Science.gov

Sample records for chemical process design

  1. DESIGNING ENVIRONMENTALLY FRIENDLY CHEMICAL PROCESSES

    EPA Science Inventory

    The design of a chemical process involves many aspects: from profitability, flexibility and reliability to safety to the environment. While each of these is important, in this work, the focus will be on profitability and the environment. Key to the study of these aspects is the ...

  2. WORKSHOP ON ENVIRONMENTALLY CONSCIOUS CHEMICAL PROCESS DESIGN

    EPA Science Inventory

    To encourage the consideration of environmental issues during chemical process design, the USEPA has developed techniques and software tools to evaluate the relative environmental impact of a chemical process. These techniques and tools aid in the risk management process by focus...

  3. Molecular Thermodynamics for Chemical Process Design

    ERIC Educational Resources Information Center

    Prausnitz, J. M.

    1976-01-01

    Discusses that aspect of thermodynamics which is particularly important in chemical process design: the calculation of the equilibrium properties of fluid mixtures, especially as required in phase-separation operations. (MLH)

  4. Chemical kinetics and oil shale process design

    SciTech Connect

    Burnham, A.K.

    1993-07-01

    Oil shale processes are reviewed with the goal of showing how chemical kinetics influences the design and operation of different processes for different types of oil shale. Reaction kinetics are presented for organic pyrolysis, carbon combustion, carbonate decomposition, and sulfur and nitrogen reactions.

  5. DESIGNING ENVIRONMENTAL, ECONOMIC AND ENERGY EFFICIENT CHEMICAL PROCESSES

    EPA Science Inventory

    The design and improvement of chemical processes can be very challenging. The earlier energy conservation, process economics and environmental aspects are incorporated into the process development, the easier and less expensive it is to alter the process design. Process emissio...

  6. Chemical Process Design: An Integrated Teaching Approach.

    ERIC Educational Resources Information Center

    Debelak, Kenneth A.; Roth, John A.

    1982-01-01

    Reviews a one-semester senior plant design/laboratory course, focusing on course structure, student projects, laboratory assignments, and course evaluation. Includes discussion of laboratory exercises related to process waste water and sludge. (SK)

  7. DESIGNING ENVIRONMENTALLY FRIENDLY CHEMICAL PROCESSES WITH FUGITIVE AND OPEN EMISSIONS

    EPA Science Inventory

    Designing a chemical process normally includes aspects of economic and environmental disciplines. In this work we describe methods to quickly and easily evaluate the economics and potential environmental impacts of a process, with the hydrodealkylation of toluene as an example. ...

  8. DESIGNING CHEMICAL PROCESSES WITH OPEN AND FUGITIVE EMISSIONS

    EPA Science Inventory

    Designing a chemical process normally includes aspects of economic and environmental disciplines. In this work we describe methods to quickly and easily evaluate the conomics and potential environmental impacts of a process, with the hydrodealkylation of toluene as an example. Th...

  9. New Vistas in Chemical Product and Process Design.

    PubMed

    Zhang, Lei; Babi, Deenesh K; Gani, Rafiqul

    2016-06-01

    Design of chemicals-based products is broadly classified into those that are process centered and those that are product centered. In this article, the designs of both classes of products are reviewed from a process systems point of view; developments related to the design of the chemical product, its corresponding process, and its integration are highlighted. Although significant advances have been made in the development of systematic model-based techniques for process design (also for optimization, operation, and control), much work is needed to reach the same level for product design. Timeline diagrams illustrating key contributions in product design, process design, and integrated product-process design are presented. The search for novel, innovative, and sustainable solutions must be matched by consideration of issues related to the multidisciplinary nature of problems, the lack of data needed for model development, solution strategies that incorporate multiscale options, and reliability versus predictive power. The need for an integrated model-experiment-based design approach is discussed together with benefits of employing a systematic computer-aided framework with built-in design templates. PMID:27088667

  10. Parametric design methodology for chemical processes using a simulator

    SciTech Connect

    Diwekar, U.M.; Rubin, E.S. )

    1994-02-01

    Parameter design is a method popularized by the Japanese quality expert G. Taguchi, for designing products and manufacturing processes that are robust in the face of uncontrollable variations. At the design stage, the goal of parameter design is to identify design settings that make the product performance less sensitive to the effects of manufacturing and environmental variations and deterioration. Because parameter design reduces performance variation by reducing the influence of the sources of variation rather than by controlling them, it is a cost-effective technique for improving quality. A recent study on the application of parameter design methodology for chemical processes reported that the use of Taguchi's method was not justified and a method based on Monte Carlo simulation combined with optimization was shown to be more effective. However, this method is computationally intensive as a large number of samples are necessary to achieve the given accuracy. Additionally, determination of the number of sample runs required is based on experimentation due to a lack of systematic sampling methods. In an attempt to overcome these problems, the use of a stochastic modeling capability combined with an optimizer is presented in this paper. The objective is that of providing an effective means for application of parameter design methodologies to chemical processes using the ASPEN simulator. This implementation not only presents a generalized tool for use by chemical engineers at large but also provides systematic estimates of the number of sample runs required to attain the specified accuracy. The stochastic model employs the technique of Latin hypercube sampling instead of the traditional Monte Carlo technique and hence has a great potential to reduce the required number of samples. The methodology is illustrated via an example problem of designing a chemical process.

  11. A FRAMEWORK TO DESIGN AND OPTIMIZE CHEMICAL FLOODING PROCESSES

    SciTech Connect

    Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori

    2005-07-01

    The goal of this proposed research is to provide an efficient and user friendly simulation framework for screening and optimizing chemical/microbial enhanced oil recovery processes. The framework will include (1) a user friendly interface to identify the variables that have the most impact on oil recovery using the concept of experimental design and response surface maps, (2) UTCHEM reservoir simulator to perform the numerical simulations, and (3) an economic model that automatically imports the simulation production data to evaluate the profitability of a particular design. Such a reservoir simulation framework is not currently available to the oil industry. The objectives of Task 1 are to develop three primary modules representing reservoir, chemical, and well data. The modules will be interfaced with an already available experimental design model. The objective of the Task 2 is to incorporate UTCHEM reservoir simulator and the modules with the strategic variables and developing the response surface maps to identify the significant variables from each module. The objective of the Task 3 is to develop the economic model designed specifically for the chemical processes targeted in this proposal and interface the economic model with UTCHEM production output. Task 4 is on the validation of the framework and performing simulations of oil reservoirs to screen, design and optimize the chemical processes.

  12. A FRAMEWORK TO DESIGN AND OPTIMIZE CHEMICAL FLOODING PROCESSES

    SciTech Connect

    Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori

    2004-11-01

    The goal of this proposed research is to provide an efficient and user friendly simulation framework for screening and optimizing chemical/microbial enhanced oil recovery processes. The framework will include (1) a user friendly interface to identify the variables that have the most impact on oil recovery using the concept of experimental design and response surface maps, (2) UTCHEM reservoir simulator to perform the numerical simulations, and (3) an economic model that automatically imports the simulation production data to evaluate the profitability of a particular design. Such a reservoir simulation framework is not currently available to the oil industry. The objectives of Task 1 are to develop three primary modules representing reservoir, chemical, and well data. The modules will be interfaced with an already available experimental design model. The objective of the Task 2 is to incorporate UTCHEM reservoir simulator and the modules with the strategic variables and developing the response surface maps to identify the significant variables from each module. The objective of the Task 3 is to develop the economic model designed specifically for the chemical processes targeted in this proposal and interface the economic model with UTCHEM production output. Task 4 is on the validation of the framework and performing simulations of oil reservoirs to screen, design and optimize the chemical processes.

  13. A Framework to Design and Optimize Chemical Flooding Processes

    SciTech Connect

    Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori

    2006-08-31

    The goal of this proposed research is to provide an efficient and user friendly simulation framework for screening and optimizing chemical/microbial enhanced oil recovery processes. The framework will include (1) a user friendly interface to identify the variables that have the most impact on oil recovery using the concept of experimental design and response surface maps, (2) UTCHEM reservoir simulator to perform the numerical simulations, and (3) an economic model that automatically imports the simulation production data to evaluate the profitability of a particular design. Such a reservoir simulation framework is not currently available to the oil industry. The objectives of Task 1 are to develop three primary modules representing reservoir, chemical, and well data. The modules will be interfaced with an already available experimental design model. The objective of the Task 2 is to incorporate UTCHEM reservoir simulator and the modules with the strategic variables and developing the response surface maps to identify the significant variables from each module. The objective of the Task 3 is to develop the economic model designed specifically for the chemical processes targeted in this proposal and interface the economic model with UTCHEM production output. Task 4 is on the validation of the framework and performing simulations of oil reservoirs to screen, design and optimize the chemical processes.

  14. Portfolio Assessment on Chemical Reactor Analysis and Process Design Courses

    ERIC Educational Resources Information Center

    Alha, Katariina

    2004-01-01

    Assessment determines what students regard as important: if a teacher wants to change students' learning, he/she should change the methods of assessment. This article describes the use of portfolio assessment on five courses dealing with chemical reactor and process design during the years 1999-2001. Although the use of portfolio was a new…

  15. INCORPORATING INDUSTRIAL ECOLOGY INTO HIERARCHICAL CHEMICAL PROCESS DESIGN

    EPA Science Inventory

    Incorporating Industrial Ecology into Hierarchical Chemical Process Design: Determining Targets for the Exchange of Waste

    The exchange of waste to be used as a recycled feed has long been encouraged by practitioners of industrial ecology. Industrial ecology is a field t...

  16. EVALUATING AND DESIGNING CHEMICAL PROCESSES FOR ENVIRONMENTAL SUSTAINABILITY

    EPA Science Inventory

    Chemicals and chemical processes are at the heart of most environmental problems. This isn't surprising since chemicals make up all of the products we use in our lives. The common use of cjhemicals makes them of high interest for systems analysis, particularly because of environ...

  17. POLLUTION PREVENTION IN THE DESIGN OF CHEMICAL PROCESSES USING HIERARCHICAL DESIGN AND SIMULATION

    EPA Science Inventory

    The design of chemical processes is normally an interactive process of synthesis and analysis. When one also desires or needs to limit the amount of pollution generated by the process the difficulty of the task can increase substantially. In this work, we show how combining hier...

  18. METHODS FOR INTEGRATING ENVIRONMENTAL CONSIDERATIONS INTO CHEMICAL PROCESS DESIGN DECISIONS

    EPA Science Inventory

    The objective of this cooperative agreement was to postulate a means by which an engineer could routinely include environmental considerations in day-to-day conceptual design problems; a means that could easily integrate with existing design processes, and thus avoid massive retr...

  19. DECISION SUPPORT SYSTEM TO ENHANCE AND ENCOURAGE SUSTAINABLE CHEMICAL PROCESS DESIGN

    EPA Science Inventory

    There is an opportunity to minimize the potential environmental impacts (PEIs) of industrial chemical processes by providing process designers with timely data nad models elucidating environmentally favorable design options. The second generation of the Waste Reduction (WAR) algo...

  20. DESIGNING EFFICIENT, ECONOMIC AND ENVIRONMENTALLY FRIENDLY CHEMICAL PROCESSES

    EPA Science Inventory

    A catalytic reforming process has been studied using hierarchical design and simulation calculations. Approximations for the fugitive emissions indicate which streams allow the most value to be lost and which have the highest potential environmental impact. One can use this infor...

  1. DESIGNING EFFICIENT, ECONOMIC AND ENVIRONMENTALLY FRIENDLY CHEMICAL PROCESSES

    EPA Science Inventory

    A catalytic reforming process has been studied using hierarchical design and simulation calculations. Aproximations for the fugitive emissions indicate which streams allow the most value to be lost and which have the highest potential environmental impact. One can use tis inform...

  2. Fiber optic sensor design for chemical process and environmental monitoring

    NASA Astrophysics Data System (ADS)

    Mahendran, R. S.; Harris, D.; Wang, L.; Machavaram, V. R.; Chen, R.; Kukureka, St. N.; Fernando, G. F.

    2007-07-01

    Cure monitoring is a term that is used to describe the cross-linking reactions in a thermosetting resin system. Advanced fiber reinforced composites are being used increasingly in a number of industrial sectors including aerospace, marine, sport, automotive and civil engineering. There is a general realization that the processing conditions that are used to manufacture the composites can have a major influence on its hot-wet mechanical properties. This paper is concerned with the design and demonstration of a number of sensor designs for in-situ cure monitoring of a model thermosetting resin system. Simple fixtures were constructed to enable a pair of cleaved optical fibers with a defined gap between the end-faces to be held in position. The resin system was introduced into this gap and the cure kinetics were followed by transmission infrared spectroscopy. A semi-empirical model was used to describe the cure process using the data obtained at different cure temperatures. The same sensor system was used to detect the ingress of moisture in the cured resin system.

  3. Development of Chemical Process Design and Control for Sustainability

    EPA Science Inventory

    This contribution describes a novel process systems engineering framework that couples advanced control with sustainability evaluation and decision making for the optimization of process operations to minimize environmental impacts associated with products, materials, and energy....

  4. GREENER CHEMICAL PROCESS DESIGN ALTERNATIVES ARE REVEALED USING THE WASTE REDUCTION DECISION SUPPORT SYSTEM (WAR DSS)

    EPA Science Inventory

    The Waste Reduction Decision Support System (WAR DSS) is a Java-based software product providing comprehensive modeling of potential adverse environmental impacts (PEI) predicted to result from newly designed or redesigned chemical manufacturing processes. The purpose of this so...

  5. EVALUATING THE ECONOMICS AND ENVIRONMENTAL FRIENDLINESS OF NEWLY DESIGNED OR RETROFITTED CHEMICAL PROCESSES: JOURNAL ARTICLE

    EPA Science Inventory

    NRMRL-CIN-1646 Smith*, R.L. Evaluating the Economics and Environmental Friendliness of Newly Designed or Retrofitted Chemical Processes. Clean Products and Processes (Springer-Verlag) 3:383-391 (2002). 10/22/2001 This work describes a method for using spreadsheet analyses of ...

  6. XPERT DESIGN AND DIAGNOSTICS' (XDD) IN-SITU CHEMICAL OXIDATION PROCESS USING POTASSIUM PERMANGANATE (KMNO4)

    EPA Science Inventory

    Xpert Design and Diagnostic's (XDD)potassium permanganate in situ chemical oxidation (ISCO) process was evaluated under the EPA Superfund Innovative Technology Evaluation (SITE) Program at the former MEC Building site located in Hudson, New Hampshire. At this site, both soil and ...

  7. A novel double loop control model design for chemical unstable processes.

    PubMed

    Cong, Er-Ding; Hu, Ming-Hui; Tu, Shan-Tung; Xuan, Fu-Zhen; Shao, Hui-He

    2014-03-01

    In this manuscript, based on Smith predictor control scheme for unstable process in industry, an improved double loop control model is proposed for chemical unstable processes. Inner loop is to stabilize integrating the unstable process and transform the original process to first-order plus pure dead-time dynamic stable process. Outer loop is to enhance the performance of set point response. Disturbance controller is designed to enhance the performance of disturbance response. The improved control system is simple with exact physical meaning. The characteristic equation is easy to realize stabilization. Three controllers are separately design in the improved scheme. It is easy to design each controller and good control performance for the respective closed-loop transfer function separately. The robust stability of the proposed control scheme is analyzed. Finally, case studies illustrate that the improved method can give better system performance than existing design methods. PMID:24309506

  8. Membrane process designs in the recovery of bio-fuels and bio-chemicals

    SciTech Connect

    Leeper, S.A.

    1990-01-01

    In this presentation, the emerging membrane unit operations and process designs that can be used in recovery of fuels and organic chemicals produced via bioconversion are briefly summarized. Product recovery costs are a major barrier to increased use of bioconversion for the production of fuels and chemicals. The integration of developing membrane unit operations into product recovery schemes may reduce process energy requirements and cost. Membrane unit operations that are used or studied in recovery of bio-fuels and organic chemicals include pervaporation (PV), vapor permeation (VPe), reverse osmosis (RO), membrane extraction, and electrodialysis (ED). Although it can be argued that ultrafiltration (UF) is used to purify bio-fuels and bio-chemicals, UF is not included in this survey for two reasons: (1) the primary uses of UF in bioprocessing are to clarify fermentation broth and to retain cells/enzymes in bioreactors and (2) the literature on UF in biotechnology is expansive. Products of bioconversion for which data are compiled include ethanol, acetone, butanol, glycerol, isopropanol, ethyl acetate, fusel oils, acetaldehyde, acetic acid, butyric acid, citric acid, propionic acid, succinic acid, and tartaric acid. 13 refs.

  9. Chemical feedstock from hardwood by organosolv hydrolysis: Computer-aided process design and economic evaluation

    NASA Astrophysics Data System (ADS)

    Nguyen, X. N.

    1982-12-01

    A two stage catalyzed organosolv plant producing ethanol, furfural, acetic acid, and soluble lignin from wood waste was investigated. The GEMS computer system was used to aid the preliminary design and cost estimation of the proposed wood chemical plant. For a plant processing 1000 ovendry tons of wood per day, a capital investment of $66 million and an operating expense of about $20 million per year were estimated. The capital cost calculated compares favorably with other published estimates. Sensitivity analyses of some key factors in the proposed process disclose that the recovery efficiency of ethanol used in the lignin extraction stage is most important in determining the process economics. Ethanol solvent recovery of about 98% is required. At 95% recovery efficiency, conversion to glucose in the acid hydrolysis step above 90% is necessary for the ethanol selling price to be comparable to the current market price.

  10. Chemical process hazards analysis

    SciTech Connect

    1996-02-01

    The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.

  11. WAR DSS: A DECISION SUPPORT SYSTEM FOR ENVIRONMENTALLY CONSCIOUS CHEMICAL PROCESS DESIGN

    EPA Science Inventory

    The second generation of the Waste Reduction (WAR) Algorithm is constructed as a decision support system (DSS) in the design of chemical manufacturing facilities. The WAR DSS is a software tool that can help reduce the potential environmental impacts (PEIs) of industrial chemical...

  12. EVALUATING THE ECONOMICS AND ENVIRONMENTAL FRIENDLINESS OF NEWLY DESIGNED OR RETROFITTED CHEMICAL PROCESSES

    EPA Science Inventory

    This work describes a method for using spreadsheet analyses of process designs and retrofits to provide simple and quick economic and environmental evaluations simultaneously. The method focuses attention onto those streams and components that have the largest monetary values and...

  13. COMPUTER AIDED CHEMICAL PROCESS DESIGN METHODOLOGIES FOR POLLUTION REDUCTION(SYSTEMS ANALYSIS BRANCH, SUSTAINABLE TECHNOLOGY DIVISION, NRMRL)

    EPA Science Inventory

    The objective of the project is to develop computer optimization and simulation methodologies for the design of economical chemical manufacturing processes with a minimum of impact on the environment. The computer simulation and optimization tools developed in this project can be...

  14. Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide

    SciTech Connect

    Mark Eiteman

    2007-07-31

    This report describes results toward developing a process to sequester CO{sub 2} centered on the enzymes PEP carboxylase and pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The study reports on strain development and process development. In the area of strain development, knockouts in genes which divert carbon from the enzymatic steps involved in CO{sub 2} consumption were completed, and were shown not to affect significantly the rate of CO{sub 2} sequestration and succinic acid generation. Furthermore, the pyc gene encoding for pyruvate carboxylase proved to be unstable when integrated onto the chromosome. In the area of process development, an optimal medium, pH and base counterion were obtained, leading to a sequestration rate as great as 800 mg/Lh. Detailed studies of gas phase composition demonstrated that CO{sub 2} composition has a significant affect on CO{sub 2} sequestration, while the presence of 'toxic' compounds in the gas, including NO{sub 2}, CO and SO{sub 2} did not have a detrimental effect on sequestration. Some results on prolonging the rate of sequestration indicate that enzyme activities decrease with time, suggesting methods to prolong enzyme activity may benefit the overall process.

  15. Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide

    SciTech Connect

    Mark A. Eiteman

    2005-11-01

    This report describes results toward developing a process to sequester CO{sub 2} centered on the enzyme pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The first phase of this research has focused on strain development and on process development. Progress in strain development has been made in three areas. The gene encoding for alcohol dehydrogenase has been ''knocked out'' of the bacteria, and thereby eliminating the synthesis of the by-product ethanol. The gene for glucokinase has been overexpressed in the production strain with the goal of faster utilization of glucose (and hence CO{sub 2}). Efforts have continued toward integrating pyruvate carboxylase gene (pyc) onto the E. coli chromosome. Progress in process development has come in conducting several dozen fermentation experiments to find a defined medium that would be successful for the growth of the bacteria, while permitting a high rate of CO{sub 2} utilization in a subsequent prolonged production phase. Using this defined medium, the strains that continue to be constructed are being compared for CO{sub 2} utilization, so that we may understand the factors that govern the biological sequestration process.

  16. Chemical Processing Manual

    NASA Technical Reports Server (NTRS)

    Beyerle, F. J.

    1972-01-01

    Chemical processes presented in this document include cleaning, pickling, surface finishes, chemical milling, plating, dry film lubricants, and polishing. All types of chemical processes applicable to aluminum, for example, are to be found in the aluminum alloy section. There is a separate section for each category of metallic alloy plus a section for non-metals, such as plastics. The refractories, super-alloys and titanium, are prime candidates for the space shuttle, therefore, the chemical processes applicable to these alloys are contained in individual sections of this manual.

  17. Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide

    SciTech Connect

    Mark A. Eiteman

    2006-07-31

    This report describes results toward developing a process to sequester CO{sub 2} centered on the enzyme pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The phases of research have included strain development and process development. Though we continue to work on one important component of strain development, the research has principally focused on process development. In the previous year we constructed several strains which would serve as templates for the CO{sub 2} sequestration, including the knock-out of genes involved in the formation of undesirable byproducts. This project period the focus has been on the integration of the pyruvate carboxylase gene (pyc) onto the E. coli chromosome. This has proven to be a difficult task because of relatively low expression of the gene and resulting low enzyme activity when only one copy of the gene is present on the chromosome. Several molecular biology techniques have been applied, with some success, to improve the level of protein activity as described herein. Progress in process development has come as a result of conducting numerous fermentation experiments to select optimal conditions for CO{sub 2} sequestration. This process-related research has progressed in four areas. First, we have clarified the range of pH which results in the optimal rate of sequestration. Second, we have determined how the counterion used to control the pH affects the sequestration rate. Third, we have determined how CO{sub 2} gas phase composition impacts sequestration rate. Finally, we have made progress in determining the affect of several potential gaseous impurities on CO{sub 2} sequestration; in particular we have completed a study using NO{sub 2}. Although the results provide significant guidance as to process conditions for CO{sub 2} sequestration and succinate production, in some cases we do not yet understand

  18. DESIGNING PROCESSES FOR ENVIRONMENTAL PROBLEMS

    EPA Science Inventory

    Designing for the environment requires consideration of environmental impacts. The Generalized WAR Algorithm is the methodology that allows the user to evaluate the potential environmental impact of the design of a chemical process. In this methodology, chemicals are assigned val...

  19. Fiber-optic sensor design for chemical process and environmental monitoring

    NASA Astrophysics Data System (ADS)

    Mahendran, R. S.; Wang, L.; Machavaram, V. R.; Pandita, S. D.; Chen, R.; Kukureka, S. N.; Fernando, G. F.

    2009-10-01

    "Curing" is a term that is used to describe the cross-linking reactions in a thermosetting resin system. Advanced fiber-reinforced composites are being used increasingly in a number of industrial sectors including aerospace, marine, sport, automotive and civil engineering. There is a general realization that the processing conditions that are used to manufacture the composite can have a major influence on its hot-wet mechanical properties. This paper is concerned with the design and demonstration of a number of sensor designs for in situ monitoring of the cross-linking reactions of a commercially available thermosetting resin system. Simple fixtures were constructed to enable a pair of cleaved optical fibers with a defined gap between the end-faces to be held in position. The resin system was introduced into this gap and the cure kinetics were followed by transmission infrared spectroscopy. A semi-empirical model was used to describe the cure process using the data obtained at different cure temperatures. The same sensor system was used to detect the ingress of moisture into the cured resin system.

  20. Chemical and process thermodynamics

    SciTech Connect

    Kyle, B.G.

    1984-01-01

    The book is intended mainly to be used as a text for undergraduate chemical engineering studies. Presented is a unified and up-to-date treatment of the major chemical and engineering applications of thermodynamics. Special features include a four chapter sequence on phase equilibrium which begins with simple concepts discussions. More difficult concepts are introduced gradually. Partial molar properties and infinite dilution activity coefficients appear toward the end of the sequence. Solution behavior, including activity coefficients via UNIVAC, is covered. Chapter 14 discusses heat exchange, separation processes, and second law analysis of chemical processes. Chapter 12 provides a firm foundation for chemical equilibrium, and Chapter 13 includes complex chemical equilibrium and free energy minimization. A selection of end-of-chapter problems is included to help the student apply principles and concepts in practical situations.

  1. Design of a compact ultrahigh vacuum-compatible setup for the analysis of chemical vapor deposition processes

    SciTech Connect

    Weiss, Theodor; Nowak, Martin; Zielasek, Volkmar Bäumer, Marcus; Mundloch, Udo; Kohse-Höinghaus, Katharina

    2014-10-15

    Optimizing thin film deposition techniques requires contamination-free transfer from the reactor into an ultrahigh vacuum (UHV) chamber for surface science analysis. A very compact, multifunctional Chemical Vapor Deposition (CVD) reactor for direct attachment to any typical UHV system for thin film analysis was designed and built. Besides compactness, fast, easy, and at the same time ultimately clean sample transfer between reactor and UHV was a major goal. It was achieved by a combination of sample manipulation parts, sample heater, and a shutter mechanism designed to fit all into a NW38 Conflat six-ways cross. The present reactor design is versatile to be employed for all commonly employed variants of CVD, including Atomic Layer Deposition. A demonstration of the functionality of the system is provided. First results of the setup (attached to an Omicron Multiprobe x-ray photoelectron spectroscopy system) on the temperature dependence of Pulsed Spray Evaporation-CVD of Ni films from Ni acetylacetonate as the precursor demonstrate the reactor performance and illustrate the importance of clean sample transfer without breaking vacuum in order to obtain unambiguous results on the quality of CVD-grown thin Ni films. The widely applicable design holds promise for future systematic studies of the fundamental processes during chemical vapor deposition or atomic layer deposition.

  2. Design of a compact ultrahigh vacuum-compatible setup for the analysis of chemical vapor deposition processes

    NASA Astrophysics Data System (ADS)

    Weiss, Theodor; Nowak, Martin; Mundloch, Udo; Zielasek, Volkmar; Kohse-Höinghaus, Katharina; Bäumer, Marcus

    2014-10-01

    Optimizing thin film deposition techniques requires contamination-free transfer from the reactor into an ultrahigh vacuum (UHV) chamber for surface science analysis. A very compact, multifunctional Chemical Vapor Deposition (CVD) reactor for direct attachment to any typical UHV system for thin film analysis was designed and built. Besides compactness, fast, easy, and at the same time ultimately clean sample transfer between reactor and UHV was a major goal. It was achieved by a combination of sample manipulation parts, sample heater, and a shutter mechanism designed to fit all into a NW38 Conflat six-ways cross. The present reactor design is versatile to be employed for all commonly employed variants of CVD, including Atomic Layer Deposition. A demonstration of the functionality of the system is provided. First results of the setup (attached to an Omicron Multiprobe x-ray photoelectron spectroscopy system) on the temperature dependence of Pulsed Spray Evaporation-CVD of Ni films from Ni acetylacetonate as the precursor demonstrate the reactor performance and illustrate the importance of clean sample transfer without breaking vacuum in order to obtain unambiguous results on the quality of CVD-grown thin Ni films. The widely applicable design holds promise for future systematic studies of the fundamental processes during chemical vapor deposition or atomic layer deposition.

  3. Sustainability in the Design, Synthesis and Analysis of Chemical Engineering Processes 1st edition

    EPA Science Inventory

    This book preface explains the needs found by the book editors for assembling the state of the art of technical and scientific knowledge relevant to chemical engineering, sustainability, and sustainable uses of wastes and materials management, and to do so in an accessible and c...

  4. Experiments To Demonstrate Chemical Process Safety Principles.

    ERIC Educational Resources Information Center

    Dorathy, Brian D.; Mooers, Jamisue A.; Warren, Matthew M.; Mich, Jennifer L.; Murhammer, David W.

    2001-01-01

    Points out the need to educate undergraduate chemical engineering students on chemical process safety and introduces the content of a chemical process safety course offered at the University of Iowa. Presents laboratory experiments demonstrating flammability limits, flash points, electrostatic, runaway reactions, explosions, and relief design.…

  5. Chemical Sensing in Process Analysis.

    ERIC Educational Resources Information Center

    Hirschfeld, T.; And Others

    1984-01-01

    Discusses: (1) rationale for chemical sensors in process analysis; (2) existing types of process chemical sensors; (3) sensor limitations, considering lessons of chemometrics; (4) trends in process control sensors; and (5) future prospects. (JN)

  6. Evaluation of a no-clean soldering process designed to eliminate the use of ozone depleting chemicals

    SciTech Connect

    Iman, R.L.; Armendariz, M.E.; Anderson, D.J. |; Lichtenberg, L.; Van Buren, P.; Paffett, M.T.

    1992-11-01

    The destruction of the Earth`s protective ozone layer is one of today`s largest environmental concerns. Solvent emissions released during the cleaning of printed wiring boards (PWBs) have been identified as a primary contributor to ozone destruction. No-clean soldering (sometimes referred to as self-cleaning) processes represent an ideal solution since they eliminate the need for cleaning after soldering. Elimination of solvent cleaning operations significantly reduces the emissions of ozone depleting chemicals (ODCs), reduces energy consumption, and reduces product costs. Several no-clean soldering processes have been developed over the past few years. The program`s purpose was to evaluate the no-clean soldering process and to determine if hardware produced by the process is acceptable for military applications. That is, determine if the no-clean process produces hardware that is as reliable as that soldered with the existing rosin-based flux solvent cleaning process.

  7. Teaching Process Design through Integrated Process Synthesis

    ERIC Educational Resources Information Center

    Metzger, Matthew J.; Glasser, Benjamin J.; Patel, Bilal; Hildebrandt, Diane; Glasser, David

    2012-01-01

    The design course is an integral part of chemical engineering education. A novel approach to the design course was recently introduced at the University of the Witwatersrand, Johannesburg, South Africa. The course aimed to introduce students to systematic tools and techniques for setting and evaluating performance targets for processes, as well as…

  8. A Course in Chemical Reactor Design.

    ERIC Educational Resources Information Center

    Takoudis, Christos G.

    1983-01-01

    Presents course outline, topics covered, and final project (doubling as a take home final exam) for a one-semester, interdisciplinary course on the design and behavior of chemical reactors. Interplay of chemical and physical rate processes is stressed in the course. (JM)

  9. Chemical processing of lunar materials

    NASA Technical Reports Server (NTRS)

    Criswell, D. R.; Waldron, R. D.

    1979-01-01

    The paper highlights recent work on the general problem of processing lunar materials. The discussion covers lunar source materials, refined products, motivations for using lunar materials, and general considerations for a lunar or space processing plant. Attention is given to chemical processing through various techniques, including electrolysis of molten silicates, carbothermic/silicothermic reduction, carbo-chlorination process, NaOH basic-leach process, and HF acid-leach process. Several options for chemical processing of lunar materials are well within the state of the art of applied chemistry and chemical engineering to begin development based on the extensive knowledge of lunar materials.

  10. Future integrated design process

    NASA Technical Reports Server (NTRS)

    Meyer, D. D.

    1980-01-01

    The design process is one of the sources used to produce requirements for a computer system to integrate and manage product design data, program management information, and technical computation and engineering data management activities of the aerospace design process. Design activities were grouped chronologically and explored for activity type, activity interface, data quantity, and data flow. The work was based on analysis of the design process of several typical aerospace products, including both conventional and supersonic airplanes and a hydrofoil design. Activities examined included research, preliminary design, detail design, manufacturing interface, product verification, and product support. The design process was then described in an IPAD environment--the future.

  11. Evaluation of no-clean solder process designed to eliminate the use of ozone-depleting chemicals

    SciTech Connect

    Paffett, M.T.; Farr, J.D.; Rogers, Y.C.; Hutchinson, W.B.

    1993-10-01

    This paper summarizes the LANL contributions to a joint Motorola/SNLA/LANL cooperative research and development agreement study on the reliability of an alternative solder process that is intended to reduce or eliminate the use of ozone-depleting chemicals in the manufacture of printed wire boards (PWBs). This process is termed self-cleaning because of the nature of the thermal chemistry associated with the adipic and formic acid components used in place of traditional solder rosin fluxes. Traditional rosin fluxes used in military electronic hardware applications are cleaned (by requirement) using chlorofluorohydrocarbons. The LANL contribution centers around analytical determination of PWB cleanliness after soldering using the self-cleaning method. Results of these analytical determinations involving primarily surface analysis of boards following temperature, temperature and humidity, and long-term storage testing are described with representative data. It is concluded that the self-cleaning process leaves behind levels of solid residue that are visually and analytically observable using most of these surface analysis techniques. The materials compatibility of electronic components soldered using the self-cleaning soldering process is more fully described in the project report issued by SNLA that encompasses the complete project with statistical lifetime and accelerated aging studies. Analytical surface specificity and suggestions for further work are also given.

  12. Chemical waterflood process development

    SciTech Connect

    Chang, H.L.

    1980-04-01

    A waterflood process is claimed wherein a slug of biopolymer is injected into a formation, followed by a slug of synthetic polymer. The biopolymer slug protects the synthetic polymer from degradation due to presence of salts or surfactants in the formation.

  13. Ethylene process design optimization

    SciTech Connect

    2001-09-01

    Integration of Advanced Technologies will Update Ethylene Plants. Nearly 93 million tons of ethylene are produced annually in chemical plants worldwide, using an energy intensive process that consumes 2.5 quadrillion Btu per year.

  14. Process Security in Chemical Engineering Education

    ERIC Educational Resources Information Center

    Piluso, Cristina; Uygun, Korkut; Huang, Yinlun; Lou, Helen H.

    2005-01-01

    The threats of terrorism have greatly alerted the chemical process industries to assure plant security at all levels: infrastructure-improvement-focused physical security, information-protection-focused cyber security, and design-and-operation-improvement-focused process security. While developing effective plant security methods and technologies…

  15. Estimation of environment-related properties of chemicals for design of sustainable processes: development of group-contribution+ (GC+) property models and uncertainty analysis.

    PubMed

    Hukkerikar, Amol Shivajirao; Kalakul, Sawitree; Sarup, Bent; Young, Douglas M; Sin, Gürkan; Gani, Rafiqul

    2012-11-26

    of the developed property models for the estimation of environment-related properties and uncertainties of the estimated property values is highlighted through an illustrative example. The developed property models provide reliable estimates of environment-related properties needed to perform process synthesis, design, and analysis of sustainable chemical processes and allow one to evaluate the effect of uncertainties of estimated property values on the calculated performance of processes giving useful insights into quality and reliability of the design of sustainable processes. PMID:23039255

  16. Synthesis and optimization of integrated chemical processes

    SciTech Connect

    Barton, Paul I.; Evans, Lawrence B.

    2002-04-26

    This is the final technical report for the project titled ''Synthesis and optimization of integrated chemical processes''. Progress is reported on novel algorithms for the computation of all heteroazeotropic compositions present in complex liquid mixtures; the design of novel flexible azeotropic separation processes using middle vessel batch distillation columns; and theory and algorithms for sensitivity analysis and numerical optimization of hybrid discrete/continuous dynamic systems.

  17. Microcomponent chemical process sheet architecture

    DOEpatents

    Wegeng, R.S.; Drost, M.K.; Call, C.J.; Birmingham, J.G.; McDonald, C.E.; Kurath, D.E.; Friedrich, M.

    1998-09-22

    The invention is a microcomponent sheet architecture wherein macroscale unit processes are performed by microscale components. The sheet architecture may be a single laminate with a plurality of separate microcomponent sections or the sheet architecture may be a plurality of laminates with one or more microcomponent sections on each laminate. Each microcomponent or plurality of like microcomponents perform at least one chemical process unit operation. A first laminate having a plurality of like first microcomponents is combined with at least a second laminate having a plurality of like second microcomponents thereby combining at least two unit operations to achieve a system operation. 26 figs.

  18. Microcomponent chemical process sheet architecture

    DOEpatents

    Wegeng, Robert S.; Drost, M. Kevin; Call, Charles J.; Birmingham, Joseph G.; McDonald, Carolyn Evans; Kurath, Dean E.; Friedrich, Michele

    1998-01-01

    The invention is a microcomponent sheet architecture wherein macroscale unit processes are performed by microscale components. The sheet architecture may be a single laminate with a plurality of separate microcomponent sections or the sheet architecture may be a plurality of laminates with one or more microcomponent sections on each laminate. Each microcomponent or plurality of like microcomponents perform at least one chemical process unit operation. A first laminate having a plurality of like first microcomponents is combined with at least a second laminate having a plurality of like second microcomponents thereby combining at least two unit operations to achieve a system operation.

  19. Idaho Chemical Processing Plant Process Efficiency improvements

    SciTech Connect

    Griebenow, B.

    1996-03-01

    In response to decreasing funding levels available to support activities at the Idaho Chemical Processing Plant (ICPP) and a desire to be cost competitive, the Department of Energy Idaho Operations Office (DOE-ID) and Lockheed Idaho Technologies Company have increased their emphasis on cost-saving measures. The ICPP Effectiveness Improvement Initiative involves many activities to improve cost effectiveness and competitiveness. This report documents the methodology and results of one of those cost cutting measures, the Process Efficiency Improvement Activity. The Process Efficiency Improvement Activity performed a systematic review of major work processes at the ICPP to increase productivity and to identify nonvalue-added requirements. A two-phase approach was selected for the activity to allow for near-term implementation of relatively easy process modifications in the first phase while obtaining long-term continuous improvement in the second phase and beyond. Phase I of the initiative included a concentrated review of processes that had a high potential for cost savings with the intent of realizing savings in Fiscal Year 1996 (FY-96.) Phase II consists of implementing long-term strategies too complex for Phase I implementation and evaluation of processes not targeted for Phase I review. The Phase II effort is targeted for realizing cost savings in FY-97 and beyond.

  20. CHEMICAL PROCESSES IN PROTOPLANETARY DISKS

    SciTech Connect

    Walsh, Catherine; Millar, T. J.; Nomura, Hideko

    2010-10-20

    We have developed a high-resolution combined physical and chemical model of a protoplanetary disk surrounding a typical T Tauri star. Our aims were to use our model to calculate the chemical structure of disks on small scales (submilliarcsecond in the inner disk for objects at the distance of Taurus, {approx}140 pc) to investigate the various chemical processes thought to be important in disks and to determine potential molecular tracers of each process. Our gas-phase network was extracted from the UMIST Database for Astrochemistry to which we added gas-grain interactions including freezeout and thermal and non-thermal desorption (cosmic-ray-induced desorption, photodesorption, and X-ray desorption), and a grain-surface network. We find that cosmic-ray-induced desorption has the least effect on our disk chemical structure while photodesorption has a significant effect, enhancing the abundances of most gas-phase molecules throughout the disk and affecting the abundances and distribution of HCN, CN, and CS, in particular. In the outer disk, we also see enhancements in the abundances of H{sub 2}O and CO{sub 2}. X-ray desorption is a potentially powerful mechanism in disks, acting to homogenize the fractional abundances of gas-phase species across the depth and increasing the column densities of most molecules, although there remain significant uncertainties in the rates adopted for this process. The addition of grain-surface chemistry enhances the fractional abundances of several small complex organic molecules including CH{sub 3}OH, HCOOCH{sub 3}, and CH{sub 3}OCH{sub 3} to potentially observable values (i.e., a fractional abundance of {approx}>10{sup -11}).

  1. Chemically assisted mechanical refrigeration process

    DOEpatents

    Vobach, Arnold R.

    1987-01-01

    There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer (11) at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer (11) to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator (10) to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing he evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator.

  2. Chemically assisted mechanical refrigeration process

    DOEpatents

    Vobach, Arnold R.

    1987-01-01

    There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer (11) at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer (11) to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator (10) to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator.

  3. Chemically assisted mechanical refrigeration process

    DOEpatents

    Vobach, A.R.

    1987-06-23

    There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.

  4. Chemically assisted mechanical refrigeration process

    DOEpatents

    Vobach, A.R.

    1987-11-24

    There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.

  5. Flow Chemistry for Designing Sustainable Chemical Synthesis (journal article)

    EPA Science Inventory

    An efficiently designed continuous flow chemical process can lead to significant advantages in developing a sustainable chemical synthesis or process. These advantages are the direct result of being able to impart a higher degree of control on several key reactor and reaction par...

  6. [Signal Processing Suite Design

    NASA Technical Reports Server (NTRS)

    Sahr, John D.; Mir, Hasan; Morabito, Andrew; Grossman, Matthew

    2003-01-01

    Our role in this project was to participate in the design of the signal processing suite to analyze plasma density measurements on board a small constellation (3 or 4) satellites in Low Earth Orbit. As we are new to space craft experiments, one of the challenges was to simply gain understanding of the quantity of data which would flow from the satellites, and possibly to interact with the design teams in generating optimal sampling patterns. For example, as the fleet of satellites were intended to fly through the same volume of space (displaced slightly in time and space), the bulk plasma structure should be common among the spacecraft. Therefore, an optimal, limited bandwidth data downlink would take advantage of this commonality. Also, motivated by techniques in ionospheric radar, we hoped to investigate the possibility of employing aperiodic sampling in order to gain access to a wider spatial spectrum without suffering aliasing in k-space.

  7. Chemical Processing. Resources in Technology.

    ERIC Educational Resources Information Center

    Technology Teacher, 1991

    1991-01-01

    Reviews major organic and inorganic chemicals, their products, and the sociocultural impact of the chemical industry. Provides the following learning activity components: objectives, list of materials and equipment, procedures, student quiz with answers, and three references. (SK)

  8. RUBBER-PROCESSING CHEMICALS DATA BASE

    EPA Science Inventory

    The objective of this research program was to compile a data base covering all the commercially significant organic rubber-processing chemicals produced or imported in the United States. The Rubber-Processing Chemicals Data Base contains the following elements: chemical informati...

  9. EVALUATING POLLUTION PREVENTION PROGRESS (P2P) III: AN ENVIRONMENTAL TOOL FOR SCREENING IN PRODUCT LIFE CYCLE ASSESSMENT AND CHEMICAL PROCESS DESIGN

    EPA Science Inventory

    P2P is a computer-based tool that supports the comparison of process and product alternatives in terms of environmental impacts. This tool provides screening-level information for use in process design and in product LCA. Twenty one impact categories and data for approximately ...

  10. Life cycle costs for chemical process pumps

    SciTech Connect

    Urwin, B.; Blong, R.; Jamieson, C.; Erickson, B.

    1998-01-01

    Though construction and startup costs are always a concern, proper investment in equipment and installation will save money down the line. This is particularly important for heavily used items, such as centrifugal pumps, one of the workhouses of the chemical process industries (CPI). By properly sizing and installing a centrifugal pump, the life and efficiency of the pump can be increased. At the same time, maintenance costs can be reduced. When considering a new pump, there are several areas that require attention. The first is the baseplate design. The impeller is another area of concern. The seal chamber, the third area of importance, must be designed for proper heat dissipation and lubrication of seal faces. Lastly, the power end must be considered. Optimum bearing life, effective oil cooling and minimum shaft deflection are all vital. The paper discusses installation costs, operating cost, maintenance cost, seal environment, and extended bearing life.

  11. Design of Chemical Stores--Or Not!

    ERIC Educational Resources Information Center

    Piggott, Andy

    2010-01-01

    When science departments are designed for new builds, or are to be refurbished or moved to other parts of the school, design of preparation areas should be a major feature. It is vital that the brief contains everything that is needed including, in particular, a chemical store. But no matter how well a brief is specified, the people who actually…

  12. Chemical Processing of Electrons and Holes.

    ERIC Educational Resources Information Center

    Anderson, Timothy J.

    1990-01-01

    Presents a synopsis of four lectures given in an elective senior-level electronic material processing course to introduce solid state electronics. Provides comparisons of a large scale chemical processing plant and an integrated circuit. (YP)

  13. Chemical engineering design of CO oxidation catalysts

    NASA Technical Reports Server (NTRS)

    Herz, Richard K.

    1987-01-01

    How a chemical reaction engineer would approach the challenge of designing a CO oxidation catalyst for pulsed CO2 lasers is described. CO oxidation catalysts have a long history of application, of course, so it is instructive to first consider the special requirements of the laser application and then to compare them to the characteristics of existing processes which utilize CO oxidation catalysts. All CO2 laser applications require a CO oxidation catalyst with the following characteristics: (1) active at stoichiometric ratios of O2 and CO, (2) no inhibition by CO2 or other components of the laser environment, (3) releases no particulates during vibration or thermal cycling, and (4) long lifetime with a stable activity. In all applications, low consumption of power is desirable, a characteristic especially critical in aerospace applications and, thus, catalyst activity at low temperatures is highly desirable. High power lasers with high pulse repetition rates inherently require circulation of the gas mixture and this forced circulation is available for moving gas past the catalyst. Low repetition rate lasers, however, do not inherently require gas circulation, so a catalyst that did not require such circulation would be favorable from the standpoint of minimum power consumption. Lasers designed for atmospheric penetration of their infrared radiation utilize CO2 formed from rare isotopes of oxygen and this application has the additional constraint that normal abundance oxygen isotopes in the catalyst must not exchange with rare isotopes in the gas mixture.

  14. A Process for Design Engineering

    NASA Technical Reports Server (NTRS)

    Briggs, Clark

    2004-01-01

    The American Institute of Aeronautics and Astronautics Design Engineering Technical Committee has developed a draft Design Engineering Process with the participation of the technical community. This paper reviews similar engineering activities, lays out common terms for the life cycle and proposes a Design Engineering Process.

  15. PILOT PLANT DESIGN FOR CHEMICAL DESULFURIZATION OF COAL

    EPA Science Inventory

    The report gives results of a program for design and operational planning of facilities for testing the Meyers Process for chemical removal of pyritic sulfur from coal. Two options were evaluated: a complete pilot plant test of the process at a 0.5-ton per hour scale; and scale-u...

  16. Analysis of chemical coal cleaning processes. Final report

    SciTech Connect

    Not Available

    1980-06-01

    Six chemical coal cleaning processes were examined. Conceptual designs and costs were prepared for these processes and coal preparation facilities, including physical cleaning and size reduction. Transportation of fine coal in agglomerated and unagglomerated forms was also discussed. Chemical cleaning processes were: Pittsburgh Energy Technology Center, Ledgemont, Ames Laboratory, Jet Propulsion Laboratory (two versions), and Guth Process (KVB). Three of the chemical cleaning processes are similar in concept: PETC, Ledgemont, and Ames. Each of these is based on the reaction of sulfur with pressurized oxygen, with the controlling factor being the partial pressure of oxygen in the reactor. All of the processes appear technically feasible. Economic feasibility is less certain. The recovery of process chemicals is vital to the JPL and Guth processes. All of the processes consume significant amounts of energy in the form of electric power and coal. Energy recovery and increased efficiency are potential areas for study in future more detailed designs. The Guth process (formally designed KVB) appears to be the simplest of the systems evaluated. All of the processes require future engineering to better determine methods for scaling laboratory designs/results to commercial-scale operations. A major area for future engineering is to resolve problems related to handling, feeding, and flow control of the fine and often hot coal.

  17. Chemical designs of functional photoactive molecular assemblies.

    PubMed

    Yan, Qifan; Luo, Zhouyang; Cai, Kang; Ma, Yuguo; Zhao, Dahui

    2014-06-21

    Molecular assemblies with well-defined structures capable of photo-induced electron transfer and charge transport or photochemical reactions are reviewed. Hierarchical supramolecular architectures, which assemble the modular units into specific spatial arrangements and facilitate them to work cooperatively, are vital for the achievement of photo-functions in these systems. The chemical design of molecular building blocks and noncovalent interactions exploited to realize supramolecular organizations are particularly discussed. Reviewing and recapitulating the chemical evolution traces of these accomplished systems will hopefully delineate certain fundamental design principles and guidelines useful for developing more advanced functions in the future. PMID:24492680

  18. Book Processing Facility Design.

    ERIC Educational Resources Information Center

    Sheahan (Drake)-Stewart Dougall, Marketing and Physical Distribution Consultants, New York, NY.

    The Association of New York Libraries for Technical Services (ANYLTS) is established to develop and run a centralized book processing facility for the public library systems in New York State. ANYLTS plans to receive book orders from the 22 library systems, transmit orders to publishers, receive the volumes from the publishers, print and attach…

  19. Microwave-enhanced chemical processes

    DOEpatents

    Varma, Ravi

    1990-01-01

    A process for disposal of toxic wastes including chlorinated hydrocarbons, comprising, establishing a bed of non-metallic particulates having a high dielectric loss factor. Effecting intimate contact of the particulates and the toxic wastes at a temperature in excess of about 400.degree. C. in the presence of microwave radiation for a time sufficient to break the hydrocarbon chlorine bonds and provide detoxification values in excess of 80 and further detoxifying the bed followed by additional disposal of toxic wastes.

  20. Microwave-enhanced chemical processes

    DOEpatents

    Varma, R.

    1990-06-19

    A process is disclosed for the disposal of toxic wastes including chlorinated hydrocarbons, comprising, establishing a bed of non-metallic particulates having a high dielectric loss factor. Intimate contact of the particulates and the toxic wastes at a temperature in excess of about 400 C in the presence of microwave radiation for a time sufficient breaks the hydrocarbon chlorine bonds. Detoxification values in excess of 80 are provided and further detoxification of the bed is followed by additional disposal of toxic wastes. 1 figure.

