WorldWideScience

Sample records for environmental kinetics analysis

  1. The Center for Environmental Kinetics Analysis: an NSF- and DOE-funded Environmental Molecular Science Institute (EMSI) at Penn State

    Energy Technology Data Exchange (ETDEWEB)

    S. L. Brantley; William D. Burgos; Brian A. Dempsey; Peter J. Heaney; James D. Kubicki; Peter C. Lichtner; Bruce E. Logan; Carmen E. Martinez; Karl T. Mueller; Kwadwo A. Osseo-Asare; Ming Tien; Carl I. Steefel, Glenn A. Waychunas; and John M. Zachara

    2007-04-19

    Physicochemical and microbiological processes taking place at environmental interfaces influence natural processes as well as the transport and fate of environmental contaminants, the remediation of toxic chemicals, and the sequestration of anthropogenic CO2. A team of scientists and engineers has been assembled to develop and apply new experimental and computational techniques to expand our knowledge of environmental kinetics. We are also training a cohort of talented and diverse students to work on these complex problems at multiple length scales and to compile and synthesize the kinetic data. Development of the human resources capable of translating molecular-scale information into parameters that are applicable in real world, field-scale problems of environmental kinetics is a major and relatively unique objective of the Institute's efforts. The EMSI team is a partnership among 10 faculty at The Pennsylvania State University (funded by the National Science Foundation Divisions of Chemistry and Earth Sciences), one faculty member at Juniata College, one faculty member at the University of Florida, and four researchers drawn from Los Alamos National Laboratory, Pacific Northwest National Laboratory, and Lawrence Berkeley National Laboratory (funded by the Department of Energy Division of Environmental Remediation Sciences). Interactions among the applied and academic scientists drives research approaches aimed toward solving important problems of national interest. The Institute is organized into three interest groups (IGs) focusing on the processes of dissolution (DIG), precipitation (PIG), and microbial reactions at surfaces (BIG). Some of the research activity from each IG is highlighted to the right. The IGs interact with each other as each interest group studies reactions across the molecular, microscopic, mesoscopic and, in most cases, field scales. For example, abiotic dissolution and precipitation reactions of Fe oxides as studied in the Dissolution

  2. Ion Exchange Equilibrium and Kinetic Properties of Polyacrylate Films and Applications to Chemical Analysis and Environmental Decontamination

    Science.gov (United States)

    Tanner, Stephen P.

    1997-01-01

    One of the goals of the original proposal was to study how cross-linking affects the properties of an ion exchange material(IEM) developed at Lewis Research Center. However, prior to the start of this work, other workers at LERC investigated the effect of cross-linking on the properties of this material. Other than variation in the ion exchange capacity, the chemical characteristics were shown to be independent of the cross-linking agent, and the degree of cross-linking. New physical forms of the film were developed (film, supported film, various sizes of beads, and powder). All showed similar properties with respect to ion exchange equilibria but the kinetics of ion exchange depended on the surface area per unit mass; the powder form of the IEM exchanging much more rapidly than the other forms. The research performed under this grant was directed towards the application of the IEM to the analysis of metal ions at environmental concentrations.

  3. Phototrophic sulfide oxidation: environmental insights and a method for kinetic analysis

    Directory of Open Access Journals (Sweden)

    Thomas E Hanson

    2013-12-01

    Full Text Available Previously, we presented data that indicated microbial sulfide oxidation would out-compete strictly chemical, abiotic sulfide oxidation reactions under nearly all conditions relevant to extant ecosystems (Luther et al., 2011. In particular, we showed how anaerobic microbial sulfide oxidation rates were several orders of magnitude higher than even metal catalyzed aerobic sulfide oxidation processes. The fact that biotic anaerobic sulfide oxidation is kinetically superior to abiotic reactions implies that nearly all anaerobic and sulfidic environments should host microbial populations that oxidize sulfide at appreciable rates. This was likely an important biogeochemical process during long stretches of euxinia in the oceans suggested by the geologic record. In particular, phototrophic sulfide oxidation allows the utilization of carbon dioxide as the electron acceptor suggesting that this process should be particularly widespread rather than relying on the presence of other chemical oxidants. Using the Chesapeake Bay as an example, we argue that phototrophic sulfide oxidation may be more important in many environments than is currently appreciated. Finally, we present methodological considerations to assist other groups that wish to study this process.

  4. Analysis of kinetic reaction mechanisms

    CERN Document Server

    Turányi, Tamás

    2014-01-01

    Chemical processes in many fields of science and technology, including combustion, atmospheric chemistry, environmental modelling, process engineering, and systems biology, can be described by detailed reaction mechanisms consisting of numerous reaction steps. This book describes methods for the analysis of reaction mechanisms that are applicable in all these fields. Topics addressed include: how sensitivity and uncertainty analyses allow the calculation of the overall uncertainty of simulation results and the identification of the most important input parameters, the ways in which mechanisms can be reduced without losing important kinetic and dynamic detail, and the application of reduced models for more accurate engineering optimizations. This monograph is invaluable for researchers and engineers dealing with detailed reaction mechanisms, but is also useful for graduate students of related courses in chemistry, mechanical engineering, energy and environmental science and biology.

  5. Adsorption analysis equilibria and kinetics

    CERN Document Server

    Do, Duong D

    1998-01-01

    This book covers topics of equilibria and kinetics of adsorption in porous media. Fundamental equilibria and kinetics are dealt with for homogeneous as well as heterogeneous particles. Five chapters of the book deal with equilibria and eight chapters deal with kinetics. Single component as well as multicomponent systems are discussed. In kinetics analysis, we deal with the various mass transport processes and their interactions inside a porous particle. Conventional approaches as well as the new approach using Maxwell-Stefan equations are presented. Various methods to measure diffusivity, such

  6. Environmental Analysis

    Science.gov (United States)

    1980-01-01

    Burns & McDonnell Engineering's environmental control study is assisted by NASA's Computer Software Management and Information Center's programs in environmental analyses. Company is engaged primarily in design of such facilities as electrical utilities, industrial plants, wastewater treatment systems, dams and reservoirs and aviation installations. Company also conducts environmental engineering analyses and advises clients as to the environmental considerations of a particular construction project. Company makes use of many COSMIC computer programs which have allowed substantial savings.

  7. Relative effectiveness of kinetic analysis vs single point readings for classifying environmental samples based on community-level physiological profiles (CLPP)

    Science.gov (United States)

    Garland, J. L.; Mills, A. L.; Young, J. S.

    2001-01-01

    The relative effectiveness of average-well-color-development-normalized single-point absorbance readings (AWCD) vs the kinetic parameters mu(m), lambda, A, and integral (AREA) of the modified Gompertz equation fit to the color development curve resulting from reduction of a redox sensitive dye from microbial respiration of 95 separate sole carbon sources in microplate wells was compared for a dilution series of rhizosphere samples from hydroponically grown wheat and potato ranging in inoculum densities of 1 x 10(4)-4 x 10(6) cells ml-1. Patterns generated with each parameter were analyzed using principal component analysis (PCA) and discriminant function analysis (DFA) to test relative resolving power. Samples of equivalent cell density (undiluted samples) were correctly classified by rhizosphere type for all parameters based on DFA analysis of the first five PC scores. Analysis of undiluted and 1:4 diluted samples resulted in misclassification of at least two of the wheat samples for all parameters except the AWCD normalized (0.50 abs. units) data, and analysis of undiluted, 1:4, and 1:16 diluted samples resulted in misclassification for all parameter types. Ordination of samples along the first principal component (PC) was correlated to inoculum density in analyses performed on all of the kinetic parameters, but no such influence was seen for AWCD-derived results. The carbon sources responsible for classification differed among the variable types with the exception of AREA and A, which were strongly correlated. These results indicate that the use of kinetic parameters for pattern analysis in CLPP may provide some additional information, but only if the influence of inoculum density is carefully considered. c2001 Elsevier Science Ltd. All rights reserved.

  8. MBS Analysis Of Kinetic Structures Using ADAMS

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R.K.

    2009-01-01

    The present paper considers multibody system (MBS) analysis of kinetic structures using the software package ADAMS. Deployable, foldable, expandable and reconfigurable kinetic structures can provide a change in the geometric morphology of the envelope by contributing to making it adaptable to e......-called multibody system (MBS) formalism. The present paper considers MBS modeling of kinetic architectural structures using the software packages ADAMS. As a result, it is found that symbolic MBS simulation tools facilitate a useful evaluation environment for MBS users during a design phase of responsive kinetic...

  9. Robustness Analysis of Kinetic Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

    2009-01-01

    The present paper considers robustness of kinetic structures. Robustness of structures has obtained a renewed interest due to a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. Especially for these types of structural syst...... systems, it is of interest to investigate how robust the structures are, or what happens if a structural element is added to or removed from the original structure. The present paper discusses this issue for kinetic structures in architecture.......The present paper considers robustness of kinetic structures. Robustness of structures has obtained a renewed interest due to a much more frequent use of advanced types of structures with limited redundancy and serious consequences in case of failure. Especially for these types of structural...

  10. Kinetics of Carbaryl Hydrolysis: An Undergraduate Environmental Chemistry Laboratory

    Science.gov (United States)

    Hawker, Darryl

    2015-01-01

    Kinetics is an important part of undergraduate environmental chemistry curricula and relevant laboratory exercises are helpful in assisting students to grasp concepts. Such exercises are also useful in general chemistry courses because students can see relevance to real-world issues. The laboratory exercise described here involves determination of…

  11. Ligand Exchange Kinetics of Environmentally Relevant Metals

    Energy Technology Data Exchange (ETDEWEB)

    Panasci, Adele Frances [Univ. of California, Davis, CA (United States)

    2014-07-15

    The interactions of ground water with minerals and contaminants are of broad interest for geochemists but are not well understood. Experiments on the molecular scale can determine reaction parameters (i.e. rates of ligand exchange, activation entropy, activation entropy, and activation volume) that can be used in computations to gain insight into reactions that occur in natural groundwaters. Experiments to determine the rate of isotopic ligand exchange for three environmentally relevant metals, rhodium (Rh), iron (Fe), and neptunium (Np), are described. Many environmental transformations of metals (e.g. reduction) in soil occur at trivalent centers, Fe(III) in particular. Contaminant ions absorb to mineral surfaces via ligand exchange, and the reversal of this reaction can be dangerous, releasing contaminants into the environment. Ferric iron is difficult to study spectroscopically because most of its complexes are paramagnetic and are generally reactive toward ligand exchange; therefore, Rh(III), which is diamagnetic and less reactive, was used to study substitution reactions that are analogous to those that occur on mineral oxide surfaces. Studies on both Np(V) and Np(VI) are important in their own right, as 237Np is a radioactive transuranic element with a half-life of 2 million years.

  12. Robustness Analysis of Kinetic Structures

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Sørensen, John Dalsgaard

    2009-01-01

    Kinetic structures in architecture follows a new trend which is emerging in responsive architecture coined by Nicholas Negroponte when he proposed that architecture may benefit from the integration of computing power into built spaces and structures, and that better performing, more rational...

  13. Analysis of lipid peroxidation kinetics. I

    DEFF Research Database (Denmark)

    Doktorov, Alexander B.; Lukzen, Nikita N.; Pedersen, Jørgen Boiden

    2008-01-01

    concentrations of reactants or different ways of initiating the re-  action. Nor has it been possible to predict the time dependence of the  products. The reason for these problems is the complicated structure  of the kinetic scheme, which includes a chain reaction. In this work  we perform an in depth analysis...

  14. PET kinetic analysis. Compartmental model

    International Nuclear Information System (INIS)

    Watabe, Hiroshi; Ikoma, Yoko; Shidahara, Miho; Kimura, Yuichi; Naganawa, Mika

    2006-01-01

    Positron emission tomography (PET) enables not only visualization of the distribution of radiotracer, but also has ability to quantify several biomedical functions. Compartmental model is a basic idea to analyze dynamic PET data. This review describes the principle of the compartmental model and categorizes the techniques and approaches for the compartmental model according to various aspects: model design, experimental design, invasiveness, and mathematical solution. We also discussed advanced applications of the compartmental analysis with PET. (author)

  15. Kinetic analysis of decreased sperm fertilizing ability by fluorides and fluoroaluminates: a tool for analyzing the effect of environmental substances on biological events

    Czech Academy of Sciences Publication Activity Database

    Bosáková, Z.; Tockstein, A.; Adamusová, H.; Coufal, P.; Šebková, Nataša; Dvořáková-Hortová, Kateřina

    2016-01-01

    Roč. 45, č. 1 (2016), s. 71-79 ISSN 0175-7571 R&D Projects: GA ČR(CZ) GA14-05547S; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : kinetics * fluoride complexes * capacitation * tyrosine phosphorylation * acrosome reaction * sperm fertilizing ability Subject RIV: CE - Biochemistry Impact factor: 1.472, year: 2016

  16. Chemical kinetic functional sensitivity analysis: Elementary sensitivities

    International Nuclear Information System (INIS)

    Demiralp, M.; Rabitz, H.

    1981-01-01

    Sensitivity analysis is considered for kinetics problems defined in the space--time domain. This extends an earlier temporal Green's function method to handle calculations of elementary functional sensitivities deltau/sub i//deltaα/sub j/ where u/sub i/ is the ith species concentration and α/sub j/ is the jth system parameter. The system parameters include rate constants, diffusion coefficients, initial conditions, boundary conditions, or any other well-defined variables in the kinetic equations. These parameters are generally considered to be functions of position and/or time. Derivation of the governing equations for the sensitivities and the Green's funciton are presented. The physical interpretation of the Green's function and sensitivities is given along with a discussion of the relation of this work to earlier research

  17. Kinetic Analysis of Horizontal Plyometric Exercise Intensity.

    Science.gov (United States)

    Kossow, Andrew J; Ebben, William P

    2018-05-01

    Kossow, AJ, DeChiara, TG, Neahous, SM, and Ebben, WP. Kinetic analysis of horizontal plyometric exercise intensity. J Strength Cond Res 32(5): 1222-1229, 2018-Plyometric exercises are frequently performed as part of a strength and conditioning program. Most studies assessed the kinetics of plyometric exercises primarily performed in the vertical plane. The purpose of this study was to evaluate the multiplanar kinetic characteristics of a variety of plyometric exercises, which have a significant horizontal component. This study also sought to assess sex differences in the intensity progression of these exercises. Ten men and 10 women served as subjects. The subjects performed a variety of plyometric exercises including the double-leg hop, standing long jump, single-leg standing long jump, bounding, skipping, power skipping, cone hops, and 45.72-cm hurdle hops. Subjects also performed the countermovement jump for comparison. All plyometric exercises were evaluated using a force platform. Dependent variables included the landing rate of force development and landing ground reaction forces for each exercise in the vertical, frontal, and sagittal planes. A 2-way mixed analysis of variance with repeated-measures for plyometric exercise type demonstrated main effects for exercise type for all dependent variables (p ≤ 0.001). There was no significant interaction between plyometric exercise type and sex for any of the variable assessed. Bonferroni-adjusted pairwise comparisons identified a number of differences between the plyometric exercises for the dependent variables assessed (p ≤ 0.05). These findings should be used to guide practitioners in the progression of plyometric exercise intensity, and thus program design, for those who require significant horizontal power in their sport.

  18. A Century of Enzyme Kinetic Analysis, 1913 to 2013

    Science.gov (United States)

    Johnson, Kenneth A.

    2013-01-01

    This review traces the history and logical progression of methods for quantitative analysis of enzyme kinetics from the 1913 Michaelis and Menten paper to the application of modern computational methods today. Following a brief review of methods for fitting steady state kinetic data, modern methods are highlighted for fitting full progress curve kinetics based upon numerical integration of rate equations, including a re-analysis of the original Michaelis-Menten full time course kinetic data. Finally, several illustrations of modern transient state kinetic methods of analysis are shown which enable the elucidation of reactions occurring at the active sites of enzymes in order to relate structure and function. PMID:23850893

  19. Kinetic and thermal analysis of polymeric materials

    Science.gov (United States)

    Peterson, Jeffery David

    2002-09-01

    Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques have been used to study the thermal degradation of polymeric materials. These polymers were subjected to a variety of heating programs as well as numerous types of atmospheric conditions. The results from these analyses were then used to determine activation energies as a function of an extent of reaction variable, alpha. This technique, known as the model-free isoconversional method, allows for changes in energies to occur as decomposition pathways change. This produces a more realistic means of observing complex kinetic schemes and is a better representation of kinetic analysis. Chapters 1 and 2 provide introductory backgrounds into both polymer chemistry and the isoconversional analysis technique, respectively. A brief description of the research goals and motivations is also discussed. Thermal analysis of pure polystyrene (PS), polyethylene (PE), and polypropylene (PP) samples are presented in Chapter 3. The obtained activation energy dependencies are interpreted in terms of degradation mechanisms. These mechanisms vary greatly according to the gaseous environment in which they were analyzed. The thermal degradation of poly(methyl methacrylate) (PMMA) in both pure nitrogen and in various oxygen-containing atmospheres is discussed in Chapter 4. It was observed that oxygen exhibits a stabilizing effect on PMMA decomposition. Activation energies for these processes, and their mechanistic interpretations, will also be presented. Chapter 5 builds off the understanding gained in Chapter 4 by investigating the char-forming effects of silica gel and potassium carbonate additives on PMMA. These additives are known for their fire-resistant properties when combined in a 3:1 silica gel to potassium carbonate ratio. The effects of these additives, and their respective ratio amounts, on PMMA char formation are reported. Chapters 6 and 7 conclude the dissertation by looking at the thermal

  20. Environmental analysis support

    International Nuclear Information System (INIS)

    Miller, R.L.

    1994-01-01

    Activities in environmental analysis support included assistance to the Morgantown and Pittsburgh Energy Technology Centers (METC and PETC) in reviewing and preparing documents required by the National Environmental Policy Act (NEPA) for several projects selected for the Clean Coal Technology (CCT) Program. A key milestone was the completion for PETC of the final Environmental Impact Statement (EIS) for the Healy Clean Coal Project (HCCP) in Healy, Alaska. This work is notable because it is the first site-specific EIS completed for the CCT Program. Another important activity was the preparation for METC of a draft Environmental Assessment (EA) for the Externally Fired Combined Cycle (EFCC) Project in Warren, Pennsylvania. Also, the final EA was completed for the Gasification Product Improvement Facility (GPIF), a proposed project near Morgantown, West Virginia, which is part of METC's R ampersand D Program. In addition, ORNL staff members published a Technical Memorandum entitled open-quotes Potential Effects of Clean Coal Technologies on Acid Precipitation, Greenhouse Gases, and Solid Waste Disposalclose quotes which documents the findings of three open-quotes white papersclose quotes prepared for DOE/FE

  1. Environmental analysis and evaluation

    International Nuclear Information System (INIS)

    Cooper, M.B.; Tracy, B.L.

    1990-01-01

    One of the requirements of an environmental radiation surveillance program is to identify and determine long-lived radioactive elements which may be released to the environment during the operation of a uranium (or thorium) mine and mill. Radioanalytical techniques which are suitable for quantitative and qualitative determination of long-lived radionuclides of the natural uranium and thorium series are reviewed. The general features of an analytical program are discussed in terms of sample preparation, radiochemical separation of radioactive elements, and radioactive measurement. There are situations in environmental analysis to which high-resolution γ-spectrometry can be applied and the advantages and limitations of this technique are considered. Quality assurance is an essential component of any monitoring program in order to ensure that reliable and precise data are available for the assessment of the radiological impact of the mining and milling operation

  2. NAFTA Guidance for Evaluating and Calculating Degradation Kinetics in Environmental Media :DD Memo

    Science.gov (United States)

    Signed Division Director memo, December 17, 2012, with original announcement to EFED scientists of tools and approaches for evaluating and calculating degradation kinetics in environmental media. There is more updated information that this available.

  3. Kinetic analysis of the human knee joint

    Directory of Open Access Journals (Sweden)

    E Wiczkowski

    2008-03-01

    Full Text Available The pathology of the calcaneal (Achilles tendon constitutes a serious therapeutical and social problem. Indeed, this tendon is the strongest plantar flexor of the foot that plays an important role in the humangait. Although well known for a long time, no explicit description of the spontaneous subcutaneous rupture of the Achilles tendon can be found in medical or biomechanical literature. So far, neither pathomechanism nor the underlying causes of the tendon’s disruption have been fully elucidated. Many authors concentrate mostly on medical and biological aspects of the condition. The commonly held view is that it is the vascular supply to the tendon that plays a crucial role in pathogenesis of the tendon’s injuries. In fact, the vasculature a change with time and after the age of 30 is significantly reduced leading to the development of regressive alterations within as well as the decrement of the mechanical strength of the tendon. Obviously, interdisciplinary approach encompassing not only medical and biological but also the broadly taken mechanical viewpoint is needed to more comprehensively describe and explain this phenomenon. In the present paper, kinetic analysis of the knee was employed to define the trajectory of the point of initial insertion of the medial head of gastrocnemius, which was then used to determine the point’s route within the motor area extending from the flexion to the full extension of the knee. The obtained data on the trajectory are further utilized to present and define the pathomechanism of the spontaneous rupture of the calcaneal tendon.

  4. GC in Environmental Analysis

    Science.gov (United States)

    Gosink, Thomas A.

    1975-01-01

    Gas chromatography can be used to quantitate various gases, complex organic molecules, metals, anions, and pesticides in the lab or in the field. Important advances in gas chromatography and how they directly apply to environmental analyses plus suggestions where they will be of importance to environmental chemists are discussed. (BT)

  5. Kinetic analysis of boron carbide sintering

    International Nuclear Information System (INIS)

    Borchert, W.; Kerler, A.R.

    1975-01-01

    The kinetics of the sintering of boron carbide were investigated by shrinkage measurements with a high-temperature dilatometer under argon atmosphere in dependence on temperature, grain size, and pressure. The activation energies and the reaction mechanisms of the different stages of sintering were determined. (orig.) [de

  6. Analysis of microtubule assembly kinetics using turbidimetry.

    Science.gov (United States)

    Gaskin, Felicia

    2011-01-01

    Turbidity measurements are rapid and reliable methods to follow the effects of drugs, proteins, nucleotides, metals, and other factors on the assembly kinetics of tubulin into microtubules in vitro and have been in use since 1974. Improvements in spectrophotometers and software have resulted in the use of less protein, and more curves can be analyzed continuously and almost simultaneously.

  7. COMPARATIVE ANALYSIS OF SOME EXISTING KINETIC MODELS ...

    African Journals Online (AJOL)

    The biosorption of three heavy metal ions namely; Zn2+, Cu2+ and Mn2+ using five microorganisms namely; Bacillus circulans, Pseudomonas aeruginosa, Staphylococcus xylosus, Streptomyces rimosus and Yeast (Saccharomyces sp.) were studied. In this paper, the effectiveness of six existing and two proposed kinetic ...

  8. Thermodynamic and kinetic analysis of heterogeneous photocatalysis for semiconductor systems.

    Science.gov (United States)

    Liu, Baoshun; Zhao, Xiujian; Terashima, Chiaki; Fujishima, Akira; Nakata, Kazuya

    2014-05-21

    Since the report of the Honda-Fujishima effect, heterogeneous photocatalysis has attracted much attention around the world because of its potential energy and environmental applications. Although great progresses have been made in recent years, most were focused on preparing highly-active photocatalysts and investigating visible light utilization. In fact, we are still unclear on the thermodynamic and kinetic nature of photocatalysis to date, which sometimes leads to misunderstandings for experimental results. It is timely to give a review and discussion on the thermodynamics and kinetics of photocatalysis, so as to direct future researches. However, there is an absence of a detailed review on this topic until now. In this article, we tried to review and discuss the thermodynamics and kinetics of photocatalysis. We explained the thermodynamic driving force of photocatalysis, and distinguished the functions of light and heat in photocatalysis. The Langmuir-Hinshelwood kinetic model, the ˙OH oxidation mechanism, and the direct-indirect (D-I) kinetic model were reviewed and compared. Some applications of the D-I model to study photocatalytic kinetics were also discussed. The electron transport mode and its importance in photocatalysis were investigated. Finally, the intrinsic relation between the kinetics and the thermodynamics of photocatalytic reactions was discussed.

  9. Piezoresistive microcantilever aptasensor for ricin detection and kinetic analysis

    Directory of Open Access Journals (Sweden)

    Zhi-Wei Liu

    2015-04-01

    Full Text Available Up to now, there has been no report on target molecules detection by a piezoresistive microcantilever aptasensor. In order to evaluate the test performance and investigate the response dynamic characteristics of a piezoresistive microcantilever aptasensor, a novel method for ricin detection and kinetic analysis based on a piezoresistive microcantilever aptasensor was proposed, where ricin aptamer was immobilised on the microcantilever surface by biotin-avidin binding system. Results showed that the detection limit of ricin was 0.04μg L−1 (S/N ≥ 3. A linear relationship between the response voltage and the concentration of ricin in the range of 0.2μg L−1-40μg L−1 was obtained, with the linear regression equation of ΔUe = 0.904C + 5.852 (n = 5, R = 0.991, p < 0.001. The sensor showed no response for abrin, BSA, and could overcome the influence of complex environmental disruptors, indicating high specificity and good selectivity. Recovery and reproducibility in the result of simulated samples (simulated water, soil, and flour sample determination met the analysis requirements, which was 90.5∼95.5% and 7.85%∼9.39%, respectively. On this basis, a reaction kinetic model based on ligand-receptor binding and the relationship with response voltage was established. The model could well reflect the dynamic response of the sensor. The correlation coefficient (R was greater than or equal to 0.9456 (p < 0.001. Response voltage (ΔUe and response time (t0 obtained from the fitting equation on different concentrations of ricin fitted well with the measured values.

  10. Kinetic analysis of dynamic PET data

    Energy Technology Data Exchange (ETDEWEB)

    Knittel, B.

    1983-12-01

    Our goal is to quantify regional physiological processes such as blood flow and metabolism by means of tracer kinetic modeling and positron emission tomography (PET). Compartmental models are one way of characterizing the behavior of tracers in physiological systems. This paper describes a general method of estimating compartmental model rate constants from measurements of the concentration of tracers in blood and tissue, taken at multiple time intervals. A computer program which applies the method is described, and examples are shown for simulated and actual data acquired from the Donner 280-Crystal Positron Tomograph.

  11. Kinetic analysis of dynamic PET data

    International Nuclear Information System (INIS)

    Knittel, B.

    1983-12-01

    Our goal is to quantify regional physiological processes such as blood flow and metabolism by means of tracer kinetic modeling and positron emission tomography (PET). Compartmental models are one way of characterizing the behavior of tracers in physiological systems. This paper describes a general method of estimating compartmental model rate constants from measurements of the concentration of tracers in blood and tissue, taken at multiple time intervals. A computer program which applies the method is described, and examples are shown for simulated and actual data acquired from the Donner 280-Crystal Positron Tomograph

  12. Environmental conditions analysis program

    International Nuclear Information System (INIS)

    Holten, J.

