarizes the most relevant manuscripts from 1980 to date referred to analysis using optical chemical sensors in FIA.

Neoteric Media as Tools for Process Intensification

NASA Astrophysics Data System (ADS)

Beh, C. C.; Mammucari, R.; Foster, N. R.

2017-06-01

Process intensification (PI) is a commonly used term in the chemical processing industry. When the concept of PI was first introduced in the late 1970s within the Imperial Chemical Industries (ICI) company, the main impetus was to reduce the processing cost without impairing the production rate. Neoteric media present as alternatives in chemical processing include gas-expanded liquids, ionic liquids, subcritical water, and combination of gas-expanded liquids and ionic liquids. The applications of neoteric media include particle engineering for improved bioavailability, controlled release of therapeutic implants, pharmaceutical formulations, extraction of natural products, nano-carriers for drug delivery, sterilisation of implants, and chemical reactions. This paper provides an overview of the use of these neoteric media.

Emissions model of waste treatment operations at the Idaho Chemical Processing Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schindler, R.E.

1995-03-01

An integrated model of the waste treatment systems at the Idaho Chemical Processing Plant (ICPP) was developed using a commercially-available process simulation software (ASPEN Plus) to calculate atmospheric emissions of hazardous chemicals for use in an application for an environmental permit to operate (PTO). The processes covered by the model are the Process Equipment Waste evaporator, High Level Liquid Waste evaporator, New Waste Calcining Facility and Liquid Effluent Treatment and Disposal facility. The processes are described along with the model and its assumptions. The model calculates emissions of NO{sub x}, CO, volatile acids, hazardous metals, and organic chemicals. Some calculatedmore » relative emissions are summarized and insights on building simulations are discussed.« less

Potential Applications of Zeolite Membranes in Reaction Coupling Separation Processes

PubMed Central

Daramola, Michael O.; Aransiola, Elizabeth F.; Ojumu, Tunde V.

2012-01-01

Future production of chemicals (e.g., fine and specialty chemicals) in industry is faced with the challenge of limited material and energy resources. However, process intensification might play a significant role in alleviating this problem. A vision of process intensification through multifunctional reactors has stimulated research on membrane-based reactive separation processes, in which membrane separation and catalytic reaction occur simultaneously in one unit. These processes are rather attractive applications because they are potentially compact, less capital intensive, and have lower processing costs than traditional processes. Therefore this review discusses the progress and potential applications that have occurred in the field of zeolite membrane reactors during the last few years. The aim of this article is to update researchers in the field of process intensification and also provoke their thoughts on further research efforts to explore and exploit the potential applications of zeolite membrane reactors in industry. Further evaluation of this technology for industrial acceptability is essential in this regard. Therefore, studies such as techno-economical feasibility, optimization and scale-up are of the utmost importance.

Cheminformatics Applications and Physicochemical Property Calculators: A Powerful Combination for the Encoding of Process Science

EPA Science Inventory

The registration of new chemicals under the Toxic Substances Control Act (TSCA) and new pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requires knowledge of the process science underlying the transport and transformation of organic chemicals in n...

Solar and chemical reaction-induced heating in the terrestrial mesosphere and lower thermosphere

NASA Technical Reports Server (NTRS)

Mlynczak, Martin G.

1992-01-01

Airglow and chemical processes in the terrestrial mesosphere and lower thermosphere are reviewed, and initial parameterizations of the processes applicable to multidimensional models are presented. The basic processes by which absorbed solar energy participates in middle atmosphere energetics for absorption events in which photolysis occurs are illustrated. An approach that permits the heating processes to be incorporated in numerical models is presented.

Reflow process stabilization by chemical characteristics and process conditions

NASA Astrophysics Data System (ADS)

Kim, Myoung-Soo; Park, Jeong-Hyun; Kim, Hak-Joon; Kim, Il-Hyung; Jeon, Jae-Ha; Gil, Myung-Goon; Kim, Bong-Ho

2002-07-01

With the shrunken device rule below 130nm, the patterning of smaller contact hole with enough process margin is required for mass production. Therefore, shrinking technology using thermal reflow process has been applied for smaller contact hole formation. In this paper, we have investigated the effects of chemical characteristics such as molecular weight, blocking ratio of resin, cross-linker amount and solvent type with its composition to reflow process of resist and found the optimized chemical composition for reflow process applicable condition. And several process conditions like resist coating thickness and multi-step thermal reflow method have been also evaluated to stabilize the pattern profile and improve CD uniformity after reflow process. From the experiment results, it was confirmed that the effect of crosslinker in resist to reflow properties such as reflow temperature and reflow rate were very critical and it controlled the pattern profile during reflow processing. And also, it showed stable CD uniformity and improved resist properties for top loss, film shrinkage and etch selectivity. The application of lower coating thickness of resist induced symmetric pattern profile even at edge with wider process margin. The introduction of two-step baking method for reflow process showed uniform CD value, also. It is believed that the application of resist containing crosslinker and optimized process conditions for smaller contact hole patterning is necessary for the mass production with a design rule below 130nm.

Downstream processing of stevioside and its potential applications.

PubMed

Puri, Munish; Sharma, Deepika; Tiwari, Ashok K

2011-01-01

Stevioside is a natural sweetener extracted from leaves of Stevia rebaudiana Bertoni, which is commercially produced by conventional (chemical/physical) processes. This article gives an overview of the stevioside structure, various analysis technique, new technologies required and the advances achieved in recent years. An enzymatic process is established, by which the maximum efficacy and benefit of the process can be achieved. The efficiency of the enzymatic process is quite comparable to that of other physical and chemical methods. Finally, we believe that in the future, the enzyme-based extraction will ensure more cost-effective availability of stevioside, thus assisting in the development of more food-based applications. Copyright © 2011 Elsevier Inc. All rights reserved.

An integrated decision model for the application of airborne sensors for improved response to accidental and terrorist chemical vapor releases

NASA Astrophysics Data System (ADS)

Kapitan, Loginn

This research created a new model which provides an integrated approach to planning the effective selection and employment of airborne sensor systems in response to accidental or intentional chemical vapor releases. The approach taken was to use systems engineering and decision analysis methods to construct a model architecture which produced a modular structure for integrating both new and existing components into a logical procedure to assess the application of airborne sensor systems to address chemical vapor hazards. The resulting integrated process model includes an internal aggregation model which allowed differentiation among alternative airborne sensor systems. Both models were developed and validated by experts and demonstrated using appropriate hazardous chemical release scenarios. The resultant prototype integrated process model or system fills a current gap in capability allowing improved planning, training and exercise for HAZMAT teams and first responders when considering the selection and employment of airborne sensor systems. Through the research process, insights into the current response structure and how current airborne capability may be most effectively used were generated. Furthermore, the resultant prototype system is tailorable for local, state, and federal application, and can potentially be modified to help evaluate investments in new airborne sensor technology and systems. Better planning, training and preparedness exercising holds the prospect for the effective application of airborne assets for improved response to large scale chemical release incidents. Improved response will result in fewer casualties and lives lost, reduced economic impact, and increased protection of critical infrastructure when faced with accidental and intentional terrorist release of hazardous industrial chemicals. With the prospect of more airborne sensor systems becoming available, this prototype system integrates existing and new tools into an effective process for the selection and employment of airborne sensors to better plan, train and exercise ahead of potential chemical release events.

Production of chemicals and fuels from biomass

DOEpatents

Woods, Elizabeth; Qiao, Ming; Myren, Paul; Cortright, Randy D.; Kania, John

2015-12-15

Described are methods, reactor systems, and catalysts for converting biomass to fuels and chemicals in a batch and/or continuous process. The process generally involves the conversion of water insoluble components of biomass, such as hemicellulose, cellulose and lignin, to volatile C.sub.2+O.sub.1-2 oxygenates, such as alcohols, ketones, cyclic ethers, esters, carboxylic acids, aldehydes, and mixtures thereof. In certain applications, the volatile C.sub.2+O.sub.1-2 oxygenates can be collected and used as a final chemical product, or used in downstream processes to produce liquid fuels, chemicals and other products.

On Study of Application of Micro-reactor in Chemistry and Chemical Field

NASA Astrophysics Data System (ADS)

Zhang, Yunshen

2018-02-01

Serving as a micro-scale chemical reaction system, micro-reactor is characterized by high heat transfer efficiency and mass transfer, strictly controlled reaction time and good safety performance; compared with the traditional mixing reactor, it can effectively shorten reaction time by virtue of these advantages and greatly enhance the chemical reaction conversion rate. However, problems still exist in the process where micro-reactor is used for production in chemistry and chemical field, and relevant researchers are required to optimize and perfect the performance of micro-reactor. This paper analyzes specific application of micro-reactor in chemistry and chemical field.

ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE REACTOR SYSTEM - APPLICATIONS ANALYSIS REPORT

EPA Science Inventory

The ELI Eco Logic International Inc. (Eco Logic) process thermally separates organics, then chemically reduces them in a hydrogen atmosphere, converting them to a reformed gas that consists of light hydrocarbons and water. A scrubber treats the reformed gas to remove hydrogen chl...

ECO LOGIC INTERNATIONAL GAS-PHASE CHEMICAL REDUCTION PROCESS - THE THERMAL DESORPTION UNIT - APPLICATIONS ANALYSIS REPORT

EPA Science Inventory

ELI ECO Logic International, Inc.'s Thermal Desorption Unit (TDU) is specifically designed for use with Eco Logic's Gas Phase Chemical Reduction Process. The technology uses an externally heated bath of molten tin in a hydrogen atmosphere to desorb hazardous organic compounds fro...

Teaching Population Balances for Chemical Engineering Students: Application to Granulation Processes

ERIC Educational Resources Information Center

Bucala, Veronica; Pina, Juliana

2007-01-01

The population balance equation (PBE) is a useful tool to predict particle size distributions in granulation processes. When PBE is taught to advanced chemical engineering students, the internal coordinates (particle properties) are particularly hard to understand. In this paper, the flow of particles along different coordinates is carefully…

Review of computational fluid dynamics applications in biotechnology processes.

PubMed

Sharma, C; Malhotra, D; Rathore, A S

2011-01-01

Computational fluid dynamics (CFD) is well established as a tool of choice for solving problems that involve one or more of the following phenomena: flow of fluids, heat transfer,mass transfer, and chemical reaction. Unit operations that are commonly utilized in biotechnology processes are often complex and as such would greatly benefit from application of CFD. The thirst for deeper process and product understanding that has arisen out of initiatives such as quality by design provides further impetus toward usefulness of CFD for problems that may otherwise require extensive experimentation. Not surprisingly, there has been increasing interest in applying CFD toward a variety of applications in biotechnology processing in the last decade. In this article, we will review applications in the major unit operations involved with processing of biotechnology products. These include fermentation,centrifugation, chromatography, ultrafiltration, microfiltration, and freeze drying. We feel that the future applications of CFD in biotechnology processing will focus on establishing CFD as a tool of choice for providing process understanding that can be then used to guide more efficient and effective experimentation. This article puts special emphasis on the work done in the last 10 years. © 2011 American Institute of Chemical Engineers

MarChem 93, The Proceedings, The 1993 Workshop on Marine Chemistry Instrumentation

DTIC Science & Technology

1994-01-01

technologies that are becom- chemical analysis, and record keeping ing available was tempered by the processes . These advances could be (largely...surface and meet the future needs of the chemical near bottom samples. oceanography research community? If not, how should they be improved? Difficulty...theoretical models where applicable (from box to embedded mixing and circulation) linking physical, biological, and chemical processes . I I I EDWARD J

Application of ultra high pressure (UHP) in starch chemistry.

PubMed

Kim, Hyun-Seok; Kim, Byung-Yong; Baik, Moo-Yeol

2012-01-01

Ultra high pressure (UHP) processing is an attractive non-thermal technique for food treatment and preservation at room temperature, with the potential to achieve interesting functional effects. The majority of UHP process applications in food systems have focused on shelf-life extension associated with non-thermal sterilization and a reduction or increase in enzymatic activity. Only a few studies have investigated modifications of structural characteristics and/or protein functionalities. Despite the rapid expansion of UHP applications in food systems, limited information is available on the effects of UHP on the structural and physicochemical properties of starch and/or its chemical derivatives included in most processed foods as major ingredients or minor additives. Starch and its chemical derivatives are responsible for textural and physical properties of food systems, impacting their end-use quality and/or shelf-life. This article reviews UHP processes for native (unmodified) starch granules and their effects on the physicochemical properties of UHP-treated starch. Furthermore, functional roles of UHP in acid-hydrolysis, hydroxypropylation, acetylation, and cross-linking reactions of starch granules, as well as the physicochemical properties of UHP-assisted starch chemical derivatives, are discussed.

The Utilization of Urine Processing for the Advancement of Life Support Technologies

NASA Technical Reports Server (NTRS)

Grossi-Soyster, Elysse; Hogan, John; Flynn, Michael

2014-01-01

The success of long-duration missions will depend on resource recovery and the self-sustainability of life support technologies. Current technologies used on the International Space Station (ISS) utilize chemical and mechanical processes, such as filtration, to recover potable water from urine produced by crewmembers. Such technologies have significantly reduced the need for water resupply through closed-loop resource recovery and recycling. Harvesting the important components of urine requires selectivity, whether through the use of membranes or other physical barriers, or by chemical or biological processes. Given the chemical composition of urine, the downstream benefits of urine processing for resource recovery will be critical for many aspects of life support, such as food production and the synthesis of biofuels. This paper discusses the beneficial components of urine and their potential applications, and the challenges associated with using urine for nutrient recycling for space application.

Recovery Processes of Organic Acids from Fermentation Broths in the Biomass-Based Industry.

PubMed

Li, Qian-Zhu; Jiang, Xing-Lin; Feng, Xin-Jun; Wang, Ji-Ming; Sun, Chao; Zhang, Hai-Bo; Xian, Mo; Liu, Hui-Zhou

2016-01-01

The new movement towards green chemistry and renewable feedstocks makes microbial production of chemicals more competitive. Among the numerous chemicals, organic acids are more attractive targets for process development efforts in the renewable-based biorefinery industry. However, most of the production costs in microbial processes are higher than that in chemical processes, among which over 60% are generated by separation processes. Therefore, the research of separation and purification processes is important for a promising biorefinery industry. This review highlights the progress of recovery processes in the separation and purification of organic acids, including their advantages and disadvantages, current situation, and future prospects in terms of recovery yields and industrial application.

Advanced Modeling Techniques to Study Anthropogenic Influences on Atmospheric Chemical Budgets

NASA Technical Reports Server (NTRS)

Mathur, Rohit

1997-01-01

This research work is a collaborative effort between research groups at MCNC and the University of North Carolina at Chapel Hill. The overall objective of this research is to improve the level of understanding of the processes that determine the budgets of chemically and radiatively active compounds in the atmosphere through development and application of advanced methods for calculating the chemical change in atmospheric models. The research performed during the second year of this project focused on four major aspects: (1) The continued development and refinement of multiscale modeling techniques to address the issue of the disparate scales of the physico-chemical processes that govern the fate of atmospheric pollutants; (2) Development and application of analysis methods utilizing process and mass balance techniques to increase the interpretive powers of atmospheric models and to aid in complementary analysis of model predictions and observations; (3) Development of meteorological and emission inputs for initial application of the chemistry/transport model over the north Atlantic region; and, (4) The continued development and implementation of a totally new adaptive chemistry representation that changes the details of what is represented as the underlying conditions change.

CFD studies on biomass thermochemical conversion.

PubMed

Wang, Yiqun; Yan, Lifeng

2008-06-01

Thermochemical conversion of biomass offers an efficient and economically process to provide gaseous, liquid and solid fuels and prepare chemicals derived from biomass. Computational fluid dynamic (CFD) modeling applications on biomass thermochemical processes help to optimize the design and operation of thermochemical reactors. Recent progression in numerical techniques and computing efficacy has advanced CFD as a widely used approach to provide efficient design solutions in industry. This paper introduces the fundamentals involved in developing a CFD solution. Mathematical equations governing the fluid flow, heat and mass transfer and chemical reactions in thermochemical systems are described and sub-models for individual processes are presented. It provides a review of various applications of CFD in the biomass thermochemical process field.

CFD Studies on Biomass Thermochemical Conversion

PubMed Central

Wang, Yiqun; Yan, Lifeng

2008-01-01

Thermochemical conversion of biomass offers an efficient and economically process to provide gaseous, liquid and solid fuels and prepare chemicals derived from biomass. Computational fluid dynamic (CFD) modeling applications on biomass thermochemical processes help to optimize the design and operation of thermochemical reactors. Recent progression in numerical techniques and computing efficacy has advanced CFD as a widely used approach to provide efficient design solutions in industry. This paper introduces the fundamentals involved in developing a CFD solution. Mathematical equations governing the fluid flow, heat and mass transfer and chemical reactions in thermochemical systems are described and sub-models for individual processes are presented. It provides a review of various applications of CFD in the biomass thermochemical process field. PMID:19325848

40 CFR 439.30 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PHARMACEUTICAL MANUFACTURING POINT SOURCE CATEGORY Chemical Synthesis Products § 439.30 Applicability. This subpart applies to discharges of process wastewater resulting from the manufacture of pharmaceutical...

How chemistry supports cell biology: the chemical toolbox at your service.

PubMed

Wijdeven, Ruud H; Neefjes, Jacques; Ovaa, Huib

2014-12-01

Chemical biology is a young and rapidly developing scientific field. In this field, chemistry is inspired by biology to create various tools to monitor and modulate biochemical and cell biological processes. Chemical contributions such as small-molecule inhibitors and activity-based probes (ABPs) can provide new and unique insights into previously unexplored cellular processes. This review provides an overview of recent breakthroughs in chemical biology that are likely to have a significant impact on cell biology. We also discuss the application of several chemical tools in cell biology research. Copyright © 2014 Elsevier Ltd. All rights reserved.

Prioritization methodology for chemical replacement

NASA Technical Reports Server (NTRS)

Cruit, Wendy; Goldberg, Ben; Schutzenhofer, Scott

1995-01-01

Since United States of America federal legislation has required ozone depleting chemicals (class 1 & 2) to be banned from production, The National Aeronautics and Space Administration (NASA) and industry have been required to find other chemicals and methods to replace these target chemicals. This project was initiated as a development of a prioritization methodology suitable for assessing and ranking existing processes for replacement 'urgency.' The methodology was produced in the form of a workbook (NASA Technical Paper 3421). The final workbook contains two tools, one for evaluation and one for prioritization. The two tools are interconnected in that they were developed from one central theme - chemical replacement due to imposed laws and regulations. This workbook provides matrices, detailed explanations of how to use them, and a detailed methodology for prioritization of replacement technology. The main objective is to provide a GUIDELINE to help direct the research for replacement technology. The approach for prioritization called for a system which would result in a numerical rating for the chemicals and processes being assessed. A Quality Function Deployment (QFD) technique was used in order to determine numerical values which would correspond to the concerns raised and their respective importance to the process. This workbook defines the approach and the application of the QFD matrix. This technique: (1) provides a standard database for technology that can be easily reviewed, and (2) provides a standard format for information when requesting resources for further research for chemical replacement technology. Originally, this workbook was to be used for Class 1 and Class 2 chemicals, but it was specifically designed to be flexible enough to be used for any chemical used in a process (if the chemical and/or process needs to be replaced). The methodology consists of comparison matrices (and the smaller comparison components) which allow replacement technology to be quantitatively compared in several categories, and a QFD matrix which allows process/chemical pairs to be rated against one another for importance (using consistent categories). Depending on the need for application, one can choose the part(s) needed or have the methodology completed in its entirety. For example, if a program needs to show the risk of changing a process/chemical one may choose to use part of Matrix A and Matrix C. If a chemical is being used, and the process must be changed; one might use the Process Concerns part of Matrix D for the existing process and all possible replacement processes. If an overall analysis of a program is needed, one may request the QFD to be completed.

Coupling Computer-Aided Process Simulation and Estimations of Emissions and Land Use for Rapid Life Cycle Inventory Modeling

EPA Science Inventory

A methodology is described for developing a gate-to-gate life cycle inventory (LCI) of a chemical manufacturing process to support the application of life cycle assessment in the design and regulation of sustainable chemicals. The inventories were derived by first applying proces...

Introduction to Stochastic Simulations for Chemical and Physical Processes: Principles and Applications

ERIC Educational Resources Information Center

Weiss, Charles J.

2017-01-01

An introduction to digital stochastic simulations for modeling a variety of physical and chemical processes is presented. Despite the importance of stochastic simulations in chemistry, the prevalence of turn-key software solutions can impose a layer of abstraction between the user and the underlying approach obscuring the methodology being…

Dynamic control and information processing in chemical reaction systems by tuning self-organization behavior

NASA Astrophysics Data System (ADS)

Lebiedz, Dirk; Brandt-Pollmann, Ulrich

2004-09-01

Specific external control of chemical reaction systems and both dynamic control and signal processing as central functions in biochemical reaction systems are important issues of modern nonlinear science. For example nonlinear input-output behavior and its regulation are crucial for the maintainance of the life process that requires extensive communication between cells and their environment. An important question is how the dynamical behavior of biochemical systems is controlled and how they process information transmitted by incoming signals. But also from a general point of view external forcing of complex chemical reaction processes is important in many application areas ranging from chemical engineering to biomedicine. In order to study such control issues numerically, here, we choose a well characterized chemical system, the CO oxidation on Pt(110), which is interesting per se as an externally forced chemical oscillator model. We show numerically that tuning of temporal self-organization by input signals in this simple nonlinear chemical reaction exhibiting oscillatory behavior can in principle be exploited for both specific external control of dynamical system behavior and processing of complex information.

Electrochemical assembly of organic molecules by the reduction of iodonium salts

DOEpatents

Dirk, Shawn M [Albuquerque, NM; Howell, Stephen W [Albuquerque, NM; Wheeler, David R [Albuquerque, NM

2009-06-23

Methods are described for the electrochemical assembly of organic molecules on silicon, or other conducting or semiconducting substrates, using iodonium salt precursors. Iodonium molecules do not assemble on conducting surfaces without a negative bias. Accordingly, the iodonium salts are preferred for patterning applications that rely on direct writing with negative bias. The stability of the iodonium molecule to acidic conditions allows them to be used with standard silicon processing. As a directed assembly process, the use of iodonium salts provides for small features while maintaining the ability to work on a surface and create structures on a wafer level. Therefore, the process is amenable for mass production. Furthermore, the assembled monolayer (or multilayer) is chemically robust, allowing for subsequent chemical manipulations and the introduction of various molecular functionalities for various chemical and biological applications.

Extraterrestrial materials processing and construction

NASA Technical Reports Server (NTRS)

Criswell, D. R.

1978-01-01

Applications of available terrestrial skills to the gathering of lunar materials and the processing of raw lunar materials into industrial feed stock were investigated. The literature on lunar soils and rocks was reviewed and the chemical processes by which major oxides and chemical elements can be extracted were identified. The gathering of lunar soil by means of excavation equipment was studied in terms of terrestrial experience with strip mining operations on earth. The application of electrostatic benefication techniques was examined for use on the moon to minimize the quantity of materials requiring surface transport and to optimize the stream of raw materials to be transported off the moon for subsequent industrial use.

Empirical Force Fields for Mechanistic Studies of Chemical Reactions in Proteins.

PubMed

Das, A K; Meuwly, M

2016-01-01

Following chemical reactions in atomistic detail is one of the most challenging aspects of current computational approaches to chemistry. In this chapter the application of adiabatic reactive MD (ARMD) and its multistate version (MS-ARMD) are discussed. Both methods allow to study bond-breaking and bond-forming processes in chemical and biological processes. Particular emphasis is put on practical aspects for applying the methods to investigate the dynamics of chemical reactions. The chapter closes with an outlook of possible generalizations of the methods discussed. © 2016 Elsevier Inc. All rights reserved.

Production of chemicals and fuels from biomass

DOEpatents

Qiao, Ming; Woods, Elizabeth; Myren, Paul; Cortright, Randy; Kania, John

2018-01-23

Methods, reactor systems, and catalysts are provided for converting in a continuous process biomass to fuels and chemicals, including methods of converting the water insoluble components of biomass, such as hemicellulose, cellulose and lignin, to volatile C.sub.2+O.sub.1-2 oxygenates, such as alcohols, ketones, cyclic ethers, esters, carboxylic acids, aldehydes, and mixtures thereof. In certain applications, the volatile C.sub.2+O.sub.1-2 oxygenates can be collected and used as a final chemical product, or used in downstream processes to produce liquid fuels, chemicals and other products.

40 CFR 63.1412 - Continuous process vent applicability assessment procedures and methods.

Code of Federal Regulations, 2010 CFR

2010-07-01

... engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of... values, and engineering assessment control applicability assessment requirements are to be determined... by using the engineering assessment procedures in paragraph (k) of this section. (f) Volumetric flow...

40 CFR 63.1412 - Continuous process vent applicability assessment procedures and methods.

Code of Federal Regulations, 2012 CFR

2012-07-01

... engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of... values, and engineering assessment control applicability assessment requirements are to be determined... by using the engineering assessment procedures in paragraph (k) of this section. (f) Volumetric flow...

40 CFR 63.1412 - Continuous process vent applicability assessment procedures and methods.

Code of Federal Regulations, 2014 CFR

2014-07-01

... engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of... values, and engineering assessment control applicability assessment requirements are to be determined... by using the engineering assessment procedures in paragraph (k) of this section. (f) Volumetric flow...

40 CFR 63.1412 - Continuous process vent applicability assessment procedures and methods.

Code of Federal Regulations, 2013 CFR

2013-07-01

... engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of... values, and engineering assessment control applicability assessment requirements are to be determined... by using the engineering assessment procedures in paragraph (k) of this section. (f) Volumetric flow...

40 CFR 63.1412 - Continuous process vent applicability assessment procedures and methods.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engineering principles, measurable process parameters, or physical or chemical laws or properties. Examples of... values, and engineering assessment control applicability assessment requirements are to be determined... by using the engineering assessment procedures in paragraph (k) of this section. (f) Volumetric flow...

Space processing applications payload equipment study. Volume 2A: Experiment requirements

NASA Technical Reports Server (NTRS)

Smith, A. G.; Anderson, W. T., Jr.

1974-01-01

An analysis of the space processing applications payload equipment was conducted. The primary objective was to perform a review and an update of the space processing activity research equipment requirements and specifications that were derived in the first study. The analysis is based on the six major experimental classes of: (1) biological applications, (2) chemical processes in fluids, (3) crystal growth, (4) glass technology, (5) metallurgical processes, and (6) physical processes in fluids. Tables of data are prepared to show the functional requirements for the areas of investigation.

Flow chemistry vs. flow analysis.

PubMed

Trojanowicz, Marek

2016-01-01

The flow mode of conducting chemical syntheses facilitates chemical processes through the use of on-line analytical monitoring of occurring reactions, the application of solid-supported reagents to minimize downstream processing and computerized control systems to perform multi-step sequences. They are exactly the same attributes as those of flow analysis, which has solid place in modern analytical chemistry in several last decades. The following review paper, based on 131 references to original papers as well as pre-selected reviews, presents basic aspects, selected instrumental achievements and developmental directions of a rapidly growing field of continuous flow chemical synthesis. Interestingly, many of them might be potentially employed in the development of new methods in flow analysis too. In this paper, examples of application of flow analytical measurements for on-line monitoring of flow syntheses have been indicated and perspectives for a wider application of real-time analytical measurements have been discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Conservation of Life as a Unifying Theme for Process Safety in Chemical Engineering Education

ERIC Educational Resources Information Center

Klein, James A.; Davis, Richard A.

2011-01-01

This paper explores the use of "conservation of life" as a concept and unifying theme for increasing awareness, application, and integration of process safety in chemical engineering education. Students need to think of conservation of mass, conservation of energy, and conservation of life as equally important in engineering design and analysis.…

Enzymes from Extreme Environments and Their Industrial Applications

PubMed Central

Littlechild, Jennifer A.

2015-01-01

This article will discuss the importance of specific extremophilic enzymes for applications in industrial biotechnology. It will specifically address those enzymes that have applications in the area of biocatalysis. Such enzymes now play an important role in catalyzing a variety of chemical conversions that were previously carried out by traditional chemistry. The biocatalytic process is carried out under mild conditions and with greater specificity. The enzyme process does not result in the toxic waste that is usually produced in a chemical process that would require careful disposal. In this sense, the biocatalytic process is referred to as carrying out “green chemistry” which is considered to be environmentally friendly. Some of the extremophilic enzymes to be discussed have already been developed for industrial processes such as an l-aminoacylase and a γ-lactamase. The industrial applications of other extremophilic enzymes, including transaminases, carbonic anhydrases, dehalogenases, specific esterases, and epoxide hydrolases, are currently being assessed. Specific examples of these industrially important enzymes that have been studied in the authors group will be presented in this review. PMID:26528475

How to Ignite an Atmospheric Pressure Microwave Plasma Torch without Any Additional Igniters

PubMed Central

Leins, Martina; Gaiser, Sandra; Schulz, Andreas; Walker, Matthias; Schumacher, Uwe; Hirth, Thomas

2015-01-01

This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a stable and continuous operation of the plasma is possible and the plasma torch can be used for many different applications. On one hand, the hot (3,600 K gas temperature) plasma can be used for chemical processes and on the other hand the cold afterglow (temperatures down to almost RT) can be applied for surface processes. For example chemical syntheses are interesting volume processes. Here the microwave plasma torch can be used for the decomposition of waste gases which are harmful and contribute to the global warming but are needed as etching gases in growing industry sectors like the semiconductor branch. Another application is the dissociation of CO2. Surplus electrical energy from renewable energy sources can be used to dissociate CO2 to CO and O2. The CO can be further processed to gaseous or liquid higher hydrocarbons thereby providing chemical storage of the energy, synthetic fuels or platform chemicals for the chemical industry. Applications of the afterglow of the plasma torch are the treatment of surfaces to increase the adhesion of lacquer, glue or paint, and the sterilization or decontamination of different kind of surfaces. The movie will explain how to ignite the plasma solely by microwave power without any additional igniters, e.g., electric sparks. The microwave plasma torch is based on a combination of two resonators — a coaxial one which provides the ignition of the plasma and a cylindrical one which guarantees a continuous and stable operation of the plasma after ignition. The plasma can be operated in a long microwave transparent tube for volume processes or shaped by orifices for surface treatment purposes. PMID:25938699

Overview of Sea-Ice Properties, Distribution and Temporal Variations, for Application to Ice-Atmosphere Chemical Processes.

NASA Astrophysics Data System (ADS)

Moritz, R. E.

2005-12-01

The properties, distribution and temporal variation of sea-ice are reviewed for application to problems of ice-atmosphere chemical processes. Typical vertical structure of sea-ice is presented for different ice types, including young ice, first-year ice and multi-year ice, emphasizing factors relevant to surface chemistry and gas exchange. Time average annual cycles of large scale variables are presented, including ice concentration, ice extent, ice thickness and ice age. Spatial and temporal variability of these large scale quantities is considered on time scales of 1-50 years, emphasizing recent and projected changes in the Arctic pack ice. The amount and time evolution of open water and thin ice are important factors that influence ocean-ice-atmosphere chemical processes. Observations and modeling of the sea-ice thickness distribution function are presented to characterize the range of variability in open water and thin ice.

Process development for waveguide chemical sensors with integrated polymeric sensitive layers

NASA Astrophysics Data System (ADS)

Amberkar, Raghu; Gao, Zhan; Park, Jongwon; Henthorn, David B.; Kim, Chang-Soo

2008-02-01

Due to the proper optical property and flexibility in the process development, an epoxy-based, high-aspect ratio photoresist SU-8 is now attracting attention in optical sensing applications. Manipulation of the surface properties of SU-8 waveguides is critical to attach functional films such as chemically-sensitive layers. We describe a new integration process to immobilize fluorescence molecules on SU-8 waveguide surface for application to intensity-based optical chemical sensors. We use two polymers for this application. Spin-on, hydrophobic, photopatternable silicone is a convenient material to contain fluorophore molecules and to pattern a photolithographically defined thin layer on the surface of SU-8. We use fumed silica powders as an additive to uniformly disperse the fluorophores in the silicone precursor. In general, additional processes are not critically required to promote the adhesion between the SU-8 and silicone. The other material is polyethylene glycol diacrylate (PEGDA). Recently we demonstrated a novel photografting method to modify the surface of SU-8 using a surface bound initiator to control its wettability. The activated surface is then coated with a monomer precursor solution. Polymerization follows when the sample is exposed to UV irradiation, resulting in a grafted PEGDA layer incorporating fluorophores within the hydrogel matrix. Since this method is based the UV-based photografting reaction, it is possible to grow off photolithographically defined hydrogel patterns on the waveguide structures. The resulting films will be viable integrated components in optical bioanalytical sensors. This is a promising technique for integrated chemical sensors both for planar type waveguide and vertical type waveguide chemical sensors.

Recent advances in chemical modification and processing of cotton fibers for specific end-use applications

USDA-ARS?s Scientific Manuscript database

The Cotton Chemistry and Utilization Research Unit is part of the Agricultural Research Service, the U.S. Department of Agriculture's chief scientific in-house research agency. The Research Unit develops new processes, applications and product enabling technologies which facilitate the expanded use ...

Recent developments on ion-exchange membranes and electro-membrane processes.

PubMed

Nagarale, R K; Gohil, G S; Shahi, Vinod K

2006-02-28

Rapid growth of chemical and biotechnology in diversified areas fuels the demand for the need of reliable green technologies for the down stream processes, which include separation, purification and isolation of the molecules. Ion-exchange membrane technologies are non-hazardous in nature and being widely used not only for separation and purification but their application also extended towards energy conversion devices, storage batteries and sensors etc. Now there is a quite demand for the ion-exchange membrane with better selectivities, less electrical resistance, high chemical, mechanical and thermal stability as well as good durability. A lot of work has been done for the development of these types of ion-exchange membranes during the past twenty-five years. Herein we have reviewed the preparation of various types of ion-exchange membranes, their characterization and applications for different electro-membrane processes. Primary attention has been given to the chemical route used for the membrane preparation. Several general reactions used for the preparation of ion-exchange membranes were described. Methodologies used for the characterization of these membranes and their applications were also reviewed for the benefit of readers, so that they can get all information about the ion-exchange membranes at one platform. Although there are large number of reports available regarding preparations and applications of ion-exchange membranes more emphasis were predicted for the usefulness of these membranes or processes for solving certain type of industrial or social problems. More efforts are needed to bring many products or processes to pilot scale and extent their applications.

40 CFR 60.660 - Applicability and designation of affected facility.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Performance for Volatile Organic Compound (VOC) Emissions From Synthetic Organic Chemical Manufacturing... section that is part of a process unit that produces any of the chemicals listed in § 60.667 as a product... chemicals produced within that unit of less than one gigagram per year is exempt from all provisions of this...

40 CFR 60.700 - Applicability and designation of affected facility.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Performance for Volatile Organic Compound Emissions From Synthetic Organic Chemical Manufacturing Industry... part of a process unit that produces any of the chemicals listed in § 60.707 as a product, co-product... design capacity for all chemicals produced within that unit of less than 1 gigagram per year (1,100 tons...

40 CFR 60.660 - Applicability and designation of affected facility.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Performance for Volatile Organic Compound (VOC) Emissions From Synthetic Organic Chemical Manufacturing... section that is part of a process unit that produces any of the chemicals listed in § 60.667 as a product... chemicals produced within that unit of less than one gigagram per year is exempt from all provisions of this...

40 CFR 60.660 - Applicability and designation of affected facility.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Performance for Volatile Organic Compound (VOC) Emissions From Synthetic Organic Chemical Manufacturing... section that is part of a process unit that produces any of the chemicals listed in § 60.667 as a product... chemicals produced within that unit of less than one gigagram per year is exempt from all provisions of this...

40 CFR 60.700 - Applicability and designation of affected facility.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Performance for Volatile Organic Compound Emissions From Synthetic Organic Chemical Manufacturing Industry... part of a process unit that produces any of the chemicals listed in § 60.707 as a product, co-product... design capacity for all chemicals produced within that unit of less than 1 gigagram per year (1,100 tons...

40 CFR 63.100 - Applicability and designation of source.

Code of Federal Regulations, 2014 CFR

2014-07-01

... National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical..., and H of this part apply to chemical manufacturing process units that meet all the criteria specified... more of the chemicals listed in paragraphs (b)(1)(i) or (b)(1)(ii) of this section. (i) One or more of...

40 CFR 63.100 - Applicability and designation of source.

Code of Federal Regulations, 2012 CFR

2012-07-01

... National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical..., and H of this part apply to chemical manufacturing process units that meet all the criteria specified... more of the chemicals listed in paragraphs (b)(1)(i) or (b)(1)(ii) of this section. (i) One or more of...

40 CFR 63.100 - Applicability and designation of source.

Code of Federal Regulations, 2013 CFR

2013-07-01

... National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical..., and H of this part apply to chemical manufacturing process units that meet all the criteria specified... more of the chemicals listed in paragraphs (b)(1)(i) or (b)(1)(ii) of this section. (i) One or more of...

40 CFR 63.100 - Applicability and designation of source.

Code of Federal Regulations, 2011 CFR

2011-07-01

... National Emission Standards for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical..., and H of this part apply to chemical manufacturing process units that meet all the criteria specified... more of the chemicals listed in paragraphs (b)(1)(i) or (b)(1)(ii) of this section. (i) One or more of...

On Study of New Progress and Application of Coordination Chemistry in Chemistry and Chemical Industry in Recent Years

NASA Astrophysics Data System (ADS)

Zhang, Yunshen

2017-12-01

Coordination chemistry refers to a branch of chemistry, and its research results are widely used in industry and people's daily life. Many edge disciplines emerge during the development, which propels the process of disciplines and technology. This paper briefly discusses new progress of coordination chemistry and its application in chemistry and chemical industry in recent years.

40 CFR 463.1 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... development laboratories. (f) Chemical and thermal reticulation processes for polyurethane foam are not... or form the reticulated foam are subject, however, to this regulation if they discharge process water...

Continuous roll-to-roll growth of graphene films by chemical vapor deposition

NASA Astrophysics Data System (ADS)

Hesjedal, Thorsten

2011-03-01

Few-layer graphene is obtained in atmospheric chemical vapor deposition on polycrystalline copper in a roll-to-roll process. Raman and x-ray photoelectron spectroscopy were employed to confirm the few-layer nature of the graphene film, to map the inhomogeneities, and to study and optimize the growth process. This continuous growth process can be easily scaled up and enables the low-cost fabrication of graphene films for industrial applications.

Application of a combined process of moving-bed biofilm reactor (MBBR) and chemical coagulation for dyeing wastewater treatment.

PubMed

Shin, D H; Shin, W S; Kim, Y H; Han, Myung Ho; Choi, S J

2006-01-01

A combined process consisted of a Moving-Bed Biofilm Reactor (MBBR) and chemical coagulation was investigated for textile wastewater treatment. The pilot scale MBBR system is composed of three MBBRs (anaerobic, aerobic-1 and aerobic-2 in series), each reactor was filled with 20% (v/v) of polyurethane-activated carbon (PU-AC) carrier for biological treatment followed by chemical coagulation with FeCl2. ln the MBBR process, 85% of COD and 70% of color (influent COD = 807.5 mg/L and color = 3,400 PtCo unit) were removed using relatively low MLSS concentration and short hydraulic retention time (HRT = 44 hr). The biologically treated dyeing wastewater was subjected to chemical coagulation. After coagulation with FeCl2, 95% of COD and 97% of color were removed overall. The combined process of MBBR and chemical coagulation has promising potential for dyeing wastewater treatment.

Design of an embedded inverse-feedforward biomolecular tracking controller for enzymatic reaction processes.

PubMed

Foo, Mathias; Kim, Jongrae; Sawlekar, Rucha; Bates, Declan G

2017-04-06

Feedback control is widely used in chemical engineering to improve the performance and robustness of chemical processes. Feedback controllers require a 'subtractor' that is able to compute the error between the process output and the reference signal. In the case of embedded biomolecular control circuits, subtractors designed using standard chemical reaction network theory can only realise one-sided subtraction, rendering standard controller design approaches inadequate. Here, we show how a biomolecular controller that allows tracking of required changes in the outputs of enzymatic reaction processes can be designed and implemented within the framework of chemical reaction network theory. The controller architecture employs an inversion-based feedforward controller that compensates for the limitations of the one-sided subtractor that generates the error signals for a feedback controller. The proposed approach requires significantly fewer chemical reactions to implement than alternative designs, and should have wide applicability throughout the fields of synthetic biology and biological engineering.

Flow Tube Studies of Gas Phase Chemical Processes of Atmospheric Importance

NASA Technical Reports Server (NTRS)

Molina, Mario J.

1997-01-01

The objective of this project is to conduct measurements of elementary reaction rate constants and photochemistry parameters for processes of importance in the atmosphere. These measurements are being carried out under temperature and pressure conditions covering those applicable to the stratosphere and upper troposphere, using the chemical ionization mass spectrometry turbulent flow technique developed in our laboratory.

Mathematical modeling of high-pH chemical flooding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhuyan, D.; Lake, L.W.; Pope, G.A.

1990-05-01

This paper describes a generalized compositional reservoir simulator for high-pH chemical flooding processes. This simulator combines the reaction chemistry associated with these processes with the extensive physical- and flow-property modeling schemes of an existing micellar/polymer flood simulator, UTCHEM. Application of the model is illustrated for cases from a simple alkaline preflush to surfactant-enhanced alkaline-polymer flooding.

Multivariate Quantitative Chemical Analysis

NASA Technical Reports Server (NTRS)

Kinchen, David G.; Capezza, Mary

1995-01-01

Technique of multivariate quantitative chemical analysis devised for use in determining relative proportions of two components mixed and sprayed together onto object to form thermally insulating foam. Potentially adaptable to other materials, especially in process-monitoring applications in which necessary to know and control critical properties of products via quantitative chemical analyses of products. In addition to chemical composition, also used to determine such physical properties as densities and strengths.

Application of Chemistry in Materials Research at NASA GRC

NASA Technical Reports Server (NTRS)

Kavandi, Janet L.

2016-01-01

Overview of NASA GRC Materials Development. New materials enabled by new chemistries offering unique properties and chemical processing techniques. Durability of materials in harsh environments requires understanding and modeling of chemical interaction of materials with the environment.

Streamers and their applications

NASA Astrophysics Data System (ADS)

Pemen, A. J. M.

2011-10-01

In this invited lecture we give an overview of our 15 years of experience on streamer plasma research. Efforts are directed to integrating the competence areas of plasma physics, pulsed power technology and chemical processing. The current status is the development of a large scale pulsed corona system for gas treatment. Applications on biogas conditioning, VOC removal, odor abatement and control of traffic emissions have been demonstrated. Detailed research on electrical and chemical processes resulted in a boost of efficiencies. Energy transfer efficiency to the plasma was raised to above 90%. Simultaneous improvement of the plasma chemistry resulted in a highly efficient radical generation: O-radical production up to 50% of the theoretical maximum has been achieved. A major challenge in pulsed power driven streamers is to unravel, understand and ultimately control the complex interactions between the transient plasma, electrical circuits, and process. Even more a challenge is to yield electron energies that fit activation energies of the process. We will discuss our ideas on adjusting pulsed power waveforms and plasma reactor settings to obtain more controlled catalytic processing: the ``Chemical Transistor'' concept.

Chemical-Looping Combustion and Gasification of Coals and Oxygen Carrier Development: A Brief Review

DOE PAGES

Wang, Ping; Means, Nicholas; Shekhawat, Dushyant; ...

2015-09-24

Chemical-looping technology is one of the promising CO 2 capture technologies. It generates a CO 2 enriched flue gas, which will greatly benefit CO 2 capture, utilization or sequestration. Both chemical-looping combustion (CLC) and chemical-looping gasification (CLG) have the potential to be used to generate power, chemicals, and liquid fuels. Chemical-looping is an oxygen transporting process using oxygen carriers. Recently, attention has focused on solid fuels such as coal. Coal chemical-looping reactions are more complicated than gaseous fuels due to coal properties (like mineral matter) and the complex reaction pathways involving solid fuels. The mineral matter/ash and sulfur in coalmore » may affect the activity of oxygen carriers. Oxygen carriers are the key issue in chemical-looping processes. Thermogravimetric analysis (TGA) has been widely used for the development of oxygen carriers (e.g., oxide reactivity). Two proposed processes for the CLC of solid fuels are in-situ Gasification Chemical-Looping Combustion (iG-CLC) and Chemical-Looping with Oxygen Uncoupling (CLOU). The objectives of this review are to discuss various chemical-looping processes with coal, summarize TGA applications in oxygen carrier development, and outline the major challenges associated with coal chemical-looping in iG-CLC and CLOU.« less

Analytical considerations and dimensionless analysis for a description of particle interactions in high pressure processes

NASA Astrophysics Data System (ADS)

Rauh, Cornelia; Delgado, Antonio

2010-12-01

High pressures of up to several hundreds of MPa are utilized in a wide range of applications in chemical, bio-, and food engineering, aiming at selective control of (bio-)chemical reactions. Non-uniformity of process conditions may threaten the safety and quality of the resulting products because processing conditions such as pressure, temperature, and treatment history are crucial for the course of (bio-)chemical reactions. Therefore, thermofluid-dynamical phenomena during the high pressure process have to be examined, and numerical tools to predict process uniformity and to optimize the processes have to be developed. Recently applied mathematical models and numerical simulations of laboratory and industrial scale high pressure processes investigating the mentioned crucial phenomena are based on continuum balancing models of thermofluid dynamics. Nevertheless, biological systems are complex fluids containing the relevant (bio-)chemical compounds (enzymes and microorganisms). These compounds are particles that interact with the surrounding medium and between each other. This contribution deals with thermofluid-dynamical interactions of the relevant particulate (bio-)chemical compounds (enzymes and microorganisms) with the surrounding fluid. By consideration of characteristic time and length scales and particle forces, the motion of the (bio-)chemical compounds is characterized.

Bacterial dye-decolorizing peroxidases: biochemical ...

EPA Pesticide Factsheets

In biorefineries, processing biomass begins with separating lignin from cellulose and hemicellulose. The latter two are depolymerized to give monosaccharides (e.g. glucose and xylose), which can be converted to fuels or chemicals. In contrast, lignin presents a challenging target for further processing due to its inherent heterogeneity and recalcitrance. Therefore, it has only been used in low-value applications. For example, lignin is burnt to recover energy in cellulosic ethanol production. Valorization of lignin is critical for biorefineries as it may generate high revenue. Lignin is the obvious candidate to provide renewable aromatic chemicals. As long as it can be depolymerized, the phenylpropane units can be converted into useful phenolic chemicals, which are currently derived from fossil fuels. This is a survey of an emerging group of enzymes that may have applications in lignin valorization.

The surface science of nanocrystals

NASA Astrophysics Data System (ADS)

Boles, Michael A.; Ling, Daishun; Hyeon, Taeghwan; Talapin, Dmitri V.

2016-02-01

All nanomaterials share a common feature of large surface-to-volume ratio, making their surfaces the dominant player in many physical and chemical processes. Surface ligands -- molecules that bind to the surface -- are an essential component of nanomaterial synthesis, processing and application. Understanding the structure and properties of nanoscale interfaces requires an intricate mix of concepts and techniques borrowed from surface science and coordination chemistry. Our Review elaborates these connections and discusses the bonding, electronic structure and chemical transformations at nanomaterial surfaces. We specifically focus on the role of surface ligands in tuning and rationally designing properties of functional nanomaterials. Given their importance for biomedical (imaging, diagnostics and therapeutics) and optoelectronic (light-emitting devices, transistors, solar cells) applications, we end with an assessment of application-targeted surface engineering.

Brewer's spent grain: a valuable feedstock for industrial applications.