  1. Reengineering the Project Design Process

    NASA Technical Reports Server (NTRS)

    Casani, E.; Metzger, R.

    1994-01-01

    In response to NASA's goal of working faster, better and cheaper, JPL has developed extensive plans to minimize cost, maximize customer and employee satisfaction, and implement small- and moderate-size missions. These plans include improved management structures and processes, enhanced technical design processes, the incorporation of new technology, and the development of more economical space- and ground-system designs. The Laboratory's new Flight Projects Implementation Office has been chartered to oversee these innovations and the reengineering of JPL's project design process, including establishment of the Project Design Center and the Flight System Testbed. Reengineering at JPL implies a cultural change whereby the character of its design process will change from sequential to concurrent and from hierarchical to parallel. The Project Design Center will support missions offering high science return, design to cost, demonstrations of new technology, and rapid development. Its computer-supported environment will foster high-fidelity project life-cycle development and cost estimating.

  2. Chemical production processes and systems

    DOEpatents

    Holladay, Johnathan E.; Muzatko, Danielle S.; White, James F.; Zacher, Alan H.

    2014-06-17

    Hydrogenolysis systems are provided that can include a reactor housing an Ru-comprising hydrogenolysis catalyst and wherein the contents of the reactor is maintained at a neutral or acidic pH. Reactant reservoirs within the system can include a polyhydric alcohol compound and a base, wherein a weight ratio of the base to the compound is less than 0.05. Systems also include the product reservoir comprising a hydrogenolyzed polyhydric alcohol compound and salts of organic acids, and wherein the moles of base are substantially equivalent to the moles of salts or organic acids. Processes are provided that can include an Ru-comprising catalyst within a mixture having a neutral or acidic pH. A weight ratio of the base to the compound can be between 0.01 and 0.05 during exposing.

  3. Chemical production processes and systems

    SciTech Connect

    Holladay, Johnathan E; Muzatko, Danielle S; White, James F; Zacher, Alan H

    2015-04-21

    Hydrogenolysis systems are provided that can include a reactor housing an Ru-comprising hydrogenolysis catalyst and wherein the contents of the reactor is maintained at a neutral or acidic pH. Reactant reservoirs within the system can include a polyhydric alcohol compound and a base, wherein a weight ratio of the base to the compound is less than 0.05. Systems also include the product reservoir comprising a hydrogenolyzed polyhydric alcohol compound and salts of organic acids, and wherein the moles of base are substantially equivalent to the moles of salts or organic acids. Processes are provided that can include an Ru-comprising catalyst within a mixture having a neutral or acidic pH. A weight ratio of the base to the compound can be between 0.01 and 0.05 during exposing.

  4. Efficient Nonlinear Programming Algorithms for Chemical Process Control and Operations

    NASA Astrophysics Data System (ADS)

    Biegler, Lorenz T.

    Optimization is applied in numerous areas of chemical engineering including the development of process models from experimental data, design of process flowsheets and equipment, planning and scheduling of chemical process operations, and the analysis of chemical processes under uncertainty and adverse conditions. These off-line tasks require the solution of nonlinear programs (NLPs) with detailed, large-scale process models. Recently, these tasks have been complemented by time-critical, on-line optimization problems with differential-algebraic equation (DAE) process models that describe process behavior over a wide range of operating conditions, and must be solved sufficiently quickly. This paper describes recent advances in this area especially with dynamic models. We outline large-scale NLP formulations and algorithms as well as NLP sensitivity for on-line applications, and illustrate these advances on a commercial-scale low density polyethylene (LDPE) process.

  5. Energy conservation in regenerated chemical absorption processes

    SciTech Connect

    Thompson, R.E.

    1986-01-01

    Energy savings from split-flow design modifications or the installation of absorber intercoolers are quantified for solvent-based separation processes. Absorber-stripper systems that use aqueous monoethanolamine (MEA) or diethanolamine (DEA) to remove CO/sub 2/ or H/sub 2/S from natural gas streams are modeled. Use of split flow in regenerated chemical absorption processes with isothermal columns resulted in energy savings of over 50% for systems with large solute-recovery fractions. The energy savings are a linear function of the logarithm of percent unrecovered solute. Optimal values are found for the flow rate and withdrawal point of the split-flow stream. The optimal design and operating conditions for CO/sub 2/ systems with adiabatic columns are determined by the stripper column; the stripper exhibits a steam-consumption minimum with respect to the total solvent flow rate and the composition of the lean-solvent stream. In contrast, optimal conditions for H/sub 2/S systems are set by the absorber. These absorber-limited systems exhibit a steam consumption minimum for the lowest solvent flow which can achieve the specified solute recovery in the absorber. Absorber intercoolers conserve energy by reducing the solvent flow rate required for a specified solute recovery. The optimal intercooler location is near an acid-gas-to-amine ratio halfway between the same ratios for the lean and rich solvent streams. The intercooler location is near an acid-gas-to-amine ratio halfway between the same ratios for the lean and rich solvent streams. The intercooler is optically sized by equating the absorber-solvent-feed temperature, the absorber-intercooler process-outlet temperature, and the cooling-water effluent temperature.

  6. A Course in Project Evaluation in the Chemical Process Industries.

    ERIC Educational Resources Information Center

    Valle-Riestra, J. Frank

    1983-01-01

    Describes a course designed to expose neophytes to methodology used in chemical process industries to evaluate commercial feasibility of proposed projects. Previously acquired disciplines are integrated to facilitate process synthesis, gain appreciation of nature of industrial projects and industrial viewpoint in managing them, and to become adept…

  7. U-GAS process for chemical manufacture

    SciTech Connect

    Dihu, R.; Leppin, D.; Patel, J.G.

    1980-01-01

    The U-GAS coal gasification process and its potential application to the manufacture of two important industrial chemicals, methanol and ammonia, are described. Pilot plant results, the current status of the process, and economic projections for the cost of manufacture of methanol and ammonia are presented.

  8. Circumventing Graphical User Interfaces in Chemical Engineering Plant Design

    ERIC Educational Resources Information Center

    Romey, Noel; Schwartz, Rachel M.; Behrend, Douglas; Miao, Peter; Cheung, H. Michael; Beitle, Robert

    2007-01-01

    Graphical User Interfaces (GUIs) are pervasive elements of most modern technical software and represent a convenient tool for student instruction. For example, GUIs are used for [chemical] process design software (e.g., CHEMCAD, PRO/II and ASPEN) typically encountered in the senior capstone course. Drag and drop aspects of GUIs are challenging for…

  9. Process safety management for highly hazardous chemicals

    SciTech Connect

    1996-02-01

    Purpose of this document is to assist US DOE contractors who work with threshold quantities of highly hazardous chemicals (HHCs), flammable liquids or gases, or explosives in successfully implementing the requirements of OSHA Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119). Purpose of this rule is to prevent releases of HHCs that have the potential to cause catastrophic fires, explosions, or toxic exposures.

  10. Chemicals Industry New Process Chemistry Roadmap

    SciTech Connect

    none,

    2000-08-01

    The Materials Technology I workshop was held in November 1998 to address future research needs for materials technology that will support the chemical industry. Areas covered included disassembly, recovery, reuse and renewable technology; new materials; and materials measurement and characterization. The Materials Technology II workshop was held in September 1999 and covered additives, modeling and prediction and an additional segment on new materials. Materials Technology Institute (MTI) for the Chemical Process Industries, Inc. and Air Products & Chemicals lead the workshops. The Materials Technology Roadmap presents the results from both workshops.

  11. Enzymes toughen up for chemical processing

    SciTech Connect

    Hairston, D.

    1995-05-01

    While enzymes have been making tremendous inroads into detergent formulation and food processing, the penetration of these protein-based catalysts into other chemical-process manufacture and hazardous waste treatment--where they are slated to replace heavy metal catalysts and other processing aids--has been relatively slow. Recently, however, enhancements in the enzyme`s properties are opening the door wider for such broadened usage. Some of these non-traditional uses of enzymes are described.

  12. Process/Equipment Co-Simulation on Syngas Chemical Looping Process

    SciTech Connect

    Zeng, Liang; Zhou, Qiang; Fan, Liang-Shih

    2012-09-30

    The chemical looping strategy for fossil energy applications promises to achieve an efficient energy conversion system for electricity, liquid fuels, hydrogen and/or chemicals generation, while economically separate CO{sub 2} by looping reaction design in the process. Chemical looping particle performance, looping reactor engineering, and process design and applications are the key drivers to the success of chemical looping process development. In order to better understand and further scale up the chemical looping process, issues such as cost, time, measurement, safety, and other uncertainties need to be examined. To address these uncertainties, advanced reaction/reactor modeling and process simulation are highly desired and the modeling efforts can accelerate the chemical looping technology development, reduce the pilot-scale facility design time and operating campaigns, as well as reduce the cost and technical risks. The purpose of this work is thus to conduct multiscale modeling and simulations on the key aspects of chemical looping technology, including particle reaction kinetics, reactor design and operation, and process synthesis and optimization.

  13. Design of intelligent controllers for exothermal processes

    NASA Astrophysics Data System (ADS)

    Nagarajan, Ramachandran; Yaacob, Sazali

    2001-10-01

    Chemical Industries such as resin or soap manufacturing industries have reaction systems which work with at least two chemicals. Mixing of chemicals even at room temperature can create the process of exothermic reaction. This processes produces a sudden increase of heat energy within the mixture. The quantity of heat and the dynamics of heat generation are unknown, unpredictable and time varying. Proper control of heat has to be accomplished in order to achieve a high quality of product. Uncontrolled or poorly controlled heat causes another unusable product and the process may damage materials and systems and even human being may be harmed. Controlling of heat due to exothermic reaction cannot be achieved using conventional control methods such as PID control, identification and control etc. All of the conventional methods require at least approximate mathematical model of the exothermic process. Modeling an exothermal process is yet to be properly conceived. This paper discusses a design methodology for controlling such a process. A pilot plant of a reaction system has been constructed and utilized for designing and incorporating the proposed fuzzy logic based intelligent controller. Both the conventional and then an adaptive form of fuzzy logic control were used in testing the performance. The test results ensure the effectiveness of controllers in controlling exothermic heat.

  14. Optimization process in helicopter design

    NASA Technical Reports Server (NTRS)

    Logan, A. H.; Banerjee, D.

    1984-01-01

    In optimizing a helicopter configuration, Hughes Helicopters uses a program called Computer Aided Sizing of Helicopters (CASH), written and updated over the past ten years, and used as an important part of the preliminary design process of the AH-64. First, measures of effectiveness must be supplied to define the mission characteristics of the helicopter to be designed. Then CASH allows the designer to rapidly and automatically develop the basic size of the helicopter (or other rotorcraft) for the given mission. This enables the designer and management to assess the various tradeoffs and to quickly determine the optimum configuration.

  15. A POLLUTION REDUCTION METHODOLOGY FOR CHEMICAL PROCESS SIMULATORS

    EPA Science Inventory

    A pollution minimization methodology was developed for chemical process design using computer simulation. It is based on a pollution balance that at steady state is used to define a pollution index with units of mass of pollution per mass of products. The pollution balance has be...

  16. Chemical Processes in Astrophysical Radiation Fields

    SciTech Connect

    Stancil, P.C.; Dalgarno, A.

    1997-12-31

    The effects of stimulated photon emission on chemical processes in a radiation field are considered and their influence on the chemistry of the early universe and other astrophysical environments is investigated. Spontaneous and stimulated radiative attachment rate coefficients for H(-), Li(-) and C(-) are presented.

  17. Safety Considerations in the Chemical Process Industries

    NASA Astrophysics Data System (ADS)

    Englund, Stanley M.

    There is an increased emphasis on chemical process safety as a result of highly publicized accidents. Public awareness of these accidents has provided a driving force for industry to improve its safety record. There has been an increasing amount of government regulation.

  18. A Novel Chemical Nitrate Destruction Process

    SciTech Connect

    Dziewinski, J.; Marczak, S.

    1999-03-01

    Nitrates represent one of the most significant pollutant discharged to the Baltic Sea by the Sliiamae hydrometallurgical plant. This article contains a brief overview of the existing nitrate destruction technologies followed by the description of a new process developed by the authors. The new chemical process for nitrate destruction is cost effective and simple to operate. It converts the nitrate to nitrogen gas which goes to the atmosphere.

  19. Total chemical management in photographic processing

    USGS Publications Warehouse

    Luden, Charles; Schultz, Ronald

    1985-01-01

    The mission of the U. S. Geological Survey's Earth Resources Observation Systems (EROS) Data Center is to produce high-quality photographs of the earth taken from aircraft and Landsat satellite. In order to meet the criteria of producing research-quality photographs, while at the same time meeting strict environmental restrictions, a total photographic chemical management system was installed. This involved a three-part operation consisting of the design of a modern chemical analysis laboratory, the implementation of a chemical regeneration system, and the installation of a waste treatment system, including in-plant pretreatment and outside secondary waste treatment. Over the last ten years the result of this program has yielded high-quality photographs while saving approximately 30,000 per year and meeting all Environmental Protection Agency (EPA) restrictions.

  20. VCM Process Design: An ABET 2000 Fully Compliant Project

    ERIC Educational Resources Information Center

    Benyahia, Farid

    2005-01-01

    A long experience in undergraduate vinyl chloride monomer (VCM) process design projects is shared in this paper. The VCM process design is shown to be fully compliant with ABET 2000 criteria by virtue of its abundance in chemical engineering principles, integration of interpersonal and interdisciplinary skills in design, safety, economics, and…

  1. The Process Design Courses at Pennsylvania: Impact of Process Simulators.

    ERIC Educational Resources Information Center

    Seider, Warren D.

    1984-01-01

    Describes the use and impact of process design simulators in process design courses. Discusses topics covered, texts used, computer design simulations, and how they are integrated into the process survey course as well as in plant design projects. (JM)

  2. Hydroforming design and process advisor

    SciTech Connect

    Greer, J.T.; Ni, C.M.

    1996-10-10

    The hydroforming process involves hydraulically forming components by conforming them to the inner contours of a die. These contours can be complex and can often cause the material being formed to be stressed to rupture. Considerable process knowledge and materials modeling expertise is required to design hydroform dies and hydroformed parts that are readily formed without being overly stressed. For this CRADA, materials properties for steel tubes subjected to hydraulic stresses were collected; algorithms were developed which combined the materials properties data with process knowledge; and a user friendly graphical interface was utilized to make the system usable by a design engineer. A prototype hydroforming advisor was completed and delivered to GM. The technical objectives of the CRADA were met allowing for the development of an intelligent design systems, prediction of forming properties related to hydroforming, simulation and modeling of process execution, and design optimization. The design advisor allows a rapid and seamless approach to integration an otherwise enormous and onerous task of analysis and evaluation.

  3. 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. PMID:26078345

  4. Estimation of Environment-Related Properties of Chemicals for Design of Sustainable Processes: Development of Group-Contribution+ (GC+) Property Models and Uncertainty Analysis

    EPA Science Inventory

    The aim of this work is to develop group-contribution+ (GC+) method (combined group-contribution (GC) method and atom connectivity index (CI) method) based property models to provide reliable estimations of environment-related properties of organic chemicals together with uncert...

  5. Advanced microlithography process with chemical shrink technology

    NASA Astrophysics Data System (ADS)

    Kanda, Takashi; Tanaka, Hatsuyuki; Kinoshita, Yoshiaki; Watase, Natsuo; Eakin, Ronald J.; Ishibashi, Takeo; Toyoshima, Toshiyuki; Yasuda, Naoki; Tanaka, Mikihiro

    2000-06-01

    Mitsubishi Electric Corporation (MELCO) has developed an advanced microlithographic process for producing 0.1 micrometer contact holes (CH). A chemical shrink technology, RELACSTM (Resolution Enhancement Lithography Assisted by Chemical Shrink), utilizes the crosslinking reaction catalyzed by the acid component existing in a predefined resist pattern. This 'RELACSTM' process is a hole shrinking procedure that includes simple coating, baking, and rinse steps applied after conventional photolithography. This paper examines the process parameters affecting shrinkage of CH size. We subsequently evaluated the dependency of CH shrinkage on resist formulation. We conducted investigations of shrink magnitude dependency on each process parameter. (1) Photoresist lithography process: CH size, exposure dose, post development bake temperature. (2) AZR R200 [a product of Clariant, Japan) K.K.] RELACSTM process: Soft bake temperature, film thickness, mixing bake temperature (diffusion bake temperature), etc. We found that the mixing bake condition (diffusion bake temperature) is one of most critical parameters to affect the amount of CH shrink. Additionally, the structural influence of photoacid generators on shrinkage performance was also investigated in both high and low activation energy resist systems. The shrinkage behavior by the photoacid generator of the resist is considered in terms of the structure (molecular volume) of the photogenerated acid and its acidity (pKa). The results of these studies are discussed in terms of base polymer influence on shrinkage performance and tendency. Process impact of the structure and acidity of the photogenerated acid is explored. Though the experimental acetal type KrF positive resist (low activation energy system) can achieve around 0.1 micrometer CH after RELACSTM processing under the optimized condition, the experimental acrylate type positive resist (high activation energy system) showed less shrinkage under the same process

  6. ESS Cryogenic System Process Design

    NASA Astrophysics Data System (ADS)

    Arnold, P.; Hees, W.; Jurns, J.; Su, X. T.; Wang, X. L.; Weisend, J. G., II

    2015-12-01

    The European Spallation Source (ESS) is a neutron-scattering facility funded and supported in collaboration with 17 European countries in Lund, Sweden. Cryogenic cooling at ESS is vital particularly for the linear accelerator, the hydrogen target moderators, a test stand for cryomodules, the neutron instruments and their sample environments. The paper will focus on specific process design criteria, design decisions and their motivations for the helium cryoplants and auxiliary equipment. Key issues for all plants and their process concepts are energy efficiency, reliability, smooth turn-down behaviour and flexibility. The accelerator cryoplant (ACCP) and the target moderator cryoplant (TMCP) in particular need to be prepared for a range of refrigeration capacities due to the intrinsic uncertainties regarding heat load definitions. Furthermore the paper addresses questions regarding process arrangement, 2 K cooling methodology, LN2 precooling, helium storage, helium purification and heat recovery.

  7. Designing Endocrine Disruption Out of the Next Generation of Chemicals.

    PubMed

    Schug, T T; Abagyan, R; Blumberg, B; Collins, T J; Crews, D; DeFur, P L; Dickerson, S M; Edwards, T M; Gore, A C; Guillette, L J; Hayes, T; Heindel, J J; Moores, A; Patisaul, H B; Tal, T L; Thayer, K A; Vandenberg, L N; Warner, J; Watson, C S; Saal, F S Vom; Zoeller, R T; O'Brien, K P; Myers, J P

    2013-01-01

    A central goal of green chemistry is to avoid hazard in the design of new chemicals. This objective is best achieved when information about a chemical's potential hazardous effects is obtained as early in the design process as feasible. Endocrine disruption is a type of hazard that to date has been inadequately addressed by both industrial and regulatory science. To aid chemists in avoiding this hazard, we propose an endocrine disruption testing protocol for use by chemists in the design of new chemicals. The Tiered Protocol for Endocrine Disruption (TiPED) has been created under the oversight of a scientific advisory committee composed of leading representatives from both green chemistry and the environmental health sciences. TiPED is conceived as a tool for new chemical design, thus it starts with a chemist theoretically at "the drawing board." It consists of five testing tiers ranging from broad in silico evaluation up through specific cell- and whole organism-based assays. To be effective at detecting endocrine disruption, a testing protocol must be able to measure potential hormone-like or hormone-inhibiting effects of chemicals, as well as the many possible interactions and signaling sequellae such chemicals may have with cell-based receptors. Accordingly, we have designed this protocol to broadly interrogate the endocrine system. The proposed protocol will not detect all possible mechanisms of endocrine disruption, because scientific understanding of these phenomena is advancing rapidly. To ensure that the protocol remains current, we have established a plan for incorporating new assays into the protocol as the science advances. In this paper we present the principles that should guide the science of testing new chemicals for endocrine disruption, as well as principles by which to evaluate individual assays for applicability, and laboratories for reliability. In a 'proof-of-principle' test, we ran 6 endocrine disrupting chemicals (EDCs) that act via

  8. Denitrification as a Model Chemical Process

    NASA Astrophysics Data System (ADS)

    Grguric, Gordan

    2002-02-01

    Bacterial denitrification in seawater facilities such as aquaria and mariculture systems is a process particularly well suited for illustrating important concepts in chemistry to undergraduates. Students can gain firsthand experience related to these concepts, for example by (i) analyzing and quantifying chemical reactions based on empirical data, (ii) employing stoichiometry and mass balance to determine the amounts of reactants required and products produced in a chemical reaction, and (iii) using acid-base speciation diagrams and other information to quantify the changes in pH and carbonic acid speciation in an aqueous medium. At the Richard Stockton College of New Jersey, we have utilized actual data from several seawater systems to discuss topics such as stoichiometry, mass and charge balance, and limiting reagents. This paper describes denitrification in closed seawater systems and how the process can be used to enhance undergraduate chemistry education. A number of possible student exercises are described that can be used as practical tools to enhance the students' quantitative understanding of chemical reactions.

  9. Using GREENSCOPE for Sustainable Process Design: An Educational Opportunity

    EPA Science Inventory

    Increasing sustainability can be approached through the education of those who design, construct, and operate facilities. As chemical engineers learn elements of process systems engineering, they can be introduced to sustainability concepts. The EPA’s GREENSCOPE methodology and...

  10. Automation of Design Engineering Processes

    NASA Technical Reports Server (NTRS)

    Torrey, Glenn; Sawasky, Gerald; Courey, Karim

    2004-01-01

    A method, and a computer program that helps to implement the method, have been developed to automate and systematize the retention and retrieval of all the written records generated during the process of designing a complex engineering system. It cannot be emphasized strongly enough that all the written records as used here is meant to be taken literally: it signifies not only final drawings and final engineering calculations but also such ancillary documents as minutes of meetings, memoranda, requests for design changes, approval and review documents, and reports of tests. One important purpose served by the method is to make the records readily available to all involved users via their computer workstations from one computer archive while eliminating the need for voluminous paper files stored in different places. Another important purpose served by the method is to facilitate the work of engineers who are charged with sustaining the system and were not involved in the original design decisions. The method helps the sustaining engineers to retrieve information that enables them to retrace the reasoning that led to the original design decisions, thereby helping them to understand the system better and to make informed engineering choices pertaining to maintenance and/or modifications of the system. The software used to implement the method is written in Microsoft Access. All of the documents pertaining to the design of a given system are stored in one relational database in such a manner that they can be related to each other via a single tracking number.

  11. Designing Endocrine Disruption Out of the Next Generation of Chemicals

    PubMed Central

    Schug, T.T; Abagyan, R.; Blumberg, B.; Collins, T.J.; Crews, D.; DeFur, P.L.; Dickerson, S.M.; Edwards, T.M.; Gore, A.C.; Guillette, L.J.; Hayes, T.; Heindel, J.J.; Moores, A.; Patisaul, H.B.; Tal, T.L.; Thayer, K.A.; Vandenberg, L.N.; Warner, J.; Watson, C.S.; Saal, F.S. vom; Zoeller, R.T.; O’Brien, K.P.; Myers, J.P.

    2013-01-01

    A central goal of green chemistry is to avoid hazard in the design of new chemicals. This objective is best achieved when information about a chemical’s potential hazardous effects is obtained as early in the design process as feasible. Endocrine disruption is a type of hazard that to date has been inadequately addressed by both industrial and regulatory science. To aid chemists in avoiding this hazard, we propose an endocrine disruption testing protocol for use by chemists in the design of new chemicals. The Tiered Protocol for Endocrine Disruption (TiPED) has been created under the oversight of a scientific advisory committee composed of leading representatives from both green chemistry and the environmental health sciences. TiPED is conceived as a tool for new chemical design, thus it starts with a chemist theoretically at “the drawing board.” It consists of five testing tiers ranging from broad in silico evaluation up through specific cell- and whole organism-based assays. To be effective at detecting endocrine disruption, a testing protocol must be able to measure potential hormone-like or hormone-inhibiting effects of chemicals, as well as the many possible interactions and signaling sequellae such chemicals may have with cell-based receptors. Accordingly, we have designed this protocol to broadly interrogate the endocrine system. The proposed protocol will not detect all possible mechanisms of endocrine disruption, because scientific understanding of these phenomena is advancing rapidly. To ensure that the protocol remains current, we have established a plan for incorporating new assays into the protocol as the science advances. In this paper we present the principles that should guide the science of testing new chemicals for endocrine disruption, as well as principles by which to evaluate individual assays for applicability, and laboratories for reliability. In a ‘proof-of-principle’ test, we ran 6 endocrine disrupting chemicals (EDCs) that act

  12. Treatment Process Requirements for Waters Containing Hydraulic Fracturing Chemicals

    NASA Astrophysics Data System (ADS)

    Stringfellow, W. T.; Camarillo, M. K.; Domen, J. K.; Sandelin, W.; Varadharajan, C.; Cooley, H.; Jordan, P. D.; Heberger, M. G.; Reagan, M. T.; Houseworth, J. E.; Birkholzer, J. T.

    2015-12-01

    A wide variety of chemical additives are used as part of the hydraulic fracturing (HyF) process. There is concern that HyF chemicals will be released into the environment and contaminate drinking water, agricultural water, or other water used for beneficial purposes. There is also interest in using produced water (water extracted from the subsurface during oil and gas production) for irrigation and other beneficial purposes, especially in the arid Southwest US. Reuse of produced water is not speculative: produced water can be low in salts and is being used in California for irrigation after minimal treatment. In this study, we identified chemicals that are used for hydraulic fracturing in California and conducted an analysis to determine if those chemicals would be removed by a variety of technically available treatment processes, including oil/water separation, air stripping, a variety of sorption media, advanced oxidation, biological treatment, and a variety of membrane treatment systems. The approach taken was to establish major physiochemical properties for individual chemicals (log Koc, Henry's constant, biodegradability, etc.), group chemicals by function (e.g corrosion inhibition, biocides), and use those properties to predict the fate of chemical additives in a treatment process. Results from this analysis is interpreted in the context of what is known about existing systems for the treatment of produced water before beneficial reuse, which includes a range of treatment systems from oil/water separators (the most common treatment) to sophisticated treatment trains used for purifying produced water for groundwater recharge. The results show that most HyF chemical additives will not be removed in existing treatment systems, but that more sophisticated treatment trains can be designed to remove additives before beneficial reuse.

  13. The concepts of energy, environment, and cost for process design

    SciTech Connect

    Abu-Khader, M.M.; Speight, J.G.

    2004-05-01

    The process industries (specifically, energy and chemicals) are characterized by a variety of reactors and reactions to bring about successful process operations. The design of energy-related and chemical processes and their evolution is a complex process that determines the competitiveness of these industries, as well as their environmental impact. Thus, we have developed an Enviro-Energy Concept designed to facilitate sustainable industrial development. The Complete Onion Model represents a complete methodology for chemical process design and illustrates all of the requirements to achieve the best possible design within the accepted environmental standards. Currently, NOx emissions from industrial processes continue to receive maximum attention, therefore the issue problem of NOx emissions from industrial sources such as power stations and nitric acid plants is considered. The Selective Catalytic Reduction (SCR) is one of the most promising and effective commercial technologies. It is considered the Best Available Control Technology (BACT) for NOx reduction. The solution of NOx emissions problem is either through modifying the chemical process design and/or installing an end-of-pipe technology. The degree of integration between the process design and the installed technology plays a critical role in the capital cost evaluation. Therefore, integrating process units and then optimizing the design has a vital effect on the total cost. Both the environmental regulations and the cost evaluation are the boundary constraints of the optimum solution.

  14. Principles of technological design of wasteless chemical processes based on the use of wastes for production of alkaline slag cements and concretes

    SciTech Connect

    Glukhovskii, V.D.; Chernobaev, I.P.; Emel'yanov, B.M.; Semenyuk, A.P.

    1985-05-20

    The strength characteristics of alkaline slag-cement made with the use of waste from alkaline sealing of metals are presented. The cement was prepared from granulated blast-furnance slag with average component contents in the following ranges (mass %): SiO/sub 2/ 36.0-40.2, Al/sub 2/O/sub 3/ 4-18.2, FeO 0.1-3.7, MnO 0.4-5.2, CaO 33.1-48.8, MgO 2.2-9.8. With the use of wastes from the descaling process in alkali melts for production of alkaline slag cements it is possible to obtain highly effective cements of type 700-900, which is 2 to 3 times the value for portland cements. Therefore, the use of wastes from alkaline descaling for production of alkaline slag cements is of great economic and conservational significance. It is possible to devise a wasteless process of scale removal from metals; this is an important advantage of the alkaline scaling method over acid pickling.

  15. THE SECOND GENERATION OF THE WASTE REDUCTION (WAR) ALGORITHM: A DECISION SUPPORT SYSTEM FOR GREENER CHEMICAL PROCESSES

    EPA Science Inventory

    chemical process designers using simulation software generate alternative designs for one process. One criterion for evaluating these designs is their potential for adverse environmental impacts due to waste generated, energy consumed, and possibilities for fugitive emissions. Co...

  16. EVALUATING THE ENVIRONMENTAL FRIENDLINESS, ECONOMICS, AND ENERGY EFFICIENCY OF CHEMICAL PROCESSES: HEAT INTEGRATION

    EPA Science Inventory

    The design and improvement of chemical processes can be very challenging. The earlier energy conservation, process economics and environmental aspects are incorporated into the process development, the easier and less expensive it is to alter the process design. In this work diff...

  17. Idaho Chemical Processing Plant failure rate database

    SciTech Connect

    Alber, T.G.; Hunt, C.R.; Fogarty, S.P.; Wilson, J.R.

    1995-08-01

    This report represents the first major upgrade to the Idaho Chemical Processing Plant (ICPP) Failure Rate Database. This upgrade incorporates additional site-specific and generic data while improving on the previous data reduction techniques. In addition, due to a change in mission at the ICPP, the status of certain equipment items has changed from operating to standby or off-line. A discussion of how this mission change influenced the relevance of failure data also has been included. This report contains two data sources: the ICPP Failure Rate Database and a generic failure rate database. A discussion is presented on the approaches and assumptions used to develop the data in the ICPP Failure Rate Database. The generic database is included along with a short discussion of its application. A brief discussion of future projects recommended to strengthen and lend credibility to the ICPP Failure Rate Database also is included.

  18. Quantification of chemical transport processes from soil to surface runoff

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although there is a conceptual understanding on processes governing chemical transport from soil to surface runoff, there are little literature and research results actually quantifying these individual processes. We developed a laboratory flow cell and experimental procedures to quantify chemical ...

  19. GAX absorption cycle design process

    SciTech Connect

    Priedeman, D.K.; Christensen, R.N.

    1999-07-01

    This paper presents an absorption system design process that relies on computer simulations that are validated by experimental findings. An ammonia-water absorption heat pump cycle at 3 refrigeration tons (RT) and chillers at 3.3 RT and 5 RT (10.5 kW, 11.6 kW, and 17.6 kW) were initially modeled and then built and tested. The experimental results were used to calibrate both the cycle simulation and the component simulations, yielding computer design routines that could accurately predict component and cycle performance. Each system was a generator-absorber heat exchange (GAX) cycle, and all were sized for residential and light commercial use, where very little absorption equipment is currently used. The specific findings of the 5 RT (17.6 kW) chiller are presented. Modeling incorporated a heat loss from the gas-fired generator and pressure drops in both the evaporator and absorber. Simulation results and experimental findings agreed closely and validated the modeling method and simulation software.

  20. INCORPORATING ENVIRONMENTAL AND ECONOMIC CONSIDERATIONS INTO PROCESS DESIGN: THE WASTE REDUCTION (WAR) ALGORITHM

    EPA Science Inventory

    A general theory known as the WAste Reduction (WASR) algorithm has been developed to describe the flow and the generation of potential environmental impact through a chemical process. This theory integrates environmental impact assessment into chemical process design Potential en...

  1. Effects of Semiconductor Processing Chemicals on Conductivity of Graphene

    SciTech Connect

    Chen, Chung Wei; Ren, F.; Chi, G.C.; Hung, S. C.; Huang, Y. P.; Kim, J.; Kravchenko, Ivan I; Pearton, S. J.

    2012-01-01

    Graphene layers on SiO2/Si substrates were exposed to chemicals or gases commonly used in semiconductor fabrication processes, including solvents (isopropanol, acetone), acids (HCl), bases (ammonium hydroxide), UV ozone, H2O and O2 plasmas. The recovery of the initial graphene properties after these exposures was monitored by measuring both the layer resistance and Raman 2D peak position as a function of time in air or vacuum. Solvents and UV ozone were found to have the least affect while oxygen plasma exposure caused an increase of resistance of more than 3 orders of magnitude. Recovery is accelerated under vacuum but changes can persist for more than 5 hours. Careful design of fabrication schemes involving graphene is necessary to minimize these interactions with common processing chemicals.

  2. Film processing investigation. [improved chemical mixing system

    NASA Technical Reports Server (NTRS)

    Kelly, J. L.

    1972-01-01

    The present operational chemical mixing system for the Photographic Technology Division is evaluated, and the limitations are defined in terms of meeting the present and programmed chemical supply and delivery requirements. A major redesign of the entire chemical mixing, storage, analysis, and supply system is recommended. Other requirements for immediate and future implementations are presented.

  3. Design Thinking in Elementary Students' Collaborative Lamp Designing Process

    ERIC Educational Resources Information Center

    Kangas, Kaiju; Seitamaa-Hakkarainen, Pirita; Hakkarainen, Kai

    2013-01-01

    Design and Technology education is potentially a rich environment for successful learning, if the management of the whole design process is emphasised, and students' design thinking is promoted. The aim of the present study was to unfold the collaborative design process of one team of elementary students, in order to understand their multimodal…

  4. BEHAVIOR OF MERCURY DURING DWPF CHEMICAL PROCESS CELL PROCESSING

    SciTech Connect

    Zamecnik, J.; Koopman, D.

    2012-04-09

    The Defense Waste Processing Facility has experienced significant issues with the stripping and recovery of mercury in the Chemical Processing Cell (CPC). The stripping rate has been inconsistent, often resulting in extended processing times to remove mercury to the required endpoint concentration. The recovery of mercury in the Mercury Water Wash Tank has never been high, and has decreased significantly since the Mercury Water Wash Tank was replaced after the seventh batch of Sludge Batch 5. Since this time, essentially no recovery of mercury has been seen. Pertinent literature was reviewed, previous lab-scale data on mercury stripping and recovery was examined, and new lab-scale CPC Sludge Receipt and Adjustment Tank (SRAT) runs were conducted. For previous lab-scale data, many of the runs with sufficient mercury recovery data were examined to determine what factors affect the stripping and recovery of mercury and to improve closure of the mercury material balance. Ten new lab-scale SRAT runs (HG runs) were performed to examine the effects of acid stoichiometry, sludge solids concentration, antifoam concentration, form of mercury added to simulant, presence of a SRAT heel, operation of the SRAT condenser at higher than prototypic temperature, varying noble metals from none to very high concentrations, and higher agitation rate. Data from simulant runs from SB6, SB7a, glycolic/formic, and the HG tests showed that a significant amount of Hg metal was found on the vessel bottom at the end of tests. Material balance closure improved from 12-71% to 48-93% when this segregated Hg was considered. The amount of Hg segregated as elemental Hg on the vessel bottom was 4-77% of the amount added. The highest recovery of mercury in the offgas system generally correlated with the highest retention of Hg in the slurry. Low retention in the slurry (high segregation on the vessel bottom) resulted in low recovery in the offgas system. High agitation rates appear to result in lower

  5. Foundations for Excellence in the Chemical Process Industries. Voluntary Industry Standards for Chemical Process Industries Technical Workers.

    ERIC Educational Resources Information Center

    Hofstader, Robert; Chapman, Kenneth

    This document discusses the Voluntary Industry Standards for Chemical Process Industries Technical Workers Project and issues of relevance to the education and employment of chemical laboratory technicians (CLTs) and process technicians (PTs). Section 1 consists of the following background information: overview of the chemical process industries,…

  6. ESS Accelerator Cryoplant Process Design

    NASA Astrophysics Data System (ADS)

    Wang, X. L.; Arnold, P.; Hees, W.; Hildenbeutel, J.; Weisend, J. G., II

    2015-12-01

    The European Spallation Source (ESS) is a neutron-scattering facility being built with extensive international collaboration in Lund, Sweden. The ESS accelerator will deliver protons with 5 MW of power to the target at 2.0 GeV, with a nominal current of 62.5 mA. The superconducting part of the accelerator is about 300 meters long and contains 43 cryomodules. The ESS accelerator cryoplant (ACCP) will provide the cooling for the cryomodules and the cryogenic distribution system that delivers the helium to the cryomodules. The ACCP will cover three cryogenic circuits: Bath cooling for the cavities at 2 K, the thermal shields at around 40 K and the power couplers thermalisation with 4.5 K forced helium cooling. The open competitive bid for the ACCP took place in 2014 with Linde Kryotechnik AG being selected as the vendor. This paper summarizes the progress in the ACCP development and engineering. Current status including final cooling requirements, preliminary process design, system configuration, machine concept and layout, main parameters and features, solution for the acceptance tests, exergy analysis and efficiency is presented.

  7. Optimal design of solidification processes

    NASA Technical Reports Server (NTRS)

    Dantzig, Jonathan A.; Tortorelli, Daniel A.

    1991-01-01

    An optimal design algorithm is presented for the analysis of general solidification processes, and is demonstrated for the growth of GaAs crystals in a Bridgman furnace. The system is optimal in the sense that the prespecified temperature distribution in the solidifying materials is obtained to maximize product quality. The optimization uses traditional numerical programming techniques which require the evaluation of cost and constraint functions and their sensitivities. The finite element method is incorporated to analyze the crystal solidification problem, evaluate the cost and constraint functions, and compute the sensitivities. These techniques are demonstrated in the crystal growth application by determining an optimal furnace wall temperature distribution to obtain the desired temperature profile in the crystal, and hence to maximize the crystal's quality. Several numerical optimization algorithms are studied to determine the proper convergence criteria, effective 1-D search strategies, appropriate forms of the cost and constraint functions, etc. In particular, we incorporate the conjugate gradient and quasi-Newton methods for unconstrained problems. The efficiency and effectiveness of each algorithm is presented in the example problem.

  8. Chemical kinetics models for semiconductor processing

    SciTech Connect

    Coltrin, M.E.; Creighton, J.R.; Meeks, E.; Grcar, J.F.; Houf, W.G.; Kee, R.J.

    1997-12-31

    Chemical reactions in the gas-phase and on surfaces are important in the deposition and etching of materials for microelectronic applications. A general software framework for describing homogeneous and heterogeneous reaction kinetics utilizing the Chemkin suite of codes is presented. Experimental, theoretical and modeling approaches to developing chemical reaction mechanisms are discussed. A number of TCAD application modules for simulating the chemically reacting flow in deposition and etching reactors have been developed and are also described.

  9. Physical-chemical processes in a protoplanetary cloud

    NASA Technical Reports Server (NTRS)

    Lavrukhina, Avgusta K.

    1991-01-01

    Physical-chemical processes in a protoplanetary cloud are discussed. The following subject areas are covered: (1) characteristics of the chemical composition of molecular interstellar clouds; (2) properties and physico-chemical process in the genesis of interstellar dust grains; and (3) the isotope composition of volatiles in bodies of the Solar System.

  10. CHEMICAL AND PHYSICAL PROCESS AND MECHANISM MODELING

    EPA Science Inventory

    The goal of this task is to develop and test chemical and physical mechanisms for use in the chemical transport models of EPA's Models-3. The target model for this research is the Community Multiscale Air Quality (CMAQ) model. These mechanisms include gas and aqueous phase ph...

  11. Speleothems as Examples of Chemical Equilibrium Processes.

    ERIC Educational Resources Information Center

    Wilson, James R.

    1984-01-01

    The chemical formation of speleothems such as stalactites and stalagmites is poorly understood by introductory geology instructors and misrepresented in most textbooks. Although evaporation may be a controlling factor in some caves, it is necessary to consider chemical precipitation as more important in controlling the diagenesis of calcium…

  12. Designer cell signal processing circuits for biotechnology

    PubMed Central

    Bradley, Robert W.; Wang, Baojun

    2015-01-01

    Microorganisms are able to respond effectively to diverse signals from their environment and internal metabolism owing to their inherent sophisticated information processing capacity. A central aim of synthetic biology is to control and reprogramme the signal processing pathways within living cells so as to realise repurposed, beneficial applications ranging from disease diagnosis and environmental sensing to chemical bioproduction. To date most examples of synthetic biological signal processing have been built based on digital information flow, though analogue computing is being developed to cope with more complex operations and larger sets of variables. Great progress has been made in expanding the categories of characterised biological components that can be used for cellular signal manipulation, thereby allowing synthetic biologists to more rationally programme increasingly complex behaviours into living cells. Here we present a current overview of the components and strategies that exist for designer cell signal processing and decision making, discuss how these have been implemented in prototype systems for therapeutic, environmental, and industrial biotechnological applications, and examine emerging challenges in this promising field. PMID:25579192

  13. Designer cell signal processing circuits for biotechnology.

    PubMed

    Bradley, Robert W; Wang, Baojun

    2015-12-25

    Microorganisms are able to respond effectively to diverse signals from their environment and internal metabolism owing to their inherent sophisticated information processing capacity. A central aim of synthetic biology is to control and reprogramme the signal processing pathways within living cells so as to realise repurposed, beneficial applications ranging from disease diagnosis and environmental sensing to chemical bioproduction. To date most examples of synthetic biological signal processing have been built based on digital information flow, though analogue computing is being developed to cope with more complex operations and larger sets of variables. Great progress has been made in expanding the categories of characterised biological components that can be used for cellular signal manipulation, thereby allowing synthetic biologists to more rationally programme increasingly complex behaviours into living cells. Here we present a current overview of the components and strategies that exist for designer cell signal processing and decision making, discuss how these have been implemented in prototype systems for therapeutic, environmental, and industrial biotechnological applications, and examine emerging challenges in this promising field. PMID:25579192

  14. ADVANCED OXIDATION PROCESSES (AOP'S FOR THE TREATMENT OF CCL CHEMICALS

    EPA Science Inventory

    Research on treatment of Contaminant Candidate List (CCL) chemicals is being conducted. Specific groups of contaminants on the CCL will be evaluated using numerous advanced oxidation processes (AOPs). Initially, these CCL contaminants will be evaluated in groups based on chemical...

  15. 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…

  16. High-lift chemical heat pump technologies for industrial processes

    SciTech Connect

    Olszewski, M.; Zaltash, A.

    1995-03-01

    Traditionally industrial heat pumps (IHPs) have found applications on a process specific basis with reject heat from a process being upgraded and returned to the process. The IHP must be carefully integrated into a process since improper placement may result in an uneconomic application. Industry has emphasized a process integration approach to the design and operation of their plants. Heat pump applications have adopted this approach and the area of applicability was extended by utilizing a process integrated approach where reject heat from one process is upgraded and then used as input for another process. The DOE IHP Program has extended the process integration approach of heat pump application with a plant utility emphasis. In this design philosophy, reject heat from a process is upgraded to plant utility conditions and fed into the plant distribution system. This approach has the advantage that reject heat from any pr@s can be used as input and the output can be used at any location within the plant. Thus the approach can be easily integrated into existing industrial applications and all reject heat streams are potential targets of opportunity. The plant utility approach can not be implemented without having heat pumps with high-lift capabilities (on the order of 65{degree}C). Current heat pumps have only about half the lift capability required. Thus the current emphasis for the DOE IHP Program is the development of high lift chemical heat pumps that can deliver heat more economically to higher heat delivery temperatures. This is achieved with innovative cooling (refrigeration) and heating technologies which are based on advanced cycles and advanced working fluids or a combination of both. This paper details the plan to develop economically competitive, environmentally acceptable heat pump technologies that are capable of providing the delivery temperature and lift required to supply industrial plant utility-grade process heating and/or cooling.

  17. Managing Analysis Models in the Design Process

    NASA Technical Reports Server (NTRS)

    Briggs, Clark

    2006-01-01

    Design of large, complex space systems depends on significant model-based support for exploration of the design space. Integrated models predict system performance in mission-relevant terms given design descriptions and multiple physics-based numerical models. Both the design activities and the modeling activities warrant explicit process definitions and active process management to protect the project from excessive risk. Software and systems engineering processes have been formalized and similar formal process activities are under development for design engineering and integrated modeling. JPL is establishing a modeling process to define development and application of such system-level models.

  18. 76 FR 70368 - Disaster Designation Process

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-14

    ... USDA Secretarial disaster designation process. FSA proposes to simplify the processes and delegate them... rule would update the language to reflect current practice. The current regulations require that a... proposes to simplify the USDA Secretarial designation process from a six-step process to a two-step...

  19. Photonic IC design software and process design kits

    NASA Astrophysics Data System (ADS)

    Korthorst, Twan; Stoffer, Remco; Bakker, Arjen

    2015-04-01

    This review discusses photonic IC design software tools, examines existing design flows for photonics design and how these fit different design styles and describes the activities in collaboration and standardization within the silicon photonics group from Si2 and by members of the PDAFlow Foundation to improve design flows. Moreover, it will address the lowering of access barriers to the technology by providing qualified process design kits (PDKs) and improved integration of photonic integrated circuit simulations, physical simulations, mask layout, and verification.

  20. CHEMICAL PROCESSES AND MODELING IN ECOSYSTEMS

    EPA Science Inventory

    Trends in regulatory strategies require EPA to understand better chemical behavior in natural and impacted ecosystems and in biological systems to carry out the increasingly complex array of exposure and risk assessments needed to develop scientifically defensible regulations (GP...

  1. Biochemical Engineering. Part II: Process Design

    ERIC Educational Resources Information Center

    Atkinson, B.

    1972-01-01

    Describes types of industrial techniques involving biochemical products, specifying the advantages and disadvantages of batch and continuous processes, and contrasting biochemical and chemical engineering. See SE 506 318 for Part I. (AL)

  2. Industrial Scale Synthesis of Carbon Nanotubes Via Fluidized Bed Chemical Vapor Deposition: A Senior Design Project

    ERIC Educational Resources Information Center

    Smith, York R.; Fuchs, Alan; Meyyappan, M.

    2010-01-01

    Senior year chemical engineering students designed a process to produce 10 000 tonnes per annum of single wall carbon nanotubes (SWNT) and also conducted bench-top experiments to synthesize SWNTs via fluidized bed chemical vapor deposition techniques. This was an excellent pedagogical experience because it related to the type of real world design…

  3. Instructional Design Processes and Traditional Colleges

    ERIC Educational Resources Information Center

    Vasser, Nichole

    2010-01-01

    Traditional colleges who have implemented distance education programs would benefit from using instructional design processes to develop their courses. Instructional design processes provide the framework for designing and delivering quality online learning programs in a highly-competitive educational market. Traditional college leaders play a…

  4. Graphic Design in Libraries: A Conceptual Process

    ERIC Educational Resources Information Center

    Ruiz, Miguel

    2014-01-01

    Providing successful library services requires efficient and effective communication with users; therefore, it is important that content creators who develop visual materials understand key components of design and, specifically, develop a holistic graphic design process. Graphic design, as a form of visual communication, is the process of…

  5. 77 FR 41248 - Disaster Designation Process

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ... designation regulations to provide for changes in the designation process (76 FR 70368-70374). In general, that rule proposed to simplify the disaster designation process and to delegate the authority for... 759.6 has also been changed from the proposed rule to remove proposed language referring to a...

  6. Reengineering the JPL Spacecraft Design Process

    NASA Technical Reports Server (NTRS)

    Briggs, C.

    1995-01-01

    This presentation describes the factors that have emerged in the evolved process of reengineering the unmanned spacecraft design process at the Jet Propulsion Laboratory in Pasadena, California. Topics discussed include: New facilities, new design factors, new system-level tools, complex performance objectives, changing behaviors, design integration, leadership styles, and optimization.

  7. NASA System Engineering Design Process

    NASA Technical Reports Server (NTRS)

    Roman, Jose

    2011-01-01

    This slide presentation reviews NASA's use of systems engineering for the complete life cycle of a project. Systems engineering is a methodical, disciplined approach for the design, realization, technical management, operations, and retirement of a system. Each phase of a NASA project is terminated with a Key decision point (KDP), which is supported by major reviews.

  8. Design of Nanomaterial Synthesis by Aerosol Processes

    PubMed Central

    Buesser, Beat; Pratsinis, Sotiris E.

    2013-01-01

    Aerosol synthesis of materials is a vibrant field of particle technology and chemical reaction engineering. Examples include the manufacture of carbon blacks, fumed SiO2, pigmentary TiO2, ZnO vulcanizing catalysts, filamentary Ni, and optical fibers, materials that impact transportation, construction, pharmaceuticals, energy, and communications. Parallel to this, development of novel, scalable aerosol processes has enabled synthesis of new functional nanomaterials (e.g., catalysts, biomaterials, electroceramics) and devices (e.g., gas sensors). This review provides an access point for engineers to the multiscale design of aerosol reactors for the synthesis of nanomaterials using continuum, mesoscale, molecular dynamics, and quantum mechanics models spanning 10 and 15 orders of magnitude in length and time, respectively. Key design features are the rapid chemistry; the high particle concentrations but low volume fractions; the attainment of a self-preserving particle size distribution by coagulation; the ratio of the characteristic times of coagulation and sintering, which controls the extent of particle aggregation; and the narrowing of the aggregate primary particle size distribution by sintering. PMID:22468598

  9. Information-Processing Models and Curriculum Design

    ERIC Educational Resources Information Center

    Calfee, Robert C.