    1991-01-01

    The PC-based program discussed in this paper has the capability of determining the steady state temperatures of environmental zones (rooms). A program overview will be provided along with examples of formula use. Required input and output from the program will also be discussed. Specific application of plant monitored temperatures and utilization of this program will be offered. The presentation will show how the program can project individual room temperature profiles without continual temperature monitoring of equipment. A discussion will also be provided for the application of the program generated data. Evaluations of anticipated or planned plant modifications and the use of the subject program will also be covered

  13. Analysis of a kinetic multi-segment foot model part II: kinetics and clinical implications.

    Science.gov (United States)

    Bruening, Dustin A; Cooney, Kevin M; Buczek, Frank L

    2012-04-01

    Kinematic multi-segment foot models have seen increased use in clinical and research settings, but the addition of kinetics has been limited and hampered by measurement limitations and modeling assumptions. In this second of two companion papers, we complete the presentation and analysis of a three segment kinetic foot model by incorporating kinetic parameters and calculating joint moments and powers. The model was tested on 17 pediatric subjects (ages 7-18 years) during normal gait. Ground reaction forces were measured using two adjacent force platforms, requiring targeted walking and the creation of two sub-models to analyze ankle, midtarsal, and 1st metatarsophalangeal joints. Targeted walking resulted in only minimal kinematic and kinetic differences compared with walking at self selected speeds. Joint moments and powers were calculated and ensemble averages are presented as a normative database for comparison purposes. Ankle joint powers are shown to be overestimated when using a traditional single-segment foot model, as substantial angular velocities are attributed to the mid-tarsal joint. Power transfer is apparent between the 1st metatarsophalangeal and mid-tarsal joints in terminal stance/pre-swing. While the measurement approach presented here is limited to clinical populations with only minimal impairments, some elements of the model can also be incorporated into routine clinical gait analysis. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Friction analysis of kinetic schemes : the friction coefficient

    NARCIS (Netherlands)

    Lolkema, Juke S.

    1995-01-01

    Friction analysis is proposed as the application of general control analysis to single enzymes to describe the control of elementary kinetic steps on the overall catalytic rate. For each transition, a friction coefficient is defined that measures the sensitivity of the turnover rate to the free

  15. Kinetics of enzyme action on surface-attached substrates: a practical guide to progress curve analysis in any kinetic situation.

    Science.gov (United States)

    Anne, Agnès; Demaille, Christophe

    2012-10-16

    In the present work, exact kinetic equations describing the action of an enzyme in solution on a substrate attached to a surface have been derived in the framework of the Michaelis-Menten mechanism but without resorting to the often-used steady-state approximation. The here-derived kinetic equations are cast in a workable format, allowing us to introduce a simple and universal procedure for the quantitative analysis of enzyme surface kinetics that is valid for any kinetic situation. The results presented here should allow experimentalists studying the kinetics of enzyme action on immobilized substrates to analyze their data in a perfectly rigorous way.

  16. Analysis of environmental sounds

    Science.gov (United States)

    Lee, Keansub

    Environmental sound archives - casual recordings of people's daily life - are easily collected by MPS players or camcorders with low cost and high reliability, and shared in the web-sites. There are two kinds of user generated recordings we would like to be able to handle in this thesis: Continuous long-duration personal audio and Soundtracks of short consumer video clips. These environmental recordings contain a lot of useful information (semantic concepts) related with activity, location, occasion and content. As a consequence, the environment archives present many new opportunities for the automatic extraction of information that can be used in intelligent browsing systems. This thesis proposes systems for detecting these interesting concepts on a collection of these real-world recordings. The first system is to segment and label personal audio archives - continuous recordings of an individual's everyday experiences - into 'episodes' (relatively consistent acoustic situations lasting a few minutes or more) using the Bayesian Information Criterion and spectral clustering. The second system is for identifying regions of speech or music in the kinds of energetic and highly-variable noise present in this real-world sound. Motivated by psychoacoustic evidence that pitch is crucial in the perception and organization of sound, we develop a noise-robust pitch detection algorithm to locate speech or music-like regions. To avoid false alarms resulting from background noise with strong periodic components (such as air-conditioning), a new scheme is added in order to suppress these noises in the domain of autocorrelogram. In addition, the third system is to automatically detect a large set of interesting semantic concepts; which we chose for being both informative and useful to users, as well as being technically feasible. These 25 concepts are associated with people's activities, locations, occasions, objects, scenes and sounds, and are based on a large collection of

  17. Kinetics and correlation analysis of reactivity in the oxidation of ...

    Indian Academy of Sciences (India)

    Administrator

    Department of Chemistry, J.N.V. University, Jodhpur 342 005. 1. 4F/13, New Power House Road, Jodhpur 342 ... The rates of oxidation of sulfides were determined in nineteen organic solvents. An analysis of the solvent effect by ... report the kinetics of the oxidation of 34 organic sul- fides by BTPPD in dimethyl sulphoxide ...

  18. Suramin Treatment for Onchocerciasis: Cost Analysis of a Kinetically ...

    African Journals Online (AJOL)

    Aim: To conduct an economic analysis of two different suramin regimens (the new kinetically optimized 4-dose regimen, KOR and the standard WHO 6-dose regimen) for the treatment of onchocerciasis. Methods: Ten patients were treated with each regimen in a hospital-based clinical study, with follow-up visits for up to one ...

  19. Kinetic study of Mongolian coals by thermal analysis

    Directory of Open Access Journals (Sweden)

    Jargalmaa S

    2018-02-01

    Full Text Available Thermal analysis was used for the thermal characterization of the coal samples. The experiments were performed to study the pyrolysis and gasification kinetics of typical Mongolian brown coals. Low rank coals from Shivee ovoo, Ulaan ovoo, Aduun chuluun and Baganuur deposits have been investigated. Coal samples were heated in the thermogravimetric apparatus under argon at a temperature ranges of 25-1020ºC with heating rates of 10, 20, 30 and 40ºC/min. Thermogravimetry (TG and derivative thermogravimetry (DTG were performed to measure weight changes and rates of weight losses used for calculating the kinetic parameters. The activation energy (Ea was calculated from the experimental results by using an Arrhenius type kinetic model.

  20. Uncertainty analysis of environmental models

    International Nuclear Information System (INIS)

    Monte, L.

    1990-01-01

    In the present paper an evaluation of the output uncertainty of an environmental model for assessing the transfer of 137 Cs and 131 I in the human food chain are carried out on the basis of a statistical analysis of data reported by the literature. The uncertainty analysis offers the oppotunity of obtaining some remarkable information about the uncertainty of models predicting the migration of non radioactive substances in the environment mainly in relation to the dry and wet deposition

  1. Timor-Leste : Country Environmental Analysis

    OpenAIRE

    World Bank

    2009-01-01

    The Country Environmental Analysis (CEA) for Timor-Leste identifies environmental priorities through a systematic review of environmental issues in natural resources management and environmental health in the context of the country's economic development and environmental institutions. Lack of data has been the main limitation in presenting a more rigorous analysis. Nevertheless, the repor...

  2. Environmental sampling for trace analysis

    International Nuclear Information System (INIS)

    Markert, B.

    1994-01-01

    Often too little attention is given to the sampling before and after actual instrumental measurement. This leads to errors, despite increasingly sensitive analytical systems. This is one of the first books to pay proper attention to representative sampling. It offers an overview of the most common techniques used today for taking environmental samples. The techniques are clearly presented, yield accurate and reproducible results and can be used to sample -air - water - soil and sediments - plants and animals. A comprehensive handbook, this volume provides an excellent starting point for researchers in the rapidly expanding field of environmental analysis. (orig.)

  3. LSENS - GENERAL CHEMICAL KINETICS AND SENSITIVITY ANALYSIS CODE

    Science.gov (United States)

    Bittker, D. A.

    1994-01-01

    LSENS has been developed for solving complex, homogeneous, gas-phase, chemical kinetics problems. The motivation for the development of this program is the continuing interest in developing detailed chemical reaction mechanisms for complex reactions such as the combustion of fuels and pollutant formation and destruction. A reaction mechanism is the set of all elementary chemical reactions that are required to describe the process of interest. Mathematical descriptions of chemical kinetics problems constitute sets of coupled, nonlinear, first-order ordinary differential equations (ODEs). The number of ODEs can be very large because of the numerous chemical species involved in the reaction mechanism. Further complicating the situation are the many simultaneous reactions needed to describe the chemical kinetics of practical fuels. For example, the mechanism describing the oxidation of the simplest hydrocarbon fuel, methane, involves over 25 species participating in nearly 100 elementary reaction steps. Validating a chemical reaction mechanism requires repetitive solutions of the governing ODEs for a variety of reaction conditions. Analytical solutions to the systems of ODEs describing chemistry are not possible, except for the simplest cases, which are of little or no practical value. Consequently, there is a need for fast and reliable numerical solution techniques for chemical kinetics problems. In addition to solving the ODEs describing chemical kinetics, it is often necessary to know what effects variations in either initial condition values or chemical reaction mechanism parameters have on the solution. Such a need arises in the development of reaction mechanisms from experimental data. The rate coefficients are often not known with great precision and in general, the experimental data are not sufficiently detailed to accurately estimate the rate coefficient parameters. The development of a reaction mechanism is facilitated by a systematic sensitivity analysis

  4. Kinetic analysis of the multistep aggregation mechanism of monoclonal antibodies.

    Science.gov (United States)

    Nicoud, Lucrèce; Arosio, Paolo; Sozo, Margaux; Yates, Andrew; Norrant, Edith; Morbidelli, Massimo

    2014-09-11

    We investigate by kinetic analysis the aggregation mechanism of two monoclonal antibodies belonging to the IgG1 and IgG2 subclass under thermal stress. For each IgG, we apply a combination of size exclusion chromatography and light scattering techniques to resolve the time evolution of the monomer, dimer, and trimer concentrations, as well as the average molecular weight and the average hydrodynamic radius of the aggregate distribution. By combining the detailed experimental characterization with a theoretical kinetic model based on population balance equations, we extract relevant information on the contribution of the individual elementary steps on the global aggregation process. The analysis shows that the two molecules follow different aggregation pathways under the same operating conditions. In particular, while the monomer depletion of the IgG1 is found to be rate-limited by monomeric conformational changes, bimolecular collision is identified as the rate-limiting step in the IgG2 aggregation process. The measurement of the microscopic rate constants by kinetic analysis allows the quantification of the protein-protein interaction potentials expressed in terms of the Fuchs stability ratio (W). It is found that the antibody solutions exhibit large W values, which are several orders of magnitude larger than the values computed in the frame of the DLVO theory. This indicates that, besides net electrostatic repulsion, additional effects delay the aggregation kinetics of the antibody solutions with respect to diffusion-limited conditions. These effects likely include the limited efficiency of the collision events due to the presence of a limited number of specific aggregation-prone patches on the heterogeneous protein surface, and the contribution of additional repulsive non-DLVO forces to the protein-protein interaction potential, such as hydration forces.

  5. Radioimmunoassay for phencyclidine: application to kinetic analysis in the rat

    International Nuclear Information System (INIS)

    Ward, D.P.; Trevor, A.J.

    1980-01-01

    We report the development of a radioimmunoassay for phencyclidine (PCP) that is simple, rapid and sensitive to 0.5 ng/ml. Antibodies were raised in rabbits against the hapten, N-succinyl-3-aminophencyclidine. These antibodies proved to be very specific for PCP and exhibited less than 4% cross reactivity with the drug's two major metabolites. The assay was used for kinetic analysis of PCP in the rat following subcutaneous injection of 5 mg/kg of the drug. Serum and brain tissues were analyzed for PCP and the respective half lives were calculated to be 36 and 29 min for the α phase and 130 and 121 min for the β phase. The accuracy of the method was verified by concomitant assay of a number of kinetic samples by gas chromatography employing a nitrogen-phosphorus detector

  6. Visualizing data for environmental analysis

    International Nuclear Information System (INIS)

    Benson, J.

    1997-01-01

    The Environmental Restoration Project at Los Alamos National Laboratory (LANL) has over 11,000 sampling locations in a 44 square mile area. The sample analyses contain raw analytical chemistry values for over 2,300 analytes and compounds used to define and remediate contaminated areas at LANL. The data consist of 2.5 million records in an oracle database. Maps are often used to visualize the data. Problems arise when a client specifies a particular kind of map without fully understanding the limitations of the data or the map. The ability of maps to convey information is dependent on many factors, though all maps are data dependent. The quantity, spatial distribution, and numerical range of the data can limit use with certain kinds of maps. To address these issues and educate the clients, several types of statistical maps (e.g., choropleth, isarithm, and graduated symbol such as bubble and spike) used for environmental analysis were chosen to show the advantages, disadvantages, and data limitations of each. By examining both the complexity of the analytical data and the limitations of the map type, it is possible to consider how reality has been transformed through the map, and if that transformation accurately conveys the information present

  7. Thermogravimetric Analysis and Kinetic Study on Pyrolysis of Veteri-narian Solid Waste

    Directory of Open Access Journals (Sweden)

    Andrés Felipe Rojas González

    2016-10-01

    Full Text Available Context: Institutional waste from clinical centers can be classified as those coming from health institutions dedicated to human attention and those coming from centers for animal veterinary care. The latter are mainly hazardous wastes, hence their disposal requires incineration. Most of such waste is organic, and it is possible, therefore, to take advantage of their energetic power in combustion or pyrolysis processes. This work is motivated because no literature was found on the pyrolysis kinetics veterinary waste, as this kind of studies are mainly focused on hospital waste of human health care. Method: The kinetics of pyrolysis is characterized and studied by means of thermogravimetric analysis of 6 major veterinary waste (gauze, cotton swabs, cotton, nails, hair, plastic syringes. The characterization is performed by proximate and elemental analysis, and thermogravimetric analysis. Reactivity characteristics and pyrolytic capability of wastes are established. The kinetics study on pyrolysis was carried out by determining the kinetic triplet by isoconversional Starink method. Results: It was established that the pyrolysis index increases with the heating rate and that the thermal degradation depends on the material type of the waste. Similarly, it was found that the temperature (ΔT = Tf - Ti for the thermal decomposition of veterinary waste is: ΔTnails> ΔThair > ΔTcotton swabs > ΔTgauze > ΔTcotton > ΔTplastic syringes; the activation energy is Enails> E hair > Eplastic syringes > Ecotton swabs > E gauze > Ecotton, and the reaction order is: n hair > nnails > ncotton swabs > ncotton > n gauze > n plastic syringes. Conclusions: These results suggest the possibility of using veterinary wastes for power generation, providing an alternative for sustainable energy development to cities in continuous growth, from both, energetic and environmental points of view.

  8. Formulation, construction and analysis of kinetic models of metabolism: A review of modelling frameworks

    DEFF Research Database (Denmark)

    Saa, Pedro A.; Nielsen, Lars K.

    2017-01-01

    Kinetic models are critical to predict the dynamic behaviour of metabolic networks. Mechanistic kinetic models for large networks remain uncommon due to the difficulty of fitting their parameters. Recent modelling frameworks promise new ways to overcome this obstacle while retaining predictive...... capabilities. In this review, we present an overview of the relevant mathematical frameworks for kinetic formulation, construction and analysis. Starting with kinetic formalisms, we next review statistical methods for parameter inference, as well as recent computational frameworks applied to the construction...

  9. Speciative determination of total V and dissolved inorganic vanadium species in environmental waters by catalytic–kinetic spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Ramazan Gürkan

    2017-02-01

    Full Text Available A kinetic determination of V(V as a catalyst was spectrophotometrically performed by using the indicator reaction of Gallamine blue (GB+ and bromate at pH 2.0. The reaction was followed by measuring absorbance change for a fixed-time of 3 min at 537 nm. The variables such as reagent concentration, pH, buffer concentration, ionic strength and temperature were optimized to improve the selectivity and sensitivity. Under the optimized conditions, the determination of V(V was performed in the range 1–100 μg L−1 with limits of detection and quantification of 0.31 and 0.94 μg L−1. The developed kinetic method is sufficiently sensitive, selective and simple. It was successfully applied to the speciative determination of total V and inorganic dissolved vanadium species, V(V and V(IV in environmental water samples. The oxidizing property of permanganate is used to differentiate between V(IV and V(V species. The V(IV content was found by subtracting the V(V content from those of total V. The recovery is above 95% for V(V spiked samples. Additionally, the accuracy was validated by analysis of a certified water sample, CRM TMDA-53.3, and the results were in good agreement with the certified value.

  10. Comparative analysis of solution methods of the punctual kinetic equations

    International Nuclear Information System (INIS)

    Hernandez S, A.

    2003-01-01

    The following one written it presents a comparative analysis among different analytical solutions for the punctual kinetics equation, which present two variables of interest: a) the temporary behavior of the neutronic population, and b) The temporary behavior of the different groups of precursors of delayed neutrons. The first solution is based on a method that solves the transfer function of the differential equation for the neutronic population, in which intends to obtain the different poles that give the stability of this transfer function. In this section it is demonstrated that the temporary variation of the reactivity of the system can be managed as it is required, since the integration time for this method doesn't affect the result. However, the second solution is based on an iterative method like that of Runge-Kutta or the Euler method where the algorithm was only used to solve first order differential equations giving this way solution to each differential equation that conforms the equations of punctual kinetics. In this section it is demonstrated that only it can obtain a correct temporary behavior of the neutronic population when it is integrated on an interval of very short time, forcing to the temporary variation of the reactivity to change very quick way without one has some control about the time. In both methods the same change is used so much in the reactivity of the system like in the integration times, giving validity to the results graph the one the temporary behavior of the neutronic population vs. time. (Author)

  11. [Efficient method of analysis of optical spectra from kinetic studies].

    Science.gov (United States)

    Skvortsov, A N

    2009-01-01

    The application of principal components for the analysis of kinetic data obtained by optical spectroscopy is described. The use of singular value decomposition (SVD) for stable and reproducible generation of principal components, details of realization, advantages and drawbacks of the method are discussed. The described method with minor modifications may be used in a wide variety of UV-spectroscopy applications in molecular biology and biophysics. The developed method was applied to study the reaction of platinum anticancer drug, cisplatin, with DNA and methionine. Use of sensitive UV-spectroscopy allowed to study low platinum concentrations, typical for biological systems. It has been shown, that reactions of cisplatin with DNA and L-methionine generally follow the same pathway both at high and low concentrations.

  12. Isoconversional kinetic analysis of the alkyd/melamine resins curing

    Directory of Open Access Journals (Sweden)

    Jovičić Mirjana

    2013-01-01

    Full Text Available The curing reaction for the mixtures of alkyd resins based on ricinoleic acid, phthalic anhydride and three polyols (glycerin, trimethylolpropane or ethoxylated pentaerythritol with two different commercial melamine resins was investigated by differential scanning calorimetry (DSC. The curing kinetics analysis was performed using the isoconversional methods (Ozawa-Flynn-Wall, Kissinger-Akahira-Sunose and Friedman. Isoconversional methods were carried out with three heating rates (5, 10 and 20°C/min in a scanning temperature range from 40 to 250°C. It was found that the curing activation energy of resin mixtures is influenced by alkyd and melamine resin type due to the catalytic effect of hydroxyl group on the reactions. The dependence of apparent curing degree on time, which was obtained by mathematical transformations of dynamic DSC data using Ozawa-Flynn-Wall method, describes well the isothermal DSC experiments.

  13. Kinetic analysis of pulsed laser induced phosphorescence for uranium determination

    International Nuclear Information System (INIS)

    Serdeiro, Nelida H.

    2003-01-01

    The laser induced kinetic phosphorescence allows the uranium determination in different kind of matrices, with a lower detection limit than those reached by other spectroscopic methods. It involves the uranyl ions excitation by a pulsed dye-laser source, followed by temporal resolution of the phosphorescence. This method is used for the determination of trace quantities of uranium in aqueous solution, with a suitable complexant agent, without chemical separation before the analysis. The objective of this paper is to present the results of uranium determinations in different standard samples, water, soil, filter and urine, and a comparison with other methods such as fluorimetry, alpha spectrometry and mass spectrometry. Moreover, the measurement conditions, the advantages and disadvantages, the sample preparation, the interferences and the detection limit are described. (author)

  14. Analysis of Network Topologies Underlying Ethylene Growth Response Kinetics.

    Science.gov (United States)

    Prescott, Aaron M; McCollough, Forest W; Eldreth, Bryan L; Binder, Brad M; Abel, Steven M

    2016-01-01

    Most models for ethylene signaling involve a linear pathway. However, measurements of seedling growth kinetics when ethylene is applied and removed have resulted in more complex network models that include coherent feedforward, negative feedback, and positive feedback motifs. The dynamical responses of the proposed networks have not been explored in a quantitative manner. Here, we explore (i) whether any of the proposed models are capable of producing growth-response behaviors consistent with experimental observations and (ii) what mechanistic roles various parts of the network topologies play in ethylene signaling. To address this, we used computational methods to explore two general network topologies: The first contains a coherent feedforward loop that inhibits growth and a negative feedback from growth onto itself (CFF/NFB). In the second, ethylene promotes the cleavage of EIN2, with the product of the cleavage inhibiting growth and promoting the production of EIN2 through a positive feedback loop (PFB). Since few network parameters for ethylene signaling are known in detail, we used an evolutionary algorithm to explore sets of parameters that produce behaviors similar to experimental growth response kinetics of both wildtype and mutant seedlings. We generated a library of parameter sets by independently running the evolutionary algorithm many times. Both network topologies produce behavior consistent with experimental observations, and analysis of the parameter sets allows us to identify important network interactions and parameter constraints. We additionally screened these parameter sets for growth recovery in the presence of sub-saturating ethylene doses, which is an experimentally-observed property that emerges in some of the evolved parameter sets. Finally, we probed simplified networks maintaining key features of the CFF/NFB and PFB topologies. From this, we verified observations drawn from the larger networks about mechanisms underlying ethylene

  15. Analysis of Network Topologies Underlying Ethylene Growth Response Kinetics

    Directory of Open Access Journals (Sweden)

    Aaron M. Prescott

    2016-08-01

    Full Text Available Most models for ethylene signaling involve a linear pathway. However, measurements of seedling growth kinetics when ethylene is applied and removed have resulted in more complex network models that include coherent feedforward, negative feedback, and positive feedback motifs. However, the dynamical responses of the proposed networks have not been explored in a quantitative manner. Here, we explore (i whether any of the proposed models are capable of producing growth-response behaviors consistent with experimental observations and (ii what mechanistic roles various parts of the network topologies play in ethylene signaling. To address this, we used computational methods to explore two general network topologies: The first contains a coherent feedforward loop that inhibits growth and a negative feedback from growth onto itself (CFF/NFB. In the second, ethylene promotes the cleavage of EIN2, with the product of the cleavage inhibiting growth and promoting the production of EIN2 through a positive feedback loop (PFB. Since few network parameters for ethylene signaling are known in detail, we used an evolutionary algorithm to explore sets of parameters that produce behaviors similar to experimental growth response kinetics of both wildtype and mutant seedlings. We generated a library of parameter sets by independently running the evolutionary algorithm many times. Both network topologies produce behavior consistent with experimental observations and analysis of the parameter sets allows us to identify important network interactions and parameter constraints. We additionally screened these parameter sets for growth recovery in the presence of sub-saturating ethylene doses, which is an experimentally-observed property that emerges in some of the evolved parameter sets. Finally, we probed simplified networks maintaining key features of the CFF/NFB and PFB topologies. From this, we verified observations drawn from the larger networks about mechanisms

  16. Stochastic lumping analysis for linear kinetics and its application to the fluctuation relations between hierarchical kinetic networks.

    Science.gov (United States)

    Deng, De-Ming; Chang, Cheng-Hung

    2015-05-14

    Conventional studies of biomolecular behaviors rely largely on the construction of kinetic schemes. Since the selection of these networks is not unique, a concern is raised whether and under which conditions hierarchical schemes can reveal the same experimentally measured fluctuating behaviors and unique fluctuation related physical properties. To clarify these questions, we introduce stochasticity into the traditional lumping analysis, generalize it from rate equations to chemical master equations and stochastic differential equations, and extract the fluctuation relations between kinetically and thermodynamically equivalent networks under intrinsic and extrinsic noises. The results provide a theoretical basis for the legitimate use of low-dimensional models in the studies of macromolecular fluctuations and, more generally, for exploring stochastic features in different levels of contracted networks in chemical and biological kinetic systems.

  17. Stochastic lumping analysis for linear kinetics and its application to the fluctuation relations between hierarchical kinetic networks

    Science.gov (United States)

    Deng, De-Ming; Chang, Cheng-Hung

    2015-05-01

    Conventional studies of biomolecular behaviors rely largely on the construction of kinetic schemes. Since the selection of these networks is not unique, a concern is raised whether and under which conditions hierarchical schemes can reveal the same experimentally measured fluctuating behaviors and unique fluctuation related physical properties. To clarify these questions, we introduce stochasticity into the traditional lumping analysis, generalize it from rate equations to chemical master equations and stochastic differential equations, and extract the fluctuation relations between kinetically and thermodynamically equivalent networks under intrinsic and extrinsic noises. The results provide a theoretical basis for the legitimate use of low-dimensional models in the studies of macromolecular fluctuations and, more generally, for exploring stochastic features in different levels of contracted networks in chemical and biological kinetic systems.

  18. Environmental Gradient Analysis, Ordination, and Classification in Environmental Impact Assessments.

    Science.gov (United States)

    1987-09-01

    associations. The proposed methodology can also be applied to land-use management, maintenance and monitoring programs, and to environmental impact...analysis. Analytical results were then examined and the advantages and disadvantages of each stastistical analysis method used were noted. Mode of Technology...and S. Wearden, Statistics for Research (John Wiley & Sons, New York, NY, 1983). 20a. Draper, N. R., and H. Smith, Applied Regression Analysis, 2nd

  19. Characterization of the human kinetic adjustment factor for the health risk assessment of environmental contaminants.

    Science.gov (United States)

    Valcke, Mathieu; Krishnan, Kannan

    2014-03-01

    A default uncertainty factor of 3.16 (√10) is applied to account for interindividual variability in toxicokinetics when performing non-cancer risk assessments. Using relevant human data for specific chemicals, as WHO/IPCS suggests, it is possible to evaluate, and replace when appropriate, this default factor by quantifying chemical-specific adjustment factors for interindividual variability in toxicokinetics (also referred to as the human kinetic adjustment factor, HKAF). The HKAF has been determined based on the distributions of pharmacokinetic parameters (e.g., half-life, area under the curve, maximum blood concentration) in relevant populations. This article focuses on the current state of knowledge of the use of physiologically based algorithms and models in characterizing the HKAF for environmental contaminants. The recent modeling efforts on the computation of HKAF as a function of the characteristics of the population, chemical and its mode of action (dose metrics), as well as exposure scenario of relevance to the assessment are reviewed here. The results of these studies, taken together, suggest the HKAF varies as a function of the sensitive subpopulation and dose metrics of interest, exposure conditions considered (route, duration, and intensity), metabolic pathways involved and theoretical model underlying its computation. The HKAF seldom exceeded the default value of 3.16, except in very young children (i.e., risk assessments of environmental contaminants. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Environmental analysis in small and medium enterprises

    International Nuclear Information System (INIS)

    Luciani, R.; Andriola, L.; Di Franco, N.