PubMed

Mussatto, Solange I

2014-05-01

Brewer's spent grain (BSG) is the most abundant by-product generated from the beer-brewing process, representing approximately 85% of the total by-products obtained. This material is basically constituted by the barley grain husks obtained as solid residue after the wort production. Since BSG is rich in sugars and proteins, the main and quickest alternative for elimination of this industrial by-product has been as animal feed. However, BSG is a raw material of interest for application in different areas because of its low cost, large availability throughout the year and valuable chemical composition. In the last decade, many efforts have been directed towards the reuse of BSG, taking into account the incentive that has been given to recycle the wastes and by-products generated by industrial activities. Currently, many interesting and advantageous methods for application of BSG in foods, in energy production and in chemical and biotechnological processes have been reported. The present study presents and discusses the most recent perspectives for BSG application in such areas. © 2013 Society of Chemical Industry.

A review on applications of nanotechnology in the enhanced oil recovery part A: effects of nanoparticles on interfacial tension

NASA Astrophysics Data System (ADS)

Cheraghian, Goshtasp; Hendraningrat, Luky

2016-01-01

Chemical enhanced oil recovery is another strong growing technology with the potential of a step change innovation, which will help to secure future oil supply by turning resources into reserves. While Substantial amount of crude oil remains in the reservoir after primary and secondary production, conventional production methods give access to on average only one-third of original oil in place, the use of surfactants and polymers allows for recovery of up to another third of this oil. Chemical flooding is of increasing interest and importance due to high oil prices and the need to increase oil production. Research in nanotechnology in the petroleum industry is advancing rapidly and an enormous progress in the application of nanotechnology in this area is to be expected. Nanotechnology has the potential to profoundly change enhanced oil recovery and to improve mechanism of recovery. This paper, therefore, focuses on the reviews of the application of nano technology in chemical flooding process in oil recovery and reviews the application nano in the polymer and surfactant flooding on the interfacial tension process.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferrada, J.J.; Osborne-Lee, I.W.; Grizzaffi, P.A.

Expert systems are known to be useful in capturing expertise and applying knowledge to chemical engineering problems such as diagnosis, process control, process simulation, and process advisory. However, expert system applications are traditionally limited to knowledge domains that are heuristic and involve only simple mathematics. Neural networks, on the other hand, represent an emerging technology capable of rapid recognition of patterned behavior without regard to mathematical complexity. Although useful in problem identification, neural networks are not very efficient in providing in-depth solutions and typically do not promote full understanding of the problem or the reasoning behind its solutions. Hence, applicationsmore » of neural networks have certain limitations. This paper explores the potential for expanding the scope of chemical engineering areas where neural networks might be utilized by incorporating expert systems and neural networks into the same application, a process called hybridization. In addition, hybrid applications are compared with those using more traditional approaches, the results of the different applications are analyzed, and the feasibility of converting the preliminary prototypes described herein into useful final products is evaluated. 12 refs., 8 figs.« less

Edible holography: the application of holographic techniques to food processing

NASA Astrophysics Data System (ADS)

Begleiter, Eric

1991-07-01

Reports on current research efforts in the application of holographic techniques to food processing. Through a simple and inexpensive production process, diffractive and holographic effects of color, depth, and motion can be transferred to edible products. Processes are discussed which can provide a competitive advantage to the marketing of a diverse group of sugar and non-sugar-based consumable products, i.e. candies, chocolates, lollipops, snacks, cereals and pharmaceuticals. Techniques, applications, and products are investigated involving the shift from a chemical to a physical basis for the production of food coloring and decorating.

Adverse outcome pathway networks: Development, analytics and applications

EPA Science Inventory

The US EPA is developing more cost effective and efficient ways to evaluate chemical safety using high throughput and computationally based testing strategies. An important component of this approach is the ability to translate chemical effects on fundamental biological processes...

Adverse outcome pathway networks I: Development and applications

EPA Science Inventory

The US EPA is developing more cost effective and efficient ways to evaluate chemical safety using high throughput and computationally based testing strategies. An important component of this approach is the ability to translate chemical effects on fundamental biological processes...

Micropyrolyzer for chemical analysis of liquid and solid samples

DOEpatents

Mowry, Curtis D.; Morgan, Catherine H.; Manginell, Ronald P.; Frye-Mason, Gregory C.

2006-07-18

A micropyrolyzer has applications to pyrolysis, heated chemistry, and thermal desorption from liquid or solid samples. The micropyrolyzer can be fabricated from semiconductor materials and metals using standard integrated circuit technologies. The micropyrolyzer enables very small volume samples of less than 3 microliters and high sample heating rates of greater than 20.degree. C. per millisecond. A portable analyzer for the field analysis of liquid and solid samples can be realized when the micropyrolyzer is combined with a chemical preconcentrator, chemical separator, and chemical detector. Such a portable analyzer can be used in a variety of government and industrial applications, such as non-proliferation monitoring, chemical and biological warfare detection, industrial process control, water and air quality monitoring, and industrial hygiene.

Value-added processing of crude glycerol into chemicals and polymers.

PubMed

Luo, Xiaolan; Ge, Xumeng; Cui, Shaoqing; Li, Yebo

2016-09-01

Crude glycerol is a low-value byproduct which is primarily obtained from the biodiesel production process. Its composition is significantly different from that of pure glycerol. Crude glycerol usually contains various impurities, such as water, methanol, soap, fatty acids, and fatty acid methyl esters. Considerable efforts have been devoted to finding applications for converting crude glycerol into high-value products, such as biofuels, chemicals, polymers, and animal feed, to improve the economic viability of the biodiesel industry and overcome environmental challenges associated with crude glycerol disposal. This article reviews recent advances of biological and chemical technologies for value-added processing of crude glycerol into chemicals and polymers, and provides strategies for addressing production challenges. Copyright © 2016 Elsevier Ltd. All rights reserved.

CheD: chemical database compilation tool, Internet server, and client for SQL servers.

PubMed

Trepalin, S V; Yarkov, A V

2001-01-01

An efficient program, which runs on a personal computer, for the storage, retrieval, and processing of chemical information, is presented, The program can work both as a stand-alone application or in conjunction with a specifically written Web server application or with some standard SQL servers, e.g., Oracle, Interbase, and MS SQL. New types of data fields are introduced, e.g., arrays for spectral information storage, HTML and database links, and user-defined functions. CheD has an open architecture; thus, custom data types, controls, and services may be added. A WWW server application for chemical data retrieval features an easy and user-friendly installation on Windows NT or 95 platforms.

Design and preparation of plant oil-based polymers and their applications

NASA Astrophysics Data System (ADS)

Ahn, Byung-Jun Kollbe

Renewable materials are desirable for many applications due to the finite fossil resources and environmental issues. Plant oil is one of the most promising renewable feedstocks. Plant oils and functionalized oleo-chemicals including functionalized soybean oils have become attractive sustainable chemicals for industrial applications. Especially, epoxidized oleo-chemicals such as epoxidized soybean oil (ESO) are one of the most well-known readily available inexpensive functionalized plant oils. In this study, novel polymers and nanocomposites for sustainable materials applications were designed and prepared via ring-opening of epoxide in plant oils, and their chemical and physical properties were characterized. The novel transparent elastomers derived from functionalized plant oils have a great potential as flexible electronic and biological applications with their inherent low toxicity. Especially, their rheological properties showed a potential for pressure sensitive adhesives (PSAs). The dominant thermal stability and transparency were obtained via green processing: one pot, single step, fast reactions in moderate conditions, or solvent-free UV curing conditions. These oleo-based elastomers presented excellent end-use properties for PSAs application comparable to commercial PSA tapes. Based on the principal chemical studies, the roles of the each component have been identified: polymer derived from the ring-opening of epoxides as an elastomer, and dihydroxylated triglycerides as a tackifier. Their interaction was also elucidated with an element label analysis. The mechanical and rheological properties of the oleo-polymer as PSAs were able to be improved with a rosin ester tackifier. In addition, biogreases and bio-thermoplastics were developed via the environmentally benign process, which will contribute to further application on the production of new bio-based materials. Further, this study essays a novel acid functionalized iron/iron oxide nanoparticles catalyst with excellent product yields for epoxide ring opening of oleochemicals for a greener synthetic method of biopolyols, and excellent environmental benefits with life cycle assessment of syntheses. Those functionalized iron/iron oxide core shell nanoparticles catalysts has great potential for biomedical engineering process with the highest magnetization of Fe(0) core among all metals.

Physical/chemical closed-loop water-recycling

NASA Technical Reports Server (NTRS)

Herrmann, Cal C.; Wydeven, Theodore

1991-01-01

Water needs, water sources, and means for recycling water are examined in terms appropriate to the water quality requirements of a small crew and spacecraft intended for long duration exploration missions. Inorganic, organic, and biological hazards are estimated for waste water sources. Sensitivities to these hazards for human uses are estimated. The water recycling processes considered are humidity condensation, carbon dioxide reduction, waste oxidation, distillation, reverse osmosis, pervaporation, electrodialysis, ion exchange, carbon sorption, and electrochemical oxidation. Limitations and applications of these processes are evaluated in terms of water quality objectives. Computerized simulation of some of these chemical processes is examined. Recommendations are made for development of new water recycling technology and improvement of existing technology for near term application to life support systems for humans in space. The technological developments are equally applicable to water needs on Earth, in regions where extensive water recycling is needed or where advanced water treatment is essential to meet EPA health standards.

Application of high-pressure homogenization on gums.

PubMed

Belmiro, Ricardo Henrique; Tribst, Alline Artigiani Lima; Cristianini, Marcelo

2018-04-01

High-pressure homogenization (HPH) is an emerging process during which a fluid product is pumped by pressure intensifiers, forcing it to flow through a narrow gap, usually measured in the order of micrometers. Gums are polysaccharides from vegetal, animal or microbial origin and are widely employed in food and chemical industries as thickeners, stabilizers, gelling agents and emulsifiers. The choice of a specific gum depends on its application and purpose because each form of gum has particular values with respect to viscosity, intrinsic viscosity, stability, and emulsifying and gelling properties, with these parameters being determined by its structure. HPH is able to alter those properties positively by inducing changes in the original polymer, allowing for new applications and improvements with respect to the technical properties of gums. This review highlights the most important advances when this process is applied to change polysaccharides from distinct sources and molecular structures, as well as the future challenges that remain. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Active biopolymers in green non-conventional media: a sustainable tool for developing clean chemical processes.

PubMed

Lozano, Pedro; Bernal, Juana M; Nieto, Susana; Gomez, Celia; Garcia-Verdugo, Eduardo; Luis, Santiago V

2015-12-21

The greenness of chemical processes turns around two main axes: the selectivity of catalytic transformations, and the separation of pure products. The transfer of the exquisite catalytic efficiency shown by enzymes in nature to chemical processes is an important challenge. By using appropriate reaction systems, the combination of biopolymers with supercritical carbon dioxide (scCO2) and ionic liquids (ILs) resulted in synergetic and outstanding platforms for developing (multi)catalytic green chemical processes, even under flow conditions. The stabilization of biocatalysts, together with the design of straightforward approaches for separation of pure products including the full recovery and reuse of enzymes/ILs systems, are essential elements for developing clean chemical processes. By understanding structure-function relationships of biopolymers in ILs, as well as for ILs themselves (e.g. sponge-like ionic liquids, SLILs; supported ionic liquids-like phases, SILLPs, etc.), several integral green chemical processes of (bio)catalytic transformation and pure product separation are pointed out (e.g. the biocatalytic production of biodiesel in SLILs, etc.). Other developments based on DNA/ILs systems, as pathfinder studies for further technological applications in the near future, are also considered.

Kinetics of heterogeneous chemical reactions: a theoretical model for the accumulation of pesticides in soil.

PubMed

Lin, S H; Sahai, R; Eyring, H

1971-04-01

A theoretical model for the accumulation of pesticides in soil has been proposed and discussed from the viewpoint of heterogeneous reaction kinetics with a basic aim to understand the complex nature of soil processes relating to the environmental pollution. In the bulk of soil, the pesticide disappears by diffusion and a chemical reaction; the rate processes considered on the surface of soil are diffusion, chemical reaction, vaporization, and regular pesticide application. The differential equations involved have been solved analytically by the Laplace-transform method.

Kinetics of Heterogeneous Chemical Reactions: A Theoretical Model for the Accumulation of Pesticides in Soil

PubMed Central

Lin, S. H.; Sahai, R.; Eyring, H.

1971-01-01

A theoretical model for the accumulation of pesticides in soil has been proposed and discussed from the viewpoint of heterogeneous reaction kinetics with a basic aim to understand the complex nature of soil processes relating to the environmental pollution. In the bulk of soil, the pesticide disappears by diffusion and a chemical reaction; the rate processes considered on the surface of soil are diffusion, chemical reaction, vaporization, and regular pesticide application. The differential equations involved have been solved analytically by the Laplace-transform method. PMID:5279519

Applications of Solubility Data

ERIC Educational Resources Information Center

Tomkins, Reginald P. T.

2008-01-01

This article describes several applications of the use of solubility data. It is not meant to be exhaustive but rather to show that knowledge of solubility data is required in a variety of technical applications that assist in the design of chemical processes. (Contains 3 figures and 1 table.)

Technologies for Upgrading Light Water Reactor Outlet Temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniel S. Wendt; Piyush Sabharwall; Vivek Utgikar

Nuclear energy could potentially be utilized in hybrid energy systems to produce synthetic fuels and feedstocks from indigenous carbon sources such as coal and biomass. First generation nuclear hybrid energy system (NHES) technology will most likely be based on conventional light water reactors (LWRs). However, these LWRs provide thermal energy at temperatures of approximately 300°C, while the desired temperatures for many chemical processes are much higher. In order to realize the benefits of nuclear hybrid energy systems with the current LWR reactor fleets, selection and development of a complimentary temperature upgrading technology is necessary. This paper provides an initial assessmentmore » of technologies that may be well suited toward LWR outlet temperature upgrading for powering elevated temperature industrial and chemical processes during periods of off-peak power demand. Chemical heat transformers (CHTs) are a technology with the potential to meet LWR temperature upgrading requirements for NHESs. CHTs utilize chemical heat of reaction to change the temperature at which selected heat sources supply or consume thermal energy. CHTs could directly utilize LWR heat output without intermediate mechanical or electrical power conversion operations and the associated thermodynamic losses. CHT thermal characteristics are determined by selection of the chemical working pair and operating conditions. This paper discusses the chemical working pairs applicable to LWR outlet temperature upgrading and the CHT operating conditions required for providing process heat in NHES applications.« less

CHEMICAL ENGINEERING DIVISION SUMMARY REPORT, OCTOBER, NOVEMBER, DECEMBER 1960

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1961-03-01

Chemical-metallurgical processing studies were made of pyrometallurgical development snd research, and fuel processing facilities for EBR-II. Fuel-cycle applications of fluidization and volatility techniques included laboratory investigations of fluoride volatility processes, engineeringscale development, and conversion of UF/sub 6/ to UO/sub 2/. Reactor safety studies consisted of metal oxidation and ignition kinetics, and metal-water reactions. Reactor chemistry investigations were conducted to determine nuclear constants and suitable reactor decontamination methods. Routine operations are summarized for the high-level gammairradiation facillty and waste processing. (B.O.G.)

Developments in hydrogenation technology for fine-chemical and pharmaceutical applications.

PubMed

Machado, R M; Heier, K R; Broekhuis, R R

2001-11-01

The continuous innovation in hydrogenation technology is testimony to its growing importance in the manufacture of specialty and fine chemicals. New developments in equipment, process intensification and catalysis represent major themes that have undergone recent advances. Developments in chiral catalysis, methods to support and fix homogeneous catalysts, novel reactor and mixing technology, high-throughput screening, supercritical processing, spectroscopic and electrochemical online process monitoring, monolithic and structured catalysts, and sonochemical activation methods illustrate the scope and breadth of evolving technology applied to hydrogenation.

Who Would Have Thought? The Story of a Food Engineer.

PubMed

Lund, Daryl B

2017-02-28

Food engineering is a hybrid of food science and an engineering science, like chemical engineering in my particular case, resulting in the application of chemical engineering principles to food systems and their constituents. With the complexity of food and food processing, one generally narrows his or her interests, and my primary interests were in the kinetics of reactions important in foods, thermal processing, deposition of unwanted materials from food onto heated surfaces (fouling), and microwave heat transfer in baking. This review describes how I developed an interest in these topics and the contributions I have hopefully made to understanding food and to the application of engineering.

Technology resource document for the assembled chemical weapons assessment environmental impact statement. Vol. 4 : assembled systems for weapons destruction at Pueblo Chemical Depot.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimmell, T.; Folga, S., Frey, G.; Molberg, J.

2001-04-30

This volume of the Technical Resource Document (TRD) for the ''Environmental Impact Statement (EIS) for the Design, Construction and Operation of One or More Pilot Test Facilities for Assembled Chemical Weapons Destruction Technologies at One or More Sites'' (PMACWA 2001c) pertains to the destruction of assembled chemical weapons (ACW) stored at Pueblo Chemical Depot (PCD), located outside Pueblo, Colorado. This volume presents technical and process information on each of the destruction technologies applicable to treatment of the specific ACW stored at PCD. The destruction technologies described are those that have been demonstrated during Phase I of the Assembled Chemical Weaponsmore » Assessment (ACWA) demonstration process (see Volume 1).« less

Computational Chemistry and Lubrication

NASA Technical Reports Server (NTRS)

Zehe, Michael J.

1998-01-01

Members of NASA Lewis Research Center's Tribology and Surface Science Branch are applying high-level computational chemistry techniques to the development of new lubrication systems for space applications and for future advanced aircraft engines. The next generation of gas turbine engines will require a liquid lubricant to function at temperatures in excess of 350 C in oxidizing environments. Conventional hydrocarbon-based lubricants are incapable of operating in these extreme environments, but a class of compounds known as the perfluoropolyether (PFAE) liquids (see the preceding illustration) shows promise for such applications. These commercially available products are already being used as lubricants in conditions where low vapor pressure and chemical stability are crucial, such as in satellite bearings and composite disk platters. At higher temperatures, however, these compounds undergo a decomposition process that is assisted (catalyzed) by metal and metal oxide bearing surfaces. This decomposition process severely limits the applicability of PFAE's at higher temperatures. A great deal of laboratory experimentation has revealed that the extent of fluid degradation depends on the chemical properties of the bearing surface materials. Lubrication engineers would like to understand the chemical breakdown mechanism to design a less vulnerable PFAE or to develop a chemical additive to block this degradation.

15 CFR 713.3 - Annual declaration and reporting requirements for exports and imports of Schedule 2 chemicals.

Code of Federal Regulations, 2013 CFR

2013-01-01

... reports of exports and imports of Schedule 2 chemicals—(1) Declarations. A Schedule 2 plant site that is declared because it produced, processed or consumed a Schedule 2 chemical at one or more plants above the... plant site that same Schedule 2 chemical above the applicable threshold, must submit export and import...

15 CFR 713.3 - Annual declaration and reporting requirements for exports and imports of Schedule 2 chemicals.

Code of Federal Regulations, 2014 CFR

2014-01-01

... reports of exports and imports of Schedule 2 chemicals—(1) Declarations. A Schedule 2 plant site that is declared because it produced, processed or consumed a Schedule 2 chemical at one or more plants above the... plant site that same Schedule 2 chemical above the applicable threshold, must submit export and import...

15 CFR 713.3 - Annual declaration and reporting requirements for exports and imports of Schedule 2 chemicals.

Code of Federal Regulations, 2012 CFR

2012-01-01

... reports of exports and imports of Schedule 2 chemicals—(1) Declarations. A Schedule 2 plant site that is declared because it produced, processed or consumed a Schedule 2 chemical at one or more plants above the... plant site that same Schedule 2 chemical above the applicable threshold, must submit export and import...

Chemical vs. biotechnological synthesis of C13-apocarotenoids: current methods, applications and perspectives.

PubMed

Cataldo, Vicente F; López, Javiera; Cárcamo, Martín; Agosin, Eduardo

2016-07-01

Apocarotenoids are natural compounds derived from the oxidative cleavage of carotenoids. Particularly, C13-apocarotenoids are volatile compounds that contribute to the aromas of different flowers and fruits and are highly valued by the Flavor and Fragrance industry. So far, the chemical synthesis of these terpenoids has dominated the industry. Nonetheless, the increasing consumer demand for more natural and sustainable processes raises an interesting opportunity for bio-production alternatives. In this regard, enzymatic biocatalysis and metabolically engineered microorganisms emerge as attractive biotechnological options. The present review summarizes promising bioengineering approaches with regard to chemical production methods for the synthesis of two families of C13-apocarotenoids: ionones/dihydroionones and damascones/damascenone. We discuss each method and its applicability, with a thorough comparative analysis for ionones, focusing on the production process, regulatory aspects, and sustainability.

Non-thermal hydrogen plasma processing effectively increases the antibacterial activity of graphene oxide

NASA Astrophysics Data System (ADS)

Ke, Zhigang; Ma, Yulong; Zhu, Zhongjie; Zhao, Hongwei; Wang, Qi; Huang, Qing

2018-01-01

Graphene-based materials (GMs) are promising antibacterial agents which provide an alternative route to treat pathogenic bacteria with resistance to conventional antibiotics. To further improve their antibacterial activity, many methods have been developed to functionalize the GMs with chemicals. However, the application of additional chemicals may pose potential risks to the environment and human being. Herein, a radio-frequency-driven inductively coupled non-thermal hydrogen plasma was used to treat and reduce graphene oxide (GO) without using any other chemicals, and we found that the plasma-reduced GO (prGO) is with significantly higher bactericidal activity against Escherichia coli. The mechanism of the increased antibacterial activity of prGO is due to that plasma processing breaks down the GO sheets into smaller layers with more rough surface defects, which can thus induce more destructive membrane damages to the bacteria. This work sets another good example, showing that plasma processing is a green and low-cost alternative for GM modification for biomedical applications.

Perspectives on Validation of High-Throughput Assays Supporting 21st Century Toxicity Testing1

PubMed Central

Judson, Richard; Kavlock, Robert; Martin, Matt; Reif, David; Houck, Keith; Knudsen, Thomas; Richard, Ann; Tice, Raymond R.; Whelan, Maurice; Xia, Menghang; Huang, Ruili; Austin, Christopher; Daston, George; Hartung, Thomas; Fowle, John R.; Wooge, William; Tong, Weida; Dix, David

2014-01-01

Summary In vitro, high-throughput screening (HTS) assays are seeing increasing use in toxicity testing. HTS assays can simultaneously test many chemicals, but have seen limited use in the regulatory arena, in part because of the need to undergo rigorous, time-consuming formal validation. Here we discuss streamlining the validation process, specifically for prioritization applications in which HTS assays are used to identify a high-concern subset of a collection of chemicals. The high-concern chemicals could then be tested sooner rather than later in standard guideline bioassays. The streamlined validation process would continue to ensure the reliability and relevance of assays for this application. We discuss the following practical guidelines: (1) follow current validation practice to the extent possible and practical; (2) make increased use of reference compounds to better demonstrate assay reliability and relevance; (3) deemphasize the need for cross-laboratory testing, and; (4) implement a web-based, transparent and expedited peer review process. PMID:23338806

Supercritical fluids as alternative, safe, food-processing media: an overview.

PubMed

Da Cruz Francisco, José; Szwajcer Dey, Estera

2003-01-01

The continuous growth of world population and its concentration in the urban areas require food supplies that are continuous, sufficient and of good quality. To resolve this problem techniques have been developed for increasing food quantity and quality. The techniques are applied throughout the food chain from production, conservation and during distribution to the consumers (from "the field to the fork"). During handling of food, chemicals are often deliberately added to achieve improved processing and better quality. This is one of the main reasons food undergoes different kinds of contamination. This overview focuses on the application of supercritical fluids as media for handling food materials during processing with the perspective of reducing chemical contamination of food. Examples of developmental applications of this technique and on research work in process are presented. Emphasis is given to extraction and biotransformation techniques.

Simple Chemical Vapor Deposition Experiment

ERIC Educational Resources Information Center

Pedersen, Henrik

2014-01-01

Chemical vapor deposition (CVD) is a process commonly used for the synthesis of thin films for several important technological applications, for example, microelectronics, hard coatings, and smart windows. Unfortunately, the complexity and prohibitive cost of CVD equipment makes it seldom available for undergraduate chemistry students. Here, a…

Progress in Nano-Engineered Anodic Aluminum Oxide Membrane Development.

PubMed

Poinern, Gerrard Eddy Jai; Ali, Nurshahidah; Fawcett, Derek

2011-02-25

The anodization of aluminum is an electro-chemical process that changes the surface chemistry of the metal, via oxidation, to produce an anodic oxide layer. During this process a self organized, highly ordered array of cylindrical shaped pores can be produced with controllable pore diameters, periodicity and density distribution. This enables anodic aluminum oxide (AAO) membranes to be used as templates in a variety of nanotechnology applications without the need for expensive lithographical techniques. This review article is an overview of the current state of research on AAO membranes and the various applications of nanotechnology that use them in the manufacture of nano-materials and devices or incorporate them into specific applications such as biological/chemical sensors, nano-electronic devices, filter membranes and medical scaffolds for tissue engineering.

Progress in Nano-Engineered Anodic Aluminum Oxide Membrane Development

PubMed Central

Poinern, Gerrard Eddy Jai; Ali, Nurshahidah; Fawcett, Derek

2011-01-01

The anodization of aluminum is an electro-chemical process that changes the surface chemistry of the metal, via oxidation, to produce an anodic oxide layer. During this process a self organized, highly ordered array of cylindrical shaped pores can be produced with controllable pore diameters, periodicity and density distribution. This enables anodic aluminum oxide (AAO) membranes to be used as templates in a variety of nanotechnology applications without the need for expensive lithographical techniques. This review article is an overview of the current state of research on AAO membranes and the various applications of nanotechnology that use them in the manufacture of nano-materials and devices or incorporate them into specific applications such as biological/chemical sensors, nano-electronic devices, filter membranes and medical scaffolds for tissue engineering. PMID:28880002

Chemical vapor deposition modeling for high temperature materials

NASA Technical Reports Server (NTRS)

Gokoglu, Suleyman A.

1992-01-01

The formalism for the accurate modeling of chemical vapor deposition (CVD) processes has matured based on the well established principles of transport phenomena and chemical kinetics in the gas phase and on surfaces. The utility and limitations of such models are discussed in practical applications for high temperature structural materials. Attention is drawn to the complexities and uncertainties in chemical kinetics. Traditional approaches based on only equilibrium thermochemistry and/or transport phenomena are defended as useful tools, within their validity, for engineering purposes. The role of modeling is discussed within the context of establishing the link between CVD process parameters and material microstructures/properties. It is argued that CVD modeling is an essential part of designing CVD equipment and controlling/optimizing CVD processes for the production and/or coating of high performance structural materials.

40 CFR 63.1420 - Applicability and designation of affected sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... limited to, records of chemicals purchased for the process, analyses of process stream composition, engineering calculations, or process knowledge. (ii) When requested by the Administrator, demonstrate that the... applies. (3) Reactions or processing that occur after the epoxide polymerization is complete and after all...

TREATING CHLORINATED WASTES WITH THE KPEG PROCESS

EPA Science Inventory

The two reports summarized here describe development of the alkali metal (polyethylene gylycolate (APEG) chemical technology to dechlorinate hazardous hydrocarbons in soils and its application at four demonstration sites: field-scale application to contaminated soils on the isla...

Nanomaterial Based Sensors for NASA Missions

NASA Technical Reports Server (NTRS)

Koehne, Jessica E.

2016-01-01

Nanomaterials such as carbon nanotubes (CNTs), carbon nanofibers (CNFs), graphene and metal nanowires have shown interesting electronic properties and therefore have been pursued for a variety of space applications requiring ultrasensitive and light-weight sensor and electronic devices. We have been pursuing development of chemical and biosensors using carbon nanotubes and carbon nanofibers for the last several years and this talk will present the benefits of nanomaterials these applications. More recently, printing approaches to manufacturing these devices have been explored as a strategy that is compatible to a microgravity environment. Nanomaterials are either grown in house or purchased and processed as electrical inks. Chemical modification or coatings are added to the nanomaterials to tailor the nanomaterial to the exact application. The development of printed chemical sensors and biosensors will be discussed for applications ranging from crew life support to exploration missions.

Surface CHEMKIN (Version 4. 0): A Fortran package for analyzing heterogeneous chemical kinetics at a solid-surface---gas-phase interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coltrin, M.E.; Kee, R.J.; Rupley, F.M.

1991-07-01

Heterogeneous reaction at the interface between a solid surface and adjacent gas is central to many chemical processes. Our purpose for developing the software package SURFACE CHEMKIN was motivated by our need to understand the complex surface chemistry in chemical vapor deposition systems involving silicon, silicon nitride, and gallium arsenide. However, we have developed the approach and implemented the software in a general setting. Thus, we expect it will find use in such diverse applications as chemical vapor deposition, chemical etching, combustion of solids, and catalytic processes, and for a wide range of chemical systems. We believe that it providesmore » a powerful capability to help model, understand, and optimize important industrial and research chemical processes. The SURFACE CHEMKIN software is designed to work in conjunction with the CHEMKIN-2 software, which handles the chemical kinetics in the gas phase. It may also be used in conjunction with the Transport Property Package, which provides information about molecular diffusion. Thus, these three packages provide a foundation on which a user can build applications software to analyze gas-phase and heterogeneous chemistry in flowing systems. These packages should not be considered programs'' in the ordinary sense. That is, they are not designed to accept input, solve a particular problem, and report the answer. Instead, they are software tools intended to help a user work efficiently with large systems of chemical reactions and develop Fortran representations of systems of equations that define a particular problem. It is up the user to solve the problem and interpret the answer. 11 refs., 15 figs., 5 tabs.« less

Chemical preparation of graphene-based nanomaterials and their applications in chemical and biological sensors.

PubMed

Jiang, Hongji

2011-09-05

Graphene is a flat monolayer of carbon atoms packed tightly into a 2D honeycomb lattice that shows many intriguing properties meeting the key requirements for the implementation of highly excellent sensors, and all kinds of proof-of-concept sensors have been devised. To realize the potential sensor applications, the key is to synthesize graphene in a controlled way to achieve enhanced solution-processing capabilities, and at the same time to maintain or even improve the intrinsic properties of graphene. Several production techniques for graphene-based nanomaterials have been developed, ranging from the mechanical cleavage and chemical exfoliation of high-quality graphene to direct growth onto different substrates and the chemical routes using graphite oxide as a precusor to the newly developed bottom-up approach at the molecular level. The current review critically explores the recent progress on the chemical preparation of graphene-based nanomaterials and their applications in sensors. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhancing the functional properties of thermophilic enzymes by chemical modification and immobilization.

PubMed

Cowan, Don A; Fernandez-Lafuente, Roberto

2011-09-10

The immobilization of proteins (mostly typically enzymes) onto solid supports is mature technology and has been used successfully to enhance biocatalytic processes in a wide range of industrial applications. However, continued developments in immobilization technology have led to more sophisticated and specialized applications of the process. A combination of targeted chemistries, for both the support and the protein, sometimes in combination with additional chemical and/or genetic engineering, has led to the development of methods for the modification of protein functional properties, for enhancing protein stability and for the recovery of specific proteins from complex mixtures. In particular, the development of effective methods for immobilizing large multi-subunit proteins with multiple covalent linkages (multi-point immobilization) has been effective in stabilizing proteins where subunit dissociation is the initial step in enzyme inactivation. In some instances, multiple benefits are achievable in a single process. Here we comprehensively review the literature pertaining to immobilization and chemical modification of different enzyme classes from thermophiles, with emphasis on the chemistries involved and their implications for modification of the enzyme functional properties. We also highlight the potential for synergies in the combined use of immobilization and other chemical modifications. Copyright © 2011 Elsevier Inc. All rights reserved.

10 CFR 725.15 - Requirements for approval of applications.

Code of Federal Regulations, 2010 CFR

2010-01-01

... and/or operation of production or manufacturing facilities and offers reasonable assurance of adequacy... Production will be approved only if the application demonstrates also that the applicant: (i) Is directly engaged in a substantial effort to develop, design, build or operate a chemical processing plant or other...

ENVIRONMENTAL TECHNOLOGY INITIATIVE: CHEMICAL-FREE CLEANING OF SEMICONDUCTORS BY THE RADIANCE PROCESS

EPA Science Inventory

The Radiance Process is a patented dry process for removing contaminants from surfaces. It uses light, usually from a pulsed laser and a gas inert to the surface, to entrain released contaminants. The focus of this effort is to assess the applicability of the Radiance Process t...

Industrial applications using BASF eco-efficiency analysis: perspectives on green engineering principles.

PubMed

Shonnard, David R; Kicherer, Andreas; Saling, Peter

2003-12-01

Life without chemicals would be inconceivable, but the potential risks and impacts to the environment associated with chemical production and chemical products are viewed critically. Eco-efficiency analysis considers the economic and life cycle environmental effects of a product or process, giving these equal weighting. The major elements of the environmental assessment include primary energy use, raw materials utilization, emissions to all media, toxicity, safety risk, and land use. The relevance of each environmental category and also for the economic versus the environmental impacts is evaluated using national emissions and economic data. The eco-efficiency analysis method of BASF is briefly presented, and results from three applications to chemical processes and products are summarized. Through these applications, the eco-efficiency analyses mostly confirm the 12 Principles listed in Anastas and Zimmerman (Environ. Sci. Technol. 2003, 37(5), 94A), with the exception that, in one application, production systems based on bio-based feedstocks were not the most eco-efficient as compared to those based on fossil resources. Over 180 eco-efficiency analyses have been conducted at BASF, and their results have been used to support strategic decision-making, marketing, research and development, and communication with external parties. Eco-efficiency analysis, as one important strategy and success factor in sustainable development, will continue to be a very strong operational tool at BASF.

Synthetic Talc and Talc-Like Structures: Preparation, Features and Applications.

PubMed

Claverie, Marie; Dumas, Angela; Carême, Christel; Poirier, Mathilde; Le Roux, Christophe; Micoud, Pierre; Martin, François; Aymonier, Cyril

2018-01-12

This contribution gives a comprehensive review about the progress in preparation methods, properties and applications of the different synthetic talc types: i) crystalline nanotalc synthesized by hydrothermal treatment; ii) amorphous and/or short-range order nanotalc obtained by precipitation, and iii) organic-inorganic hybrid talc-like structures obtained through a sol-gel process or a chemical grafting. Several advantages of nanotalc such as high chemical purity, high surface area, tunable submicronic size, high thermal stability, and hydrophilic character (leading to be the first fluid mineral) are emphasized. Synthetic nanotalc applications are also considered including its use as nanofiller in composite materials, as absorbers of organic compounds, as anticorrosion coatings and as agents for cosmetic applications. Regarding their high industrial application potential, intensive research has been carried out to better understand their behavior and develop processes to produce them. To facilitate further research and development, scientific and technical challenges are discussed in this Review article. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Commercialization of New Beam Applications

NASA Astrophysics Data System (ADS)

McKeown, Joseph

1996-05-01

The commercialization of electron processing applications is driven by demonstrated technical advantages over current practice. Mature and reliable accelerator technology has permitted more consistent product quality and the development of new processes. However, the barriers to commercial adoption are often not amenable to solution within the laboratory alone. Aspects of the base accelerator technology, plant engineering, production, project management, financing, regulatory control, product throughput and plant operational efficiency all contribute to the business risk. Experiences in building three 10 MeV, 50 kW, IMPELA electron accelerators at approximately 8 M each and achieving cumulative operational availability greater than 98% in commercial environments have identified key parameters defining those aspects. The allowed ranges of these parameters to generate the 1.5 M annual revenue that is typically necessary to support outlays of this scale are presented. Such data have been used in proposals to displace expensive chemicals in the viscose industry, sterilize sewage sludge, detoxify chemically contaminated soils and build radiation service centers for a diversity of applications. The proposals face stiff competition from traditional chemical methods. Quantitative technical and business details of these activities are provided and an attempt is made to establish realistic expectations for the exploitation of electron beam technologies in emerging applications.

Process for derivatizing carbon nanotubes with diazonium species and compositions thereof

NASA Technical Reports Server (NTRS)

Bahr, Jeffrey L. (Inventor); Tour, James M. (Inventor); Yang, Jiping (Inventor)

2011-01-01

Methods for the chemical modification of carbon nanotubes involve the derivatization of multi- and single-wall carbon nanotubes, including small diameter (ca. 0.7 nm) single-wall carbon nanotubes, with diazonium species. The method allows the chemical attachment of a variety of organic compounds to the side and ends of carbon nanotubes. These chemically modified nanotubes have applications in polymer composite materials, molecular electronic applications, and sensor devices. The methods of derivatization include electrochemical induced reactions, thermally induced reactions, and photochemically induced reactions. Moreover, when modified with suitable chemical groups, the derivatized nanotubes are chemically compatible with a polymer matrix, allowing transfer of the properties of the nanotubes (such as, mechanical strength or electrical conductivity) to the properties of the composite material as a whole. Furthermore, when modified with suitable chemical groups, the groups can be polymerized to form a polymer that includes carbon nanotubes.

Reduction of uranium hexafluoride to tetrafluoride by using the hydrogen atoms

NASA Astrophysics Data System (ADS)

Aleksandrov, B. P.; Gordon, E. B.; Ivanov, A. V.; Kotov, A. A.; Smirnov, V. E.

2016-09-01

We consider the reduction of UF6 to UF4 by chemical reaction with hydrogen atoms originated in the powerful chemical generator. The principal design of such a chemical convertor is described. The results of the mathematical modeling of the thermodynamics and kinetics of the UF6 to UF4 reduction process are analyzed. The few options for the hydrogen atom generator design are proposed. A layout of the experimental setup with the chemical reactor is presented. The high efficiency together with the ability of the process scaling without loss of its efficiency makes this approach to the uranium hexafluoride depletion into tetrafluoride promising for its application in the industry.

Pulsed excimer laser processing for cost-effective solar cells

NASA Technical Reports Server (NTRS)

Wong, David C.

1985-01-01

The application of excimer laser in the fabrication of photovoltaic devices was investigated extensively. Processes included junction formation, laser assisted chemical vapor deposition metallization, and laser assisted chemical vapor deposition surface passivation. Results demonstrated that implementation of junction formation by laser annealing in production is feasible because of excellent control in junction depth and quality. Both metallization and surface passivation, however, were found impractical to be considered for manufacturing at this stage.

Magnetically levitated nano-robots: an application to visualization of nerve cells injuries.

PubMed

Lou, Mingji; Jonckheere, Edmond

2007-01-01

This paper proposes a swarm of magnetically levitated nano-robots with high sensitivity nano-sensors as a mean to detect chemical sources, specifically the chemical signals released by injured nervous cells. In the aftermath of the process, further observation by these nano-robots would be used to monitor the healing process and assess the amount of regeneration, if any, or even the repair, of the injured nervous cells.

Laboratory Studies of Homogeneous and Heterogeneous Chemical Processes of Importance in the Upper Atmosphere

NASA Technical Reports Server (NTRS)

Molina, Mario J.

2003-01-01

The objective of this study was to conduct measurements of chemical kinetics parameters for reactions of importance in the stratosphere and upper troposphere, and to study the interaction of trace gases with ice surfaces in order to elucidate the mechanism of heterogeneous chlorine activation processes, using both a theoretical and an experimental approach. The measurements were carried out under temperature and pressure conditions covering those applicable to the stratosphere and upper troposphere. The main experimental technique employed was turbulent flow-chemical ionization mass spectrometry, which is particularly well suited for investigations of radical-radical reactions.

Numerical Validation of Chemical Compositional Model for Wettability Alteration Processes

NASA Astrophysics Data System (ADS)

Bekbauov, Bakhbergen; Berdyshev, Abdumauvlen; Baishemirov, Zharasbek; Bau, Domenico

2017-12-01

Chemical compositional simulation of enhanced oil recovery and surfactant enhanced aquifer remediation processes is a complex task that involves solving dozens of equations for all grid blocks representing a reservoir. In the present work, we perform a numerical validation of the newly developed mathematical formulation which satisfies the conservation laws of mass and energy and allows applying a sequential solution approach to solve the governing equations separately and implicitly. Through its application to the numerical experiment using a wettability alteration model and comparisons with existing chemical compositional model's numerical results, the new model has proven to be practical, reliable and stable.

Chemical analysis of extracting transition metal oxides from polymetallic ore by sulphate process

NASA Astrophysics Data System (ADS)

Enkh-Uyanga, Otgon-Uul; Munkhtsetseg, Baatar; Urangoo, Urtnasan; Tserendulam, Enkhtur; Agiimaa, Davaadorj

2017-06-01

In this research work we attempt to improve the purity of polymetallic ores in Mongolia whilst developing practical applications of its refinement processes and this paper presents the results of chemical research of extracting transition metal titanium oxides, ferrous oxide and rare earth oxides from polymetallic ore. Thereby, chemical and mineral analysis of polymetallic ore is carried out basis of responses to the support process at various degrees of water whereas transition metal sulphates solubility differ. As a result of sulphate and resulphurization process we have extracted anatase with 62.5 percent titanium dioxide and brookite mineral with 89.6 percent of titanium dioxide as well as mineral with 83.8 percent of ferrous oxide hematite and rare earth oxides with 57.6 percent of cerium oxide. These oxides are identified under various conditions in the thermal processing. The morphology structure and chemical content compound of the mineral has been verified as a result of the XRF, XRD, SEM-EDX analysis.

NORTH AMERICA'S SOUND MANAGEMENT OF CHEMICALS INITIATIVE: APPLICATION OF SELECTION CRITERIA TO DIOXINS/FURANS, HEXACHLOROBENZENE, AND HEXACHLOROCYCLOHEXANES

EPA Science Inventory

In October 1997, the North American Commission for Environmental Cooperation finalized its process for identifying candidate substances for regional action under the Sound Management of Chemicals Initiative. Regional action plans will be prepared if substantive risk to human he...

BioMOL: a computer-assisted biological modeling tool for complex chemical mixtures and biological processes at the molecular level.

PubMed Central

Klein, Michael T; Hou, Gang; Quann, Richard J; Wei, Wei; Liao, Kai H; Yang, Raymond S H; Campain, Julie A; Mazurek, Monica A; Broadbelt, Linda J

2002-01-01

A chemical engineering approach for the rigorous construction, solution, and optimization of detailed kinetic models for biological processes is described. This modeling capability addresses the required technical components of detailed kinetic modeling, namely, the modeling of reactant structure and composition, the building of the reaction network, the organization of model parameters, the solution of the kinetic model, and the optimization of the model. Even though this modeling approach has enjoyed successful application in the petroleum industry, its application to biomedical research has just begun. We propose to expand the horizons on classic pharmacokinetics and physiologically based pharmacokinetics (PBPK), where human or animal bodies were often described by a few compartments, by integrating PBPK with reaction network modeling described in this article. If one draws a parallel between an oil refinery, where the application of this modeling approach has been very successful, and a human body, the individual processing units in the oil refinery may be considered equivalent to the vital organs of the human body. Even though the cell or organ may be much more complicated, the complex biochemical reaction networks in each organ may be similarly modeled and linked in much the same way as the modeling of the entire oil refinery through linkage of the individual processing units. The integrated chemical engineering software package described in this article, BioMOL, denotes the biological application of molecular-oriented lumping. BioMOL can build a detailed model in 1-1,000 CPU sec using standard desktop hardware. The models solve and optimize using standard and widely available hardware and software and can be presented in the context of a user-friendly interface. We believe this is an engineering tool with great promise in its application to complex biological reaction networks. PMID:12634134

Observation of negative differential resistance in mesoscopic graphene oxide devices.

PubMed

Rathi, Servin; Lee, Inyeal; Kang, Moonshik; Lim, Dongsuk; Lee, Yoontae; Yamacli, Serhan; Joh, Han-Ik; Kim, Seongsu; Kim, Sang-Woo; Yun, Sun Jin; Choi, Sukwon; Kim, Gil-Ho

2018-05-08

The fractions of various functional groups in graphene oxide (GO) are directly related to its electrical and chemical properties and can be controlled by various reduction methods like thermal, chemical and optical. However, a method with sufficient controllability to regulate the reduction process has been missing. In this work, a hybrid method of thermal and joule heating processes is demonstrated where a progressive control of the ratio of various functional groups can be achieved in a localized area. With this precise control of carbon-oxygen ratio, negative differential resistance (NDR) is observed in the current-voltage characteristics of a two-terminal device in the ambient environment due to charge-activated electrochemical reactions at the GO surface. This experimental observation correlates with the optical and chemical characterizations. This NDR behavior offers new opportunities for the fabrication and application of such novel electronic devices in a wide range of devices applications including switches and oscillators.

Optical fiber sensors: Systems and applications. Volume 2

NASA Astrophysics Data System (ADS)

Culshaw, Brian; Dakin, John

State-of-the-art fiber-optic (FO) sensors and their applications are described in chapters contributed by leading experts. Consideration is given to interferometers, FO gyros, intensity- and wavelength-based sensors and optical actuators, Si in FO sensors, point-sensor multiplexing principles, and distributed FO sensor systems. Also examined are chemical, biochemical, and medical sensors; physical and chemical sensors for process control; FO-sensor applications in the marine and aerospace industries; FO-sensor monitoring systems for security and safety, structural integrity, NDE, and the electric-power industry; and the market situation for FO-sensor technology. Diagrams, drawings, graphs, and photographs are provided.

[Near infrared spectroscopy based process trajectory technology and its application in monitoring and controlling of traditional Chinese medicine manufacturing process].

PubMed

Li, Wen-Long; Qu, Hai-Bin

2016-10-01

In this paper, the principle of NIRS (near infrared spectroscopy)-based process trajectory technology was introduced.The main steps of the technique include:① in-line collection of the processes spectra of different technics; ② unfolding of the 3-D process spectra;③ determination of the process trajectories and their normal limits;④ monitoring of the new batches with the established MSPC (multivariate statistical process control) models.Applications of the technology in the chemical and biological medicines were reviewed briefly. By a comprehensive introduction of our feasibility research on the monitoring of traditional Chinese medicine technical process using NIRS-based multivariate process trajectories, several important problems of the practical applications which need urgent solutions are proposed, and also the application prospect of the NIRS-based process trajectory technology is fully discussed and put forward in the end. Copyright© by the Chinese Pharmaceutical Association.

Manufacturing of polylactic acid nanocomposite 3D printer filaments for smart textile applications

NASA Astrophysics Data System (ADS)

Hashemi Sanatgar, R.; Cayla, A.; Campagne, C.; Nierstrasz, V.

2017-10-01

In this paper, manufacturing of polylactic acid nanocomposite 3D printer filaments was considered for smart textile applications. 3D printing process was applied as a novel process for deposition of nanocomposites on PLA fabrics to introduce more flexible, resourceefficient and cost effective textile functionalization processes than conventional printing process like screen and inkjet printing. The aim is to develop an integrated or tailored production process for smart and functional textiles which avoid unnecessary use of water, energy, chemicals and minimize the waste to improve ecological footprint and productivity.

40 CFR 68.90 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Emergency Response § 68.90 Applicability. (a) Except as provided in... processes shall comply with the requirements of § 68.95. (b) The owner or operator of stationary source...

The application and use of chemical space mapping to interpret crystallization screening results

PubMed Central

Snell, Edward H.; Nagel, Ray M.; Wojtaszcyk, Ann; O’Neill, Hugh; Wolfley, Jennifer L.; Luft, Joseph R.

2008-01-01

Macromolecular crystallization screening is an empirical process. It often begins by setting up experiments with a number of chemically diverse cocktails designed to sample chemical space known to promote crystallization. Where a potential crystal is seen a refined screen is set up, optimizing around that condition. By using an incomplete factorial sampling of chemical space to formulate the cocktails and presenting the results graphically, it is possible to readily identify trends relevant to crystallization, coarsely sample the phase diagram and help guide the optimization process. In this paper, chemical space mapping is applied to both single macromolecules and to a diverse set of macromolecules in order to illustrate how visual information is more readily understood and assimilated than the same information presented textually. PMID:19018100

The application and use of chemical space mapping to interpret crystallization screening results.