    1970-01-01

    "This paper consists of three sections--(a) the relation of theoretical analyses of learning to curriculum design, (b) the role of information-processing models in analyses of learning processes, and (c) selected examples of the application of information-processing models to curriculum design problems." (Author)

  10. Development of the chemical and electrochemical coal cleaning (CECC) process

    SciTech Connect

    Yoon, Roe-Hoan; Basilio, C.I.

    1992-05-01

    The Chemical and Electrochemical Coal Cleaning (CECC) process developed at Virginia Polytechnic Institute and State University was studied further in this project. This process offers a new method of physically cleaning both low- and high-rank coals without requiring fine grinding. The CECC process is based on liberating mineral matter from coal by osmotic pressure. The majority of the work was conducted on Middle Wyodak, Pittsburgh No. 8 and Elkhorn No. 3 coals. The coal samples were characterized for a variety of physical and chemical properties. Parametric studies were then conducted to identify the important operating parameters and to establish the optimum conditions. In addition, fundamental mechanisms of the process were studied, including mineral matter liberation, kinetics of mineral matter and pyrite dissolution, ferric ion regeneration schemes and alternative methods of separating the cleaned coal from the liberated mineral matter. The information gathered from the parametric and fundamental studies was used in the design, construction and testing of a bench-scale continuous CECC unit. Using this unit, the ash content of a Middle Wyodak coal was reduced from 6.96 to 1.61% at a 2 lbs/hr throughput. With an Elkhorn No. 3 sample, the ash content was reduced from 9.43 to 1.8%, while the sulfur content was reduced from 1.57 to 0.9%. The mass balance and liberation studies showed that liberation played a more dominant role than the chemical dissolution in removing mineral matter and inorganic sulfur from the different bituminous coals tested. However, the opposite was found to be the case for the Wyodak coal since this coal contained a significant amount of acid-soluble minerals.

  11. NANEX: Process design and optimization.

    PubMed

    Baumgartner, Ramona; Matić, Josip; Schrank, Simone; Laske, Stephan; Khinast, Johannes; Roblegg, Eva

    2016-06-15

    Previously, we introduced a one-step nano-extrusion (NANEX) process for transferring aqueous nano-suspensions into solid formulations directly in the liquid phase. Nano-suspensions were fed into molten polymers via a side-feeding device and excess water was eliminated via devolatilization. However, the drug content in nano-suspensions is restricted to 30 % (w/w), and obtaining sufficiently high drug loadings in the final formulation requires the processing of high water amounts and thus a fundamental process understanding. To this end, we investigated four polymers with different physicochemical characteristics (Kollidon(®) VA64, Eudragit(®) E PO, HPMCAS and PEG 20000) in terms of their maximum water uptake/removal capacity. Process parameters as throughput and screw speed were adapted and their effect on the mean residence time and filling degree was studied. Additionally, one-dimensional discretization modeling was performed to examine the complex interactions between the screw geometry and the process parameters during water addition/removal. It was established that polymers with a certain water miscibility/solubility can be manufactured via NANEX. Long residence times of the molten polymer in the extruder and low filling degrees in the degassing zone favored the addition/removal of significant amounts of water. The residual moisture content in the final extrudates was comparable to that of extrudates manufactured without water. PMID:27090153

  12. The Architectural and Interior Design Planning Process.

    ERIC Educational Resources Information Center

    Cohen, Elaine

    1994-01-01

    Explains the planning process in designing effective library facilities and discusses library building requirements that result from electronic information technologies. Highlights include historical structures; Americans with Disabilities Act; resource allocation; electrical power; interior spaces; lighting; design development; the roles of…

  13. USING GENETIC ALGORITHMS TO DESIGN ENVIRONMENTALLY FRIENDLY PROCESSES

    EPA Science Inventory

    Genetic algorithm calculations are applied to the design of chemical processes to achieve improvements in environmental and economic performance. By finding the set of Pareto (i.e., non-dominated) solutions one can see how different objectives, such as environmental and economic ...

  14. Stereodynamics: From elementary processes to macroscopic chemical reactions

    SciTech Connect

    Kasai, Toshio; Che, Dock-Chil; Tsai, Po-Yu; Lin, King-Chuen; Palazzetti, Federico; Aquilanti, Vincenzo

    2015-12-31

    This paper aims at discussing new facets on stereodynamical behaviors in chemical reactions, i.e. the effects of molecular orientation and alignment on reactive processes. Further topics on macroscopic processes involving deviations from Arrhenius behavior in the temperature dependence of chemical reactions and chirality effects in collisions are also discussed.

  15. Program Prepares Students for Chemical-Processing Careers

    ERIC Educational Resources Information Center

    Jorgensen, Haley

    2005-01-01

    This article describes a chemical-processing program at Saginaw Career Complex in Saginaw, Michigan. The program is preparing 42 11th- and 12th-graders to work as chemical-processing operators or technicians by the time they graduate from high school. It was developed in partnership with the Saginaw Career Complex--one of 51 centers in the state…

  16. Chemical process safety management within the Department of Energy

    SciTech Connect

    Piatt, J.A.

    1995-07-01

    Although the Department of Energy (DOE) is not well known for its chemical processing activities, the DOE does have a variety of chemical processes covered under OSHA`s Rule for Process Safety Management of Highly Hazardous Chemicals (the PSM Standard). DOE, like industry, is obligated to comply with the PSM Standard. The shift in the mission of DOE away from defense programs toward environmental restoration and waste management has affected these newly forming process safety management programs within DOE. This paper describes the progress made in implementing effective process safety management programs required by the PSM Standard and discusses some of the trends that have supported efforts to reduce chemical process risks within the DOE. In June of 1994, a survey of chemicals exceeding OSHA PSM or EPA Risk Management Program threshold quantities (TQs) at DOE sites found that there were 22 processes that utilized toxic or reactive chemicals over TQs; there were 13 processes involving flammable gases and liquids over TQs; and explosives manufacturing occurred at 4 sites. Examination of the survey results showed that 12 of the 22 processes involving toxic chemicals involved the use of chlorine for water treatment systems. The processes involving flammable gases and liquids were located at the Strategic Petroleum Reserve and Naval petroleum Reserve sites.

  17. Practical Multimedia Courseware Design for Learner's Difficulties in Chemical Education.

    ERIC Educational Resources Information Center

    Tsoi, Mun Fie; Goh, Ngoh Khang; Chia, Lian Sai

    The designing of multimedia chemistry courseware is a complex and challenging task for many instructional developers and writers especially in the initial stage of the prototype to be developed. As such, this paper provides insights gained into some practical design considerations in developing a multimedia courseware in chemical education at…

  18. News: Good chemical manufacturing process criteria

    EPA Science Inventory

    This news column covers topics relating to manufacturing criteria, machine to machine technology, novel process windows, green chemistry indices, business resilience, immobilized enzymes, and Bt crops.

  19. Conversion of lignocellulosic biomass to nanocellulose: structure and chemical process.

    PubMed

    Lee, H V; Hamid, S B A; Zain, S K

    2014-01-01

    Lignocellulosic biomass is a complex biopolymer that is primary composed of cellulose, hemicellulose, and lignin. The presence of cellulose in biomass is able to depolymerise into nanodimension biomaterial, with exceptional mechanical properties for biocomposites, pharmaceutical carriers, and electronic substrate's application. However, the entangled biomass ultrastructure consists of inherent properties, such as strong lignin layers, low cellulose accessibility to chemicals, and high cellulose crystallinity, which inhibit the digestibility of the biomass for cellulose extraction. This situation offers both challenges and promises for the biomass biorefinery development to utilize the cellulose from lignocellulosic biomass. Thus, multistep biorefinery processes are necessary to ensure the deconstruction of noncellulosic content in lignocellulosic biomass, while maintaining cellulose product for further hydrolysis into nanocellulose material. In this review, we discuss the molecular structure basis for biomass recalcitrance, reengineering process of lignocellulosic biomass into nanocellulose via chemical, and novel catalytic approaches. Furthermore, review on catalyst design to overcome key barriers regarding the natural resistance of biomass will be presented herein. PMID:25247208

  20. Conversion of Lignocellulosic Biomass to Nanocellulose: Structure and Chemical Process

    PubMed Central

    Lee, H. V.; Hamid, S. B. A.; Zain, S. K.

    2014-01-01

    Lignocellulosic biomass is a complex biopolymer that is primary composed of cellulose, hemicellulose, and lignin. The presence of cellulose in biomass is able to depolymerise into nanodimension biomaterial, with exceptional mechanical properties for biocomposites, pharmaceutical carriers, and electronic substrate's application. However, the entangled biomass ultrastructure consists of inherent properties, such as strong lignin layers, low cellulose accessibility to chemicals, and high cellulose crystallinity, which inhibit the digestibility of the biomass for cellulose extraction. This situation offers both challenges and promises for the biomass biorefinery development to utilize the cellulose from lignocellulosic biomass. Thus, multistep biorefinery processes are necessary to ensure the deconstruction of noncellulosic content in lignocellulosic biomass, while maintaining cellulose product for further hydrolysis into nanocellulose material. In this review, we discuss the molecular structure basis for biomass recalcitrance, reengineering process of lignocellulosic biomass into nanocellulose via chemical, and novel catalytic approaches. Furthermore, review on catalyst design to overcome key barriers regarding the natural resistance of biomass will be presented herein. PMID:25247208

  1. Incorporating Risk Assessment and Inherently Safer Design Practices into Chemical Engineering Education

    ERIC Educational Resources Information Center

    Seay, Jeffrey R.; Eden, Mario R.

    2008-01-01

    This paper introduces, via case study example, the benefit of including risk assessment methodology and inherently safer design practices into the curriculum for chemical engineering students. This work illustrates how these tools can be applied during the earliest stages of conceptual process design. The impacts of decisions made during…

  2. Chemical Sensing for Buried Landmines - Fundamental Processes Influencing Trace Chemical Detection

    SciTech Connect

    PHELAN, JAMES M.

    2002-05-01

    Mine detection dogs have a demonstrated capability to locate hidden objects by trace chemical detection. Because of this capability, demining activities frequently employ mine detection dogs to locate individual buried landmines or for area reduction. The conditions appropriate for use of mine detection dogs are only beginning to emerge through diligent research that combines dog selection/training, the environmental conditions that impact landmine signature chemical vapors, and vapor sensing performance capability and reliability. This report seeks to address the fundamental soil-chemical interactions, driven by local weather history, that influence the availability of chemical for trace chemical detection. The processes evaluated include: landmine chemical emissions to the soil, chemical distribution in soils, chemical degradation in soils, and weather and chemical transport in soils. Simulation modeling is presented as a method to evaluate the complex interdependencies among these various processes and to establish conditions appropriate for trace chemical detection. Results from chemical analyses on soil samples obtained adjacent to landmines are presented and demonstrate the ultra-trace nature of these residues. Lastly, initial measurements of the vapor sensing performance of mine detection dogs demonstrates the extreme sensitivity of dogs in sensing landmine signature chemicals; however, reliability at these ultra-trace vapor concentrations still needs to be determined. Through this compilation, additional work is suggested that will fill in data gaps to improve the utility of trace chemical detection.

  3. Reinventing The Design Process: Teams and Models

    NASA Technical Reports Server (NTRS)

    Wall, Stephen D.

    1999-01-01

    The future of space mission designing will be dramatically different from the past. Formerly, performance-driven paradigms emphasized data return with cost and schedule being secondary issues. Now and in the future, costs are capped and schedules fixed-these two variables must be treated as independent in the design process. Accordingly, JPL has redesigned its design process. At the conceptual level, design times have been reduced by properly defining the required design depth, improving the linkages between tools, and managing team dynamics. In implementation-phase design, system requirements will be held in crosscutting models, linked to subsystem design tools through a central database that captures the design and supplies needed configuration management and control. Mission goals will then be captured in timelining software that drives the models, testing their capability to execute the goals. Metrics are used to measure and control both processes and to ensure that design parameters converge through the design process within schedule constraints. This methodology manages margins controlled by acceptable risk levels. Thus, teams can evolve risk tolerance (and cost) as they would any engineering parameter. This new approach allows more design freedom for a longer time, which tends to encourage revolutionary and unexpected improvements in design.

  4. Process Design Manual for Nitrogen Control.

    ERIC Educational Resources Information Center

    Parker, Denny S.; And Others

    This manual presents theoretical and process design criteria for the implementation of nitrogen control technology in municipal wastewater treatment facilities. Design concepts are emphasized through examination of data from full-scale and pilot installations. Design data are included on biological nitrification and denitrification, breakpoint…

  5. Profit opportunities for the chemical process industries

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Papers given at a seminar designed to assist industry in the utilization of NASA-developed technology are presented. The topics include the following: the Technology Utilization program, NASA patent policy changes, transfer of Hysttl resin technology, nonflammable cellulosic materials development, nonflammable paper technology, circuit board laminates and construction, polymide resins and other polymers, and intumescent coatings.

  6. Chemical and biological processes of evaporation ponds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural evaporation ponds are designed to impound and dissipate saline agricultural drainage water in areas with no opportunities for offsite disposal in the San Joaquin Valley of California. This paper reviews and summarizes research findings on the pond chemistry. Drainage waters in these pon...

  7. Laser/plasma chemical processing of substrates

    DOEpatents

    Gee, James M.; Hargis, Jr., Philip J.

    1986-01-01

    A process for the modification of substrate surfaces is described, wherein etching or deposition at a surface occurs only in the presence of both reactive species and a directed beam of coherent light.

  8. Water in Biological and Chemical Processes

    NASA Astrophysics Data System (ADS)

    Bagchi, Biman

    2013-11-01

    Part I. Bulk Water: 1. Uniqueness of water; 2. Anomalies of water; 3. Dynamics of water: molecular motions and hydrogen bond breaking kinetics; 4. Inherent structures of liquid water; 5. pH of water; Part II. Water in Biology: Dynamical View and Function: 6. Biological water; 7. Explicit role of water in biological functions; 8. Hydration of proteins; 9. Can we understand protein hydration layer: lessons from computer simulations; 10. Water in and around DNA and RNA; 11. Role of water in protein-DNA interaction; 12. Water surrounding lipid bilayers; 13. Water in Darwin's world; Part III. Water in Complex Chemical Systems: 14. Hydrophilic effects; 15. Hydrophobic effects; 16. Aqueous binary mixtures: amphiphilic effect; 17. Water in and around micelles, reverse micelles and microemulsions; 18. Water in carbon nanotubes; Part IV. Bulk Water: Advanced Topics: 19. Entropy of water; 20. Freezing of water into ice; 21. Supercritical water; 22. Microscopic approaches to understand water anomalies.

  9. Hydrocarbon Processing`s process design and optimization `96

    SciTech Connect

    1996-06-01

    This paper compiles information on hydrocarbon processes, describing the application, objective, economics, commercial installations, and licensor. Processes include: alkylation, ammonia, catalytic reformer, crude fractionator, crude unit, vacuum unit, dehydration, delayed coker, distillation, ethylene furnace, FCCU, polymerization, gas sweetening, hydrocracking, hydrogen, hydrotreating (naphtha, distillate, and resid desulfurization), natural gas processing, olefins, polyethylene terephthalate, refinery, styrene, sulfur recovery, and VCM furnace.

  10. Chemical surface modification of fluorocarbon polymers by excimer laser processing

    NASA Astrophysics Data System (ADS)

    Niino, Hiroyuki; Yabe, Akira

    1996-04-01

    Surface of poly(tetrafluoroethylene) [PTFE] film was modified chemically by an ArF excimer laser-induced reaction in a hydrazine gas atmosphere. The polymer surface modified upon the irradiation of 1000 pulses at 27 mJ cm -2, which was a fairly lower fluence than the ablation threshold for usual polymer films, showed hydrophilicity (contact angle for water: 30°) enough to be metallized by chemical plating. The mechanism for chemical surface modification was investigated by FTIR, XPS, and SIMS analyses. The laser-treated PTFE film was metallized by a chemical plating process. These processes will be used to fabricate printed wiring boards for high frequency electronics.

  11. Process for controlling accidents in chemical laboratories

    SciTech Connect

    Delvin, W.L.

    1980-10-01

    Most laboratory safety programs include inspections to identify hazards and thereby control accidents. There are certain elements that must be a part of a successful inspection and control process. These are a systematic and consistent inspection procedure, a reliable evaluation of identified hazards, and effective follow-up actions. Laboratory management, through its responsibility for the total system, has a key role in the inspection and control process for follow-up actions and accepting risks. If any of the above requirements are missing, the process will be less than adequate. Understanding the relationship between accidents, hazards, and risks is important in establishing an effective inspection and control program. Hazards are potential sources of accidents (accidents waiting to happen). Associated with each is a risk, which has two components: probability and consequence. Probability refers to the likelihood that a hazard will turn into an accident and consequence is the result of such an accident. In assessing the seriousness of a hazard, both probability and consequence must be considered in terms of risk level and acceptability. This paper presents a process that can be used by laboratory management to establish an effective inspection and control program for the laboratory. A discussion of safety concepts and their relationships that affect the process is included.

  12. 32nm design rule and process exploration flow

    NASA Astrophysics Data System (ADS)

    Zhang, Yunqiang; Cobb, Jonathan; Yang, Amy; Li, Ji; Lucas, Kevin; Sethi, Satyendra

    2008-10-01

    Semiconductor manufacturers spend hundreds of millions of dollars and years of development time to create a new manufacturing process and to design frontrunner products to work on the new process. A considerable percentage of this large investment is aimed at producing the process design rules and related lithography technology to pattern the new products successfully. Significant additional cost and time is needed in both process and design development if the design rules or lithography strategy must be modified. Therefore, early and accurate prediction of both process design rules and lithography options is necessary for minimizing cost and timing in semiconductor development. This paper describes a methodology to determine the optimum design rules and lithography conditions with high accuracy early in the development lifecycle. We present results from the 32nm logic node but the methodology can be extended to the 22nm node or any other node. This work involves: automated generation of extended realistic logic test layouts utilizing programmed teststructures for a variety of design rules; determining a range of optical illumination and process conditions to test for each critical design layer; using these illumination conditions to create a extrapolatable process window OPC model which is matched to rigorous TCAD lithography focus-exposure full chemically amplified resist models; creating reticle enhancement technique (RET) recipes which are flexible enough to be used over a variety of design rule and illumination conditions; OPC recipes which are flexible enough to be used over a variety of design rule and illumination conditions; and OPC verification to find, categorize and report all patterning issues found in the different design and illumination variations. In this work we describe in detail the individual steps in the methodology, and provide results of its use for 32nm node design rule and process optimization.

  13. Chemical mass transfer in magmatic processes

    NASA Astrophysics Data System (ADS)

    Ghiorso, Mark S.

    1987-07-01

    Lasaga's (1982) Master Equation for crystal growth is solved for multicomponent systems in situations which allow for coupled diffusion of melt species. The structure of the solution is explored in some detail for the case of a constant diffusion coefficient matrix. Incorporating these results, the growth of plagioclase is modeled in undercooled tholeiitic melts by approximating interface growth rates with (1) a reduced growth rate function and with (2) calculated solid-liquid solution properties obtained from the silicate liquid solution model of Ghiorso et al. (1983; appendix of Ghiorso 1985). For this purpose algorithms are provided for estimating the liquidus temperature or the chemical affinity of a multicomponent solid solution precipitating from a complex melt of specified bulk composition. Compositional trends in initial solids produced by successive degrees of undercooling are opposite to those predicted in the binary system NaAlSi3O8-CaAl2Si2O8. Calculations suggest that the solid phase and interface melt compositions rapidly approach a “steady state” for a given degree of undercooling. Consequently, the overall isothermal growth rate of plagioclase forming from tholeiitic melts appears to be entirely diffusion controlled. In magmatic systems the multicomponent growth equations allow for the formation of oscillatory zoned crystals as a consequence of the “couplingr” between interface reaction kinetics and melt diffusion. The magnitude of this effect is largely dependent upon the asymmetry of the diffusion coefficient matrix. Methods are described to facilitate the calibration of diffusion matrices from experimental data on multicomponent penetration curves. Experimental results (Lesher and Walker 1986) on steady state Soret concentration profiles resulting from thermal diffusion in MORB and andesitic liquids are analyzed using the theory of multicomponent linear irreversible thermodynamics. Under conditions where the entropy production is

  14. Dynamic displays of chemical process flowsheet models

    SciTech Connect

    Aull, J.E.

    1996-11-01

    This paper describes the algorithms used in constructing dynamic graphical displays of a process flowsheet. Movies are created which portray changes in the process over time using animation in the flowsheet such as individual streams that take on a color keyed to the current flow rate, tank levels that visibly rise and fall and {open_quotes}gauges{close_quotes} that move to display parameter values. Movies of this type can be a valuable tool for visualizing, analyzing, and communicating the behavior of a process model. This paper describes the algorithms used in constructing displays of this kind for dynamic models using the SPEEDUP{trademark} modeling package and the GMS{trademark} graphics package. It also tells how data is exported from the SPEEDUP{trademark} package to GMS{trademark} and describes how a user environment for running movies and editing flowsheets is set up. The algorithms are general enough to be applied to other processes and graphics packages. In fact the techniques described here can be used to create movies of any time-dependent data.

  15. (New process modeling, design and control strategies for energy efficiency, high product quality and improved productivity in the process industries)

    SciTech Connect

    Not Available

    1991-01-01

    Highlights are reported of work to date on: resilient design and control of chemical reactors (polymerization, packed bed), operation of complex processing systems (compensators for multivariable systems with delays and Right Half Plane zeroes, process identification and controller design for multivariable systems, nonlinear systems control, distributed parameter systems), and computer-aided design software (CONSYD, POLYRED, expert systems). 15 figs, 54 refs. (DLC)

  16. [New process modeling, design and control strategies for energy efficiency, high product quality and improved productivity in the process industries

    SciTech Connect

    Not Available

    1991-12-31

    Highlights are reported of work to date on: resilient design and control of chemical reactors (polymerization, packed bed), operation of complex processing systems (compensators for multivariable systems with delays and Right Half Plane zeroes, process identification and controller design for multivariable systems, nonlinear systems control, distributed parameter systems), and computer-aided design software (CONSYD, POLYRED, expert systems). 15 figs, 54 refs. (DLC)

  17. Chemical processing in geothermal nuclear chimney

    DOEpatents

    Krikorian, O.H.

    1973-10-01

    A closed rubble filled nuclear chimney is provided in a subterranean geothermal formation by detonation of a nuclear explosive device therein, with reagent input and product output conduits connecting the chimney cavity with appropriate surface facilities. Such facilities will usually comprise reagent preparation, product recovery and recycle facilities. Proccsses are then conducted in the nuclear chimney which processes are facilitated by temperature, pressure, catalytic and other conditions existent or which are otherwise provided in the nuclear chimney. (auth)

  18. Sustainability Indicators for Chemical Processes: III. Biodiesel Case Study

    EPA Science Inventory

    The chemical industry is one of the most important business sectors, not only economically, but also societally; as it allows humanity to attain higher standards and quality of life. Simultaneously, chemical products and processes can be the origin of potential human health and ...

  19. Evaluation of Chemical Coating Processes for AXAF

    NASA Technical Reports Server (NTRS)

    Engelhaupt, Darell; Ramsey, Brian; Mendrek, Mitchell

    1998-01-01

    The need existed at MSFC for the development and fabrication of radioisotope calibration sources of cadmium 109 and iron 55 isotopes. This was in urgent response to the AXA-F program. Several issues persisted in creating manufacturing difficulties for the supplier. In order to meet the MSFC requirements very stringent control needed to be maintained for the coating quality, specific activity and thickness. Due to the difficulties in providing the precisely controlled devices for testing, the delivery of the sources was seriously delayed. It became imperative that these fabrication issues be resolved to avoid further delays in this AXA-F observatory key component. The objectives are: 1) Research and provide expert advice on coating materials and procedures. 2) Research and recommend solutions to problems that have been experienced with the coating process. 3) Provide recommendations on the selection and preparation of substrates. 4) Provide consultation on the actual coating process including the results of the qualification and acceptance test programs. 5) Perform independent tests at UAH or MSFC as necessary.

  20. Engineering design: A cognitive process approach

    NASA Astrophysics Data System (ADS)

    Strimel, Greg Joseph

    The intent of this dissertation was to identify the cognitive processes used by advanced pre-engineering students to solve complex engineering design problems. Students in technology and engineering education classrooms are often taught to use an ideal engineering design process that has been generated mostly by educators and curriculum developers. However, the review of literature showed that it is unclear as to how advanced pre-engineering students cognitively navigate solving a complex and multifaceted problem from beginning to end. Additionally, it was unclear how a student thinks and acts throughout their design process and how this affects the viability of their solution. Therefore, Research Objective 1 was to identify the fundamental cognitive processes students use to design, construct, and evaluate operational solutions to engineering design problems. Research Objective 2 was to determine identifiers within student cognitive processes for monitoring aptitude to successfully design, construct, and evaluate technological solutions. Lastly, Research Objective 3 was to create a conceptual technological and engineering problem-solving model integrating student cognitive processes for the improved development of problem-solving abilities. The methodology of this study included multiple forms of data collection. The participants were first given a survey to determine their prior experience with engineering and to provide a description of the subjects being studied. The participants were then presented an engineering design challenge to solve individually. While they completed the challenge, the participants verbalized their thoughts using an established "think aloud" method. These verbalizations were captured along with participant observational recordings using point-of-view camera technology. Additionally, the participant design journals, design artifacts, solution effectiveness data, and teacher evaluations were collected for analysis to help achieve the

  1. Chemical Processing monthly report, April 1985

    NASA Astrophysics Data System (ADS)

    1985-04-01

    In the PUREX/UO3 operations, 151 tones of N reactor fuel were charged to the PUREX dissolvers in April 1985, bringing the Fiscal Year-to-Date (FYTD) total to 667, which is now only 61 tones behind the 1200 tone recovery plan. One hundred thirty-nine tonnes of UO3 were shipped to the Feed Materials Production Center (FMPC), bringing the FYTD total to 644 tones. Twenty-two percent of the PUO2 shipments were achieved, bringing the cumulative shipments to 52%. In the plutonium finishing (PF) plant/nuclear materials management program, 10% of plutonium nitrate was loaded out. Total Operating Efficiency for Plutonium Reclamation Facility (PRF) was 53% for the month, compared to a goal of 70%. Remote Mechanical C (RMC) metal line reactivation activities are 95% complete. Terminal clean out operations are about one month behind schedule, due to diversion of personnel to the RMC reactivation effort. Within the area of decontamination and decommissioning activities, removal of the Sorter/Chopper hood in 232-Z Building was completed. Design on B-339, vault safety and inventory system was completed on schedule.

  2. Post cleaning of chemical mechanical polishing process

    NASA Astrophysics Data System (ADS)

    Liu, Chi-Wen; Dai, Bau-Tong; Yeh, Ching-Fa

    1996-02-01

    We describe a study on the effect of the electrostatic nature in silica particles on the post CMP cleaning behavior. A fall-off for the zeta potential of silica particles is observed as the pH of dip solutions is increased. In this study, we also observed that particle counts on the SiO 2 and the Si 3N 4 dielectric films had a similar dependence on the pH. Furthermore, we confirmed that surface hardness of the wafer is an important factor for particles physically embedded in different dielectric materials during and after the CMP process. The nanoscale surface hardness of dielectric films was measured by the nanoindentation technique. Experimental results showed that particles had difficulty attaching to a harder surface of the dielectric film.

  3. DIOXINS. VOLUME III. ASSESSMENT OF DIOXIN-FORMING CHEMICAL PROCESSES

    EPA Science Inventory

    Chemical reaction mechanisms by which dioxins may be formed are reviewed, particularly those likely to occur within commercially significant processes. Various routes of formation are identified in addition to the classical route of the hydrolysis of trichlorophenol. Basic organi...

  4. Chemical etching for automatic processing of integrated circuits

    NASA Technical Reports Server (NTRS)

    Kennedy, B. W.

    1981-01-01

    Chemical etching for automatic processing of integrated circuits is discussed. The wafer carrier and loading from a receiving air track into automatic furnaces and unloading onto a sending air track are included.

  5. 64. SOUTH PLANT PROCESS PIPING, CHEMICAL STORAGE TANKS AND BUILDINGS. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    64. SOUTH PLANT PROCESS PIPING, CHEMICAL STORAGE TANKS AND BUILDINGS. VIEW TO NORTHEAST. - Rocky Mountain Arsenal, Bounded by Ninety-sixth Avenue & Fifty-sixth Avenue, Buckley Road, Quebec Street & Colorado Highway 2, Commerce City, Adams County, CO

  6. 2. OVERHEAD CHEMICAL PROCESS PIPING BETWEEN BUILDINGS 422, ON RIGHT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. OVERHEAD CHEMICAL PROCESS PIPING BETWEEN BUILDINGS 422, ON RIGHT, AND 431, ON LEFT. - Rocky Mountain Arsenal, Crude Mustard & Aldrin Manufacturing, 1200 feet South of December Seventh Avenue; 600 feet East of D Street, Commerce City, Adams County, CO

  7. SCREENING PROTOCOL FOR ASSESSING TOXICITY OF ORGANIC CHEMICALS TOANAEROBIC PROCESSES

    EPA Science Inventory

    A screening protocol has been developed to provide a rapid andrepeatable assessment of the effect of toxic organic chemicals onanaerobic treatment processes. his protocol also providesinformation on the rate limiting biological reactions and theconcentrations at which changes in ...

  8. Priorities in the design of chemical shops at coke plants

    SciTech Connect

    V.I. Rudyka; Y.E. Zingerman; V.V. Grabko; L.A. Kazak

    2009-07-15

    Recent trends in the design of chemical equipment at coke plants are described, through the lens of experience at Giprokoks. The main priorities were to improve the removal of impurities from coke oven gas; to improve equipment design on the basis of new materials; to reduce reagent consumption; to reduce the materials and energy consumed in the construction of new equipment; and to minimize impacts on the environment and worker health. Some technological equipment is briefly characterized.

  9. Numerical simulations supporting the process design of ring rolling processes

    NASA Astrophysics Data System (ADS)

    Jenkouk, V.; Hirt, G.; Seitz, J.

    2013-05-01

    In conventional Finite Element Analysis (FEA) of radial-axial ring rolling (RAR) the motions of all tools are usually defined prior to simulation in the preprocessing step. However, the real process holds up to 8 degrees of freedom (DOF) that are controlled by industrial control systems according to actual sensor values and preselected control strategies. Since the histories of the motions are unknown before the experiment and are dependent on sensor data, the conventional FEA cannot represent the process before experiment. In order to enable the usage of FEA in the process design stage, this approach integrates the industrially applied control algorithms of the real process including all relevant sensors and actuators into the FE model of ring rolling. Additionally, the process design of a novel process 'the axial profiling', in which a profiled roll is used for rolling axially profiled rings, is supported by FEA. Using this approach suitable control strategies can be tested in virtual environment before processing.

  10. The Engineering Process in Construction & Design

    ERIC Educational Resources Information Center

    Stoner, Melissa A.; Stuby, Kristin T.; Szczepanski, Susan

    2013-01-01

    Recent research suggests that high-impact activities in science and math classes promote positive attitudinal shifts in students. By implementing high-impact activities, such as designing a school and a skate park, mathematical thinking can be linked to the engineering design process. This hands-on approach, when possible, to demonstrate or…

  11. Distributed Group Design Process: Lessons Learned.

    ERIC Educational Resources Information Center

    Eseryel, Deniz; Ganesan, Radha

    A typical Web-based training development team consists of a project manager, an instructional designer, a subject-matter expert, a graphic artist, and a Web programmer. The typical scenario involves team members working together in the same setting during the entire design and development process. What happens when the team is distributed, that is…

  12. Identifying and designing chemicals with minimal acute aquatic toxicity

    PubMed Central

    Kostal, Jakub; Voutchkova-Kostal, Adelina; Anastas, Paul T.; Zimmerman, Julie Beth

    2015-01-01

    Industrial ecology has revolutionized our understanding of material stocks and flows in our economy and society. For this important discipline to have even deeper impact, we must understand the inherent nature of these materials in terms of human health and the environment. This paper focuses on methods to design synthetic chemicals to reduce their intrinsic ability to cause adverse consequence to the biosphere. Advances in the fields of computational chemistry and molecular toxicology in recent decades allow the development of predictive models that inform the design of molecules with reduced potential to be toxic to humans or the environment. The approach presented herein builds on the important work in quantitative structure–activity relationships by linking toxicological and chemical mechanistic insights to the identification of critical physical–chemical properties needed to be modified. This in silico approach yields design guidelines using boundary values for physiochemical properties. Acute aquatic toxicity serves as a model endpoint in this study. Defining value ranges for properties related to bioavailability and reactivity eliminates 99% of the chemicals in the highest concern for acute aquatic toxicity category. This approach and its future implementations are expected to yield very powerful tools for life cycle assessment practitioners and molecular designers that allow rapid assessment of multiple environmental and human health endpoints and inform modifications to minimize hazard. PMID:24639521

  13. Chemical Processes and Thresholds in Hawaiin Soils

    NASA Astrophysics Data System (ADS)

    Chadwick, O.

    2007-12-01

    The Hawaiian Islands are a useful natural laboratory for studying soil development particularly those that can be understood using a matrix of chonosequences and climosequences. The islands are formed over a stationary mantle plume and then are carried to the northwest on the Pacific Plate. Thus the islands get older with distance from the hotspot; Kauai has remnant shield surfaces whose lavas date to about 4,000 ky. It is possible to sample soils that are developing on different age flows ranging from a few hundred years to a few million years. Additionally, individual volcanoes are impacted by differing amounts of rainfall depending on location with respect to the northeasterly trade winds. Whereas rainfall over the open ocean near Hawaii is about 700 mm, rainfall over the Islands ranges from 150 to 11,000 mm. Hawaii is minimally impacted by mineral aerosol additions compared to continental areas and this has a significant impact on soil development. More than 100 soil profiles have been sampled along the Hawaii time-climate matrix with some surprising results. For example, in arid soils might be expected to develop smectite clays, but they are rich in halloysite and allophane. Importantly, these same soils show a trend from high-Mg calcite to dolomite as carbonates accumulate within the profiles - this is one of the first documented occurrences of pedogenic dolomite that is not associated with high levels of salts. It appears that lack of smectite formation lowers the incorporation of Mg into silicate clays and increases its incorporation into carbonates. This is an unusual pedogenic process that seems to be enhanced by the lack of substantial amounts of mica in the basalt derived soils. The only mica is in surface horizons that receive dust derived from distant continents. Without mica there is no template to allow smectite clay formation under the rapid wetting and drying regimes encountered in the arid soils. At the same time that halloysite is forming, iron

  14. Some aspects of mathematical and chemical modeling of complex chemical processes

    NASA Technical Reports Server (NTRS)

    Nemes, I.; Botar, L.; Danoczy, E.; Vidoczy, T.; Gal, D.

    1983-01-01

    Some theoretical questions involved in the mathematical modeling of the kinetics of complex chemical process are discussed. The analysis is carried out for the homogeneous oxidation of ethylbenzene in the liquid phase. Particular attention is given to the determination of the general characteristics of chemical systems from an analysis of mathematical models developed on the basis of linear algebra.

  15. Microlenses with focal length controlled by chemical processes

    NASA Astrophysics Data System (ADS)

    Muric, B. D.; Panic, B. M.

    2012-05-01

    The influence of chemical processing on the optical properties of microlenses formed on a gelatin-sensitized layer was investigated. The gelatin is sensitized with tot'hema and eosin, irradiated with a Gaussian profile laser beam and subsequently chemically processed. Microlenses with a focal length of 400 μm were obtained after alcohol processing. Additionally, focal lengths could be controlled by varying the alum concentration, and lenses with focal length up to 1.2 mm were obtained. The microlenses become stable after alum processing. Their optical properties remain unchanged.

  16. Chemical processing and shampooing impact cortisol measured in human hair

    PubMed Central

    Hoffman, M. Camille; Karban, Laura V.; Benitez, Patrick; Goodteacher, Angela; Laudenslager, Mark L.

    2015-01-01

    Purpose The assessment of cortisol in hair has gained popularity as a means to measure retrospective hypothalamic-pituitary-adrenal activity in a number of species; however, cortisol levels from human hair subjected to typical chemicals for cosmetic or hygienic purposes may be altered by the chemicals used. The purposed of this study was to determine if exposure of hair to chemical processing or shampooing impacts cortisol values. Methods Human hair not exposed to prior chemical processing was cut from the posterior vertex region of the head of 106 human subjects as close to the scalp as possible. The hair sample was divided into 4-6 full-length clusters depending on quantity of hair available. Each hair sample was processed for baseline (native) cortisol and remaining clusters were exposed to five standard chemical hair treatments (Experiment 1) or were shampooed 15 or 30 times (Experiment 2). Hair was ground and cortisol levels were determined by enzyme immunoassay (EIA). Comparisons were made between native hair and processed hair using paired t-tests and Pearson correlation. Results Hair cortisol as assessed by EIA was significantly altered by chemical processing but in somewhat different ways. Exposure to bleach (harshest exposure), demi-perm (least exposure) or 15-30 shampoos resulted in a significant decrease in cortisol level while exposure to varying percentages of peroxides increased cortisol measured. There were no differences in cortisol levels associated with sex, age or tobacco use in the native hair for this particular group. Conclusion Chemical processing and frequent shampooing affect cortisol levels measured in hair. Chemically processed or excessively shampooed hair should be avoided when recruiting subjects for hair cortisol studies. PMID:25090265

  17. Poly(ADP-ribose): From chemical synthesis to drug design.

    PubMed

    Drenichev, Mikhail S; Mikhailov, Sergey N

    2016-08-01

    Poly(ADP-ribose) (PAR) is an important biopolymer, which is involved in various life processes such as DNA repair and replication, modulation of chromatin structure, transcription, cell differentiation, and in pathogenesis of various diseases such as cancer, diabetes, ischemia and inflammations. PAR is the most electronegative biopolymer and this property is essential for its binding with a wide range of proteins. Understanding of PAR functions in cell on molecular level requires chemical synthesis of regular PAR oligomers. Recently developed methodologies for chemical synthesis of PAR oligomers, will facilitate the study of various cellular processes, involving PAR. PMID:27318540

  18. HYNOL PROCESS ENGINEERING: PROCESS CONFIGURATION, SITE PLAN, AND EQUIPMENT DESIGN

    EPA Science Inventory

    The report describes the design of the hydropyrolysis reactor system of the Hynol process. (NOTE: A bench scale methanol production facility is being constructed to demonstrate the technical feasibility of producing methanol from biomass using the Hynol process. The plant is bein...

  19. De Novo Fragment Design for Drug Discovery and Chemical Biology.

    PubMed

    Rodrigues, Tiago; Reker, Daniel; Welin, Martin; Caldera, Michael; Brunner, Cyrill; Gabernet, Gisela; Schneider, Petra; Walse, Björn; Schneider, Gisbert

    2015-12-01

    Automated molecular de novo design led to the discovery of an innovative inhibitor of death-associated protein kinase 3 (DAPK3). An unprecedented crystal structure of the inactive DAPK3 homodimer shows the fragment-like hit bound to the ATP pocket. Target prediction software based on machine learning models correctly identified additional macromolecular targets of the computationally designed compound and the structurally related marketed drug azosemide. The study validates computational de novo design as a prime method for generating chemical probes and starting points for drug discovery. PMID:26486226

  20. Modeling operators' emergency response time for chemical processing operations.

    PubMed

    Murray, Susan L; Harputlu, Emrah; Mentzer, Ray A; Mannan, M Sam

    2014-01-01

    Operators have a crucial role during emergencies at a variety of facilities such as chemical processing plants. When an abnormality occurs in the production process, the operator often has limited time to either take corrective actions or evacuate before the situation becomes deadly. It is crucial that system designers and safety professionals can estimate the time required for a response before procedures and facilities are designed and operations are initiated. There are existing industrial engineering techniques to establish time standards for tasks performed at a normal working pace. However, it is reasonable to expect the time required to take action in emergency situations will be different than working at a normal production pace. It is possible that in an emergency, operators will act faster compared to a normal pace. It would be useful for system designers to be able to establish a time range for operators' response times for emergency situations. This article develops a modeling approach to estimate the time standard range for operators taking corrective actions or following evacuation procedures in emergency situations. This will aid engineers and managers in establishing time requirements for operators in emergency situations. The methodology used for this study combines a well-established industrial engineering technique for determining time requirements (predetermined time standard system) and adjustment coefficients for emergency situations developed by the authors. Numerous videos of workers performing well-established tasks at a maximum pace were studied. As an example, one of the tasks analyzed was pit crew workers changing tires as quickly as they could during a race. The operations in these videos were decomposed into basic, fundamental motions (such as walking, reaching for a tool, and bending over) by studying the videos frame by frame. A comparison analysis was then performed between the emergency pace and the normal working pace operations

  1. Planar Inlet Design and Analysis Process (PINDAP)

    NASA Technical Reports Server (NTRS)

    Slater, John W.; Gruber, Christopher R.

    2005-01-01

    The Planar Inlet Design and Analysis Process (PINDAP) is a collection of software tools that allow the efficient aerodynamic design and analysis of planar (two-dimensional and axisymmetric) inlets. The aerodynamic analysis is performed using the Wind-US computational fluid dynamics (CFD) program. A major element in PINDAP is a Fortran 90 code named PINDAP that can establish the parametric design of the inlet and efficiently model the geometry and generate the grid for CFD analysis with design changes to those parameters. The use of PINDAP is demonstrated for subsonic, supersonic, and hypersonic inlets.

  2. National toxicology program chemical nomination and selection process

    SciTech Connect

    Selkirk, J.K.

    1990-12-31

    The National Toxicology Program (NTP) was organized to support national public health programs by initiating research designed to understand the physiological, metabolic, and genetic basis for chemical toxicity. The primary mandated responsibilities of NTP were in vivo and vitro toxicity testing of potentially hazardous chemicals; broadening the spectrum of toxicological information on known hazardous chemicals; validating current toxicological assay systems as well as developing new and innovative toxicity testing technology; and rapidly communicating test results to government agencies with regulatory responsibilities and to the medical and scientific communities. 2 figs.

  3. Considerations for designing chemical screening strategies in plant biology

    PubMed Central

    Serrano, Mario; Kombrink, Erich; Meesters, Christian

    2015-01-01

    Traditionally, biologists regularly used classical genetic approaches to characterize and dissect plant processes. However, this strategy is often impaired by redundancy, lethality or pleiotropy of gene functions, which prevent the isolation of viable mutants. The chemical genetic approach has been recognized as an alternative experimental strategy, which has the potential to circumvent these problems. It relies on the capacity of small molecules to modify biological processes by specific binding to protein target(s), thereby conditionally modifying protein function(s), which phenotypically resemble mutation(s) of the encoding gene(s). A successful chemical screening campaign comprises three equally important elements: (1) a reliable, robust, and quantitative bioassay, which allows to distinguish between potent and less potent compounds, (2) a rigorous validation process for candidate compounds to establish their selectivity, and (3) an experimental strategy for elucidating a compound's mode of action and molecular target. In this review we will discuss details of this general strategy and additional aspects that deserve consideration in order to take full advantage of the power provided by the chemical approach to plant biology. In addition, we will highlight some success stories of recent chemical screenings in plant systems, which may serve as teaching examples for the implementation of future chemical biology projects. PMID:25904921

  4. Sealed-bladdered chemical processing method and apparatus

    DOEpatents

    Harless, D. Phillip

    1999-01-01

    A method and apparatus which enables a complete multi-stepped chemical treatment process to occur within a single, sealed-bladdered vessel 31. The entire chemical process occurs without interruption of the sealed-bladdered vessel 31 such as opening the sealed-bladdered vessel 31 between various steps of the process. The sealed-bladdered vessel 31 is loaded with a batch to be dissolved, treated, decanted, rinsed and/or dried. A pressure filtration step may also occur. The self-contained chemical processing apparatus 32 contains a sealed-bladder 32, a fluid pump 34, a reservoir 20, a compressed gas inlet, a vacuum pump 24, and a cold trap 23 as well as the associated piping 33, numerous valves 21,22,25,26,29,30,35,36 and other controls associated with such an apparatus. The claimed invention allows for dissolution and/or chemical treatment without the operator of the self-contained chemical processing apparatus 38 coming into contact with any of the process materials.

  5. Dust as interstellar catalyst. I. Quantifying the chemical desorption process

    NASA Astrophysics Data System (ADS)

    Minissale, M.; Dulieu, F.; Cazaux, S.; Hocuk, S.

    2016-01-01

    Context. The presence of dust in the interstellar medium has profound consequences on the chemical composition of regions where stars are forming. Recent observations show that many species formed onto dust are populating the gas phase, especially in cold environments where UV- and cosmic-ray-induced photons do not account for such processes. Aims: The aim of this paper is to understand and quantify the process that releases solid species into the gas phase, the so-called chemical desorption process, so that an explicit formula can be derived that can be included in astrochemical models. Methods: We present a collection of experimental results of more than ten reactive systems. For each reaction, different substrates such as oxidized graphite and compact amorphous water ice were used. We derived a formula for reproducing the efficiencies of the chemical desorption process that considers the equipartition of the energy of newly formed products, followed by classical bounce on the surface. In part II of this study we extend these results to astrophysical conditions. Results: The equipartition of energy correctly describes the chemical desorption process on bare surfaces. On icy surfaces, the chemical desorption process is much less efficient, and a better description of the interaction with the surface is still needed. Conclusions: We show that the mechanism that directly transforms solid species into gas phase species is efficient for many reactions.

  6. Resist roughness improvement by a chemical shrink process

    NASA Astrophysics Data System (ADS)

    Nagahara, Tatsuro; Sekito, Takashi; Matsuura, Yuriko

    2016-04-01

    In this paper, we will discuss the improvement of resist pattern roughness on NTD (Negative Tone Development) resist by chemical shrink process. Chemical shrink process is one of the most practical approaches to achieve small feature size CH (Contact Hole) or trench with ArF immersion lithography. We found that this shrink material has not only general benefits of shrink process like DOF (Depth of Focus) margin improvement, but also demonstrates a pattern smoothing effect through observation of the surface of shrink layer using SPM (Scanning Probe Microscope). Additionally, an improvement of LWR (Line Width Roughness) over 16% and an improvement of LCDU (Local Critical Dimension Uniformity) around 60% were observed.

  7. Chemical Changes in Carbohydrates Produced by Thermal Processing.

    ERIC Educational Resources Information Center

    Hoseney, R. Carl

    1984-01-01

    Discusses chemical changes that occur in the carbohydrates found in food products when these products are subjected to thermal processing. Topics considered include browning reactions, starch found in food systems, hydrolysis of carbohydrates, extrusion cooking, processing of cookies and candies, and alterations in gums. (JN)

  8. The National Toxicology Program chemical nomination selection and testing process.

    PubMed

    Heindel, J J

    1988-01-01

    The NTP is an interagency program of the Federal Government which coordinates toxicological programs at the NIH (NIEHS), FDA (NCTR), and CDC (NIOSH) with input from NCI, NIH, OSHA, CPSC, EPA, and ATSDR. The NTP has the capability to completely characterize the toxicologic profile of a chemical, including studies of chemical disposition, genetic toxicity, immunotoxicity, teratology, reproductive toxicity, carcinogenicity, neurotoxicity, and specific organ toxicity. The NTP encourages nominations of chemicals of human health concern from all sectors of the public, including industry, labor, and the general public. The specific process of nomination, evaluation, and selection of chemicals for testing by the NTP is described. It is a multicomponent system with several evaluations and a public peer review step to assure adequate consideration of all nominated chemicals. The results of NTP studies are all peer reviewed and available to the general public as well as to the scientific community. PMID:2980357

  9. Chemical industrial wastewater treated by combined biological and chemical oxidation process.

    PubMed

    Guomin, Cao; Guoping, Yang; Mei, Sheng; Yongjian, Wang

    2009-01-01

    Wastewaters from phenol and rubber synthesis were treated by the activated sludge process in a large-scale chemical factory in Shanghai, but the final effluent quality cannot conform with the local discharge limit without using river water for dilution. Therefore, this chemical factory had to upgrade its wastewater treatment plant. To fully use the present buildings and equipment during upgrading of the chemical factory's wastewater treatment plant and to save operation costs, a sequential biological pre-treatement, chemical oxidation, and biological post-treatment (or BCB for short) process had been proposed and investigated in a pilot trial. The pilot trial results showed that about 80% COD in the chemical wastewater could be removed through anoxic and aerobic degradation in the biological pre-treatement section, and the residual COD in the effluent of the biological pre-treatment section belongs to refractory chemicals which cannot be removed by the normal biological process. The refractory chemicals were partial oxidized using Fenton's reagent in the chemical oxidation section to improve their biodegradability; subsequently the wastewater was treated by the SBR process in the biological post-treatment section. The final effluent COD reached the first grade discharge limit (<100 mg l(-1)) of Chinese Notational Integrated Wastewater Discharge Standard (GB8978-1996) even if without using any dilution water. Compared with the original dilution and biological process, the operation cost of the BCB process increased by about 0.5 yuan (RMB) per cubic metre wastewater, but about 1,240,000 m(3) a(-1) dilution water could be saved and the COD emission could be cut down by 112 tonne each year. PMID:19273902

  10. Macrocell design for concurrent signal processing

    SciTech Connect

    Pope, S.P.; Brodersen, R.W.

    1983-01-01

    Macrocells serve as subsystems at the top level of the hardware design hierarchy. The authors present the macrocell design technique as applied to the implementation of real-time, sampled-data signal processing functions. The design of such circuits is particularly challenging due to the computationally intensive nature of signal-processing algorithms and the constraints of real-time operation. The most efficient designs make use of a high degree of concurrency-a property facilitated by the microcell approach. Two circuit projects whose development resulted largely from the macrocell methodology described are used as examples throughout the report: a linear-predictive vocoder circuit, and a front-end filter-bank chip for a speech recognition system. Both are monolithic multiprocessor implementations: the lpc vocoder circuit contains three processors, the filter-bank chip two processors. 10 references.