    2001-01-01

    An environmental analysis is considered to be one of the primary goals for an enterprise environmental management. Nevertheless the complexity of the environmental problems and of its regulations prevents the small enterprises the possibility to perform an environmental policy (EMAS, ISO 14001). One of the most correct evaluation instrument for creating a datum-point standard could be the filling up a questionnaire, built up in according to the industrial enterprises need. It has the function of creating a primary step for a subsequent environmental management [it

  1. The Hill analysis and co-ion-driven transporter kinetics

    NARCIS (Netherlands)

    Lolkema, Juke S; Slotboom, Dirk-Jan

    Interaction of multiple ligands with a protein or protein complex is a widespread phenomenon that allows for cooperativity. Here, we review the use of the Hill equation, which is commonly used to analyze binding or kinetic data, to analyze the kinetics of ion-coupled transporters and show how the

  2. What environmental transmission electron microscopy measures and how this links to diffusivity: thermodynamics versus kinetics.

    Science.gov (United States)

    Walther, T

    2015-02-01

    Environmental or in situ electron microscopy means the observation of material in its native environment, which can be gaseous or liquid, as compared to more traditional post-mortem electron microscopy carried out under (ultra) high vacuum conditions. Experiments can be performed on bulk samples in scanning electron microscopes or on thinned samples in transmission (scanning) electron microscopes. In the latter, the movement, in real time and in situ, of nanoparticles, clusters or even single atoms on the surfaces of thinned material or within a liquid can be observed. It is argued here that due to the changes that a specimen typically undergoes during in situ observation, electron irradiation effects are difficult to evaluate and so thermodynamic parameters, such as activation energies for diffusion and segregation, which are governed by movements of only a minority of atoms in the specimen, cannot be reliably determined because of the potentially high energy transfer by the irradiating electron beam to some atoms in the sample. In order to measure diffusivities reliably, radiation effects and surface diffusion need to be excluded or kept minimal so as not to disturb the measurements, which can be checked by repeating experiments and comparing results as function of time and dose for the same position, at different positions or for different specimen thicknesses. Kinetic measurements of nucleation and growth phenomena, such as Ostwald ripening, are possibly influenced to a far lesser degree by irradiation effects, as a majority of atoms actively participate in these processes and if a small fraction of them will get extra energy from the irradiation process then their influence on the overall kinetics may be rather minor. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

  3. Application of Uncertainty and Sensitivity Analysis to a Kinetic Model for Enzymatic Biodiesel Production

    DEFF Research Database (Denmark)

    Price, Jason Anthony; Nordblad, Mathias; Woodley, John

    2014-01-01

    This paper demonstrates the added benefits of using uncertainty and sensitivity analysis in the kinetics of enzymatic biodiesel production. For this study, a kinetic model by Fedosov and co-workers is used. For the uncertainty analysis the Monte Carlo procedure was used to statistically quantify...

  4. Kinetic analysis of MHD ballooning modes in tokamaks

    International Nuclear Information System (INIS)

    Tang, W.M.; Rewoldt, G.; Cheng, C.Z.; Chance, M.S.

    1984-10-01

    A comprehensive analysis of the stability properties of the appropriate kinetically generalized form of MHD ballooning modes together with the usual trapped-particle drift modes is presented. The calculations are fully electromagnetic and include the complete dynamics associated with compressional ion acoustic waves. Trapped-particle effects along with all forms of collisionless dissipation are taken into account without approximations. The influence of collisions is estimated with a model Krook operator. Results from the application of this analysis to realistic tokamak operating conditions indicate that unstable short-wavelength modes with significant growth rates can extend from β = 0 to value above the upper ideal-MHD-critical-beta associated with the so-called second stability regime. Since the strength of the relevant modes appears to vary gradually with β, these results support a soft beta limit picture involving a continuous (rather than abrupt or hard) modification of anomalous transport already present in low-β-tokamaks. However, at higher beta the increasing dominance of the electromagnetic component of the perturbations indicated by these calculations could also imply significantly different transport scaling properties

  5. In situ X-ray pair distribution function analysis of geopolymer gel nanostructure formation kinetics.

    Science.gov (United States)

    White, Claire E; Provis, John L; Bloomer, Breaunnah; Henson, Neil J; Page, Katharine

    2013-06-14

    With the ever-increasing environmentally-driven demand for technologically advanced structural materials, geopolymer cement is fast becoming a viable alternative to traditional cements due to its proven engineering characteristics and the reduction in CO2 emitted during manufacturing (as much as 80% less CO2 emitted in manufacture, compared to ordinary Portland cement). Nevertheless, much remains unknown regarding the kinetics of reaction responsible for nanostructural evolution during the geopolymerisation process. Here, in situ X-ray total scattering measurements and pair distribution function (PDF) analysis are used to quantify the extent of reaction as a function of time for alkali-activated metakaolin/slag geopolymer binders, including the impact of various activators (alkali hydroxide/silicate) on the kinetics of the geopolymerisation reaction. Quantifying the reaction process in situ from X-ray PDF data collected during the initial ten hours can provide an estimate of the total reaction extent, but when combined with data obtained at longer times (128 days here) enables more accurate determination of the overall rate of reaction. To further assess the initial stages of the geopolymerisation reaction process, a pseudo-single step first order rate equation is fitted to the extent of reaction data, which reveals important mechanistic information regarding the role of free silica in the activators in the evolution of the binder systems. Hence, it is shown that in situ X-ray PDF analysis is an ideal experimental local structure tool to probe the reaction kinetics of complex reacting systems involving transitions between disordered/amorphous phases, of which geopolymerisation is an important example.

  6. Environmental Management Strategy: Four Forces Analysis

    Science.gov (United States)

    Doyle, Martin W.; Von Windheim, Jesko

    2015-01-01

    We develop an analytical approach for more systematically analyzing environmental management problems in order to develop strategic plans. This approach can be deployed by agencies, non-profit organizations, corporations, or other organizations and institutions tasked with improving environmental quality. The analysis relies on assessing the underlying natural processes followed by articulation of the relevant societal forces causing environmental change: (1) science and technology, (2) governance, (3) markets and the economy, and (4) public behavior. The four forces analysis is then used to strategize which types of actions might be most effective at influencing environmental quality. Such strategy has been under-used and under-valued in environmental management outside of the corporate sector, and we suggest that this four forces analysis is a useful analytic to begin developing such strategy.

  7. Multigroup perturbation model for kinetic analysis of nuclear reactors

    International Nuclear Information System (INIS)

    Souza, G.M.

    1989-01-01

    The scope of this work is the development of a multigroup perturbation theory for the purpose of Kinetic and dynamic analysis of nuclear reactors. The equations that describe the reactor behavior were presented in all generality and written in the shorthand notation of matrices and vectors. In the derivation of those equations indetermined operators and discretizing factors were introduced and then determined by comparision with conventional equations. Fick's Law was developed in higher orders for neutron and importance current density. The solution of the direct and adjoint fields were represented by combination of the eigenfunctions of the B and B* operators and the eigenvalue modulus equality was established mathematically. In the derivation of the reactivity expression the B operator perturbation was split in two non coupled to the flux form and level. The prompt neutrons effective mean life was derived from reactor equations and importance conservation. The establishment of the Nordheim's equation, although modified, was based on Gandini. Finally, a mathematical interpretation of the flux-trap region was avented. (author)

  8. Kinetic analysis of thermally relativistic flow with dissipation

    International Nuclear Information System (INIS)

    Yano, Ryosuke; Suzuki, Kojiro

    2011-01-01

    Nonequilibrium flow of thermally relativistic matter with dissipation is considered in the framework of the relativistic kinetic theory. As an object of the analysis, the supersonic rarefied flow of thermally relativistic matter around the triangle prism is analyzed using the Anderson-Witting model. Obtained numerical results indicate that the flow field changes in accordance with the flow velocity and temperature of the uniform flow owing to both effects derived from the Lorentz contraction and thermally relativistic effects, even when the Mach number of the uniform flow is fixed. The profiles of the heat flux along the stagnation streamline can be approximated on the basis of the relativistic Navier-Stokes-Fourier (NSF) law except for a strong nonequilibrium regime such as the middle of the shock wave and the vicinity of the wall, whereas the profile of the heat flux behind the triangle prism cannot be approximated on the basis of the relativistic NSF law owing to rarefied effects via the expansion behind the triangle prism. Additionally, the heat flux via the gradient of the static pressure is non-negligible owing to thermally relativistic effects. The profile of the dynamic pressure is different from that approximated on the basis of the NSF law, which is obtained by the Eckart decomposition. Finally, variations of convections of the mass and momentum owing to the effects derived from the Lorentz contraction and thermally relativistic effects are numerically confirmed.

  9. Thermal decomposition kinetics of sorghum straw via thermogravimetric analysis.

    Science.gov (United States)

    Dhyani, Vaibhav; Kumar, Jitendra; Bhaskar, Thallada

    2017-12-01

    The thermal decomposition of sorghum straw was investigated by non-isothermal thermogravimetric analysis, where the determination of kinetic triplet (activation energy, pre-exponential factor, and reaction model), was the key objective. The activation energy was determined using different isoconversional methods: Friedman, Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), Starink, Iterative method of Chai & Chen, Vyazovkin AIC method, and Li & Tang equation. The pre-exponential factor was calculated using Kissinger's equation; while the reaction model was predicted by comparison of z-master plot obtained from experimental values with the theoretical plots. The values of activation energy obtained from isoconversional methods were further used for evaluation of thermodynamic parameters, enthalpy, entropy and Gibbs free energy. Results showed three zones of pyrolysis having average activation energy values of 151.21kJ/mol, 116.15kJ/mol, and 136.65kJ/mol respectively. The data was well fitting with two-dimension 'Valensi' model for conversion values from 0 to 0.4 with a coefficient of determination (R 2 ) value of 0.988, and with third order reaction model for values from 0.4 to 0.9 with an R 2 value of 0.843. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Thermogravimetric and Kinetic Analysis of Raw and Torrefied Biomass Combustion

    Directory of Open Access Journals (Sweden)

    Kopczyński Marcin

    2015-06-01

    Full Text Available The use of torrefied biomass as a substitute for untreated biomass may decrease some technological barriers that exist in biomass co-firing technologies e.g. low grindability, high moisture content, low energy density and hydrophilic nature of raw biomass. In this study the TG-MS-FTIR analysis and kinetic analysis of willow (Salix viminalis L. and samples torrefied at 200, 220, 240, 260, 280 and 300 °C (TSWE 200, 220, 240, 260, 280 and 300, were performed. The TG-DTG curves show that in the case of willow and torrefied samples TSWE 200, 220, 240 and 260 there are pyrolysis and combustion stages, while in the case of TSWE 280 and 300 samples the peak associated with the pyrolysis process is negligible, in contrast to the peak associated with the combustion process. Analysis of the TG-MS results shows m/z signals of 18, 28, 29 and 44, which probably represent H2O, CO and CO2. The gaseous products were generated in two distinct ranges of temperature. H2O, CO and CO2 were produced in the 500 K to 650 K range with maximum yields at approximately 600 K. In the second range of temperature, 650 K to 800 K, only CO2 was produced with maximum yields at approximately 710 K as a main product of combustion process. Analysis of the FTIR shows that the main gaseous products of the combustion process were H2O, CO2, CO and some organics including bonds: C=O (acids, aldehydes and ketones, C=C (alkenes, aromatics, C-O-C (ethers and C-OH. Lignin mainly contributes hydrocarbons (3000-2800 cm−1, while cellulose is the dominant origin of aldehydes (2860-2770 cm−1 and carboxylic acids (1790-1650 cm−1. Hydrocarbons, aldehydes, ketones and various acids were also generated from hemicellulose (1790-1650 cm−1. In the kinetic analysis, the two-steps first order model (F1F1 was assumed. Activation energy (Ea values for the first stage (pyrolysis increased with increasing torrefaction temperature from 93 to 133 kJ/mol, while for the second stage (combustion it

  11. 23 CFR 710.305 - Environmental analysis.

    Science.gov (United States)

    2010-04-01

    ... FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RIGHT-OF-WAY AND ENVIRONMENT RIGHT-OF-WAY AND REAL ESTATE Project Development § 710.305 Environmental analysis. The National Environmental Policy Act... agreement for acquisition of right-of-way. Where applicable, a State also must complete Clean Air Act (42 U...

  12. Kinetic Monte Carlo Simulations of Diffusion in Environmental Barrier Coating Materials

    Science.gov (United States)

    Good, Brian

    2017-01-01

    Ceramic Matrix Components (CMC) components for use in turbine engines offer a number of advantages compared with current practice. However, such components are subject to degradation through a variety of mechanisms. In particular, in the hot environment inside a turbine in operation a considerable amount of water vapor is present, and this can lead to corrosion and recession. Environmental Barrier Coating (EBC) systems that limit the amount of oxygen and water reaching the component are required to reduce this degradation and extend component life. A number of silicate-based materials are under consideration for use in such coating systems, including Yttterbium and Yttrium di- and monosilicates. In this work, we present results of kinetic Monte Carlo computer simulations of oxygen diffusion in Yttrium disilicate, and compare with previous work on Yttterbium disilicate. Coatings may also exhibit cracking, and the cracks can provide a direct path for oxygen to reach the component. There is typically a bond coat between the coating and component surface, but the bond coat material is generally chosen for properties other than low oxygen diffusivity. Nevertheless, the degree to which the bond coat can inhibit oxygen diffusion is of interest, as it may form the final defense against oxygen impingement on the component. We have therefore performed similar simulations of oxygen diffusion through HfSiO4, a proposed bond coat material.

  13. Thermodynamic Activity-Based Progress Curve Analysis in Enzyme Kinetics.

    Science.gov (United States)

    Pleiss, Jürgen

    2018-03-01

    Macrokinetic Michaelis-Menten models based on thermodynamic activity provide insights into enzyme kinetics because they separate substrate-enzyme from substrate-solvent interactions. Kinetic parameters are estimated from experimental progress curves of enzyme-catalyzed reactions. Three pitfalls are discussed: deviations between thermodynamic and concentration-based models, product effects on the substrate activity coefficient, and product inhibition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Comparing Distributions of Environmental Outcomes for Regulatory Environmental Justice Analysis

    Directory of Open Access Journals (Sweden)

    Glenn Sheriff

    2011-05-01

    Full Text Available Economists have long been interested in measuring distributional impacts of policy interventions. As environmental justice (EJ emerged as an ethical issue in the 1970s, the academic literature has provided statistical analyses of the incidence and causes of various environmental outcomes as they relate to race, income, and other demographic variables. In the context of regulatory impacts, however, there is a lack of consensus regarding what information is relevant for EJ analysis, and how best to present it. This paper helps frame the discussion by suggesting a set of questions fundamental to regulatory EJ analysis, reviewing past approaches to quantifying distributional equity, and discussing the potential for adapting existing tools to the regulatory context.

  15. Evaluation of Kinetic Entropy of Breast Masses Initially Found on MRI using Whole-lesion Curve Distribution Data: Comparison with the Standard Kinetic Analysis.

    Science.gov (United States)

    Shimauchi, Akiko; Abe, Hiroyuki; Schacht, David V; Yulei, Jian; Pineda, Federico D; Jansen, Sanaz A; Ganesh, Rajiv; Newstead, Gillian M

    2015-08-01

    To quantify kinetic heterogeneity of breast masses that were initially detected with dynamic contrast-enhanced MRI, using whole-lesion kinetic distribution data obtained from computer-aided evaluation (CAE), and to compare that with standard kinetic curve analysis. Clinical MR images from 2006 to 2011 with breast masses initially detected with MRI were evaluated with CAE. The relative frequencies of six kinetic patterns (medium-persistent, medium-plateau, medium-washout, rapid-persistent, rapid-plateau, rapid-washout) within the entire lesion were used to calculate kinetic entropy (KE), a quantitative measure of enhancement pattern heterogeneity. Initial uptake (IU) and signal enhancement ratio (SER) were obtained from the most-suspicious kinetic curve. Mann-Whitney U test and ROC analysis were conducted for differentiation of malignant and benign masses. Forty benign and 37 malignant masses comprised the case set. IU and SER were not significantly different between malignant and benign masses, whereas KE was significantly greater for malignant than benign masses (p = 0.748, p = 0.083, and p kinetic heterogeneity of whole-lesion time-curve data with KE has the potential to improve differentiation of malignant from benign breast masses on breast MRI. • Kinetic heterogeneity can be quantified by computer-aided evaluation of breast MRI • Kinetic entropy was greater in malignant masses than benign masses • Kinetic entropy has the potential to improve differentiation of breast masses.

  16. Environmental exergy analysis of wastewater treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Mora Bejarano, C.H.; Oliveira Junior, S. de [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia Mecanica]. E-mail: carlos.bejarano@poli.usp.br; silvio.oliveira@poli.usp.br

    2006-12-15

    This work evaluates the environmental impact of Wastewater Treatment Plants (WTP) based on data generated by the exergy analysis, calculating and applying environmental impact indexes for two WTP located in the Metropolitan Area of Sao Paulo. The environmental impact of the waste water treatment plants was done by means of evaluating two environmental impact exergy based indexes: the environmental exergy efficiency and the total pollution rate (Rpol,t). The environmental exergy efficiency is defined as the ratio of the exergy of the useful effect of the WTP to the total exergy consumed by human and natural resources, including all the exergy inputs. That relation is an indication of the theoretical potential of future improvements of the process. Besides the environmental exergy efficiency, it is also used the total pollution rate, based on the definition done by Makarytchev (1997), as the ratio of the destroyed exergy associated to the process wastes to the exergy of the useful effect of the process. The analysis of the results shows that this method can be used to quantify and also optimise the environmental performance of Wastewater Treatment Plants. (author)

  17. Data analysis and interpretation for environmental surveillance

    International Nuclear Information System (INIS)

    1992-06-01

    The Data Analysis and Interpretation for Environmental Surveillance Conference was held in Lexington, Kentucky, February 5--7, 1990. The conference was sponsored by what is now the Office of Environmental Compliance and Documentation, Oak Ridge National Laboratory. Participants included technical professionals from all Martin Marietta Energy Systems facilities, Westinghouse Materials Company of Ohio, Pacific Northwest Laboratory, and several technical support contractors. Presentations at the conference ranged the full spectrum of issues that effect the analysis and interpretation of environmental data. Topics included tracking systems for samples and schedules associated with ongoing programs; coalescing data from a variety of sources and pedigrees into integrated data bases; methods for evaluating the quality of environmental data through empirical estimates of parameters such as charge balance, pH, and specific conductance; statistical applications to the interpretation of environmental information; and uses of environmental information in risk and dose assessments. Hearing about and discussing this wide variety of topics provided an opportunity to capture the subtlety of each discipline and to appreciate the continuity that is required among the disciplines in order to perform high-quality environmental information analysis

  18. Degradation kinetics of a potent antifouling agent, butenolide, under various environmental conditions

    KAUST Repository

    Chen, Lianguo

    2015-01-01

    © 2014 Elsevier Ltd. Here, we investigated the degradation kinetics of butenolide, a promising antifouling compound, under various environmental conditions. The active ingredient of the commercial antifoulant SeaNine 211, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT), was used as positive control. The results showed that the degradation rate increased with increasing temperature. Half-lives of butenolide at 4. °C, 25. °C and 40. °C were. >64. d, 30.5. d and 3.9. d, respectively. Similar half-lives were recorded for DCOIT: >64. d at 4. °C, 27.9. d at 25. °C and 4.5. d at 40. °C. Exposure to sunlight accelerated the degradation of both butenolide and DCOIT. The photolysis half-lives of butenolide and DCOIT were 5.7. d and 6.8. d, respectively, compared with 9.7. d and 14.4. d for the dark control. Biodegradation led to the fastest rate of butenolide removal from natural seawater, with a half-life of 0.5. d, while no obvious degradation was observed for DCOIT after incubation for 4. d. The biodegradative ability of natural seawater for butenolide was attributed mainly to marine bacteria. During the degradation of butenolide and DCOIT, a gradual decrease in antifouling activity was observed, as indicated by the increased settlement percentage of cypris larvae from barnacle Balanus amphitrite. Besides, increased cell growth of marine diatom Skeletonema costatum demonstrated that the toxicity of seawater decreased gradually without generation of more toxic by-products. Overall, rapid degradation of butenolide in natural seawater supported its claim as a promising candidate for commercial antifouling industry.

  19. Analysis procedure for americium in environmental samples

    International Nuclear Information System (INIS)

    Holloway, R.W.; Hayes, D.W.

    1982-01-01

    Several methods for the analysis of 241 Am in environmental samples were evaluated and a preferred method was selected. This method was modified and used to determine the 241 Am content in sediments, biota, and water. The advantages and limitations of the method are discussed. The method is also suitable for 244 Cm analysis

  20. Kinetic Analysis of the Thermal Processing of Silica and Organosilica

    NARCIS (Netherlands)

    Kappert, Emiel; Bouwmeester, Henricus J.M.; Benes, Nieck Edwin; Nijmeijer, Arian

    2014-01-01

    The incorporation of an organic group into sol–gel-derived silica causes significant changes in the structure and properties of these materials. Therefore, the thermal treatment of organosilica materials may require a different approach. In the present paper, kinetic parameters (activation energy,

  1. Kinetics analysis of step and jump forward lunge among badminton ...

    African Journals Online (AJOL)

    This study was conducted to determine and compare the kinetics during step forward lunge (SFL) and jump forward lunge (JFL) in badminton. Fifteen university badminton players (mean age = 22.07 ± 1.39 years old) were recruited and were assigned to perform SFL and JFL while holding a badminton racquet using their ...

  2. Kinetic analysis of glutathione transferase from rats exposed to sub ...

    African Journals Online (AJOL)

    The effects of lethal and sublethal doses of lead acetate on the induction and kinetic characteristics of glutathione transferase (GST) isozymes in rat liver and kidney were investigated. GST isozymes induction was monitored by the ability of the induced enzyme to conjugate glutathione (GSH) with model GST substrates.

  3. Isotope dilution analysis of environmental samples

    International Nuclear Information System (INIS)

    Tolgyessy, J.; Lesny, J.; Korenova, Z.; Klas, J.; Klehr, E.H.

    1986-01-01

    Isotope dilution analysis has been used for the determination of several trace elements - especially metals - in a variety of environmental samples, including aerosols, water, soils, biological materials and geological materials. Variations of the basic concept include classical IDA, substoichiometric IDA, and more recently, sub-superequivalence IDA. Each variation has its advantages and limitations. A periodic chart has been used to identify those elements which have been measured in environmental samples using one or more of these methods. (author)

  4. Kinetic stability analysis of protein assembly on the center manifold around the critical point.

    Science.gov (United States)

    Tsuruyama, Tatsuaki

    2017-02-02

    Non-linear kinetic analysis is a useful method for illustration of the dynamic behavior of cellular biological systems. To date, center manifold theory (CMT) has not been sufficiently applied for stability analysis of biological systems. The aim of this study is to demonstrate the application of CMT to kinetic analysis of protein assembly and disassembly, and to propose a novel framework for nonlinear multi-parametric analysis. We propose a protein assembly model with nonlinear kinetics provided by the fluctuation in monomer concentrations during their diffusion. When the diffusion process of a monomer is self-limited to give kinetics non-linearity, numerical simulations suggest the probability that the assembly and disassembly oscillate near the critical point. We applied CMT to kinetic analysis of the center manifold around the critical point in detail, and successfully demonstrated bifurcation around the critical point, which explained the observed oscillation. The stability kinetics of the present model based on CMT illustrates a unique feature of protein assembly, namely non-linear behavior. Our findings are expected to provide methodology for analysis of biological systems.

  5. Environmentally based Cost-Benefit Analysis

    International Nuclear Information System (INIS)

    Magnell, M.

    1993-11-01

    The fundamentals of the basic elements of a new comprehensive economic assessment, MILA, developed in Sweden with inspiration from the Total Cost Assessment-model are presented. The core of the MILA approach is an expanded cost and benefit inventory. But MILA also includes a complementary addition of an internal waste stream analysis, a tool for evaluation of environmental conflicts in monetary terms, an extended time horizon and direct allocation of costs and revenues to products and processes. However, MILA does not ensure profitability for environmentally sound projects. Essentially, MILA is an approach of refining investment and profitability analysis of a project, investment or product. 109 refs., 38 figs

  6. The analysis of one-dimensional reactor kinetics benchmark computations

    International Nuclear Information System (INIS)

    Sidell, J.

    1975-11-01

    During March 1973 the European American Committee on Reactor Physics proposed a series of simple one-dimensional reactor kinetics problems, with the intention of comparing the relative efficiencies of the numerical methods employed in various codes, which are currently in use in many national laboratories. This report reviews the contributions submitted to this benchmark exercise and attempts to assess the relative merits and drawbacks of the various theoretical and computer methods. (author)

  7. Kinetic therapy reduces complications and shortens hospital stay in patients with cardiogenic shock - a retrospective analysis.

    Science.gov (United States)

    Simonis, Gregor; Flemming, Kerstin; Ziegs, Enrico; Haacke, Katrin; Rauwolf, Thomas; Strasser, Ruth H

    2007-03-01

    Kinetic therapy (KT) has been shown to reduce complications and to shorten hospital stay in trauma patients. Data in non-surgical patients are inconclusive, and kinetic therapy has not been tested in patients with cardiogenic shock. The present analysis compares KT with standard care in patients with cardiogenic shock. A retrospective analysis of 133 patients with cardiogenic shock admitted to 1 academic heart center was performed. Patients with standard care (SC, turning every 2 h by the staff) were compared with kinetic therapy (KT, using oscillating air-flotation beds). 68 patients with KT were compared with 65 patients with SC. Length of ventilator therapy was 11 days in KT and 18 days in SC (p=0.048). The mortality was comparable in both groups. Pneumonia occurred in 14 patients in KT and 39 patients in SC (ppatients treated with kinetic therapy. The use of KT shortens hospital stay and reduces rates of pneumonia and pressure ulcers as compared to SC.

  8. Environmental impact analysis for typical office facades

    Energy Technology Data Exchange (ETDEWEB)

    Kolokotroni, M.; Robinson-Gayle, S.; Tanno, S.; Cripps, A.

    2004-02-01

    The design of a building facade influences internal thermal and lighting conditions and use associated with the provision of these conditions. Key decisions about the building are usually taken during the concept design stage of a building, while decisions about method of providing the environmental conditions are often made later in the design. This dilemma is addressed by the development of a concept design tool that allows the team to investigate the effect of facade design on the resulting internal environmental conditions, energy use and environmental impact. The concept design tool was developed performing detailed thermal, lighting and environmental modelling for a number of office building facade designs and a range of parameters that affect directly the environmental performance of an office building. The results are presented in a user-friendly interface as a minimum number of inputs. Key parameter outputs (such as temperature, lighting, heating/cooling energy demand, embodied energy and eco-points) can then be viewed, more detailed analysis can also be created for specified facade designs. A parametric analysis of the summary result outputs for selected facade parameters indicates that natural ventilation and cooling can reduce the environmental impact of offices by up to 16%, although the energy demand could increase significantly. Improving the construction standard and reducing the internal heat loads can reduce the environmental impact by up to 2 this tool at early design stages will benefit the design team through an improved understanding of the dynamics between facade design and building services and assist with a more integrated approach. (author)

  9. Comparative analysis of mineral and secundary raw materials screening kinetics

    Directory of Open Access Journals (Sweden)

    Stojanović Aleksandra

    2015-01-01

    Full Text Available Efficiency of screening shows screening performance compared to an ideal screening to achieve a complete separation of the fractions without the presence of grains of size less than the mesh openings left on sieve and grains of size larger than the mesh opening that passed through the sieve. Efficiency is growing rapidly and after a certain time is reduced. This is explained by the fact that the speed of screening depends on the percentage of 'small', 'small-to large' and 'large' grain. The paper shows how for the given grain, their shape and density affect the kinetics of screening.

