designing focused chemical: Topics by WorldWideScience.org

Sample records for designing focused chemical

Designing Focused Chemical Libraries Enriched in Protein-Protein Interaction Inhibitors using Machine-Learning Methods

Science.gov (United States)

Reynès, Christelle; Host, Hélène; Camproux, Anne-Claude; Laconde, Guillaume; Leroux, Florence; Mazars, Anne; Deprez, Benoit; Fahraeus, Robin; Villoutreix, Bruno O.; Sperandio, Olivier

2010-01-01

Protein-protein interactions (PPIs) may represent one of the next major classes of therapeutic targets. So far, only a minute fraction of the estimated 650,000 PPIs that comprise the human interactome are known with a tiny number of complexes being drugged. Such intricate biological systems cannot be cost-efficiently tackled using conventional high-throughput screening methods. Rather, time has come for designing new strategies that will maximize the chance for hit identification through a rationalization of the PPI inhibitor chemical space and the design of PPI-focused compound libraries (global or target-specific). Here, we train machine-learning-based models, mainly decision trees, using a dataset of known PPI inhibitors and of regular drugs in order to determine a global physico-chemical profile for putative PPI inhibitors. This statistical analysis unravels two important molecular descriptors for PPI inhibitors characterizing specific molecular shapes and the presence of a privileged number of aromatic bonds. The best model has been transposed into a computer program, PPI-HitProfiler, that can output from any drug-like compound collection a focused chemical library enriched in putative PPI inhibitors. Our PPI inhibitor profiler is challenged on the experimental screening results of 11 different PPIs among which the p53/MDM2 interaction screened within our own CDithem platform, that in addition to the validation of our concept led to the identification of 4 novel p53/MDM2 inhibitors. Collectively, our tool shows a robust behavior on the 11 experimental datasets by correctly profiling 70% of the experimentally identified hits while removing 52% of the inactive compounds from the initial compound collections. We strongly believe that this new tool can be used as a global PPI inhibitor profiler prior to screening assays to reduce the size of the compound collections to be experimentally screened while keeping most of the true PPI inhibitors. PPI-HitProfiler is
Designing focused chemical libraries enriched in protein-protein interaction inhibitors using machine-learning methods.

Directory of Open Access Journals (Sweden)

Christelle Reynès

2010-03-01

Full Text Available Protein-protein interactions (PPIs may represent one of the next major classes of therapeutic targets. So far, only a minute fraction of the estimated 650,000 PPIs that comprise the human interactome are known with a tiny number of complexes being drugged. Such intricate biological systems cannot be cost-efficiently tackled using conventional high-throughput screening methods. Rather, time has come for designing new strategies that will maximize the chance for hit identification through a rationalization of the PPI inhibitor chemical space and the design of PPI-focused compound libraries (global or target-specific. Here, we train machine-learning-based models, mainly decision trees, using a dataset of known PPI inhibitors and of regular drugs in order to determine a global physico-chemical profile for putative PPI inhibitors. This statistical analysis unravels two important molecular descriptors for PPI inhibitors characterizing specific molecular shapes and the presence of a privileged number of aromatic bonds. The best model has been transposed into a computer program, PPI-HitProfiler, that can output from any drug-like compound collection a focused chemical library enriched in putative PPI inhibitors. Our PPI inhibitor profiler is challenged on the experimental screening results of 11 different PPIs among which the p53/MDM2 interaction screened within our own CDithem platform, that in addition to the validation of our concept led to the identification of 4 novel p53/MDM2 inhibitors. Collectively, our tool shows a robust behavior on the 11 experimental datasets by correctly profiling 70% of the experimentally identified hits while removing 52% of the inactive compounds from the initial compound collections. We strongly believe that this new tool can be used as a global PPI inhibitor profiler prior to screening assays to reduce the size of the compound collections to be experimentally screened while keeping most of the true PPI inhibitors. PPI
Designing focused chemical libraries enriched in protein-protein interaction inhibitors using machine-learning methods.

Science.gov (United States)

Reynès, Christelle; Host, Hélène; Camproux, Anne-Claude; Laconde, Guillaume; Leroux, Florence; Mazars, Anne; Deprez, Benoit; Fahraeus, Robin; Villoutreix, Bruno O; Sperandio, Olivier

2010-03-05

Protein-protein interactions (PPIs) may represent one of the next major classes of therapeutic targets. So far, only a minute fraction of the estimated 650,000 PPIs that comprise the human interactome are known with a tiny number of complexes being drugged. Such intricate biological systems cannot be cost-efficiently tackled using conventional high-throughput screening methods. Rather, time has come for designing new strategies that will maximize the chance for hit identification through a rationalization of the PPI inhibitor chemical space and the design of PPI-focused compound libraries (global or target-specific). Here, we train machine-learning-based models, mainly decision trees, using a dataset of known PPI inhibitors and of regular drugs in order to determine a global physico-chemical profile for putative PPI inhibitors. This statistical analysis unravels two important molecular descriptors for PPI inhibitors characterizing specific molecular shapes and the presence of a privileged number of aromatic bonds. The best model has been transposed into a computer program, PPI-HitProfiler, that can output from any drug-like compound collection a focused chemical library enriched in putative PPI inhibitors. Our PPI inhibitor profiler is challenged on the experimental screening results of 11 different PPIs among which the p53/MDM2 interaction screened within our own CDithem platform, that in addition to the validation of our concept led to the identification of 4 novel p53/MDM2 inhibitors. Collectively, our tool shows a robust behavior on the 11 experimental datasets by correctly profiling 70% of the experimentally identified hits while removing 52% of the inactive compounds from the initial compound collections. We strongly believe that this new tool can be used as a global PPI inhibitor profiler prior to screening assays to reduce the size of the compound collections to be experimentally screened while keeping most of the true PPI inhibitors. PPI-HitProfiler is
Conceptual Chemical Process Design for Sustainability.

Science.gov (United States)

This chapter examines the sustainable design of chemical processes, with a focus on conceptual design, hierarchical and short-cut methods, and analyses of process sustainability for alternatives. The chapter describes a methodology for incorporating process sustainability analyse...
Design of diversity and focused combinatorial libraries in drug discovery.

Science.gov (United States)

Young, S Stanley; Ge, Nanxiang

2004-05-01

Using well-characterized chemical reactions and readily available monomers, chemists are able to create sets of compounds, termed libraries, which are useful in drug discovery processes. The design of combinatorial chemical libraries can be complex and there has been much information recently published offering suggestions on how the design process can be carried out. This review focuses on literature with the goal of organizing current thinking. At this point in time, it is clear that benchmarking of current suggested methods is required as opposed to further new methods.
Design of chemical plant

International Nuclear Information System (INIS)

Lee, Dong Il; Kim, Seung Jae; Yang, Jae Ho; Ryu, Hwa Won

1993-01-01

This book describes design of chemical plant, which includes chemical engineer and plan for chemical plant, development of chemical process, cost engineering pattern, design and process development, general plant construction plan, project engineering, foundation for economy on assets and depreciation, estimation for cost on capital investment and manufacturing cost, design with computers optimal design and method like fluid mechanics design chemical device and estimation for cost, such as dispatch of material and device writing on design report and appendixes.
Chemical Product Design

DEFF Research Database (Denmark)

Gani, Rafiqul

2004-01-01

This paper highlights for a class of chemical products, the design process, their design with respect to the important issues, the need for appropriate tools and finally, lists some of the challenges and opportunities for the process systems engineering (PSE)/computer-aided process engineering...... (CAPE) community. The chemical products considered belong to the following types: chemical/biochemical/agrochemical products, coatings and solvents, food (nutraceuticals), HIM (household, industrial and institutional), personal care, pharmaceuticals and drugs. The challenges and opportunities...... are highlighted in terms of the needs for multi-level modeling with emphasis on property models that are suitable for computer-aided applications, flexible solution strategies that are able to solve a large range of chemical product design problems and finally, a systems chemical product design framework...
Chemical-Based Formulation Design: Virtual Experimentation

DEFF Research Database (Denmark)

Conte, Elisa; Gani, Rafiqul

This paper presents a software, the virtual Product-Process Design laboratory (virtual PPD-lab) and the virtual experimental scenarios for design/verification of consumer oriented liquid formulated products where the software can be used. For example, the software can be employed for the design......, the additives and/or their mixtures (formulations). Therefore, the experimental resources can focus on a few candidate product formulations to find the best product. The virtual PPD-lab allows various options for experimentations related to design and/or verification of the product. For example, the selection...... design, model adaptation). All of the above helps to perform virtual experiments by blending chemicals together and observing their predicted behaviour. The paper will highlight the application of the virtual PPD-lab in the design and/or verification of different consumer products (paint formulation...
Process Design and Evaluation for Chemicals Based on Renewable Resources

DEFF Research Database (Denmark)

Fu, Wenjing

. In addition, another characteristic of chemicals based on renewable feedstocks is that many alternative technologies and possible routes exist, resulting in many possible process flowsheets. The challenge for process engineers is then to choose between possible process routes and alternative technologies...... development of chemicals based on renewable feedstocks. As an example, this thesis especially focuses on applying the methodology in process design and evaluation of the synthesis of 5-hydroxymethylfurfural (HMF) from the renewable feedstock glucose/fructose. The selected example is part of the chemoenzymatic......One of the key steps in process design is choosing between alternative technologies, especially for processes producing bulk and commodity chemicals. Recently, driven by the increasing oil prices and diminishing reserves, the production of bulk and commodity chemicals from renewable feedstocks has...
Focus Section on Design Anthropology in Participatory Design

DEFF Research Database (Denmark)

2015-01-01

This focus section explores the opportunities of design anthropology in participatory design as an approach to research and design in an increasingly global and digital world. Traditionally, ethnography has been used in Participatory design to research real-life contexts and challenges, and as ways...... to involve people in defining user-needs and design opportunities. As the boundaries between diverse – material, digital and networked – spaces and experiences become increasingly blurred, so do the conventional distinctions between research and design. The papers presented in this focus section explore...... opportunities of using design anthropology as a holistic and critical approach to addressing societal challenges and change, and a way for anthropologists and designers to engage in participatory research and design that extend beyond the empirical....
Advances in chemical product design

DEFF Research Database (Denmark)

Zhang, Lei; Fung, Ka Yip; Wibowo, Christianto

2018-01-01

The nature of chemical product design problems is diverse and multidisciplinary. It involves many design issues such as project management, market study, product design, process design, and economic analysis for better organizing the product design project and achieving better products. This arti......The nature of chemical product design problems is diverse and multidisciplinary. It involves many design issues such as project management, market study, product design, process design, and economic analysis for better organizing the product design project and achieving better products....... This article provides an overview of chemical product design with a multidisciplinary hierarchical framework including all the design issues and tasks. Each of the design issues and tasks are introduced and discussed, methods and tools are summarized and compared, challenges and perspectives are presented...... to help the chemical product design researchers on finding more novel, innovative and sustainable products, by the combined effort from academia and industry to develop a systematic generic framework, and tools including product simulator, process simulator, database manager, modeling tool, and templates...
Quantum Chemical: New name and focus for National Distillers

Energy Technology Data Exchange (ETDEWEB)

Reisch, M.S.

1988-03-14

This article explains why the National Distillers and Chemical Corporation has narrowed its focus on petrochemicals and energy. At one time the company had diversified into wine and spirits, insurance, metals, chemicals and energy. However, the company decided to reexamine where its commitments should be. It decided to stick with chemicals and energy because it could be a leader in these fields and not in its other interests. The article explains how the new company, Quantum Chemical, is doing and where it is headed in the future.
Identifying and designing chemicals with minimal acute aquatic toxicity.

Science.gov (United States)

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

2015-05-19

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.
The rational design of a Au(I) precursor for focused electron beam induced deposition

NARCIS (Netherlands)

Marashdeh, Ali; Tiesma, Thiadrik; van Velzen, Niels J. C.; Harder, Sjoerd; Havenith, Remco W. A.; De Hosson, Jeff T. M.; van Dorp, Willem F.

2017-01-01

Au(I) complexes are studied as precursors for focused electron beam induced processing (FEBIP). FEBIP is an advanced direct-write technique for nanometer-scale chemical synthesis. The stability and volatility of the complexes are characterized to design an improved precursor for pure Au deposition.
An expanded conceptual framework for solution-focused management of chemical pollution in European waters.

Science.gov (United States)

Munthe, John; Brorström-Lundén, Eva; Rahmberg, Magnus; Posthuma, Leo; Altenburger, Rolf; Brack, Werner; Bunke, Dirk; Engelen, Guy; Gawlik, Bernd Manfred; van Gils, Jos; Herráez, David López; Rydberg, Tomas; Slobodnik, Jaroslav; van Wezel, Annemarie

2017-01-01

This paper describes a conceptual framework for solutions-focused management of chemical contaminants built on novel and systematic approaches for identifying, quantifying and reducing risks of these substances. The conceptual framework was developed in interaction with stakeholders representing relevant authorities and organisations responsible for managing environmental quality of water bodies. Stakeholder needs were compiled via a survey and dialogue. The content of the conceptual framework was thereafter developed with inputs from relevant scientific disciplines. The conceptual framework consists of four access points: Chemicals, Environment, Abatement and Society, representing different aspects and approaches to engaging in the issue of chemical contamination of surface waters. It widens the scope for assessment and management of chemicals in comparison to a traditional (mostly) perchemical risk assessment approaches by including abatement- and societal approaches as optional solutions. The solution-focused approach implies an identification of abatement- and policy options upfront in the risk assessment process. The conceptual framework was designed for use in current and future chemical pollution assessments for the aquatic environment, including the specific challenges encountered in prioritising individual chemicals and mixtures, and is applicable for the development of approaches for safe chemical management in a broader sense. The four access points of the conceptual framework are interlinked by four key topics representing the main scientific challenges that need to be addressed, i.e.: identifying and prioritising hazardous chemicals at different scales; selecting relevant and efficient abatement options; providing regulatory support for chemicals management; predicting and prioritising future chemical risks. The conceptual framework aligns current challenges in the safe production and use of chemicals. The current state of knowledge and implementation
El diseño curricular desde la perspectiva de la actividad profesional / Curricular design: focus on professional performance

Directory of Open Access Journals (Sweden)

Idielyn Cabrera Marrero

2017-09-01

Full Text Available The analysis of the curricular design theories shows that the concept of performance has not yet been sufficiently studied, this explains actual inconsistencies in the design methodologies that claim to be focused on professional activity. However, in practice they are focusing professional problems instead, or simply copying other universities curricula without considering the particular country stage of development. Taking Chemical engineers as a referent point, the authors devise a methodology of curricular design focused on professional activity leading to the comprehension of this particular engineers ‘performance. The findings result from the application of the functional structural systemic method.
Sustainable Chemical Processes and Products. New Design Methodology and Design Tools

OpenAIRE

Korevaar, G.

2004-01-01

The current chemical industry is not sustainable, which leads to the fact that innovation of chemical processes and products is too often hazardous for society in general and the environment in particular. It really is a challenge to implement sustainability considerations in the design activities of chemical engineers. Therefore, the main question of this thesis is: how can a trained chemical engineer develop a conceptual design of a chemical process or a chemical product in such a way that ...
Optimum Design of Plasma Focus

International Nuclear Information System (INIS)

Ramos, Ruben; Gonzalez, Jose; Clausse, Alejandro

2000-01-01

The optimum design of Plasma Focus devices is presented based in a lumped parameter model of the MHD equations.Maps in the design parameters space are obtained, which determine the length and deuterium pressure required to produce a given neutron yield.Sensitivity analyses of the main effective numbers (sweeping efficiencies) was performed, and lately the optimum values were determined in order to set a basis for the conceptual design
Chemical process and plant design bibliography 1959-1989

International Nuclear Information System (INIS)

Ray, M.S.

1991-01-01

This book is concerned specifically with chemical process in formation and plant equipment design data. It is a source for chemical engineers, students and academics involved in process and design evaluation. Over 500 chemical categories are included, from Acetaldehyde to zirconium Dioxide, with cross-referencing within the book to appropriate associated chemicals
Protocols for the Design of Kinase-focused Compound Libraries.

Science.gov (United States)

Jacoby, Edgar; Wroblowski, Berthold; Buyck, Christophe; Neefs, Jean-Marc; Meyer, Christophe; Cummings, Maxwell D; van Vlijmen, Herman

2018-05-01

Protocols for the design of kinase-focused compound libraries are presented. Kinase-focused compound libraries can be differentiated based on the design goal. Depending on whether the library should be a discovery library specific for one particular kinase, a general discovery library for multiple distinct kinase projects, or even phenotypic screening, there exists today a variety of in silico methods to design candidate compound libraries. We address the following scenarios: 1) Datamining of SAR databases and kinase focused vendor catalogues; 2) Predictions and virtual screening; 3) Structure-based design of combinatorial kinase inhibitors; 4) Design of covalent kinase inhibitors; 5) Design of macrocyclic kinase inhibitors; and 6) Design of allosteric kinase inhibitors and activators. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Design of a new type synchronous focusing mechanism

Science.gov (United States)

Zhang, Jintao; Tan, Ruijun; Chen, Zhou; Zhang, Yongqi; Fu, Panlong; Qu, Yachen

2018-05-01

Aiming at the dual channel telescopic imaging system composed of infrared imaging system, low-light-level imaging system and image fusion module, In the fusion of low-light-level images and infrared images, it is obvious that using clear source images is easier to obtain high definition fused images. When the target is imaged at 15m to infinity, focusing is needed to ensure the imaging quality of the dual channel imaging system; therefore, a new type of synchronous focusing mechanism is designed. The synchronous focusing mechanism realizes the focusing function through the synchronous translational imaging devices, mainly including the structure of the screw rod nut, the shaft hole coordination structure and the spring steel ball eliminating clearance structure, etc. Starting from the synchronous focusing function of two imaging devices, the structure characteristics of the synchronous focusing mechanism are introduced in detail, and the focusing range is analyzed. The experimental results show that the synchronous focusing mechanism has the advantages of ingenious design, high focusing accuracy and stable and reliable operation.
Modeling chemical reactions for drug design.

Science.gov (United States)

Gasteiger, Johann

2007-01-01

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

Science.gov (United States)

Schomburg, Karen T; Wetzer, Lars; Rarey, Matthias

2013-07-01

Every medicinal chemist has to create chemical patterns occasionally for querying databases, applying filters or describing functional groups. However, the representations of chemical patterns have been so far limited to languages with highly complex syntax, handicapping the application of patterns. Graphic pattern editors similar to chemical editors can facilitate the work with patterns. In this article, we review the interfaces of frequently used web search engines for chemical patterns. We take a look at pattern editing concepts of standalone chemical editors and finally present a completely new, unpublished graphical approach to pattern design, the SMARTSeditor. Copyright © 2013 Elsevier Ltd. All rights reserved.
CRISPR-FOCUS: A web server for designing focused CRISPR screening experiments

OpenAIRE

Cao, Qingyi; Ma, Jian; Chen, Chen-Hao; Xu, Han; Chen, Zhi; Li, Wei; Liu, X. Shirley

2017-01-01

The recently developed CRISPR screen technology, based on the CRISPR/Cas9 genome editing system, enables genome-wide interrogation of gene functions in an efficient and cost-effective manner. Although many computational algorithms and web servers have been developed to design single-guide RNAs (sgRNAs) with high specificity and efficiency, algorithms specifically designed for conducting CRISPR screens are still lacking. Here we present CRISPR-FOCUS, a web-based platform to search and prioriti...
Computerized method and system for designing an aerodynamic focusing lens stack

Science.gov (United States)

Gard, Eric [San Francisco, CA; Riot, Vincent [Oakland, CA; Coffee, Keith [Diablo Grande, CA; Woods, Bruce [Livermore, CA; Tobias, Herbert [Kensington, CA; Birch, Jim [Albany, CA; Weisgraber, Todd [Brentwood, CA

2011-11-22

A computerized method and system for designing an aerodynamic focusing lens stack, using input from a designer related to, for example, particle size range to be considered, characteristics of the gas to be flowed through the system, the upstream temperature and pressure at the top of a first focusing lens, the flow rate through the aerodynamic focusing lens stack equivalent at atmosphere pressure; and a Stokes number range. Based on the design parameters, the method and system determines the total number of focusing lenses and their respective orifice diameters required to focus the particle size range to be considered, by first calculating for the orifice diameter of the first focusing lens in the Stokes formula, and then using that value to determine, in iterative fashion, intermediate flow values which are themselves used to determine the orifice diameters of each succeeding focusing lens in the stack design, with the results being output to a designer. In addition, the Reynolds numbers associated with each focusing lens as well as exit nozzle size may also be determined to enhance the stack design.
Recycling of poly(ethylene terephthalate – A review focusing on chemical methods

Directory of Open Access Journals (Sweden)

B. Geyer

2016-07-01

Full Text Available Recycling of poly(ethylene terephthalate (PET is of crucial importance, since worldwide amounts of PETwaste increase rapidly due to its widespread applications. Hence, several methods have been developed, like energetic, material, thermo-mechanical and chemical recycling of PET. Most frequently, PET-waste is incinerated for energy recovery, used as additive in concrete composites or glycolysed to yield mixtures of monomers and undefined oligomers. While energetic and thermo-mechanical recycling entail downcycling of the material, chemical recycling requires considerable amounts of chemicals and demanding processing steps entailing toxic and ecological issues. This review provides a thorough survey of PET-recycling including energetic, material, thermo-mechanical and chemical methods. It focuses on chemical methods describing important reaction parameters and yields of obtained reaction products. While most methods yield monomers, only a few yield undefined low molecular weight oligomers for impaired applications (dispersants or plasticizers. Further, the present work presents an alternative chemical recycling method of PET in comparison to existing chemical methods.
Focus Group Evidence: Implications for Design and Analysis

Science.gov (United States)

Ryan, Katherine E.; Gandha, Tysza; Culbertson, Michael J.; Carlson, Crystal

2014-01-01

In evaluation and applied social research, focus groups may be used to gather different kinds of evidence (e.g., opinion, tacit knowledge). In this article, we argue that making focus group design choices explicitly in relation to the type of evidence required would enhance the empirical value and rigor associated with focus group utilization. We…
Design and simulation of an accelerating and focusing system

Directory of Open Access Journals (Sweden)

A Sadeghipanah

2011-06-01

Full Text Available Electrostatic focusing lenses have a vast field of applications in electrostatic accelerators and particularly in electron guns. In this paper, we first express a parametric mathematical analysis of an electrostatic accelerator and focusing system for an electron beam. Next, we At design a system of electron emission slit, accelerating electrodes and focusing lens for an electron beam emitted from a cathode with 4 mm radius and 2 mA current, in a distance less than 10 cm and up to the energy of 30 keV with the beam divergence less than 5°. This is achieved by solving the yielded equations in mathematical analysis using MATLAB. At the end, we simulate the behavior of above electron beam in the designed accelerating and focusing system using CST EM Studio. The results of simulation are in high agreement with required specifications of the electron beam, showing the accuracy of the used method in analysis and design of the accelerating and focusing system.
A Novel Final Focus Design for Future Linear Colliders

Energy Technology Data Exchange (ETDEWEB)

Seryi, Andrei

2000-05-30

The length, complexity and cost of the present Final Focus designs for linear colliders grows very quickly with the beam energy. In this letter, a novel final focus system is presented and compared with the one proposed for NLC. This new design is simpler, shorter and cheaper, with comparable bandwidth, tolerances and tunability. Moreover, the length scales slower than linearly with energy allowing for a more flexible design which is applicable over a much larger energy range.
Computational chemical product design problems under property uncertainties

DEFF Research Database (Denmark)

Frutiger, Jerome; Cignitti, Stefano; Abildskov, Jens

2017-01-01

Three different strategies of how to combine computational chemical product design with Monte Carlo based methods for uncertainty analysis of chemical properties are outlined. One method consists of a computer-aided molecular design (CAMD) solution and a post-processing property uncertainty...... fluid design. While the higher end of the uncertainty range of the process model output is similar for the best performing fluids, the lower end of the uncertainty range differs largely....
Sustainable Chemical Processes and Products. New Design Methodology and Design Tools

NARCIS (Netherlands)

Korevaar, G.

2004-01-01

The current chemical industry is not sustainable, which leads to the fact that innovation of chemical processes and products is too often hazardous for society in general and the environment in particular. It really is a challenge to implement sustainability considerations in the design activities
General method for final focus system design for circular colliders

Directory of Open Access Journals (Sweden)

Riccardo de Maria

2008-03-01

Full Text Available Colliders use final focus systems to reduce the transverse beam sizes at the interaction point in order to increase collision event rates. The maximum focal strength (gradient of the quadrupoles, and the maximum beam size in them, together limit the beam size reduction that is possible. The goal of a final focus system design is to find the best compromise between quadrupole aperture and quadrupole gradient, for the magnet technology that is used. This paper develops a design method that identifies the intrinsic limitations of a final focus system, validates the results of the method against realistic designs, and reports its application to the upgrade of the Large Hadron Collider final focus.
New Vistas in Chemical Product and Process Design

DEFF Research Database (Denmark)

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

2016-01-01

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...
Systematic methods for synthesis and design of sustainable chemical and biochemical processes

DEFF Research Database (Denmark)

Gani, Rafiqul

Chemical and biochemical process design consists of designing the process that can sustainably manufacture an identified chemical product through a chemical or biochemical route. The chemical product tree is potentially very large; starting from a set of basic raw materials (such as petroleum...... for process intensification, sustainable process design, identification of optimal biorefinery models as well as integrated process-control design, and chemical product design. The lecture will present the main concepts, the decomposition based solution approach, the developed methods and tools together...
Designing focusing solenoids for superconducting RF accelerators

Energy Technology Data Exchange (ETDEWEB)

Davis, G.; Kashikhin, V.V.; Page, T.; Terechkine, I.; Tompkins, J.; Wokas, T.; /Fermilab

2006-08-01

The design of a focusing solenoid for use in a superconducting RF linac requires resolving a range of problems with conflicting requirements. Providing the required focusing strength contradicts the goal of minimizing the stray field on the surfaces of adjacent superconducting RF cavities. The requirement of a compact solenoid, able to fit into a gap between cavities, contradicts the need of mechanical support necessary to restrain electromagnetic forces that can result in coil motion and subsequent quenching. In this report we will attempt to address these and other issues arising during the development of focusing solenoids. Some relevant test data will also be presented.
Chemically Induced Phase Transformation in Austenite by Focused Ion Beam

Science.gov (United States)

Basa, Adina; Thaulow, Christian; Barnoush, Afrooz

2014-03-01

A highly stable austenite phase in a super duplex stainless steel was subjected to a combination of different gallium ion doses at different acceleration voltages. It was shown that contrary to what is expected, an austenite to ferrite phase transformation occurred within the focused ion beam (FIB) milled regions. Chemical analysis of the FIB milled region proved that the gallium implantation preceded the FIB milling. High resolution electron backscatter diffraction analysis also showed that the phase transformation was not followed by the typical shear and plastic deformation expected from the martensitic transformation. On the basis of these observations, it was concluded that the change in the chemical composition of the austenite and the local increase in gallium, which is a ferrite stabilizer, results in the local selective transformation of austenite to ferrite.
Design and analysis of all-dielectric subwavelength focusing flat lens

Science.gov (United States)

Turduev, M.; Bor, E.; Kurt, H.

2017-09-01

In this letter, we numerically designed and experimentally demonstrated a compact photonic structure for the subwavelength focusing of light using all-dielectric absorption-free and nonmagnetic scattering objects distributed in an air medium. In order to design the subwavelength focusing flat lens, an evolutionary algorithm is combined with the finite-difference time-domain method for determining the locations of cylindrical scatterers. During the multi-objective optimization process, a specific objective function is defined to reduce the full width at half maximum (FWHM) and diminish side lobe level (SLL) values of light at the focal point. The time-domain response of the optimized flat lens exhibits subwavelength light focusing with an FWHM value of 0.19λ and an SLL value of 0.23, where λ denotes the operating wavelength of light. Experimental analysis of the proposed flat lens is conducted in a microwave regime and findings exactly verify the numerical results with an FWHM of 0.192λ and an SLL value of 0.311 at the operating frequency of 5.42 GHz. Moreover, the designed flat lens provides a broadband subwavelength focusing effect with a 9% bandwidth covering frequency range of 5.10 GHz-5.58 GHz, where corresponding FWHM values remain under 0.21λ. Also, it is important to note that the designed flat lens structure performs a line focusing effect. Possible applications of the designed structure in telecom wavelengths are speculated upon for future perspectives. Namely, the designed structure can perform well in photonic integrated circuits for different fields of applications such as high efficiency light coupling, imaging and optical microscopy, with its compact size and ability for strong focusing.
Method for innovative synthesis-design of chemical process flowsheets

DEFF Research Database (Denmark)

Kumar Tula, Anjan; Gani, Rafiqul

Chemical process synthesis-design involve the identification of the processing route to reach a desired product from a specified set of raw materials, design of the operations involved in the processing route, the calculations of utility requirements, the calculations of waste and emission...... to the surrounding and many more. Different methods (knowledge-based [1], mathematical programming [2], hybrid, etc.) have been proposed and are also currently employed to solve these synthesis-design problems. D’ Anterroches [3] proposed a group contribution based approach to solve the synthesis-design problem...... of chemical processes, where, chemical process flowsheets could be synthesized in the same way as atoms or groups of atoms are synthesized to form molecules in computer aided molecular design (CAMD) techniques [4]. That, from a library of building blocks (functional process-groups) and a set of rules to join...
New Vistas in Chemical Product and Process Design.

Science.gov (United States)

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

2016-06-07

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.
A RECIPE FOR LINEAR COLLIDER FINAL FOCUS SYSTEM DESIGN

International Nuclear Information System (INIS)

Seryi, Andrei

2003-01-01

The design of Final Focus systems for linear colliders is challenging because of the large demagnifications needed to produce nanometer-sized beams at the interaction point. Simple first- and second-order matrix matching have proven insufficient for this task, and minimization of third- and higher-order aberrations is essential. An appropriate strategy is required for the latter to be successful. A recipe for Final Focus design, and a set of computational tools used to implement this approach, are described herein. An example of the use of this procedure is given

Innovation policy of European chemical companies with special focus on large companies

Directory of Open Access Journals (Sweden)

Supriyo Das

2015-07-01

Full Text Available According to Arora et alii (1998, the chemical industry is one of the largest and most R&D-intensive manufacturing sectors in all the advanced economies, and its innovative patterns and productivity growth processes can have profound impacts on economic growth as a whole. The European chemical industry supplies virtually all sectors of the economy and accounts for 17.8% of the total sales of chemicals in the world. This paper gives an overview of the European chemical industry and the changing scenario of the world chemical industry by focusing on the top fifteen chemical companies in Europe. It describes the current problems this industry is facing in Europe especially after the economic crisis and shows that the region and the top companies are investing in R&D to bring about innovation and overcome the current challenges. It shows that R&D spending in absolute terms has hardly changed over the years and that the industry is still globally the largest investor in R&D activities. In terms of R&D, BASF has made the greatest investment followed by Bayer and Syngenta, while R&D intensity is highest for Syngenta and Bayer. BASF and Bayer have made most patent applications and have also had the highest number of patents granted. The quality of research in most chemical companies is very high and most of the large European companies make their first patent application in Europe rather than elsewhere. All the large chemical companies use Merger & Acquisition (M&A to gain access to innovation. Industry-academia collaboration is one way to generate innovation in the chemical industry in Europe. Chemical clusters and the geographical distribution of chemical companies play a significant role in generating innovation.
Design of a chemical batch plant : a study of dedicated parallel lines with intermediate storage and the plant performance

OpenAIRE

Verbiest, Floor; Cornelissens, Trijntje; Springael, Johan

2016-01-01

Abstract: Production plants worldwide face huge challenges in satisfying high service levels and outperforming competition. These challenges require appropriate strategic decisions on plant design and production strategies. In this paper, we focus on multiproduct chemical batch plants, which are typically equipped with multiple production lines and intermediate storage tanks. First we extend the existing MI(N) LP design models with the concept of parallel production lines, and optimise the as...
Designing Solutions by a Student Centred Approach: Integration of Chemical Process Simulation with Statistical Tools to Improve Distillation Systems

Directory of Open Access Journals (Sweden)

Isabel M. Joao

2017-09-01

Full Text Available Projects thematically focused on simulation and statistical techniques for designing and optimizing chemical processes can be helpful in chemical engineering education in order to meet the needs of engineers. We argue for the relevance of the projects to improve a student centred approach and boost higher order thinking skills. This paper addresses the use of Aspen HYSYS by Portuguese chemical engineering master students to model distillation systems together with statistical experimental design techniques in order to optimize the systems highlighting the value of applying problem specific knowledge, simulation tools and sound statistical techniques. The paper summarizes the work developed by the students in order to model steady-state processes, dynamic processes and optimize the distillation systems emphasizing the benefits of the simulation tools and statistical techniques in helping the students learn how to learn. Students strengthened their domain specific knowledge and became motivated to rethink and improve chemical processes in their future chemical engineering profession. We discuss the main advantages of the methodology from the students’ and teachers perspective
An expanded conceptual framework for solution-focused management of chemical pollution in European waters

NARCIS (Netherlands)

Munthe, John; Brorström-Lundén, Eva; Rahmberg, Magnus; Posthuma, Leo; Altenburger, Rolf; Brack, Werner; Bunke, Dirk; Engelen, Guy; Gawlik, Bernd Manfred; van Gils, Jos; Herráez, David López; Rydberg, Tomas; Slobodnik, Jaroslav; van Wezel, Annemarie

2017-01-01

Background: This paper describes a conceptual framework for solutions-focused management of chemical contaminants built on novel and systematic approaches for identifying, quantifying and reducing risks of these substances. Methods: The conceptual framework was developed in interaction with
Design of High Precise Focusing System in Laser Direct Writer

International Nuclear Information System (INIS)

Liang, Y Y; Tian, F; Luo, J B; Yang, G G

2006-01-01

In order to improve the accuracy and efficiency of fabricating lines with laser pattern generator, a novel focusing system was designed. Focusing system is based on optical off-axis detection principle. The detector is a two-quadrant photocell and the defocus signal is constructed by division. Focusing system has the character of second-order system with overdamp. The new embedded PID controller improves the performance of focusing system and upgrades the closed-loop precision to 0.2 μm. Furthermore focusing system has the fabrication capabilities for alterable-width lines under various defocus amount
Designing Endocrine Disruption Out of the Next Generation of Chemicals.

Science.gov (United States)

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
The completed design of the SLC Final Focus System

International Nuclear Information System (INIS)

Murray, J.J.; Brown, K.L.; Fieguth, T.

1987-02-01

The design of the SLC Final Focus System has evolved from its initial conceptual design into its final form. This final design is described including a review of the critical decisions influencing the adoption of particular features. The creation of a feasible design has required that these decisions be tempered by practical considerations such as site constraints, correction of optical errors caused by imperfections, and accommodations requested by engineers and particle detector physicists. As this is the first such system to be built, it is hoped that the experience gained will be useful for the design of future systems
Chemical degradation and morphological instabilities during focused ion beam prototyping of polymers.

Science.gov (United States)

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

2014-01-28

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

Science.gov (United States)

Ikebata, Hisaki; Hongo, Kenta; Isomura, Tetsu; Maezono, Ryo; Yoshida, Ryo

2017-04-01

The aim of computational molecular design is the identification of promising hypothetical molecules with a predefined set of desired properties. We address the issue of accelerating the material discovery with state-of-the-art machine learning techniques. The method involves two different types of prediction; the forward and backward predictions. The objective of the forward prediction is to create a set of machine learning models on various properties of a given molecule. Inverting the trained forward models through Bayes' law, we derive a posterior distribution for the backward prediction, which is conditioned by a desired property requirement. Exploring high-probability regions of the posterior with a sequential Monte Carlo technique, molecules that exhibit the desired properties can computationally be created. One major difficulty in the computational creation of molecules is the exclusion of the occurrence of chemically unfavorable structures. To circumvent this issue, we derive a chemical language model that acquires commonly occurring patterns of chemical fragments through natural language processing of ASCII strings of existing compounds, which follow the SMILES chemical language notation. In the backward prediction, the trained language model is used to refine chemical strings such that the properties of the resulting structures fall within the desired property region while chemically unfavorable structures are successfully removed. The present method is demonstrated through the design of small organic molecules with the property requirements on HOMO-LUMO gap and internal energy. The R package iqspr is available at the CRAN repository.
Conceptual Design and Simulation of a Miniature Plasma Focus

International Nuclear Information System (INIS)

Jafari, H.; Habibi, M.; Amrollahi, R.

2012-01-01

Design and construction of a miniature plasma focus device with 3.6 J of energy bank is reported. In design the device, some of very important parameters of designing such as plasma energy density and derive parameter was used. Regarding to the electrical and geometrical parameters of the device, a simulation is carried out by MATLAB software. Simulation results showed that the formation of the pinch have occurred at the moment of the peak discharge current.
The Virtual Product-Process Design Laboratory for Structured Chemical Product Design and Analysis

DEFF Research Database (Denmark)

Mattei, Michele; Yunus, Nor Alafiza Binti; Kalakul, Sawitree

2014-01-01

The objective of this paper is to present new methods for design of chemicals based formulated products and their implementation in the software, the Virtual Product-Process Design Laboratory. The new products are tailor-made blended liquid products and emulsion-based products. The new software...
Teaching chemical product design to engineering students: course contents and challenges

DEFF Research Database (Denmark)

Skov, Anne Ladegaard; Kiil, Søren

Chemical product design is not taught in the same way as traditional engineering courses like unit operations or transport phenomena. This paper gives an overview of the challenges that we, as teachers, have faced when teaching chemical product design to engineering students. Specific course...
Design of tailor-made chemical blend using a decomposition-based computer-aided approach

DEFF Research Database (Denmark)

Yunus, Nor Alafiza; Gernaey, Krist; Manan, Z.A.

2011-01-01

Computer aided techniques form an efficient approach to solve chemical product design problems such as the design of blended liquid products (chemical blending). In chemical blending, one tries to find the best candidate, which satisfies the product targets defined in terms of desired product...... methodology for blended liquid products that identifies a set of feasible chemical blends. The blend design problem is formulated as a Mixed Integer Nonlinear Programming (MINLP) model where the objective is to find the optimal blended gasoline or diesel product subject to types of chemicals...... and their compositions and a set of desired target properties of the blended product as design constraints. This blend design problem is solved using a decomposition approach, which eliminates infeasible and/or redundant candidates gradually through a hierarchy of (property) model based constraints. This decomposition...
Chemicals-Based Formulation Design: Virtual Experimentations

DEFF Research Database (Denmark)

Conte, Elisa; Gani, Rafiqul

2011-01-01

This paper presents a systematic procedure for virtual experimentations related to the design of liquid formulated products. All the experiments that need to be performed when designing a liquid formulated product (lotion), such as ingredients selection and testing, solubility tests, property mea...... on the design of an insect repellent lotion will show that the software is an essential instrument in decision making, and that it reduces time and resources since experimental efforts can be focused on one or few product alternatives....
Process Security in Chemical Engineering Education

Science.gov (United States)

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…
Model-Based Integrated Process Design and Controller Design of Chemical Processes

DEFF Research Database (Denmark)

Abd Hamid, Mohd Kamaruddin Bin

that is typically formulated as a mathematical programming (optimization with constraints) problem is solved by the so-called reverse approach by decomposing it into four sequential hierarchical sub-problems: (i) pre-analysis, (ii) design analysis, (iii) controller design analysis, and (iv) final selection......This thesis describes the development and application of a new systematic modelbased methodology for performing integrated process design and controller design (IPDC) of chemical processes. The new methodology is simple to apply, easy to visualize and efficient to solve. Here, the IPDC problem...... are ordered according to the defined performance criteria (objective function). The final selected design is then verified through rigorous simulation. In the pre-analysis sub-problem, the concepts of attainable region and driving force are used to locate the optimal process-controller design solution...
On various metrics used for validation of predictive QSAR models with applications in virtual screening and focused library design.

Science.gov (United States)

Roy, Kunal; Mitra, Indrani

2011-07-01

Quantitative structure-activity relationships (QSARs) have important applications in drug discovery research, environmental fate modeling, property prediction, etc. Validation has been recognized as a very important step for QSAR model development. As one of the important objectives of QSAR modeling is to predict activity/property/toxicity of new chemicals falling within the domain of applicability of the developed models and QSARs are being used for regulatory decisions, checking reliability of the models and confidence of their predictions is a very important aspect, which can be judged during the validation process. One prime application of a statistically significant QSAR model is virtual screening for molecules with improved potency based on the pharmacophoric features and the descriptors appearing in the QSAR model. Validated QSAR models may also be utilized for design of focused libraries which may be subsequently screened for the selection of hits. The present review focuses on various metrics used for validation of predictive QSAR models together with an overview of the application of QSAR models in the fields of virtual screening and focused library design for diverse series of compounds with citation of some recent examples.
Design and Control of Chemical Grouting : Volume 3 - Engineering Practice

Science.gov (United States)

1983-04-01

Recent improvements in the engineering practice of chemical grouting have provided increased confidence in this method of ground modification. Designers can significantly improve the success of chemical grouting by defining their grouting program obj...
Plasma focus system: Design, construction and experiments

International Nuclear Information System (INIS)

Alacakir, A.; Akguen, Y.; Boeluekdemir, A. S.

2007-01-01

The aim of this work is to construct a compact experimental system for fusion research. The design, construction and experiments of the 3 kJ Mather type plasma focus machine is described. This machine is established for neutron yield and fast neutron radiography by D-D reaction which is given by D + D→ 3 He (0.82 MeV) + n (2.45 MeV) . Investigation of the geometry of plasma focus machine in the presence of high voltage drive and vacuum system setup is shown. 108 neutron per pulse and 200 kA peak current is obtained for many shots. Scintillator screen for fast neutron imaging, sensitive to 2.45 MeV neutrons, is also manufactured in our labs. Structural neutron shielding computations for safety is also completed
Chemical kinetics and oil shale process design

Energy Technology Data Exchange (ETDEWEB)

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.

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

Science.gov (United States)

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

Science.gov (United States)

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.
Design of a self-focusing linear electron accelerator

International Nuclear Information System (INIS)

Hddab, S.

1983-06-01

In this report we tackle the principal physical and technical problems related to the design of a self-focusing linear electron accelerator. The study of the dynamic phenomena occurring at the entrance to the first resonant cell allows us, by an adequate choice of the longitudinal height of this cell, to avoid the use of an external magnetic focusing coil. Optimization of the ultra high frequency properties of the resonant structure has been achieved by polishing the internal surfaces of the cavities, by adapting a new brazing technique and optimizing the geometry of the cells. A simulation code has been adapted to an interactive use on microcomputer [fr
Molecular modeling for the design of novel performance chemicals and materials

CERN Document Server

Rai, Beena

2012-01-01

Molecular modeling (MM) tools offer significant benefits in the design of industrial chemical plants and material processing operations. While the role of MM in biological fields is well established, in most cases MM works as an accessory in novel products/materials development rather than a tool for direct innovation. As a result, MM engineers and practitioners are often seized with the question: ""How do I leverage these tools to develop novel materials or chemicals in my industry?"" Molecular Modeling for the Design of Novel Performance Chemicals and Materials answers this important questio
Property Model-Based Chemcal Substitution and Chemical Formulation Design

DEFF Research Database (Denmark)

Jhamb, Spardha Virendra; Liang, Xiaodong; Hukkerikar, Amol Shivajirao

Chemical-based products including structured product formulations and single molecule products have proven to be a boon to mankind and have been a significant part of our economies. Our life and the changes around us cannot be imagined without the presence or involvement of chemicals. But like...... with environmentally benign chemicals. Additionally, the decisions taken during chemical product design also have an impact on the process and product performance and are influenced by company strategy, availability of market and government policies [2]. Hence, undoubtedly there is a need to develop a systematic...... [3] will also be highlighted. A set of new group contribution-based models for a number of useful properties of amino acids will be presented. Through examples on substitution of chemicals from chemical-based products from various sectors namely cosmetics and personal care, pharmaceutical and food...
Designing Intelligent Secure Android Application for Effective Chemical Inventory

Science.gov (United States)

Shukran, Mohd Afizi Mohd; Naim Abdullah, Muhammad; Nazri Ismail, Mohd; Maskat, Kamaruzaman; Isa, Mohd Rizal Mohd; Shahfee Ishak, Muhammad; Adib Khairuddin, Muhamad

2017-08-01

Mobile services support various situations in everyday life and with the increasing sophistication of phone functions, the daily life is much more easier and better especially in term of managing tools and apparatus. Since chemical inventory management system has been experiencing a new revolution from antiquated to an automated inventory management system, some additional features should be added in current chemical inventory system. Parallel with the modern technologies, chemical inventory application using smart phone has been developed. Several studies about current related chemical inventory management using smart phone application has been done in this paper in order to obtain an overview on recent studies in smartphone application for chemical inventory system which are needed in schools, universities or other education institutions. This paper also discuss about designing the proposed secure mobile chemical inventory system. The study of this paper can provide forceful review analysis support for the chemical inventory management system related research.
Using Genome Sequence to Enable the Design of Medicines and Chemical Probes.

Science.gov (United States)

Angelbello, Alicia J; Chen, Jonathan L; Childs-Disney, Jessica L; Zhang, Peiyuan; Wang, Zi-Fu; Disney, Matthew D

2018-02-28

Rapid progress in genome sequencing technology has put us firmly into a postgenomic era. A key challenge in biomedical research is harnessing genome sequence to fulfill the promise of personalized medicine. This Review describes how genome sequencing has enabled the identification of disease-causing biomolecules and how these data have been converted into chemical probes of function, preclinical lead modalities, and ultimately U.S. Food and Drug Administration (FDA)-approved drugs. In particular, we focus on the use of oligonucleotide-based modalities to target disease-causing RNAs; small molecules that target DNA, RNA, or protein; the rational repurposing of known therapeutic modalities; and the advantages of pharmacogenetics. Lastly, we discuss the remaining challenges and opportunities in the direct utilization of genome sequence to enable design of medicines.
Design of electrolyzer for carbon dioxide conversion to fuels and chemicals

Science.gov (United States)

Rosen, Jonathan S.

The stabilization of global atmospheric CO2 levels requires a transition towards a renewable energy based economy as well as methods for handling current CO2 output from fossil fuels. Challenges with renewable energy intermittency have thus far limited the use of these alternative energy sources to only a fraction of the current energy portfolio. To enable more widespread use of renewable energy systems, methods of large scale energy storage must be developed to store excess renewable energy when demand is low and allow for combined use of energy storage and renewable systems when demand is high. To date, no one technique has demonstrated energy storage methods on the gigawatt scale needed for integration with renewable sources; therefore the development of suitable energy storage technologies, such as CO2 electrolysis to fuels is needed. In this work, research efforts have focused on two major thrusts related to electrochemical methods of CO 2 conversion to fuels. The first thrust focuses on the synthesis and design of highly efficient anode and cathode catalysts with emphasis on understanding structure-property relationships. A second thrust focuses on the design of novel electrochemical devices for CO2 conversion and integration of synthesized materials into flow cell systems. On the anode side, the synthesis of highly active catalysts using abundant transition metals is crucial to reducing capital costs and enabling widespread use of electrochemical CO2 conversion devices. Highly active mesoporous Co3O4 and metal-substituted Co3O4 water oxidation catalysts were designed to investigate the role of the spinel structure on water oxidation activity. Further analysis of metal substituted samples reveal the importance of the octahedral sites in the spinel structure, which was later used to design an Mg-Co3O4 sample with improved water oxidation activity. The design of efficient cathode materials which can selectivity reduce CO2 to fuels and chemicals is critical to
Imaging chemical interfaces perpendicular to the optical axis with focus-engineered coherent anti-Stokes Raman scattering microscopy

International Nuclear Information System (INIS)

Krishnamachari, Vishnu Vardhan; Potma, Eric Olaf

2007-01-01

In vibrational microscopy, it is often necessary to distinguish between chemically distinct microscopic objects and to highlight the 'chemical interfaces' present in the sample under investigation. Here we apply the concept of focus engineering to enhance the sensitivity of coherent anti-Stokes Raman scattering (CARS) microscopy to these interfaces. Based on detailed numerical simulations, we show that using a focused Stokes field with a sharp phase jump along the longitudinal direction leads to the suppression of the signal from bulk regions and improves the signal contrast from vibrational resonant interfaces oriented perpendicular to the axis of beam propagation. We also demonstrate that the CARS spectral response from chemical interfaces exhibits a clean, Raman-like band-shape with such a phase-shaped excitation. This phenomenon of interface highlighting is a consequence of the coherent nature of CARS signal generation and it involves a complex interplay of the spectral phase of the sample and the spatial phase of the excitation fields
Reducing aquatic hazards of industrial chemicals: probabilistic assessment of sustainable molecular design guidelines.

Science.gov (United States)

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 P9 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. © 2014 SETAC.
Design and development of permanent magnet based focusing lens for J-Band Klystron

Energy Technology Data Exchange (ETDEWEB)

Singh, Kumud; Itteera, Janvin; Ukarde, Priti; Malhotra, Sanjay; Taly, Y.K., E-mail: kumuds@barc.gov.in [Control Instrumentation Division, Bhabha Atomic Research Centre, Mumbai (India); Bandyopadhay, Ayan; Meena, Rakesh; Rawat, Vikram; Joshi, L.M [Microwave Tubes Division, Central Electronics Engineering Research Institute, Pilani (India)

2014-07-01

Applying permanent magnet technology to beam focusing in klystrons can reduce their power consumption and increase their reliability of operation. Electromagnetic design of the beam focusing elements, for high frequency travelling wave tubes, is very critical. The magnitude and profile of the magnetic field need to match the optics requirement from beam dynamics studies. The rise of the field from cathode gun region to the uniform field region (RF section) is important as the desired transition from zero to peak axial field must occur over a short axial distance. Confined flow regime is an optimum choice to minimize beam scalloping but demands an axial magnetic field greater than 2 - 3 times the Brillouin flow field. This necessitates optimization in the magnet design achieve high magnetic field within given spatial constraints. Electromagnetic design and simulations were done using 3D Finite element method (FEM) analysis software. A permanent magnet based focusing lens for a miniature J-Band klystron has been designed and developed at Control Instrumentation Division, BARC. This paper presents the design, simulation studies, beam transmission and RF tests results for J Band klystron with permanent magnet focusing lens. (author)
Three-Dimensional Design of a Non-Axisymmetric Periodic Permanent Magnet Focusing System

CERN Document Server

Chen Chi Ping; Radovinsky, Alexey; Zhou, Jing

2005-01-01

A three-dimensional (3D) design is presented of a non-axisymmetric periodic permanent magnet focusing system which will be used to focus a large-aspect-ratio, ellipse-shaped, space-charge-dominated electron beam. In this design, an analytic theory is used to specify the magnetic profile for beam transport. The OPERA3D code is used to compute and optimize a realizable magnet system. Results of the magnetic design are verified by two-dimensional particle-in-cell and three-dimensional trajectory simulations of beam propagation using PFB2D and OMNITRAK, respectively. Results of fabrication tolerance studies are discussed.
Integrated Computer-aided Framework for Sustainable Chemical Product Design and Evaluation

DEFF Research Database (Denmark)

Kalakul, Sawitree; Cignitti, Stefano; Zhang, Lei

2016-01-01

This work proposes an integrated model-based framework for chemical product design and evaluation based on which the software, VPPD-Lab (The Virtual Product-Process Design Laboratory) has been developed. The framework allows the following options: (1) design a product using design templates...
EXPLORING THE DESIGN AND USE OF MOLECULAR ANIMATIONS THAT CONFLICT FOR UNDERSTANDING CHEMICAL REACTIONS

Directory of Open Access Journals (Sweden)

Resa M. Kelly

Full Text Available Understanding chemical reactions conceptually involves recognizing characteristics of observable phenomena and envisioning how atoms, ions and molecules move and interact to cause the macroscopic changes. Our research focuses on the development of effective strategies for designing and presenting visualizations (videos and animations to assist students with making connections between macroscopic and molecular level behaviors of chemical reactions. Specifically, we study how students, who view videos of a redox reaction that exhibits obvious signs of macroscopic chemical change, can determine which molecular animation of a set of contrasting animations is best supported by its fit with experimental evidence. Herein we describe how we develop our videos and animations, and how students are learning from this animation task. Students who select inaccurate animation models are often enticed by a model that is easier to explain and fits with their understanding of reaction equations. We note that even though students indicate a preference for one animation over another, they often revise their drawn representations to fit with features from multiple animations. With the assistance of eye tracking research, we are gaining a better understanding of what students view and how they make sense of it.
Assessment Focus in Studio: What Is Most Prominent in Architecture, Art and Design?

Science.gov (United States)

de La Harpe, Barbara; Peterson, J. Fiona; Frankham, Noel; Zehner, Robert; Neale, Douglas; Musgrave, Elizabeth; McDermott, Ruth

2009-01-01

What can be learned about assessment from what educators in the creative practices focus their studio publications on? What should form the focus of assessment in architecture, art and design studios? In this article we draw on 118 journal articles on studio published over the last decade in three disciplines; architecture, art and design to…
Models and Modelling Tools for Chemical Product and Process Design

DEFF Research Database (Denmark)

Gani, Rafiqul

2016-01-01

The design, development and reliability of a chemical product and the process to manufacture it, need to be consistent with the end-use characteristics of the desired product. One of the common ways to match the desired product-process characteristics is through trial and error based experiments......-based framework is that in the design, development and/or manufacturing of a chemical product-process, the knowledge of the applied phenomena together with the product-process design details can be provided with diverse degrees of abstractions and details. This would allow the experimental resources...... to be employed for validation and fine-tuning of the solutions from the model-based framework, thereby, removing the need for trial and error experimental steps. Also, questions related to economic feasibility, operability and sustainability, among others, can be considered in the early stages of design. However...
Integrating chemical engineering fundamentals in the capstone process design project

DEFF Research Database (Denmark)

von Solms, Nicolas; Woodley, John; Johnsson, Jan Erik

2010-01-01

Reaction Engineering. In order to incorporate reactor design into process design in a meaningful way, the teachers of the respective courses need to collaborate (Standard 9 – Enhancement of Faculty CDIO skills). The students also see that different components of the chemical engineering curriculum relate......All B.Eng. courses offered at the Technical University of Denmark (DTU) must now follow CDIO standards. The final “capstone” course in the B.Eng. education is Process Design, which for many years has been typical of chemical engineering curricula worldwide. The course at DTU typically has about 30...... of the CDIO standards – especially standard 3 – Integrated Curriculum - means that the course projects must draw on competences provided in other subjects which the students are taking in parallel with Process Design – specifically Process Control and Reaction Engineering. In each semester of the B...
Introduction to Chemical Engineering Reactor Analysis: A Web-Based Reactor Design Game

Science.gov (United States)

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…
Statistically designed experiments to screen chemical mixtures for possible interactions

NARCIS (Netherlands)

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
Design of the Accounting Course Focusing on the Development of Competences

Science.gov (United States)

Ciudad-Gomez, Adelaida

2011-01-01

The aim of this work is to develop a proposal for a methodology in the university environment that enables us to design our course with an approach based on the development and acquisition of competences within the framework of the European Higher Education Area (EHEA), allowing a transition from a model focused on teaching to a model focused on…

Methods and tools for sustainable chemical process design

DEFF Research Database (Denmark)

Loureiro da Costa Lira Gargalo, Carina; Chairakwongsa, Siwanat; Quaglia, Alberto

2015-01-01

As the pressure on chemical and biochemical processes to achieve a more sustainable performance increases, the need to define a systematic and holistic way to accomplish this is becoming more urgent. In this chapter, a multilevel computer-aided framework for systematic design of more sustainable...
Proof of principle for epitope-focused vaccine design

Science.gov (United States)

Correia, Bruno E.; Bates, John T.; Loomis, Rebecca J.; Baneyx, Gretchen; Carrico, Chris; Jardine, Joseph G.; Rupert, Peter; Correnti, Colin; Kalyuzhniy, Oleksandr; Vittal, Vinayak; Connell, Mary J.; Stevens, Eric; Schroeter, Alexandria; Chen, Man; MacPherson, Skye; Serra, Andreia M.; Adachi, Yumiko; Holmes, Margaret A.; Li, Yuxing; Klevit, Rachel E.; Graham, Barney S.; Wyatt, Richard T.; Baker, David; Strong, Roland K.; Crowe, James E.; Johnson, Philip R.; Schief, William R.