  11. Design of penicillin fermentation process simulation system

    NASA Astrophysics Data System (ADS)

    Qi, Xiaoyu; Yuan, Zhonghu; Qi, Xiaoxuan; Zhang, Wenqi

    2011-10-01

    Real-time monitoring for batch process attracts increasing attention. It can ensure safety and provide products with consistent quality. The design of simulation system of batch process fault diagnosis is of great significance. In this paper, penicillin fermentation, a typical non-linear, dynamic, multi-stage batch production process, is taken as the research object. A visual human-machine interactive simulation software system based on Windows operation system is developed. The simulation system can provide an effective platform for the research of batch process fault diagnosis.

  12. Interdisciplinary Learning for Chemical Engineering Students from Organic Chemistry Synthesis Lab to Reactor Design to Separation

    ERIC Educational Resources Information Center

    Armstrong, Matt; Comitz, Richard L.; Biaglow, Andrew; Lachance, Russ; Sloop, Joseph

    2008-01-01

    A novel approach to the Chemical Engineering curriculum sequence of courses at West Point enabled our students to experience a much more realistic design process, which more closely replicated a real world scenario. Students conduct the synthesis in the organic chemistry lab, then conduct computer modeling of the reaction with ChemCad and…

  13. DEVELOPMENT OF A CHEMICAL PROCESS MODELING ENVIRONMENT BASED ON CAPE-OPEN INTERFACE STANDARDS AND THE MICROSOFT .NET FRAMEWORK

    EPA Science Inventory

    Chemical process simulation has long been used as a design tool in the development of chemical plants, and has long been considered a means to evaluate different design options. With the advent of large scale computer networks and interface models for program components, it is po...

  14. Design principles of chemical penetration enhancers for transdermal drug delivery

    PubMed Central

    Karande, Pankaj; Jain, Amit; Ergun, Kaitlin; Kispersky, Vincent; Mitragotri, Samir

    2005-01-01

    Chemical penetration enhancers (CPEs) are present in a large number of transdermal, dermatological, and cosmetic products to aid dermal absorption of curatives and aesthetics. This wide spectrum of use is based on only a handful of molecules, the majority of which belong to three to four typical chemical functionalities, sporadically introduced as CPEs in the last 50 years. Using >100 CPEs representing several chemical functionalities, we report on the fundamental mechanisms that determine the barrier disruption potential of CPEs and skin safety in their presence. Fourier transform infrared spectroscopy studies revealed that regardless of their chemical make-up, CPEs perturb the skin barrier via extraction or fluidization of lipid bilayers. Irritation response of CPEs, on the other hand, correlated with the denaturation of stratum corneum proteins, making it feasible to use protein conformation changes to map CPE safety in vitro. Most interestingly, the understanding of underlying molecular forces responsible for CPE safety and potency reveals inherent constraints that limit CPE performance. Reengineering this knowledge back into molecular structure, we designed >300 potential CPEs. These molecules were screened in silico and subsequently tested in vitro for molecular delivery. These molecules significantly broaden the repertoire of CPEs that can aid the design of optimized transdermal, dermatological, and cosmetic formulations in the future. PMID:15774584

  15. Teaching sustainable design: A collaborative process

    SciTech Connect

    Theis, C.C.

    1997-12-31

    This paper describes a collaborative educational experience in the Schools of Architecture and Landscape Architecture at Louisiana State University. During the Fall Semester of 1996 an upper-level architectural design studio worked with a peer group of landscape architecture students on the design of a master plan for an environmentally sensitive residential development on Cat Island, a barrier island located approximately eight miles south of Gulfport, Mississippi. This paper presents the methodology and results of the project, describes the collaborative process, and assesses both the viability of the design solutions and the value of the educational experience.

  16. WATER AS A REACTION MEDIUM FOR CLEAN CHEMICAL PROCESSES.

    EPA Science Inventory

    Green chemistry is a rapid developing new field that provides us a pro-active avenue for the sustainable development of future science and technologies. When designed properly, clean chemical technology can be developed in water as a reaction media. The technologies generated f...

  17. Design of the HTGR for process heat applications

    SciTech Connect

    Vrable, D.L.; Quade, R.N.

    1980-05-01

    This paper discusses a design study of an advanced 842-MW(t) HTGR with a reactor outlet temperature of 850/sup 0/C (1562/sup 0/F), coupled with a chemical process whose product is hydrogen (or a mixture of hydrogen and carbon monoxide) generated by steam reforming of a light hydrocarbon mixture. This paper discusses the plant layout and design for the major components of the primary and secondary heat transfer systems. Typical parametric system study results illustrate the capability of a computer code developed to model the plant performance and economics.

  18. Process design for Al backside contacts

    SciTech Connect

    Chalfoun, L.L.; Kimerling, L.C.

    1995-08-01

    It is known that properly alloyed aluminum backside contacts can improve silicon solar cell efficiency. To use this knowledge to fullest advantage, we have studied the gettering process that occurs during contact formation and the microstructure of the contact and backside junction region. With an understanding of the alloying step, optimized fabrication processes can be designed. To study gettering, single crystal silicon wafers were coated with aluminim on both sides and subjected to heat treatments. Results are described.

  19. Reduced product yield in chemical processes by second law effects

    NASA Technical Reports Server (NTRS)

    England, C.; Funk, J. E.

    1980-01-01

    An analysis of second law effects in chemical processes, where product yield is explicitly related to the individual irreversibilities within the process to indicate a maximum theoretical yield, is presented. Examples are given that indicate differences between first and second law approaches toward process efficiency and process yield. This analysis also expresses production capacity in terms of the heating value of a product. As a result, it is particularly convenient in analyzing fuel conversion plants and their potential for improvement. Relationships are also given for the effects of irreversibilities on requirements for process heat and for feedstocks.

  20. Signal Processing For Chemical Sensing: Statistics or Biological Inspiration

    NASA Astrophysics Data System (ADS)

    Marco, Santiago

    2011-09-01

    Current analytical instrumentation and continuous sensing can provide huge amounts of data. Automatic signal processing and information evaluation is needed to overcome drowning in data. Today, statistical techniques are typically used to analyse and extract information from continuous signals. However, it is very interesting to note that biology (insects and vertebrates) has found alternative solutions for chemical sensing and information processing. This is a brief introduction to the developments in the European Project: Bio-ICT NEUROCHEM: Biologically Inspired Computation for Chemical Sensing (grant no. 216916) Fp7 project devoted to biomimetic olfactory systems.

  1. Influence of chemical processing on the imaging properties of microlenses

    NASA Astrophysics Data System (ADS)

    Vasiljević, Darko; Murić, Branka; Pantelić, Dejan; Panić, Bratimir

    2009-07-01

    Microlenses are produced by irradiation of a layer of tot'hema and eosin sensitized gelatin (TESG) by using a laser beam (Nd:YAG 2nd harmonic; 532 nm). All the microlenses obtained are concave with a parabolic profile. After the production, the microlenses are chemically processed with various concentrations of alum. The following imaging properties of microlenses were calculated and analyzed: the root mean square (rms) wavefront aberration, the geometric encircled energy and the spot diagram. The microlenses with higher concentrations of alum in solution had a greater effective focal length and better image quality. The microlenses chemically processed with 10% alum solution had near-diffraction-limited performance.

  2. Statistically designed experiments to screen chemical mixtures for possible interactions.

    PubMed Central

    Groten, J P; Tajima, O; Feron, V J; Schoen, E D

    1998-01-01

    For the accurate analysis of possible interactive effects of chemicals in a defined mixture, statistical designs are necessary to develop clear and manageable experiments. For instance, factorial designs have been successfully used to detect two-factor interactions. Particularly useful for this purpose are fractionated factorial designs, requiring only a fraction of all possible combinations of a full factorial design. Once the potential interaction has been detected with a fractionated design, a more accurate analysis can be performed for the particular binary mixtures to ensure and characterize these interactions. In this paper this approach is illustrated using an in vitro cytotoxicity assay to detect the presence of mixtures of Fusarium mycotoxins in contaminated food samples. We have investigated interactions between five mycotoxin species (Trichothecenes, Fumonisins, and Zearalenone) using the DNA synthesis inhibition assay in L929 fibroblasts. First, a central composite design was applied to identify possible interactive effects between mycotoxins in the mixtures (27 combinations from 5(5) possible combinations). Then two-factor interactions of particular interest were further analyzed by the use of a full factorial design (5 x 5 design) to characterize the nature of those interactions more precisely. Results show that combined exposure to several classes of mycotoxins generally results in effect addition with a few minor exceptions indicating synergistic interactions. In general, the nature of the interactions characterized in the full factorial design was similar to the nature of those observed in the central composite design. However, the magnitude of interaction was relatively small in the full factorial design. PMID:9860893

  3. Dynamic Process Simulation for Analysis and Design.

    ERIC Educational Resources Information Center

    Nuttall, Herbert E., Jr.; Himmelblau, David M.

    A computer program for the simulation of complex continuous process in real-time in an interactive mode is described. The program is user oriented, flexible, and provides both numerical and graphic output. The program has been used in classroom teaching and computer aided design. Typical input and output are illustrated for a sample problem to…

  4. Flexible Processing and the Design of Grammar

    ERIC Educational Resources Information Center

    Sag, Ivan A.; Wasow, Thomas

    2015-01-01

    We explore the consequences of letting the incremental and integrative nature of language processing inform the design of competence grammar. What emerges is a view of grammar as a system of local monotonic constraints that provide a direct characterization of the signs (the form-meaning correspondences) of a given language. This…

  5. Interface design in the process industries

    NASA Technical Reports Server (NTRS)

    Beaverstock, M. C.; Stassen, H. G.; Williamson, R. A.

    1977-01-01

    Every operator runs his plant in accord with his own mental model of the process. In this sense, one characteristic of an ideal man-machine interface is that it be in harmony with that model. With this theme in mind, the paper first reviews the functions of the process operator and compares them with human operators involved in control situations previously studied outside the industrial environment (pilots, air traffic controllers, helmsmen, etc.). A brief history of the operator interface in the process industry and the traditional methodology employed in its design is then presented. Finally, a much more fundamental approach utilizing a model definition of the human operator's behavior is presented.

  6. Composition and placement process for oil field chemicals

    SciTech Connect

    Cantu, L.A.; Yost, M.E.

    1991-01-22

    This patent describes a process for the continuous release of an oil field chemical within a subterranean hydrocarbon bearing formation or wellbore penetrating such formation. It comprises placing the oil field chemical in a polymeric microcapsule; dispersing such polymeric microcapsules; introducing the wellbore fluid containing the microcapsules into a well bore or subterranean formation through a wellbore; then allowing water and temperature at formation conditions to degrade; continuously releasing the chemical from the degraded microcapsules. This patent describes a composition comprising an oil field chemical incorporated in a polymeric microcapsule comprising the condensation product of hydroxyacetic acid monomer or hydroxyacetic acid co-condensed with up to 15 percent by weight of other hydroxy-, carboxylic acid-, or hydroxycarboxylic acid- containing moieties. The product has a number average molecular weight of from about 200 to about 4000.

  7. Using scoping as a design process

    SciTech Connect

    Mulvihill, P.R. ); Jacobs, P. )

    1998-07-01

    Skillful use of the scoping phase of environment assessment (EA) is critical in cases involving a wide diversity of stakeholders and perspectives. Scoping can exert a strong influence in shaping a relevant impact assessment and increasing the probability of a process that satisfies stakeholders. This article explores key challenges facing scoping processes conducted in highly pluralistic settings. Elements of a notable case study--the scoping process conducted in 1992 for the proposed Great Whale Hydroelectric project in Northern Quebec--are discussed to illustrate innovative approaches. When used as a design process, scoping can ensure that EA reflects the different value sets and cultures that are at play, particularly where diverse knowledge systems and ways of describing environmental components and impacts exist. As it sets the stage for subsequent steps in the EA process, scoping needs to be a sufficiently broad umbrella that accommodates diverse approaches to identifying, classifying, and assessing impacts.

  8. Combined system of monothermal chemical exchange process with electrolysis and thermal diffusion process for enriching tritium

    SciTech Connect

    Kitamoto, A.; Hasegawa, K.; Masui, T.

    1988-09-01

    Monothermal chemical exchange process with electrolysis (wellknown as the CECE process) is an effective method for enriching and removing tritium from tritiated water of low to middle level activity. The thermal diffusion process (ThD) is a low inventory gas phase method for enriching tritium from hydrogen. ThD and CECE process can be combined with each other by hydrogen gas line.

  9. 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...

  10. 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.…

  11. GREENSCOPE: A Method for Modeling Chemical Process Sustainability

    EPA Science Inventory

    Current work within the U.S. Environmental Protection Agency’s National Risk Management Research Laboratory is focused on the development of a method for modeling chemical process sustainability. The GREENSCOPE methodology, defined for the four bases of Environment, Economics, Ef...

  12. Chemical vapor deposition for automatic processing of integrated circuits

    NASA Technical Reports Server (NTRS)

    Kennedy, B. W.

    1980-01-01

    Chemical vapor deposition for automatic processing of integrated circuits including the wafer carrier and loading from a receiving air track into automatic furnaces and unloading on to a sending air track is discussed. Passivation using electron beam deposited quartz is also considered.

  13. ASSESSING TOXICITY OF ORGANIC CHEMICALS TO ANAEROBIC TREATMENT PROCESSES

    EPA Science Inventory

    A screening protocol has been developed to provide a rapid but dependable and repeatable assessment of the effect of toxic organic chemicals on anaerobic treatment processes. his protocol provides information on the rate limiting biological reactions and the concentration of toxi...

  14. 26. PROCESS PIPING AND CHEMICAL STORAGE TANKS AT SOUTH PLANT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    26. PROCESS PIPING AND CHEMICAL STORAGE TANKS AT SOUTH PLANT NORTH EDGE FROM DECEMBER 7TH AVENUE. VIEW TO SOUTHWEST. - Rocky Mountain Arsenal, Bounded by Ninety-sixth Avenue & Fifty-sixth Avenue, Buckley Road, Quebec Street & Colorado Highway 2, Commerce City, Adams County, CO

  15. Illinois Occupational Skill Standards: Chemical Process Technical Operators.

    ERIC Educational Resources Information Center

    Illinois Occupational Skill Standards and Credentialing Council, Carbondale.

    This document, which is intended for workforce preparation program providers, details the Illinois Occupational Skill Standards for programs preparing students for employment as chemical process technical operators. The document begins with a brief overview of the Illinois perspective on occupational skill standards and credentialing, the process…

  16. Hazardous Waste Processing in the Chemical Engineering Curriculum.

    ERIC Educational Resources Information Center

    Dorland, Dianne; Baria, Dorab N.

    1995-01-01

    Describes a sequence of two courses included in the chemical engineering program at the University of Minnesota, Duluth that deal with the processing of hazardous wastes. Covers course content and structure, and discusses developments in pollution prevention and waste management that led to the addition of these courses to the curriculum.…

  17. Secondary cleanup of Idaho Chemical Processing Plant solvent

    SciTech Connect

    Mailen, J.C.

    1985-01-01

    Solvent from the Idaho Chemical Processing Plant (ICPP) (operated by Westinghouse Idaho Nuclear Company, Inc.) has been tested to determine the ability of activated alumina to remove secondary degradation products - those degradation products which are not removed by scrubbing with sodium carbonate.

  18. Coexistence of superconductivity and magnetism by chemical design.

    PubMed

    Coronado, Eugenio; Martí-Gastaldo, Carlos; Navarro-Moratalla, Efrén; Ribera, Antonio; Blundell, Stephen J; Baker, Peter J

    2010-12-01

    Although the coexistence of superconductivity and ferromagnetism in one compound is rare, some examples of such materials are known to exist. Methods to physically prepare hybrid structures with both competing phases are also known, which rely on the nanofabrication of alternating conducting layers. Chemical methods of building up hybrid materials with organic molecules (superconducting layers) and metal complexes (magnetic layers) have provided examples of superconductivity with some magnetic properties, but not fully ordered. Now, we report a chemical design strategy that uses the self assembly in solution of macromolecular nanosheet building blocks to engineer the coexistence of superconductivity and magnetism in [Ni(0.66)Al(0.33)(OH)(2)][TaS(2)] at ∼4 K. The method is further demonstrated in the isostructural [Ni(0.66)Fe(0.33)(OH)(2)][TaS(2)], in which the magnetic ordering is shifted from 4 K to 16 K. PMID:21107366

  19. Forest Canopy Processes in a Regional Chemical Transport Model

    NASA Astrophysics Data System (ADS)

    Makar, Paul; Staebler, Ralf; Akingunola, Ayodeji; Zhang, Junhua; McLinden, Chris; Kharol, Shailesh; Moran, Michael; Robichaud, Alain; Zhang, Leiming; Stroud, Craig; Pabla, Balbir; Cheung, Philip

    2016-04-01

    Forest canopies have typically been absent or highly parameterized in regional chemical transport models. Some forest-related processes are often considered - for example, biogenic emissions from the forests are included as a flux lower boundary condition on vertical diffusion, as is deposition to vegetation. However, real forest canopies comprise a much more complicated set of processes, at scales below the "transport model-resolved scale" of vertical levels usually employed in regional transport models. Advective and diffusive transport within the forest canopy typically scale with the height of the canopy, and the former process tends to dominate over the latter. Emissions of biogenic hydrocarbons arise from the foliage, which may be located tens of metres above the surface, while emissions of biogenic nitric oxide from decaying plant matter are located at the surface - in contrast to the surface flux boundary condition usually employed in chemical transport models. Deposition, similarly, is usually parameterized as a flux boundary condition, but may be differentiated between fluxes to vegetation and fluxes to the surface when the canopy scale is considered. The chemical environment also changes within forest canopies: shading, temperature, and relativity humidity changes with height within the canopy may influence chemical reaction rates. These processes have been observed in a host of measurement studies, and have been simulated using site-specific one-dimensional forest canopy models. Their influence on regional scale chemistry has been unknown, until now. In this work, we describe the results of the first attempt to include complex canopy processes within a regional chemical transport model (GEM-MACH). The original model core was subdivided into "canopy" and "non-canopy" subdomains. In the former, three additional near-surface layers based on spatially and seasonally varying satellite-derived canopy height and leaf area index were added to the original model

  20. Process for preparing a chemical compound enriched in isotope content

    DOEpatents

    Michaels, Edward D.

    1982-01-01

    A process to prepare a chemical enriched in isotope content which includes: (a) A chemical exchange reaction between a first and second compound which yields an isotopically enriched first compound and an isotopically depleted second compound; (b) the removal of a portion of the first compound as product and the removal of a portion of the second compound as spent material; (c) the conversion of the remainder of the first compound to the second compound for reflux at the product end of the chemical exchange reaction region; (d) the conversion of the remainder of the second compound to the first compound for reflux at the spent material end of the chemical exchange region; and the cycling of the additional chemicals produced by one conversion reaction to the other conversion reaction, for consumption therein. One of the conversion reactions is an oxidation reaction, and the energy that it yields is used to drive the other conversion reaction, a reduction. The reduction reaction is carried out in a solid polymer electrolyte electrolytic reactor. The overall process is energy efficient and yields no waste by-products.

  1. Influence of surface coverage on the chemical desorption process

    SciTech Connect

    Minissale, M.; Dulieu, F.

    2014-07-07

    In cold astrophysical environments, some molecules are observed in the gas phase whereas they should have been depleted, frozen on dust grains. In order to solve this problem, astrochemists have proposed that a fraction of molecules synthesized on the surface of dust grains could desorb just after their formation. Recently the chemical desorption process has been demonstrated experimentally, but the key parameters at play have not yet been fully understood. In this article, we propose a new procedure to analyze the ratio of di-oxygen and ozone synthesized after O atoms adsorption on oxidized graphite. We demonstrate that the chemical desorption efficiency of the two reaction paths (O+O and O+O{sub 2}) is different by one order of magnitude. We show the importance of the surface coverage: for the O+O reaction, the chemical desorption efficiency is close to 80% at zero coverage and tends to zero at one monolayer coverage. The coverage dependence of O+O chemical desorption is proved by varying the amount of pre-adsorbed N{sub 2} on the substrate from 0 to 1.5 ML. Finally, we discuss the relevance of the different physical parameters that could play a role in the chemical desorption process: binding energy, enthalpy of formation, and energy transfer from the new molecule to the surface or to other adsorbates.

  2. Composting process design criteria. II. Detention time

    SciTech Connect

    Haug, R.T.

    1986-09-01

    Attention has always been directed to detention time as a criteria for design and operation of composting systems. Perhaps this is a logical outgrowth of work on liquid phase systems, where detention time is a fundamental parameter of design. Unlike liquid phase systems, however, the interpretation of detention time and actual values required for design have not been universally accepted in the case of composting. As a case in point, most compost systems incorporate facilities for curing the compost product. However, curing often is considered after the fact or as an add on with little relationship to the first stage, high-rate phase, whether reactor (in-vessel), static pile, or windrow. Design criteria for curing and the relationships between the first-stage, high-rate and second-stage, curing phases of a composting system have been unclear. In Part 2 of this paper, the concepts of hydraulic retention time (HRT) and solids residence time (SRT) are applied to the composting process. Definitions and design criteria for each are proposed. Based on these criteria, the first and second-stages can be designed and integrated into a complete composting system.

  3. PROCESS DESIGN FOR ENVIRONMENT: A MULTI-OBJECTIVE FRAMEWORK UNDER UNCERTAINTY

    EPA Science Inventory

    Designing chemical processes for environment requires consideration of several indexes of environmental impact including ozone depletion and global warming potentials, human and aquatic toxicity, and photochemical oxidation, and acid rain potentials. Current methodologies like t...

  4. Laboratory Studies of Heterogeneous Chemical Processes of Atmospheric Importance

    NASA Technical Reports Server (NTRS)

    Molina, Mario J.

    2004-01-01

    The objective of this study is to conduct measurements of chemical kinetics parameters for heterogeneous reactions of importance in the stratosphere and the troposphere. It involves the elucidation of the mechanism of the interaction of HCl vapor with ice surfaces, which is the first step in the heterogeneous chlorine activation processes, as well as the investigation of the atmospheric oxidation mechanism of soot particles emitted by biomass and fossil fuels. The techniques being employed include turbulent flow-chemical ionization mass spectrometry and optical ellipsometry, among others.

  5. Chemical Modification for PAN Fibers during Heat-treatment Process

    NASA Astrophysics Data System (ADS)

    Wang, Yi; Yin, Wenyan

    Chemical modification for Polyacrylonitrile (PAN) fibers during heat-treatment process were systematically studied by DSC, FT-IR, EA, XPS, etal. Comparing with original PAN fibers, chemical reactions, structures and elemental compositions of fibers modified with potassium permanganate (KMnO4) solutions were totally changed at a certain extent. KMnO4 had reduced the activation energy of cyclization, decreased the area and widened the peak of exothermic curve, decreased the velocity of cyclization reaction, increased the oxygen content about 67%, hence increased C-O-C and C=O groups and the core/shell ratio.

  6. Multiwavelet design for cardiac signal processing.

    PubMed

    Peelers, R L M; Karel, J M H; Westra, R L; Haddad, S A P; Serdijn, W A

    2006-01-01

    An approach for designing multiwavelets is introduced, for use in cardiac signal processing. The parameterization of the class of multiwavelets is in terms of associated FIR polyphase all-pass filters. Orthogonality and a balanced vanishing moment of order 1 are built into the parameterization. An optimization criterion is developed to associate the wavelets with different meaningful segments of a signal. This approach is demonstrated on the simultaneous detection of QRS-complexes and T-peaks in ECG signals. PMID:17946917

  7. Approaches to Chemical and Biochemical Information and Signal Processing

    NASA Astrophysics Data System (ADS)

    Privman, Vladimir

    2012-02-01

    We outline models and approaches for error control required to prevent buildup of noise when ``gates'' and other ``network elements'' based on (bio)chemical reaction processes are utilized to realize stable, scalable networks for information and signal processing. We also survey challenges and possible future research. [4pt] [1] Control of Noise in Chemical and Biochemical Information Processing, V. Privman, Israel J. Chem. 51, 118-131 (2010).[0pt] [2] Biochemical Filter with Sigmoidal Response: Increasing the Complexity of Biomolecular Logic, V. Privman, J. Halamek, M. A. Arugula, D. Melnikov, V. Bocharova and E. Katz, J. Phys. Chem. B 114, 14103-14109 (2010).[0pt] [3] Towards Biosensing Strategies Based on Biochemical Logic Systems, E. Katz, V. Privman and J. Wang, in: Proc. Conf. ICQNM 2010 (IEEE Comp. Soc. Conf. Publ. Serv., Los Alamitos, California, 2010), pages 1-9.

  8. Chip Design Process Optimization Based on Design Quality Assessment

    NASA Astrophysics Data System (ADS)

    Häusler, Stefan; Blaschke, Jana; Sebeke, Christian; Rosenstiel, Wolfgang; Hahn, Axel

    2010-06-01

    Nowadays, the managing of product development projects is increasingly challenging. Especially the IC design of ASICs with both analog and digital components (mixed-signal design) is becoming more and more complex, while the time-to-market window narrows at the same time. Still, high quality standards must be fulfilled. Projects and their status are becoming less transparent due to this complexity. This makes the planning and execution of projects rather difficult. Therefore, there is a need for efficient project control. A main challenge is the objective evaluation of the current development status. Are all requirements successfully verified? Are all intermediate goals achieved? Companies often develop special solutions that are not reusable in other projects. This makes the quality measurement process itself less efficient and produces too much overhead. The method proposed in this paper is a contribution to solve these issues. It is applied at a German design house for analog mixed-signal IC design. This paper presents the results of a case study and introduces an optimized project scheduling on the basis of quality assessment results.

  9. Architectural design of heterogeneous metallic nanocrystals--principles and processes.

    PubMed

    Yu, Yue; Zhang, Qingbo; Yao, Qiaofeng; Xie, Jianping; Lee, Jim Yang

    2014-12-16

    CONSPECTUS: Heterogeneous metal nanocrystals (HMNCs) are a natural extension of simple metal nanocrystals (NCs), but as a research topic, they have been much less explored until recently. HMNCs are formed by integrating metal NCs of different compositions into a common entity, similar to the way atoms are bonded to form molecules. HMNCs can be built to exhibit an unprecedented architectural diversity and complexity by programming the arrangement of the NC building blocks ("unit NCs"). The architectural engineering of HMNCs involves the design and fabrication of the architecture-determining elements (ADEs), i.e., unit NCs with precise control of shape and size, and their relative positions in the design. Similar to molecular engineering, where structural diversity is used to create more property variations for application explorations, the architectural engineering of HMNCs can similarly increase the utility of metal NCs by offering a suite of properties to support multifunctionality in applications. The architectural engineering of HMNCs calls for processes and operations that can execute the design. Some enabling technologies already exist in the form of classical micro- and macroscale fabrication techniques, such as masking and etching. These processes, when used singly or in combination, are fully capable of fabricating nanoscopic objects. What is needed is a detailed understanding of the engineering control of ADEs and the translation of these principles into actual processes. For simplicity of execution, these processes should be integrated into a common reaction system and yet retain independence of control. The key to architectural diversity is therefore the independent controllability of each ADE in the design blueprint. The right chemical tools must be applied under the right circumstances in order to achieve the desired outcome. In this Account, after a short illustration of the infinite possibility of combining different ADEs to create HMNC design

  10. Chemical oxygen demand reduction in coffee wastewater through chemical flocculation and advanced oxidation processes.

    PubMed

    Zayas Pérez, Teresa; Geissler, Gunther; Hernandez, Fernando

    2007-01-01

    The removal of the natural organic matter present in coffee processing wastewater through chemical coagulation-flocculation and advanced oxidation processes (AOP) had been studied. The effectiveness of the removal of natural organic matter using commercial flocculants and UV/H2O2, UV/O3 and UV/H2O2/O3 processes was determined under acidic conditions. For each of these processes, different operational conditions were explored to optimize the treatment efficiency of the coffee wastewater. Coffee wastewater is characterized by a high chemical oxygen demand (COD) and low total suspended solids. The outcomes of coffee wastewater treatment using coagulation-flocculation and photodegradation processes were assessed in terms of reduction of COD, color, and turbidity. It was found that a reduction in COD of 67% could be realized when the coffee wastewater was treated by chemical coagulation-flocculation with lime and coagulant T-1. When coffee wastewater was treated by coagulation-flocculation in combination with UV/H2O2, a COD reduction of 86% was achieved, although only after prolonged UV irradiation. Of the three advanced oxidation processes considered, UV/H2O2, UV/O3 and UV/H2O2/O3, we found that the treatment with UV/H2O2/O3 was the most effective, with an efficiency of color, turbidity and further COD removal of 87%, when applied to the flocculated coffee wastewater. PMID:17918591

  11. Thinking and the Design Process. DIUL-RR-8414.

    ERIC Educational Resources Information Center

    Moulin, Bernard

    Designed to focus attention on the design process in such computer science activities as information systems design, database design, and expert systems design, this paper examines three main phases of the design process: understanding the context of the problem, identifying the problem, and finding a solution. The processes that these phases…

  12. Basic physical and chemical processes in space radiation effects on polymers

    NASA Technical Reports Server (NTRS)

    Kamaratos, E.; Wilson, J. W.; Chang, C. K.; Xu, Y. J.

    1982-01-01

    The effects of space ionizing radiation on polymers is investigated in terms of operative physical and chemical processes. A useful model of charged particle impact with a polymer was designed. Principle paths of molecular relaxation were identified and energy handling processes were considered. The focus of the study was on energy absorption and the immediately following events. Further study of the radiation degradation of polymers is suggested.

  13. Computer-aided software development process design

    NASA Technical Reports Server (NTRS)

    Lin, Chi Y.; Levary, Reuven R.

    1989-01-01

    The authors describe an intelligent tool designed to aid managers of software development projects in planning, managing, and controlling the development process of medium- to large-scale software projects. Its purpose is to reduce uncertainties in the budget, personnel, and schedule planning of software development projects. It is based on dynamic model for the software development and maintenance life-cycle process. This dynamic process is composed of a number of time-varying, interacting developmental phases, each characterized by its intended functions and requirements. System dynamics is used as a modeling methodology. The resulting Software LIfe-Cycle Simulator (SLICS) and the hybrid expert simulation system of which it is a subsystem are described.

  14. ENHANCED CHEMICAL CLEANING: A NEW PROCESS FOR CHEMICALLY CLEANING SAVANNAH RIVER WASTE TANKS

    SciTech Connect

    Ketusky, E; Neil Davis, N; Renee Spires, R

    2008-01-17

    The Savannah River Site (SRS) has 49 high level waste (HLW) tanks that must be emptied, cleaned, and closed as required by the Federal Facilities Agreement. The current method of chemical cleaning uses several hundred thousand gallons per tank of 8 weight percent (wt%) oxalic acid to partially dissolve and suspend residual waste and corrosion products such that the waste can be pumped out of the tank. This adds a significant quantity of sodium oxalate to the tanks and, if multiple tanks are cleaned, renders the waste incompatible with the downstream processing. Tank space is also insufficient to store this stream given the large number of tanks to be cleaned. Therefore, a search for a new cleaning process was initiated utilizing the TRIZ literature search approach, and Chemical Oxidation Reduction Decontamination--Ultraviolet (CORD-UV), a mature technology currently used for decontamination and cleaning of commercial nuclear reactor primary cooling water loops, was identified. CORD-UV utilizes oxalic acid for sludge dissolution, but then decomposes the oxalic acid to carbon dioxide and water by UV treatment outside the system being treated. This allows reprecipitation and subsequent deposition of the sludge into a selected container without adding significant volume to that container, and without adding any new chemicals that would impact downstream treatment processes. Bench top and demonstration loop measurements on SRS tank sludge stimulant demonstrated the feasibility of applying CORD-UV for enhanced chemical cleaning of SRS HLW tanks.

  15. Microfabricated Instrumentation for Chemical Sensing in Industrial Process Control

    SciTech Connect

    Ramsey, J. M.

    2000-06-01

    The monitoring of chemical constituents in manufacturing processes is of economic importance to most industries. The monitoring and control of chemical constituents may be of importance for product quality control or, in the case of process effluents, of environmental concern. The most common approach now employed for chemical process control is to collect samples which are returned to a conventional chemical analysis laboratory. This project attempts to demonstrate the use of microfabricated structures, referred to as 'lab-on-a-chip' devices, that accomplish chemical measurement tasks that emulate those performed in the conventional laboratory. The devices envisioned could be used as hand portable chemical analysis instruments where samples are analyzed in the field or as emplaced sensors for continuous 'real-time' monitoring. This project focuses on the development of filtration elements and solid phase extraction elements that can be monolithically integrated onto electrophoresis and chromatographic structures pioneered in the laboratory. Successful demonstration of these additional functional elements on integrated microfabricated devices allows lab-on-a-chip technologies to address real world samples that would be encountered in process control environments. The resultant technology has a broad application to industrial environmental monitoring problems. such as monitoring municipal water supplies, waste water effluent from industrial facilities, or monitoring of run-off from agricultural activities. The technology will also be adaptable to manufacturing process control scenarios. Microfabricated devices integrating sample filtration, solid phase extraction, and chromatographic separation with solvent programming were demonstrated. Filtering of the sample was accomplished at the same inlet with an array of seven channels each 1 {micro}m deep and 18 {micro}m wide. Sample concentration and separation were performed on channels 5 {micro}m deep and 25 {micro

  16. Forging process design for risk reduction

    NASA Astrophysics Data System (ADS)

    Mao, Yongning

    In this dissertation, forging process design has been investigated with the primary concern on risk reduction. Different forged components have been studied, especially those ones that could cause catastrophic loss if failure occurs. As an effective modeling methodology, finite element analysis is applied extensively in this work. Three examples, titanium compressor disk, superalloy turbine disk, and titanium hip prosthesis, have been discussed to demonstrate this approach. Discrete defects such as hard alpha anomalies are known to cause disastrous failure if they are present in those stress critical components. In this research, hard-alpha inclusion movement during forging of titanium compressor disk is studied by finite element analysis. By combining the results from Finite Element Method (FEM), regression modeling and Monte Carlo simulation, it is shown that changing the forging path is able to mitigate the failure risk of the components during the service. The second example goes with a turbine disk made of superalloy IN 718. The effect of forging on microstructure is the main consideration in this study. Microstructure defines the as-forged disk properties. Considering specific forging conditions, preform has its own effect on the microstructure. Through a sensitivity study it is found that forging temperature and speed have significant influence on the microstructure. In order to choose the processing parameters to optimize the microstructure, the dependence of microstructure on die speed and temperature is thoroughly studied using design of numerical experiments. For various desired goals, optimal solutions are determined. The narrow processing window of titanium alloy makes the isothermal forging a preferred way to produce forged parts without forging defects. However, the cost of isothermal forging (dies at the same temperature as the workpiece) limits its wide application. In this research, it has been demonstrated that with proper process design, the die

  17. Process Control Systems in the Chemical Industry: Safety vs. Security

    SciTech Connect

    Jeffrey Hahn; Thomas Anderson

    2005-04-01

    Traditionally, the primary focus of the chemical industry has been safety and productivity. However, recent threats to our nation’s critical infrastructure have prompted a tightening of security measures across many different industry sectors. Reducing vulnerabilities of control systems against physical and cyber attack is necessary to ensure the safety, security and effective functioning of these systems. The U.S. Department of Homeland Security has developed a strategy to secure these vulnerabilities. Crucial to this strategy is the Control Systems Security and Test Center (CSSTC) established to test and analyze control systems equipment. In addition, the CSSTC promotes a proactive, collaborative approach to increase industry's awareness of standards, products and processes that can enhance the security of control systems. This paper outlines measures that can be taken to enhance the cybersecurity of process control systems in the chemical sector.

  18. Devising efficient biotechnological processes for the production of fuels and chemicals from biomass

    NASA Astrophysics Data System (ADS)

    Villet, R. H.

    1982-05-01

    Research directed toward improving ethanol processes based on readily fermentable feedstocks is discussed. Efforts were also made to develop novel fermentation systems. Reducing the cost of producing ethanol and other chemicals requires using cellulosics as feedstocks, which when hydrolyzed form hexose sugars readily metabolized by yeast. A program was undertaken to discover thermophilic organisms that convert various biopolymers to ethanol and other chemical products. Lipids suitable as diesel oil extenders are produced by microorganisms. A screening program was undertaken to identify microbial strains with a biotechnological potential. This involved a precise, quantitative chemical analysis of lipid products. Some work on developing a 2,3-butanediol fermentation process is described. During the fermentation process ethanol is also produced. To improve the ratio of butanediol to ethanol, a program of genetic and physiological research was designed and initiated.

  19. Reliability Methods for Shield Design Process

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Wilson, J. W.

    2002-01-01

    Providing protection against the hazards of space radiation is a major challenge to the exploration and development of space. The great cost of added radiation shielding is a potential limiting factor in deep space operations. In this enabling technology, we have developed methods for optimized shield design over multi-segmented missions involving multiple work and living areas in the transport and duty phase of space missions. The total shield mass over all pieces of equipment and habitats is optimized subject to career dose and dose rate constraints. An important component of this technology is the estimation of two most commonly identified uncertainties in radiation shield design, the shielding properties of materials used and the understanding of the biological response of the astronaut to the radiation leaking through the materials into the living space. The largest uncertainty, of course, is in the biological response to especially high charge and energy (HZE) ions of the galactic cosmic rays. These uncertainties are blended with the optimization design procedure to formulate reliability-based methods for shield design processes. The details of the methods will be discussed.

  20. Magnetic Resonance Current Density Imaging of Chemical Processes and Reactions

    NASA Astrophysics Data System (ADS)

    Beravs, Katarina; Demš Ar, Alojz; Demsar, Franci

    1999-03-01

    Electric current density imaging was used to image conductivity changes that occur as a chemical process or reaction progresses. Feasibility was assessed in two models representing the dissolving of an ionic solid and the formation of an insoluble precipitate. In both models, temporal and spatial changes in ionic concentrations were obtained on current density images. As expected, the images showed significant signal enhancement along the ionization/dissociation sites.

  1. DAWN (Design Assistant Workstation) for advanced physical-chemical life support systems

    NASA Technical Reports Server (NTRS)

    Rudokas, Mary R.; Cantwell, Elizabeth R.; Robinson, Peter I.; Shenk, Timothy W.

    1989-01-01

    This paper reports the results of a project supported by the National Aeronautics and Space Administration, Office of Aeronautics and Space Technology (NASA-OAST) under the Advanced Life Support Development Program. It is an initial attempt to integrate artificial intelligence techniques (via expert systems) with conventional quantitative modeling tools for advanced physical-chemical life support systems. The addition of artificial intelligence techniques will assist the designer in the definition and simulation of loosely/well-defined life support processes/problems as well as assist in the capture of design knowledge, both quantitative and qualitative. Expert system and conventional modeling tools are integrated to provide a design workstation that assists the engineer/scientist in creating, evaluating, documenting and optimizing physical-chemical life support systems for short-term and extended duration missions.

  2. Supercritical Water Process for the Chemical Recycling of Waste Plastics

    NASA Astrophysics Data System (ADS)

    Goto, Motonobu

    2010-11-01

    The development of chemical recycling of waste plastics by decomposition reactions in sub- and supercritical water is reviewed. Decomposition reactions proceed rapidly and selectively using supercritical fluids compared to conventional processes. Condensation polymerization plastics such as PET, nylon, and polyurethane, are relatively easily depolymerized to their monomers in supercritical water. The monomer components are recovered in high yield. Addition polymerization plastics such as phenol resin, epoxy resin, and polyethylene, are also decomposed to monomer components with or without catalysts. Recycling process of fiber reinforced plastics has been studied. Pilot scale or commercial scale plants have been developed and are operating with sub- and supercritical fluids.

  3. Solar Processes for the Destruction of Hazardous Chemicals

    SciTech Connect

    Blake, D. M.

    1993-06-01

    Solar technologies are being developed to address a wide range of environmental problems. Sunlight plays a role in the passive destruction of hazardous substances in soil, water, and air. Development of processes that use solar energy to remediate environmental problems or to treat process wastes is underway in laboratories around the world. This paper reviews progress in understanding the role of solar photochemistry in removing man-made chemicals from the environment, and developing technology that uses solar photochemistry for this purpose in an efficient manner.

  4. Process for converting cellulosic materials into fuels and chemicals

    DOEpatents

    Scott, Charles D.; Faison, Brendlyn D.; Davison, Brian H.; Woodward, Jonathan

    1994-01-01

    A process for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attritor and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system.

  5. Extended Characterization of Chemical Processes in Hot Cells Using Environmental Swipe Samples

    SciTech Connect

    Olsen, Khris B.; Mitroshkov, Alexandre V.; Thomas, M-L; Lepel, Elwood A.; Brunson, Ronald R.; Ladd-Lively, Jennifer

    2012-09-15

    Environmental sampling is used extensively by the International Atomic Energy Agency (IAEA) for verification of information from State declarations or a facility’s design regarding nuclear activities occurring within the country or a specific facility. Environmental sampling of hot cells within a facility under safeguards is conducted using 10.2 cm x 10.2 cm cotton swipe material or cellulose swipes. Traditional target analytes used by the IAEA to verify operations within a facility include a select list of gamma-emitting radionuclides and total and isotopic U and Pu. Analysis of environmental swipe samples collected within a hot-cell facility where chemical processing occurs may also provide information regarding specific chemicals used in fuel processing. However, using swipe material to elucidate what specific chemical processes were/are being used within a hot cell has not been previously evaluated. Staff from Pacific Northwest National Laboratory (PNNL) and Oak Ridge National Laboratory (ORNL) teamed to evaluate the potential use of environmental swipe samples as collection media for volatile and semivolatile organic compounds. This evaluation was initiated with sample collection during a series of Coupled End-to-End (CETE) reprocessing runs at ORNL. The study included measurement of gamma emitting radionuclides, total and isotopic U and Pu, and volatile and semivolatile organic compounds. These results allowed us to elucidate what chemical processes used in the hot cells during reprocessing of power reactor and identify other legacy chemicals used in hot cell operations which predate the CETE process.

  6. 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. PMID:26497761

  7. Innovative machine designs for radiation processing

    NASA Astrophysics Data System (ADS)

    Vroom, David

    2007-12-01

    In the 1990s Raychem Corporation established a program to investigate the commercialization of several promising applications involving the combined use of its core competencies in materials science, radiation chemistry and e-beam radiation technology. The applications investigated included those that would extend Raychem's well known heat recoverable polymer and wire and cable product lines as well as new potential applications such as remediation of contaminated aqueous streams. A central part of the program was the development of new accelerator technology designed to improve quality, lower processing costs and efficiently process conformable materials such at liquids. A major emphasis with this new irradiation technology was to look at the accelerator and product handling systems as one integrated, not as two complimentary systems.

  8. ACTINIDE REMOVAL PROCESS SAMPLE ANALYSIS, CHEMICAL MODELING, AND FILTRATION EVALUATION

    SciTech Connect

    Martino, C.; Herman, D.; Pike, J.; Peters, T.

    2014-06-05

    Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.

  9. Application of repetitive pulsed power technology to chemical processing

    SciTech Connect

    Kaye, R.J.; Hamil, R.

    1995-12-31

    The numerous sites of soil and water contaminated with organic chemicals present an urgent environmental concern that continues to grow. Electron and x-ray irradiation have been shown to be effective methods to destroy a wide spectrum of organic chemicals, nitrates, nitrites, and cyanide in water by breaking molecules to non-toxic products or entirely mineralizing the by-products to gas, water, and salts. Sandia National Laboratories is developing Repetitive High Energy Pulsed Power (RHEPP) technology capable of producing high average power, broad area electron or x-ray beams. The 300 kW RHEPP-II facility accelerates electrons to 2.5 MeV at 25 kA over 1,000 cm{sup 2} in 60 ns pulses at repetition rates of over 100 Hz. Linking this modular treatment capability with the rapid optical-sensing diagnostics and neutral network characterization software algorithms will provide a Smart Waste Treatment (SWaT) system. Such a system would also be applicable for chemical manufacture and processing of industrial waste for reuse or disposal. This talk describes both the HREPP treatment capability and sensing technologies. Measurements of the propagated RHEPP-II beam and dose profiles are presented. Sensors and rapid detection software are discussed with application toward chemical treatment.

  10. Flexible conductive polymer polarizer designed for a chemical tag

    NASA Astrophysics Data System (ADS)

    Washburn, C. M.; Jones, J. C.; Vigil, S. R.; Finnegan, P. S.; Boye, R. R.; Hunker, J. D.; Scrymgeour, D. A.; Dirk, S. M.; Hance, B. G.; Strong, J. M.; Massey, L. M.; Brumbach, M. T.

    2013-03-01

    Conductive polymers with high solids loading (> 40wt.%) are challenging to pattern to single micron feature sizes and require unique techniques or templates to mold the material. The development of a conductive polymer optical tag is discussed for identifying the presence of hydrofluoric acid (HF) and leverages free standing silicon fins as a template utilizing deep reactive ion etching (DRIE) techniques will be discussed. This work is aimed towards a future flexible conductive polymer tag to be transferred via adhesive or epoxy for a novel sensor surface. The advantage to this technique over wafer thinning is a higher throughput of device manufacture without damage to the silicon fins or polymer due to chemical-mechanical interactions or added protective layers. The gratings consist of a high spatial frequency (1.15 μm pitch) grating consisting of lines of conductive polymer and lines of silicon which are free standing. A novel running bond pattern aims to minimize the intrinsic stress and allows the conductive polymer to infiltrate without distorting the template. The polymer conductivity mechanism has been designed to break down under a chemical binding to fluorine; changing its conductivity upon exposure, and results in a change in the polarization response. The use of the polarization response makes the signal more robust to intensity fluctuations in the background or interrogation system. Additionally, the use of optical interrogation allows for standoff detection in instances where hazardous conditions may be present. Examples of material and device responses will be shown and directions for further investigation are discussed.

  11. Cogeneration handbook for the chemical process industries. [Contains glossary

    SciTech Connect

    Fassbender, A.G.; Fassbender, L.L.; Garrett-Price, B.A.; Moore, N.L.; Eakin, D.E.; Gorges, H.A.

    1984-03-01

    The desision of whether to cogenerate involves several considerations, including technical, economic, environmental, legal, and regulatory issues. Each of these issues is addressed separately in this handbook. In addition, a chapter is included on preparing a three-phase work statement, which is needed to guide the design of a cogeneration system. In addition, an annotated bibliography and a glossary of terminology are provided. Appendix A provides an energy-use profile of the chemical industry. Appendices B through O provide specific information that will be called out in subsequent chapters.

  12. Slaughterhouse Wastewater Treatment by Combined Chemical Coagulation and Electrocoagulation Process

    PubMed Central

    Bazrafshan, Edris; Kord Mostafapour, Ferdos; Farzadkia, Mehdi; Ownagh, Kamal Aldin; Mahvi, Amir Hossein

    2012-01-01

    Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards. The influence of the operating variables such as coagulant dose, electrical potential and reaction time on the removal efficiencies of major pollutants was determined. The rate of removal of pollutants linearly increased with increasing doses of PACl and applied voltage. COD and BOD5 removal of more than 99% was obtained by adding 100 mg/L PACl and applied voltage 40 V. The experiments demonstrated the effectiveness of chemical and electrochemical techniques for the treatment of slaughterhouse wastewaters. Consequently, combined processes are inferred to be superior to electrocoagulation alone for the removal of both organic and inorganic compounds from cattle-slaughterhouse wastewater. PMID:22768233

  13. [Design of an HACCP program for a cocoa processing facility].

    PubMed

    López D'Sola, Patrizia; Sandia, María Gabriela; Bou Rached, Lizet; Hernández Serrano, Pilar

    2012-12-01

    The HACCP plan is a food safety management tool used to control physical, chemical and biological hazards associated to food processing through all the processing chain. The aim of this work is to design a HACCP Plan for a Venezuelan cocoa processing facility.The production of safe food products requires that the HACCP system be built upon a solid foundation of prerequisite programs such as Good Manufacturing Practices (GMP) and Sanitation Standard Operating Procedures (SSOP). The existence and effectiveness of these prerequisite programs were previously assessed.Good Agriculture Practices (GAP) audit to cocoa nibs suppliers were performed. To develop the HACCP plan, the five preliminary tasks and the seven HACCP principles were accomplished according to Codex Alimentarius procedures. Three Critical Control Points (CCP) were identified using a decision tree: winnowing (control of ochratoxin A), roasting (Salmonella control) and metallic particles detection. For each CCP, Critical limits were established, the Monitoring procedures, Corrective actions, Procedures for Verification and Documentation concerning all procedures and records appropriate to these principles and their application was established. To implement and maintain a HACCP plan for this processing plant is suggested. Recently OchratoxinA (OTA) has been related to cocoa beans. Although the shell separation from the nib has been reported as an effective measure to control this chemical hazard, ochratoxin prevalence study in cocoa beans produced in the country is recommended, and validate the winnowing step as well PMID:24020255

  14. A process for treatment of mixed waste containing chemical plating wastes

    SciTech Connect

    Anast, K.R.; Dziewinski, J.; Lussiez, G.