  10. Environmental Resources Analysis System, A Prototype DSS

    Science.gov (United States)

    Flug, M.; Campbell, S.G.; Bizier, P.; DeBarry, P.

    2003-01-01

    Since the 1960's, an increase in the public's environmental ethics, federal species preservation, water quality protection, and interest in free flowing rivers have evolved to the current concern for stewardship and conservation of natural resources. This heightened environmental awareness creates an appetite for data, models, information management, and systematic analysis of multiple scientific disciplines. A good example of this information and analysis need resides in the Green and Yampa Rivers, tributary to the Upper Colorado River. These rivers are home to endangered native fish species including the pikeminnow and razorback sucker. Two dams, Fontenelle and Flaming Gorge, impound the Green River headwaters. The respective reservoirs store water supplies as well as generate hydropower. Conversely, the Yampa River is considered unregulated and encompasses most of Dinosaur National Monument. Recreation is highly regarded on both rivers including fishing, whitewater rafting, and aesthetic values. Vast areas of irrigated agriculture, forestry, and mineral extraction also surround these rivers. To address this information need, we developed a prototype Environmental Resources Analysis System (ERAS) spreadsheet-based decision support system (DSS). ERAS provides access to historic data sets, scientific information, statistical analysis, model outputs, and comparative methods all in a familiar and user-friendly format. This research project demonstrates a simplified decision support system for use by a diverse mix of resource managers, special interest groups, and individuals concerned about the sustainability of the Green and Yampa River ecosystem.

  11. Crystallization kinetics of poly-(lactic acid) with and without talc: Optical microscopy and calorimetric analysis

    Science.gov (United States)

    Refaa, Z.; Boutaous, M.; Rousset, F.; Fulchiron, R.; Zinet, M.; Xin, S.; Bourgin, P.

    2014-05-01

    Poly-(lactic acid) or PLA is a biodegradable polymer synthesized from renewable resources. Recently, the discovery of new polymerization routes has allowed increasing the produced volumes. As a consequence, PLA is becoming of great interest for reducing the dependence on petroleum-based plastics. Because of its interesting mechanical properties, PLA is seen as a potential substitute for some usual polymers. However, its relatively slow crystallization kinetics can be a disadvantage with regard to industrial applications. The crystallization kinetics of PLA can be enhanced by adding nucleating agents, which also influences on crystalline morphology and rheological behavior. In the present work, the isothermal quiescent crystallization kinetics of both neat PLA and PLA/talc composite (5 wt% talc) are investigated. The effects of talc on the overall crystallization kinetics and on the crystalline morphology are analyzed using both optical microscopy measurements and thermal analysis by differential scanning calorimetry.

  12. Thermogravimetric analysis and kinetics modeling of isothermal carbonization of olive wood in inert atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Grioui, Najla; Halouani, Kamel [Micro-Electro-Thermal Systems - Industrial Energy Systems Group METS-IESG, Institut Preparatoire aux Etudes d' Ingenieurs de Sfax IPEIS, B.P. 805, 3000 Sfax (Tunisia); Zoulalian, Andre [Laboratoire d' Etudes et de Recherches sur le Materiau Bois LERMAB, Universite Henri Point Carre Nancy 1 UHP, B.P. 239, 54506 Vandoeuvre les Nancy Cedex (France); Halouani, Foued [Ecole Nationale d' Ingenieurs de Sfax ENIS, B.P. 3038, Sfax (Tunisia)

    2006-01-01

    The kinetics of olive wood carbonization is investigated by means of isothermal thermogravimetric analysis method. Measurements were carried out in a thermobalance for different fixed temperatures between 498 and 648K. A two-stage semi-global kinetic model consisting of four sequential steps was proposed to derive kinetic parameters. The olive wood is classified in three pseudo-components. For the first two, similar thermal degradation mechanisms take place in a single reaction step. For the third, the thermal degradation takes place in two consecutive steps. The isothermal conditions allow the kinetic constants (activation energy and pre-exponential factors) to be estimated by means of the analytical solution of the mass conservation equations. An overall good agreement was obtained with activation energy values available in the literature.

  13. Kinetic global analysis of Alfven eigenmodes in toroidal plasmas

    International Nuclear Information System (INIS)

    Fukuyama, A.

    2002-01-01

    Systematic study on low to medium n (toroidal mode number) Alfven eigenmodes (AE) in tokamaks and helical systems is presented. Linear stability of AE in the presence of energetic ions was studied using the kinetic full-wave code TASK/WM.We have reproduced the destabilizing effect of toroidal co-rotation on TAE for JT-60U parameters. We have found the existence of reversed-shear-induced Alfven eigenmode (RSAE) which localizes near the q minimum in a reversed magnetic shear configuration. Two kinds of mode structures are identified for energetic particle mode (EPM) below the TAE frequency gap. The coupling to lower-frequency modes such as drift waves and MHD modes as well as the effect of trapped particles are also taken into account. For a helical plasma, the existence of GAE in the central region and TAE in the off-axis region was confirmed. (author)

  14. Kinetic analysis of several variations of push-ups.

    Science.gov (United States)

    Ebben, William P; Wurm, Bradley; VanderZanden, Tyler L; Spadavecchia, Mark L; Durocher, John J; Bickham, Curtis T; Petushek, Erich J

    2011-10-01

    Push-ups are a common and practical exercise that is used to enhance fitness, including upper body strength or endurance. The kinetic characteristics of push-ups and its variations are yet to be quantified. Kinetic quantification is necessary to accurately evaluate the training load, and thus the nature of the training stimulus, for these exercise variations. This study assessed the peak vertical ground reaction forces (GRFs) of push-up variations including the regular push-up and those performed with flexed knee, feet elevated on a 30.48-cm box, and a 60.96-cm box, and hands elevated on a 30.48-cm box and a 60.96-cm box. Twenty-three recreationally fit individuals (14 men, 9 women) performed each of the 6 push-up variations in a randomized order. Peak GRF and peak GRF expressed as a coefficient of subject body mass were obtained with a force platform. Push-ups with the feet elevated produced a higher GRF than all other push-up variations (p ≤ 0.05). Push-ups with hands elevated and push-ups from the flexed knee position produced a lower GRF than all other push-up variations (p ≤ 0.05). No gender differences in response to these push-up variations were found (p > 0.05). Additionally, subject height was not related to the GRF for any of the push-up conditions (p > 0.05) other than the condition where hands were elevated on a 60.96-cm box (p ≤ 0.05; r = 0.63). These data can be used to progress the intensity of push-ups in a program and to quantify the training load as a percentage of body mass.

  15. Trace-element analysis in environmental sciences

    International Nuclear Information System (INIS)

    Valkovic, V.; Moschini, G.

    1988-01-01

    The use of charged-particle accelerators in trace-element analysis in the field of environmental sciences is described in this article. Nuclear reactions, charged-particle-induced X-ray emission as well as other nuclear and atomic processes can be used individually, or combined, in developing adequate analytical systems. In addition to concentration levels, concentration levels, concentration profiles can be measured, resulting in unique information. Some examples of experiments performed are described together with the suggestions for future measurements [pt

  16. Nuclear techniques for analysis of environmental samples

    International Nuclear Information System (INIS)

    1986-12-01

    The main purposes of this meeting were to establish the state-of-the-art in the field, to identify new research and development that is required to provide an adequate framework for analysis of environmental samples and to assess needs and possibilities for international cooperation in problem areas. This technical report was prepared on the subject based on the contributions made by the participants. A separate abstract was prepared for each of the 9 papers

  17. Treating experimental data of inverse kinetic method by unitary linear regression analysis

    International Nuclear Information System (INIS)

    Zhao Yusen; Chen Xiaoliang

    2009-01-01

    The theory of treating experimental data of inverse kinetic method by unitary linear regression analysis was described. Not only the reactivity, but also the effective neutron source intensity could be calculated by this method. Computer code was compiled base on the inverse kinetic method and unitary linear regression analysis. The data of zero power facility BFS-1 in Russia were processed and the results were compared. The results show that the reactivity and the effective neutron source intensity can be obtained correctly by treating experimental data of inverse kinetic method using unitary linear regression analysis and the precision of reactivity measurement is improved. The central element efficiency can be calculated by using the reactivity. The result also shows that the effect to reactivity measurement caused by external neutron source should be considered when the reactor power is low and the intensity of external neutron source is strong. (authors)

  18. k-OptForce: integrating kinetics with flux balance analysis for strain design.

    Directory of Open Access Journals (Sweden)

    Anupam Chowdhury

    2014-02-01

    Full Text Available Computational strain design protocols aim at the system-wide identification of intervention strategies for the enhanced production of biochemicals in microorganisms. Existing approaches relying solely on stoichiometry and rudimentary constraint-based regulation overlook the effects of metabolite concentrations and substrate-level enzyme regulation while identifying metabolic interventions. In this paper, we introduce k-OptForce, which integrates the available kinetic descriptions of metabolic steps with stoichiometric models to sharpen the prediction of intervention strategies for improving the bio-production of a chemical of interest. It enables identification of a minimal set of interventions comprised of both enzymatic parameter changes (for reactions with available kinetics and reaction flux changes (for reactions with only stoichiometric information. Application of k-OptForce to the overproduction of L-serine in E. coli and triacetic acid lactone (TAL in S. cerevisiae revealed that the identified interventions tend to cause less dramatic rearrangements of the flux distribution so as not to violate concentration bounds. In some cases the incorporation of kinetic information leads to the need for additional interventions as kinetic expressions render stoichiometry-only derived interventions infeasible by violating concentration bounds, whereas in other cases the kinetic expressions impart flux changes that favor the overproduction of the target product thereby requiring fewer direct interventions. A sensitivity analysis on metabolite concentrations shows that the required number of interventions can be significantly affected by changing the imposed bounds on metabolite concentrations. Furthermore, k-OptForce was capable of finding non-intuitive interventions aiming at alleviating the substrate-level inhibition of key enzymes in order to enhance the flux towards the product of interest, which cannot be captured by stoichiometry-alone analysis

  19. Visual evaluation of kinetic characteristics of PET probe for neuroreceptors using a two-phase graphic plot analysis.

    Science.gov (United States)

    Ito, Hiroshi; Ikoma, Yoko; Seki, Chie; Kimura, Yasuyuki; Kawaguchi, Hiroshi; Takuwa, Hiroyuki; Ichise, Masanori; Suhara, Tetsuya; Kanno, Iwao

    2017-05-01

    Objectives In PET studies for neuroreceptors, tracer kinetics are described by the two-tissue compartment model (2-TCM), and binding parameters, including the total distribution volume (V T ), non-displaceable distribution volume (V ND ), and binding potential (BP ND ), can be determined from model parameters estimated by kinetic analysis. The stability of binding parameter estimates depends on the kinetic characteristics of radioligands. To describe these kinetic characteristics, we previously developed a two-phase graphic plot analysis in which V ND and V T can be estimated from the x-intercept of regression lines for early and delayed phases, respectively. In this study, we applied this graphic plot analysis to visual evaluation of the kinetic characteristics of radioligands for neuroreceptors, and investigated a relationship between the shape of these graphic plots and the stability of binding parameters estimated by the kinetic analysis with 2-TCM in simulated brain tissue time-activity curves (TACs) with various binding parameters. Methods 90-min TACs were generated with the arterial input function and assumed kinetic parameters according to 2-TCM. Graphic plot analysis was applied to these simulated TACs, and the curvature of the plot for each TAC was evaluated visually. TACs with several noise levels were also generated with various kinetic parameters, and the bias and variation of binding parameters estimated by kinetic analysis were calculated in each TAC. These bias and variation were compared with the shape of graphic plots. Results The graphic plots showed larger curvature for TACs with higher specific binding and slower dissociation of specific binding. The quartile deviations of V ND and BP ND determined by kinetic analysis were smaller for radioligands with slow dissociation. Conclusions The larger curvature of graphic plots for radioligands with slow dissociation might indicate a stable determination of V ND and BP ND by kinetic analysis. For

  20. Coherent Energy and Environmental System Analysis

    DEFF Research Database (Denmark)

    Hvelplund, Frede; Mathiesen, Brian Vad; Østergaard, Poul Alberg

    This report presents a summary of results of the strategic research project “Coherent Energy and Environmental System Analysis” (CEESA) which was conducted in the period 2007-2011 and funded by the Danish Strategic Research Council together with the participating parties. The project was interdis......This report presents a summary of results of the strategic research project “Coherent Energy and Environmental System Analysis” (CEESA) which was conducted in the period 2007-2011 and funded by the Danish Strategic Research Council together with the participating parties. The project...... energy and environmental analysis tools as well as analyses of the design and implementation of future renewable energy systems. For practical reasons, the work has been carried out as an interaction between five work packages, and a number of reports, papers and tools have been reported separately from...... of the different project parts in a coherent way by presenting tools and methodologies as well as analyses of the design and implementation of renewable energy systems – including both energy and environmental aspects. The authors listed in the report represent those who have contributed directly as well...

  1. Multisteps Global Kinetic Analysis of MSW Slow Pyrolysis

    Directory of Open Access Journals (Sweden)

    Dwi Aries Himawanto

    2013-12-01

    Full Text Available The goal of this research is to find relationships between single components slow pyrolysis characteristics and mixed component slow pyrolysis characteristics of segregated municipal solid wastes (MSW. The material of this research consists of organic wastes (bamboo wastes and banana leaves wastes and inorganic wastes (styrofoam wastes and snack wrapping wastes. The materials which used to study were the unprosessing waste. The samples were collected, dried and crushed until passing 20 mesh shieves then characterized in self manufactured macro balance. The thermogravimetry analyses were done to find the MSW slow pyrolysis characteristics. The 20 gram sample was placed in the furnace whose temperature is increased with 10 0C/min heating rate until reached 400 0 final temperature and held for 30 minutes before the sample is cooled into room temperature. One hundred ml/min nitrogen introduced from the bottom of furnace as a swept gas. The results of the research show that the global kinetic method could be used to predict the MSW single component activation energy but it should be modified to calculate the mixed sample activation energy . The predictive activation energy values which calculated based on weighed sum of single component have 18.5 % deviations if compared with experimental result.

  2. Kinetic analysis of microbial respiratory response to substrate addition

    Science.gov (United States)

    Blagodatskaya, Evgenia; Blagodatsky, Sergey; Yuyukina, Tatayna; Kuzyakov, Yakov

    2010-05-01

    Heterotrophic component of CO2 emitted from soil is mainly due to the respiratory activity of soil microorganisms. Field measurements of microbial respiration can be used for estimation of C-budget in soil, while laboratory estimation of respiration kinetics allows the elucidation of mechanisms of soil C sequestration. Physiological approaches based on 1) time-dependent or 2) substrate-dependent respiratory response of soil microorganisms decomposing the organic substrates allow to relate the functional properties of soil microbial community with decomposition rates of soil organic matter. We used a novel methodology combining (i) microbial growth kinetics and (ii) enzymes affinity to the substrate to show the shift in functional properties of the soil microbial community after amendments with substrates of contrasting availability. We combined the application of 14C labeled glucose as easily available C source to soil with natural isotope labeling of old and young soil SOM. The possible contribution of two processes: isotopic fractionation and preferential substrate utilization to the shifts in δ13C during SOM decomposition in soil after C3-C4 vegetation change was evaluated. Specific growth rate (µ) of soil microorganisms was estimated by fitting the parameters of the equation v(t) = A + B * exp(µ*t), to the measured CO2 evolution rate (v(t)) after glucose addition, and where A is the initial rate of non-growth respiration, B - initial rate of the growing fraction of total respiration. Maximal mineralization rate (Vmax), substrate affinity of microbial enzymes (Ks) and substrate availability (Sn) were determined by Michaelis-Menten kinetics. To study the effect of plant originated C on δ13C signature of SOM we compared the changes in isotopic composition of different C pools in C3 soil under grassland with C3-C4 soil where C4 plant Miscanthus giganteus was grown for 12 years on the plot after grassland. The shift in 13δ C caused by planting of M. giganteus

  3. Kinetic analysis of oxygen dynamics under a variable work rate.

    Science.gov (United States)

    Artiga Gonzalez, Alexander; Bertschinger, Raphael; Brosda, Fabian; Dahmen, Thorsten; Thumm, Patrick; Saupe, Dietmar

    2017-09-14

    Measurements of oxygen uptake are central to methods for the assessment of physical fitness and endurance capabilities in athletes. Two important parameters extracted from such data of incremental exercise tests are the maximal oxygen uptake and the critical power. A commonly accepted model of the dynamics of oxygen uptake during exercise at a constant work rate comprises a constant baseline oxygen uptake, an exponential fast component, and another exponential slow component for heavy and severe work rates. We have generalized this model to variable load protocols with differential equations that naturally correspond to the standard model for a constant work rate. This provides the means for predicting the oxygen uptake response to variable load profiles including phases of recovery. The model parameters have been fitted for individual subjects from a cycle ergometer test, including the maximal oxygen uptake and critical power. The model predictions have been validated by data collected in separate tests. Our findings indicate that the oxygen kinetics for a variable exercise load can be predicted using the generalized mathematical standard model. Such models can be applied in the field where the constant work rate assumption generally is not valid. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Part I. Evaluation of thermodynamic and kinetic parameters for electron transfer and following chemical reaction from a global analysis of current-potential-time data. Part II. Electro-catalytic detection in high-performance liquid chromatography of vitamin B[sub 12] and other molecules of biological and environmental interest

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, V.T.

    1992-01-01

    Simultaneous evaluation of electron transfer rate constant, k[sup 0], following chemical reaction rate constant, k[sub f], electron transfer coefficient, [alpha] and standard potential, E[sup 0][prime] for an electrochemical reaction following the EC mechanism is described. A mathematical model for the current response to a potential step is developed, starting with the Butler-Volmer equation for electrode kinetics and concentration expressions for the redox couple. The resulting integral equations are solved numerically via the Step Function method. Current-potential and current-time curves are simulated and tested under limiting conditions. The four parameters of the system are evaluated by fitting simulated current-voltage-time (i-E-t) surface to the theoretical equation. The method is applied to study an important biological molecule, viz., methyl cobalamin, in DMSO. Included in the discussion part is the use of kinetic zone diagrams to depict chronoamperometric current response as a function of dimensionless rate constants for the EC reaction scheme. This compact display of the influence of the two rate constants on current in all time windows can be used to select the best data for analysis. Theoretical limits of measurable rate constants can be estimated from the zone diagram. The development of a dropping mercury electrode detector for High Performance Liquid Chromatography (HPLC) and its application to analysis of B[sub 12] and other vitamins is described. This EC detector is able to achieve high levels of sensitivity by exploiting the catalytic hydrogen evolution undergone by many nitrogenous organic molecules. Vitamin B[sub 12], thiamine, riboflavin and niacinamide were analyzed individually and in mixtures on reverse phase C18 column. Preliminary results from the analysis of commercial multivitamin preparations are also discussed.

  5. Environmental systems analysis of wastewater management

    International Nuclear Information System (INIS)

    Kaerrman, Erik

    2000-01-01

    The history of wastewater management tells us that efforts have been made at solving only one problem at the time; sanitation during the first half of the 20th Century followed by eutrophication of lakes and sea and, for the past ten years, recycling of nutrients. After the 'Brundtland Report', 1987, a reversal of the debate occurred where water management was discussed in a more holistic manner than before. The concept sustainable development became widely accepted and was put into practice. This thesis suggests a framework for evaluating the sustainability of wastewater systems, which contains the use of criteria and system analytical evaluation methods matching each criterion. The main categories of criteria are identified as: Health and Hygiene, Social and Cultural, Environmental, Economic and Functional and Technical. The usability of different concepts of Environmental Systems Analysis for evaluating environmental criteria of wastewater systems is also investigated. These studies show that a substance-flow model combined with evaluation methods from Life Cycle Assessment (LCA), sometimes complemented with Exergy Analysis or Analysis of Primary Energy, is a beneficial approach for evaluating environmental impacts and the usage of resources. The substance-flow model ORWARE (ORganic WAste REsearch) combined with LCA was used to compare four systems structures for the management of household wastewater and solid organic waste, namely Conventional System, Irrigation of Energy Forests, Liquid Composting and Urine Separation. This study shows a potential for further development of the three alternative systems. The comparative study also included some development of system analytical methods. This thesis shows how the contribution from oxidation of ammonia should be included in the eutrophication impact category. Furthermore, a method is given for prioritization of the most relevant impacts from wastewater management by using normalisation of these impacts in

  6. Analysis of DOE international environmental management activities

    Energy Technology Data Exchange (ETDEWEB)

    Ragaini, R.C.

    1995-09-01

    The Department of Energy`s (DOE) Strategic Plan (April 1994) states that DOE`s long-term vision includes world leadership in environmental restoration and waste management activities. The activities of the DOE Office of Environmental Management (EM) can play a key role in DOE`s goals of maintaining U.S. global competitiveness and ensuring the continuation of a world class science and technology community. DOE`s interest in attaining these goals stems partly from its participation in organizations like the Trade Policy Coordinating Committee (TPCC), with its National Environmental Export Promotion Strategy, which seeks to strengthen U.S. competitiveness and the building of public-private partnerships as part of U.S. industrial policy. The International Interactions Field Office task will build a communication network which will facilitate the efficient and effective communication between DOE Headquarters, Field Offices, and contractors. Under this network, Headquarters will provide the Field Offices with information on the Administration`s policies and activities (such as the DOE Strategic Plan), interagency activities, as well as relevant information from other field offices. Lawrence Livermore National Laboratory (LLNL) will, in turn, provide Headquarters with information on various international activities which, when appropriate, will be included in reports to groups like the TPCC and the EM Focus Areas. This task provides for the collection, review, and analysis of information on the more significant international environmental restoration and waste management initiatives and activities which have been used or are being considered at LLNL. Information gathering will focus on efforts and accomplishments in meeting the challenges of providing timely and cost effective cleanup of its environmentally damaged sites and facilities, especially through international technical exchanges and/or the implementation of foreign-development technologies.

  7. Coherent Energy and Environmental System Analysis

    DEFF Research Database (Denmark)

    Hvelplund, Frede Kloster; Mathiesen, Brian Vad; Østergaard, Poul Alberg

    This report presents a summary of results of the strategic research project “Coherent Energy and Environmental System Analysis” (CEESA) which was conducted in the period 2007-2011 and funded by the Danish Strategic Research Council together with the participating parties. The project...... energy and environmental analysis tools as well as analyses of the design and implementation of future renewable energy systems. For practical reasons, the work has been carried out as an interaction between five work packages, and a number of reports, papers and tools have been reported separately from...... each part of the project. A list of the separate work package reports is given at the end of this foreword while a complete list of all papers and reports can be found at the end of the report as well as at the following website: www.ceesa.dk. This report provides a summary of the results...

  8. A study on the dissolution rates of K-Cr(VI)-jarosites: kinetic analysis and implications.

    Science.gov (United States)

    Reyes, Iván A; Mireles, Ister; Patiño, Francisco; Pandiyan, Thangarasu; Flores, Mizraim U; Palacios, Elia G; Gutiérrez, Emmanuel J; Reyes, Martín

    2016-01-01

    The presence of natural and industrial jarosite type-compounds in the environment could have important implications in the mobility of potentially toxic elements such as lead, mercury, arsenic, chromium, among others. Understanding the dissolution reactions of jarosite-type compounds is notably important for an environmental assessment (for water and soil), since some of these elements could either return to the environment or work as temporary deposits of these species, thus would reduce their immediate environmental impact. This work reports the effects of temperature, pH, particle diameter and Cr(VI) content on the initial dissolution rates of K-Cr(VI)-jarosites (KFe3[(SO4)2 - X(CrO4)X](OH)6). Temperature (T) was the variable with the strongest effect, followed by pH in acid/alkaline medium (H3O(+)/OH(-)). It was found that the substitution of CrO4 (2-)in Y-site and the substitution of H3O(+) in M-site do not modify the dissolution rates. The model that describes the dissolution process is the unreacted core kinetic model, with the chemical reaction on the unreacted core surface. The dissolution in acid medium was congruent, while in alkaline media was incongruent. In both reaction media, there is a release of K(+), SO4 (2-) and CrO4 (2-) from the KFe3[(SO4)2 - X(CrO4)X](OH)6 structure, although the latter is rapidly absorbed by the solid residues of Fe(OH)3 in alkaline medium dissolutions. The dissolution of KFe3[(SO4)2 - X(CrO4)X](OH)6 exhibited good stability in a wide range of pH and T conditions corresponding to the calculated parameters of reaction order n, activation energy E A and dissolution rate constants for each kinetic stages of induction and progressive conversion. The kinetic analysis related to the reaction orders and calculated activation energies confirmed that extreme pH and T conditions are necessary to obtain considerably high dissolution rates. Extreme pH conditions (acidic or alkaline) cause the preferential release of K(+), SO4 (2

  9. Post-construction environmental and social impact analysis (ESIA ...

    African Journals Online (AJOL)

    harcourt – Eungu highway in Southeastern Nigeria. The impact study focused on the Environmental and Social Impact Analysis (ESIA) because of the social and environmental impacts of road projects. The basic tool used in this analysis is ...

  10. Thermal degradation kinetics and isoconversional analysis of biodegradable poly(3-hydroxybutyrate)/organomodified montmorillonite nanocomposites

    International Nuclear Information System (INIS)

    Achilias, Dimitris S.; Panayotidou, Elpiniki; Zuburtikudis, Ioannis

    2011-01-01

    Poly(3-hydroxybutyrate) (PHB)/organically modified clay nanocomposites were prepared by the melt mixing method and were characterized using wide-angle X-ray diffraction. Their thermal degradation kinetics was investigated using thermogravimetric analysis at various heating rates. Further kinetic analysis was performed using isoconversional methods and the invariant kinetic parameters method was used to estimate the so-called 'true' kinetic parameters, i.e. the pre-exponential factor, A and the activation energy, E, as well as the reaction model. It was found that intercalated structures are formed and the thermal stability of the material is improved by the addition of the nano-filler. From the isoconversional analysis, it was found that the activation energy does not vary significantly with the degree of degradation denoting degradation in one step with similar values for pure PHB and for all nanocomposites. Using the invariant kinetic parameters method, it was found that the model that best describes the experimental data was that of Sestak-Berggren's with f(a) = α n (1 - α) m , where the value of n is always larger than m and is increasing with the amount of the nano-filler. The value of the 'true' activation energy was found to be about 100 kJ mol -1 for all nanocomposites and the pre-exponential factor for PHB was estimated equal to 5.35 x 10 9 min -1 . Finally, the values of the kinetic rate constant k were found to decrease with the amount of the nano-filler up to 3 wt%, while for amounts larger than 3 wt% k increased reaching a value greater than that of pure PHB for the 10 wt% nanocomposites.

  11. Kinetic analysis of the reduction of zinc and iron oxides from dust and slurry

    OpenAIRE

    Melamud, S. G.; Mal'tsev, V. A.; Yur'ev, B. P.