2014-03-01

Vaccines prevent infectious disease largely by inducing protective neutralizing antibodies against vulnerable epitopes. Several major pathogens have resisted traditional vaccine development, although vulnerable epitopes targeted by neutralizing antibodies have been identified for several such cases. Hence, new vaccine design methods to induce epitope-specific neutralizing antibodies are needed. Here we show, with a neutralization epitope from respiratory syncytial virus, that computational protein design can generate small, thermally and conformationally stable protein scaffolds that accurately mimic the viral epitope structure and induce potent neutralizing antibodies. These scaffolds represent promising leads for the research and development of a human respiratory syncytial virus vaccine needed to protect infants, young children and the elderly. More generally, the results provide proof of principle for epitope-focused and scaffold-based vaccine design, and encourage the evaluation and further development of these strategies for a variety of other vaccine targets, including antigenically highly variable pathogens such as human immunodeficiency virus and influenza.
Versatile Chemical Derivatizations to Design Glycol Chitosan-Based Drug Carriers

Directory of Open Access Journals (Sweden)

Sung Eun Kim

2017-10-01

Full Text Available Glycol chitosan (GC and its derivatives have been extensively investigated as safe and effective drug delivery carriers because of their unique physiochemical and biological properties. The reactive functional groups such as the amine and hydroxyl groups on the GC backbone allow for easy chemical modification with various chemical compounds (e.g., hydrophobic molecules, crosslinkers, and acid-sensitive and labile molecules, and the versatility in chemical modifications enables production of a wide range of GC-based drug carriers. This review summarizes the versatile chemical modification methods that can be used to design GC-based drug carriers and describes their recent applications in disease therapy.
Design of a repetitively pulsed megajoule dense-plasma focus

International Nuclear Information System (INIS)

Zucker, O.; Bostick, W.; Gullickson, R.; Long, J.; Luce, J.; Sahlin, H.

1975-01-01

This report describes a 1 pulse per second, dense-plasma-focus (DPF) materials-testing device capable of delivering a minimum of 10 15 neutrons per pulse. Moderate scaling up from existing designs is shown to be sufficient to provide 2 x 10 13 neutrons/ cm 2 . s to a suitable target. The average power consumption, which has become a major issue due to the energy crisis, is analyzed with respect to other plasma devices and is shown to be highly favorable. Also discussed is a novel approach to capacitor-bank and switch design with respect to repetitive-pulse operation. (auth)
A systems engineering approach to manage the complexity in sustainable chemical product-process design

DEFF Research Database (Denmark)

Gani, Rafiqul

This paper provides a perspective on model-data based solution approaches for chemical product-process design, which consists of finding the identity of the candidate chemical product, designing the process that can sustainably manufacture it and verifying the performance of the product during...... application. The chemical product tree is potentially very large and a wide range of options exist for selecting the product to make, the raw material to use as well as the processing route to employ. It is shown that systematic computer-aided methods and tools integrated within a model-data based design...
Design of High Quality Chemical XOR Gates with Noise Reduction.

Science.gov (United States)

Wood, Mackenna L; Domanskyi, Sergii; Privman, Vladimir

2017-07-05

We describe a chemical XOR gate design that realizes gate-response function with filtering properties. Such gate-response function is flat (has small gradients) at and in the vicinity of all the four binary-input logic points, resulting in analog noise suppression. The gate functioning involves cross-reaction of the inputs represented by pairs of chemicals to produce a practically zero output when both are present and nearly equal. This cross-reaction processing step is also designed to result in filtering at low output intensities by canceling out the inputs if one of the latter has low intensity compared with the other. The remaining inputs, which were not reacted away, are processed to produce the output XOR signal by chemical steps that result in filtering at large output signal intensities. We analyze the tradeoff resulting from filtering, which involves loss of signal intensity. We also discuss practical aspects of realizations of such XOR gates. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Healthy by Design: Using a Gender Focus to Influence Complete Streets Policy.

Science.gov (United States)

Keippel, April Ennis; Henderson, Melissa A; Golbeck, Amanda L; Gallup, TommiLee; Duin, Diane K; Hayes, Stephen; Alexander, Stephanie; Ciemins, Elizabeth L

2017-10-17

Public health leaders in Yellowstone County, Montana, formed an alliance to address community-wide issues. One such issue is Complete Streets, with its vision of safe streets for all. This case study focuses on development and adoption of a Complete Streets policy. It examines how a community coalition, Healthy By Design, infused a gender focus into the policymaking process. An incremental and nonlinear policymaking process was aided by a focus on gender and health equity. The focus on a large constituency helped to frame advocacy in terms of a broad population's needs, not just special interests. The city council unanimously adopted a Complete Streets resolution, informed by a gender lens. Healthy By Design further used gender information to successfully mobilize the community in response to threats of repeal of the policy, and then influenced the adoption of a revised policy. Policies developed with a focus on equity, including gender equity, may have broader impact on the community. Such policies may pave the way for future policies that seek to transform gender norms toward building a healthier community for all residents. Published by Elsevier Inc.
A conceptual design of Final Focus Systems for linear colliders

International Nuclear Information System (INIS)

Brown, K.L.

1987-06-01

Linear colliders are a relatively recent development in the evolution of particle accelerators. This report discusses some of the approaches that have been considered for the design of Final Focus Systems to demagnify the beam exiting from a linac to the small size suitable for collisions at the interaction point. The system receiving the most attention is the one adopted for the SLAC Linear Collider. However, the theory and optical techniques discussed should be applicable to the design efforts for future machines
Computer-Aided Chemical Product Design Framework: Design of High Performance and Environmentally Friendly Refrigerants

DEFF Research Database (Denmark)

Cignitti, Stefano; Zhang, Lei; Gani, Rafiqul

properties and needs should carefully be selected for a given heat pump cycle to ensure that an optimum refrigerant is found? How can cycle performance and environmental criteria be integrated at the product design stage and not in post-design analysis? Computer-aided product design methods enable...... the possibility of designing novel molecules, mixtures and blends, such as refrigerants through a systematic framework (Cignitti et al., 2015; Yunus et al., 2014). In this presentation a computer-aided framework is presented for chemical product design through mathematical optimization. Here, molecules, mixtures...... and blends, are systematically designed through a decomposition based solution method. Given a problem definition, computer-aided molecular design (CAMD) problem is defined, which is formulated into a mixed integer nonlinear program (MINLP). The decomposed solution method then sequentially divides the MINLP...
Properties, synthesis, and growth mechanisms of carbon nanotubes with special focus on thermal chemical vapor deposition.

Science.gov (United States)

Nessim, Gilbert D

2010-08-01

Carbon nanotubes (CNTs) have been extensively investigated in the last decade because their superior properties could benefit many applications. However, CNTs have not yet made a major leap into industry, especially for electronic devices, because of fabrication challenges. This review provides an overview of state-of-the-art of CNT synthesis techniques and illustrates their major technical difficulties. It also charts possible in situ analyses and new reactor designs that might enable commercialization. After a brief description of the CNT properties and of the various techniques used to synthesize substrate-free CNTs, the bulk of this review analyzes chemical vapor deposition (CVD). This technique receives special attention since it allows CNTs to be grown in predefined locations, provides a certain degree of control of the types of CNTs grown, and may have the highest chance to succeed commercially. Understanding the primary growth mechanisms at play during CVD is critical for controlling the properties of the CNTs grown and remains the major hurdle to overcome. Various factors that influence CNT growth receive a special focus: choice of catalyst and substrate materials, source gases, and process parameters. This review illustrates important considerations for in situ characterization and new reactor designs that may enable researchers to better understand the physical growth mechanisms and to optimize the synthesis of CNTs, thus contributing to make carbon nanotubes a manufacturing reality.
Design of voice coil motor dynamic focusing unit for a laser scanner

Energy Technology Data Exchange (ETDEWEB)

Lee, Moon G.; Kim, Gaeun; Lee, Chan-Woo; Lee, Soo-Hun; Jeon, Yongho, E-mail: princaps@ajou.ac.kr [Department of Mechanical Engineering, Ajou University, San 5, Woncheon-dong, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-749 (Korea, Republic of)

2014-04-15

Laser scanning systems have been used for material processing tasks such as welding, cutting, marking, and drilling. However, applications have been limited by the small range of motion and slow speed of the focusing unit, which carries the focusing optics. To overcome these limitations, a dynamic focusing system with a long travel range and high speed is needed. In this study, a dynamic focusing unit for a laser scanning system with a voice coil motor (VCM) mechanism is proposed to enable fast speed and a wide focusing range. The VCM has finer precision and higher speed than conventional step motors and a longer travel range than earlier lead zirconium titanate actuators. The system has a hollow configuration to provide a laser beam path. This also makes it compact and transmission-free and gives it low inertia. The VCM's magnetics are modeled using a permeance model. Its design parameters are determined by optimization using the Broyden–Fletcher–Goldfarb–Shanno method and a sequential quadratic programming algorithm. After the VCM is designed, the dynamic focusing unit is fabricated and assembled. The permeance model is verified by a magnetic finite element method simulation tool, Maxwell 2D and 3D, and by measurement data from a gauss meter. The performance is verified experimentally. The results show a resolution of 0.2 μm and travel range of 16 mm. These are better than those of conventional focusing systems; therefore, this focusing unit can be applied to laser scanning systems for good machining capability.
Selectivity on-target of bromodomain chemical probes by structure-guided medicinal chemistry and chemical biology.

Science.gov (United States)

Galdeano, Carles; Ciulli, Alessio

2016-09-01

Targeting epigenetic proteins is a rapidly growing area for medicinal chemistry and drug discovery. Recent years have seen an explosion of interest in developing small molecules binding to bromodomains, the readers of acetyl-lysine modifications. A plethora of co-crystal structures has motivated focused fragment-based design and optimization programs within both industry and academia. These efforts have yielded several compounds entering the clinic, and many more are increasingly being used as chemical probes to interrogate bromodomain biology. High selectivity of chemical probes is necessary to ensure biological activity is due to an on-target effect. Here, we review the state-of-the-art of bromodomain-targeting compounds, focusing on the structural basis for their on-target selectivity or lack thereof. We also highlight chemical biology approaches to enhance on-target selectivity.
NASA universities advanced space design program, focus on nuclear engineering

International Nuclear Information System (INIS)

Lyon, W.F. III; George, J.A.; Alred, J.W.; Peddicord, K.L.

1987-01-01

In January 1985, the National Aeronautics and Space Administration (NASA), in affiliation with the Universities Space Research Association (USRA), inaugurated the NASA Universities Advanced Space Design Program. The purpose of the program was to encourage participating universities to utilize design projects for the senior and graduate level design courses that would focus on topics relevant to the nation's space program. The activities and projects being carried out under the NASA Universities Advanced Space Design Program are excellent experiences for the participants. This program is a well-conceived, well-planned effort to achieve the maximum benefit out of not only the university design experience but also of the subsequent summer programs. The students in the university design classes have the opportunity to investigate dramatic and new concepts, which at the same time have a place in a program of national importance. This program could serve as a very useful model for the development of university interaction with other federal agencies
Project-Based Learning and Design-Focused Projects to Motivate Secondary Mathematics Students

Science.gov (United States)

Remijan, Kelly W.

2017-01-01

This article illustrates how mathematics teachers can develop design-focused projects, related to project-based learning, to motivate secondary mathematics students. With first-hand experience as a secondary mathematics teacher, I provide a series of steps related to the engineering design process, which are helpful to teachers in developing…
Designing stellarator coils by a modified Newton method using FOCUS

Science.gov (United States)

Zhu, Caoxiang; Hudson, Stuart R.; Song, Yuntao; Wan, Yuanxi

2018-06-01

To find the optimal coils for stellarators, nonlinear optimization algorithms are applied in existing coil design codes. However, none of these codes have used the information from the second-order derivatives. In this paper, we present a modified Newton method in the recently developed code FOCUS. The Hessian matrix is calculated with analytically derived equations. Its inverse is approximated by a modified Cholesky factorization and applied in the iterative scheme of a classical Newton method. Using this method, FOCUS is able to recover the W7-X modular coils starting from a simple initial guess. Results demonstrate significant advantages.
WAR DSS: A DECISION SUPPORT SYSTEM FOR ENVIRONMENTALLY CONSCIOUS CHEMICAL PROCESS DESIGN

Science.gov (United States)

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...
Intelligent Controller Design for a Chemical Process

OpenAIRE

Mr. Glan Devadhas G; Dr.Pushpakumar S.

2010-01-01

Chemical process control is a challenging problem due to the strong on*line non*linearity and extreme sensitivity to disturbances of the process. Ziegler – Nichols tuned PI and PID controllers are found to provide poor performances for higher*order and non–linear systems. This paper presents an application of one*step*ahead fuzzy as well as ANFIS (adaptive*network*based fuzzy inference system) tuning scheme for an Continuous Stirred Tank Reactor CSTR process. The controller is designed based ...
Educational Design for Learning Games with a focus on the teacher’s roles

DEFF Research Database (Denmark)

Sørensen, Birgitte Holm; Meyer, Bente Tobiesen

2010-01-01

of the educational design of game-based learning. In the paper we shall conceptualize these texts as paratexts, following Genette’s terminology. In the paper we shall present an on-going development of an educational design concept for learning games with a focus on how teachers are and can be included in the design...
Probabilistic risk criteria and their application to nuclear chemical plant design

International Nuclear Information System (INIS)

Arthur, T.; Barnes, D.S.; Brown, M.L.; Taig, A.R.; Johnston, B.D.; Hayns, M.

1989-01-01

A nuclear chemical plant safety strategy is presented. The use of risk criteria in design is demonstrated by reference to a particular area of the plant. This involves the application of Probabilistic Risk Assessment (PRA) techniques. Computer programs developed by the UK Atomic Energy Authority (UKAEA) at its Safety and Reliability Directorate (SRD) are used toe valuate and analyze the resultant fault trees. the magnitude of releases are estimated and individual and societal risks determined. The paper concludes that the application of PRA to a nuclear chemical plant can be structured in such a way as to allow a designer to work to quantitative risk targets
Design and tests of an adaptive focusing neutron guide

International Nuclear Information System (INIS)

Valicu, Roxana Georgiana

2012-01-01

This work contains the Monte Carlo Simulations, as well as the first tests with an adaptive focusing neutron guide for creating a focus that does not depend on the wavelength of the incoming neutrons. All known neutron guides consist of a rectangular shape, built out of four glass plates. The inner side of the guide is coated with a complex structure of metal layers. This reflects and guides the neutrons (in analogy with the reflection of the light). For beam focusing neutron guides with fixed curvature can be built. For most experiments it is important that the beam is focused on to a small surface of the sample. In the case of focusing guides with fixed curvature it has been observed that the focusing (dimension and position of the beam focus) is wavelength dependent. This is why for measurements that are performed with different wavelengths it is very important to change the curvature of the neutron guide in order to obtain optimal results. In this work we have designed, constructed and tested a guide where we can change the curvature during the experiment. In this way we can obtain a variable curvature in horizontal as well as in vertical direction. For a curvature in the horizontal or vertical direction it is not necessary to move all four walls, only two of the opposed plates. The element that changes the curvature of the guide consists of an acting element (piezomotor) as well as a rod that can be operated by the piezomotor and that acts through a lever onto the plate. The action of a force and a consecutive torsion momentum at the free end of the plate changes the curvature of the whole plate in an almost parabolic way. Making use of the Monte Carlo simulations we were able to determine the optimal curvature for each wavelength of a neutron guide for the spectrometer TOFTOF installed at the Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II). First tests have shown that with an adaptive focusing guide one can gain up to a factor three in intensity at

Design and tests of an adaptive focusing neutron guide

Energy Technology Data Exchange (ETDEWEB)

Valicu, Roxana Georgiana

2012-08-23

This work contains the Monte Carlo Simulations, as well as the first tests with an adaptive focusing neutron guide for creating a focus that does not depend on the wavelength of the incoming neutrons. All known neutron guides consist of a rectangular shape, built out of four glass plates. The inner side of the guide is coated with a complex structure of metal layers. This reflects and guides the neutrons (in analogy with the reflection of the light). For beam focusing neutron guides with fixed curvature can be built. For most experiments it is important that the beam is focused on to a small surface of the sample. In the case of focusing guides with fixed curvature it has been observed that the focusing (dimension and position of the beam focus) is wavelength dependent. This is why for measurements that are performed with different wavelengths it is very important to change the curvature of the neutron guide in order to obtain optimal results. In this work we have designed, constructed and tested a guide where we can change the curvature during the experiment. In this way we can obtain a variable curvature in horizontal as well as in vertical direction. For a curvature in the horizontal or vertical direction it is not necessary to move all four walls, only two of the opposed plates. The element that changes the curvature of the guide consists of an acting element (piezomotor) as well as a rod that can be operated by the piezomotor and that acts through a lever onto the plate. The action of a force and a consecutive torsion momentum at the free end of the plate changes the curvature of the whole plate in an almost parabolic way. Making use of the Monte Carlo simulations we were able to determine the optimal curvature for each wavelength of a neutron guide for the spectrometer TOFTOF installed at the Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II). First tests have shown that with an adaptive focusing guide one can gain up to a factor three in intensity at
Computational Chemical Synthesis Analysis and Pathway Design

Directory of Open Access Journals (Sweden)

Fan Feng

2018-06-01

Full Text Available With the idea of retrosynthetic analysis, which was raised in the 1960s, chemical synthesis analysis and pathway design have been transformed from a complex problem to a regular process of structural simplification. This review aims to summarize the developments of computer-assisted synthetic analysis and design in recent years, and how machine-learning algorithms contributed to them. LHASA system started the pioneering work of designing semi-empirical reaction modes in computers, with its following rule-based and network-searching work not only expanding the databases, but also building new approaches to indicating reaction rules. Programs like ARChem Route Designer replaced hand-coded reaction modes with automatically-extracted rules, and programs like Chematica changed traditional designing into network searching. Afterward, with the help of machine learning, two-step models which combine reaction rules and statistical methods became the main stream. Recently, fully data-driven learning methods using deep neural networks which even do not require any prior knowledge, were applied into this field. Up to now, however, these methods still cannot replace experienced human organic chemists due to their relatively low accuracies. Future new algorithms with the aid of powerful computational hardware will make this topic promising and with good prospects.
A systems engineering approach to manage the complexity in sustainable chemical product-process design

DEFF Research Database (Denmark)

Gani, Rafiqul

This paper provides a perspective on model-data based solution approaches for chemical product-process design, which consists of finding the identity of the candidate chemical product, designing the process that can sustainably manufacture it and verifying the performance of the product during...... framework can manage the complexity associated with product-process problems very efficiently. Three specific computer-aided tools (ICAS, Sustain-Pro and VPPDLab) have been presented and their applications to product-process design, highlighted....
Learnings from LCA-based methods: should chemicals in food packaging be a priority focus to protect human health?

DEFF Research Database (Denmark)

Ernstoff, Alexi; Stylianou, Katerina S.; Fantke, Peter

2017-01-01

Given the scale and variety of human health damage (HHD) caused by food systems, prioritization methods are urgently needed. In this study HHD is estimated for case studies on red meat and sugary sweetened beverages (SSB) packaged in high-impact polystyrene (HIPS) due to various relevant health...... impacts. Specifically, we aim to asses if chemicals in food packaging are important to HHD in a life cycle context. The functional unit is "daily consumption of a packaged food per person in the United States." Method developments focus on human toxicity characterization of chemicals migrating from...... packaging into food. Chemicals and their concentrations in HIPS were identified from regulatory lists. A new high-throughput model estimated migration into food, depending on properties of chemicals, packaging, food, and scenario, and HHD was extrapolated following LCA characterization methods. An LCA...
Design of titania nanotube structures by focused laser beam direct writing

International Nuclear Information System (INIS)

Enachi, Mihai; Stevens-Kalceff, Marion A.; Sarua, Andrei; Ursaki, Veaceslav; Tiginyanu, Ion

2013-01-01

In this work, we report on electrochemical fabrication of titania films consisting of nanotubes (NTs) and their treatment by focused laser beam. The results of sample characterization by optical and scanning electron microscopy, cathodoluminescence imaging, and Raman scattering scanning spectroscopy are compared to those inherent to specimens subjected to thermal treatment in a furnace. The obtained data demonstrate possibilities for controlling crystallographic structure of TiO 2 NTs by focused laser beam direct writing. These findings open new prospects for the design and fabrication of spatial architectures based on titania nanotubes
Property Modelling for Applications in Chemical Product and Process Design

DEFF Research Database (Denmark)

Gani, Rafiqul

such as database, property model library, model parameter regression, and, property-model based product-process design will be presented. The database contains pure component and mixture data for a wide range of organic chemicals. The property models are based on the combined group contribution and atom...... is missing, the atom connectivity based model is employed to predict the missing group interaction. In this way, a wide application range of the property modeling tool is ensured. Based on the property models, targeted computer-aided techniques have been developed for design and analysis of organic chemicals......, polymers, mixtures as well as separation processes. The presentation will highlight the framework (ICAS software) for property modeling, the property models and issues such as prediction accuracy, flexibility, maintenance and updating of the database. Also, application issues related to the use of property...
Analysis of Chemical Constituents of Melastoma dodecandrum Lour. by UPLC-ESI-Q-Exactive Focus-MS/MS

Directory of Open Access Journals (Sweden)

Jinfeng Wang

2017-03-01

Full Text Available The ethnic drug Melastoma dodecandrum Lour. (MDL is widely distributed throughout South China, and is the major component of Gong Yan Ping Tablets/Capsules and Zi Di Ning Xue San. Although the pharmacological effects of MDL have been well documented, its chemical profile has not been fully determined. In this study, we have developed a rapid and sensitive UPLC-ESI-Q-Exactive Focus-MS/MS method to characterize the chemical constituents of MDL in the positive and negative ionization modes. A comparison of the chromatographic and spectrometric data obtained using this method with data from databases, the literature and reference standards allowed us to identify or tentatively characterize 109 compounds, including 26 fatty acids, 26 organic acids, 33 flavonoids, six tannins, 10 triterpenoids, two steroids and six other compounds. Notably, 55 of the compounds characterized in this study have never been detected before in this plant. The information obtained in this study therefore enriches our understanding of the chemical composition of MDL and could be used in quality control, pharmacological research and the development of drugs based on MDL. In addition, this study represents the first reported comprehensive analysis of the chemical constituents of MDL.
Circumventing Graphical User Interfaces in Chemical Engineering Plant Design

Science.gov (United States)

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…
Design and performance of the focusing DIRC detector

Energy Technology Data Exchange (ETDEWEB)

Dey, B. [University of California, Riverside, CA 92521 (United States); Borsato, M.; Arnaud, N. [Laboratoire de l' Accélérateur Linéaire, Centre Scientifique d' Orsay, F-91898 Orsay Cedex (France); Leith, D.W.G.S.; Nishimura, K. [SLAC National Accelerator Laboratory, Stanford, CA 94309 (United States); Roberts, D.A. [University of Maryland, College Park, MD 20742, USA. (United States); Ratcliff, B.N. [SLAC National Accelerator Laboratory, Stanford, CA 94309 (United States); Varner, G. [University of Hawaii, Honolulu, HI 96822, USA. (United States); Va' vra, J., E-mail: jjv@slac.stanford.edu [SLAC National Accelerator Laboratory, Stanford, CA 94309 (United States)

2015-03-01

We present the final results from a novel Cherenkov imaging detector called the Focusing DIRC (FDIRC). This detector was designed as a full-scale prototype of the particle identification system for the SuperB experiment [1], and comprises 1/12 of the SuperB barrel azimuthal coverage, with partial photodetector and electronics implementation. The prototype was tested in the SLAC Cosmic Ray Telescope which provided 3D tracking of cosmic muons with an angular resolution of ~1.5 mrad, a position resolution of 4–5 mm, a start time resolution of 70 ps, and muon tracks above ~2 GeV tagged using an iron range stack. The fused silica focusing photon camera was coupled to a full-size BaBar DIRC bar box and was read out, over part of the full coverage, by 12 Hamamatsu H8500 multi-anode photomultipliers (MaPMTs) providing 768 pixels. We used waveform digitizing electronics to read out the MaPMTs. We give a detailed description of our data analysis methods and point out limitations on the present performance. We present results that demonstrate some basic performance characteristics of this design, including (a) single photon Cherenkov angle resolutions with and without chromatic corrections, (b) signal-to-noise (S/N) ratio between the Cherenkov peak and background, which primarily consists of ambiguities of the possible photon paths from emission along the track to a given pixel, (c) dTOP=TOP{sub measured} – TOP{sub expected} resolutions (with TOP being the photon Time-of-Propagation in fused silica), and (d) performance of the detector in the presence of high-rate backgrounds.
Focusing the Sun: State Considerations for Designing Community Solar Policy

Energy Technology Data Exchange (ETDEWEB)

Cook, Jeffrey J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Shah, Monisha R [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-01-31

This report summarizes outcomes from the National Community Solar Partnership State Best Practices working group by identifying key differences in state policies that enable community solar and illustrating how various policy design approaches may impact the market. For the latter question, it is too early to quantify a relationship between policy design and market impacts, because most state programs have not been fully implemented. So, the authors conducted interviews with 19 subject matter experts, including project developers, regulators, and utilities to better understand how various policy design approaches may impact community solar markets. These perspectives, along with those gleaned from the working group and relevant literature were synthesized to identify key considerations for policymakers designing community solar programs. Though state community solar policies vary in numerous ways, the report focuses on the following critical elements: program cap, project size cap, subscriber location requirements, subscriber eligibility requirements, low- and moderate-income stipulations, and subscriber compensation.
Designing and testing glaser lens for focusing low energy charged particle beam

International Nuclear Information System (INIS)

Rashid, M.H.; Mallik, C.; Bhandari, R.K.

2009-01-01

A Glaser lens is an iron shielded solenoid magnet having bell-shaped distribution of axial field along the central z-axis. Like a simple solenoid, it also rotates the beam about the axis and focuses it. The axial field can be generated analytically from one of the several devised expressions for scalar potentials or it can be computed using 2D codes. One or more of the methods can be used to set the geometrical and electrical parameters of a Glaser solenoid of particular focal length (f) for focusing a beam of given rigidity (Bρ). The measured field data along the axis of a designed and constructed lens is used to verify the design. A scheme of sectionalizing a thick lens into a number of thin lenses improves the values of the cardinal points. The section model is proposed for the first time to track particles through an accurately designed Glaser solenoid. It can be used to study electric and magnetic combined lens and/ or uni-potential lens too. It is of interest and benefit for the accelerator persons in general and lens designers in particular. (author)
LCA of Chemicals and Chemical Products

DEFF Research Database (Denmark)

Fantke, Peter; Ernstoff, Alexi

2018-01-01

This chapter focuses on the application of Life Cycle Assessment (LCA) to evaluate the environmental performance of chemicals as well as of products and processes where chemicals play a key role. The life cycle stages of chemical products, such as pharmaceuticals drugs or plant protection products......, are discussed and differentiated into extraction of abiotic and biotic raw materials, chemical synthesis and processing, material processing, product manufacturing, professional or consumer product use, and finally end-of-life . LCA is discussed in relation to other chemicals management frameworks and concepts...... including risk assessment , green and sustainable chemistry , and chemical alternatives assessment. A large number of LCA studies focus on contrasting different feedstocks or chemical synthesis processes, thereby often conducting a cradle to (factory) gate assessment. While typically a large share...
Designing SQCRA as a Software to Semi-quantitative Chemical Risk Assessment in Workplace

Directory of Open Access Journals (Sweden)

Ali Karimi

2014-06-01

Full Text Available Background & Objectives : The aim of chemical risk assessment is to identify and evaluate risks originated from chemicals usages. This study aims to design a practical tool for facilitating chemical risk assessment. Methods: The proposed software was derived from chemical risk assessment method which was recommended by Ministry of Human Resources of Malaysia. All of the processes in question are designed in operating system software. Based on some revisions, this software was developed using Visual Basic (VB titled as SQCRA. The developed software was used for chemical risk assessment in Narges Vegetale Oil Company in Shiraz (center of Iran. Result: The output of software showed that the level of risk derived from sulfuric acid, phosphoric acid, aluminum sulphate, nickel catalyst, acetic acid used as a raw material were 2.4, 2.84, 2.3, 3.5 and 2.66, respectively. Moreover, risk rank and proposed control methods for each of these materials were determined. Conclusions : The developed software calculates the health risk level based on the degree of hazard and exposure in shorttime and without using risk matrix and chemical formula. After determining the risk rank, the software proposes the control procedures to reduce occupational exposure.
Enhancing the design of in situ chemical barriers with multicomponent reactive transport modeling

International Nuclear Information System (INIS)

Sevougian, S.D.; Steefel, C.I.; Yabusaki, S.B.

1994-11-01

This paper addresses the need for systematic control of field-scale performance in the emplacement and operation of in situ chemical treatment barriers; in particular, it addresses the issue of how the local coupling of reaction kinetics and material heterogeneities at the laboratory or bench scale can be accurately upscaled to the field. The authors have recently developed modeling analysis tools that can explicitly account for all relevant chemical reactions that accompany the transport of reagents and contaminants through a chemically and physically heterogeneous subsurface rock or soil matrix. These tools are incorporated into an enhanced design methodology for in situ chemical treatment technologies, and the new methodology is demonstrated in the ongoing design of a field experiment for the In Situ Redox Manipulation (ISRM) project at the U.S. Department of Energy (DOE) Hanford Site. The ISRM design approach, which systematically integrates bench-scale and site characterization information, provides an ideal test for the new reactive transport techniques. The need for the enhanced chemistry capability is demonstrated by an example that shows how intra-aqueous redox kinetics can affect the transport of reactive solutes. Simulations are carried out on massively parallel computer architectures to resolve the influence of multiscale heterogeneities on multicomponent, multidimensional reactive transport. The technology will soon be available to design larger-scale remediation schemes
Tailor-made Design of Chemical Blends using Decomposition-based Computer-aided Approach

DEFF Research Database (Denmark)

Yunus, Nor Alafiza; Manan, Zainuddin Abd.; Gernaey, Krist

(properties). In this way, first the systematic computer-aided technique establishes the search space, and then narrows it down in subsequent steps until a small number of feasible and promising candidates remain and then experimental work may be conducted to verify if any or all the candidates satisfy......Computer aided technique is an efficient approach to solve chemical product design problems such as design of blended liquid products (chemical blending). In chemical blending, one tries to find the best candidate, which satisfies the product targets defined in terms of desired product attributes...... is decomposed into two stages. The first stage investigates the mixture stability where all unstable mixtures are eliminated and the stable blend candidates are retained for further testing. In the second stage, the blend candidates have to satisfy a set of target properties that are ranked according...
Design and Application of Sensors for Chemical Cytometry.

Science.gov (United States)

Vickerman, Brianna M; Anttila, Matthew M; Petersen, Brae V; Allbritton, Nancy L; Lawrence, David S

2018-02-08

The bulk cell population response to a stimulus, be it a growth factor or a cytotoxic agent, neglects the cell-to-cell variability that can serve as a friend or as a foe in human biology. Biochemical variations among closely related cells furnish the basis for the adaptability of the immune system but also act as the root cause of resistance to chemotherapy by tumors. Consequently, the ability to probe for the presence of key biochemical variables at the single-cell level is now recognized to be of significant biological and biomedical impact. Chemical cytometry has emerged as an ultrasensitive single-cell platform with the flexibility to measure an array of cellular components, ranging from metabolite concentrations to enzyme activities. We briefly review the various chemical cytometry strategies, including recent advances in reporter design, probe and metabolite separation, and detection instrumentation. We also describe strategies for improving intracellular delivery, biochemical specificity, metabolic stability, and detection sensitivity of probes. Recent applications of these strategies to small molecules, lipids, proteins, and other analytes are discussed. Finally, we assess the current scope and limitations of chemical cytometry and discuss areas for future development to meet the needs of single-cell research.
Priorities in the design of chemical shops at coke plants

Energy Technology Data Exchange (ETDEWEB)

V.I. Rudyka; Y.E. Zingerman; V.V. Grabko; L.A. Kazak [Giprokoks, the State Institute for the Design of Coke-Industry Enterprises, Kharkov (Ukraine)

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.
Inertial confinement fusion driver enhancements: Final focusing systems and compact heavy-ion driver designs

International Nuclear Information System (INIS)

Bieri, R.L.

1991-01-01

Required elements of an inertial confinement fusion power plant are modeled and discussed. A detailed analysis of two critical elements of candidate drivers is done, and new component designs are proposed to increase the credibility and feasibility of each driver system. An analysis of neutron damage to the final elements of a laser focusing system is presented, and multilayer -- dielectric mirrors are shown to have damage lifetimes which axe too short to be useful in a commercial power plant. A new final-focusing system using grazing incidence metal mirrors to protect sensitive laser optics is designed and shown to be effective in extending the lifetime of the final focusing system. The reflectivities and damage limits of grazing incidence metal mirrors are examined in detail, and the required mirror sizes are shown to be compatible with the beam sizes and illumination geometries currently envisioned for laser drivers. A detailed design and analysis is also done for compact arrays of superconducting magnetic quadrupoles, which are needed in a multi-beam heavy-ion driver. The new array model is developed in more detail than some previous conceptual designs and models arrays which are more compact than arrays scaled from existing single -- quadrupole designs. The improved integrated model for compact arrays is used to compare the effects of various quadrupole array design choices on the size and cost of a heavy-ion driver. Array design choices which significantly affect the cost of a heavy-ion driver include the choice of superconducting material and the thickness of the collar used to support the winding stresses. The effect of these array design choices on driver size and cost is examined and the array model is used to estimate driver cost savings and performance improvements attainable with aggressive quadrupole array designs with high-performance superconductors
Design of chemical treatment unit for radioactive liquid wastes in Serpong nuclear facilities

International Nuclear Information System (INIS)

Salimin, Z.; Walman, E.; Santoso, P.; Purnomo, S.; Sugito; Suwardiyono; Wintono

1996-01-01

The chemical treatment unit for radioactive liquid wastes arising from nuclear fuel fabrication, radioisotopes production and radiometallurgy facility has been designed. The design of chemical processing unit is based on the characteristics of liquid wastes containing fluors from uranium fluoride conversion process to ammonium uranyl carbonate on the fuel fabrication. The chemical treatment has the following process steps: coagulation-precipitation of fluoride ion by calcium hydroxide coagulant, separation of supernatant solution from sludge, coagulation of remaining fluoride on the supernatant solution by alum, separation of supernatant from sludge, and than precipitation of fluors on the supernatant by polymer resin WWS 116. The processing unit is composed of 3 storage tanks for raw liquid wastes (capacity 1 m 3 per tank), 5 storage tanks for chemicals (capacity 0.5 m 3 per tank), 2 mixing reactors (capacity 0.5 m 3 per reactor), 1 storage tank for supernatant solution (capacity 1 m 3 ), and 1 storage tank for sludge (capacity 1 m 3 )
Surrogate models and optimal design of experiments for chemical kinetics applications

KAUST Repository

Bisetti, Fabrizio

2015-01-07

Kinetic models for reactive flow applications comprise hundreds of reactions describing the complex interaction among many chemical species. The detailed knowledge of the reaction parameters is a key component of the design cycle of next-generation combustion devices, which aim at improving conversion efficiency and reducing pollutant emissions. Shock tubes are a laboratory scale experimental configuration, which is widely used for the study of reaction rate parameters. Important uncertainties exist in the values of the thousands of parameters included in the most advanced kinetic models. This talk discusses the application of uncertainty quantification (UQ) methods to the analysis of shock tube data as well as the design of shock tube experiments. Attention is focused on a spectral framework in which uncertain inputs are parameterized in terms of canonical random variables, and quantities of interest (QoIs) are expressed in terms of a mean-square convergent series of orthogonal polynomials acting on these variables. We outline the implementation of a recent spectral collocation approach for determining the unknown coefficients of the expansion, namely using a sparse, adaptive pseudo-spectral construction that enables us to obtain surrogates for the QoIs accurately and efficiently. We first discuss the utility of the resulting expressions in quantifying the sensitivity of QoIs to uncertain inputs, and in the Bayesian inference key physical parameters from experimental measurements. We then discuss the application of these techniques to the analysis of shock-tube data and the optimal design of shock-tube experiments for two key reactions in combustion kinetics: the chain-brancing reaction H + O2 ←→ OH + O and the reaction of Furans with the hydroxyl radical OH.

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

Energy Technology Data Exchange (ETDEWEB)

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.
Chemical Engineering Education - Current and Future Trends

DEFF Research Database (Denmark)

Gani, Rafiqul

topics (transport phenomena, separations, reaction engineering, etc.) must remain strong, should the applications that currently emphasize commodity chemicals also include new topics such as sustainability, and product design? In Europe, the European Federation of Chemical Engineering (EFCE) has taken...... has a product focus. With this shift of the chemical industry, what should be the curriculum of the chemical engineering degrees at the BSc- and MSc-levels, and, are the skill set of chemical engineers appropriate for this altered chemical industry? While the basic skill set, defined by the core...... a leading role to define the chemical engineering curriculum. The result has been a set of recommendations for the first (BSc), second (MSc) and third (PhD) cycle chemical engineering education aligned to the Bologna Process. They recommend that students studying towards bachelor and masters qualifications...
Chemical and non-chemical stressors affecting childhood obesity: a systematic scoping review.

Science.gov (United States)

Lichtveld, Kim; Thomas, Kent; Tulve, Nicolle S

2018-01-01

Childhood obesity in the United States has doubled over the last three decades and currently affects 17% of children and adolescents. While much research has focused on individual behaviors impacting obesity, little research has emphasized the complex interactions of numerous chemical and non-chemical stressors found in a child's environment and how these interactions affect a child's health and well-being. The objectives of this systematic scoping review were to (1) identify potential chemical stressors in the context of non-chemical stressors that impact childhood obesity; and, (2) summarize our observations for chemical and non-chemical stressors in regards to child-specific environments within a community setting. A review was conducted to identify chemical and non-chemical stressors related to childhood obesity for the childhood life stages ranging from prenatal to adolescence. Stressors were identified and grouped into domains: individual behaviors, family/household behaviors, community stressors, and chemical exposures. Stressors were related to the child and the child's everyday environments and used to characterize child health and well-being. This review suggests that the interactions of chemical and non-chemical stressors are important for understanding a child's overall health and well-being. By considering these relationships, the exposure science research community can better design and implement strategies to reduce childhood obesity.
NIF: Impacts of chemical accidents and comparison of chemical/radiological accident approaches

International Nuclear Information System (INIS)

Lazaro, M.A.; Policastro, A.J.; Rhodes, M.

1996-01-01

The US Department of Energy (DOE) proposes to construct and operate the National Ignition Facility (NIF). The goals of the NIF are to (1) achieve fusion ignition in the laboratory for the first time by using inertial confinement fusion (ICF) technology based on an advanced-design neodymium glass solid-state laser, and (2) conduct high-energy-density experiments in support of national security and civilian applications. The primary focus of this paper is worker-public health and safety issues associated with postulated chemical accidents during the operation of NIF. The key findings from the accident analysis will be presented. Although NIF chemical accidents will be emphasized, the important differences between chemical and radiological accident analysis approaches and the metrics for reporting results will be highlighted. These differences are common EIS facility and transportation accident assessments
Synthetic Biology for Specialty Chemicals.

Science.gov (United States)

Markham, Kelly A; Alper, Hal S

2015-01-01

In this review, we address recent advances in the field of synthetic biology and describe how those tools have been applied to produce a wide variety of chemicals in microorganisms. Here we classify the expansion of the synthetic biology toolbox into three different categories based on their primary function in strain engineering-for design, for construction, and for optimization. Next, focusing on recent years, we look at how chemicals have been produced using these new synthetic biology tools. Advances in producing fuels are briefly described, followed by a more thorough treatment of commodity chemicals, specialty chemicals, pharmaceuticals, and nutraceuticals. Throughout this review, an emphasis is placed on how synthetic biology tools are applied to strain engineering. Finally, we discuss organism and host strain diversity and provide a future outlook in the field.
An Intelligent System for Modelling, Design and Analysis of Chemical Processes

DEFF Research Database (Denmark)

Gani, Rafiqul

ICAS, Integrated Computer Aided System, is a software that consists of a number of intelligent tools, which are very suitable, among others, for computer aided modelling, sustainable design of chemical and biochemical processes, and design-analysis of product-process monitoring systems. Each...... the computer aided modelling tool will illustrate how to generate a desired process model, how to analyze the model equations, how to extract data and identify the model and make it ready for various types of application. In sustainable process design, the example will highlight the issue of integration...
Consumer exposure to chemicals in indoor environment : A specific focus on chemicals from textile products

NARCIS (Netherlands)

Wijnhoven SWP; Kooi MW; te Biesebeek JD; SIR; vgc

2010-01-01

Textile products in indoor environment contain a variety of chemicals. Well-known examples are flame retardants, phthalates, formaldehyde and dimethylfumarate. Consumers are potentially exposed to these chemicals since a lot of textile products are present in indoor environment (clothing, curtains,
Design Research with a Focus on Learning Processes: An Overview on Achievements and Challenges

Science.gov (United States)

Prediger, Susanne; Gravemeijer, Koeno; Confrey, Jere

2015-01-01

Design research continues to gain prominence as a significant methodology in the mathematics education research community. This overview summarizes the origins and the current state of design research practices focusing on methodological requirements and processes of theorizing. While recognizing the rich variations in the foci and scale of design…
Integrated Process Design, Control and Analysis of Intensified Chemical Processes

DEFF Research Database (Denmark)

Mansouri, Seyed Soheil

chemical processes; for example, intensified processes such as reactive distillation. Most importantly, it identifies and eliminates potentially promising design alternatives that may have controllability problems later. To date, a number of methodologies have been proposed and applied on various problems......, that the same principles that apply to a binary non-reactive compound system are valid also for a binary-element or a multi-element system. Therefore, it is advantageous to employ the element based method for multicomponent reaction-separation systems. It is shown that the same design-control principles...
Design of high-energy high-current linac with focusing by superconducting solenoids

Energy Technology Data Exchange (ETDEWEB)

Batskikh, G.I.; Belugin, V.M.; Bondarev, B.I. [Moscow Radiotechnical Institute (Russian Federation)] [and others

1995-10-01

The advancement of MRTI design for 1.5 GeV and 250 mA ion CW linac was presented in a previous report. In this new linac version all the way from input to output the ions are focused by magnetic fields of superconducting solenoids. The ion limit current is far beyond the needed value. The linac focusing channel offers major advantages over the more conventional ones. The acceptance is 1.7 times as large for such focusing channel as for quadrupole one. Concurrently, a random perturbation sensitivity for such channel is one order of magnitude smaller than in quadrupole channel. These focusing channel features allow to decrease beam matched radius and increase a linac radiation purity without aperture growth. {open_quotes}Regotron{close_quotes} is used as high power generator in linac main part. But D&W cavities need not be divided into sections connected by RF-bridges which denuded them of high coupling factor.
Recognized focused practice: Does sub-specialty designation offer value to the neurosurgeon?

Directory of Open Access Journals (Sweden)

Maya A Babu

Full Text Available Vehicles for life-long assessment such as Maintenance of Certification tend to focus on generalist neurosurgical knowledge. However, as neurosurgeons advance in their careers, they tend to narrow their practice and increase volumes in certain specific types of operations. Failing to test the type of procedures most relevant to the practitioner is a lost opportunity to improve the knowledge and practice of the individual neurosurgeon. In this study, we assess the neurosurgical community's appetite for designations of board-recognized Recognized Focused Practice (RFP. We administered a validated, online, confidential survey to 4,899 neurosurgeons (2,435 American Board of Neurological Surgery (ABNS Diplomates participating in MOC, 1,440 Diplomates certified prior to 1999 (grandfathered, and 1,024 retired Diplomates. We received 1,449 responses overall (30% response rate. A plurality of respondents were in practice 11-15 years (18.5%, in private practice (40% and participate in MOC (61%. 49% of respondents felt that a RFP designation would not be helpful. For the 30% who felt that RFP would be helpful, 61.3% felt that it would support recognition by their hospital or practice, it would motivate them to stay current on medical knowledge (53.4%, or it would help attract patients (46.4%;. The most popular suggestions for RFP were Spine (56.2%, Cerebrovascular (62.9%, Pediatrics (64.1%, and Functional/Stereotactic (52%. A plurality of neurosurgeons (35.7% felt that RFP should recognize neurosurgeons with accredited and non-accredited fellowship experience and sub-specialty experience. Ultimately, Recognized Focused Practice may provide value to individual neurosurgeons, but the neurosurgical community shows tepid interest for pursuing this designation.
Recognized focused practice: Does sub-specialty designation offer value to the neurosurgeon?

Science.gov (United States)

Babu, Maya A; Liau, Linda M; Meyer, Fredric B

2017-01-01

Vehicles for life-long assessment such as Maintenance of Certification tend to focus on generalist neurosurgical knowledge. However, as neurosurgeons advance in their careers, they tend to narrow their practice and increase volumes in certain specific types of operations. Failing to test the type of procedures most relevant to the practitioner is a lost opportunity to improve the knowledge and practice of the individual neurosurgeon. In this study, we assess the neurosurgical community's appetite for designations of board-recognized Recognized Focused Practice (RFP). We administered a validated, online, confidential survey to 4,899 neurosurgeons (2,435 American Board of Neurological Surgery (ABNS) Diplomates participating in MOC, 1,440 Diplomates certified prior to 1999 (grandfathered), and 1,024 retired Diplomates). We received 1,449 responses overall (30% response rate). A plurality of respondents were in practice 11-15 years (18.5%), in private practice (40%) and participate in MOC (61%). 49% of respondents felt that a RFP designation would not be helpful. For the 30% who felt that RFP would be helpful, 61.3% felt that it would support recognition by their hospital or practice, it would motivate them to stay current on medical knowledge (53.4%), or it would help attract patients (46.4%;). The most popular suggestions for RFP were Spine (56.2%), Cerebrovascular (62.9%), Pediatrics (64.1%), and Functional/Stereotactic (52%). A plurality of neurosurgeons (35.7%) felt that RFP should recognize neurosurgeons with accredited and non-accredited fellowship experience and sub-specialty experience. Ultimately, Recognized Focused Practice may provide value to individual neurosurgeons, but the neurosurgical community shows tepid interest for pursuing this designation.
Focus group positioning and analysis: a commentary on adjuncts for enhancing the design of health care research.

Science.gov (United States)

Johnson, B C

1990-01-01

As health care competition increases, and as the penalties for making poor decisions become potentially more devastating, market research continues to play an increasingly important role in the decision-making process for hospitals. Concern over the appropriate use of market research and the costs related to it remains high. As such, efficiency in research design and clarity in research outcome are clearly the goals. This paper examines the focus group process and its adjunctive role in enhancing the overall design of health care market research. Specifically, the function and placement of focus groups within the research plan as well as several methods of creative focus group analysis are considered within the context of an effective research design.
Implications and control of fuel-cladding chemical interaction for LMFBR fuel pin design

International Nuclear Information System (INIS)

Roake, W.E.

1977-01-01

Fuel-cladding-chemical-interaction (FCCI) is typically incorporated into the design of an LMFBR fuel pin as a wastage allowance. Several interrelated factors are considered during the evolution of an LMFBR fuel pin design. Those which are indirectly affected by FCCI include: allowable pin power, fuel restructuring, fission gas migration and release from the fuel, fuel cracking, fuel swelling, in-reactor cladding creep, cladding swelling, and the cladding mechanical strain. Chemical activity of oxygen is the most readily controlled factor in FCCI. Two methods are being investigated: control of total oxygen inventory by limiting fuel O/M, and control of oxygen activity with buffer metals
Essentials of water systems design in the oil, gas, and chemical processing industries

CERN Document Server

Bahadori, Alireza; Boyd, Bill

2013-01-01

Essentials of Water Systems Design in the Oil, Gas and Chemical Processing Industries provides valuable insight for decision makers by outlining key technical considerations and requirements of four critical systems in industrial processing plants—water treatment systems, raw water and plant water systems, cooling water distribution and return systems, and fire water distribution and storage facilities. The authors identify the key technical issues and minimum requirements related to the process design and selection of various water supply systems used in the oil, gas, and chemical processing industries. This book is an ideal, multidisciplinary work for mechanical engineers, environmental scientists, and oil and gas process engineers.
Implications and control of fuel-cladding chemical interaction for LMFBR fuel pin design

Energy Technology Data Exchange (ETDEWEB)

Roake, W E [Westinghouse-Hanford Co., Richland, WA (United States)

1977-04-01

Fuel-cladding-chemical-interaction (FCCI) is typically incorporated into the design of an LMFBR fuel pin as a wastage allowance. Several interrelated factors are considered during the evolution of an LMFBR fuel pin design. Those which are indirectly affected by FCCI include: allowable pin power, fuel restructuring, fission gas migration and release from the fuel, fuel cracking, fuel swelling, in-reactor cladding creep, cladding swelling, and the cladding mechanical strain. Chemical activity of oxygen is the most readily controlled factor in FCCI. Two methods are being investigated: control of total oxygen inventory by limiting fuel O/M, and control of oxygen activity with buffer metals.
Optimization-based design of waste heat recovery systems

DEFF Research Database (Denmark)

Cignitti, Stefano

/or selected. This dissertation focuses on the chemical product and process systems used for waste heat recovery. Here, chemical products are working fluids, which are under continuous development and screening to fulfill regulatory environmental protection and safe operation requirements. Furthermore......, for the recovery of low-grade waste heat, new fluids and processes are needed to make the recovery technically and economically feasible. As the chemical product is influential in the design of the process system, the design of novel chemical products must be considered with the process system. Currently, state...... product and process system in terms of efficiency and sustainability. Today, some of the most important chemical product design problems are solvents and working fluids. Solvents are a vital part in the recovery of valuable resources in separation processes or waste water treatment. Working fluids...
Implementation Plan for Chemical Industry R&D Roadmap for Nanomaterials by Design

Energy Technology Data Exchange (ETDEWEB)

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.
Assessment of infant exposure to food chemicals: the French Total Diet Study design.

Science.gov (United States)

Hulin, M; Bemrah, N; Nougadère, A; Volatier, J L; Sirot, V; Leblanc, J C

2014-01-01

As part of the previous French Total Diet Studies (TDS) focusing on exposure to food chemicals in the population aged 3 years and older, the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) launched a specific TDS on infants to complete its overall chemical food safety programme for the general population. More than 500 chemical substances were analysed in food products consumed by children under 3 years old, including nutrients, several endocrine disruptors resulting from human activities (polychlorinated biphenyls, dioxins and furans, brominated flame retardants, perfluoroalkyl acids, pesticide residues, etc.) or migrating from food contact materials such as bisphenol A or phthalates, but also natural substances such as mycotoxins, phytoestrogens and steroids. To obtain a representative and general view of infant food consumption, food items were selected based on results of a national consumption survey conducted specifically on this population. Moreover, a specific study on food was conducted on 429 households to determine which home-cooking practices are employed to prepare food consumed by infants. Overall, the targeted chemical substances were analysed in more than 450 food samples, representing the purchase and home-cooking practices of over 5500 food products. Foods included common foods such as vegetables, fruit or cakes as well as specific infant foods such as infant formula or jarred baby food. The sampling plan covered over 80% of the total diet. Specificities in infant food consumption and habits were therefore considered to define this first infant TDS. This study, conducted on a large scale and focusing on a particularly sensitive population, will provide accurate information on the dietary exposure of children under 3 years to food chemicals, especially endocrine disruptors, and will be particularly useful for risk assessment analysis under the remit of ANSES' expert committees.
Design optimization of the International Linear Collider Final Focus System with a long L*

CERN Document Server

Plassard, Fabien

This Master's Thesis work has been done in the Aerospace Engineering master's programme framework and carried out at the European Organization for Nuclear Research (CERN). It was conducted under the 500 GeV e-e+ International Linear Collider (ILC) study and focused on the design and performance optimization of the Final Focus System (FFS). The purpose of the final focus system of the future linear colliders (ILC and CLIC) is to demagnify the beam to the required transverse size at the interaction point (IP). The FFS is designed for a flat-beam in a compact way based on a local chromaticity correction which corrects both horizontal and vertical chromaticities simultaneously. An alternative FFS configuration based on the traditional scheme with two dedicated chromatic correction sections for horizontal and vertical chromaticities and a long L * option has been developed. A longer free space between the last quadrupole and the IP allows to place the last quadrupole on a stable ground, with fewer engineering ...

Designing with video focusing the user-centred design process

CERN Document Server

Ylirisku, Salu Pekka

2007-01-01

Digital video for user-centered co-design is an emerging field of design, gaining increasing interest in both industry and academia. It merges the techniques and approaches of design ethnography, participatory design, interaction analysis, scenario-based design, and usability studies. This book covers the complete user-centered design project. It illustrates in detail how digital video can be utilized throughout the design process, from early user studies to making sense of video content and envisioning the future with video scenarios to provoking change with video artifacts. The text includes
Property Model-based Tailor-made Design of Chemical-based Products

DEFF Research Database (Denmark)

Kalakul, Sawitree

Computer-aided model-based methods and tools are increasingly playing important roles in chemical product design. They have the potential to very quickly search for and identify reliable product candidates that can then be verified through experiments. Inthis way, the time and resources spent...... on experiment are reduced leading to faster and cheaper to market the products. The tools also help to manage the solution of product design problems, which usually require efficient handling of model-data-knowledge from different sources and at different time and size scales. The main contribution...... the needed template for a desired product is not available. VPPD-Lab employs a suite of algorithms(such as database search, molecular and mixture blend design) and toolboxes (such asproperty calculations and property model consistency tests) for specific product property prediction, design, and/or analysis...
Design and preliminary results of the IMA plasma focus experiment

Energy Technology Data Exchange (ETDEWEB)

Soliman, H M; Masoud, M M [Arab Republic of Egypt, Atomic Energy Authority Plasma physics and Nuclear Fusion department, Cairo (Egypt)

1994-12-31

The present paper describes the design, operation and characteristics of aton 1MA plasma focus device, which built in egypt at the plasma physics department, N.R.C., atomic energy authority. The main parts of the system are: the coaxial electrodes of mather type, the expansion chamber, the condenser bank of 75 kJ stored energy, the pressurized spark gap switches and Blumlein trigger system. Measurement of the breakdown voltage between plasma focus electrodes and discharge current, using half of the condenser bank, showed that, for U{sub c} h = 32 kV, the discharge current was 0.5 Ma. In the discharge current and voltage traces a sharp drop in discharge current correspondingly to a sudden rise in voltage have been observed, which characterize the focus regime. Time structure of the x-ray emission measurements have been performed by means of scintillation detectors. by using a hydrogen gas the results showed that, the x-ray intensity is increased with increasing the hydrogen gas pressure. plasma sheath current density, J-Z distribution in axial direction during the acceleration phase of the discharge is studied, using a miniature Rogovsky coil. The results cleared that J{sub z} is increased with the axial distance from breech to muzzle at different hydrogen gas pressures. 12 figs.
Design and preliminary results of the IMA plasma focus experiment

International Nuclear Information System (INIS)

Soliman, H.M.; Masoud, M.M.