PubMed

Snell, Edward H; Nagel, Ray M; Wojtaszcyk, Ann; O'Neill, Hugh; Wolfley, Jennifer L; Luft, Joseph R

2008-12-01

Macromolecular crystallization screening is an empirical process. It often begins by setting up experiments with a number of chemically diverse cocktails designed to sample chemical space known to promote crystallization. Where a potential crystal is seen a refined screen is set up, optimizing around that condition. By using an incomplete factorial sampling of chemical space to formulate the cocktails and presenting the results graphically, it is possible to readily identify trends relevant to crystallization, coarsely sample the phase diagram and help guide the optimization process. In this paper, chemical space mapping is applied to both single macromolecules and to a diverse set of macromolecules in order to illustrate how visual information is more readily understood and assimilated than the same information presented textually.

Chemistry Division. Quarterly progress report for period ending June 30, 1949

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1949-09-14

Progress reports are presented for the following tasks: (1) nuclear and chemical properties of heavy elements (solution chemistry, phase rule studies); (2) nuclear and chemical properties of elements in the fission product region; (3) general nuclear chemistry; (4) radio-organic chemistry; (5) chemistry of separations processes; (6) physical chemistry and chemical physics; (7) radiation chemistry; (8) physical measurements and instrumentation; and (9) analytical chemistry. The program of the chemistry division is divided into two efforts of approximately equal weight with respect to number of personnel, chemical research, and analytical service for the Laboratory. The various research problems fall into the followingmore » classifications: (1) chemical separation processes for isolation and recovery of fissionable material, production of radioisotopes, and military applications; (2) reactor development; and (3) fundamental research.« less

Second Aerospace Environmental Technology Conference

NASA Technical Reports Server (NTRS)

Whitaker, A. F. (Editor); Clark-Ingram, M. (Editor)

1997-01-01

The mandated elimination of CFC'S, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application, verification, compliant coatings including corrosion protection system and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards.

Second Aerospace Environmental Technology Conference

NASA Technical Reports Server (NTRS)

Whitaker, A. F.; Clark-Ingram, M.; Hessler, S. L.

1997-01-01

The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards.

Solvent replacement for green processing.

PubMed Central

Sherman, J; Chin, B; Huibers, P D; Garcia-Valls, R; Hatton, T A

1998-01-01

The implementation of the Montreal Protocol, the Clean Air Act, and the Pollution Prevention Act of 1990 has resulted in increased awareness of organic solvent use in chemical processing. The advances made in the search to find "green" replacements for traditional solvents are reviewed, with reference to solvent alternatives for cleaning, coatings, and chemical reaction and separation processes. The development of solvent databases and computational methods that aid in the selection and/or design of feasible or optimal environmentally benign solvent alternatives for specific applications is also discussed. Images Figure 2 Figure 3 PMID:9539018

Coupling Computer-Aided Process Simulation and ...

EPA Pesticide Factsheets

A methodology is described for developing a gate-to-gate life cycle inventory (LCI) of a chemical manufacturing process to support the application of life cycle assessment in the design and regulation of sustainable chemicals. The inventories were derived by first applying process design and simulation of develop a process flow diagram describing the energy and basic material flows of the system. Additional techniques developed by the U.S. Environmental Protection Agency for estimating uncontrolled emissions from chemical processing equipment were then applied to obtain a detailed emission profile for the process. Finally, land use for the process was estimated using a simple sizing model. The methodology was applied to a case study of acetic acid production based on the Cativa tm process. The results reveal improvements in the qualitative LCI for acetic acid production compared to commonly used databases and top-down methodologies. The modeling techniques improve the quantitative LCI results for inputs and uncontrolled emissions. With provisions for applying appropriate emission controls, the proposed method can provide an estimate of the LCI that can be used for subsequent life cycle assessments. As part of its mission, the Agency is tasked with overseeing the use of chemicals in commerce. This can include consideration of a chemical's potential impact on health and safety, resource conservation, clean air and climate change, clean water, and sustainable

Elucidating rhizosphere processes by mass spectrometry - A review.

PubMed

Rugova, Ariana; Puschenreiter, Markus; Koellensperger, Gunda; Hann, Stephan

2017-03-01

The presented review discusses state-of-the-art mass spectrometric methods, which have been developed and applied for investigation of chemical processes in the soil-root interface, the so-called rhizosphere. Rhizosphere soil's physical and chemical characteristics are to a great extent influenced by a complex mixture of compounds released from plant roots, i.e. root exudates, which have a high impact on nutrient and trace element dynamics in the soil-root interface as well as on microbial activities or soil physico-chemical characteristics. Chemical characterization as well as accurate quantification of the compounds present in the rhizosphere is a major prerequisite for a better understanding of rhizosphere processes and requires the development and application of advanced sampling procedures in combination with highly selective and sensitive analytical techniques. During the last years, targeted and non-targeted mass spectrometry-based methods have emerged and their combination with specific separation methods for various elements and compounds of a wide polarity range have been successfully applied in several studies. With this review we critically discuss the work that has been conducted within the last decade in the context of rhizosphere research and elemental or molecular mass spectrometry emphasizing different separation techniques as GC, LC and CE. Moreover, selected applications such as metal detoxification or nutrient acquisition will be discussed regarding the mass spectrometric techniques applied in studies of root exudates in plant-bacteria interactions. Additionally, a more recent isotope probing technique as novel mass spectrometry based application is highlighted. Copyright © 2017 Elsevier B.V. All rights reserved.

Immobilized biocatalytic process development and potential application in membrane separation: a review.

PubMed

Chakraborty, Sudip; Rusli, Handajaya; Nath, Arijit; Sikder, Jaya; Bhattacharjee, Chiranjib; Curcio, Stefano; Drioli, Enrico

2016-01-01

Biocatalytic membrane reactors have been widely used in different industries including food, fine chemicals, biological, biomedical, pharmaceuticals, environmental treatment and so on. This article gives an overview of the different immobilized enzymatic processes and their advantages over the conventional chemical catalysts. The application of a membrane bioreactor (MBR) reduces the energy consumption, and system size, in line with process intensification. The performances of MBR are considerably influenced by substrate concentration, immobilized matrix material, types of immobilization and the type of reactor. Advantages of a membrane associated bioreactor over a free-enzyme biochemical reaction, and a packed bed reactor are, large surface area of immobilization matrix, reuse of enzymes, better product recovery along with heterogeneous reactions, and continuous operation of the reactor. The present research work highlights immobilization techniques, reactor setup, enzyme stability under immobilized conditions, the hydrodynamics of MBR, and its application, particularly, in the field of sugar, starch, drinks, milk, pharmaceutical industries and energy generation.

Physical/chemical closed-loop water-recycling for long-duration missions

NASA Technical Reports Server (NTRS)

Herrmann, Cal C.; Wydeven, Ted

1990-01-01

Water needs, water sources, and means for recycling water are examined in terms appropriate to the water quality requirements of a small crew and spacecraft intended for long duration exploration missions. Inorganic, organic, and biological hazards are estimated for waste water sources. Sensitivities to these hazards for human uses are estimated. The water recycling processes considered are humidity condensation, carbon dioxide reduction, waste oxidation, distillation, reverse osmosis, pervaporation, electrodialysis, ion exchange, carbon sorption, and electrochemical oxidation. Limitations and applications of these processes are evaluated in terms of water quality objectives. Computerized simulation of some of these chemical processes is examined. Recommendations are made for development of new water recycling technology and improvement of existing technology for near term application to life support systems for humans in space. The technological developments are equally applicable to water needs on earth, in regions where extensive water ecycling is needed or where advanced water treatment is essential to meet EPA health standards.

76 FR 41365 - Impact of Reducing the Mixture Concentration Threshold for Commercial Schedule 2A Chemical...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-13

...The Bureau of Industry and Security (BIS) is seeking public comments on the impact of amending the Chemical Weapons Convention Regulations (CWCR) to reduce the concentration level below which the CWCR exempt certain mixtures containing a Schedule 2A chemical from the declaration requirements that apply to Schedule 2A chemical production, processing, and consumption under the Chemical Weapons Convention (CWC). To make these declaration requirements consistent with the international agreement adopted by the Organization for the Prohibition of Chemical Weapons (OPCW), BIS is considering amending the CWCR to replace the current low concentration exemption (a concentration of ``less than 30%'' by volume or weight) with a two-tiered low concentration exemption that is based, in part, on whether the total amount of a Schedule 2A chemical produced, processed, or consumed at one or more plants on a plant site during a calendar year is less than the applicable verification threshold in the CWCR. Under this two- tiered approach, the declaration and reporting requirements in the CWCR would not apply to a chemical mixture containing a Schedule 2A chemical if: The concentration of the Schedule 2A chemical in the mixture is ``1% or less,'' or the concentration of the Schedule 2A chemical in the mixture is ``more than 1%, but less than or equal to 10%,'' and the annual amount of the Schedule 2A chemical produced, processed, or consumed is less than the relevant verification threshold. Legislative amendment of the Chemical Weapons Convention Implementation Act (CWCIA) is required in order to implement this proposed amendment to the CWCR. In addition, at U.S. national discretion, BIS is considering amending the CWCR to require declarations/reports for exports and imports of any mixtures that contain ``more than 10%'' of a Schedule 2A chemical by volume or weight (whichever method yields the lesser percentage), if the total quantity of the Schedule 2A chemical exported or imported during a calendar year exceeds the applicable CWCR declaration threshold.

Development and application of bond cleavage reactions in bioorthogonal chemistry.

PubMed

Li, Jie; Chen, Peng R

2016-03-01

Bioorthogonal chemical reactions are a thriving area of chemical research in recent years as an unprecedented technique to dissect native biological processes through chemistry-enabled strategies. However, current concepts of bioorthogonal chemistry have largely centered on 'bond formation' reactions between two mutually reactive bioorthogonal handles. Recently, in a reverse strategy, a collection of 'bond cleavage' reactions has emerged with excellent biocompatibility. These reactions have expanded our bioorthogonal chemistry repertoire, enabling an array of exciting new biological applications that range from the chemically controlled spatial and temporal activation of intracellular proteins and small-molecule drugs to the direct manipulation of intact cells under physiological conditions. Here we highlight the development and applications of these bioorthogonal cleavage reactions. Furthermore, we lay out challenges and propose future directions along this appealing avenue of research.

Sensors, Volume 3, Part II, Chemical and Biochemical Sensors Part II

NASA Astrophysics Data System (ADS)

Göpel, Wolfgang; Jones, T. A.; Kleitz, Michel; Lundström, Ingemar; Seiyama, Tetsuro

1997-06-01

'Sensors' is the first self-contained series to deal with the whole area of sensors. It describes general aspects, technical and physical fundamentals, construction, function, applications and developments of the various types of sensors. This is the second of two volumes focusing on chemical and biochemical sensors. It includes a detailed description of biosensors which often make use of transducer properties of the basic sensors and usually have additional biological components. This volume provides a unique overview of the applications, the possibilities and limitations of sensors in comparison with conventional instrumentation in analytical chemistry. Specific facettes of applications are presented by specialists from different fields including environmental, biotechnological, medical, or chemical process control. This book is an indispensable reference work for both specialits and newcomers, researchers and developers.

40 CFR 161.162 - Description of production process.

Code of Federal Regulations, 2010 CFR

2010-07-01

... applicant must submit information on the production (reaction) processes used to produce the active... continuous (a single reaction process from starting materials to active ingredient), but is accomplished in...) A flow chart of the chemical equations of each intended reaction occurring at each step of the...

40 CFR 161.162 - Description of production process.

Code of Federal Regulations, 2011 CFR

2011-07-01

... applicant must submit information on the production (reaction) processes used to produce the active... continuous (a single reaction process from starting materials to active ingredient), but is accomplished in...) A flow chart of the chemical equations of each intended reaction occurring at each step of the...

Polymer surface treatment with particle beams

DOEpatents

Stinnett, Regan W.; VanDevender, J. Pace

1999-01-01

A polymer surface and near surface treatment process produced by irradiation with high energy particle beams. The process is preferably implemented with pulsed ion beams. The process alters the chemical and mechanical properties of the polymer surface in a manner useful for a wide range of commercial applications.

Application and further development of diffusion based 2D chemical imaging techniques in the rhizosphere

NASA Astrophysics Data System (ADS)

Hoefer, Christoph; Santner, Jakob; Borisov, Sergey; Kreuzeder, Andreas; Wenzel, Walter; Puschenreiter, Markus

2015-04-01

Two dimensional chemical imaging of root processes refers to novel in situ methods to investigate and map solutes at a high spatial resolution (sub-mm). The visualization of these solutes reveals new insights in soil biogeochemistry and root processes. We derive chemical images by using data from DGT-LA-ICP-MS (Diffusive Gradients in Thin Films and Laser Ablation Inductively Coupled Plasma Mass Spectrometry) and POS (Planar Optode Sensors). Both technologies have shown promising results when applied in aqueous environment but need to be refined and improved for imaging at the soil-plant interface. Co-localized mapping using combined DGT and POS technologies and the development of new gel combinations are in our focus. DGTs are smart and thin (<0.4 mm) hydrogels; containing a binding resin for the targeted analytes (e.g. trace metals, phosphate, sulphide or radionuclides). The measurement principle is passive and diffusion based. The present analytes are diffusing into the gel and are bound by the resin. Thereby, the resin acts as zero sink. After application, DGTs are retrieved, dried, and analysed using LA-ICP-MS. The data is then normalized by an internal standard (e.g. 13C), calibrated using in-house standards and chemical images of the target area are plotted using imaging software. POS are, similar to DGT, thin sensor foils containing a fluorophore coating depending on the target analyte. The measurement principle is based on excitation of the flourophore by a specific wavelength and emission of the fluorophore depending on the presence of the analyte. The emitted signal is captured using optical filters and a DSLR camera. While DGT analysis is destructive, POS measurements can be performed continuously during the application. Both semi-quantitative techniques allow an in situ application to visualize chemical processes directly at the soil-plant interface. Here, we present a summary of results from rhizotron experiments with different plants in metal contaminated and agricultural soils.

Enabling continuous-flow chemistry in microstructured devices for pharmaceutical and fine-chemical production.

PubMed

Kockmann, Norbert; Gottsponer, Michael; Zimmermann, Bertin; Roberge, Dominique M

2008-01-01

Microstructured devices offer unique transport capabilities for rapid mixing, enhanced heat and mass transfer and can handle small amounts of dangerous or unstable materials. The integration of reaction kinetics into fluid dynamics and transport phenomena is essential for successful application from process design in laboratory to chemical production. Strategies to implement production campaigns up to tons of pharmaceutical chemicals are discussed, based on Lonza projects.

Modeling the characteristic etch morphologies along specific crystallographic orientations by anisotropic chemical etching

NASA Astrophysics Data System (ADS)

Li, Kun-Dar; Miao, Jin-Ru

2018-02-01

To improve the advanced manufacturing technology for functional materials, a sophisticated control of chemical etching process is highly demanded, especially in the fields of environment and energy related applications. In this study, a phase-field-based model is utilized to investigate the etch morphologies influenced by the crystallographic characters during anisotropic chemical etching. Three types of etching modes are inspected theoretically, including the isotropic, <100> and <111> preferred oriented etchings. Owing to the specific etching behavior along the crystallographic directions, different characteristic surface structures are presented in the simulations, such as the pimple-like, pyramidal hillock and ridge-like morphologies. In addition, the processing parameters affecting the surface morphological formation and evolution are also examined systematically. According to the numerical results, the growth mechanism of surface morphology in a chemical etching is revealed distinctly. While the etching dynamics plays a dominant role on the surface formation, the characteristic surface morphologies corresponding to the preferred etching direction become more apparent. As the atomic diffusion turned into a determinative factor, a smoothened surface would appear, even under the anisotropic etching conditions. These simulation results provide fundamental information to enhance the development and application of anisotropic chemical etching techniques.

Industrial applications of nanoparticles.

PubMed

Stark, W J; Stoessel, P R; Wohlleben, W; Hafner, A

2015-08-21

Research efforts in the past two decades have resulted in thousands of potential application areas for nanoparticles - which materials have become industrially relevant? Where are sustainable applications of nanoparticles replacing traditional processing and materials? This tutorial review starts with a brief analysis on what makes nanoparticles attractive to chemical product design. The article highlights established industrial applications of nanoparticles and then moves to rapidly emerging applications in the chemical industry and discusses future research directions. Contributions from large companies, academia and high-tech start-ups are used to elucidate where academic nanoparticle research has revolutionized industry practice. A nanomaterial-focused analysis discusses new trends, such as particles with an identity, and the influence of modern instrument advances in the development of novel industrial products.

From single-substance evaluation to ecological process concept: the dilemma of processing gold with cyanide.

PubMed

Korte, F; Coulston, F

1995-10-01

In the past decades, limit concentration values for environmentally dangerous synthetic and natural chemical substances have been established in industrialized countries. Depending on the range of application, state of aggregation, propagation velocity, specific action on living organisms, long- or short-time effect, etc., different terms are used to specify these limit concentrations (acceptable daily intakes, TLV, LD50, emission values, water quality standards, etc.). Several parameters (e.g., range of application, ethic and social valuation, environmental factors, scientific knowledge) have led to nationally and internationally varying values depending on the region and time. The accuracy of this system of evaluation cannot necessarily be improved by listing further analytical data, but rather by furnishing sufficiently secured scientific data for a serious discussion, with the public concepts influenced more and more by the mass media. The best-established scientific knowledge has been acquired by the chemical industry. National and international groups demand that ecological-chemical problems in other fields of industry be dealt with as well; this research should, without doubt, be intensified. The example of the mining industry, which must employ chemical methods to isolate small concentrations (ppm), demonstrates the environmental conflict caused by the increasing world population, requiring the adaptation of the process by industry to the modern environmental concept. This is illustrated by the evolution of the gold recovery process.

Engineering Design and Automation in the Applied Engineering Technologies (AET) Group at Los Alamos National Laboratory.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wantuck, P. J.; Hollen, R. M.

2002-01-01

This paper provides an overview of some design and automation-related projects ongoing within the Applied Engineering Technologies (AET) Group at Los Alamos National Laboratory. AET uses a diverse set of technical capabilities to develop and apply processes and technologies to applications for a variety of customers both internal and external to the Laboratory. The Advanced Recovery and Integrated Extraction System (ARIES) represents a new paradigm for the processing of nuclear material from retired weapon systems in an environment that seeks to minimize the radiation dose to workers. To achieve this goal, ARIES relies upon automation-based features to handle and processmore » the nuclear material. Our Chemical Process Development Team specializes in fuzzy logic and intelligent control systems. Neural network technology has been utilized in some advanced control systems developed by team members. Genetic algorithms and neural networks have often been applied for data analysis. Enterprise modeling, or discrete event simulation, as well as chemical process simulation has been employed for chemical process plant design. Fuel cell research and development has historically been an active effort within the AET organization. Under the principal sponsorship of the Department of Energy, the Fuel Cell Team is now focusing on technologies required to produce fuel cell compatible feed gas from reformation of a variety of conventional fuels (e.g., gasoline, natural gas), principally for automotive applications. This effort involves chemical reactor design and analysis, process modeling, catalyst analysis, as well as full scale system characterization and testing. The group's Automation and Robotics team has at its foundation many years of experience delivering automated and robotic systems for nuclear, analytical chemistry, and bioengineering applications. As an integrator of commercial systems and a developer of unique custom-made systems, the team currently supports the automation needs of many Laboratory programs.« less

Effects of chemical, physical, and technological processes on the nature of food allergens.

PubMed

Poms, Roland E; Anklam, Elke

2004-01-01

A review is presented of studies of different processing techniques and their effect on the allergenicity and antigenicity of certain allergenic foods. An overview of investigated technologies is given with regard to their impact on the protein structure and their potential application in the production of hypoallergenic foods. The use of physical processes (such as heating, high pressure, microparticulation, ultrafiltration, and irradiation), chemical processes (such as proteolysis, fermentation, and refining by extraction), and biotechnological approaches, as well as the effects of these processes on individual allergenic foods, are included. Additionally, the implications of food processing for food allergen analysis with respect to food safety assessment and industrial quality control are briefly discussed.

The Application of Nano-TiO2 Photo Semiconductors in Agriculture

NASA Astrophysics Data System (ADS)

Wang, Yan; Sun, Changjiao; Zhao, Xiang; Cui, Bo; Zeng, Zhanghua; Wang, Anqi; Liu, Guoqiang; Cui, Haixin

2016-11-01

Nanometer-sized titanium dioxide (TiO2) is an environmentally friendly optical semiconductor material. It has wide application value in many fields due to its excellent structural, optical, and chemical properties. The photocatalytic process of nano-TiO2 converts light energy into electrical or chemical energy under mild conditions. In recent years, the study and application of nano-TiO2 in the agricultural sector has gradually attracted attention. The nano-TiO2 applications of degrading pesticides, plant germination and growth, crop disease control, water purification, pesticide residue detection, etc. are good prospects. This review describes all of these applications and the research status and development, including the underlying principles, features, comprehensive applications, functional modification, and potential future directions, for TiO2 in agriculture.

Box-Behnken Design of Experiments Investigation of Hydroxyapatite Synthesis for Orthopedic Applications

NASA Astrophysics Data System (ADS)

Kehoe, S.; Stokes, J.

2011-03-01

Physicochemical properties of hydroxyapatite (HAp) synthesized by the chemical precipitation method are heavily dependent on the chosen process parameters. A Box-Behnken three-level experimental design was therefore, chosen to determine the optimum set of process parameters and their effect on various HAp characteristics. These effects were quantified using design of experiments (DoE) to develop mathematical models using the Box-Behnken design, in terms of the chemical precipitation process parameters. Findings from this research show that the HAp possessing optimum powder characteristics for orthopedic application via a thermal spray technique can therefore be prepared using the following chemical precipitation process parameters: reaction temperature 60 °C, ripening time 48 h, and stirring speed 1500 rpm using high reagent concentrations. Ripening time and stirring speed significantly affected the final phase purity for the experimental conditions of the Box-Behnken design. An increase in both the ripening time (36-48 h) and stirring speed (1200-1500 rpm) was found to result in an increase of phase purity from 47(±2)% to 85(±2)%. Crystallinity, crystallite size, lattice parameters, and mean particle size were also optimized within the research to find desired settings to achieve results suitable for FDA regulations.

RMP Guidance for Chemical Distributors - Chapter 1: General Applicability

EPA Pesticide Factsheets

The Risk Management Program rule covers you if you are: the owner/operator of a stationary source, that has more than a threshold quantity, of a regulated substance, in a process. Follow the flowchart, definitions, and Q & A's to determine applicability.

40 CFR 68.10 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS General § 68.10 Applicability. (a) An owner or operator of a stationary source that has more than a threshold quantity of a regulated substance in a process, as determined under...

APOLLO: A computer program for the calculation of chemical equilibrium and reaction kinetics of chemical systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, H.D.

1991-11-01

Several of the technologies being evaluated for the treatment of waste material involve chemical reactions. Our example is the in situ vitrification (ISV) process where electrical energy is used to melt soil and waste into a ``glass like`` material that immobilizes and encapsulates any residual waste. During the ISV process, various chemical reactions may occur that produce significant amounts of products which must be contained and treated. The APOLLO program was developed to assist in predicting the composition of the gases that are formed. Although the development of this program was directed toward ISV applications, it should be applicable tomore » other technologies where chemical reactions are of interest. This document presents the mathematical methodology of the APOLLO computer code. APOLLO is a computer code that calculates the products of both equilibrium and kinetic chemical reactions. The current version, written in FORTRAN, is readily adaptable to existing transport programs designed for the analysis of chemically reacting flow systems. Separate subroutines EQREACT and KIREACT for equilibrium ad kinetic chemistry respectively have been developed. A full detailed description of the numerical techniques used, which include both Lagrange multiplies and a third-order integrating scheme is presented. Sample test problems are presented and the results are in excellent agreement with those reported in the literature.« less

APOLLO: A computer program for the calculation of chemical equilibrium and reaction kinetics of chemical systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nguyen, H.D.

1991-11-01

Several of the technologies being evaluated for the treatment of waste material involve chemical reactions. Our example is the in situ vitrification (ISV) process where electrical energy is used to melt soil and waste into a glass like'' material that immobilizes and encapsulates any residual waste. During the ISV process, various chemical reactions may occur that produce significant amounts of products which must be contained and treated. The APOLLO program was developed to assist in predicting the composition of the gases that are formed. Although the development of this program was directed toward ISV applications, it should be applicable tomore » other technologies where chemical reactions are of interest. This document presents the mathematical methodology of the APOLLO computer code. APOLLO is a computer code that calculates the products of both equilibrium and kinetic chemical reactions. The current version, written in FORTRAN, is readily adaptable to existing transport programs designed for the analysis of chemically reacting flow systems. Separate subroutines EQREACT and KIREACT for equilibrium ad kinetic chemistry respectively have been developed. A full detailed description of the numerical techniques used, which include both Lagrange multiplies and a third-order integrating scheme is presented. Sample test problems are presented and the results are in excellent agreement with those reported in the literature.« less

Industrial applications of enzyme biocatalysis: Current status and future aspects.

PubMed

Choi, Jung-Min; Han, Sang-Soo; Kim, Hak-Sung

2015-11-15

Enzymes are the most proficient catalysts, offering much more competitive processes compared to chemical catalysts. The number of industrial applications for enzymes has exploded in recent years, mainly owing to advances in protein engineering technology and environmental and economic necessities. Herein, we review recent progress in enzyme biocatalysis, and discuss the trends and strategies that are leading to broader industrial enzyme applications. The challenges and opportunities in developing biocatalytic processes are also discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

Implementation of environmentally compliant cleaning and insulation bonding for MNASA

NASA Technical Reports Server (NTRS)

Hutchens, Dale E.; Keen, Jill M.; Smith, Gary M.; Dillard, Terry W.; Deweese, C. Darrell; Lawson, Seth W.

1995-01-01

Historically, many subscale and full-scale rocket motors have employed environmentally and physiologically harmful chemicals during the manufacturing process. This program examines the synergy and interdependency between environmentally acceptable materials for solid rocket motor insulation applications, bonding, corrosion inhibiting, painting, priming, and cleaning, and then implements new materials and processes in subscale motors. Tests have been conducted to eliminate or minimize hazardous chemicals used in the manufacture of modified-NASA materials test motor (MNASA) components and identify alternate materials and/or processes following NASA Operational Environmental Team (NOET) priorities. This presentation describes implementation of high pressure water refurbishment cleaning, aqueous precision cleaning using both Brulin 815 GD and Jettacin, and insulation case bonding using ozone depleting chemical (ODC) compliant primers and adhesives.

Application of chemical, biological and membrane separation processes in textile industry with recourse to zero effluent discharge--a case study.

PubMed

Nandy, T; Dhodapkar, R S; Pophali, G R; Kaul, S N; Devotta, S

2005-09-01

Environmental concerns associated with textile processing had placed the textile sector in a Southern State of India under serious threat of survival. The textile industries were closed under the orders of the Statutory Board for reason of inadequate compliance to environmental discharge norms of the State for the protection of the drinking water source of the State capital. In compliance with the direction of the Board for zero effluent discharge, advanced treatment process have been implemented for recovery of boiler feed quality water with recourse to effluent recycling/reuse. The paper describes to a case study on the adequacy assessment of the full scale effluent treatment plant comprising chemical, biological and filtration processes in a small scale textile industry. In addition, implementation of measures for discernable improvement in the performance of the existing units through effective operation & maintenance, and application of membrane separation processes leading to zero effluent discharge is also highlighted.

Application of polyurethane foam as a sorbent for trace metal pre-concentration — A review

NASA Astrophysics Data System (ADS)

Lemos, V. A.; Santos, M. S.; Santos, E. S.; Santos, M. J. S.; dos Santos, W. N. L.; Souza, A. S.; de Jesus, D. S.; das Virgens, C. F.; Carvalho, M. S.; Oleszczuk, N.; Vale, M. G. R.; Welz, B.; Ferreira, S. L. C.

2007-01-01

The first publication on the use of polyurethane foam (PUF) for sorption processes dates back to 1970, and soon after the material was applied for separation processes. The application of PUF as a sorbent for solid phase extraction of inorganic analytes for separation and pre-concentration purposes is reviewed. The physical and chemical characteristics of PUF (polyether and polyester type) are discussed and an introduction to the characterization of these sorption processes using different types of isotherms is given. Separation and pre-concentration methods using unloaded and loaded PUF in batch and on-line procedures with continuous flow and flow injection systems are presented. Methods for the direct solid sampling analysis of the PUF after pre-concentration are discussed as well as approaches for speciation analysis. Thermodynamic proprieties of some extraction processes are evaluated and the interpretation of determined parameters, such as enthalpy, entropy and Gibbs free energy in light of the physico-chemical processes is explained.

Basin-scale hydrogeologic modeling

NASA Astrophysics Data System (ADS)

Person, Mark; Raffensperger, Jeff P.; Ge, Shemin; Garven, Grant

1996-02-01

Mathematical modeling of coupled groundwater flow, heat transfer, and chemical mass transport at the sedimentary basin scale has been increasingly used by Earth scientists studying a wide range of geologic processes including the formation of excess pore pressures, infiltration-driven metamorphism, heat flow anomalies, nuclear waste isolation, hydrothermal ore genesis, sediment diagenesis, basin tectonics, and petroleum generation and migration. These models have provided important insights into the rates and pathways of groundwater migration through basins, the relative importance of different driving mechanisms for fluid flow, and the nature of coupling between the hydraulic, thermal, chemical, and stress regimes. The mathematical descriptions of basin transport processes, the analytical and numerical solution methods employed, and the application of modeling to sedimentary basins around the world are the subject of this review paper. The special considerations made to represent coupled transport processes at the basin scale are emphasized. Future modeling efforts will probably utilize three-dimensional descriptions of transport processes, incorporate greater information regarding natural geological heterogeneity, further explore coupled processes, and involve greater field applications.

Polymer surface treatment with particle beams

DOEpatents

Stinnett, R.W.; VanDevender, J.P.

1999-05-04

A polymer surface and near surface treatment process produced by irradiation with high energy particle beams is disclosed. The process is preferably implemented with pulsed ion beams. The process alters the chemical and mechanical properties of the polymer surface in a manner useful for a wide range of commercial applications. 16 figs.

A Novel Surface Treatment for Titanium Alloys

NASA Technical Reports Server (NTRS)

Lowther, S. E.; Park, C.; SaintClair, T. L.

2004-01-01

High-speed commercial aircraft require a surface treatment for titanium (Ti) alloy that is both environmentally safe and durable under the conditions of supersonic flight. A number of pretreatment procedures for Ti alloy requiring multi-stages have been developed to produce a stable surface. Among the stages are, degreasing, mechanical abrasion, chemical etching, and electrochemical anodizing. These treatments exhibit significant variations in their long-term stability, and the benefits of each step in these processes still remain unclear. In addition, chromium compounds are often used in many chemical treatments and these materials are detrimental to the environment. Recently, a chromium-free surface treatment for Ti alloy has been reported, though not designed for high temperature applications. In the present study, a simple surface treatment process developed at NASA/LaRC is reported, offering a high performance surface for a variety of applications. This novel surface treatment for Ti alloy is conventionally achieved by forming oxides on the surface with a two-step chemical process without mechanical abrasion. This acid-followed-by-base treatment was designed to be cost effective and relatively safe to use in a commercial application. In addition, it is chromium-free, and has been successfully used with a sol-gel coating to afford a strong adhesive bond after exposure to hot-wet environments. Phenylethynyl containing adhesives were used to evaluate this surface treatment with sol-gel solutions made of novel imide silanes developed at NASA/LaRC. Oxide layers developed by this process were controlled by immersion time and temperature and solution concentration. The morphology and chemical composition of the oxide layers were investigated using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Auger electron spectroscopy (AES). Bond strengths made with this new treatment were evaluated using single lap shear tests.

Control of laser-ablated aluminum surface wettability to superhydrophobic or superhydrophilic through simple heat treatment or water boiling post-processing

NASA Astrophysics Data System (ADS)

Ngo, Chi-Vinh; Chun, Doo-Man

2018-03-01

Recently, controlling the wettability of a metallic surface so that it is either superhydrophobic or superhydrophilic has become important for many applications. However, conventional techniques require long fabrication times or involve toxic chemicals. Herein, through a combination of pulse laser ablation and simple post-processing, the surface of aluminum was controlled to either superhydrophobic or superhydrophilic in a short time of only a few hours. In this study, grid patterns were first fabricated on aluminum using a nanosecond pulsed laser, and then additional post-processing without any chemicals was used. Under heat treatment, the surface became superhydrophobic with a contact angle (CA) greater than 150° and a sliding angle (SA) lower than 10°. Conversely, when immersed in boiling water, the surface became superhydrophilic with a low contact angle. The mechanism for wettability change was also explained. The surfaces, obtained in a short time with environmentally friendly fabrication and without the use of toxic chemicals, could potentially be applied in various industry and manufacturing applications such as self-cleaning, anti-icing, and biomedical devices.

Implementation of an innovative teaching project in a Chemical Process Design course at the University of Cantabria, Spain

NASA Astrophysics Data System (ADS)

Galan, Berta; Muñoz, Iciar; Viguri, Javier R.

2016-09-01

This paper shows the planning, the teaching activities and the evaluation of the learning and teaching process implemented in the Chemical Process Design course at the University of Cantabria, Spain. Educational methods to address the knowledge, skills and attitudes that students who complete the course are expected to acquire are proposed and discussed. Undergraduate and graduate engineers' perceptions of the methodology used are evaluated by means of a questionnaire. Results of the teaching activities and the strengths and weaknesses of the proposed case study are discussed in relation to the course characteristics. The findings of the empirical evaluation shows that the excessive time students had to dedicate to the case study project and dealing with limited information are the most negative aspects obtained, whereas an increase in the students' self-confidence and the practical application of the methodology are the most positive aspects. Finally, improvements are discussed in order to extend the application of the methodology to other courses offered as part of the chemical engineering degree.

Exact results in nonequilibrium statistical mechanics: Formalism and applications in chemical kinetics and single-molecule free energy estimation

NASA Astrophysics Data System (ADS)

Adib, Artur B.

In the last two decades or so, a collection of results in nonequilibrium statistical mechanics that departs from the traditional near-equilibrium framework introduced by Lars Onsager in 1931 has been derived, yielding new fundamental insights into far-from-equilibrium processes in general. Apart from offering a more quantitative statement of the second law of thermodynamics, some of these results---typified by the so-called "Jarzynski equality"---have also offered novel means of estimating equilibrium quantities from nonequilibrium processes, such as free energy differences from single-molecule "pulling" experiments. This thesis contributes to such efforts by offering three novel results in nonequilibrium statistical mechanics: (a) The entropic analog of the Jarzynski equality; (b) A methodology for estimating free energies from "clamp-and-release" nonequilibrium processes; and (c) A directly measurable symmetry relation in chemical kinetics similar to (but more general than) chemical detailed balance. These results share in common the feature of remaining valid outside Onsager's near-equilibrium regime, and bear direct applicability in protein folding kinetics as well as in single-molecule free energy estimation.

Cheminformatics Applications and Physicochemical Property ...

EPA Pesticide Factsheets

The registration of new chemicals under the Toxic Substances Control Act (TSCA) and new pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) requires knowledge of the process science underlying the transport and transformation of organic chemicals in natural ecosystems. The purpose of this presentation is to demonstrate how cheminformatics, using chemical terms language in combination with the output of physicochemical property calculators, can be employed to encode this knowledge and make it available to the appropriate decision makers. The encoded process science is realized through the execution of reaction libraries in simulators such as EPA’s Chemical Transformation Simulator (CTS). In support of the CTS, reaction libraries have, or are currently being developed for a number of transformation processes including hydrolysis, abiotic reduction, photolysis and disinfection by-product formation. Examples of how the process science in the peer-reviewed literature is being encoded will be presented. The purpose of this presentation is to demonstrate how cheminformatics, using chemical terms language in combination with the output of physicochemical property calculators, can be employed to encode this knowledge and make it available to the appropriate decision makers.

Modeling chemical reactions for drug design.

PubMed

Gasteiger, Johann

2007-01-01

Chemical reactions are involved at many stages of the drug design process. This starts with the analysis of biochemical pathways that are controlled by enzymes that might be downregulated in certain diseases. In the lead discovery and lead optimization process compounds have to be synthesized in order to test them for their biological activity. And finally, the metabolism of a drug has to be established. A better understanding of chemical reactions could strongly help in making the drug design process more efficient. We have developed methods for quantifying the concepts an organic chemist is using in rationalizing reaction mechanisms. These methods allow a comprehensive modeling of chemical reactivity and thus are applicable to a wide variety of chemical reactions, from gas phase reactions to biochemical pathways. They are empirical in nature and therefore allow the rapid processing of large sets of structures and reactions. We will show here how methods have been developed for the prediction of acidity values and of the regioselectivity in organic reactions, for designing the synthesis of organic molecules and of combinatorial libraries, and for furthering our understanding of enzyme-catalyzed reactions and of the metabolism of drugs.

A framework for the analysis of the security of supply of utilising carbon dioxide as a chemical feedstock.

PubMed

Fraga, Eric S; Ng, Melvin

2015-01-01

Recent developments in catalysts have enhanced the potential for the utilisation of carbon dioxide as a chemical feedstock. Using the appropriate energy efficient catalyst enables a range of chemical pathways leading to desirable products. In doing so, CO2 provides an economically and environmentally beneficial source of C1 feedstock, while improving the issues relating to security of supply that are associated with fossil-based feedstocks. However, the dependence on catalysts brings other supply chains into consideration, supply chains that may also have security of supply issues. The choice of chemical pathways for specific products will therefore entail an assessment not only of economic factors but also the security of supply issues for the catalysts. This is a multi-criteria decision making problem. In this paper, we present a modified 4A framework based on the framework suggested by the Asian Pacific Energy Research centre for macro-economic applications. The 4A methodology is named after the criteria used to compare alternatives: availability, acceptability, applicability and affordability. We have adapted this framework for the consideration of alternative chemical reaction processes using a micro-economic outlook. Data from a number of sources were collected and used to quantify each of the 4A criteria. A graphical representation of the assessments is used to support the decision maker in comparing alternatives. The framework not only allows for the comparison of processes but also highlights current limitations in the CCU processes. The framework presented can be used by a variety of stakeholders, including regulators, investors, and process industries, with the aim of identifying promising routes within a broader multi-criteria decision making process.

Application of kernel functions for accurate similarity search in large chemical databases.

PubMed

Wang, Xiaohong; Huan, Jun; Smalter, Aaron; Lushington, Gerald H

2010-04-29

Similarity search in chemical structure databases is an important problem with many applications in chemical genomics, drug design, and efficient chemical probe screening among others. It is widely believed that structure based methods provide an efficient way to do the query. Recently various graph kernel functions have been designed to capture the intrinsic similarity of graphs. Though successful in constructing accurate predictive and classification models, graph kernel functions can not be applied to large chemical compound database due to the high computational complexity and the difficulties in indexing similarity search for large databases. To bridge graph kernel function and similarity search in chemical databases, we applied a novel kernel-based similarity measurement, developed in our team, to measure similarity of graph represented chemicals. In our method, we utilize a hash table to support new graph kernel function definition, efficient storage and fast search. We have applied our method, named G-hash, to large chemical databases. Our results show that the G-hash method achieves state-of-the-art performance for k-nearest neighbor (k-NN) classification. Moreover, the similarity measurement and the index structure is scalable to large chemical databases with smaller indexing size, and faster query processing time as compared to state-of-the-art indexing methods such as Daylight fingerprints, C-tree and GraphGrep. Efficient similarity query processing method for large chemical databases is challenging since we need to balance running time efficiency and similarity search accuracy. Our previous similarity search method, G-hash, provides a new way to perform similarity search in chemical databases. Experimental study validates the utility of G-hash in chemical databases.

Rad-Release

ScienceCinema

None

2017-12-09

The R&D 100 Award winning Rad-Release Chemical Decontamination Technology is a highly effective (up to 99% removal rate), affordable, patented chemical-foam-clay decontamination process tailored to specific radiological and metal contaminants, which is applicable to a wide variety of substrates. For more information about this project, visit http://www.inl.gov/rd100/2011/rad-release/

Application of LC/MS/MS Techniques to Development of US EPA Standardized Methods for Chemicals of Emerging Concern

EPA Science Inventory

This presentation will describe the U.S. EPA’s drinking water and ambient water method development program in relation to the process employed and the typical challenges encountered in developing standardized LC/MS/MS methods for chemicals of emerging concern. The EPA&rsquo...

Solution plasma applications for the synthesis/modification of inorganic nanostructured materials and the treatment of natural polymers

NASA Astrophysics Data System (ADS)

Watthanaphanit, Anyarat; Saito, Nagahiro

2018-01-01

Reducing the use of toxic chemicals, production steps, and time consumption are important concerns for researchers and process engineers to contribute in the quest for an efficient process in any production. If an equipment setup is simple, the process additionally becomes more profitable. Combination of the mentioned requirements has opened up various applications of the solution plasma process (SPP) — a physical means of generating plasma through an electrical discharge in a liquid medium at atmospheric pressure and room temperature. This review shows the progress of scientific research on the applications of the SPP for the synthesis/modification of inorganic nanostructured materials and the treatment of natural polymers. Development achieved in each application is demonstrated.

Advanced physical-chemical life support systems research

NASA Technical Reports Server (NTRS)

Evanich, Peggy L.

1988-01-01

A proposed NASA space research and technology development program will provide adequate data for designing closed loop life support systems for long-duration manned space missions. This program, referred to as the Pathfinder Physical-Chemical Closed Loop Life Support Program, is to identify and develop critical chemical engineering technologies for the closure of air and water loops within the spacecraft, surface habitats or mobility devices. Computerized simulation can be used both as a research and management tool. Validated models will guide the selection of the best known applicable processes and in the development of new processes. For the integration of the habitat system, a biological subsystem would be introduced to provide food production and to enhance the physical-chemical life support functions on an ever-increasing basis.

Technology resource document for the assembled chemical weapons assessment environmental impact statement. Vol. 2 : assembled systems for weapons destruction at Anniston Army Depot.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimmell, T.; Folga, S., Frey, G.; Molberg, J.

2001-05-04

This volume of the Technical Resource Document (TRD) for the ''Environmental Impact Statement (EIS) for the Design, Construction and Operation of One or More Pilot Test Facilities for Assembled Chemical Weapons Destruction Technologies at One or More Sites'' (PMACWA 2001g) pertains to the destruction of assembled chemical weapons (ACW) stored at Anniston Army Depot (ANAD), located outside Anniston, Alabama. This volume presents technical and process information on each of the destruction technologies applicable to treatment of the specific ACW stored at ANAD. The destruction technologies described are those that have been demonstrated as part of the Assembled Chemical Weapons Assessmentmore » (ACWA) selection process (see Volume 1).« less

Potential use and perspectives of nitric oxide donors in agriculture.

PubMed

Marvasi, Massimiliano

2017-03-01

Nitric oxide (NO) has emerged in the last 30 years as a key molecule involved in many physiological processes in plants, animals and bacteria. Current research has shown that NO can be delivered via donor molecules. In such cases, the NO release rate is dependent on the chemical structure of the donor itself and on the chemical environment. Despite NO's powerful signaling effect in plants and animals, the application of NO donors in agriculture is currently not implemented and research remains mainly at the experimental level. Technological development in the field of NO donors is rapidly expanding in scope to include controlling seed germination, plant development, ripening and increasing shelf-life of produce. Potential applications in animal production have also been identified. This concise review focuses on the use of donors that have shown potential biotechnological applications in agriculture. Insights are provided into (i) the role of donors in plant production, (ii) the potential use of donors in animal production and (iii) future approaches to explore the use and applications of donors for the benefit of agriculture. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Advanced Chemical Propulsion Study

NASA Technical Reports Server (NTRS)

Woodcock, Gordon; Byers, Dave; Alexander, Leslie A.; Krebsbach, Al

2004-01-01

A study was performed of advanced chemical propulsion technology application to space science (Code S) missions. The purpose was to begin the process of selecting chemical propulsion technology advancement activities that would provide greatest benefits to Code S missions. Several missions were selected from Code S planning data, and a range of advanced chemical propulsion options was analyzed to assess capabilities and benefits re these missions. Selected beneficial applications were found for higher-performing bipropellants, gelled propellants, and cryogenic propellants. Technology advancement recommendations included cryocoolers and small turbopump engines for cryogenic propellants; space storable propellants such as LOX-hydrazine; and advanced monopropellants. It was noted that fluorine-bearing oxidizers offer performance gains over more benign oxidizers. Potential benefits were observed for gelled propellants that could be allowed to freeze, then thawed for use.

Microelectrode voltammetry of multi-electron transfers complicated by coupled chemical equilibria: a general theory for the extended square scheme.

PubMed

Laborda, Eduardo; Gómez-Gil, José María; Molina, Angela

2017-06-28

A very general and simple theoretical solution is presented for the current-potential-time response of reversible multi-electron transfer processes complicated by homogeneous chemical equilibria (the so-called extended square scheme). The expressions presented here are applicable regardless of the number of electrons transferred and coupled chemical processes, and they are particularized for a wide variety of microelectrode geometries. The voltammetric response of very different systems presenting multi-electron transfers is considered for the most widely-used techniques (namely, cyclic voltammetry, square wave voltammetry, differential pulse voltammetry and steady state voltammetry), studying the influence of the microelectrode geometry and the number and thermodynamics of the (electro)chemical steps. Most appropriate techniques and procedures for the determination of the 'interaction' between successive transfers are discussed. Special attention is paid to those situations where homogeneous chemical processes, such as protonation, complexation or ion association, affect the electrochemical behaviour of the system by different stabilization of the oxidation states.

40 CFR 68.67 - Process hazard analysis.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) CHEMICAL ACCIDENT PREVENTION PROVISIONS Program 3 Prevention Program § 68.67 Process hazard analysis. (a... potential for catastrophic consequences. (3) Engineering and administrative controls applicable to the... engineering and administrative controls; (5) Stationary source siting; (6) Human factors; and (7) A...

40 CFR 68.67 - Process hazard analysis.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) CHEMICAL ACCIDENT PREVENTION PROVISIONS Program 3 Prevention Program § 68.67 Process hazard analysis. (a... potential for catastrophic consequences. (3) Engineering and administrative controls applicable to the... engineering and administrative controls; (5) Stationary source siting; (6) Human factors; and (7) A...

40 CFR 68.67 - Process hazard analysis.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) CHEMICAL ACCIDENT PREVENTION PROVISIONS Program 3 Prevention Program § 68.67 Process hazard analysis. (a... potential for catastrophic consequences. (3) Engineering and administrative controls applicable to the... engineering and administrative controls; (5) Stationary source siting; (6) Human factors; and (7) A...

Analysis of the influence of chemical treatment to the strength and surface roughness of FDM

NASA Astrophysics Data System (ADS)

Hambali, R. H.; Cheong, K. M.; Azizan, N.

2017-06-01

The applications of Additive Manufacturing (AM) technology have a greater functionality and wider range of application beyond an intention of prototyping. AM is the process of joining materials to form objects from Computer-Aided Design (CAD) models via layer upon layer process. One of AM technologies is the Fused Deposition Modelling (FDM), which use an extrusion method to create a part. FDM has been applied in many manufacturing applications includes an end-used parts. However, FDM tends to have bad surface quality due to staircase effect and post treatment is required. This chemical treatment is one of a way to improve the surface roughness of FDM fabricated parts. This method is one of economical and faster method. In order to enhance the surface finish of Acrylonitrile-Butadiene-Styrene (ABS) FDM parts by performing chemical treatment in an acetone solution as acetone has very low toxicity, high diffusion and low cost chemical solution. Therefore, the aim of this research is to investigate the influence of chemical treatment to the FDM used part in terms of surface roughness as well as the strength. In this project, ten specimens of standard ASTM D638 dogbone specimens have been fabricated using MOJO 3D printer. Five specimens from the dogbone were tested for surface roughness and tensile testing while another five were immersed in the chemical solution before the same testing. Based on results, the surface roughness of chemically treated dogbone has dramatically improved, compared to untreated dogbone with 97.2% of improvement. However, in term of strength, the tensile strength of dogbone is reduced 42.58% due to the rearrange of material properties and chemical effects to the joining of the filaments. In conclusion, chemical treatment is an economical and sustainable approach to enhance the surface quality of AM parts.