    2013-01-01

    The reduction of zinc and iron oxides from blast-furnace slurry and gas-purification dust at steel furnaces by heating with carbon is studied in physicochemical terms. Kinetic analysis reveals the optimal parameters of furnace reduction. Initial data are obtained for the development of a reduction technology for zinc and iron oxides. © 2013 Allerton Press, Inc.

  12. In silico modelling and analysis of ribosome kinetics and aa-tRNA competition

    NARCIS (Netherlands)

    Bošnački, D.; Pronk, T.E.; de Vink, E.P.

    2008-01-01

    We present a formal analysis of ribosome kinetics using probabilistic model checking and the tool Prism. We compute different parameters of the model, like probabilities of translation errors and average insertion times per codon. The model predicts strong correlation to the quotient of the

  13. Noise and ac impedance analysis of ion transfer kinetics at the micro liquid/liquid interface

    Czech Academy of Sciences Publication Activity Database

    Josypčuk, Oksana; Holub, Karel; Mareček, Vladimír

    2015-01-01

    Roč. 56, JUL 2015 (2015), s. 43-45 ISSN 1388-2481 R&D Projects: GA ČR GA13-04630S Institutional support: RVO:61388955 Keywords : noise analysis * liquid/liquid interface * ion transfer kinetics Subject RIV: CG - Electrochemistry Impact factor: 4.569, year: 2015

  14. Critical Analysis of Underground Coal Gasification Models. Part II: Kinetic and Computational Fluid Dynamics Models

    Directory of Open Access Journals (Sweden)

    Alina Żogała

    2014-01-01

    Originality/value: This paper presents state of art in the field of coal gasification modeling using kinetic and computational fluid dynamics approach. The paper also presents own comparative analysis (concerned with mathematical formulation, input data and parameters, basic assumptions, obtained results etc. of the most important models of underground coal gasification.

  15. On the graph and systems analysis of reversible chemical reaction networks with mass action kinetics

    NARCIS (Netherlands)

    Rao, Shodhan; Jayawardhana, Bayu; Schaft, Arjan van der

    2012-01-01

    Motivated by the recent progresses on the interplay between the graph theory and systems theory, we revisit the analysis of reversible chemical reaction networks described by mass action kinetics by reformulating it using the graph knowledge of the underlying networks. Based on this formulation, we

  16. Kinetic and thermodynamic analysis of the polymerization of polyurethanes by a rheological method

    Energy Technology Data Exchange (ETDEWEB)

    Lucio, Beatriz; Fuente, José Luis de la, E-mail: fuentegj@inta.es

    2016-02-10

    Graphical abstract: - Highlights: • Kinetic and thermodynamic analysis for the formation of a functional polyurethane (PU) has been carried out. • Rheological parameters were used to obtain the profile of the resin's curing degree. • Kamal-Sourour autocatalytic kinetic model describes well this polyaddition reaction. • A deeper understanding of the mechanism of PU systems has been achieved. • This metallo-PU finds its application in the chemistry of advanced energetic materials. - Abstract: As part of an investigation into the mechanism and chemorheology of linear segmented polyurethane (PU) systems, this paper presents the kinetic and thermodynamic characterization of the reaction between an advanced functional metallo-polyol derivative of hydroxyl-terminated polybutadiene (HTPB), (ferrocenylbutyl)dimethylsilane grafted HTPB, and isophorone diisocyanate (IPDI). The evolution of viscoelastic properties, such as the storage modulus (G′), was recorded in bulk under isothermal conditions at four different temperatures between 50 and 80 °C, and a resin curing degree profile was obtained for this elastic modulus. The use of the Kamal-Sourour autocatalytic kinetic model was proposed, describing the overall curing process perfectly. All the kinetic and thermodynamic parameters, including reaction orders, kinetic constants and activation energy, were determined for the polyaddition reaction under study. A relevant autocatalysis effect, promoted by the urethane group, has been found. The isoconversion method was also used to analyze the variation of the global activation energy with conversion. The global activation energy increases slightly as the curing reaction proceeds with a maximum value reached at approximately 30% conversion. In addition, the Eyring parameters were calculated from the obtained kinetic data.

  17. Kinetic Analysis for Macrocyclizations Involving Anionic Template at the Transition State

    Directory of Open Access Journals (Sweden)

    Vicente Martí-Centelles

    2012-01-01

    competitive oligomerization/polymerization processes yielding undesired oligomeric/polymeric byproducts. The effect of anions has also been included in the kinetic models, as they can act as catalytic templates in the transition state reducing and stabilizing the transition state. The corresponding differential equation systems for each kinetic model can be solved numerically. Through a comprehensive analysis of these results, it is possible to obtain a better understanding of the different parameters that are involved in the macrocyclization reaction mechanism and to develop strategies for the optimization of the desired processes.

  18. Comparative analysis among several methods used to solve the point kinetic equations

    International Nuclear Information System (INIS)

    Nunes, Anderson L.; Goncalves, Alessandro da C.; Martinez, Aquilino S.; Silva, Fernando Carvalho da

    2007-01-01

    The main objective of this work consists on the methodology development for comparison of several methods for the kinetics equations points solution. The evaluated methods are: the finite differences method, the stiffness confinement method, improved stiffness confinement method and the piecewise constant approximations method. These methods were implemented and compared through a systematic analysis that consists basically of confronting which one of the methods consume smaller computational time with higher precision. It was calculated the relative which function is to combine both criteria in order to reach the goal. Through the analyses of the performance factor it is possible to choose the best method for the solution of point kinetics equations. (author)

  19. Comparative analysis among several methods used to solve the point kinetic equations

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Anderson L.; Goncalves, Alessandro da C.; Martinez, Aquilino S.; Silva, Fernando Carvalho da [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Nuclear; E-mails: alupo@if.ufrj.br; agoncalves@con.ufrj.br; aquilino@lmp.ufrj.br; fernando@con.ufrj.br

    2007-07-01

    The main objective of this work consists on the methodology development for comparison of several methods for the kinetics equations points solution. The evaluated methods are: the finite differences method, the stiffness confinement method, improved stiffness confinement method and the piecewise constant approximations method. These methods were implemented and compared through a systematic analysis that consists basically of confronting which one of the methods consume smaller computational time with higher precision. It was calculated the relative which function is to combine both criteria in order to reach the goal. Through the analyses of the performance factor it is possible to choose the best method for the solution of point kinetics equations. (author)

  20. Two-dimensional kinetic analysis suggests nonsequential gating of mechanosensitive channels in Xenopus oocytes.

    OpenAIRE

    Gil, Z; Magleby, K L; Silberberg, S D

    2001-01-01

    Xenopus oocytes express mechanosensitive (MS(XO)) channels that can be studied in excised patches of membrane with the patch-clamp technique. This study examines the steady-state kinetic gating properties of MS(XO) channels using detailed single-channel analysis. The open and closed one-dimensional dwell-time distributions were described by the sums of 2-3 open and 5-7 closed exponential components, respectively, indicating that the channels enter at least 2-3 open and 5-7 closed kinetic stat...

  1. Environmentally-friendly aqueous Li (or Na)-ion battery with fast electrode kinetics and super-long life.

    Science.gov (United States)

    Dong, Xiaoli; Chen, Long; Liu, Jingyuan; Haller, Servane; Wang, Yonggang; Xia, Yongyao

    2016-01-01

    Current rechargeable batteries generally display limited cycle life and slow electrode kinetics and contain environmentally unfriendly components. Furthermore, their operation depends on the redox reactions of metal elements. We present an original battery system that depends on the redox of I(-)/I3 (-) couple in liquid cathode and the reversible enolization in polyimide anode, accompanied by Li(+) (or Na(+)) diffusion between cathode and anode through a Li(+)/Na(+) exchange polymer membrane. There are no metal element-based redox reactions in this battery, and Li(+) (or Na(+)) is only used for charge transfer. Moreover, the components (electrolyte/electrode) of this system are environment-friendly. Both electrodes are demonstrated to have very fast kinetics, which gives the battery a supercapacitor-like high power. It can even be cycled 50,000 times when operated within the electrochemical window of 0 to 1.6 V. Such a system might shed light on the design of high-safety and low-cost batteries for grid-scale energy storage.

  2. Development, validation and application of multi-point kinetics model in RELAP5 for analysis of asymmetric nuclear transients

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Santosh K., E-mail: santosh@aerb.gov.in [Nuclear Safety Analysis Division, Atomic Energy Regulatory Board, Mumbai 400094 (India); Obaidurrahman, K. [Nuclear Safety Analysis Division, Atomic Energy Regulatory Board, Mumbai 400094 (India); Iyer, Kannan N. [Department of Mechanical Engineering, IIT Bombay, Mumbai 400076 (India); Gaikwad, Avinash J. [Nuclear Safety Analysis Division, Atomic Energy Regulatory Board, Mumbai 400094 (India)

    2016-04-15

    Highlights: • A multi-point kinetics model is developed for RELAP5 system thermal hydraulics code. • Model is validated against extensive 3D kinetics code. • RELAP5 multi-point kinetics formulation is used to investigate critical break for LOCA in PHWR. - Abstract: Point kinetics approach in system code RELAP5 limits its use for many of the reactivity induced transients, which involve asymmetric core behaviour. Development of fully coupled 3D core kinetics code with system thermal-hydraulics is the ultimate requirement in this regard; however coupling and validation of 3D kinetics module with system code is cumbersome and it also requires access to source code. An intermediate approach with multi-point kinetics is appropriate and relatively easy to implement for analysis of several asymmetric transients for large cores. Multi-point kinetics formulation is based on dividing the entire core into several regions and solving ODEs describing kinetics in each region. These regions are interconnected by spatial coupling coefficients which are estimated from diffusion theory approximation. This model offers an advantage that associated ordinary differential equations (ODEs) governing multi-point kinetics formulation can be solved using numerical methods to the desired level of accuracy and thus allows formulation based on user defined control variables, i.e., without disturbing the source code and hence also avoiding associated coupling issues. Euler's method has been used in the present formulation to solve several coupled ODEs internally at each time step. The results have been verified against inbuilt point-kinetics models of RELAP5 and validated against 3D kinetics code TRIKIN. The model was used to identify the critical break in RIH of a typical large PHWR core. The neutronic asymmetry produced in the core due to the system induced transient was effectively handled by the multi-point kinetics model overcoming the limitation of in-built point kinetics model

  3. Environmental analysis for pipeline gas demonstration plants

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, L.H.

    1978-09-01

    The Department of Energy (DOE) has implemented programs for encouraging the development and commercialization of coal-related technologies, which include coal gasification demonstration-scale activities. In support of commercialization activities the Environmental Analysis for Pipeline Gas Demonstration Plants has been prepared as a reference document to be used in evaluating potential environmental and socioeconomic effects from construction and operation of site- and process-specific projects. Effluents and associated impacts are identified for six coal gasification processes at three contrasting settings. In general, impacts from construction of a high-Btu gas demonstration plant are similar to those caused by the construction of any chemical plant of similar size. The operation of a high-Btu gas demonstration plant, however, has several unique aspects that differentiate it from other chemical plants. Offsite development (surface mining) and disposal of large quantities of waste solids constitute important sources of potential impact. In addition, air emissions require monitoring for trace metals, polycyclic aromatic hydrocarbons, phenols, and other emissions. Potential biological impacts from long-term exposure to these emissions are unknown, and additional research and data analysis may be necessary to determine such effects. Possible effects of pollutants on vegetation and human populations are discussed. The occurrence of chemical contaminants in liquid effluents and the bioaccumulation of these contaminants in aquatic organisms may lead to adverse ecological impact. Socioeconomic impacts are similar to those from a chemical plant of equivalent size and are summarized and contrasted for the three surrogate sites.

  4. Mechanistic study of manganese-substituted glycerol dehydrogenase using a kinetic and thermodynamic analysis.

    Directory of Open Access Journals (Sweden)

    Baishan Fang

    Full Text Available Mechanistic insights regarding the activity enhancement of dehydrogenase by metal ion substitution were investigated by a simple method using a kinetic and thermodynamic analysis. By profiling the binding energy of both the substrate and product, the metal ion's role in catalysis enhancement was revealed. Glycerol dehydrogenase (GDH from Klebsiella pneumoniae sp., which demonstrated an improvement in activity by the substitution of a zinc ion with a manganese ion, was used as a model for the mechanistic study of metal ion substitution. A kinetic model based on an ordered Bi-Bi mechanism was proposed considering the noncompetitive product inhibition of dihydroxyacetone (DHA and the competitive product inhibition of NADH. By obtaining preliminary kinetic parameters of substrate and product inhibition, the number of estimated parameters was reduced from 10 to 4 for a nonlinear regression-based kinetic parameter estimation. The simulated values of time-concentration curves fit the experimental values well, with an average relative error of 11.5% and 12.7% for Mn-GDH and GDH, respectively. A comparison of the binding energy of enzyme ternary complex for Mn-GDH and GDH derived from kinetic parameters indicated that metal ion substitution accelerated the release of dioxyacetone. The metal ion's role in catalysis enhancement was explicated.

  5. Gasification kinetic analysis of the three pseudocomponents of biomass-cellulose, semicellulose and lignin.

    Science.gov (United States)

    Chen, Tianju; Wu, Jingli; Zhang, Jinzhi; Wu, Jinhu; Sun, Li

    2014-02-01

    The gasification kinetic analysis of the three pseudocomponents (hemicellulose, cellulose and lignin) of biomass decomposition in the agent of CO2 were investigated. The Multi-peaks method was used to fit the Gaussian distribution model of DTG curves. The Friedman method was used to estimate the effective Eα, and the master plot method was used for the determination of the kinetic model. The results showed that there were two reaction stages for semi-cellulose and lignin. The DTG curves of semicellulose and lignin cannot be fitted by Gaussian distribution model. The Eα were ranged from 80 to 220kJmol(-1) for the three pseudocomponents. The Fn model could describe the kinetic process of stage I of semi-cellulose decomposition. Both cellulose and stage II of semicellulose decomposition could be described by An model and the two reaction stages of the lignin were fitted the Rn model very well. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Kinetics and correlation analysis of reactivity in the oxidation of ...

    Indian Academy of Sciences (India)

    The rates of oxidation of sulfides were determined in nineteen organic solvents. An analysis of the solvent effect by multi-parametric equations indicated the relatively greater importance of the cation-solvating power of the solvents. A mechanism involving a single-step electrophilic oxygen transfer from BTPPD to the sulfide ...

  7. A kinetic sensitivity analysis for the SO2 and NOx removal using the electron beam technology

    Science.gov (United States)

    Zwolińska, Ewa; Gogulancea, Valentina; Sun, Yongxia; Lavric, Vasile; Chmielewski, Andrzej

    2017-09-01

    The mathematical modeling of the phenomena taking place during the electron beam flue gas treatment is a complex endeavor due to the different time scales of the processes occurring as accelerated electrons are bombarding the flue gas. The paper presents a complex kinetic model for these gas phase interactions, consisting of 1034 chemical reactions with the participation of 115 reactive species. The mathematical model couples the complex gas phase kinetics with a liquid phase kinetic model, taking into account the nucleation and condensation phenomena occurring due to the presence of sulfuric acid. The modeling results for both coupled and uncoupled gas phase kinetics are validated against a set of literature experimental data with satisfactory outcome. The work aims to identify the most important chemical reactions influencing the pollutants removal, proposing a sensitivity analysis using the concept of generated entropy. To the best of the authors' knowledge a sensitivity analysis of this extent has not been performed for the electron beam flue gas treatment. The results of this analysis emphasize the link between the removal efficiencies of NOx and SO2, the importance of hydroxyl radicals and can aid in future model reduction efforts.

  8. Kinetic and Thermodynamic Analysis of Acetyl-CoA Activation of Staphylococcus aureus Pyruvate Carboxylase.

    Science.gov (United States)

    Westerhold, Lauren E; Bridges, Lance C; Shaikh, Saame Raza; Zeczycki, Tonya N

    2017-07-11

    Allosteric regulation of pyruvate carboxylase (PC) activity is pivotal to maintaining metabolic homeostasis. In contrast, dysregulated PC activity contributes to the pathogenesis of numerous diseases, rendering PC a possible target for allosteric therapeutic development. Recent research efforts have focused on demarcating the role of acetyl-CoA, one of the most potent activators of PC, in coordinating catalytic events within the multifunctional enzyme. Herein, we report a kinetic and thermodynamic analysis of acetyl-CoA activation of the Staphylococcus aureus PC (SaPC)-catalyzed carboxylation of pyruvate to identify novel means by which acetyl-CoA synchronizes catalytic events within the PC tetramer. Kinetic and linked-function analysis, or thermodynamic linkage analysis, indicates that the substrates of the biotin carboxylase and carboxyl transferase domain are energetically coupled in the presence of acetyl-CoA. In contrast, both kinetic and energetic coupling between the two domains is lost in the absence of acetyl-CoA, suggesting a functional role for acetyl-CoA in facilitating the long-range transmission of substrate-induced conformational changes within the PC tetramer. Interestingly, thermodynamic activation parameters for the SaPC-catalyzed carboxylation of pyruvate are largely independent of acetyl-CoA. Our results also reveal the possibility that global conformational changes give rise to observed species-specific thermodynamic activation parameters. Taken together, our kinetic and thermodynamic results provide a possible allosteric mechanism by which acetyl-CoA coordinates catalysis within the PC tetramer.

  9. Hydrolysis of tert-butyl formate: Kinetics, products, and implications for the environmental impact of methyl tert-butyl ether

    Science.gov (United States)

    Church, Clinton D.; Pankow, James F.; Tratnyek, Paul G.

    1999-01-01

    Asessing the environmental fate of methyl tert-butyl ether (MTBE) has become a subject of renewed interest because of the large quantities of this compound that are being used as an oxygenated additive in gasoline. Various studies on the fate of MTBE have shown that it can be degraded to tert-butyl formate (TBF), particularly in the atmosphere. Although it is generally recognized that TBF is subject to hydrolysis, the kinetics and products of this reaction under environmentally relevant conditions have not been described previously. In this study, we determined the kinetics of TBF hydrolysis as a function of pH and temperature. Over the pH range of 5 to 7, the neutral hydrolysis pathway predominates, with kN = (1.0 ± 0.2) × 10−6/s. Outside this range, strong pH effects were observed because of acidic and basic hydrolyses, from which we determined that kA = (2.7 ± 0.5) × 10−3/(M·s) and kB = 1.7 ± 0.3/(M·s). Buffered and unbuffered systems gave the same hydrolysis rates for a given pH, indicating that buffer catalysis was not significant under the conditions tested. The activation energies corresponding to kN, kA, and kBwere determined to be 78 ± 5, 59 ± 4, and 88 ±11 kJ/mol, respectively. In all experiments, tert-butyl alcohol was found at concentrations corresponding to stoichiometric formation from TBF. Based on our kinetics data, the expected half-life for hydrolysis of TBF at pH = 2 and 4°C (as per some standard preservation protocols for water sampling) is 6 h. At neutral pH and 22°C, the estimated half-life is 5 d, and at pH = 11 and 22°C, the value is only 8 min.

  10. Instrumental neutron activation analysis in environmental research

    International Nuclear Information System (INIS)

    Bruin, M. de.

    1985-01-01

    The main characteristics of instrumental neutron activation analysis (INAA),relevant for environmental research and monitoring, was reviewed and discussed-sensitivity, suitable for detection of many toxic elements, the low risks of contamination of element loss, lack of matrix effects, lack of light element interference except for 24 Na, capability for multi-element determination, comparatively low costs. A detailed description of the IRI analysis system for routine INAA is given. The system is based on the single comparator method of standartization to take full advantage of multi-element without preparation and use the trace element standards. Zinc was used as mono element standard, the element concentrations are calculated on the basis of 65 Zn and 69m Zn-activities. The irradiations were carried out in a thermal neutron flux of 1.10 13 n/cm 2 .s. The gamma spectra is converted into element concentrations using a set of dedicated software, performing the following functions: spectrum analysis and interpretation, comparison and combination of the intermediate results from different decay times, generation of the final report, bookkeeping of the results obtained. The main applications of the INAA system mentioned are: identification of sources of heavy metal air pollution using air filters or biological indicators such as mosses, lichens, toe-nails, bird feathers, molusks and waterplants; and study of the uptake and translocation of heavy element in plants. Special attention was paid to mathematical techniques for a reliable interpretation of the element concentration patterns observed in sets of lichen samples. Future developments in INAA in environmental science are briefly mentioned

  11. Kinetic analysis of single molecule FRET transitions without trajectories

    Science.gov (United States)

    Schrangl, Lukas; Göhring, Janett; Schütz, Gerhard J.

    2018-03-01

    Single molecule Förster resonance energy transfer (smFRET) is a popular tool to study biological systems that undergo topological transitions on the nanometer scale. smFRET experiments typically require recording of long smFRET trajectories and subsequent statistical analysis to extract parameters such as the states' lifetimes. Alternatively, analysis of probability distributions exploits the shapes of smFRET distributions at well chosen exposure times and hence works without the acquisition of time traces. Here, we describe a variant that utilizes statistical tests to compare experimental datasets with Monte Carlo simulations. For a given model, parameters are varied to cover the full realistic parameter space. As output, the method yields p-values which quantify the likelihood for each parameter setting to be consistent with the experimental data. The method provides suitable results even if the actual lifetimes differ by an order of magnitude. We also demonstrated the robustness of the method to inaccurately determine input parameters. As proof of concept, the new method was applied to the determination of transition rate constants for Holliday junctions.

  12. In situ reaction kinetic analysis of dental restorative materials

    Science.gov (United States)

    Younas, Basma; Samad Khan, Abdul; Muzaffar, Danish; Hussain, Ijaz; Chaudhry, Aqif Anwar; Rehman, Ihtesham Ur

    2013-12-01

    The objective of this study was to evaluate in situ structural and thermal changes of dental restorative materials at periodical time intervals. The commercial materials included zinc oxide eugenol (ZOE), zinc phosphate type I (ZnPO4), glass ionomer cement type II (GIC) and resin-based nano-omposite (Filtek Z350 XT). These materials were processed according to manufacturer's instructions. For the structural analysis Fourier transform infrared spectroscopy (FTIR) was used at high resolution. TGA was used to evaluate thermal weight-loss. The FTIR spectra were collected at periodic time intervals. FTIR spectra showed that with time passing all materials exhibited an increase in peak intensities and a new appearance of shoulders and shifting of peaks for example, ZnPO4 (P-O), ZOE (C═O, C═N, C-O-C), GIC (COO-, C-H, Si-OH), composites (C═O, C═C, C═N, C-N-H). The peaks were replaced by bands and these bands became broader with time interval. Composites showed a degree of conversion and new peaks corresponded to the cross-linking of polymer composites. TGA analysis showed that significant changes in weight loss of set materials were observed after 24 h, where ZOE showed continuous changes in thermal degradation. The spectral changes and thermal degradation with time interval elucidated in situ setting behaviour and understanding of their bonding compatibility with tooth structure and change in relation to time.

  13. Second-generation method for analysis of chromatin binding with formaldehyde-cross-linking kinetics.

    Science.gov (United States)

    Zaidi, Hussain; Hoffman, Elizabeth A; Shetty, Savera J; Bekiranov, Stefan; Auble, David T

    2017-11-24

    Formaldehyde-cross-linking underpins many of the most commonly used experimental approaches in the chromatin field, especially in capturing site-specific protein-DNA interactions. Extending such assays to assess the stability and binding kinetics of protein-DNA interactions is more challenging, requiring absolute measurements with a relatively high degree of physical precision. We previously described an experimental framework called the cross-linking kinetics (CLK) assay, which uses time-dependent formaldehyde-cross-linking data to extract kinetic parameters of chromatin binding. Many aspects of formaldehyde behavior in cells are unknown or undocumented, however, and could potentially affect CLK data analyses. Here, we report biochemical results that better define the properties of formaldehyde-cross-linking in budding yeast cells. These results have the potential to inform interpretations of "standard" chromatin assays, including chromatin immunoprecipitation. Moreover, the chemical complexity we uncovered resulted in the development of an improved method for measuring binding kinetics with the CLK approach. Optimum conditions included an increased formaldehyde concentration and more robust glycine-quench conditions. Notably, we observed that formaldehyde-cross-linking rates can vary dramatically for different protein-DNA interactions in vivo Some interactions were cross-linked much faster than the in vivo macromolecular interactions, making them suitable for kinetic analysis. For other interactions, we found the cross-linking reaction occurred on the same time scale or slower than binding dynamics; for these interactions, it was sometimes possible to compute the in vivo equilibrium-binding constant but not binding on- and off-rates. This improved method yields more accurate in vivo binding kinetics estimates on the minute time scale. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Sensitivity analysis in oxidation ditch modelling: the effect of variations in stoichiometric, kinetic and operating parameters on the performance indices

    NARCIS (Netherlands)

    Abusam, A.A.A.; Keesman, K.J.; Straten, van G.; Spanjers, H.; Meinema, K.

    2001-01-01

    This paper demonstrates the application of the factorial sensitivity analysis methodology in studying the influence of variations in stoichiometric, kinetic and operating parameters on the performance indices of an oxidation ditch simulation model (benchmark). Factorial sensitivity analysis

  15. 10 CFR 503.13 - Environmental impact analysis.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Environmental impact analysis. 503.13 Section 503.13... Exemptions § 503.13 Environmental impact analysis. In order to enable OFE to comply with NEPA, a petitioner..., and land resources; (3) Direct and indirect environmental impacts of the proposed action including...

  16. Integrating health and environmental impact analysis.

    Science.gov (United States)

    Reis, S; Morris, G; Fleming, L E; Beck, S; Taylor, T; White, M; Depledge, M H; Steinle, S; Sabel, C E; Cowie, H; Hurley, F; Dick, J McP; Smith, R I; Austen, M

    2015-10-01

    Scientific investigations have progressively refined our understanding of the influence of the environment on human health, and the many adverse impacts that human activities exert on the environment, from the local to the planetary level. Nonetheless, throughout the modern public health era, health has been pursued as though our lives and lifestyles are disconnected from ecosystems and their component organisms. The inadequacy of the societal and public health response to obesity, health inequities, and especially global environmental and climate change now calls for an ecological approach which addresses human activity in all its social, economic and cultural complexity. The new approach must be integral to, and interactive, with the natural environment. We see the continuing failure to truly integrate human health and environmental impact analysis as deeply damaging, and we propose a new conceptual model, the ecosystems-enriched Drivers, Pressures, State, Exposure, Effects, Actions or 'eDPSEEA' model, to address this shortcoming. The model recognizes convergence between the concept of ecosystems services which provides a human health and well-being slant to the value of ecosystems while equally emphasizing the health of the environment, and the growing calls for 'ecological public health' as a response to global environmental concerns now suffusing the discourse in public health. More revolution than evolution, ecological public health will demand new perspectives regarding the interconnections among society, the economy, the environment and our health and well-being. Success must be built on collaborations between the disparate scientific communities of the environmental sciences and public health as well as interactions with social scientists, economists and the legal profession. It will require outreach to political and other stakeholders including a currently largely disengaged general public. The need for an effective and robust science-policy interface has

  17. Advancing the diagnostic analysis of environmental problems

    Directory of Open Access Journals (Sweden)

    Michael Cox

    2011-09-01

    Full Text Available Social-ecological systems exhibit patterns across multiple levels along spatial, temporal, and functional scales. The outcomes that are produced in these systems result from complex, non-additive interactions between different types of social and biophysical components, some of which are common to many systems, and some of which are relatively unique to a particular system. These properties, along with the mostly non-experimental nature of the analysis, make it difficult to construct theories regarding the sustainability of social-ecological systems. This paper builds on previous work that has initiated a diagnostic approach to the analysis of these systems. The process of diagnosis involves asking a series of questions of a system at increasing levels of specificity based on the answers to previous questions. The answer to each question further unpacks the complexity of a system, allowing an analyst to explore patterns of interactions that produce outcomes. An important feature of this approach is the use of multilevel analysis. This paper explores this concept and introduces another – multilevel causation – to further develop the diagnostic approach. It demonstrates that these concepts can be used to analyze a diversity of environmental problems.