1993-01-01

The present paper describes the design, operation and characteristics of aton 1MA plasma focus device, which built in egypt at the plasma physics department, N.R.C., atomic energy authority. The main parts of the system are: the coaxial electrodes of mather type, the expansion chamber, the condenser bank of 75 kJ stored energy, the pressurized spark gap switches and Blumlein trigger system. Measurement of the breakdown voltage between plasma focus electrodes and discharge current, using half of the condenser bank, showed that, for U c h = 32 kV, the discharge current was 0.5 Ma. In the discharge current and voltage traces a sharp drop in discharge current correspondingly to a sudden rise in voltage have been observed, which characterize the focus regime. Time structure of the x-ray emission measurements have been performed by means of scintillation detectors. by using a hydrogen gas the results showed that, the x-ray intensity is increased with increasing the hydrogen gas pressure. plasma sheath current density, J-Z distribution in axial direction during the acceleration phase of the discharge is studied, using a miniature Rogovsky coil. The results cleared that J z is increased with the axial distance from breech to muzzle at different hydrogen gas pressures. 12 figs
Experimental and Theoretical Progress of Linear Collider Final Focus Design and ATF2 Facility

CERN Document Server

Seryi, Andrei; Zimmermann, Frank; Kubo, Kiyoshi; Kuroda, Shigeru; Okugi, Toshiyuki; Tauchi, Toshiaki; Terunuma, Nobuhiro; Urakawa, Junji; White, Glen; Woodley, Mark; Angal-Kalinin, Deepa

2014-01-01

In this brief overview we will reflect on the process of the design of the linear collider (LC) final focus (FF) optics, and will also describe the theoretical and experimental efforts on design and practical realisation of a prototype of the LC FF optics implemented in the ATF2 facility at KEK, Japan, presently being commissioned and operated.
Design of an Emulsion-based Personal Detergent through a Model-based Chemical Product Design Methodology

DEFF Research Database (Denmark)

Mattei, Michele; Hill, Michael; Kontogeorgis, Georgios

2013-01-01

An extended systematic methodology for the design of emulsion-based Chemical products is presented. The methodology consists of a model-based framework involving seven sequential hierarchical steps: starting with the identification of the needs to be satisfied by the product and then adding one-b...... to obtain one or more candidate formulations. A conceptual casestudy representing a personal detergent is presented to highlight the methodology....
Design of an Emulsion-based Personal Detergent through a Model-based Chemical Product Design Methodology

DEFF Research Database (Denmark)

Mattei, Michele; Hill, Michael; Kontogeorgis, Georgios

2013-01-01

An extended systematic methodology for the design of emulsion-based Chemical products is presented. The methodology consists of a model-based framework involving seven sequential hierarchical steps: starting with the identification of the needs to be satisfied by the product and then adding one...... to obtain one or more candidate formulations. A conceptual casestudy representing a personal detergent is presented to highlight the methodology....
Affordable Design: A Methodolgy to Implement Process-Based Manufacturing Cost into the Traditional Performance-Focused Multidisciplinary Design Optimization

Science.gov (United States)

Bao, Han P.; Samareh, J. A.

2000-01-01

The primary objective of this paper is to demonstrate the use of process-based manufacturing and assembly cost models in a traditional performance-focused multidisciplinary design and optimization process. The use of automated cost-performance analysis is an enabling technology that could bring realistic processbased manufacturing and assembly cost into multidisciplinary design and optimization. In this paper, we present a new methodology for incorporating process costing into a standard multidisciplinary design optimization process. Material, manufacturing processes, and assembly processes costs then could be used as the objective function for the optimization method. A case study involving forty-six different configurations of a simple wing is presented, indicating that a design based on performance criteria alone may not necessarily be the most affordable as far as manufacturing and assembly cost is concerned.
Design and Fabrication of Piezoresistive Based Encapsulated Poly-Si Cantilevers for Bio/chemical Sensing

Science.gov (United States)

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.
Protein engineering approaches to chemical biotechnology.

Science.gov (United States)

Chen, Zhen; Zeng, An-Ping

2016-12-01

Protein engineering for the improvement of properties of biocatalysts and for the generation of novel metabolic pathways plays more and more important roles in chemical biotechnology aiming at the production of chemicals from biomass. Although widely used in single-enzyme catalysis process, protein engineering is only being increasingly explored in recent years to achieve more complex in vitro and in vivo biocatalytic processes. This review focuses on major contributions of protein engineering to chemical biotechnology in the field of multi-enzymatic cascade catalysis and metabolic engineering. Especially, we discuss and highlight recent strategies for combining pathway design and protein engineering for the production of novel products. Copyright Â© 2016. Published by Elsevier Ltd.
Toxic industrial chemicals (TICs) as asymmetric weapons: the design basis threat

International Nuclear Information System (INIS)

Skinner, L.

2009-01-01

Asymmetric warfare concepts relate well to the use of improvised chemical weapons against urban targets. Sources of information on toxic industrial chemicals (TICs) and lists of high threat chemicals are available that point to likely choices for an attack. Accident investigations can be used as a template for attacks, and to judge the possible effectiveness of an attack using TICs. The results of a chlorine rail car accident in South Carolina, USA and the Russian military assault on a Moscow theater provide many illustrative points for similar incidents that mighty be carried out deliberately. Computer modeling of outdoor releases shows how an attack might take into consideration issues of stand-off distance and dilution. Finally, the preceding may be used to estimate with some accuracy the design basis threat posed by the used of TICs as weapons.(author)
[The recent development of fiber-optic chemical sensor].

Science.gov (United States)

Wang, Jian; Wei, Jian-ping; Yang, Bo; Gao, Zhi-yang; Zhang, Li-wei; Yang, Xue-feng

2014-08-01

The present article provides a brief review of recent research on fiber-optic chemical sensor technology and the future development trends. Especially, fiber-optic pH chemical sensor, fiber-optic ion chemicl sensor, and fiber-optic gas chemical sensor are introduced respectively. Sensing film preparation methods such as chemical bonding method and sol-gel method were briefly reviewed. The emergence of new type fiber-microstructured optical fiber opened up a new development direction for fiber-optic chemical sensor. Because of its large inner surface area, flexible design of structure, having internal sensing places in fibers, it has rapidly become an important development direction and research focus of the fiber-optic chemical sensors. The fiber-optic chemical sensor derived from microstructured optical fiber is also discussed in detail. Finally, we look to the future of the fiber-optic chemical sensor.
Chemical looping reactor system design double loop circulating fluidized bed (DLCFB)

Energy Technology Data Exchange (ETDEWEB)

Bischi, Aldo

2012-05-15

Chemical looping combustion (CLC) is continuously gaining more importance among the carbon capture and storage (CCS) technologies. It is an unmixed combustion process which takes place in two steps. An effective way to realize CLC is to use two interconnected fluidized beds and a metallic powder circulating among them, acting as oxygen carrier. The metallic powder oxidizes at high temperature in one of the two reactors, the air reactor (AR). It reacts in a highly exothermic reaction with the oxygen of the injected fluidising air. Afterwards the particles are sent to the other reactor where the fuel is injected, the fuel reactor (FR). There, they transport heat and oxygen necessary for the reaction with the injected fuel to take place. At high temperatures, the particle's oxygen reacts with the fuel producing Co2 and steam, and the particles are ready to start the loop again. The overall reaction, the sum of the enthalpy changes of the oxygen carrier oxidation and reduction reactions, is the same as for the conventional combustion. Two are the key features, which make CLC promising both for costs and capture efficiency. First, the high inherent irreversibility of the conventional combustion is avoided because the energy is utilized stepwise. Second, the Co2 is intrinsically separated within the process; so there is in principle no need either of extra carbon capture devices or of expensive air separation units to produce oxygen for oxy-combustion. A lot of effort is taking place worldwide on the development of new chemical looping oxygen carrier particles, reactor systems and processes. The current work is focused on the reactor system: a new design is presented, for the construction of an atmospheric 150kWth prototype working with gaseous fuel and possibly with inexpensive oxygen carriers derived from industrial by-products or natural minerals. It consists of two circulating fluidized beds capable to operate in fast fluidization regime; this will increase the
Phase I Focused Corrective Measures Study/Feasibility Study for the L-Area Oil and Chemical Basin (904-83G)

Energy Technology Data Exchange (ETDEWEB)

Palmer, E. [Westinghouse Savannah River Company, AIKEN, SC (United States)

1997-02-01

This report presents the completed Resource Conservation and Recovery Act (RCRA) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Focused Corrective Measures Study/Feasibility Study (CMS/FS) for the L-Area Oil and Chemical Basin (LAOCB)/L-Area Acid Caustic Basin (9LAACB) Solid Waste Management Unit/Operable Unit (SWMU/OU) at the Savannah River Site (SRS).
Applicable safety-related design and operations considerations from the oil and chemical industries

International Nuclear Information System (INIS)

Mulvihill, R.J.; Deshotels, R.L.; Master, C.A.

1987-01-01

Fluor Daniel has conducted several hazards and risk analyses on petroleum and chemical facilities. These analyses included qualitative hazards and operability (HAZOP) studies, preliminary hazards analyses, and qualitative fault-tree analysis as well as quantitative event-tree/fault-tree risk analysis. Several design-related problem areas were uncovered as a result of these analyses as well as deficiencies in operations and maintenance. Design deficiency areas include potential common-mode failures associated with redundant functions sharing a common distributed digital control (DDC) logic circuit board and failures in pressure relief systems. Many of the design weaknesses and potential operator errors discussed have a direct counterpart in nuclear fuel processing plants and nuclear power reactors. Counterparts that are discussed are common cause/common mode failures in control systems and failures in pressure relief systems. Overpressurization of piping and vessels resulting in rupture is discussed. Mitigating design features and operations procedures that have been implemented in the chemical process industry are described and their applicability to the nuclear industry is discussed
Design study of superconducting sextupole magnet using HTS coated conductor for neutron-focusing device

International Nuclear Information System (INIS)

Tosaka, T.; Koyanagi, K.; Ono, M.; Kuriyama, T.; Watanabe, I.; Tsuchiya, K.; Suzuki, J.; Adachi, T.; Shimizu, H.M.

2006-01-01

We performed a design study of sextupole magnet using high temperature superconducting (HTS) wires. The sextupole magnet is used as a focusing lens for neutron-focusing devices. A neutron-focusing device is desired to have a large aperture and a high magnetic field gradient of G, where G = 2B/r 2 , B is the magnetic field and r is a distance from the sextupole magnet axis. Superconducting magnets offer promising prospects to meet the demands of a neutron-focusing device. Recently NbTi coils of low temperature superconducting (LTS) have been developed for a sextupole magnet with a 46.8 mm aperture. The maximum magnetic field gradient G of this magnet is 9480 T/m 2 at 4.2 K and 12,800 T/m 2 at 1.8 K. On the other hand, rapid progress on second generation HTS wire has been made in increasing the performance of critical current and in demonstrating a long length. The second generation HTS wire is referred to as coated conductor. It consists of tape-shaped base upon which a thin coating of superconductor, usually YBCO, is deposited or grown. This paper describes a design study of sextupole magnet using coated conductors
FOREWORD: Focus on Advanced Ceramics Focus on Advanced Ceramics

Science.gov (United States)

Ohashi, Naoki

2011-06-01

Much research has been devoted recently to developing technologies for renewable energy and improving the efficiency of the processes and devices used in industry and everyday life. Efficient solutions have been found using novel materials such as platinum and palladium-based catalysts for car exhaust systems, samarium-cobalt and neodymium-iron-boron permanent magnets for electrical motors, and so on. However, their realization has resulted in an increasing demand for rare elements and in their deficit, the development of new materials based on more abundant elements and new functionalities of traditional materials. Moreover, increasing environmental and health concerns demand substitution of toxic or hazardous substances with nature-friendly alternatives. In this context, this focus issue on advanced ceramics aims to review current trends in ceramics science and technology. It is related to the International Conference on Science and Technology of Advanced Ceramics (STAC) held annually to discuss the emerging issues in the field of ceramics. An important direction of ceramic science is the collaboration between experimental and theoretical sciences. Recent developments in density functional theory and computer technology have enabled the prediction of physical and chemical properties of ceramics, thereby assisting the design of new materials. Therefore, this focus issue includes articles devoted to theory and advanced characterization techniques. As mentioned above, the potential shortage of rare elements is becoming critical to the industry and has resulted in a Japanese government initiative called the 'Ubiquitous Element Strategy'. This focus issue also includes articles related to this strategy and to the associated topics of energy conversion, such as phosphors for high-efficiency lighting and photocatalysts for solar-energy harvesting. We hope that this focus issue will provide a timely overview of current trends and problems in ceramics science and
Rotary Bed Reactor for Chemical-Looping Combustion with Carbon Capture. Part 1: Reactor Design and Model Development

KAUST Repository

Zhao, Zhenlong

2013-01-17

Chemical-looping combustion (CLC) is a novel and promising technology for power generation with inherent CO2 capture. Currently, almost all of the research has been focused on developing CLC-based interconnected fluidized-bed reactors. In this two-part series, a new rotary reactor concept for gas-fueled CLC is proposed and analyzed. In part 1, the detailed configuration of the rotary reactor is described. In the reactor, a solid wheel rotates between the fuel and air streams at the reactor inlet and exit. Two purging sectors are used to avoid the mixing between the fuel stream and the air stream. The rotary wheel consists of a large number of channels with copper oxide coated on the inner surface of the channels. The support material is boron nitride, which has high specific heat and thermal conductivity. Gas flows through the reactor at elevated pressure, and it is heated to a high temperature by fuel combustion. Typical design parameters for a thermal capacity of 1 MW have been proposed, and a simplified model is developed to predict the performances of the reactor. The potential drawbacks of the rotary reactor are also discussed. © 2012 American Chemical Society.
Consumer exposure to chemicals in indoor environment : A specific focus on chemicals from textile products

OpenAIRE

Wijnhoven SWP; Kooi MW; te Biesebeek JD; SIR; vgc

2010-01-01

Textile products in indoor environment contain a variety of chemicals. Well-known examples are flame retardants, phthalates, formaldehyde and dimethylfumarate. Consumers are potentially exposed to these chemicals since a lot of textile products are present in indoor environment (clothing, curtains, floor covering, and upholstery of furniture) and consumers are in contact with these products for up to 24 hours a day. The Food and Consumer Product Safety Authority (VWA) commissioned RIVM to mak...
Designing new nuclear chemical processing plants for safeguards accountability

International Nuclear Information System (INIS)

Sprouse, K.M.

1987-01-01

New nuclear chemical processing plants will be required to develop material accountability control limits from measurement error propagation analysis rather than historical inventory difference data as performed in the past. In order for measurement error propagation methods to be viable alternatives, process designers must ensure that two nondimensional accountability parameters are maintained below 0.1. These parameters are ratios between the material holdup increase and the variance in inventory difference measurement uncertainty. Measurement uncertainty data for use in error propagation analysis is generally available in the open literature or readily derived from instrument calibration data. However, nuclear material holdup data has not been adequately developed for use in the material accountability design process. Long duration development testing on isolated unit operations is required to generate this necessary information

Focused cathode design to reduce anode heating during vircator operation

Energy Technology Data Exchange (ETDEWEB)

Lynn, Curtis F.; Dickens, James C.; Neuber, Andreas A. [Center for Pulsed Power and Power Electronics, Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)

2013-10-15

Virtual cathode oscillators, or vircators, are a type of high power microwave device which operates based on the instability of a virtual cathode, or cloud of electrons, which forms when electron current injected into the drift tube exceeds the space charge limited current within the drift tube. Anode heating by the electron beam during vircator operation ultimately limits achievable pulse lengths, repetition rates, and the duration of burst mode operation. This article discusses a novel cathode design that focuses electrons through holes in the anode, thus significantly reducing anode heating by the electrons emitted from the cathode during the first transit through the A-K gap. Reflexing electrons continue to deposit energy on the anode; however, the discussed minimization of anode heating by main beam electrons has the potential to enable higher repetition rates as well as efficiency and longer diode lifetime. A simulation study of this type of cathode design illustrates possible advantages.
Integrated design course of applied optics focusing on operating and maintaining abilities

Science.gov (United States)

Xu, Zhongjie; Ning, Yu; Jiang, Tian; Cheng, Xiangai

2017-08-01

The abilities of operating and maintaining optical instruments are crucial in modern society. Besides the basic knowledge in optics, the optics courses in the National University of Defense Technology also focus on the training on handling typical optical equipment. As the link between classroom courses on applied optics and the field trips, the integrated design course of applied optics aims to give the students a better understanding on several instantly used optical equipment, such as hand-held telescope and periscope, etc. The basic concepts of optical system design are also emphasized as well. The course is arranged rightly after the classroom course of applied optics and composed of experimental and design tasks. The experimental tasks include the measurements of aberrations and major parameters of a primitive telescope, while in the design parts, the students are asked to design a Keplerian telescope. The whole course gives a deepened understandings on the concepts, assembling, and operating of telescopes. The students are also encouraged to extend their interests on other typical optical instruments.
Design of chemical space networks using a Tanimoto similarity variant based upon maximum common substructures.

Science.gov (United States)

Zhang, Bijun; Vogt, Martin; Maggiora, Gerald M; Bajorath, Jürgen

2015-10-01

Chemical space networks (CSNs) have recently been introduced as an alternative to other coordinate-free and coordinate-based chemical space representations. In CSNs, nodes represent compounds and edges pairwise similarity relationships. In addition, nodes are annotated with compound property information such as biological activity. CSNs have been applied to view biologically relevant chemical space in comparison to random chemical space samples and found to display well-resolved topologies at low edge density levels. The way in which molecular similarity relationships are assessed is an important determinant of CSN topology. Previous CSN versions were based on numerical similarity functions or the assessment of substructure-based similarity. Herein, we report a new CSN design that is based upon combined numerical and substructure similarity evaluation. This has been facilitated by calculating numerical similarity values on the basis of maximum common substructures (MCSs) of compounds, leading to the introduction of MCS-based CSNs (MCS-CSNs). This CSN design combines advantages of continuous numerical similarity functions with a robust and chemically intuitive substructure-based assessment. Compared to earlier version of CSNs, MCS-CSNs are characterized by a further improved organization of local compound communities as exemplified by the delineation of drug-like subspaces in regions of biologically relevant chemical space.
Designing of the chemical composition of steels basing on the hardenability of constructional steels

International Nuclear Information System (INIS)

Dobrzanski, L.A.; Sitek, W.

2003-01-01

The paper presents the original method of modelling of the relationships between chemical composition of alloy constructional steel and its hardenability, employing neural networks. Basing on the experimental results of the hardenability investigations, which employed Jominy method, the model of the neural networks was developed and fully verified experimentally. The model makes it possible to obtain Jominy hardenability curves basing on the steel chemical composition. The model of neural networks, making it possible to design the steel chemical composition, basing on the known Jominy hardenability curve shape, was developed also and fully verified numerically. (author)
Enforcement Alert: EPA Enforcement Efforts Focus on Prevention of Chemical Accidents

Science.gov (United States)

This Alert is intended to inform the industry that companies must take responsibility to prevent accidental releases of dangerous chemicals like anhydrous ammonia through compliance with CAA’s Chemical Accident Prevention Program.
Design, fabrication, and characterization of a 2.3 kJ plasma focus of negative inner electrode

International Nuclear Information System (INIS)

Mathuthu, M.; Zengeni, T.G.; Gholap, A.V.

1997-01-01

The design, fabrication, and characterization of a 2.3 kJ plasma focus device with negative inner electrode are discussed. The purpose of the design was to initiate research in and study of plasma dynamics, nuclear reactions, and neutron emission mechanisms at the university. Also the device will be used to teach and demonstrate plasma phenomena at the postgraduate level and to perform experiments with inverted polarity to examine different operating regimes with nonstandard gases. It is hoped that in the long run the research work will help find a solution to the polarity riddle of plasma focus devices. When the system was operated with spectrographic argon as the filling gas, the best focus was obtained at a pressure range of 0.1 endash 1.25 Torr. With nitrogen as the filling gas, the best focus was obtained at pressures between 0.1 and 1.25 Torr. Air gave the best focus at a pressure range of 0.5 endash 1.5 Torr. The observed good focus action is attributed to the small inner electrode length (this reduces the amount of anode material ablated into the current sheath) and tapering of the inner electrode. Positive z-directed electrons contribute to the temperature and further ionization of the plasma gas during focusing. The performance of the device compares quite well with other known devices. copyright 1997 American Institute of Physics
The mechanical design for the WEAVE prime focus corrector system

Science.gov (United States)

Abrams, Don Carlos; Dee, Kevin; Agócs, Tibor; Lhome, Emilie; Peñate, José; Jaskó, Attila; Bányai, Evelin; Burgal, José A.; Dalton, Gavin; Middleton, Kevin; Bonifacio, Piercarlo; Aguerri, J. Alfonso L.; Trager, S. C.; Balcells, Marc

2014-08-01

WEAVE is the next-generation, wide-field, optical spectroscopy facility for the William Herschel Telescope (WHT) in La Palma, Canary Islands, Spain. The WHT will undergo a significant adaptation to accommodate this facility. A two- degree Prime Focus Corrector (PFC), that includes an Atmospheric Dispersion Compensator, is being planned and is currently in its final design phase. To compensate for the effects of temperature-induced image degradation, the entire PFC system will be translated along the telescope optical axis. The optical system comprises six lenses, the largest of which will have a diameter of 1.1m. Now that the optical elements are in production, the designs for the lens cells and the mounting arrangements are being analysed to ensure that the image quality of the complete system is better than 1.0 arcsec (80% encircled energy diameter) over the full field of view. The new PFC system is designed to be routinely interchanged with the existing top-end ring. This will maximise the versatility of the WHT and allow the two top-end systems to be interchanged as dictated by the scientific needs of the astronomers that will use WEAVE and other instruments on the telescope. This manuscript describes the work that has been carried out in developing the designs for the mechanical subsystems and the plans for mounting the lenses to attain an optical performance that is commensurate with the requirements derived from planning the WEAVE surveys.
Design of focused and restrained subsets from extremely large virtual libraries.

Science.gov (United States)

Jamois, Eric A; Lin, Chien T; Waldman, Marvin

2003-11-01

With the current and ever-growing offering of reagents along with the vast palette of organic reactions, virtual libraries accessible to combinatorial chemists can reach sizes of billions of compounds or more. Extracting practical size subsets for experimentation has remained an essential step in the design of combinatorial libraries. A typical approach to computational library design involves enumeration of structures and properties for the entire virtual library, which may be unpractical for such large libraries. This study describes a new approach termed as on the fly optimization (OTFO) where descriptors are computed as needed within the subset optimization cycle and without intermediate enumeration of structures. Results reported herein highlight the advantages of coupling an ultra-fast descriptor calculation engine to subset optimization capabilities. We also show that enumeration of properties for the entire virtual library may not only be unpractical but also wasteful. Successful design of focused and restrained subsets can be achieved while sampling only a small fraction of the virtual library. We also investigate the stability of the method and compare results obtained from simulated annealing (SA) and genetic algorithms (GA).
Chemical Education Research: Improving Chemistry Learning

Science.gov (United States)

Dudley Herron, J.; Nurrenbern, Susan C.

1999-10-01

Chemical education research is the systematic investigation of learning grounded in a theoretical foundation that focuses on understanding and improving learning of chemistry. This article reviews many activities, changes, and accomplishments that have taken place in this area of scholarly activity despite its relatively recent emergence as a research area. The article describes how the two predominant broad perspectives of learning, behaviorism and constructivism, have shaped and influenced chemical education research design, analysis, and interpretation during the 1900s. Selected research studies illustrate the range of research design strategies and results that have contributed to an increased understanding of learning in chemistry. The article also provides a perspective of current and continuing challenges that researchers in this area face as they strive to bridge the gap between chemistry and education - disciplines with differing theoretical bases and research paradigms.
Crossbar H-mode drift-tube linac design with alternative phase focusing for muon linac

Science.gov (United States)

Otani, M.; Futatsukawa, K.; Hasegawa, K.; Kitamura, R.; Kondo, Y.; Kurennoy, S.

2017-07-01

We have developed a Crossbar H-mode (CH) drift-tube linac (DTL) design with an alternative phase focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and electric dipole moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J-PARC). The CH-DTL accelerates muons from β = v/c = 0.08 to 0.28 at an operational frequency of 324 MHz. The design and results are described in this paper.
DCEO Biotechnology: Tools To Design, Construct, Evaluate, and Optimize the Metabolic Pathway for Biosynthesis of Chemicals

DEFF Research Database (Denmark)

Chen, Xiulai; Gao, Cong; Guo, Liang

2018-01-01

, and pathway optimization at the systems level, offers a conceptual and technological framework to exploit potential pathways, modify existing pathways and create new pathways for the optimal production of desired chemicals. Here, we summarize recent progress of DCEO biotechnology and examples of its......Chemical synthesis is a well established route for producing many chemicals on a large scale, but some drawbacks still exist in this process, such as unstable intermediates, multistep reactions, complex process control, etc. Biobased production provides an attractive alternative to these challenges......, but how to make cells into efficient factories is challenging. As a key enabling technology to develop efficient cell factories, design-construction-evaluation-optimization (DCEO) biotechnology, which incorporates the concepts and techniques of pathway design, pathway construction, pathway evaluation...
Direct fabrication of a W-C SNS Josephson junction using focused-ion-beam chemical vapour deposition

International Nuclear Information System (INIS)

Dai, Jun; Kometani, Reo; Ishihara, Sunao; Warisawa, Shin’ichi; Onomitsu, Koji; Krockenberger, Yoshiharu; Yamaguchi, Hiroshi

2014-01-01

A tungsten-carbide (W-C) superconductor/normal metal/superconductor (SNS) Josephson junction has been fabricated using focused-ion-beam chemical vapour deposition (FIB-CVD). Under certain process conditions, the component ratio has been tuned from W: C: Ga = 26%: 66%: 8% in the superconducting wires to W: C: Ga = 14%: 79%: 7% in the metallic junction. The critical current density at 2.5 K in the SNS Josephson junction is 1/3 of that in W-C superconducting nanowire. Also, a Fraunhofer-like oscillation of critical current in the junction with four periods is observed. FIB-CVD opens avenues for novel functional superconducting nanodevices. (paper)
Doing Textiles Experiments in Game-Based Virtual Reality: A Design of the Stereoscopic Chemical Laboratory (SCL) for Textiles Education

Science.gov (United States)

Lau, Kung Wong; Kan, Chi Wai; Lee, Pui Yuen

2017-01-01

Purpose: The purpose of this paper is to discuss the use of stereoscopic virtual technology in textile and fashion studies in particular to the area of chemical experiment. The development of a designed virtual platform, called Stereoscopic Chemical Laboratory (SCL), is introduced. Design/methodology/approach: To implement the suggested…
DESIGN, SYNTHESIS, AND APPLICATION OF THE TRIMETHOPRIM-BASED CHEMICAL TAG FOR LIVE CELL IMAGING

Science.gov (United States)

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
Rationalizing the chemical space of protein-protein interaction inhibitors.

Science.gov (United States)

Sperandio, Olivier; Reynès, Christelle H; Camproux, Anne-Claude; Villoutreix, Bruno O

2010-03-01

Protein-protein interactions (PPIs) are one of the next major classes of therapeutic targets, although they are too intricate to tackle with standard approaches. This is due, in part, to the inadequacy of today's chemical libraries. However, the emergence of a growing number of experimentally validated inhibitors of PPIs (i-PPIs) allows drug designers to use chemoinformatics and machine learning technologies to unravel the nature of the chemical space covered by the reported compounds. Key characteristics of i-PPIs can then be revealed and highlight the importance of specific shapes and/or aromatic bonds, enabling the design of i-PPI-enriched focused libraries and, therefore, of cost-effective screening strategies. 2009 Elsevier Ltd. All rights reserved.
Near miss reporting in the chemical process industry: an overview

NARCIS (Netherlands)

Schaaf, van der T.W.

1995-01-01

The research programme described in this paper focuses on the human component of system failure in general, and more specifically on the design and implementation of information systems for registration and analysis of so called near misses (or: near accidents) in the chemical process industry. Its
Design and fabrication of uniquely shaped thiol-ene microfibers using a two-stage hydrodynamic focusing design.

Science.gov (United States)

Boyd, Darryl A; Shields, Adam R; Howell, Peter B; Ligler, Frances S

2013-08-07

Microfluidic systems have advantages that are just starting to be realized for materials fabrication. In addition to the more common use for fabrication of particles, hydrodynamic focusing has been used to fabricate continuous polymer fibers. We have previously described such a microfluidics system which has the ability to generate fibers with controlled cross-sectional shapes locked in place by in situ photopolymerization. The previous fiber fabrication studies produced relatively simple round or ribbon shapes, demonstrated the use of a variety of polymers, and described the interaction between sheath-core flow-rate ratios used to control the fiber diameter and the impact on possible shapes. These papers documented the fact that no matter what the intended shape, higher flow-rate ratios produced rounder fibers, even in the absence of interfacial tension between the core and sheath fluids. This work describes how to fabricate the next generation of fibers predesigned to have a much more complex geometry, as exemplified by the "double anchor" shape. Critical to production of the pre-specified fibers with complex features was independent control over both the shape and the size of the fabricated microfibers using a two-stage hydrodynamic focusing system. Design and optimization of the channels was performed using finite element simulations and confocal imaging to characterize each of the two stages theoretically and experimentally. The resulting device design was then used to generate thiol-ene fibers with a unique double anchor shape. Finally, proof-of-principle functional experiments demonstrated the ability of the fibers to transport fluids and to interlock laterally.
Design of a rotary reactor for chemical-looping combustion. Part 1: Fundamentals and design methodology

KAUST Repository

Zhao, Zhenlong

2014-04-01

Chemical-looping combustion (CLC) is a novel and promising option for several applications including carbon capture (CC), fuel reforming, H 2 generation, etc. Previous studies demonstrated the feasibility of performing CLC in a novel rotary design with micro-channel structures. In the reactor, a solid wheel rotates between the fuel and air streams at the reactor inlet, and depleted air and product streams at exit. The rotary wheel consists of a large number of micro-channels with oxygen carriers (OC) coated on the inner surface of the channel walls. In the CC application, the OC oxidizes the fuel while the channel is in the fuel zone to generate undiluted CO2, and is regenerated while the channel is in the air zone. In this two-part series, the effect of the reactor design parameters is evaluated and its performance with different OCs is compared. In Part 1, the design objectives and criteria are specified and the key parameters controlling the reactor performance are identified. The fundamental effects of the OC characteristics, the design parameters, and the operating conditions are studied. The design procedures are presented on the basis of the relative importance of each parameter, enabling a systematic methodology of selecting the design parameters and the operating conditions with different OCs. Part 2 presents the application of the methodology to the designs with the three commonly used OCs, i.e., nickel, copper, and iron, and compares the simulated performances of the designs. © 2013 Elsevier Ltd. All rights reserved.
Designing Fresnel microlenses for focusing astigmatic multi-Gaussian beams by using fractional order Fourier transforms

International Nuclear Information System (INIS)

Patino, A; Durand, P-E; Fogret, E; Pellat-Finet, P

2011-01-01

According to a scalar theory of diffraction, light propagation can be expressed by two-dimensional fractional order Fourier transforms. Since the fractional Fourier transform of a chirp function is a Dirac distribution, focusing a light beam is optically achieved by using a diffractive screen whose transmission function is a two-dimensional chirp function. This property is applied to designing Fresnel microlenses, and the orders of the involved Fourier fractional transforms depend on diffraction distances as well as on emitter and receiver radii of curvature. If the emitter is astigmatic (with two principal radii of curvature), the diffraction phenomenon involves two one-dimensional fractional Fourier transforms whose orders are different. This degree of freedom allows us to design microlenses that can focus astigmatic Gaussian beams, as produced by a line-shaped laser diode source.
An infrared free-electron laser for the Chemical Dynamics Research Laboratory. Design report

Energy Technology Data Exchange (ETDEWEB)

Vaughan, D. [comp.

1992-04-01

This document describes a free-electron laser (FEL) proposed as part of the Chemical Dynamics Research Laboratory (CDRL), a user facility that also incorporates several advanced lasers of conventional design and two beamlines for the ALS. The FEL itself addresses the needs of the chemical sciences community for a high-brightness, tunable source covering a broad region of the infrared spectrum -- from 3 to 50 {mu}m. All of these sources, together with a variety of sophisticated experimental stations, will be housed in a new building to be located adjacent to the ALS. The radiation sources can be synchronized to permit powerful two-color, pump-probe experiments that will further our fundamental understanding of chemical dynamics at the molecular level, especially those aspects relevant to practical issues in combustion chemistry. The technical approach adopted in this design makes use of superconducting radiofrequency (SCRF) accelerating structures. The primary motivation for adopting this approach was to meet the user requirement for wavelength stability equal to one part in 10{sup 4}. Previous studies concluded that a wavelength stability of only one part in 10{sup 3} could be achieved with currently available room-temperature technology. In addition, the superconducting design operates in a continuous-wave (cw) mode and hence offers considerably higher average optical output power. It also allows for various pulse-gating configurations that will permit simultaneous multiuser operations. A summary of the comparative performance attainable with room-temperature and superconducting designs is given. The FEL described in this report provides a continuous train of 30-ps micropulses, with 100{mu}J of optical energy per micropulse, at a repetition rate of 6.1 MHz. The device can also deliver pulses at a cw repetition rate of 12.2 MHz, with a peak power of 50 {mu}J per micropulse. 70 ref.

OSHA and Experimental Safety Design.

Science.gov (United States)

Sichak, Stephen, Jr.

1983-01-01

Suggests that a governmental agency, most likely Occupational Safety and Health Administration (OSHA) be considered in the safety design stage of any experiment. Focusing on OSHA's role, discusses such topics as occupational health hazards of toxic chemicals in laboratories, occupational exposure to benzene, and role/regulations of other agencies.…
Chemical control and design considerations for CANDU-PHW steam generators

International Nuclear Information System (INIS)

Frost, C.R.; Churchill, B.R.

1978-01-01

Ontario Hydro presently operates eight nuclear power units with a total capacitiy of about 4000 MW(e) net. Operating experience has been with Monel-400 and with Inconel-600 tubed steam generators using sodium phosphate or all volatile control of the boiler steam and water system. With a heavy water Heat Transport System, steam generator tube integrity is an essential ingredient of economical power production. Only three steam generator tube failures have occurred so far in about 40 unit-years operation. None was attributable to corrosion. Factors in the good reliability are, careful engineering design, good quality control at all stages of tubing and steam generator manufacture and close chemical control. The continuing evolution of our steam generator design means that future requirements will be more stringent. (author)
Industrial Scale Synthesis of Carbon Nanotubes Via Fluidized Bed Chemical Vapor Deposition: A Senior Design Project

Science.gov (United States)

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…
Designing multifunctional chemical sensors using Ni and Cu doped carbon nanotubes

DEFF Research Database (Denmark)

Mowbray, Duncan; García Lastra, Juan Maria; Thygesen, Kristian Sommer

2010-01-01

We demonstrate a “bottom up” approach to the computational design of a multifunctional chemical sensor. General techniques are employed for describing the adsorption coverage and resistance properties of the sensor based on density functional theory and non-equilibrium Green's function...... methodologies, respectively. Specifically, we show how Ni and Cu doped metallic (6,6) single-walled carbon nanotubes may work as effective multifunctional sensors for both CO and NH3....
An integrated computer aided system for integrated design of chemical processes

DEFF Research Database (Denmark)

Gani, Rafiqul; Hytoft, Glen; Jaksland, Cecilia

1997-01-01

In this paper, an Integrated Computer Aided System (ICAS), which is particularly suitable for solving problems related to integrated design of chemical processes; is presented. ICAS features include a model generator (generation of problem specific models including model simplification and model ...... form the basis for the toolboxes. The available features of ICAS are highlighted through a case study involving the separation of binary azeotropic mixtures. (C) 1997 Elsevier Science Ltd....
Design of a nanopatterned long focal-length planar focusing collector for concentrated solar power

Science.gov (United States)

Ding, Qing; Choubal, Aakash; Toussaint, Kimani C.

2017-02-01

Concentrated solar power (CSP) facilities heavily utilize parabolic troughs to collect and concentrate sunlight onto receivers that deliver solar thermal energy to heat engines for generating electricity. However, parabolic troughs are bulky and heavy and result in a large capital investment for CSP plants, thereby making it difficult for CSP technology to be competitive with photovoltaics. We present the design of a planar focusing collector (PFC) with focal length beyond the micron scale. The PFC design is based on the use of a nanostructured silver surface for linearly polarized singlewavelength light. The designed PFC consists of metallic nanogrooves on a dielectric substrate. The geometric properties, namely the width and depth, of a single-unit nanogroove allows for full control of the optical phase at desired spatial coordinates along the nanogroove short-axis for a single wavelength. Moreover, we show numerically that such phase control can be used to construct a phase front that mimics that of a cylindrical lens. In addition, we determine the concentration ratio by comparing the width of our PFC design to the cross-sectional width of its focal spot. We also determine the conversion efficiency at long focal lengths by evaluating the ratio of the collected optical power to the incoming optical power. Finally, we examine the focusing behavior across multiple wavelengths and angles of incidence. Our work shows how nano-optics and plasmonics could contribute to this important area of CSP technology.
Design and Activation of a LOX/GH Chemical Steam Generator

Science.gov (United States)

Saunders, G. P.; Mulkey, C. A.; Taylor, S. A.

2009-01-01

The purpose of this paper is to give a detailed description of the design and activation of the LOX/GH fueled chemical steam generator installed in Cell 2 of the E3 test facility at Stennis Space Center, MS (SSC). The steam generator uses a liquid oxygen oxidizer with gaseous hydrogen fuel. The combustion products are then quenched with water to create steam at pressures from 150 to 450 psig at temperatures from 350 to 750 deg F (from saturation to piping temperature limits).
Low emittance design of the electron gun and the focusing channel of the Compact Linear Collider drive beam

Directory of Open Access Journals (Sweden)

M. Dayyani Kelisani

2017-04-01

Full Text Available For the Compact Linear Collider project at CERN, the power for the main linacs is extracted from a drive beam generated from a high current electron source. The design of the electron source and its subsequent focusing channel has a great impact on the beam dynamic considerations of the drive beam. We report the design of a thermionic electron source and the subsequent focusing channels with the goal of production of a high quality beam with a very small emittance.
The Signal Detection and Control Circuit Design for Confocal Auto-Focus System

OpenAIRE

Yin Liu; Jin Yu; Zeqiang Mo

2016-01-01

Based on the demands of Confocal Auto-Focus system, the implementation method of signal measurement circuit and control circuit is given. Using the high performance instrumental amplifier AD620BN, low noise precision FET Op amplifier AD795JRZ and ultralow offset voltage Op amplifier OP07EP, a signal measurement circuit used to converse the two differential light intensity signal to electric signal is designed. And a control circuit which takes MCU MSP430F149 as core processes the former signa...
Engineering of multi-segmented light tunnel and flattop focus with designed axial lengths and gaps

Science.gov (United States)

Yu, Yanzhong; Huang, Han; Zhou, Mianmian; Zhan, Qiwen

2018-01-01

Based on the radiation pattern from a sectional-uniform line source antenna, a three-dimensional (3D) focus engineering technique for the creation of multi-segmented light tunnel and flattop focus with designed axial lengths and gaps is proposed. Under a 4Pi focusing system, the fields radiated from sectional-uniform magnetic and electromagnetic current line source antennas are employed to generate multi-segmented optical tube and flattop focus, respectively. Numerical results demonstrate that the produced light tube and flattop focus remain homogeneous along the optical axis; and their lengths of the nth segment and the nth gap between consecutive segments can be easily adjusted and only depend on the sizes of the nth section and the nth blanking between adjacent sectional antennas. The optical tube is a pure azimuthally polarized field but for the flattop focus the longitudinal polarization is dominant on the optical axis. To obtain the required pupil plane illumination for constructing the above focal field with prescribed characteristics, the inverse problem of the antenna radiation field is solved. These peculiar focusing fields might find potential applications in multi-particle acceleration, multi-particle trapping and manipulation.
Learning by Brewing: Beer Production Experiments in the Chemical Engineering Laboratory

Science.gov (United States)

Cerretani, Colin; Kelkile, Esayas; Landry, Alexandra

2017-01-01

We discuss the successful creation and implementation of a biotechnology track within the chemical engineering unit operations course. The track focuses on engineering principles relevant to brewing. Following laboratory modules investigating heat transfer processes and yeast fermentation kinetics, student groups design and implement a project to…
Enhanced Etching, Surface Damage Recovery, and Submicron Patterning of Hybrid Perovskites using a Chemically Gas-Assisted Focused-Ion Beam for Subwavelength Grating Photonic Applications

KAUST Repository

Alias, Mohd Sharizal; Yang, Yang; Ng, Tien Khee; Dursun, Ibrahim; Shi, Dong; Saidaminov, Makhsud I.; Priante, Davide; Bakr, Osman; Ooi, Boon S.

2015-01-01

is challenging, particularly for patterning. Here, we report the direct patterning of perovskites using chemically gas-assisted focused-ion beam (GAFIB) etching with XeF2 and I2 precursors. We demonstrate etching enhancement in addition to controllability
National Ignition Facility design focuses on optics

International Nuclear Information System (INIS)

Hogan, W.J.; Atherton, L.J.; Paisner, J.A.

1996-01-01

Sometime in the year 2002, scientists at the National Ignition Facility (NIF) will focus 192 separate high-power ultraviolet laser beams onto a tiny capsule of deuterium and tritium, heating and compressing the material until it ignites and burns with a burst of fusion energy. The mission of NIF, which will contain the largest laser in the world, is to obtain fusion ignition and gain and to use inertial confinement fusion capabilities in nuclear weapons science experiments. The physics data provided by NIF experiments will help scientists ensure nuclear weapons reliability without the need for actual weapons tests; basic sciences such as astrophysics will also benefit. The facility faces stringent weapons-physics user requirements demanding peak pulse powers greater than 750 TW at 0.35 microm (only 500 TW is required for target ignition), pulse durations of 0.1 to 20 ns, beam steering on the order of several degrees, and target isolation from residual 1- and 0.5-microm radiation. Additional requirements include 50% fractional encircled beam energy in a 100-microm-diameter spot, with 95% encircled in a 200-microm spot. The weapons-effects community requires 1- and 0.5-microm light on target, beam steering to widely spaced targets, a target chamber accommodating oversized objects, well-shielded diagnostic areas, and elimination of stray light in the target chamber. The beamline design, amplifier configuration and requirements for optics are discussed here
Design, manufacturing and commissioning of mobile unit for EDF (Dow Chemical process)

International Nuclear Information System (INIS)

Cangini, D.; Cordier, J.P.; PEC Engineering, Osny, France)

1985-01-01

To process their spent ion exchange resins and the liquid wastes, EDF has ordered from PEC a mobile unit using the DOW CHEMICAL binder. This paper presents the EDF's design requirements as well as the new French regulation for waste embedding. The mobile unit was started in January 1983 and commissioned successfully in January 1985 in the TRICASTIN EDF's power plant
Predicted accommodative response from image quality in young eyes fitted with different dual-focus designs.

Science.gov (United States)

Faria-Ribeiro, Miguel; Amorim-de-Sousa, Ana; González-Méijome, José M

2018-05-01

To investigate the separated and combined influences of inner zone (IZ) diameter and effective add power of dual-focus contact lenses (CL) in the image quality at distance and near viewing, in a functional accommodating model eye. Computational wave-optics methods were used to define zonal bifocal pupil functions, representing the optic zones of nine dual-focus centre-distance CLs. The dual-focus pupil functions were defined having IZ diameters of 2.10 mm, 3.36 mm and 4.00 mm, with add powers of 1.5 D, 2.0 D and 2.5 D (dioptres), for each design, that resulted in a ratio of 64%/36% between the distance and treatment zone areas, bounded by a 6 mm entrance pupil. A through-focus routine was implemented in MATLAB to simulate the changes in image quality, calculated from the Visual Strehl ratio, as the eye with the dual-focus accommodates, from 0 to -3.00 D target vergences. Accommodative responses were defined as the changes in the defocus coefficient, combined with a change in fourth and sixth order spherical aberration, which produced a peak in image quality at each target vergence. Distance viewing image quality was marginally affected by IZ diameter but not by add power. Near image quality obtained when focussing the image formed by the near optics was only higher by a small amount compared to the other two IZ diameters. The mean ± standard deviation values obtained with the three adds were 0.28 ± 0.02, 0.23 ± 0.02 and 0.22 ± 0.02, for the small, medium and larger IZ diameters, respectively. On the other hand, near image quality predicted by focussing the image formed by the distance optics was considerably lower relatively to the other two IZ diameters. The mean ± standard deviation values obtained with the three adds were 0.15 ± 0.01, 0.38 ± 0.00 and 0.54 ± 0.01, for the small, medium and larger IZ diameters, respectively. During near viewing through dual-focus CLs, image quality depends on the diameter of the most inner zone of the CL, while add power
Chemical engineering design of CO oxidation catalysts

Science.gov (United States)

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.
Rotary Bed Reactor for Chemical-Looping Combustion with Carbon Capture. Part 1: Reactor Design and Model Development

KAUST Repository

Zhao, Zhenlong; Chen, Tianjiao; Ghoniem, Ahmed F.

2013-01-01

Chemical-looping combustion (CLC) is a novel and promising technology for power generation with inherent CO2 capture. Currently, almost all of the research has been focused on developing CLC-based interconnected fluidized-bed reactors. In this two
Ti film deposition process of a plasma focus: Study by an experimental design

Directory of Open Access Journals (Sweden)

M. J. Inestrosa-Izurieta

2017-10-01

Full Text Available The plasma generated by plasma focus (PF devices have substantially different physical characteristics from another plasma, energetic ions and electrons, compared with conventional plasma devices used for plasma nanofabrication, offering new and unique opportunities in the processing and synthesis of Nanomaterials. This article presents the use of a plasma focus of tens of joules, PF-50J, for the deposition of materials sprayed from the anode by the plasma dynamics in the axial direction. This work focuses on the determination of the most significant effects of the technological parameters of the system on the obtained depositions through the use of a statistical experimental design. The results allow us to give a qualitative understanding of the Ti film deposition process in our PF device depending on four different events provoked by the plasma dynamics: i an electric erosion of the outer material of the anode; ii substrate ablation generating an interlayer; iii electron beam deposition of material from the center of the anode; iv heat load provoking clustering or even melting of the deposition surface.
Design features in Korean next generation reactor focused on performance and economic viability

International Nuclear Information System (INIS)

Lee, J.S.; Chung, M.S.; Na, J.H.; Kim, M.C.; Choi, Y.S.

2001-01-01

As of the end of Dec. 1999, Korea's total nuclear power capacity reached 13,716 MWe with 16 units in operation and 4 units under construction. In addition, as part of the national long-term R and D programme launched in 1992, the Korean Next Generation Reactor (KNGR) is being developed to meet the electricity demands in the years to come and is expected to be safer and more economically competitive than any other conventional electric power sources in Korea. The KNGR project has successfully completed its second phase and is now on the third phase. In Phase III of the KNGR design development project, KNGR aims at reinforcing the economic competitiveness while maintaining safety goals. To achieve these objectives, the design options studied and the design requirements set up in the first phase are pursued while the second phase are being reviewed. This paper summarizes such efforts for design improvement in terms of performance and economic viability along with the status of nuclear power generation in Korea, focusing on KNGR currently. (author)
Chemical laser exhaust pipe design research

Science.gov (United States)

Sun, Yunqiang; Huang, Zhilong; Chen, Zhiqiang; Ren, Zebin; Guo, Longde

2016-10-01

In order to weaken the chemical laser exhaust gas influence of the optical transmission, a vent pipe is advised to emissions gas to the outside of the optical transmission area. Based on a variety of exhaust pipe design, a flow field characteristic of the pipe is carried out by numerical simulation and analysis in detail. The research results show that for uniform deflating exhaust pipe, although the pipeline structure is cyclical and convenient for engineering implementation, but there is a phenomenon of air reflows at the pipeline entrance slit which can be deduced from the numerical simulation results. So, this type of pipeline structure does not guarantee seal. For the design scheme of putting the pipeline contract part at the end of the exhaust pipe, or using the method of local area or tail contraction, numerical simulation results show that backflow phenomenon still exists at the pipeline entrance slit. Preliminary analysis indicates that the contraction of pipe would result in higher static pressure near the wall for the low speed flow field, so as to produce counter pressure gradient at the entrance slit. In order to eliminate backflow phenomenon at the pipe entrance slit, concerned with the pipeline type of radial size increase gradually along the flow, flow field property in the pipe is analyzed in detail by numerical simulation methods. Numerical simulation results indicate that there is not reflow phenomenon at entrance slit of the dilated duct. However the cold air inhaled in the slit which makes the temperature of the channel wall is lower than the center temperature. Therefore, this kind of pipeline structure can not only prevent the leak of the gas, but also reduce the wall temperature. In addition, compared with the straight pipe connection way, dilated pipe structure also has periodic structure, which can facilitate system integration installation.

A Combined Heuristic and Indicator-based Methodology for Design of Sustainable Chemical Process Plants

DEFF Research Database (Denmark)

Halim, Iskandar; Carvalho, Ana; Srinivasan, Rajagopalan

2011-01-01

The current emphasis on sustainable production has prompted chemical plants to minimize raw material and energy usage without compromising on economics. While computer tools are available to assistin sustainability assessment, their applications are constrained to a specific domain of the design...
Focusing behavior of the fractal vector optical fields designed by fractal lattice growth model.

Science.gov (United States)

Gao, Xu-Zhen; Pan, Yue; Zhao, Meng-Dan; Zhang, Guan-Lin; Zhang, Yu; Tu, Chenghou; Li, Yongnan; Wang, Hui-Tian

2018-01-22

We introduce a general fractal lattice growth model, significantly expanding the application scope of the fractal in the realm of optics. This model can be applied to construct various kinds of fractal "lattices" and then to achieve the design of a great diversity of fractal vector optical fields (F-VOFs) combinating with various "bases". We also experimentally generate the F-VOFs and explore their universal focusing behaviors. Multiple focal spots can be flexibly enginnered, and the optical tweezers experiment validates the simulated tight focusing fields, which means that this model allows the diversity of the focal patterns to flexibly trap and manipulate micrometer-sized particles. Furthermore, the recovery performance of the F-VOFs is also studied when the input fields and spatial frequency spectrum are obstructed, and the results confirm the robustness of the F-VOFs in both focusing and imaging processes, which is very useful in information transmission.
Board on chemical sciences and technology

International Nuclear Information System (INIS)

1991-01-01

The Board on Chemical Sciences and Technology organizes and provides direction for standing and ad-hoc committees charged with addressing specific issues relevant to the continued health of the chemical sciences and technology community. Studies currently under the oversight of the BCST include a major survey of the chemical sciences, a complementary survey of chemical engineering, an examination of the problems of biohazards in the laboratory, and an analysis of the roots and magnitude of the problem of obsolescent facilities for research and teaching in departments in the chemical sciences and engineering. The Board continues to respond to specific agency requests for program assessments and advice. BCST members are designated to serve as liaison with major federal agencies or departments that support research in order to help identify ways for the Board to assist these organizations. The BCST maintains close contact with professional societies and non-governmental organizations that share the Board's concern for the health of chemical sciences and technology. Individual Board members are assigned responsibility for liaison with the American Chemical Society, the American Institute of Chemical Engineers, the American Society of Biological Chemists, the Council for Chemical Research, the NAS Chemistry and Biochemistry Sections, and the National Academy of Engineering. In the past few years, the Board has served as a focus and a forum for a variety of issues that relate specifically to the health of chemistry
Conceptual design of bend, compression, and final focus components of ILSE [Induction Linac System Experiment

International Nuclear Information System (INIS)

Lee, E.P.; Fong, C.; Mukherjee, S.; Thur, W.

1989-03-01

The Induction Linac System Experiment (ILSE) includes a 180/degree/ bend system, drift compression line and a final focus, which test the analogous features of a heavy ion driver for inertial fusion. These components are novel in their transport of a space-charge-dominated ion beam with large head-to-tail velocity tilt. Their conceptual design is presented, including calculations of the beam envelope, momentum dispersion, and engineering design of magnets, vacuum system, diagnostics, alignment, and support. 3 refs., 5 figs
Design Course for Micropower Generation Devices

Science.gov (United States)

Mitsos, Alexander

2009-01-01

A project-based design course is developed for man-portable power generation via microfabricated fuel cell systems. Targeted audience are undergraduate chemical/process engineering students in their final year. The course covers 6 weeks, with three hours of lectures per week. Two alternative projects are developed, one focusing on selection of…
Design and fabrication of soft x-ray mirrors

Energy Technology Data Exchange (ETDEWEB)

Kawata, Masaru; Sasai, Hiroyuki; Sano, Kazuo [Shimadzu Corp., Production Engineering Laboratory, Kyoto (Japan)

2000-03-01

Soft x-ray photoelectron spectroscopic technology is important for measuring the chemical status of material surface in the LSI manufacturing process. We report on non-spherical mirrors focusing laser-induced plasma soft x-ray to fine sample surface. We designed toric and ellipsoidal mirror as soft x-ray condensing means, simulated focusing image, manufactured mirror surface on fused quartz substrate, and measured form accuracy. (author)
Robotics Focused Capstone Senior Design Course

Science.gov (United States)

Rios-Gutierrez, Fernando; Alba-Flores, Rocio

2017-01-01

This work describes the educational experiences gained teaching the Senior Design I & II courses, a senior level, two-semester sequence in the Electrical Engineering (EE) program at Georgia Southern University (GSU). In particular, the authors present their experiences in using robotics as the main area to develop the capstone senior design,…
Chemical alternatives assessment: the case of flame retardants.

Science.gov (United States)

Howard, Gregory J

2014-12-01

Decisions on chemical substitution are made rapidly and by many stakeholders; these decisions may have a direct impact on consumer exposures, and, when a hazard exists, to consumer risks. Flame retardants (FRs) represent particular challenges, including very high production volumes, designed-in persistence, and often direct consumer exposure. Newer FR products, as with other industrial chemicals, typically lack data on hazard and exposure, and in many cases even basic information on structure and use in products is unknown. Chemical alternatives assessment (CAA) provides a hazard-focused approach to distinguishing between possible substitutions; variations on this process are used by several government and numerous corporate entities. By grouping chemicals according to functional use, some information on exposure potential can be inferred, allowing for decisions based on those hazard properties that are most distinguishing. This approach can help prevent the "regrettable substitution" of one chemical with another of equal, or even higher, risk. Copyright © 2014 Elsevier Ltd. All rights reserved.
Coupled sensor/platform control design for low-level chemical detection with position-adaptive micro-UAVs

Science.gov (United States)

Goodwin, Thomas; Carr, Ryan; Mitra, Atindra K.; Selmic, Rastko R.