A Chemical Route to Activation of Open Metal Sites in the Copper-Based Metal-Organic Framework Materials HKUST-1 and Cu-MOF-2.

PubMed

Kim, Hong Ki; Yun, Won Seok; Kim, Min-Bum; Kim, Jeung Yoon; Bae, Youn-Sang; Lee, JaeDong; Jeong, Nak Cheon

2015-08-12

Open coordination sites (OCSs) in metal-organic frameworks (MOFs) often function as key factors in the potential applications of MOFs, such as gas separation, gas sorption, and catalysis. For these applications, the activation process to remove the solvent molecules coordinated at the OCSs is an essential step that must be performed prior to use of the MOFs. To date, the thermal method performed by applying heat and vacuum has been the only method for such activation. In this report, we demonstrate that methylene chloride (MC) itself can perform the activation role: this process can serve as an alternative "chemical route" for the activation that does not require applying heat. To the best of our knowledge, no previous study has demonstrated this function of MC, although MC has been popularly used in the pretreatment step prior to the thermal activation process. On the basis of a Raman study, we propose a plausible mechanism for the chemical activation, in which the function of MC is possibly due to its coordination with the Cu(2+) center and subsequent spontaneous decoordination. Using HKUST-1 film, we further demonstrate that this chemical activation route is highly suitable for activating large-area MOF films.

Visualizing Chemistry: The Progess and Promise of Advanced Chemical Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Committee on Revealing Chemistry Through Advanced Chemical Imaging

2006-09-01

The field of chemical imaging can provide detailed structural, functional, and applicable information about chemistry and chemical engineering phenomena that have enormous impacts on medicine, materials, and technology. In recognizing the potential for more research development in the field of chemical imaging, the National Academies was asked by the National Science Foundation, Department of Energy, U.S. Army, and National Cancer Institute to complete a study that would review the current state of molecular imaging technology, point to promising future developments and their applications, and suggest a research and educational agenda to enable breakthrough improvements in the ability to image molecularmore » processes simultaneously in multiple physical dimensions as well as time. The study resulted in a consensus report that provides guidance for a focused research and development program in chemical imaging and identifies research needs and possible applications of imaging technologies that can provide the breakthrough knowledge in chemistry, materials science, biology, and engineering for which we should strive. Public release of this report is expected in early October.« less

Biotechnology and genetic engineering in the new drug development. Part III. Biocatalysis, metabolic engineering and molecular modelling.

PubMed

Stryjewska, Agnieszka; Kiepura, Katarzyna; Librowski, Tadeusz; Lochyński, Stanisław

2013-01-01

Industrial biotechnology has been defined as the use and application of biotechnology for the sustainable processing and production of chemicals, materials and fuels. It makes use of biocatalysts such as microbial communities, whole-cell microorganisms or purified enzymes. In the review these processes are described. Drug design is an iterative process which begins when a chemist identifies a compound that displays an interesting biological profile and ends when both the activity profile and the chemical synthesis of the new chemical entity are optimized. Traditional approaches to drug discovery rely on a stepwise synthesis and screening program for large numbers of compounds to optimize activity profiles. Over the past ten to twenty years, scientists have used computer models of new chemical entities to help define activity profiles, geometries and relativities. This article introduces inter alia the concepts of molecular modelling and contains references for further reading.

SILICATE TECHNOLOGY CORPORATION'S SOLIDIFICATION/ STABILIZATION TECHNOLOGY FOR ORGANIC AND INORGANIC CONTAMINANTS IN SOILS - APPLICATIONS ANALYSIS REPORT

EPA Science Inventory

This Applications Analysis Report evaluates the solidification/stabilization treatment process of Silicate Technology Corporation (STC) for the on-site treatment of hazardous waste. The STC immobilization technology utilizes a proprietary product (FMS Silicate) to chemically stab...

Applications of Technology to CAS Data-Base Production.

ERIC Educational Resources Information Center

Weisgerber, David W.

1984-01-01

Reviews the economic importance of applying computer technology to Chemical Abstracts Service database production from 1973 to 1983. Database building, technological applications for editorial processing (online editing, Author Index Manufacturing System), and benefits (increased staff productivity, reduced rate of increase of cost of services,…

Environmental applications of HTC technology: Biochar production, carbon sequestration, and waste conversion

USDA-ARS?s Scientific Manuscript database

Motivations for the development and use of hydrothermal carbonization (or wet pyrolysis) have been primarily directed towards the sustainable creation of carbon nanomaterials/nanostructures for use in applications ranging from hydrogen storage to chemical adsorption. The utility of this process, how...

Removal of polycyclic aromatic hydrocarbons in aqueous environment by chemical treatments: a review.

PubMed

Rubio-Clemente, Ainhoa; Torres-Palma, Ricardo A; Peñuela, Gustavo A

2014-04-15

Due to their carcinogenic, mutagenic and teratogenic potential, the removal of polycyclic aromatic hydrocarbons (PAHs) from aqueous environment using physical, biological and chemical processes has been studied by several researchers. This paper reviews the current state of knowledge concerning PAHs including their physico-chemical properties, input sources, occurrence, adverse effects and conventional and alternative chemical processes applied for their removal from water. The mechanisms and reactions involved in each treatment method are reported, and the effects of various variables on the PAH degradation rate as well as the extent of degradation are also discussed. Extensive literature analysis has shown that an effective way to perform the conversion and mineralization of this type of substances is the application of advanced oxidation processes (AOPs). Furthermore, combined processes, particularly AOPs coupled with biological treatments, seem to be one of the best solutions for the treatment of effluents containing PAHs. Copyright © 2013 Elsevier B.V. All rights reserved.

Technology resource document for the assembled chemical weapons assessment environmental impact statement. Vol. 5 : assembled systems for weapons destruction at Blue Grass Army Depot.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kimmell, T.; Folga, S., Frey, G.; Molberg, J.

2001-05-02

This volume of the Technical Resource Document (TRD) for the ''Environmental Impact Statement (EIS) for the Design, Construction and Operation of One or More Pilot Test Facilities for Assembled Chemical Weapons Destruction Technologies at One or More Sites'' (PMACWA 2001g) pertains to the destruction of assembled chemical weapons (ACW) stored in the U.S. Army's unitary chemical stockpile at Blue Grass Army Depot (BGAD), located outside Richmond, Kentucky. This volume presents technical and process information on each of the destruction technologies applicable to treatment of the specific ACW stored at BGAD. The destruction technologies described are those that have been demonstratedmore » as part of the Assembled Chemical Weapons Assessment (ACWA) selection process (see Volume 1).« less

The use of selective adsorbents in capillary electrophoresis-mass spectrometry for analyte preconcentration and microreactions: a powerful three-dimensional tool for multiple chemical and biological applications.

PubMed

Guzman, N A; Stubbs, R J

2001-10-01

Much attention has recently been directed to the development and application of online sample preconcentration and microreactions in capillary electrophoresis using selective adsorbents based on chemical or biological specificity. The basic principle involves two interacting chemical or biological systems with high selectivity and affinity for each other. These molecular interactions in nature usually involve noncovalent and reversible chemical processes. Properly bound to a solid support, an "affinity ligand" can selectively adsorb a "target analyte" found in a simple or complex mixture at a wide range of concentrations. As a result, the isolated analyte is enriched and highly purified. When this affinity technique, allowing noncovalent chemical interactions and biochemical reactions to occur, is coupled on-line to high-resolution capillary electrophoresis and mass spectrometry, a powerful tool of chemical and biological information is created. This paper describes the concept of biological recognition and affinity interaction on-line with high-resolution separation, the fabrication of an "analyte concentrator-microreactor", optimization conditions of adsorption and desorption, the coupling to mass spectrometry, and various applications of clinical and pharmaceutical interest.

Soft Sensors: Chemoinformatic Model for Efficient Control and Operation in Chemical Plants.

PubMed

Funatsu, Kimito

2016-12-01

Soft sensor is statistical model as an essential tool for controlling pharmaceutical, chemical and industrial plants. I introduce soft sensor, the roles, the applications, the problems and the research examples such as adaptive soft sensor, database monitoring and efficient process control. The use of soft sensor enables chemical industrial plants to be operated more effectively and stably. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Conversion of bioprocess ethanol to industrial chemical products - Applications of process models for energy-economic assessments

NASA Technical Reports Server (NTRS)

Rohatgi, Naresh K.; Ingham, John D.

1992-01-01

An assessment approach for accurate evaluation of bioprocesses for large-scale production of industrial chemicals is presented. Detailed energy-economic assessments of a potential esterification process were performed, where ethanol vapor in the presence of water from a bioreactor is catalytically converted to ethyl acetate. Results show that such processes are likely to become more competitive as the cost of substrates decreases relative to petrolium costs. A commercial ASPEN process simulation provided a reasonably consistent comparison with energy economics calculated using JPL developed software. Detailed evaluations of the sensitivity of production cost to material costs and annual production rates are discussed.

Metal injection molding of titanium for medical and aerospace applications

NASA Astrophysics Data System (ADS)

Scharvogel, Matthias; Winkelmueller, Wendelin

2011-02-01

Mixing of titanium powder and thermoplastic binders creates a feedstock that is injection molded similar to plastic, has a chemical and thermal debinding process, and then is sintered to form a net-shape or near-net shape part. TiJet Medizintechnik GmbH (TiJet) developed and uses its own feedstock and powder processing technology to achieve desired mechanical properties. This paper explains the theory of the process and the possibilities that result from the development of this new powder processing technology, such as new alloys, design possibilities, etc. Discussed will be the microstructure, chemical composition, and mechanical properties of the manufactured parts.

Facile Dry Surface Cleaning of Graphene by UV Treatment

NASA Astrophysics Data System (ADS)

Kim, Jin Hong; Haidari, Mohd Musaib; Choi, Jin Sik; Kim, Hakseong; Yu, Young-Jun; Park, Jonghyurk

2018-05-01

Graphene has been considered an ideal material for application in transparent lightweight wearable electronics due to its extraordinary mechanical, optical, and electrical properties originating from its ordered hexagonal carbon atomic lattice in a layer. Precise surface control is critical in maximizing its performance in electronic applications. Graphene grown by chemical vapor deposition is widely used but it produces polymeric residue following wet/chemical transfer process, which strongly affects its intrinsic electrical properties and limits the doping efficiency by adsorption. Here, we introduce a facile dry-cleaning method based on UV irradiation to eliminate the organic residues even after device fabrication. Through surface topography, Raman analysis, and electrical transport measurement characteristics, we confirm that the optimized UV treatment can recover the clean graphene surface and improve graphene-FET performance more effectively than thermal treatment. We propose our UV irradiation method as a systematically controllable and damage-free post process for application in large-area devices.

Applications of de-oiled microalgal biomass towards development of sustainable biorefinery.

PubMed

Maurya, Rahulkumar; Paliwal, Chetan; Ghosh, Tonmoy; Pancha, Imran; Chokshi, Kaumeel; Mitra, Madhusree; Ghosh, Arup; Mishra, Sandhya

2016-08-01

In view of commercialization of microalgal biofuel, the de-oiled microalgal biomass (DMB) is a surplus by-product in the biorefinery process that needs to be exploited to make the process economically attractive and feasible. This DMB, rich in carbohydrates, proteins, and minerals, can be used as feed, fertilizer, and substrate for the production of bioethanol/bio-methane. Further, thermo-chemical conversion of DMB results into fuels and industrially important chemicals. Future prospects of DMB also lie with its conversion into novel biomaterials like nanoparticles and carbon-dot which have biomedical importance. The lowest valued application of DMB is to use it for adsorption of dyes and heavy metals from industrial effluents. This study reviews how DMB can be utilized for different applications and in the generation of valuable co-products. The value addition of DMB would thereby improve the overall cost economics of the microalgal bio-refinery. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microorganisms in inorganic chemical analysis.

PubMed

Godlewska-Zyłkiewicz, Beata

2006-01-01

There are innumerable strains of microbes (bacteria, yeast and fungi) that degrade or transform chemicals and compounds into simpler, safer or less toxic substances. These bioprocesses have been used for centuries in the treatment of municipal wastes, in wine, cheese and bread making, and in bioleaching and metal recovery processes. Recent literature shows that microorganisms can be also used as effective sorbents for solid phase extraction procedures. This review reveals that fundamental nonanalytical studies on the parameters and conditions of biosorption processes and on metal-biomass interactions often result in efficient analytical procedures and biotechnological applications. Some selected examples illustrate the latest developments in the biosorption of metals by microbial biomass, which have opened the door to the application of microorganisms to analyte preconcentration, matrix separation and speciation analysis.

Application of a geographic information system in analyzing the occurrence of atrazine in groundwater of the mid-continental United States

USGS Publications Warehouse

Burkart, M.R.; Kolpin, D.W.

1993-01-01

The US Geological Survey, US Department of Agriculture, and US Environmental Protection Agency are conducting research and regional assessments in support of policy alternatives intended to protect water resources from agricultural chemical contamination. The mid-continent was selected because of the intense row crop agriculture and associated herbicide application in this region. An application of a geographic information system is demonstrated for analyzing and comparing the distribution of estimated atrazine use to the detection rate of atrazine in groundwater. Understanding the relations between atrazine use and detection in groundwater is important in policy deliberations to protect water resources. Relational analyses between measures of chemical use and detection rate by natural resource units may provide insight into critical factors controlling the processes that result in groundwater contamination from agricultural chemicals. 

Chemical formation of soft metal electrodes for flexible and wearable electronics.

PubMed

Wang, Dongrui; Zhang, Yaokang; Lu, Xi; Ma, Zhijun; Xie, Chuan; Zheng, Zijian

2018-06-18

Flexible and wearable electronics is one major technology after smartphones. It shows remarkable application potential in displays and informatics, robotics, sports, energy harvesting and storage, and medicine. As an indispensable part and the cornerstone of these devices, soft metal electrodes (SMEs) are of great significance. Compared with conventional physical processes such as vacuum thermal deposition and sputtering, chemical approaches for preparing SMEs show significant advantages in terms of scalability, low-cost, and compatibility with the soft materials and substrates used for the devices. This review article provides a detailed overview on how to chemically fabricate SMEs, including the material preparation, fabrication technologies, methods to characterize their key properties, and representative studies on different wearable applications.

Functionalization of graphene nanoribbons

NASA Astrophysics Data System (ADS)

Genorio, Bostjan; Znidarsic, Andrej

2014-03-01

Graphene nanoribbon (GNR) is a recently discovered carbon allotrope, which can be described as a stripe of graphene. Pseudo-one-dimensionality exerts additional confinement on the electrons resulting in the formation of a band gap relevant for electronic devices. Due to distinct physical and chemical properties it is a promising material for several applications. To expand the range of potential applications and to improve processability, chemical functionalization of GNRs is required. This review aims to provide a concise and systematic coverage of recent work in chemical functionalization of GNRs. We will focus on longitudinal carbon nanotube unzipping, functionalization with aryl diazonium salts, non-covalent functionalization, bottom-up synthesis and one pot carbon nanotube unzipping with in situ edge functionalization.

Quarterly progress report for the Chemical and Energy Research Section of the Chemical Technology Division, April--June 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jubin, R.T.

The Chemical and Energy Research Section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within six major areas of research: Hot Cell Operations, Process Chemistry and thermodynamics, Separations and Materials Synthesis, Solution Thermodynamics, biotechnology Research, and Molecular Studies. The name of a technical contact is included with each task described, and readers are encouraged to contact these individuals if they need additional information.

Control of electro-chemical processes using energy harvesting materials and devices.

PubMed

Zhang, Yan; Xie, Mengying; Adamaki, Vana; Khanbareh, Hamideh; Bowen, Chris R

2017-12-11

Energy harvesting is a topic of intense interest that aims to convert ambient forms of energy such as mechanical motion, light and heat, which are otherwise wasted, into useful energy. In many cases the energy harvester or nanogenerator converts motion, heat or light into electrical energy, which is subsequently rectified and stored within capacitors for applications such as wireless and self-powered sensors or low-power electronics. This review covers the new and emerging area that aims to directly couple energy harvesting materials and devices with electro-chemical systems. The harvesting approaches to be covered include pyroelectric, piezoelectric, triboelectric, flexoelectric, thermoelectric and photovoltaic effects. These are used to influence a variety of electro-chemical systems such as applications related to water splitting, catalysis, corrosion protection, degradation of pollutants, disinfection of bacteria and material synthesis. Comparisons are made between the range harvesting approaches and the modes of operation are described. Future directions for the development of electro-chemical harvesting systems are highlighted and the potential for new applications and hybrid approaches are discussed.

Molecule database framework: a framework for creating database applications with chemical structure search capability

PubMed Central

2013-01-01

Background Research in organic chemistry generates samples of novel chemicals together with their properties and other related data. The involved scientists must be able to store this data and search it by chemical structure. There are commercial solutions for common needs like chemical registration systems or electronic lab notebooks. However for specific requirements of in-house databases and processes no such solutions exist. Another issue is that commercial solutions have the risk of vendor lock-in and may require an expensive license of a proprietary relational database management system. To speed up and simplify the development for applications that require chemical structure search capabilities, I have developed Molecule Database Framework. The framework abstracts the storing and searching of chemical structures into method calls. Therefore software developers do not require extensive knowledge about chemistry and the underlying database cartridge. This decreases application development time. Results Molecule Database Framework is written in Java and I created it by integrating existing free and open-source tools and frameworks. The core functionality includes: • Support for multi-component compounds (mixtures) • Import and export of SD-files • Optional security (authorization) For chemical structure searching Molecule Database Framework leverages the capabilities of the Bingo Cartridge for PostgreSQL and provides type-safe searching, caching, transactions and optional method level security. Molecule Database Framework supports multi-component chemical compounds (mixtures). Furthermore the design of entity classes and the reasoning behind it are explained. By means of a simple web application I describe how the framework could be used. I then benchmarked this example application to create some basic performance expectations for chemical structure searches and import and export of SD-files. Conclusions By using a simple web application it was shown that Molecule Database Framework successfully abstracts chemical structure searches and SD-File import and export to simple method calls. The framework offers good search performance on a standard laptop without any database tuning. This is also due to the fact that chemical structure searches are paged and cached. Molecule Database Framework is available for download on the projects web page on bitbucket: https://bitbucket.org/kienerj/moleculedatabaseframework. PMID:24325762

Molecule database framework: a framework for creating database applications with chemical structure search capability.

PubMed

Kiener, Joos

2013-12-11

Research in organic chemistry generates samples of novel chemicals together with their properties and other related data. The involved scientists must be able to store this data and search it by chemical structure. There are commercial solutions for common needs like chemical registration systems or electronic lab notebooks. However for specific requirements of in-house databases and processes no such solutions exist. Another issue is that commercial solutions have the risk of vendor lock-in and may require an expensive license of a proprietary relational database management system. To speed up and simplify the development for applications that require chemical structure search capabilities, I have developed Molecule Database Framework. The framework abstracts the storing and searching of chemical structures into method calls. Therefore software developers do not require extensive knowledge about chemistry and the underlying database cartridge. This decreases application development time. Molecule Database Framework is written in Java and I created it by integrating existing free and open-source tools and frameworks. The core functionality includes:•Support for multi-component compounds (mixtures)•Import and export of SD-files•Optional security (authorization)For chemical structure searching Molecule Database Framework leverages the capabilities of the Bingo Cartridge for PostgreSQL and provides type-safe searching, caching, transactions and optional method level security. Molecule Database Framework supports multi-component chemical compounds (mixtures).Furthermore the design of entity classes and the reasoning behind it are explained. By means of a simple web application I describe how the framework could be used. I then benchmarked this example application to create some basic performance expectations for chemical structure searches and import and export of SD-files. By using a simple web application it was shown that Molecule Database Framework successfully abstracts chemical structure searches and SD-File import and export to simple method calls. The framework offers good search performance on a standard laptop without any database tuning. This is also due to the fact that chemical structure searches are paged and cached. Molecule Database Framework is available for download on the projects web page on bitbucket: https://bitbucket.org/kienerj/moleculedatabaseframework.

Aerospace Environmental Technology Conference

NASA Technical Reports Server (NTRS)

Whitaker, A. F. (Editor)

1995-01-01

The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards. The Executive Summary of this Conference is published as NASA CP-3297.

State of the art in on-line techniques coupled to flow injection analysis FIA/on-line- a critical review

PubMed Central

Puchades, R.; Maquieira, A.; Atienza, J.; Herrero, M. A.

1990-01-01

Flow injection analysis (FIA) has emerged as an increasingly used laboratory tool in chemical analysis. Employment of the technique for on-line sample treatment and on-line measurement in chemical process control is a growing trend. This article reviews the recent applications of FlA. Most papers refer to on-line sample treatment. Although FIA is very well suited to continuous on-line process monitoring, few examples have been found in this areamost of them have been applied to water treatment or fermentation processes. PMID:18925271

Sequential chemical-biological processes for the treatment of industrial wastewaters: review of recent progresses and critical assessment.

PubMed

Guieysse, Benoit; Norvill, Zane N

2014-02-28

When direct wastewater biological treatment is unfeasible, a cost- and resource-efficient alternative to direct chemical treatment consists of combining biological treatment with a chemical pre-treatment aiming to convert the hazardous pollutants into more biodegradable compounds. Whereas the principles and advantages of sequential treatment have been demonstrated for a broad range of pollutants and process configurations, recent progresses (2011-present) in the field provide the basis for refining assessment of feasibility, costs, and environmental impacts. This paper thus reviews recent real wastewater demonstrations at pilot and full scale as well as new process configurations. It also discusses new insights on the potential impacts of microbial community dynamics on process feasibility, design and operation. Finally, it sheds light on a critical issue that has not yet been properly addressed in the field: integration requires complex and tailored optimization and, of paramount importance to full-scale application, is sensitive to uncertainty and variability in the inputs used for process design and operation. Future research is therefore critically needed to improve process control and better assess the real potential of sequential chemical-biological processes for industrial wastewater treatment. Copyright © 2013 Elsevier B.V. All rights reserved.

Heat transfer correlations for kerosene fuels and mixtures and physical properties for Jet A fuel

NASA Technical Reports Server (NTRS)

Ackerman, G. H.; Faith, L. E.

1972-01-01

Heat transfer correlations are reported for conventional Jet A fuel for both laminar and turbulent flow in circular tubes. Correlations were developed for cooling in turbine engines, but have broader applications in petroleum and chemical processing, and other industrial applications.

Pharmaceutical Applications of Ion-Exchange Resins

ERIC Educational Resources Information Center

Elder, David

2005-01-01

The historical uses of ion-exchanged resins and a summary of the basic chemical principles involved in the ion-exchanged process are discussed. Specific applications of ion-exchange are provided that include drug stabilization, pharmaceutical excipients, taste-masking agents, oral sustained-release products, topical products for local application…

Co-processed excipients: a patent review.

PubMed

Garg, Nidhi; Dureja, Harish; Kaushik, Deepak

2013-04-01

The introduction of high speed tableting machines and the preference of direct compression as a method of tableting have increased the demands on the functionality of excipients mainly in terms of flowability and compressibility. Co-processed excipients, where in, excipients are combined by virtue of sub-particle level interaction have provided an attractive tool for developing high functionality excipients. The multifold advantages offered by co-processed excipients such as production of synergism in functionality of individual components, reduction of company's regulatory concern because of absence of chemical change during co-processing and improvement in physico-chemical properties have expanded their use in the pharmaceutical industry. In the recent years, there has been a spurt in the number of patents filed on co-processed excipients. Hence, the present review focuses on co-processed excipients and their application in pharmaceutical industry. The worldwide databases of European patent office (http://ep.espacenet.com) and United States patent office (www.uspto.gov) were employed to collect the patents and patent applications. The advantages, limitations, basis for the selection of excipients to be co-processed, methods of co-processing and regulatory perspective of co-processed excipients are also briefly discussed.

A corporate product integrity assurance process.

PubMed

Weiler, E D; Keener, R

1991-10-01

One of the more difficult challenges that confronts the chemical industry throughout the industrialized world is how to effectively manage the various and often diverse regulatory requirements. What follows is a description of a process designed to help with new product introductions. The process is generic and is applicable to almost any corporate environment and structure.

Twenty-five Years of DNA-Encoded Chemical Libraries.

PubMed

Neri, Dario

2017-05-04

Reference library: The availability of DNA-encoded chemical libraries containing billions of compounds facilitates the discovery of binding molecules for pharmaceutical applications and for investigating biological processes. This Special Issue highlights the use of this library technology and some of the latest developments in the field. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Neutralization and Biodegradation of Sulfur Mustard.

DTIC Science & Technology

1997-02-01

public release; distribution is unlimited. 13. ABSTRACT (Maximum 200 words) The chemical warfare agent sulfur mustard was hydrolyzed to products that...scale bioreactors processing hydrolyzed munitions-grade sulfur mustard obtained directly from the U.S. Chemical Stockpile. The bioreactor effluent was...Hydrolysis has been previously utili ed for the detoxification of Canadian HD stockpiles (Reichert, 1975). Biodegradation has widespread application in

Investigation of optimal chemical composition of cast aluminum alloys for vibrational mechanical-chemical polishing and deposition of protective and decorative coatings

NASA Astrophysics Data System (ADS)

Ivanov, V. V.; Popov, S. I.; Kirichek, A. V.

2018-03-01

The article suggests the technology of vibration finishing processing of aluminum alloys with simultaneous coating. On the basis of experimental studies, cast alloys, working media, operating modes of equipment, activating solutions were chosen. The practical application of the developed technology on real parts is shown.

Industrial uses and applications of ionic liquids

NASA Astrophysics Data System (ADS)

Gutowski, Keith E.

2018-02-01

Ionic liquids are salts that melt at low temperatures (usually defined as less than 100 °C) and have a number of interesting properties that make them useful for industrial applications. Typical ionic liquid properties include high thermal stabilities, negligible vapor pressures, wide liquidus ranges, broad electrochemical windows, and unique solvation properties. Furthermore, the potential combinations of cations and anions provide nearly unlimited chemical tunability. This article will describe the diverse industrial uses of ionic liquids and how their unique properties are leveraged, with examples ranging from chemical processing to consumer packaged goods.

Thermo-hydro-mechanical-chemical processes in fractured-porous media: Benchmarks and examples

NASA Astrophysics Data System (ADS)

Kolditz, O.; Shao, H.; Görke, U.; Kalbacher, T.; Bauer, S.; McDermott, C. I.; Wang, W.

2012-12-01

The book comprises an assembly of benchmarks and examples for porous media mechanics collected over the last twenty years. Analysis of thermo-hydro-mechanical-chemical (THMC) processes is essential to many applications in environmental engineering, such as geological waste deposition, geothermal energy utilisation, carbon capture and storage, water resources management, hydrology, even climate change. In order to assess the feasibility as well as the safety of geotechnical applications, process-based modelling is the only tool to put numbers, i.e. to quantify future scenarios. This charges a huge responsibility concerning the reliability of computational tools. Benchmarking is an appropriate methodology to verify the quality of modelling tools based on best practices. Moreover, benchmarking and code comparison foster community efforts. The benchmark book is part of the OpenGeoSys initiative - an open source project to share knowledge and experience in environmental analysis and scientific computation.

Exergie /4th revised and enlarged edition/

NASA Astrophysics Data System (ADS)

Baloh, T.; Wittwer, E.

The theoretical concept of exergy is explained and its practical applications are discussed. Equilibrium and thermal equilibrium are reviewed as background, and exergy is considered as a reference point for solid-liquid, liquid-liquid, and liquid-gas systems. Exergetic calculations and their graphic depictions are covered. The concepts of enthalpy and entropy are reviewed in detail, including their applications to gas mixtures, solutions, and isolated substances. The exergy of gas mixtures, solutions, and isolated substances is discussed, including moist air, liquid water in water vapor, dry air, and saturation-limited solutions. Mollier exergy-enthalpy-entropy diagrams are presented for two-component systems, and exergy losses for throttling, isobaric mixing, and heat transfer are addressed. The relationship of exergy to various processes is covered, including chemical processes, combustion, and nuclear reactions. The optimization of evaporation plants through exergy is discussed. Calculative examples are presented for energy production and heating, industrial chemical processes, separation of liquid air, nuclear reactors, and others.

High-performance vitrimers from commodity thermoplastics through dioxaborolane metathesis

NASA Astrophysics Data System (ADS)

Röttger, Max; Domenech, Trystan; van der Weegen, Rob; Breuillac, Antoine; Nicolaÿ, Renaud; Leibler, Ludwik

2017-04-01

Windmills, cars, and dental restoration demand polymer materials and composites that are easy to process, assemble, and recycle while exhibiting outstanding mechanical, thermal, and chemical resistance. Vitrimers, which are polymer networks able to shuffle chemical bonds through exchange reactions, could address these demands if they were prepared from existing plastics and processed with fast production rates and current equipment. We report the metathesis of dioxaborolanes, which is rapid and thermally robust, and use it to prepare vitrimers from polymers as different as poly(methyl methacrylate), polystyrene, and high-density polyethylene that, although permanently cross-linked, can be processed multiple times by means of extrusion or injection molding. They show superior chemical resistance and dimensional stability and can be efficiently assembled. The strategy is applicable to polymers with backbones made of carbon-carbon single bonds.

Treating an aged pentachlorophenol- (PCP-) contaminated soil through three sludge handling processes, anaerobic sludge digestion, post-sludge digestion and sludge land application.

PubMed

Chen, S T; Berthouex, P M

2001-01-01

The extensive pentachlorophenol (PCP) contamination and its increasing treatment costs motivate the search for a more competitive treatment alternative. In a municipal wastewater treatment plant, anaerobic sludge-handling processes comprises three bio-processes, namely the anaerobic sludge digestion, post-sludge digestion and sludge land application, which reduce sludge organic content and make sludge a good fertilizer for land application. Availability and effectiveness make the anaerobic sludge handling processes potential technologies to treat PCP-contaminated soil. The technical feasibility of using anaerobic sludge bioprocesses was studied by treating PCP soil in two pilot digesters to simulate the primary sludge digestion, in serum bottles to mimic the post-sludge digestion, and in glass pans to represent the on-site sludge application. For primary digestion, the results showed that up to 0.98 and 0.6 mM of chemical and soil PCP, respectively, were treated at nearly 100% and 97.5% efficiencies. The PCP was transformed 95% to 3-MCP, 4.5% to 3,4-DCP, and 0.5% to 3,5-DCP. For post-digestion, 100% pure chemical PCP and greater than 95% soil PCP were removed in less than 6 months with no chlorophenol residues of any kind. Complete removal of PCP by-products makes this process a good soil cleanup method. For on-site treatment, PCP was efficiently treated by multiple sludge application; however, the PCP residue was observed due to the high initial PCP content in soil. Overall, more mass PCP per unit sludge per day was processed using the primary sludge digestion than the on-site soil treatment or post-sludge digestion. And, sludge acclimation resulted in better PCP treatment efficiencies with all three processes.

Chemical Hygiene Program

NASA Technical Reports Server (NTRS)

Mayor, Antoinette C.

1999-01-01

The Chemical Management Team is responsible for ensuring compliance with the OSHA Laboratory Standard. The program at Lewis Research Center (LeRC) evolved over many years to include training, developing Standard Operating Procedures (SOPS) for each laboratory process, coordinating with other safety and health organizations and teams at the Center, and issuing an SOP binder. The Chemical Hygiene Policy was first established for the Center. The Chemical Hygiene Plan was established and reviewed by technical, laboratory and management for viability and applicability to the Center. A risk assessment was conducted for each laboratory. The laboratories were prioritized by order of risk, higher risk taking priority. A Chemical Management Team staff member interviewed the lead researcher for each laboratory process to gather the information needed to develop the SOP for the process. A binder containing the Chemical Hygiene Plan, the SOP, a map of the laboratory identifying the personal protective equipment and best egress, and glove guides, as well as other guides for safety and health. Each laboratory process has been captured in the form of an SOP. The chemicals used in the procedure have been identified and the information is used to reduce the number of chemicals in the lab. The Chemical Hygiene Plan binder is used as a training tool for new employees. LeRC is in compliance with the OSHA Standard. The program was designed to comply with the OSHA standard. In the process, we have been able to assess the usage of chemicals in the laboratories, as well as reduce or relocate the chemicals being stored in the laboratory. Our researchers are trained on the hazards of the materials they work with and have a better understanding of the hazards of the process and what is needed to prevent any incident. From the SOP process, we have been able to reduce our chemical inventory, determine and implement better hygiene procedures and equipment in the laboratories, and provide specific training to our employees. As a result of this program, we are adding labeling to the laboratories for emergency responders and initiating a certified chemical user program.

Label-assisted mass spectrometry for the acceleration of reaction discovery and optimization

NASA Astrophysics Data System (ADS)

Cabrera-Pardo, Jaime R.; Chai, David I.; Liu, Song; Mrksich, Milan; Kozmin, Sergey A.

2013-05-01

The identification of new reactions expands our knowledge of chemical reactivity and enables new synthetic applications. Accelerating the pace of this discovery process remains challenging. We describe a highly effective and simple platform for screening a large number of potential chemical reactions in order to discover and optimize previously unknown catalytic transformations, thereby revealing new chemical reactivity. Our strategy is based on labelling one of the reactants with a polyaromatic chemical tag, which selectively undergoes a photoionization/desorption process upon laser irradiation, without the assistance of an external matrix, and enables rapid mass spectrometric detection of any products originating from such labelled reactants in complex reaction mixtures without any chromatographic separation. This method was successfully used for high-throughput discovery and subsequent optimization of two previously unknown benzannulation reactions.

Dissecting the assays to assess microbial tolerance to toxic chemicals in bioprocessing.

PubMed

Zingaro, Kyle A; Nicolaou, Sergios A; Papoutsakis, Eleftherios T

2013-11-01

Microbial strains are increasingly used for the industrial production of chemicals and biofuels, but the toxicity of components in the feedstock and product streams limits process outputs. Selected or engineered microbes that thrive in the presence of toxic chemicals can be assessed using tolerance assays. Such assays must reasonably represent the conditions the cells will experience during the intended process and measure the appropriate physiological trait for the desired application. We review currently used tolerance assays, and examine the many parameters that affect assay outcomes. We identify and suggest the use of the best-suited assays for each industrial bioreactor operating condition, discuss next-generation assays, and propose a standardized approach for using assays to examine tolerance to toxic chemicals. Copyright © 2013 Elsevier Ltd. All rights reserved.

Atomistic Modeling of Corrosion Events at the Interface between a Metal and Its Environment

DOE PAGES

Taylor, Christopher D.

2012-01-01

Atomistic simulation is a powerful tool for probing the structure and properties of materials and the nature of chemical reactions. Corrosion is a complex process that involves chemical reactions occurring at the interface between a material and its environment and is, therefore, highly suited to study by atomistic modeling techniques. In this paper, the complex nature of corrosion processes and mechanisms is briefly reviewed. Various atomistic methods for exploring corrosion mechanisms are then described, and recent applications in the literature surveyed. Several instances of the application of atomistic modeling to corrosion science are then reviewed in detail, including studies ofmore » the metal-water interface, the reaction of water on electrified metallic interfaces, the dissolution of metal atoms from metallic surfaces, and the role of competitive adsorption in controlling the chemical nature and structure of a metallic surface. Some perspectives are then given concerning the future of atomistic modeling in the field of corrosion science.« less

Efficient use of shrimp waste: present and future trends.

PubMed

Kandra, Prameela; Challa, Murali Mohan; Jyothi, Hemalatha Kalangi Padma

2012-01-01

The production of shrimp waste from shrimp processing industries has undergone a dramatic increase in recent years. Continued production of this biomaterial without corresponding development of utilizing technology has resulted in waste collection, disposal, and pollution problems. Currently used chemical process releases toxic chemicals such as HCl, acetic acid, and NaOH into aquatic ecosystem as byproducts which will spoil the aquatic flora and fauna. Environmental protection regulations have become stricter. Now, there is a need to treat and utilize the waste in most efficient manner. The shrimp waste contains several bioactive compounds such as chitin, pigments, amino acids, and fatty acids. These bioactive compounds have a wide range of applications including medical, therapies, cosmetics, paper, pulp and textile industries, biotechnology, and food applications. This current review article present the utilization of shrimp waste as well as an alternative technology to replace hazardous chemical method that address the future trends in total utilization of shrimp waste for recovery of bioactive compounds.

DEVELOPMENT AND APPLICATION OF A NEW AIR POLLUTION MODELING SYSTEM--II. AEROSOL MODULE STRUCTURE AND DESIGN (R823186)

EPA Science Inventory

The methods used for simulating aerosol physical and chemical processes in a new air pollution modeling system are discussed and analyzed. Such processes include emissions, nucleation, coagulation, reversible chemistry, condensation, dissolution, evaporation, irreversible chem...

Computational Modeling in Structural Materials Processing

NASA Technical Reports Server (NTRS)

Meyyappan, Meyya; Arnold, James O. (Technical Monitor)

1997-01-01

High temperature materials such as silicon carbide, a variety of nitrides, and ceramic matrix composites find use in aerospace, automotive, machine tool industries and in high speed civil transport applications. Chemical vapor deposition (CVD) is widely used in processing such structural materials. Variations of CVD include deposition on substrates, coating of fibers, inside cavities and on complex objects, and infiltration within preforms called chemical vapor infiltration (CVI). Our current knowledge of the process mechanisms, ability to optimize processes, and scale-up for large scale manufacturing is limited. In this regard, computational modeling of the processes is valuable since a validated model can be used as a design tool. The effort is similar to traditional chemically reacting flow modeling with emphasis on multicomponent diffusion, thermal diffusion, large sets of homogeneous reactions, and surface chemistry. In the case of CVI, models for pore infiltration are needed. In the present talk, examples of SiC nitride, and Boron deposition from the author's past work will be used to illustrate the utility of computational process modeling.

Sequential ozone advanced oxidation and biological oxidation processes to remove selected pharmaceutical contaminants from an urban wastewater.

PubMed

Espejo, Azahara; Aguinaco, Almudena; García-Araya, J F; Beltrán, Fernando J

2014-01-01

Sequential treatments consisting in a chemical process followed by a conventional biological treatment, have been applied to remove mixtures of nine contaminants of pharmaceutical type spiked in a primary sedimentation effluent of a municipal wastewater. Combinations of ozone, UVA black light (BL) and Fe(III) or Fe₃O₄ catalysts constituted the chemical systems. Regardless of the Advanced Oxidation Process (AOP), the removal of pharmaceutical compounds was achieved in 1 h of reaction, while total organic carbon (TOC) only diminished between 3.4 and 6%. Among selected ozonation systems to be implemented before the biological treatment, the application of ozone alone in the pre-treatment stage is recommended due to the increase of the biodegradability observed. The application of ozone followed by the conventional biological treatment leads high TOC and COD removal rates, 60 and 61%, respectively, and allows the subsequent biological treatment works with shorter hydraulic residence time (HRT). Moreover, the influence of the application of AOPs before and after a conventional biological process was compared, concluding that the decision to take depends on the characterization of the initial wastewater with pharmaceutical compounds.

Surface and interface sciences of Li-ion batteries. -Research progress in electrode-electrolyte interface-

NASA Astrophysics Data System (ADS)

Minato, Taketoshi; Abe, Takeshi

2017-12-01

The application potential of Li-ion batteries is growing as demand increases in different fields at various stages in energy systems, in addition to their conventional role as power sources for portable devices. In particular, applications in electric vehicles and renewable energy storage are increasing for Li-ion batteries. For these applications, improvements in battery performance are necessary. The Li-ion battery produces and stores electric power from the electrochemical redox reactions between the electrode materials. The interface between the electrodes and electrolyte strongly affects the battery performance because the charge transfer causing the electrode redox reaction begins at this interface. Understanding of the surface structure, electronic structure, and chemical reactions at the electrode-electrolyte interface is necessary to improve battery performance. However, the interface is located between the electrode and electrolyte materials, hindering the experimental analysis of the interface; thus, the physical properties and chemical processes have remained poorly understood until recently. Investigations of the physical properties and chemical processes at the interface have been performed using advanced surface science techniques. In this review, current knowledge and future research prospects regarding the electrode-electrolyte interface are described for the further development of Li-ion batteries.

Handheld hyperspectral imager for standoff detection of chemical and biological aerosols

NASA Astrophysics Data System (ADS)

Hinnrichs, Michele; Jensen, James O.; McAnally, Gerard

2004-02-01

Pacific Advanced Technology has developed a small hand held imaging spectrometer, Sherlock, for gas leak and aerosol detection and imaging. The system is based on a patent technique that uses diffractive optics and image processing algorithms to detect spectral information about objects in the scene of the camera (IMSS Image Multi-spectral Sensing). This camera has been tested at Dugway Proving Ground and Dstl Porton Down facility looking at Chemical and Biological agent simulants. The camera has been used to investigate surfaces contaminated with chemical agent simulants. In addition to Chemical and Biological detection the camera has been used for environmental monitoring of green house gases and is currently undergoing extensive laboratory and field testing by the Gas Technology Institute, British Petroleum and Shell Oil for applications for gas leak detection and repair. The camera contains an embedded Power PC and a real time image processor for performing image processing algorithms to assist in the detection and identification of gas phase species in real time. In this paper we will present an over view of the technology and show how it has performed for different applications, such as gas leak detection, surface contamination, remote sensing and surveillance applications. In addition a sampling of the results form TRE field testing at Dugway in July of 2002 and Dstl at Porton Down in September of 2002 will be given.

Multiphysics Modeling and Simulations of Mil A46100 Armor-Grade Martensitic Steel Gas Metal Arc Welding Process

DTIC Science & Technology

2013-05-23

simulation of the conventional Gas Metal Arc Welding (GMAW) process, and the application of the developed methods and tools for prediction of the...technology in many industries such as chemical, oil , aerospace, and shipbuilding construction. In fact, within the metal fabrication industry as a...Mechanical Properties of Low Alloy Steel Products. Hardenability Concepts with Applications to Steel, The Metallurgical Society of AIME, Chicago, 1978, p

High Sensitivity, Low Power Nano Sensors and Devices for Chemical Sensing

NASA Technical Reports Server (NTRS)

Li, Jing; Powell, Dan; Getty, Stephanie; Lu, Yi-Jiang

2004-01-01

The chemical sensor market has been projected to grow to better than $40 billion dollars worldwide within the next 10 years. Some of the primary motivations to develop nanostructured chemical sensors are monitoring and control of environmental pollution; improved diagnostics for consumption; improvement in measurement precision and accuracy; and improved detection limits for Homeland security, battlefield environments, and process and quality control of industrial applications. In each of these applications, there is demand for sensitivity, selectivity and stability of environmental and biohazard detection and capture beyond what is currently commercially available. Nanotechnology offers the ability to work at the molecular level, atom by atom, to create large structures with fundamentally new molecular organization. It is essentially concerned with materials, devices, and systems whose structures and components exhibit novel and significantly improved physical, chemical and biological properties, phenomena, and process control due to their nanoscale size. One such nanotechnology-enabled chemical sensor has been developed at NASA Ames leveraging nanostructures, such as single walled carbon nanotubes (SWNTs) and metal oxide nanobelts or nanowires, as a sensing medium bridging a pair of interdigitated electrodes (IDE) realized through a silicon-based microfabrication and micromachining technique. The DE fingers are fabricated on a silicon substrate using standard photolithography and thin film metallization techniques. It is noteworthy that the fabrication techniques employed are not confined to the silicon substrate. Through spin casting and careful substrate selection (i.e. clothing, glass, polymer, etc.), additional degrees of freedom can be exploited to enhance sensitivity or to conform to unique applications. Both in-situ growth of nanostructured materials and casting of nanostructured dispersions were used to produce analogous chemical sensing devices.

Nanomotor dynamics in a chemically oscillating medium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robertson, Bryan, E-mail: bryan.robertson@mail.utoronto.ca; Kapral, Raymond, E-mail: rkapral@chem.utoronto.ca

2015-04-21

Synthetic nanomotors powered by chemical reactions have potential uses as cargo transport vehicles in both in vivo and in vitro applications. In many situations, motors will have to operate in out-of-equilibrium complex chemically reacting media, which supply fuel to the motors and remove the products they produce. Using molecular simulation and mean-field theory, this paper describes some of the new features that arise when a chemically powered nanomotor, operating through a diffusiophoretic mechanism, moves in an environment that supports an oscillatory chemical reaction network. It is shown how oscillations in the concentrations in chemical species in the environment give risemore » to oscillatory motor dynamics. More importantly, since the catalytic reactions on the motor that are responsible for its propulsion couple to the bulk phase reaction network, the motor can change its local environment. This process can give rise to distinctive spatiotemporal structures in reaction-diffusion media that occur as a result of active motor motion. Such locally induced nonequilibrium structure will play an important role in applications that involve motor dynamics in complex chemical media.« less

Listed waste determination report. Environmental characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-06-01

On September 23, 1988, the US Environmental Protection Agency (EPA) published a notice clarifying interim status requirements for the management of radioactive mixed waste thereby subjecting the Idaho National Engineering Laboratory (INEL) and other applicable Department of Energy (DOE) sites to regulation under the Resource Conservation and Recovery Act (RCRA). Therefore, the DOE was required to submit a Part A Permit application for each treatment, storage, and disposal (TSD) unit within the INEL, defining the waste codes and processes to be regulated under RCRA. The September 1990 revised Part A Permit application, that was approved by the State of Idahomore » identified 101 potential acute and toxic hazardous waste codes (F-, P-, and U- listed wastes according to 40 CFR 261.31 and 40 CFR 261.33) for some TSD units at the Idaho Chemical Processing Plant. Most of these waste were assumed to have been introduced into the High-level Liquid Waste TSD units via laboratory drains connected to the Process Equipment Waste (PEW) evaporator (PEW system). At that time, a detailed and systematic evaluation of hazardous chemical use and disposal practices had not been conducted to determine if F-, P-, or Unlisted waste had been disposed to the PEW system. The purpose of this investigation was to perform a systematic and detailed evaluation of the use and disposal of the 101 F-, P-, and Unlisted chemicals found in the approved September 1990 Part A Permit application. This investigation was aimed at determining which listed wastes, as defined in 40 CFR 261.31 (F-listed) and 261.33 (P & Unlisted) were discharged to the PEW system. Results of this investigation will be used to support revisions to the RCRA Part A Permit application.« less

Silicone Resin Applications for Ceramic Precursors and Composites

PubMed Central

Narisawa, Masaki

2010-01-01

This article reviews the applications of silicone resins as ceramic precursors. The historical background of silicone synthesis chemistry is introduced to explain the production costs and supply availability of various silicones. Thermal degradation processes of silicones are classified in terms of the main chain structure and cyclic oligomer expulsion process, which determine the resulting ceramic yield and the chemical composition. The high temperature decomposition of Si-O-C beyond 1,400 °C in an inert atmosphere and formation of a protective silica layer on material surfaces beyond 1,200 °C in an oxidative atmosphere are discussed from the viewpoints of the wide chemical composition of the Si-O-C materials. Applications of the resins for binding agents, as starting materials for porous ceramics, matrix sources with impregnation, fiber spinning and ceramic adhesions are introduced. The recent development of the process of filler or cross-linking agent additions to resin compounds is also introduced. Such resin compounds are useful for obtaining thick coatings, MEMS parts and bulk ceramics, which are difficult to obtain by pyrolysis of simple organometallic precursors without additives.

A new approach for remediation of As-contaminated soil: ball mill-based technique.

PubMed

Shin, Yeon-Jun; Park, Sang-Min; Yoo, Jong-Chan; Jeon, Chil-Sung; Lee, Seung-Woo; Baek, Kitae

2016-02-01

In this study, a physical ball mill process instead of chemical extraction using toxic chemical agents was applied to remove arsenic (As) from contaminated soil. A statistical analysis was carried out to establish the optimal conditions for ball mill processing. As a result of the statistical analysis, approximately 70% of As was removed from the soil at the following conditions: 5 min, 1.0 cm, 10 rpm, and 5% of operating time, media size, rotational velocity, and soil loading conditions, respectively. A significant amount of As remained in the grinded fine soil after ball mill processing while more than 90% of soil has the original properties to be reused or recycled. As a result, the ball mill process could remove the metals bound strongly to the surface of soil by the surface grinding, which could be applied as a pretreatment before application of chemical extraction to reduce the load.