    1995-02-01

    The Waste Treatment and Minimization Group at Los Alamos National Laboratory has designed and will be constructing a transportable treatment system to treat low-level radioactive mixed waste generated during plating operations. The chemical and plating waste treatment system is composed of two modules with six submodules, which can be trucked to user sites to treat a wide variety of aqueous waste solutions. The process is designed to remove the hazardous components from the waste stream, generating chemically benign, disposable liquids and solids with low level radioactivity. The chemical and plating waste treatment system is designed as a multifunctional process capable of treating several different types of wastes. At this time, the unit has been the designated treatment process for these wastes: Destruction of free cyanide and metal-cyanide complexes from spent plating solutions; destruction of ammonia in solution from spent plating solutions; reduction of Cr{sup VI} to Cr{sup III} from spent plating solutions, precipitation, solids separation, and immobilization; heavy metal precipitation from spent plating solutions, solids separation, and immobilization, and acid or base neutralization from unspecified solutions.

  15. Incorporation of chemical kinetic models into process control

    SciTech Connect

    Herget, C.J.; Frazer, J.W.

    1981-07-08

    An important consideration in chemical process control is to determine the precise rationing of reactant streams, particularly when a large time delay exists between the mixing of the reactants and the measurement of the product. In this paper, a method is described for incorporating chemical kinetic models into the control strategy in order to achieve optimum operating conditions. The system is first characterized by determining a reaction rate surface as a function of all input reactant concentrations over a feasible range. A nonlinear constrained optimization program is then used to determine the combination of reactants which produces the specified yield at minimum cost. This operating condition is then used to establish the nominal concentrations of the reactants. The actual operation is determined through a feedback control system employing a Smith predictor. The method is demonstrated on a laboratory bench scale enzyme reactor.

  16. Laboratory Studies of Heterogeneous Chemical Processes of Atmospheric Importance

    NASA Technical Reports Server (NTRS)

    Molina, Mario J.

    2003-01-01

    The objective of this study is to conduct measurements of chemical kinetics parameters for heterogeneous reactions of importance in the stratosphere and the troposphere. It involves the elucidation of the mechanism of the interaction of HC1 vapor with ice surfaces, which is the first step in the heterogeneous chlorine activation processes, as well as the investigation of the atmospheric oxidation mechanism of soot particles emitted by biomass and fossil fuels. The techniques being employed include turbulent flow- chemical ionization mass spectrometry and optical ellipsometry, among others. The next section summarizes our research activities during the first year of the project, and the section that follows consists of the statement of work for the second year.

  17. Chemical evolution of the Earth: Equilibrium or disequilibrium process?

    NASA Technical Reports Server (NTRS)

    Sato, M.

    1985-01-01

    To explain the apparent chemical incompatibility of the Earth's core and mantle or the disequilibrium process, various core forming mechanisms have been proposed, i.e., rapid disequilibrium sinking of molten iron, an oxidized core or protocore materials, and meteorite contamination of the upper mantle after separation from the core. Adopting concepts used in steady state thermodynamics, a method is devised for evaluating how elements should distribute stable in the Earth's interior for the present gradients of temperature, pressure, and gravitational acceleration. Thermochemical modeling gives useful insights into the nature of chemical evolution of the Earth without overly speculative assumptions. Further work must be done to reconcile siderophile elements, rare gases, and possible light elements in the outer core.

  18. Mechanistic, kinetic, and processing aspects of tungsten chemical mechanical polishing

    NASA Astrophysics Data System (ADS)

    Stein, David

    This dissertation presents an investigation into tungsten chemical mechanical polishing (CMP). CMP is the industrially predominant unit operation that removes excess tungsten after non-selective chemical vapor deposition (CVD) during sub-micron integrated circuit (IC) manufacture. This work explores the CMP process from process engineering and fundamental mechanistic perspectives. The process engineering study optimized an existing CMP process to address issues of polish pad and wafer carrier life. Polish rates, post-CMP metrology of patterned wafers, electrical test data, and synergy with a thermal endpoint technique were used to determine the optimal process. The oxidation rate of tungsten during CMP is significantly lower than the removal rate under identical conditions. Tungsten polished without inhibition during cathodic potentiostatic control. Hertzian indenter model calculations preclude colloids of the size used in tungsten CMP slurries from indenting the tungsten surface. AFM surface topography maps and TEM images of post-CMP tungsten do not show evidence of plow marks or intergranular fracture. Polish rate is dependent on potassium iodate concentration; process temperature is not. The colloid species significantly affects the polish rate and process temperature. Process temperature is not a predictor of polish rate. A process energy balance indicates that the process temperature is predominantly due to shaft work, and that any heat of reaction evolved during the CMP process is negligible. Friction and adhesion between alumina and tungsten were studied using modified AFM techniques. Friction was constant with potassium iodate concentration, but varied with applied pressure. This corroborates the results from the energy balance. Adhesion between the alumina and the tungsten was proportional to the potassium iodate concentration. A heuristic mechanism, which captures the relationship between polish rate, pressure, velocity, and slurry chemistry, is presented

  19. Design of an artificial skin. II. Control of chemical composition.

    PubMed

    Yannas, I V; Burke, J F; Gordon, P L; Huang, C; Rubenstein, R H

    1980-03-01

    Detailed methodology is described for the reproducible preparation of collagen--glycosaminoglycan (GAG) membranes with known chemical composition. These membranes have been used to cover satisfactorily large experimental full-thickness skin wounds in guinea pigs over the past few years. Such membranes have effectively protected these wounds from infection and fluid loss for over 25 days without rejection and without requiring change or other invasive manipulation. When appropriately designed for the purpose, the membranes have also strongly retarded wound contraction and have become replaced by newly synthesized, stable connective tissue. In our work, purified, fully native collagen from two mammalian sources is precipitated from acid dispersion by addition of chondroitin 6-sulfate. The relative amount of GAG in the coprecipitate varies with the amount of GAG added and with the pH. Since coprecipitated GAG is generally eluted from collagen fibers by physiological fluids, control of the chemical composition of membranes is arrived at by crosslinking the collagen--GAG ionic complex with glutaraldehyde, or, alternately, by use of high-temperature vacuum dehydration. Appropriate use of the crosslinking treatment allows separate study of changes in membrane composition due to elution of GAG by extracellular fluid in animal studies from changes in composition due to enzymatic degradation of the grafted or implanted membrane in these studies. Exhaustive in vitro elution studies extending up to 20 days showed that these crosslinking treatments insolubilize in an apparently permanent manner a fraction of the ionically complexed GAG, although it could not be directly confirmed that glutaraldehyde treatment covalently crosslinks GAG to collagen. By contrast, the available evidence suggests strongly that high-temperature vacuum dehydration leads to formation of chemical bonds between collagen and GAG. Procedures are described for control of insolubilized and "free" GAG in

  20. Innovative soil treatment process design for removal of trivalent chromium

    SciTech Connect

    Stallings, J.H.; Durkin, M.E.

    1997-12-31

    A soil treatment process has been developed as part of a US Air Force environmental compliance project at Air Force Plant 44, Tucson, AZ for treating soil contaminated with heavy metals including trivalent chromium, cadmium, copper, and nickel. The process was designed to treat a total of 133,000 tons of soil in a 400 ton per day facility. Features of the soil treatment process include physical treatment and separation, and a chemical treatment process of the remaining fines using a hypochlorite leach allowing chromium to be solubilized at a high pH. After treating, fines are washed in three stage countercurrent thickeners and chromium hydroxide cake is recovered as a final produce from the leach solution. Treatability studies were conducted, laboratory and a pilot plant was built. Process design criteria and flow sheet, material balances, as well as preliminary equipment selection and sizing for the facility have been completed. Facility was designed for the removal of Cr at a concentration of an average of 1230 mg/kg from the soil and meeting a risk based clean-closure limit of 400 mg/kg of Cr. Capital costs for the 400 tpd plant were estimated at 9.6 million with an operating and maintenance cost of $54 per ton As process is most economic for large quantities of soil with relatively low concentrations of contaminants, it was not used in final closure when the estimated volume of contaminated soil removed dropped to 65,000 tons and concentration of chromium increased up to 4000 mg/kg. However, the process could have application in situations where economics and location warrant.

  1. Optical instrumentation for on-line analysis of chemical processes

    SciTech Connect

    Hartford, A. Jr.; Cremers, D.A.; Loree, T.R.; Quigley, G.P.

    1983-01-01

    Optical diagnostics provide the capability for nonintrusive, on-line, real time analysis of chemical process streams. Several laser-based methods for monitoring fossil energy processes have been evaluated. Among the instrumentation techniques which appear quite promising are coherent anti-Stokes Raman spectroscopy (CARS), laser-induced breakdown spectroscopy (LIBS), and synchronous detection of laser-induced fluorescence (SDLIF). A CARS diagnostic was implemented on a coal gasifier and was successfully employed to measure species concentrations and temperatures within the process stream. The LIBS approach has been used to identify total trace impurities (e.g., Na, K, and S) within a gasifier. Recently, individual components in mixtures of aromatics hydrocarbons have been resolved via the synchronous detection of laser-induced fluorescence. 9 figures.

  2. Physics-based model for electro-chemical process

    SciTech Connect

    Zhang, Jinsuo

    2013-07-01

    Considering the kinetics of electrochemical reactions and mass transfer at the surface and near-surface of the electrode, a physics-based separation model for separating actinides from fission products in an electro-refiner is developed. The model, taking into account the physical, chemical and electrochemical processes at the electrode surface, can be applied to study electrorefining kinetics. One of the methods used for validation has been to apply the developed model to the computation of the cyclic voltammetry process of PuCl{sub 3} and UCl{sub 3} at a solid electrode in molten KCl-LiCl. The computed results appear to be similar to experimental measures. The separation model can be applied to predict materials flows under normal and abnormal operation conditions. Parametric studies can be conducted based on the model to identify the most important factors that affect the electrorefining processes.

  3. Nuclear Technology Series. Course 23: Nuclear Chemical Processes.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    This technical specialty course is one of thirty-five courses designed for use by two-year postsecondary institutions in five nuclear technician curriculum areas: (1) radiation protection technician, (2) nuclear instrumentation and control technician, (3) nuclear materials processing technician, (4) nuclear quality-assurance/quality-control…

  4. Remote Maintenance Design Guide for Compact Processing Units

    SciTech Connect

    Draper, J.V.

    2000-07-13

    Oak Ridge National Laboratory (ORNL) Robotics and Process Systems (RPSD) personnel have extensive experience working with remotely operated and maintained systems. These systems require expert knowledge in teleoperation, human factors, telerobotics, and other robotic devices so that remote equipment may be manipulated, operated, serviced, surveyed, and moved about in a hazardous environment. The RPSD staff has a wealth of experience in this area, including knowledge in the broad topics of human factors, modular electronics, modular mechanical systems, hardware design, and specialized tooling. Examples of projects that illustrate and highlight RPSD's unique experience in remote systems design and application include the following: (1) design of a remote shear and remote dissolver systems in support of U.S. Department of Energy (DOE) fuel recycling research and nuclear power missions; (2) building remotely operated mobile systems for metrology and characterizing hazardous facilities in support of remote operations within those facilities; (3) construction of modular robotic arms, including the Laboratory Telerobotic Manipulator, which was designed for the National Aeronautics and Space Administration (NASA) and the Advanced ServoManipulator, which was designed for the DOE; (4) design of remotely operated laboratories, including chemical analysis and biochemical processing laboratories; (5) construction of remote systems for environmental clean up and characterization, including underwater, buried waste, underground storage tank (UST) and decontamination and dismantlement (D&D) applications. Remote maintenance has played a significant role in fuel reprocessing because of combined chemical and radiological contamination. Furthermore, remote maintenance is expected to play a strong role in future waste remediation. The compact processing units (CPUs) being designed for use in underground waste storage tank remediation are examples of improvements in systems processing

  5. Process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition

    DOEpatents

    Lackey, Jr., Walter J.; Caputo, Anthony J.

    1986-01-01

    A chemical vapor deposition (CVD) process for preparing fiber-reinforced ceramic composites. A specially designed apparatus provides a steep thermal gradient across the thickness of a fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.

  6. Fundamental studies of chemical vapor deposition diamond growth processes

    SciTech Connect

    Shaw, R.W.; Whitten, W.B.; Ramsey, J.M.; Heatherly, L.

    1991-01-01

    We are developing laser spectroscopic techniques to foster a fundamental understanding of diamond film growth by hot filament chemical vapor deposition (CVD). Several spectroscopic techniques are under investigation to identify intermediate species present in the bulk reactor volume, the thin active volume immediately above the growing film, and the actual growing surface. Such a comprehensive examination of the overall deposition process is necessary because a combination of gas phase and surface chemistry is probably operating. Resonantly enhanced multiphoton ionization (REMPI) techniques have been emphasized. A growth rector that permits through-the-substrate gas sampling for REMPI/time-of-flight mass spectroscopy has been developed. 7 refs., 2 figs.

  7. Inhomogeneous chemical evolution of r-process elements

    NASA Astrophysics Data System (ADS)

    Wehmeyer, B.; Pignatari, M.; Thielemann, F.-K.

    2016-06-01

    We report the results of a galactic chemical evolution (GCE) study for r-process- and alpha elements. For this work, we used the inhomogeneous GCE model "ICE", which allows to keep track of the galactic abundances of elements produced by different astrophysical sites. The main input parameters for this study were: a) The Neutron Star Merger (NSM) coalescence time scale, the probability of NSMs, and for the sub-class of "magneto-rotationally driven Supernovae" ("Jet-SNe"), their occurence rate in comparison to "standard" Supernovae (SNe).

  8. LARES: an artificial chemical process approach for optimization.

    PubMed

    Irizarry, Roberto

    2004-01-01

    This article introduces a new global optimization procedure called LARES. LARES is based on the concept of an artificial chemical process (ACP), a new paradigm which is described in this article. The algorithm's performance was studied using a test bed with a wide spectrum of problems including random multi-modal random problem generators, random LSAT problem generators with various degrees of epistasis, and a test bed of real-valued functions with different degrees of multi-modality, discontinuity and flatness. In all cases studied, LARES performed very well in terms of robustness and efficiency. PMID:15768524

  9. Parametric Design within an Atomic Design Process (ADP) applied to Spacecraft Design

    NASA Astrophysics Data System (ADS)

    Ramos Alarcon, Rafael

    This thesis describes research investigating the development of a model for the initial design of complex systems, with application to spacecraft design. The design model is called an atomic design process (ADP) and contains four fundamental stages (specifications, configurations, trade studies and drivers) that constitute the minimum steps of an iterative process that helps designers find a feasible solution. Representative design models from the aerospace industry are reviewed and are compared with the proposed model. The design model's relevance, adaptability and scalability features are evaluated through a focused design task exercise with two undergraduate teams and a long-term design exercise performed by a spacecraft payload team. The implementation of the design model is explained in the context in which the model has been researched. This context includes the organization (a student-run research laboratory at the University of Michigan), its culture (academically oriented), members that have used the design model and the description of the information technology elements meant to provide support while using the model. This support includes a custom-built information management system that consolidates relevant information that is currently being used in the organization. The information is divided in three domains: personnel development history, technical knowledge base and laboratory operations. The focused study with teams making use of the design model to complete an engineering design exercise consists of the conceptual design of an autonomous system, including a carrier and a deployable lander that form the payload of a rocket with an altitude range of over 1000 meters. Detailed results from each of the stages of the design process while implementing the model are presented, and an increase in awareness of good design practices in the teams while using the model are explained. A long-term investigation using the design model consisting of the

  10. High Lifetime Solar Cell Processing and Design

    NASA Technical Reports Server (NTRS)

    Swanson, R. M.

    1985-01-01

    In order to maximize efficiency a solar cell must: (1) absorb as much light as possible in electron-hole production, (2) transport as large a fraction as possible of the electrons to the n-type terminal and holes to the p-type terminal without their first recombining, and (3) produce as high as possible terminal voltage. Step (1) is largely fixed by the spectrum of sunlight and the fundamental absorption characteristics of silicon, although some improvements are possible through texturizing induced light trapping and back surface reflectors. Steps (2) and (3) are, however, dependent on the recombination mechanisms of the cell. The recombination, on the contrary, is strongly influenced by cell processing and design. Some of the lessons during the development of point-contact-cell are discussed. Cell dependence on recombination, surface recombination, and contact recombination are discussed. Results show the overwhelming influence of contact recombination on the operation of the cell when the other sources of recombination are reduced by careful processing.

  11. Design and characterization of integrated-optic-based chemical sensors

    NASA Astrophysics Data System (ADS)

    Beregovskii, Iouri

    A novel line of integrated-optic-based chemical sensors was developed. The sensors are based on modification of the optical cavity of a single-mode semiconductor distributed Bragg reflector (DBR) laser. A sensitive layer changes its refractive index in presence of a specific chemical, thus changing the effective refractive index of the section and the optical length of the cavity. This results in laser frequency shift measured either directly or by heterodyne detection using a reference laser as the second source. It is shown that DBR-laser-based sensors can achieve in principle a much higher sensitivity than passive sensors, such as Mach- Zehnder interferometers, due to the narrow linewidth of DBR lasers. The theory of DBR-laser-based sensors is described. It allows optimizing the sensitive section length and field confinement in the sensitive layer for the lowest detection limit. The optimum parameters depend on cavity losses and absorption of the sensitive material. Numerical modeling shows a wide acceptable range of sensitive section parameters for low-loss materials, while for higher-loss materials this range becomes much narrower. Narrow-linewidth DBR lasers are required for high sensitivity. In this respect, sol-gel waveguides with and without Bragg grating were incorporated in the DBR laser scheme. Single-mode operation of DBR lasers with sol-gel waveguide gratings was demonstrated for the first time, with 34-dB side mode suppression and a short-term linewidth of 150 to 500 kHz. A 3-section configuration with sol-gel waveguides and fiber grating showed 28-dB side mode suppression and a short-term linewidth of 600 kHz. Chemical sensing was performed with fiber grating, sol- gel waveguide grating, and 3-section DBR lasers. The first two types showed frequency shift of over 130 MHz in the presence of acetone vapors, and reversibility within experimental errors. The 3-section scheme showed significant dispersion of response and lack of reversibility due to

  12. Process for converting cellulosic materials into fuels and chemicals

    DOEpatents

    Scott, C.D.; Faison, B.D.; Davison, B.H.; Woodward, J.

    1994-09-20

    A process is described for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attrition mill and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system. 1 fig.

  13. Dynamic designing of microstructures by chemical gradient-mediated growth

    PubMed Central

    Shim, Tae Soup; Yang, Seung-Man; Kim, Shin-Hyun

    2015-01-01

    Shape is one of the most important determinants of the properties of microstructures. Despite of a recent progress on microfabrication techniques, production of three-dimensional micro-objects are yet to be fully achieved. Nature uses reaction–diffusion process during bottom-up self-assembly to create functional shapes and patterns with high complexity. Here we report a method to produce polymeric microstructures by using a dynamic reaction–diffusion process during top-down photolithography, providing unprecedented control over shape and composition. In radical polymerization, oxygen inhibits reaction, and therefore diffusion of oxygen significantly alters spatial distribution of growth rate. Therefore, growth pathways of the microstructures can be controlled by engineering a concentration gradient of oxygen. Moreover, stepwise control of chemical gradients enables the creation of highly complex microstructures. The ease of use and high controllability of this technology provide new opportunities for microfabrication and for fundamental studies on the relationships between shape and function for the materials. PMID:25766762

  14. Universal Design: Process, Principles, and Applications

    ERIC Educational Resources Information Center

    Burgstahler, Sheryl

    2009-01-01

    Designing any product or environment involves the consideration of many factors, including aesthetics, engineering options, environmental issues, safety concerns, industry standards, and cost. Typically, designers focus their attention on the average user. In contrast, universal design (UD), according to the Center for Universal Design," is the…

  15. Designing Allosteric Control into Enzymes by Chemical Rescue of Structure

    SciTech Connect

    Deckert, Katelyn; Budiardjo, S. Jimmy; Brunner, Luke C.; Lovell, Scott; Karanicolas, John

    2012-08-07

    Ligand-dependent activity has been engineered into enzymes for purposes ranging from controlling cell morphology to reprogramming cellular signaling pathways. Where these successes have typically fused a naturally allosteric domain to the enzyme of interest, here we instead demonstrate an approach for designing a de novo allosteric effector site directly into the catalytic domain of an enzyme. This approach is distinct from traditional chemical rescue of enzymes in that it relies on disruption and restoration of structure, rather than active site chemistry, as a means to achieve modulate function. We present two examples, W33G in a {beta}-glycosidase enzyme ({beta}-gly) and W492G in a {beta}-glucuronidase enzyme ({beta}-gluc), in which we engineer indole-dependent activity into enzymes by removing a buried tryptophan side chain that serves as a buttress for the active site architecture. In both cases, we observe a loss of function, and in both cases we find that the subsequent addition of indole can be used to restore activity. Through a detailed analysis of {beta}-gly W33G kinetics, we demonstrate that this rescued enzyme is fully functionally equivalent to the corresponding wild-type enzyme. We then present the apo and indole-bound crystal structures of {beta}-gly W33G, which together establish the structural basis for enzyme inactivation and rescue. Finally, we use this designed switch to modulate {beta}-glycosidase activity in living cells using indole. Disruption and recovery of protein structure may represent a general technique for introducing allosteric control into enzymes, and thus may serve as a starting point for building a variety of bioswitches and sensors.

  16. Designed CVD growth of graphene via process engineering.

    PubMed

    Yan, Kai; Fu, Lei; Peng, Hailin; Liu, Zhongfan

    2013-10-15

    Graphene, the atomic thin carbon film with honeycomb lattice, holds great promise in a wide range of applications, due to its unique band structure and excellent electronic, optical, mechanical, and thermal properties. Scientists are researching this star material because of the development of various emerging preparation techniques, among which chemical vapor deposition (CVD) has received the fastest advances in the past few years. For the CVD growth of graphene, the ultimate goal is to achieve the highest quality in the largest scale and lowest cost with a precise control of layer thickness, stacking order, and crystallinity. To meet this goal, researchers need a comprehensive understanding and effective controlling of the growth process, especially to its elementary steps. In this Account, we focus on our recent progresses toward the controlled surface growth of graphene and its two-dimensional (2D) hybrids via rational designs of CVD elementary processes, namely, process engineering. A typical CVD process consists of four main elementary steps: (A) adsorption and catalytic decomposition of precursor gas, (B) diffusion and dissolution of decomposed carbon species into bulk metal, (C) segregation of dissolved carbon atoms onto the metal surface, and finally, (D) surface nucleation and growth of graphene. Absence or enhancement of each elementary step would lead to significant changes in the whole growth process. Metals with certain carbon solubility, such as nickel and cobalt, involve all four elementary steps in a typical CVD process, thus providing us an ideal system for process engineering. The elementary segregation process can be completely blocked if molybdenum is introduced into the system as an alloy catalyst, yielding perfect monolayer graphene almost independent of growth parameters. On the other hand, the segregation-only process of predissolved solid carbons is also capable of high-quality graphene growth. By using a synergetic Cu-Ni alloy, we are

  17. Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 2: The design process

    NASA Technical Reports Server (NTRS)

    Gillette, W. B.; Turner, M. J.; Southall, J. W.; Whitener, P. C.; Kowalik, J. S.

    1973-01-01

    The extent to which IPAD is to support the design process is identified. Case studies of representative aerospace products were developed as models to characterize the design process and to provide design requirements for the IPAD computing system.

  18. New process modeling [sic], design, and control strategies for energy efficiency, high product quality, and improved productivity in the process industries. Final project report

    SciTech Connect

    Ray, W. Harmon

    2002-06-05

    This project was concerned with the development of process design and control strategies for improving energy efficiency, product quality, and productivity in the process industries. In particular, (i) the resilient design and control of chemical reactors, and (ii) the operation of complex processing systems, was investigated. Specific topics studied included new process modeling procedures, nonlinear controller designs, and control strategies for multiunit integrated processes. Both fundamental and immediately applicable results were obtained. The new design and operation results from this project were incorporated into computer-aided design software and disseminated to industry. The principles and design procedures have found their way into industrial practice.

  19. Enhanced Chemical Cleaning: A New Process for Chemically Cleaning Savannah River Waste Tanks

    SciTech Connect

    Ketusky, Edward; Spires, Renee; Davis, Neil

    2009-02-11

    At the Savannah River Site (SRS) there are 49 High Level Waste (HLW) tanks that eventually must be emptied, cleaned, and closed. The current method of chemically cleaning SRS HLW tanks, commonly referred to as Bulk Oxalic Acid Cleaning (BOAC), requires about a half million liters (130,000 gallons) of 8 weight percent (wt%) oxalic acid to clean a single tank. During the cleaning, the oxalic acid acts as the solvent to digest sludge solids and insoluble salt solids, such that they can be suspended and pumped out of the tank. Because of the volume and concentration of acid used, a significant quantity of oxalate is added to the HLW process. This added oxalate significantly impacts downstream processing. In addition to the oxalate, the volume of liquid added competes for the limited available tank space. A search, therefore, was initiated for a new cleaning process. Using TRIZ (Teoriya Resheniya Izobretatelskikh Zadatch or roughly translated as the Theory of Inventive Problem Solving), Chemical Oxidation Reduction Decontamination with Ultraviolet Light (CORD-UV{reg_sign}), a mature technology used in the commercial nuclear power industry was identified as an alternate technology. Similar to BOAC, CORD-UV{reg_sign} also uses oxalic acid as the solvent to dissolve the metal (hydr)oxide solids. CORD-UV{reg_sign} is different, however, since it uses photo-oxidation (via peroxide/UV or ozone/UV to form hydroxyl radicals) to decompose the spent oxalate into carbon dioxide and water. Since the oxalate is decomposed and off-gassed, CORD-UV{reg_sign} would not have the negative downstream oxalate process impacts of BOAC. With the oxalate destruction occurring physically outside the HLW tank, re-precipitation and transfer of the solids, as well as regeneration of the cleaning solution can be performed without adding additional solids, or a significant volume of liquid to the process. With a draft of the pre-conceptual Enhanced Chemical Cleaning (ECC) flowsheet, taking full

  20. PROCESS DESIGN MANUAL FOR STRIPPING OF ORGANICS

    EPA Science Inventory

    Procedures and correlations for designing and costing stripping towers for the removal of organics from aqueous streams are presented. The emphasis is on practical methods suitable for engineering estimates. The designs cover steam strippers with and without condensers and reflux...

  1. Lessons learned from the design of chemical space networks and opportunities for new applications.

    PubMed

    Vogt, Martin; Stumpfe, Dagmar; Maggiora, Gerald M; Bajorath, Jürgen

    2016-03-01

    The concept of chemical space is of fundamental relevance in chemical informatics and computer-aided drug discovery. In a series of articles published in the Journal of Computer-Aided Molecular Design, principles of chemical space design were evaluated, molecular networks proposed as an alternative to conventional coordinate-based chemical reference spaces, and different types of chemical space networks (CSNs) constructed and analyzed. Central to the generation of CSNs was the way in which molecular similarity relationships were assessed and a primary focal point was the network-based representation of biologically relevant chemical space. The design and comparison of CSNs based upon alternative similarity measures can be viewed as an evolutionary path with interesting lessons learned along the way. CSN design has matured to the point that such chemical space representations can be used in practice. In this contribution, highlights from the sequence of CSN design efforts are discussed in context, providing a perspective for future practical applications. PMID:26945865

  2. Designed Chemical Intervention with Thiols for Prophylactic Contraception

    PubMed Central

    Jain, Ashish; Verma, Vikas; Sharma, Vikas; Kushwaha, Bhavana; Lal, Nand; Kumar, Lalit; Rawat, Tara; Dwivedi, Anil K.; Maikhuri, Jagdamba P.; Sharma, Vishnu L.; Gupta, Gopal

    2013-01-01

    Unlike somatic cells, sperm have several-fold more available-thiols that are susceptible to redox-active agents. The present study explains the mechanism behind the instant sperm-immobilizing and trichomonacidal activities of pyrrolidinium pyrrolidine-1-carbodithioate (PPC), a novel thiol agent rationally created for prophylactic contraception by minor chemical modifications of some known thiol drugs. PPC, and its three derivatives (with potential active-site blocked by alkylation), were synthesized and evaluated against live human sperm and metronidazole-susceptible and resistant Trichomonas vaginalis, in vitro. Sperm hexokinase activity was evaluated by coupled enzyme assay. PPC irreversibly immobilized 100% human sperm in ∼30 seconds and totally eliminated Trichomonas vaginalis more efficiently than nonoxynol-9 and metronidazole. It significantly inhibited (P<0.001) thiol-sensitive sperm hexokinase. However, the molecule completely lost all its biological activities once its thiol group was blocked by alkylation. PPC was subsequently formulated into a mucoadhesive vaginal film using GRaS excipients and evaluated for spermicidal and microbicidal activities (in vitro), and contraceptive efficacy in rabbits. PPC remained fully active in quick-dissolving, mucoadhesive vaginal-film formulation, and these PPC-films significantly reduced pregnancy and fertility rates in rabbits. The films released ∼90% of PPC in simulated vaginal fluid (pH 4.2) at 37°C in 5 minutes, in vitro. We have thus discovered a common target (reactive thiols) on chiefly-anaerobic, redox-sensitive cells like sperm and Trichomonas, which is susceptible to designed chemical interference for prophylactic contraception. The active thiol in PPC inactivates sperm and Trichomonas via interference with crucial sulfhydryl-disulfide based reactions, e.g. hexokinase activation in human sperm. In comparison to non-specific surfactant action of OTC spermicide nonoxynol-9, the action of thiol-active PPC

  3. Designed Chemical Intervention with Thiols for Prophylactic Contraception.

    PubMed

    Sharma, Monika; Kumar, Lokesh; Jain, Ashish; Verma, Vikas; Sharma, Vikas; Kushwaha, Bhavana; Lal, Nand; Kumar, Lalit; Rawat, Tara; Dwivedi, Anil K; Maikhuri, Jagdamba P; Sharma, Vishnu L; Gupta, Gopal

    2013-01-01

    Unlike somatic cells, sperm have several-fold more available-thiols that are susceptible to redox-active agents. The present study explains the mechanism behind the instant sperm-immobilizing and trichomonacidal activities of pyrrolidinium pyrrolidine-1-carbodithioate (PPC), a novel thiol agent rationally created for prophylactic contraception by minor chemical modifications of some known thiol drugs. PPC, and its three derivatives (with potential active-site blocked by alkylation), were synthesized and evaluated against live human sperm and metronidazole-susceptible and resistant Trichomonas vaginalis, in vitro. Sperm hexokinase activity was evaluated by coupled enzyme assay. PPC irreversibly immobilized 100% human sperm in ∼30 seconds and totally eliminated Trichomonas vaginalis more efficiently than nonoxynol-9 and metronidazole. It significantly inhibited (P<0.001) thiol-sensitive sperm hexokinase. However, the molecule completely lost all its biological activities once its thiol group was blocked by alkylation. PPC was subsequently formulated into a mucoadhesive vaginal film using GRaS excipients and evaluated for spermicidal and microbicidal activities (in vitro), and contraceptive efficacy in rabbits. PPC remained fully active in quick-dissolving, mucoadhesive vaginal-film formulation, and these PPC-films significantly reduced pregnancy and fertility rates in rabbits. The films released ∼90% of PPC in simulated vaginal fluid (pH 4.2) at 37°C in 5 minutes, in vitro. We have thus discovered a common target (reactive thiols) on chiefly-anaerobic, redox-sensitive cells like sperm and Trichomonas, which is susceptible to designed chemical interference for prophylactic contraception. The active thiol in PPC inactivates sperm and Trichomonas via interference with crucial sulfhydryl-disulfide based reactions, e.g. hexokinase activation in human sperm. In comparison to non-specific surfactant action of OTC spermicide nonoxynol-9, the action of thiol-active PPC

  4. Design and Fabrication of Piezoresistive Based Encapsulated Poly-Si Cantilevers for Bio/chemical Sensing

    NASA Astrophysics Data System (ADS)

    Krishna, N. P. Vamsi; Murthy, T. R. Srinivasa; Reddy, K. Jayaprakash; Sangeeth, K.; Hegde, G. M.

    Cantilever-based sensing is a growing research field not only within micro regime but also in nano technology. The technology offers a method for rapid, on-line and in-situ monitoring of specific bio/chemical substances by detecting the nanomechanical responses of a cantilever sensor. Cantilever with piezoresistive based detection scheme is more attractive because of its electronics compatibility. Majority of commercially available micromachined piezoresistive sensors are bulk micromachined devices and are fabricated using single crystal silicon wafers. As substrate properties are not important in surface micromachining, the expensive silicon wafers can be replaced by cheaper substrates, such as poly-silicon, glass or plastic. Here we have designed SU-8 based bio/chemical compatible micro electro mechanical device that includes an encapsulated polysilicon piezoresistor for bio/chemical sensing. In this paper we report the design, fabrication and analysis of the encapsulated poly-Si cantilevers. Design and theoretical analysis are carried out using Finite Element Analysis software. For fabrication of poly-silicon piezoresistive cantilevers we followed the surface micromachining process steps. Preliminary characterization of the cantilevers is presented.

  5. Cognitive and psychomotor performance tests and experiment design in multiple chemical sensitivity.

    PubMed Central

    Wetherell, A

    1997-01-01

    People suffering from multiple chemical sensitivity (MCS) complain of a variety of symptoms that could impair cognitive and psychomotor function either directly or indirectly. This paper discusses the use of cognitive and psychomotor performance tests together with some experiment designs that could be considered for use to assess fitness of MCS sufferers for work or the efficacy of diagnostic, preventative, or therapeutic measures. The tests could also contribute to the body of objective information on MCS and help sway the opinion of those who are dubious of its authenticity. The credentials of cognitive and psychomotor performance tests are derived from their successful use in studying the effects of drugs, and the types of tests are illustrated by describing those used by the United Kingdom Defence Evaluation and Research Agency Chemical and Biological Defence Human Studies Group, which has been involved in the assessment of drugs and chemicals on work performance for many years. The tests include mathematical, verbal and spatial processing, tracking, reaction time, attention and vigilance, and memory tests. The discussion of experiment designs includes both repeated measures and parallel groups designs together with their advantages and disadvantages and some suggested modifications to accommodate the particular problems posed by MCS. PMID:9167986

  6. TREATMENT TANK CORROSION STUDIES FOR THE ENHANCED CHEMICAL CLEANING PROCESS

    SciTech Connect

    Wiersma, B.

    2011-08-24

    Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than

  7. Corrosion study in the chemical air separation (MOLTOX trademark ) process

    SciTech Connect

    Kang, Doohee; Wong, Kai P.; Archer, R.A.; Cassano, A.A.

    1988-12-01

    This report presents the results of studies aimed at solving the corrosion problems encountered during operation of the MOLTOX{trademark} pilot plant. These studies concentrated on the screening of commercial and developmental alloys under conditions simulating operation conditions in this high temperature molten salt process. Process economic studies were preformed in parallel with the laboratory testing to ensure that an economically feasible solution would be achieved. In addition to the above DOE co-funded studies, Air Products and Chemicals pursued proprietary studies aimed at developing a less corrosive salt mixture which would potentially allow the use of chemurgically available alloys such as stainless steels throughout the system. These studies will not be reported here; however, the results of corrosion tests in the new less corrosive salt mixtures are reported. Because our own studies on salt chemistry impacts heavily on the overall process and thereby has an influence on the experimental work conducted under this contract, some of the studies discussed here were impacted by our own proprietary data. Therefore, the reasons behind some of the experiments presented herein will not be explained because that information is proprietary to Air Products. 14 refs., 42 figs., 21 tabs.

  8. Radon: Chemical and physical processes associated with its distribution

    SciTech Connect

    Castleman, A.W. Jr.

    1992-01-01

    Assessing the mechanisms which govern the distribution, fate, and pathways of entry into biological systems, as well as the ultimate hazards associated with the radon progeny and their secondary reaction products, depends on knowledge of their chemistry. Our studies are directed toward developing fundamental information which will provide a basis for modeling studies that are requisite in obtaining a complete picture of growth, attachment to aerosols, and transport to the bioreceptor and ultimate incorporation within. Our program is divided into three major areas of research. These include measurement of the determination of their mobilities, study of the role of radon progeny ions in affecting reactions, including study of the influence of the degree of solvation (clustering), and examination of the important secondary reaction products, with particular attention to processes leading to chemical conversion of either the core ions or the ligands as a function of the degree of clustering.

  9. Chemical Reactions in the Processing of Mosi2 + Carbon Compacts

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.; Lee, Kang N.; Maloy, Stuart A.; Heuer, Arthur H.

    1993-01-01

    Hot-pressing of MoSi2 powders with carbon at high temperatures reduces the siliceous grain boundary phase in the resultant compact. The chemical reactions in this process were examined using the Knudsen cell technique. A 2.3 wt pct oxygen MoSi2 powder and a 0.59 wt pct oxygen MoSi2 powder, both with additions of 2 wt pct carbon, were examined. The reduction of the siliceous grain boundary phase was examined at 1350 K and the resultant P(SiO)/P(CO) ratios interpreted in terms of the SiO(g) and CO(g) isobars on the Si-C-O predominance diagram. The MoSi2 + carbon mixtures were then heated at the hot-pressing temperature of 2100 K. Large weight losses were observed and could be correlated with the formation of a low-melting eutectic and the formation and vaporization of SiC.

  10. Material flow simulation in a nuclear chemical process

    SciTech Connect

    Mahgerefteh, M.

    1984-01-01

    At a nuclear fuel reprocessing plant the special nuclear materials (SNM) are received as constituents of spent fuel assemblies, are converted to liquid form, and undergo a series of chemical processes. Uncertainties in measurements of SNM at each stage of reprocessing limit the accuracy of simple material balance accounting as a safeguards method. To be effective, a formal safeguards program must take into account all sources of measurement error yet detect any diversion of SNM. An analytical method for assessing the accountability of selected constituent SNM is demonstrated. A combined discrete-continuous, time-dependent model using the GASP IV simulation language is developed to simulate mass flow, material accountability and measurement error at each stage of the reprocessing plant.

  11. P80 SRM low torque flex-seal development - thermal and chemical modeling of molding process

    NASA Astrophysics Data System (ADS)

    Descamps, C.; Gautronneau, E.; Rousseau, G.; Daurat, M.

    2009-09-01

    The development of the flex-seal component of the P80 nozzle gave the opportunity to set up new design and manufacturing process methods. Due to the short development lead time required by VEGA program, the usual manufacturing iterative tests work flow, which is usually time consuming, had to be enhanced in order to use a more predictive approach. A newly refined rubber vulcanization description was built up and identified on laboratory samples. This chemical model was implemented in a thermal analysis code. The complete model successfully supports the manufacturing processes. These activities were conducted with the support of ESA/CNES Research & Technologies and DGA (General Delegation for Armament).

  12. Creativity Processes of Students in the Design Studio

    ERIC Educational Resources Information Center

    Huber, Amy Mattingly; Leigh, Katharine E.; Tremblay, Kenneth R., Jr.

    2012-01-01

    The creative process is a multifaceted and dynamic path of thinking required to execute a project in design-based disciplines. The goal of this research was to test a model outlining the creative design process by investigating student experiences in a design project assignment. The study used an exploratory design to collect data from student…

  13. Radioactive decay as a forced nuclear chemical process: Phenomenology

    NASA Astrophysics Data System (ADS)

    Timashev, S. F.

    2015-11-01

    Concepts regarding the mechanism of radioactive decay of nuclei are developed on the basis of a hypothesis that there is a dynamic relationship between the electronic and nuclear subsystems of an atom, and that fluctuating initiating effects of the electronic subsystem on a nucleus are possible. Such relationship is reflected in experimental findings that show the radioactive decay of nuclei might be determined by a positive difference between the mass of an initial nucleus and the mass of an atom's electronic subsystem, i.e., the mass of the entire atom (rather than that of its nucleus) and the total mass of the decay products. It is established that an intermediate nucleus whose charge is lower by unity than the charge of the initial radioactive nucleus is formed as a result of the above fluctuating stimuli that initiate radioactive decay, and its nuclear matter is thus in an unbalanced metastable state of inner shakeup, affecting the quark subsystem of nucleons. The intermediate nucleus thus experiences radioactive decay with the emission of α or β particles. At the same time, the high energy (with respect to the chemical scale) of electrons in plasma served as a factor initiating the processes in different nuclear chemical transformations and radioactive decays in low-temperature plasma studied earlier, particularly during the laser ablation of metals in aqueous solutions of different compositions and in near-surface cathode layers upon glow discharge. It is shown that a wide variety of nucleosynthesis processes in the Universe can be understood on the same basis, and a great many questions regarding the formation of light elements in the solar atmosphere and some heavy elements (particularly p-nuclei) in the interiors of massive stars at late stages of their evolution can also be resolved.

  14. Accelerating chemical database searching using graphics processing units.

    PubMed

    Liu, Pu; Agrafiotis, Dimitris K; Rassokhin, Dmitrii N; Yang, Eric

    2011-08-22

    The utility of chemoinformatics systems depends on the accurate computer representation and efficient manipulation of chemical compounds. In such systems, a small molecule is often digitized as a large fingerprint vector, where each element indicates the presence/absence or the number of occurrences of a particular structural feature. Since in theory the number of unique features can be exceedingly large, these fingerprint vectors are usually folded into much shorter ones using hashing and modulo operations, allowing fast "in-memory" manipulation and comparison of molecules. There is increasing evidence that lossless fingerprints can substantially improve retrieval performance in chemical database searching (substructure or similarity), which have led to the development of several lossless fingerprint compression algorithms. However, any gains in storage and retrieval afforded by compression need to be weighed against the extra computational burden required for decompression before these fingerprints can be compared. Here we demonstrate that graphics processing units (GPU) can greatly alleviate this problem, enabling the practical application of lossless fingerprints on large databases. More specifically, we show that, with the help of a ~$500 ordinary video card, the entire PubChem database of ~32 million compounds can be searched in ~0.2-2 s on average, which is 2 orders of magnitude faster than a conventional CPU. If multiple query patterns are processed in batch, the speedup is even more dramatic (less than 0.02-0.2 s/query for 1000 queries). In the present study, we use the Elias gamma compression algorithm, which results in a compression ratio as high as 0.097. PMID:21696144

  15. Trace chemical contaminant generation rates for spacecraft contamination control system design

    NASA Technical Reports Server (NTRS)

    Perry, J. L.

    1995-01-01

    A spacecraft presents a unique design challenge with respect to providing a comfortable environment in which people can live and work. All aspects of the spacecraft environmental design including the size of the habitable volume, its temperature, relative humidity, and composition must be considered to ensure the comfort and health of the occupants. The crew members and the materials selected for outfitting the spacecraft play an integral part in designing a habitable spacecraft because material offgassing and human metabolism are the primary sources for continuous trace chemical contaminant generation onboard a spacecraft. Since these contamination sources cannot be completely eliminated, active control processes must be designed and deployed onboard the spacecraft to ensure an acceptably clean cabin atmosphere. Knowledge of the expected rates at which contaminants are generated is very important to the design of these processes. Data from past spacecraft missions and human contaminant production studies have been analyzed to provide this knowledge. The resulting compilation of contaminants and generation rates serve as a firm basis for past, present, and future contamination control system designs for space and aeronautics applications.

  16. Hairy root culture: bioreactor design and process intensification.

    PubMed

    Stiles, Amanda R; Liu, Chun-Zhao

    2013-01-01

    The cultivation of hairy roots for the production of secondary metabolites offers numerous advantages; hairy roots have a fast growth rate, are genetically stable, and are relatively simple to maintain in phytohormone free media. Hairy roots provide a continuous source of secondary metabolites, and are useful for the production of chemicals for pharmaceuticals, cosmetics, and food additives. In order for hairy roots to be utilized on a commercial scale, it is necessary to scale-up their production. Over the last several decades, significant research has been conducted on the cultivation of hairy roots in various types of bioreactor systems. In this review, we discuss the advantages and disadvantages of various bioreactor systems, the major factors related to large-scale bioreactor cultures, process intensification technologies and overview the mathematical models and computer-aided methods that have been utilized for bioreactor design and development. PMID:23604206

  17. Primary Polymer Aging Processes Identified from Weapon Headspace Chemicals

    SciTech Connect

    Chambers, D M; Bazan, J M; Ithaca, J G

    2002-03-25

    A current focus of our weapon headspace sampling work is the interpretation of the volatile chemical signatures that we are collecting. To help validate our interpretation we have been developing a laboratory-based material aging capability to simulate material decomposition chemistries identified. Key to establishing this capability has been the development of an automated approach to process, analyze, and quantify arrays of material combinations as a function of time and temperature. Our initial approach involves monitoring the formation and migration of volatile compounds produced when a material decomposes. This approach is advantageous in that it is nondestructive and provides a direct comparison with our weapon headspace surveillance initiative. Nevertheless, this approach requires us to identify volatile material residue and decomposition byproducts that are not typically monitored and reported in material aging studies. Similar to our weapon monitoring method, our principle laboratory-based method involves static headspace collection by solid phase microextraction (SPME) followed by gas chromatography/mass spectrometry (GC/MS). SPME is a sorbent collection technique that is ideally suited for preconcentration and delivery of trace gas-phase compounds for analysis by GC. When combined with MS, detection limits are routinely in the low- and sub-ppb ranges, even for semivolatile and polar compounds. To automate this process we incorporated a robotic sample processor configured for SPME collection. The completed system will thermally process, sample, and analyze a material sample. Quantification of the instrument response is another process that has been integrated into the system. The current system screens low-milligram quantities of material for the formation or outgas of small compounds as initial indicators of chemical decomposition. This emerging capability offers us a new approach to identify and non-intrusively monitor decomposition mechanisms that are

  18. Economic-Oriented Stochastic Optimization in Advanced Process Control of Chemical Processes

    PubMed Central

    Dobos, László; Király, András; Abonyi, János

    2012-01-01

    Finding the optimal operating region of chemical processes is an inevitable step toward improving economic performance. Usually the optimal operating region is situated close to process constraints related to product quality or process safety requirements. Higher profit can be realized only by assuring a relatively low frequency of violation of these constraints. A multilevel stochastic optimization framework is proposed to determine the optimal setpoint values of control loops with respect to predetermined risk levels, uncertainties, and costs of violation of process constraints. The proposed framework is realized as direct search-type optimization of Monte-Carlo simulation of the controlled process. The concept is illustrated throughout by a well-known benchmark problem related to the control of a linear dynamical system and the model predictive control of a more complex nonlinear polymerization process. PMID:23213298

  19. Chemical Processing and Characterization of Fiber Reinforced Nanocomposite Silica Materials

    NASA Astrophysics Data System (ADS)

    Burnett, Steven Shannon

    Ultrasound techniques, acoustic and electroacoustic spectroscopy, are used to investigate and characterize concentrated fluid phase nanocomposites. In particular, the data obtained from ultrasound methods are used as tools to improve the understanding of the fundamental process chemistry of concentrated, multicomponent, nanomaterial dispersions. Silicon nitride nanofibers embedded in silica are particularly interesting for lightweight nanocomposites, because silicon nitride is isostructural to carbon nitride, a super hard material. However, the major challenge with processing these composites is retarding particle-particle aggregation, to maintain highly dispersed systems. Therefore, a systematic approach was developed to evaluate the affect of process parameters on particle-particle aggregation, and improving the chemical kinetics for gelation. From the acoustic analysis of the nanofibers, this thesis was able to deduce that changes in aspect ratio affects the ultrasound propagation. In particular, higher aspect ratio fibers attenuate the ultrasound wave greater than lower aspect fibers of the same material. Furthermore, our results confirm that changes in attenuation depend on the hydrodynamical interactions between particles, the aspect ratio, and the morphology of the dispersant. The results indicate that the attenuation is greater for fumed silica due to its elastic nature and its size, when compared to silica Ludox. Namely, the larger the size, the greater the attenuation. This attenuation is mostly the result of scattering loss in the higher frequency range. In addition, the silica nanofibers exhibit greater attenuation than their nanoparticle counterparts because of their aspect ratio influences their interaction with the ultrasound wave. In addition, this study observed how 3M NH 4 Cl's acoustic properties changes during the gelation process, and during that change, the frequency dependency deviates from the expected squared of the frequency, until the

  20. Launch Vehicle Design Process: Characterization, Technical Integration, and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Blair, J. C.; Ryan, R. S.; Schutzenhofer, L. A.; Humphries, W. R.

    2001-01-01

    Engineering design is a challenging activity for any product. Since launch vehicles are highly complex and interconnected and have extreme energy densities, their design represents a challenge of the highest order. The purpose of this document is to delineate and clarify the design process associated with the launch vehicle for space flight transportation. The goal is to define and characterize a baseline for the space transportation design process. This baseline can be used as a basis for improving effectiveness and efficiency of the design process. The baseline characterization is achieved via compartmentalization and technical integration of subsystems, design functions, and discipline functions. First, a global design process overview is provided in order to show responsibility, interactions, and connectivity of overall aspects of the design process. Then design essentials are delineated in order to emphasize necessary features of the design process that are sometimes overlooked. Finally the design process characterization is presented. This is accomplished by considering project technical framework, technical integration, process description (technical integration model, subsystem tree, design/discipline planes, decision gates, and tasks), and the design sequence. Also included in the document are a snapshot relating to process improvements, illustrations of the process, a survey of recommendations from experienced practitioners in aerospace, lessons learned, references, and a bibliography.