2009-05-01

We discuss the development of Position-Adaptive Sensors [1] for purposes for detecting embedded chemical substances in challenging environments. This concept is a generalization of patented Position-Adaptive Radar Concepts developed at AFRL for challenging conditions such as urban environments. For purposes of investigating the detection of chemical substances using multiple MAV (Micro-UAV) platforms, we have designed and implemented an experimental testbed with sample structures such as wooden carts that contain controlled leakage points. Under this general concept, some of the members of a MAV swarm can serve as external position-adaptive "transmitters" by blowing air over the cart and some of the members of a MAV swarm can serve as external position-adaptive "receivers" that are equipped with chemical or biological (chem/bio) sensors that function as "electronic noses". The objective can be defined as improving the particle count of chem/bio concentrations that impinge on a MAV-based position-adaptive sensor that surrounds a chemical repository, such as a cart, via the development of intelligent position-adaptive control algorithms. The overall effect is to improve the detection and false-alarm statistics of the overall system. Within the major sections of this paper, we discuss a number of different aspects of developing our initial MAV-Based Sensor Testbed. This testbed includes blowers to simulate position-adaptive excitations and a MAV from Draganfly Innovations Inc. with stable design modifications to accommodate our chem/bio sensor boom design. We include details with respect to several critical phases of the development effort including development of the wireless sensor network and experimental apparatus, development of the stable sensor boom for the MAV, integration of chem/bio sensors and sensor node onto the MAV and boom, development of position-adaptive control algorithms and initial tests at IDCAST (Institute for the Development and
NuFact muon storage ring: study of a triangle design based on solenoid focusing decay straights

Energy Technology Data Exchange (ETDEWEB)

Meot, F. [Service Accelerateurs, Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier / CNRS-IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France)]|[Commissariat a l' Energie Atomique, CEA, 31-33, rue de la Federation (Paris 15e), BP 510, 75752 Paris Cedex 15 (France); Reesy, G. [Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot OX11 0QX (United Kingdom)

2006-06-15

Properties of acceptance and beam transmission in a triangle design of the neutrino factory muon decay ring, with decay straights based on solenoidal focusing, are reported.The muon storage ring in the neutrino factory, NuFact, is located at the high energy end of the muon acceleration chain. It delivers the {mu}{sup +}/{mu}{sup -} decay neutrinos to physics detectors. The design of concern here, is a triangle geometry 20 GeV storage ring, upgradable to 50 GeV, (the parameters are given), which features two decay straight sections, each one aiming at a distant detector. The third straight section of the ring is devoted to tuning, collimation and RF. A particularity of the proposed design, is in its being based on solenoid focusing decay straights, which has the virtue of minimizing the betatron amplitudes, compared to equivalent quadrupole focusing. The solenoidal focusing ensures the requested ratio, for the r.m.s. divergences of the 20 GeV muon and the neutrino beam, of 0.1 for an assumed muon normalized r.m.s. emittance of 4800 {pi} mm mr (3 {pi} cm, total). The goal of the present work is to show the viability of this design, in particular as concerns the impact of the solenoid focusing on machine behavior. It addresses the questions of residual coupling, machine acceptance, and concludes with a computation of beam transmission over 1000 turns. The paper has the following structure: 1. Introduction; 2. Working hypothesis; 3. Building-up ray-tracing data; 3.1. Arcs; 3.2. Solenoid straight; 3.3. Tuning/Collimation/RF straight; 3.4. Full ring; 3.4.1. Beam envelopes; 3.4.2. Closed orbits; 3.4.3. Momentum dispersion; 3.5 Large amplitude tracking, preliminary tests; 4. Tracking, linear machine; 4.1. Large amplitude tracking; 4.1.1. 2-D horizontal initial conditions; 4.1.2. 2-D vertical initial conditions; 4.1.3. 4-D + {delta}p/p initial conditions; 4.2. Transmission, 4-D + {delta}p/p, no sextupoles; 4.2.1. {epsilon}{sub x} {epsilon}{sub z} = 3 {pi} cm (norm.), {delta
NuFact muon storage ring: study of a triangle design based on solenoid focusing decay straights

International Nuclear Information System (INIS)

Meot, F.; Reesy, G.

2006-06-01

Properties of acceptance and beam transmission in a triangle design of the neutrino factory muon decay ring, with decay straights based on solenoidal focusing, are reported.The muon storage ring in the neutrino factory, NuFact, is located at the high energy end of the muon acceleration chain. It delivers the μ + /μ - decay neutrinos to physics detectors. The design of concern here, is a triangle geometry 20 GeV storage ring, upgradable to 50 GeV, (the parameters are given), which features two decay straight sections, each one aiming at a distant detector. The third straight section of the ring is devoted to tuning, collimation and RF. A particularity of the proposed design, is in its being based on solenoid focusing decay straights, which has the virtue of minimizing the betatron amplitudes, compared to equivalent quadrupole focusing. The solenoidal focusing ensures the requested ratio, for the r.m.s. divergences of the 20 GeV muon and the neutrino beam, of 0.1 for an assumed muon normalized r.m.s. emittance of 4800 π mm mr (3 π cm, total). The goal of the present work is to show the viability of this design, in particular as concerns the impact of the solenoid focusing on machine behavior. It addresses the questions of residual coupling, machine acceptance, and concludes with a computation of beam transmission over 1000 turns. The paper has the following structure: 1. Introduction; 2. Working hypothesis; 3. Building-up ray-tracing data; 3.1. Arcs; 3.2. Solenoid straight; 3.3. Tuning/Collimation/RF straight; 3.4. Full ring; 3.4.1. Beam envelopes; 3.4.2. Closed orbits; 3.4.3. Momentum dispersion; 3.5 Large amplitude tracking, preliminary tests; 4. Tracking, linear machine; 4.1. Large amplitude tracking; 4.1.1. 2-D horizontal initial conditions; 4.1.2. 2-D vertical initial conditions; 4.1.3. 4-D + δp/p initial conditions; 4.2. Transmission, 4-D + δp/p, no sextupoles; 4.2.1. ε x ε z = 3 π cm (norm.), δp/p = ±1%; 4.2.2. ε x ε z = 6 π cm (norm.), δp/p ±4
Model Reduction in Chemical Engineering : Case studies applied to process analysis, design and operation

NARCIS (Netherlands)

Dorneanu, B.

2011-01-01

During the last decades, models have become widely used for supporting a broad range of chemical engineering activities, such as product and process design and development, process monitoring and control, real time optimization of plant operation or supply chain management. Although tremendous
Designing continuous safety improvement within chemical industrial areas

NARCIS (Netherlands)

Reniers, G.L.L.; Ale, B. J.M.; Dullaert, W.; Soudan, K.

This article provides support in organizing and implementing novel concepts for enhancing safety on a cluster level of chemical plants. The paper elaborates the requirements for integrating Safety Management Systems of chemical plants situated within a so-called chemical cluster. Recommendations of
Toward crustacean without chemicals: a descriptive analysis of consumer response using price comparisons

Directory of Open Access Journals (Sweden)

Charles Odilichukwu R. Okpala

2016-10-01

Full Text Available Background: To date, there seems to be limited-to-zero emphasis about how consumers perceive crustacean products subject to either chemical and or non-chemical preservative treatments. In addition, studies that investigated price comparisons of crustacean products subject to either chemical or chemical-free preservative methods seem unreported. Objective: This study focused on providing some foundational knowledge about how consumers perceive traditionally harvested crustaceans that are either chemical-treated and or free of chemicals, incorporating price comparisons using a descriptive approach. Design: The study design employed a questionnaire approach via interview using a computer-assisted telephone system and sampled 1,540 participants across five key locations in Italy. To actualize consumer sensitivity, ‘price’ was the focus given its crucial role as a consumption barrier. Prior to this, variables such as demographic characteristics of participants, frequency of purchasing, quality attributes/factors that limit the consumption of crustaceans were equally considered. Results: By price comparisons, consumers are likely to favor chemical-free (modified atmosphere packaging crustacean products amid a price increase of up to 15%. But, a further price increase such as by 25% could markedly damage consumers’ feelings, which might lead to a considerable number opting out in favor of either chemical-treated or other seafood products. Comparing locations, the studied variables showed no statistical differences (p>0.05. On the contrary, the response weightings fluctuated across the studied categories. Both response weightings and coefficient of variation helped reveal more about how responses deviated per variable categories. Conclusions: This study has revealed some foundational knowledge about how consumers perceive traditionally harvested crustaceans that were either chemical-treated or subject to chemical-free preservative up to price
Sub-micrometer-scale patterning on Zr-based metallic glass using focused ion beam irradiation and chemical etching

Energy Technology Data Exchange (ETDEWEB)

Kawasegi, Noritaka [Graduate School of Science and Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); Morita, Noboru [Graduate School of Science and Engineering for Research, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); Yamada, Shigeru [Graduate School of Science and Engineering for Research, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); Takano, Noboru [Graduate School of Science and Engineering for Research, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); Oyama, Tatsuo [Department of Mechanical and Intellectual Systems Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan); Ashida, Kiwamu [Advanced Manufacturing Research Institute, National Institute of Advanced Industrial Science and Technology, 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564 (Japan); Momota, Sadao [Department of Intelligent Mechanical Systems Engineering, Kochi University of Technology, 185 Tosayamada, Kochi 782-8502 (Japan); Taniguchi, Jun [Department of Applied Electronics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Miyamoto, Iwao [Department of Applied Electronics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan); Ofune, Hitoshi [YKK Corporation, 200 Yoshida, Kurobe, Toyama 938-8601 (Japan)

2007-09-19

This report describes a method of sub-micrometer-scale rapid patterning on a Zr-based metallic glass surface using a combination of focused ion beam irradiation and wet chemical etching. We found that a Zr-based metallic glass surface irradiated with Ga{sup +} ions could be selectively etched; a concave structure with a width and depth of several tens to hundreds of nanometers rapidly formed in the irradiated area. Moreover, we determined that the etching was enhanced by the presence of Ga{sup +} ions rather than a change in the crystal structure, and the structure could be fabricated while the substrate remained amorphous. The shape of the structure was principally a function of the dose and the etch time.
A multimedia exposure assessment methodology for evaluating the performance of the design of structures containing chemical and radioactive wastes

International Nuclear Information System (INIS)

Stephanatos, B.N.; Molholt, B.; Walter, K.P.; MacGregor, A.

1991-01-01

The objectives of this work are to develop a multimedia exposure assessment methodology for the evaluation of existing and future design of structures containing chemical and radioactive wastes and to identify critical parameters for design optimization. The designs are evaluated in terms of their compliance with various federal and state regulatory requirements. Evaluation of the performance of a particular design is presented within the scope of a given exposure pathway. An exposure pathway has four key components: (1) a source and mechanism of chemical release, (2) a transport medium; (3) a point of exposure; and (4) a route of exposure. The first step in the analysis is the characterization of the waste source behavior. The rate and concentration of releases from the source are evaluated using appropriate mathematical models. The migration of radionuclides and chemicals is simulated through each environmental medium to the exposure point. The total exposure to the potential receptor is calculated, and an estimate of the health effects of the exposure is made. Simulation of the movement of radionuclides and chemical wastes from the source to the receptor point includes several processes. If the predicted human exposure to contaminants meets the performance criteria, the design has been validated. Otherwise the structure design is improved to meet the performance criteria. A phased modeling approach is recommended at a particular mixed waste site. A relatively simple model is initially used to pinpoint critical fate and transport processes and design parameters. The second phase of the modeling effort involves the use of more complex and resource intensive fate and transport models. This final step in the modeling process provides more accurate estimates of contaminant concentrations at the point of exposure. Thus the human dose is more accurately predicted, providing better design validation
Study on optimum aseismic design of complex structure system focusing on damping effect

International Nuclear Information System (INIS)

Takahashi, Yoshitaka; Suzuki, Kohei

1995-01-01

Optimum design technique for the purpose of aseismic design of complex plant structures such as piping and boiler structures is proposed. Particular attention is focused on the evaluation of the optimum damping and stiffness of the structures and components. Pseudo least square algorithm is introduced to determine the optimum design parameters. Under the requirement of certain allowable maximum response to a given earthquake excitation, optimum stiffness and damping values of the structure can be simultaneously calculated by this proposed method. The applicability of the method is demonstrated through three structural models; (1) linear multi-storied building model in which stiffness and damping constant of each floor are optimized; (2) nonlinear multi-storied building model having the isolated floor in which hysteretic energy absorber of the isolator is optimized; (3) combined boiler-supporting structure model connected by the inelastic seismic ties with each other is optimized. In this model, optimum values of damping characteristic of the seismic ties are evaluated. This work is particularly important for the aseismic design of complex plant structures like integrated boiler-supporting structure in thermal power plant and piping-containment vessel structure in nuclear power plant
Procafd: Computer Aided Tool for Synthesis-Design & Analysis of Chemical Process Flowsheets

DEFF Research Database (Denmark)

Kumar Tula, Anjan; Eden, Mario R.; Gani, Rafiqul

2015-01-01

and emission to the surrounding and many more. In terms of approaches to solve the synthesis-design problem three major lines of attack have emerged: (a) the knowledge based approach [1] which relies on engineering knowledge & problem insights, (b) the optimization approach [2] which relies on the use...... of mathematical programming techniques, (c) hybrid approach which combine two or more approaches. D’Anterroches [3] proposed a group contribution based hybrid approach to solve the synthesis-design problem where, chemical process flowsheets could be synthesized in the same way as atoms or groups of atoms...... parameters for the operations of the high ranked flowsheets are established through reverse engineering approaches based on driving forces available for each operation. In the final stage, rigorous simulation is performed to validate the synthesis-design. Note that since the flowsheet is synthesized...
Improved focus solenoid design for linear induction accelerators

International Nuclear Information System (INIS)

Zentler, J.M.; Van Maren, R.D.; Nexsen, W.E.

1992-08-01

Our FXR linear induction accelerator produces a 2 KA, 17 MeV electron beam of 60 ns duration. The beam is focused on a tantalum target to produce x-rays for radiography. The FWHM spot size of the focused beam is currently 2.2 mm. We strive to reduce the spot size by 30% by improving the field characteristics of focusing solenoids housed in each of 50 induction cells along the beamline. Tilts in the magnetic axis of the existing solenoids range up to 12 mrad (0.7 degrees). We are building new solenoid assemblies which include ferromagnetic homogenizer rings. These dramatically reduce field errors. A field tilt of under 0.5 mrad has been achieved. Mechanical alignment of the rings is critical. We developed a novel construction method in which the rings are wound with 4 mil thick Si-Fe ribbon into grooves on an aluminum cylinder. The cylinder then becomes the winding mandrel for the focus solenoids. This forms a more accurate and compact assembly than the standard practice of pressing individual solid rings onto a tube
Mechanical design of a pre-isolator for the CLIC final focusing magnets

CERN Document Server

Gaddi, A; Ramos, F; Siegrist, N

2012-01-01

Due to the very small vertical beam sizes, the final focusing elements at the future CLIC linear collider need to be stable against vibrations to below 0.15 nanometres at frequencies above about 4 Hz. One of the key elements in the strategy to achieve such a stable environment is a passive, heavy pre-isolator. In this report, the results from the dynamic finite element analyses of the proposed design for such a passive preisolator are summarized. Furthermore, the results from a low frequency, heavy mass passive vibration isolation test set-up used to validate the calculations are shown.

A Combined Solar Electric and Storable Chemical Propulsion Vehicle for Piloted Mars Missions

Science.gov (United States)

Mercer, Carolyn R.; Oleson, Steven R.; Drake, Bret G.

2014-01-01

The Mars Design Reference Architecture (DRA) 5.0 explored a piloted Mars mission in the 2030 timeframe, focusing on architecture and technology choices. The DRA 5.0 focused on nuclear thermal and cryogenic chemical propulsion system options for the mission. Follow-on work explored both nuclear and solar electric options. One enticing option that was found in a NASA Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) design study used a combination of a 1-MW-class solar electric propulsion (SEP) system combined with storable chemical systems derived from the planned Orion crew vehicle. It was found that by using each propulsion system at the appropriate phase of the mission, the entire SEP stage and habitat could be placed into orbit with just two planned Space Launch System (SLS) heavy lift launch vehicles assuming the crew would meet up at the Earth-Moon (E-M) L2 point on a separate heavy-lift launch. These appropriate phases use high-thrust chemical propulsion only in gravity wells when the vehicle is piloted and solar electric propulsion for every other phase. Thus the SEP system performs the spiral of the unmanned vehicle from low Earth orbit (LEO) to E-M L2 where the vehicle meets up with the multi-purpose crew vehicle. From here SEP is used to place the vehicle on a trajectory to Mars. With SEP providing a large portion of the required capture and departure changes in velocity (delta V) at Mars, the delta V provided by the chemical propulsion is reduced by a factor of five from what would be needed with chemical propulsion alone at Mars. This trajectory also allows the SEP and habitat vehicle to arrive in the highly elliptic 1-sol parking orbit compatible with envisioned Mars landing concepts. This paper explores mission options using between SEP and chemical propulsion, the design of the SEP system including the solar array and electric propulsion systems, and packaging in the SLS shroud. Design trades of stay time, power level
Compact electron beam focusing column

Science.gov (United States)

Persaud, Arun; Leung, Ka-Ngo; Reijonen, Jani

2001-12-01

A novel design for an electron beam focusing column has been developed at LBNL. The design is based on a low-energy spread multicusp plasma source which is used as a cathode for electron beam production. The focusing column is 10 mm in length. The electron beam is focused by means of electrostatic fields. The column is designed for a maximum voltage of 50 kV. Simulations of the electron trajectories have been performed by using the 2D simulation code IGUN and EGUN. The electron temperature has also been incorporated into the simulations. The electron beam simulations, column design and fabrication will be discussed in this presentation.
Design Tool for Estimating Chemical Hydrogen Storage System Characteristics for Light-Duty Fuel Cell Vehicles

Energy Technology Data Exchange (ETDEWEB)

Brooks, Kriston P.; Sprik, Sam; Tamburello, David; Thornton, Matthew

2018-05-03

The U.S. Department of Energy (DOE) has developed a vehicle framework model to simulate fuel cell-based light-duty vehicle operation for various hydrogen storage systems. This transient model simulates the performance of the storage system, fuel cell, and vehicle for comparison to DOE’s Technical Targets using four drive cycles/profiles. Chemical hydrogen storage models have been developed for the Framework model for both exothermic and endothermic materials. Despite the utility of such models, they require that material researchers input system design specifications that cannot be easily estimated. To address this challenge, a design tool has been developed that allows researchers to directly enter kinetic and thermodynamic chemical hydrogen storage material properties into a simple sizing module that then estimates the systems parameters required to run the storage system model. Additionally, this design tool can be used as a standalone executable file to estimate the storage system mass and volume outside of the framework model and compare it to the DOE Technical Targets. These models will be explained and exercised with existing hydrogen storage materials.
Design Tool for Estimating Chemical Hydrogen Storage System Characteristics for Light-Duty Fuel Cell Vehicles

Energy Technology Data Exchange (ETDEWEB)

Thornton, Matthew J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sprik, Samuel [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brooks, Kriston P. [Pacific Northwest National Laboratory; Tamburello, David A. [Savannah River National Laboratory

2018-04-07

The U.S. Department of Energy (DOE) developed a vehicle Framework model to simulate fuel cell-based light-duty vehicle operation for various hydrogen storage systems. This transient model simulates the performance of the storage system, fuel cell, and vehicle for comparison to Technical Targets established by DOE for four drive cycles/profiles. Chemical hydrogen storage models have been developed for the Framework for both exothermic and endothermic materials. Despite the utility of such models, they require that material researchers input system design specifications that cannot be estimated easily. To address this challenge, a design tool has been developed that allows researchers to directly enter kinetic and thermodynamic chemical hydrogen storage material properties into a simple sizing module that then estimates system parameters required to run the storage system model. Additionally, the design tool can be used as a standalone executable file to estimate the storage system mass and volume outside of the Framework model. These models will be explained and exercised with the representative hydrogen storage materials exothermic ammonia borane (NH3BH3) and endothermic alane (AlH3).
Influences of chemical and non-chemical stressors on childhood obesity

Science.gov (United States)

Background/Aim: Children are exposed to diverse chemical and non-chemical stressors in their built, natural, and social environments; and these are thought to contribute to their health and well-being during each developmental stage throughout life. Here we focus on growing evide...
Designation of Alpha-Phenylacetoacetonitrile (APAAN), a Precursor Chemical Used in the Illicit Manufacture of Phenylacetone, Methamphetamine, and Amphetamine, as a List I Chemical. Final rule.

Science.gov (United States)

2017-07-14

The Drug Enforcement Administration (DEA) is finalizing the designation of the chemical alpha-phenylacetoacetonitrile (APAAN) and its salts, optical isomers, and salts of optical isomers, as a list I chemical under the Controlled Substances Act (CSA). The DEA proposed control of APAAN, due to its use in clandestine laboratories to illicitly manufacture the schedule II controlled substances phenylacetone (also known as phenyl-2-propanone or P2P), methamphetamine, and amphetamine. This rulemaking finalizes, without change, the control of APAAN as a list I chemical. This action does not establish a threshold for domestic and international transactions of APAAN. As such, all transactions involving APAAN, regardless of size, shall be regulated. In addition, chemical mixtures containing APAAN are not exempt from regulatory requirements at any concentration. Therefore, all transactions of chemical mixtures containing any quantity of APAAN shall be regulated pursuant to the CSA. However, manufacturers may submit an application for exemption for those mixtures that do not qualify for automatic exemption.
Design Evolution and Verification of the A-3 Chemical Steam Generator

Science.gov (United States)

Kirchner, Casey K.

2009-01-01

Following is an overview of the Chemical Steam Generator system selected to provide vacuum conditions for a new altitude test facility, the A-3 Test Stand at Stennis Space Center (SSC) in Bay St. Louis, MS. A-3 will serve as NASA s primary facility for altitude testing of the J-2X rocket engine, to be used as the primary propulsion device for the upper stages of the Ares launch vehicles. The Chemical Steam Generators (CSGs) will produce vacuum conditions in the test cell through the production and subsequent supersonic ejection of steam into a diffuser downstream of the J-2X engine nozzle exit. The Chemical Steam Generators chosen have a rich heritage of operation at rocket engine altitude test facilities since the days of the Apollo program and are still in use at NASA White Sands Test Facility (WSTF) in New Mexico. The generators at WSTF have been modified to a degree, but are still very close to the heritage design. The intent for the A-3 implementation is to maintain this heritage design as much as possible, making minimal updates only where necessary to substitute for obsolete parts and to increase reliability. Reliability improvements are especially desired because the proposed system will require 27 generators, which is nine times the largest system installed in the 1960s. Improvements were suggested by the original design firm, Reaction Motors, by NASA SSC and NASA WSTF engineers, and by the A-3 test stand design contractor, Jacobs Technology, Inc. (JTI). This paper describes the range of improvements made to the design to date, starting with the heritage generator and the minor modifications made over time at WSTF, to the modernized configuration which will be used at A-3. The paper will discuss NASA s investment in modifications to SSC s E-2 test facility fire a full-scale Chemical Steam Generator in advance of the larger steam system installation at A-3. Risk mitigation testing will be performed in early 2009 at this test facility to verify that the CSGs
The Use of Chemical-Chemical Interaction and Chemical Structure to Identify New Candidate Chemicals Related to Lung Cancer.

Directory of Open Access Journals (Sweden)

Lei Chen

Full Text Available Lung cancer causes over one million deaths every year worldwide. However, prevention and treatment methods for this serious disease are limited. The identification of new chemicals related to lung cancer may aid in disease prevention and the design of more effective treatments. This study employed a weighted network, constructed using chemical-chemical interaction information, to identify new chemicals related to two types of lung cancer: non-small lung cancer and small-cell lung cancer. Then, a randomization test as well as chemical-chemical interaction and chemical structure information were utilized to make further selections. A final analysis of these new chemicals in the context of the current literature indicates that several chemicals are strongly linked to lung cancer.
Environmental Chemicals in Breast Milk

Science.gov (United States)

Most of the information available on environmental chemicals in breast milk is focused on persistent, lipophilic chemicals; the database on levels of these chemicals has expanded substantially since the 1950s. Currently, various types of chemicals are measured in breast milk and ...
Design and analysis of questionnaires for survey skills in chemical engineering

Directory of Open Access Journals (Sweden)

Susana Lucas

2011-09-01

Full Text Available 800x600 Normal 0 21 false false false CA X-NONE X-NONE The new reorganization of university education has involved relevant changes in teaching and learning methodologies in order to help students to learn more effectively and to develop important skills and competences demanded by the professional world. In this sense the new configuration of the degree in Chemical Engineering required the identification of the main general and transferable skills, the implementation of the new teaching and learning strategies necessary to achieve them and, in addition, an evaluation procedure for determining the importance and the degree of development of a student´s skills and competences. In this exercise, two obligatory chemical reactor engineering subjects of the still in effect Chemical Engineering degree were chosen as examples of competence-based learning disciplines. For each one, a significant group of transferable and specific skills were selected to be developed. The identification and selection of skills was made according to the recommendations of the European Federation of Chemical Engineering (EFCE together with the established requirements in the ministerial order for the new Chemical Engineering Degree (Ministerial order CIN/351/2009. In order to check the effectiveness of teaching strategies in helping students to acquire these abilities, specific questionnaires were designed. These tests allowed for the utility of the competences in question to be evaluated in terms of the students´ professional work as future chemical engineering graduates and also facilitated the perception of skill development acquired through the methodology implemented in these subjects. The results of the skill evaluation questionnaires revealed the importance that both university collectives (students and professors give to the development of transferable skills. These skills included the ability to communicate effectively (including in English, to work in
XPERT DESIGN AND DIAGNOSTICS' (XDD) IN-SITU CHEMICAL OXIDATION PROCESS USING POTASSIUM PERMANGANATE (KMNO4)

Science.gov (United States)

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 ...
Final focus nomenclature

International Nuclear Information System (INIS)

Erickson, R.

1986-01-01

The formal names and common names for all devices in the final focus system of the SLC are listed. The formal names consist of a device type designator, microprocessor designator, and a four-digit unit number
An experimental design method leading to chemical Turing patterns.

Science.gov (United States)

Horváth, Judit; Szalai, István; De Kepper, Patrick

2009-05-08

Chemical reaction-diffusion patterns often serve as prototypes for pattern formation in living systems, but only two isothermal single-phase reaction systems have produced sustained stationary reaction-diffusion patterns so far. We designed an experimental method to search for additional systems on the basis of three steps: (i) generate spatial bistability by operating autoactivated reactions in open spatial reactors; (ii) use an independent negative-feedback species to produce spatiotemporal oscillations; and (iii) induce a space-scale separation of the activatory and inhibitory processes with a low-mobility complexing agent. We successfully applied this method to a hydrogen-ion autoactivated reaction, the thiourea-iodate-sulfite (TuIS) reaction, and noticeably produced stationary hexagonal arrays of spots and parallel stripes of pH patterns attributed to a Turing bifurcation. This method could be extended to biochemical reactions.
Design Evolution of the Wide Field Infrared Survey Telescope Using Astrophysics Focused Telescope Assets (WFIRST-AFTA) and Lessons Learned

Science.gov (United States)

Peabody, Hume L.; Peters, Carlton V.; Rodriguez-Ruiz, Juan E.; McDonald, Carson S.; Content, David A.; Jackson, Clifton E.

2015-01-01

The design of the Wide Field Infrared Survey Telescope using Astrophysics Focused Telescope Assets (WFIRST-AFTA) continues to evolve as each design cycle is analyzed. In 2012, two Hubble sized (2.4 m diameter) telescopes were donated to NASA from elsewhere in the Federal Government. NASA began investigating potential uses for these telescopes and identified WFIRST as a mission to benefit from these assets. With an updated, deeper, and sharper field of view than previous design iterations with a smaller telescope, the optical designs of the WFIRST instruments were updated and the mechanical and thermal designs evolved around the new optical layout. Beginning with Design Cycle 3, significant analysis efforts yielded a design and model that could be evaluated for Structural-Thermal-Optical-Performance (STOP) purposes for the Wide Field Imager (WFI) and provided the basis for evaluating the high level observatory requirements. Development of the Cycle 3 thermal model provided some valuable analysis lessons learned and established best practices for future design cycles. However, the Cycle 3 design did include some major liens and evolving requirements which were addressed in the Cycle 4 Design. Some of the design changes are driven by requirements changes, while others are optimizations or solutions to liens from previous cycles. Again in Cycle 4, STOP analysis was performed and further insights into the overall design were gained leading to the Cycle 5 design effort currently underway. This paper seeks to capture the thermal design evolution, with focus on major design drivers, key decisions and their rationale, and lessons learned as the design evolved.
Final focus nomenclature

Energy Technology Data Exchange (ETDEWEB)

Erickson, R.

1986-08-08

The formal names and common names for all devices in the final focus system of the SLC are listed. The formal names consist of a device type designator, microprocessor designator, and a four-digit unit number. (LEW)
Ontario Hydro's experience in implementing on-the-job training for chemical technicians

International Nuclear Information System (INIS)

Cooper, G.A.

1996-01-01

Since 1989, Ontario Hydro Nuclear has been developing and implementing formalized On-the-Job Training for qualifying its nuclear power plant chemical laboratory staff. This paper focuses on the process followed in designing, developing and implementing this training, with emphasis on the strengths and weaknesses of the program. 7 refs, 3 figs
Design and validation of an MR-conditional robot for transcranial focused ultrasound surgery in infants

Energy Technology Data Exchange (ETDEWEB)

Price, Karl D., E-mail: karl.price@sickkids.ca [Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, Ontario M5G 1X8 (Canada); The Department of Mechanical Engineering, The University of Toronto, Toronto, Ontario M5S 3G8 (Canada); Sin, Vivian W. [Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, Ontario M5G 1X8 (Canada); Mougenot, Charles [Philips Healthcare Canada, Markham, Ontario L6C 2S3 (Canada); Pichardo, Samuel [Electrical Engineering, Lakehead University, Thunder Bay, Ontario P7B 5E1 (Canada); Looi, Thomas [Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, Ontario M5G 1X8 (Canada); The Institute of Biomaterials and Biomedical Engineering, The University of Toronto, Toronto, Ontario M5G 3G9 (Canada); Waspe, Adam C. [Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, Ontario M5G 1X8 (Canada); Department of Medical Imaging, The University of Toronto, Toronto, Ontario M5T 1W7 (Canada); Drake, James M. [Centre for Image Guided Innovation and Therapeutic Intervention, The Hospital for Sick Children, Toronto, Ontario M5G 1X8 (Canada); Department of Neurosurgery, The University of Toronto, Toronto, Ontario M5S 1A1 (Canada); The Institute of Biomaterials and Biomedical Engineering, The University of Toronto, Toronto, Ontario M5G 3G9 (Canada)

2016-09-15

Purpose: Current treatment of intraventricular hemorrhage (IVH) involves cerebral shunt placement or an invasive brain surgery. Magnetic resonance-guided focused ultrasound (MRgFUS) applied to the brains of pediatric patients presents an opportunity to treat IVH in a noninvasive manner, termed “incision-less surgery.” Current clinical and research focused ultrasound systems lack the capability to perform neonatal transcranial surgeries due to either range of motion or dexterity requirements. A novel robotic system is proposed to position a focused ultrasound transducer accurately above the head of a neonatal patient inside an MRI machine to deliver the therapy. Methods: A clinical Philips Sonalleve MRgFUS system was expanded to perform transcranial treatment. A five degree-of-freedom MR-conditional robot was designed and manufactured using MR compatible materials. The robot electronics and control were integrated into existing Philips electronics and software interfaces. The user commands the position of the robot with a graphical user interface, and is presented with real-time MR imaging of the patient throughout the surgery. The robot is validated through a series of experiments that characterize accuracy, signal-to-noise ratio degeneration of an MR image as a result of the robot, MR imaging artifacts generated by the robot, and the robot’s ability to operate in a representative surgical environment inside an MR machine. Results: Experimental results show the robot responds reliably within an MR environment, has achieved 0.59 ± 0.25 mm accuracy, does not produce severe MR-imaging artifacts, has a workspace providing sufficient coverage of a neonatal brain, and can manipulate a 5 kg payload. A full system demonstration shows these characteristics apply in an application environment. Conclusions: This paper presents a comprehensive look at the process of designing and validating a new robot from concept to implementation for use in an MR environment. An MR
Design and validation of an MR-conditional robot for transcranial focused ultrasound surgery in infants

International Nuclear Information System (INIS)

Price, Karl D.; Sin, Vivian W.; Mougenot, Charles; Pichardo, Samuel; Looi, Thomas; Waspe, Adam C.; Drake, James M.

2016-01-01

Purpose: Current treatment of intraventricular hemorrhage (IVH) involves cerebral shunt placement or an invasive brain surgery. Magnetic resonance-guided focused ultrasound (MRgFUS) applied to the brains of pediatric patients presents an opportunity to treat IVH in a noninvasive manner, termed “incision-less surgery.” Current clinical and research focused ultrasound systems lack the capability to perform neonatal transcranial surgeries due to either range of motion or dexterity requirements. A novel robotic system is proposed to position a focused ultrasound transducer accurately above the head of a neonatal patient inside an MRI machine to deliver the therapy. Methods: A clinical Philips Sonalleve MRgFUS system was expanded to perform transcranial treatment. A five degree-of-freedom MR-conditional robot was designed and manufactured using MR compatible materials. The robot electronics and control were integrated into existing Philips electronics and software interfaces. The user commands the position of the robot with a graphical user interface, and is presented with real-time MR imaging of the patient throughout the surgery. The robot is validated through a series of experiments that characterize accuracy, signal-to-noise ratio degeneration of an MR image as a result of the robot, MR imaging artifacts generated by the robot, and the robot’s ability to operate in a representative surgical environment inside an MR machine. Results: Experimental results show the robot responds reliably within an MR environment, has achieved 0.59 ± 0.25 mm accuracy, does not produce severe MR-imaging artifacts, has a workspace providing sufficient coverage of a neonatal brain, and can manipulate a 5 kg payload. A full system demonstration shows these characteristics apply in an application environment. Conclusions: This paper presents a comprehensive look at the process of designing and validating a new robot from concept to implementation for use in an MR environment. An MR
Chemically modified graphene based supercapacitors for flexible and miniature devices

Science.gov (United States)

Ghosh, Debasis; Kim, Sang Ouk

2015-09-01

Rapid progress in the portable and flexible electronic devises has stimulated supercapacitor research towards the design and fabrication of high performance flexible devices. Recent research efforts for flexible supercapacitor electrode materials are highly focusing on graphene and chemically modified graphene owing to the unique properties, including large surface area, high electrical and thermal conductivity, excellent mechanical flexibility, and outstanding chemical stability. This invited review article highlights current status of the flexible electrode material research based on chemically modified graphene for supercapacitor application. A variety of electrode architectures prepared from chemically modified graphene are summarized in terms of their structural dimensions. Novel prototypes for the supercapacitor aiming at flexible miniature devices, i.e. microsupercapacitor with high energy and power density are highlighted. Future challenges relevant to graphene-based flexible supercapacitors are also suggested. [Figure not available: see fulltext.
Virtual Exploration of the Ring Systems Chemical Universe.

Science.gov (United States)

Visini, Ricardo; Arús-Pous, Josep; Awale, Mahendra; Reymond, Jean-Louis

2017-11-27

Here, we explore the chemical space of all virtually possible organic molecules focusing on ring systems, which represent the cyclic cores of organic molecules obtained by removing all acyclic bonds and converting all remaining atoms to carbon. This approach circumvents the combinatorial explosion encountered when enumerating the molecules themselves. We report the chemical universe database GDB4c containing 916 130 ring systems up to four saturated or aromatic rings and maximum ring size of 14 atoms and GDB4c3D containing the corresponding 6 555 929 stereoisomers. Almost all (98.6%) of these ring systems are unknown and represent chiral 3D-shaped macrocycles containing small rings and quaternary centers reminiscent of polycyclic natural products. We envision that GDB4c can serve to select new ring systems from which to design analogs of such natural products. The database is available for download at www.gdb.unibe.ch together with interactive visualization and search tools as a resource for molecular design.

An overview of the challenges in designing, integrating, and delivering BARD: a public chemical biology resource and query portal across multiple organizations, locations, and disciplines

Science.gov (United States)

de Souza, Andrea; Bittker, Joshua; Lahr, David; Brudz, Steve; Chatwin, Simon; Oprea, Tudor I.; Waller, Anna; Yang, Jeremy; Southall, Noel; Guha, Rajarshi; Schurer, Stephan; Vempati, Uma; Southern, Mark R.; Dawson, Eric S.; Clemons, Paul A.; Chung, Thomas D.Y.

2015-01-01

Recent industry-academic partnerships involve collaboration across disciplines, locations, and organizations using publicly funded “open-access” and proprietary commercial data sources. These require effective integration of chemical and biological information from diverse data sources, presenting key informatics, personnel, and organizational challenges. BARD (BioAssay Research Database) was conceived to address these challenges and to serve as a community-wide resource and intuitive web portal for public-sector chemical biology data. Its initial focus is to enable scientists to more effectively use the NIH Roadmap Molecular Libraries Program (MLP) data generated from 3-year pilot and 6-year production phases of the Molecular Libraries Probe Production Centers Network (MLPCN), currently in its final year. BARD evolves the current data standards through structured assay and result annotations that leverage the BioAssay Ontology (BAO) and other industry-standard ontologies, and a core hierarchy of assay definition terms and data standards defined specifically for small-molecule assay data. We have initially focused on migrating the highest-value MLP data into BARD and bringing it up to this new standard. We review the technical and organizational challenges overcome by the inter-disciplinary BARD team, veterans of public and private sector data-integration projects, collaborating to describe (functional specifications), design (technical specifications), and implement this next-generation software solution. PMID:24441647
An Overview of the Challenges in Designing, Integrating, and Delivering BARD: A Public Chemical-Biology Resource and Query Portal for Multiple Organizations, Locations, and Disciplines.

Science.gov (United States)

de Souza, Andrea; Bittker, Joshua A; Lahr, David L; Brudz, Steve; Chatwin, Simon; Oprea, Tudor I; Waller, Anna; Yang, Jeremy J; Southall, Noel; Guha, Rajarshi; Schürer, Stephan C; Vempati, Uma D; Southern, Mark R; Dawson, Eric S; Clemons, Paul A; Chung, Thomas D Y

2014-06-01

Recent industry-academic partnerships involve collaboration among disciplines, locations, and organizations using publicly funded "open-access" and proprietary commercial data sources. These require the effective integration of chemical and biological information from diverse data sources, which presents key informatics, personnel, and organizational challenges. The BioAssay Research Database (BARD) was conceived to address these challenges and serve as a community-wide resource and intuitive web portal for public-sector chemical-biology data. Its initial focus is to enable scientists to more effectively use the National Institutes of Health Roadmap Molecular Libraries Program (MLP) data generated from the 3-year pilot and 6-year production phases of the Molecular Libraries Probe Production Centers Network (MLPCN), which is currently in its final year. BARD evolves the current data standards through structured assay and result annotations that leverage BioAssay Ontology and other industry-standard ontologies, and a core hierarchy of assay definition terms and data standards defined specifically for small-molecule assay data. We initially focused on migrating the highest-value MLP data into BARD and bringing it up to this new standard. We review the technical and organizational challenges overcome by the interdisciplinary BARD team, veterans of public- and private-sector data-integration projects, who are collaborating to describe (functional specifications), design (technical specifications), and implement this next-generation software solution. © 2014 Society for Laboratory Automation and Screening.
Computing Equilibrium Chemical Compositions

Science.gov (United States)

Mcbride, Bonnie J.; Gordon, Sanford

1995-01-01

Chemical Equilibrium With Transport Properties, 1993 (CET93) computer program provides data on chemical-equilibrium compositions. Aids calculation of thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93/PC is version of CET93 specifically designed to run within 640K memory limit of MS-DOS operating system. CET93/PC written in FORTRAN.
Reactor design, cold-model experiment and CFD modeling for chemical looping combustion

Energy Technology Data Exchange (ETDEWEB)

Zhang, Shaohua; Ma, Jinchen; Hu, Xintao; Zhao, Haibo; Wang, Baowen; Zheng, Chuguang [Huazhong Univ. of Science and Technology, Wuhan (China). State Key Lab. of Coal Combustion

2013-07-01

Chemical looping combustion (CLC) is an efficient, clean and cheap technology for CO{sub 2} capture, and an interconnected fluidized bed is more appropriate solution for CLC. This paper aims to design a reactor system for CLC, carry out cold-model experiment of the system, and model fuel reactor using commercial CFD software. As for the CLC system, the air reactor (AR) is designed as a fast fluidized bed while the fuel reactor (FR) is a bubbling bed; a cyclone is used for solid separation of the AR exit flow. The AR and FR are separated by two U-type loop seals to remain gas sealed. Considered the chemical kinetics of oxygen carrier, fluid dynamics, pressure balance and mass balance of the system simultaneously, some key design parameters of a CH{sub 4}-fueled and Fe{sub 2}O{sub 3}/Al{sub 2}O{sub 3}-based CLC reactor (thermal power of 50 kWth) are determined, including key geometric parameters (reactor cross-sectional area and reactor height) and operation parameters (bed material quantity, solid circulation rate, apparent gas velocity of each reactor). A cold-model bench having same geometric parameters with its prototype is built up to study the effects of various operation conditions (including gas velocity in the reactors and loop seals, and bed material height, etc.) on the solids circulation rate, gas leakage, and pressure balance. It is witnessed the cold-model system is able to meet special requirements for CLC system such as gas sealing between AR and FR, the circulation rate and particles residence time. Furthermore, the thermal FR reactor with oxygen carrier of Fe{sub 2}O{sub 3}/Al{sub 2}O{sub 3} and fuel of CH{sub 4} is simulated by commercial CFD solver FLUENT. It is found that for the design case the combustion efficiency of CH{sub 4} reaches 88.2%. A few part of methane is unburned due to fast, large bubbles rising through the reactor.
Meta-Analysis of the Chemical and Non-Chemical Stressors Affecting Childhood Obesity

Science.gov (United States)

Worldwide, approximately 42 million children under the age of 5 years are considered overweight or obese. While much research has focused on individual behaviors impacting obesity, little research has emphasized the complex interactions of numerous chemical and non-chemical stres...
Testing Requirements to Manage Data Exchange Specifications in Enterprise Integration - A Schema Design Quality Focus.

Energy Technology Data Exchange (ETDEWEB)

Kulvatunyou, Boonserm [ORNL; Ivezic, Nenad [ORNL; Buhwan, Jeong [POSTECH University, South Korea

2004-07-01

In this paper, we describe the requirements to test W3C XML Schema usage when defining message schemas for data exchange in any large and evolving enterprise integration project. We then decompose the XML Schema testing into four (4) aspects including the message schema conformance to the XML Schema specification grammar, the message schema conformance to the XML Schema specification semantics, the message schema conformance to design quality testing, and canonical semantics testing of the message schema. We describe these four testing aspects in some detail and point to other related efforts. We further focus to provide some technical details for the message schema design quality testing. As a future work, we describe the requirements for canonical semantics testing and potential solution approaches. Finally, we describe an implementation architecture for the message schema design quality testing.
MICE - Absorber and focus coil safety working group design document: Preliminary design and assessments

International Nuclear Information System (INIS)

Barr, Giles; Baynham, Elwyn; Black, Edgar; Bradshaw, Tom; Cummings, Mary Anne; Green, Michael A.; Ishimoto, Shigeru; Ivanyushenkov, Yury; Lau, Wing; Zisman, Michael

2003-01-01

A Neutrino Factory based on a muon storage ring is the ultimate tool for studies of neutrino oscillations, including possibly the discovery of leptonic CP violation. it is also the first step toward a muon collider. To develop a stored-muon-beam facility to serve as a Neutrino Factory, it is necessary to ''cool'' a muon beam (decrease its phase-space volume). The short lifetime of the muon, 2.2 (micro)s at rest, eliminates all currently demonstrated cooling techniques and requires that a new, heretofore untried, technique--ionization cooling--be employed. Although ionization cooling of muons has never been demonstrated in practice, it has been shown by end-to-end simulation and design studies to be an important factor both for the performance and for the cost of a Neutrino Factory. This motivates an international program of R and D, including an experimental demonstration at Rutherford Appleton Laboratory (RAL). The aims of the international Muon Ionization Cooling Experiment are: (1) to show that it is possible to design, engineer and build a section of cooling channel capable of giving the desired performance for a Neutrino Factory; and (2) to place it in a muon beam and measure its performance in various modes of operation and beam conditions, thereby investigating the limits and practicality of cooling. The MICE collaboration has designed an experiment in which a section of an ionization cooling channel is exposed to a muon beam. This cooling channel assembles liquid-hydrogen absorbers providing energy loss and high-gradient radio frequency (RF) cavities to re-accelerate the particles, all tightly contained in a magnetic channel. It reduces the beam transverse emittance by > 10% for muon momenta between 140 and 240 MeV/c. The layout of the experiment is shown. They utilize one complete magnetic cell of the cooling channel, comprising three absorber-focus-coil (AFC) modules and two RF-coupling-coil (RFCC) modules. Spectrometers placed before and after the
Development and Application of 3D Printed Mesoreactors in Chemical Engineering Education

Science.gov (United States)

Tabassum, Tahseen; Iloska, Marija; Scuereb, Daniel; Taira, Noriko; Jin, Chongguang; Zaitsev, Vladimir; Afshar, Fara; Kim, Taejin

2018-01-01

3D printing technology has an enormous potential to apply to chemical engineering education. In this paper, we describe several designs of 3D printed mesoreactors (Y-shape, T-shape, and Long channel shape) using the following steps: reactor sketching, CAD modeling, and reactor printing. With a focus on continuous plug flow mesoreactors (PFRs, i.d.…
GREENER CHEMICAL PROCESS DESIGN ALTERNATIVES ARE REVEALED USING THE WASTE REDUCTION DECISION SUPPORT SYSTEM (WAR DSS)

Science.gov (United States)

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...
Chemical Hazards and Safety Issues in Fusion Safety Design

International Nuclear Information System (INIS)

Cadwallader, L.C.

2003-01-01

Radiological inventory releases have dominated accident consequences for fusion; these consequences are important to analyze and are generally the most severe result of a fusion facility accident event. However, the advent of, or plan for, large-scale usage of some toxic materials poses the additional hazard of chemical exposure from an accident event. Examples of toxic chemicals are beryllium for magnetic fusion and fluorine for laser fusion. Therefore, chemical exposure consequences must also be addressed in fusion safety assessment. This paper provides guidance for fusion safety analysis. US Department of Energy (DOE) chemical safety assessment practices for workers and the public are reviewed. The US Environmental Protection Agency (EPA) has published some guidance on public exposure to releases of mixtures of chemicals, this guidance has been used to create an initial guideline for treating mixed radiological and toxicological releases in fusion; for example, tritiated hazardous dust from a tokamak vacuum vessel. There is no convenient means to judge the hazard severity of exposure to mixed materials. The chemical fate of mixed material constituents must be reviewed to determine if there is a separate or combined radiological and toxicological carcinogenesis, or if other health threats exist with radiological carcinogenesis. Recommendations are made for fusion facility chemical safety evaluation and safety guidance for protecting the public from chemical releases, since such levels are not specifically identified in the DOE fusion safety standard
Focusing on real-world nuclear issues at the University of New Mexico

International Nuclear Information System (INIS)

Busch, R.D.

1996-01-01

Traditional nuclear engineering education in the universities has focused on nuclear power and reactor physics. Since 1980, the United States has had little need for reactor designers and few job opportunities available in the nuclear power industry. Although slow to get the message, most university nuclear engineering programs have shifted focus in the 1990s from neutron physics and power generation to environmental and regulatory issues. In the University of New Mexico (UNM) chemical and nuclear engineering department, we have done this in two ways: through a shift of emphasis in our basic theory classes and by introducing new courses. One example of the shift of emphasis is illustrated by the way we now teach our senior computational methods class. Rather than focusing on ways to analyze the neutronics of reactor cores, we now look at using computational tools - particularly, diffusion, transport, and Monte Carlo codes - to evaluate the criticality safety aspects of processes involving fissile material
Transport phenomena in solid oxide fuel cell electrodes focusing on heat transfer related to chemical reactions

International Nuclear Information System (INIS)

Navasa, M; Andersson, M; Yuan, J; Sundén, B

2012-01-01

Solid oxide fuel cells (SOFCs) are widely studied for their advantages especially at high temperatures. However, operating at high temperatures represents a high cost due to the strict requirements the materials are expected to fulfill. Thus, the main goal in SOFC research has been to decrease the operating temperature so that the range of available materials is widened and hence, the operating cost can be reduced. In this paper, the different heat sources that contribute to the cell energy balance are presented with strong emphasis on the chemical reactions that take place in SOFCs. The knowledge of which heat sources or sinks taking place and their locations within the SOFC can provide useful information for further design and efficiency improvements.
Design of a New Concentration Series for the Orthogonal Sample Design Approach and Estimation of the Number of Reactions in Chemical Systems.

Science.gov (United States)

Shi, Jiajia; Liu, Yuhai; Guo, Ran; Li, Xiaopei; He, Anqi; Gao, Yunlong; Wei, Yongju; Liu, Cuige; Zhao, Ying; Xu, Yizhuang; Noda, Isao; Wu, Jinguang

2015-11-01

A new concentration series is proposed for the construction of a two-dimensional (2D) synchronous spectrum for orthogonal sample design analysis to probe intermolecular interaction between solutes dissolved in the same solutions. The obtained 2D synchronous spectrum possesses the following two properties: (1) cross peaks in the 2D synchronous spectra can be used to reflect intermolecular interaction reliably, since interference portions that have nothing to do with intermolecular interaction are completely removed, and (2) the two-dimensional synchronous spectrum produced can effectively avoid accidental collinearity. Hence, the correct number of nonzero eigenvalues can be obtained so that the number of chemical reactions can be estimated. In a real chemical system, noise present in one-dimensional spectra may also produce nonzero eigenvalues. To get the correct number of chemical reactions, we classified nonzero eigenvalues into significant nonzero eigenvalues and insignificant nonzero eigenvalues. Significant nonzero eigenvalues can be identified by inspecting the pattern of the corresponding eigenvector with help of the Durbin-Watson statistic. As a result, the correct number of chemical reactions can be obtained from significant nonzero eigenvalues. This approach provides a solid basis to obtain insight into subtle spectral variations caused by intermolecular interaction.
Molecular design chemical structure generation from the properties of pure organic compounds

CERN Document Server

Horvath, AL

1992-01-01

This book is a systematic presentation of the methods that have been developed for the interpretation of molecular modeling to the design of new chemicals. The main feature of the compilation is the co-ordination of the various scientific disciplines required for the generation of new compounds. The five chapters deal with such areas as structure and properties of organic compounds, relationships between structure and properties, and models for structure generation. The subject is covered in sufficient depth to provide readers with the necessary background to understand the modeling
Exposure to chemicals in food packaging as a sustainability trade-off in LCA

DEFF Research Database (Denmark)

Ernstoff, Alexi; Muncke, Jane; Trier, Xenia

2016-01-01

Hazardous chemicals in packaging, including ‘eco-friendly’ and recycled food packaging, can migrate into food and expose humans. LCA has been fundamental to indicate more ‘eco-friendly’ packages, but currently LCA does not consider exposure to chemical migrants and methods have not yet been...... but to provide life cycle context to compare the magnitude of characterized exposure to chemicals in packaging, in order to elucidate if this exposure pathway is important. We detail estimates of life cycle exposure to one known hazardous chemical in polystyrene packaging (styrene) that has data available...... developed. In this study we question if exposure to chemicals in food packaging should be considered as a sustainable design consideration, i.e. if this human health risk is relevant in a life cycle context. To answer this question, we focus on developing methods to quantify exposure to chemicals in food...
Application of Bayesian network and multi-criteria decision analysis to risk-based design of chemical plants

NARCIS (Netherlands)

Khakzad Rostami, N.; Reniers, G.L.L.M.E.

2016-01-01

Fires and explosions in chemical plants are still among the major accidents threatening human lives and causing huge asset losses. Although might not completely be eliminated, the risks of such accidents can be reduced by allocating safety measures, applying inherently safer design (ISD) methods,
Development of a hybrid chemical/mechanical heat pump

Science.gov (United States)

Grzyll, Lawrence R.; Silvestri, John J.; Scaringe, Robert P.

1991-01-01

The authors present the current development status of a hybrid chemical/mechanical heat pump for low-lift applications. The heat pump provides electronics cooling by evaporating a pure refrigerant from an absorbent/refrigerant mixture in a generator/cold plate. The current development focused on evaluation of absorbent/refrigerant pairs, corrosion testing, pump and compressor design, and electronic cold plate design. Two cycle configurations were considered. The first configuration utilized a standard mechanical compressor and pump. The second cycle configuration investigated pumps and compressors with non-moving parts. An innovative generator/cold plate design is also presented. The development to date shows that this cycle has about the same performance as standard vapor compression heat pumps with standard refrigerants but may have some performance and reliability advantages over vapor compression heat pumps.
Chemical Frustration. A Design Principle for the Discovery of New Complex Alloy and Intermetallic Phases, Final Report

Energy Technology Data Exchange (ETDEWEB)

Fredrickson, Daniel C [Univ. of Wisconsin, Madison, WI (United States)

2015-06-23

Final technical report for "Chemical Frustration: A Design Principle for the Discovery of New Complex Alloy and Intermetallic Phases" funded by the Office of Science through the Materials Chemistry Program of the Office of Basic Energy Sciences.
Solar fuels and chemicals system design study (ammonia/nitric acid production process). Volume 2. Conceptual design. Final report

Energy Technology Data Exchange (ETDEWEB)

1986-06-01

As part of the Solar Central Receiver Fuels and Chemicals Program, Foster Wheeler Solar Development Corporation (FWSDC), under contract to Sandia National Laboratories-Livermore (SNLL), developed a conceptual design of a facility to produce ammonia and nitric acid using solar energy as the principal external source of process heat. In the selected process, ammonia is produced in an endothermic reaction within a steam methane (natural gas) reformer. The heat of reaction is provided by molten carbonate salt heated by both a solar central receiver and an exothermic ammonia-fired heater. After absorption by water, the product of the latter reaction is nitric acid.
Preliminary design of a 150 kJ repetitive plasma focus for the production of 18-F

Science.gov (United States)

Sumini, Marco; Mostacci, Domiziano; Rocchi, Federico; Frignani, Michele; Tartari, Agostino; Angeli, Ergisto; Galaverni, Dario; Coli, Ugo; Ascione, Bernardino; Cucchi, Giorgio

2006-06-01

Experiments in the past five years have demonstrated production of short-lived radioisotopes with a Plasma Focus device, using the so-termed Endogenous Mode. So far radioisotope activities of only a few microcuries have been obtained from single discharges in small scale Plasma Focus machines (capacitor bank energies of approximately 7 kJ). It is expected that higher activities could be obtained with larger bank energies, operating at high pulse repetition rates, e.g. 1 Hz. However, many scientific and technological issues must be addressed for a high-energy Plasma Focus device to run at one pulse per second. Aim of this paper is to present preliminary results pertaining to the plasma, electrical, fluid-dynamical, thermal, material and mechanical design of a 150 kJ Plasma Focus, capable of a repetition rate of 1 Hz, that will be operated at 30 kV with a 350 μF capacitor bank and a maximum total current of 1.5 MA. This device will be used to breed 18-F for the synthesis of drugs used in positron-emission medical examinations, such as FDG for PET.