Controlled membrane translocation provides a mechanism for signal transduction and amplification

NASA Astrophysics Data System (ADS)

Langton, Matthew J.; Keymeulen, Flore; Ciaccia, Maria; Williams, Nicholas H.; Hunter, Christopher A.

2017-05-01

Transmission and amplification of chemical signals across lipid bilayer membranes is of profound significance in many biological processes, from the development of multicellular organisms to information processing in the nervous system. In biology, membrane-spanning proteins are responsible for the transmission of chemical signals across membranes, and signal transduction is often associated with an amplified signalling cascade. The ability to reproduce such processes in artificial systems has potential applications in sensing, controlled drug delivery and communication between compartments in tissue-like constructs of synthetic vesicles. Here we describe a mechanism for transmitting a chemical signal across a membrane based on the controlled translocation of a synthetic molecular transducer from one side of a lipid bilayer membrane to the other. The controlled molecular motion has been coupled to the activation of a catalyst on the inside of a vesicle, which leads to a signal-amplification process analogous to the biological counterpart.

Gaalas/Gaas Solar Cell Process Study

NASA Technical Reports Server (NTRS)

Almgren, D. W.; Csigi, K. I.

1980-01-01

Available information on liquid phase, vapor phase (including chemical vapor deposition) and molecular beam epitaxy growth procedures that could be used to fabricate single crystal, heteroface, (AlGa) As/GaAs solar cells, for space applications is summarized. A comparison of the basic cost elements of the epitaxy growth processes shows that the current infinite melt LPE process has the lower cost per cell for an annual production rate of 10,000 cells. The metal organic chemical vapor deposition (MO-CVD) process has the potential for low cost production of solar cells but there is currently a significant uncertainty in process yield, i.e., the fraction of active material in the input gas stream that ends up in the cell. Additional work is needed to optimize and document the process parameters for the MO-CVD process.

Thermozymes and their applications: a review of recent literature and patents.

PubMed

Bruins, M E; Janssen, A E; Boom, R M

2001-02-01

Enzymes from thermophilic microorganisms, thermozymes, have unique characteristics such as temperature, chemical, and pH stability. They can be used in several industrial processes, in which they replace mesophilic enzymes or chemicals. Thermozymes are often used when the enzymatic process is compatible with existing (high-temperature) process conditions. The main advantages of performing processes at higher temperatures are reduced risk of microbial contamination, lower viscosity, improved transfer rates, and improved solubility of substrates. However, cofactors, substrates, or products might be unstable or other side reactions may occur. Recent developments show that thermophiles are a good source of novel catalysts that are of great industrial interest. Thermostable polymer-degrading enzymes such as amylases, pullulanases, xylanases, proteases, and cellulases are expected to play an important role in food, chemical, pharmaceutical, paper, pulp, and waste-treatment industries. Considerable research efforts have been made to better understand the stability of thermozymes. There are no major conformational differences with mesophilic enzymes, and a small number of extra salt bridges, hydrophobic interactions, or hydrogen bounds seem to confer the extra degree of stabilization. Currently, overexpression of thermozymes in standard Escherichia coli allows the production of much larger quantities of enzymes, which are easy to purify by heat treatment. With wider availability and lower cost, thermophilic enzymes will see more application in industry.

Chemical degradation and morphological instabilities during focused ion beam prototyping of polymers.

PubMed

Orthacker, A; Schmied, R; Chernev, B; Fröch, J E; Winkler, R; Hobisch, J; Trimmel, G; Plank, H

2014-01-28

Focused ion beam processing of low melting materials, such as polymers or biological samples, often leads to chemical and morphological instabilities which prevent the straight-forward application of this versatile direct-write structuring method. In this study the behaviour of different polymer classes under ion beam exposure is investigated using different patterning parameters and strategies with the aim of (i) correlating local temperatures with the polymers' chemistry and its morphological consequences; and (ii) finding a way of processing sensitive polymers with lowest chemical degradation while maintaining structuring times. It is found that during processing of polymers three temperature regimes can be observed: (1) at low temperatures all polymers investigated show stable chemical and morphological behaviour; (2) very high temperatures lead to strong chemical degradation which entails unpredictable morphologies; and (3) in the intermediate temperature regime the behaviour is found to be strongly material dependent. A detailed look reveals that polymers which rather cross-link in the proximity of the beam show stable morphologies in this intermediate regime, while polymers that rather undergo chain scission show tendencies to develop a creeping phase, where material follows the ion beam movement leading to instable and unpredictable morphologies. Finally a simple, alternative patterning strategy is suggested, which allows stable processing conditions with lowest chemical damage even for challenging polymers undergoing chain scission.

Chemicals to enhance microalgal growth and accumulation of high-value bioproducts

PubMed Central

Yu, Xinheng; Chen, Lei; Zhang, Weiwen

2015-01-01

Photosynthetic microalgae have attracted significant attention as they can serve as important sources for cosmetic, food and pharmaceutical products, industrial materials and even biofuel biodiesels. However, current productivity of microalga-based processes is still very low, which has restricted their scale-up application. In addition to various efforts in strain improvement and cultivation optimization, it was proposed that the productivity of microalga-based processes can also be increased using various chemicals to trigger or enhance cell growth and accumulation of bioproducts. Herein, we summarized recent progresses in applying chemical triggers or enhancers to improve cell growth and accumulation of bioproducts in algal cultures. Based on their enhancing mechanisms, these chemicals can be classified into four categories:chemicals regulating biosynthetic pathways, chemicals inducing oxidative stress responses, phytohormones and analogs regulating multiple aspects of microalgal metabolism, and chemicals directly as metabolic precursors. Taken together, the early researches demonstrated that the use of chemical stimulants could be a very effective and economical way to improve cell growth and accumulation of high-value bioproducts in large-scale cultivation of microalgae. PMID:25741321

Low-temperature ({<=}200 Degree-Sign C) plasma enhanced atomic layer deposition of dense titanium nitride thin films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samal, Nigamananda; Du Hui; Luberoff, Russell

Titanium nitride (TiN) has been widely used in the semiconductor industry for its diffusion barrier and seed layer properties. However, it has seen limited adoption in other industries in which low temperature (<200 Degree-Sign C) deposition is a requirement. Examples of applications which require low temperature deposition are seed layers for magnetic materials in the data storage (DS) industry and seed and diffusion barrier layers for through-silicon-vias (TSV) in the MEMS industry. This paper describes a low temperature TiN process with appropriate electrical, chemical, and structural properties based on plasma enhanced atomic layer deposition method that is suitable for themore » DS and MEMS industries. It uses tetrakis-(dimethylamino)-titanium as an organometallic precursor and hydrogen (H{sub 2}) as co-reactant. This process was developed in a Veeco NEXUS Trade-Mark-Sign chemical vapor deposition tool. The tool uses a substrate rf-biased configuration with a grounded gas shower head. In this paper, the complimentary and self-limiting character of this process is demonstrated. The effects of key processing parameters including temperature, pulse time, and plasma power are investigated in terms of growth rate, stress, crystal morphology, chemical, electrical, and optical properties. Stoichiometric thin films with growth rates of 0.4-0.5 A/cycle were achieved. Low electrical resistivity (<300 {mu}{Omega} cm), high mass density (>4 g/cm{sup 3}), low stress (<250 MPa), and >85% step coverage for aspect ratio of 10:1 were realized. Wet chemical etch data show robust chemical stability of the film. The properties of the film have been optimized to satisfy industrial viability as a Ruthenium (Ru) preseed liner in potential data storage and TSV applications.« less

Lanthipeptides: chemical synthesis versus in vivo biosynthesis as tools for pharmaceutical production.

PubMed

Ongey, Elvis Legala; Neubauer, Peter

2016-06-07

Lanthipeptides (also called lantibiotics for those with antibacterial activities) are ribosomally synthesized post-translationally modified peptides having thioether cross-linked amino acids, lanthionines, as a structural element. Lanthipeptides have conceivable potentials to be used as therapeutics, however, the lack of stable, high-yield, well-characterized processes for their sustainable production limit their availability for clinical studies and further pharmaceutical commercialization. Though many reviews have discussed the various techniques that are currently employed to produce lanthipeptides, a direct comparison between these methods to assess industrial applicability has not yet been described. In this review we provide a synoptic comparison of research efforts on total synthesis and in vivo biosynthesis aimed at fostering lanthipeptides production. We further examine current applications and propose measures to enhance product yields. Owing to their elaborate chemical structures, chemical synthesis of these biomolecules is economically less feasible for large-scale applications, and hence biological production seems to be the only realistic alternative.

Carbon nanotubes: engineering biomedical applications.

PubMed

Gomez-Gualdrón, Diego A; Burgos, Juan C; Yu, Jiamei; Balbuena, Perla B

2011-01-01

Carbon nanotubes (CNTs) are cylinder-shaped allotropic forms of carbon, most widely produced under chemical vapor deposition. They possess astounding chemical, electronic, mechanical, and optical properties. Being among the most promising materials in nanotechnology, they are also likely to revolutionize medicine. Among other biomedical applications, after proper functionalization carbon nanotubes can be transformed into sophisticated biosensing and biocompatible drug-delivery systems, for specific targeting and elimination of tumor cells. This chapter provides an introduction to the chemical and electronic structure and properties of single-walled carbon nanotubes, followed by a description of the main synthesis and post-synthesis methods. These sections allow the reader to become familiar with the specific characteristics of these materials and the manner in which these properties may be dependent on the specific synthesis and post-synthesis processes. The chapter ends with a review of the current biomedical applications of carbon nanotubes, highlighting successes and challenges. Copyright © 2011 Elsevier Inc. All rights reserved.

Linking performance benchmarking of refinery process chemicals to refinery key performance indicators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cook, J.M.; Nieman, L.D.

In 1977 Solomon Associates, Inc. issued its first study of refining in the US entitled, Comparative Performance Analysis for Fuel Product Refineries, most commonly referred to as the Solomon Study, or the Fuels Study. In late 1993, both the Water and Waste Water Management, and Petroleum Divisions of Nalco Chemical Company came to the same conclusion; that they must have a better understanding of the Solomon Study process, and have some input to this system of measurement. The authors first approached Solomon Associates with the idea that a specific study should be done of specialty chemicals used in the refinery.more » They felt that this would result in two studies, one for water treatment applications, and one for process. The water treatment study came first, and was completed in 1993 with the United States Petroleum Refineries Water Treatment Performance Analysis for Operating Year 1993. The process study, entitled United States Petroleum Refinery Process Treatment Performance Analysis for Operating Years 1994--95 will be issued in the 2nd quarter of this year by Nalco/Exxon Energy Chemicals, L.P, which includes the combined resources of the former Petroleum Division of Nalco Chemical Company (including the petroleum related portions of most of its overseas companies), and the petroleum related specialty chemical operations of Exxon Chemical on a global basis. What follows is a recap of the process study focus, some examples of output, and comment on both the linkage to key refinery operating indicators, as well as the perception of the effect of such measurement on the supplier relationship of the future.« less

Tuning of PID controller using optimization techniques for a MIMO process

NASA Astrophysics Data System (ADS)

Thulasi dharan, S.; Kavyarasan, K.; Bagyaveereswaran, V.

2017-11-01

In this paper, two processes were considered one is Quadruple tank process and the other is CSTR (Continuous Stirred Tank Reactor) process. These are majorly used in many industrial applications for various domains, especially, CSTR in chemical plants.At first mathematical model of both the process is to be done followed by linearization of the system due to MIMO process and controllers are the major part to control the whole process to our desired point as per the applications so the tuning of the controller plays a major role among the whole process. For tuning of parameters we use two optimizations techniques like Particle Swarm Optimization, Genetic Algorithm. The above techniques are majorly used in different applications to obtain which gives the best among all, we use these techniques to obtain the best tuned values among many. Finally, we will compare the performance of the each process with both the techniques.

Lift-off process with bi-layer photoresist patterns for conformal-coated superhydrophilic pulsed plasma chemical vapor deposition-SiOx on SiCx for lab-on-a-chip applications

NASA Astrophysics Data System (ADS)

Konishi, Satoshi; Nakagami, Chise; Kobayashi, Taizo; Tonomura, Wataru; Kaizuma, Yoshihiro

2015-04-01

In this work, a lift-off process with bi-layer photoresist patterns was applied to the formation of hydrophobic/hydrophilic micropatterns on practical polymer substrates used in healthcare diagnostic commercial products. The bi-layer photoresist patterns with undercut structures made it possible to peel the conformal-coated silicon oxide (SiOx) films from substrates. SiOx and silicon carbide (SiCx) layers were deposited by pulsed plasma chemical vapor deposition (PPCVD) method which can form roughened surfaces to enhance hydrophilicity of SiOx and hydrophobicity of SiCx. Microfluidic applications using hydrophobic/hydrophilic patterns were also demonstrated on low-cost substrates such as poly(ethylene terephthalate) (PET) and paper films.

Applications of a job classification system in occupational epidemiology.

PubMed Central

Gamble, J F; Spirtas, R; Easter, P

1976-01-01

An occupational preventive medicine program attempts to control exposure so workers experience no detrimental effect on health. In a chemically complex industry, the definition of exposure is difficult because of the many different chemicals used and produced, the many different jobs and processes with qualitatively different exposures, and the movement of workers from job to job. Jobs have therefore been grouped on the basis of process or product into functionally homogeneous categories called occupational titles (OT's). Work experience can now be quantified independent of exposure (or by the dominant toxicants in each OT) and compared to health outcomes. Examples are discussed of the application of OT's to studies of the mortality and morbidity experience in the rubber industry, and the development of dose-response relations. PMID:961945

A breakthrough in enzyme technology to fight penicillin resistance-industrial application of penicillin amidase.

PubMed

Buchholz, Klaus

2016-05-01

Enzymatic penicillin hydrolysis by penicillin amidase (also penicillin acylase, PA) represents a Landmark: the first industrially and economically highly important process using an immobilized biocatalyst. Resistance of infective bacteria to antibiotics had become a major topic of research and industrial activities. Solutions to this problem, the antibiotics resistance of infective microorganisms, required the search for new antibiotics, but also the development of derivatives, notably penicillin derivatives, that overcame resistance. An obvious route was to hydrolyse penicillin to 6-aminopenicillanic acid (6-APA), as a first step, for the introduction via chemical synthesis of various different side chains. Hydrolysis via chemical reaction sequences was tedious requiring large amounts of toxic chemicals, and they were cost intensive. Enzymatic hydrolysis using penicillin amidase represented a much more elegant route. The basis for such a solution was the development of techniques for enzyme immobilization, a highly difficult task with respect to industrial application. Two pioneer groups started to develop solutions to this problem in the late 1960s and 1970s: that of Günter Schmidt-Kastner at Bayer AG (Germany) and that of Malcolm Lilly of Imperial College London. Here, one example of this development, that at Bayer, will be presented in more detail since it illustrates well the achievement of a solution to the problems of industrial application of enzymatic processes, notably development of an immobilization method for penicillin amidase suitable for scale up to application in industrial reactors under economic conditions. A range of bottlenecks and technical problems of large-scale application had to be overcome. Data giving an inside view of this pioneer achievement in the early phase of the new field of biocatalysis are presented. The development finally resulted in a highly innovative and commercially important enzymatic process to produce 6-APA that created a new antibiotics industry and that opened the way for the establishment of over 100 industrial processes with immobilized biocatalysts worldwide today.

In situ chemical synthesis of ruthenium oxide/reduced graphene oxide nanocomposites for electrochemical capacitor applications.

PubMed

Kim, Ji-Young; Kim, Kwang-Heon; Yoon, Seung-Beom; Kim, Hyun-Kyung; Park, Sang-Hoon; Kim, Kwang-Bum

2013-08-07

An in situ chemical synthesis approach has been developed to prepare ruthenium oxide/reduced graphene oxide (RGO) nanocomposites. It is found that as the C/O ratio increases, the number density of RuO2 nanoparticles decreases, because the chemical interaction between the Ru ions and the oxygen-containing functional groups provides anchoring sites where the nucleation of particles takes place. For electrochemical capacitor applications, the microwave-hydrothermal process was carried out to improve the conductivity of RGO in RuO2/RGO nanocomposites. The significant improvement in capacitance and high rate capability might result from the RuO2 nanoparticles used as spacers that make the interior layers of the reduced graphene oxide electrode available for electrolyte access.

Metabolic engineering of yeast for production of fuels and chemicals.

PubMed

Nielsen, Jens; Larsson, Christer; van Maris, Antonius; Pronk, Jack

2013-06-01

Microbial production of fuels and chemicals from renewable carbohydrate feedstocks offers sustainable and economically attractive alternatives to their petroleum-based production. The yeast Saccharomyces cerevisiae offers many advantages as a platform cell factory for such applications. Already applied on a huge scale for bioethanol production, this yeast is easy to genetically engineer, its physiology, metabolism and genetics have been intensively studied and its robustness enables it to handle harsh industrial conditions. Introduction of novel pathways and optimization of its native cellular processes by metabolic engineering are rapidly expanding its range of cell-factory applications. Here we review recent scientific progress in metabolic engineering of S. cerevisiae for the production of bioethanol, advanced biofuels, and chemicals. Copyright © 2013 Elsevier Ltd. All rights reserved.

A process for the chemical preparation of high-field ZnO varistors

DOEpatents

Brooks, R.A.; Dosch, R.G.; Tuttle, B.A.

1986-02-19

Chemical preparation techniques involving co-precipitation of metals are used to provide microstructural characteristics necessary in order to produce ZnO varistors and their precursors for high field applications. The varistors produced have homogeneous and/or uniform dopant distributions and a submicron average grain size with a narrow size distribution. Precursor powders are prepared via chemical precipitation techniques and varistors made by sintering uniaxially and/or isostatically pressed pellets. Using these methods, varistors were made which were suitable for high-power applications, having values of breakdown field, E/sub B/, in the 10 to 100 kV/cm range, ..cap alpha.. > 30 and densities in the range of 65 to 99% of theoretical, depending on both composition and sintering temperature.

Process for the chemical preparation of high-field ZnO varistors

DOEpatents

Brooks, Robert A.; Dosch, Robert G.; Tuttle, Bruce A.

1987-01-01

Chemical preparation techniques involving co-precipitation of metals are used to provide micro-structural characteristics necessary in order to produce ZnO varistors and their precursors for high field applications. The varistors produced have homogeneous and/or uniform dopant distributions and a submicron average grain size with a narrow size distribution. Precursor powders are prepared via chemical precipitation techniques and varistors made by sintering uniaxially and/or isostatically pressed pellets. Using these methods, varistors were made which were suitable for high-power applications, having values of breakdown field, E.sub.B, in the 10-100 kV/cm range, .alpha.>30 and densities in the range of 65-99% of theoretical, depending on both composition and sintering temperature.

Modeling of Laser Material Interactions

NASA Astrophysics Data System (ADS)

Garrison, Barbara

2009-03-01

Irradiation of a substrate by laser light initiates the complex chemical and physical process of ablation where large amounts of material are removed. Ablation has been successfully used in techniques such as nanolithography and LASIK surgery, however a fundamental understanding of the process is necessary in order to further optimize and develop applications. To accurately describe the ablation phenomenon, a model must take into account the multitude of events which occur when a laser irradiates a target including electronic excitation, bond cleavage, desorption of small molecules, ongoing chemical reactions, propagation of stress waves, and bulk ejection of material. A coarse grained molecular dynamics (MD) protocol with an embedded Monte Carlo (MC) scheme has been developed which effectively addresses each of these events during the simulation. Using the simulation technique, thermal and chemical excitation channels are separately studied with a model polymethyl methacrylate system. The effects of the irradiation parameters and reaction pathways on the process dynamics are investigated. The mechanism of ablation for thermal processes is governed by a critical number of bond breaks following the deposition of energy. For the case where an absorbed photon directly causes a bond scission, ablation occurs following the rapid chemical decomposition of material. The study provides insight into the influence of thermal and chemical processes in polymethyl methacrylate and facilitates greater understanding of the complex nature of polymer ablation.

Enhanced Teaching and Student Learning through a Simulator-Based Course in Chemical Unit Operations Design

ERIC Educational Resources Information Center

Ghasem, Nayef

2016-01-01

This paper illustrates a teaching technique used in computer applications in chemical engineering employed for designing various unit operation processes, where the students learn about unit operations by designing them. The aim of the course is not to teach design, but rather to teach the fundamentals and the function of unit operation processes…

Technologies for deposition of transition metal oxide thin films: application as functional layers in “Smart windows” and photocatalytic systems

NASA Astrophysics Data System (ADS)

Gesheva, K.; Ivanova, T.; Bodurov, G.; Szilágyi, I. M.; Justh, N.; Kéri, O.; Boyadjiev, S.; Nagy, D.; Aleksandrova, M.

2016-02-01

“Smart windows” are envisaged for future low-energy, high-efficient architectural buildings, as well as for the car industry. By switching from coloured to fully bleached state, these windows regulate the energy of solar flux entering the interior. Functional layers in these devices are the transition metals oxides. The materials (transitional metal oxides) used in smart windows can be also applied as photoelectrodes in water splitting photocells for hydrogen production or as photocatalytic materials for self-cleaning surfaces, waste water treatment and pollution removal. Solar energy utilization is recently in the main scope of numerous world research laboratories and energy organizations, working on protection against conventional fuel exhaustion. The paper presents results from research on transition metal oxide thin films, fabricated by different methods - atomic layer deposition, atmospheric pressure chemical vapour deposition, physical vapour deposition, and wet chemical methods, suitable for flowthrough production process. The lower price of the chemical deposition processes is especially important when the method is related to large-scale glazing applications. Conclusions are derived about which processes are recently considered as most prospective, related to electrochromic materials and devices manufacturing.

Encapsulation of Natural Polyphenolic Compounds; a Review

PubMed Central

Munin, Aude; Edwards-Lévy, Florence

2011-01-01

Natural polyphenols are valuable compounds possessing scavenging properties towards radical oxygen species, and complexing properties towards proteins. These abilities make polyphenols interesting for the treatment of various diseases like inflammation or cancer, but also for anti-ageing purposes in cosmetic formulations, or for nutraceutical applications. Unfortunately, these properties are also responsible for a lack in long-term stability, making these natural compounds very sensitive to light and heat. Moreover, polyphenols often present a poor biodisponibility mainly due to low water solubility. Lastly, many of these molecules possess a very astringent and bitter taste, which limits their use in food or in oral medications. To circumvent these drawbacks, delivery systems have been developed, and among them, encapsulation would appear to be a promising approach. Many encapsulation methods are described in the literature, among which some have been successfully applied to plant polyphenols. In this review, after a general presentation of the large chemical family of plant polyphenols and of their main chemical and biological properties, encapsulation processes applied to polyphenols are classified into physical, physico-chemical, chemical methods, and other connected stabilization methods. After a brief description of each encapsulation process, their applications to polyphenol encapsulation for pharmaceutical, food or cosmetological purposes are presented. PMID:24309309

Perspective: Aerosol microphysics: From molecules to the chemical physics of aerosols

NASA Astrophysics Data System (ADS)

Bzdek, Bryan R.; Reid, Jonathan P.

2017-12-01

Aerosols are found in a wide diversity of contexts and applications, including the atmosphere, pharmaceutics, and industry. Aerosols are dispersions of particles in a gas, and the coupling of the two phases results in highly dynamic systems where chemical and physical properties like size, composition, phase, and refractive index change rapidly in response to environmental perturbations. Aerosol particles span a wide range of sizes from 1 nm to tens of micrometres or from small molecular clusters that may more closely resemble gas phase molecules to large particles that can have similar qualities to bulk materials. However, even large particles with finite volumes exhibit distinct properties from the bulk condensed phase, due in part to their higher surface-to-volume ratio and their ability to easily access supersaturated solute states inaccessible in the bulk. Aerosols represent a major challenge for study because of the facile coupling between the particle and gas, the small amounts of sample available for analysis, and the sheer breadth of operative processes. Time scales of aerosol processes can be as short as nanoseconds or as long as years. Despite their very different impacts and applications, fundamental chemical physics processes serve as a common theme that underpins our understanding of aerosols. This perspective article discusses challenges in the study of aerosols and highlights recent chemical physics advancements that have enabled improved understanding of these complex systems.

Chemical copatterning strategies using azlactone-based block copolymers

DOE PAGES

Masigol, Mohammadali; Barua, Niloy; Retterer, Scott T.; ...

2017-09-01

Interfaces can be modified with azlactone-functional polymers in order to manipulate the chemical surface reactivity. Azlactone groups are highly reactive toward amine, thiol, and alcohol nucleophiles, providing a versatile coupling chemistry for secondary surface modification. Azlactone-based surface polymers have been explored in numerous applications, including chemical and biological capture, sensing, and cell culture. These applications often require that the polymer is copatterned within a chemically or biologically inert background; however, common fabrication methods degrade azlactone groups during processing steps or result in polymer films with poorly controlled thicknesses. Here, the authors develop fabrication strategies using parylene lift-off and interface-directed assemblymore » methods to generate microscale patterns of azlactone-based block copolymer in chemically or biologically inert backgrounds. The functionality of azlactone groups was preserved during fabrication, and patterned films appeared as uniform, 80–120nm brushlike films. The authors also develop a patterning approach that uses a novel microcontact stamping method to generate cross-linked, three-dimensional structures of azlactone-based polymers with controllable, microscale thicknesses. The authors identify the benefits of each approach and expect these polymers and patterning strategies to provide a versatile toolbox for developing synthetic interfaces with tuned chemical and physical features for sensing, cell culture, or material capture applications.« less

Chemical copatterning strategies using azlactone-based block copolymers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masigol, Mohammadali; Barua, Niloy; Retterer, Scott T.

Interfaces can be modified with azlactone-functional polymers in order to manipulate the chemical surface reactivity. Azlactone groups are highly reactive toward amine, thiol, and alcohol nucleophiles, providing a versatile coupling chemistry for secondary surface modification. Azlactone-based surface polymers have been explored in numerous applications, including chemical and biological capture, sensing, and cell culture. These applications often require that the polymer is copatterned within a chemically or biologically inert background; however, common fabrication methods degrade azlactone groups during processing steps or result in polymer films with poorly controlled thicknesses. Here, the authors develop fabrication strategies using parylene lift-off and interface-directed assemblymore » methods to generate microscale patterns of azlactone-based block copolymer in chemically or biologically inert backgrounds. The functionality of azlactone groups was preserved during fabrication, and patterned films appeared as uniform, 80–120nm brushlike films. The authors also develop a patterning approach that uses a novel microcontact stamping method to generate cross-linked, three-dimensional structures of azlactone-based polymers with controllable, microscale thicknesses. The authors identify the benefits of each approach and expect these polymers and patterning strategies to provide a versatile toolbox for developing synthetic interfaces with tuned chemical and physical features for sensing, cell culture, or material capture applications.« less

Silk fibroin as biomaterial for bone tissue engineering.

PubMed

Melke, Johanna; Midha, Swati; Ghosh, Sourabh; Ito, Keita; Hofmann, Sandra

2016-02-01

Silk fibroin (SF) is a fibrous protein which is produced mainly by silkworms and spiders. Its unique mechanical properties, tunable biodegradation rate and the ability to support the differentiation of mesenchymal stem cells along the osteogenic lineage, have made SF a favorable scaffold material for bone tissue engineering. SF can be processed into various scaffold forms, combined synergistically with other biomaterials to form composites and chemically modified, which provides an impressive toolbox and allows SF scaffolds to be tailored to specific applications. This review discusses and summarizes recent advancements in processing SF, focusing on different fabrication and functionalization methods and their application to grow bone tissue in vitro and in vivo. Potential areas for future research, current challenges, uncertainties and gaps in knowledge are highlighted. Silk fibroin is a natural biomaterial with remarkable biomedical and mechanical properties which make it favorable for a broad range of bone tissue engineering applications. It can be processed into different scaffold forms, combined synergistically with other biomaterials to form composites and chemically modified which provides a unique toolbox and allows silk fibroin scaffolds to be tailored to specific applications. This review discusses and summarizes recent advancements in processing silk fibroin, focusing on different fabrication and functionalization methods and their application to grow bone tissue in vitro and in vivo. Potential areas for future research, current challenges, uncertainties and gaps in knowledge are highlighted. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Dense Non-Aqueous Phase Liquids (DNAPLs): Review of Emerging Characterization and Remediation Technologies

DTIC Science & Technology

2000-06-01

the chemical can contact and fully react with contaminants in situ. The advantage of in situ destruction is that the process is completed in the ground...Because chemical oxidation is primarily targeted at dissolved plumes and is only marginally applicable to DNAPL source zones exhibiting relatively low...refer to a “DNAPL plume .” Certainly, a portion of the chemical components of a DNAPL may become dissolved in ground water, and this solution may spread

Laser-enhanced chemical reactions and the liquid state. II. Possible applications to nuclear fuel reprocessing

DOE Office of Scientific and Technical Information (OSTI.GOV)

DePoorter, G.L.; Rofer-DePoorter, C.K.

1976-01-01

Laser photochemistry is surveyed as a possible improvement upon the Purex process for reprocessing spent nuclear fuel. Most of the components of spent nuclear fuel are photochemically active, and lasers can be used to selectively excite individual chemical species. The great variety of chemical species present and the degree of separation that must be achieved present difficulties in reprocessing. Lasers may be able to improve the necessary separations by photochemical reaction or effects on rates and equilibria of reactions. (auth)

Fluid Mixing in the Eye Under Rapid Eye Movement

NASA Astrophysics Data System (ADS)

Huang, Jinglin; Gharib, Morteza

2017-11-01

Drug injection is an important technique in certain treatments of eye diseases. The efficacy of chemical mixing plays an important role in determining pharmacokinetics of injected drugs. In this study, we build a device to study the chemical mixing behavior in a spherical structure. The mixing process is visualized and analyzed qualitatively. We hope to understand the chemical convection and diffusion behaviors in correlation with controlled rapid mechanical movements. The results will have potential applications in treatment of eye diseases. Resnick Institute at Caltech.

40 CFR 439.2 - General monitoring requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... assessment of the process chemistry, products and by-products resulting from each of the manufacturing... applications for approval by the permitting authority, reconfirmed by an annual chemical analysis of wastewater...

40 CFR 439.2 - General monitoring requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... assessment of the process chemistry, products and by-products resulting from each of the manufacturing... applications for approval by the permitting authority, reconfirmed by an annual chemical analysis of wastewater...

40 CFR 439.2 - General monitoring requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... assessment of the process chemistry, products and by-products resulting from each of the manufacturing... applications for approval by the permitting authority, reconfirmed by an annual chemical analysis of wastewater...

Exploring the Q-marker of "sweat soaking method" processed radix Wikstroemia indica: Based on the "effect-toxicity-chemicals" study.

PubMed

Feng, Guo; Chen, Yun-Long; Li, Wei; Li, Lai-Lai; Wu, Zeng-Guang; Wu, Zi-Jun; Hai, Yue; Zhang, Si-Chao; Zheng, Chuan-Qi; Liu, Chang-Xiao; He, Xin

2018-06-01

Radix Wikstroemia indica (RWI), named "Liao Ge Wang" in Chinese, is a kind of toxic Chinese herbal medicine (CHM) commonly used in Miao nationality of South China. "Sweat soaking method" processed RWI could effectively decrease its toxicity and preserve therapeutic effect. However, the underlying mechanism of processing is still not clear, and the Q-markers database for processed RWI has not been established. Our study is to investigate and establish the quality evaluation system and potential Q-markers based on "effect-toxicity-chemicals" relationship of RWI for quality/safety assessment of "sweat soaking method" processing. The variation of RWI in efficacy and toxicity before and after processing was investigated by pharmacological and toxicological studies. Cytotoxicity test was used to screen the cytotoxicity of components in RWI. The material basis in ethanol extract of raw and processed RWI was studied by UPLC-Q-TOF/MS. And the potential Q-markers were analyzed and predicted according to "effect-toxicity-chemical" relationship. RWI was processed by "sweat soaking method", which could preserve efficacy and reduce toxicity. Raw RWI and processed RWI did not show significant difference on the antinociceptive and anti-inflammatory effect, however, the injury of liver and kidney by processed RWI was much weaker than that by raw RWI. The 20 compounds were identified from the ethanol extract of raw product and processed product of RWI using UPLC-Q-TOF/MS, including daphnoretin, emodin, triumbelletin, dibutyl phthalate, Methyl Paraben, YH-10 + OH and matairesinol, arctigenin, kaempferol and physcion. Furthermore, 3 diterpenoids (YH-10, YH-12 and YH-15) were proved to possess the high toxicity and decreased by 48%, 44% and 65%, respectively, which could be regarded as the potential Q-markers for quality/safety assessment of "sweat soaking method" processed RWI. A Q-marker database of processed RWI by "sweat soaking method" was established according to the results and relationship of "effect-toxicity-chemicals", which provided a scientific evidence for processing methods, mechanism and the clinical application of RWI, also provided experimental results to explore the application of Q-marker in CHM. Copyright © 2018 Elsevier GmbH. All rights reserved.

A transformation theory of stochastic evolution in Red Moon methodology to time evolution of chemical reaction process in the full atomistic system.

PubMed

Suzuki, Yuichi; Nagaoka, Masataka

2017-05-28

Atomistic information of a whole chemical reaction system, e.g., instantaneous microscopic molecular structures and orientations, offers important and deeper insight into clearly understanding unknown chemical phenomena. In accordance with the progress of a number of simultaneous chemical reactions, the Red Moon method (a hybrid Monte Carlo/molecular dynamics reaction method) is capable of simulating atomistically the chemical reaction process from an initial state to the final one of complex chemical reaction systems. In the present study, we have proposed a transformation theory to interpret the chemical reaction process of the Red Moon methodology as the time evolution process in harmony with the chemical kinetics. For the demonstration of the theory, we have chosen the gas reaction system in which the reversible second-order reaction H 2 + I 2  ⇌ 2HI occurs. First, the chemical reaction process was simulated from the initial configurational arrangement containing a number of H 2 and I 2 molecules, each at 300 K, 500 K, and 700 K. To reproduce the chemical equilibrium for the system, the collision frequencies for the reactions were taken into consideration in the theoretical treatment. As a result, the calculated equilibrium concentrations [H 2 ] eq and equilibrium constants K eq at all the temperatures were in good agreement with their corresponding experimental values. Further, we applied the theoretical treatment for the time transformation to the system and have shown that the calculated half-life τ's of [H 2 ] reproduce very well the analytical ones at all the temperatures. It is, therefore, concluded that the application of the present theoretical treatment with the Red Moon method makes it possible to analyze reasonably the time evolution of complex chemical reaction systems to chemical equilibrium at the atomistic level.

Aerospace Environmental Technology Conference: Exectutive summary

NASA Technical Reports Server (NTRS)

Whitaker, A. F. (Editor)

1995-01-01

The mandated elimination of CFC's, Halons, TCA, and other ozone depleting chemicals and specific hazardous materials has required changes and new developments in aerospace materials and processes. The aerospace industry has been involved for several years in providing product substitutions, redesigning entire production processes, and developing new materials that minimize or eliminate damage to the environment. These activities emphasize replacement cleaning solvents and their application verifications, compliant coatings including corrosion protection systems, and removal techniques, chemical propulsion effects on the environment, and the initiation of modifications to relevant processing and manufacturing specifications and standards. The papers from this conference are being published in a separate volume as NASA CP-3298.

[Application of enzymes in pulp and paper industry].

PubMed

Lin, Ying

2014-01-01

The application of enzymes has a high potential in the pulp and paper industry to improve the economics of the paper production process and to achieve, at the same time, a reduced environmental burden. Specific enzymes contribute to reduce the amount of chemicals, water and energy in various processes. This review is aimed at presenting the latest progresses of applying enzymes in bio-pulping, bio-bleaching, bio-deinking, enzymatic control of pitch and enzymatic modification of fibers.

Convergent spray process for environmentally friendly coatings

NASA Technical Reports Server (NTRS)

Scarpa, Jack

1995-01-01

Conventional spray application processes have poor transfer efficiencies, resulting in an exorbitant loss in materials, solvents, and time. Also, with ever tightening Environmental Protection Agency (EPA) regulations and Occupational Safety and Health Administration requirements, the low transfer efficiencies have a significant impact on the quantities of materials and solvents that are released into the environment. High solids spray processes are also limited by material viscosities, thus requiring many passes over the surface to achieve a thickness in the 0.125 -inch range. This results in high application costs and a negative impact on the environment. Until recently, requirements for a 100 percent solid sprayable, environmentally friendly, lightweight thermal protection system that can be applied in a thick (greater than 0.125 inch) single-pass operation exceeded the capability of existing systems. Such coatings must be applied by hand lay-up techniques, especially for thermal and/or fire protection systems. The current formulation of these coatings has presented many problems such as worker safety, environmental hazards, waste, high cost, and application constraints. A system which can apply coatings without using hazardous materials would alleviate many of these problems. Potential applications include the aerospace thermal protective specialty coatings, chemical and petroleum industries that require fire-protection coatings that resist impact, chemicals, and weather. These markets can be penetrated by offering customized coatings applied by automated processes that are environmentally friendly.

Expanding the molecular-ruler process through vapor deposition of hexadecanethiol

PubMed Central

Patron, Alexandra M; Hooker, Timothy S; Santavicca, Daniel F

2017-01-01

The development of methods to produce nanoscale features with tailored chemical functionalities is fundamental for applications such as nanoelectronics and sensor fabrication. The molecular-ruler process shows great utility for this purpose as it combines top-down lithography for the creation of complex architectures over large areas in conjunction with molecular self-assembly, which enables precise control over the physical and chemical properties of small local features. The molecular-ruler process, which most commonly uses mercaptoalkanoic acids and metal ions to generate metal-ligated multilayers, can be employed to produce registered nanogaps between metal features. Expansion of this methodology to include molecules with other chemical functionalities could greatly expand the overall versatility, and thus the utility, of this process. Herein, we explore the use of alkanethiol molecules as the terminating layer of metal-ligated multilayers. During this study, it was discovered that the solution deposition of alkanethiol molecules resulted in low overall surface coverage with features that varied in height. Because features with varied heights are not conducive to the production of uniform nanogaps via the molecular-ruler process, the vapor-phase deposition of alkanethiol molecules was explored. Unlike the solution-phase deposition, alkanethiol islands produced by vapor-phase deposition exhibited markedly higher surface coverages of uniform heights. To illustrate the applicability of this method, metal-ligated multilayers, both with and without an alkanethiol capping layer, were utilized to create nanogaps between Au features using the molecular-ruler process. PMID:29181290

Further Investigation Into the Use of Laser Surface Preparation of Ti-6Al-4V Alloy for Adhesive Bonding

NASA Technical Reports Server (NTRS)

Palmieri, Frank L.; Crow, Allison; Zetterberg, Anna; Hopkins, John; Wohl, Christopher J.; Connell, John W.; Belcher, Tony; Blohowiak, Kay Y.

2014-01-01

Adhesive bonding offers many advantages over mechanical fastening, but requires robust materials and processing methodologies before it can be incorporated in primary structures for aerospace applications. Surface preparation is widely recognized as one of the key steps to producing robust and predictable bonds. This report documents an ongoing investigation of a surface preparation technique based on Nd:YAG laser ablation as a replacement for the chemical etch and/or abrasive processes currently applied to Ti-6Al-4V alloys. Laser ablation imparts both topographical and chemical changes to a surface that can lead to increased bond durability. A laser based process provides an alternative to chemical-immersion, manual abrasion, and grit blast process steps which are expensive, hazardous, environmentally unfriendly, and less precise. In addition, laser ablation is amenable to process automation, which can improve reproducibility to meet quality standards for surface preparation. An update on work involving adhesive property testing, surface characterization, surface stability, and the effect of laser surface treatment on fatigue behavior is presented. Based on the tests conducted, laser surface treatment is a viable replacement for the immersion chemical surface treatment processes. Testing also showed that the fatigue behavior of the Ti-6Al-4V alloy is comparable for surfaces treated with either laser ablation or chemical surface treatment.

Vadose Zone Fate and Transport Simulation of Chemicals Associated with Coal Seam Gas Extraction

NASA Astrophysics Data System (ADS)

Simunek, J.; Mallants, D.; Jacques, D.; Van Genuchten, M.

2017-12-01

The HYDRUS-1D and HYDRUS (2D/3D) computer software packages are widely used finite element models for simulating the one-, and two- or three-dimensional movement of water, heat, and multiple solutes in variably-saturated media, respectively. While the standard HYDRUS models consider only the fate and transport of individual solutes or solutes subject to first-order degradation reactions, several specialized HYDRUS add-on modules can simulate far more complex biogeochemical processes. The objective of this presentation is to provide an overview of the HYDRUS models and their add-on modules, and to demonstrate applications of the software to the subsurface fate and transport of chemicals involved in coal seam gas extraction and water management operations. One application uses the standard HYDRUS model to evaluate the natural soil attenuation potential of hydraulic fracturing chemicals and their transformation products in case of an accidental release. By coupling the processes of retardation, first-order degradation and convective-dispersive transport of the biocide bronopol and its degradation products, we demonstrated how natural attenuation reduces initial concentrations by more than a factor of hundred in the top 5 cm of the vadose zone. A second application uses the UnsatChem module to explore the possible use of coal seam gas produced water for sustainable irrigation. Simulations with different irrigation waters (untreated, amended with surface water, and reverse osmosis treated) provided detailed results regarding chemical indicators of soil and plant health, notably SAR, EC and sodium concentrations. A third application uses the coupled HYDRUS-PHREEQC module to analyze trace metal transport involving cation exchange and surface complexation sorption reactions in the vadose zone leached with coal seam gas produced water following some accidental water release scenario. Results show that the main process responsible for trace metal migration is complexation of naturally present trace metals with inorganic ligands such as (bi)carbonate that enter the soil upon infiltration with alkaline produced water.

7 CFR 319.40-8 - Processing at facilities operating under compliance agreements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... compliance agreement shall specify the requirements necessary to prevent spread of plant pests from the facility, requirements to ensure the processing method effectively destroys plant pests, and the requirements for the application of chemical materials in accordance with part 305 of this chapter. The...

7 CFR 319.40-8 - Processing at facilities operating under compliance agreements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... compliance agreement shall specify the requirements necessary to prevent spread of plant pests from the facility, requirements to ensure the processing method effectively destroys plant pests, and the requirements for the application of chemical materials in accordance with part 305 of this chapter. The...

Jar Test. Training Module 5.230.2.77.

ERIC Educational Resources Information Center

Bonte, John L.; Davidson, Arnold C.

This document is an instructional module package prepared in objective form for use by an instructor familiar with the jar test and its application to the coagulation, floculation and sedimentation processes, and the chemical precipitation process. Included are objectives, an instructor guide, student handouts, and transparency masters. A video…

The AgroEcoSystem-Watershed (AgES-W) model: overview and application to experimental watersheds

USDA-ARS?s Scientific Manuscript database

Progress in the understanding of physical, chemical, and biological processes influencing water quality, coupled with advances in the collection and analysis of hydrologic data, provide opportunities for significant innovations in the manner and level with which watershed-scale processes may be quan...

40 CFR 63.645 - Test methods and procedures for miscellaneous process vents.

Code of Federal Regulations, 2014 CFR

2014-07-01

... applicable to the process vent. (iv) Design analysis based on accepted chemical engineering principles..., dry standard cubic meters per minute, at a temperature of 20 °C. (g) Engineering assessment may be... the highest daily emission rate. (1) Engineering assessment includes, but is not limited to, the...

Advanced technology applications for second and third generation coal gasification systems. Appendix

NASA Technical Reports Server (NTRS)

Bradford, R.; Hyde, J. D.; Mead, C. W.

1980-01-01

Sixteen coal conversion processes are described and their projected goals listed. Tables show the reactants used, products derived, typical operating data, and properties of the feed coal. A history of the development of each process is included along with a drawing of the chemical reactor used.

The application of ultrasound and enzymes in textile processing of greige cotton

USDA-ARS?s Scientific Manuscript database

Research progress made at the USDA’s Southern Regional Research Center to provide an ultrasound and enzymatic alternative to the current textile processing method of scouring greige cotton textile with caustic chemicals is reported. The review covers early efforts to measure pectin and wax removal ...

Chapter 28: Nanomaterials for Energy Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurst, Katherine E; Luther, Joseph M; Ban, Chunmei

2017-01-02

A wide variety of nanomaterials have been applied to energy related applications, including nanofibers, nanocrystalline materials, nanoparticles, and thin film nanocoatings. Solid-state lighting offers significant advantages in energy efficiency compared to traditional lighting technologies. The potential for nanostructured solid-state lighting devices is excellent as it enjoys significant economic drivers in energy efficiency. Fuel cells convert chemical energy to electrical energy through electrochemical reactions at an anode and cathode. The conversion of biomass to fuels and chemicals offers great potential to reduce energy dependence on petroleum and reduce green house gas emissions. Batteries involve the production and storage of electrical charge,more » the transfer of cations and electrical current, each based on electrochemical reactions and chemical reactants. Battery performance relies on the complex processes and factors that affect the transport of charge in the reactants, and across the interface between the chemical phases.« less

Irradiation of wastewater with electron beam is a key to sustainable smart/green cities: a review

NASA Astrophysics Data System (ADS)

Hossain, Kaizar; Maruthi, Y. Avasn; Das, N. Lakshmana; Rawat, K. P.; Sarma, K. S. S.

2018-03-01

Remediation of wastewater, sludge and removal of objectionable substances from our environment using radiation technology is neglected. Hardly, a couple of decades ago, application of electron beam (EB) technology has gained attention for waste management. When wastewater is irradiated with electron beam, the beam can alter the physico-chemical properties of irradiated aqueous material and also transform wastewater chemicals due to the excitation or ionization of chemical molecules. Thus, chemical reactions may be capable of producing new compounds. The beam of electrons initiates primary reactions to induce the excitation or ionization of molecules at varied rates. This review paper will help to a budding researcher how to optimize the irradiation process to achieve high efficiency with low electron beam energy which is economically viable/feasible. Application of E-beam radiation for wastewater treatment may ensure future smart cities with sustainable water resources management.

CFD Code Development for Combustor Flows

NASA Technical Reports Server (NTRS)

Norris, Andrew

2003-01-01

During the lifetime of this grant, work has been performed in the areas of model development, code development, code validation and code application. For model development, this has included the PDF combustion module, chemical kinetics based on thermodynamics, neural network storage of chemical kinetics, ILDM chemical kinetics and assumed PDF work. Many of these models were then implemented in the code, and in addition many improvements were made to the code, including the addition of new chemistry integrators, property evaluation schemes, new chemistry models and turbulence-chemistry interaction methodology. Validation of all new models and code improvements were also performed, while application of the code to the ZCET program and also the NPSS GEW combustor program were also performed. Several important items remain under development, including the NOx post processing, assumed PDF model development and chemical kinetic development. It is expected that this work will continue under the new grant.

Systematic development of reduced reaction mechanisms for dynamic modeling

NASA Technical Reports Server (NTRS)

Frenklach, M.; Kailasanath, K.; Oran, E. S.

1986-01-01

A method for systematically developing a reduced chemical reaction mechanism for dynamic modeling of chemically reactive flows is presented. The method is based on the postulate that if a reduced reaction mechanism faithfully describes the time evolution of both thermal and chain reaction processes characteristic of a more complete mechanism, then the reduced mechanism will describe the chemical processes in a chemically reacting flow with approximately the same degree of accuracy. Here this postulate is tested by producing a series of mechanisms of reduced accuracy, which are derived from a full detailed mechanism for methane-oxygen combustion. These mechanisms were then tested in a series of reactive flow calculations in which a large-amplitude sinusoidal perturbation is applied to a system that is initially quiescent and whose temperature is high enough to start ignition processes. Comparison of the results for systems with and without convective flow show that this approach produces reduced mechanisms that are useful for calculations of explosions and detonations. Extensions and applicability to flames are discussed.

77 FR 26507 - Application(s) for Duty-Free Entry of Scientific Instruments

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-04

...: FEI Company, Czech Republic. Intended Use: The instrument will be used for research on primitive solar system materials extracted from meteorites as well as on samples from NASA sample return missions, such... chemical origin of the solar system and the processes by which its small bodies evolved. Justification for...