  1. In vitro perturbations of targets in cancer hallmark processes predict rodent chemical carcinogenesis.

    PubMed

    Kleinstreuer, Nicole C; Dix, David J; Houck, Keith A; Kavlock, Robert J; Knudsen, Thomas B; Martin, Matthew T; Paul, Katie B; Reif, David M; Crofton, Kevin M; Hamilton, Kerry; Hunter, Ronald; Shah, Imran; Judson, Richard S

    2013-01-01

    Thousands of untested chemicals in the environment require efficient characterization of carcinogenic potential in humans. A proposed solution is rapid testing of chemicals using in vitro high-throughput screening (HTS) assays for targets in pathways linked to disease processes to build models for priority setting and further testing. We describe a model for predicting rodent carcinogenicity based on HTS data from 292 chemicals tested in 672 assays mapping to 455 genes. All data come from the EPA ToxCast project. The model was trained on a subset of 232 chemicals with in vivo rodent carcinogenicity data in the Toxicity Reference Database (ToxRefDB). Individual HTS assays strongly associated with rodent cancers in ToxRefDB were linked to genes, pathways, and hallmark processes documented to be involved in tumor biology and cancer progression. Rodent liver cancer endpoints were linked to well-documented pathways such as peroxisome proliferator-activated receptor signaling and TP53 and novel targets such as PDE5A and PLAUR. Cancer hallmark genes associated with rodent thyroid tumors were found to be linked to human thyroid tumors and autoimmune thyroid disease. A model was developed in which these genes/pathways function as hypothetical enhancers or promoters of rat thyroid tumors, acting secondary to the key initiating event of thyroid hormone disruption. A simple scoring function was generated to identify chemicals with significant in vitro evidence that was predictive of in vivo carcinogenicity in different rat tissues and organs. This scoring function was applied to an external test set of 33 compounds with carcinogenicity classifications from the EPA's Office of Pesticide Programs and successfully (p = 0.024) differentiated between chemicals classified as "possible"/"probable"/"likely" carcinogens and those designated as "not likely" or with "evidence of noncarcinogenicity." This model represents a chemical carcinogenicity prioritization tool supporting targeted

  2. Microcavity array plasma system for remote chemical processing at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Lee, Dae-Sung; Hamaguchi, Satoshi; Sakai, Osamu; Park, Sung-Jin; Eden, J. Gary

    2012-06-01

    A microplasma system designed for chemical processing at atmospheric pressure is fabricated and characterized with flowing He/O2 gas mixtures. At the heart of this microcavity dielectric barrier discharge (MDBD) system are two arrays of half-ellipsoidal microcavities engraved by micropowder blasting into dielectric surfaces facing a flowing, low-temperature plasma. Experiments demonstrate that the ignition voltage is reduced, and the spatially averaged optical emission is doubled, for an MDBD flowing plasma array relative to an equivalent system having no microcavities. As an example of the potential of flowing atmospheric microplasma systems for chemical processing, the decomposition of methylene blue (as evidenced by decoloration at 650.2 nm) is shown to proceed at a rate as much as a factor of two greater than that for a non-microcavity equivalent.

  3. Computer Applications in the Design Process.

    ERIC Educational Resources Information Center

    Winchip, Susan

    Computer Assisted Design (CAD) and Computer Assisted Manufacturing (CAM) are emerging technologies now being used in home economics and interior design applications. A microcomputer in a computer network system is capable of executing computer graphic functions such as three-dimensional modeling, as well as utilizing office automation packages to…

  4. Lunar fiberglass: Properties and process design

    NASA Technical Reports Server (NTRS)

    Dalton, Robert; Nichols, Todd

    1987-01-01

    A Clemson University ceramic engineering design for a lunar fiberglass plant is presented. The properties of glass fibers and metal-matrix composites are examined. Lunar geology is also discussed. A raw material and site are selected based on this information. A detailed plant design is presented, and summer experiments to be carried out at Johnson Space Center are reviewed.

  5. Space bioreactor: Design/process flow

    NASA Technical Reports Server (NTRS)

    Cross, John H.

    1987-01-01

    The design of the space bioreactor stems from three considerations. First, and foremost, it must sustain cells in microgravity. Closely related is the ability to take advantage of the weightlessness and microgravity. Lastly, it should fit into a bioprocess. The design of the space bioreactor is described in view of these considerations. A flow chart of the bioreactor is presented and discussed.

  6. REMOVAL OF ENDOCRINE DISRUPTING CHEMICALS USING DRINKING WATER TREATMENT PROCESSES

    EPA Science Inventory

    A group of chemicals, known as endocrine disrupting chemicals (EDCs), has been identified as having the potential to cause adverse health effect in humans and wildlife. Among this group DDT, DDE, PCBs, endosulfan, methoxychlor, diethylphthalate, diethylhexylphalate, and bisphenol...

  7. Instructional Design and Directed Cognitive Processing.

    ERIC Educational Resources Information Center

    Bovy, Ruth Colvin

    This paper argues that the information processing model provides a promising basis on which to build a comprehensive theory of instruction. Characteristics of the major information processing constructs are outlined including attention, encoding and rehearsal, working memory, long term memory, retrieval, and metacognitive processes, and a unifying…

  8. Tuning the Interfacial Electronic Structure at Organic Heterojunctions by Chemical Design.

    PubMed

    Mothy, Sébastien; Guillaume, Maxime; Idé, Julien; Castet, Frédéric; Ducasse, Laurent; Cornil, Jérôme; Beljonne, David

    2012-09-01

    Quantum-chemical techniques are applied to assess the electronic structure at donor/acceptor heterojunctions of interest for organic solar cells. We show that electrostatic effects at the interface of model 1D stacks profoundly modify the energy landscape explored by charge carriers in the photoconversion process and that these can be tuned by chemical design. When fullerene C60 molecules are used as acceptors and unsubstituted oligothiophenes or pentacene are used as donors, the uncompensated quadrupolar electric field at the interface provides the driving force for splitting of the charge-transfer states into free charges. This quadrupolar field can be either enhanced by switching from a C60 to a perylene-tetracarboxylic-dianhydride (PTCDA) acceptor or suppressed by grafting electron-withdrawing groups on the donor. PMID:26292117

  9. Strategies and chemical design approaches to reduce the potential for formation of reactive metabolic species.

    PubMed

    Argikar, Upendra A; Mangold, James B; Harriman, Shawn P

    2011-01-01

    Metabolic activation of new chemical entities to reactive intermediates is routinely monitored in drug discovery and development. Reactive intermediates may bind to cellular macromolecules such as proteins, DNA and may eventually lead to cell death via necrosis, apoptosis or oxidative stress. The evidence that the ultimate outcome of metabolic activation is an adverse drug reaction manifested as in vivo toxicity, is at best circumstantial. However, understanding the process of bioactivation of structural alerts by trapping the reactive intermediates is critical to guide medicinal chemistry efforts in quest for safer and potent molecules. This commentary provides a brief introduction to adverse drug reactions and mechanisms of reactive intermediate formation for various functional groups, followed by a review of chemical design approaches, examples of such strategies, possible isosteric replacements for structural alerts and rationalization of laboratory approaches to determine reactive intermediates, as a guide to today's medicinal chemist. PMID:21320068

  10. Chemical and Electrochemical Processing of Aluminum Dross Using Molten Salts

    NASA Astrophysics Data System (ADS)

    Yan, Xiao Y.

    2008-04-01

    A novel molten salt process was investigated, where Al, as metal or contained in Al2O3 and AlN, was recovered from Al dross by chemical or direct electrochemical reduction in electrolytic cells. Electrolysis experiments were carried out under argon at temperatures from 1123 to 1243 K. In order to better understand the reduction behavior, the as-received Al dross was simulated using simplified systems, including pure Al2O3, pure AlN, an Al2O3/AlN binary mixture, and an Al2O3/AlN/Al ternary mixture. The reduction of the as-received dross was also studied experimentally. The studies showed that solid Al2O3 was chemically reduced by the Ca in a Ca-saturated Ca-CaCl2 melt to form Al2Ca or electrochemically reduced to Al-rich Al-Ca alloys and that the Al value in the Al2O3 was easily recovered from the Al drosses. It was found experimentally that solid AlN in the drosses could not be calciothermically reduced to any extent, consistent with thermodynamic evaluations. It was also found that the direct electrochemical reduction of the AlN in the drosses was confined to three phase boundaries (3PBs) between the AlN, the electrolyte, and the current collector and could not be enhanced by using the LiCl-containing chloride melt or the chloride-fluoride melts studied. The presence of Al powder in the Al2O3/AlN mixture facilitated the direct electrochemical reduction of both Al2O3 and AlN. The reduction mechanisms are discussed based upon the present experimental observations. Flow sheets for recovering the metallic Al and the Al in the Al2O3 and AlN from Al dross are finally proposed.

  11. DS-OPTIMAL DESIGNS FOR STUDYING COMBINATIONS OF CHEMICALS USING MULTIPLE FIXED-RATIO RAY EXPERIMENTS

    EPA Science Inventory

    ABSTRACT

    Detecting and characterizing interactions among chemicals is an important environmental issue. Traditional factorial designs become infeasible as the number of compounds under study increases. Ray designs, which reduce the amount of experimental effort, can be...

  12. Chemical inhibition of PCDD/F formation in incineration processes.

    PubMed

    Ruokojärvi, Päivi H; Asikainen, Arja H; Tuppurainen, Kari A; Ruuskanen, Juhani

    2004-06-01

    This review summarises results of our pilot-scale experiments to find suitable inhibitors for preventing the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) during waste incineration and to specify the role of the main factors affecting the inhibition process, and is based on doctoral dissertation of Ruokojaärvi (2002). Results of previous experiments reported by other researchers are also presented and compared with ours. The detailed aims of our experiments were (1) to compare the effects of different inhibitors on PCDD/F formation during incineration in a pilot plant, (2) to investigate the role of the particle size distribution of the flue gas on the inhibition of PCDD/Fs, and (3) to find the main parameters affecting PCDD/F inhibition in waste incineration. Prevention of the formation of PCDD/Fs with chemical inhibitors and the effects of different supply points, feed temperatures and process parameters were studied in a pilot scale incinerator (50 kW) using light heating oil and refuse-derived fuel as test fuels. Various concentrations of the gaseous inhibitors (sulfur dioxide, ammonia, dimethylamine and methyl mercaptan) were sprayed into the flue gases after the furnace, in addition to which urea was dissolved in water and injected in at different concentrations. The residence time of the flue gas between the furnace and the PCDD/F sampling point was varied in the tests. In another set of urea tests, urea-water solutions at three concentrations were mixed with the RDF prior to incineration. PCDD/F and chlorophenol concentrations, together with other flue gas parameters (e.g. temperature, O2, CO, CO2 and NO), were analysed in the cooling flue gases. The gaseous and liquid inhibitors both notably reduced PCDD/F concentrations in the flue gas, the reductions achieved with the gaseous inhibitors varying from 50 to 78%, with dimethyl amine the most effective, while that produced with urea was up to 90%. The PCDD/F reductions were

  13. The process of glauconitization: chemical and isotopic evidence

    NASA Astrophysics Data System (ADS)

    Stille, Peter; Clauer, Norbert

    1994-08-01

    Sequential leaching experiments were made on Recent glauconies and clay fractions of the associated mud from off-shore Africa near the estuary of the Congo River. Analyses of major/rare earth elements (REE) and Nd isotopic compositions on the resulting leachate and residue pairs allow identification of at least three important and isotopically distinct components which contributed to the glauconitization process: (1) a detrital component with relatively high 87Sr/86Sr and relatively low 143Nd/144Nd isotopic ratios; (2) a phosphate phase rich in REE and Sr with sea water Sr and Nd isotopic characteristics; (3) a component rich in organic matter and Ca with a sea water Sr isotopic signature, a relatively low Nd isotopic composition and elevated Sm/Nd ratios. This latter component probably represents the suspended organic and carbonate-rich river load. The detrital and the river components were mixed up in the muddy off-shore sediment, ingested by worms, and integrated into faecal pellets. The resulting material has Sr and Nd isotopic signatures intermediate between those of the detrital and river components, and represents the precursor of the glaucony minerals. During the subsequent dissolution-crystallization process, the glauconitic pellets remain isotopically closed to any external supply, but expulsion of Sr and Nd with increasing degree of maturation is observed without any effect on the Sr and Nd isotopic compositions. At a higher maturation stage (K2O>4.5%), the Sr and Nd isotopic compositions tend to decrease and increase, respectively, approximating the isotopic composition values of the phosphate-rich phase. Because the Sr and Nd concentrations decrease, the evolution of the glauconies toward lower Sr and higher Nd isotopic compositions can only be explained by expulsion of Sr and Nd of the detrital component with high Sr and low Nd isotopic signatures. Dissolution of the chemically unstable, wormdigested clay material from mud may be responsible for the

  14. Study on Product Innovative Design Process Driven by Ideal Solution

    NASA Astrophysics Data System (ADS)

    Zhang, Fuying; Lu, Ximei; Wang, Ping; Liu, Hui

    Product innovative design in companies today relies heavily on individual members’ experience and creative ideation as well as their skills of integrating creativity and innovation tools with design methods agilely. Creative ideation and inventive ideas generation are two crucial stages in product innovative design process. Ideal solution is the desire final ideas for given problem, and the striving reaching target for product design. In this paper, a product innovative design process driven by ideal solution is proposed. This design process encourages designers to overcome their psychological inertia, to foster creativity in a systematic way for acquiring breakthrough creative and innovative solutions in a reducing sphere of solution-seeking, and results in effective product innovative design rapidly. A case study example is also presented to illustrate the effectiveness of the proposed design process.

  15. Automating the design process - Progress, problems, prospects, potential.

    NASA Technical Reports Server (NTRS)

    Heldenfels, R. R.

    1973-01-01

    The design process for large aerospace vehicles is discussed, with particular emphasis on structural design. Problems with current procedures are identified. Then, the contributions possible from automating the design process (defined as the best combination of men and computers) are considered. Progress toward automated design in the aerospace and other communities is reviewed, including NASA studies of the potential development of Integrated Programs for Aerospace-Vehicle Design (IPAD). The need for and suggested directions of future research on the design process, both technical and social, are discussed. Although much progress has been made to exploit the computer in design, it is concluded that technology is available to begin using the computer to speed communications and management as well as calculations in the design process and thus build man-computer teams that can design better, faster and cheaper.

  16. Designing Educative Curriculum Materials: A Theoretically and Empirically Driven Process

    ERIC Educational Resources Information Center

    Davis, Elizabeth A.; Palincsar, Annemarie Sullivan; Arias, Anna Maria; Bismack, Amber Schultz; Marulis, Loren M.; Iwashyna, Stefanie K.

    2014-01-01

    In this article, the authors argue for a design process in the development of educative curriculum materials that is theoretically and empirically driven. Using a design-based research approach, they describe their design process for incorporating educative features intended to promote teacher learning into existing, high-quality curriculum…

  17. Information Architecture without Internal Theory: An Inductive Design Process.

    ERIC Educational Resources Information Center

    Haverty, Marsha

    2002-01-01

    Suggests that information architecture design is primarily an inductive process, partly because it lacks internal theory and partly because it is an activity that supports emergent phenomena (user experiences) from basic design components. Suggests a resemblance to Constructive Induction, a design process that locates the best representational…

  18. Learning Objects: A User-Centered Design Process

    ERIC Educational Resources Information Center

    Branon, Rovy F., III

    2011-01-01

    Design research systematically creates or improves processes, products, and programs through an iterative progression connecting practice and theory (Reinking, 2008; van den Akker, 2006). Developing a new instructional systems design (ISD) processes through design research is necessary when new technologies emerge that challenge existing practices…

  19. Flexible cold cathode with ultralow threshold field designed through wet chemical route

    NASA Astrophysics Data System (ADS)

    Maiti, U. N.; Maiti, S.; Thapa, R.; Chattopadhyay, K. K.

    2010-12-01

    A flexible cold cathode based on a uniform array of ZnO nanowires over carbon fabrics was designed via a simple wet chemical route. The structural parameters of the nanowires (i.e. length, diameter) as well as their arrangement over the carbon fibers were tailored by adjusting nutrient solution composition and growth duration. The optimized arrays of ZnO nanowires exhibit excellent electron emission performance with ultralow turn-on as well as threshold fields of 0.27 and 0.56 V µm - 1. This threshold field value is the lowest compared to any of the previous zinc-oxide-based cold cathodes realized through either chemical or vapor phase processes. In addition, the current density can reach an exceptionally high value of ~ 11 mA cm - 2 at an applied electric field of only 0.8 V µm - 1. Flexible electronic devices based on a field emitter cold cathode may thus be realized through chemical processing at low budget but having high efficiency.

  20. Introduction to Chemical Engineering Reactor Analysis: A Web-Based Reactor Design Game

    ERIC Educational Resources Information Center

    Orbey, Nese; Clay, Molly; Russell, T.W. Fraser

    2014-01-01

    An approach to explain chemical engineering through a Web-based interactive game design was developed and used with college freshman and junior/senior high school students. The goal of this approach was to demonstrate how to model a lab-scale experiment, and use the results to design and operate a chemical reactor. The game incorporates both…

  1. Optimality criteria design and stress constraint processing

    NASA Technical Reports Server (NTRS)

    Levy, R.

    1982-01-01

    Methods for pre-screening stress constraints into either primary or side-constraint categories are reviewed; a projection method, which is developed from prior cycle stress resultant history, is introduced as an additional screening parameter. Stress resultant projections are also employed to modify the traditional stress-ratio, side-constraint boundary. A special application of structural modification reanalysis is applied to the critical stress constraints to provide feasible designs that are preferable to those obtained by conventional scaling. Sample problem executions show relatively short run times and fewer design cycle iterations to achieve low structural weights; those attained are comparable to the minimum values developed elsewhere.

  2. The production of fuels and chemicals from food processing wastes & cellulosics. Final research report

    SciTech Connect

    Dale, M.C.; Okos, M.; Burgos, N.

    1997-06-15

    High strength food wastes of about 15-20 billion pounds solids are produced annually by US food producers. Low strength food wastes of 5-10 billion pounds/yr. are produced. Estimates of the various components of these waste streams are shown in Table 1. Waste paper/lignocellulosic crops could produce 2 to 5 billion gallons of ethanol per year or other valuable chemicals. Current oil imports cost the US about $60 billion dollars/yr. in out-going balance of trade costs. Many organic chemicals that are currently derived from petroleum can be produced through fermentation processes. Petroleum based processes have been preferred over biotechnology processes because they were typically cheaper, easier, and more efficient. The technologies developed during the course of this project are designed to allow fermentation based chemicals and fuels to compete favorably with petroleum based chemicals. Our goals in this project have been to: (1) develop continuous fermentation processes as compared to batch operations; (2) combine separation of the product with the fermentation, thus accomplishing the twin goals of achieving a purified product from a fermentation broth and speeding the conversion of substrate to product in the fermentation broth; (3) utilize food or cellulosic waste streams which pose a current cost or disposal problem as compared to high cost grains or sugar substrates; (4) develop low energy recovery methods for fermentation products; and finally (5) demonstrate successful lab scale technologies on a pilot/production scale and try to commercialize the processes. The scale of the wastes force consideration of {open_quotes}bulk commodity{close_quotes} type products if a high fraction of the wastes are to be utilized.

  3. The Idaho Chemical Processing Plant Special Nuclear Material vault upgrade

    SciTech Connect

    Anderson, R.C.; Holloway, E.R.

    1992-06-24

    This document discusses storage space in a Special Nuclear Material (SNM) product storage vault at the Idaho Chemical Processing Plant (ICPP) which has been recently expanded by approximately 175%. This expansion required a minimum of space and funding and resulted in a large increase in net storage capacity. Security for the additional storage is provided by standard intrusion sensors and by a real-time monitoring system, which monitors the weight of the material as it rests on weight sensors (load cells). The monitoring system also feeds weight data to a Safeguards processor which provides further confidence to Safeguards personnel. The Department of Energy requirements for bimonthly inventories for SNM stored in a particular part of this facility have been eliminated because of the guarantees provided by a real-time monitoring system. A higher efficiency has been obtained by using the expensive real estate inside a hardened product storage vault. This project has provided the ICPP with a relatively inexpensive vault upgrade and when product material is placed in this area of the vault the manpower requirements to inventory it will be reduced, resulting in a net reduction in plant worker radiation exposure.

  4. Erlang Behaviours: Programming with Process Design Patterns

    NASA Astrophysics Data System (ADS)

    Cesarini, Francesco; Thompson, Simon

    Erlang processes run independently of each other, each using separate memory and communicating with each other by message passing. These processes, while executing different code, do so following a number of common patterns. By examining different examples of Erlang-style concurrency in client/server architectures, we identify the generic and specific parts of the code and extract the generic code to form a process skeleton. In Erlang, the most commonly used patterns have been implemented in library modules, commonly referred to as OTP behaviours. They contain the generic code framework for concurrency and error handling, simplifying the complexity of concurrent programming and protecting the developer from many common pitfalls.

  5. Design Science Research for Business Process Design: Organizational Transition at Intersport Sweden

    NASA Astrophysics Data System (ADS)

    Lind, Mikael; Rudmark, Daniel; Seigerroth, Ulf

    Business processes need to be aligned with business strategies. This paper elaborates on experiences from a business process design effort in an action research project performed at Intersport Sweden. The purpose with this project was to create a solid base for taking the retail chain Intersport into a new organizational state where the new process design is aligned with strategic goals. Although business process modeling is concerned with creating artifacts, traditionally information systems design science research has had little impact on research on business process models. In this paper, we address the question of how design science research can contribute to business process design. Three heuristic guidelines for creating organizational commitment and strategic alignment in process design are presented. The guidelines are derived from the successful actions taken in the research project. The development of these guidelines is used as a basis to reflect upon the contribution of design science research to business process design.

  6. Processes and Knowledge in Designing Instruction.

    ERIC Educational Resources Information Center

    Greeno, James G.; And Others

    Results from a study of problem solving in the domain of instructional design are presented. Subjects were eight teacher trainees who were recent graduates of or were enrolled in the Stanford Teacher Education Program at Stanford University (California). Subjects studied a computer-based tutorial--the VST2000--about a fictitious vehicle. The…

  7. Electric utility engineer`s FGD manual -- Volume 1: FGD process design. Final report

    SciTech Connect

    1996-03-04

    Part 1 of the Electric Utility Engineer`s Flue Gas Desulfurization (FGD) Manual emphasizes the chemical and physical processes that form the basis for design and operation of lime- and limestone-based FGD systems applied to coal- or oil-fired steam electric generating stations. The objectives of Part 1 are: to provide a description of the chemical and physical design basis for lime- and limestone-based wet FGD systems; to identify and discuss the various process design parameters and process options that must be considered in developing a specification for a new FGD system; and to provide utility engineers with process knowledge useful for operating and optimizing a lime- or limestone-based wet FGD system.

  8. Understanding the Processes behind Student Designing: Cases from Singapore

    ERIC Educational Resources Information Center

    Lim, Susan Siok Hiang; Lim-Ratnam, Christina; Atencio, Matthew

    2013-01-01

    A common perception of designing is that it represents a highly complex activity that is manageable by only a few. However it has also been argued that all individuals are innately capable of designing. Taking up this latter view, we explored the processes behind student designing in the context of Design and Technology (D&T), a subject taught at…

  9. Thermo-Chemical Modelling Strategies for the Pultrusion Process

    NASA Astrophysics Data System (ADS)

    Baran, Ismet; Hattel, Jesper H.; Tutum, Cem C.

    2013-12-01

    In the present study, three dimensional (3D) numerical modeling strategies of a thermosetting pultrusion process are investigated considering both transient and steady state approaches. For the transient solution, an unconditionally stable alternating direction implicit Douglas-Gunn (ADI-DG) scheme is implemented as a first contribution of its kind in this specific field of application. The corresponding results are compared with the results obtained from the transient fully implicit scheme, the straightforward extension of the 2D ADI and the steady state approach. The implementation of the proposed approach is described in detail. The calculated temperature and cure degree profiles at steady state are found to agree well with results obtained from similar analyses in the literature. Detailed case studies are carried out investigating the computational accuracy and the efficiency of the 3D ADI-DG solver. It is found that the steady state approach is much faster than the transient approach in terms of the computational time and the number of iteration loops to obtain converged results for reaching the steady state. Hence, it is highly suitable for automatic process optimization which often involves many design evaluations. On the other hand sometimes the transient regime may be of interest and here the proposed ADI-DG method shows to be considerably faster than the transient fully implicit method which is generally used by the general purpose commercial finite element solvers. Finally, using the proposed steady-state approach, a design of experiments is carried out for the curing characteristic of the product based on pulling speed and part thickness.

  10. Whole Wafer Design and Fabrication for the Alignment of Nanostructures for Chemical Sensor Applications

    NASA Technical Reports Server (NTRS)

    Biaggi-Labiosa, Azlin M.; Hunter, Gary W.

    2013-01-01

    A major objective in aerospace sensor development is to produce sensors that are small in size, easy to batch fabricate and low in cost, and have low power consumption The fabrication of chemical sensors involving nanostructured materials can provide these properties as well as the potential for the development of sensor systems with unique properties and improved performance. However, the fabrication and processing of nanostructures for sensor applications currently is limited in the ability to control their location on the sensor. Currently, our group at NASA Glenn Research Center has demonstrated the controlled placement of nanostructures in sensors using a sawtooth patterned electrode design. With this design the nanostructures are aligned between opposing sawtooth electrodes by applying an alternating current.

  11. Enhanced teaching and student learning through a simulator-based course in chemical unit operations design

    NASA Astrophysics Data System (ADS)

    Ghasem, Nayef

    2016-07-01

    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 through simulators. A case study presenting the teaching method was evaluated using student surveys and faculty assessments, which were designed to measure the quality and effectiveness of the teaching method. The results of the questionnaire conclusively demonstrate that this method is an extremely efficient way of teaching a simulator-based course. In addition to that, this teaching method can easily be generalised and used in other courses. A student's final mark is determined by a combination of in-class assessments conducted based on cooperative and peer learning, progress tests and a final exam. Results revealed that peer learning can improve the overall quality of student learning and enhance student understanding.

  12. Chemical and Metallurgy Research (CMR) Sample Tracking System Design Document

    SciTech Connect

    Bargelski, C. J.; Berrett, D. E.

    1998-09-01

    The purpose of this document is to describe the system architecture of the Chemical and Metallurgy Research (CMR) Sample Tracking System at Los Alamos National Laboratory. During the course of the document observations are made concerning the objectives, constraints and limitations, technical approaches, and the technical deliverables.

  13. Reducing Design Cycle Time and Cost Through Process Resequencing

    NASA Technical Reports Server (NTRS)

    Rogers, James L.

    2004-01-01

    In today's competitive environment, companies are under enormous pressure to reduce the time and cost of their design cycle. One method for reducing both time and cost is to develop an understanding of the flow of the design processes and the effects of the iterative subcycles that are found in complex design projects. Once these aspects are understood, the design manager can make decisions that take advantage of decomposition, concurrent engineering, and parallel processing techniques to reduce the total time and the total cost of the design cycle. One software tool that can aid in this decision-making process is the Design Manager's Aid for Intelligent Decomposition (DeMAID). The DeMAID software minimizes the feedback couplings that create iterative subcycles, groups processes into iterative subcycles, and decomposes the subcycles into a hierarchical structure. The real benefits of producing the best design in the least time and at a minimum cost are obtained from sequencing the processes in the subcycles.

  14. NASA Now: Engineering Design Process: Hubble Space Telescope

    NASA Video Gallery

    In this episode of NASA Now, NASA engineer Russ Werneth discusses the continuous nature of the engineering design process and shares what it was like to design and plan the spacewalks that were key...

  15. Integrating Thermal Tools Into the Mechanical Design Process

    NASA Technical Reports Server (NTRS)

    Tsuyuki, Glenn T.; Siebes, Georg; Novak, Keith S.; Kinsella, Gary M.

    1999-01-01

    The intent of mechanical design is to deliver a hardware product that meets or exceeds customer expectations, while reducing cycle time and cost. To this end, an integrated mechanical design process enables the idea of parallel development (concurrent engineering). This represents a shift from the traditional mechanical design process. With such a concurrent process, there are significant issues that have to be identified and addressed before re-engineering the mechanical design process to facilitate concurrent engineering. These issues also assist in the integration and re-engineering of the thermal design sub-process since it resides within the entire mechanical design process. With these issues in mind, a thermal design sub-process can be re-defined in a manner that has a higher probability of acceptance, thus enabling an integrated mechanical design process. However, the actual implementation is not always problem-free. Experience in applying the thermal design sub-process to actual situations provides the evidence for improvement, but more importantly, for judging the viability and feasibility of the sub-process.

  16. Sustainability Indicators for Chemical Processes : II. Data Needs

    EPA Science Inventory

    In order to begin repair of the environmental quality of the planet, there is a need to embrace sustainable development at many levels of the chemical industry and society. One way that the chemical industry is responding to this need is through sustainability evaluations, retrof...

  17. Control and optimization system and method for chemical looping processes

    DOEpatents

    Lou, Xinsheng; Joshi, Abhinaya; Lei, Hao

    2014-06-24

    A control system for optimizing a chemical loop system includes one or more sensors for measuring one or more parameters in a chemical loop. The sensors are disposed on or in a conduit positioned in the chemical loop. The sensors generate one or more data signals representative of an amount of solids in the conduit. The control system includes a data acquisition system in communication with the sensors and a controller in communication with the data acquisition system. The data acquisition system receives the data signals and the controller generates the control signals. The controller is in communication with one or more valves positioned in the chemical loop. The valves are configured to regulate a flow of the solids through the chemical loop.

  18. Control and optimization system and method for chemical looping processes

    DOEpatents

    Lou, Xinsheng; Joshi, Abhinaya; Lei, Hao

    2015-02-17

    A control system for optimizing a chemical loop system includes one or more sensors for measuring one or more parameters in a chemical loop. The sensors are disposed on or in a conduit positioned in the chemical loop. The sensors generate one or more data signals representative of an amount of solids in the conduit. The control system includes a data acquisition system in communication with the sensors and a controller in communication with the data acquisition system. The data acquisition system receives the data signals and the controller generates the control signals. The controller is in communication with one or more valves positioned in the chemical loop. The valves are configured to regulate a flow of the solids through the chemical loop.

  19. The application of image processing software: Photoshop in environmental design

    NASA Astrophysics Data System (ADS)

    Dong, Baohua; Zhang, Chunmi; Zhuo, Chen

    2011-02-01

    In the process of environmental design and creation, the design sketch holds a very important position in that it not only illuminates the design's idea and concept but also shows the design's visual effects to the client. In the field of environmental design, computer aided design has made significant improvement. Many types of specialized design software for environmental performance of the drawings and post artistic processing have been implemented. Additionally, with the use of this software, working efficiency has greatly increased and drawings have become more specific and more specialized. By analyzing the application of photoshop image processing software in environmental design and comparing and contrasting traditional hand drawing and drawing with modern technology, this essay will further explore the way for computer technology to play a bigger role in environmental design.

  20. INTEGRATION OF SYSTEMS ENGINEERING AND PROCESS INTENSIFICATION IN THE DESIGN OF PROCESSES FOR UTILIZING BIOBASED GLYCEROL

    EPA Science Inventory

    The expected results include an integrated process and mechanical design including a fabrication plan for the glycerol dehydration reactor, comprehensive heat and material balance, environmental impact assessment and comprehensive safety review. The resulting process design w...

  1. Algorithmic Processes for Increasing Design Efficiency.

    ERIC Educational Resources Information Center

    Terrell, William R.

    1983-01-01

    Discusses the role of algorithmic processes as a supplementary method for producing cost-effective and efficient instructional materials. Examines three approaches to problem solving in the context of developing training materials for the Naval Training Command: application of algorithms, quasi-algorithms, and heuristics. (EAO)

  2. Adding Users to the Website Design Process

    ERIC Educational Resources Information Center

    Tomeo, Megan L.

    2012-01-01

    Alden Library began redesigning its website over a year ago. Throughout the redesign process the students, faculty, and staff that make up the user base were added to the conversation by utilizing several usability test methods. This article focuses on the usability testing conducted at Alden Library and delves into future usability testing, which…

  3. A design optimization process for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Chamberlain, Robert G.; Fox, George; Duquette, William H.

    1990-01-01

    The Space Station Freedom Program is used to develop and implement a process for design optimization. Because the relative worth of arbitrary design concepts cannot be assessed directly, comparisons must be based on designs that provide the same performance from the point of view of station users; such designs can be compared in terms of life cycle cost. Since the technology required to produce a space station is widely dispersed, a decentralized optimization process is essential. A formulation of the optimization process is provided and the mathematical models designed to facilitate its implementation are described.

  4. CAD tool environment for MEMS process design support

    NASA Astrophysics Data System (ADS)

    Schmidt, T.; Wagener, A.; Popp, J.; Hahn, K.; Bruck, R.

    2005-07-01

    MEMS fabrication processes are characterized by a numerous useable process steps, materials and effects to fabricate the intended microstructure. Up to now CAD support in this domain concentrates mainly on the structural design (e.g. simulation programs on FEM basis). These tools often assume fixed interfaces to fabrication process like material parameters or design rules. Taking into account that MEMS design requires concurrently structural design (defining the lateral 2-dim shapes) as well as process design (responsible for the third dimension) it turns out that technology interfaces consisting only of sets of static data are no longer sufficient. For successful design flows in these areas it is necessary to incorporate a higher degree of process related data. A broader interface between process configuration on the one side and the application design on the other side seems to be needed. This paper proposes a novel approach. A process management system is introduced. It allows the specification of processes for specific applications. The system is based on a dedicated database environment that is able to store and manage all process related design constraints linked to the fabrication process data itself. The interdependencies between application specific processes and all stages of the design flow will be discussed and the complete software system PRINCE will be introduced meeting the requirements of this new approach. Based on a concurrent design methodology presented in the beginning of this paper, a system is presented that supports application specific process design. The paper will highlight the incorporated tools and the present status of the software system. A complete configuration of an Si-thin film process example will demonstrate the usage of PRINCE.

  5. In vitro Perturbations of Targets in Cancer Hallmark Processes Predict Rodent Chemical Carcinogenesis

    EPA Science Inventory

    Thousands of untested chemicals in the environment require efficient characterization of carcinogenic potential in humans. A proposed solution is rapid testing of chemicals using in vitro high-throughput screening (HTS) assays for targets in pathways linked to disease processes ...

  6. Launch Vehicle Design Process Description and Training Formulation

    NASA Technical Reports Server (NTRS)

    Atherton, James; Morris, Charles; Settle, Gray; Teal, Marion; Schuerer, Paul; Blair, James; Ryan, Robert; Schutzenhofer, Luke

    1999-01-01

    A primary NASA priority is to reduce the cost and improve the effectiveness of launching payloads into space. As a consequence, significant improvements are being sought in the effectiveness, cost, and schedule of the launch vehicle design process. In order to provide a basis for understanding and improving the current design process, a model has been developed for this complex, interactive process, as reported in the references. This model requires further expansion in some specific design functions. Also, a training course for less-experienced engineers is needed to provide understanding of the process, to provide guidance for its effective implementation, and to provide a basis for major improvements in launch vehicle design process technology. The objective of this activity is to expand the description of the design process to include all pertinent design functions, and to develop a detailed outline of a training course on the design process for launch vehicles for use in educating engineers whose experience with the process has been minimal. Building on a previously-developed partial design process description, parallel sections have been written for the Avionics Design Function, the Materials Design Function, and the Manufacturing Design Function. Upon inclusion of these results, the total process description will be released as a NASA TP. The design function sections herein include descriptions of the design function responsibilities, interfaces, interactive processes, decisions (gates), and tasks. Associated figures include design function planes, gates, and tasks, along with other pertinent graphics. Also included is an expanded discussion of how the design process is divided, or compartmentalized, into manageable parts to achieve efficient and effective design. A detailed outline for an intensive two-day course on the launch vehicle design process has been developed herein, and is available for further expansion. The course is in an interactive lecture

  7. Experimental investigation of Mars meandering rivers: Chemical precipitation process

    NASA Astrophysics Data System (ADS)

    Kim, W.; Lim, Y.; Cleveland, J.; Reid, E.; Jew, C.

    2014-12-01

    On Earth, meandering streams occur where the banks are resistant to erosion, which enhances narrow and deep channels. Often this is because the stream banks are held firm by vegetation. The ancient, highly sinuous channels with cutoffs found on Mars are enigmatic because vegetation played no role in providing bank cohesion and enhancing fine sediment deposition. Possible causes of the meandering therefore include ice under permafrost conditions and chemical processes. We conducted carbonate flume experiments to investigate possible mechanisms creating meandering channels other than vegetation. The experiment includes a tank that dissolves limestone by adding CO2 gas and produces artificial spring water, peristaltic pumps to drive water through the system, a heater to control the temperature of the spring water, and a flume where carbonate sediment deposits. Spring water containing dissolved calcium and carbonate ions moves through a heater to increase temperature, and then into the flume. The flume surface is open to the air to allow CO2 degassing, decrease temperature, and increase pH, which promotes carbonate precipitation. A preliminary experiment was done and successfully created a meander pattern that evolved over a 3-day experiment. The experiment showed lateral migration of the bend and avulsion of the stream, similar to a natural meander. The lateral variation in flow speed increased the local residence time of water, thus increasing the degassing of CO2 on the two sides of the flow and promoting more precipitation. This enhanced precipitation on the sides provided a mechanism to build levees along the channel and created a stream confined in a narrow path. This mechanism also potentially applies to Earthly single thread and/or meandering rivers developed and recorded before vegetation appeared on Earth's surface.

  8. Lignocellulosic ethanol: Technology design and its impact on process efficiency.

    PubMed

    Paulova, Leona; Patakova, Petra; Branska, Barbora; Rychtera, Mojmir; Melzoch, Karel

    2015-11-01

    This review provides current information on the production of ethanol from lignocellulosic biomass, with the main focus on relationships between process design and efficiency, expressed as ethanol concentration, yield and productivity. In spite of unquestionable advantages of lignocellulosic biomass as a feedstock for ethanol production (availability, price, non-competitiveness with food, waste material), many technological bottlenecks hinder its wide industrial application and competitiveness with 1st generation ethanol production. Among the main technological challenges are the recalcitrant structure of the material, and thus the need for extensive pretreatment (usually physico-chemical followed by enzymatic hydrolysis) to yield fermentable sugars, and a relatively low concentration of monosaccharides in the medium that hinder the achievement of ethanol concentrations comparable with those obtained using 1st generation feedstocks (e.g. corn or molasses). The presence of both pentose and hexose sugars in the fermentation broth, the price of cellulolytic enzymes, and the presence of toxic compounds that can inhibit cellulolytic enzymes and microbial producers of ethanol are major issues. In this review, different process configurations of the main technological steps (enzymatic hydrolysis, fermentation of hexose/and or pentose sugars) are discussed and their efficiencies are compared. The main features, benefits and drawbacks of simultaneous saccharification and fermentation (SSF), simultaneous saccharification and fermentation with delayed inoculation (dSSF), consolidated bioprocesses (CBP) combining production of cellulolytic enzymes, hydrolysis of biomass and fermentation into one step, together with an approach combining utilization of both pentose and hexose sugars are discussed and compared with separate hydrolysis and fermentation (SHF) processes. The impact of individual technological steps on final process efficiency is emphasized and the potential for use

  9. Development of a polysilicon process based on chemical vapor deposition (phase 1)

    NASA Technical Reports Server (NTRS)

    Mccormick, J.; Arvidson, A.; Sawyer, D.; Plahutnik, F.

    1981-01-01

    A dichlorosilane-based reductive chemical vapor deposition (CVD) process demonstrated is capable of producing, at low cost, high quality polycrystalline silicon. Testing of decomposition reactor heat shields to insure that the shield provides adequate personnel protection assuming a worst case explosion was completed. Minor modifications to a production reactor heat shield provided adequate heat shield integrity. Construction of the redesigned PDU (Process Development Unit) to accommodate all safety related information proceeded on schedule. Structural steel work was completed as is the piping and instrumentation design work. Major pieces of process equipment were received and positioned in the support structure and all transfer piping and conduits to the PDU were installed. Construction was completed on a feed system for supplying DCS to an intermediate sized reactor. The feed system was successfully interfaced with a reactor equipped with a modified heat shield. Reactor checkout was completed.

  10. Hydrodeoxygenation processes: advances on catalytic transformations of biomass-derived platform chemicals into hydrocarbon fuels.

    PubMed

    De, Sudipta; Saha, Basudeb; Luque, Rafael

    2015-02-01

    Lignocellulosic biomass provides an attractive source of renewable carbon that can be sustainably converted into chemicals and fuels. Hydrodeoxygenation (HDO) processes have recently received considerable attention to upgrade biomass-derived feedstocks into liquid transportation fuels. The selection and design of HDO catalysts plays an important role to determine the success of the process. This review has been aimed to emphasize recent developments on HDO catalysts in effective transformations of biomass-derived platform molecules into hydrocarbon fuels with reduced oxygen content and improved H/C ratios. Liquid hydrocarbon fuels can be obtained by combining oxygen removal processes (e.g. dehydration, hydrogenation, hydrogenolysis, decarbonylation etc.) as well as by increasing the molecular weight via C-C coupling reactions (e.g. aldol condensation, ketonization, oligomerization, hydroxyalkylation etc.). Fundamentals and mechanistic aspects of the use of HDO catalysts in deoxygenation reactions will also be discussed. PMID:25443804

  11. Design, fabrication, and bench testing of a solar chemical receiver

    NASA Technical Reports Server (NTRS)

    Summers, W. A.; Pierre, J. F.

    1981-01-01

    Solar thermal energy can be effectively collected, transported, stored, and utilized by means of a chemical storage and transport system employing the reversible SO2 oxidation reaction. A solar chemical receiver for SO3 thermal decomposition to SO2 and oxygen was analyzed. Bench tests of a ten foot section of a receiver module were conducted with dissociated sulfuric acid (SO3 and H2O) in an electrical furnace. Measured percent conversion of SO3 was 85% of the equilibrium value. Methods were developed to fabricate and assemble a complete receiver module. These methods included applying an aluminide coating to certain exposed surfaces, assembling concentric tubes with a wire spacer, applying a platinum catalyst to the tubing wall, and coiling the entire assembly into the desired configuration.

  12. MIDAS: a framework for integrated design and manufacturing process

    NASA Astrophysics Data System (ADS)

    Chung, Moon Jung; Kwon, Patrick; Pentland, Brian

    2000-10-01

    In this paper, we present a development of a framework for managing design and manufacturing process in a distributed environment. The framework offers the following facilities: (1) to represent the complicated engineering design processes (2) to coordinate design activities and execute the process in a distributed environment and (3) to support a collaborative design by sharing data and processes. In this paper, the process flow graphs, which consist in tasks and the corresponding input and output data, are used to depict the engineering design process on a process modeling browser. The engineering activities in the represented processes can be executed in a distributed environment through the cockpit of the framework. The communication among the related engineers to support a collaborative design is made on the collaborative design browser with SML underlying data structures of representing process information to make the framework extensible and platform- independent. The formal and flexible approach of the proposed framework to integrate the engineering design processes can be also effectively applied to coordinate concurrent engineering activities in a distributed environment.

  13. Ceramic processing: Experimental design and optimization

    NASA Technical Reports Server (NTRS)

    Weiser, Martin W.; Lauben, David N.; Madrid, Philip

    1992-01-01

    The objectives of this paper are to: (1) gain insight into the processing of ceramics and how green processing can affect the properties of ceramics; (2) investigate the technique of slip casting; (3) learn how heat treatment and temperature contribute to density, strength, and effects of under and over firing to ceramic properties; (4) experience some of the problems inherent in testing brittle materials and learn about the statistical nature of the strength of ceramics; (5) investigate orthogonal arrays as tools to examine the effect of many experimental parameters using a minimum number of experiments; (6) recognize appropriate uses for clay based ceramics; and (7) measure several different properties important to ceramic use and optimize them for a given application.

  14. Clutter suppression interferometry system design and processing

    NASA Astrophysics Data System (ADS)

    Knight, Chad; Deming, Ross; Gunther, Jake

    2015-05-01

    Clutter suppression interferometry (CSI) has received extensive attention due to its multi-modal capability to detect slow-moving targets, and concurrently form high-resolution synthetic aperture radar (SAR) images from the same data. The ability to continuously augment SAR images with geo-located ground moving target indicators (GMTI) provides valuable real-time situational awareness that is important for many applications. CSI can be accomplished with minimal hardware and processing resources. This makes CSI a natural candidate for applications where size, weight and power (SWaP) are constrained, such as unmanned aerial vehicles (UAVs) and small satellites. This paper will discuss the theory for optimal CSI system configuration focusing on sparse time-varying transmit and receive array manifold due to SWaP considerations. The underlying signal model will be presented and discussed as well as the potential benefits that a sparse time-varying transmit receive manifold provides. The high-level processing objectives will be detailed and examined on simulated data. Then actual SAR data collected with the Space Dynamic Laboratory (SDL) FlexSAR radar system will be analyzed. The simulated data contrasted with actual SAR data helps illustrate the challenges and limitations found in practice vs. theory. A new novel approach incorporating sparse signal processing is discussed that has the potential to reduce false- alarm rates and improve detections.

  15. H-Coal process and plant design

    DOEpatents

    Kydd, Paul H.; Chervenak, Michael C.; DeVaux, George R.

    1983-01-01

    A process for converting coal and other hydrocarbonaceous materials into useful and more valuable liquid products. The process comprises: feeding coal and/or other hydrocarbonaceous materials with a hydrogen-containing gas into an ebullated catalyst bed reactor; passing the reaction products from the reactor to a hot separator where the vaporous and distillate products are separated from the residuals; introducing the vaporous and distillate products from the separator directly into a hydrotreater where they are further hydrogenated; passing the residuals from the separator successively through flash vessels at reduced pressures where distillates are flashed off and combined with the vaporous and distillate products to be hydrogenated; transferring the unseparated residuals to a solids concentrating and removal means to remove a substantial portion of solids therefrom and recycling the remaining residual oil to the reactor; and passing the hydrogenated vaporous and distillate products to an atmospheric fractionator where the combined products are fractionated into separate valuable liquid products. The hydrogen-containing gas is generated from sources within the process.

  16. Experimental design for improved ceramic processing, emphasizing the Taguchi Method

    SciTech Connect

    Weiser, M.W. . Mechanical Engineering Dept.); Fong, K.B. )

    1993-12-01

    Ceramic processing often requires substantial experimentation to produce acceptable product quality and performance. This is a consequence of ceramic processes depending upon a multitude of factors, some of which can be controlled and others that are beyond the control of the manufacturer. Statistical design of experiments is a procedure that allows quick, economical, and accurate evaluation of processes and products that depend upon several variables. Designed experiments are sets of tests in which the variables are adjusted methodically. A well-designed experiment yields unambiguous results at minimal cost. A poorly designed experiment may reveal little information of value even with complex analysis, wasting valuable time and resources. This article will review the most common experimental designs. This will include both nonstatistical designs and the much more powerful statistical experimental designs. The Taguchi Method developed by Grenichi Taguchi will be discussed in some detail. The Taguchi method, based upon fractional factorial experiments, is a powerful tool for optimizing product and process performance.

  17. DESIGNING SUSTAINABLE PROCESSES WITH SIMULATION: THE WASTE REDUCTION (WAR) ALGORITHM

    EPA Science Inventory

    The WAR Algorithm, a methodology for determining the potential environmental impact (PEI) of a chemical process, is presented with modifications that account for the PEI of the energy consumed within that process. From this theory, four PEI indexes are used to evaluate the envir...

  18. Chemical Equilibrium And Transport (CET)

    NASA Technical Reports Server (NTRS)

    Mcbride, B. J.

    1991-01-01

    Powerful, machine-independent program calculates theoretical thermodynamic properties of chemical systems. Aids in design of compressors, turbines, engines, heat exchangers, and chemical processing equipment.

  19. FY13 GLYCOLIC-NITRIC ACID FLOWSHEET DEMONSTRATIONS OF THE DWPF CHEMICAL PROCESS CELL WITH SIMULANTS

    SciTech Connect

    Lambert, D.; Zamecnik, J.; Best, D.

    2014-03-13

    Savannah River Remediation is evaluating changes to its current Defense Waste Processing Facility flowsheet to replace formic acid with glycolic acid in order to improve processing cycle times and decrease by approximately 100x the production of hydrogen, a potentially flammable gas. Higher throughput is needed in the Chemical Processing Cell since the installation of the bubblers into the melter has increased melt rate. Due to the significant maintenance required for the safety significant gas chromatographs and the potential for production of flammable quantities of hydrogen, eliminating the use of formic acid is highly desirable. Previous testing at the Savannah River National Laboratory has shown that replacing formic acid with glycolic acid allows the reduction and removal of mercury without significant catalytic hydrogen generation. Five back-to-back Sludge Receipt and Adjustment Tank (SRAT) cycles and four back-to-back Slurry Mix Evaporator (SME) cycles were successful in demonstrating the viability of the nitric/glycolic acid flowsheet. The testing was completed in FY13 to determine the impact of process heels (approximately 25% of the material is left behind after transfers). In addition, back-to-back experiments might identify longer-term processing problems. The testing was designed to be prototypic by including sludge simulant, Actinide Removal Product simulant, nitric acid, glycolic acid, and Strip Effluent simulant containing Next Generation Solvent in the SRAT processing and SRAT product simulant, decontamination frit slurry, and process frit slurry in the SME processing. A heel was produced in the first cycle and each subsequent cycle utilized the remaining heel from the previous cycle. Lower SRAT purges were utilized due to the low hydrogen generation. Design basis addition rates and boilup rates were used so the processing time was shorter than current processing rates.

  20. Development of Integrated Programs for Aerospace-vehicle design (IPAD): Reference design process

    NASA Technical Reports Server (NTRS)

    Meyer, D. D.

    1979-01-01

    The airplane design process and its interfaces with manufacturing and customer operations are documented to be used as criteria for the development of integrated programs for the analysis, design, and testing of aerospace vehicles. Topics cover: design process management, general purpose support requirements, design networks, and technical program elements. Design activity sequences are given for both supersonic and subsonic commercial transports, naval hydrofoils, and military aircraft.