Preliminary design of a 150 kJ repetitive plasma focus for the production of 18-F

International Nuclear Information System (INIS)

Sumini, Marco; Mostacci, Domiziano; Rocchi, Federico; Frignani, Michele; Tartari, Agostino; Angeli, Ergisto; Galaverni, Dario; Coli, Ugo; Ascione, Bernardino; Cucchi, Giorgio

2006-01-01

Experiments in the past five years have demonstrated production of short-lived radioisotopes with a Plasma Focus device, using the so-termed Endogenous Mode. So far radioisotope activities of only a few microcuries have been obtained from single discharges in small scale Plasma Focus machines (capacitor bank energies of approximately 7 kJ). It is expected that higher activities could be obtained with larger bank energies, operating at high pulse repetition rates, e.g. 1 Hz. However, many scientific and technological issues must be addressed for a high-energy Plasma Focus device to run at one pulse per second. Aim of this paper is to present preliminary results pertaining to the plasma, electrical, fluid-dynamical, thermal, material and mechanical design of a 150 kJ Plasma Focus, capable of a repetition rate of 1 Hz, that will be operated at 30 kV with a 350 μF capacitor bank and a maximum total current of 1.5 MA. This device will be used to breed 18-F for the synthesis of drugs used in positron-emission medical examinations, such as FDG for PET
Integrated supply chain design for commodity chemicals production via woody biomass fast pyrolysis and upgrading.

Science.gov (United States)

Zhang, Yanan; Hu, Guiping; Brown, Robert C

2014-04-01

This study investigates the optimal supply chain design for commodity chemicals (BTX, etc.) production via woody biomass fast pyrolysis and hydroprocessing pathway. The locations and capacities of distributed preprocessing hubs and integrated biorefinery facilities are optimized with a mixed integer linear programming model. In this integrated supply chain system, decisions on the biomass chipping methods (roadside chipping vs. facility chipping) are also explored. The economic objective of the supply chain model is to maximize the profit for a 20-year chemicals production system. In addition to the economic objective, the model also incorporates an environmental objective of minimizing life cycle greenhouse gas emissions, analyzing the trade-off between the economic and environmental considerations. The capital cost, operating cost, and revenues for the biorefinery facilities are based on techno-economic analysis, and the proposed approach is illustrated through a case study of Minnesota, with Minneapolis-St. Paul serving as the chemicals distribution hub. Copyright © 2014 Elsevier Ltd. All rights reserved.
Millimeter positron focusing using a hybrid lens design

International Nuclear Information System (INIS)

Cheung, C.K.; Kwan, P.Y.; Shan, Y.Y.; Naik, P.S.; Weng, H.M.; Beling, C.D.; Fung, S.

2004-01-01

The study of metal-semiconductor and metal-oxide-semiconductor systems with low energy positrons is made considerably easier if structures of millimeter dimension can be studied. For this reason the production of a positron beam of sub-millimeter dimension has been a long-term goal of the positron research group at the university of Hong Kong. The hybrid lens system employed consists of a standard Soa extraction lens in a magnetic field free region followed by a gridded Einzel lens that focuses positrons into a 100G magnetic funnel at an energy of 10keV for transportation to the target. Here we report on the present progress, by showing the capability of obtaining millimeter diameter focusing at a preliminary 7.5 kV beam energy. (orig.)
CMOS-MEMS Chemiresistive and Chemicapacitive Chemical Sensor System

Science.gov (United States)

Lazarus, Nathan S.

Integrating chemical sensors with testing electronics is a powerful technique with the potential to lower power and cost and allow for lower system limits of detection. This thesis explores the possibility of creating an integrated sensor system intended to be embedded within respirator cartridges to notify the user that hazardous chemicals will soon leak into the face mask. For a chemical sensor designer, this application is particularly challenging due to the need for a very sensitive and cheap sensor that will be exposed to widely varying environmental conditions during use. An octanethiol-coated gold nanoparticle chemiresistor to detect industrial solvents is developed, focusing on characterizing the environmental stability and limits of detection of the sensor. Since the chemiresistor was found to be highly sensitive to water vapor, a series of highly sensitive humidity sensor topologies were developed, with sensitivities several times previous integrated capacitive humidity sensors achieved. Circuit techniques were then explored to reduce the humidity sensor limits of detection, including the analysis of noise, charge injection, jitter and clock feedthrough in a charge-based capacitance measurement (CBCM) circuit and the design of a low noise Colpitts LC oscillator. The characterization of high resistance gold nanoclusters for capacitive chemical sensing was also performed. In the final section, a preconcentrator, a heater element intended to release a brief concentrated pulse of analate, was developed and tested for the purposes of lowering the system limit of detection.
Development of New Generation of Ceramics for Environmentally Focused Chemical Separations

Science.gov (United States)

Ramakrishnan, Girish

This dissertation focuses on the use of composite materials for environmental applications. For the first time, applications of both fresh and aged concrete as inexpensive adsorbents for nitrogen dioxide (NO2) removal is demonstrated. Concrete is the most widely used composite material of the modern era. Cement manufacturing (a major component of concrete) is considered to be one of the leading contributors to air pollution, resulting in 7% of the global carbon dioxide emissions along with a number of other harmful pollutants such as oxides, mercury and particulates. These emissions aide in the formation of acid rain, smog, and toxic ground level ozone, causing detrimental effects such as respiratory illnesses, visibility reduction, eutrification and global warming. This thesis offers a novel and sustainable solution in mitigating NOX emissions, by introducing the significant adsorption potential of recycled concrete. The work is based on both commercially available cement paste and already aged concrete samples, providing truly scalable solutions. The concrete samples aged for different periods of time were exposed to NO2 to measure their adsorption capacity. The results show that all of the concrete samples (fresh and aged) exhibited excellent NO2 adsorption capacity, with the fresh concrete samples removing almost 100% of the NO2. Furthermore, to compare the effects of long term aging, 12 year-old recently demolished concrete samples were obtained and its NOX removal was shown to be almost 60%. The experimental results provide evidence of nitrate and nitrite species formation from chemical reactions occurring between NO2 and surface alkaline species. This important discovery can be utilized for NO2 removal and subsequent NOX sequestered demolished concrete (NSDC) recycling in new concrete, either as a set accelerating admixture or as a corrosion inhibitor, a big leap towards better sustainability and longevity of the new reinforced concrete structures. The rest
Board on chemical sciences and technology

International Nuclear Information System (INIS)

1991-01-01

The Board on Chemical Sciences and Technology organizes and provides direction for standing and ad hoc committees charged with addressing specific issues relevant to the continued health of the chemical sciences and technology community. Studies currently under the oversight of the BCST include a major survey of chemical engineering, an examination of the problems of biohazards in the laboratory, and an analysis of the roots and magnitude of the problem of obsolescent facilities for research and teaching in departments in the chemical sciences and engineering. The Board continues to respond to specific agency requests for program assessments and advice. BCST members are designated to serve as liaison with major federal agencies or departments that support research in order to help identify ways for the board to assist the these organizations. The BCST also maintains close contact with professional societies and nongovernmental organizations that share the Board's concern for the health of chemical sciences and technology. Individual Board members are assigned responsibility for liaison with the American Chemical Society, the American Institute of Chemical Engineers, the American Society of Biological Chemists, the Council for Chemical Research, the Chemistry and Biochemistry Sections of the National Academy of Sciences (NAS), and the National Academy of Engineering (NAE). In the past few years, the Board has served as a focus and a forum for a variety of issues that relate specifically to the health of chemistry. A sampling of these concerns include: industry-university cooperation; basic research funding in DOD, DOE, NIH, and NSF; basic research in the chemistry of life processes; basic research in biochemical engineering; basic research in the science and technology of new materials; and undergraduate education in chemistry and chemical engineering
FOREWORD: Focus on Novel Nanoelectromechanical 3D Structures: Fabrication and Properties Focus on Novel Nanoelectromechanical 3D Structures: Fabrication and Properties

Science.gov (United States)

Yamada, Shooji; Yamaguchi, Hiroshi; Ishihara, Sunao

2009-06-01

Microelectromechanical systems (MEMS) are widely used small electromechanical systems made of micrometre-sized components. Presently, we are witnessing a transition from MEMS to nanoelectromechanical systems (NEMS), which comprise devices integrating electrical and mechanical functionality on the nanoscale and offer new exciting applications. Similarly to MEMS, NEMS typically include a central transistor-like nanoelectronic unit for data processing, as well as mechanical actuators, pumps, and motors; and they may combine with physical, biological and chemical sensors. In the transition from MEMS to NEMS, component sizes need to be reduced. Therefore, many fabrication methods previously developed for MEMS are unsuitable for the production of high-precision NEMS components. The key challenge in NEMS is therefore the development of new methods for routine and reproducible nanofabrication. Two complementary types of method for NEMS fabrication are available: 'top-down' and 'bottom-up'. The top-down approach uses traditional lithography technologies, whereas bottom-up techniques include molecular self-organization, self-assembly and nanodeposition. The NT2008 conference, held at Ishikawa High-Tech Conference Center, Ishikawa, Japan, between 23-25 October 2008, focused on novel NEMS fabricated from new materials and on process technologies. The topics included compound semiconductors, small mechanical structures, nanostructures for micro-fluid and bio-sensors, bio-hybrid micro-machines, as well as their design and simulation. This focus issue compiles seven articles selected from 13 submitted manuscripts. The articles by Prinz et al and Kehrbusch et al introduce the frontiers of the top-down production of various operational NEMS devices, and Kometani et al present an example of the bottom-up approach, namely ion-beam induced deposition of MEMS and NEMS. The remaining articles report novel technologies for biological sensors. Taira et al have used manganese nanoparticles
Analytical Chemical Sensing in the Submillimeter/terahertz Spectral Range

Science.gov (United States)

Moran, Benjamin L.; Fosnight, Alyssa M.; Medvedev, Ivan R.; Neese, Christopher F.

2012-06-01

Highly sensitive and selective Terahertz sensor utilized to quantitatively analyze a complex mixture of Volatile Organic Compounds is reported. To best demonstrate analytical capabilities of THz chemical sensors we chose to perform analytical quantitative analysis of a certified gas mixture using a novel prototype chemical sensor that couples a commercial preconcentration system (Entech 7100A) to a high resolution THz spectrometer. We selected Method TO-14A certified mixture of 39 volatile organic compounds (VOCs) diluted to 1 part per million (ppm) in nitrogen. 26 of the 39 chemicals were identified by us as suitable for THz spectroscopic detection. Entech 7100A system is designed and marketed as an inlet system for Gas Chromatography-Mass Spectrometry (GC-MS) instruments with a specific focus on TO-14 and TO-15 EPA sampling methods. Its preconcentration efficiency is high for the 39 chemicals in the mixture used for this study and our preliminary results confirm this. Here we present the results of this study which serves as basis for our ongoing research in environmental sensing and analysis of exhaled human breath.
Mechatronics design principles for biotechnology product development.

Science.gov (United States)

Mandenius, Carl-Fredrik; Björkman, Mats

2010-05-01

Traditionally, biotechnology design has focused on the manufacture of chemicals and biologics. Still, a majority of biotechnology products that appear on the market today is the result of mechanical-electric (mechatronic) construction. For these, the biological components play decisive roles in the design solution; the biological entities are either integral parts of the design, or are transformed by the mechatronic system. This article explains how the development and production engineering design principles used for typical mechanical products can be adapted to the demands of biotechnology products, and how electronics, mechanics and biology can be integrated more successfully. We discuss three emerging areas of biotechnology in which mechatronic design principles can apply: stem cell manufacture, artificial organs, and bioreactors. Copyright 2010 Elsevier Ltd. All rights reserved.
Quality Evaluation Focusing on Tissue Fractal Dimension and Chemical Changes for Frozen Tilapia with Treatment by Tangerine Peel Extract

Science.gov (United States)

He, Qi; Yang, Zhao; Gong, Bin; Wang, Jingjing; Xiao, Kaijun; Yang, Shang-Tian

2017-02-01

This work aimed to establish an effective approach to evaluate the quality of frozen fish, focusing on changes in fish tissue structure and chemical composition during storage. Fresh tilapia samples were treated by coating with tangerine peel (TP) extract and then stored at -4, -8 and -18 °C, respectively, for 40 days. The frozen fish tissues were analyzed for structural and chemical changes. Fractal dimension, which quantifies the porous structure formed in the tissue samples, texture properties including hardness and springiness, and moisture content and water activity all decreased during the storage, while the extents of lipid oxidation, measured as peroxide value and thiobarbituric acid concentration, and protein degradation, monitored with total volatile basic nitrogen and trichloroacetic acid soluble peptides, increased. The change rates of these parameters decreased with decreasing the storage temperature and by applying TP extract. A model was developed for predicting fractal dimension, which indicated the quality of preserved tilapia and thus can be used to predict the shelf life under different storage temperatures. The results demonstrated that TP extract could extend the shelf life of frozen tilapia by 35-45% by inhibiting changes in tissue structure, moisture loss, lipid oxidation and protein degradation during frozen storage.
The Design Process and User Focused Digital Spaces

OpenAIRE

Keating, Elaine M.

2004-01-01

This thesis presents a qualitative inquiry into how the graphic design process is being reconfigured within the new digital media landscape. The literature review looks at the historical relationship between graphic design and technology from the invention of the printing press to the personal computer and reviews how this relationship is again affected by the emergence of the computer as a medium for communication. The products of digital design are no longer static and fixed but are dynamic...
A generic methodology for the design of sustainable carbon dioxide utilization processes using superstructure optimization

DEFF Research Database (Denmark)

Frauzem, Rebecca; Gani, Rafiqul

, including as an extractive agent or raw material. Chemical conversion, an important element of utilization, involves the use of carbon dioxide as a reactant in the production of chemical compounds [2]. However, for feasible implementation, a systematic methodology is needed for the design of the utilization......, especially chemical conversion, processes. To achieve this, a generic methodology has been developed, which adopts a three-stage approach consisting in (i) process synthesis, (ii) process design, and (iii) innovative and sustainable design [3]. This methodology, with the individual steps and associated...... methods and tools, has been developed and applied to carbon dioxide utilization networks. This work will focus on the first stage, process synthesis, of this three-stage methodology; process synthesis is important in determining the appropriate processing route to produce products from a selection...
Designing Tailored Messages about Smoking and Breast Cancer: A Focus Group Study with Youth.

Science.gov (United States)

Bottorff, Joan L; Haines-Saah, Rebecca; Oliffe, John L; Struik, Laura L; Bissell, Laura J L; Richardson, Chris P; Gotay, Carolyn; Johnson, Kenneth C; Hutchinson, Peter

2014-03-01

The purpose of this study was to design an approach to supporting the development of gender- and Aboriginal-specific messages regarding the link between tobacco exposure and breast cancer, drawing on youth perspectives. Focus groups were held with 18 girls (8 First Nations and Métis) and 25 boys (12 First Nations and Métis) to solicit advice in the design of messages. Transcribed data were analyzed for themes. Girls preferred messages that included the use of novel images, a personal story of breast cancer, and ways to avoid secondhand smoke. Boys endorsed messages that were "catchy" but not "cheesy" and had masculine themes. First Nations and Métis participants confirmed the use of Aboriginal symbols in messages as signalling their relevance to youth in their communities. The results can be used as a guide in developing tailored health promotion messages. Challenges in developing gender-appropriate messages for youth are described. Copyright© by Ingram School of Nursing, McGill University.
Construction technique for a chemical plant (II)

International Nuclear Information System (INIS)

1978-08-01

This book deals with design and construction for a chemical plant which includes design and building of steel structure for a chemical plant with types, basic regulation, plan, shop fabrication for steel structure and field construction. It explains design and construction of making building for a chemical construction with measurement, types of building and basic rule of the building, design of the building, constructing plumbing for a chemical plant with plan, management of material, checking for construction, construction of electrical installation on plan, know-how to construction and maintenance.
Automatic focusing system of BSST in Antarctic

Science.gov (United States)

Tang, Peng-Yi; Liu, Jia-Jing; Zhang, Guang-yu; Wang, Jian

2015-10-01

Automatic focusing (AF) technology plays an important role in modern astronomical telescopes. Based on the focusing requirement of BSST (Bright Star Survey Telescope) in Antarctic, an AF system is set up. In this design, functions in OpenCV is used to find stars, the algorithm of area, HFD or FWHM are used to degree the focus metric by choosing. Curve fitting method is used to find focus position as the method of camera moving. All these design are suitable for unattended small telescope.
Heat-activated Plasmonic Chemical Sensors for Harsh Environments

Energy Technology Data Exchange (ETDEWEB)

Carpenter, Michael [SUNY Polytechnic Inst., Albany, NY (United States); Oh, Sang-Hyun [Univ. of Minnesota, Minneapolis, MN (United States)

2015-12-01

A passive plasmonics based chemical sensing system to be used in harsh operating environments was investigated and developed within this program. The initial proposed technology was based on combining technologies developed at the SUNY Polytechnic Institute Colleges of Nanoscale Science and Engineering (CNSE) and at the University of Minnesota (UM). Specifically, a passive wireless technique developed at UM was to utilize a heat-activated plasmonic design to passively harvest the thermal energy from within a combustion emission stream and convert this into a narrowly focused light source. This plasmonic device was based on a bullseye design patterned into a gold film using focused ion beam methods (FIB). Critical to the design was the use of thermal stabilizing under and overlayers surrounding the gold film. These stabilizing layers were based on both atomic layer deposited films as well as metal laminate layers developed by United Technologies Aerospace Systems (UTAS). While the bullseye design was never able to be thermally stabilized for operating temperatures of 500oC or higher, an alternative energy harvesting design was developed by CNSE within this program. With this new development, plasmonic sensing results are presented where thermal energy is harvested using lithographically patterned Au nanorods, replacing the need for an external incident light source. Gas sensing results using the harvested thermal energy are in good agreement with sensing experiments, which used an external incident light source. Principal Component Analysis (PCA) was used to reduce the wavelength parameter space from 665 variables down to 4 variables with similar levels of demonstrated selectivity. The method was further improved by patterning rods which harvested energy in the near infrared, which led to a factor of 10 decrease in data acquisition times as well as demonstrated selectivity with a reduced wavelength data set. The combination of a plasmonic-based energy harvesting
Importance of deposit information in the design and execution of steam generator chemical cleaning

International Nuclear Information System (INIS)

Flores, O.; Remark, J.

1997-01-01

During the planning stages of the chemical cleaning of the San Onofre Nuclear Generating Station (SONGS) units 2 and 3 steam generators, it was determined that an understanding of the steam generator deposit loading and composition was essential to the design and success of the project. It was also determined that qualification testing, preferably with actual deposits from the SONGS steam generators, was also essential. SONGS units 2 and 3 have Combustion Engineering (CE)-designed pressurized water reactors. Each unit has two CE model 3410 steam generators. Each steam generator has 9350 alloy 600 tubes with 1.9-cm (3/4 in.) outside diameter. Unit 2 began commercial operation in 1983, and unit 3, in 1984. The purpose of this technical paper is to explain the effort and methodology for deposit composition, characterization, and quantification. In addition, the deposit qualification testing and design of the cleaning are discussed
Design criteria for the new waste calcining facility at the Idaho Chemical Processing Plant

International Nuclear Information System (INIS)

Anderson, F.H.; Bingham, G.E.; Buckham, J.A.; Dickey, B.R.; Slansky, C.M.; Wheeler, B.R.

1976-01-01

The New Waste Calcining Facility (NWCF) at the Idaho Chemical Processing Plant (ICPP) is being built to replace the existing fluidized-bed, high-level waste calcining facility (WCF). Performance of the WCF is reviewed, equipment failures in WCF operation are examined, and pilot-plant studies on calciner improvements are given in relation to NWCF design. Design features of the NWCF are given with emphasis on process and equipment improvements. A major feature of the NWCF is the use of remote maintenance facilities for equipment with high maintenance requirements, thereby reducing personnel exposures during maintenance and reducing downtime resulting from plant decontamination. The NWCF will have a design net processing rate of 11.36 m 3 of high-level waste per day, and will incorporate in-bed combustion of kerosene for heating the fluidized bed calciner. The off-gas cleaning system will be similar to that for the WCF
Global chemical pollution

International Nuclear Information System (INIS)

Travis, C.C.; Hester, S.T.

1991-01-01

Over the past decade, public and governmental awareness of environmental problems has grown steadily, with an accompanying increase in the regulation of point sources of pollution. As a result, great strides have been made in cleaning polluted rivers and decreasing air pollution near factories. However, traditional regulatory approaches to environmental pollution have focused primarily on protecting the maximally exposed individual located in the immediate vicinity of the pollution source. Little attention has been given to the global implications of human production and use of synthetic chemicals. A consensus is emerging that even trace levels of environmental contamination can have potentially devastating environmental consequences. The authors maintain that ambient levels of pollution have risen to the point where human health is being affected on a global scale. Atmospheric transport is recognized as the primary mode of global distribution and entry into the food chain for organic chemicals. The following are examples of global chemical pollutants that result in human exposure of significant proportions: PCBs, dioxins, benzene, mercury and lead. Current regulatory approaches for environmental pollution do not incorporate ways of dealing with global pollution. Instead the major focus has been on protecting the maximally exposed individual. If we do not want to change our standard of living, the only way to reduce global chemical pollution is to make production and consumption processes more efficient and to lower the levels of production of these toxic chemicals. Thus the only reasonable solution to global pollution is not increased regulation of isolated point sources, but rather an increased emphasis on waste reduction and materials recycling. Until we focus on these issues, we will continue to experience background cancer risk in the 10 -3 range
Design of Chemical Literacy Assessment by Using Model of Educational Reconstruction (MER) on Solubility Topic

Science.gov (United States)

Yusmaita, E.; Nasra, Edi

2018-04-01

This research aims to produce instrument for measuring chemical literacy assessment in basic chemistry courses with solubility topic. The construction of this measuring instrument is adapted to the PISA (Programme for International Student Assessment) problem’s characteristics and the Syllaby of Basic Chemistry in KKNI-IndonesianNational Qualification Framework. The PISA is a cross-country study conducted periodically to monitor the outcomes of learners' achievement in each participating country. So far, studies conducted by PISA include reading literacy, mathematic literacy and scientific literacy. Refered to the scientific competence of the PISA study on science literacy, an assessment designed to measure the chemical literacy of the chemistry department’s students in UNP. The research model used is MER (Model of Educational Reconstruction). The validity and reliability values of discourse questions is measured using the software ANATES. Based on the acquisition of these values is obtained a valid and reliable chemical literacy questions.There are seven question items limited response on the topic of solubility with valid category, the acquisition value of test reliability is 0,86, and has a difficulty index and distinguishing good

Investigation of certain physical–chemical features of oil recovery by an optimized alkali–surfactant–foam (ASF) system

NARCIS (Netherlands)

Hosseini Nasab, S.M.; Zitha, P.L.J.

2017-01-01

The objective of this study is to discover a synergistic effect between foam stability in bulk and micro-emulsion phase behaviour to design a high-performance chemical system for an optimized alkaline–surfactant–foam (ASF) flooding for enhanced oil recovery (EOR). The focus is on the interaction
Identification of Chemical Toxicity Using Ontology Information of Chemicals

Directory of Open Access Journals (Sweden)

Zhanpeng Jiang

2015-01-01

Full Text Available With the advance of the combinatorial chemistry, a large number of synthetic compounds have surged. However, we have limited knowledge about them. On the other hand, the speed of designing new drugs is very slow. One of the key causes is the unacceptable toxicities of chemicals. If one can correctly identify the toxicity of chemicals, the unsuitable chemicals can be discarded in early stage, thereby accelerating the study of new drugs and reducing the R&D costs. In this study, a new prediction method was built for identification of chemical toxicities, which was based on ontology information of chemicals. By comparing to a previous method, our method is quite effective. We hope that the proposed method may give new insights to study chemical toxicity and other attributes of chemicals.
Whole Wafer Design and Fabrication for the Alignment of Nanostructures for Chemical Sensor Applications

Science.gov (United States)

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.
Student Teachers' Knowledge about Chemical Representations

Science.gov (United States)

Taskin, Vahide; Bernholt, Sascha; Parchmann, Ilka

2017-01-01

Chemical representations serve as a communication tool not only in exchanges between scientists but also in chemistry lessons. The goals of the present study were to measure the extent of student teachers' knowledge about chemical representations, focusing on chemical formulae and structures in particular, and to explore which factors related to…
Final Focus Systems in Linear Colliders

International Nuclear Information System (INIS)

Raubenheimer, Tor

1998-01-01

In colliding beam facilities, the ''final focus system'' must demagnify the beams to attain the very small spot sizes required at the interaction points. The first final focus system with local chromatic correction was developed for the Stanford Linear Collider where very large demagnifications were desired. This same conceptual design has been adopted by all the future linear collider designs as well as the SuperConducting Supercollider, the Stanford and KEK B-Factories, and the proposed Muon Collider. In this paper, the over-all layout, physics constraints, and optimization techniques relevant to the design of final focus systems for high-energy electron-positron linear colliders are reviewed. Finally, advanced concepts to avoid some of the limitations of these systems are discussed
Design and evaluation of an IGCC power plant using iron-based syngas chemical-looping (SCL) combustion

International Nuclear Information System (INIS)

Sorgenfrei, Max; Tsatsaronis, George

2014-01-01

Highlights: • A new concept for power generation including carbon capture was found. • The air reactor temperature significantly influences the net efficiency. • The use of a CO 2 turbine decreases the net efficiency. • Compared to a conventional IGCC with 90% CO 2 capture the net efficiency increases. - Abstract: Chemical-looping combustion (CLC) is a novel and promising combustion technology with inherent separation of the greenhouse gas CO 2 . This paper focuses on the design and thermodynamic evaluation of an integrated gasification combined-cycle (IGCC) process using syngas chemical looping (SCL) combustion for generating electricity. The syngas is provided by coal gasification; the gas from the gasifier is cleaned using high-temperature gas desulfurization (HGD). In this study, the oxygen carrier iron oxide (Fe 2 O 3 ) is selected to oxidize the syngas in a multistage moving-bed reactor. The resulting reduced iron particles then consist of FeO and Fe 3 O 4 . To create a closed-cycle operation, these particles are partially re-oxidized with steam in a fluidized-bed regenerator to pure Fe 3 O 4 and then fully re-oxidized in a fluidized-bed air combustor to Fe 2 O 3 . One advantage of this process is the co-production of hydrogen diluted with water vapor within the steam regenerator. Both the HGD and CLC systems are not under commercial operation so far. This mixture is fed to a gas turbine for the purpose of generating electricity. The gas turbine is expected to exhibit low NO x emissions due to the high ratio of water in the combustion chamber. Cooling the flue gas in the HRSG condenses the water vapor to yield high-purity CO 2 for subsequent compression and disposal. To evaluate the net efficiency, two conventional syngas gasifiers are considered, namely the BGL slagging gasifier and the Shell entrained-flow gasifier. The option of using a CO 2 turbine after the SCL-fuel reactor is also investigated. A sensitivity analysis is performed on the SCL
"Intelligent" design of molecular materials: Understanding the concepts of design in supramolecular synthesis of network solids

Science.gov (United States)

Moulton, Brian D.

This work endeavors to delineate modern paradigms for crystal engineering, i.e. the design and supramolecular synthesis of functional molecular materials. Paradigms predicated on an understanding of the geometry of polygons and polyhedra are developed. The primary focus is on structural determination by single crystal X-ray crystallography, structural interpretation using a suite of graphical visualization and molecular modeling software, and on the importance of proper graphical representation in the presentation and explanation of crystal structures. A detailed analysis of a selected series of crystal structures is presented. The reduction of these molecular networks to schematic representations that illustrate their fundamental connectivity facilitates the understanding of otherwise complex supramolecular solids. Circuit symbols and Schlafli notation are used to describe the network topologies, which enables networks of different composition and metrics to be easily compared. This reveals that molecular orientations in the crystals and networks are commensurate with networks that can be derived from spherical close packed lattices. The development of a logical design strategy for a new class of materials based on our understanding of the chemical composition and topology of these networks is described. The synthesis and crystal structure of a series of new materials generated by exploitation of this design strategy is presented, in addition to a detailed analysis of the topology of these materials and their relationship to a 'parent' structure. In summary, this dissertation demonstrates that molecular polygons can self-assemble at their vertexes to produce molecular architectures and crystal structures that are consistent with long established geometric dogma. The design strategy represents a potentially broad ranging approach to the design of nanoporous structures from a wide range of chemical components that are based on molecular shape rather than chemical
A concept for a usability focused design method

NARCIS (Netherlands)

Hoolhorst, F.W.B.; van der Voort, Mascha C.

2009-01-01

Many user-centered design methods (UCDM) have been developed within the last decades. However, industry increasingly demands for a new-generation UCDM since only few of the existing UCDM seem to be applicable to the daily design practice. This paper first discusses the main criteria regarding such
Enhanced teaching and student learning through a simulator-based course in chemical unit operations design

Science.gov (United States)

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.
Chemical optimization algorithm for fuzzy controller design

CERN Document Server

Astudillo, Leslie; Castillo, Oscar

2014-01-01

In this book, a novel optimization method inspired by a paradigm from nature is introduced. The chemical reactions are used as a paradigm to propose an optimization method that simulates these natural processes. The proposed algorithm is described in detail and then a set of typical complex benchmark functions is used to evaluate the performance of the algorithm. Simulation results show that the proposed optimization algorithm can outperform other methods in a set of benchmark functions. This chemical reaction optimization paradigm is also applied to solve the tracking problem for the dynamic model of a unicycle mobile robot by integrating a kinematic and a torque controller based on fuzzy logic theory. Computer simulations are presented confirming that this optimization paradigm is able to outperform other optimization techniques applied to this particular robot application
[Focus Notified Bodies. New requirements for designation and monitoring].

Science.gov (United States)

Poos, U; Edelhäuser, R

2014-12-01

For medical devices with a higher risk, Notified Bodies assess whether the manufacturers and their products fulfill the requirements laid down in the European directives on medical devices. Notified Bodies are designated through a designation procedure by the designating authority, in Germany by ZLG. The requirements for the designation arise from the respective annexes of the directives on medical devices. Since these are only minimal criteria, different documents have been compiled on a European and national level to concretize these minimal criteria regarding the organization, quality management system, resources, and certification procedure. The rules of the ZLG are thereby the essential documents for designation in Germany. Moreover, according to Implementing Regulation (EU) no. 912/2013, the European commission and the other European designating authorities also have to be involved in the designation process. The aim of continuous monitoring of the Notified Bodies with assessments on the bodies' premises as well as with observed audits is to ensure the permanent fulfillment of the requirements. If nonconformities are found in a body's quality management system or in its implementation of the conformity assessment procedures, the body is obliged to provide ZLG with a corrective actions plan. In the case that the nonconformities are not resolved in time or critical nonconformities are found, ZLG may take actions, e.g., restrict the scope of designation, suspend, or - as last resort - withdraw the designation.
An Experimental Framework for Generating Evolvable Chemical Systems in the Laboratory

Science.gov (United States)

Baum, David A.; Vetsigian, Kalin

2017-12-01

Most experimental work on the origin of life has focused on either characterizing the chemical synthesis of particular biochemicals and their precursors or on designing simple chemical systems that manifest life-like properties such as self-propagation or adaptive evolution. Here we propose a new class of experiments, analogous to artificial ecosystem selection, where we select for spontaneously forming self-propagating chemical assemblages in the lab and then seek evidence of a response to that selection as a key indicator that life-like chemical systems have arisen. Since surfaces and surface metabolism likely played an important role in the origin of life, a key experimental challenge is to find conditions that foster nucleation and spread of chemical consortia on surfaces. We propose high-throughput screening of a diverse set of conditions in order to identify combinations of "food," energy sources, and mineral surfaces that foster the emergence of surface-associated chemical consortia that are capable of adaptive evolution. Identification of such systems would greatly advance our understanding of the emergence of self-propagating entities and the onset of adaptive evolution during the origin of life.
Toward crustacean without chemicals: a descriptive analysis of consumer response using price comparisons.

Science.gov (United States)

Okpala, Charles Odilichukwu R; Bono, Gioacchino; Pipitone, Vito; Vitale, Sergio; Cannizzaro, Leonardo

2016-01-01

To date, there seems to be limited-to-zero emphasis about how consumers perceive crustacean products subject to either chemical and or non-chemical preservative treatments. In addition, studies that investigated price comparisons of crustacean products subject to either chemical or chemical-free preservative methods seem unreported. This study focused on providing some foundational knowledge about how consumers perceive traditionally harvested crustaceans that are either chemical-treated and or free of chemicals, incorporating price comparisons using a descriptive approach. The study design employed a questionnaire approach via interview using a computer-assisted telephone system and sampled 1,540 participants across five key locations in Italy. To actualize consumer sensitivity, 'price' was the focus given its crucial role as a consumption barrier. Prior to this, variables such as demographic characteristics of participants, frequency of purchasing, quality attributes/factors that limit the consumption of crustaceans were equally considered. By price comparisons, consumers are likely to favor chemical-free (modified atmosphere packaging) crustacean products amid a price increase of up to 15%. But, a further price increase such as by 25% could markedly damage consumers' feelings, which might lead to a considerable number opting out in favor of either chemical-treated or other seafood products. Comparing locations, the studied variables showed no statistical differences ( p >0.05). On the contrary, the response weightings fluctuated across the studied categories. Both response weightings and coefficient of variation helped reveal more about how responses deviated per variable categories. This study has revealed some foundational knowledge about how consumers perceive traditionally harvested crustaceans that were either chemical-treated or subject to chemical-free preservative up to price sensitivity using Italy as a reference case, which is applicable to other parts
Development of High Temperature/High Sensitivity Novel Chemical Resistive Sensor

Energy Technology Data Exchange (ETDEWEB)

Ma, Chunrui [Univ. of Texas, San Antonio, TX (United States); Enriquez, Erik [Univ. of Texas, San Antonio, TX (United States); Wang, Haibing [Univ. of Texas, San Antonio, TX (United States); Xu, Xing [Univ. of Texas, San Antonio, TX (United States); Bao, Shangyong [Univ. of Texas, San Antonio, TX (United States); Collins, Gregory [Univ. of Texas, San Antonio, TX (United States)

2013-08-13

The research has been focused to design, fabricate, and develop high temperature/high sensitivity novel multifunctional chemical sensors for the selective detection of fossil energy gases used in power and fuel systems. By systematically studying the physical properties of the LnBaCo₂O_5+d (LBCO) [Ln=Pr or La] thin-films, a new concept chemical sensor based high temperature chemical resistant change has been developed for the application for the next generation highly efficient and near zero emission power generation technologies. We also discovered that the superfast chemical dynamic behavior and an ultrafast surface exchange kinetics in the highly epitaxial LBCO thin films. Furthermore, our research indicates that hydrogen can superfast diffuse in the ordered oxygen vacancy structures in the highly epitaxial LBCO thin films, which suggest that the LBCO thin film not only can be an excellent candidate for the fabrication of high temperature ultra sensitive chemical sensors and control systems for power and fuel monitoring systems, but also can be an excellent candidate for the low temperature solid oxide fuel cell anode and cathode materials.
Formulation design of oral pediatric Acetazolamide suspension: dose uniformity and physico-chemical stability study.

Science.gov (United States)

Santoveña, Ana; Suárez-González, Javier; Martín-Rodríguez, Cristina; Fariña, José B

2017-03-01

The formulation of an active pharmaceutical ingredient (API) as oral solution or suspension in pediatrics is a habitual practice, due to the non-existence of many commercialized medicines in pediatric doses. It is also the simplest way to prepare and administer them to this vulnerable population. The design of a formulation that assures the dose and the system stability depends on the physico-chemical properties of the API. In this study, we formulate a class IV API, Acetazolamide (AZM) as suspension for oral administration to pediatric population. The suspension must comply attributes of quality, safety and efficacy for this route of administration. We use simple compounding procedures, as well as fewer pure excipients, as recommended for children. Mass and uniformity content assays and physical and chemical stability studies were performed. To quantify the API an UPLC method was used. We verified the physico-chemical stability of the suspensions and that they passed the mass test of the European Pharmacopeia (EP), but not the dose uniformity test. This reveals that AZM must be formulated as liquid forms with a more complex system of excipients (not usually indicated in pediatrics), or otherwise solid forms capable of assuring uniformity of mass and dose for every dosage unit.
ENDOCRINE-DISRUPTING CHEMICALS: PREPUBERTAL EXPOSURES AND EFFECTS ON SEXUAL MATURATION AND THYROID FUNCTION IN THE MALE RAT. A FOCUS ON THE EDSTAC RECOMMENDATIONS. ENDOCRINE DISRUPTER SCREENING AND TESTING ADVISORY COMMITTEE

Science.gov (United States)

Endocrine-disrupting chemicals: prepubertal exposures and effects on sexual maturation and thyroid function in the male rat. A focus on the EDSTAC recommendations. Endocrine Disrupter Screening and Testing Advisory Committee.Stoker TE, Parks LG, Gray LE, Cooper RL.
Incorporation of environmental impact criteria in the design and operation of chemical processes

Directory of Open Access Journals (Sweden)

P.E. Bauer

2004-09-01

Full Text Available Environmental impact assessment is becoming indispensable for the design and operation of chemical plants. Structured and consistent methods for this purpose have experienced a rapid development. The more rigorous and sophisticated these methods become, the greater is the demand for convenient tools. On the other hand, despite the incredible advances in process simulators, some aspects have still not been sufficiently covered. To date, applications of these programs to quantify environmental impacts have been restricted to straightforward examples of steady-state processes. In this work, a life-cycle assessment implementation with the aim of process design will be described, with a brief discussion of a dynamic simulation for analysis of transient state operations, such as process start-up. A case study shows the importance of this analysis in making possible operation at a high performance level with reduced risks to the environment.
Final focus systems for linear colliders

International Nuclear Information System (INIS)

Erickson, R.A.

1987-11-01

The final focus system of a linear collider must perform two primary functions, it must focus the two opposing beams so that their transverse dimensions at the interaction point are small enough to yield acceptable luminosity, and it must steer the beams together to maintain collisions. In addition, the final focus system must transport the outgoing beams to a location where they can be recycled or safely dumped. Elementary optical considerations for linear collider final focus systems are discussed, followed by chromatic aberrations. The design of the final focus system of the SLAC Linear Collider (SLC) is described. Tuning and diagnostics and steering to collision are discussed. Most of the examples illustrating the concepts covered are drawn from the SLC, but the principles and conclusions are said to be generally applicable to other linear collider designs as well. 26 refs., 17 figs
Chemical Leasing business models and corporate social responsibility.

Science.gov (United States)

Moser, Frank; Jakl, Thomas; Joas, Reihard; Dondi, Francesco

2014-11-01

Chemical Leasing is a service-oriented business model that shifts the focus from increasing sales volume of chemicals towards a value-added approach. Recent pilot projects have shown the economic benefits of introducing Chemical Leasing business models in a broad range of sectors. A decade after its introduction, the promotion of Chemical Leasing is still predominantly done by the public sector and international organizations. We show in this paper that awareness-raising activities to disseminate information on this innovative business model mainly focus on the economic benefits. We argue that selling Chemical Leasing business models solely on the grounds of economic and ecological considerations falls short of branding it as a corporate social responsibility initiative, which, for this paper, is defined as a stakeholder-oriented concept that extends beyond the organization's boundaries and is driven by an ethical understanding of the organization's responsibility for the impact of its business activities. For the analysis of Chemical Leasing business models, we introduce two case studies from the water purification and metal degreasing fields, focusing on employees and local communities as two specific stakeholder groups of the company introducing Chemical Leasing. The paper seeks to demonstrate that Chemical Leasing business models can be branded as a corporate social responsibility initiative by outlining the vast potential of Chemical Leasing to improve occupational health and safety and to strengthen the ability of companies to protect the environment from the adverse effects of the chemicals they apply.
Adaptation and focusing of optode configurations for fluorescence optical tomography by experimental design methods.

Science.gov (United States)

Freiberger, Manuel; Clason, Christian; Scharfetter, Hermann

2010-01-01

Fluorescence tomography excites a fluorophore inside a sample by light sources on the surface. From boundary measurements of the fluorescent light, the distribution of the fluorophore is reconstructed. The optode placement determines the quality of the reconstructions in terms of, e.g., resolution and contrast-to-noise ratio. We address the adaptation of the measurement setup. The redundancy of the measurements is chosen as a quality criterion for the optodes and is computed from the Jacobian of the mathematical formulation of light propagation. The algorithm finds a subset with minimum redundancy in the measurements from a feasible pool of optodes. This allows biasing the design in order to favor reconstruction results inside a given region. Two different variations of the algorithm, based on geometric and arithmetic averaging, are compared. Both deliver similar optode configurations. The arithmetic averaging is slightly more stable, whereas the geometric averaging approach shows a better conditioning of the sensitivity matrix and mathematically corresponds more closely with entropy optimization. Adapted illumination and detector patterns are presented for an initial set of 96 optodes placed on a cylinder with focusing on different regions. Examples for the attenuation of fluorophore signals from regions outside the focus are given.

THE USE OF CHEMICALS AS PLANT REGULATORS. AGRICULTURAL CHEMICALS TECHNOLOGY, NUMBER 8.

Science.gov (United States)

Ohio State Univ., Columbus. Center for Vocational and Technical Education.

ONE OF A SERIES DESIGNED TO ASSIST TEACHERS IN PREPARING POST-SECONDARY STUDENTS FOR AGRICULTURAL CHEMICAL OCCUPATIONS, THIS MODULE IS SPECIFICALLY CONCERNED WITH CHEMICALS AS PLANT REGULATORS. IT WAS DEVELOPED BY A NATIONAL TASK FORCE ON THE BASIS OF DATA FROM STATE STUDIES. SECTIONS INCLUDE -- (1) CHEMICALS AS MODIFIERS OF PLANT GROWTH, (2)…
PumpKin: A tool to find principal pathways in plasma chemical models

Science.gov (United States)

Markosyan, A. H.; Luque, A.; Gordillo-Vázquez, F. J.; Ebert, U.

2014-10-01

PumpKin is a software package to find all principal pathways, i.e. the dominant reaction sequences, in chemical reaction systems. Although many tools are available to integrate numerically arbitrarily complex chemical reaction systems, few tools exist in order to analyze the results and interpret them in relatively simple terms. In particular, due to the large disparity in the lifetimes of the interacting components, it is often useful to group reactions into pathways that recycle the fastest species. This allows a researcher to focus on the slow chemical dynamics, eliminating the shortest timescales. Based on the algorithm described by Lehmann (2004), PumpKin automates the process of finding such pathways, allowing the user to analyze complex kinetics and to understand the consumption and production of a certain species of interest. We designed PumpKin with an emphasis on plasma chemical systems but it can also be applied to atmospheric modeling and to industrial applications such as plasma medicine and plasma-assisted combustion.
Participatory design in Parkinson's research with focus on the symptomatic domains to be measured.

Science.gov (United States)

Serrano, J Artur; Larsen, Frank; Isaacs, Tom; Matthews, Helen; Duffen, Joy; Riggare, Sara; Capitanio, Fulvio; Ferreira, Joaquim J; Domingos, Josefa; Maetzler, Walter; Graessner, Holm

2015-01-01

There is a growing interest in the objective assessment of health related outcomes using technology providing quality measurements to be applied not only in daily clinical practice, but also in scientific research. Differences in the understandings of the condition and the terminology used between people with Parkinson's (PwPs), clinicians and technical developers may influence the progress of a participatory design process. This paper reports on a participatory design process to achieve a consensus among PwPs, clinicians and technologists over the selection of a set of symptomatic domains to be continuously assessed, in order to provide results relevant to both PwPs and clinicians. The methods used were a Web based user survey, end-user focus groups, ranking by combined methods, a Delphi process performed among clinicians and scientists, and prioritization of the results in a concertation workshop for PwPs, clinicians and technologists. The following symptomatic domains were commonly agreed by PwPs and clinicians to be of central importance in a system of continuous assessment: hypokinesia/bradykinesia, tremor, sway, gait, sleep and cognition. This list satisfied both the needs of the PwPs and the concerns of the clinicians regarding the means of advancing new strategies in assessment and interventions in PD. A participatory design strategy allowed the definition of a consensual list of symptomatic domains. Both the strategy and the achieved results may be of relevance for similar interdisciplinary approaches in the field of PD using a participatory design involving patients, clinicians and technologists.
Advanced Chemical Propulsion

Science.gov (United States)

Bai, S. Don

2000-01-01

Design, propellant selection, and launch assistance for advanced chemical propulsion system is discussed. Topics discussed include: rocket design, advance fuel and high energy density materials, launch assist, and criteria for fuel selection.
Focus group discussions

CERN Document Server

Hennink, Monique M

2014-01-01

The Understanding Research series focuses on the process of writing up social research. The series is broken down into three categories: Understanding Statistics, Understanding Measurement, and Understanding Qualitative Research. The books provide researchers with guides to understanding, writing, and evaluating social research. Each volume demonstrates how research should be represented, including how to write up the methodology as well as the research findings. Each volume also reviews how to appropriately evaluate published research. Focus Group Discussions addresses the challenges associated with conducting and writing focus group research. It provides detailed guidance on the practical and theoretical considerations in conducting focus group discussions including: designing the discussion guide, recruiting participants, training a field team, moderating techniques and ethical considerations. Monique Hennink describes how a methodology section is read and evaluated by others, such as journal reviewers or ...
Design and processing of nanogels as delivery systems for peptides and proteins

DEFF Research Database (Denmark)

Arnfast, Lærke; Madsen, Claus Greve; Jorgensen, Lene

2014-01-01

and controlled release. The focus of this review is to provide an overview of the recent developments within the nanogel field, and how the chemical design of the nanogel polymer has been found to influence the properties of the nanogel system. Novel nanogel systems are discussed with respect to their type...
A quantitative infrared spectral library of vapor phase chemicals: applications to environmental monitoring and homeland defense

Science.gov (United States)

Sharpe, Steven W.; Johnson, Timothy J.; Sams, Robert L.

2004-12-01

The utility of infrared spectroscopy for monitoring and early warning of accidental or deliberate chemical releases to the atmosphere is well documented. Regardless of the monitoring technique (open-path or extractive) or weather the spectrometer is passive or active (Fourier transform or lidar) a high quality, quantitative reference library is essential for meaningful interpretation of the data. Pacific Northwest National Laboratory through the support of the Department of Energy has been building a library of pure, vapor phase chemical species for the last 4 years. This infrared spectral library currently contains over 300 chemicals and is expected to grow to over 400 chemicals before completion. The library spectra are based on a statistical fit to many spectra at different concentrations, allowing for rigorous error analysis. The contents of the library are focused on atmospheric pollutants, naturally occurring chemicals, toxic industrial chemicals and chemicals specifically designed to do damage. Applications, limitations and technical details of the spectral library will be discussed.
Identification of chemicals related to the chemical weapons convention during an interlaboratory proficiency test

NARCIS (Netherlands)

Hooijschuur, E.W.J.; Hulst, A.G.; Jong, A.L. de; Reuver, L.P. de; Krimpen, S.H. van; Baar, B.L.M. van; Wils, E.R.J.; Kientz, C.E.; Brinkman, U.A.Th

2002-01-01

In order to test the ability of laboratories to detect and identify chemicals related to the Chemical Weapons Convention (CWC), which prohibits the development, production, stockpiling and use of chemical weapons, and to designate laboratories for this task, the Technical Secretariat of the
An integrated multi-label classifier with chemical-chemical interactions for prediction of chemical toxicity effects.

Science.gov (United States)

Liu, Tao; Chen, Lei; Pan, Xiaoyong

2018-05-31

Chemical toxicity effect is one of the major reasons for declining candidate drugs. Detecting the toxicity effects of all chemicals can accelerate the procedures of drug discovery. However, it is time-consuming and expensive to identify the toxicity effects of a given chemical through traditional experiments. Designing quick, reliable and non-animal-involved computational methods is an alternative way. In this study, a novel integrated multi-label classifier was proposed. First, based on five types of chemical-chemical interactions retrieved from STITCH, each of which is derived from one aspect of chemicals, five individual classifiers were built. Then, several integrated classifiers were built by integrating some or all individual classifiers. By testing the integrated classifiers on a dataset with chemicals and their toxicity effects in Accelrys Toxicity database and non-toxic chemicals with their performance evaluated by jackknife test, an optimal integrated classifier was selected as the proposed classifier, which provided quite high prediction accuracies and wide applications. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.
TE-polarized design for metallic slit lenses: a way to deep-subwavelength focusing over a broad wavelength range.

Science.gov (United States)

Zhu, Yechuan; Yuan, Weizheng; Li, Wenli; Sun, Hao; Qi, Kunlun; Yu, Yiting

2018-01-15

Slit arrays based on noble metals have been widely proposed as planar transverse-magnetic (TM)-lenses, illuminated by a linearly polarized light with the polarization perpendicular to slits and implementing the focusing capability beyond the diffraction limit. However, due to intrinsic plasmonic losses, these TM-lenses cannot work efficiently in the ultraviolet wavelengths. In this Letter, taking advantage of the unique transmission through metallic slits not involving plasmonic losses, a metallic slit array with transverse-electric (TE)-polarized design is proposed, showing for the first time, to the best of our knowledge, the realization of sub-diffraction-limit focusing for ultraviolet light. Additionally, in contrast to the situations of TM-lenses, a wider slit leads to a greater phase delay and much larger slits can be arranged to construct the TE-lenses, which is quite beneficial for practical fabrication. Furthermore, deep-subwavelength focusing can be achieved by utilizing the immersing technology.
Design of a high-pressure single pulse shock tube for chemical kinetic investigations

International Nuclear Information System (INIS)

Tranter, R. S.; Brezinsky, K.; Fulle, D.

2001-01-01

A single pulse shock tube has been designed and constructed in order to achieve extremely high pressures and temperatures to facilitate gas-phase chemical kinetic experiments. Postshock pressures of greater than 1000 atmospheres have been obtained. Temperatures greater than 1400 K have been achieved and, in principle, temperatures greater than 2000 K are easily attainable. These high temperatures and pressures permit the investigation of hydrocarbon species pyrolysis and oxidation reactions. Since these reactions occur on the time scale of 0.5--2 ms the shock tube has been constructed with an adjustable length driven section that permits variation of reaction viewing times. For any given reaction viewing time, samples can be withdrawn through a specially constructed automated sampling apparatus for subsequent species analysis with gas chromatography and mass spectrometry. The details of the design and construction that have permitted the successful generation of very high-pressure shocks in this unique apparatus are described. Additional information is provided concerning the diaphragms used in the high-pressure shock tube
Design and implementation of a micron-sized electron column fabricated by focused ion beam milling

Energy Technology Data Exchange (ETDEWEB)

Wicki, Flavio, E-mail: flavio.wicki@physik.uzh.ch; Longchamp, Jean-Nicolas; Escher, Conrad; Fink, Hans-Werner

2016-01-15

We have designed, fabricated and tested a micron-sized electron column with an overall length of about 700 microns comprising two electron lenses; a micro-lens with a minimal bore of 1 micron followed by a second lens with a bore of up to 50 microns in diameter to shape a coherent low-energy electron wave front. The design criteria follow the notion of scaling down source size, lens-dimensions and kinetic electron energy for minimizing spherical aberrations to ensure a parallel coherent electron wave front. All lens apertures have been milled employing a focused ion beam and could thus be precisely aligned within a tolerance of about 300 nm from the optical axis. Experimentally, the final column shapes a quasi-planar wave front with a minimal full divergence angle of 4 mrad and electron energies as low as 100 eV. - Highlights: • Electron optics • Scaling laws • Low-energy electrons • Coherent electron beams • Micron-sized electron column.
Two-Dimensional Photonic Crystals for Sensitive Microscale Chemical and Biochemical Sensing

Science.gov (United States)

Miller, Benjamin L.

2015-01-01

Photonic crystals – optical devices able to respond to changes in the refractive index of a small volume of space – are an emerging class of label-free chemical-and bio-sensors. This review focuses on one class of photonic crystal, in which light is confined to a patterned planar material layer of sub-wavelength thickness. These devices are small (on the order of tens to 100s of microns square), suitable for incorporation into lab-on-a-chip systems, and in theory can provide exceptional sensitivity. We introduce the defining characteristics and basic operation of two-dimensional photonic crystal sensors, describe variations of their basic design geometry, and summarize reported detection results from chemical and biological sensing experiments. PMID:25563402
Plutonium focus area

International Nuclear Information System (INIS)

1996-08-01

To ensure research and development programs focus on the most pressing environmental restoration and waste management problems at the U.S. Department of Energy (DOE), the Assistant Secretary for the Office of Environmental Management (EM) established a working group in August 1993 to implement a new approach to research and technology development. As part of this new approach, EM developed a management structure and principles that led to the creation of specific Focus Areas. These organizations were designed to focus the scientific and technical talent throughout DOE and the national scientific community on the major environmental restoration and waste management problems facing DOE. The Focus Area approach provides the framework for intersite cooperation and leveraging of resources on common problems. After the original establishment of five major Focus Areas within the Office of Technology Development (EM-50, now called the Office of Science and Technology), the Nuclear Materials Stabilization Task Group (EM-66) followed the structure already in place in EM-50 and chartered the Plutonium Focus Area (PFA). The following information outlines the scope and mission of the EM, EM-60, and EM-66 organizations as related to the PFA organizational structure
Chemical Equilibrium And Transport (CET)

Science.gov (United States)

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.
Designer Drug Confusion: A Focus on MDMA.

Science.gov (United States)

Beck, Jerome; Morgan, Patricia A.

1986-01-01

Discusses the competing definitions and issues surrounding various designer drugs, primarily 3, 4-methylenedioxy-methamphetamine (MDMA). Offers a rationale for why interest in MDMA, which possesses both stimulant and psychedelic properties, will continue to grow despite the drug's recent illegality and increasing evidence of neurotoxicity.…
The Chemical Product Simulator - ProCAPD

DEFF Research Database (Denmark)

Kalakul, Sawitree; Eden, Mario Richard; Gani, Rafiqul

2017-01-01

In this paper, a chemical product design simulator called ProCAPD is presented. ProCAPD works in the same way as a chemical process simulator, that is, it helps to verify product design decisions and generates information that can be used to make design decisions. Like the contents of the process...... simulator, the product simulator needs a database of chemicals and properties, a library of models, numerical routines to solve mathematical problems as well as various calculation options. Also, like the process simulator, the product simulator comes with a user-interface to describe the problems.......); calculation tools (product attributes, blend compositions, environmental impact, etc.); design templates (single molecules, blends, formulations, emulsions, devices); and, design-simulation-analysis functions. All these capabilities are based on the prototype tool developed by Kalakul et al. (2017...
Focus on Novel Nanoelectromechanical 3D Structures: Fabrication and Properties

Directory of Open Access Journals (Sweden)

Shooji Yamada, Hiroshi Yamaguchi and Sunao Ishihara

2009-01-01

Full Text Available Microelectromechanical systems (MEMS are widely used small electromechanical systems made of micrometre-sized components. Presently, we are witnessing a transition from MEMS to nanoelectromechanical systems (NEMS, which comprise devices integrating electrical and mechanical functionality on the nanoscale and offer new exciting applications. Similarly to MEMS, NEMS typically include a central transistor-like nanoelectronic unit for data processing, as well as mechanical actuators, pumps, and motors; and they may combine with physical, biological and chemical sensors. In the transition from MEMS to NEMS, component sizes need to be reduced. Therefore, many fabrication methods previously developed for MEMS are unsuitable for the production of high-precision NEMS components. The key challenge in NEMS is therefore the development of new methods for routine and reproducible nanofabrication. Two complementary types of method for NEMS fabrication are available: 'top-down' and 'bottom-up'. The top-down approach uses traditional lithography technologies, whereas bottom-up techniques include molecular self-organization, self-assembly and nanodeposition.The NT2008 conference, held at Ishikawa High-Tech Conference Center, Ishikawa, Japan, between 23–25 October 2008, focused on novel NEMS fabricated from new materials and on process technologies. The topics included compound semiconductors, small mechanical structures, nanostructures for micro-fluid and bio-sensors, bio-hybrid micro-machines, as well as their design and simulation.This focus issue compiles seven articles selected from 13 submitted manuscripts. The articles by Prinz et al and Kehrbusch et al introduce the frontiers of the top-down production of various operational NEMS devices, and Kometani et al present an example of the bottom-up approach, namely ion-beam induced deposition of MEMS and NEMS. The remaining articles report novel technologies for biological sensors. Taira et al have used
Entering new publication territory in chemoinformatics and chemical information science.