40 CFR 63.190 - Applicability and designation of source.

Code of Federal Regulations, 2010 CFR

2010-07-01

... rubber production (butadiene emissions only). (3) The processes producing the agricultural chemicals...), and (g), or accepted engineering practices. If the total annual HAP emissions for the plant site are...

40 CFR 63.190 - Applicability and designation of source.

Code of Federal Regulations, 2011 CFR

2011-07-01

... rubber production (butadiene emissions only). (3) The processes producing the agricultural chemicals...), and (g), or accepted engineering practices. If the total annual HAP emissions for the plant site are...

40 CFR 63.190 - Applicability and designation of source.

Code of Federal Regulations, 2012 CFR

2012-07-01

... rubber production (butadiene emissions only). (3) The processes producing the agricultural chemicals...), and (g), or accepted engineering practices. If the total annual HAP emissions for the plant site are...

40 CFR 63.190 - Applicability and designation of source.

Code of Federal Regulations, 2014 CFR

2014-07-01

... rubber production (butadiene emissions only). (3) The processes producing the agricultural chemicals...), and (g), or accepted engineering practices. If the total annual HAP emissions for the plant site are...

40 CFR 63.190 - Applicability and designation of source.

Code of Federal Regulations, 2013 CFR

2013-07-01

... rubber production (butadiene emissions only). (3) The processes producing the agricultural chemicals...), and (g), or accepted engineering practices. If the total annual HAP emissions for the plant site are...

Groundwater contamination from an inactive uranium mill tailings pile: 2. Application of a dynamic mixing model

NASA Astrophysics Data System (ADS)

Narasimhan, T. N.; White, A. F.; Tokunaga, T.

1986-12-01

At Riverton, Wyoming, low pH process waters from an abandoned uranium mill tailings pile have been infiltrating into and contaminating the shallow water table aquifer. The contamination process has been governed by transient infiltration rates, saturated-unsaturated flow, as well as transient chemical reactions between the many chemical species present in the mixing waters and the sediments. In the first part of this two-part series [White et al., 1984] we presented field data as well as an interpretation based on a static mixing model. As an upper bound, we estimated that 1.7% of the tailings water had mixed with the native groundwater. In the present work we present the results of numerical investigation of the dynamic mixing process. The model, DYNAMIX (DYNAmic MIXing), couples a chemical speciation algorithm, PHREEQE, with a modified form of the transport algorithm, TRUMP, specifically designed to handle the simultaneous migration of several chemical constituents. The overall problem of simulating the evolution and migration of the contaminant plume was divided into three sub problems that were solved in sequential stages. These were the infiltration problem, the reactive mixing problem, and the plume-migration problem. The results of the application agree reasonably with the detailed field data. The methodology developed in the present study demonstrates the feasibility of analyzing the evolution of natural hydrogeochemical systems through a coupled analysis of transient fluid flow as well as chemical reactions. It seems worthwhile to devote further effort toward improving the physicochemical capabilities of the model as well as to enhance its computational efficiency.

Groundwater contamination from an inactive uranium mill tailings pile. 2. Application of a dynamic mixing model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Narashimhan, T.N.; White, A.F.; Tokunaga, T.

1986-12-01

At Riverton, Wyoming, low pH process waters from an abandoned uranium mill tailings pile have been infiltrating into and contaminating the shallow water table aquifer. The contamination process has been governed by transient infiltration rates, saturated-unsaturated flow, as well as transient chemical reactions between the many chemical species present in the mixing waters and the sediments. In the first part of this two-part series the authors presented field data as well as an interpretation based on a static mixing models. As an upper bound, the authors estimated that 1.7% of the tailings water had mixed with the native groundwater. Inmore » the present work they present the results of numerical investigation of the dynamic mixing process. The model, DYNAMIX (DYNamic MIXing), couples a chemical speciation algorithm, PHREEQE, with a modified form of the transport algorithm, TRUMP, specifically designed to handle the simultaneous migration of several chemical constituents. The overall problem of simulating the evolution and migration of the contaminant plume was divided into three sub problems that were solved in sequential stages. These were the infiltration problem, the reactive mixing problem, and the plume-migration problem. The results of the application agree reasonably with the detailed field data. The methodology developed in the present study demonstrates the feasibility of analyzing the evolution of natural hydrogeochemical systems through a coupled analysis of transient fluid flow as well as chemical reactions. It seems worthwhile to devote further effort toward improving the physicochemical capabilities of the model as well as to enhance its computational efficiency.« less

Spice use in food: Properties and benefits.

PubMed

Jessica Elizabeth, De La Torre; Gassara, Fatma; Kouassi, Anne Patricia; Brar, Satinder Kaur; Belkacemi, Khaled

2017-04-13

Spices are parts of plants that due to their properties are used as colorants, preservatives, or medicine. The uses of spices have been known since long time, and the interest in the potential of spices is remarkable due to the chemical compounds contained in spices, such as phenylpropanoids, terpenes, flavonoids, and anthocyanins. Spices, such as cumin (cuminaldehyde), clove (eugenol), and cinnamon (cinnamaldehyde) among others, are known and studied for their antimicrobial and antioxidant properties due to their main chemical compounds. These spices have the potential to be used as preservatives in many foods namely in processed meat to replace chemical preservatives. Main chemical compounds in spices also confer other properties providing a variety of applications to spices, such as insecticidal, medicines, colorants, and natural flavoring. Spices provide beneficial effects, such as antioxidant activity levels that are comparable to regular chemical antioxidants used so they can be used as a natural alternative to synthetic preservatives. In this review, the main characteristics of spices will be described as well as their chemical properties, different applications of these spices, and the advantages and disadvantages of their use.

Applications of Neutron Scattering in the Chemical Industry: Proton Dynamics of Highly Dispersed Materials, Characterization of Fuel Cell Catalysts, and Catalysts from Large-Scale Chemical Processes

NASA Astrophysics Data System (ADS)

Albers, Peter W.; Parker, Stewart F.

The attractiveness of neutron scattering techniques for the detailed characterization of materials of high degrees of dispersity and structural complexity as encountered in the chemical industry is discussed. Neutron scattering picks up where other analytical methods leave off because of the physico-chemical properties of finely divided products and materials whose absorption behavior toward electromagnetic radiation and electrical conductivity causes serious problems. This is demonstrated by presenting typical applications from large-scale production technology and industrial catalysis. These include the determination of the proton-related surface chemistry of advanced materials that are used as reinforcing fillers in the manufacture of tires, where interrelations between surface chemistry, rheological properties, improved safety, and significant reduction of fuel consumption are the focus of recent developments. Neutron scattering allows surface science studies of the dissociative adsorption of hydrogen on nanodispersed, supported precious metal particles of fuel cell catalysts under in situ loading at realistic gas pressures of about 1 bar. Insight into the occupation of catalytically relevant surface sites provides valuable information about the catalyst in the working state and supplies essential scientific input for tailoring better catalysts by technologists. The impact of deactivation phenomena on industrial catalysts by coke deposition, chemical transformation of carbonaceous deposits, and other processes in catalytic hydrogenation processes that result in significant shortening of the time of useful operation in large-scale plants can often be traced back in detail to surface or bulk properties of catalysts or materials of catalytic relevance. A better understanding of avoidable or unavoidable aspects of catalyst deactivation phenomena under certain in-process conditions and the development of effective means for reducing deactivation leads to more energy-efficient and, therefore, environmentally friendly processes and helps to save valuable resources. Even small or gradual improvements in all these fields are of considerable economic impact.

Chemical coloring on stainless steel by ultrasonic irradiation.

PubMed

Cheng, Zuohui; Xue, Yongqiang; Ju, Hongbin

2018-01-01

To solve the problems of high temperature and non-uniformity of coloring on stainless steel, a new chemical coloring process, applying ultrasonic irradiation to the traditional chemical coloring process, was developed in this paper. The effects of ultrasonic frequency and power density (sound intensity) on chemical coloring on stainless steel were studied. The uniformity of morphology and colors was observed with the help of polarizing microscope and scanning electron microscopy (SEM), and the surface compositions were characterized by X-ray photoelectric spectroscopy (XPS), meanwhile, the wear resistance and the corrosion resistance were investigated, and the effect mechanism of ultrasonic irradiation on chemical coloring was discussed. These results show that in the process of chemical coloring on stainless steel by ultrasonic irradiation, the film composition is the same as the traditional chemical coloring, and this method can significantly enhance the uniformity, the wear and corrosion resistances of the color film and accelerate the coloring rate which makes the coloring temperature reduced to 40°C. The effects of ultrasonic irradiation on the chemical coloring can be attributed to the coloring rate accelerated and the coloring temperature reduced by thermal-effect, the uniformity of coloring film improved by dispersion-effect, and the wear and corrosion resistances of coloring film enhanced by cavitation-effect. Ultrasonic irradiation not only has an extensive application prospect for chemical coloring on stainless steel but also provides an valuable reference for other chemical coloring. Copyright © 2017 Elsevier B.V. All rights reserved.

Soft chemical synthesis of silicon nanosheets and their applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakano, Hideyuki; Ikuno, Takashi

2016-12-15

Two-dimensional silicon nanomaterials are expected to show different properties from those of bulk silicon materials by virtue of surface functionalization and quantum size effects. Since facile fabrication processes of large area silicon nanosheets (SiNSs) are required for practical applications, a development of soft chemical synthesis route without using conventional vacuum processes is a challenging issue. We have recently succeeded to prepare SiNSs with sub-nanometer thicknesses by exfoliating layered silicon compounds, and they are found to be composed of crystalline single-atom-thick silicon layers. In this review, we present the synthesis and modification methods of SiNSs. These SiNSs have atomically flat andmore » smooth surfaces due to dense coverage of organic moieties, and they are easily self-assembled in a concentrated state to form a regularly stacked structure. We have also characterized the electron transport properties and the electronic structures of SiNSs. Finally, the potential applications of these SiNSs and organic modified SiNSs are also reviewed.« less

40 CFR 415.160 - Applicability; description of the sodium chloride production subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS INORGANIC CHEMICALS MANUFACTURING POINT... the production of sodium chloride by the solution brine-mining process and by the solar evaporation...

Semisupervised Gaussian Process for Automated Enzyme Search.

PubMed

Mellor, Joseph; Grigoras, Ioana; Carbonell, Pablo; Faulon, Jean-Loup

2016-06-17

Synthetic biology is today harnessing the design of novel and greener biosynthesis routes for the production of added-value chemicals and natural products. The design of novel pathways often requires a detailed selection of enzyme sequences to import into the chassis at each of the reaction steps. To address such design requirements in an automated way, we present here a tool for exploring the space of enzymatic reactions. Given a reaction and an enzyme the tool provides a probability estimate that the enzyme catalyzes the reaction. Our tool first considers the similarity of a reaction to known biochemical reactions with respect to signatures around their reaction centers. Signatures are defined based on chemical transformation rules by using extended connectivity fingerprint descriptors. A semisupervised Gaussian process model associated with the similar known reactions then provides the probability estimate. The Gaussian process model uses information about both the reaction and the enzyme in providing the estimate. These estimates were validated experimentally by the application of the Gaussian process model to a newly identified metabolite in Escherichia coli in order to search for the enzymes catalyzing its associated reactions. Furthermore, we show with several pathway design examples how such ability to assign probability estimates to enzymatic reactions provides the potential to assist in bioengineering applications, providing experimental validation to our proposed approach. To the best of our knowledge, the proposed approach is the first application of Gaussian processes dealing with biological sequences and chemicals, the use of a semisupervised Gaussian process framework is also novel in the context of machine learning applied to bioinformatics. However, the ability of an enzyme to catalyze a reaction depends on the affinity between the substrates of the reaction and the enzyme. This affinity is generally quantified by the Michaelis constant KM. Therefore, we also demonstrate using Gaussian process regression to predict KM given a substrate-enzyme pair.

Study of the suitability of a commercial hydroxyapatite powder to obtain sintered compacts for medical applications

NASA Astrophysics Data System (ADS)

Palacio, C.; Jaramillo, D.; Correa, S.; Arroyave, M.

2017-06-01

Hydroxyapatite (HA) is a material widely used by the medical community due to its Ca/P ratio is comparable to the Ca/P ratio of bones and teeth, which promotes osteoinduction and osteoconduction processes when in contact with bone tissue, either as volume piece or coating. This work focuses on studying the quality of the commercial HA powder MKnano-#MKN-HXAP-S12 µm, after processing, to obtain sintered compact discs with suitable physical and chemical characteristics for implants applications. The HA powder was processed through calcination, grinding, pressing and sintering to evaluate the effect of such as procedures in the compacts dics quality. The raw powder was characterized by laser diffraction, SEM, XRF, XRD, TGA and DSC while the characteristics of the obtained compact discs were determined by dilatometry and XRD to identify the sintering temperature range, constituent phases, the amorphous content and the crystallinity degree, parameters that allow determining their suitability for implants applications. Although, it was not possible to obtain sintered compacts with the suitable chemical composition and without fractures, this work allowed to identify the parameters that determine the suitability of a HA powder to obtain sintered compacts for medical applications, as well as the characterization protocol that allows the evaluation of such parameters.

40 CFR Table 2 to Subpart Ffff of... - Emission Limits and Work Practice Standards for Batch Process Vents

Code of Federal Regulations, 2010 CFR

2010-07-01

...: Miscellaneous Organic Chemical Manufacturing Pt. 63, Subpt. FFFF, Table 2 Table 2 to Subpart FFFF of Part 63... vents a. Reduce collective uncontrolled organic HAP emissions from the sum of all batch process vents... applicable. b. Reduce collective uncontrolled organic HAP emissions from the sum of all batch process vents...

40 CFR Table 2 to Subpart Ffff of... - Emission Limits and Work Practice Standards for Batch Process Vents

Code of Federal Regulations, 2011 CFR

2011-07-01

...: Miscellaneous Organic Chemical Manufacturing Pt. 63, Subpt. FFFF, Table 2 Table 2 to Subpart FFFF of Part 63... vents a. Reduce collective uncontrolled organic HAP emissions from the sum of all batch process vents... applicable. b. Reduce collective uncontrolled organic HAP emissions from the sum of all batch process vents...

Statistical medium optimization of an alkaline protease from Pseudomonas aeruginosa MTCC 10501, its characterization and application in leather processing.

PubMed

Boopathy, Naidu Ramachandra; Indhuja, Devadas; Srinivasan, Krishnan; Uthirappan, Mani; Gupta, Rishikesh; Ramudu, Kamini Numbi; Chellan, Rose

2013-04-01

Proteases are shown to have greener mode of application in leather processing for dehairing of goat skins and cow hides. Production of protease by submerged fermentation with potent activity is reported using a new isolate P. aeruginosa MTCC 10501. The production parameters were optimized by statistical methods such as Plackett-Burman and response surface methodology. The optimized production medium contained (g/L); tryptone, 2.5; yeast extract, 3.0; skim milk 30.0; dextrose 1.0; inoculum concentration 4%: initial pH 6.0; incubation temperature 30 degrees C and optimum production at 48 h with protease activity of 7.6 U/mL. The protease had the following characteristics: pH optima, 9.0; temperature optima 50 degrees C; pH stability between 5.0-10.0 and temperature stability between 10-40 degrees C. The protease was observed to have high potential for dehairing of goat skins in the pre- tanning process comparable to that of the chemical process as evidenced by histology. The method offers cleaner processing using enzyme only instead of toxic chemicals in the pre-tanning process of leather manufacture.

Laboratory Studies of Homogeneous and Heterogeneous Chemical Processes of Importance in the Upper Atmosphere

NASA Technical Reports Server (NTRS)

Molina, Mario J.

2001-01-01

The objective of this study is to conduct measurements of chemical kinetics parameters for reactions of importance in the stratosphere and upper troposphere, and to study the interaction of trace gases such as HCl with ice surfaces in order to elucidate the mechanism of heterogeneous chlorine activation processes, using both a theoretical and an experimental approach. The measurements will be carried out under temperature and pressure conditions covering those applicable to the stratosphere and upper troposphere. The techniques to be employed include turbulent flow - chemical ionization mass spectrometry, and optical ellipsometry. The next section summarizes our research activities during the second year of the project, and the section that follows consists of the statement of work for the third year.

15 CFR 752.8 - SCL application review process.

Code of Federal Regulations, 2011 CFR

2011-01-01

... weapons, or missiles; (3) The types of assurances against design, development, production, stockpiling, or use of nuclear or chemical and biological weapons, or missiles that are included in the ICP; (4) The...

15 CFR 752.8 - SCL application review process.

Code of Federal Regulations, 2013 CFR

2013-01-01

... weapons, or missiles; (3) The types of assurances against design, development, production, stockpiling, or use of nuclear or chemical and biological weapons, or missiles that are included in the ICP; (4) The...

15 CFR 752.8 - SCL application review process.

Code of Federal Regulations, 2014 CFR

2014-01-01

... weapons, or missiles; (3) The types of assurances against design, development, production, stockpiling, or use of nuclear or chemical and biological weapons, or missiles that are included in the ICP; (4) The...

15 CFR 752.8 - SCL application review process.

Code of Federal Regulations, 2012 CFR

2012-01-01

... weapons, or missiles; (3) The types of assurances against design, development, production, stockpiling, or use of nuclear or chemical and biological weapons, or missiles that are included in the ICP; (4) The...

Fuel Spray Diagnostics

NASA Technical Reports Server (NTRS)

Humenik, F. M.; Bosque, M. A.

1983-01-01

Fundamental experimental data base for turbulent flow mixing models is provided and better prediction of the more complex turbulent chemical reacting flows. Analytical application to combustor design is provided and a better fundamental understanding of the combustion process.

32 CFR 172.2 - Applicability and scope.

Code of Federal Regulations, 2010 CFR

2010-07-01

... chemical processing. The recycling of hazardous materials or hazardous waste shall be accomplished with due...-bearing scrap and those items that may be used again for their original purposes or functions without any...

32 CFR 172.2 - Applicability and scope.

Code of Federal Regulations, 2013 CFR

2013-07-01

... chemical processing. The recycling of hazardous materials or hazardous waste shall be accomplished with due...-bearing scrap and those items that may be used again for their original purposes or functions without any...

32 CFR 172.2 - Applicability and scope.

Code of Federal Regulations, 2012 CFR

2012-07-01

... chemical processing. The recycling of hazardous materials or hazardous waste shall be accomplished with due...-bearing scrap and those items that may be used again for their original purposes or functions without any...

32 CFR 172.2 - Applicability and scope.

Code of Federal Regulations, 2014 CFR

2014-07-01

... chemical processing. The recycling of hazardous materials or hazardous waste shall be accomplished with due...-bearing scrap and those items that may be used again for their original purposes or functions without any...

32 CFR 172.2 - Applicability and scope.

Code of Federal Regulations, 2011 CFR

2011-07-01

... chemical processing. The recycling of hazardous materials or hazardous waste shall be accomplished with due...-bearing scrap and those items that may be used again for their original purposes or functions without any...

Integration between chemical oxidation and membrane thermophilic biological process.

PubMed

Bertanza, G; Collivignarelli, M C; Crotti, B M; Pedrazzani, R

2010-01-01

Full scale applications of activated sludge thermophilic aerobic process for treatment of liquid wastes are rare. This experimental work was carried out at a facility, where a thermophilic reactor (1,000 m(3) volume) is operated. In order to improve the global performance of the plant, it was decided to upgrade it, by means of two membrane filtration units (ultrafiltration -UF-, in place of the final sedimentation, and nanofiltration -NF-). Subsequently, the integration with chemical oxidation (O(3) and H(2)O(2)/UV processes) was taken into consideration. Studied solutions dealt with oxidation of both the NF effluents (permeate and concentrate). Based on experimental results and economic evaluation, an algorithm was proposed for defining limits of convenience of this process.

Process Analyzer

NASA Technical Reports Server (NTRS)

1994-01-01

The ChemScan UV-6100 is a spectrometry system originally developed by Biotronics Technologies, Inc. under a Small Business Innovation Research (SBIR) contract. It is marketed to the water and wastewater treatment industries, replacing "grab sampling" with on-line data collection. It analyzes the light absorbance characteristics of a water sample, simultaneously detects hundreds of individual wavelengths absorbed by chemical substances in a process solution, and quantifies the information. Spectral data is then processed by ChemScan analyzer and compared with calibration files in the system's memory in order to calculate concentrations of chemical substances that cause UV light absorbance in specific patterns. Monitored substances can be analyzed for quality and quantity. Applications include detection of a variety of substances, and the information provided enables an operator to control a process more efficiently.

Towards large-scale plasma-assisted synthesis of nanowires

NASA Astrophysics Data System (ADS)

Cvelbar, U.

2011-05-01

Large quantities of nanomaterials, e.g. nanowires (NWs), are needed to overcome the high market price of nanomaterials and make nanotechnology widely available for general public use and applications to numerous devices. Therefore, there is an enormous need for new methods or routes for synthesis of those nanostructures. Here plasma technologies for synthesis of NWs, nanotubes, nanoparticles or other nanostructures might play a key role in the near future. This paper presents a three-dimensional problem of large-scale synthesis connected with the time, quantity and quality of nanostructures. Herein, four different plasma methods for NW synthesis are presented in contrast to other methods, e.g. thermal processes, chemical vapour deposition or wet chemical processes. The pros and cons are discussed in detail for the case of two metal oxides: iron oxide and zinc oxide NWs, which are important for many applications.

Recent developments on ultrasound assisted catalyst-free organic synthesis.

PubMed

Banerjee, Bubun

2017-03-01

Mother Nature needs to be protected from ever increasing chemical pollutions associated with synthetic organic processes. The fundamental challenge for today's methodologists is to make their protocols more environmentally benign and sustainable by avoiding the extensive use of hazardous reagents and solvents, harsh reaction conditions, and toxic metal catalysts. However, the people of the twenty-first century are well aware about the side effects of those hazardous substances used and generated by the chemical processes. As a result, the last decade has seen a tremendous outburst in modifying chemical processes to make them 'sustainable' for the betterment of our environment. Catalysts play a crucial role in organic synthesis and thus they find huge applications and uses. Scientists' continuously trying to modify the catalysts to reduce their toxicity level, but the most benign way is to design an organic reaction without catalyst(s), if possible. It is worthy to mention that the involvement of ultrasound in organic synthesis is sometimes fulfilling this goal. In many occasions the applications of ultrasound can avoid the use of catalysts in organic reactions. Such beneficial features as a whole have motivated the organic chemists to apply ultrasonic irradiation in more heights and as a results, in recent past, there were immense applications of ultrasound in organic reactions for the synthesis of diverse organic scaffolds under catalyst-free condition. The present review summarizes the latest developments on ultrasound assisted catalyst-free organic synthesis reported so far. Copyright © 2016 Elsevier B.V. All rights reserved.

Non-chemically amplified 248-nm resist materials

NASA Astrophysics Data System (ADS)

Willson, C. Grant; Yueh, Wang; Leeson, Michael J.; Steinhausler, Thomas; McAdams, Christopher L.; Dammel, Ralph R.; Sounik, James R.; Aslam, M.; Vicari, Richard; Sheehan, Michael

1997-07-01

Remarkable progress has been made in the formulation of chemically amplified resists for deep-UV (DUV or 248 nm) lithography. These materials are now in general use in full scale manufacturing. One of the deterrents to rapid and universal adoption of DUV lithography has been the combination of high cost of ownership and a narrow process latitude when compared to conventional i-line process alternatives. A significant part of the high cost of the DUV process is associated with installing and maintaining special air handling equipment that is required to remove basic contaminants from the ambient. Manufacture process latitude demands this special air handling. The chemically amplified resists were developed originally to support mercury lamp powered exposure systems. The sensitivity realized by chemical amplification is required to enable useful productivity with such systems that generate very little DUV flux at the wafer plane. With the advent of high powered excimer laser based illumination systems for 248 nm steppers and step-and-scan systems, it is appropriate to re-examine the applicability of non-chemically amplified DUV resist systems. These systems are less sensitive but have the potential to offer both lower cost of ownership and improved process latitude. A series of photoactive compounds (PACs) have been synthesized and auditioned for use in the formulation of a non-chemically amplified 248 nm resist. The most promising of these materials are analogs of 3-oxo-3-diazocoumarin. This chromophore displays photochemistry that is analogous to that of the diazonaphthoquinones (DNQ) that are the basis of i-line resist formulations, but it bleaches at 248 nm. Several structural analogs of the chromophore have been synthesized and a variety of ballast groups have been studied with the goal of enhancing the dissolution inhibition properties of the molecule. The diazocoumarin PACs have been formulated with customized phenolic resins that were designed to provide the combination of optical transparency, dry etch resistance and the dissolution characteristics that are required for manufacturing applications. The resins are copolymers of poly(4-hydroxystyrene) and blends of these polymers with novolac.

Semiconductor nanocrystal quantum dot synthesis approaches towards large-scale industrial production for energy applications

DOE PAGES

Hu, Michael Z.; Zhu, Ting

2015-12-04

This study reviews the experimental synthesis and engineering developments that focused on various green approaches and large-scale process production routes for quantum dots. Fundamental process engineering principles were illustrated. In relation to the small-scale hot injection method, our discussions focus on the non-injection route that could be scaled up with engineering stir-tank reactors. In addition, applications that demand to utilize quantum dots as "commodity" chemicals are discussed, including solar cells and solid-state lightings.

Mirror Technology

NASA Technical Reports Server (NTRS)

1992-01-01

Under a NASA contract, MI-CVD developed a process for producing bulk silicon carbide by means of a chemical vapor deposition process. The technology allows growth of a high purity material with superior mechanical/thermal properties and high polishability - ideal for mirror applications. The company employed the technology to develop three research mirrors for NASA Langley and is now marketing it as CVD SILICON CARBIDE. Its advantages include light weight, thermal stability and high reflectivity. The material has nuclear research facility applications and is of interest to industrial users of high power lasers.

Zinc Oxide—From Synthesis to Application: A Review

PubMed Central

Kołodziejczak-Radzimska, Agnieszka; Jesionowski, Teofil

2014-01-01

Zinc oxide can be called a multifunctional material thanks to its unique physical and chemical properties. The first part of this paper presents the most important methods of preparation of ZnO divided into metallurgical and chemical methods. The mechanochemical process, controlled precipitation, sol-gel method, solvothermal and hydrothermal method, method using emulsion and microemulsion enviroment and other methods of obtaining zinc oxide were classified as chemical methods. In the next part of this review, the modification methods of ZnO were characterized. The modification with organic (carboxylic acid, silanes) and inroganic (metal oxides) compounds, and polymer matrices were mainly described. Finally, we present possible applications in various branches of industry: rubber, pharmaceutical, cosmetics, textile, electronic and electrotechnology, photocatalysis were introduced. This review provides useful information for specialist dealings with zinc oxide. PMID:28788596

Graphene Inks with Cellulosic Dispersants: Development and Applications for Printed Electronics

NASA Astrophysics Data System (ADS)

Secor, Ethan Benjamin

Graphene offers promising opportunities for applications in printed and flexible electronic devices due to its high electrical and thermal conductivity, mechanical flexibility and strength, and chemical and environmental stability. However, scalable production and processing of graphene presents a critical technological challenge preventing the application of graphene for flexible electronic interconnects, electrochemical energy storage, and chemically robust electrical contacts. In this thesis, a promising and versatile platform for the production, patterning, and application of graphene inks is presented based on cellulosic dispersants. Graphene is produced from flake graphite using scalable liquid-phase exfoliation methods, using the polymers ethyl cellulose and nitrocellulose as multifunctional dispersing agents. These cellulose derivatives offer high colloidal stability and broadly tunable rheology for graphene dispersions, providing an effective and tunable platform for graphene ink development. Thermal or photonic annealing decomposes the polymer dispersant to yield high conductivity, flexible graphene patterns for various electronics applications. In particular, the chemical stability of graphene enables robust electrical contacts for ceramic, metallic, organic and electrolytic materials, validating the diverse applicability of graphene in printed electronics. Overall, the strategy for graphene ink design presented here offers a simple, efficient, and versatile method for integrating graphene in a wide range of printed devices and systems, providing both fundamental insight for nanomaterial ink development and realistic opportunities for practical applications.

Engineered soy oils for new value added applications

NASA Astrophysics Data System (ADS)

Tran, Phuong T.

Soybean oil is an abundant annually renewable resource. It is composed of triglycerides with long chain saturated and unsaturated fatty acids. The presence of unsaturated fatty acids allows for chemical modification to introduce new functionalities to soybean oil. A portfolio of chemically modified soy oil with suitable functional groups has been designed and engineered to serve as the starting material in applications such as polyamides, polyesters, polyurethanes, composites, and lubricants. Anhydride, hydroxyl, and silicone functionalities were introduced to soy oil. Anhydride functionality was introduced using a single-step free radical initiated process, and the chemically modified soy oils were evaluated for potential applications as a composite and lubricant. Hydroxyl functionalities were introduced in a single-step catalytic ozonolysis process recently developed in our labs, which proceeds rapidly and efficiently at room temperature without solvent. The transformed soy oil was used to successfully prepare bio-lubricants with good thermal/oxidative stability and bio-plastics such as polyamides, polyesters, and polyurethanes. A new class of organic-inorganic hybrid materials was prepared by curing vinyltrimethoxysilane functionalized soy oil. This hybrid material could have potential as biobased sealant through a moisture initiated room temperature cure. These new classes of soy-based materials are competitive both in cost and performance to petroleum based materials, but offer the advantage of being biobased.

Electron-beam Induced Processes and their Applicability to Mask Repair

NASA Astrophysics Data System (ADS)

Boegli, Volker A.; Koops, Hans W. P.; Budach, Michael; Edinger, Klaus; Hoinkis, Ottmar; Weyrauch, Bernd; Becker, Rainer; Schmidt, Rudolf; Kaya, Alexander; Reinhardt, Andreas; Braeuer, Stephan; Honold, Heinz; Bihr, Johannes; Greiser, Jens; Eisenmann, Michael

2002-12-01

The applicability of electron-beam induced chemical reactions to mask repair is investigated. To achieve deposition and chemical etching with a focused electron-beam system, it is required to disperse chemicals in a molecular beam to the area of interest with a well-defined amount of molecules and monolayers per second. For repair of opaque defects the precursor gas reacts with the absorber material of the mask and forms a volatile reaction product, which leaves the surface. In this way the surface atoms are removed layer by layer. For clear defect repair, additional material, which is light absorbing in the UV, is deposited onto the defect area. This material is rendered as a nanocrystalline deposit from metal containing precursors. An experimental electron-beam mask repair system is developed and used to perform exploratory work applicable to photo mask, EUV mask, EPL and LEEPL stencil mask repair. The tool is described and specific repair actions are demonstrated. Platinum deposited features with lateral dimensions down to 20 nm demonstrate the high resolution obtainable with electron beam induced processes, while AFM and AIMS measurements indicate, that specifications for mask repair at the 70 nm device node can be met. In addition, examples of etching quartz and TaN are given.

Chemistry and physics of a single atomic layer: strategies and challenges for functionalization of graphene and graphene-based materials.

PubMed

Yan, Liang; Zheng, Yue Bing; Zhao, Feng; Li, Shoujian; Gao, Xingfa; Xu, Bingqian; Weiss, Paul S; Zhao, Yuliang

2012-01-07

Graphene has attracted great interest for its superior physical, chemical, mechanical, and electrical properties that enable a wide range of applications from electronics to nanoelectromechanical systems. Functionalization is among the significant vectors that drive graphene towards technological applications. While the physical properties of graphene have been at the center of attention, we still lack the knowledge framework for targeted graphene functionalization. In this critical review, we describe some of the important chemical and physical processes for graphene functionalization. We also identify six major challenges in graphene research and give perspectives and practical strategies for both fundamental studies and applications of graphene (315 references). This journal is © The Royal Society of Chemistry 2012

Chemical Vapor Deposition Of Silicon Carbide

NASA Technical Reports Server (NTRS)

Powell, J. Anthony; Larkin, David J.; Matus, Lawrence G.; Petit, Jeremy B.

1993-01-01

Large single-crystal SiC boules from which wafers of large area cut now being produced commerically. Availability of wafers opens door for development of SiC semiconductor devices. Recently developed chemical vapor deposition (CVD) process produces thin single-crystal SiC films on SiC wafers. Essential step in sequence of steps used to fabricate semiconductor devices. Further development required for specific devices. Some potential high-temperature applications include sensors and control electronics for advanced turbine engines and automobile engines, power electronics for electromechanical actuators for advanced aircraft and for space power systems, and equipment used in drilling of deep wells. High-frequency applications include communication systems, high-speed computers, and microwave power transistors. High-radiation applications include sensors and controls for nuclear reactors.

Exopolysaccharides enriched in rare sugars: bacterial sources, production, and applications.

PubMed

Roca, Christophe; Alves, Vitor D; Freitas, Filomena; Reis, Maria A M

2015-01-01

Microbial extracellular polysaccharides (EPS), produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and composition. They may be used in many applications, depending on their chemical and physical properties. A rather unexplored aspect is the presence of rare sugars in the composition of some EPS. Rare sugars, such as rhamnose or fucose, may provide EPS with additional biological properties compared to those composed of more common sugar monomers. This review gives a brief overview of these specific EPS and their producing bacteria. Cultivation conditions are summarized, demonstrating their impact on the EPS composition, together with downstream processing. Finally, their use in different areas, including cosmetics, food products, pharmaceuticals, and biomedical applications, are discussed.

Elucidating the thermal, chemical, and mechanical mechanisms of ultraviolet ablation in poly(methyl methacrylate) via molecular dynamics simulations.

PubMed

Conforti, Patrick F; Prasad, Manish; Garrison, Barbara J

2008-08-01

[Figure: see text]. Laser ablation harnesses photon energy to remove material from a surface. Although applications such as laser-assisted in situ keratomileusis (LASIK) surgery, lithography, and nanoscale device fabrication take advantage of this process, a better understanding the underlying mechanism of ablation in polymeric materials remains much sought after. Molecular simulation is a particularly attractive technique to study the basic aspects of ablation because it allows control over specific process parameters and enables observation of microscopic mechanistic details. This Account describes a hybrid molecular dynamics-Monte Carlo technique to simulate laser ablation in poly(methyl methacrylate) (PMMA). It also discusses the impact of thermal and chemical excitation on the ensuing ejection processes. We used molecular dynamics simulation to study the molecular interactions in a coarse-grained PMMA substrate following photon absorption. To ascertain the role of chemistry in initiating ablation, we embedded a Monte Carlo protocol within the simulation framework. These calculations permit chemical reactions to occur probabilistically during the molecular dynamics calculation using predetermined reaction pathways and Arrhenius rates. With this hybrid scheme, we can examine thermal and chemical pathways of decomposition separately. In the simulations, we observed distinct mechanisms of ablation for each type of photoexcitation pathway. Ablation via thermal processes is governed by a critical number of bond breaks following the deposition of energy. For the case in which an absorbed photon directly causes a bond scission, ablation occurs following the rapid chemical decomposition of material. A detailed analysis of the processes shows that a critical energy for ablation can describe this complex series of events. The simulations show a decrease in the critical energy with a greater amount of photochemistry. Additionally, the simulations demonstrate the effects of the energy deposition rate on the ejection mechanism. When the energy is deposited rapidly, not allowing for mechanical relaxation of the sample, the formation of a pressure wave and subsequent tensile wave dominates the ejection process. This study provides insight into the influence of thermal, chemical, and mechanical processes in PMMA and facilitates greater understanding of the complex nature of polymer ablation. These simulations complement experiments that have used chemical design to harness the photochemical properties of materials to enhance laser ablation. We successfully fit the results of the simulations to established analytical models of both photothermal and photochemical ablation and demonstrate their relevance. Although the simulations are for PMMA, the mechanistic concepts are applicable to a large range of systems and provide a conceptual foundation for interpretation of experimental data.

Focusing on energy and optoelectronic applications: a journey for graphene and graphene oxide at large scale.

PubMed

Wan, Xiangjian; Huang, Yi; Chen, Yongsheng

2012-04-17

Carbon is the only element that has stable allotropes in the 0th through the 3rd dimension, all of which have many outstanding properties. Graphene is the basic building block of other important carbon allotropes. Studies of graphene became much more active after the Geim group isolated "free" and "perfect" graphene sheets and demonstrated the unprecedented electronic properties of graphene in 2004. So far, no other individual material combines so many important properties, including high mobility, Hall effect, transparency, mechanical strength, and thermal conductivity. In this Account, we briefly review our studies of bulk scale graphene and graphene oxide (GO), including their synthesis and applications focused on energy and optoelectronics. Researchers use many methods to produce graphene materials: bottom-up and top-down methods and scalable methods such as chemical vapor deposition (CVD) and chemical exfoliation. Each fabrication method has both advantages and limitations. CVD could represent the most important production method for electronic applications. The chemical exfoliation method offers the advantages of easy scale up and easy solution processing but also produces graphene oxide (GO), which leads to defects and the introduction of heavy functional groups. However, most of these additional functional groups and defects can be removed by chemical reduction or thermal annealing. Because solution processing is required for many film and device applications, including transparent electrodes for touch screens, light-emitting devices (LED), field-effect transistors (FET), and photovoltaic devices (OPV), flexible electronics, and composite applications, the use of GO is important for the production of graphene. Because graphene has an intrinsic zero band gap, this issue needs to be tackled for its FET applications. The studies for transparent electrode related applications have made great progress, but researchers need to improve sheet resistance while maintaining reasonable transparency. Proposals for solving these issues include doping or controlling the sheet size and defects, and theory indicates that graphene can match the overall performance of indium tin oxide (ITO). We have significantly improved the specific capacitance in graphene supercapacitor devices, though our results do not yet approach theoretical values. For composite applications, the key issue is to prevent the restacking of graphene sheets, which we achieved by adding blocking molecules. The continued success of graphene studies will require further development in two areas: (1) the large scale and controlled synthesis of graphene, producing different structures and quantities that are needed for a variety of applications and (2) on table applications, such as transparent electrodes and energy storage devices. Overall, graphene has demonstrated performance that equals or surpasses that of other new carbon allotropes. These features, combined with its easier access and better processing ability, offer the potential basis for truly revolutionary applications and as a future fundamental technological material beyond the silicon age.

Analysis of exhaled breath by laser detection

NASA Astrophysics Data System (ADS)

Thrall, Karla D.; Toth, James J.; Sharpe, Steven W.

1996-04-01

The goal of our work is two fold: (1) to develop a portable rapid laser based breath analyzer for monitoring metabolic processes, and (2) predict these metabolic processes through physiologically based pharmacokinetic (PBPK) modeling. Small infrared active molecules such as ammonia, carbon monoxide, carbon dioxide, methane and ethane are present in exhaled breath and can be readily detected by laser absorption spectroscopy. In addition, many of the stable isotopomers of these molecules can be accurately detected, making it possible to follow specific metabolic processes. Potential areas of applications for this technology include the diagnosis of certain pathologies (e.g. Helicobacter Pylori infection), detection of trauma due to either physical or chemical causes and monitoring nutrient uptake (i.e., malnutrition). In order to understand the origin and elucidate the metabolic processes associated with these small molecules, we are employing physiologically based pharmacokinetic (PBPK) models. A PBPK model is founded on known physiological processes (i.e., blood flow rates, tissue volumes, breathing rate, etc.), chemical-specific processes (i.e., tissue solubility coefficients, molecular weight, chemical density, etc.), and on metabolic processes (tissue site and rate of metabolic biotransformation). Since many of these processes are well understood, a PBPK model can be developed and validated against the more readily available experimental animal data, and then by extrapolating the parameters to apply to man, the model can predict chemical behavior in humans.

Characterization of Non-Newtonian Fluids for Environmental Applications

NASA Astrophysics Data System (ADS)

Espinoza, I.; Hauswirth, S.; Cerda, C. C.; Sadeghi, S.

2017-12-01

Non-Newtonian fluids are fluids that exhibit viscosity changes with time, stress, or changing shear rates. This distinctive quality is advantageous to a number of applications, such as hydraulic fracturing and contaminant remediation. The use of non-Newtonian fluids in contaminant remediation has recently increased as a method of improving delivery of chemical oxidants and surfactants in hard-to-reach, low permeability zones within the subsurface. As the application of these fluids continues to increase, a need to improve upon the basic understanding of non-Newtonian fluid rheology becomes increasingly important. This study investigates the characteristics of guar gum and xanthan gum, two common non-Newtonian polymers, and how factors such as composition, preparation method, and chemical and biological degradation impact the rheology of the fluids. Because the polymers are semi-hydrophobic, preparation of solutions requires blending, heating, pre-dissolution in alcohol, addition of surfactant, or stirring for extended time periods. Additionally, fluids are commonly filtered to remove undissolved material and gels, and subsequently stored under a variety of conditions. We investigated the effect of these processes on the fluids' rheology by producing solutions at a range of concentrations with a variety of preparation and storage methods. The rheological properties of the solutions were then measured over a period of months with a rotational rheometer. The experimental data were fit to standard rheological models, and the parameters of these models were used to quantitatively assess the effect of chemical composition, physical processing, and storage on the fluid rheology. The results of this study provide an improved basis with which to predict physical, chemical, and temporal alterations of guar and xanthan gum rheology, and thereby allow for improved design of experimental, modeling, and field applications utilizing non-Newtonian fluids.

Immobilization of pH-sensitive CdTe Quantum Dots in a Poly(acrylate) Hydrogel for Microfluidic Applications

NASA Astrophysics Data System (ADS)

Franke, M.; Leubner, S.; Dubavik, A.; George, A.; Savchenko, T.; Pini, C.; Frank, P.; Melnikau, D.; Rakovich, Y.; Gaponik, N.; Eychmüller, A.; Richter, A.

2017-04-01

Microfluidic devices present the basis of modern life sciences and chemical information processing. To control the flow and to allow optical readout, a reliable sensor material that can be easily utilized for microfluidic systems is in demand. Here, we present a new optical readout system for pH sensing based on pH sensitive, photoluminescent glutathione capped cadmium telluride quantum dots that are covalently immobilized in a poly(acrylate) hydrogel. For an applicable pH sensing the generated hybrid material is integrated in a microfluidic sensor chip setup. The hybrid material not only allows in situ readout, but also possesses valve properties due to the swelling behavior of the poly(acrylate) hydrogel. In this work, the swelling property of the hybrid material is utilized in a microfluidic valve seat, where a valve opening process is demonstrated by a fluid flow change and in situ monitored by photoluminescence quenching. This discrete photoluminescence detection (ON/OFF) of the fluid flow change (OFF/ON) enables upcoming chemical information processing.

Micromotors for "Chemistry-on-the-Fly".

PubMed

Karshalev, Emil; Esteban-Fernández de Ávila, Berta; Wang, Joseph

2018-03-21

This perspective reviews mobile micro/nanomotor scaffolds for performing "chemistry-on-the-fly". Synthetic nano/micromotors offer great versatility and distinct advantages in diverse chemical applications owing to their efficient propulsion and facile surface functionalization that allow these mobile platforms to move and disperse reactive materials across the solution. Such dynamic microreactors have led to accelerated chemical processes, including organic pollutant degradation, metal chelation, biorecognition, redox chemistry, chemical "writing", and a variety of other chemical transformations. Representative examples of such micromotor-enhanced chemical reactions are discussed, focusing on the specific chemical role of these mobile microreactors. The advantages, gaps and limitations of using micromotors as mobile chemical platforms are discussed, concluding with the future prospects of this emerging field. We envision that artificial nano/micromotors will become attractive dynamic tools for speeding up and enhancing "on-the-fly" chemical reactions.

Advances in distributed watershed modeling: a review and application of the AgroEcoSystem-Watershed (AgES-W) model

USDA-ARS?s Scientific Manuscript database

Progress in the understanding of physical, chemical, and biological processes influencing water quality, coupled with advancements in the collection and analysis of hydrologic data, provide opportunities for significant innovations in the manner and level with which watershed-scale processes may be ...

7 CFR 319.40-8 - Processing at facilities operating under compliance agreements.

Code of Federal Regulations, 2011 CFR

2011-01-01

... plant pests from the facility, requirements to ensure the processing method effectively destroys plant pests, and the requirements for the application of chemical materials in accordance with part 305 of... and Budget under control number 0579-0049) [60 FR 27674, May 25, 1995, as amended at 69 FR 52418, Aug...

7 CFR 319.40-8 - Processing at facilities operating under compliance agreements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... plant pests from the facility, requirements to ensure the processing method effectively destroys plant pests, and the requirements for the application of chemical materials in accordance with part 305 of... and Budget under control number 0579-0049) [60 FR 27674, May 25, 1995, as amended at 69 FR 52418, Aug...

7 CFR 319.40-8 - Processing at facilities operating under compliance agreements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... plant pests from the facility, requirements to ensure the processing method effectively destroys plant pests, and the requirements for the application of chemical materials in accordance with part 305 of... and Budget under control number 0579-0049) [60 FR 27674, May 25, 1995, as amended at 69 FR 52418, Aug...

Challenges and progress in distributed watershed modeling: applications of the AgroEcoSystem-Watershed (AgES-W) model

USDA-ARS?s Scientific Manuscript database

Progress in the understanding of physical, chemical, and biological processes influencing water quality, coupled with advances in the collection and analysis of hydrologic data, provide opportunities for significant innovations in the manner and level with which watershed-scale processes may be quan...

APPLICATION OF A NEW LAND-SURFACE, DRY DEPOSITION, AND PBL MODEL IN THE MODELS-3 COMMUNITY MULTI-SCALE AIR QUALITY (CMAQ) MODEL SYSTEM

EPA Science Inventory

Like most air quality modeling systems, CMAQ divides the treatment of meteorological and chemical/transport processes into separate models run sequentially. A potential drawback to this approach is that it creates the illusion that these processes are minimally interdependent an...

An Interactive Virtual Tour of a Milk Powder Plant

ERIC Educational Resources Information Center

Herritsch, Alfred; Rahim, Elin Abdul; Fee, Conan J.; Morison, Ken R.; Gostomski, Peter A.

2013-01-01

Immersive learning applications in chemical and process engineering are creating the opportunity to bring entire process plants to the student. While meant to complement field trips, in some cases, this is the only opportunity for students to engage with certain industrial sites due to site regulations (health and safety, hygiene, intellectual…

Application of membrane processes to alcohol-water separation: Improving the energy efficiency of biofuel production(Singapore)

EPA Science Inventory

The prospect of dwindling oil supplies, concern over the carbon balance of the planet, and the availability of waste and non-waste biomass materials has generated renewed interest in the use of fermentation processes to produce commodity chemicals and fuels. The economics of fer...

Experimental Air Pressure Tank Systems for Process Control Education

ERIC Educational Resources Information Center

Long, Christopher E.; Holland, Charles E.; Gatzke, Edward P.

2006-01-01

In process control education, particularly in the field of chemical engineering, there is an inherent need for industrially relevant hands-on apparatuses that enable one to bridge the gap between the theoretical content of coursework and real-world applications. At the University of South Carolina, two experimental air-pressure tank systems have…

Which Came First, the MCnest or the MCnugget? A Survey of Markov Chain Applications in Avian Ecology, Population Biology and Chemical Risk Assessment.

EPA Science Inventory

Stochastic processes, such as survival and reproductive success, govern the trajectories of animal populations. Models of such processes have become increasingly important in understanding the effects of environmental change and anthropogenic disturbance on the ability of popula...

Strength Analysis and Process Simulation of Subway Contact Rail Support Bracket of Composite Materials

NASA Astrophysics Data System (ADS)

Fedulov, Boris N.; Safonov, Alexander A.; Sergeichev, Ivan V.; Ushakov, Andrey E.; Klenin, Yuri G.; Makarenko, Irina V.

2016-10-01

An application of composites for construction of subway brackets is a very effective approach to extend their lifetime. However, this approach involves the necessity to prevent process-induced distortions of the bracket due to thermal deformation and chemical shrinkage. At present study, a process simulation has been carried out to support the design of the production tooling. The simulation was based on the application of viscoelastic model for the resin. Simulation results were verified by comparison with results of manufacturing experiments. To optimize the bracket structure the strength analysis was carried out as well.

An Easy to Manufacture Micro Gas Preconcentrator for Chemical Sensing Applications.