  1. Debating Professional Designations for Evaluators: Reflections on the Canadian Process

    ERIC Educational Resources Information Center

    Cousins, J. Bradley; Cullen, Jim; Malik, Sumbal; Maicher, Brigitte

    2009-01-01

    This paper provides a reflective account of a consultation process on professional designations for evaluators initiated and coordinated by the Canadian Evaluation Society (CES). Described are: (1) the forces leading CES to generate discussion and debate about professional designations for Canadian evaluators, (2) the process of developing and…

  2. Process Design Manual for Land Treatment of Municipal Wastewater.

    ERIC Educational Resources Information Center

    Crites, R.; And Others

    This manual presents a procedure for the design of land treatment systems. Slow rate, rapid infiltration, and overland flow processes for the treatment of municipal wastewaters are given emphasis. The basic unit operations and unit processes are discussed in detail, and the design concepts and criteria are presented. The manual includes design…

  3. Laser processing with specially designed laser beam

    NASA Astrophysics Data System (ADS)

    Asratyan, A. A.; Bulychev, N. A.; Feofanov, I. N.; Kazaryan, M. A.; Krasovskii, V. I.; Lyabin, N. A.; Pogosyan, L. A.; Sachkov, V. I.; Zakharyan, R. A.

    2016-04-01

    The possibility of using laser systems to form beams with special spatial configurations has been studied. The laser systems applied had a self-conjugate cavity based on the elements of copper vapor lasers (LT-5Cu, LT-10Cu, LT-30Cu) with an average power of 5, 10, or 30 W. The active elements were pumped by current pulses of duration 80-100 ns. The duration of laser generation pulses was up to 25 ns. The generator unit included an unstable cavity, where one reflector was a special mirror with a reflecting coating. Various original optical schemes used were capable of exploring spatial configurations and energy characteristics of output laser beams in their interaction with micro- and nanoparticles fabricated from various materials. In these experiments, the beam dimensions of the obtained zones varied from 0.3 to 5 µm, which is comparable with the minimum permissible dimensions determined by the optical elements applied. This method is useful in transforming a large amount of information at the laser pulse repetition rate of 10-30 kHz. It was possible to realize the high-precision micromachining and microfabrication of microscale details by direct writing, cutting and drilling (with the cutting width and through-hole diameters ranging from 3 to 100 µm) and produce microscale, deep, intricate and narrow grooves on substrate surfaces of metals and nonmetal materials. This system is used for producing high-quality microscale details without moving the object under treatment. It can also be used for microcutting and microdrilling in a variety of metals such as molybdenum, copper and stainless steel, with a thickness of up to 300 µm, and in nonmetals such as silicon, sapphire and diamond with a thickness ranging from 10 µm to 1 mm with different thermal parameters and specially designed laser beam.

  4. Solid propellant processing factor in rocket motor design

    NASA Technical Reports Server (NTRS)

    1971-01-01

    The ways are described by which propellant processing is affected by choices made in designing rocket engines. Tradeoff studies, design proof or scaleup studies, and special design features are presented that are required to obtain high product quality, and optimum processing costs. Processing is considered to include the operational steps involved with the lining and preparation of the motor case for the grain; the procurement of propellant raw materials; and propellant mixing, casting or extrusion, curing, machining, and finishing. The design criteria, recommended practices, and propellant formulations are included.

  5. An Elective Course on Computer-Aided Process Design.

    ERIC Educational Resources Information Center

    Sommerfeld, Jude T.

    1979-01-01

    Describes an undergraduate chemical engineering course which has been offered at the Georgia Institute of Technology. The objectives, structure, instructional materials and content of this course, which emphasizes the structure and usage of computer-aided design systems, are also included. (HM)

  6. Design of smart imagers with image processing

    NASA Astrophysics Data System (ADS)

    Serova, Evgeniya N.; Shiryaev, Yury A.; Udovichenko, Anton O.

    2005-06-01

    This paper is devoted to creation of novel CMOS APS imagers with focal plane parallel image preprocessing for smart technical vision and electro-optical systems based on neural implementation. Using analysis of main biological vision features, the desired artificial vision characteristics are defined. Image processing tasks can be implemented by smart focal plane preprocessing CMOS imagers with neural networks are determined. Eventual results are important for medicine, aerospace ecological monitoring, complexity, and ways for CMOS APS neural nets implementation. To reduce real image preprocessing time special methods based on edge detection and neighbored frame subtraction will be considered and simulated. To select optimal methods and mathematical operators for edge detection various medical, technical and aerospace images will be tested. The important research direction will be devoted to analogue implementation of main preprocessing operations (addition, subtraction, neighbored frame subtraction, module, and edge detection of pixel signals) in focal plane of CMOS APS imagers. We present the following results: the algorithm of edge detection for analog realization, and patented focal plane circuits for analog image reprocessing (edge detection and motion detection).

  7. Peer Evaluation in Chemical Engineering Capstone Design via Wikis

    ERIC Educational Resources Information Center

    Heldt, Caryn L.

    2012-01-01

    Inter-group peer evaluation through wikis was implemented as a method for senior capstone design teams to improve writing and the critical evaluation of data. Each group was evaluated by peers using a qualitative discussion and evaluated quantitatively by instructors. Students had an increased interest in contributing to online knowledge centers,…

  8. XML-based product information processing method for product design

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen Yu

    2012-01-01

    Design knowledge of modern mechatronics product is based on information processing as the center of the knowledge-intensive engineering, thus product design innovation is essentially the knowledge and information processing innovation. Analysis of the role of mechatronics product design knowledge and information management features, a unified model of XML-based product information processing method is proposed. Information processing model of product design includes functional knowledge, structural knowledge and their relationships. For the expression of product function element, product structure element, product mapping relationship between function and structure based on the XML model are proposed. The information processing of a parallel friction roller is given as an example, which demonstrates that this method is obviously helpful for knowledge-based design system and product innovation.

  9. XML-based product information processing method for product design

    NASA Astrophysics Data System (ADS)

    Zhang, Zhen Yu

    2011-12-01

    Design knowledge of modern mechatronics product is based on information processing as the center of the knowledge-intensive engineering, thus product design innovation is essentially the knowledge and information processing innovation. Analysis of the role of mechatronics product design knowledge and information management features, a unified model of XML-based product information processing method is proposed. Information processing model of product design includes functional knowledge, structural knowledge and their relationships. For the expression of product function element, product structure element, product mapping relationship between function and structure based on the XML model are proposed. The information processing of a parallel friction roller is given as an example, which demonstrates that this method is obviously helpful for knowledge-based design system and product innovation.

  10. Integration of MGDS design into the licensing process

    SciTech Connect

    1997-12-01

    This paper presents an overview of how the Mined Geologic Disposal System (MGDS) design for a potential repository is integrated into the licensing process. The integration process employs a two-told approach: (1) ensure that the MGDS design complies with applicable Nuclear Regulatory Commission (NRC) licensing requirements, and (2) ensure that the MGDS design is appropriately reflected in a license application that is acceptable to the NRC for performing acceptance and compliance reviews.

  11. Reducing the emission of ozone depleting chemicals through use of a self-cleaning soldering process

    SciTech Connect

    Lichtenberg, L.; Martin, G.; Van Buren, P.; Iman, R.; Paffett, M.T.

    1991-12-31

    Motorola has jointed with Sandia and Los Alamos National Laboratories to perform work under a Cooperative Research and Development Agreement (CRADA) to reduce the use of CFC`s and other ozone depleting printing wiring board (PWB) cleaning solvents. This study evaluated the use of a new soldering process that uses dilute adipic acid in lieu of rosin flux. The process consumes the adipic acid in lieu of rosin flux. The process consumes the adipic acid during the soldering process and precludes the need for subsequent cleaning with ozone depleting solvents. This paper presents results from a series of designed experiments that evaluated PWB cleanliness as a function of various levels of machine control parameters. The study included a comprehensive hardware reliability evaluation, which included environmental conditioning, cleanliness testing, surface chemical analysis, surface insulation resistance testing, along with electrical, mechanical and long term storage testing. The results of this study that the new process produces quality, reliable hardware over a wide range of processing parameters. Adoption of this process, which eliminates the need for supplemental cleaning, will have a positive impact on many environmental problems, including depletion of the ozone layer.

  12. Reducing the emission of ozone depleting chemicals through use of a self-cleaning soldering process

    SciTech Connect

    Lichtenberg, L.; Martin, G.; Van Buren, P. . Government Electronics Group); Iman, R. ); Paffett, M.T. )

    1991-01-01

    Motorola has jointed with Sandia and Los Alamos National Laboratories to perform work under a Cooperative Research and Development Agreement (CRADA) to reduce the use of CFC's and other ozone depleting printing wiring board (PWB) cleaning solvents. This study evaluated the use of a new soldering process that uses dilute adipic acid in lieu of rosin flux. The process consumes the adipic acid in lieu of rosin flux. The process consumes the adipic acid during the soldering process and precludes the need for subsequent cleaning with ozone depleting solvents. This paper presents results from a series of designed experiments that evaluated PWB cleanliness as a function of various levels of machine control parameters. The study included a comprehensive hardware reliability evaluation, which included environmental conditioning, cleanliness testing, surface chemical analysis, surface insulation resistance testing, along with electrical, mechanical and long term storage testing. The results of this study that the new process produces quality, reliable hardware over a wide range of processing parameters. Adoption of this process, which eliminates the need for supplemental cleaning, will have a positive impact on many environmental problems, including depletion of the ozone layer.

  13. Laser studies of chemical reaction and collision processes

    SciTech Connect

    Flynn, G.

    1993-12-01

    This work has concentrated on several interrelated projects in the area of laser photochemistry and photophysics which impinge on a variety of questions in combustion chemistry and general chemical kinetics. Infrared diode laser probes of the quenching of molecules with {open_quotes}chemically significant{close_quotes} amounts of energy in which the energy transferred to the quencher has, for the first time, been separated into its vibrational, rotational, and translational components. Probes of quantum state distributions and velocity profiles for atomic fragments produced in photodissociation reactions have been explored for iodine chloride.

  14. Defining process design space for monoclonal antibody cell culture.

    PubMed

    Abu-Absi, Susan Fugett; Yang, LiYing; Thompson, Patrick; Jiang, Canping; Kandula, Sunitha; Schilling, Bernhard; Shukla, Abhinav A

    2010-08-15

    The concept of design space has been taking root as a foundation of in-process control strategies for biopharmaceutical manufacturing processes. During mapping of the process design space, the multidimensional combination of operational variables is studied to quantify the impact on process performance in terms of productivity and product quality. An efficient methodology to map the design space for a monoclonal antibody cell culture process is described. A failure modes and effects analysis (FMEA) was used as the basis for the process characterization exercise. This was followed by an integrated study of the inoculum stage of the process which includes progressive shake flask and seed bioreactor steps. The operating conditions for the seed bioreactor were studied in an integrated fashion with the production bioreactor using a two stage design of experiments (DOE) methodology to enable optimization of operating conditions. A two level Resolution IV design was followed by a central composite design (CCD). These experiments enabled identification of the edge of failure and classification of the operational parameters as non-key, key or critical. In addition, the models generated from the data provide further insight into balancing productivity of the cell culture process with product quality considerations. Finally, process and product-related impurity clearance was evaluated by studies linking the upstream process with downstream purification. Production bioreactor parameters that directly influence antibody charge variants and glycosylation in CHO systems were identified. PMID:20589669

  15. Tools for efficient design of multicomponent separation processes

    NASA Astrophysics Data System (ADS)

    Huff, Joshua Lee

    Separations account for as much as 85% of plant operating costs in chemical production; it is therefore important that they be designed with energy efficiency in mind. This can only be achieved if two things are achieved: the complete space of design options is known, and an accurate way is developed to compare all possible design options. For both membrane separation cascades and multicomponent distillation configurations, this dissertation explores methods for designing energy efficient separations. The operating cost of membranes used in production of nitrogen gas from air is largely driven by the compressors required to maintain a pressure differential. Optimization of the total compressor duty can reveal an ideal cascade arrangement and set of operating conditions for a given feed and recovery. With this optimization technique in hand, it is then possible to examine the effect of introducing extra stages to form intermediate stage cascades. Furthermore, the effect of varying the recovery of the nitrogen stream can be examined to discover a U-shaped relationship between recovery and energy requirement. Conventional distillation configurations use n -- 1 distillation columns to separate a multicomponent feed mixture into pure products. Past research has identified a way to quickly and algorithmically generate the complete ranklist of regular-column configurations using an integer programming formulation called the matrix method. Using this method, a formulation is here presented for the complete nonlinear programming problem which, for a given configuration, can ensure the globally minimum vapor duty of the configuration. Furthermore, a set of nonlinear equations designed to represent the capital and operating costs of the system are described. The need for a global optimization algorithm in the formulation of the cost product is demonstrated by comparison with a two-stage search algorithm; in addition, the cost formulation is compared to that of the vapor duty

  16. Chemical Industry R&D Roadmap for Nanomaterials By Design. From Fundamentals to Function

    SciTech Connect

    none,

    2003-12-01

    Vision2020 agreed to join NNI and the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (DOE/EERE) in sponsoring the "Nanomaterials and the Chemical Industry Roadmap Workshop" on September 30-October 2, 2002. This roadmap, Chemical Industry R&D Roadmap for Nanomaterials By Design: From Fundamentals to Function, is based on the scientific priorities expressed by workshop participants from the chemical industry, universities, and government laboratories.

  17. The Monte Carlo Integration Computer as an Instructional Model for the Simulation of Equilibrium and Kinetic Chemical Processes: The Development and Evaluation of a Teaching Aid.

    ERIC Educational Resources Information Center

    Wood, Dean Arthur

    A special purpose digital computer which utilizes the Monte Carlo integration method of obtaining simulations of chemical processes was developed and constructed. The computer, designated as the Monte Carlo Integration Computer (MCIC), was designed as an instructional model for the illustration of kinetic and equilibrium processes, and was…

  18. Evaluation of alternative chemical additives for high-level waste vitrification feed preparation processing

    SciTech Connect

    Seymour, R.G.

    1995-06-07

    During the development of the feed processing flowsheet for the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS), research had shown that use of formic acid (HCOOH) could accomplish several processing objectives with one chemical addition. These objectives included the decomposition of tetraphenylborate, chemical reduction of mercury, production of acceptable rheological properties in the feed slurry, and controlling the oxidation state of the glass melt pool. However, the DEPF research had not shown that some vitrification slurry feeds had a tendency to evolve hydrogen (H{sub 2}) and ammonia (NH{sub 3}) as the result of catalytic decomposition of CHOOH with noble metals (rhodium, ruthenium, palladium) in the feed. Testing conducted at Pacific Northwest Laboratory and later at the Savannah River Technical Center showed that the H{sub 2} and NH{sub 3} could evolve at appreciable rates and quantities. The explosive nature of H{sub 2} and NH{sub 3} (as ammonium nitrate) warranted significant mitigation control and redesign of both facilities. At the time the explosive gas evolution was discovered, the DWPF was already under construction and an immediate hardware fix in tandem with flowsheet changes was necessary. However, the Hanford Waste Vitrification Plant (HWVP) was in the design phase and could afford to take time to investigate flowsheet manipulations that could solve the problem, rather than a hardware fix. Thus, the HWVP began to investigate alternatives to using HCOOH in the vitrification process. This document describes the selection, evaluation criteria, and strategy used to evaluate the performance of the alternative chemical additives to CHOOH. The status of the evaluation is also discussed.

  19. Development of the chemical and electrochemical coal cleaning (CECC) process. Final report

    SciTech Connect

    Yoon, Roe-Hoan; Basilio, C.I.

    1992-05-01

    The Chemical and Electrochemical Coal Cleaning (CECC) process developed at Virginia Polytechnic Institute and State University was studied further in this project. This process offers a new method of physically cleaning both low- and high-rank coals without requiring fine grinding. The CECC process is based on liberating mineral matter from coal by osmotic pressure. The majority of the work was conducted on Middle Wyodak, Pittsburgh No. 8 and Elkhorn No. 3 coals. The coal samples were characterized for a variety of physical and chemical properties. Parametric studies were then conducted to identify the important operating parameters and to establish the optimum conditions. In addition, fundamental mechanisms of the process were studied, including mineral matter liberation, kinetics of mineral matter and pyrite dissolution, ferric ion regeneration schemes and alternative methods of separating the cleaned coal from the liberated mineral matter. The information gathered from the parametric and fundamental studies was used in the design, construction and testing of a bench-scale continuous CECC unit. Using this unit, the ash content of a Middle Wyodak coal was reduced from 6.96 to 1.61% at a 2 lbs/hr throughput. With an Elkhorn No. 3 sample, the ash content was reduced from 9.43 to 1.8%, while the sulfur content was reduced from 1.57 to 0.9%. The mass balance and liberation studies showed that liberation played a more dominant role than the chemical dissolution in removing mineral matter and inorganic sulfur from the different bituminous coals tested. However, the opposite was found to be the case for the Wyodak coal since this coal contained a significant amount of acid-soluble minerals.

  20. Dynamic Processes of Conceptual Change: Analysis of Constructing Mental Models of Chemical Equilibrium.

    ERIC Educational Resources Information Center

    Chiu, Mei-Hung; Chou, Chin-Cheng; Liu, Chia-Ju

    2002-01-01

    Investigates students' mental models of chemical equilibrium using dynamic science assessments. Reports that students at various levels have misconceptions about chemical equilibrium. Involves 10th grade students (n=30) in the study doing a series of hands-on chemical experiments. Focuses on the process of constructing mental models, dynamic…

  1. Perspectives on the design of safer nanomaterials and manufacturing processes

    PubMed Central

    Geraci, Charles; Heidel, Donna; Sayes, Christie; Hodson, Laura; Schulte, Paul; Eastlake, Adrienne; Brenner, Sara

    2015-01-01

    A concerted effort is being made to insert Prevention through Design principles into discussions of sustainability, occupational safety and health, and green chemistry related to nanotechnology. Prevention through Design is a set of principles that includes solutions to design out potential hazards in nanomanufacturing including the design of nanomaterials, and strategies to eliminate exposures and minimize risks that may be related to the manufacturing processes and equipment at various stages of the lifecycle of an engineered nanomaterial. PMID:26435688

  2. The Chemistry of Lightsticks: Demonstrations to Illustrate Chemical Processes

    ERIC Educational Resources Information Center

    Kuntzleman, Thomas Scott; Rohrer, Kristen; Schultz, Emeric

    2012-01-01

    Lightsticks, or glowsticks as they are sometimes called, are perhaps the chemist's quintessential toy. Because they are easy to activate and appealing to observe, experimenting with lightsticks provides a great way to get young people interested in science. Thus, we have used lightsticks to teach chemical concepts in a variety of outreach settings…

  3. Chemical Changes in Lipids Produced by Thermal Processing.

    ERIC Educational Resources Information Center

    Nawar, Wassef W.

    1984-01-01

    Describes heat effects on lipids, indicating that the chemical and physical changes that occur depend on the lipid's composition and conditions of treatment. Thermolytic and oxidation reactions, thermal/oxidative interaction of lipids with other food components and the chemistry of frying are considered. (JN)

  4. Helping Students Develop a Critical Attitude towards Chemical Process Calculations.

    ERIC Educational Resources Information Center

    de Nevers, Noel; Seader, J. D.

    1992-01-01

    Discusses the use of computer-assisted programs that allow chemical engineering students to study textbook thermodynamics problems from different perspectives, including the classical graphical method, while utilizing more than one property correlation and/or operation model so that comparisons can be made and sensitivities determined more…

  5. Implementation Plan for Chemical Industry R&D Roadmap for Nanomaterials by Design

    SciTech Connect

    none,

    2006-04-01

    The purpose of this effort is to develop an implementation plan to realize the vision and goals identified in the Chemical Industry R&D Roadmap for Nanomaterials By Design: From Fundamentals to Function.

  6. Simplifying Chemical Reactor Design by using Molar Quantities Instead of Fractional Conversion.

    ERIC Educational Resources Information Center

    Brown, Lee F.; Falconer, John L.

    1987-01-01

    Explains the advantages of using molar quantities in chemical reactor design. Advocates the use of differential versions of reactor mass balances rather than the integrated forms. Provides specific examples and cases to illustrate the principles. (ML)

  7. 78 FR 77108 - Surplus Property Notice at a Military Installation Designated for Disposal: Pueblo Chemical Depot...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... Property List 1. Addition Colorado Pueblo Chemical Depot: 45825 Hwy 96E, Building 1, Pueblo, CO 81006- 9330... Department of the Army Surplus Property Notice at a Military Installation Designated for Disposal: Pueblo Chemical Depot, Colorado AGENCY: Department of the Army, DoD. ACTION: Notice. SUMMARY: This notice...

  8. Design criteria for extraction with chemical reaction and liquid membrane permeation

    NASA Technical Reports Server (NTRS)

    Bart, H. J.; Bauer, A.; Lorbach, D.; Marr, R.

    1988-01-01

    The design criteria for heterogeneous chemical reactions in liquid/liquid systems formally correspond to those of classical physical extraction. More complex models are presented which describe the material exchange at the individual droplets in an extraction with chemical reaction and in liquid membrane permeation.

  9. Strategic Considerations in the Design of a Screening System for Substructure Searches of Chemical Structure Files

    ERIC Educational Resources Information Center

    Adamson, George W.; And Others

    1973-01-01

    A major problem in the design of screening systems for substructure searches of chemical structure files is the development of a methodology for selection of an optimal set of structural characteristics to act as screens. Distributions of several structural characteristics of the Chemical Abstracts Service Registry System are summarized. (13…

  10. Chemical Thinning Process for Fabricating UV-Imaging CCDs

    NASA Technical Reports Server (NTRS)

    Jones, TOdd; Grunthaner, Paula; Nikzad, Shouleh; Wilson, Rick

    2004-01-01

    The thinning stage of the postfabrication process reported in the immediately preceding article is notable in its own right. Although the thinning process was described in the preceding article as part of an overall process of fabrication of a supported charge-coupled device (CCD), it is more generally applicable to both free-standing and supported devices that have been fabricated in die and wafer formats. Like the thermocompression bonding process described in the preceding article, the thinning process is compatible with CCD-fabrication processes, as well as postfabrication processes that enhance the response of CCDs to ultraviolet (UV) light, including the delta-doping process. CCDs that are thinned by this process and then delta-doped exhibit high quantum efficiencies that are stable with time and with exposure to the environment.

  11. New insights into chemical processes within martian high latitude soils

    NASA Astrophysics Data System (ADS)

    Horgan, B.; Bell, J. F.

    2010-12-01

    Our analysis of near-infrared spectra of low albedo soils in the northern lowlands of Mars has revealed that they can be classified into three compositional groups: (1) relatively unaltered and high-calcium pyroxene-rich, (2) pervasively leached and glass-rich, and (3) gypsum-rich. Here we present results from spectral and morphologic studies, which together show that the diversity of soils observed from orbit and those observed in situ by the Phoenix lander can largely be explained by aqueous processes acting on high-calcium pyroxene-rich soils. Soils in Acidalia Planitia, parts of the north polar sand sea, and certain units within the north polar plateau exhibit spectral signatures consistent with an enrichment in iron-bearing glass, as well as signatures consistent with leached glass rinds, which form during acidic alteration of glass surfaces. As glass enrichment can be produced during acidic leaching of basaltic sand, we have proposed that these soils are the endproducts of widespread and pervasive acidic leaching. If these altered sands originally had a composition similar to the relatively unaltered high-calcium pyroxene-rich soils observed elsewhere in the northern lowlands, then we should also expect them to contain calcium-bearing secondary precipitates, primarily gypsum. While spectral analysis of Acidalia-type soils places an approximate upper limit on their gypsum concentration of 15-20 wt.%, our results suggest that the gypsum-rich (up to 40 wt.%) sands in the Olympia Undae region of the north polar sand sea could also be sourced from Acidalia-type materials within the north polar plateau. Although Olympia Undae gypsum concentrations appear too high to justify this hypothesis, our morphologic studies of the region suggest that the high concentrations are most likely surficial and do not represent the volumetric concentrations. By mapping the distribution of tensional surface cracks on sand dunes in HiRISE images, we have shown that the strength of

  12. PARTITIONING OF GADOLINIUM IN THE CHEMICAL PROCESSING CELL

    SciTech Connect

    Reboul, S.; Best, D.; Stone, M.; Click, D.

    2011-04-27

    A combination of short-term beaker tests and longer-duration Sludge Receipt and Adjustment Tank (SRAT) simulations were performed to investigate the relative partitioning behaviors of gadolinium and iron under conditions applicable to the Chemical Processing Cell (CPC). The testing was performed utilizing non-radioactive simple Fe-Gd slurries, non-radioactive Sludge Batch 6 simulant slurries, and a radioactive real-waste slurry representative of Sludge Batch 7 material. The testing focused on the following range of conditions: (a) Fe:Gd ratios of 25-100; (b) pH values of 2-6; (c) acidification via addition of nitric, formic, and glycolic acids; (d) temperatures of {approx}93 C and {approx}22 C; and (e) oxalate concentrations of <100 mg/kg and {approx}10,000 mg/kg. The purpose of the testing was to provide data for assessing the potential use of gadolinium as a supplemental neutron poison when dispositioning excess plutonium. Understanding of the partitioning behavior of gadolinium in the CPC was the first step in assessing gadolinium's potential applicability. Significant fractions of gadolinium partitioned to the liquid-phase at pH values of 4.0 and below, regardless of the Fe:Gd ratio. In SRAT simulations targeting nitric and formic acid additions of 150% acid stoichiometry, the pH dropped to a minimum of 3.5-4.0, and the maximum fractions of gadolinium and iron partitioning to solution were both {approx}20%. In contrast, in a SRAT simulation utilizing a nitric and formic acid addition under atypical conditions (due to an anomalously low insoluble solids content), the pH dropped to a minimum of 3.7, and the maximum fractions of gadolinium and iron partitioning to solution were {approx}60% and {approx}70%, respectively. When glycolic acid was used in combination with nitric and formic acids at 100% acid stoichiometry, the pH dropped to a minimum of 3.6-4.0, and the maximum fractions of gadolinium and iron partitioning to solution were 60-80% and 3-5%, respectively

  13. Design and analysis of a silicon-based antiresonant reflecting optical waveguide chemical sensor

    NASA Astrophysics Data System (ADS)

    Remley, Kate A.; Weisshaar, Andreas

    1996-08-01

    The design of a silicon-based antiresonant reflecting optical waveguide (ARROW) chemical sensor is presented, and its theoretical performance is compared with that of a conventional structure. The use of an ARROW structure permits incorporation of a thick guiding region for efficient coupling to a single-mode fiber. A high-index overlay is added to fine tune the sensitivity of the ARROW chemical sensor. The sensitivity of the sensor is presented, and design trade-offs are discussed.

  14. Conceptual design for remote handling methods using the HIP process in the Calcine Immobilization Program

    SciTech Connect

    Berry, S.M.; Cox, C.G.; Hoover, M.A.

    1994-03-01

    This report recommends the remote conceptual design philosophy for calcine immobilization using the hot isostatic press (HIP) process. Areas of remote handling operations discussed in this report include: (1) introducing the process can into the front end of the HIP process, (2) filling and compacting the calcine/frit mixture into the process can, (3) evacuating and sealing the process can, (4) non-destructive testing of the seal on the process can, (5) decontamination of the process can, (6) HIP furnace loading and unloading the process can for the HIPing operation, (7) loading an overpack canister with processed HIP cans, (8) sealing the canister, with associated non-destructive examination (NDE) and decontamination, and (9) handling canisters for interim storage at the Idaho Chemical Processing Plant (ICPP) located on the Idaho National Engineering Laboratory (INEL) site.

  15. Designing a process for executing projects under an international agreement

    NASA Technical Reports Server (NTRS)

    Mohan, S. N.

    2003-01-01

    Projects executed under an international agreement require special arrangements in order to operate within confines of regulations issued by the State Department and the Commerce Department. In order to communicate enterprise-level guidance and procedural information uniformly to projects based on interpretations that carry the weight of institutional authority, a process was developed. This paper provides a script for designing processes in general, using this particular process for context. While the context is incidental, the method described is applicable to any process in general. The paper will expound on novel features utilized for dissemination of the procedural details over the Internet following such process design.

  16. Evaluating two process scale chromatography column header designs using CFD.

    PubMed

    Johnson, Chris; Natarajan, Venkatesh; Antoniou, Chris

    2014-01-01

    Chromatography is an indispensable unit operation in the downstream processing of biomolecules. Scaling of chromatographic operations typically involves a significant increase in the column diameter. At this scale, the flow distribution within a packed bed could be severely affected by the distributor design in process scale columns. Different vendors offer process scale columns with varying design features. The effect of these design features on the flow distribution in packed beds and the resultant effect on column efficiency and cleanability needs to be properly understood in order to prevent unpleasant surprises on scale-up. Computational Fluid Dynamics (CFD) provides a cost-effective means to explore the effect of various distributor designs on process scale performance. In this work, we present a CFD tool that was developed and validated against experimental dye traces and tracer injections. Subsequently, the tool was employed to compare and contrast two commercially available header designs. PMID:24616438

  17. A microfabricated nanocalorimeter: design, characterization, and chemical calibration.

    PubMed

    Xu, Junkai; Reiserer, Ron; Tellinghuisen, Joel; Wikswo, John P; Baudenbacher, Franz J

    2008-04-15

    A microfabricated titration calorimeter having nanowatt sensitivity is presented. The device is achieved by modifying a commercial, suspended-membrane, thin-film thermopile infrared sensor. Chemical reactions are studied by placing a 50.0 nL droplet of one reagent directly on the sensor and injecting nanoliter droplets of a second reagent through a micropipette by means of a pressure-driven droplet injector with 1% reliability in volume delivery. External thermal noise is minimized by a two-layer thermal shielding system. Evaporation is prevented by positioning the micropipette through a tiny hole in a cover glass, sealed by a drop of oil. The device is calibrated using two acid-base reactions: H2SO4 + HEPES buffer, and NaOH + HCl. The measured power sensitivity is 2.90(4) V/W, giving a detection limit of 22 nW. The 1/e time constant for a single injection is 1.1 s. The day-to-day power sensitivity is reproducible to approximately 2%. A computational model of the sensor reproduces the power sensitivity within 10% and the time constant within 20%. For a 50 nL sample and 0.8-1.5 nL titrant injection volumes, the heat uncertainty of 44 nJ corresponds to a 3sigma detection limit of 132 nJ, or the binding energy associated with 2.9 pM of IgG-protein A complex. PMID:18351750

  18. Indicators and Metrics for Evaluating the Sustainability of Chemical Processes

    EPA Science Inventory

    A metric-based method, called GREENSCOPE, has been developed for evaluating process sustainability. Using lab-scale information and engineering assumptions the method evaluates full-scale epresentations of processes in environmental, efficiency, energy and economic areas. The m...

  19. Context-Aware Design for Process Flexibility and Adaptation

    ERIC Educational Resources Information Center

    Yao, Wen

    2012-01-01

    Today's organizations face continuous and unprecedented changes in their business environment. Traditional process design tools tend to be inflexible and can only support rigidly defined processes (e.g., order processing in the supply chain). This considerably restricts their real-world applications value, especially in the dynamic and…

  20. Concurrent materials and process selection in conceptual design

    SciTech Connect

    Kleban, S.D.

    1998-07-01

    The sequential manner in which materials and processes for a manufactured product are selected is inherently less than optimal. Designers` tendency to choose processes and materials with which they are familiar exacerbate this problem. A method for concurrent selection of materials and a joining process based on product requirements using a knowledge-based, constraint satisfaction approach is presented.

  1. Reducing aquatic hazards of industrial chemicals: probabilistic assessment of sustainable molecular design guidelines.

    PubMed

    Connors, Kristin A; Voutchkova-Kostal, Adelina M; Kostal, Jakub; Anastas, Paul; Zimmerman, Julie B; Brooks, Bryan W

    2014-08-01

    Basic toxicological information is lacking for the majority of industrial chemicals. In addition to increasing empirical toxicity data through additional testing, prospective computational approaches to drug development aim to serve as a rational basis for the design of chemicals with reduced toxicity. Recent work has resulted in the derivation of a "rule of 2," wherein chemicals with an octanol-water partition coefficient (log P) less than 2 and a difference between the lowest unoccupied molecular orbital and the highest occupied molecular orbital (ΔE) greater than 9 (log P<2 and ΔE >9 eV) are predicted to be 4 to 5 times less likely to elicit acute or chronic toxicity to model aquatic organisms. The present study examines potential reduction of aquatic toxicity hazards from industrial chemicals if these 2 molecular design guidelines were employed. Probabilistic hazard assessment approaches were used to model the likelihood of encountering industrial chemicals exceeding toxicological categories of concern both with and without the rule of 2. Modeling predicted that utilization of these molecular design guidelines for log P and ΔE would appreciably decrease the number of chemicals that would be designated to be of "high" and "very high" concern for acute and chronic toxicity to standard model aquatic organisms and end points as defined by the US Environmental Protection Agency. For example, 14.5% of chemicals were categorized as having high and very high acute toxicity to the fathead minnow model, whereas only 3.3% of chemicals conforming to the design guidelines were predicted to be in these categories. Considerations of specific chemical classes (e.g., aldehydes), chemical attributes (e.g., ionization), and adverse outcome pathways in representative species (e.g., receptor-mediated responses) could be used to derive future property guidelines for broader classes of contaminants. PMID:24839109

  2. Dynamic Characteristics Analysis of Analogue Networks Design Process

    NASA Astrophysics Data System (ADS)

    Zemliak, Alexander M.

    The process of designing analogue circuits is formulated as a controlled dynamic system. For analysis of such system's properties it is suggested to use the concept of Lyapunov's function for a dynamic system. Various forms of Lyapunov's function are suggested. Analyzing the behavior of Lyapunov's function and its first derivative allowed us to determine significant correlation between this function's properties and processor time used to design the circuit. Numerical results prove the possibility of forecasting the behavior of various designing strategies and processor time based on the properties of Lyapunov's function for the process of designing the circuit.

  3. Research on chemical vapor deposition processes for advanced ceramic coatings

    NASA Technical Reports Server (NTRS)

    Rosner, Daniel E.

    1993-01-01

    Our interdisciplinary background and fundamentally-oriented studies of the laws governing multi-component chemical vapor deposition (VD), particle deposition (PD), and their interactions, put the Yale University HTCRE Laboratory in a unique position to significantly advance the 'state-of-the-art' of chemical vapor deposition (CVD) R&D. With NASA-Lewis RC financial support, we initiated a program in March of 1988 that has led to the advances described in this report (Section 2) in predicting chemical vapor transport in high temperature systems relevant to the fabrication of refractory ceramic coatings for turbine engine components. This Final Report covers our principal results and activities for the total NASA grant of $190,000. over the 4.67 year period: 1 March 1988-1 November 1992. Since our methods and the technical details are contained in the publications listed (9 Abstracts are given as Appendices) our emphasis here is on broad conclusions/implications and administrative data, including personnel, talks, interactions with industry, and some known applications of our work.

  4. CHEMICALLY ACTIVE FLUID BED FOR SOX CONTROL. VOLUME I. PROCESS EVALUATION STUDIES

    EPA Science Inventory

    The report describes selected process evaluation studies supporting the development of an atmospheric-pressure, fluidized-bed, chemically active gasification process, using a regenerative limestone sulfur sorbent to produce low- to intermediate-Btu fuel gas. Limestone sorbent sel...

  5. 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...

  6. EFFECTIVE RISK MANAGEMENT OF ENDOCRINE DISRUPTING CHEMICALS USING DRINKING WATER TREATMENT PROCESSES

    EPA Science Inventory

    The conventional drinking water treamtent processes of coagulation, flocculation, and filtration as well as specialized treatment processes have been examined for their capacity to remove endocrine disrupting chemicals (EDCs). A groupf od EDCs including 4-nonylphenol, diethylphth...

  7. Integrating rock mechanics issues with repository design through design process principles and methodology

    SciTech Connect

    Bieniawski, Z.T.

    1996-04-01

    A good designer needs not only knowledge for designing (technical know-how that is used to generate alternative design solutions) but also must have knowledge about designing (appropriate principles and systematic methodology to follow). Concepts such as {open_quotes}design for manufacture{close_quotes} or {open_quotes}concurrent engineering{close_quotes} are widely used in the industry. In the field of rock engineering, only limited attention has been paid to the design process because design of structures in rock masses presents unique challenges to the designers as a result of the uncertainties inherent in characterization of geologic media. However, a stage has now been reached where we are be able to sufficiently characterize rock masses for engineering purposes and identify the rock mechanics issues involved but are still lacking engineering design principles and methodology to maximize our design performance. This paper discusses the principles and methodology of the engineering design process directed to integrating site characterization activities with design, construction and performance of an underground repository. Using the latest information from the Yucca Mountain Project on geology, rock mechanics and starter tunnel design, the current lack of integration is pointed out and it is shown how rock mechanics issues can be effectively interwoven with repository design through a systematic design process methodology leading to improved repository performance. In essence, the design process is seen as the use of design principles within an integrating design methodology, leading to innovative problem solving. In particular, a new concept of {open_quotes}Design for Constructibility and Performance{close_quotes} is introduced. This is discussed with respect to ten rock mechanics issues identified for repository design and performance.

  8. Using a Readily Available Commercial Spreadsheet to Teach a Graduate Course on Chemical Process Simulation

    ERIC Educational Resources Information Center

    Clarke, Matthew A.; Giraldo, Carlos

    2009-01-01

    Chemical process simulation is one of the most fundamental skills that is expected from chemical engineers, yet relatively few graduates have the opportunity to learn, in depth, how a process simulator works, from programming the unit operations to the sequencing. The University of Calgary offers a "hands-on" postgraduate course in Chemical…

  9. Comprehensive Mass Analysis for Chemical Processes, a Case Study on L-Dopa Manufacture

    EPA Science Inventory

    To evaluate the “greenness” of chemical processes in route selection and process development, we propose a comprehensive mass analysis to inform the stakeholders from different fields. This is carried out by characterizing the mass intensity for each contributing chemical or wast...

  10. HYBRID SULFUR PROCESS REFERENCE DESIGN AND COST ANALYSIS

    SciTech Connect

    Gorensek, M.; Summers, W.; Boltrunis, C.; Lahoda, E.; Allen, D.; Greyvenstein, R.

    2009-05-12

    This report documents a detailed study to determine the expected efficiency and product costs for producing hydrogen via water-splitting using energy from an advanced nuclear reactor. It was determined that the overall efficiency from nuclear heat to hydrogen is high, and the cost of hydrogen is competitive under a high energy cost scenario. It would require over 40% more nuclear energy to generate an equivalent amount of hydrogen using conventional water-cooled nuclear reactors combined with water electrolysis compared to the proposed plant design described herein. There is a great deal of interest worldwide in reducing dependence on fossil fuels, while also minimizing the impact of the energy sector on global climate change. One potential opportunity to contribute to this effort is to replace the use of fossil fuels for hydrogen production by the use of water-splitting powered by nuclear energy. Hydrogen production is required for fertilizer (e.g. ammonia) production, oil refining, synfuels production, and other important industrial applications. It is typically produced by reacting natural gas, naphtha or coal with steam, which consumes significant amounts of energy and produces carbon dioxide as a byproduct. In the future, hydrogen could also be used as a transportation fuel, replacing petroleum. New processes are being developed that would permit hydrogen to be produced from water using only heat or a combination of heat and electricity produced by advanced, high temperature nuclear reactors. The U.S. Department of Energy (DOE) is developing these processes under a program known as the Nuclear Hydrogen Initiative (NHI). The Republic of South Africa (RSA) also is interested in developing advanced high temperature nuclear reactors and related chemical processes that could produce hydrogen fuel via water-splitting. This report focuses on the analysis of a nuclear hydrogen production system that combines the Pebble Bed Modular Reactor (PBMR), under development by

  11. Reload design process at Yankee Atomic Electric Company

    SciTech Connect

    Weader, R.J.

    1986-01-01

    Yankee Atomic Electric Company (YAEC) performs reload design and licensing for their nuclear power plants: Yankee Rowe, Maine Yankee, and Vermont Yankee. Significant savings in labor and computer costs have been achieved in the reload design process by the use of the SIMULATE nodal code using the CASMO assembly burnup code or LEOPARD pin cell burnup code inputs to replace the PDQ diffusion theory code in many required calculations for the Yankee Rowe and Maine Yankee pressurized water reactors (PWRs). An efficient process has evolved for the design of reloads for the Vermont Yankee boiling water reactor (BWR). Due to the major differences in the core design of the three plants, different reload design processes have evolved for each plant.

  12. Outsourcing chemical synthesis in the drug discovery process.

    PubMed

    Festel, Gunter

    2011-03-01

    The positive effects of outsourcing chemical synthesis are enhanced if the provider offers, as the strategic partner, unique expertise and complements the existing internal competencies of pharmaceutical companies. The emerging cooperation model of leased competence offers additional access to high-level specialist knowledge: external service providers are temporarily integrated into internal R&D teams and can support R&D projects flexibly and quickly. Practice examples show that this cooperation model supports the efficient realization of milestones and, in the long-term, helps to build up a high internal competence level, especially in small pharmaceutical companies. PMID:21262378

  13. Chemical Changes in Proteins Produced by Thermal Processing.

    ERIC Educational Resources Information Center

    Dutson, T. R.; Orcutt, M. W.

    1984-01-01

    Discusses effects of thermal processing on proteins, focusing on (1) the Maillard reaction; (2) heat denaturation of proteins; (3) aggregation, precipitation, gelation, and degradation; and (4) other thermally induced protein reactions. Also discusses effects of thermal processing on muscle foods, egg proteins, fruits and vegetables, and cereal…

  14. EXPOSURE TO CHEMICAL ADDITIVES FROM POLYVINYL CHLORIDE POLYMER EXTRUSION PROCESSING

    EPA Science Inventory

    This report presents a model to predict worker inhalation exposure due to off-gassing of additives during polyvinyl chloride (PVC) extrusion processing. ata on off-gassing of additives were reviewed in the literature, the off-gassing at normal PVC processing temperatures was stud...

  15. Case study: Lockheed-Georgia Company integrated design process

    NASA Technical Reports Server (NTRS)

    Waldrop, C. T.

    1980-01-01

    A case study of the development of an Integrated Design Process is presented. The approach taken in preparing for the development of an integrated design process includes some of the IPAD approaches such as developing a Design Process Model, cataloging Technical Program Elements (TPE's), and examining data characteristics and interfaces between contiguous TPE's. The implementation plan is based on an incremental development of capabilities over a period of time with each step directed toward, and consistent with, the final architecture of a total integrated system. Because of time schedules and different computer hardware, this system will not be the same as the final IPAD release; however, many IPAD concepts will no doubt prove applicable as the best approach. Full advantage will be taken of the IPAD development experience. A scenario that could be typical for many companies, even outside the aerospace industry, in developing an integrated design process for an IPAD-type environment is represented.

  16. SYSTEMATIC PROCEDURE FOR DESIGNING PROCESSES WITH MULTIPLE ENVIRONMENTAL OBJECTIVES

    EPA Science Inventory

    Evaluation of multiple objectives is very important in designing environmentally benign processes. It requires a systematic procedure for solving multiobjective decision-making problems, due to the complex nature of the problems, the need for complex assessments, and complicated ...

  17. An investigation of radiometer design using digital processing techniques

    NASA Technical Reports Server (NTRS)

    Lawrence, R. W.

    1981-01-01

    The use of digital signal processing techniques in Dicke switching radiometer design was investigated. The general approach was to develop an analytical model of the existing analog radiometer and identify factors which adversly affect its performance. A digital processor was then proposed to verify the feasibility of using digital techniques to minimize these adverse effects and improve the radiometer performance. Analysis and preliminary test results comparing the digital and analog processing approaches in radiometers design were analyzed.

  18. Effects of chemical additives on microbial enhanced oil recovery processes

    SciTech Connect

    Bryant, R.S.; Chase, K.L.; Bertus, K.M.; Stepp, A.K.

    1989-12-01

    An extensive laboratory study has been conducted to determine (1) the role of the microbial cells and products in oil displacement, (2) the relative rates of transport of microbial cells and chemical products from the metabolism of nutrient in porous media, and (3) the effects of chemical additives on the oil recovery efficiency of microbial formulations. This report describes experiments relating to the effects of additives on oil recovery efficiency of microbial formulations. The effects of additives on the oil recovery efficiency of microbial formulations were determined by conducting oil displacement experiments in 1-foot-long Berea sandstone cores. Sodium tripolyphosphate (STPP), a low-molecular-weight polyacrylamide polymer, a lignosulfonate surfactant, and sodium bicarbonate were added to a microbial formulation at a concentration of 1%. The effects of using these additives in a preflush prior to injection of the microbial formulation were also evaluated. Oil-displacement experiments with and without a sodium bicarbonate preflush were conducted in 4-foot-long Berea sandstone cores, and samples of in situ fluids were collected at various times at four intermediate points along the core. The concentrations of metabolic products and microbes in the fluid samples were determined. 9 refs., 22 figs., 8 tabs.

  19. Forced chemical vapor infiltration of tubular geometries: Modeling, design, and scale-up

    SciTech Connect

    Stinton, D.P.; Besmann, T.M.; Matlin, W.M.

    1995-06-01

    In advanced indirectly fired coal combustion systems and externally fired combined cycle concepts, ceramic heat exchangers are required to transfer heat from the hot combustion gases to the clean air that drives the gas turbines. For high efficiencies, the temperature of the turbine inlet needs to exceed 1100{degrees}C and preferably be about 1260{degrees}C. The heat exchangers will operate under pressure and experience thermal and mechanical stresses during heating and cooling, and some transients will be severe under upset conditions. Silicon carbide-matrix composites are promising for such applications because of their high strength at elevated temperature, light weight, thermal and mechanical resistance, damage tolerance, and oxidation and corrosion resistance. Fiber-reinforced composite tubes of several fiber architectures were fabricated by forced chemical vapor infiltration (FCVI) and characterized. Unfortunately, long times ({approximately}150 hours) were required to thoroughly density the tubes. An objective of the current investigation was to optimize the forced CVI process so that composite tubes could be fabricated in much shorter times. To aid in such optimization, a computer code which models the CVI process was used to identify critical process parameters. Finally, successful demonstration of the utility of composite tubes for these applications will require the testing of near-full scale components. As a result a new infiltration system was designed and constructed to prepare 10-cm diameter tubes, and is described in this report.

  20. PROCESS DESIGN MANUAL: LAND TREATMENT OF MUNICIPAL WASTEWATER

    EPA Science Inventory

    The manual presents a rational procedure for the design of land treatment systems. Slow rate, rapid infiltration, and overland flow processes for the treatment of municipal wastewaters are discussed in detail, and the design concepts and criteria are presented. A two-phased plann...

  1. Relating Right Brain Studies to the Design Process.

    ERIC Educational Resources Information Center

    Hofland, John

    Intended for teachers of theatrical design who need to describe a design process for their students, this paper begins by giving a brief overview of recent research that has described the different functions of the right and left cerebral hemispheres. It then notes that although the left hemisphere tends to dominate the right hemisphere, it is the…

  2. Risk Informed Design as Part of the Systems Engineering Process

    NASA Technical Reports Server (NTRS)

    Deckert, George

    2010-01-01

    This slide presentation reviews the importance of Risk Informed Design (RID) as an important feature of the systems engineering process. RID is based on the principle that risk is a design commodity such as mass, volume, cost or power. It also reviews Probabilistic Risk Assessment (PRA) as it is used in the product life cycle in the development of NASA's Constellation Program.

  3. Design, Control and in Situ Visualization of Gas Nitriding Processes

    PubMed Central

    Ratajski, Jerzy; Olik, Roman; Suszko, Tomasz; Dobrodziej, Jerzy; Michalski, Jerzy

    2010-01-01

    The article presents a complex system of design, in situ visualization and control of the commonly used surface treatment process: the gas nitriding process. In the computer design conception, analytical mathematical models and artificial intelligence methods were used. As a result, possibilities were obtained of the poly-optimization and poly-parametric simulations of the course of the process combined with a visualization of the value changes of the process parameters in the function of time, as well as possibilities to predict the properties of nitrided layers. For in situ visualization of the growth of the nitrided layer, computer procedures were developed which make use of the results of the correlations of direct and differential voltage and time runs of the process result sensor (magnetic sensor), with the proper layer growth stage. Computer procedures make it possible to combine, in the duration of the process, the registered voltage and time runs with the models of the process. PMID:22315536

  4. Design, control and in situ visualization of gas nitriding processes.

    PubMed

    Ratajski, Jerzy; Olik, Roman; Suszko, Tomasz; Dobrodziej, Jerzy; Michalski, Jerzy

    2010-01-01

    The article presents a complex system of design, in situ visualization and control of the commonly used surface treatment process: the gas nitriding process. In the computer design conception, analytical mathematical models and artificial intelligence methods were used. As a result, possibilities were obtained of the poly-optimization and poly-parametric simulations of the course of the process combined with a visualization of the value changes of the process parameters in the function of time, as well as possibilities to predict the properties of nitrided layers. For in situ visualization of the growth of the nitrided layer, computer procedures were developed which make use of the results of the correlations of direct and differential voltage and time runs of the process result sensor (magnetic sensor), with the proper layer growth stage. Computer procedures make it possible to combine, in the duration of the process, the registered voltage and time runs with the models of the process. PMID:22315536

  5. Alternative Processes for Water Reclamation and Solid Waste Processing in a Physical/chemical Bioregenerative Life Support System

    NASA Technical Reports Server (NTRS)

    Rogers, Tom D.

    1990-01-01

    Viewgraphs on alternative processes for water reclamation and solid waste processing in a physical/chemical-bioregenerative life support system are presented. The main objective is to focus attention on emerging influences of secondary factors (i.e., waste composition, type and level of chemical contaminants, and effects of microorganisms, primarily bacteria) and to constructively address these issues by discussing approaches which attack them in a direct manner.