Science.gov (United States)

Bajorath, Jürgen

2015-01-01

The F1000Research publishing platform offers the opportunity to launch themed article collections as a part of its dynamic publication environment. The idea of article collections is further expanded through the generation of publication channels that focus on specific scientific areas or disciplines. This editorial introduces the Chemical Information Science channel of F1000Research designed to collate high-quality publications and foster a culture of open peer review. Articles will be selected by guest editor(s) and a group of experts, the channel Editorial Board, and subjected to open peer review.
Evaluation of Chemical Warfare Agent Percutaneous Vapor Toxicity: Derivation of Toxicity Guidelines for Assessing Chemical Protective Ensembles.

Energy Technology Data Exchange (ETDEWEB)

Watson, A.P.

2003-07-24

Percutaneous vapor toxicity guidelines are provided for assessment and selection of chemical protective ensembles (CPEs) to be used by civilian and military first responders operating in a chemical warfare agent vapor environment. The agents evaluated include the G-series and VX nerve agents, the vesicant sulfur mustard (agent HD) and, to a lesser extent, the vesicant Lewisite (agent L). The focus of this evaluation is percutaneous vapor permeation of CPEs and the resulting skin absorption, as inhalation and ocular exposures are assumed to be largely eliminated through use of SCBA and full-face protective masks. Selection of appropriately protective CPE designs and materials incorporates a variety of test parameters to ensure operability, practicality, and adequacy. One aspect of adequacy assessment should be based on systems tests, which focus on effective protection of the most vulnerable body regions (e.g., the groin area), as identified in this analysis. The toxicity range of agent-specific cumulative exposures (Cts) derived in this analysis can be used as decision guidelines for CPE acceptance, in conjunction with weighting consideration towards more susceptible body regions. This toxicity range is bounded by the percutaneous vapor estimated minimal effect (EME{sub pv}) Ct (as the lower end) and the 1% population threshold effect (ECt{sub 01}) estimate. Assumptions of exposure duration used in CPE certification should consider that each agent-specific percutaneous vapor cumulative exposure Ct for a given endpoint is a constant for exposure durations between 30 min and 2 hours.

Additive mixture effects of estrogenic chemicals in human cell-based assays can be influenced by inclusion of chemicals with differing effect profiles.

Directory of Open Access Journals (Sweden)

Richard Mark Evans

Full Text Available A growing body of experimental evidence indicates that the in vitro effects of mixtures of estrogenic chemicals can be well predicted from the estrogenicity of their components by the concentration addition (CA concept. However, some studies have observed small deviations from CA. Factors affecting the presence or observation of deviations could include: the type of chemical tested; number of mixture components; mixture design; and assay choice. We designed mixture experiments that address these factors, using mixtures with high numbers of components, chemicals from diverse chemical groups, assays with different in vitro endpoints and different mixture designs and ratios. Firstly, the effects of mixtures composed of up to 17 estrogenic chemicals were examined using estrogenicity assays with reporter-gene (ERLUX and cell proliferation (ESCREEN endpoints. Two mixture designs were used: 1 a 'balanced' design with components present in proportion to a common effect concentration (e.g. an EC(10 and 2 a 'non-balanced' design with components in proportion to potential human tissue concentrations. Secondly, the individual and simultaneous ability of 16 potential modulator chemicals (each with minimal estrogenicity to influence the assay outcome produced by a reference mixture of estrogenic chemicals was examined. Test chemicals included plasticizers, phthalates, metals, PCBs, phytoestrogens, PAHs, heterocyclic amines, antioxidants, UV filters, musks, PBDEs and parabens. In all the scenarios tested, the CA concept provided a good prediction of mixture effects. Modulation studies revealed that chemicals possessing minimal estrogenicity themselves could reduce (negatively modulate the effect of a mixture of estrogenic chemicals. Whether the type of modulation we observed occurs in practice most likely depends on the chemical concentrations involved, and better information is required on likely human tissue concentrations of estrogens and of potential
Additive mixture effects of estrogenic chemicals in human cell-based assays can be influenced by inclusion of chemicals with differing effect profiles.

Science.gov (United States)

Evans, Richard Mark; Scholze, Martin; Kortenkamp, Andreas

2012-01-01

A growing body of experimental evidence indicates that the in vitro effects of mixtures of estrogenic chemicals can be well predicted from the estrogenicity of their components by the concentration addition (CA) concept. However, some studies have observed small deviations from CA. Factors affecting the presence or observation of deviations could include: the type of chemical tested; number of mixture components; mixture design; and assay choice. We designed mixture experiments that address these factors, using mixtures with high numbers of components, chemicals from diverse chemical groups, assays with different in vitro endpoints and different mixture designs and ratios. Firstly, the effects of mixtures composed of up to 17 estrogenic chemicals were examined using estrogenicity assays with reporter-gene (ERLUX) and cell proliferation (ESCREEN) endpoints. Two mixture designs were used: 1) a 'balanced' design with components present in proportion to a common effect concentration (e.g. an EC(10)) and 2) a 'non-balanced' design with components in proportion to potential human tissue concentrations. Secondly, the individual and simultaneous ability of 16 potential modulator chemicals (each with minimal estrogenicity) to influence the assay outcome produced by a reference mixture of estrogenic chemicals was examined. Test chemicals included plasticizers, phthalates, metals, PCBs, phytoestrogens, PAHs, heterocyclic amines, antioxidants, UV filters, musks, PBDEs and parabens. In all the scenarios tested, the CA concept provided a good prediction of mixture effects. Modulation studies revealed that chemicals possessing minimal estrogenicity themselves could reduce (negatively modulate) the effect of a mixture of estrogenic chemicals. Whether the type of modulation we observed occurs in practice most likely depends on the chemical concentrations involved, and better information is required on likely human tissue concentrations of estrogens and of potential modulators
A review of engineering aspects of intensification of chemical synthesis using ultrasound.

Science.gov (United States)

Sancheti, Sonam V; Gogate, Parag R

2017-05-01

Cavitation generated using ultrasound can enhance the rates of several chemical reactions giving better selectivity based on the physical and chemical effects. The present review focuses on overview of the different reactions that can be intensified using ultrasound followed by the discussion on the chemical kinetics for ultrasound assisted reactions, engineering aspects related to reactor designs and effect of operating parameters on the degree of intensification obtained for chemical synthesis. The cavitational effects in terms of magnitudes of collapse temperatures and collapse pressure, number of free radicals generated and extent of turbulence are strongly dependent on the operating parameters such as ultrasonic power, frequency, duty cycle, temperature as well as physicochemical parameters of liquid medium which controls the inception of cavitation. Guidelines have been presented for the optimum selection based on the critical analysis of the existing literature so that maximum process intensification benefits can be obtained. Different reactor designs have also been analyzed with guidelines for efficient scale up of the sonochemical reactor, which would be dependent on the type of reaction, controlling mechanism of reaction, catalyst and activation energy requirements. Overall, it has been established that sonochemistry offers considerable potential for green and sustainable processing and efficient scale up procedures are required so as to harness the effects at actual commercial level. Copyright © 2016 Elsevier B.V. All rights reserved.
HF/DF chemical labs

International Nuclear Information System (INIS)

Meinzer, R.A.

1987-01-01

This paper provides the essential details to understand and design HF/DF and related types of chemical lasers. The basic operation of the HF/DF chemical laser is described. The details of the excitation chemistry are presented and the pertinent laser physics is described. A description of the various laser components is given and the analytical models for the HF/DF chemical laser are discussed. A brief description of the chain reaction HF/DF chemical laser is offered
Design Features of a Planar Hybrid/Permanent Magnet Strong Focusing Undulator for Free Electron Laser (FEL) And Synchrotron Radiation (SR) Applications

Energy Technology Data Exchange (ETDEWEB)

Tatchyn, Roman; /SLAC

2011-09-09

Insertion devices for Angstrom-wavelength Free Electron Laser (FEL) amplifiers driven by multi-GeV electron beams generally require distributed focusing substantially stronger than their own natural focusing fields. Over the last several years a wide variety of focusing schemes and configurations have been proposed for undulators of this class, ranging from conventional current-driven quadrupoles external to the undulator magnets to permanent magnet (PM) lattices inserted into the insertion device gap. In this paper we present design studies of a flexible high-field hybrid/PM undulator with strong superimposed planar PM focusing proposed for a 1.5 Angstrom Linac Coherent Light Source (LCLS) driven by an electron beam with a 1 mm-mr normalized emittance. Attainable field parameters, tuning modes, and potential applications of the proposed structure are discussed.
Expanding Rational Molecular Design beyond Pharma: Metrics to Guide Safer Chemical Design

Science.gov (United States)

The demand for safer, healthier and sustainable products, materials and processes has been increasing over the past several years. Differentiating which chemicals are relatively less hazardous than others, often referred to as “greener” or “sustainable, demands a comprehensive, h...
Sardasht-Iran cohort study of chemical warfare victims: design and methods.

Science.gov (United States)

Ghazanfari, Tooba; Faghihzadeh, Soghrat; Aragizadeh, Hassan; Soroush, Mohammad-Reza; Yaraee, Roya; Mohammad Hassan, Zuhair; Foroutan, Abbas; Vaez-Mahdavi, Mohammad-Reza; Javadi, Mohammad-Ali; Moaiedmohseni, Sakine; Azizi, Fereidoun; Panahi, Yunes; Mostafaie, Ali; Ghasemi, Hassan; Shams, Jalaleddin; Pourfarzam, Shahryar; Jalali-Nadoushan, Mohammad-Reza; Fallahi, Faramarz; Ebtekar, Massoumeh; Davoudi, Seyyed-Masoud; Ghazanfari, Zeinab; Ardestani, Sussan K; Shariat-Panahi, Shamsa; Moin, Athar; Rezaei, Abbas; Kariminia, Amina; Ajdary, Soheila; Mahmoudi, Mahmoud; Roshan, Rasoul; Ghaderi, Sulayman; Babai, Mahmoud; Naghizadeh, Mohammad-Mehdi; Ghanei, Mohammad-Mostafa

2009-01-01

Insights into long-term clinical consequences of sulfur mustard have emerged from some investigations but less is known about the basic and molecular mechanisms of these complications. Sardasht-Iran Cohort Study is a comprehensive historical cohort study on Sardasht chemical victims' population which was designed to find out the long-term complications of sulfur mustard exposure and the basic mechanisms underlying clinical manifestations. This paper describes the design and methodology of Sardasht-Iran Cohort Study. In Sardasht-Iran Cohort Study, 500 individuals including 372 subjects from Sardasht, as the exposed group, and 128 subjects from Rabat, as the unexposed age-matched control group were evaluated. The exposed group was divided into two groups based on the severity of clinical complications at the time of exposure. Different samples including blood, sputum, saliva, tear, urine, and semen were collected for immunologic, hematologic, biochemical, and other laboratory analysis. Data were gathered from medical records, clinical examinations, laboratory tests, and questionnaires for psychological and lifestyle situations. The important distinctions setting this study apart from the previous ones are discussed. The Sardasht-Iran Cohort Study provides important information on various aspects of long-term consequences of sulfur mustard exposure. This database will provide a better position to suggest guidelines for the diagnosis, treatment, and prevention of delayed complications in the patients exposed to sulfur mustard.
Oslo Art and Design Education (University College 1966–1994 – An educational institution with corporate responsibility and sustainability in focus

Directory of Open Access Journals (Sweden)

Randi Veiteberg Kvellestad

2015-12-01

Full Text Available The artile chronicles the Department of Art, Design and Drama at Oslo and Akershus University College ca. 1950 to 1990. The school bore the name Oslo Art and Design Education College (SLFO from 1966 to 1975 and Oslo Art and Design Education University College from 1975 to 1994. The institution had a clear teaching focus while running extensive programs on professional training, pilot projects and guidance service. The tradition of quality in the choice of material as well as work with engineering and design was strong, but greater emphasis was eventually placed on experimentation with material, tools and techniques. The students were both encouraged and challenged to be creative and rely on their own ideas in experimentation. The article set its focus on change and training in textiles needlework teacher education. The source materials are annual reports, published texts found in the Institute's history collection and interviews of seven employees who worked at the school in part or the whole period. Informants’ arguments and the analysis of texts are related to recent research in Sweden and Norway. The article shows that the institution once stood for attitudes that one would today call sustainable, with strong quality requirements. Thus, the institution showed social responsibility through education and industrial initiatives.
Construction technique for a chemical plant (I)

International Nuclear Information System (INIS)

1978-08-01

This book mentions the order of plant construction, building plant and related regulations, basic engineering design data, provide of equipment, plan and management on building plant, quality control, the budget and contract for building plant, public works for building chemical plant like road construction, basic plan and building for a chemical plant, introduction and principle on foundation improvement method, including pile foundation and design for footing, construction and installation for a chemical plant and a rotary machine for a chemical plant.
Focus on Organic Conductors

Directory of Open Access Journals (Sweden)

Shinya Uji, Takehiko Mori and Toshihiro Takahashi

2009-01-01

Full Text Available Organic materials are usually thought of as electrical insulators. Progress in chemical synthesis, however, has brought us a rich variety of conducting organic materials, which can be classified into conducting polymers and molecular crystals. Researchers can realize highly conducting molecular crystals in charge-transfer complexes, where suitable combinations of organic electron donor or acceptor molecules with counter ions or other organic molecules provide charge carriers. By means of a kind of chemical doping, the charge-transfer complexes exhibit high electrical conductivity and, thanks to their highly crystalline nature, even superconductivity has been observed. This focus issue of Science and Technology of Advanced Materials is devoted to the research into such 'organic conductors'The first organic metal was (TTF(TCNQ, which was found in 1973 to have high conductivity at room temperature and a metal–insulator transition at low temperatures. The first organic superconductor was (TMTSF2PF6, whose superconductivity under high pressures was reported by J´erome in 1980. After these findings, the research on organic conductors exploded. Hundreds of organic conductors have been reported, among which more than one hundred exhibit superconductivity. Recently, a single-component organic conductor has been found with metallic conductivity down to low temperatures.In these organic conductors, in spite of their simple electronic structures, much new physics has arisen from the low dimensionality. Examples are charge and spin density waves, characteristic metal–insulator transitions, charge order, unconventional superconductivity, superconductor–insulator transitions, and zero-gap conductors with Dirac cones. The discovery of this new physics is undoubtedly derived from the development of many intriguing novel organic conductors. High quality single crystals are indispensable to the precise measurement of electronic states.This focus issue
A New Paradigm for Chemical Engineering?

DEFF Research Database (Denmark)

Gani, Rafiqul

evidence of this change comes from the jobs taken by graduating chemical engineering professionals in North America, Europe, and some of the Asian countries. In terms of where the graduating chemical engineers are going to work, a clear shift from the commodity chemical industry to the product oriented...... businesses has been observed. There is an increasing trend within the chemical industry to focus on products and the sustainable processes that can make them. Do these changes point to a paradigm shift in chemical engineering as a discipline? Historically, two previous paradigm shifts in chemical engineering...... corresponded to major shifts in chemical engineering as a discipline, which affected not only the education of chemical engineers, but also the development of chemical engineering as a discipline. Has the time come for a new paradigm shift that will prepare the current and future chemical engineering graduates...
Product design - Molecules, devices, functional products, and formulated products

DEFF Research Database (Denmark)

Gani, Rafiqul; Ng, Ka M.

2015-01-01

Chemical product design is a multidisciplinary and diverse subject. This article provides an overview of product design while focusing on product conceptualization. Four product types are considered - molecular products, formulated products, devices and functional products. For molecular products......, computer-aided design tools are used to predict the physicochemical properties of single molecules and blends. For formulated products, an integrated experiment-modeling approach is used to generate the formula with the specified product attributes. For devices and functional products, conceptual product...... design is carried out by modeling the product based on thermodynamics, kinetics and transport processes, by performing experiments, and by decision making based on rule-based methods The results are product specifications in terms of the type of ingredients, composition, and the structure, form, shape...
Analysis and Study of Safety Problems in Chemical Process Design%化工工艺设计中的安全问题分析与研究

Institute of Scientific and Technical Information of China (English)

王玲

2016-01-01

In the chemical industry,because of the special reaction conditions such as high temperature and high pressure, catalyst and so on,there will be a lot of gas and heat,often dangerous chemicals are added to the reaction,often leading to some safety accidents.Such safety accidents on the lives of people and the interests of chemical companies posed a great threat,so the chemical industry should begiven to the chemical process design in the safety of a high degree of attention to improve the quality of chemical process design,chemical technology as much as possible To avoid the emergence of security issues.The contents and characteristics of the chemical process design,the safety problems in the chemical process design and the countermeasures are discussed.%在化工生产中，因为高温高压、催化剂等特殊的反应条件，会产生大量的气体与热量，加上反应时经常使用危险化学品，常常引发一些安全事故。这类安全事故对人们的生命安全以及化工企业的利益造成了很大的威胁，因此化工企业应给予化工工艺设计中的安全问题高度的重视，提高化工工艺设计质量，在化学工艺中尽可能地避免安全问题的出现。就化工工艺设计的内容与特点、化工工艺设计中存在的安全问题以及解决对策进行了论述。
Chemical systems, chemical contiguity and the emergence of life

Directory of Open Access Journals (Sweden)

Terrence P. Kee

2017-08-01

Full Text Available Charting the emergence of living cells from inanimate matter remains an intensely challenging scientific problem. The complexity of the biochemical machinery of cells with its exquisite intricacies hints at cells being the product of a long evolutionary process. Research on the emergence of life has long been focusing on specific, well-defined problems related to one aspect of cellular make-up, such as the formation of membranes or the build-up of information/catalytic apparatus. This approach is being gradually replaced by a more “systemic” approach that privileges processes inherent to complex chemical systems over specific isolated functional apparatuses. We will summarize the recent advances in system chemistry and show that chemical systems in the geochemical context imply a form of chemical contiguity in the syntheses of the various molecules that precede modern biomolecules.
Chemical defences against herbivores

DEFF Research Database (Denmark)

Pavia, Henrik; Baumgartner, Finn; Cervin, Gunnar

2012-01-01

This chapter focuses on the recent and emerging research involving chemical defences against herbivory in aquatic primary producers. It provides an overview of plant chemical defence theories and highlights recent research on aquatic primary producers addressing a number of aspects...... of these theories, concluding with new chemical approaches to tackle the questions and suggestions for future research directions. It explains that aquatic primary producers are a taxonomically and functionally diverse group of organisms that includes macroalgae, microalgae, and vascular plants. It also states...... that despite the fact that aquatic primary producers constitute a large and diverse group of organisms that vary in their evolutionary histories, selection for chemical defences to resist or reduce grazing are commonplace across the phylogenetic boundaries....
Chemical transport reactions

CERN Document Server

Schäfer, Harald

2013-01-01

Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and
Case study on chemical plant accidents for flow-sheet design of the HTTR-IS system

International Nuclear Information System (INIS)

Homma, Hiroyuki; Sato, Hiroyuki; Kasahara, Seiji; Hara, Teruo; Kato, Ryoma; Sakaba, Nariaki; Ohashi, Hirofumi

2007-02-01

At the present time, we are alarmed by depletion of fossil energy and adverse effect of rapid increase in fossil fuel burning on environment such as climate changes and acid rain, because our lives depend still heavily upon fossil energy. It is thus widely recognized that hydrogen is one of important future energy carriers in which it is used without emission of carbon dioxide greenhouse gas and atmospheric pollutants and that hydrogen demand will increase greatly as fuel cells are developed and applied widely in the near future. To meet massive demand of hydrogen, hydrogen production from water utilizing nuclear, especially by thermochemical water-splitting Iodine-Sulphur (IS) process utilizing heat from High-Temperature Gas-cooled Reactors (HTGRs), offers one of the most attractive zero-emission energy strategies and the only one practical on a substantial scale. However, to establish a technology based for the HTGR hydrogen production by the IS process, we should close several technology gaps through R and D with the High-Temperature Engineering Test Reactor (HTTR), which is the only Japanese HTGR built and operated at the Oarai Research and Development Centre of Japan Atomic Energy Agency (JAEA). We have launched design studies of the IS process hydrogen production system coupled with the HTTR (HTTR-IS system) to demonstrate HTGR hydrogen production. In designing the HTTR-IS system, it is necessary to consider preventive and breakdown maintenance against accidents occurred in the IS process as a chemical plant. This report describes case study on chemical plant accidents relating to the IS process plant and shows a proposal of accident protection measures based on above case study, which is necessary for flow-sheet design of the HTTR-IS system. (author)
Process/Equipment Co-Simulation on Syngas Chemical Looping Process

Energy Technology Data Exchange (ETDEWEB)

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.
VPPD Lab - The Chemical Product Simulator

DEFF Research Database (Denmark)

Kalakul, Sawitree; Hussain, Rehan; Elbashir, Nimir

2015-01-01

, detergent, etc.). It has interface to identify workflow/data-flow for the inter-related activities between knowledge-based system and model-based calculation procedures to systematically, efficiently and robustly solve various types of product design-analysis problems. The application of the software......In this paper, the development of a systematic model-based framework for product design, implemented in the new product design software called VPPD-Lab is presented. This framework employs its in-house knowledge-based system to design and evaluate chemical products. The built-in libraries...... of product performance models and product-chemical property models are used to evaluate different classes of product. The product classes are single molecular structure chemicals (lipids, solvents, aroma, etc.), blended products (gasoline, jet-fuels, lubricants, etc.), and emulsified product (hand wash...
Study on chemical reactivity control of liquid sodium. Research program

International Nuclear Information System (INIS)

Saito, Jun-ichi; Ara, Kuniaki; Sugiyama, Ken-ichiro; Kitagawa, Hiroshi; Oka, Nobuki; Yoshioka, Naoki

2007-01-01

Liquid sodium has the excellent properties as coolant of the fast breeder reactor (FBR). On the other hand, it reacts high with water and oxygen. So an innovative technology to suppress the reactivity is desired. The purpose of this study is to control the chemical reactivity of liquid sodium by dispersing the nanometer-size metallic particles (we call them Nano-particles) into liquid sodium. We focus on the atomic interaction between Nano-particles and sodium atoms. And we try to apply it to suppress the chemical reactivity of liquid sodium. Liquid sodium dispersing Nano-particles is named 'Nano-fluid'. Research programs of this study are the Nano-particles production, the evaluation of reactivity suppression of liquid sodium and the feasibility study to FBR plant. In this paper, the research programs and status are described. The important factors for particle production were understood. In order to evaluate the chemical reactivity of Nano-fluid the research programs were planned. The feasibility of the application of Nano-fluid to the coolant of FBR plant was evaluated preliminarily from the viewpoint of design and operation. (author)

Final focus test beam

International Nuclear Information System (INIS)

1991-03-01

This report discusses the following: the Final Focus Test Beam Project; optical design; magnets; instrumentation; magnetic measurement and BPM calibration; mechanical alignment and stabilization; vacuum system; power supplies; control system; radiation shielding and personnel protection; infrastructure; and administration
Enhancing biomedical design with design thinking.

Science.gov (United States)

Kemnitzer, Ronald; Dorsa, Ed

2009-01-01

The development of biomedical equipment is justifiably focused on making products that "work." However, this approach leaves many of the people affected by these designs (operators, patients, etc.) with little or no representation when it comes to the design of these products. Industrial design is a "user focused" profession which takes into account the needs of diverse groups when making design decisions. The authors propose that biomedical equipment design can be enhanced, made more user and patient "friendly" by adopting the industrial design approach to researching, analyzing, and ultimately designing biomedical products.
A focused fragment library targeting the antibiotic resistance enzyme - Oxacillinase-48: Synthesis, structural evaluation and inhibitor design.

Science.gov (United States)

Akhter, Sundus; Lund, Bjarte Aarmo; Ismael, Aya; Langer, Manuel; Isaksson, Johan; Christopeit, Tony; Leiros, Hanna-Kirsti S; Bayer, Annette

2018-02-10

β-Lactam antibiotics are of utmost importance when treating bacterial infections in the medical community. However, currently their utility is threatened by the emergence and spread of β-lactam resistance. The most prevalent resistance mechanism to β-lactam antibiotics is expression of β-lactamase enzymes. One way to overcome resistance caused by β-lactamases, is the development of β-lactamase inhibitors and today several β-lactamase inhibitors e.g. avibactam, are approved in the clinic. Our focus is the oxacillinase-48 (OXA-48), an enzyme reported to spread rapidly across the world and commonly identified in Escherichia coli and Klebsiella pneumoniae. To guide inhibitor design, we used diversely substituted 3-aryl and 3-heteroaryl benzoic acids to probe the active site of OXA-48 for useful enzyme-inhibitor interactions. In the presented study, a focused fragment library containing 49 3-substituted benzoic acid derivatives were synthesised and biochemically characterized. Based on crystallographic data from 33 fragment-enzyme complexes, the fragments could be classified into R 1 or R 2 binders by their overall binding conformation in relation to the binding of the R 1 and R 2 side groups of imipenem. Moreover, binding interactions attractive for future inhibitor design were found and their usefulness explored by the rational design and evaluation of merged inhibitors from orthogonally binding fragments. The best inhibitors among the resulting 3,5-disubstituted benzoic acids showed inhibitory potential in the low micromolar range (IC 50  = 2.9 μM). For these inhibitors, the complex X-ray structures revealed non-covalent binding to Arg250, Arg214 and Tyr211 in the active site and the interactions observed with the mono-substituted fragments were also identified in the merged structures. Copyright © 2018 Elsevier Masson SAS. All rights reserved.
Enhanced Etching, Surface Damage Recovery, and Submicron Patterning of Hybrid Perovskites using a Chemically Gas-Assisted Focused-Ion Beam for Subwavelength Grating Photonic Applications

KAUST Repository

Alias, Mohd Sharizal

2015-12-22

The high optical gain and absorption of organic–inorganic hybrid perovskites have attracted attention for photonic device applications. However, owing to the sensitivity of organic moieties to solvents and temperature, device processing is challenging, particularly for patterning. Here, we report the direct patterning of perovskites using chemically gas-assisted focused-ion beam (GAFIB) etching with XeF2 and I2 precursors. We demonstrate etching enhancement in addition to controllability and marginal surface damage compared to focused-ion beam (FIB) etching without precursors. Utilizing the GAFIB etching, we fabricated a uniform and periodic submicron perovskite subwavelength grating (SWG) absorber with broadband absorption and nanoscale precision. Our results demonstrate the use of FIB as a submicron patterning tool and a means of providing surface treatment (after FIB patterning to minimize optical loss) for perovskite photonic nanostructures. The SWG absorber can be patterned on perovskite solar cells to enhance the device efficiency through increasing light trapping and absorption.
HINS Linac front end focusing system R&D

Energy Technology Data Exchange (ETDEWEB)

Apollinari, G.; Carcagno, R.H.; Dimarco, J.; Huang, Y.; Kashikhin, V.V.; Orris, D.F.; Page, T.M.; Rabehl, R.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; /Fermilab /Argonne

2008-08-01

This report summarizes current status of an R&D program to develop a focusing system for the front end of a superconducting RF linac. Superconducting solenoids will be used as focusing lenses in the low energy accelerating sections of the front end. The development of focusing lenses for the first accelerating section is in the production stage, and lens certification activities are in preparation at FNAL. The report contains information about the focusing lens design and performance, including solenoid, dipole corrector, and power leads, and about cryogenic system design and performance. It also describes the lens magnetic axis position measurement technique and discusses scope of an acceptance/certification process.
DESIGNING GREENER SOLVENTS

Science.gov (United States)

Computer-aided design of chemicals and chemical mixtures provides a powerful tool to help engineers identify cleaner process designs and more-benign alternatives to toxic industrial solvents. Three software programs are discussed: (1) PARIS II (Program for Assisting the Replaceme...
Amineborane Based Chemical Hydrogen Storage - Final Report

International Nuclear Information System (INIS)

Sneddon, Larry G.

2011-01-01

The development of efficient and safe methods for hydrogen storage is a major hurdle that must be overcome to enable the use of hydrogen as an alternative energy carrier. The objectives of this project in the DOE Center of Excellence in Chemical Hydride Storage were both to develop new methods for on-demand, low temperature hydrogen release from chemical hydrides and to design high-conversion off-board methods for chemical hydride regeneration. Because of their reactive protic (N-H) and hydridic (B-H) hydrogens and high hydrogen contents, amineboranes such as ammonia borane, NH 3 BH 3 (AB), 19.6-wt% H 2 , and ammonia triborane NH 3 B 3 H 7 (AT), 17.7-wt% H 2 , were initially identified by the Center as promising, high-capacity chemical hydrogen storage materials with the potential to store and deliver molecular hydrogen through dehydrogenation and hydrolysis reactions. In collaboration with other Center partners, the Penn project focused both on new methods to induce amineborane H 2 -release and on new strategies for the regeneration the amineborane spent-fuel materials. The Penn approach to improving amineborane H 2 -release focused on the use of ionic liquids, base additives and metal catalysts to activate AB dehydrogenation and these studies successfully demonstrated that in ionic liquids the AB induction period that had been observed in the solid-state was eliminated and both the rate and extent of AB H2-release were significantly increased. These results have clearly shown that, while improvements are still necessary, many of these systems have the potential to achieve DOE hydrogen-storage goals. The high extent of their H 2 -release, the tunability of both their H 2 materials weight-percents and release rates, and their product control that is attained by either trapping or suppressing unwanted volatile side products, such as borazine, continue to make AB/ionic-liquid based systems attractive candidates for chemical hydrogen storage applications. These
Amineborane Based Chemical Hydrogen Storage - Final Report

Energy Technology Data Exchange (ETDEWEB)

Sneddon, Larry G.

2011-04-21

The development of efficient and safe methods for hydrogen storage is a major hurdle that must be overcome to enable the use of hydrogen as an alternative energy carrier. The objectives of this project in the DOE Center of Excellence in Chemical Hydride Storage were both to develop new methods for on-demand, low temperature hydrogen release from chemical hydrides and to design high-conversion off-board methods for chemical hydride regeneration. Because of their reactive protic (N-H) and hydridic (B-H) hydrogens and high hydrogen contents, amineboranes such as ammonia borane, NH3BH3 (AB), 19.6-wt% H2, and ammonia triborane NH3B3H7 (AT), 17.7-wt% H2, were initially identified by the Center as promising, high-capacity chemical hydrogen storage materials with the potential to store and deliver molecular hydrogen through dehydrogenation and hydrolysis reactions. In collaboration with other Center partners, the Penn project focused both on new methods to induce amineborane H2-release and on new strategies for the regeneration the amineborane spent-fuel materials. The Penn approach to improving amineborane H2-release focused on the use of ionic liquids, base additives and metal catalysts to activate AB dehydrogenation and these studies successfully demonstrated that in ionic liquids the AB induction period that had been observed in the solid-state was eliminated and both the rate and extent of AB H2-release were significantly increased. These results have clearly shown that, while improvements are still necessary, many of these systems have the potential to achieve DOE hydrogen-storage goals. The high extent of their H2-release, the tunability of both their H2 materials weight-percents and release rates, and their product control that is attained by either trapping or suppressing unwanted volatile side products, such as borazine, continue to make AB/ionic-liquid based systems attractive candidates for chemical hydrogen storage applications. These studies also
Plasma focus project

International Nuclear Information System (INIS)

Sahlin, H.L.

1975-12-01

The primary objective of this project is to provide a relatively simple pulsed power source for high density pulsed fusion studies with a variety of DT and other fusion microexplosion targets. The plasma focus operated on DT at 1 MJ should produce greater than or equal to 10 15 DT neutrons per pulse corresponding to 2800 J of nuclear energy release and for low pressure operation and appropriately configured high Z anode center should yield an x-ray burst of about 1000 J with a substantial fraction of this x-ray energy concentrated in the 5-100 kV range. Because of its x-ray and neutron production potential, the operation of the focus as an x-ray source is also under study and an initial design study for a repetitively pulsed 1 MJ plasma focus as a pulsed neutron materials testing source has been completed. The plasma focus seems particularly appropriate for application as a materials testing source for pulsed fusion reactors, for example, based on laser driven fusion microexplosions. The construction status of the device is described
Meta-Analysis of the Chemical and Non-Chemical Stressors Affecting Childhood Obesity?

Science.gov (United States)

Background: Worldwide, approximately 42 million children under the age of 5 years are considered overweight or obese. While much research has focused on individual behaviors impacting obesity, little research has emphasized the complex interactions of numerous chemical and non-ch...
Green chemistry for chemical synthesis

OpenAIRE

Li, Chao-Jun; Trost, Barry M.

2008-01-01

Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign.
Green chemistry for chemical synthesis.

Science.gov (United States)

Li, Chao-Jun; Trost, Barry M

2008-09-09

Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign.
Managing the impacts of endocrine disrupting chemicals in wastewater-impacted streams

Science.gov (United States)

Journey, Celeste A.; Bradley, Paul M.; Kolpin, Dana W.; Bradley, Paul M.

2013-01-01

A revolution in analytical instrumentation circa 1920 greatly improved the ability to characterize chemical substances [1]. This analytical foundation resulted in an unprecedented explosion in the design and production of synthetic chemicals during and post-World War II. What is now often referred to as the 2nd Chemical Revolution has provided substantial societal benefits; with modern chemical design and manufacturing supporting dramatic advances in medicine, increased food production, and expanding gross domestic products at the national and global scales as well as improved health, longevity, and lifestyle convenience at the individual scale [1, 2]. Presently, the chemical industry is the largest manufacturing sector in the United States (U.S.) and the second largest in Europe and Japan, representing approximately 5% of the Gross Domestic Product (GDP) in each of these countries [2]. At the turn of the 21st century, the chemical industry was estimated to be worth more than $1.6 trillion and to employ over 10 million people, globally [2]. During the first half of the 20th century, the chemical sector expanded rapidly, the chemical industry enjoyed a generally positive status in society, and chemicals were widely appreciated as fundamental to individual and societal quality of life. Starting in the 1960s, however, the environmental costs associated with the chemical industry increasingly became the focus, due in part to the impact of books like “Silent Spring” [3] and “Our Stolen Future” [4] and to a number of highly publicized environmental disasters. Galvanizing chemical industry disasters included the 1976 dioxin leak north of Milan, Italy, the Love Canal evacuations in Niagara, New York beginning in 1978, and the Union Carbide leak in Bhopal, India in 1984 [2]. Understanding the environmental impact of synthetic compounds is essential to any informed assessment of net societal benefit, for the simple reason that any chemical substance that is in
Managing the effects of endocrine disrupting chemicals in wastewater-impacted streams

Science.gov (United States)

Bradley, Paul M.; Kolpin, Dana W.

2013-01-01

A revolution in analytical instrumentation circa 1920 greatly improved the ability to characterize chemical substances. This analytical foundation resulted in an unprecedented explosion in the design and production of synthetic chemicals during and post-World War II. What is now often referred to as the 2nd Chemical Revolution has provided substantial societal benefits; with modern chemical design and manufacturing supporting dramatic advances in medicine, increased food production, and expanding gross domestic products at the national and global scales as well as improved health, longevity, and lifestyle convenience at the individual scale. Presently, the chemical industry is the largest manufacturing sector in the United States (U.S.) and the second largest in Europe and Japan, representing approximately 5% of the Gross Domestic Product (GDP) in each of these countries. At the turn of the 21st century, the chemical industry was estimated to be worth more than $1.6 trillion and to employ over 10 million people, globally. During the first half of the 20th century, the chemical sector expanded rapidly, the chemical industry enjoyed a generally positive status in society, and chemicals were widely appreciated as fundamental to individual and societal quality of life. Starting in the 1960s, however, the environmental costs associated with the chemical industry increasingly became the focus, due in part to the impact of books like “Silent Spring” and “Our Stolen Future” and to a number of highly publicized environmental disasters. Galvanizing chemical industry disasters included the 1976 dioxin leak north of Milan, Italy, the Love Canal evacuations in Niagara, New York beginning in 1978, and the Union Carbide leak in Bhopal, India in 1984. Understanding the environmental impact of synthetic compounds is essential to any informed assessment of net societal benefit, for the simple reason that any chemical substance that is in commercial production or use will
Design of a new focused multipassage mass spectrometer

Energy Technology Data Exchange (ETDEWEB)

Boulanger, P [National Research Council of Canada, Ottawa, ON (Canada). Photonic and Sensors Section; Baril, M [Laval Univ., Quebec City (Canada). Dept. de Physique

1990-12-01

This paper descirbes a new type of multipassage mass spectrometer using tricylindrical mirrors as reflexive elements and a symmetric quadrupolar lens triplet as focusing element. We study the first order optics and then emphasize on beam transport problems as well as on conditions for maximum mass resolution. The effect of first and second order aberrations on the ultimate resolution of the spectrometer and the procedure for minimizing them by selecting proper operating conditions are discussed. The contributions of the third order aberration terms and of space charge are not considered. (orig.).
Chemical sensors

International Nuclear Information System (INIS)

Hubbard, C.W.; Gordon, R.L.

1987-05-01

The revolution in analytical chemistry promised by recent developments in the field of chemical sensors has potential for significant positive impact on both research and production activities conducted by and for the Department of Energy. Analyses which were, in the past, performed only with a roomful of expensive equipment can now be performed with miniature solid-state electronic devices or small optical probes. Progress in the development of chemical sensors has been rapid, and the field is currently growing at a great rate. In accordance, Pacific Northwest Laboratory initiated a survey of recent literature so that contributors to active programs in research on analytical methods could be made aware of principles and applications of this new technology. This report presents the results of that survey. The sensors discussed here are divided into three types: micro solid-state devices, optical sensors, and piezoelectric crystal devices. The report is divided into three corresponding sections. The first section, ''Micro Solid-State Devices,'' discusses the design, operation, and application of electronic sensors that are produced in much the same way as standard solid-state electronic devices. The second section, ''Optrodes,'' covers the design and operation of chemical sensors that use fiber optics to detect chemically induced changes in optical properties. The final section, ''Piezoelectric Crystal Detectors,'' discusses two types of chemical sensors that depend on the changes in the properties of an oscillating piezoelectric crystal to detect the presence of certain materials. Advantages and disadvantages of each type of sensor are summarized in each section
Off-design performance of a chemical looping combustion (CLC) combined cycle: effects of ambient temperature

Science.gov (United States)

Chi, Jinling; Wang, Bo; Zhang, Shijie; Xiao, Yunhan

2010-02-01

The present work investigates the influence of ambient temperature on the steady-state off-design thermodynamic performance of a chemical looping combustion (CLC) combined cycle. A sensitivity analysis of the CLC reactor system was conducted, which shows that the parameters that influence the temperatures of the CLC reactors most are the flow rate and temperature of air entering the air reactor. For the ambient temperature variation, three off-design control strategies have been assumed and compared: 1) without any Inlet Guide Vane (IGV) control, 2) IGV control to maintain air reactor temperature and 3) IGV control to maintain constant fuel reactor temperature, aside from fuel flow rate adjusting. Results indicate that, compared with the conventional combined cycle, due to the requirement of pressure balance at outlet of the two CLC reactors, CLC combined cycle shows completely different off-design thermodynamic characteristics regardless of the control strategy adopted. For the first control strategy, temperatures of the two CLC reactors both rise obviously as ambient temperature increases. IGV control adopted by the second and the third strategy has the effect to maintain one of the two reactors' temperatures at design condition when ambient temperature is above design point. Compare with the second strategy, the third would induce more severe decrease of efficiency and output power of the CLC combined cycle.
Study of New Materials Design based on Hadoop

Directory of Open Access Journals (Sweden)

Wu Jun

2016-01-01

Full Text Available With the rapid development of information technology, the scientific research shows that the data mining and other information technology could be used in the design of new materials. It is explicit that Intelligent Materials research focuses on using physical and chemical principles combined with computer techniques such as Big Data, Cloud computing and Intelligent modeling and simulation to solve chemical problems. In this paper, based on the cluster based outlier algorithm as the main body, this paper discusses the definition New Materials research In the Hadoop cloud platform, and the parallel processing of Map-Reduce model. The performance this model of new material was established by using the method of Map-Reduction provided the basis for the performance optimization.
Research on the Design of Automatic Instrument in Chemical Industry%化工企业中自动化仪表的设计探究

Institute of Scientific and Technical Information of China (English)

鞠伟亚

2015-01-01

The production and operation environment of chemical enterprises is high pressure, high temperature, vacuum and other special environment, but in this special environment, automatic instrument plays a very important role. Therefore, we must do a good job in the design of chemical enterprise automation instrument; improve the stability and reliability of the automation instrument. Through the analysis of common chemical enterprise automatic instrument classification and instrument design selection, this paper describes the chemical enterprise automation instrument design technology, for reference.%化工企业的生产运营环境多是高压、高温、真空等特殊环境,而在这种特殊环境中,自动化仪表发挥着非常重要的作用.因此,必须做好化工企业的自动化仪表设计工作,提高自动化仪表的稳定性和可靠性.通过分析常见的化工企业自动化仪表分类和仪表设计选型,阐述了化工企业自动化仪表设计技术,以供参考.
QUIC: a chemical kinetics code for use with the chemical equilibrium code QUIL

International Nuclear Information System (INIS)

Lunsford, J.L.

1977-10-01

A chemical rate kinetics code QUIC is described, along with a support code RATE. QUIC is designed to allow chemical kinetics calculations on a wide variety of chemical environments while operating in the overlay environment of the chemical equilibrium code QUIL. QUIC depends upon a rate-data library called LIBR. This library is maintained by RATE. RATE enters into the library all reactions in a standardized format. The code QUIC, operating in conjunction with QUIL, is interactive and written to be used from a remote terminal, with paging control provided. Plotted output is also available

Whole system chemical geothermometry

International Nuclear Information System (INIS)

Pang Zhonghe

1999-01-01

Chemical and isotopic geothermometers are equations or models based on temperature dependent chemical reactions or isotope equilibrium fractionation reactions from which equilibrium temperatures of these reactions can be calculated. The major drawback of all the conventional geothermometry methods lies in their incapability on making a judgement on the equilibrium status of the studied systems. This review will focus on two of recent approaches in this field. Zhangzhou Geothermal Field in SE China will be used as an example to demonstrate the applications
Chemical transformations of chlorophyll and its application in the design of a new generation of environmentally safe dyes

International Nuclear Information System (INIS)

Berezin, Boris D; Rumyantseva, Svetlana V; Moryganov, Andrey P; Berezin, Mikhail B

2004-01-01

Chemical transformations of chlorophyll and physicochemical properties of its derivatives are considered. These compounds can be used in the design of a new generation of chlorophyll- and porphyrin-based dyes environmentally more safe than currently used arene dyes and possessing renewable sources of raw materials. The first results on the use of chlorophyll derivatives for dyeing wool, acetate fibres and cotton are reported.
Chemical transformations of chlorophyll and its application in the design of a new generation of environmentally safe dyes

Energy Technology Data Exchange (ETDEWEB)

Berezin, Boris D; Rumyantseva, Svetlana V; Moryganov, Andrey P; Berezin, Mikhail B [Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo (Russian Federation)

2004-02-28

Chemical transformations of chlorophyll and physicochemical properties of its derivatives are considered. These compounds can be used in the design of a new generation of chlorophyll- and porphyrin-based dyes environmentally more safe than currently used arene dyes and possessing renewable sources of raw materials. The first results on the use of chlorophyll derivatives for dyeing wool, acetate fibres and cotton are reported.
Mechanical design of multiple zone plates precision alignment apparatus for hard X-ray focusing in twenty-nanometer scale

Energy Technology Data Exchange (ETDEWEB)

Shu, Deming; Liu, Jie; Gleber, Sophie C.; Vila-Comamala, Joan; Lai, Barry; Maser, Jorg M.; Roehrig, Christian; Wojcik, Michael J.; Vogt, Franz Stefan

2017-04-04

An enhanced mechanical design of multiple zone plates precision alignment apparatus for hard x-ray focusing in a twenty-nanometer scale is provided. The precision alignment apparatus includes a zone plate alignment base frame; a plurality of zone plates; and a plurality of zone plate holders, each said zone plate holder for mounting and aligning a respective zone plate for hard x-ray focusing. At least one respective positioning stage drives and positions each respective zone plate holder. Each respective positioning stage is mounted on the zone plate alignment base frame. A respective linkage component connects each respective positioning stage and the respective zone plate holder. The zone plate alignment base frame, each zone plate holder and each linkage component is formed of a selected material for providing thermal expansion stability and positioning stability for the precision alignment apparatus.
Views on chemical safety information and influences on chemical disposal behaviour in the UK

International Nuclear Information System (INIS)

Hinks, J.; Bush, J.; Andras, P.; Garratt, J.; Pigott, G.; Kennedy, A.; Pless-Mulloli, T.

2009-01-01

This study examined how groups representing four tiers in the chemical supply chain (manufacturers, vendors, workers and consumers) understood safety information, and the factors that influenced disposal behaviour. Data from seven, semi-structured, focus groups was analysed both qualitatively (textual analysis) and quantitatively (network analysis). Such combined analytical methods enabled us to achieve both detailed insights into perceptions and behaviour and an objective understanding of the prevailing opinions that occurred within and between the focus group discussions. We found issues around awareness, trust, access and disposal behaviours differed between groups within the supply chain. Participants from the lower tiers perceived chemical safety information to be largely inaccessible. Labels were the main source of information on chemical risks for the middle and bottom tiers of the supply chain. Almost all of the participants were aware of the St Andrew's Cross and skull and crossbones symbols but few were familiar with the Volatile Organic Compound logo or the fish and tree symbol. Both the network and thematic analysis demonstrated that whilst frequent references to health risks associated with chemicals were made environmental risks were usually only articulated after prompting. It is clear that the issues surrounding public understanding of chemical safety labels are highly complex and this is compounded by inconsistencies in the cognitive profiles of chemical users. Substantially different cognitive profiles are likely to contribute towards communication difficulties between different tiers of the supply chain. Further research is needed to examine the most effective ways of communicating chemical hazards information to the public. The findings demonstrate a need to improve and simplify disposal guidance to members of the public, to raise public awareness of the graphic symbols in the CHIP 3.1, 2005 regulations and to improve access to disposal guidance
Weighted voting-based consensus clustering for chemical structure databases

Science.gov (United States)

Saeed, Faisal; Ahmed, Ali; Shamsir, Mohd Shahir; Salim, Naomie

2014-06-01

The cluster-based compound selection is used in the lead identification process of drug discovery and design. Many clustering methods have been used for chemical databases, but there is no clustering method that can obtain the best results under all circumstances. However, little attention has been focused on the use of combination methods for chemical structure clustering, which is known as consensus clustering. Recently, consensus clustering has been used in many areas including bioinformatics, machine learning and information theory. This process can improve the robustness, stability, consistency and novelty of clustering. For chemical databases, different consensus clustering methods have been used including the co-association matrix-based, graph-based, hypergraph-based and voting-based methods. In this paper, a weighted cumulative voting-based aggregation algorithm (W-CVAA) was developed. The MDL Drug Data Report (MDDR) benchmark chemical dataset was used in the experiments and represented by the AlogP and ECPF_4 descriptors. The results from the clustering methods were evaluated by the ability of the clustering to separate biologically active molecules in each cluster from inactive ones using different criteria, and the effectiveness of the consensus clustering was compared to that of Ward's method, which is the current standard clustering method in chemoinformatics. This study indicated that weighted voting-based consensus clustering can overcome the limitations of the existing voting-based methods and improve the effectiveness of combining multiple clusterings of chemical structures.
Synthesis of focusing-and-deflection columns

International Nuclear Information System (INIS)

Szilagyi, M.; Mui, P.H.

1995-01-01

Szilagyi and Szep have demonstrated that focusing lenses of high performances can be constructed from a column of circular plate electrodes. Later, Szilagyi modified that system to include dipole, quadrupole, and octupole components by partitioning each plate into eight equal sectors. It has already been shown that the additional quadrupole components can indeed bring about substantial improvements in the focusing of charged particle beams. In this article, that design procedure is expanded to construct columns capable of both focusing and deflecting particle beams by just introducing additional dipole components. In this new design, the geometry of the system remains unchanged. The only extra complication is the demand for more individual controls of the sector voltages. Two sample designs, one for negative ions and one for electrons, are presented showing that in both cases a ±2.3 mrad diverging beam can be focused down to a spot of less than 50 nm in radius over a scanning circular area of radius 0.25 mm. The details of the two systems are given in Sec. IV along with the source conditions. The performance of the negative ion system is found to be comparable to the published data. For the relativistic electron system, the interaction of individual components to reduce various aberrations is investigated. copyright 1995 American Vacuum Society
Final focus designs for crab waist colliders

Directory of Open Access Journals (Sweden)

A. Bogomyagkov

2016-12-01

Full Text Available The crab waist collision scheme promises significant luminosity gain. The successful upgrade of the DAΦNE collider proved the principle of crab waist collision and increased luminosity 3 times. Therefore, several new projects try to implement the scheme. The paper reviews interaction region designs with the crab waist collision scheme for already existent collider DAΦNE and SuperKEKB, presently undergoing commissioning, for the projects of SuperB in Italy, CTau in Novosibirsk and FCC-ee at CERN.
The Role of Diet in Shaping the Chemical Signal Design of Lacertid Lizards.

Science.gov (United States)

Baeckens, Simon; García-Roa, Roberto; Martín, José; Van Damme, Raoul

2017-09-01

Lizards communicate with others via chemical signals, the composition of which may vary among species. Although the selective pressures and constraints affecting chemical signal diversity at the species level remain poorly understood, the possible role of diet has been largely neglected. The chemical signals of many lizards originate from the femoral glands that exude a mixture of semiochemicals, and may be used in a variety of contexts. We analyzed the lipophilic fraction of the glandular secretions of 45 species of lacertid lizard species by gas chromatography/mass spectrometry. The proportions of nine major chemical classes (alcohols, aldehydes, fatty acids, furanones, ketones, steroids, terpenoids, tocopherols and waxy esters), the relative contributions of these different classes ('chemical diversity'), and the total number of different lipophilic compounds ('chemical richness') varied greatly among species. We examined whether interspecific differences in these chemical variables could be coupled to interspecific variation in diet using data from the literature. In addition, we compared chemical signal composition among species that almost never, occasionally, or often eat plant material. We found little support for the hypothesis that the chemical profile of a given species' secretion depends on the type of food consumed. Diet breadth did not correlate with chemical diversity or richness. The amount of plants or ants consumed did not affect the relative contribution of any of the nine major chemical classes to the secretion. Chemical diversity did not differ among lizards with different levels of plant consumption; however, chemical richness was low in species with an exclusive arthropod diet, suggesting that incorporating plants in the diet enables lizards to increase the number of compounds allocated to secretions, likely because a (partly) herbivorous diet allows them to include compounds of plant origin that are unavailable in animal prey. Still, overall
Development and Analysis of Group Contribution Plus Models for Property Prediction of Organic Chemical Systems

DEFF Research Database (Denmark)

Mustaffa, Azizul Azri

for the GIPs are then used in the UNIFAC model to calculate activity coefficients. This approach can increase the application range of any “host” UNIFAC model by providing a reliable predictive model towards fast and efficient product development. This PhD project is focused on the analysis and further......Prediction of properties is important in chemical process-product design. Reliable property models are needed for increasingly complex and wider range of chemicals. Group-contribution methods provide useful tool but there is a need to validate them and improve their accuracy when complex chemicals...... are present in the mixtures. In accordance with that, a combined group-contribution and atom connectivity approach that is able to extend the application range of property models has been developed for mixture properties. This so-called Group-ContributionPlus (GCPlus) approach is a hybrid model which combines...
Target discovery focused approaches to overcome bottlenecks in the exploitation of antimycobacterial natural products.

Science.gov (United States)

Baptista, Rafael; Bhowmick, Sumana; Nash, Robert J; Baillie, Les; Mur, Luis Aj

2018-04-01

Tuberculosis is a major global health hazard. The search for new antimycobacterials has focused on such as screening combinational chemistry libraries or designing chemicals to target predefined pockets of essential bacterial proteins. The relative ineffectiveness of these has led to a reappraisal of natural products for new antimycobacterial drug leads. However, progress has been limited, we suggest through a failure in many cases to define the drug target and optimize the hits using this information. We highlight methods of target discovery needed to develop a drug into a candidate for clinical trials. We incorporate these into suggested analysis pipelines which could inform the research strategies to accelerate the development of new drug leads from natural products.
Exploring road design factors influencing tram road safety - Melbourne tram driver focus groups.

Science.gov (United States)

Naznin, Farhana; Currie, Graham; Logan, David

2018-01-01

Melbourne, Australia has the largest tram/streetcar network in the world including the largest mixed traffic tram operating environment. Therefore, Melbourne tram drivers are responsible for controlling one of the heaviest vehicles on road ranging from shared tram lanes to exclusive tram lanes. In addition to different tram lane configurations, tram drivers need to follow different traffic signal phases at intersections including tram priority signals as well as need to serve passengers at various types of closely spaced tram stops. Despite all these challenges, no research has explored tram driver perceptions of the risk factors on different tram route road design configurations. Therefore, the aim of this study is to investigate how tram drivers' safety perceptions alter along various tram route sections, signal settings and stop configurations. A tram driver focus group approach was adopted for this research involving thirty tram drivers (4 female and 26 male drivers). The tram drivers' age ranged from 29 to 63 years, with an average age of 47.6 years (standard deviation of 10.1 years), and their experience of tram driving ranged from 1.17 to 31 years, with an average experience of 12.5 years (standard deviation of 10.2 years). The participating tram drivers perceived that the raised tram tracks and tramways with raised yellow curbing beside tracks are safer lane priority features on the Melbourne tram network compared to full-time, part-time and mixed traffic tram lanes. They regarded 'hook turns' as a safe form of tram signal priority treatment at intersections and platform tram stops as the safest tram stop design for all passengers among all other tram stop designs in Melbourne. Findings of this research could enhance the understanding of crash risk factors for different tram route features and thus can offer effective planning strategies for transit agencies to improve tram road safety. Copyright © 2017 Elsevier Ltd. All rights reserved.
The chemical industry of Ukraine

International Nuclear Information System (INIS)

Novikov, I.N.

1995-01-01

This work deals with the chemical industry of Ukraine and more particularly with the restructuring proposed by the Ministry of Industry. After having presented some generalities the author focuses on the restructuring programme which includes the improvement of the fertilizers supply for agriculture, the development of facilities for basic organic synthesis, the increase of petroleum based chemicals production, the increase of consumer products production and the reorientation of the chemical industry to more accessible and alternative sources of raw materials such as black and brown coal, oil shale, coke, oil-refining gases, plant raw materials... (O.L.)
RobOKoD: microbial strain design for (over)production of target compounds.