  18. Kinetic analysis of human homogentisate 1,2-dioxygenase.

    Science.gov (United States)

    Amaya, Alphonso A; Brzezinski, Kotanee T; Farrington, Natasha; Moran, Graham R

    2004-01-01

    Homogentisate 1,2-dioxygenase (HGD) is a mononuclear Fe(II)-dependent oxygenase that catalyzes the third step in the pathway for the catabolism of tyrosine, the conversion of homogentisate (HG) to maleylacetoacetate (MAA). We have heterologously expressed and purified native human HGD in the apo form. Steady-state analysis varying the concentration of both HG and molecular oxygen shows that the purified enzyme has a turnover number of 16 s(-1). Our data suggest that HG binds to the apo-enzyme and that the apo-HGD.HG complex does not bind Fe(II) and dissociates slowly at approximately 0.028 s(-1). The rate constant for the dissociation of Fe(II) from the holo-enzyme as measured under anaerobic conditions is 0.00004 s(-1) and indicates that this process is not relevant in steady-state turnover. The addition of HG and molecular oxygen to the holo-enzyme is formally random as the holo-enzyme reduces molecular oxygen at a rate of 1.35x10(3) M(-1) s(-1) at 4 degrees C. The term ordered with respect to the addition of substrates is most descriptive as the rate of reduction of molecular oxygen must increase in the presence of HG to sustain the observed turnover number.

  19. Full mode and attribution mode in environmental analysis

    NARCIS (Netherlands)

    De Udo Haes, Helias A.; Heijungs, Reinout; Huppes, Gjalt; Van Der Voet, Ester; Hettelingh, Jean Paul

    2000-01-01

    Several tools exist for the analysis of the environmental impacts of chains or networks of processes. These relatively simple tools include materials flow accounting (MFA), substance flow analysis (SFA), life-cycle assessment (LCA), energy analysis, and environmentally extended input-output analysis

  20. Measures of the zero power nuclear reactor's kinetic parameters with application of noise analysis

    International Nuclear Information System (INIS)

    Martins, F.R.

    1992-01-01

    The purpose of this work was to establish an experimental technique based on noise analysis for measuring the ratio of kinetic parameters β/ Λ and the power of the Zero Power Nuclear Reactor IPEN-MB 01. A through study of the microscopic and macroscopic noise analysis techniques has been carried out. The Langevin technique and the point kinetic model were chosen to describe the stochastic phenomena that occur in the zero power reactor. Measurements have been made using two compensated ionization chambers localized in the water reflector at symmetric positions in order to minimize spatial effects on the neutron flux fluctuation. Power calibrations based on the low frequency plateau of the cross-power spectral density has also been carried out. (author)

  1. Nuclear spectrometry for environmental analysis and mapping

    International Nuclear Information System (INIS)

    Simon, Aliz

    2013-01-01

    visits, and provision of equipment. This talk gives an overview of the lAEA Physics Section activities with a special emphasis on the following activities: 1)Improving the analytical performance of PIXE and other IBA techniques; 2)Networking for environmental analysis; 3)Radioisotope environmental mapping; 4)Future perspectives for new IBA methods, especially Heavy lon PIXE combined with MeVSIMS. (author)

  2. Environmental Technology (Laboratory Analysis and Environmental Sampling) Curriculum Development Project. Final Report.

    Science.gov (United States)

    Hinojosa, Oscar V.; Guillen, Alfonso

    A project assessed the need and developed a curriculum for environmental technology (laboratory analysis and environmental sampling) in the emerging high technology centered around environmental safety and health in Texas. Initial data were collected through interviews by telephone and in person and through onsite visits. Additional data was…

  3. Thermal behavior and kinetics assessment of ethanol/gasoline blends during combustion by thermogravimetric analysis

    International Nuclear Information System (INIS)

    3, CEP 12.516-410 Guaratinguetá, SP (Brazil); U.T.P. – Universidad Tecnológica de Pereira, Faculty of Mechanical Engineering, Pereira, Risaralda (Colombia))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil); U.T.P. – Universidad Tecnológica de Pereira, Faculty of Mechanical Engineering, Pereira, Risaralda (Colombia))" >Rios Quiroga, Luis Carlos; 3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" >Balestieri, José 3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" >Antonio Perrella; 3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" data-affiliation=" (UNESP – Univ Estadual Paulista, Campus of Guaratinguetá, Department of Energy, Laboratory of Combustion and Carbon Capture LC3, CEP 12.516-410 Guaratinguetá, SP (Brazil))" >Ávila, Ivonete

    2017-01-01

    Highlights: • Kinetic parameters of thermal decomposition events were obtained. • Thermal analysis was used as a tool for understanding combustion processes. • Blends would be classified using thermogravimetric analysis technics. • Synergistic effect of ethanol mixed with gasoline was studied and defined. • Relative error and activation energy values were used to analyze the synergy. - Abstract: The use of ethanol as a fuel or as an additive blended with gasoline is very important for most countries, which aim to reduce the heavy dependence on fossil fuels and mitigate greenhouse gases emission. An increased use of ethanol-gasoline blends has placed great relevance on acquiring knowledge about their physical and chemical properties. Thus, knowledge of such properties favors a better understanding of the effect of the percentage of ethanol/gasoline blends on engine performance. Thence, the present study has established a correlation between activation energy and synergetic effects, obtained by a thermal analysis, and ethanol content in gasoline for different blends in order to use this technique as a tool to classify these blends in the process in order to obtain useful energy in spark ignition engines. For such a purpose, a kinetic study has been conducted through a simultaneous thermal analysis system – TGA (thermogravimetry analysis) and DTA (differential thermal analysis) by following the methodology of non-isothermal tests. Thermogravimetric tests were performed and fuel activation energies for gasoline, ethanol, and percentages of 5, 10, 15, 20, 25, 30, 50, and 75% (%v) ethanol mixed with gasoline, which was achieved by the model free kinetics. The analysis results suggest that the theoretical curves characteristics of the thermal decomposition of ethanol-gasoline blends are rather different due to their ethanol content. Furthermore, it was observed significant interactions and synergistic effects, especially regarding those with low ethanol

  4. Kinetic and thermodynamic analysis of Creosote degradation process under isothermal experimental conditions.

    Science.gov (United States)

    Janković, Bojan Ž; Janković, Marija M

    2013-01-01

    Isothermal degradation process of commercial Creosote was analyzed by the thermogravimetric (TG) technique in a nitrogen atmosphere, at four different operating temperatures (230, 250, 270 and 290°C). The kinetic triplet [Ea , A and f(α)] and the thermodynamic parameters (ΔH (≠), ΔS (≠)and ΔG (≠)) for investigated Creosote samples were calculated. It was found that two-parameter autocatalytic Šesták-Berggren (SB) kinetic model best describes the process, but in the form of accommodation function with phenomenological character. Applying the multiplicative factor, the true value of activation energy (E (true) a ) was calculated. The experimental density distribution function of the apparent activation energy values was evaluated from isoconversional kinetic analysis. Based of the characteristic shape of distribution curve, it was concluded that the isothermal degradation of Creosote represents a complex physico-chemical process, given the chemical structure of the studied system. It is assumed that the considered process probably includes primary and secondary (autocatalytic) pyrolysis reactions, together with various decomposition reactions and radicals recombination pathways. The objective of the presented work is the proof of principle of the pyrolysis-based thermo-chemical conversion technologies for the production of value-added chemicals from the complex organic compounds, which even include chemical contaminants (such as PAHs). Also, the present work allows us that by using a unified kinetic approach we can obtain a significant physico-chemical characteristics of the tested system, which can then be used in the procedure for the separation of organics from creosote-treated woods and creosote-contaminated soils. The significance of this research is to identify the global kinetic behavior of some target contaminant compounds for pyrolysis, which are primarily PAHs.

  5. Bioclim Deliverable D1: environmental change analysis

    International Nuclear Information System (INIS)

    2001-01-01

    The BIOCLIM project on modelling sequential Biosphere systems under Climate change for radioactive waste disposal is part of the EURATOM fifth European framework programme. The project was launched in October 2000 for a three-year period. The project aims at providing a scientific basis and practical methodology for assessing the possible long term impacts on the safety of radioactive waste repositories in deep formations due to climate and environmental change. The project brings together a number of representatives from both European radioactive waste management organisations which have national responsibilities for the safe disposal of radioactive waste, either as disposers or regulators, and several highly experienced climate research teams. In particular, BIOCLIM aims to address the important objective of how to represent the development of future biosphere systems by addressing both how to model long-term climate change, the relevant environmental consequences of such changes and the implementation of a sequential approach to such changes. The results from the development of this sophisticated approach will be of great benefit for improving long term radiological impact calculations and the information presented in a safety case. Simulations will be conducted to represent the time series of long-term climate in three European areas within which disposal sites may be established (i.e. Central/Southern Spain, Northeast of France and Central Britain). Two complementary strategies will provide representations of future climate predictions together with associated vegetation patterns using either an analysis of distinct climate states or a continuous climate simulation over at least one glacial-interglacial cycle and possibly for other selected periods over the next 1,000,000 years. These results will be used to derive the characteristics of possible future human environments (i.e. biosphere systems) through which radionuclides, emerging from the repository, may

  6. Selected industrial and environmental applications of neutron activation analysis

    International Nuclear Information System (INIS)

    Kucera, J.

    1999-01-01

    A review of the applications of Instrumental Neutron Activation Analysis (INAA) in the industrial and environmental fields is given. Detection limits for different applications are also given. (author)

  7. 32 CFR 651.10 - Actions requiring environmental analysis.

    Science.gov (United States)

    2010-07-01

    ...) ENVIRONMENTAL QUALITY ENVIRONMENTAL ANALYSIS OF ARMY ACTIONS (AR 200-2) National Environmental Policy Act and..., renewal, or amendment), in accordance with AR 95-50. (f) Materiel development, operation and support... engineering, laser testing, and electromagnetic pulse generation. (i) Leases, easements, permits, licenses, or...

  8. 15 CFR 971.204 - Environmental and use conflict analysis.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Environmental and use conflict... Applications Contents § 971.204 Environmental and use conflict analysis. (a) Environmental information... parameters listed in NOAA's Technical Guidance Document pertaining to the upper and lower water column should...

  9. Validity of the Nintendo Wii Balance Board for Kinetic Gait Analysis

    Directory of Open Access Journals (Sweden)

    Ryo Eguchi

    2018-02-01

    Full Text Available The Nintendo Wii Balance Board (WBB has been suggested as an inexpensive, portable and accessible alternative to costly laboratory-grade force plates for measuring the vertical ground reaction force (vGRF and center of pressure (COP. Kinetic gait analysis provides important information for the rehabilitation of patients with gait disorders; however, the validity of the WBB for measuring kinetic gait parameters has not been evaluated. Therefore, the purpose of this study is to determine the accuracy of walking force measurements—which change dynamically in a short period of stance time—collected with the WBB. Three healthy adults were asked to walk 10 steps along both straight and curved paths in clockwise (CW and counterclockwise (CCW directions while measurements were taken using the WBB and the force plate. The accuracy of the vGRF, COP trajectory, and stance duration were evaluated using the root-mean-square error (RMSE, Pearson’s correlation coefficient and Bland–Altman plots (BAPs to compare the WBB and the force plate. The results of the vGRF showed high accuracy (r > 0.96 and %RMSE < 6.1% in the mean values, and the stance duration as defined by the vGRF and COP trajectory was equivalent to that of commercial instrumented insoles, which are used as an alternative to the force plates. From these results, we determined that the WBB may be used for kinetic gait analysis in clinical settings where lower accuracy is acceptable.

  10. Pyrolysis and combustion kinetics of sludge–camphor pellet thermal decomposition using thermogravimetric analysis

    International Nuclear Information System (INIS)

    Jiang, Longbo; Yuan, Xingzhong; Li, Hui; Xiao, Zhihua; Liang, Jie; Wang, Hou; Wu, Zhibin; Chen, Xiaohong; Zeng, Guangming

    2015-01-01

    Highlights: • First attempt on pyrolysis/combustion kinetics of densified sludge–camphor pellet. • E a value for the sludge–camphor pellet was lower than the single pellet (SP, CP). • Enhanced thermal degradation takes place in air as oxygen acceleration effect. • E a is highly depended on conversion indicating a complex multi-step mechanism. • Some synergistic effects happen between sludge and camphor during pyrolysis. - Abstract: The pyrolysis and combustion characteristics of sludge pellet (SP), camphor pellet (CP) and sludge–camphor pellet (SCP, 50% sludge ratio) were studied via thermogravimetric analysis. The samples were heated from ambient temperature to 1073 K at various heating rate (5, 10, 20, 40 K/min) in nitrogen and air atmosphere. Heating rate had a substantial effect on mass loss and mass loss rate in both pyrolyzing and oxidizing conditions. The thermal behavior of SCP was the integration of SP and CP. Onset and offset temperatures of SCP lay between that of CP and SP in various heating rate. The kinetic parameters of the process were evaluated using two iso-conversional models (Flynn–Wall–Ozawa and Starink). Kinetic analysis results showed that activation energy was highly depended on conversion which indicated the existence of a complex multi-step mechanism. E α value for the sludge–camphor pellet (SCP) was lower than the single pellet (SP and CP). Some synergistic effects happened between sludge and camphor during pyrolysis.

  11. Coupled fully 3D neutron kinetics thermal-hydraulic computations for DNB analysis on PWRs

    International Nuclear Information System (INIS)

    Pitot, Samuel; Alborghetti, Nicolas

    2007-01-01

    Departure from Nucleate Boiling (DNB) is one of the major limiting factors of Pressurized Water Reactors (PWRs). Safety requires that occurrence of DNB should be precluded under normal or incidental operating conditions. To perform Main Steam Line Break (MSLB) accident calculations EDF have developed its own numerical tool OSCARD based on: the thermal-hydraulic THYC code for DNB analysis, the neutron kinetics COCCINELLE code for power distribution computations, the thermal-hydraulic CATHARE code to provide boundary conditions analysis with system scale computation. With OSCARD a fully three-dimensional (3D) representation of the core is proposed in conjunction with a two-phase flow porous-body approach (THYC) and two-group diffusion equations in the axial and lateral directions with Doppler and void reactivity feedback effects (COCCINELLE). OSCARD provides EDF with an alternative and independent way of evaluating fuel performance and safety margins. In the licensed approach, the coupled 3D neutron kinetics and thermal-hydraulic part of OSCARD steady computations is used to produce 3D power distribution in the reactor core at the most penalizing moment of the transient. Then this distribution is used as an input for THYC to perform thermal-hydraulic subchannel analysis. This 3 steps approach is used with simple conservative and bounding analysis assumptions, that can not occur in reality. In a prospective approach, OSCARD enables to combine thermal-hydraulic subchannel analysis with the neutron kinetics radial average channel model using a nodalization of one quarter of fuel assembly in order to perform one step DNB analysis. (author)

  12. Color changes in wood during heating: kinetic analysis by applying a time-temperature superposition method

    Science.gov (United States)

    Matsuo, Miyuki; Yokoyama, Misao; Umemura, Kenji; Gril, Joseph; Yano, Ken'ichiro; Kawai, Shuichi

    2010-04-01

    This paper deals with the kinetics of the color properties of hinoki ( Chamaecyparis obtusa Endl.) wood. Specimens cut from the wood were heated at 90-180°C as accelerated aging treatment. The specimens completely dried and heated in the presence of oxygen allowed us to evaluate the effects of thermal oxidation on wood color change. Color properties measured by a spectrophotometer showed similar behavior irrespective of the treatment temperature with each time scale. Kinetic analysis using the time-temperature superposition principle, which uses the whole data set, was successfully applied to the color changes. The calculated values of the apparent activation energy in terms of L *, a *, b *, and Δ E^{*}_{ab} were 117, 95, 114, and 113 kJ/mol, respectively, which are similar to the values of the literature obtained for other properties such as the physical and mechanical properties of wood.

  13. A Numerical Procedure for Model Identifiability Analysis Applied to Enzyme Kinetics

    DEFF Research Database (Denmark)

    Daele, Timothy, Van; Van Hoey, Stijn; Gernaey, Krist

    2015-01-01

    The proper calibration of models describing enzyme kinetics can be quite challenging. In the literature, different procedures are available to calibrate these enzymatic models in an efficient way. However, in most cases the model structure is already decided on prior to the actual calibration...... and Pronzato (1997) and which can be easily set up for any type of model. In this paper the proposed approach is applied to the forward reaction rate of the enzyme kinetics proposed by Shin and Kim(1998). Structural identifiability analysis showed that no local structural model problems were occurring......) identifiability problems. By using the presented approach it is possible to detect potential identifiability problems and avoid pointless calibration (and experimental!) effort....

  14. Analysis for the Sorption Kinetics of Ag Nanoparticles on Natural Clinoptilolite

    Directory of Open Access Journals (Sweden)

    Alvaro Ruíz-Baltazar

    2015-01-01

    Full Text Available The kinetic adsorption behavior of silver nanoparticles deposited on a natural zeolite from Oaxaca is presented. Theoretical models as Lagergren first-order, pseudo-second-order, Elovich, and intraparticle diffusion were employed and compared with experimental data obtained by atomic absorption spectrophotometry technique. Correlation factors R2 of the order of 0.99 were observed. Analysis by transmission electron microscopy revealed that the silver nanoparticles were homogeneously distributed on the zeolite. Additionally, chemical characterization of the material was carried out through a dilution process with lithium metaborate. An average value of 9.3 in the Si/Al ratio was observed and related to the kinetic adsorption behavior of the zeolite.

  15. Non-isothermal kinetic characterisation of a gas–solid reaction by TG analysis

    Directory of Open Access Journals (Sweden)

    ZELJKO CUPIC

    2005-11-01

    Full Text Available A series of silica-supported Ni-catalyst precursors was synthesized, with different SiO2/Nimole ratios between 0.2 and 1.15. The reduction of all the prepared samples was studied by thermogravimetry (TG in a hydrogen flow. The results of the TG analysis were analyzed by the multi-thermal history model-fitting method, with non-linear regression. The activation energies for the reduction of each sample were determined. The statistical F-test was performed to discriminate between various models. It was found that increasing the SiO2/Ni mole ratio leads to a change in the reaction mechanism of the nickel reduction, resulting finally in a change from second order reaction kinetics to three halves order reaction kinetics.

  16. A Lexical Analysis of Environmental Sound Categories

    Science.gov (United States)

    Houix, Olivier; Lemaitre, Guillaume; Misdariis, Nicolas; Susini, Patrick; Urdapilleta, Isabel

    2012-01-01

    In this article we report on listener categorization of meaningful environmental sounds. A starting point for this study was the phenomenological taxonomy proposed by Gaver (1993b). In the first experimental study, 15 participants classified 60 environmental sounds and indicated the properties shared by the sounds in each class. In a second…

  17. Database-Centric Method for Automated High-Throughput Deconvolution and Analysis of Kinetic Antibody Screening Data.

    Science.gov (United States)

    Nobrega, R Paul; Brown, Michael; Williams, Cody; Sumner, Chris; Estep, Patricia; Caffry, Isabelle; Yu, Yao; Lynaugh, Heather; Burnina, Irina; Lilov, Asparouh; Desroches, Jordan; Bukowski, John; Sun, Tingwan; Belk, Jonathan P; Johnson, Kirt; Xu, Yingda

    2017-10-01

    The state-of-the-art industrial drug discovery approach is the empirical interrogation of a library of drug candidates against a target molecule. The advantage of high-throughput kinetic measurements over equilibrium assessments is the ability to measure each of the kinetic components of binding affinity. Although high-throughput capabilities have improved with advances in instrument hardware, three bottlenecks in data processing remain: (1) intrinsic molecular properties that lead to poor biophysical quality in vitro are not accounted for in commercially available analysis models, (2) processing data through a user interface is time-consuming and not amenable to parallelized data collection, and (3) a commercial solution that includes historical kinetic data in the analysis of kinetic competition data does not exist. Herein, we describe a generally applicable method for the automated analysis, storage, and retrieval of kinetic binding data. This analysis can deconvolve poor quality data on-the-fly and store and organize historical data in a queryable format for use in future analyses. Such database-centric strategies afford greater insight into the molecular mechanisms of kinetic competition, allowing for the rapid identification of allosteric effectors and the presentation of kinetic competition data in absolute terms of percent bound to antigen on the biosensor.

  18. Environmental analysis of biomass-ethanol facilities

    Energy Technology Data Exchange (ETDEWEB)

    Corbus, D.; Putsche, V.

    1995-12-01

    This report analyzes the environmental regulatory requirements for several process configurations of a biomass-to-ethanol facility. It also evaluates the impact of two feedstocks (municipal solid waste [MSW] and agricultural residues) and three facility sizes (1000, 2000, and 3000 dry tons per day [dtpd]) on the environmental requirements. The basic biomass ethanol process has five major steps: (1) Milling, (2) Pretreatment, (3) Cofermentation, (4) Enzyme production, (5) Product recovery. Each step could have environmental impacts and thus be subject to regulation. Facilities that process 2000 dtpd of MSW or agricultural residues would produce 69 and 79 million gallons of ethanol, respectively.

  19. Environmental Impact Analysis Process Chemical Release Experiment

    National Research Council Canada - National Science Library

    1999-01-01

    The U.S. Air Force proposes to conduct an experiment to identify the potential environmental consequences of an inadvertent release of hydrazine rocket propellant in space, during orbital or suborbital operations...

  20. Applied research of environmental monitoring using instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Young Sam; Moon, Jong Hwa; Chung, Young Ju

    1997-08-01

    This technical report is written as a guide book for applied research of environmental monitoring using Instrumental Neutron Activation Analysis. The contents are as followings; sampling and sample preparation as a airborne particulate matter, analytical methodologies, data evaluation and interpretation, basic statistical methods of data analysis applied in environmental pollution studies. (author). 23 refs., 7 tabs., 9 figs.

  1. Sustainable Process Design under uncertainty analysis: targeting environmental indicators

    DEFF Research Database (Denmark)

    L. Gargalo, Carina; Gani, Rafiqul

    2015-01-01

    This study focuses on uncertainty analysis of environmental indicators used to support sustainable process design efforts. To this end, the Life Cycle Assessment methodology is extended with a comprehensive uncertainty analysis to propagate the uncertainties in input LCA data to the environmental...

  2. Regional environmental analysis and management: New techniques for current problems

    Science.gov (United States)

    Honea, R. B.; Paludan, C. T. N.

    1974-01-01

    Advances in data acquisition and processing procedures for regional environmental analysis are discussed. Automated and semi-automated techniques employing Earth Resources Technology Satellite data and conventional data sources are presented. Experiences are summarized. The ERTS computer compatible tapes provide a very complete and flexible record of earth resources data and represent a viable medium to enhance regional environmental analysis research.

  3. California geothermal resource development environmental implications for ERCDC Environmental Analysis Office. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, J.A.

    1977-02-01

    The results of an analysis of the environmental implications for ERCDC Environmental Analysis Office (EAO) in relation to the development of California's geothermal resources are reported. While focusing primarily on environmental implications, particularly the natural, social, and economic elements, the report includes some ERCDC-wide policy and program considerations. The primary thrusts of the work have been in the development of an understanding of the interagency and intergovernmental environmental data and data-management roles and responsibilities and in the formulation of recommendations related thereto. Five appendices are included, one of which is a tax credit agreement between a power company and Skagit County, Washington. (JGB)

  4. Selected environmental applications of neutron activation analysis

    International Nuclear Information System (INIS)

    Kucera, J.

    2001-01-01

    NAA is very useful for the determination of trace and minor elements in many environmental applications. While instrumental NAA (INAA) has a number of valid applications in this field, radiochemical NAA (RNAA) prior to, or post irradiation provides some significant advantages. One of the major focus points for environmental applications of NAA is to assess the magnitude of various pollutants. This paper discusses doing this via two methods, namely air monitoring and biological monitoring. (author)

  5. Curing kinetics of visible light curing dental resin composites investigated by dielectric analysis (DEA).

    Science.gov (United States)

    Steinhaus, Johannes; Hausnerova, Berenika; Haenel, Thomas; Großgarten, Mandy; Möginger, Bernhard

    2014-03-01

    During the curing process of light curing dental composites the mobility of molecules and molecule segments is reduced leading to a significant increase of the viscosity as well as the ion viscosity. Thus, the kinetics of the curing behavior of 6 different composites was derived from dielectric analysis (DEA) using especially redesigned flat sensors with interdigit comb electrodes allowing for irradiation at the top side and measuring the ion viscosity at the bottom side. As the ion viscosities of dental composites change 1-3 orders of magnitude during the curing process, DEA provides a sensitive approach to evaluate their curing behavior, especially in the phase of undisturbed chain growth. In order to determine quantitative kinetic parameters a kinetic model is presented and examined for the evaluation of the ion viscosity curves. From the obtained results it is seen that DEA might be employed in the investigation of the primary curing process, the quality assurance of ingredients as well as the control of processing stability of the light curing dental composites. Copyright © 2014 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Analysis of a kinetic multi-segment foot model. Part I: Model repeatability and kinematic validity.

    Science.gov (United States)

    Bruening, Dustin A; Cooney, Kevin M; Buczek, Frank L

    2012-04-01

    Kinematic multi-segment foot models are still evolving, but have seen increased use in clinical and research settings. The addition of kinetics may increase knowledge of foot and ankle function as well as influence multi-segment foot model evolution; however, previous kinetic models are too complex for clinical use. In this study we present a three-segment kinetic foot model and thorough evaluation of model performance during normal gait. In this first of two companion papers, model reference frames and joint centers are analyzed for repeatability, joint translations are measured, segment rigidity characterized, and sample joint angles presented. Within-tester and between-tester repeatability were first assessed using 10 healthy pediatric participants, while kinematic parameters were subsequently measured on 17 additional healthy pediatric participants. Repeatability errors were generally low for all sagittal plane measures as well as transverse plane Hindfoot and Forefoot segments (medianplane and Hallux transverse plane. Joint translations were generally less than 2mm in any one direction, while segment rigidity analysis suggested rigid body behavior for the Shank and Hindfoot, with the Forefoot violating the rigid body assumptions in terminal stance/pre-swing. Joint excursions were consistent with previously published studies. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Architectural analysis, viability assessment and growth kinetics of Candida albicans and Candida glabrata biofilms.