  6. 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. PMID:24440651

  7. Sketching in Design Journals: An Analysis of Visual Representations in the Product Design Process

    ERIC Educational Resources Information Center

    Lau, Kimberly; Oehlberg, Lora; Agogino, Alice

    2009-01-01

    This paper explores the sketching behavior of designers and the role of sketching in the design process. Observations from a descriptive study of sketches provided in design journals, characterized by a protocol measuring sketching activities, are presented. A distinction is made between journals that are entirely tangible and those that contain…

  8. Exposure to chemical additives from polyvinyl chloride polymer extrusion processing

    SciTech Connect

    Lamb, C.S.

    1989-12-01

    The report presents a model to predict worker inhalation exposure due to off-gassing of additives during polyvinyl chloride (PVC) extrusion processing. Data on off-gassing of additives were reviewed in the literature, the off-gassing at normal PVC processing temperatures was studied in the laboratory, process variables were estimated from an equipment manufacturer survey, and worker-activities and possible exposure sources were observed in an industrial survey. The purpose of the study was to develop a theoretical model to predict worker inhalation exposure to additives used during PVC extrusion processing. A model to estimate the generation rate of the additive from the polymer extrudate was derived from the mass transport equations governing diffusion. The mass flow rate, initial additive volatile weight fraction, off-gassing time, diffusivity, and slab thickness are required to determine the generation rate from the model.

  9. Reducing the complexity of the software design process with object-oriented design

    NASA Technical Reports Server (NTRS)

    Schuler, M. P.

    1991-01-01

    Designing software is a complex process. How object-oriented design (OOD), coupled with formalized documentation and tailored object diagraming techniques, can reduce the complexity of the software design process is described and illustrated. The described OOD methodology uses a hierarchical decomposition approach in which parent objects are decomposed into layers of lower level child objects. A method of tracking the assignment of requirements to design components is also included. Increases in the reusability, portability, and maintainability of the resulting products are also discussed. This method was built on a combination of existing technology, teaching experience, consulting experience, and feedback from design method users. The discussed concepts are applicable to hierarchal OOD processes in general. Emphasis is placed on improving the design process by documenting the details of the procedures involved and incorporating improvements into those procedures as they are developed.

  10. Numerical Simulation of Rheological, Chemical and Hydromechanical Processes of Thrombolysis

    NASA Astrophysics Data System (ADS)

    Khramchenkov, E.; Khramchenkov, M.

    2015-04-01

    Mathematical model of clot lysis in blood vessels is developed on the basis of equations of convection-diffusion. Fibrin of the clot is considered stationary solid phase, and plasminogen, plasmin and plasminogen-activators - as dissolved fluid phases. As a result of numerical solution of the model predictions of lysis process are gained. Important influence of clot swelling on the process of lysis is revealed.

  11. Theory and Practice Meets in Industrial Process Design -Educational Perspective-

    NASA Astrophysics Data System (ADS)

    Aramo-Immonen, Heli; Toikka, Tarja

    Software engineer should see himself as a business process designer in enterprise resource planning system (ERP) re-engineering project. Software engineers and managers should have design dialogue. The objective of this paper is to discuss the motives to study the design research in connection of management education in order to envision and understand the soft human issues in the management context. Second goal is to develop means of practicing social skills between designers and managers. This article explores the affective components of design thinking in industrial management domain. In the conceptual part of this paper are discussed concepts of network and project economy, creativity, communication, use of metaphors, and design thinking. Finally is introduced empirical research plan and first empirical results from design method experiments among the multi-disciplined groups of the master-level students of industrial engineering and management and software engineering.

  12. Application of hazard assessment techniques in the CISF design process

    SciTech Connect

    Thornton, J.R.; Henry, T.

    1997-10-29

    The Department of Energy has submitted to the NRC staff for review a topical safety analysis report (TSAR) for a Centralized Interim Storage Facility (CISF). The TSAR will be used in licensing the CISF when and if a site is designated. CISF1 design events are identified based on thorough review of design basis events (DBEs) previously identified by dry storage system suppliers and licensees and through the application of hazard assessment techniques. A Preliminary Hazards Assessment (PHA) is performed to identify design events applicable to a Phase 1 non site specific CISF. A PHA is deemed necessary since the Phase 1 CISF is distinguishable from previous dry store applications in several significant operational scope and design basis aspects. In addition to assuring all design events applicable to the Phase 1 CISF are identified, the PHA served as an integral part of the CISF design process by identifying potential important to safety and defense in depth facility design and administrative control features. This paper describes the Phase 1 CISF design event identification process and summarizes significant PHA contributions to the CISF design.

  13. Experience of Hot Cell Renovation Work in CPF (Chemical Processing Facility)

    SciTech Connect

    Toyonobu Nabemoto; Fujio Katahira; Tadatsugu Sakaya; Shinichi Aose; Takafumi Kitajima; Kouji Ogasawara; Kazunori Nomura; Shigehiko Miyachi; Yoshiaki Ichige; Tadahiro Shinozaki; Shinichi Ohuchi

    2008-01-15

    Renovation work for operation room A of the Chemical Processing Facility (CPF) was carried out. Cell renovation work involved disassembly, removal and installation of new equipment for the CA-3 cell of operation room A and the crane renovation work involved the repair of the in-cell crane for the CA-5 cell of operation room A. There were not many examples of renovation work performed on cells under high radiation environment and alpha contamination in Japan. Lessons learnt: With respect to the cell renovation work and crane repair work, a method that gave full consideration to safety was employed and the work was performed without accidents or disaster. Moreover, through improvement of the method, reduction of radioactive exposure of the workers was achieved and a melt reduction device was designed to deal with the radioactive waste material that was generated in the renovation work to achieve significant melt reduction of waste material.

  14. Mathematical modeling of quartz particle melting process in plasma-chemical reactor

    NASA Astrophysics Data System (ADS)

    Volokitin, Oleg; Vlasov, Viktor; Volokitin, Gennady; Skripnikova, Nelli; Shekhovtsov, Valentin

    2016-01-01

    Among silica-based materials vitreous silica has a special place. The paper presents the melting process of a quartz particle under conditions of low-temperature plasma. A mathematical model is designed for stages of melting in the experimental plasma-chemical reactor. As calculation data show, quartz particles having the radius of 0.21≤ rp ≤0.64 mm completely melt at W = 0.65 l/s particle feed rate depending on the Nusselt number, while 0.14≤ rp ≤0.44 mm particles melt at W = 1.4 l/s. Calculation data showed that 2 mm and 0.4 mm quartz particles completely melted during and 0.1 s respectively. Thus, phase transformations occurred in silicon dioxide play the important part in its heating up to the melting temperature.

  15. Modeling of multiphase flow with solidification and chemical reaction in materials processing

    NASA Astrophysics Data System (ADS)

    Wei, Jiuan

    Understanding of multiphase flow and related heat transfer and chemical reactions are the keys to increase the productivity and efficiency in industrial processes. The objective of this thesis is to utilize the computational approaches to investigate the multiphase flow and its application in the materials processes, especially in the following two areas: directional solidification, and pyrolysis and synthesis. In this thesis, numerical simulations will be performed for crystal growth of several III-V and II-VI compounds. The effects of Prandtl and Grashof numbers on the axial temperature profile, the solidification interface shape, and melt flow are investigated. For the material with high Prandtl and Grashof numbers, temperature field and growth interface will be significantly influenced by melt flow, resulting in the complicated temperature distribution and curved interface shape, so it will encounter tremendous difficulty using a traditional Bridgman growth system. A new design is proposed to reduce the melt convection. The geometric configuration of top cold and bottom hot in the melt will dramatically reduce the melt convection. The new design has been employed to simulate the melt flow and heat transfer in crystal growth with large Prandtl and Grashof numbers and the design parameters have been adjusted. Over 90% of commercial solar cells are made from silicon and directional solidification system is the one of the most important method to produce multi-crystalline silicon ingots due to its tolerance to feedstock impurities and lower manufacturing cost. A numerical model is developed to simulate the silicon ingot directional solidification process. Temperature distribution and solidification interface location are presented. Heat transfer and solidification analysis are performed to determine the energy efficiency of the silicon production furnace. Possible improvements are identified. The silicon growth process is controlled by adjusting heating power and

  16. COMPUTER ASSISTED PRELIMINARY DESIGN FOR DRINKING WATER TREATMENT PROCESS SYSTEMS

    EPA Science Inventory

    The purpose of the study was to develop an interactive computer program to aid the design engineer in evaluating the performance and cost for any proposed drinking water treatment system consisting of individual unit processes. The 25 unit process models currently in the program ...

  17. Design requirements for operational earth resources ground data processing

    NASA Technical Reports Server (NTRS)

    Baldwin, C. J.; Bradford, L. H.; Burnett, E. S.; Hutson, D. E.; Kinsler, B. A.; Kugle, D. R.; Webber, D. S.

    1972-01-01

    Realistic tradeoff data and evaluation techniques were studied that permit conceptual design of operational earth resources ground processing systems. Methodology for determining user requirements that utilize the limited information available from users is presented along with definitions of sensor capabilities projected into the shuttle/station era. A tentative method is presented for synthesizing candidate ground processing concepts.

  18. A computer-assisted process for supersonic aircraft conceptual design

    NASA Technical Reports Server (NTRS)

    Johnson, V. S.

    1985-01-01

    Design methodology was developed and existing major computer codes were selected to carry out the conceptual design of supersonic aircraft. A computer-assisted design process resulted from linking the codes together in a logical manner to implement the design methodology. The process does not perform the conceptual design of a supersonic aircraft but it does provide the designer with increased flexibility, especially in geometry generation and manipulation. Use of the computer-assisted process for the conceptual design of an advanced technology Mach 3.5 interceptor showed the principal benefit of the process to be the ability to use a computerized geometry generator and then directly convert the geometry between formats used in the geometry code and the aerodynamics codes. Results from the interceptor study showed that a Mach 3.5 standoff interceptor with a 1000 nautical-mile mission radius and a payload of eight Phoenix missiles appears to be feasible with the advanced technologies considered. A sensitivity study showed that technologies affecting the empty weight and propulsion system would be critical in the final configuration characteristics with aerodynamics having a lesser effect for small perturbations around the baseline.

  19. Incorporating manufacturability constraints into the design process of heterogeneous objects

    NASA Astrophysics Data System (ADS)

    Hu, Yuna; Blouin, Vincent Y.; Fadel, Georges M.

    2004-11-01

    Rapid prototyping (RP) technology, such as Laser Engineering Net Shaping (LENSTM), can be used to fabricate heterogeneous objects with gradient variations in material composition. These objects are generally characterized by enhanced functional performance. Past research on the design of such objects has focused on representation, modeling, and functional performance. However, the inherent constraints in RP processes, such as system capability and processing time, lead to heterogeneous objects that may not meet the designer's original intent. To overcome this situation, the research presented in this paper focuses on the identification and implementation of manufacturing constraints into the design process. A node-based finite element modeling technique is used for the representation and analysis and the multicriteria design problem corresponds to finding the nodal material compositions that minimize structural weight and maximize thermal performance. The optimizer used in this research is a real-valued Evolutionary Strategies (ES), which is well suited for this type of multi-modal problem. Two limitations of the LENS manufacturing process, which have an impact on the design process, are identified and implemented. One of them is related to the manufacturing time, which is considered as an additional criterion to be minimized in the design problem for a preselected tool path. A brake disc rotor made of two materials, aluminum for lightweight and steel for superior thermal characteristics, is used to illustrate the tradeoff between manufacturability and functionality.

  20. Processes for converting biomass-derived feedstocks to chemicals and liquid fuels

    DOEpatents

    Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew

    2016-07-05

    The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.

  1. Modeling of the acid-leaching process in the preparation of chemical ultraclean coal

    SciTech Connect

    Wang, H.; Wang, Z.

    1995-12-31

    The paper is continued from ``Modeling of the Preparation of Chemical Ultraclean Coal`` presented at 11th Pittsburgh Coal Conference. As to acid-alkali deashing process, acid-leaching is a post-processing for the preparation of ultraclean coal, which can be used to remove chemical products caused by alkali-leaching processing. A soluble model is developed to establish an acid-leaching rate equation, which indicates that model result is compatible well with the experimental data.

  2. Evaluation of the FCHART/SLR solar design process

    SciTech Connect

    Fanning, M.W.

    1982-01-01

    The actual heating requirements of 137 passive solar houses were compared to the requirements predicted by a typical design process that used the FCHART/SLR design tool. The calculation of the actual space-heating auxiliary energy needed by the houses during the 1979-1980 heating season was based on fuel bills and appliance use information. The prediction for each residence relied on site-specific weather data for that period, on owner-estimated occupancy patterns, and on measured building characteristics. FCHART/SLR was used with this information to predict the space-heating auxiliary. A statistical comparison of the actual and predicted auxiliaries showed that the design process overpredicted the auxiliary requirement by 60% with 112% standard deviation. A simple heat-loss calculation that ignored the solar contribution proved as accurate a predictor of the heating requirement as the solar design process in some cases.

  3. A Biophysicochemical Model for NO Removal by the Chemical Absorption-Biological Reduction Integrated Process.

    PubMed

    Zhao, Jingkai; Xia, Yinfeng; Li, Meifang; Li, Sujing; Li, Wei; Zhang, Shihan

    2016-08-16

    The chemical absorption-biological reduction (CABR) integrated process is regarded as a promising technology for NOx removal from flue gas. To advance the scale-up of the CABR process, a mathematic model based on mass transfer with reaction in the gas, liquid, and biofilm was developed to simulate and predict the NOx removal by the CABR system in a biotrickling filter. The developed model was validated by the experimental results and subsequently was used to predict the system performance under different operating conditions, such as NO and O2 concentration and gas and liquid flow rate. NO distribution in the gas phase along the biotrickling filter was also modeled and predicted. On the basis of the modeling results, the liquid flow rate and total iron concentration were optimized to achieve >90% NO removal efficiency. Furthermore, sensitivity analysis of the model revealed that the performance of the CABR process was controlled by the bioreduction activity of Fe(III)EDTA. This work will provide the guideline for the design and operation of the CABR process in the industrial application. PMID:27442232

  4. Natural gas operations: considerations on process transients, design, and control.

    PubMed

    Manenti, Flavio

    2012-03-01

    This manuscript highlights tangible benefits deriving from the dynamic simulation and control of operational transients of natural gas processing plants. Relevant improvements in safety, controllability, operability, and flexibility are obtained not only within the traditional applications, i.e. plant start-up and shutdown, but also in certain fields apparently time-independent such as the feasibility studies of gas processing plant layout and the process design of processes. Specifically, this paper enhances the myopic steady-state approach and its main shortcomings with respect to the more detailed studies that take into consideration the non-steady state behaviors. A portion of a gas processing facility is considered as case study. Process transients, design, and control solutions apparently more appealing from a steady-state approach are compared to the corresponding dynamic simulation solutions. PMID:22056010

  5. The shielding design process--new plants to decommissioning.

    PubMed

    Jeffries, Graham; Cooper, Andrew; Hobson, John

    2005-01-01

    BNFL have over 25 years experience of designing nuclear plant for the whole-fuel cycle. In the UK, a Nuclear Decommissioning Authority (NDA) is to be set up to ensure that Britain's nuclear legacy is cleaned up safely, securely and cost effectively. The resulting challenges and opportunities for shielding design will be substantial as the shielding design process was originally devised for the design of new plants. Although its underlying principles are equally applicable to decommissioning and remediation of old plants, there are many aspects of detailed application that need to adapt to this radically different operating environment. The paper describes both the common issues and the different challenges of shielding design at different operational phases. Sample applications will be presented of both new plant and decommissioning projects that illustrate not only the robust nature of the processes being used, but also how they lead to cost-effective solutions making a substantive and appropriate contribution to radiological protection goals. PMID:16604700

  6. Computer-aided design tools for economical MEMS fabrication processes

    NASA Astrophysics Data System (ADS)

    Schneider, Christian; Priebe, Andreas; Brueck, Rainer; Hahn, Kai

    1999-03-01

    Since the early 70s when microsystem technology was first introduce an enormous market for MST-products has been developed. Airbag sensors, micro pumps, ink jet nozzles etc. and the market is just about to start up. Establishing these products for a reasonable price requires mass production. Meanwhile, also computer-based design-tools have been developed in order to reduce the expenses for MST-design. In contrast to other physical design processes like e.g. in micro electronics, MEMS physical design is characterized by the fact that each product requires a tailored sequence of fabrication steps, usually selected from a variety of processing alternatives. The selection from these alternatives is based on economical constraints. Therefore, the design has a strong influence on the money and time spent to take an MST-product to market.

  7. On Chemical Modeling an Alchemical Process: The Use of Combined Chemical Methods in a Historical Study

    NASA Astrophysics Data System (ADS)

    Rodygin, Mikhail Yu.; Rodygin, Irene V.

    1997-08-01

    Laboratory work is an important component of a course in the History of Chemistry and Alchemy, though it can only be illustrative and not comprehensive. The course should exercise both the cognitive and research abilities of an university student. Therefore methods of modeling are of prime importance at this stage of instruction. Modeling can be both a priori and experimental. The experiment can use the alchemist's materials, or it can reproduce the procedure with modern reagents. A good example for the use of this method is a recipe for the preparation of the Philosopher's Stone attributed to Lullius and cited by J. Ripley in Liber Duodecium Portarum. Thus, the Ripley's recipe is not only considered to be the first indication of the existence of acetone, but it may also indicate the formation of acetyl acetone and its derivatives. Thus, as far as the history of alchemy is concerned, the use of an experimental model not only allows us to solve a number of specific problems such as recipe interpretation and product identification, but it allows also to probe the essence of alchemical work. The combination of empirical and speculative modelings leads to the interaction of the exact methods of chemistry with the broad historico-chemical generalizations, thus introducing some additional dimensions to the definition of historico-chemical practice.

  8. Information Flow in the Launch Vehicle Design/Analysis Process

    NASA Technical Reports Server (NTRS)

    Humphries, W. R., Sr.; Holland, W.; Bishop, R.

    1999-01-01

    This paper describes the results of a team effort aimed at defining the information flow between disciplines at the Marshall Space Flight Center (MSFC) engaged in the design of space launch vehicles. The information flow is modeled at a first level and is described using three types of templates: an N x N diagram, discipline flow diagrams, and discipline task descriptions. It is intended to provide engineers with an understanding of the connections between what they do and where it fits in the overall design process of the project. It is also intended to provide design managers with a better understanding of information flow in the launch vehicle design cycle.

  9. A new design concept for an automated peanut processing facility

    SciTech Connect

    Ertas, A.; Tanju, B.T.; Fair, W.T.; Butts, C.

    1996-12-31

    Peanut quality is a major concern in all phases of the peanut industry from production to manufacturing. Postharvest processing of peanuts can have profound effects on the quality and safety of peanut food products. Curing is a key step in postharvest processing. Curing peanuts improperly can significantly reduce quality, and result in significant losses to both farmers and processors. The conventional drying system designed in the 1960`s is still being used in the processing of the peanuts today. The objectives of this paper is to design and develop a new automated peanut drying system for dry climates capable of handling approximately 20 million lbm of peanuts per harvest season.

  10. Concurrent materials and process selection in conceptual design

    SciTech Connect

    Kleban, Stephen D.; Knorovsky, Gerald A.

    2000-08-16

    A method for concurrent selection of materials and a joining process based on product requirements using a knowledge-based, constraint satisfaction approach facilitates the product design and manufacturing process. Using a Windows-based computer video display and a data base of materials and their properties, the designer can ascertain the preferred composition of two parts based on various operating/environmental constraints such as load, temperature, lifetime, etc. Optimum joinder of the two parts may simultaneously be determined using a joining process data base based upon the selected composition of the components as well as the operating/environmental constraints.

  11. Critical Zone Experimental Design to Assess Soil Processes and Function

    NASA Astrophysics Data System (ADS)

    Banwart, Steve

    2010-05-01

    Through unsustainable land use practices, mining, deforestation, urbanisation and degradation by industrial pollution, soil losses are now hypothesized to be much faster (100 times or more) than soil formation - with the consequence that soil has become a finite resource. The crucial challenge for the international research community is to understand the rates of processes that dictate soil mass stocks and their function within Earth's Critical Zone (CZ). The CZ is the environment where soils are formed, degrade and provide their essential ecosystem services. Key among these ecosystem services are food and fibre production, filtering, buffering and transformation of water, nutrients and contaminants, storage of carbon and maintaining biological habitat and genetic diversity. We have initiated a new research project to address the priority research areas identified in the European Union Soil Thematic Strategy and to contribute to the development of a global network of Critical Zone Observatories (CZO) committed to soil research. Our hypothesis is that the combined physical-chemical-biological structure of soil can be assessed from first-principles and the resulting soil functions can be quantified in process models that couple the formation and loss of soil stocks with descriptions of biodiversity and nutrient dynamics. The objectives of this research are to 1. Describe from 1st principles how soil structure influences processes and functions of soils, 2. Establish 4 European Critical Zone Observatories to link with established CZOs, 3. Develop a CZ Integrated Model of soil processes and function, 4. Create a GIS-based modelling framework to assess soil threats and mitigation at EU scale, 5. Quantify impacts of changing land use, climate and biodiversity on soil function and its value and 6. Form with international partners a global network of CZOs for soil research and deliver a programme of public outreach and research transfer on soil sustainability. The

  12. Functionalized sorbent for chemical separations and sequential forming process

    DOEpatents

    Fryxell, Glen E.; Zemanian, Thomas S.

    2012-03-20

    A highly functionalized sorbent and sequential process for making are disclosed. The sorbent includes organic short-length amino silanes and organic oligomeric polyfunctional amino silanes that are dispersed within pores of a porous support that form a 3-dimensional structure containing highly functionalized active binding sites for sorption of analytes.

  13. Microlithographic wet chemical processing in a capillary space

    NASA Astrophysics Data System (ADS)

    Morgan, Russell

    1994-05-01

    The patented device and procedure described provide a method of processing the flat, thin-film coated surfaces encountered in the ultraclean manufacture of integrated circuit wafers, photomasks, panel displays or other similar substrates. The device provides a means of delivering liquids and vapors to those surfaces while temperature, evaporation and particulate contamination are controlled as a natural consequent of its physical configuration. The essential mechanism exploits the surface tension of liquids and the differences in the wettability of surfaces. By juxtaposing the target surface with a prepared surface on the processing device and maintaining a separation of a few millimeters, the gap formed provides a reaction space into which liquids are easily distributed exploiting so-called capillary behavior. While placing the liquid reagent on the hydrophobic, horizontal surface of the processor, the hydrophilic substrate surface suspended above it is transported laterally. The substrate surface then engages the liquid edge which, driven by its own surface tension, quickly fills the gap. The ending of the reaction and removal of the liquid is effected by further transporting the substrate with its captive liquid reactants to a trench provided in the processor surface where the liquid flows down and away. Thus, the processor surface is seen as a series of 'mesas' allowing a sequence of wet process, rinse and vapor treatments, all with the simple lateral movement of the substrate. The effects of improved reaction kinetics on process precision as well as the benefits mentioned above are discussed and compared to previous immersion and spin methods. Critical dimension measurement data are presented from large photomask substrates processed by the instrument.

  14. Application of chemical mechanical polishing process on titanium based implants.

    PubMed

    Ozdemir, Z; Ozdemir, A; Basim, G B

    2016-11-01

    Modification of the implantable biomaterial surfaces is known to improve the biocompatibility of metallic implants. Particularly, treatments such as etching, sand-blasting or laser treatment are commonly studied to understand the impact of nano/micro roughness on cell attachment. Although, the currently utilized surface modification techniques are known to improve the amount of cell attachment, it is critical to control the level of attachment due to the fact that promotion of bioactivity is needed for prosthetic implants while the cardiac valves, which are also made of titanium, need demotion of cells attachment to be able to function. In this study, a new alternative is proposed to treat the implantable titanium surfaces by chemical mechanical polishing (CMP) technique. It is demonstrated that the application of CMP on the titanium surface helps in modifying the surface roughness of the implant in a controlled manner (inducing nano-scale smoothness or controlled nano/micro roughness). Simultaneously, it is observed that the application of CMP limits the bacteria growth by forming a protective thin surface oxide layer on titanium implants. It is further shown that there is an optimal level of surface roughness where the cell attachment reaches a maximum and the level of roughness is controllable through CMP. PMID:27524033

  15. Radical formation, chemical processing, and explosion of interstellar grains

    NASA Technical Reports Server (NTRS)

    Greenberg, J. M.

    1976-01-01

    The ultraviolet radiation in interstellar space is shown to create a sufficient steady-state density of free radicals in the grain mantle material consisting of oxygen, carbon, nitrogen, and hydrogen to satisfy the critical condition for initiation of chain reactions. The criterion for minimum critical particle size for maintaining the chain reaction is of the order of the larger grain sizes in a distribution satisfying the average extinction and polarization measures. The triggering of the explosion of interstellar grains leading to the ejection of complex interstellar molecules is shown to be most probable where the grains are largest and where radiation is suddenly introduced; i.e., in regions of new star formation. Similar conditions prevail at the boundaries between very dark clouds and H II regions. When the energy released by the chemical activity of the free radicals is inadequate to explode the grain, the resulting mantle material must consist of extremely large organic molecules which are much more resistant to the hostile environment of H II regions than the classical dirty-ice mantles made up of water, methane, and ammonia.

  16. Influence of process parameters on the surface and chemical properties of activated carbon obtained from biochar by chemical activation.

    PubMed

    Angın, Dilek; Altintig, Esra; Köse, Tijen Ennil

    2013-11-01

    Activated carbons were produced from biochar obtained through pyrolysis of safflower seed press cake by chemical activation with zinc chloride. The influences of process variables such as the activation temperature and the impregnation ratio on textural and chemical-surface properties of the activated carbons were investigated. Also, the adsorptive properties of activated carbons were tested using methylene blue dye as the targeted adsorbate. The experimental data indicated that the adsorption isotherms are well described by the Langmuir equilibrium isotherm equation. The optimum conditions resulted in activated carbon with a monolayer adsorption capacity of 128.21 mg g(-1) and carbon content 76.29%, while the BET surface area and total pore volume corresponded to 801.5m(2)g(-1) and 0.393 cm(3)g(-1), respectively. This study demonstrated that high surface area activated carbons can be prepared from the chemical activation of biochar with zinc chloride as activating agents. PMID:24080293

  17. DESIGN, SYNTHESIS, AND APPLICATION OF THE TRIMETHOPRIM-BASED CHEMICAL TAG FOR LIVE CELL IMAGING

    PubMed Central

    Jing, Chaoran; Cornish, Virginia W.

    2013-01-01

    Over the past decade chemical tags have been developed to complement the use of fluorescent proteins in live cell imaging. Chemical tags retain the specificity of protein labeling achieved with fluorescent proteins through genetic encoding, but provide smaller, more robust tags and modular use of organic fluorophores with high photon-output and tailored functionalities. The trimethoprim-based chemical tag (TMP-tag) was initially developed based on the high affinity interaction between E.coli dihydrofolatereductase and the antibiotic trimethoprim and subsequently rendered covalent and fluorogenic via proximity-induced protein labeling reactions. To date, the TMP-tag is one of the few chemical tags that enable intracellular protein labeling and high-resolution live cell imaging. Here we describe the general design, chemical synthesis, and application of TMP-tag for live cell imaging. Alternative protocols for synthesizing and using the covalent and the fluorogenic TMP-tags are also included. PMID:23839994

  18. Chemical inertness of UV-cured optical elastomers within the printed circuit board manufacturing process for embedded waveguide applications

    NASA Astrophysics Data System (ADS)

    Kruse, Kevin; Walczak, Karl; Thomas, Nicholas; Swatowski, Brandon; Demars, Casey; Middlebrook, Christopher

    2014-03-01

    Embedding polymer optical waveguides (WGs) into printed circuit boards (PCBs) for intra-board or board-to-board high speed data communications requires polymer materials that are compatible and inert when exposed to common PCB manufacturing processes. Ensuring both WG functionality after chemical exposure and maintaining PCB manufacturing integrities within the production process is crucial for successful implementation. The PCB manufacturing flow is analyzed to expose major requirements that would be required for the successful implementation of polymer materials for embedded WG development. Chemical testing and analysis were performed on Dow Corning ® OE-4140 UV-Cured Optical Elastomer Core and Dow Corning® OE-4141 UV-Cured Optical Elastomer Cladding which are designed for low loss embedded optical WGs. Contamination testing was conducted to demonstrate polymer compatibility in both cured and uncured form. Various PCB chemicals were treated with uncured polymer material and tested for effective contamination. Fully polymerized multimode WGs were fabricated and exposed to PCB chemicals at temperatures and durations comparable to PCB manufacturing conditions. Chemical analysis shows that the chosen polymer is compatible and inert with most common PCB manufacturing processes.

  19. Design of silicone rubber according to requirements based on the multi-objective optimization of chemical reactions

    SciTech Connect

    Jia Yuxi; Sun Sheng; Liu Lili; Mu Yue; An Lijia

    2004-08-16

    The explicit expression between composition and mechanical properties of silicone rubber was derived from the physics of polymer elasticity, the implicit expression among material composition, reaction conditions and reaction efficiency was obtained from chemical thermodynamics and kinetics, and then an implicit multi-objective optimization model was constructed. Genetic algorithm was applied to optimize material composition and reaction conditions, and the finite element method of cross-linking reaction processes was used to solve multi-objective functions, on the basis of which a new optimization methodology of cross-linking reaction processes was established. Using this methodology, rubber materials can be designed according to pre-specified requirements.

  20. Urban street canyons: Coupling dynamics, chemistry and within-canyon chemical processing of emissions

    NASA Astrophysics Data System (ADS)

    Bright, Vivien Bianca; Bloss, William James; Cai, Xiaoming

    2013-04-01

    Street canyons, formed by rows of buildings in urban environments, are associated with high levels of atmospheric pollutants emitted primarily from vehicles, and substantial human exposure. The street canyon forms a semi-enclosed environment, within which emissions may be entrained in a re-circulatory system; chemical processing of emitted compounds alters the composition of the air vented to the overlying boundary layer, compared with the primary emissions. As the prevailing atmospheric chemistry is highly non-linear, and the canyon mixing and predominant chemical reaction timescales are comparable, the combined impacts of dynamics and chemistry must be considered to quantify these effects. Here we report a model study of the coupled impacts of dynamical and chemical processing upon the atmospheric composition in a street canyon environment, to assess the impacts upon air pollutant levels within the canyon, and to quantify the extent to which within-canyon chemical processing alters the composition of canyon outflow, in comparison to the primary emissions within the canyon. A new model for the simulation of street canyon atmospheric chemical processing has been developed, by integrating an existing Large-Eddy Simulation (LES) dynamical model of canyon atmospheric motion with a detailed chemical reaction mechanism, a Reduced Chemical Scheme (RCS) comprising 51 chemical species and 136 reactions, based upon a subset of the Master Chemical Mechanism (MCM). The combined LES-RCS model is used to investigate the combined effects of mixing and chemical processing upon air quality within an idealised street canyon. The effect of the combination of dynamical (segregation) and chemical effects is determined by comparing the outputs of the full LES-RCS canyon model with those obtained when representing the canyon as a zero-dimensional box model (i.e. assuming mixing is complete and instantaneous). The LES-RCS approach predicts lower (canyon-averaged) levels of NOx, OH and HO

  1. Design considerations for fume hoods for process plants.

    PubMed

    Goodfellow, H D; Bender, M

    1980-07-01

    Proper design of fume hoods is a necessary requisite for a clean working environment for many industrial processes. Until recently, the design of these hoods has been rather a trial and error approach and not based on sound engineering design principles. Hatch Associates have developed and applied new techniques to establish hood parameters for different industrail processes. The paper reviews the developed techniques and illustrates practical application of these techniques to the solving of difficult and comples fume hood design and operating performance problems. The scope of the paper covers the following subject areas: definitions and general considerations: evaluation of volume and heat flow rates for emission sources; local capture of process emissions; remote capture of process emissions and case studies of fume hood applications. The purpose of the paper is to detail a coherent approach in the analysis of emission problems which will result in the development of an efficient design of a fume capture hood. An efficient fume hood can provide a safe working place as well as a clean external environment. Although the techniques can be applied to smaller sources, the case studies which will be examined will be for fume hoods in the flow design range of 50 000 CFM to +1 000 000 CFM. PMID:7415967

  2. Design of a Pu-238 Waste Incineration Process

    SciTech Connect

    Charlesworth, D.L.

    2001-05-29

    Combustible Pu-238 waste is generated as a result of normal operation and decommissioning activity at the Savannah River Plant and is being retrievably stored there. As part of the long-term plan to process the stored waste and current waste in preparation for future disposition, a Pu-238 incineration process is being cold-tested at Savannah River Laboratory (SRL). The incineration process consists of a continuous-feed preparation system, a two-stage, electrically fired incinerator, and a filtration off-gas system. Process equipment has been designed, fabricated, and installed for nonradioactive testing and cold run-in. Design features to maximize the ability to remotely maintain the equipment were incorporated into the process. Interlock, alarm, and control functions are provided by a programmable controller. Cold testing is scheduled to be completed in 1986.

  3. Design and development of a space station hazardous material system for assessing chemical compatibility

    NASA Technical Reports Server (NTRS)

    Congo, Richard T.

    1990-01-01

    As the Space Station nears reality in funding support from Congress, NASA plans to perform over a hundred different missions in the coming decade. Incrementally deployed, the Space Station will evolve into modules linked to an integral structure. Each module will have characteristic functions, such as logistics, habitation, and materials processing. Because the Space Station is to be user friendly for experimenters, NASA is anticipating that a variety of different chemicals will be taken on-board. Accidental release of these potentially toxic chemicals and their chemical compatibility is the focus of this discourse. The Microgravity Manufacturing Processing Facility (MMPF) will contain the various facilities within the U.S. Laboratory (USL). Each facility will have a characteristic purpose, such as alloy solidification or vapor crystal growth. By examining the proposed experiments for each facility, identifying the chemical constituents, their physical state and/or changes, byproducts and effluents, those payloads can be identified which may contain toxic, explosive, or reactive compounds that require processing or containment in mission peculiar waste management systems. Synergistic reactions from mixed effluent streams is of major concern. Each experiment will have it own data file, complete with schematic, chemical listing, physical data, etc. Chemical compatibility information from various databases will provide assistance in the analysis of alternate disposal techniques (pretreatment, separate storage, etc.). Along with data from the Risk Analysis of the Proposed USL Waste Management System, accidental release of potentially toxic and catastrophic chemicals would be eliminated or reduced.

  4. Review of Catalytic Hydrogen Generation in the Defense Waste Processing Facility (DWPF) Chemical Processing Cell

    SciTech Connect

    Koopman, D. C.

    2004-12-31

    This report was prepared to fulfill the Phase I deliverable for HLW/DWPF/TTR-98-0018, Rev. 2, ''Hydrogen Generation in the DWPF Chemical Processing Cell'', 6/4/2001. The primary objective for the preliminary phase of the hydrogen generation study was to complete a review of past data on hydrogen generation and to prepare a summary of the findings. The understanding was that the focus should be on catalytic hydrogen generation, not on hydrogen generation by radiolysis. The secondary objective was to develop scope for follow-up experimental and analytical work. The majority of this report provides a summary of past hydrogen generation work with radioactive and simulated Savannah River Site (SRS) waste sludges. The report also includes some work done with Hanford waste sludges and simulants. The review extends to idealized systems containing no sludge, such as solutions of sodium formate and formic acid doped with a noble metal catalyst. This includes general information from the literature, as well as the focused study done by the University of Georgia for the SRS. The various studies had a number of points of universal agreement. For example, noble metals, such as Pd, Rh, and Ru, catalyze hydrogen generation from formic acid and formate ions, and more acid leads to more hydrogen generation. There were also some points of disagreement between different sources on a few topics such as the impact of mercury on the noble metal catalysts and the identity of the most active catalyst species. Finally, there were some issues of potential interest to SRS that apparently have not been systematically studied, e.g. the role of nitrite ion in catalyst activation and reactivity. The review includes studies covering the period from about 1924-2002, or from before the discovery of hydrogen generation during simulant sludge processing in 1988 through the Shielded Cells qualification testing for Sludge Batch 2. The review of prior studies is followed by a discussion of proposed

  5. Vesicle-based method for collecting, manipulating, and chemically processing trace macromolecular species

    DOEpatents

    Davalos, Rafael V.; Ellis, Christopher R. B.

    2010-08-17

    Disclosed is an apparatus and method for inserting one or several chemical or biological species into phospholipid containers that are controlled within a microfluidic network, wherein individual containers are tracked and manipulated by electric fields and wherein the contained species may be chemically processed.

  6. Vesicle-based method and apparatus for collecting, manipulating, and chemically processing trace macromolecular species

    DOEpatents

    Davalos, Rafael V.; Ellis, Christopher R. B.

    2008-03-04

    Disclosed is an apparatus and method for inserting one or several chemical or biological species into phospholipid containers that are controlled within a microfluidic network, wherein individual containers are tracked and manipulated by electric fields and wherein the contained species may be chemically processed.

  7. SIMULATION OF ECOLOGICALLY CONSCIOUS CHEMICAL PROCESSES: FUGITIVE EMISSIONS VERSUS OPERATING CONDITIONS: JOURNAL ARTICLE

    EPA Science Inventory

    NRMRL-CIN-1531A Mata, T.M., Smith*, R.L., Young*, D., and Costa, C.A.V. "Simulation of Ecologically Conscious Chemical Processes: Fugitive Emissions versus Operating Conditions." Paper published in: CHEMPOR' 2001, 8th International Chemical Engineering Conference, Aveiro, Portu...

  8. 40 CFR 372.20 - Process for modifying covered chemicals and facilities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... chemicals and facilities. 372.20 Section 372.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SUPERFUND, EMERGENCY PLANNING, AND COMMUNITY RIGHT-TO-KNOW PROGRAMS TOXIC CHEMICAL RELEASE REPORTING: COMMUNITY RIGHT-TO-KNOW Reporting Requirements § 372.20 Process for modifying covered...

  9. Swimming Pool Water Treatment Chemicals and/or Processes. Standard No. 22.

    ERIC Educational Resources Information Center

    National Sanitation Foundation, Ann Arbor, MI.

    Chemicals or processes used or intended for use, in the treatment of swimming pool water are covered. Minimum public health limits or acceptability in regard to toxicity, biocidal effectiveness, and chemical behavior and analysis are presented. The appendices give guidelines to the scientific and statistically sound evaluations to determine the…

  10. Using a Laboratory Simulator in the Teaching and Study of Chemical Processes in Estuarine Systems

    ERIC Educational Resources Information Center

    Garcia-Luque, E.; Ortega, T.; Forja, J. M.; Gomez-Parra, A.

    2004-01-01

    The teaching of Chemical Oceanography in the Faculty of Marine and Environmental Sciences of the University of Cadiz (Spain) has been improved since 1994 by the employment of a device for the laboratory simulation of estuarine mixing processes and the characterisation of the chemical behaviour of many substances that pass through an estuary. The…

  11. Rational design of a binary metal alloy for chemical vapour deposition growth of uniform single-layer graphene.

    PubMed

    Dai, Boya; Fu, Lei; Zou, Zhiyu; Wang, Min; Xu, Haitao; Wang, Sheng; Liu, Zhongfan

    2011-01-01

    Controlled growth of high-quality graphene is still the bottleneck of practical applications. The widely used chemical vapour deposition process generally suffers from an uncontrollable carbon precipitation effect that leads to inhomogeneous growth and strong correlation to the growth conditions. Here we report the rational design of a binary metal alloy that effectively suppresses the carbon precipitation process and activates a self-limited growth mechanism for homogeneous monolayer graphene. As demonstrated by an Ni-Mo alloy, the designed binary alloy contains an active catalyst component for carbon source decomposition and graphene growth and a black hole counterpart for trapping the dissolved carbons and forming stable metal carbides. This type of process engineering has been used to grow strictly single-layer graphene with 100% surface coverage and excellent tolerance to variations in growth conditions. With simplicity, scalability and a very large growth window, the presented approach may facilitate graphene research and industrial applications. PMID:22045001

  12. Benzene as a Chemical Hazard in Processed Foods

    PubMed Central

    Salviano dos Santos, Vânia Paula; Medeiros Salgado, Andréa; Guedes Torres, Alexandre; Signori Pereira, Karen

    2015-01-01

    This paper presents a literature review on benzene in foods, including toxicological aspects, occurrence, formation mechanisms, and mitigation measures and analyzes data reporting benzene levels in foods. Benzene is recognized by the IARC (International Agency for Research on Cancer) as carcinogenic to humans, and its presence in foods has been attributed to various potential sources: packaging, storage environment, contaminated drinking water, cooking processes, irradiation processes, and degradation of food preservatives such as benzoates. Since there are no specific limits for benzene levels in beverages and food in general studies have adopted references for drinking water in a range from 1–10 ppb. The presence of benzene has been reported in various food/beverage substances with soft drinks often reported in the literature. Although the analyses reported low levels of benzene in most of the samples studied, some exceeded permissible limits. The available data on dietary exposure to benzene is minimal from the viewpoint of public health. Often benzene levels were low as to be considered negligible and not a consumer health risk, but there is still a need of more studies for a better understanding of their effects on human health through the ingestion of contaminated food. PMID:26904662

  13. Benzene as a Chemical Hazard in Processed Foods.

    PubMed

    Salviano Dos Santos, Vânia Paula; Medeiros Salgado, Andréa; Guedes Torres, Alexandre; Signori Pereira, Karen

    2015-01-01

    This paper presents a literature review on benzene in foods, including toxicological aspects, occurrence, formation mechanisms, and mitigation measures and analyzes data reporting benzene levels in foods. Benzene is recognized by the IARC (International Agency for Research on Cancer) as carcinogenic to humans, and its presence in foods has been attributed to various potential sources: packaging, storage environment, contaminated drinking water, cooking processes, irradiation processes, and degradation of food preservatives such as benzoates. Since there are no specific limits for benzene levels in beverages and food in general studies have adopted references for drinking water in a range from 1-10 ppb. The presence of benzene has been reported in various food/beverage substances with soft drinks often reported in the literature. Although the analyses reported low levels of benzene in most of the samples studied, some exceeded permissible limits. The available data on dietary exposure to benzene is minimal from the viewpoint of public health. Often benzene levels were low as to be considered negligible and not a consumer health risk, but there is still a need of more studies for a better understanding of their effects on human health through the ingestion of contaminated food. PMID:26904662

  14. Green process for chemical functionalization of nanocellulose with carboxylic acids.

    PubMed

    Espino-Pérez, Etzael; Domenek, Sandra; Belgacem, Naceur; Sillard, Cécile; Bras, Julien

    2014-12-01

    An environmentally friendly and simple method, named SolReact, has been developed for a solvent-free esterification of cellulose nanocrystals (CNC) surface by using two nontoxic carboxylic acids (CA), phenylacetic acid and hydrocinnamic acid. In this process, the carboxylic acids do not only act as grafting agent, but also as solvent media above their melting point. Key is the in situ solvent exchange by water evaporation driving the esterification reaction without drying the CNC. Atomic force microscopy and X-ray diffraction analyses showed no significant change in the CNC dimensions and crystallinity index after this green process. The presence of the grafted carboxylic was characterized by analysis of the "bulk" CNC with elemental analysis, infrared spectroscopy, and (13)C NMR. The ability to tune the surface properties of grafted nanocrystals (CNC-g-CA) was evaluated by X-ray photoelectron spectroscopy analysis. The hydrophobicity behavior of the functionalized CNC was studied through the water contact-angle measurements and vapor adsorption. The functionalization of these bionanoparticles may offer applications in composite manufacturing, where these nanoparticles have limited dispersibility in hydrophobic polymer matrices and as nanoadsorbers due to the presence of phenolic groups attached on the surface. PMID:25353612

  15. Expertise in professional software design: a process study.

    PubMed

    Sonnentag, S

    1998-10-01

    Forty professional software designers participated in a study in which they worked on a software design task and reported strategies for accomplishing that task. High performers were identified by a peer-nomination method and performance on a design. Verbal protocol analysis based on a comparison of 12 high and 12 moderate performers indicated that high performers structured their design process by local planning and showed more feedback processing, whereas moderate performers were more engaged in analyzing requirements and verbalizing task-irrelevant cognitions. High performers more often described problem comprehension and cooperation with colleagues as useful strategies. High and moderate performers did not differ with respect to length of experience. None of the differences between the two performance groups could be explained by length of experience. PMID:9806013

  16. SLUDGE BATCH 6/TANK 40 SIMULANT CHEMICAL PROCESS CELL SIMULATIONS

    SciTech Connect

    Koopman, David

    2010-04-28

    Phase III simulant flowsheet testing was completed using the latest composition estimates for SB6/Tank 40 feed to DWPF. The goals of the testing were to determine reasonable operating conditions and assumptions for the startup of SB6 processing in the DWPF. Testing covered the region from 102-159% of the current DWPF stoichiometric acid equation. Nitrite ion concentration was reduced to 90 mg/kg in the SRAT product of the lowest acid run. The 159% acid run reached 60% of the DWPF Sludge Receipt and Adjustment Tank (SRAT) limit of 0.65 lb H2/hr, and then sporadically exceeded the DWPF Slurry Mix Evaporator (SME) limit of 0.223 lb H2/hr. Hydrogen generation rates peaked at 112% of the SME limit, but higher than targeted wt% total solids levels may have been partially responsible for rates seen. A stoichiometric factor of 120% met both objectives. A processing window for SB6 exists from 102% to something close to 159% based on the simulant results. An initial recommendation for SB6 processing is at 115-120% of the current DWPF stoichiometric acid equation. The addition of simulated Actinide Removal Process (ARP) and Modular Caustic Side Solvent Extraction Unit (MCU) streams to the SRAT cycle had no apparent impact on the preferred stoichiometric factor. Hydrogen generation occurred continuously after acid addition in three of the four tests. The three runs at 120%, 118.4% with ARP/MCU, and 159% stoichiometry were all still producing around 0.1 lb hydrogen/hr at DWPF scale after 36 hours of boiling in the SRAT. The 120% acid run reached 23% of the SRAT limit and 37% of the SME limit. Conversely, nitrous oxide generation was subdued compared to previous sludge batches, staying below 29 lb/hr in all four tests or about a fourth as much as in comparable SB4 testing. Two processing issues, identified during SB6 Phase II flowsheet testing and qualification simulant testing, were monitored during Phase III. Mercury material balance closure was impacted by acid stoichiometry

  17. Processing electric arc furnace dust into saleable chemical products

    SciTech Connect

    1998-04-01

    The modern steel industry uses electric arc furnace (EAF) technology to manufacture steel. A major drawback of this technology is the production of EAF dust, which is listed by the U.S. Environmental Protection Agency as a hazardous waste under the Resource Conservation and Recovery Act. The annual disposal of approximately 0.65 million tons of EAF dust in the United States and Canada is an expensive, unresolved problem for the steel industry. EAF dust byproducts are generated during the manufacturing process by a variety of mechanisms. The dust consists of various metals (e.g., zinc, lead, cadmium) that occur as vapors at 1,600{degrees}C (EAF hearth temperature); these vapors are condensed and collected in a baghouse. The production of one ton of steel will generate approximately 25 pounds of EAF dust as a byproduct, which is currently disposed of in landfills.

  18. Chemical methods for degradation of target proteins using designed light-activatable organic molecules.

    PubMed

    Tanimoto, Shuho; Takahashi, Daisuke; Toshima, Kazunobu

    2012-08-11

    Molecular design, chemical synthesis, and biological evaluation of several designed organic molecules, which target-selectively degrade proteins upon photo-irradiation, are introduced. The designed molecules for protein photo-degradation include 2-phenylquinoline-steroid hormone hybrids and porphyrin derivatives, both of which selectively photo-degrade estrogen receptor-α, and fullerene-sugar and -sulfonic acid hybrids, which selectively photo-degrade HIV-1 protease and amyloid β, respectively. The information will provide a novel and effective way to control specific functions of proteins, and contribute to the molecular design of novel protein photo-degrading agents, which should find wide application in chemistry, biology, and medicine. PMID:22739361

  19. DEVELOPMENT OF SULFATE RADICAL-BASED CHEMICAL OXIDATION PROCESSES FOR GROUNDWATER REMEDIATION

    EPA Science Inventory

    This study investigates the development of novel sulfate radical-based chemical oxidation processes for treatment of groundwater contaminants. Environmentally friendly transition metal (Fe (II), Fe (III)) has been evaluated for the activation of common oxidants (peroxymonosulfat...

  20. Design of launch systems using continuous improvement process

    NASA Technical Reports Server (NTRS)

    Brown, Richard W.

    1995-01-01

    The purpose of this paper is to identify a systematic process for improving ground operations for future launch systems. This approach is based on the Total Quality Management (TQM) continuous improvement process. While the continuous improvement process is normally identified with making incremental changes to an existing system, it can be used on new systems if they use past experience as a knowledge base. In the case of the Reusable Launch Vehicle (RLV), the Space Shuttle operations provide many lessons. The TQM methodology used for this paper will be borrowed from the United States Air Force 'Quality Air Force' Program. There is a general overview of the continuous improvement process, with concentration on the formulation phase. During this phase critical analyses are conducted to determine the strategy and goals for the remaining development process. These analyses include analyzing the mission from the customers point of view, developing an operations concept for the future, assessing current capabilities and determining the gap to be closed between current capabilities and future needs and requirements. A brief analyses of the RLV, relative to the Space Shuttle, will be used to illustrate the concept. Using the continuous improvement design concept has many advantages. These include a customer oriented process which will develop a more marketable product and a better integration of operations and systems during the design phase. But, the use of TQM techniques will require changes, including more discipline in the design process and more emphasis on data gathering for operational systems. The benefits will far outweigh the additional effort.