Science.gov (United States)

Stanford, Natalie J; Millard, Pierre; Swainston, Neil

2015-01-01

Sustainable production of target compounds such as biofuels and high-value chemicals for pharmaceutical, agrochemical, and chemical industries is becoming an increasing priority given their current dependency upon diminishing petrochemical resources. Designing these strains is difficult, with current methods focusing primarily on knocking-out genes, dismissing other vital steps of strain design including the overexpression and dampening of genes. The design predictions from current methods also do not translate well-into successful strains in the laboratory. Here, we introduce RobOKoD (Robust, Overexpression, Knockout and Dampening), a method for predicting strain designs for overproduction of targets. The method uses flux variability analysis to profile each reaction within the system under differing production percentages of target-compound and biomass. Using these profiles, reactions are identified as potential knockout, overexpression, or dampening targets. The identified reactions are ranked according to their suitability, providing flexibility in strain design for users. The software was tested by designing a butanol-producing Escherichia coli strain, and was compared against the popular OptKnock and RobustKnock methods. RobOKoD shows favorable design predictions, when predictions from these methods are compared to a successful butanol-producing experimentally-validated strain. Overall RobOKoD provides users with rankings of predicted beneficial genetic interventions with which to support optimized strain design.
Chemical surface tuning electrocatalysis of redox-active nanoparticles

DEFF Research Database (Denmark)

Zhu, Nan; Ulstrup, Jens; Chi, Qijin

This work focuses on electron transfer (ET) and electrocatalysis of inorganic hybrid Prussian blue nanoparticles (PBNPs, 6 nm) immobilized on different chemical surfaces. Through surface self-assembly chemistry, we have enabled to tune chemical properties of the electrode surface. Stable immobili...
Material focus

DEFF Research Database (Denmark)

Sokoler, Tomas; Vallgårda, Anna K. A.

2009-01-01

In this paper we build on the notion of computational composites, which hold a material perspective on computational technology. We argue that a focus on the material aspects of the technology could be a fruitful approach to achieve new expressions and to gain a new view on the technology's role...... in design. We study two of the computer's material properties: computed causality and connectability and through developing two computational composites that utilize these properties we begin to explore their potential expressions....
Chemical Engineering in the "BIO" world

DEFF Research Database (Denmark)

Chiarappa, Gianluca; Grassi, Mario; Abrami, Michela

2017-01-01

Modern Chemical Engineering was born around the end of the 19th century in Great Britain, Germany, and the USA, the most industrialized countries at that time. Milton C. Whitaker, in 1914, affirmed that the difference between Chemistry and Chemical Engineering lies in the capability of chemical...... engineers to transfer laboratory findings to the industrial level. Since then, Chemical Engineering underwent huge transformations determining the detachment from the original Chemistry nest. The beginning of the sixties of the 20th century saw the development of a new branch of Chemical Engineering...... baptized Biomedical Engineering by Peppas and Langer and that now we can name Biological Engineering. Interestingly, although Biological Engineering focused on completely different topics from Chemical Engineering ones, it resorted to the same theoretical tools such as, for instance, mass, energy...
A participatory parent-focused intervention promoting physical activity in preschools: design of a cluster-randomized trial

Directory of Open Access Journals (Sweden)

Hoffmann Kristina

2010-01-01

Full Text Available Abstract Background With rates of childhood obesity increasing, physical activity (PA promotion especially in young children has assumed greater importance. Given the limited effectiveness of most interventions to date, new approaches are needed. The General Systems theory suggests that involving parents as intervention targets may be effective in fostering healthier life styles in children. We describe the development of a parent-focused participatory intervention and the procedures used to evaluate its effectiveness in increasing daily PA in preschoolers. Methods/Design Thirty-seven South German preschools were identified for this study and agreed to participate. Using a two-armed, controlled cluster-randomized trial design we test a participatory intervention with parents as the primary target group and potential agents of behavioural change. Specifically, the intervention is designed to engage parents in the development, refinement and selection of project ideas to promote PA and in incorporating these ideas into daily routines within the preschool community, consisting of children, teachers and parents. Our study is embedded within an existing state-sponsored programme providing structured gym lessons to preschool children. Thus, child-based PA outcomes from the study arm with the parent-focused intervention and the state-sponsored programme are compared with those from the study arm with the state-sponsored programme alone. The evaluation entails baseline measurements of study outcomes as well as follow-up measurements at 6 and 12 months. Accelerometry measures PA intensity over a period of six days, with the mean over six days used as the primary outcome measure. Secondary outcomes include childrens' BMI, a sum of averaged skin fold thickness measurements across multiple sites, and PA behaviour. Longitudinal multilevel models are used to assess within-subject change and between-group differences in study outcomes, adjusted for covariates
Chemical Graph Transformation with Stereo-Information

DEFF Research Database (Denmark)

Andersen, Jakob Lykke; Flamm, Christoph; Merkle, Daniel

2017-01-01

Double Pushout graph transformation naturally facilitates the modelling of chemical reactions: labelled undirected graphs model molecules and direct derivations model chemical reactions. However, the most straightforward modelling approach ignores the relative placement of atoms and their neighbo......Double Pushout graph transformation naturally facilitates the modelling of chemical reactions: labelled undirected graphs model molecules and direct derivations model chemical reactions. However, the most straightforward modelling approach ignores the relative placement of atoms...... and their neighbours in space. Stereoisomers of chemical compounds thus cannot be distinguished, even though their chemical activity may differ substantially. In this contribution we propose an extended chemical graph transformation system with attributes that encode information about local geometry. The modelling...... of graph transformation, but we here propose a framework that also allows for partially specified stereoinformation. While there are several stereochemical configurations to be considered, we focus here on the tetrahedral molecular shape, and suggest general principles for how to treat all other chemically...
Experimental investigation of the chemical looping method on a 1 MW pilot plant; Experimentelle Untersuchung des Chemical Looping Verfahrens an einer 1 MW Versuchsanlage

Energy Technology Data Exchange (ETDEWEB)

Orth, Matthias

2014-08-27

Attempting to counteract the consequences of climate change, leading industrial nations have agreed on reducing their CO{sub 2} emissions significantly. To reach these reduction goals, it is essential to reduce the CO{sub 2} emissions in the field of energy conversion. This PHD thesis covers the field of chemical looping combustion, a technology that uses fossil fuels for energy conversion with inherent capture of CO{sub 2}. Since the research regarding chemical looping had so far focused mainly on lab scale or small scale experiments, a 1 MW pilot plant has been erected at Technische Universitaet Darmstadt in order to investigate the process in a semi-industrial scale and to check the process efficiency with commercially usable equipment. This pilot consists of two interconnected fluidized bed reactors and has an overall height of more than 11 m. In this thesis, some experiments with ilmenite - used as the oxygen carrier - are explained. Furthermore, the design, erection and commissioning of the pilot plant are presented as well as the results of the first test campaigns. The evaluation of the latter proves that the process can be handled in the design configuration and that CO{sub 2} can be safely captured in a pilot plant of this scale.

Near-field flat focusing mirrors

Science.gov (United States)

Cheng, Yu-Chieh; Staliunas, Kestutis

2018-03-01

This article reviews recent progress towards the design of near-field flat focusing mirrors, focusing/imaging light patterns in reflection. An important feature of such flat focusing mirrors is their transverse invariance, as they do not possess any optical axis. We start with a review of the physical background to the different focusing mechanisms of near- and far-field focusing. These near-field focusing devices like flat lenses and the reviewed near-field focusing mirrors can implement planar focusing devices without any optical axis. In contrast, various types of far-field planar focusing devices, such as high-contrast gratings and metasurfaces, unavoidably break the transverse invariance due to their radially symmetrical structures. The particular realizations of near-field flat focusing mirrors including Bragg-like dielectric mirrors and dielectric subwavelength gratings are the main subjects of the review. The first flat focusing mirror was demonstrated with a chirped mirror and was shown to manage an angular dispersion for beam focusing, similar to the management of chromatic dispersion for pulse compression. Furthermore, the reviewed optimized chirped mirror demonstrated a long near-field focal length, hardly achieved by a flat lens or a planar hyperlens. Two more different configurations of dielectric subwavelength gratings that focus a light beam at normal or oblique incidence are also reviewed. We also summarize and compare focusing performance, limitations, and future perspectives between the reviewed flat focusing mirrors and other planar focusing devices including a flat lens with a negative-index material, a planar hyperlens, a high-contrast grating, and a metasurface.
Technology of a small plasma focus

International Nuclear Information System (INIS)

Lee, S.

1990-01-01

This paper reviews plasma focus technology, including the underlying dynamic and energy balance theory, scaling of the neutron yield, cost effectiveness of the design, as well as the main subsystems, e.g., capacitor bank, spark-gap switch and triggering electronics, the plasma focus tube, some simple diagnostics, and a high-voltage charger. It discusses the range of densities and temperatures available with a small plasma focus, and the type of experiments and applications that can be carried out with it. 61 refs, 21 figs
Effect of experimental factors on magnetic properties of nickel nanoparticles produced by chemical reduction method using a statistical design

International Nuclear Information System (INIS)

Vaezi, M.R.; Barzgar Vishlaghi, M.; Farzalipour Tabriz, M.; Mohammad Moradi, O.

2015-01-01

Highlights: • Superparamagnetic nickel nanoparticles are synthesized by wet chemical reduction. • Effects of synthesis parameters on magnetic properties are studied. • Central composite experimental design is used for building an empirical model. • Solvents ratio was more influential than reactants mixing rate. - Abstract: Nickel nanoparticles were synthesized by chemical reduction method in the absence of any surface capping agent. The effect of reactants mixing rate and the volume ratio of methanol/ethanol as solvent on the morphology and magnetic properties of nickel nanoparticles were studied by design of experiment using central composite design. X-ray diffraction (XRD) technique and Transmission Electron Microscopy (TEM) were utilized to characterize the synthesized nanoparticles. Size distribution of particles was studied by Dynamic Light Scattering (DLS) technique and magnetic properties of produced nanoparticles were investigated by Vibrating Sample Magnetometer (VSM) apparatus. The results showed that the magnetic properties of nickel nanoparticles were more influenced by volume ratio of methanol/ethanol than the reactants mixing rate. Super-paramagnetic nickel nanoparticles with size range between 20 and 50 nm were achieved when solvent was pure methanol and the reactants mixing rate was kept at 70 ml/h. But addition of more ethanol to precursor solvent leads to the formation of larger particles with broader size distribution and weak ferromagnetic or super-paramagnetic behavior
HINS Linac front end focusing system R and D

International Nuclear Information System (INIS)

Apollinari, G.; Carcagno, R.H.; Dimarco, J.; Huang, Y.; Kashikhin, V.V.; Orris, D.F.; Page, T.M.; Rabehl, R.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; Fermilab; Argonne

2008-01-01

This report summarizes current status of an R and D program to develop a focusing system for the front end of a superconducting RF linac. Superconducting solenoids will be used as focusing lenses in the low energy accelerating sections of the front end. The development of focusing lenses for the first accelerating section is in the production stage, and lens certification activities are in preparation at FNAL. The report contains information about the focusing lens design and performance, including solenoid, dipole corrector, and power leads, and about cryogenic system design and performance. It also describes the lens magnetic axis position measurement technique and discusses scope of an acceptance/certification process
Computational methods in metabolic engineering for strain design.

Science.gov (United States)

Long, Matthew R; Ong, Wai Kit; Reed, Jennifer L

2015-08-01

Metabolic engineering uses genetic approaches to control microbial metabolism to produce desired compounds. Computational tools can identify new biological routes to chemicals and the changes needed in host metabolism to improve chemical production. Recent computational efforts have focused on exploring what compounds can be made biologically using native, heterologous, and/or enzymes with broad specificity. Additionally, computational methods have been developed to suggest different types of genetic modifications (e.g. gene deletion/addition or up/down regulation), as well as suggest strategies meeting different criteria (e.g. high yield, high productivity, or substrate co-utilization). Strategies to improve the runtime performances have also been developed, which allow for more complex metabolic engineering strategies to be identified. Future incorporation of kinetic considerations will further improve strain design algorithms. Copyright © 2015 Elsevier Ltd. All rights reserved.
Focused ultrasound in ophthalmology

Directory of Open Access Journals (Sweden)

Silverman RH

2016-09-01

Full Text Available Ronald H Silverman1,2 1Department of Ophthalmology, Columbia University Medical Center, 2F.L. Lizzi Center for Biomedical Engineering, Riverside Research, New York, NY, USA Abstract: The use of focused ultrasound to obtain diagnostically significant information about the eye goes back to the 1950s. This review describes the historical and technological development of ophthalmic ultrasound and its clinical application and impact. Ultrasound, like light, can be focused, which is crucial for formation of high-resolution, diagnostically useful images. Focused, single-element, mechanically scanned transducers are most common in ophthalmology. Specially designed transducers have been used to generate focused, high-intensity ultrasound that through thermal effects has been used to treat glaucoma (via cilio-destruction, tumors, and other pathologies. Linear and annular transducer arrays offer synthetic focusing in which precise timing of the excitation of independently addressable array elements allows formation of a converging wavefront to create a focus at one or more programmable depths. Most recently, linear array-based plane-wave ultrasound, in which the array emits an unfocused wavefront and focusing is performed solely on received data, has been demonstrated for imaging ocular anatomy and blood flow. While the history of ophthalmic ultrasound extends back over half-a-century, new and powerful technologic advances continue to be made, offering the prospect of novel diagnostic capabilities. Keywords: ophthalmic ultrasound, ultrasound biomicroscopy (UBM, high-intensity focused ultrasound (HIFU, ultrafast imaging, Doppler imaging
Presidential Green Chemistry Challenge: 2002 Designing Greener Chemicals Award

Science.gov (United States)

Presidential Green Chemistry Challenge 2002 award winner, Chemical Specialties, developed an alkaline copper quaternary wood preservative to replace chromated copper arsenate preservative phased out due to risk to children.
In Silico Prediction of Chemical Toxicity for Drug Design Using Machine Learning Methods and Structural Alerts

Science.gov (United States)

Yang, Hongbin; Sun, Lixia; Li, Weihua; Liu, Guixia; Tang, Yun

2018-02-01

For a drug, safety is always the most important issue, including a variety of toxicities and adverse drug effects, which should be evaluated in preclinical and clinical trial phases. This review article at first simply introduced the computational methods used in prediction of chemical toxicity for drug design, including machine learning methods and structural alerts. Machine learning methods have been widely applied in qualitative classification and quantitative regression studies, while structural alerts can be regarded as a complementary tool for lead optimization. The emphasis of this article was put on the recent progress of predictive models built for various toxicities. Available databases and web servers were also provided. Though the methods and models are very helpful for drug design, there are still some challenges and limitations to be improved for drug safety assessment in the future.
In Silico Prediction of Chemical Toxicity for Drug Design Using Machine Learning Methods and Structural Alerts

Directory of Open Access Journals (Sweden)

Hongbin Yang

2018-02-01

Full Text Available During drug development, safety is always the most important issue, including a variety of toxicities and adverse drug effects, which should be evaluated in preclinical and clinical trial phases. This review article at first simply introduced the computational methods used in prediction of chemical toxicity for drug design, including machine learning methods and structural alerts. Machine learning methods have been widely applied in qualitative classification and quantitative regression studies, while structural alerts can be regarded as a complementary tool for lead optimization. The emphasis of this article was put on the recent progress of predictive models built for various toxicities. Available databases and web servers were also provided. Though the methods and models are very helpful for drug design, there are still some challenges and limitations to be improved for drug safety assessment in the future.
In Silico Prediction of Chemical Toxicity for Drug Design Using Machine Learning Methods and Structural Alerts.

Science.gov (United States)

Yang, Hongbin; Sun, Lixia; Li, Weihua; Liu, Guixia; Tang, Yun

2018-01-01

During drug development, safety is always the most important issue, including a variety of toxicities and adverse drug effects, which should be evaluated in preclinical and clinical trial phases. This review article at first simply introduced the computational methods used in prediction of chemical toxicity for drug design, including machine learning methods and structural alerts. Machine learning methods have been widely applied in qualitative classification and quantitative regression studies, while structural alerts can be regarded as a complementary tool for lead optimization. The emphasis of this article was put on the recent progress of predictive models built for various toxicities. Available databases and web servers were also provided. Though the methods and models are very helpful for drug design, there are still some challenges and limitations to be improved for drug safety assessment in the future.
Introduction to chemical reaction engineering

International Nuclear Information System (INIS)

Kim, Yeong Geol

1990-10-01

This deals with chemical reaction engineering with thirteen chapters. The contents of this book are introduction on reaction engineering, chemical kinetics, thermodynamics and chemical reaction, abnormal reactor, non-isothermal reactor, nonideal reactor, catalysis in nonuniform system, diffusion and reaction in porosity catalyst, design catalyst heterogeneous reactor in solid bed, a high molecule polymerization, bio reaction engineering, reaction engineering in material process, control multi-variable reactor process using digital computer.
Metal-organic frameworks for the removal of toxic industrial chemicals and chemical warfare agents.

Science.gov (United States)

Bobbitt, N Scott; Mendonca, Matthew L; Howarth, Ashlee J; Islamoglu, Timur; Hupp, Joseph T; Farha, Omar K; Snurr, Randall Q

2017-06-06

Owing to the vast diversity of linkers, nodes, and topologies, metal-organic frameworks can be tailored for specific tasks, such as chemical separations or catalysis. Accordingly, these materials have attracted significant interest for capture and/or detoxification of toxic industrial chemicals and chemical warfare agents. In this paper, we review recent experimental and computational work pertaining to the capture of several industrially-relevant toxic chemicals, including NH 3 , SO 2 , NO 2 , H 2 S, and some volatile organic compounds, with particular emphasis on the challenging issue of designing materials that selectively adsorb these chemicals in the presence of water. We also examine recent research on the capture and catalytic degradation of chemical warfare agents such as sarin and sulfur mustard using metal-organic frameworks.
Chemical Sensors Based on Cyclodextrin Derivatives.

Science.gov (United States)

Ogoshi, Tomoki; Harada, Akira

2008-08-25

This review focuses on chemical sensors based on cyclodextrin (CD) derivatives. This has been a field of classical interest, and is now of current interest for numerous scientists. First, typical chemical sensors using chromophore appended CDs are mentioned. Various "turn-off" and "turn-on" fluorescent chemical sensors, in which fluorescence intensity was decreased or increased by complexation with guest molecules, respectively, were synthesized. Dye modified CDs and photoactive metal ion-ligand complex appended CDs, metallocyclodextrins, were also applied for chemical sensors. Furthermore, recent novel approaches to chemical sensing systems using supramolecular structures such as CD dimers, trimers and cooperative binding systems of CDs with the other macrocycle [2]rotaxane and supramolecular polymers consisting of CD units are mentioned. New chemical sensors using hybrids of CDs with p-conjugated polymers, peptides, DNA, nanocarbons and nanoparticles are also described in this review.
Discriminative Chemical Patterns: Automatic and Interactive Design.

Science.gov (United States)

Bietz, Stefan; Schomburg, Karen T; Hilbig, Matthias; Rarey, Matthias

2015-08-24

The classification of molecules with respect to their inhibiting, activating, or toxicological potential constitutes a central aspect in the field of cheminformatics. Often, a discriminative feature is needed to distinguish two different molecule sets. Besides physicochemical properties, substructures and chemical patterns belong to the descriptors most frequently applied for this purpose. As a commonly used example of this descriptor class, SMARTS strings represent a powerful concept for the representation and processing of abstract chemical patterns. While their usage facilitates a convenient way to apply previously derived classification rules on new molecule sets, the manual generation of useful SMARTS patterns remains a complex and time-consuming process. Here, we introduce SMARTSminer, a new algorithm for the automatic derivation of discriminative SMARTS patterns from preclassified molecule sets. Based on a specially adapted subgraph mining algorithm, SMARTSminer identifies structural features that are frequent in only one of the given molecule classes. In comparison to elemental substructures, it also supports the consideration of general and specific SMARTS features. Furthermore, SMARTSminer is integrated into an interactive pattern editor named SMARTSeditor. This allows for an intuitive visualization on the basis of the SMARTSviewer concept as well as interactive adaption and further improvement of the generated patterns. Additionally, a new molecular matching feature provides an immediate feedback on a pattern's matching behavior across the molecule sets. We demonstrate the utility of the SMARTSminer functionality and its integration into the SMARTSeditor software in several different classification scenarios.
The mechanical design for the WEAVE prime focus corrector system

NARCIS (Netherlands)

Abrams, Don Carlos; Dee, Kevin; Agócs, Tibor; Lhome, Emilie; Peñate, José; Jaskó, Attila; Bányai, Evelin; Burgal, José A.; Dalton, Gavin; Middleton, Kevin; Bonifacio, Piercarlo; Aguerri, J. Alfonso L.; Trager, S. C.; Balcells, Marc

WEAVE is the next-generation, wide-field, optical spectroscopy facility for the William Herschel Telescope (WHT) in La Palma, Canary Islands, Spain. The WHT will undergo a significant adaptation to accommodate this facility. A two- degree Prime Focus Corrector (PFC), that includes an Atmospheric
Design Processes

DEFF Research Database (Denmark)

Ovesen, Nis

2009-01-01

Inspiration for most research and optimisations on design processes still seem to focus within the narrow field of the traditional design practise. The focus in this study turns to associated businesses of the design professions in order to learn from their development processes. Through interviews...... and emerging production methods....
Effects of pesticide chemicals on the activity of metabolic enzymes: focus on thiocarbamates.

Science.gov (United States)

Mathieu, Cécile; Duval, Romain; Xu, Ximing; Rodrigues-Lima, Fernando; Dupret, Jean-Marie

2015-01-01

Thiocarbamates are chemicals widely used as pesticides. Occupational exposure is associated with acute intoxication. Populations can be exposed through food and water. Moreover, certain thiocarbamates are used clinically. The widespread use of thiocarbamates raises many issues regarding their toxicological and pharmacological impact. Thiocarbamates and their metabolites can modify biological macromolecules functions, in particular enzymes, through modification of cysteine residues, chelation of metal ions or modulation of the oxidative stress. Loss of enzyme activity can lead to the disruption of metabolic pathways, and explain, at least in part, the effects of these pesticides. Additionally, their reactivity and ability to easily cross biological barrier confer them a great interest for development of clinical applications. Many advances in the study of thiocarbamates metabolism and reactivity have led to a better knowledge of biological effects of these compounds. However, more data are needed on the determination of targets and specificity. Only few data concerning the exposure to a cocktail of pesticides/chemicals are available, raising the need to evaluate the toxic side effects of representative pesticides mixtures. Moreover, the dithiocarbamate Disulfiram has shown great potential in therapeutic applications and leads to the development of pharmacological thiocarbamates derivatives, highly specific to their target and easily distributed.
Atlantic Forest. A natural reservoir of chemical elements

International Nuclear Information System (INIS)

De Franca, E.J.; De Nadai Fernandes, E.A.; Bacchi, M.A.; Elias, C.

2008-01-01

The accumulation of chemical elements in biological compartments is one of the strategies of tropical species to adapt to a low-nutrient soil. This study focuses on the Atlantic Forest because of its eco-environmental importance as a natural reservoir of chemical elements. About 20 elements were determined by INAA in leaf, soil, litter and epiphyte compartments. There was no seasonality for chemical element concentrations in leaves, which probably indicated the maintenance of chemical elements in this compartment. Considering the estimated quantities, past deforestation events could have released large amounts of chemical elements to the environment. (author)
Using Green Chemistry and Engineering Principles to Design ...

Science.gov (United States)

The concepts of green chemistry and engineering (GC&E) have been promoted as an effective qualitative framework for developing more sustainable chemical syntheses, processes, and material management techniques. This has been demonstrated by many theoretical and practical cases. In addition, there are several approaches and frameworks focused on demonstrating that improvements were achieved through GC&E technologies. However, the application of these principles is not always straightforward. We propose using systematic frameworks and tools that help practitioners when deciding which principles can be applied, the levels of implementation, prospective of obtaining simultaneous improvements in all sustainability aspects, and ways to deal with multiobjective problems. Therefore, this contribution aims to provide a systematic combination of three different and complementary design tools for assisting designers in evaluating, developing, and improving chemical manufacturing and material management systems under GC&E perspectives. The WAR Algorithm, GREENSCOPE, and SustainPro were employed for this synergistic approach of incorporating sustainability at early stages of process development. In this demonstration, simulated ammonia production is used as a case study to illustrate this advancement. Results show how to identify process design areas for improvements, key factors, multi-criteria decision-making solutions, and optimal tradeoffs. Finally, conclusions were pre
High-field strong-focusing undulator designs for X-ray Linac Coherent Light Source (LCLS) applications

International Nuclear Information System (INIS)

Caspi, S.; Schlueter, R.; Tatchyn, R.

1995-01-01

Linac-driven X-Ray Free Electron Lasers (e.g., Linac Coherent Light Sources (LCLSs)), operating on the principle of single-pass saturation in the Self-Amplified Spontaneous Emission (SASE) regime typically require multi-GeV beam energies and undulator lengths in excess of tens of meters to attain sufficient gain in the 1 angstrom--0.1 angstrom range. In this parameter regime, the undulator structure must provide: (1) field amplitudes B 0 in excess of 1T within periods of 4cm or less, (2) peak on-axis focusing gradients on the order of 30T/m, and (3) field quality in the 0.1%--0.3% range. In this paper the authors report on designs under consideration for a 4.5--1.5 angstrom LCLS based on superconducting (SC), hybrid/PM, and pulsed-Cu technologies

Beam dynamics in the SLC final focus system

International Nuclear Information System (INIS)

Bambade, P.S.

1987-06-01

The SLC luminosity is reached by colliding beams focused to about 2 μm transverse sizes. The Final Focus System (FFS) must enable, beyond its basic optical design, the detection and correction of errors accumulated in the system. In this paper, after summarizing the design, we review the sensitivity to such errors and the ability to correct them. The overall tuning strategy involves three phases: single beam spot minimization, steering the beams in collision and luminosity optimization with beam-beam effects
A Prospective Virtual Screening Study: Enriching Hit Rates and Designing Focus Libraries To Find Inhibitors of PI3Kδ and PI3Kγ.

Science.gov (United States)

Damm-Ganamet, Kelly L; Bembenek, Scott D; Venable, Jennifer W; Castro, Glenda G; Mangelschots, Lieve; Peeters, Daniëlle C G; Mcallister, Heather M; Edwards, James P; Disepio, Daniel; Mirzadegan, Taraneh

2016-05-12

Here, we report a high-throughput virtual screening (HTVS) study using phosphoinositide 3-kinase (both PI3Kγ and PI3Kδ). Our initial HTVS results of the Janssen corporate database identified small focused libraries with hit rates at 50% inhibition showing a 50-fold increase over those from a HTS (high-throughput screen). Further, applying constraints based on "chemically intuitive" hydrogen bonds and/or positional requirements resulted in a substantial improvement in the hit rates (versus no constraints) and reduced docking time. While we find that docking scoring functions are not capable of providing a reliable relative ranking of a set of compounds, a prioritization of groups of compounds (e.g., low, medium, and high) does emerge, which allows for the chemistry efforts to be quickly focused on the most viable candidates. Thus, this illustrates that it is not always necessary to have a high correlation between a computational score and the experimental data to impact the drug discovery process.
Synthesis and Design of Biorefinery Processing Networks with Uncertainty and Sustainability analysis

DEFF Research Database (Denmark)

Cheali, Peam; Gernaey, Krist; Sin, Gürkan

combinations of processing networks. The optimization of the network is formulated as a mixed integer nonlinear programming type of problem and solved in GAMS. The methodology was applied for designing optimal biorefinery networks considering biochemical routes. Furthermore, the methodology has also been...... for processing renewable feedstocks, with the aim of bridging the gap for fuel, chemical and material production. This project is focusing on biorefinery network design, in particular for early stage design and development studies. Optimal biorefinery design is a challenging problem. It is a multi......-objective decision-making problem not only with respect to technical and economic feasibility but also with respect to environmental impacts, sustainability constraints and limited availability & uncertainties of input data at the early design stage. It is therefore useful to develop a systematic methodology...
Radiological equivalent of chemical pollutants

International Nuclear Information System (INIS)

Medina, V.O.

1982-01-01

The development of the peaceful uses of nuclear energy has caused continued effort toward public safety through radiation health protection measures and nuclear management practices. However, concern has not been focused on the development specifically in the operation of chemical pestrochemical industries as well as other industrial processes brought about by technological advancements. This article presents the comparison of the risk of radiation and chemicals. The methods used for comparing the risks of late effects of radiation and chemicals are considered at three levels. (a) as a frame of reference to give an impression of resolving power of biological tests; (b) as methods to quantify risks; (c) as instruments for an epidemiological survey of human populations. There are marked dissimilarities between chemicals and radiation and efforts to interpret chemical activity may not be achieved. Applicability of the concept of rad equivalence has many restrictions and as pointed out this approach is not an established one. (RTD)
The final focus test beam project

International Nuclear Information System (INIS)

Burke, D.

1991-05-01

An overview is given of the Final Focus Test Beam (FFTB) that is being constructed as a prototype final focus system for a future electron-positron linear collider. This beam line will use as input the 50 GeV electron beam from the SLC linac, and is designed to reduce the transverse dimensions of the beam spot at the focal point to 1 μm. 5 refs., 2 figs., 1 tab
Design of an ultraprecision computerized numerical control chemical mechanical polishing machine and its implementation

Science.gov (United States)

Zhang, Chupeng; Zhao, Huiying; Zhu, Xueliang; Zhao, Shijie; Jiang, Chunye

2018-01-01

The chemical mechanical polishing (CMP) is a key process during the machining route of plane optics. To improve the polishing efficiency and accuracy, a CMP model and machine tool were developed. Based on the Preston equation and the axial run-out error measurement results of the m circles on the tin plate, a CMP model that could simulate the material removal at any point on the workpiece was presented. An analysis of the model indicated that lower axial run-out error led to lower material removal but better polishing efficiency and accuracy. Based on this conclusion, the CMP machine was designed, and the ultraprecision gas hydrostatic guideway and rotary table as well as the Siemens 840Dsl numerical control system were incorporated in the CMP machine. To verify the design principles of machine, a series of detection and machining experiments were conducted. The LK-G5000 laser sensor was employed for detecting the straightness error of the gas hydrostatic guideway and the axial run-out error of the gas hydrostatic rotary table. A 300-mm-diameter optic was chosen for the surface profile machining experiments performed to determine the CMP efficiency and accuracy.
Health risk assessment for chemical exposures of military interest

NARCIS (Netherlands)

Langenberg, J.P.; Polhuijs, M.; Sijbranda, T.

2016-01-01

Participation in military operations is accompanied by health hazards resulting from exposure to chemical substances from natural and anthropogenic sources. Historically, focus on toxicological risks has been on the health effects of exposure to chemical warfare agents (CW A). In recent years the
Designing chemical soil characterization programs for mixed waste sites

International Nuclear Information System (INIS)

Meyers, K.A. Jr.

1989-01-01

The Weldon Spring Site Remedial Action Project is a remedial action effort funded by the U.S. Department of Energy. The Weldon Spring Site, a former uranium processing facility, is located in east-central Missouri on a portion of a former ordnance works facility which produced trinitrotoluene during World War II. As a result of both uranium and ordnance production, the soils have become both radiologically and chemically contaminated. As a part of site characterization efforts in support of the environmental documentation process, a chemical soil characterization program was developed. This program consisted of biased and unbiased sampling program which maximized areal coverage, provided a statistically sound data base and maintained cost effectiveness. This paper discusses how the general rationale and processes used at the Weldon Spring Site can be applied to other mixed and hazardous waste sites
Design, Operation and Control Modelling of SOFC/GT Hybrid Systems

OpenAIRE

Stiller, Christoph

2006-01-01

This thesis focuses on modelling-based design, operation and control of solid oxide fuel cell (SOFC) and gas turbine (GT) hybrid systems. Fuel cells are a promising approach to high-efficiency power generation, as they directly convert chemical energy to electric work. High-temperature fuel cells such as the SOFC can be integrated in gas turbine processes, which further increases the electrical efficiency to values up to 70%. However, there are a number of obstacles for safe operation of such...
Understanding the chemical vapor deposition of diamond: recent progress

International Nuclear Information System (INIS)

Butler, J E; Mankelevich, Y A; Cheesman, A; Ma, Jie; Ashfold, M N R

2009-01-01

In this paper we review and provide an overview to the understanding of the chemical vapor deposition (CVD) of diamond materials with a particular focus on the commonly used microwave plasma-activated chemical vapor deposition (MPCVD). The major topics covered are experimental measurements in situ to diamond CVD reactors, and MPCVD in particular, coupled with models of the gas phase chemical and plasma kinetics to provide insight into the distribution of critical chemical species throughout the reactor, followed by a discussion of the surface chemical process involved in diamond growth.
Assessing dose-response relationships for endocrine disrupting chemicals (EDCs): a focus on non-monotonicity.

Science.gov (United States)

Zoeller, R Thomas; Vandenberg, Laura N

2015-05-15

The fundamental principle in regulatory toxicology is that all chemicals are toxic and that the severity of effect is proportional to the exposure level. An ancillary assumption is that there are no effects at exposures below the lowest observed adverse effect level (LOAEL), either because no effects exist or because they are not statistically resolvable, implying that they would not be adverse. Chemicals that interfere with hormones violate these principles in two important ways: dose-response relationships can be non-monotonic, which have been reported in hundreds of studies of endocrine disrupting chemicals (EDCs); and effects are often observed below the LOAEL, including all environmental epidemiological studies examining EDCs. In recognition of the importance of this issue, Lagarde et al. have published the first proposal to qualitatively assess non-monotonic dose response (NMDR) relationships for use in risk assessments. Their proposal represents a significant step forward in the evaluation of complex datasets for use in risk assessments. Here, we comment on three elements of the Lagarde proposal that we feel need to be assessed more critically and present our arguments: 1) the use of Klimisch scores to evaluate study quality, 2) the concept of evaluating study quality without topical experts' knowledge and opinions, and 3) the requirement of establishing the biological plausibility of an NMDR before consideration for use in risk assessment. We present evidence-based logical arguments that 1) the use of the Klimisch score should be abandoned for assessing study quality; 2) evaluating study quality requires experts in the specific field; and 3) an understanding of mechanisms should not be required to accept observable, statistically valid phenomena. It is our hope to contribute to the important and ongoing debate about the impact of NMDRs on risk assessment with positive suggestions.
Endocrine active chemicals, pharmaceuticals, and other chemicals of concern in surface water, wastewater-treatment plant effluent, and bed sediment, and biological characteristics in selected streams, Minnesota-design, methods, and data, 2009

Science.gov (United States)

Lee, Kathy E.; Langer, Susan K.; Barber, Larry B.; Writer, Jeff H.; Ferrey, Mark L.; Schoenfuss, Heiko L.; Furlong, Edward T.; Foreman, William T.; Gray, James L.; ReVello, Rhiannon C.; Martinovic, Dalma; Woodruff, Olivia R.; Keefe, Steffanie H.; Brown, Greg K.; Taylor, Howard E.; Ferrer, Imma; Thurman, E. Michael

2011-01-01

This report presents the study design, environmental data, and quality-assurance data for an integrated chemical and biological study of selected streams or lakes that receive wastewater-treatment plant effluent in Minnesota. This study was a cooperative effort of the U.S. Geological Survey, the Minnesota Pollution Control Agency, St. Cloud State University, the University of St. Thomas, and the University of Colorado. The objective of the study was to identify distribution patterns of endocrine active chemicals, pharmaceuticals, and other organic and inorganic chemicals of concern indicative of wastewater effluent, and to identify biological characteristics of estrogenicity and fish responses in the same streams. The U.S. Geological Survey collected and analyzed water, bed-sediment, and quality-assurance samples, and measured or recorded streamflow once at each sampling location from September through November 2009. Sampling locations included surface water and wastewater-treatment plant effluent. Twenty-five wastewater-treatment plants were selected to include continuous flow and periodic release facilities with differing processing steps (activated sludge or trickling filters) and plant design flows ranging from 0.002 to 10.9 cubic meters per second (0.04 to 251 million gallons per day) throughout Minnesota in varying land-use settings. Water samples were collected from the treated effluent of the 25 wastewater-treatment plants and at one point upstream from and one point downstream from wastewater-treatment plant effluent discharges. Bed-sediment samples also were collected at each of the stream or lake locations. Water samples were analyzed for major ions, nutrients, trace elements, pharmaceuticals, phytoestrogens and pharmaceuticals, alkylphenols and other neutral organic chemicals, carboxylic acids, and steroidal hormones. A subset (25 samples) of the bed-sediment samples were analyzed for carbon, wastewater-indicator chemicals, and steroidal hormones; the
How to conduct focus groups: researching group priorities through discussion.

Science.gov (United States)

1992-01-01

Focus groups serve to uncover priorities and beliefs of a target group, but health project designers do not always take the time to seek this information beforehand. Focus groups also allow various local subgroups to communicate their concerns before the project starts. Focus groups can also breed ideas and dialogue that individual interviews cannot and they provide baseline information so managers can determine if attitudes or priorities have resulted from the project. Diverse people have different beliefs, e.g., women who have young children view oral rehydration therapy differently from women with no children. Project designers can use these basic differences to arrive at some conclusions about general attitudes. Focus group facilitators should have a discussion outline to help keep the group on the topic of concern. They should limit sessions to 60-90 minutes. Each focus groups should include 8-10 people. It is important to have members of various community subgroups in each group. Yet group designers should be careful not to include within the same group, those who may intimidate other people in the group, e.g., in situations where farmers depend on middlemen, farmers may not be open if middlemen are also in the focus group. Facilitators should launch each session with an attempt to encourage the members to be open and to feel comfortable. For example, in Malawi, a facilitator leads her focus group discussions with songs. Stories are another icebreaker. It is important that all focus groups centering around a certain project discuss the same topics. Facilitators need to stress to the group that all discussions are to be kept confidential. The designers should also carefully word the questions so that facilitators will not impart their bias. Facilitators should not direct the group to certain conclusions, but instead keep the discussions focused.
IADE: a system for intelligent automatic design of bioisosteric analogs

Science.gov (United States)

Ertl, Peter; Lewis, Richard

2012-11-01

IADE, a software system supporting molecular modellers through the automatic design of non-classical bioisosteric analogs, scaffold hopping and fragment growing, is presented. The program combines sophisticated cheminformatics functionalities for constructing novel analogs and filtering them based on their drug-likeness and synthetic accessibility using automatic structure-based design capabilities: the best candidates are selected according to their similarity to the template ligand and to their interactions with the protein binding site. IADE works in an iterative manner, improving the fitness of designed molecules in every generation until structures with optimal properties are identified. The program frees molecular modellers from routine, repetitive tasks, allowing them to focus on analysis and evaluation of the automatically designed analogs, considerably enhancing their work efficiency as well as the area of chemical space that can be covered. The performance of IADE is illustrated through a case study of the design of a nonclassical bioisosteric analog of a farnesyltransferase inhibitor—an analog that has won a recent "Design a Molecule" competition.
Mini-projects in Chemical Engineering Laboratory

Directory of Open Access Journals (Sweden)

Angeles Cancela

2013-03-01

Full Text Available Chemical engineering laboratory practices based in mini-projects were design and applied the students of forestry engineering in chemical subject. This way of practice reveals a more cooperative learning and a different style of experimentation. The stated goal was to design practices that motivate students and to enable them to develop different skills, including cross teamwork and communication. This paper describes how these practices were developed and the advantages and disadvantages of using this methodology of teaching.
Focus: Digital

DEFF Research Database (Denmark)

Technology has been an all-important and defining element within the arts throughout the 20th century, and it has fundamentally changed the ways in which we produce and consume music. With this Focus we investigate the latest developments in the digital domain – and their pervasiveness and rapid...... production and reception of contemporary music and sound art. With ‘Digital’ we present four composers' very different answers to how technology impact their work. To Juliana Hodkinson it has become an integral part of her sonic writing. Rudiger Meyer analyses the relationships between art and design and how...
Designing Teaching--Teaching Designing: Teacher's Guidance in a Virtual Design Studio

Science.gov (United States)

Lahti, Henna; Seitamaa-Hakkarainen, Pirita

2014-01-01

This study examined pedagogical aspects of virtual designing. It focused on how an industrial design teacher organised a university course in plastic product design and how the teacher guided student teams' design processes in a virtual design studio. The model of Learning by Collaborative Design was used as a pedagogical and analytical framework.…
Development of Computer Aided Modelling Templates for Model Re-use in Chemical and Biochemical Process and Product Design: Importand export of models

DEFF Research Database (Denmark)

Fedorova, Marina; Tolksdorf, Gregor; Fillinger, Sandra

2015-01-01

been established, in order to provide a wider range of modelling capabilities. Through this link, developed models can be exported/imported to/from other modelling-simulation software environments to allow model reusability in chemical and biochemical product and process design. The use of this link...
Chemical peeling in ethnic/dark skin.

Science.gov (United States)

Roberts, Wendy E

2004-01-01

Chemical peeling for skin of color arose in ancient Egypt, Mesopotamia, and other ancient cultures in and around Africa. Our current fund of medical knowledge regarding chemical peeling is a result of centuries of experience and research. The list of agents for chemical peeling is extensive. In ethnic skin, our efforts are focused on superficial and medium-depth peeling agents and techniques. Indications for chemical peeling in darker skin include acne vulgaris, postinflammatory hyperpigmentation, melasma, scarring, photodamage, and pseudofolliculitis barbae. Careful selection of patients for chemical peeling should involve not only identification of Fitzpatrick skin type, but also determining ethnicity. Different ethnicities may respond unpredictably to chemical peeling regardless of skin phenotype. Familiarity with the properties each peeling agent used is critical. New techniques discussed for chemical peeling include spot peeling for postinflammatory hyperpigmentation and combination peels for acne and photodamage. Single- or combination-agent chemical peels are shown to be efficacious and safe. In conclusion, chemical peeling is a treatment of choice for numerous pigmentary and scarring disorders arising in dark skin tones. Familiarity with new peeling agents and techniques will lead to successful outcomes.
Quantitative design of emergency monitoring network for river chemical spills based on discrete entropy theory.

Science.gov (United States)

Shi, Bin; Jiang, Jiping; Sivakumar, Bellie; Zheng, Yi; Wang, Peng

2018-05-01

Field monitoring strategy is critical for disaster preparedness and watershed emergency environmental management. However, development of such is also highly challenging. Despite the efforts and progress thus far, no definitive guidelines or solutions are available worldwide for quantitatively designing a monitoring network in response to river chemical spill incidents, except general rules based on administrative divisions or arbitrary interpolation on routine monitoring sections. To address this gap, a novel framework for spatial-temporal network design was proposed in this study. The framework combines contaminant transport modelling with discrete entropy theory and spectral analysis. The water quality model was applied to forecast the spatio-temporal distribution of contaminant after spills and then corresponding information transfer indexes (ITIs) and Fourier approximation periodic functions were estimated as critical measures for setting sampling locations and times. The results indicate that the framework can produce scientific preparedness plans of emergency monitoring based on scenario analysis of spill risks as well as rapid design as soon as the incident happened but not prepared. The framework was applied to a hypothetical spill case based on tracer experiment and a real nitrobenzene spill incident case to demonstrate its suitability and effectiveness. The newly-designed temporal-spatial monitoring network captured major pollution information at relatively low costs. It showed obvious benefits for follow-up early-warning and treatment as well as for aftermath recovery and assessment. The underlying drivers of ITIs as well as the limitations and uncertainty of the approach were analyzed based on the case studies. Comparison with existing monitoring network design approaches, management implications, and generalized applicability were also discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Chemical Product Design: A new challenge of applied thermodynamics

DEFF Research Database (Denmark)

Abildskov, Jens; Kontogeorgis, Georgios

2004-01-01

, and then to outline some specific examples from our research activities in the area of thermodynamics for chemical products. The examples cover rather diverse areas such as interrelation between thermodynamic and engineering properties in detergents (surfactants), paint thermodynamics and the development of models...
A Comprehensive Framework for Surfactant Selection and Design for Emulsion Based Chemical Product Design

DEFF Research Database (Denmark)

Mattei, Michele; Kontogeorgis, Georgios; Gani, Rafiqul

2014-01-01

The manufacture of emulsified products is of increasing interest in the consumer oriented chemical indus-try. Several cosmetic, house-hold and pharmaceutical products are in the emulsified form when soldand/or they are expected to form an emulsion when used. Therefore, there is a need...
Vicher: A Virtual Reality Based Educational Module for Chemical Reaction Engineering.

Science.gov (United States)

Bell, John T.; Fogler, H. Scott

1996-01-01

A virtual reality application for undergraduate chemical kinetics and reactor design education, Vicher (Virtual Chemical Reaction Model) was originally designed to simulate a portion of a modern chemical plant. Vicher now consists of two programs: Vicher I that models catalyst deactivation and Vicher II that models nonisothermal effects in…
Design Games

DEFF Research Database (Denmark)

Johansson, Martin Wetterstrand

2007-01-01

In this paper design games are discussed as an approach to managing design sessions. The focus is on the collaborative design session and more particular on how to set up the collaboration and reinsure progress. Design games have the advantage of framing the collaborative assignment at hand....... Experiments can be set up to explore possible futures and design games has the qualities of elegantly focus the work at the same time as it lessens the burden for the process facilitator. The present paper goes into detail about how design games can be set up to facilitate collaboration and how the design...
Bioinspired algorithm for autonomous sensor-driven guidance in turbulent chemical plumes

International Nuclear Information System (INIS)

Webster, D R; Volyanskyy, K Y; Weissburg, M J

2012-01-01

We designed and implemented a control algorithm for sensor-mediated chemical plume tracking in a turbulent flow environment. In our design, we focused on development of a signal processing strategy capable of replicating behavioral responses of actively tracking blue crabs (Callinectes sapidus) to chemical stimuli. The control algorithm is evaluated in a hardware platform that allows motion in two directions (i.e. forward–back and left–right). The geometric arrangement of the sensor array is inspired by the location of blue crab sensor populations. Upstream motion is induced by a binary response to supra-threshold spikes of concentration, and cross-stream steering is controlled by contrast between bilaterally-separated sensors. Like animal strategies, the developed control algorithm is dynamic. This property allows the algorithm to function effectively in the highly irregular turbulent environment and produces adaptive adjustments of motion to minimize the distance to the source of a plume. Tracking trials indicate that roughly 80% of the tracks successfully stop near the plume source location. Both success rate and movement patterns of the tracker compare favorably to that of blue crabs searching for odorant plume sources, thus suggesting that our sensory-mediated behavior hypothesis are generally accurate and that the associated tracking mechanisms may be successfully implemented in hardware. (paper)
Chemical Looping Combustion Reactions and Systems

Energy Technology Data Exchange (ETDEWEB)

Sarofim, Adel; Lighty, JoAnn; Smith, Philip; Whitty, Kevin; Eyring, Edward; Sahir, Asad; Alvarez, Milo; Hradisky, Michael; Clayton, Chris; Konya, Gabor; Baracki, Richard; Kelly, Kerry

2011-07-01

Chemical Looping Combustion (CLC) is one promising fuel-combustion technology, which can facilitate economic CO2 capture in coal-fired power plants. It employs the oxidation/reduction characteristics of a metal, or oxygen carrier, and its oxide, the oxidizing gas (typically air) and the fuel source may be kept separate. This work focused on two classes of oxygen carrier, one that merely undergoes a change in oxidation state, such as Fe3O4/Fe2O3 and one that is converted from its higher to its lower oxidation state by the release of oxygen on heating, i.e., CuO/Cu2O. This topical report discusses the results of four complementary efforts: (1) the development of process and economic models to optimize important design considerations, such as oxygen carrier circulation rate, temperature, residence time; (2) the development of high-performance simulation capabilities for fluidized beds and the collection, parameter identification, and preliminary verification/uncertainty quantification (3) the exploration of operating characteristics in the laboratory-scale bubbling bed reactor, with a focus on the oxygen carrier performance, including reactivity, oxygen carrying capacity, attrition resistance, resistance to deactivation, cost and availability (4) the identification of mechanisms and rates for the copper, cuprous oxide, and cupric oxide system using thermogravimetric analysis.
Advances in chemical physics advances in liquid crystals

CERN Document Server

Prigogine, Ilya; Vij, Jagdish K

2009-01-01

Prigogine and Rice's highly acclaimed series, Advances in Chemical Physics, provides a forum for critical, authoritative reviews of current topics in every area of chemical physics. Edited by J.K. Vij, this volume focuses on recent advances in liquid crystals with significant, up-to-date chapters authored by internationally recognized researchers in the field.
Evidence from pharmacology and pathophysiology suggests that chemicals with dissimilar mechanisms of action could be of bigger concern in the toxicological risk assessment of chemical mixtures than chemicals with a similar mechanism of action

DEFF Research Database (Denmark)

Hadrup, Niels

2014-01-01

Mathematical models have been developed for the toxicological risk assessment of chemical mixtures. However, exposure data as well as single chemical toxicological data are required for these models. When addressing this data need, it could be attractive to focus on chemicals with similar...... concomitantly contribute to the pathophysiology, suggesting that a grouping based on common target organs may also be inefficient. A better option may be to prioritise chemicals on the basis of potency and risk of exposure. In conclusion, there are arguments to suggest that we should concomitantly consider all...... targets that a chemical can affect in the human body and not merely a subset....
Chemically Designed Metallic/Insulating Hybrid Nanostructures with Silver Nanocrystals for Highly Sensitive Wearable Pressure Sensors.

Science.gov (United States)

Kim, Haneun; Lee, Seung-Wook; Joh, Hyungmok; Seong, Mingi; Lee, Woo Seok; Kang, Min Su; Pyo, Jun Beom; Oh, Soong Ju

2018-01-10

With the increase in interest in wearable tactile pressure sensors for e-skin, researches to make nanostructures to achieve high sensitivity have been actively conducted. However, limitations such as complex fabrication processes using expensive equipment still exist. Herein, simple lithography-free techniques to develop pyramid-like metal/insulator hybrid nanostructures utilizing nanocrystals (NCs) are demonstrated. Ligand-exchanged and unexchanged silver NC thin films are used as metallic and insulating components, respectively. The interfaces of each NC layer are chemically engineered to create discontinuous insulating layers, i.e., spacers for improved sensitivity, and eventually to realize fully solution-processed pressure sensors. Device performance analysis with structural, chemical, and electronic characterization and conductive atomic force microscopy study reveals that hybrid nanostructure based pressure sensor shows an enhanced sensitivity of higher than 500 kPa -1 , reliability, and low power consumption with a wide range of pressure sensing. Nano-/micro-hierarchical structures are also designed by combining hybrid nanostructures with conventional microstructures, exhibiting further enhanced sensing range and achieving a record sensitivity of 2.72 × 10 4 kPa -1 . Finally, all-solution-processed pressure sensor arrays with high pixel density, capable of detecting delicate signals with high spatial selectivity much better than the human tactile threshold, are introduced.
Nanotechnology for chemical engineers

CERN Document Server

Salaheldeen Elnashaie, Said; Hashemipour Rafsanjani, Hassan

2015-01-01

The book describes the basic principles of transforming nano-technology into nano-engineering with a particular focus on chemical engineering fundamentals. This book provides vital information about differences between descriptive technology and quantitative engineering for students as well as working professionals in various fields of nanotechnology. Besides chemical engineering principles, the fundamentals of nanotechnology are also covered along with detailed explanation of several specific nanoscale processes from chemical engineering point of view. This information is presented in form of practical examples and case studies that help the engineers and researchers to integrate the processes which can meet the commercial production. It is worth mentioning here that, the main challenge in nanostructure and nanodevices production is nowadays related to the economic point of view. The uniqueness of this book is a balance between important insights into the synthetic methods of nano-structures and nanomaterial...
Investigations on the optimum design of chemical addition system for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Chang, Byong Hoon [Junior College of Inchon, Inchon (Korea, Republic of); Chung, Chang Kyu; Choi, Han Rim; Kim, Eun Kee; Ro, Tae Sun [Korea Power Engineering Company, Inc. Taejon (Korea, Republic of)

1998-12-31

Mixing characteristics of the chemical additives in the chemical injection tank of the chemical and volume control system(CVCS) were investigated for the Yonggwang Nuclear units 5 and 6. Numerical calculations were performed with a low-Reynolds number turbulence model. Studies were also conducted for the injection tank with a disk located at 1/4H, 2/4H, and 3/4H from the inlet in order to see the effect in the enhancement of chemical mixing. Results show that the optimum arrangement is to locate a disk close to the inlet. 10 refs., 4 figs. (Author)
Investigations on the optimum design of chemical addition system for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Chang, Byong Hoon [Junior College of Inchon, Inchon (Korea, Republic of); Chung, Chang Kyu; Choi, Han Rim; Kim, Eun Kee; Ro, Tae Sun [Korea Power Engineering Company, Inc. Taejon (Korea, Republic of)

1997-12-31

Mixing characteristics of the chemical additives in the chemical injection tank of the chemical and volume control system(CVCS) were investigated for the Yonggwang Nuclear units 5 and 6. Numerical calculations were performed with a low-Reynolds number turbulence model. Studies were also conducted for the injection tank with a disk located at 1/4H, 2/4H, and 3/4H from the inlet in order to see the effect in the enhancement of chemical mixing. Results show that the optimum arrangement is to locate a disk close to the inlet. 10 refs., 4 figs. (Author)
Practical chemical thermodynamics for geoscientists

CERN Document Server

Fegley, Bruce, Jr

2012-01-01

Practical Chemical Thermodynamics for Geoscientists covers classical chemical thermodynamics and focuses on applications to practical problems in the geosciences, environmental sciences, and planetary sciences. This book will provide a strong theoretical foundation for students, while also proving beneficial for earth and planetary scientists seeking a review of thermodynamic principles and their application to a specific problem. Strong theoretical foundation and emphasis on applications Numerous worked examples in each chapter Brief historical summaries and biographies of key thermodynamicists-including their fundamental research and discoveries Extensive references to relevant literature.
Liquid and solid rad waste treatment in advanced nuclear power plants. Application to the SBWR design

International Nuclear Information System (INIS)

Tielas Reina, M.; Asuar Alonso, O.

1994-01-01

Rad waste treatment requirements for the new generation of American advanced passive and evolutionary power plants are listed in the URD (Utility Requirements Document) of the EPRI (Electrical Power Research Institute). These requirements focus on: - Minimization of shipped solid wastes - Minimization of liquid effluents - Simplification of design and operation, with emphasis not only on waste treatment system design but also on general plant design and operation These objectives are aimed at: - Reducing and segregating wastes at source - Minimizing chemical contamination of these wastes System design simplification is completed by providing free space in the building for the use of mobile plants, either for special services not considered in the basic design or to accommodate future technical advances. (Author)
CMSMAP : oil, chemical, search and rescue, and marine emergency response crisis management system

International Nuclear Information System (INIS)

Anderson, E.L.; Howlett, E.; Galagan, C.; Giguere, T.; Wee, F.; Chong, J.

2002-01-01

This paper describes a newly developed Crisis Management System (CMS) which makes it possible to view oil and chemical spills on the seafloor. The CMS is designed to run in a network environment, so that multiple stations can be used cooperatively to respond to a spill incident. It was developed by the Maritime and Port Authority in Singapore and represents a singular integration of a ship's bridge simulator hardware and software. It incorporates numerical models and emergency response software. The CMS is installed in a specifically designed building at the Singapore Polytechnic University, and is integrated with two shipping bridge simulators. One user interface has access to models dealing with oil spills, chemical spills, search and rescues, marine emergencies, and nuclear disasters. The interface is linked to a response management system. The entire system is used to train response personnel to marine emergencies. The histories and costs of planned response activities are described and logged for reference purposes. Estimates of damages associated with spills can be obtained. Alternative response plans can also be determined. Further research in 2002 will focus on developing real time response. 3 refs., 6 figs
Dietary antioxidant synergy in chemical and biological systems.