PubMed

McCartney, Mitchell M; Zrodnikov, Yuriy; Fung, Alexander G; LeVasseur, Michael K; Pedersen, Josephine M; Zamuruyev, Konstantin O; Aksenov, Alexander A; Kenyon, Nicholas J; Davis, Cristina E

2017-08-25

We have developed a simple-to-manufacture microfabricated gas preconcentrator for MEMS-based chemical sensing applications. Cavities and microfluidic channels were created using a wet etch process with hydrofluoric acid, portions of which can be performed outside of a cleanroom, instead of the more common deep reactive ion etch process. The integrated heater and resistance temperature detectors (RTDs) were created with a photolithography-free technique enabled by laser etching. With only 28 V DC (0.1 A), a maximum heating rate of 17.6 °C/s was observed. Adsorption and desorption flow parameters were optimized to be 90 SCCM and 25 SCCM, respectively, for a multicomponent gas mixture. Under testing conditions using Tenax TA sorbent, the device was capable of measuring analytes down to 22 ppb with only a 2 min sample loading time using a gas chromatograph with a flame ionization detector. Two separate devices were compared by measuring the same chemical mixture; both devices yielded similar peak areas and widths (fwhm: 0.032-0.033 min), suggesting reproducibility between devices.

Two Decades of Laccases: Advancing Sustainability in the Chemical Industry

DOE PAGES

Cannatelli, Mark D.; Ragauskas, Arthur J.

2016-08-05

Given the current state of environmental affairs and that our future on this planet as we know it is in jeopardy, research and development into greener and more sustainable technologies within the chemical and forest products industries is at its peak. The need for environmentally benign practices is propelling new green processes, given the global scale of these industries. These challenges are also impacting academic research and our reagents of interest are laccases. Furthermore, these enzymes are employed in a variety of biotechnological applications due to their native function as catalytic oxidants. They are about as green as it getsmore » when it comes to chemical processes, requiring O 2 as their only co-substrate and producing H 2O as the sole by-product. The following account will review our twenty year journey on the use of these enzymes within our research group, from their initial use in biobleaching of kraft pulps and for fiber modification within the pulp and paper industry, to their current application as green catalytic oxidants in the field of synthetic organic chemistry.« less

Direct fabrication of 3D graphene on nanoporous anodic alumina by plasma-enhanced chemical vapor deposition

PubMed Central

Zhan, Hualin; Garrett, David J.; Apollo, Nicholas V.; Ganesan, Kumaravelu; Lau, Desmond; Prawer, Steven; Cervenka, Jiri

2016-01-01

High surface area electrode materials are of interest for a wide range of potential applications such as super-capacitors and electrochemical cells. This paper describes a fabrication method of three-dimensional (3D) graphene conformally coated on nanoporous insulating substrate with uniform nanopore size. 3D graphene films were formed by controlled graphitization of diamond-like amorphous carbon precursor films, deposited by plasma-enhanced chemical vapour deposition (PECVD). Plasma-assisted graphitization was found to produce better quality graphene than a simple thermal graphitization process. The resulting 3D graphene/amorphous carbon/alumina structure has a very high surface area, good electrical conductivity and exhibits excellent chemically stability, providing a good material platform for electrochemical applications. Consequently very large electrochemical capacitance values, as high as 2.1 mF for a sample of 10 mm3, were achieved. The electrochemical capacitance of the material exhibits a dependence on bias voltage, a phenomenon observed by other groups when studying graphene quantum capacitance. The plasma-assisted graphitization, which dominates the graphitization process, is analyzed and discussed in detail. PMID:26805546

Principles and applications of laser-induced liquid-phase jet-chemical etching

NASA Astrophysics Data System (ADS)

Stephen, Andreas; Metev, Simeon; Vollertsen, Frank

2003-11-01

In this treatment method laser radiation, which is guided from a coaxially expanding liquid jet-stream, locally initiates a thermochemical etching reaction on a metal surface, which leads to selective material removal at high resolution and quality of the treated surface as well as low thermal influence on the workpiece. Electrochemical investigations were performed under focused laser irradiation using a cw-Nd:YAG laser with a maximum power of 15 W and a simultaneous impact of the liquid jet-stream consisting of phosphoric acid with a maximum flow rate of 20 m/s. The time resolved measurements of the electrical potential difference against an electrochemical reference electrode were correlated with the specific processing parameters and corresponding etch rates to identify processing conditions for temporally stable and enhanced chemical etching reactions. Applications of laser-induced liquid-phase jet-chemical etching in the field of sensor technology, micromechanics and micrmoulding technology are presented. This includes the microstructuring of thin film systems, cutting of foils of shape memory alloys or the generation of structures with defined shape in bulk material.

Direct fabrication of 3D graphene on nanoporous anodic alumina by plasma-enhanced chemical vapor deposition.

PubMed

Zhan, Hualin; Garrett, David J; Apollo, Nicholas V; Ganesan, Kumaravelu; Lau, Desmond; Prawer, Steven; Cervenka, Jiri

2016-01-25

High surface area electrode materials are of interest for a wide range of potential applications such as super-capacitors and electrochemical cells. This paper describes a fabrication method of three-dimensional (3D) graphene conformally coated on nanoporous insulating substrate with uniform nanopore size. 3D graphene films were formed by controlled graphitization of diamond-like amorphous carbon precursor films, deposited by plasma-enhanced chemical vapour deposition (PECVD). Plasma-assisted graphitization was found to produce better quality graphene than a simple thermal graphitization process. The resulting 3D graphene/amorphous carbon/alumina structure has a very high surface area, good electrical conductivity and exhibits excellent chemically stability, providing a good material platform for electrochemical applications. Consequently very large electrochemical capacitance values, as high as 2.1 mF for a sample of 10 mm(3), were achieved. The electrochemical capacitance of the material exhibits a dependence on bias voltage, a phenomenon observed by other groups when studying graphene quantum capacitance. The plasma-assisted graphitization, which dominates the graphitization process, is analyzed and discussed in detail.

Six Classes of Diffraction-Based Optoelectronic Instruments

NASA Technical Reports Server (NTRS)

Spremo, Stevan; Fuhr, Peter; Schipper, John

2003-01-01

Six classes of diffraction-based optoelectronic instruments have been invented as means for wavelength-based processing of light. One family of anticipated applications lies in scientific instrumentation for studying chemical and physical reactions that affect and/or are affected differently by light of different wavelengths or different combinations of wavelengths. Another family of anticipated applications lies in optoelectronic communication systems.

Computational Nanotechnology of Molecular Materials, Electronics and Machines

NASA Technical Reports Server (NTRS)

Srivastava, D.; Biegel, Bryan A. (Technical Monitor)

2002-01-01

This viewgraph presentation covers carbon nanotubes, their characteristics, and their potential future applications. The presentation include predictions on the development of nanostructures and their applications, the thermal characteristics of carbon nanotubes, mechano-chemical effects upon carbon nanotubes, molecular electronics, and models for possible future nanostructure devices. The presentation also proposes a neural model for signal processing.

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

PubMed Central

Chatgilialoglu, Chryssostomos; Ferreri, Carla; Masi, Annalisa; Melchiorre, Michele; Sansone, Anna; Terzidis, Michael A.; Torreggiani, Armida

2013-01-01

The involvement of free radicals in life sciences has constantly increased with time and has been connected to several physiological and pathological processes. This subject embraces diverse scientific areas, spanning from physical, biological and bioorganic chemistry to biology and medicine, with applications to the amelioration of quality of life, health and aging. Multidisciplinary skills are required for the full investigation of the many facets of radical processes in the biological environment and chemical knowledge plays a crucial role in unveiling basic processes and mechanisms. We developed a chemical biology approach able to connect free radical chemical reactivity with biological processes, providing information on the mechanistic pathways and products. The core of this approach is the design of biomimetic models to study biomolecule behavior (lipids, nucleic acids and proteins) in aqueous systems, obtaining insights of the reaction pathways as well as building up molecular libraries of the free radical reaction products. This context can be successfully used for biomarker discovery and examples are provided with two classes of compounds: mono-trans isomers of cholesteryl esters, which are synthesized and used as references for detection in human plasma, and purine 5',8-cyclo-2'-deoxyribonucleosides, prepared and used as reference in the protocol for detection of such lesions in DNA samples, after ionizing radiations or obtained from different health conditions. PMID:23629513

Dry Sintered Metal Coating of Halloysite Nanotubes

DOE PAGES

Nicholson, James C.; Weisman, Jeffery A.; Boyer, Christen J.; ...

2016-09-19

Halloysite nanotubes (HNTs) are a naturally-occurring aluminosilicate whose dimensions measure microns in length and tens of nanometers in diameter. Bonding defects between the alumina and silica lead to net negative and positive charges on the exterior and interior lumen, respectively. HNTs have been shown to enhance the material properties of polymer matrices and enable the sustained release of loaded chemicals, drugs, and growth factors. Due to the net charges, these nanotubes can also be readily coated in layered-depositions using the HNT exterior lumen’s net negative charge as the basis for assembly. These coatings are primarily done through wet chemical processes,more » the majority of which are limited in their use of desired chemicals, due to the polarity of the halloysite. Furthermore, this restriction in the type of chemicals used often requires the use of more toxic chemicals in place of greener options, and typically necessitates the use of a significantly longer chemical process to achieve the desired coating. In this study, we show that HNTs can be coated with metal acetylacetonates—compounds primarily employed in the synthesis of nanoparticles, as metal catalysts, and as NMR shift reagents—through a dry sintering process. This method was capable of thermally decaying the metal acetylacetonate, resulting in a free positively-charged metal ion that readily bonded to the negatively-charged HNT exterior, resulting in metallic coatings forming on the HNT surface. Our coating method may enable greater deposition of coated material onto these nanotubes as required for a desired application. Moreover, the use of chemical processes using toxic chemicals is not required, thus eliminating exposure« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicholson, James C.; Weisman, Jeffery A.; Boyer, Christen J.

Halloysite nanotubes (HNTs) are a naturally-occurring aluminosilicate whose dimensions measure microns in length and tens of nanometers in diameter. Bonding defects between the alumina and silica lead to net negative and positive charges on the exterior and interior lumen, respectively. HNTs have been shown to enhance the material properties of polymer matrices and enable the sustained release of loaded chemicals, drugs, and growth factors. Due to the net charges, these nanotubes can also be readily coated in layered-depositions using the HNT exterior lumen’s net negative charge as the basis for assembly. These coatings are primarily done through wet chemical processes,more » the majority of which are limited in their use of desired chemicals, due to the polarity of the halloysite. Furthermore, this restriction in the type of chemicals used often requires the use of more toxic chemicals in place of greener options, and typically necessitates the use of a significantly longer chemical process to achieve the desired coating. In this study, we show that HNTs can be coated with metal acetylacetonates—compounds primarily employed in the synthesis of nanoparticles, as metal catalysts, and as NMR shift reagents—through a dry sintering process. This method was capable of thermally decaying the metal acetylacetonate, resulting in a free positively-charged metal ion that readily bonded to the negatively-charged HNT exterior, resulting in metallic coatings forming on the HNT surface. Our coating method may enable greater deposition of coated material onto these nanotubes as required for a desired application. Moreover, the use of chemical processes using toxic chemicals is not required, thus eliminating exposure« less

Chemical and biological treatment technologies for leather tannery chemicals and wastewaters: a review.

PubMed

Lofrano, Giusy; Meriç, Sureyya; Zengin, Gülsüm Emel; Orhon, Derin

2013-09-01

Although the leather tanning industry is known to be one of the leading economic sectors in many countries, there has been an increasing environmental concern regarding the release of various recalcitrant pollutants in tannery wastewater. It has been shown that biological processes are presently known as the most environmental friendly but inefficient for removal of recalcitrant organics and micro-pollutants in tannery wastewater. Hence emerging technologies such as advanced oxidation processes and membrane processes have been attempted as integrative to biological treatment for this sense. This paper, as the-state-of-the-art, attempts to revise the over world trends of treatment technologies and advances for pollution prevention from tannery chemicals and wastewater. It can be elucidated that according to less extent advances in wastewater minimization as well as in leather production technology and chemicals substitution, biological and chemical treatment processes have been progressively studied. However, there has not been a full scale application yet of those emerging technologies using advanced oxidation although some of them proved good achievements to remove xenobiotics present in tannery wastewater. It can be noted that advanced oxidation technologies integrated with biological processes will remain in the agenda of the decision makers and water sector to apply the best prevention solution for the future tanneries. Copyright © 2013 Elsevier B.V. All rights reserved.

[Application prospect and expectation of fungistatic agents of plants in preservation of Chinese herbal medicines].

PubMed

Li, Yan-jun; Kong, Wei-jun; Hu, Yi-chen; Zhao, Lian-hua; Yang, Shi-hai; Yang, Mei-hua

2015-10-01

During the process of growth, harvesting, transportation, processing and storage, Chinese herbal medicines (CHMs) can be easily contaminated by fungi and their metabolites like mycotoxins, which not only express negative effects on the quality and safety of CHMs and their processed products, but also pose great threats to human health. Now, some chemical synthetic fungicides have been frequently used to control the growth of fungi and accumulation of mycotoxins in the preservation of CHMs. However, the concentration and type of chemical fungicides allowed for postharvest application are restricted due to the disadvantages of their high residual toxicity, long degradation period and pollution to the environment and so on. Therefore, it is critical to research and develop some highly effective, safe and non-toxic, natural, environment-friendly fungistatic agents from plants to prevent CHMs from being contaminated by fungi and mycotoxins. The paper reviews mycotoxins and their harmfulness, the effective compounds of fungistatic plants as well as the antifungal mechanism to provide scientific evidences for developing novel and effective fungistatic agents plants. Then, the application prospect of fungistatic agents from plants in the preservation of CHMs was discussed.

Electroslag Strip Cladding of Steam Generators With Alloy 690

DOE Office of Scientific and Technical Information (OSTI.GOV)

Consonni, M.; Maggioni, F.; Brioschi, F.

2006-07-01

The present paper details the results of electroslag cladding and tube-to-tubesheet welding qualification tests conducted by Ansaldo-Camozzi ESC with Alloy 690 (Alloy 52 filler metal) on steel for nuclear power stations' steam generators shell, tubesheet and head; the possibility of submerged arc cladding on first layer was also considered. Test results, in terms of chemical analysis, mechanical properties and microstructure are reproducible and confidently applicable to production cladding and show that electroslag process can be used for Alloy 52 cladding with exceptionally stable and regular operation and high productivity. The application of submerged arc cladding process to the first layermore » leads to a higher base metal dilution, which should be avoided. Moreover, though the heat affected zone is deeper with electroslag cladding, in both cases no coarsened grain zone is found due to recrystallization effect of second cladding layer. Finally, the application of electroslag process to cladding of Alloy 52 with modified chemical composition, was proved to be highly beneficial as it strongly reduces hot cracking sensitivity, which is typical of submerged arc cladded Alloy 52, both during tube-to-tubesheet welding and first re-welding. (authors)« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bala, Greg Alan; Bruhn, Debby Fox; Fox, Sandra Lynn

Utilization of surfactants for improved oil recovery (IOR) is an accepted technique with high potential. However, technology application is frequently limited by cost. Biosurfactants (surface-active molecules produced by microorganisms) are not widely utilized in the petroleum industry due to high production costs associated with use of expensive substrates and inefficient product recovery methods. The economics of biosurfactant production could be significantly impacted through use of media optimization and application of inexpensive carbon substrates such as agricultural process residuals. Utilization of biosurfactants produced from agricultural residuals may 1) result in an economic advantage for surfactant production and technology application, and 2)more » convert a substantial agricultural waste stream to a value-added product for IOR. A biosurfactant with high potential for use is surfactin, a lipopeptide biosurfactant, produced by Bacillus subtilis. Reported here is the production and potential IOR utilization of surfactin produced by Bacillus subtilis (American Type Culture Collection (ATCC) 21332) from starch-based media. Production of surfactants from microbiological growth media based on simple sugars, chemically pure starch medium, simulated liquid and solid potato-process effluent media, a commercially prepared potato starch in mineral salts, and process effluent from a potato processor is discussed. Additionally, the effect of chemical and physical pretreatments on starchy feedstocks is discussed.« less

Cellulosic Nanomaterials in Food and Nutraceutical Applications: A Review.

PubMed

Khan, Avik; Wen, Yangbing; Huq, Tanzina; Ni, Yonghao

2018-01-10

Cellulosic nanomaterials (CNMs) are organic, green nanomaterials that are obtained from renewable sources and possess exceptional mechanical strength and biocompatibility. The associated unique physical and chemical properties have made these nanomaterials an intriguing prospect for various applications including the food and nutraceutical industry. From the immobilization of various bioactive agents and enzymes, emulsion stabilization, direct food additives, to the development of intelligent packaging systems or pathogen or pH detectors, the potential food related applications for CNMs are endless. Over the past decade, there have been several reviews published covering different aspects of cellulosic nanomaterials, such as processing-structure-property relationship, physical and chemical properties, rheology, extraction, nanocomposites, etc. In this critical review, we have discussed and provided a summary of the recent developments in the utilization of cellulosic nanomaterials in applications related to food and nutraceuticals.

The principles of ultrasound and its application in freezing related processes of food materials: A review.

PubMed

Cheng, Xinfeng; Zhang, Min; Xu, Baoguo; Adhikari, Benu; Sun, Jincai

2015-11-01

Ultrasonic processing is a novel and promising technology in food industry. The propagation of ultrasound in a medium generates various physical and chemical effects and these effects have been harnessed to improve the efficiency of various food processing operations. Ultrasound has also been used in food quality control as diagnostic technology. This article provides an overview of recent developments related to the application of ultrasound in low temperature and closely related processes such as freezing, thawing, freeze concentration and freeze drying. The applications of high intensity ultrasound to improve the efficiency of freezing process, to control the size and size distribution of ice crystals and to improve the quality of frozen foods have been discussed in considerable detail. The use of low intensity ultrasound in monitoring the ice content and to monitor the progress of freezing process has also been highlighted. Copyright © 2015 Elsevier B.V. All rights reserved.

Development studies of a novel wet oxidation process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, T.W.; Dooge, P.M.

1996-12-31

The objective of this study is to develop a novel catalytic chemical oxidation process that can be used to effectively treat multi-component wastes with a minimum of pretreatment characterization, thus providing a versatile, non-combustion method which will destroy hazardous organic compounds while simultaneously containing and concentrating toxic and radioactive metals for recovery or disposal in a readily stabilized matrix. Although the DETOX{sup SM} process had been tested to a limited extent for potential application to mixed wastes, there had not been sufficient experience with the process to determine its range of application to multicomponent waste forms. The potential applications ofmore » the process needed to be better identified. Then, the process needed to be demonstrated on wastes and remediate types on a practical scale in order that data could be obtained on application range, equipment size, capital and operating costs, effectiveness, safety, reliability, permittability, and potential commercial applications of the process. The approach for the project was, therefore, to identify the potential range of applications of the process (Phase I), to choose demonstration sites and design a demonstration prototype (Phase II), to fabricate and shakedown the demonstration unit (Phase III), then finally to demonstrate the process on surrogate hazardous and mixed wastes, and on actual mixed wastes (Phase IV).« less

Modelling episodic acidification of surface waters: the state of science.

PubMed

Eshleman, K N; Wigington, P J; Davies, T D; Tranter, M

1992-01-01

Field studies of chemical changes in surface waters associated with rainfall and snowmelt events have provided evidence of episodic acidification of lakes and streams in Europe and North America. Modelling these chemical changes is particularly challenging because of the variability associated with hydrological transport and chemical transformation processes in catchments. This paper provides a review of mathematical models that have been applied to the problem of episodic acidification. Several empirical approaches, including regression models, mixing models and time series models, support a strong hydrological interpretation of episodic acidification. Regional application of several models has suggested that acidic episodes (in which the acid neutralizing capacity becomes negative) are relatively common in surface waters in several regions of the US that receive acid deposition. Results from physically based models have suggested a lack of understanding of hydrological flowpaths, hydraulic residence times and biogeochemical reactions, particularly those involving aluminum. The ability to better predict episodic chemical responses of surface waters is thus dependent upon elucidation of these and other physical and chemical processes.

Development of flame resistant treatment for Nomex fibrous structures

NASA Technical Reports Server (NTRS)

Toy, M. S.

1977-01-01

Flame resistant fibrous materials for space shuttle application were developed through chemical modification of commercially available aromatic polyamide fibrous products. The new surface treatment was achieved in the laboratory by ultraviolet activation of the fabric in the presence of fluoroolefin monomers and a diluent gas. The monomers grafted under these conditions provide the improved properties of the fabric in flame resistance, chemical inertness, and nonwettability without the sacrifice of color or physical properties. The laboratory reaction vessel was scaled-up to a batch continuous process, which treats ten yards of the commercial width textiles. The treated commercial width Nomex (HT-10-41) from the scaled-up reactor is self-extinguishing in an oxygen-enriched environment, water-repellent, soft, silky, and improved in chemical resistance. Unlike most textile processes, the grafting unit operates under dry conditions and no chemical by-products have to be washed out of the finished product.

Process for forming a porous silicon member in a crystalline silicon member

DOEpatents

Northrup, M. Allen; Yu, Conrad M.; Raley, Norman F.

1999-01-01

Fabrication and use of porous silicon structures to increase surface area of heated reaction chambers, electrophoresis devices, and thermopneumatic sensor-actuators, chemical preconcentrates, and filtering or control flow devices. In particular, such high surface area or specific pore size porous silicon structures will be useful in significantly augmenting the adsorption, vaporization, desorption, condensation and flow of liquids and gasses in applications that use such processes on a miniature scale. Examples that will benefit from a high surface area, porous silicon structure include sample preconcentrators that are designed to adsorb and subsequently desorb specific chemical species from a sample background; chemical reaction chambers with enhanced surface reaction rates; and sensor-actuator chamber devices with increased pressure for thermopneumatic actuation of integrated membranes. Examples that benefit from specific pore sized porous silicon are chemical/biological filters and thermally-activated flow devices with active or adjacent surfaces such as electrodes or heaters.

Recent developments in broadly applicable structure-biodegradability relationships.

PubMed

Jaworska, Joanna S; Boethling, Robert S; Howard, Philip H

2003-08-01

Biodegradation is one of the most important processes influencing concentration of a chemical substance after its release to the environment. It is the main process for removal of many chemicals from the environment and therefore is an important factor in risk assessments. This article reviews available methods and models for predicting biodegradability of organic chemicals from structure. The first section of the article briefly discusses current needs for biodegradability estimation methods related to new and existing chemicals and in the context of multimedia exposure models. Following sections include biodegradation test methods and endpoints used in modeling, with special attention given to the Japanese Ministry of International Trade and Industry test; a primer on modeling, describing the various approaches that have been used in the structure/biodegradability relationship work, and contrasting statistical and mechanistic approaches; and recent developments in structure/biodegradability relationships, divided into group contribution, chemometric, and artificial intelligence approaches.

Evidence for a chemical clock in oscillatory formation of UiO-66

NASA Astrophysics Data System (ADS)

Goesten, M. G.; de Lange, M. F.; Olivos-Suarez, A. I.; Bavykina, A. V.; Serra-Crespo, P.; Krywka, C.; Bickelhaupt, F. M.; Kapteijn, F.; Gascon, Jorge

2016-06-01

Chemical clocks are often used as exciting classroom experiments, where an induction time is followed by rapidly changing colours that expose oscillating concentration patterns. This type of reaction belongs to a class of nonlinear chemical kinetics also linked to chaos, wave propagation and Turing patterns. Despite its vastness in occurrence and applicability, the clock reaction is only well understood for liquid-state processes. Here we report a chemical clock reaction, in which a solidifying entity, metal-organic framework UiO-66, displays oscillations in crystal dimension and number, as shown by X-ray scattering. In rationalizing this result, we introduce a computational approach, the metal-organic molecular orbital methodology, to pinpoint interaction between the tectonic building blocks that construct the metal-organic framework material. In this way, we show that hydrochloric acid plays the role of autocatalyst, bridging separate processes of condensation and crystallization.

Anaerobic Fermentation for Production of Carboxylic Acids as Bulk Chemicals from Renewable Biomass.

PubMed

Wang, Jufang; Lin, Meng; Xu, Mengmeng; Yang, Shang-Tian

Biomass represents an abundant carbon-neutral renewable resource which can be converted to bulk chemicals to replace petrochemicals. Carboxylic acids have wide applications in the chemical, food, and pharmaceutical industries. This chapter provides an overview of recent advances and challenges in the industrial production of various types of carboxylic acids, including short-chain fatty acids (acetic, propionic, butyric), hydroxy acids (lactic, 3-hydroxypropionic), dicarboxylic acids (succinic, malic, fumaric, itaconic, adipic, muconic, glucaric), and others (acrylic, citric, gluconic, pyruvic) by anaerobic fermentation. For economic production of these carboxylic acids as bulk chemicals, the fermentation process must have a sufficiently high product titer, productivity and yield, and low impurity acid byproducts to compete with their petrochemical counterparts. System metabolic engineering offers the tools needed to develop novel strains that can meet these process requirements for converting biomass feedstock to the desirable product.

Overview of several applications of chemical downstream etching (CDE) for IC manufacturing: advantages and drawbacks versus WET processes

NASA Astrophysics Data System (ADS)

de Buttet, Côme; Prevost, Emilie; Campo, Alain; Garnier, Philippe; Zoll, Stephane; Vallier, Laurent; Cunge, Gilles; Maury, Patrick; Massin, Thomas; Chhun, Sonarith

2017-03-01

Today the IC manufacturing faces lots of problematics linked to the continuous down scaling of printed structures. Some of those issues are related to wet processing, which are often used in the IC manufacturing flow for wafer cleaning, material etching and surface preparation. In the current work we summarize the limitations for the next nodes of wet processing such as metallic contaminations, wafer charging, corrosion and pattern collapse. As a replacement, we promoted the isotropic chemical dry etching (CDE) which is supposed to fix all the above drawbacks. Etching steps of SI3N4 layers were evaluated in order to prove the interest of such technique.

Application of computational methods to analyse and investigate physical and chemical processes of high-temperature mineralizing of condensed substances in gas stream

NASA Astrophysics Data System (ADS)

Markelov, A. Y.; Shiryaevskii, V. L.; Kudrinskiy, A. A.; Anpilov, S. V.; Bobrakov, A. N.

2017-11-01

A computational method of analysis of physical and chemical processes of high-temperature mineralizing of low-level radioactive waste in gas stream in the process of plasma treatment of radioactive waste in shaft furnaces was introduced. It was shown that the thermodynamic simulation method allows fairly adequately describing the changes in the composition of the pyrogas withdrawn from the shaft furnace at different waste treatment regimes. This offers a possibility of developing environmentally and economically viable technologies and small-sized low-cost facilities for plasma treatment of radioactive waste to be applied at currently operating nuclear power plants.

Chemical Probes of Histone Lysine Methyltransferases

PubMed Central

2015-01-01

Growing evidence suggests that histone methyltransferases (HMTs, also known as protein methyltransferases (PMTs)) play an important role in diverse biological processes and human diseases by regulating gene expression and the chromatin state. Therefore, HMTs have been increasingly recognized by the biomedical community as a class of potential therapeutic targets. High quality chemical probes of HMTs, as tools for deciphering their physiological functions and roles in human diseases and testing therapeutic hypotheses, are critical for advancing this promising field. In this review, we focus on the discovery, characterization, and biological applications of chemical probes for HMTs. PMID:25423077

Immunosensors using a quartz crystal microbalance

NASA Astrophysics Data System (ADS)

Kurosawa, Shigeru; Aizawa, Hidenobu; Tozuka, Mitsuhiro; Nakamura, Miki; Park, Jong-Won

2003-11-01

Better analytical technology has been demanded for accurate and rapid determination of trace amounts of chemical compounds, such as marker proteins for disease or endocrine disrupters like dioxin, which might be contained in blood, food and the environment. The study of immunosensors using a quartz crystal microbalance (QCM) has recently focused on conventional detection methods for the determination of chemical compounds together with the development of reagents and processes. This paper introduces the principle of the detection method of QCM immunosensors developed at AIST and its application to the detection of trace amounts of chemical compounds.

Bioapplications of graphene constructed functional nanomaterials.

PubMed

Gulzar, Arif; Yang, Piaoping; He, Fei; Xu, Jiating; Yang, Dan; Xu, Liangge; Jan, Mohammad Omar

2017-01-25

Graphene has distinctive mechanical, electronic, and optical properties, which researchers have applied to develop innovative electronic materials including transparent conductors and ultrafast transistors. Lately, the understanding of various chemical properties of graphene has expedited its application in high-performance devices that generate and store energy. Graphene is now increasing its terrain outside electronic and chemical applications toward biomedical areas such as precise bio sensing through graphene-quenched fluorescence, graphene-enhanced cell differentiation and growth, and graphene-assisted laser desorption/ionization for mass spectrometry. In this Account, we evaluate recent efforts to apply graphene and graphene oxides (GO) to biomedical research and a few different approaches to prepare graphene materials designed for biomedical applications and a brief perspective on their future applications. Because of its outstanding aqueous processability, amphiphilicity, surface functionalizability, surface enhanced Raman scattering (SERS), and fluorescence quenching ability, GO chemically exfoliated from oxidized graphite is considered a promising material for biological applications. In addition, the hydrophobicity and flexibility of large-area graphene synthesized by chemical vapor deposition (CVD) allow this material to play an important role in cell growth and differentiation. Graphene is considered to be an encouraging and smart candidate for numerous biomedical applications such as NIR-responsive cancer therapy and fluorescence bio-imaging and drug delivery. To that end, suitable preparation and unique approaches to utilize graphene-based materials such as graphene oxides (GOs), reduced graphene oxides (rGOs), and graphene quantum dots (GQDs) in biology and medical science are gaining growing interest. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Green Synthesis of Metallic Nanoparticles via Biological Entities

PubMed Central

Shah, Monaliben; Fawcett, Derek; Sharma, Shashi; Tripathy, Suraj Kumar; Poinern, Gérrard Eddy Jai

2015-01-01

Nanotechnology is the creation, manipulation and use of materials at the nanometre size scale (1 to 100 nm). At this size scale there are significant differences in many material properties that are normally not seen in the same materials at larger scales. Although nanoscale materials can be produced using a variety of traditional physical and chemical processes, it is now possible to biologically synthesize materials via environment-friendly green chemistry based techniques. In recent years, the convergence between nanotechnology and biology has created the new field of nanobiotechnology that incorporates the use of biological entities such as actinomycetes algae, bacteria, fungi, viruses, yeasts, and plants in a number of biochemical and biophysical processes. The biological synthesis via nanobiotechnology processes have a significant potential to boost nanoparticles production without the use of harsh, toxic, and expensive chemicals commonly used in conventional physical and chemical processes. The aim of this review is to provide an overview of recent trends in synthesizing nanoparticles via biological entities and their potential applications. PMID:28793638

Performance Optimization Control of ECH using Fuzzy Inference Application

NASA Astrophysics Data System (ADS)

Dubey, Abhay Kumar

Electro-chemical honing (ECH) is a hybrid electrolytic precision micro-finishing technology that, by combining physico-chemical actions of electro-chemical machining and conventional honing processes, provides the controlled functional surfaces-generation and fast material removal capabilities in a single operation. Process multi-performance optimization has become vital for utilizing full potential of manufacturing processes to meet the challenging requirements being placed on the surface quality, size, tolerances and production rate of engineering components in this globally competitive scenario. This paper presents an strategy that integrates the Taguchi matrix experimental design, analysis of variances and fuzzy inference system (FIS) to formulate a robust practical multi-performance optimization methodology for complex manufacturing processes like ECH, which involve several control variables. Two methodologies one using a genetic algorithm tuning of FIS (GA-tuned FIS) and another using an adaptive network based fuzzy inference system (ANFIS) have been evaluated for a multi-performance optimization case study of ECH. The actual experimental results confirm their potential for a wide range of machining conditions employed in ECH.

Diamond surface functionalization with biomimicry - Amine surface tether and thiol moiety for electrochemical sensors

NASA Astrophysics Data System (ADS)

Sund, James B.; Causey, Corey P.; Wolter, Scott D.; Parker, Charles B.; Stoner, Brian R.; Toone, Eric J.; Glass, Jeffrey T.

2014-05-01

The surface of conducting diamond was functionalized with a terminal thiol group that is capable of binding and detecting nitrogen-oxygen species. The functionalization process employed multiple steps starting with doped diamond films grown by plasma enhanced chemical vapor deposition followed by hydrogen termination and photochemical attachment of a chemically protected amine alkene. The surface tether was deprotected to reveal the amine functionality, which enabled the tether to be extended with surface chemistry to add a terminal thiol moiety for electrochemical sensing applications. Each step of the process was validated using X-ray photoelectron spectroscopy analysis.

DC magnetron sputtered polyaniline-HCl thin films for chemical sensing applications.

PubMed

Menegazzo, Nicola; Boyne, Devon; Bui, Holt; Beebe, Thomas P; Booksh, Karl S

2012-07-03

Thin films of conducting polymers exhibit unique chemical and physical properties that render them integral parts in microelectronics, energy storage devices, and chemical sensors. Overall, polyaniline (PAni) doped in acidic media has shown metal-like electronic conductivity, though exact physical and chemical properties are dependent on the polymer structure and dopant type. Difficulties arising from poor processability render production of doped PAni thin films particularly challenging. In this contribution, DC magnetron sputtering, a physical vapor deposition technique, is applied to the preparation of conductive thin films of PAni doped with hydrochloric acid (PAni-HCl) in an effort to circumvent issues associated with conventional thin film preparation methods. Samples manufactured by the sputtering method are analyzed along with samples prepared by conventional drop-casting. Physical characterization (atomic force microscopy, AFM) confirm the presence of PAni-HCl and show that films exhibit a reduced roughness and potentially pinhole-free coverage of the substrate. Spectroscopic evidence (UV-vis, FT-IR, and X-ray photoelectron spectroscopy (XPS)) suggests that structural changes and loss of conductivity, not uncommon during PAni processing, does occur during the preparation process. Finally, the applicability of sputtered films to gas-phase sensing of NH(3) was investigated with surface plasmon resonance (SPR) spectroscopy and compared to previous contributions. In summary, sputtered PAni-HCl films exhibit quantifiable, reversible behavior upon exposure to NH(3) with a calculated LOD (by method) approaching 0.4 ppm NH(3) in dry air.

Physical abrasion of mafic minerals and basalt grains: application to Martian aeolian deposits

USGS Publications Warehouse

Cornwall, Carin; Bandfield, Joshua L.; Titus, Timothy N.; Schreiber, B. C.; Montgomery, D.R.

2015-01-01

Sediment maturity, or the mineralogical and physical characterization of sediment deposits, has been used to locate sediment source, transport medium and distance, weathering processes, and paleoenvironments on Earth. Mature terrestrial sands are dominated by quartz, which is abundant in source lithologies on Earth and is physically and chemically stable under a wide range of conditions. Immature sands, such as those rich in feldspars or mafic minerals, are composed of grains that are easily physically weathered and highly susceptible to chemical weathering. On Mars, which is predominately mafic in composition, terrestrial standards of sediment maturity are not applicable. In addition, the martian climate today is cold, dry and sediments are likely to be heavily influenced by physical weathering rather than chemical weathering. Due to these large differences in weathering processes and composition, martian sediments require an alternate maturity index. Abrason tests have been conducted on a variety of mafic materials and results suggest that mature martian sediments may be composed of well sorted, well rounded, spherical basalt grains. In addition, any volcanic glass present is likely to persist in a mechanical weathering environment while chemically altered products are likely to be winnowed away. A modified sediment maturity index is proposed that can be used in future studies to constrain sediment source, paleoclimate, mechanisms for sediment production, and surface evolution. This maturity index may also provide details about erosional and sediment transport systems and preservation processes of layered deposits.

Chemical and biological work-related risks across occupations in Europe: a review.

PubMed

Montano, Diego

2014-01-01

Work-related health inequalities are determined to some extent by an unequal exposure to chemical and biological risk factors of disease. Although their potential economic burden in the European Union (EU-25) might be substantial, comprehensive reviews focusing on the distribution of these risks across occupational groups are limited. Thus, the main objective of this review is to provide a synopsis of the exposure to chemical and biological hazards across occupational groups. In addition, main industrial applications of hazardous substances are identified and some epidemiological evidence is discussed regarding societal costs and incidence rates of work-related diseases. Available lists of carcinogens, sensitisers, mutagens, reprotoxic substances and biological hazards were consulted. For each work-related hazard the main industrial application was identified in order to assess which ISCO occupational groups may be associated with direct exposure. Where available, information on annual tonnage production, risk assessment of the substances and pathogens, and other relevant data were collected and reported. Altogether 308 chemical and biological hazards were identified which may account to at least 693 direct exposures. These hazards concentrate on the following major occupational groups: technicians (ISCO 3), operators (ISCO 8), agricultural workers (ISCO 6) and workers in elementary occupations (ISCO 9). Common industrial applications associated with increased exposure rates relate among others to: (1) production or application of pigments, resins, cutting fluids, adhesives, pesticides and cleaning products, (2) production of rubber, plastics, textiles, pharmaceuticals and cosmetics, and (3) in agriculture, metallurgy and food processing industry, Societal costs of the unequal distribution of chemical and biological hazards across occupations depend on the corresponding work-related diseases and may range from 2900 EUR to 126000 EUR per case/year. Risk of exposure to chemical and biological risks and work-related disease incidence are highly concentrated on four occupational groups. The unequal burden of exposure across occupations is an important contributing factor leading to health inequalities in society. The bulk of societal costs, however, are actually being borne by the workers themselves. There is an urgent need of taking into account the health impact of production processes and services on workers' health.

Chemical and biological work-related risks across occupations in Europe: a review

PubMed Central

2014-01-01

Background Work-related health inequalities are determined to some extent by an unequal exposure to chemical and biological risk factors of disease. Although their potential economic burden in the European Union (EU-25) might be substantial, comprehensive reviews focusing on the distribution of these risks across occupational groups are limited. Thus, the main objective of this review is to provide a synopsis of the exposure to chemical and biological hazards across occupational groups. In addition, main industrial applications of hazardous substances are identified and some epidemiological evidence is discussed regarding societal costs and incidence rates of work-related diseases. Methods Available lists of carcinogens, sensitisers, mutagens, reprotoxic substances and biological hazards were consulted. For each work-related hazard the main industrial application was identified in order to assess which ISCO occupational groups may be associated with direct exposure. Where available, information on annual tonnage production, risk assessment of the substances and pathogens, and other relevant data were collected and reported. Results Altogether 308 chemical and biological hazards were identified which may account to at least 693 direct exposures. These hazards concentrate on the following major occupational groups: technicians (ISCO 3), operators (ISCO 8), agricultural workers (ISCO 6) and workers in elementary occupations (ISCO 9). Common industrial applications associated with increased exposure rates relate among others to: (1) production or application of pigments, resins, cutting fluids, adhesives, pesticides and cleaning products, (2) production of rubber, plastics, textiles, pharmaceuticals and cosmetics, and (3) in agriculture, metallurgy and food processing industry, Societal costs of the unequal distribution of chemical and biological hazards across occupations depend on the corresponding work-related diseases and may range from 2900 EUR to 126000 EUR per case/year. Conclusions Risk of exposure to chemical and biological risks and work-related disease incidence are highly concentrated on four occupational groups. The unequal burden of exposure across occupations is an important contributing factor leading to health inequalities in society. The bulk of societal costs, however, are actually being borne by the workers themselves. There is an urgent need of taking into account the health impact of production processes and services on workers’ health. PMID:25071862

Long-term effects of alum-treated litter, untreated litter and NH4NO3 application on phosphorus speciation, distribution and reactivity in soils using K-edge XANES and chemical fractionation

USDA-ARS?s Scientific Manuscript database

Whereas soil test information on the fertility and chemistry of soils has been important to elaborate safe and sound agricultural practices, microscopic information can give a whole extra dimension to understand the chemical processes occurring in soils. The objective of this study was to evaluate t...

Life Cycle Assessment for Chemical Agent Resistant Coating.

DTIC Science & Technology

1996-09-01

994) document to develop HVs from 1 to 2.5. The final equivalency factor for a chemical was based on the formula: Equivalency Factor = (toxicity HV...applicable to the development of processes/procedures and their implementation, likely would fit better with a true LCA- based design exercise for a product...Johnny Springer, Jr., National Risk Management Research Laboratory, Office of Research and Development , U.S. Environmental Protection Agency

[Application of chemometrics in composition-activity relationship research of traditional Chinese medicine].

PubMed

Han, Sheng-Nan

2014-07-01

Chemometrics is a new branch of chemistry which is widely applied to various fields of analytical chemistry. Chemometrics can use theories and methods of mathematics, statistics, computer science and other related disciplines to optimize the chemical measurement process and maximize access to acquire chemical information and other information on material systems by analyzing chemical measurement data. In recent years, traditional Chinese medicine has attracted widespread attention. In the research of traditional Chinese medicine, it has been a key problem that how to interpret the relationship between various chemical components and its efficacy, which seriously restricts the modernization of Chinese medicine. As chemometrics brings the multivariate analysis methods into the chemical research, it has been applied as an effective research tool in the composition-activity relationship research of Chinese medicine. This article reviews the applications of chemometrics methods in the composition-activity relationship research in recent years. The applications of multivariate statistical analysis methods (such as regression analysis, correlation analysis, principal component analysis, etc. ) and artificial neural network (such as back propagation artificial neural network, radical basis function neural network, support vector machine, etc. ) are summarized, including the brief fundamental principles, the research contents and the advantages and disadvantages. Finally, the existing main problems and prospects of its future researches are proposed.

Evaluating a preventive biological control agent applied on grapevines against Botrytis cinerea and its influence on winemaking.

PubMed

Escribano-Viana, Rocío; Portu, Javier; Garijo, Patrocinio; Gutiérrez, Ana Rosa; Santamaría, Pilar; López-Alfaro, Isabel; López, Rosa; González-Arenzana, Lucía

2018-02-25

This research was aimed to study the influence on grape and wine quality and on the fermentation processes of the application of a preventive biological treatment against Botrytis cinerea in Tempranillo Rioja grapevines. For this purpose, a biofungicide containing Bacillus subtilis QST713 was applied twice to the vineyard. Results were compared with non-treated samples from the same vineyard and with samples treated with a chemical fungicide composed of fenhexamid. Data showed that general grape quality and spontaneous alcoholic fermentation performance were not influenced by either fungicide application. The chemical fungicide had a considerable influence on the clonal diversity of Saccharomyces cerevisiae species, which led to the alcoholic fermentation. Furthermore, it caused longer malolactic fermentation than with the biological fungicide and in the control. The biofungicide made malolactic fermentation 1 day shorter because the establishment of the commercial lactic acid bacteria used as a starter culture was total. After malolactic fermentation, the wines did not show significant differences in general oenological parameters. Preventive biofungicide treatment against B. cinerea did not negatively influence the quality of grapes and wines and the fermentation processes. Therefore, biological control of B. cinerea with B. subtilis applied on grapevines could be advisable in oenological terms. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Theoretical research program to study chemical reactions in AOTV bow shock tubes

NASA Technical Reports Server (NTRS)

Taylor, Peter R.

1993-01-01

The main focus was the development, implementation, and calibration of methods for performing molecular electronic structure calculations to high accuracy. These various methods were then applied to a number of chemical reactions and species of interest to NASA, notably in the area of combustion chemistry. Among the development work undertaken was a collaborative effort to develop a program to efficiently predict molecular structures and vibrational frequencies using energy derivatives. Another major development effort involved the design of new atomic basis sets for use in chemical studies: these sets were considerably more accurate than those previously in use. Much effort was also devoted to calibrating methods for computing accurate molecular wave functions, including the first reliable calibrations for realistic molecules using full CI results. A wide variety of application calculations were undertaken. One area of interest was the spectroscopy and thermochemistry of small molecules, including establishing small molecule binding energies to an accuracy rivaling, or even on occasion surpassing, the experiment. Such binding energies are essential input to modeling chemical reaction processes, such as combustion. Studies of large molecules and processes important in both hydrogen and hydrocarbon combustion chemistry were also carried out. Finally, some effort was devoted to the structure and spectroscopy of small metal clusters, with applications to materials science problems.

40 CFR Table 1 to Subpart Ffff of... - Emission Limits and Work Practice Standards for Continuous Process Vents

Code of Federal Regulations, 2012 CFR

2012-07-01

... Pollutants: Miscellaneous Organic Chemical Manufacturing Pt. 63, Subpt. FFFF, Table 1 Table 1 to Subpart FFFF... continuous process vent a. Not applicable i. Reduce emissions of total organic HAP by ≥98 percent by weight or to an outlet process concentration ≤20 ppmv as organic HAP or TOC by venting emissions through a...

Elastomers in mud motors for oil field applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hendrik, J.

1997-08-01

Mud motors, the most frequently used downhole drilling motors in modern drilling systems, are described in their application and function. The elastomeric liner in a mud motor acts as a huge continuous seal. Important properties of elastomers such as chemical resistance, fatigue resistance, mechanical strength, abrasion resistance, bonding to steel and processability are discussed. Advantages and disadvantages of NBR, HNBR, FKM, TFEP, and EPDM elastomers for mud motor applications are briefly described. The importance of drilling fluids and their physical and chemical impact on motor elastomers are described. Drilling fluids are categorized in: oil based-, synthetic-, and water based. Resultsmore » of compatibility tests in the different drilling muds of the presented categories demonstrate the complexity of elastomer development. Elastomers with an equally good performance in all drilling muds are not available. Future developments and improvements are directed towards higher chemical resistance at higher service temperatures. This will be possible only with improved elastomer-to-metal bonding, increased mechanical and better dynamic properties.« less

Chemical segregation in metallic glass nanowires.

PubMed

Zhang, Qi; Li, Qi-Kai; Li, Mo

2014-11-21

Nanowires made of metallic glass have been actively pursued recently due to the superb and unique properties over those of the crystalline materials. The amorphous nanowires are synthesized either at high temperature or via mechanical disruption using focused ion beam. These processes have potential to cause significant changes in structure and chemical concentration, as well as formation of defect or imperfection, but little is known to date about the possibilities and mechanisms. Here, we report chemical segregation to surfaces and its mechanisms in metallic glass nanowires made of binary Cu and Zr elements from molecular dynamics simulation. Strong concentration deviation are found in the nanowires under the conditions similar to these in experiment via focused ion beam processing, hot imprinting, and casting by rapid cooling from liquid state. Our analysis indicates that non-uniform internal stress distribution is a major cause for the chemical segregation, especially at low temperatures. Extension is discussed for this observation to multicomponent metallic glass nanowires as well as the potential applications and side effects of the composition modulation. The finding also points to the possibility of the mechanical-chemical process that may occur in different settings such as fracture, cavitation, and foams where strong internal stress is present in small length scales.

Morphology-preserving chemical conversion of bioorganic and inorganic templates

NASA Astrophysics Data System (ADS)

Vernon, Jonathan Paul

The generation of nanostructured assemblies with complex (three-dimensional, 3D) self-assembled morphologies and with complex (multicomponent) tailorable inorganic compositions is of considerable technological and scientific interest. This dissertation demonstrates self-assembled 3D organic templates of biogenic origin can be converted into replicas comprised of numerous other functional nanocrystalline inorganic materials. Nature provides a spectacular variety of biologically-assembled 3D organic structures with intricate, hierarchical (macro-to-micro-to-nanoscale) morphologies. Such processing on readily-available structurally complex templates provides a framework for chemical conversion of synthetic organic templates and, potentially, production of organic/inorganic composites. Four specific research thrusts are detailed in this document. First, chemical conversion of a nanostructured bioorganic template into a multicomponent oxide compound (tetragonal BaTiO3) via SSG coating and subsequent morphology-preserving microwave hydrothermal processing is demonstrated. Second, morphology-preserving chemical conversion of bioorganic templates into hierarchical photoluminescent microparticles is demonstrated to reveal both the dramatic change in properties such processing can provide, and the potential utility of chemically transformed templates in anti-counterfeiting / authentication applications. Third, determination of the reaction mechanism(s) for morphology-preserving microwave hydrothermal conversion of TiO2 to BaTiO3, through Au inert markers on single crystal rutile titania, is detailed. Finally, utilization of constructive coating techniques (SSG) and moderate temperature (< 500°C) heat treatments to modify and replicate structural color is coupled with deconstructive focused ion beam microsurgery to prepare samples for microscale structure interrogation. Specifically, the effects of coating thickness and composition on reflection spectra of structurally colored templates are examined. Also, the effects of the replacement of natural material with higher index of refraction inorganic materials on optical properties are discussed. The three processing research thrusts constituting chapters 1, 2 and 4 take advantage of moderate temperature processing to ensure nanocrystalline materials, either for shape preservation or to prevent scattering in optical applications. The research thrust detailed in chapter 3 examines hydrothermal conversion of TiO2 to BaTiO3, not only to identify the reaction mechanism(s) involved in hydrothermal conversion under morphology-preserving conditions, but also to introduce inert marker experiments to the field of microwave hydrothermal processing.