    Science.gov (United States)

    Seneviratne, C J; Silva, W J; Jin, L J; Samaranayake, Y H; Samaranayake, L P

    2009-11-01

    The human fungal pathogen Candida is able to form biofilms in almost all the medical devices in current use. Indeed, biofilm formation is a major virulence attribute of microorganisms and account for a majority of human infections. Therefore, understanding processes appertaining to biofilm development is an important prerequisite for devising new strategies to prevent or eradicate biofilm-related infections. In the present study we used an array of both conventional and novel analytical tools to obtain a comprehensive view of Candida biofilm development. Enumeration of colony forming units, colorimetric (XTT) assay, Scanning Electron Microscopy (SEM) and novel Confocal Laser Scanning Microscopy (CLSM) coupled with COMSTAT software analyses were utilised to evaluate growth kinetics; architecture and viability of biofilms of a reference (ATCC) and a clinical strain each of two Candida species, C. albicans and C. glabrata. Biofilm growth kinetics on a polystyrene substrate was evaluated from the initial adhesion step (1.5 h) up to 72 h. These analyses revealed substantial inter- and intra-species differences in temporal organisation of Candida biofilm architecture, spatiality and cellular viability, while reaching maturity within a period of 48 h, on a polystyrene substrate. There were substantial differences in the growth kinetics upon methodology, although general trend seemed to be the same. Detailed architectural analysis provided by COMSTAT software corroborated the SEM and CSLM views. These analyses may provide a strong foundation for down stream molecular work of fungal biofilms.

  8. Kinetic Analysis of the Anodic Carbon Oxidation Mechanism in a Molten Carbonate Medium

    International Nuclear Information System (INIS)

    Allen, Jessica A.; Tulloch, John; Wibberley, Louis; Donne, Scott W.

    2014-01-01

    The oxidation mechanism for carbon in a carbonate melt was modelled using an electrochemical kinetic approach. Through the Butler-Volmer equation for electrode kinetics, a series of expressions was derived assuming each step of the proposed carbon oxidation mechanism is in turn the rate determining step (RDS). Through the derived expressions the transfer coefficient and Tafel slope were calculated for each possible RDS of the proposed mechanism and these were compared with real data collected on carbon based electrodes including graphite and coal. It was established that the RDS of the electrochemical oxidation process is dependent on both the carbon type and the potential region of oxidation. The simplified kinetic analysis suggested that the RDS in the main oxidation region is likely to be the first or second electron transfer on a graphite electrode surface, which occurs following initial adsorption of an oxygen anion to an active carbon site. This is contrary to previous suggestions that adsorption of the second anion to the carbon surface will be rate determining. It was further shown that use of a coal based carbon introduces a change in mechanism with an additional reaction region where a different mechanism is proposed to be operating

  9. Two-dimensional kinetic analysis suggests nonsequential gating of mechanosensitive channels in Xenopus oocytes.

    Science.gov (United States)

    Gil, Z; Magleby, K L; Silberberg, S D

    2001-10-01

    Xenopus oocytes express mechanosensitive (MS(XO)) channels that can be studied in excised patches of membrane with the patch-clamp technique. This study examines the steady-state kinetic gating properties of MS(XO) channels using detailed single-channel analysis. The open and closed one-dimensional dwell-time distributions were described by the sums of 2-3 open and 5-7 closed exponential components, respectively, indicating that the channels enter at least 2-3 open and 5-7 closed kinetic states during gating. Dependency plots revealed that the durations of adjacent open and closed intervals were correlated, indicating two or more gateway states in the gating mechanism for MS channels. Maximum likelihood fitting of two-dimensional dwell-time distributions to both generic and specific models was used to examine gating mechanism and rank models. A kinetic scheme with five closed and five open states, in which each closed state could make a direct transition to an open state (two-tiered model) could account for the major features of the single-channel data. Two-tiered models that allowed direct transitions to subconductance open states in addition to the fully open state were also consistent with multiple gateway states. Thus, the gating mechanism of MS(XO) channels differs from the sequential (linear) gating mechanisms considered for MS channels in bacteria, chick skeletal muscle, and Necturus proximal tubule.

  10. Kinetic analysis of volatile formation in milk subjected to pressure-assisted thermal treatments.

    Science.gov (United States)

    Vazquez-Landaverde, P A; Qian, M C; Torres, J A

    2007-09-01

    Volatile formation in milk subjected to pressure-assisted thermal processing (PATP) was investigated from a reaction kinetic analysis point of view to illustrate the advantages of this technology. The concentration of 27 volatiles of different chemical class in milk subjected to pressure, temperature, and time treatments was fitted to zero-, 1st-, and 2nd-order chemical reaction models. Temperature and pressure effects on rate constants were analyzed to obtain activation energy (E(a)) and activation volume (deltaV*) values. Hexanal, heptanal, octanal, nonanal, and decanal followed 1st-order kinetics with rate constants characterized by E(a) values decreasing with pressure reflecting negative deltaV* values. Formation of 2-methylpropanal, 2,3-butanedione, and hydrogen sulfide followed zero-order kinetics with rate constants increasing with temperature but with unclear pressure effects. E(a) values for 2-methylpropanal and 2,3-butanedione increased with pressure, that is, deltaV* > 0, whereas values for hydrogen sulfide remained constant, that is, deltaV* = 0. The concentration of all other volatiles, including methanethiol, remained unchanged in pressure-treated samples, suggesting large negative deltaV* values. The concentration of methyl ketones, including 2-pentanone, 2-hexanone, 2-heptanone, 2-octanone, 2-nonanone, 2-decanone, and 2-undecanone, was independent of pressure and pressure-holding time. PATP promoted the formation of few compounds, had no effect on some, and inhibited the formation of volatiles reported to be factors of the consumer rejection of "cooked" milk flavor. The kinetic behavior observed suggested that new reaction formation mechanisms were not likely involved in volatile formation in PATP milk. The application of the Le Chatelier principle frequently used to explain the high quality of pressure-treated foods, often with no supporting experimental evidence, was not necessary.

  11. Determination of the temperature coefficients and the kinetic parameters for the HTTR safety analysis

    International Nuclear Information System (INIS)

    Tokuhara, K.; Nakata, T.; Murata, I.; Yamashita, K.; Shindo, R.

    1991-01-01

    This report describes the calculational methods which were employed to determine the temperature coefficients and the kinetic parameters for the safety analysis in the HTTR (High Temperature Engineering Test Reactor). The temperature coefficients (doppler, moderator temperature) and the kinetic parameters (prompt neutron life time; l, effective delayed neutron fraction; β eff) are important for the point model core dynamic analysis and should be evaluated properly. The temperature coefficients were calculated by the whole core model. Doppler coefficient was evaluated under the conditions of all control rods withdrawn and the uniform change of fuel temperature. The minimum and the maximum value of the evaluated doppler coefficients in a burnup cycle are -4.6x10 -5 and -1.5x10 -5 ΔK/K/deg. C respectively. The moderator temperature coefficient was evaluated under the conditions of all control rods withdrawn and the uniform change of moderator temperature. The minimum and the maximum value of the evaluated moderator temperature coefficients in a burnup cycle are -17.1x10 -5 and 0.99x10 -5 ΔK/K/deg. C respectively. In spite of positive moderator temperature coefficient, the power coefficient is always negative. Therefore the HTTR possesses inherent power-suppressing feed back characteristic in all operating condition. We surveyed the effects of the Xe existence, the control rods existence, the fuel temperature and the region in which the temperature was changed on the moderator temperature coefficients. The kinetic parameters were calculated by the perturbation method with the whole core model. The minimum and the maximum value of the evaluated effective delayed neutron fraction (β eff) are 0.0047 and 0.0065 respectively. These of the evaluated prompt neutron life time (l) are 0.67 and 0.78 ms respectively. We have surveyed the effects of the fuel depletion and the core power level on these parameters, and considered these effects on the kinetic parameters. From

  12. EFFECTIVENESS OF ENVIRONMENTAL TREATIES: TREND ANALYSIS OF TREATY-BASED ENVIRONMENTAL INDICATORS

    OpenAIRE

    CHENAZ B. SEELARBOKUS

    2005-01-01

    The literature on environmental regime effectiveness has shown a predilection for behaviour modification studies, whereby effectiveness is associated with a change in the behaviour of relevant actors. There has not been a systematic endeavour to link the implementation of international environmental agreements (IEAs) with improvement in environmental conditions. This article shifts away from the paradigm of behavioural analysis and focuses instead on linking IEA effectiveness with positive en...

  13. Variation of ratio kinetic profiles as a simple and novel spectrophotometric method for the simultaneous kinetic analysis of binary mixtures

    Directory of Open Access Journals (Sweden)

    Naseri Abdolhossein

    2012-01-01

    Full Text Available In this paper, a new and very simple kinetic - spectrophotometric method is developed for the simultaneous determination of binary mixtures without prior separational steps. The method is based on the calculation of the variation of ratio kinetic profiles. The mathematical explanation of the procedure is also illustrated. The proposed method can be used for simultaneous determination of two analytes A and B that react with the same reagent to give the same absorbing species. In order to evaluate the applicability of the method, a model data as well as an experimental data were tested. The results from experimental data relating to the simultaneous spectrophotometric determination of Co (II and V (IV based on their oxidation reactions with Fe (III in the presence 1, 10- Phenanthroline (Phen in micellar media were presented as a real model for resolution of the binary systems. The applicability of the method in tap water and synthesized alloy samples was also assessed by spiking experiments with different amount of Co (II and V (IV.

  14. Environmental Sustainability Analysis of Biodiesel Production

    DEFF Research Database (Denmark)

    Herrmann, Ivan Tengbjerg; Hauschild, Michael Michael Zwicky; Birkved, Morten

    like these require a life cycle perspective on the biofuel - from the cradle (production of the agricultural feedstock) to the grave (use as fuel). An environmental life cycle assessment is performed on biodiesel to compare different production schemes including chemical and enzymatic esterification...... with the use of methanol or ethanol. The life cycle assessment includes all processes needed for the production, distribution and use of the biodiesel (the product system), and it includes all relevant environmental impacts from the product system, ranging from global impacts like climate change and loss...... of non-renewable resources over regional impacts like acidification, eutrophication and photochemical ozone to more local impacts like ecotoxicity and physical impacts like land use, to allow judging on the overall environmental sustainability of the biodiesel and to support identification of the main...

  15. Spectral and kinetic analysis of radiation induced optical attenuation in silica: towards intrinsic fibre optic dosimetry?

    International Nuclear Information System (INIS)

    Borgermans, P.

    2002-01-01

    The document is an abstract of a PhD thesis. The PhD work concerns the detailed investigation of the behaviour of optical fibres in radiation fields such as is the case for various nuclear and space application,s. The core of the work concerns the spectral and kinetic analysis of the radiation induced optical attenuation. Models describing underlying physical phenomena, both for the spectral and the time dimensions, have been developed. The potential of silica optical fibre waveguides for intrinsic dosimetry has been assessed by employing specific properties of radiation induced defects in the silica waveguide material

  16. Kinetic analysis of the thermal decomposition of Li4Ti5O12 pellets

    Directory of Open Access Journals (Sweden)

    Hugo A. Mosqueda

    2011-12-01

    Full Text Available A single dynamic kinetic analysis, describing the surface decomposition of Li4Ti5O12 pellets, has been performed. Samples were analyzed by X-ray diffraction and scanning electron microscopy. The analyses were performed between 1000 and 1100°C and different times, perceiving the Li4Ti5O12 decomposition to Li2Ti3O7, with a loss of lithium. As expected, more rapid decomposition behaviour was found at higher temperatures. Finally, the activation energy for this decomposition of Li4Ti5O12 to Li2Ti3O7 was estimated to be equal to 383 kJ/mol.

  17. Blood, urine, and hair kinetic analysis following an acute lead intoxication

    OpenAIRE

    KEUTGENS, Aurore; HO, Giang; SCHOOFS, Roland; KOTOLENKO, Svelana; DENOOZ, Raphael; CHARLIER, Corinne

    2011-01-01

    A case of lead exposure resulting from the accidental ingestion of a lead-containing solution is reported. Because of clinical management rapidly performed through chelation therapy by 2,3-dimercaptopropane sulfonate sodium and meso-2,3-dimercaptosuccinic acid, blood lead levels of this 51-year-old patient were moderate (412.9 μg/L) and no clinical symptoms were observed. Numerous blood and urine samples were collected for kinetic analysis of lead elimination. However, we report the first cas...

  18. Kinetic analysis of the termal decomposition of colombian vacuum residua by termogravimetry

    Directory of Open Access Journals (Sweden)

    Fabian Andrey Diaz Mateus

    2015-09-01

    Full Text Available Five different Colombian vacuum residues were thermally decomposed in a thermogravimetric analyzer. Three heating rates were employed to heat the sample up to 650°C. The kinetic analysis was performed by the Coats-Redfern method to describe the non-isothermal pyrolysis of the residua, a reaction model where the reaction order gradually increases from first to second order is proposed and an excellent agreement of the experimental with the calculated data is presented. The results also indicate that the pyrolysis of a vacuum residue cannot be modeled by a single reaction mechanism.

  19. Oxidation kinetics and auger microprobe analysis of some oxidized zirconium alloys

    International Nuclear Information System (INIS)

    Ploc, R.A.

    1989-01-01

    Oxidation kinetics at 300 o C in dry oxygen of 0.5 wt% binary alloys of iron, nickel, and chromium in zirconium were determined for several surface preparations. Further, chemical profiles of the oxides as they existed on the matrix and on the precipitates were obtained by sputtering and Auger electron analysis. The appearance of 'breakaway' oxidation was controlled by the surface finish of the alloy, a variable that could be used to eliminate the phenomenon for all alloys except the Zr/Ni binary, which required β-quenching to accomplish the same purpose. (author)

  20. Qualitative analysis of a discrete thermostatted kinetic framework modeling complex adaptive systems

    Science.gov (United States)

    Bianca, Carlo; Mogno, Caterina

    2018-01-01

    This paper deals with the derivation of a new discrete thermostatted kinetic framework for the modeling of complex adaptive systems subjected to external force fields (nonequilibrium system). Specifically, in order to model nonequilibrium stationary states of the system, the external force field is coupled to a dissipative term (thermostat). The well-posedness of the related Cauchy problem is investigated thus allowing the new discrete thermostatted framework to be suitable for the derivation of specific models and the related computational analysis. Applications to crowd dynamics and future research directions are also discussed within the paper.

  1. Impact of spatial kinetics in severe accident analysis for a large HWR

    International Nuclear Information System (INIS)

    Morris, E.E.

    1994-01-01

    The impact on spatial kinetics on the analysis of severe accidents initiated by the unprotected withdrawal of one or more control rods is investigated for a large heavy water reactor. Large inter- and intra-assembly power shifts are observed, and the importance of detailed geometrical modeling of fuel assemblies is demonstrated. Neglect of space-time effects is shown to lead to erroneous estimates of safety margins, and of accident consequences in the event safety margins are exceeded. The results and conclusions are typical of what would be expected for any large, loosely coupled core

  2. Analysis of the effect on growth kinetics of gamma prima phase in Inconel 713C alloys

    International Nuclear Information System (INIS)

    Thorp, S.I.; Versaci, R.A.; Ges, A.; Palacio, H.A.

    1993-01-01

    This work shows the analysis of the effect on growth kinetics of gamma prima phase in Inconel 713C alloy of two thermic treatments. In this study, SEM are used and the results are analyzed by means of the theory developed by Lifshitz, Slyozov and Wagner (LSW theory). The findings have revealed that with such theory it is not possible to determine if the process of growth is controlled either through diffusion or through diffusion in the interface as to the time employed in the experiment (2600 hours); the time required is approximately 10000 hours. (Author)

  3. Interaction and kinetic analysis for coal and biomass co-gasification by TG-FTIR.

    Science.gov (United States)

    Xu, Chaofen; Hu, Song; Xiang, Jun; Zhang, Liqi; Sun, Lushi; Shuai, Chao; Chen, Qindong; He, Limo; Edreis, Elbager M A

    2014-02-01

    This study aims to investigate the interaction and kinetic behavior of CO2 gasification of coal, biomass and their blends by thermogravimetry analysis (TG). The gas products evolved from gasification were measured online with Fourier Transform Infrared Spectroscopy (FTIR) coupled with TG. Firstly, TG experiments indicated that interaction between the coals and biomasses mainly occurred during co-gasification process. The most significant synergistic interaction occurred for LN with SD at the blending mass ratio 4:1. Furthermore, thermal kinetic analysis indicated that the activation energy involved in co-gasification decreased as the SD content increased until the blending ratio of SD with coal reached 4:1. The rise of the frequency factor indicated that the increase of SD content favored their synergistic interaction. Finally, FTIR analysis of co-gasification of SD with LN indicated that except for CO, most gases including CH3COOH, C6H5OH, H2O, etc., were detected at around 50-700°C. Copyright © 2014. Published by Elsevier Ltd.

  4. Pyrolysis behaviors and kinetic studies on Eucalyptus residues using thermogravimetric analysis

    International Nuclear Information System (INIS)

    Chen, Zhihua; Zhu, Quanjie; Wang, Xun; Xiao, Bo; Liu, Shiming

    2015-01-01

    Highlights: • The first study on pyrolysis characteristics and kinetic of Eucalyptus residues. • Pyrolysis process can be divided into three stages using differential DTG method. • A new modified discrete DAEM showed better than Gaussian DAEM for kinetic studies. • Variations of activation energy reveal the mechanism change during pyrolysis process. - Abstract: The pyrolysis behaviors and kinetics of Eucalyptus leaves (EL), Eucalyptus bark (EB) and Eucalyptus sawdust (ESD) were investigated by using thermogravimetric analysis (TGA) technique. Three stages for EL, EB and ESD pyrolysis have been divided using differential derivative thermogravimetric (DDTG) method and the second stage is the main pyrolysis process with approximately 86.93% (EL), 88.96% (EB) and 97.84% (ESD) weight loss percentages. Kinetic parameters of Gaussian distributed activation energy model (DAEM) for EL, EB and ESD pyrolysis are: distributed centers (E 0 ) of 141.15 kJ/mol (EL), 149.21 kJ/mol (EB), 175.79 kJ/mol (ESD), standard deviations (σ) of 18.35 kJ/mol (EL), 18.37 kJ/mol (EB), 14.41 kJ/mol (ESD) and pre-exponential factors (A) of 1.15E+10 s −1 (EL), 4.34E+10 s −1 (EB), 7.44E+12 s −1 (ESD). A new modified discrete DAEM was performed and showed excellent fits to experimental data than Gaussian DAEM. According to the modified discrete DAEM, the activation energies are in ranges of 122.67–308.64 kJ/mol, 118.72–410.80 kJ/mol and 108.39–192.93 kJ/mol for EL, EB and ESD pyrolysis, respectively. The pre-exponential factors of discrete DAEM have wide ranges of 4.84E+13–6.12E+22 s −1 (EL), 1.91E+12–4.51E+25 s −1 (EB) and 63.43–4.36E+11 s −1 (ESD). The variation of activation energy versus conversion reveals the mechanism change during pyrolysis process. The kinetic data would be of immense benefit to model, design and develop suitable thermo-chemical systems for the application of Eucalyptus residues.

  5. Approaching messy problems: strategies for environmental analysis

    Science.gov (United States)

    L. M. Reid; R. R. Ziemer; T. E. Lisle

    1996-01-01

    Environmental problems are never neatly defined. Instead, each is a tangle of interacting processes whose manifestation and interpretation are warped by the vagaries of time, weather, expectation, and economics. Each problem involves livelihoods, values, and numerous specialized disciplines. Nevertheless, federal agencies in the Pacific Northwest have been given the...

  6. Procedures for Environmental Impact Analysis and Planning.

    Science.gov (United States)

    1982-10-01

    Novak, E., and R. Riggins, Computer-Aided Environmental Impact AnLysis : MIS- sion Change, O&M, and Training: User Manual, Technical Report E-85...there is mixed sentiment has a better chance of establishing a positive relationship with the audience. (8) Avoid using technical jargon or words that

  7. Analysis of Corporate Environmental Management: Methodological Aspects

    DEFF Research Database (Denmark)

    Madsen, Henning; Ulhøi, John Parm

    2001-01-01

    Human activities cannot avoid influencing conditions in the natural environment one way or the other. This includes as well common activities in the business sector. But during the past few decades, environmental disasters in Seveso and Bhopal, and the Exxon Valdes oil spill in Alaska have...

  8. Community succession analysis and environmental biological ...

    African Journals Online (AJOL)

    Yomi

    2011-02-14

    Feb 14, 2011 ... on abandoned hilly lands and implications for vegetation restoration strategy in Shanxi, China. X.Z Liu1, F. Zhang1*, H.B. Shao2,3* and J.T. Zhang4. 1Institute of Loess Plateau, Shanxi University, Taiyuan 030006, China. 2The CAS / Shandong Provincial Key Laboratory of Coastal Environmental Processes ...

  9. Environmental analysis of higher brominated diphenyl ethers and decabromodiphenyl ethane.

    Science.gov (United States)

    Kierkegaard, Amelie; Sellström, Ulla; McLachlan, Michael S

    2009-01-16

    Methods for environmental analysis of higher brominated diphenyl ethers (PBDEs), in particular decabromodiphenyl ether (BDE209), and the recently discovered environmental contaminant decabromodiphenyl ethane (deBDethane) are reviewed. The extensive literature on analysis of BDE209 has identified several critical issues, including contamination of the sample, degradation of the analyte during sample preparation and GC analysis, and the selection of appropriate detection methods and surrogate standards. The limited experience with the analysis of deBDethane suggests that there are many commonalities with BDE209. The experience garnered from the analysis of BDE209 over the last 15 years will greatly facilitate progress in the analysis of deBDethane.

  10. Environmental analysis applied to schools. Methodologies for data acquisition

    International Nuclear Information System (INIS)

    Andriola, L.; Ceccacci, R.

    2001-01-01

    The environment analysis is the basis of environmental management for organizations and it is considered as the first step in EMAS. It allows to identify, deal with the issues and have a clear knowledge on environmental performances of organizations. Schools can be included in the organizations. Nevertheless, the complexity of environmental issues and applicable regulations makes very difficult for a school, that wants to implement an environmental management system (EMAS, ISO 14001, etc.), to face this first step. So, it has been defined an instrument, that is easy but complete and coherent with reference standard, to let schools choose their process for elaborating the initial environmental revue. This instrument consists, essentially, in cards that, if completed, facilitate the drafting of the environmental analysis report [it

  11. CHEMKIN-III: A FORTRAN chemical kinetics package for the analysis of gas-phase chemical and plasma kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Kee, R.J.; Rupley, F.M.; Meeks, E.; Miller, J.A.

    1996-05-01

    This document is the user`s manual for the third-generation CHEMKIN package. CHEMKIN is a software package whose purpose is to facilitate the formation, solution, and interpretation of problems involving elementary gas-phase chemical kinetics. It provides a flexible and powerful tool for incorporating complex chemical kinetics into simulations of fluid dynamics. The package consists of two major software components: an Interpreter and a Gas-Phase Subroutine Library. The Interpreter is a program that reads a symbolic description of an elementary, user-specified chemical reaction mechanism. One output from the Interpreter is a data file that forms a link to the Gas-Phase Subroutine Library. This library is a collection of about 100 highly modular FORTRAN subroutines that may be called to return information on equations of state, thermodynamic properties, and chemical production rates. CHEMKIN-III includes capabilities for treating multi-fluid plasma systems, that are not in thermal equilibrium. These new capabilities allow researchers to describe chemistry systems that are characterized by more than one temperature, in which reactions may depend on temperatures associated with different species; i.e. reactions may be driven by collisions with electrons, ions, or charge-neutral species. These new features have been implemented in such a way as to require little or no changes to CHEMKIN implementation for systems in thermal equilibrium, where all species share the same gas temperature. CHEMKIN-III now has the capability to handle weakly ionized plasma chemistry, especially for application related to advanced semiconductor processing.

  12. Non-invasive differentiation of pancreatic lesions: is analysis of FDG kinetics superior to semiquantitative uptake value analysis?

    International Nuclear Information System (INIS)

    Nitzsche, E.U.; Hoegerle, S.; Mix, M.; Brink, I.; Otte, A.; Moser, E.

    2002-01-01

    The diagnostic utility of fluorine-18 2-deoxy-D-glucose positron emission tomography (FDG PET) for the non-invasive differentiation of focal pancreatic lesions originating from cancer or chronic pancreatitis by combined visual image interpretation and semiquantitative uptake value analysis has been documented. However, in clinical routine some misdiagnosis is still observed. This is because there is potential overlap between the semiquantitative uptake values obtained for active inflammatory lesions and cancer. Therefore, this prospective study was undertaken to test the hypothesis that analysis of dynamic kinetics of focal pancreatic lesions based on FDG PET may more accurately determine the benign or malignant nature of such lesions. Thirty patients (56±17 years) were studied dynamically with FDG PET for a period of 60-90 min. Patients were assigned to one of four groups: control, acute pancreatitis, chronic pancreatitis or pancreatic cancer. Two observers, blinded to the clinical data, analysed the time-activity curves of FDG kinetics based on region of interest analysis. The diagnosis predicted by FDG PET was compared with the result of histological examination of the surgical specimen. Analysis of FDG kinetics revealed significant differences in the shape of the time-activity curve for controls, pancreatic cancer and inflammatory disease. Surprisingly, there was no significant difference in the time-activity curve shape for chronic pancreatitis and acute pancreatitis; this is, however, not a clinical issue. Furthermore, acquisition time (60 min vs 90 min) did not affect interpretation of the time-activity curve, so that scanning time may be regularly shortened to 60 min. Interobserver agreement was 1. Based on these findings, non-invasive differentiation between pancreatic cancer and chronic pancreatitis was correctly predicted in all cases, as confirmed by histology. In addition, the specificity was increased compared with that obtained from standardised

  13. Non-invasive differentiation of pancreatic lesions: is analysis of FDG kinetics superior to semiquantitative uptake value analysis?

    Energy Technology Data Exchange (ETDEWEB)

    Nitzsche, E.U.; Hoegerle, S.; Mix, M.; Brink, I.; Otte, A.; Moser, E. [Freiburg Univ. (Germany). Abt. Radiologie; Imdahl, A. [Division of Visceral Surgery, Department of Surgery, Albert Ludwigs University, Medical Center, Freiburg (Germany)

    2002-02-01

    The diagnostic utility of fluorine-18 2-deoxy-D-glucose positron emission tomography (FDG PET) for the non-invasive differentiation of focal pancreatic lesions originating from cancer or chronic pancreatitis by combined visual image interpretation and semiquantitative uptake value analysis has been documented. However, in clinical routine some misdiagnosis is still observed. This is because there is potential overlap between the semiquantitative uptake values obtained for active inflammatory lesions and cancer. Therefore, this prospective study was undertaken to test the hypothesis that analysis of dynamic kinetics of focal pancreatic lesions based on FDG PET may more accurately determine the benign or malignant nature of such lesions. Thirty patients (56{+-}17 years) were studied dynamically with FDG PET for a period of 60-90 min. Patients were assigned to one of four groups: control, acute pancreatitis, chronic pancreatitis or pancreatic cancer. Two observers, blinded to the clinical data, analysed the time-activity curves of FDG kinetics based on region of interest analysis. The diagnosis predicted by FDG PET was compared with the result of histological examination of the surgical specimen. Analysis of FDG kinetics revealed significant differences in the shape of the time-activity curve for controls, pancreatic cancer and inflammatory disease. Surprisingly, there was no significant difference in the time-activity curve shape for chronic pancreatitis and acute pancreatitis; this is, however, not a clinical issue. Furthermore, acquisition time (60 min vs 90 min) did not affect interpretation of the time-activity curve, so that scanning time may be regularly shortened to 60 min. Interobserver agreement was 1. Based on these findings, non-invasive differentiation between pancreatic cancer and chronic pancreatitis was correctly predicted in all cases, as confirmed by histology. In addition, the specificity was increased compared with that obtained from standardised

  14. Pyrolysis characteristics and kinetics of microalgae via thermogravimetric analysis (TGA): A state-of-the-art review.