Science.gov (United States)

Wang, Sunan; Zhu, Fan

2017-07-24

Antioxidant (AOX) synergies have been much reported in chemical ("test-tube" based assays focusing on pure chemicals), biological (tissue culture, animal and clinical models), and food systems during the past decade. Tentative synergies differ from each other due to the composition of AOX and the quantification methods. Regeneration mechanism responsible for synergy in chemical systems has been discussed. Solvent effects could contribute to the artifacts of synergy observed in the chemical models. Synergy in chemical models may hardly be relevant to biological systems that have been much less studied. Apparent discrepancies exist in understanding the molecular mechanisms in both chemical and biological systems. This review discusses diverse variables associated with AOX synergy and molecular scenarios for explanation. Future research to better utilize the synergy is suggested.
Selection and design of solvents

DEFF Research Database (Denmark)

Gani, Rafiqul

and design of solvents will be presented together with application examples. The selection problem is defined as finding known chemicals that match the desired functions of a solvent for a specified set of applications. The design problem is defined as finding the molecular structure (or mixture of molecules....... With increasing interest on issues such as waste, sustainability, environmental impact and green chemistry, the selection and design of solvents have become important problems that need to be addressed during chemical product-process design and development. Systematic methods and tools suitable for selection......) that match the desired functions of a solvent for a specified set of applications. Use of organic chemicals and ionic liquids as solvents will be covered....
Automatic design of digital synthetic gene circuits.

Directory of Open Access Journals (Sweden)

Mario A Marchisio

2011-02-01

Full Text Available De novo computational design of synthetic gene circuits that achieve well-defined target functions is a hard task. Existing, brute-force approaches run optimization algorithms on the structure and on the kinetic parameter values of the network. However, more direct rational methods for automatic circuit design are lacking. Focusing on digital synthetic gene circuits, we developed a methodology and a corresponding tool for in silico automatic design. For a given truth table that specifies a circuit's input-output relations, our algorithm generates and ranks several possible circuit schemes without the need for any optimization. Logic behavior is reproduced by the action of regulatory factors and chemicals on the promoters and on the ribosome binding sites of biological Boolean gates. Simulations of circuits with up to four inputs show a faithful and unequivocal truth table representation, even under parametric perturbations and stochastic noise. A comparison with already implemented circuits, in addition, reveals the potential for simpler designs with the same function. Therefore, we expect the method to help both in devising new circuits and in simplifying existing solutions.
Rational Design of Mixed-Metal Oxides for Chemical Looping Combustion of Coal via Coupled Computational-Experimental Studies

Energy Technology Data Exchange (ETDEWEB)

Mishra, Amit [North Carolina State Univ., Raleigh, NC (United States); Li, Fanxing [North Carolina State Univ., Raleigh, NC (United States); Santiso, Erik [North Carolina State Univ., Raleigh, NC (United States)

2017-09-18

Energy and global climate change are two grand challenges to the modern society. An urgent need exists for development of clean and efficient energy conversion processes. The chemical looping strategy, which utilizes regenerable oxygen carriers (OCs) to indirectly convert carbonaceous fuels via redox reactions, is considered to be one of the more promising approaches for CO2 capture by the U.S. Department of Energy (USDOE). To date, most long-term chemical looping operations were conducted using gaseous fuels, even though direct conversion of coal is more desirable from both economics and CO2 capture viewpoints. The main challenges for direct coal conversion reside in the stringent requirements on oxygen carrier performances. In addition, coal char and volatile compounds are more challenging to convert than gaseous fuels. A promising approach for direct conversion of coal is the so called chemical looping with oxygen uncoupling (CLOU) technique. In the CLOU process, a metal oxide that decomposes at the looping temperature, and releases oxygen to the gas phase is used as the OC. The overarching objective of this project was to discover the fundamental principles for rational design and optimization of oxygen carriers (OC) in coal chemical looping combustion (CLC) processes. It directly addresses Topic Area B of the funding opportunity announcement (FOA) in terms of “predictive description of the phase behavior and mechanical properties” of “mixed metal oxide” based OCs and rational development of new OC materials with superior functionality. This was achieved through studies exploring i) iron-containing mixed-oxide composites as oxygen carriers for CLOU, ii) Ca1-xAxMnO3-δ (A = Sr and Ba) as oxygen carriers for CLOU, iii) CaMn1-xBxO3-δ (B=Al, V, Fe, Co, and Ni) as oxygen carrier for CLOU and iv) vacancy creation energy in Mn-containing perovskites as an indicator chemical looping with oxygen uncoupling.
Motion-free hybrid design laser beam propagation analyzer using a digital micromirror device and a variable focus liquid lens.

Science.gov (United States)

Sheikh, Mumtaz; Riza, Nabeel A

2010-06-01

To the best of our knowledge, we propose the first motion-free laser beam propagation analyzer with a hybrid design using a digital micromirror device (DMD) and a liquid electronically controlled variable focus lens (ECVFL). Unlike prior analyzers that require profiling the beam at multiple locations along the light propagation axis, the proposed analyzer profiles the beam at the same plane for multiple values of the ECVFL focal length, thus eliminating beam profiler assembly motion. In addition to measuring standard Gaussian beam parameters, the analyzer can also be used to measure the M(2) beam propagation parameter of a multimode beam. Proof-of-concept beam parameter measurements with the proposed analyzer are successfully conducted for a 633 nm laser beam. Given the all-digital nature of the DMD-based profiling and all-analog motion-free nature of the ECVFL beam focus control, the proposed analyzer versus prior art promises better repeatability, speed, and reliability.

Designing Material Materialising Design

DEFF Research Database (Denmark)

Nicholas, Paul

2013-01-01

Designing Material Materialising Design documents five projects developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts, School of Architecture. These projects explore the idea that new designed materials might require new design methods....... Focusing on fibre reinforced composites, this book sustains an exploration into the design and making of elastically tailored architectural structures that rely on the use of computational design to predict sensitive interdependencies between geometry and behaviour. Developing novel concepts...
Computing Properties Of Chemical Mixtures At Equilibrium

Science.gov (United States)

Mcbride, B. J.; Gordon, S.

1995-01-01

Scientists and engineers need data on chemical equilibrium compositions to calculate theoretical thermodynamic properties of chemical systems. Information essential in design and analysis of such equipment as compressors, turbines, nozzles, engines, shock tubes, heat exchangers, and chemical-processing equipment. CET93 is general program that calculates chemical equilibrium compositions and properties of mixtures for any chemical system for which thermodynamic data are available. Includes thermodynamic data for more than 1,300 gaseous and condensed species and thermal-transport data for 151 gases. Written in FORTRAN 77.
EDITORIAL: Focus on Micro- and Nanofluidics FOCUS ON MICRO- AND NANOFLUIDICS

Science.gov (United States)

Ajdari, Armand; Stone, Howard A.

2009-07-01

This focus issue of New Journal of Physics concentrates on recent developments in microfluidics, and related small-scale flow themes. This subject touches on many areas with the common element that they are engaged with understanding, measuring or manipulating flows at the scale of a few hundred microns or smaller. Microfluidics is of interest to many scientists and engineers from many disciplines because it is a toolbox from which they can investigate basic questions in their respective fields. In particular, the field has led to new studies of small-scale fluid flows, especially those dominated by surface effects, which is crucial for understanding electrokinetics, chemical reactions and phase changes, and multiphase systems, including those involving dispersed liquid and gas phases, suspended particles, cells, vesicles, capsules, etc. The lower length scale of these kinds of flows concerns nanoscale manipulation of objects such as DNA or nanoparticles, nanofabrication of surfaces, studies of the flow within nanometers of substrates, etc. Microfluidics has also given rise to technologies because it enables design and implementation of new devices for sensing, detection, measurement, materials characterization, combinatorial discovery, cellular-scale manipulation, miniaturization of reactors, etc. The fact that these systems are small, cheap, physically flexible, portable, multifunctional, and, when they are working, produce measurements quickly, offers many new avenues for innovation. In this issue we highlight contributions from around the world that explore research directions inspired by the manifold possibilities of microfluidics. In particular, the papers include reports of single-phase flows that are driven by electrical fields, so-called electrokinetics. Although the field has its origins in the 19th century, if not even earlier, new theoretical ideas are required to understand dynamics close to charged surfaces, and new applications of the basic ideas are
Application of computer assisted combinatorial chemistry in antivirial, antimalarial and anticancer agents design

Science.gov (United States)

Burello, E.; Bologa, C.; Frecer, V.; Miertus, S.

Combinatorial chemistry and technologies have been developed to a stage where synthetic schemes are available for generation of a large variety of organic molecules. The innovative concept of combinatorial design assumes that screening of a large and diverse library of compounds will increase the probability of finding an active analogue among the compounds tested. Since the rate at which libraries are screened for activity currently constitutes a limitation to the use of combinatorial technologies, it is important to be selective about the number of compounds to be synthesized. Early experience with combinatorial chemistry indicated that chemical diversity alone did not result in a significant increase in the number of generated lead compounds. Emphasis has therefore been increasingly put on the use of computer assisted combinatorial chemical techniques. Computational methods are valuable in the design of virtual libraries of molecular models. Selection strategies based on computed physicochemical properties of the models or of a target compound are introduced to reduce the time and costs of library synthesis and screening. In addition, computational structure-based library focusing methods can be used to perform in silico screening of the activity of compounds against a target receptor by docking the ligands into the receptor model. Three case studies are discussed dealing with the design of targeted combinatorial libraries of inhibitors of HIV-1 protease, P. falciparum plasmepsin and human urokinase as potential antivirial, antimalarial and anticancer drugs. These illustrate library focusing strategies.
Chemical buffering capacity of clay rock

International Nuclear Information System (INIS)

Beaucaire, C.; Pearson, F.J.; Gautschi, A.

2004-01-01

The long-term performance of a nuclear waste repository is strongly dependent on the chemical properties of the host rock. The host rock establishes the chemical environment that determines such important performance attributes as radionuclide solubilities from the waste and the transport rates from the repository to the accessible environment. Clay-rich rocks are especially favourable host rocks because they provide a strong buffering capacity to resist chemical changes prompted either internally, by reactions of the waste itself and emplacement materials, or externally, by changes in the hydrologic systems surrounding the host rock. This paper will focus on three aspects of the stability of clay-rich host rocks: their ability to provide pCO 2 and redox buffering, and to resist chemical changes imposed by changes in regional hydrology and hydro-chemistry. (authors)
Within-otolith variability in chemical fingerprints: implications for sampling designs and possible environmental interpretation.

Directory of Open Access Journals (Sweden)

Antonio Di Franco

Full Text Available Largely used as a natural biological tag in studies of dispersal/connectivity of fish, otolith elemental fingerprinting is usually analyzed by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS. LA-ICP-MS produces an elemental fingerprint at a discrete time-point in the life of a fish and can generate data on within-otolith variability of that fingerprint. The presence of within-otolith variability has been previously acknowledged but not incorporated into experimental designs on the presumed, but untested, grounds of both its negligibility compared to among-otolith variability and of spatial autocorrelation among multiple ablations within an otolith. Here, using a hierarchical sampling design of spatial variation at multiple scales in otolith chemical fingerprints for two Mediterranean coastal fishes, we explore: 1 whether multiple ablations within an otolith can be used as independent replicates for significance tests among otoliths, and 2 the implications of incorporating within-otolith variability when assessing spatial variability in otolith chemistry at a hierarchy of spatial scales (different fish, from different sites, at different locations on the Apulian Adriatic coast. We find that multiple ablations along the same daily rings do not necessarily exhibit spatial dependency within the otolith and can be used to estimate residual variability in a hierarchical sampling design. Inclusion of within-otolith measurements reveals that individuals at the same site can show significant variability in elemental uptake. Within-otolith variability examined across the spatial hierarchy identifies differences between the two fish species investigated, and this finding leads to discussion of the potential for within-otolith variability to be used as a marker for fish exposure to stressful conditions. We also demonstrate that a 'cost'-optimal allocation of sampling effort should typically include some level of within
Within-otolith variability in chemical fingerprints: implications for sampling designs and possible environmental interpretation.

Science.gov (United States)

Di Franco, Antonio; Bulleri, Fabio; Pennetta, Antonio; De Benedetto, Giuseppe; Clarke, K Robert; Guidetti, Paolo

2014-01-01

Largely used as a natural biological tag in studies of dispersal/connectivity of fish, otolith elemental fingerprinting is usually analyzed by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). LA-ICP-MS produces an elemental fingerprint at a discrete time-point in the life of a fish and can generate data on within-otolith variability of that fingerprint. The presence of within-otolith variability has been previously acknowledged but not incorporated into experimental designs on the presumed, but untested, grounds of both its negligibility compared to among-otolith variability and of spatial autocorrelation among multiple ablations within an otolith. Here, using a hierarchical sampling design of spatial variation at multiple scales in otolith chemical fingerprints for two Mediterranean coastal fishes, we explore: 1) whether multiple ablations within an otolith can be used as independent replicates for significance tests among otoliths, and 2) the implications of incorporating within-otolith variability when assessing spatial variability in otolith chemistry at a hierarchy of spatial scales (different fish, from different sites, at different locations on the Apulian Adriatic coast). We find that multiple ablations along the same daily rings do not necessarily exhibit spatial dependency within the otolith and can be used to estimate residual variability in a hierarchical sampling design. Inclusion of within-otolith measurements reveals that individuals at the same site can show significant variability in elemental uptake. Within-otolith variability examined across the spatial hierarchy identifies differences between the two fish species investigated, and this finding leads to discussion of the potential for within-otolith variability to be used as a marker for fish exposure to stressful conditions. We also demonstrate that a 'cost'-optimal allocation of sampling effort should typically include some level of within-otolith replication in the
Aerosol Chemical Speciation Monitor (ACSM) Instrument Handbook

Energy Technology Data Exchange (ETDEWEB)

Watson, Thomas B. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2017-08-15

The Aerodyne Aerosol Chemical Speciation Monitor (ACSM) measures particle mass loading and chemical composition in real time for non-refractory sub-micron aerosol particles. The ACSM is designed for long-term unattended deployment and routine monitoring applications.
The optics of the Final Focus Test Beam

International Nuclear Information System (INIS)

Irwin, J.; Brown, K.; Bulos, F.; Burke, D.; Helm, R.; Roy, G.; Ruth, R.; Yamamoto, N.; Oide, K.

1991-05-01

The Final Focus Test Beam (FFTB), currently under construction at the end of the SLAC Linac, is being built by an international collaboration as a test bed for ideas and methods required in the design and construction of final focus systems for next generation e + e - linear colliders. The FFTB lattice is based on the previously developed principle of using sextupole pairs in a dispersive region to compensate chromaticity. The linear lattice was optimized for length, and implementation of diagnostic procedures. The transformations between sextupole pairs (CCX and CCY) are exactly -I, the matrix for the intermediate transformer (BX) is exactly diagonal, and the dispersion function has zero slope at the sextupoles and is thus zero at the minimum of the β x function in the intermediate transformer. The introduction of sextupoles in final focus systems leads to the presence of additional optical aberrations, and synchrotron radiation in the dipoles also enlarges the final spot size. The important fourth-order optical aberrations which determine the main features of the design have been identified. Additional lower order aberrations arise in the implementation of these designs, since the real system is not the ideal design. We concentrate on these aberrations and describe strategies for their diagnosis and correction
Mitigation options for chemicals of emerging concern in surface waters operationalising solutions-focused risk assessment

NARCIS (Netherlands)

Van Wezel, Annemarie P.; Ter Laak, Thomas L.; Fischer, Astrid; Bäuerlein, Patrick S.; Munthe, John; Posthuma, Leo

2017-01-01

The water system provides many services to society; industries, municipalities and agriculture all withdraw, use and return water and demand a water quality fit for the intended purposes. Both global production of chemicals and global water withdrawal grow faster than human population. This implies
Work and Family. Special Focus.

Science.gov (United States)

Goetz, Kathy, Ed.

1992-01-01

This newsletter issue focuses on issues concerning families with both parents employed outside the home and describes several employer programs designed to help employees balance their work and family life. The newsletter includes the following articles: (1) "Work and Family: 1992"; (2) "Levi Strauss and Co.--A Work/Family Program…
The Videographic Requirements Gathering Method for Adolescent-Focused Interaction Design

Directory of Open Access Journals (Sweden)

Tamara Peyton

2014-08-01

Full Text Available We present a novel method for conducting requirements gathering with adolescent populations. Called videographic requirements gathering, this technique makes use of mobile phone data capture and participant creation of media images. The videographic requirements gathering method can help researchers and designers gain intimate insight into adolescent lives while simultaneously reducing power imbalances. We provide rationale for this approach, pragmatics of using the method, and advice on overcoming common challenges facing researchers and designers relying on this technique.
Implementation of an innovative teaching project in a Chemical Process Design course at the University of Cantabria, Spain

Science.gov (United States)

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

2016-09-01

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

International Nuclear Information System (INIS)

1978-08-01

This book mentions design of instrumentation and construction for a chemical plant, which deals with the change of instrumentation, construction, choice of material test, construction of thermal insulation work for a chemical plant, about classification and main materials, the problems on construction, painting plan and construction for a chemical plant such as paint and painting, safety and hygiene, cleaning of a chemical plant on the time for washing and decision of the way of washing, start up test for a chemical plant such as introduction of the check, construction and repair.
SKEW QUADRUPOLE FOCUSING LATTICES AND APPLICATIONS

International Nuclear Information System (INIS)

Parker, B.

2001-01-01

In this paper we revisit using skew quadrupole fields in place of traditional normal upright quadrupole fields to make beam focusing structures. We illustrate by example skew lattice decoupling, dispersion suppression and chromatic correction using the neutrino factory Study-II muon storage ring design. Ongoing BNL investigation of flat coil magnet structures that allow building a very compact muon storage ring arc and other flat coil configurations that might bring significant magnet cost reduction to a VLHC motivate our study of skew focusing
Focusing on What Counts: Using Exploratory Focus Groups to Enhance the Development of an Electronic Survey in a Mixed-Methods Research Design

Science.gov (United States)

Galliott, Natal'ya; Graham, Linda J.

2016-01-01

This paper illustrates the use of exploratory focus groups to inform the development of a survey instrument in a sequential phase mixed-methods study investigating differences in secondary students' career choice capability. Five focus groups were conducted with 23 Year 10 students in the state of New South Wales, Australia. Analysis of the focus…
Two-color QCD with non-zero chiral chemical potential

Energy Technology Data Exchange (ETDEWEB)

Braguta, V.V. [Institute for High Energy Physics NRC “Kurchatov Institute' ,142281 Protvino (Russian Federation); Far Eastern Federal University, School of Biomedicine,690950 Vladivostok (Russian Federation); Goy, V.A. [Far Eastern Federal University, School of Natural Sciences,690950 Vladivostok (Russian Federation); Ilgenfritz, E.M. [Joint Institute for Nuclear Research,BLTP, 141980 Dubna (Russian Federation); Kotov, A.Yu. [Institute of Theoretical and Experimental Physics,117259 Moscow (Russian Federation); Molochkov, A.V. [Far Eastern Federal University, School of Biomedicine,690950 Vladivostok (Russian Federation); Müller-Preussker, M.; Petersson, B. [Humboldt-Universität zu Berlin, Institut für Physik,12489 Berlin (Germany)

2015-06-16

The phase diagram of two-color QCD with non-zero chiral chemical potential is studied by means of lattice simulation. We focus on the influence of a chiral chemical potential on the confinement/deconfinement phase transition and the breaking/restoration of chiral symmetry. The simulation is carried out with dynamical staggered fermions without rooting. The dependences of the Polyakov loop, the chiral condensate and the corresponding susceptibilities on the chiral chemical potential and the temperature are presented. The critical temperature is observed to increase with increasing chiral chemical potential.
Design, simulation and construction of quadrupole magnets for focusing electron beam in powerful industrial electron accelerator

Directory of Open Access Journals (Sweden)

S KH Mousavi

2015-09-01

Full Text Available In this paper the design and simulation of quadrupole magnets and electron beam optical of that by CST Studio code has been studied. Based on simulation result the magnetic quadrupole has been done for using in beam line of first Iranian powerful electron accelerator. For making the suitable magnetic field the effects of material and core geometry and coils current variation on quadrupole magnetic field have been studied. For test of quadrupole magnet the 10 MeV beam energy and 0.5 pi mm mrad emittance of input beam has been considered. We see the electron beam through the quadrupole magnet focus in one side and defocus in other side. The optimum of distance between two quadrupole magnets for low emittance have been achieved. The simulation results have good agreement with experimental results
Designing learning curves for carbon capture based on chemical absorption according to the minimum work of separation

International Nuclear Information System (INIS)

Rochedo, Pedro R.R.; Szklo, Alexandre

2013-01-01

Highlights: • This work defines the minimum work of separation (MWS) for a capture process. • Findings of the analysis indicated a MWS of 0.158 GJ/t for post-combustion. • A review of commercially available processes based on chemical absorption was made. • A review of learning models was conducted, with the addition on a novel model. • A learning curve for post-combustion carbon capture was successfully designed. - Abstract: Carbon capture is one of the most important alternatives for mitigating greenhouse gas emissions in energy facilities. The post-combustion route based on chemical absorption with amine solvents is the most feasible alternative for the short term. However, this route implies in huge energy penalties, mainly related to the solvent regeneration. By defining the minimum work of separation (MWS), this study estimated the minimum energy required to capture the CO 2 emitted by coal-fired thermal power plants. Then, by evaluating solvents and processes and comparing it to the MWS, it proposes the learning model with the best fit for the post-combustion chemical absorption of CO 2 . Learning models are based on earnings from experience, which can include the intensity of research and development. In this study, three models are tested: Wright, DeJong and D and L. Findings of the thermochemical analysis indicated a MWS of 0.158 GJ/t for post-combustion. Conventional solvents currently present an energy penalty eight times the MWS. By using the MWS as a constraint, this study found that the D and L provided the best fit to the available data of chemical solvents and absorption plants. The learning rate determined through this model is very similar to the ones found in the literature
Opportunities Provided by the Design of a Website Focused on the Promotion of Collaborative Projects Within European IT Industry

Directory of Open Access Journals (Sweden)

Alexandru CAPATINA

2011-11-01

Full Text Available Our paper emphasizes the opportunities provided both for the academic research and business partnerships by the design of a website which promotes the collaborative projects within European IT industry. From the academic perspective, the companies registered in the website database will represent the sample for different researches focused on cross-cultural interactions, intellectual capital components and competitive intelligence strategies. From the business perspective, the registration of the companies will allow the access to the list with all the potential future partners’ in the field of software development. In the first part of the paper dedicated to literature review, we highlighted the main types of IT collaborative projects; then, we presented the tools provided by the website that was designed in view to increase the awareness of the European IT companies. In the last part of the paper, we tested by means of chi-square statistical method the correlation between R&D investments and average length of time for software design in the case of a sample of 58 IT companies included in the database. We also revealed our future research intentions related to the domain of IT partnerships patterns.

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

Science.gov (United States)

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.
Thyroid effects of endocrine disrupting chemicals.

Science.gov (United States)

Boas, Malene; Feldt-Rasmussen, Ulla; Main, Katharina M

2012-05-22

In recent years, many studies of thyroid-disrupting effects of environmental chemicals have been published. Of special concern is the exposure of pregnant women and infants, as thyroid disruption of the developing organism may have deleterious effects on neurological outcome. Chemicals may exert thyroid effects through a variety of mechanisms of action, and some animal experiments and in vitro studies have focused on elucidating the mode of action of specific chemical compounds. Long-term human studies on effects of environmental chemicals on thyroid related outcomes such as growth and development are still lacking. The human exposure scenario with life long exposure to a vast mixture of chemicals in low doses and the large physiological variation in thyroid hormone levels between individuals render human studies very difficult. However, there is now reasonably firm evidence that PCBs have thyroid-disrupting effects, and there is emerging evidence that also phthalates, bisphenol A, brominated flame retardants and perfluorinated chemicals may have thyroid disrupting properties. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
The current status of exposure-driven approaches for chemical safety assessment: A cross-sector perspective.

Science.gov (United States)

Sewell, Fiona; Aggarwal, Manoj; Bachler, Gerald; Broadmeadow, Alan; Gellatly, Nichola; Moore, Emma; Robinson, Sally; Rooseboom, Martijn; Stevens, Alexander; Terry, Claire; Burden, Natalie

2017-08-15

For the purposes of chemical safety assessment, the value of using non-animal (in silico and in vitro) approaches and generating mechanistic information on toxic effects is being increasingly recognised. For sectors where in vivo toxicity tests continue to be a regulatory requirement, there has been a parallel focus on how to refine studies (i.e. reduce suffering and improve animal welfare) and increase the value that in vivo data adds to the safety assessment process, as well as where to reduce animal numbers where possible. A key element necessary to ensure the transition towards successfully utilising both non-animal and refined safety testing is the better understanding of chemical exposure. This includes approaches such as measuring chemical concentrations within cell-based assays and during in vivo studies, understanding how predicted human exposures relate to levels tested, and using existing information on human exposures to aid in toxicity study design. Such approaches promise to increase the human relevance of safety assessment, and shift the focus from hazard-driven to risk-driven strategies similar to those used in the pharmaceutical sectors. Human exposure-based safety assessment offers scientific and 3Rs benefits across all sectors marketing chemical or medicinal products. The UK's National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) convened an expert working group of scientists across the agrochemical, industrial chemical and pharmaceutical industries plus a contract research organisation (CRO) to discuss the current status of the utilisation of exposure-driven approaches, and the challenges and potential next steps for wider uptake and acceptance. This paper summarises these discussions, highlights the challenges - particularly those identified by industry - and proposes initial steps for moving the field forward. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.
Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Chemical Sciences. Anil D Naik. Articles written in Journal of Chemical Sciences. Volume 113 Issue 4 August 2001 pp 285-290 Inorganic. Design, synthesis and physico-chemical investigation of a dinuclear zinc(II) complex with a novel 'end-off' compartmental ligand · Anil D Naik Vidyanand K ...
Journal of Chemical Sciences | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Chemical Sciences. Vidyanand K Revankar. Articles written in Journal of Chemical Sciences. Volume 113 Issue 4 August 2001 pp 285-290 Inorganic. Design, synthesis and physico-chemical investigation of a dinuclear zinc(II) complex with a novel 'end-off' compartmental ligand · Anil D Naik ...
Use of focused ultrasonication in activity-based profiling of deubiquitinating enzymes in tissue.

Science.gov (United States)

Nanduri, Bindu; Shack, Leslie A; Rai, Aswathy N; Epperson, William B; Baumgartner, Wes; Schmidt, Ty B; Edelmann, Mariola J

2016-12-15

To develop a reproducible tissue lysis method that retains enzyme function for activity-based protein profiling, we compared four different methods to obtain protein extracts from bovine lung tissue: focused ultrasonication, standard sonication, mortar & pestle method, and homogenization combined with standard sonication. Focused ultrasonication and mortar & pestle methods were sufficiently effective for activity-based profiling of deubiquitinases in tissue, and focused ultrasonication also had the fastest processing time. We used focused-ultrasonicator for subsequent activity-based proteomic analysis of deubiquitinases to test the compatibility of this method in sample preparation for activity-based chemical proteomics. Copyright © 2016 Elsevier Inc. All rights reserved.
High-resolution study of photoinduced modification in fused silica produced by a tightly focused femtosecond laser beam in the presence of aberrations

International Nuclear Information System (INIS)

Hnatovsky, C.; Taylor, R.S.; Simova, E.; Bhardwaj, V.R.; Rayner, D.M.; Corkum, P.B.

2005-01-01

An ultrahigh-resolution (20 nm) technique of selective chemical etching and atomic force microscopy has been used to study the photoinduced modification in fused silica produced at various depths by tightly focused femtosecond laser radiation affected by spherical aberration. We demonstrate that shapes of the irradiated zones near the threshold for modification can be predicted by taking proper account of spherical aberration caused by the refractive index mismatched air-silica interface. We establish a depth dependence of the pulse energy required to initiate modification and characterize the relationship between numerical aperture of the writing lens and practically achievable writing depth. We also show that spatial characteristics of the laser-modified zones can be controlled by a specially designed focusing system which allows correction for a variable amount of spherical aberration
Design Anthropology in Participatory Design

DEFF Research Database (Denmark)

Smith, Rachel Charlotte; Kjærsgaard, Mette Gislev

2015-01-01

This focus section explores the opportunities of design anthropology in participatory design as an approach to research and design in an increasingly global and digital world. Traditionally, ethnography has been used in Participatory design to research real-life contexts and challenges, and as ways...... opportunities of using design anthropology as a holistic and critical approach to addressing societal challenges and change, and a way for anthropologists and designers to engage in participatory research and design that extend beyond the empirical....
Collective focusing ion accelerator

International Nuclear Information System (INIS)

Goldin, F.J.

1986-01-01

The principal subject of this dissertation is the trapping confinement of pure electron plasmas in bumpy toroidal magnetic fields, with particular attention given to the trapping procedure and the behavior of the plasma during the final equilibrium. The most important aspects of the equilibrium studied were the qualitative nature of the plasma configuration and motion and its density, distribution and stability. The motivation for this study was that an unneutralized cloud of electrons contained in a toroidal system, sufficiently dense and stable, may serve to electrostatically focus ions (against centrifugal and self space charge forces) in a cyclic ion accelerator. Such an accelerator, known as a Collective Focusing Ion Accelerator (CFIA) could be far smaller than conventional designs (which use external magnetic fields directly to focus the ions) due to the smaller gyro-radium of an electron in a magnetic field of given strength. The electron cloud generally drifted poloidally at a finite radius from the toroidal minor axis. As this would preclude focusing ions with such clouds, damping this motion was investigated. Finite resistance in the normally perfectly conductive vessel wall did this. In further preparation for a working CFIA, additional experiments studied the effect of ions on the stability of the electron cloud
The Architecture of Chemical Alternatives Assessment.

Science.gov (United States)

Geiser, Kenneth; Tickner, Joel; Edwards, Sally; Rossi, Mark

2015-12-01

Chemical alternatives assessment is a method rapidly developing for use by businesses, governments, and nongovernment organizations seeking to substitute chemicals of concern in production processes and products. Chemical alternatives assessment is defined as a process for identifying, comparing, and selecting safer alternatives to chemicals of concern (including those in materials, processes, or technologies) on the basis of their hazards, performance, and economic viability. The process is intended to provide guidance for assuring that chemicals of concern are replaced with safer alternatives that are not likely to be later regretted. Conceptually, the assessment methods are developed from a set of three foundational pillars and five common principles. Based on a number of emerging alternatives assessment initiatives, in this commentary, we outline a chemical alternatives assessment blueprint structured around three broad steps: Scope, Assessment, and Selection and Implementation. Specific tasks and tools are identified for each of these three steps. While it is recognized that on-going practice will further refine and develop the method and tools, it is important that the structure of the assessment process remain flexible, adaptive, and focused on the substitution of chemicals of concern with safer alternatives. © 2015 Society for Risk Analysis.
Recycling and surplus chemical programs

International Nuclear Information System (INIS)

Harper, T.J.

1993-05-01

In 1988, 45 years of defense production came to a close at the US Department of Energy (DOE) Hanford Site. The mission of the Hanford Site was formally changed to environmental restoration and remediation. Westinghouse Hanford Company (WHC) is the management and operations (M ampersand O) contractor leading the cleanup. Within the framework of future Site cleanup, Hanford recycling and surplus chemical programs are making a viable contribution today to waste minimization, diversion of materials from the waste stream, and setting a standard for future operations. This paper focuses on two successful efforts: paper recycling and surplus chemical sales
Reset, Hack and Own : Media Focus in Art and Design Education

NARCIS (Netherlands)

L. Nordeman

2014-01-01

Over the past fifteen years, the professional context of arts and design, in terms of production, distribution and consumption, has largely changed as a result of technological developments. However, art and design education programmes in the Netherlands have mostly failed to constructively
Quantum mechanical tunneling in chemical physics

CERN Document Server

Nakamura, Hiroki

2016-01-01

Quantum mechanical tunneling plays important roles in a wide range of natural sciences, from nuclear and solid-state physics to proton transfer and chemical reactions in chemistry and biology. Responding to the need for further understanding of multidimensional tunneling, the authors have recently developed practical methods that can be applied to multidimensional systems. Quantum Mechanical Tunneling in Chemical Physics presents basic theories, as well as original ones developed by the authors. It also provides methodologies and numerical applications to real molecular systems. The book offers information so readers can understand the basic concepts and dynamics of multidimensional tunneling phenomena and use the described methods for various molecular spectroscopy and chemical dynamics problems. The text focuses on three tunneling phenomena: (1) energy splitting, or tunneling splitting, in symmetric double well potential, (2) decay of metastable state through tunneling, and (3) tunneling effects in chemical...
Understanding Molecular Interactions within Chemically Selective Layered Polymer Assemblies

Energy Technology Data Exchange (ETDEWEB)

Gary J. Blanchard

2009-06-30

This work focuses on two broad issues. These are (1) the molecular origin of the chemical selectivity achieved with ultrathin polymer multilayers, and (2) how the viscoelastic properties of the polymer layers are affected by exposure to solvent and analytes. These issues are inter-related, and to understand them we need to design experiments that probe both the energetic and kinetic aspects of interfacial adsorption processes. This project focuses on controling the chemical structure, thickness, morphology and sequential ordering of polymer layers bound to interfaces using maleimide-vinyl ether and closely related alternating copolymerization chemistry and efficient covalent cross-linking reactions that allow for layer-by-layer polymer deposition. This chemistry has been developed during the funding cycle of this Grant. We have measure the equilibrium constants for interactions between specific layers within the polymer interfaces and size-controlled, surface-functionalized gold nanoparticles. The ability to control both size and functionality of gold nanoparticle model analytes allows us to evaluate the average “pore size” that characterizes our polymer films. We have measured the “bulk” viscosity and shear modulus of the ultrathin polymer films as a function of solvent overlayer identity using quartz crystal microbalance complex impedance measurements. We have measured microscopic viscosity at specific locations within the layered polymer interfaces with time-resolved fluorescence lifetime and depolarization techniques. We combine polymer, cross-linking and nanoparticle synthetic expertise with a host of characterization techniques, including QCM gravimetry and complex impedance analysis, steady state and time-resolved spectroscopies.
Design studies of an electrostatic quadrupole channel for transport of a high-brightness H- beam and comparison with gas focusing

International Nuclear Information System (INIS)

Chang, C.R.; Horowitz, E.; Reiser, M.

1989-01-01

Transport of low-energy, high-brightness H - beams from the ion source to the radio-frequency quadrupole (RFQ) accelerator requires the solution of several physics and engineering problems to avoid particle losses and emittance growth. The authors developed a conceptual design of an electrostatic quadrupole channel for transport of a 120 keV, 120 mA, H - beam into a 425 MHz RFQ with low emittance growth and high transmission efficiency. This design satisfies several constraints imposed by voltage breakdown and beam optics considerations. The system will consist entirely of electrostatic lenses which prevent plasma build-up and eliminate possible emittance growth from plasma fluctuations. Pertinent design features a worst case non-linear analysis for the electrostatic quadrupole channel, and first results of a particle simulation code used to study beam loss and emittance growth are reported. As an alternative to the electrostatic quadrupole concept, gas focusing is being investigated for transporting low-energy H - beams. Recent results from the numerical simulations of such a gas focussing channel are presented
Guard Cell and Tropomyosin Inspired Chemical Sensor

Directory of Open Access Journals (Sweden)

Jacquelyn K.S. Nagel

2013-10-01

Full Text Available Sensors are an integral part of many engineered products and systems. Biological inspiration has the potential to improve current sensor designs as well as inspire innovative ones. This paper presents the design of an innovative, biologically-inspired chemical sensor that performs “up-front” processing through mechanical means. Inspiration from the physiology (function of the guard cell coupled with the morphology (form and physiology of tropomyosin resulted in two concept variants for the chemical sensor. Applications of the sensor design include environmental monitoring of harmful gases, and a non-invasive approach to detect illnesses including diabetes, liver disease, and cancer on the breath.
Automatic evaluation of task-focused parallel jaw gripper design

DEFF Research Database (Denmark)

Wolniakowski, Adam; Miatliuk, Konstantsin; Krüger, Norbert

2014-01-01

In this paper, we suggest gripper quality metrics that indicate the performance of a gripper given an object CAD model and a task description. Those, we argue, can be used in the design and selection of an appropriate gripper when the task is known. We present three different gripper metrics that...
Chemical reactor development : from laboratory synthesis to industrial production

NARCIS (Netherlands)

Thoenes, D.

1998-01-01

Chemical Reactor Development is written primarily for chemists and chemical engineers who are concerned with the development of a chemical synthesis from the laboratory bench scale, where the first successful experiments are performed, to the design desk, where the first commercial reactor is
Optimization of multi-channel neutron focusing guides for extreme sample environments

International Nuclear Information System (INIS)

Di Julio, D D; Lelièvre-Berna, E; Andersen, K H; Bentley, P M; Courtois, P

2014-01-01

In this work, we present and discuss simulation results for the design of multichannel neutron focusing guides for extreme sample environments. A single focusing guide consists of any number of supermirror-coated curved outer channels surrounding a central channel. Furthermore, a guide is separated into two sections in order to allow for extension into a sample environment. The performance of a guide is evaluated through a Monte-Carlo ray tracing simulation which is further coupled to an optimization algorithm in order to find the best possible guide for a given situation. A number of population-based algorithms have been investigated for this purpose. These include particle-swarm optimization, artificial bee colony, and differential evolution. The performance of each algorithm and preliminary results of the design of a multi-channel neutron focusing guide using these methods are described. We found that a three-channel focusing guide offered the best performance, with a gain factor of 2.4 compared to no focusing guide, for the design scenario investigated in this work.
Improved alternating gradient transport and focusing of neutral molecules

International Nuclear Information System (INIS)

Kalnins, Juris; Lambertson, Glen; Gould, Harvey

2001-01-01

Polar molecules, in strong-field seeking states, can be transported and focused by an alternating sequence of electric field gradients that focus in one transverse direction while defocusing in the other. We show by calculation and numerical simulation, how one may greatly improve the alternating gradient transport and focusing of molecules. We use a new optimized multipole lens design, a FODO lattice beam transport line, and lenses to match the beam transport line to the beam source and the final focus. We derive analytic expressions for the potentials, fields, and gradients that may be used to design these lenses. We describe a simple lens optimization procedure and derive the equations of motion for tracking molecules through a beam transport line. As an example, we model a straight beamline that transports a 560 m/s jet-source beam of methyl fluoride molecules 15 m from its source and focuses it to 2 mm diameter. We calculate the beam transport line acceptance and transmission, for a beam with velocity spread, and estimate the transmitted intensity for specified source conditions. Possible applications are discussed

Supramolecular chemistry and chemical warfare agents: from fundamentals of recognition to catalysis and sensing.

Science.gov (United States)

Sambrook, M R; Notman, S

2013-12-21

Supramolecular chemistry presents many possible avenues for the mitigation of the effects of chemical warfare agents (CWAs), including sensing, catalysis and sequestration. To-date, efforts in this field both to study fundamental interactions between CWAs and to design and exploit host systems remain sporadic. In this tutorial review the non-covalent recognition of CWAs is considered from first principles, including taking inspiration from enzymatic systems, and gaps in fundamental knowledge are indicated. Examples of synthetic systems developed for the recognition of CWAs are discussed with a focus on the supramolecular complexation behaviour and non-covalent approaches rather than on the proposed applications.
Accelerating and focusing structures for PIGMI

International Nuclear Information System (INIS)

Swenson, D.A.; Bush, E.D. Jr.; Holsinger, R.F.; Manca, J.J.; Saito, N.; Stovall, J.E.

1977-01-01

The National Cancer Institute is supporting a program of accelerator development at the Los Alamos Scientific Laboratory aimed at the extension of proton linac technologies to produce the most suitable Pion Generator for Medical Irradiations (PIGMI). An optimized design of a pion generator suitable for a radiotherapy program at a major medical center has been established, consisting of a 250-keV injector, followed by a 35-meter-long drift-tube linac that accelerates the proton beam to 150 MeV, and an 85-meter-long coupled-cavity linac that accelerates the beam to its final energy of 650 MeV, where the average beam current of 100 microamperes impinges on one or more targets producing abundant quantities of π - mesons for radiotherapeutic applications. A number of extensions to proton linac technology are being pursued under the PIGMI program at LASL. A discussion is given of recent developments in three areas relevant to the acceleration and focusing of proton beams, namely, the alternating phase focused (APF) linac structure, the disk and washer linac structure, and small permanent magnet quadrupole lenses. The APF linac structure is being developed for the acceleration and focusing role from the injection energy of 250 keV to a few MeV, where a transition is made to a permanent magnet quadrupole focused linac structure. The disk and washer linac structure is under consideration for the high velocity portion of the design
Chemical Mixtures Health Risk Assessment of Environmental Contaminants: Concepts, Methods, Applications

Science.gov (United States)

This problems-based, introductory workshop focuses on methods to assess health risks posed by exposures to chemical mixtures in the environment. Chemical mixtures health risk assessment methods continue to be developed and evolve to address concerns over health risks from multic...
Reviewing the Focus: A Summary and Critique of Child-Focused Sexual Abuse Prevention.

Science.gov (United States)

Rudolph, Julia; Zimmer-Gembeck, Melanie J

2016-10-26

Due to the high incidence, and widespread detrimental health consequences, of child sexual abuse (CSA), effective prevention remains at the forefront of public and mental health research, prevention and intervention agendas. To date much of the focus of prevention has been on school-based education programs designed to teach children skills to evade adult sexual advances, and disclose past or ongoing abuse. Evaluation of sexual abuse prevention programs demonstrate their effectiveness in increasing children's knowledge of CSA concepts and protection skills, but little is known about their effects on children's capacity to prevent abuse. Moreover, concerns persist about the unintended side-effects for young children such as anxiety, worry and wariness of touch. This paper summarizes the recent history of CSA prevention and the critique of child-focused protection programs in order to demonstrate the need to compliment or replace these programs by focusing more on protectors in the children's ecology, specifically parents, in order to create safer environments in which abuse is less likely to occur. © The Author(s) 2016.
Broadband and flexible acoustic focusing by metafiber bundles

Science.gov (United States)

Sun, Hong-Xiang; Chen, Jia-He; Ge, Yong; Yuan, Shou-Qi; Liu, Xiao-Jun

2018-06-01

We report a broadband and flexible acoustic focusing through metafiber bundles in air, in which each metafiber consists of eight circular and narrow rectangular cavities. The fractional bandwidth of the acoustic focusing could reach about 0.2, which arises from the eigenmodes of the metafiber structure. Besides, owing to the flexible characteristic of the metafibers, the focus position can be manipulated by bending the metafiber bundles, and the metafiber bundles could bypass rigid scatterers inside the lens structure. More interestingly, the acoustic propagation and focusing directions can be changed by using a designed right-angled direction converter fabricated by the metafibers, and a waveform converter and a focusing lens of the cylindrical acoustic source are realized based on the metafiber bundles. The proposed focusing lens has the advantages of broad bandwidth, flexible structure, and high focusing performance, showing great potentials in versatile applications.
Structural Analysis of Extended Plasma Focus Chamber

International Nuclear Information System (INIS)

Mohd Azhar Ahmad; Abdul Halim Baijan; Siti Aiasah Hashim

2016-01-01

Accelerator Development Centre (ADC) of Nuclear Malaysia intends to upgrade the plasma focus device. It involves the extension part placed on top of the existing plasma focus vacuum chamber. This extended vacuum chamber purposely to give an extra space in conducting experiments on the existing plasma focus chamber. The aim of upgrading the plasma focus device is to solve the limitation in research and analysis of sample due to its done in an open system that cause analysis of samples is limited and less optimal. This extended chamber was design in considering the ease of fabrication as well as durability of its structural. Thus, this paper discusses the structural analysis in term of pressure loading effect in extended chamber. (author)
Regulatory focus at work : the moderating role of regulatory focus in the job demands-resources model

NARCIS (Netherlands)

Brenninkmeijer, V.; Demerouti, E.; Blanc, Le P.M.; Emmerik, van I.J.H.

2010-01-01

Purpose – The purpose of this study is to examine the moderating role of regulatory focus in the job demands-resources model. Design/methodology/approach – A questionnaire survey was conducted among 146 teachers in secondary education. It was expected that detrimental effects of job demands (i.e.
Analysis of digester design concepts

Energy Technology Data Exchange (ETDEWEB)

Ashare, E.; Wilson, E. H.

1979-01-29

Engineering economic analyses were performed on various digester design concepts to determine the relative performance for various biomass feedstocks. A comprehensive literature survey describing the state-of-the-art of the various digestion designs is included. The digester designs included in the analyses are CSTR, plug flow, batch, CSTR in series, multi-stage digestion and biomethanation. Other process options investigated included pretreatment processes such as shredding, degritting, and chemical pretreatment, and post-digestion processes, such as dewatering and gas purification. The biomass sources considered include feedlot manure, rice straw, and bagasse. The results of the analysis indicate that the most economical (on a unit gas cost basis) digester design concept is the plug flow reactor. This conclusion results from this system providing a high gas production rate combined with a low capital hole-in-the-ground digester design concept. The costs determined in this analysis do not include any credits or penalties for feedstock or by-products, but present the costs only for conversion of biomass to methane. The batch land-fill type digester design was shown to have a unit gas cost comparable to that for a conventional stirred tank digester, with the potential of reducing the cost if a land-fill site were available for a lower cost per unit volume. The use of chemical pretreatment resulted in a higher unit gas cost, primarily due to the cost of pretreatment chemical. A sensitivity analysis indicated that the use of chemical pretreatment could improve the economics provided a process could be developed which utilized either less pretreatment chemical or a less costly chemical. The use of other process options resulted in higher unit gas costs. These options should only be used when necessary for proper process performance, or to result in production of a valuable by-product.
Development and testing of the improved focusing quadrupole for heavy ion fusion accelerators

Energy Technology Data Exchange (ETDEWEB)

Manahan, R R; Martovetsky, N N; Meinke, R B; Chiesa, L; Lietzke, A F; Sabbi, G L; Seidl, P A

2003-10-23

An improved version of the focusing magnet for a Heavy Ion Fusion (HIF) accelerator was designed, built and tested in 2002-2003. This quadrupole has higher focusing power and lower error field than the previous version of the focusing quadrupoles successfully built and tested in 2001. We discuss the features of the new design, selected fabrication issues and test results.
Nova frequency conversion and focusing system

International Nuclear Information System (INIS)

Summers, M.A.; Seppala, L.G.; Williams, J.D.

1985-01-01

New developments in crystal array technology provided significant improvements in the mechanical design and optical performance of the Nova 2 omega/3 omega array hardware. The final Nova array configuration was tested on the Novette laser and on the first arm of Nova. Ten Nova 2 omega/3 omega crystal arrays were assembled and tested for crystal alignment and wave front distortion before installation on the Nova target chamber. Ten Nova focus lens positioners were assembled and tested last year. The positioning accuracy and repeatability of each assembly were evaluated before installation on the target chamber. A cylindrical focusing system was also developed for installation in the Nova lens positioner assembly. Finally, 10 completed frequency conversion and focusing systems were activated
The stabilisation of final focus system

Indian Academy of Sciences (India)

The StaFF (stabilisation of final focus) system will use interferometers to monitor the relative ... quadrupole magnets will be the most demanding application, where mutual and beam- ... interferometers to measure lines of a geodetic network to record relative motion between two beam ... coupled interferometer design.
Molpher: a software framework for systematic chemical space exploration

Czech Academy of Sciences Publication Activity Database

Hoksza, D.; Škoda, P.; Voršilák, M.; Svozil, Daniel

2014-01-01

Roč. 6, č. 1 (2014) ISSN 1758-2946 R&D Projects: GA TA ČR TA02010212; GA ČR(CZ) GAP202/11/0968; GA ČR(CZ) GP14-29032P Keywords : Chemical space exploration * De-novo design * In silico ligand design * Chemical biology tools Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.547, year: 2014
Comparative study of the chemical properties of palm oil extracted ...

African Journals Online (AJOL)

The chemical properties of oil samples determined were free fatty acid, acid value, saponification value, peroxide value, iodine value and moisture content. The experimental design adopted was 3 x 2 x 2 factorial randomized complete block design in three replicates. The data of chemical properties of extracted palm oil ...
Designing and Developing a Programme-Focused Assessment Strategy: A Case Study

Science.gov (United States)

Brunton, James; Brown, Mark; Costello, Eamon; Walsh, Elaine

2016-01-01

This case study describes the process that the Humanities Programme Team, in Dublin City University's Open Education Unit, has undertaken with regard to developing a systematic, programme-focused assessment strategy. It charts the development of an Assessment Matrix that facilitated the enhancement of programme coherence in the context of a…
Thermoacoustic focusing lens by symmetric Airy beams with phase manipulations

Science.gov (United States)

Liu, Chen; Xia, Jian-Ping; Sun, Hong-Xiang; Yuan, Shou-Qi

2017-12-01

We report the realization of broadband acoustic focusing lenses based on two symmetric thermoacoustic phased arrays of Airy beams, in which the units of thermoacoustic phase control are designed by employing air with different temperatures surrounded by rigid insulated boundaries and thermal insulation films. The phase delays of the transmitted and reflected units could cover a whole 2π interval, which arises from the change of the sound velocity of air induced by the variation of the temperature. Based on the units of phase control, we design the transmitted and reflected acoustic focusing lenses with two symmetric Airy beams, and verify the high self-healing focusing characteristic and the feasibility of the thermal insulation films. Besides, the influences of the bending angle of the Airy beam on the focusing performance are discussed in detail. The proposed acoustic lens has advantages of broad bandwidth (about 4.8 kHz), high focusing performance, self-healing feature, and simple structure, which enable it to provide more schemes for acoustic focusing. It has excellent potential applications in acoustic devices.
Design requirements for new nuclear reactor facilities in Canada (focus on important improvements from RD-337 version 1 of 2008)

International Nuclear Information System (INIS)

Shim, S.; Harwood, C.; Ohn, M-Y; Liu, Y.C.; Young, T.

2014-01-01

The Canadian Nuclear Safety Commission (CNSC) has established the regulatory framework that includes the documentation of the requirements and guidance for each of CNSC's 14 Safety and Control Areas, one important area being the design of nuclear power plants (NPPs). For the design area, the CNSC published RD-337 version 1 Design of New Nuclear Power Plants in 2008. As such regulatory documents are reviewed on a regular basis, this document was recently updated as RD-337 version 2, and its guidance document GD-337, Guidance for the Design of New Nuclear Power Plants was developed to provide guidance on how to meet the requirements. REGDOC-2.5.2 Design of Reactor Facilities: Nuclear Power Plants that combines RD-337 version 2 and GD-337 version 1 was presented to the Commission on March 27, 2014 after two rounds of consultation with stakeholders, and was subsequently published in May 28, 2014. Although REGDOC-2.5.2 maintains the structure and the contents nearly the same as RD-337 version 1, it introduces several important improvements to: Include GD-337 guidance for further clarity to applicants, licensees and vendors on how to meet the requirements. This guidance provides the review criteria considered in CNSC staff's review in a transparent way; Ensure alignment with international standards including recent IAEA SSR 2/1, Safety of Nuclear Power Plants: Design; Implement CNSC Fukushima Task Force Report findings that pertain to the design of reactor facilities for severe accidents; and, Make necessary improvements such as addition of requirements for cyber security. This paper describes the overall regulatory framework related to CNSC's design requirements and guidance for NPPs, and focus on the important improvements included in REGDOC-2.5.2 and their reasoning. (author)
Design requirements for new nuclear reactor facilities in Canada (focus on important improvements from RD-337 version 1 of 2008)

Energy Technology Data Exchange (ETDEWEB)

Shim, S.; Harwood, C.; Ohn, M-Y; Liu, Y.C.; Young, T. [Canadian Nuclear Safety Commission, Ottawa, ON (Canada)

2014-07-01

The Canadian Nuclear Safety Commission (CNSC) has established the regulatory framework that includes the documentation of the requirements and guidance for each of CNSC's 14 Safety and Control Areas, one important area being the design of nuclear power plants (NPPs). For the design area, the CNSC published RD-337 version 1 Design of New Nuclear Power Plants in 2008. As such regulatory documents are reviewed on a regular basis, this document was recently updated as RD-337 version 2, and its guidance document GD-337, Guidance for the Design of New Nuclear Power Plants was developed to provide guidance on how to meet the requirements. REGDOC-2.5.2 Design of Reactor Facilities: Nuclear Power Plants that combines RD-337 version 2 and GD-337 version 1 was presented to the Commission on March 27, 2014 after two rounds of consultation with stakeholders, and was subsequently published in May 28, 2014. Although REGDOC-2.5.2 maintains the structure and the contents nearly the same as RD-337 version 1, it introduces several important improvements to: Include GD-337 guidance for further clarity to applicants, licensees and vendors on how to meet the requirements. This guidance provides the review criteria considered in CNSC staff's review in a transparent way; Ensure alignment with international standards including recent IAEA SSR 2/1, Safety of Nuclear Power Plants: Design; Implement CNSC Fukushima Task Force Report findings that pertain to the design of reactor facilities for severe accidents; and, Make necessary improvements such as addition of requirements for cyber security. This paper describes the overall regulatory framework related to CNSC's design requirements and guidance for NPPs, and focus on the important improvements included in REGDOC-2.5.2 and their reasoning. (author)
Effect of thermal, chemical and thermo-chemical pre-treatments to enhance methane production

Energy Technology Data Exchange (ETDEWEB)

Rafique, Rashad; Nizami, Abdul-Sattar; Murphy, Jerry D.; Kiely, Gerard [Department of Civil and Environmental Engineering, University College Cork (Ireland); Poulsen, Tjalfe Gorm [Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University (Denmark); Asam, Zaki-ul-Zaman [Department of Civil Engineering, National University of Ireland Galway (Ireland)

2010-12-15

The rise in oil price triggered the exploration and enhancement of various renewable energy sources. Producing biogas from organic waste is not only providing a clean sustainable indigenous fuel to the number of on-farm digesters in Europe, but also reducing the ecological and environmental deterioration. The lignocellulosic substrates are not completely biodegraded in anaerobic digesters operating at commercial scale due to their complex physical and chemical structure, which result in meager energy recovery in terms of methane yield. The focus of this study is to investigate the effect of pre-treatments: thermal, thermo-chemical and chemical pre-treatments on the biogas and methane potential of dewatered pig manure. A laboratory scale batch digester is used for these pre-treatments at different temperature range (25 C-150 C). Results showed that thermo-chemical pretreatment has high effect on biogas and methane potential in the temperature range (25-100 C). Maximum enhancement is observed at 70 C with increase of 78% biogas and 60% methane production. Thermal pretreatment also showed enhancement in the temperature range (50-10 C), with maximum enhancement at 100 C having 28% biogas and 25% methane increase. (author)
Design Legacies: Why Service Designers Cannot Embed Design in the Organizations

DEFF Research Database (Denmark)

Junginger, Sabine

2014-01-01

Much talk about service design has focused on how to bring design practices, design thinking and design methods into an organization in order to transform or change the way it is going about business. There is only one thing that researchers and practitioners have overlooked: Design principles...... these organizational design practices. This paper explains the concept of design legacies and describes three elements of organizational design legacies: organizational purpose, organizational design approaches and organizational design practices. Using a matrix developed around designing for, with and by, the paper...... explains how we can make sense of existing organizational design practices....
Analysis of forward and inverse problems in chemical dynamics and spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Rabitz, H. [Princeton Univ., NJ (United States)

1993-12-01

The overall scope of this research concerns the development and application of forward and inverse analysis tools for problems in chemical dynamics and chemical kinetics. The chemical dynamics work is specifically associated with relating features in potential surfaces and resultant dynamical behavior. The analogous inverse research aims to provide stable algorithms for extracting potential surfaces from laboratory data. In the case of chemical kinetics, the focus is on the development of systematic means to reduce the complexity of chemical kinetic models. Recent progress in these directions is summarized below.

Some links on this page may take you to non-federal websites. Their policies may differ from this site.