Spectrally encoded optical fibre sensor systems and their application in process control, environmental and structural monitoring

NASA Astrophysics Data System (ADS)

Willsch, Reinhardt; Ecke, Wolfgang; Schwotzer, Gunter

2005-09-01

Different types of advanced optical fibre sensor systems using similar spectral interrogation principles and potential low-cost polychromator optoelectronic signal processing instrumentation will be presented, and examples of their industrial application are demonstrated. These are such sensors as multimode fibre based humidity, temperature, and pressure sensors with extrinsic microoptical Fabry-Perot transducers for process control in gas industry, UV absorption evanescent field sensors for organic pollution monitoring in groundwater, and single mode fibre Bragg grating (FBG) multiplexed strain & vibration and temperature sensor networks for structural health monitoring applications in electric power facilities, aerospace, railways, geotechnical and civil engineering. Recent results of current investigations applying FBGs and microstructured fibres for chemical sensing will be discussed.

Conversion Coatings for Aluminum Alloys by Chemical Vapor Deposition Mechanisms

NASA Technical Reports Server (NTRS)

Reye, John T.; McFadden, Lisa S.; Gatica, Jorge E.; Morales, Wilfredo

2004-01-01

With the rise of environmental awareness and the renewed importance of environmentally friendly processes, the United States Environmental Protection Agency has targeted surface pre-treatment processes based on chromates. Indeed, this process has been subject to regulations under the Clean Water Act as well as other environmental initiatives, and there is today a marked movement to phase the process out in the near future. Therefore, there is a clear need for new advances in coating technology that could provide practical options for replacing present industrial practices. Depending on the final application, such coatings might be required to be resistant to corrosion, act as chemically resistant coatings, or both. This research examined a chemical vapor deposition (CVD) mechanism to deposit uniform conversion coatings onto aluminum alloy substrates. Robust protocols based on solutions of aryl phosphate ester and multi-oxide conversion coating (submicron) films were successfully grown onto the aluminum alloy samples. These films were characterized by X-ray Photoelectron Spectroscopy (XPS). Preliminary results indicate the potential of this technology to replace aqueous-based chromate processes.

A study of diazonium couplings with aromatic nucleophiles both in solution and on a polymer surface

NASA Astrophysics Data System (ADS)

Chng, Shuyun; Parker, Emily M.; Griffiths, Jon-Paul; Moloney, Mark G.; Wu, Linda Y. L.

2017-04-01

Diazonium coupling is a technique finding wider application to materials and biological science, for hybridization and linking processes, and for the construction of responsive surface functionality. For this reason, detailed examination of solution and surface processes was warranted, and results of such a study are reported here. The modification of polystyrene surfaces was examined as a model, and the process compared to a solution mimic using N,N-dimethylaniline. It was confirmed that solution and solid surface reactions proceed in a similar manner in terms of the chemical functionality generated, but with lower chemical efficiency and reaction times slower for the latter, in a reaction which was pH dependent. The solution process was shown to give only the trans-azo para- coupled products. Whilst there are clear similarities between the solution and surface chemistry, the efficiency of coupling at a surface is not necessarily replicated in the chemical yield of the mimicking solution processes, but nonetheless provides an alternative to other Click-type surface modifications. It should not be assumed that such couplings occur with quantitative efficiency at the surface.

Multicomponent micropatterned sol-gel materials by capillary molding

NASA Astrophysics Data System (ADS)

Lochhead, Michael J.; Yager, Paul

1997-10-01

A physically and chemically benign method for patterning multiple sol-gel materials onto a single substrate is described. Structures are demonstrated for potential micro- optical chemical sensor, biosensor, and waveguiding applications. Fabrication is based on the micro molding in capillaries (MIMIC) approach. A novel mold design allows several sols to be cast simultaneously. Closely spaced, organically modified silica ridges containing fluorescent dyes are demonstrated. Ridges have cross sectional dimensions from one to 50 micrometers and are centimeters in length. Processing issues, particularly those related to mold filling, are discussed in detail. Because sol-gel MIMIC avoids the harsh physical and chemical environments normally associated with patterning, the approach allows full exploitation of sol- gel processing advantages, such as the ability to entrap sensitive organic dopant molecules in the sol-gel matrix.

Continuous Succinic Acid Production by Actinobacillus succinogenes on Xylose-Enriched Hydrolysate

DOE PAGES

Bradfield, Michael F. A.; Mohagheghi, Ali; Salvachua, Davinia; ...

2015-11-14

Bio-manufacturing of high-value chemicals in parallel to renewable biofuels has the potential to dramatically improve the overall economic landscape of integrated lignocellulosic biorefineries. However, this will require the generation of carbohydrate streams from lignocellulose in a form suitable for efficient microbial conversion and downstream processing appropriate to the desired end use, making overall process development, along with selection of appropriate target molecules, crucial to the integrated biorefinery. Succinic acid (SA), a high-value target molecule, can be biologically produced from sugars and has the potential to serve as a platform chemical for various chemical and polymer applications. However, the feasibility ofmore » microbial SA production at industrially relevant productivities and yields from lignocellulosic biorefinery streams has not yet been reported.« less

40 CFR 279.12 - Prohibitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR THE MANAGEMENT OF USED OIL Applicability § 279.12 Prohibitions. (a) Surface impoundment prohibition... new products, including the component parts of products, by mechanical or chemical processes; (ii...

21 CFR 876.5885 - Tissue culture media for human ex vivo tissue and cell culture processing applications.

Code of Federal Regulations, 2011 CFR

2011-04-01

... chemically defined components (e.g., amino acids, vitamins, inorganic salts) that are essential for the ex... ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY...

ENVIRONMENTAL RISK MANAGEMENT OF BIOTECHNOLOGY

EPA Science Inventory

The last two decades have shown remarkable advances in the field of biotechnology. We have processes using biotechnology to produce materials from commodity chemicals to pharmaceuticals. The application to agriculture has shown the introduction of transgenic crops with pesticidal...

ENVIRONMENTAL RISK MANAGEMENT OF BIOTECHNOLOGY

EPA Science Inventory

The last two decades have shown remarkable advances in the field of biotechnology. We hav processes using biotechnology to produce materials from commodity chemicals to pharmaceuticals. The application to agriculture gas shown the introduction of transgenic crops with pesticidal ...

Biosensors with Built-In Biomolecular Logic Gates for Practical Applications

PubMed Central

Lai, Yu-Hsuan; Sun, Sin-Cih; Chuang, Min-Chieh

2014-01-01

Molecular logic gates, designs constructed with biological and chemical molecules, have emerged as an alternative computing approach to silicon-based logic operations. These molecular computers are capable of receiving and integrating multiple stimuli of biochemical significance to generate a definitive output, opening a new research avenue to advanced diagnostics and therapeutics which demand handling of complex factors and precise control. In molecularly gated devices, Boolean logic computations can be activated by specific inputs and accurately processed via bio-recognition, bio-catalysis, and selective chemical reactions. In this review, we survey recent advances of the molecular logic approaches to practical applications of biosensors, including designs constructed with proteins, enzymes, nucleic acids, nanomaterials, and organic compounds, as well as the research avenues for future development of digitally operating “sense and act” schemes that logically process biochemical signals through networked circuits to implement intelligent control systems. PMID:25587423

Recent advances in mid- and near-infrared spectroscopy with applications for research and teaching, focusing on petrochemistry and biotechnology relevant products

NASA Astrophysics Data System (ADS)

Heise, H. M.; Fritzsche, J.; Tkatsch, H.; Waag, F.; Karch, K.; Henze, K.; Delbeck, S.; Budde, J.

2013-11-01

Mid- and near-infrared spectroscopy is introduced as a versatile analytical method for characterizing liquid and solid chemicals as obtained from petrochemistry and biotechnology processes. Besides normal transmission measurements, special equipment with silver halide fiber-optic probes allowing efficient analysis based on mid-infrared attenuated total reflection, and an accessory for near-infrared diffuse reflection measurements, are presented. The latter technique can be used advantageously for powdered samples such as microalgae biomass and polysaccharides, as well as for different tissues such as meat samples. The advantages and disadvantages of both methods, which can be used for industrial process monitoring and chemical quality control applications, are discussed, and have been used in several research projects of BSc students within their degree course of bio- and nano-technologies of our University of Applied Sciences.

Regeneration of glass nanofluidic chips through a multiple-step sequential thermochemical decomposition process at high temperatures.

PubMed

Xu, Yan; Wu, Qian; Shimatani, Yuji; Yamaguchi, Koji

2015-10-07

Due to the lack of regeneration methods, the reusability of nanofluidic chips is a significant technical challenge impeding the efficient and economic promotion of both fundamental research and practical applications on nanofluidics. Herein, a simple method for the total regeneration of glass nanofluidic chips was described. The method consists of sequential thermal treatment with six well-designed steps, which correspond to four sequential thermal and thermochemical decomposition processes, namely, dehydration, high-temperature redox chemical reaction, high-temperature gasification, and cooling. The method enabled the total regeneration of typical 'dead' glass nanofluidic chips by eliminating physically clogged nanoparticles in the nanochannels, removing chemically reacted organic matter on the glass surface and regenerating permanent functional surfaces of dissimilar materials localized in the nanochannels. The method provides a technical solution to significantly improve the reusability of glass nanofluidic chips and will be useful for the promotion and acceleration of research and applications on nanofluidics.

Development of an acceptable factor to estimate chronic end points from acute toxicity data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Venman, B.C.; Flaga, C.

1985-12-01

Acceptable daily intake (ADI) values are routinely developed for threshold toxicants from NOAELs determined from human or animal chronic or subchronic data. These NOAELs are then divided by appropriate uncertainty factors ranging from 10 to 1000 depending on the quality of the data. However, for the vast majority of chemicals used industrially, adequate toxicity data needed to use this process are not available. Thus, a procedure to estimate a chronic toxicity endpoint from acute toxicity data, such as an oral rat LD50, becomes necessary. An acute-to-chronic application factor of 0.0001 was developed, which when multiplied by an oral LD50 formore » an individual chemical, yields a surrogate chronic NOAEL. This figure can then be used to estimate an acceptable daily exposure for humans. The process used to estimate this application factor is detailed.« less

The Piancatelli reaction and its variants: recent applications to high added-value chemicals and biomass valorization.

PubMed

Verrier, Charlie; Moebs-Sanchez, Sylvie; Queneau, Yves; Popowycz, Florence

2018-01-31

The Piancatelli reaction, also called the Piancatelli rearrangement, consists in the direct conversion of furfuryl alcohols to cyclopentenone derivatives through a furan ring opening-electrocyclization process. Discovered in the late 70's, this reaction has been scarcely used for more than 40 years but recently has been the focus of particular interest from the scientific community and an increasing number of publications on the topic have emerged in the last few years. The first part of this review provides an overview of the recent achievements in classical Piancatelli reactions, discussing reaction conditions and catalytic systems, whereas the second part focuses on the variants recently developed, including the use of new nucleophiles in the process. Finally, the third part of this review deals with the recent application of this transformation to the production of commodity chemicals from renewable carbon feedstocks based on sugar-derived furanic platforms.

Finding and estimating chemical property data for environmental assessment.

PubMed

Boethling, Robert S; Howard, Philip H; Meylan, William M

2004-10-01

The ability to predict the behavior of a chemical substance in a biological or environmental system largely depends on knowledge of the physicochemical properties and reactivity of that substance. We focus here on properties, with the objective of providing practical guidance for finding measured values and using estimation methods when necessary. Because currently available computer software often makes it more convenient to estimate than to retrieve measured values, we try to discourage irrational exuberance for these tools by including comprehensive lists of Internet and hard-copy data resources. Guidance for assessors is presented in the form of a process to obtain data that includes establishment of chemical identity, identification of data sources, assessment of accuracy and reliability, substructure searching for analogs when experimental data are unavailable, and estimation from chemical structure. Regarding property estimation, we cover estimation from close structural analogs in addition to broadly applicable methods requiring only the chemical structure. For the latter, we list and briefly discuss the most widely used methods. Concluding thoughts are offered concerning appropriate directions for future work on estimation methods, again with an emphasis on practical applications.

Review on the progress in synthesis and application of magnetic carbon nanocomposites.

PubMed

Zhu, Maiyong; Diao, Guowang

2011-07-01

This review focuses on the synthesis and application of nanostructured composites containing magnetic nanostructures and carbon-based materials. Great progress in fabrication of magnetic carbon nanocomposites has been made by developing methods including filling process, template-based synthesis, chemical vapor deposition, hydrothermal/solvothermal method, pyrolysis procedure, sol-gel process, detonation induced reaction, self-assembly method, etc. The applications of magnetic carbon nanocomposites expanded to a wide range of fields such as environmental treatment, microwave absorption, magnetic recording media, electrochemical sensor, catalysis, separation/recognization of biomolecules and drug delivery are discussed. Finally, some future trends and perspectives in this research area are outlined.

Review on the progress in synthesis and application of magnetic carbon nanocomposites

NASA Astrophysics Data System (ADS)

Zhu, Maiyong; Diao, Guowang

2011-07-01

This review focuses on the synthesis and application of nanostructured composites containing magnetic nanostructures and carbon-based materials. Great progress in fabrication of magnetic carbon nanocomposites has been made by developing methods including filling process, template-based synthesis, chemical vapor deposition, hydrothermal/solvothermal method, pyrolysis procedure, sol-gel process, detonation induced reaction, self-assembly method, etc. The applications of magnetic carbon nanocomposites expanded to a wide range of fields such as environmental treatment, microwave absorption, magnetic recording media, electrochemical sensor, catalysis, separation/recognization of biomolecules and drug delivery are discussed. Finally, some future trends and perspectives in this research area are outlined.

Using a low melting solvent mixture to extract value from wood biomass

NASA Astrophysics Data System (ADS)

Hiltunen, Jaakko; Kuutti, Lauri; Rovio, Stella; Puhakka, Eini; Virtanen, Tommi; Ohra-Aho, Taina; Vuoti, Sauli

2016-09-01

Green chemistry, sustainability and eco-efficiency are guiding the development of the next generation of industrial chemical processes. The use of non-edible lignocellulosic biomass as a source of chemicals and fuels has recently raised interest due to the need for an alternative to fossil resources. Valorisation mainly focuses on cellulose, which has been used for various industrial scale applications for decades. However, creating an economically more viable value chain would require the exploitation of the other main components, hemicellulose and lignin. Here, we present a new low melting mixture composition based in boric acid and choline chloride, and demonstrate its efficiency in the fractionation of wood-based biomass for the production of non-condensed lignin, suitable for further use in the search for sustainable industrial applications, and for the selective conversion of hemicelluloses into valuable platform chemicals.

Plant seed species identification from chemical fingerprints: a high-throughput application of direct analysis in real time mass spectrometry.

PubMed

Lesiak, Ashton D; Cody, Robert B; Dane, A John; Musah, Rabi A

2015-09-01

Plant species identification based on the morphological features of plant parts is a well-established science in botany. However, species identification from seeds has largely been unexplored, despite the fact that the seeds contain all of the genetic information that distinguishes one plant from another. Using seeds of genus Datura plants, we show here that the mass spectrum-derived chemical fingerprints for seeds of the same species are similar. On the other hand, seeds from different species within the same genus display distinct chemical signatures, even though they may contain similar characteristic biomarkers. The intraspecies chemical signature similarities on the one hand, and interspecies fingerprint differences on the other, can be processed by multivariate statistical analysis methods to enable rapid species-level identification and differentiation. The chemical fingerprints can be acquired rapidly and in a high-throughput manner by direct analysis in real time mass spectrometry (DART-MS) analysis of the seeds in their native form, without use of a solvent extract. Importantly, knowledge of the identity of the detected molecules is not required for species level identification. However, confirmation of the presence within the seeds of various characteristic tropane and other alkaloids, including atropine, scopolamine, scopoline, tropine, tropinone, and tyramine, was accomplished by comparison of the in-source collision-induced dissociation (CID) fragmentation patterns of authentic standards, to the fragmentation patterns observed in the seeds when analyzed under similar in-source CID conditions. The advantages, applications, and implications of the chemometric processing of DART-MS derived seed chemical signatures for species level identification and differentiation are discussed.

Chemically enhanced in situ recovery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sale, T.; Pitts, M.; Wyatt, K.

1996-08-01

Chemically enhanced recovery is a promising alternative to current technologies for management of subsurface releases of organic liquids. Through the inclusion of surfactants, solvents, polymers, and/or alkaline agents to a waterflood, the transport of targeted organic compounds can be increased and rates of recovery enhanced. By far, the vast majority of work done in the field of chemically enhanced recovery has been at a laboratory scale. The following text focuses on chemically enhanced recovery from a field application perspective with emphasis given to chlorinated solvents in a low permeability setting. While chlorinated solvents are emphasized, issues discussed are also relevantmore » to organic liquids less dense than water such as petroleum products. Topics reviewed include: (1) Description of technology; (2) General technology considerations; (3) Low permeability media considerations; (4) Cost and reliability considerations; (5) Commercial availability; and (6) Case histories. Through this paper an appreciation is developed of both the potential and limitations of chemically enhanced recovery. Excluded from the scope of this paper is the in situ destruction of organic compounds through processes such as chemical or biological oxidation, chemically enhanced recovery of inorganic compounds, and ex situ soil treatment processes. 11 refs., 2 figs., 1 tab.« less

Field-structured material media and methods for synthesis thereof

DOEpatents

Martin, James E.; Hughes, Robert C.; Anderson, Robert A.

2001-09-18

The present application is directed to a new class of composite materials, called field-structured composite (FSC) materials, which comprise a oriented aggregate structure made of magnetic particles suspended in a nonmagnetic medium, and to a new class of processes for their manufacture. FSC materials have much potential for application, including use in chemical, optical, environmental, and mechanical sensors.

40 CFR 414.90 - Applicability; description of the subcategory of direct discharge point sources that use end-of...

Code of Federal Regulations, 2010 CFR

2010-07-01

... ORGANIC CHEMICALS, PLASTICS, AND SYNTHETIC FIBERS Direct Discharge Point Sources That Use End-of-Pipe... subcategory of direct discharge point sources that use end-of-pipe biological treatment. 414.90 Section 414.90... that use end-of-pipe biological treatment. The provisions of this subpart are applicable to the process...

Enzymatic Functionalization of Carbon-Hydrogen Bonds1

PubMed Central

Lewis, Jared C.; Coelho, Pedro S.

2010-01-01

The development of new catalytic methods to functionalize carbon-hydrogen (C-H) bonds continues to progress at a rapid pace due to the significant economic and environmental benefits of these transformations over traditional synthetic methods. In nature, enzymes catalyze regio- and stereoselective C-H bond functionalization using transformations ranging from hydroxylation to hydroalkylation under ambient reaction conditions. The efficiency of these enzymes relative to analogous chemical processes has led to their increased use as biocatalysts in preparative and industrial applications. Furthermore, unlike small molecule catalysts, enzymes can be systematically optimized via directed evolution for a particular application and can be expressed in vivo to augment the biosynthetic capability of living organisms. While a variety of technical challenges must still be overcome for practical application of many enzymes for C-H bond functionalization, continued research on natural enzymes and on novel artificial metalloenzymes will lead to improved synthetic processes for efficient synthesis of complex molecules. In this critical review, we discuss the most prevalent mechanistic strategies used by enzymes to functionalize non-acidic C-H bonds, the application and evolution of these enzymes for chemical synthesis, and a number of potential biosynthetic capabilities uniquely enabled by these powerful catalysts. PMID:21079862

40 CFR Table 2 to Subpart Ffff of... - Emission Limits and Work Practice Standards for Batch Process Vents

Code of Federal Regulations, 2012 CFR

2012-07-01

... Pollutants: Miscellaneous Organic Chemical Manufacturing Pt. 63, Subpt. FFFF, Table 2 Table 2 to Subpart FFFF... Group 1 batch process vents a. Reduce collective uncontrolled organic HAP emissions from the sum of all... a flare); or Not applicable. b. Reduce collective uncontrolled organic HAP emissions from the sum of...

Long-term aging of elastomers: Chemical stress relaxation of fluorosilicone rubber and other studies

NASA Technical Reports Server (NTRS)

Kalfayan, S. H.; Mazzeo, A. A.; Silver, R. H.

1971-01-01

Aerospace applications of elastomers are considered, including: propellant binders, bladder materials for liquid propellant expulsion systems, and fuel tank sealants for high-speed aircraft. A comprehensive molecular theory for mechanical properties of these materials has been developed but has only been tested experimentally in cases where chemical degradation processes are excluded. Hence, a study is being conducted to ascertain the nature, extent, and rate of chemical changes that take place in some elastomers of interest. Chemical changes that may take place in the fluorosilicone elastomer, LS 420, which is regarded as a fuel and high-temperature-resistant rubber are investigated. The kinetic analysis of the chemical stress relaxation and gel permeation chromatography studies comprise the major portion of the report.

Chemically induced phospholipid translocation across biological membranes.

PubMed

Gurtovenko, Andrey A; Onike, Olajide I; Anwar, Jamshed

2008-09-02

Chemical means of manipulating the distribution of lipids across biological membranes is of considerable interest for many biomedical applications as a characteristic lipid distribution is vital for numerous cellular functions. Here we employ atomic-scale molecular simulations to shed light on the ability of certain amphiphilic compounds to promote lipid translocation (flip-flops) across membranes. We show that chemically induced lipid flip-flops are most likely pore-mediated: the actual flip-flop event is a very fast process (time scales of tens of nanoseconds) once a transient water defect has been induced by the amphiphilic chemical (dimethylsulfoxide in this instance). Our findings are consistent with available experimental observations and further emphasize the importance of transient membrane defects for chemical control of lipid distribution across cell membranes.

Surface engineering on CeO2 nanorods by chemical redox etching and their enhanced catalytic activity for CO oxidation

NASA Astrophysics Data System (ADS)

Gao, Wei; Zhang, Zhiyun; Li, Jing; Ma, Yuanyuan; Qu, Yongquan

2015-07-01

Controllable surface properties of nanocerias are desired for various catalytic processes. There is a lack of efficient approaches to adjust the surface properties of ceria to date. Herein, a redox chemical etching method was developed to controllably engineer the surface properties of ceria nanorods. Ascorbic acid and hydrogen peroxide were used to perform the redox chemical etching process, resulting in a rough surface and/or pores on the surface of ceria nanorods. Increasing the etching cycles induced a steady increase of the specific surface area, oxygen vacancies and surface Ce3+ fractions. As a result, the etched nanorods delivered enhanced catalytic activity for CO oxidation, compared to the non-etched ceria nanorods. Our method provides a novel and facile approach to continuously adjust the surface properties of ceria for practical applications.Controllable surface properties of nanocerias are desired for various catalytic processes. There is a lack of efficient approaches to adjust the surface properties of ceria to date. Herein, a redox chemical etching method was developed to controllably engineer the surface properties of ceria nanorods. Ascorbic acid and hydrogen peroxide were used to perform the redox chemical etching process, resulting in a rough surface and/or pores on the surface of ceria nanorods. Increasing the etching cycles induced a steady increase of the specific surface area, oxygen vacancies and surface Ce3+ fractions. As a result, the etched nanorods delivered enhanced catalytic activity for CO oxidation, compared to the non-etched ceria nanorods. Our method provides a novel and facile approach to continuously adjust the surface properties of ceria for practical applications. Electronic supplementary information (ESI) available: Diameter distributions of as-prepared and etched samples, optical images, specific catalytic data of CO oxidation and comparison of CO oxidation. See DOI: 10.1039/c5nr01846c

Exopolysaccharides enriched in rare sugars: bacterial sources, production, and applications

PubMed Central

Roca, Christophe; Alves, Vitor D.; Freitas, Filomena; Reis, Maria A. M.

2015-01-01

Microbial extracellular polysaccharides (EPS), produced by a wide range of bacteria, are high molecular weight biopolymers, presenting an extreme diversity in terms of chemical structure and composition. They may be used in many applications, depending on their chemical and physical properties. A rather unexplored aspect is the presence of rare sugars in the composition of some EPS. Rare sugars, such as rhamnose or fucose, may provide EPS with additional biological properties compared to those composed of more common sugar monomers. This review gives a brief overview of these specific EPS and their producing bacteria. Cultivation conditions are summarized, demonstrating their impact on the EPS composition, together with downstream processing. Finally, their use in different areas, including cosmetics, food products, pharmaceuticals, and biomedical applications, are discussed. PMID:25914689

Sonophotocatalysis in advanced oxidation process: a short review.

PubMed

Joseph, Collin G; Li Puma, Gianluca; Bono, Awang; Krishnaiah, Duduku

2009-06-01

Sonophotocatalysis involves the use of a combination of ultrasonic sound waves, ultraviolet radiation and a semiconductor photocatalyst to enhance a chemical reaction by the formation of free radicals in aqueous systems. Researchers have used sonophotocatalysis in a variety of investigations i.e. from water decontamination to direct pollutant degradation. This degradation process provides an excellent opportunity to reduce reaction time and the amount of reagents used without the need for extreme physical conditions. Given its advantages, the sonophotocatalysis process has a futuristic application from an engineering and fundamental aspect in commercial applications. A detailed search of published reports was done and analyzed in this paper with respect to sonication, photocatalysis and advanced oxidation processes.

Advanced Manufacturing and Value-added Products from US Agriculture

NASA Technical Reports Server (NTRS)

Villet, Ruxton H.; Child, Dennis R.; Acock, Basil

1992-01-01

An objective of the US Department of Agriculture (USDA) Agriculture Research Service (ARS) is to develop technology leading to a broad portfolio of value-added marketable products. Modern scientific disciplines such as chemical engineering are brought into play to develop processes for converting bulk commodities into high-margin products. To accomplish this, the extremely sophisticated processing devices which form the basis of modern biotechnology, namely, genes and enzymes, can be tailored to perform the required functions. The USDA/ARS is a leader in the development of intelligent processing equipment (IPE) for agriculture in the broadest sense. Applications of IPE are found in the production, processing, grading, and marketing aspects of agriculture. Various biotechnology applications of IPE are discussed.

Tuning Chemical Potential Difference across Alternately Doped Graphene p-n Junctions for High-Efficiency Photodetection.

PubMed

Lin, Li; Xu, Xiang; Yin, Jianbo; Sun, Jingyu; Tan, Zhenjun; Koh, Ai Leen; Wang, Huan; Peng, Hailin; Chen, Yulin; Liu, Zhongfan

2016-07-13

Being atomically thin, graphene-based p-n junctions hold great promise for applications in ultrasmall high-efficiency photodetectors. It is well-known that the efficiency of such photodetectors can be improved by optimizing the chemical potential difference of the graphene p-n junction. However, to date, such tuning has been limited to a few hundred millielectronvolts. To improve this critical parameter, here we report that using a temperature-controlled chemical vapor deposition process, we successfully achieved modulation-doped growth of an alternately nitrogen- and boron-doped graphene p-n junction with a tunable chemical potential difference up to 1 eV. Furthermore, such p-n junction structure can be prepared on a large scale with stable, uniform, and substitutional doping and exhibits a single-crystalline nature. This work provides a feasible method for synthesizing low-cost, large-scale, high efficiency graphene p-n junctions, thus facilitating their applications in optoelectronic and energy conversion devices.

Sewage sludge hazardous assessment: chemical evaluation and cytological effects in CHO-k1 cells.

PubMed

Bonomo, M M; Morozesk, M; Duarte, I D; Rocha, L D; Fernandes, M N; Matsumoto, S T

2016-06-01

Application of sewage sludge in agricultural lands is a growing practice in several countries due to its numerous benefits to soil and crops, where chemical and pathogen levels are determined by corresponding legislation. However, the presence of contaminants in residues must always be controlled before application due to their dangerous effects over the ecosystem and potential risks to human health. The main objective of this study was to integrate biological and chemical analysis in order to help elucidating the residue potential toxic, cytotoxic, and mutagenic effects. We evaluate samples of sewage sludge before and after the sanitizing treatment with lime in cytokinesis-block assay using CHO-k1 culture cells. The sanitizing treatment promoted a decrease in pathogen levels, which is the main purpose of this process. Even with chemical levels below the established by environmental agencies, results showed sewage sludge ability to enhance genotoxic and mutagenic effects, proving that residue should be handled with caution in order to minimize its environmental and human risk.

In situ magnetic resonance measurement of conversion, hydrodynamics and mass transfer during single- and two-phase flow in fixed-bed reactors.

PubMed

Gladden, L F; Alexander, P; Britton, M M; Mantle, M D; Sederman, A J; Yuen, E H L

2003-01-01

In recent years there has been increasing interest in applying magnetic resonance (MR) techniques in areas of engineering and chemical technology. The science that underpins many of these applications is the physics and chemistry of transport and reaction processes in porous materials. Key to the exploitation of MR methods will be our ability to demonstrate that MR yields information that cannot be obtained using conventional measurement techniques in engineering research. This article describes two case studies that highlight the power of MR to give new insights to chemical engineers. First, we demonstrate the application of MR techniques to explore both mass transfer and chemical conversion in situ within a fixed bed of catalyst, and we then use these data to identify the rate-controlling step of the chemical conversion. Second, we implement a rapid imaging technique to study the stability of the gas-liquid distribution in the low- and high-interaction two-phase flow regimes in a trickle-bed reactor.

Materials process and applications of single grain (RE)-Ba-Cu-O bulk high-temperature superconductors

NASA Astrophysics Data System (ADS)

Li, Beizhan; Zhou, Difan; Xu, Kun; Hara, Shogo; Tsuzuki, Keita; Miki, Motohiro; Felder, Brice; Deng, Zigang; Izumi, Mitsuru

2012-11-01

This paper reviews recent advances in the melt process of (RE)-Ba-Cu-O [(RE)BCO, where RE represents a rare earth element] single grain high-temperature superconductors (HTSs), bulks and its applications. The efforts on the improvement of the magnetic flux pinning with employing the top-seeded melt-growth process technique and using a seeded infiltration and growth process are discussed. Which including various chemical doping strategies and controlled pushing effect based on the peritectic reaction of (RE)BCO. The typical experiment results, such as the largest single domain bulk, the clear TEM observations and the significant critical current density, are summarized together with the magnetization techniques. Finally, we highlight the recent prominent progress of HTS bulk applications, including Maglev, flywheel, power device, magnetic drug delivery system and magnetic resonance devices.

Development of an alkaline/surfactant/polymer compositional reservoir simulator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhuyan, D.

1989-01-01

The mathematical formulation of a generalized three-dimensional compositional reservoir simulator for high-pH chemical flooding processes is presented in this work. The model assumes local thermodynamic equilibrium with respect to both reaction chemistry and phase behavior and calculates equilibrium electrolyte and phase compositions as a function of time and position. The reaction chemistry considers aqueous electrolytic chemistry, precipitation/dissolution of minerals, ion exchange reactions on matrix surface, reaction of acidic components of crude oil with the bases in the aqueous solution and cation exchange reactions with the micelles. The simulator combines this detailed reaction chemistry associated with these processes with the extensivemore » physical and flow property modeling schemes of an existing chemical flood simulator (UTCHEM) to model the multiphase, multidimensional displacement processes. The formulation of the chemical equilibrium model is quite general and is adaptable to simulate a variety of chemical descriptions. In addition to its use in the simulation of high-pH chemical flooding processes, the model will find application in the simulation of other reactive flow problems like the ground water contamination, reinjection of produced water, chemical waste disposal, etc. in one, two or three dimensions and under multiphase flow conditions. In this work, the model is used to simulate several hypothetical cases of high-pH chemical floods, which include cases from a simple alkaline preflush of a micellar/polymer flood to surfactant enhanced alkaline-polymer flooding and the results are analyzed. Finally, a few published alkaline, alkaline-polymer and surfactant-alkaline-polymer corefloods are simulated and compared with the experimental results.« less

Bacteriocins: Recent Trends and Potential Applications.

PubMed

Bali, Vandana; Panesar, Parmjit S; Bera, Manab B; Kennedy, John F

2016-01-01

In the modern era, there is great need for food preservation in both developing and developed countries due to increasing demand for extending shelf life and prevention of spoilage of food material. With the emergence of new pathogens and ability of micro-organisms to undergo changes, exploration of new avenues for the food preservation has gained importance. Moreover, awareness among consumers regarding harmful effects of chemical preservatives has been increased. Globally, altogether there is increasing demand by consumers for chemical-free and minimal processed food products. Potential of bacteriocin and its application in reducing the microbiological spoilages and in the preservation of food is long been recognized. Bacteriocins are normally specific to closely related species without disrupting the growth of other microbial populations. A number of applications of bacteriocin have been reported for humans, live stock, aquaculture etc. This review is focused on recent trends and applications of bacteriocins in different areas in addition to their biopreservative potential.

Development of an integrated chemical weather prediction system for environmental applications at meso to global scales: NMMB/BSC-CHEM

NASA Astrophysics Data System (ADS)

Jorba, O.; Pérez, C.; Karsten, K.; Janjic, Z.; Dabdub, D.; Baldasano, J. M.

2009-09-01

This contribution presents the ongoing developments of a new fully on-line chemical weather prediction system for meso to global scale applications. The modeling system consists of a mineral dust module and a gas-phase chemistry module coupled on-line to a unified global-regional atmospheric driver. This approach allows solving small scale processes and their interactions at local to global scales. Its unified environment maintains the consistency of all the physico-chemical processes involved. The atmospheric driver is the NCEP/NMMB numerical weather prediction model (Janjic and Black, 2007) developed at National Centers for Environmental Prediction (NCEP). It represents an evolution of the operational WRF-NMME model extending from meso to global scales. Its unified non-hydrostatic dynamical core supports regional and global simulations. The Barcelona Supercomputing Center is currently designing and implementing a chemistry transport model coupled online with the new global/regional NMMB. The new modeling system is intended to be a powerful tool for research and to provide efficient global and regional chemical weather forecasts at sub-synoptic and mesoscale resolutions. The online coupling of the chemistry follows the approach similar to that of the mineral dust module already coupled to the atmospheric driver, NMMB/BSC-DUST (Pérez et al., 2008). Chemical species are advected and mixed at the corresponding time steps of the meteorological tracers using the same numerical scheme. Advection is eulerian, positive definite and monotone. The chemical mechanism and chemistry solver is based on the Kinetic PreProcessor KPP (Damian et al., 2002) package with the main purpose of maintaining a wide flexibility when configuring the model. Such approach will allow using a simplified chemical mechanism for global applications or a more complete mechanism for high-resolution local or regional studies. Moreover, it will permit the implementation of a specific configuration for forecasting applications in regional or global domains. An emission process allows the coupling of different emission inventories sources such as RETRO, EDGAR and GEIA for the global domain, EMEP for Europe and HERMES for Spain. The photolysis scheme is based on the Fast-J scheme, coupled with physics of each model layer (e.g., aerosols, clouds, absorbers as ozone) and it considers grid-scale clouds from the atmospheric driver. The dry deposition scheme follows the deposition velocity analogy for gases, enabling the calculation of deposition fluxes from airborne concentrations. No cloud-chemistry processes are included in the system yet (no wet deposition, scavenging and aqueous chemistry). The modeling system developments will be presented and first results of the gas-phase chemistry at global scale will be discussed. REFERENCES Janjic, Z.I., and Black, T.L., 2007. An ESMF unified model for a broad range of spatial and temporal scales, Geophysical Research Abstracts, 9, 05025. Pérez, C., Haustein, K., Janjic, Z.I., Jorba, O., Baldasano, J.M., Black, T.L., and Nickovic, S., 2008. An online dust model within the meso to global NMMB: current progress and plans. AGU Fall Meeting, San Francisco, A41K-03, 2008. Damian, V., Sandu, A., Damian, M., Potra, F., and Carmichael, G.R., 2002. The kinetic preprocessor KPP - A software environment for solving chemical kinetics. Comp. Chem. Eng., 26, 1567-1579. Sandu, A., and Sander, R., 2006. Technical note:Simulating chemical systems in Fortran90 and Matlab with the Kinetic PreProcessor KPP-2.1. Atmos. Chem. and Phys., 6, 187-195.

Predicting drug side-effect profiles: a chemical fragment-based approach

PubMed Central

2011-01-01

Background Drug side-effects, or adverse drug reactions, have become a major public health concern. It is one of the main causes of failure in the process of drug development, and of drug withdrawal once they have reached the market. Therefore, in silico prediction of potential side-effects early in the drug discovery process, before reaching the clinical stages, is of great interest to improve this long and expensive process and to provide new efficient and safe therapies for patients. Results In the present work, we propose a new method to predict potential side-effects of drug candidate molecules based on their chemical structures, applicable on large molecular databanks. A unique feature of the proposed method is its ability to extract correlated sets of chemical substructures (or chemical fragments) and side-effects. This is made possible using sparse canonical correlation analysis (SCCA). In the results, we show the usefulness of the proposed method by predicting 1385 side-effects in the SIDER database from the chemical structures of 888 approved drugs. These predictions are performed with simultaneous extraction of correlated ensembles formed by a set of chemical substructures shared by drugs that are likely to have a set of side-effects. We also conduct a comprehensive side-effect prediction for many uncharacterized drug molecules stored in DrugBank, and were able to confirm interesting predictions using independent source of information. Conclusions The proposed method is expected to be useful in various stages of the drug development process. PMID:21586169

Quarterly progress report for the Chemical and Energy Research Section of the Chemical Technology Division: October-December 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jubin, R.T.

This report summarizes the major activities conducted in the Chemical and Energy Research Section of the Chemical Technology Division at Oak Ridge National Laboratory (ORNL) during the period October--December 1997. The section conducts basic and applied research and development in chemical engineering, applied chemistry, and bioprocessing, with an emphasis on energy-driven technologies and advanced chemical separations for nuclear and waste applications. The report describes the various tasks performed within six major areas of research: Hot Cell Operations, Process Chemistry and Thermodynamics, Separations and Materials Synthesis, Fluid Structure and Properties, Biotechnology Research, and Molecular Studies. The name of a technical contactmore » is included with each task described, and readers are encouraged to contact these individuals if they need additional information. Activities conducted within the area of Hot Cell Operations included efforts to optimize the processing conditions for Enhanced Sludge Washing of Hanford tank sludge, the testing of candidate absorbers and ion exchangers under continuous-flow conditions using actual supernatant from the Melton Valley Storage Tanks, and attempts to develop a cesium-specific spherical inorganic sorbent for the treatment of acidic high-salt waste solutions. Within the area of Process Chemistry and Thermodynamics, the problem of solids formation in process solutions from caustic treatment of Hanford sludge was addressed and experimental collaborative efforts with Russian scientists to determine the solidification conditions of yttrium barium, and copper oxides from their melts were completed.« less

Solvent free chemical oxidative polymerization as a universal method for the synthesis of ultra high molecular weight conjugated polymers based on 3,4-propylenedioxythiophenes.

PubMed

Kumar, Anshu; Singh, Rekha; Gopinathan, Sreelekha P; Kumar, Anil

2012-05-18

In this communication, we report on a solvent free chemical oxidative polymerization route for the monomers based on 3,4-propylenedioxythiophenes wherein the process is applicable to both solid as well as liquid monomers and results in the bulk synthesis of ultra high molecular weight polymers. This journal is © The Royal Society of Chemistry 2012

Water Purification Systems

NASA Technical Reports Server (NTRS)

1992-01-01

A water purification/recycling system developed by Photo-Catalytics, Inc. (PCI) for NASA is commercially available. The system cleanses and recycles water, using a "photo-catalysis" process in which light or radiant energy sparks a chemical reaction. Chemically stable semiconductor powders are added to organically polluted water. The powder absorbs ultraviolet light, and pollutants are oxidized and converted to carbon dioxide. Potential markets for the system include research and pharmaceutical manufacturing applications, as well as microchip manufacture and wastewater cleansing.

Corrosion protection

DOEpatents

Brown, Donald W.; Wagh, Arun S.

2003-05-27

There has been invented a chemically bonded phosphate corrosion protection material and process for application of the corrosion protection material for corrosion prevention. A slurry of iron oxide and phosphoric acid is used to contact a warm surface of iron, steel or other metal to be treated. In the presence of ferrous ions from the iron, steel or other metal, the slurry reacts to form iron phosphates which form grains chemically bonded onto the surface of the steel.

Aqueous organic geochemistry at high temperature/high pressure

NASA Technical Reports Server (NTRS)

Simoneit, Bernd R. T.

1992-01-01

A description of the fate and chemical alterations of organic matter under hydrothermal conditions is given, with a brief overview of the geographic localities where these processes have been investigated to date. Two major aspects are examined: (1) alteration and degradation processes and reactions, both reductive and oxidative; and (2) synthesis processes and reactions which are primarily reductive. Examples of industrial applications of the related supercritical fluid technology are discussed.

Classical and Quantum Thermal Physics

NASA Astrophysics Data System (ADS)

Prasad, R.

2016-11-01

List of figures; List of tables; Preface; Acknowledgement; Dedication; 1. The kinetic theory of gases; 2. Ideal to real gas, viscosity, conductivity and diffusion; 3. Thermodynamics: definitions and Zeroth law; 4. First Law of Thermodynamics and some of its applications; 5. Second Law of Thermodynamics and some of its applications; 6. TdS equations and their applications; 7. Thermodynamic functions, potentials, Maxwell equations, the Third Law and equilibrium; 8. Some applications of thermodynamics to problems of physics and engineering; 9. Application of thermodynamics to chemical reactions; 10. Quantum thermodynamics; 11. Some applications of quantum thermodynamics; 12. Introduction to the thermodynamics of irreversible processes; Index.

Chemical computing with reaction-diffusion processes.

PubMed

Gorecki, J; Gizynski, K; Guzowski, J; Gorecka, J N; Garstecki, P; Gruenert, G; Dittrich, P

2015-07-28

Chemical reactions are responsible for information processing in living organisms. It is believed that the basic features of biological computing activity are reflected by a reaction-diffusion medium. We illustrate the ideas of chemical information processing considering the Belousov-Zhabotinsky (BZ) reaction and its photosensitive variant. The computational universality of information processing is demonstrated. For different methods of information coding constructions of the simplest signal processing devices are described. The function performed by a particular device is determined by the geometrical structure of oscillatory (or of excitable) and non-excitable regions of the medium. In a living organism, the brain is created as a self-grown structure of interacting nonlinear elements and reaches its functionality as the result of learning. We discuss whether such a strategy can be adopted for generation of chemical information processing devices. Recent studies have shown that lipid-covered droplets containing solution of reagents of BZ reaction can be transported by a flowing oil. Therefore, structures of droplets can be spontaneously formed at specific non-equilibrium conditions, for example forced by flows in a microfluidic reactor. We describe how to introduce information to a droplet structure, track the information flow inside it and optimize medium evolution to achieve the maximum reliability. Applications of droplet structures for classification tasks are discussed. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Integrated aerobic biological-chemical treatment of winery wastewater diluted with urban wastewater. LED-based photocatalysis in the presence of monoperoxysulfate.

PubMed

Solís, Rafael R; Rivas, Francisco Javier; Ferreira, Leonor C; Pirra, Antonio; Peres, José A

2018-01-28

The oxidation of Winery Wastewater (WW) by conventional aerobic biological treatment usually leads to inefficient results due to the presence of organic substances, which are recalcitrant or toxic in conventional procedures. This study explores the combination of biological and chemical processes in order to complete the oxidation of biodegradable and non-biodegradable compounds in two sequential steps. Thus, a biological oxidation of a diluted WW is carried out by using the activated sludge process. Activated sludge was gradually acclimated to the Diluted Winery Wastewater (DWW). Some aspects concerning the biological process were evaluated (kinetics of the oxidation and sedimentation of the sludge produced). The biological treatment of the DWW led to a 40-50% of Chemical Oxygen Demand (COD) removal in 8 h, being necessary the application of an additional process. Different chemical processes combining UVA-LEDs radiation, monoperoxysulfate (MPS) and photocatalysts were applied in order to complete the COD depletion and efficient removal of polyphenols content, poorly oxidized in the previous biological step. From the options tested, the combination of UVA, MPS and a novel LaCoO 3 -TiO 2 composite, with double route of MPS decomposition through heterogeneous catalysis and photocatalysis, led to the best results (95% of polyphenol degradation, and additional 60% of COD removal). Initial MPS concentration and pH effect in this process were assessed.

MRI of chemical reactions and processes.

PubMed

Britton, Melanie M

2017-08-01

As magnetic resonance imaging (MRI) can spatially resolve a wealth of molecular information available from nuclear magnetic resonance (NMR), it is able to non-invasively visualise the composition, properties and reactions of a broad range of spatially-heterogeneous molecular systems. Hence, MRI is increasingly finding applications in the study of chemical reactions and processes in a diverse range of environments and technologies. This article will explain the basic principles of MRI and how it can be used to visualise chemical composition and molecular properties, providing an overview of the variety of information available. Examples are drawn from the disciplines of chemistry, chemical engineering, environmental science, physics, electrochemistry and materials science. The review introduces a range of techniques used to produce image contrast, along with the chemical and molecular insight accessible through them. Methods for mapping the distribution of chemical species, using chemical shift imaging or spatially-resolved spectroscopy, are reviewed, as well as methods for visualising physical state, temperature, current density, flow velocities and molecular diffusion. Strategies for imaging materials with low signal intensity, such as those containing gases or low sensitivity nuclei, using compressed sensing, para-hydrogen or polarisation transfer, are discussed. Systems are presented which encapsulate the diversity of chemical and physical parameters observable by MRI, including one- and two-phase flow in porous media, chemical pattern formation, phase transformations and hydrodynamic (fingering) instabilities. Lastly, the emerging area of electrochemical MRI is discussed, with studies presented on the visualisation of electrochemical deposition and dissolution processes during corrosion and the operation of batteries, supercapacitors and fuel cells. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Current Strategies for the Detoxification of Jatropha curcas Seed Cake: A Review.

PubMed

Gomes, Taisa G; Hadi, Sámed I I A; Costa Alves, Gabriel S; Mendonça, Simone; De Siqueira, Felix G; Miller, Robert N G

2018-03-21

Jatropha curcas is an important oilseed plant, with considerable potential in the development of biodiesel. Although Jatropha seed cake, the byproduct of oil extraction, is a residue rich in nitrogen, phosphorus, potassium, and carbon, with high protein content suitable for application in animal feed, the presence of toxic phorbol esters limits its application in feed supplements and fertilizers. This review summarizes the current methods available for detoxification of this residue, based upon chemical, physical, biological, or combined processes. The advantages and disadvantages of each process are discussed, and future directions involving genomic and proteomic approaches for advancing our understanding of biodegradation processes involving microorganisms are highlighted.

Research & Development of Materials/Processing Methods for Continuous Fiber Ceramic Composites (CFCC) Phase 2 Final Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szweda, A.

2001-01-01

The Department of Energy's Continuous Fiber Ceramic Composites (CFCC) Initiative that begun in 1992 has led the way for Industry, Academia, and Government to carry out a 10 year R&D plan to develop CFCCs for these industrial applications. In Phase II of this program, Dow Corning has led a team of OEM's, composite fabricators, and Government Laboratories to develop polymer derived CFCC materials and processes for selected industrial applications. During this phase, Dow Corning carried extensive process development and representative component demonstration activities on gas turbine components, chemical pump components and heat treatment furnace components.