    Science.gov (United States)

    Bach, Quang-Vu; Chen, Wei-Hsin

    2017-12-01

    Pyrolysis is a promising route for biofuels production from microalgae at moderate temperatures (400-600°C) in an inert atmosphere. Depending on the operating conditions, pyrolysis can produce biochar and/or bio-oil. In practice, knowledge for thermal decomposition characteristics and kinetics of microalgae during pyrolysis is essential for pyrolyzer design and pyrolysis optimization. Recently, the pyrolysis kinetics of microalgae has become a crucial topic and received increasing interest from researchers. Thermogravimetric analysis (TGA) has been employed as a proven technique for studying microalgae pyrolysis in a kinetic control regime. In addition, a number of kinetic models have been applied to process the TGA data for kinetic evaluation and parameters estimation. This paper aims to provide a state-of-the art review on recent research activities in pyrolysis characteristics and kinetics of various microalgae. Common kinetic models predicting the thermal degradation of microalgae are examined and their pros and cons are illustrated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Structure and Kinetic Analysis of H2S Production by Human Mercaptopyruvate Sulfurtransferase*

    Science.gov (United States)

    Yadav, Pramod Kumar; Yamada, Kazuhiro; Chiku, Taurai; Koutmos, Markos; Banerjee, Ruma

    2013-01-01

    Mercaptopyruvate sulfurtransferase (MST) is a source of endogenous H2S, a gaseous signaling molecule implicated in a wide range of physiological processes. The contribution of MST versus the other two H2S generators, cystathionine β-synthase and γ-cystathionase, has been difficult to evaluate because many studies on MST have been conducted at high pH and have used varied reaction conditions. In this study, we have expressed, purified, and crystallized human MST in the presence of the substrate 3-mercaptopyruvate (3-MP). The kinetics of H2S production by MST from 3-MP was studied at pH 7.4 in the presence of various physiological persulfide acceptors: cysteine, dihydrolipoic acid, glutathione, homocysteine, and thioredoxin, and in the presence of cyanide. The crystal structure of MST reveals a mixture of the product complex containing pyruvate and an active site cysteine persulfide (Cys248-SSH) and a nonproductive intermediate in which 3-MP is covalently linked via a disulfide bond to an active site cysteine. The crystal structure analysis allows us to propose a detailed mechanism for MST in which an Asp-His-Ser catalytic triad is positioned to activate the nucleophilic cysteine residue and participate in general acid-base chemistry, whereas our kinetic analysis indicates that thioredoxin is likely to be the major physiological persulfide acceptor for MST. PMID:23698001

  16. Managing the environmental impacts of land transport: integrating environmental analysis with urban planning

    International Nuclear Information System (INIS)

    Irving, Paul; Moncrieff, Ian

    2004-01-01

    Ecological systems have limits or thresholds that vary by pollutant type, emissions sources and the sensitivity of a given location. Human health can also indicate sensitivity. Good environmental management requires any problem to be defined to obtain efficient and effective solutions. Cities are where transport activities, effects and resource management decisions are often most focussed. The New Zealand Ministry of Transport has developed two environmental management tools. The Vehicle Fleet Model (VFM) is a predictive database of the environmental performance of the New Zealand traffic fleet (and rail fleet). It calculates indices of local air quality, stormwater, and greenhouse gases emissions. The second is an analytical process based on Environmental Capacity Analysis (ECA). Information on local traffic is combined with environmental performance data from the Vehicle Fleet Model. This can be integrated within a live, geo-spatially defined analysis of the overall environmental effects within a defined local area. Variations in urban form and activity (traffic and other) that contribute to environmental effects can be tracked. This enables analysis of a range of mitigation strategies that may contribute, now or in the future, to maintaining environmental thresholds or meeting targets. A case study of the application of this approach was conducted within Waitakere City. The focus was on improving the understanding of the relative significance of stormwater contaminants derived from land transport

  17. Managing the environmental impacts of land transport: integrating environmental analysis with urban planning.

    Science.gov (United States)

    Irving, Paul; Moncrieff, Ian

    2004-12-01

    Ecological systems have limits or thresholds that vary by pollutant type, emissions sources and the sensitivity of a given location. Human health can also indicate sensitivity. Good environmental management requires any problem to be defined to obtain efficient and effective solutions. Cities are where transport activities, effects and resource management decisions are often most focussed. The New Zealand Ministry of Transport has developed two environmental management tools. The Vehicle Fleet Model (VFM) is a predictive database of the environmental performance of the New Zealand traffic fleet (and rail fleet). It calculates indices of local air quality, stormwater, and greenhouse gases emissions. The second is an analytical process based on Environmental Capacity Analysis (ECA). Information on local traffic is combined with environmental performance data from the Vehicle Fleet Model. This can be integrated within a live, geo-spatially defined analysis of the overall environmental effects within a defined local area. Variations in urban form and activity (traffic and other) that contribute to environmental effects can be tracked. This enables analysis of a range of mitigation strategies that may contribute, now or in the future, to maintaining environmental thresholds or meeting targets. A case study of the application of this approach was conducted within Waitakere City. The focus was on improving the understanding of the relative significance of stormwater contaminants derived from land transport.

  18. An Analysis of Base Level Environmental Organizations

    Science.gov (United States)

    1991-09-01

    Success," Engineering and Services Update, 1: 1-2 (January 1991). 35. Sutermeister , Robert A. People and Productivity (Second Edition). New York: McGraw...some form. Sutermeister includes Formal Organization, which is influenced by Structure, as a major factor affecting productivity (35). In his total...Department of Defense (DoD) there is a growing commitment towards environmental quality and compliance. As of 1988, DoD had more than 5,000 people working

  19. Development of a New Bio-Kinetic Model for Assessing the Environmental Property of Military Hydraulic Fluids

    National Research Council Canada - National Science Library

    Rhee, In-Sik

    2006-01-01

    ... (POL) products utilized in the current and future combat systems. As part of these efforts, a bio-kinetic model was developed to predict the biodegradability of lubricants including hydraulic fluids...

  20. Dosimetric features and kinetic analysis of thermoluminescence from ultra-high molecular weight polyethylene

    Science.gov (United States)

    Chithambo, M. L.

    2012-08-01

    Thermoluminescence (TL) from beta irradiated ultra-high molecular weight polyethylene has been studied for measurements between 30 and 200 °C. An aliquot studied in this work produced TL glow curves consisting of two peaks, the main peak at 88 °C and a weaker intensity peak at 148 °C for heating at 1 °C s-1 following an excitation dose of 215 Gy. The position of the main peak is poorly reproducible for heating rates of 0.2 and 0.6 °C s-1 investigated with the peak position decreasing when the sample is freshly irradiated and the TL re-measured. The said change in peak position is however less of an effect for measurements made at 1 °C s-1 with the peak position being fairly reproducible in this case. Further measurements of the dosimetric properties of ultra-high molecular weight polyethylene showed that its dose response is linear from 26 Gy to about 161 Gy but exhibits slower growth in intensity with dose from about 860 Gy after regions of sub- and supra-linearity in between. If the TL is not measured immediately after irradiation, the signal fades with the delay approximately exponentially. In addition, a number of tests including phosphorescence analysis showed the possibility that the order of kinetics might not be unique but sensitive to several factors including measurement temperature. Thus for instance, the dependence of the peak position on the stop temperature in the partial heating procedure Tm - Tstop implied first-order kinetics but analysis of the geometrical factor μg for the same set of data gave μg = 0.46 ± 0.03 a value corresponding to characteristics somewhat intermediate between first and second order. In comparison, the results of analysis of the phosphorescence recorded at several temperatures on the rising edge of the main peak were only in agreement for measurements at 40 °C with general-order analysis suggesting second-order kinetics apply as did TL-like transformation of the monotonic phosphorescence decay. Both results were

  1. Environmental Education in Macedonian Schools: A Comparative Analysis of Textbooks

    Science.gov (United States)

    Srbinovski, Mile

    2013-01-01

    The purpose of this article is to describe and discuss an analysis of the extent to which environmental issues are addressed in the textbooks in the schools of the Republic of Macedonia. Research has analyzed a range of textbooks (279) published in the past 15 years. Our fundamental conclusion is that the inclusion of environmental issues in the…

  2. Numerical Investigation of Desulfurization Kinetics in Gas-Stirred Ladles by a Quick Modeling Analysis Approach

    Science.gov (United States)

    Cao, Qing; Nastac, Laurentiu; Pitts-Baggett, April; Yu, Qiulin

    2018-03-01

    A quick modeling analysis approach for predicting the slag-steel reaction and desulfurization kinetics in argon gas-stirred ladles has been developed in this study. The model consists of two uncoupled components: (i) a computational fluid dynamics (CFD) model for predicting the fluid flow and the characteristics of slag-steel interface, and (ii) a multicomponent reaction kinetics model for calculating the desulfurization evolution. The steel-slag interfacial area and mass transfer coefficients predicted by the CFD simulation are used as the processing data for the reaction model. Since the desulfurization predictions are uncoupled from the CFD simulation, the computational time of this uncoupled predictive approach is decreased by at least 100 times for each case study when compared with the CFD-reaction kinetics fully coupled model. The uncoupled modeling approach was validated by comparing the evolution of steel and slag compositions with the experimentally measured data during ladle metallurgical furnace (LMF) processing at Nucor Steel Tuscaloosa, Inc. Then, the validated approach was applied to investigate the effects of the initial steel and slag compositions, as well as different types of additions during the refining process on the desulfurization efficiency. The results revealed that the sulfur distribution ratio and the desulfurization reaction can be promoted by making Al and CaO additions during the refining process. It was also shown that by increasing the initial Al content in liquid steel, both Al oxidation and desulfurization rates rapidly increase. In addition, it was found that the variation of the initial Si content in steel has no significant influence on the desulfurization rate. Lastly, if the initial CaO content in slag is increased or the initial Al2O3 content is decreased in the fluid-slag compositional range, the desulfurization rate can be improved significantly during the LMF process.

  3. A critical analysis of the accuracy of several numerical techniques for combustion kinetic rate equations

    Science.gov (United States)

    Radhadrishnan, Krishnan

    1993-01-01

    A detailed analysis of the accuracy of several techniques recently developed for integrating stiff ordinary differential equations is presented. The techniques include two general-purpose codes EPISODE and LSODE developed for an arbitrary system of ordinary differential equations, and three specialized codes CHEMEQ, CREK1D, and GCKP4 developed specifically to solve chemical kinetic rate equations. The accuracy study is made by application of these codes to two practical combustion kinetics problems. Both problems describe adiabatic, homogeneous, gas-phase chemical reactions at constant pressure, and include all three combustion regimes: induction, heat release, and equilibration. To illustrate the error variation in the different combustion regimes the species are divided into three types (reactants, intermediates, and products), and error versus time plots are presented for each species type and the temperature. These plots show that CHEMEQ is the most accurate code during induction and early heat release. During late heat release and equilibration, however, the other codes are more accurate. A single global quantity, a mean integrated root-mean-square error, that measures the average error incurred in solving the complete problem is used to compare the accuracy of the codes. Among the codes examined, LSODE is the most accurate for solving chemical kinetics problems. It is also the most efficient code, in the sense that it requires the least computational work to attain a specified accuracy level. An important finding is that use of the algebraic enthalpy conservation equation to compute the temperature can be more accurate and efficient than integrating the temperature differential equation.

  4. Simultaneous kinetic spectrophotometric analysis of five synthetic food colorants with the aid of chemometrics.

    Science.gov (United States)

    Ni, Yongnian; Wang, Yong; Kokot, Serge

    2009-04-30

    This paper describes a simple and sensitive kinetic spectrophotometric method for the simultaneous determination of Amaranth, Ponceau 4R, Sunset Yellow, Tartrazine and Brilliant Blue in mixtures with the aid of chemometrics. The method involved two coupled reactions, viz. the reduction of iron(III) by the analytes to iron(II) in sodium acetate/hydrochloric acid solution (pH 1.71) and the chromogenic reaction between iron(II) and hexacyanoferrate(III) ions to yield a Prussian blue peak at 760 nm. The spectral data were recorded over the 500-1000 nm wavelength range every 2s for 600 s. The kinetic data were collected at 760 nm and 600 s, and linear calibration models were satisfactorily constructed for each of the dyes with detection limits in the range of 0.04-0.50 mg L(-1). Multivariate calibration models for kinetic data were established and verified for methods such as the Iterative target transform factor analysis (ITTFA), principal component regression (PCR), partial least squares (PLS), and principal component-radial basis function-artificial neural network (PC-RBF-ANN) with and without wavelet packet transform (WPT) pre-treatment. The PC-RBF-ANN with WPT calibration performed somewhat better than others on the basis of the %RPE(T) (approximately 9) and %Recovery parameters (approximately 108), although the effect of the WPT pre-treatment was marginal (approximately 0.5% RPE(T)). The proposed method was applied for the simultaneous determination of the five colorants in foodstuff samples, and the results were comparable with those from a reference HPLC method.

  5. Variations analysis of the Society's preference structure regarding environmental issues

    International Nuclear Information System (INIS)

    Angel S, Enrique; Zambrano B, Ana Maria

    2005-01-01

    Society's preference structure regarding environmental issues is understood as the relative importance the society gives to various topics that collectively conform the environmental issues. Based on the hypothesis that this structure behavior and its definition vary with time, proposals are presented related to the concepts and a working plan allowing performing the structure's dynamic analysis. A method is described to gather information based on the systematic reading of a nation wide newspaper during a period time. A comparison is done between the resulting structure and several aspects as the environmental legislation, government plans and summits and environmental milestones

  6. Environmental analysis by electrochemical sensors and biosensors fundamentals

    CERN Document Server

    Moretto, Ligia Maria

    2014-01-01

    This book presents an exhaustive overview of electrochemical sensors and biosensors for the analysis and monitoring of the most important analytes in the environmental field, in industry, in treatment plants and in environmental research. The chapters give the reader a comprehensive, state-of-the-art picture of the field of electrochemical sensors suitable to environmental analytes, from the theoretical principles of their design to their implementation, realization and application. The first three chapters discuss fundamentals, and the last three chapters cover the main groups of analytes of environmental interest.

  7. Instrumental Analysis in Environmental Chemistry - Gas Phase Detection Systems

    Science.gov (United States)

    Stedman, Donald H.; Meyers, Philip A.

    1974-01-01

    Discusses advances made in chemical analysis instrumentation used in environmental monitoring. This first of two articles is concerned with analytical instrumentation in which detection and dispersion depend ultimately on the properties of gaseous molecules. (JR)

  8. Environmental impact analysis of aquaculture in net cages in a ...

    African Journals Online (AJOL)

    Environmental impact analysis of aquaculture in net cages in a Brazilian water reservoir, based in zooplankton communities. Maria Cristina Crispim, Karla Patrícia Ponte Araújo, Hênio do Nascimento Melo Júnior ...

  9. Kinetics of diuron under aerobic condition and residue analysis in sugarcane under subtropical field conditions.

    Science.gov (United States)

    Tandon, Shishir; Pant, Ravi

    2017-10-10

    The phenylureas group includes persistent herbicides which are major pollutants to soil and water. Dissipation kinetics of diuron in different soils under sugarcane field conditions was investigated. Diuron was extracted with acetone and florisil solid phase extraction clean-up and characterized by high-performance liquid chromatography-UV. Diuron persisted for more than 100 days and dissipation followed monophasic first-order kinetics. Persistence was more in sandy loam compared to silty clay loam soil. Half-life of diuron in silty clay loam soil was 22.57 and 32.37 days and in sandy loam was 28.35 and 43.93 days at 2 and 4 kg ha-1applications, respectively. Average recovery in soil, bagasse, leaf-straw and juice ranged from 75.95% to 84.20%, 80.15% to 89.35%, 77.46% to 86.19% and 81.88% to 92.68%, respectively. The quantitation limits for soil, bagasse, leaf-straw and juice were 0.01, 0.03, 0.04 μg g -1 and 0.008 μg mL -1 , respectively. Application of diuron inhibited growth of soil microbes initially but they recovered later. At harvest, diuron residues were below maximum residue limits in all samples. The study revealed that under subtropical conditions, diuron is safe for use in weed management and would not pose any residual/environmental problem and that sugarcane crop could be used safe for human/animal consumption.

  10. Goal-oriented sensitivity analysis for lattice kinetic Monte Carlo simulations.

    Science.gov (United States)

    Arampatzis, Georgios; Katsoulakis, Markos A

    2014-03-28

    In this paper we propose a new class of coupling methods for the sensitivity analysis of high dimensional stochastic systems and in particular for lattice Kinetic Monte Carlo (KMC). Sensitivity analysis for stochastic systems is typically based on approximating continuous derivatives with respect to model parameters by the mean value of samples from a finite difference scheme. Instead of using independent samples the proposed algorithm reduces the variance of the estimator by developing a strongly correlated-"coupled"- stochastic process for both the perturbed and unperturbed stochastic processes, defined in a common state space. The novelty of our construction is that the new coupled process depends on the targeted observables, e.g., coverage, Hamiltonian, spatial correlations, surface roughness, etc., hence we refer to the proposed method as goal-oriented sensitivity analysis. In particular, the rates of the coupled Continuous Time Markov Chain are obtained as solutions to a goal-oriented optimization problem, depending on the observable of interest, by considering the minimization functional of the corresponding variance. We show that this functional can be used as a diagnostic tool for the design and evaluation of different classes of couplings. Furthermore, the resulting KMC sensitivity algorithm has an easy implementation that is based on the Bortz-Kalos-Lebowitz algorithm's philosophy, where events are divided in classes depending on level sets of the observable of interest. Finally, we demonstrate in several examples including adsorption, desorption, and diffusion Kinetic Monte Carlo that for the same confidence interval and observable, the proposed goal-oriented algorithm can be two orders of magnitude faster than existing coupling algorithms for spatial KMC such as the Common Random Number approach. We also provide a complete implementation of the proposed sensitivity analysis algorithms, including various spatial KMC examples, in a supplementary MATLAB

  11. Goal-oriented sensitivity analysis for lattice kinetic Monte Carlo simulations

    International Nuclear Information System (INIS)

    Arampatzis, Georgios; Katsoulakis, Markos A.

    2014-01-01

    In this paper we propose a new class of coupling methods for the sensitivity analysis of high dimensional stochastic systems and in particular for lattice Kinetic Monte Carlo (KMC). Sensitivity analysis for stochastic systems is typically based on approximating continuous derivatives with respect to model parameters by the mean value of samples from a finite difference scheme. Instead of using independent samples the proposed algorithm reduces the variance of the estimator by developing a strongly correlated-“coupled”- stochastic process for both the perturbed and unperturbed stochastic processes, defined in a common state space. The novelty of our construction is that the new coupled process depends on the targeted observables, e.g., coverage, Hamiltonian, spatial correlations, surface roughness, etc., hence we refer to the proposed method as goal-oriented sensitivity analysis. In particular, the rates of the coupled Continuous Time Markov Chain are obtained as solutions to a goal-oriented optimization problem, depending on the observable of interest, by considering the minimization functional of the corresponding variance. We show that this functional can be used as a diagnostic tool for the design and evaluation of different classes of couplings. Furthermore, the resulting KMC sensitivity algorithm has an easy implementation that is based on the Bortz–Kalos–Lebowitz algorithm's philosophy, where events are divided in classes depending on level sets of the observable of interest. Finally, we demonstrate in several examples including adsorption, desorption, and diffusion Kinetic Monte Carlo that for the same confidence interval and observable, the proposed goal-oriented algorithm can be two orders of magnitude faster than existing coupling algorithms for spatial KMC such as the Common Random Number approach. We also provide a complete implementation of the proposed sensitivity analysis algorithms, including various spatial KMC examples, in a supplementary

  12. Goal-oriented sensitivity analysis for lattice kinetic Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Arampatzis, Georgios, E-mail: garab@math.uoc.gr [Department of Applied Mathematics, University of Crete (Greece); Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003 (United States); Katsoulakis, Markos A., E-mail: markos@math.umass.edu [Department of Mathematics and Statistics, University of Massachusetts, Amherst, Massachusetts 01003 (United States)

    2014-03-28

    In this paper we propose a new class of coupling methods for the sensitivity analysis of high dimensional stochastic systems and in particular for lattice Kinetic Monte Carlo (KMC). Sensitivity analysis for stochastic systems is typically based on approximating continuous derivatives with respect to model parameters by the mean value of samples from a finite difference scheme. Instead of using independent samples the proposed algorithm reduces the variance of the estimator by developing a strongly correlated-“coupled”- stochastic process for both the perturbed and unperturbed stochastic processes, defined in a common state space. The novelty of our construction is that the new coupled process depends on the targeted observables, e.g., coverage, Hamiltonian, spatial correlations, surface roughness, etc., hence we refer to the proposed method as goal-oriented sensitivity analysis. In particular, the rates of the coupled Continuous Time Markov Chain are obtained as solutions to a goal-oriented optimization problem, depending on the observable of interest, by considering the minimization functional of the corresponding variance. We show that this functional can be used as a diagnostic tool for the design and evaluation of different classes of couplings. Furthermore, the resulting KMC sensitivity algorithm has an easy implementation that is based on the Bortz–Kalos–Lebowitz algorithm's philosophy, where events are divided in classes depending on level sets of the observable of interest. Finally, we demonstrate in several examples including adsorption, desorption, and diffusion Kinetic Monte Carlo that for the same confidence interval and observable, the proposed goal-oriented algorithm can be two orders of magnitude faster than existing coupling algorithms for spatial KMC such as the Common Random Number approach. We also provide a complete implementation of the proposed sensitivity analysis algorithms, including various spatial KMC examples, in a

  13. Atomic spectrometry update : a review of advances in environmental analysis

    OpenAIRE

    Butler, Owen T.; Cairns, Warren R. L.; Cook, Jennifer M.; Davidson, Christine M.

    2016-01-01

    This is the 31st annual review of the application of atomic spectrometry to the chemical analysis of environmental samples. This update refers to papers published approximately between August 2014 and July 2015 and continues the series of Atomic Spectrometry Updates (ASUs) in Environmental Analysis that should be read in conjunction with other related ASUs in the series, namely: clinical and biological materials, foods and beverages; advances in atomic spectrometry and related techniques; ele...

  14. Environmental impact analysis of mine tailing reservoir

    Science.gov (United States)

    Gong, J. Z.

    2016-08-01

    Under certain conditions landscape topography which utilizes mine tailing reservoir construction using is likely to increase lateral recharge source regions, resulting in dramatic changes to the local hydrological dynamic field and recharge of downstream areas initiated by runoff, excretion state, elevated groundwater depth, shallow groundwater, rainfall direct communication, and thinning of the vadose zone. Corrosive leaching of topsoil over many years of exposure to chemical fertilizers and pesticides may result in their dissolution into the groundwater system, which may lead to excessive amounts of many harmful chemicals, therby affecting the physical and mental health of human residents and increase environmental vulnerability and risk associated with the water and soil. According to field survey data from Yujiakan, Qian'an City, and Hebei provinces, this paper analyzes the hydrogeological environmental mechanisms of areas adjacent to mine tailing reservoirs and establishes a conceptual model of the local groundwater system and the concentration-response function between NO3 - content in groundwater and the incidence of cancer in local residents.

  15. Environmental Performance in Countries Worldwide: Determinant Factors and Multivariate Analysis

    Directory of Open Access Journals (Sweden)

    Isabel Gallego-Alvarez

    2014-11-01

    Full Text Available The aim of this study is to analyze the environmental performance of countries and the variables that can influence it. At the same time, we performed a multivariate analysis using the HJ-biplot, an exploratory method that looks for hidden patterns in the data, obtained from the usual singular value decomposition (SVD of the data matrix, to contextualize the countries grouped by geographical areas and the variables relating to environmental indicators included in the environmental performance index. The sample used comprises 149 countries of different geographic areas. The findings obtained from the empirical analysis emphasize that socioeconomic factors, such as economic wealth and education, as well as institutional factors represented by the style of public administration, in particular control of corruption, are determinant factors of environmental performance in the countries analyzed. In contrast, no effect on environmental performance was found for factors relating to the internal characteristics of a country or political factors.

  16. Upper limb kinetic analysis of three sitting pivot wheelchair transfer techniques.

    Science.gov (United States)

    Koontz, Alicia M; Kankipati, Padmaja; Lin, Yen-Sheng; Cooper, Rory A; Boninger, Michael L

    2011-11-01

    The objective of this study was to investigate differences in shoulder, elbow and hand kinetics while performing three different SPTs that varied in terms of hand and trunk positioning. Fourteen unimpaired individuals (8 male and 6 female) performed three variations of sitting pivot transfers in a random order from a wheelchair to a level tub bench. Two transfers involved a forward flexed trunk (head-hips technique) and the third with the trunk remaining upright. The two transfers involving a head hips technique were performed with two different leading hand initial positions. Motion analysis equipment recorded upper body movements and force sensors recorded hand reaction forces. Shoulder and elbow joint and hand kinetics were computed for the lift phase of the transfer. Transferring using either of the head hips techniques compared to the trunk upright style of transferring resulted in reduced superior forces at the shoulder (Pforces in the leading elbow (P=0.049) for both head hip transfers and the trailing hand for the head hip technique with the arm further away from the body (P<0.028). The head hip techniques resulted in higher shoulder external rotation, flexion and extension moments compared to the trunk upright technique (P<0.021). Varying the hand placement and trunk positioning during transfers changes the load distribution across all upper limb joints. The results of this study may be useful for determining a technique that helps preserve upper limb function overtime. Published by Elsevier Ltd.

  17. Analysis of kinematic, kinetic and electromyographic patterns during root canal preparation with rotary and manual instruments

    Directory of Open Access Journals (Sweden)

    Braulio Pasternak-Júnior

    2012-02-01

    Full Text Available OBJECTIVE: This study assessed the muscular activity during root canal preparation through kinematics, kinetics, and electromyography (EMG. MATERIAL AND METHODS: The operators prepared one canal with RaCe rotary instruments and another with Flexo-files. The kinematics of the major joints was reconstructed using an optoelectronic system and electromyographic responses of the flexor carpi radialis, extensor carpi radialis, brachioradialis, biceps brachii, triceps brachii, middle deltoid, and upper trapezius were recorded. The joint torques of the shoulder, elbow and wrist were calculated using inverse dynamics. In the kinematic analysis, angular movements of the wrist and elbow were classified as low risk factors for work-related musculoskeletal disorders. With respect to the shoulder, the classification was medium-risk. RESULTS: There was no significant difference revealed by the kinetic reports. The EMG results showed that for the middle deltoid and upper trapezius the rotary instrumentation elicited higher values. The flexor carpi radialis and extensor carpi radialis, as well as the brachioradialis showed a higher value with the manual method. CONCLUSION: The muscular recruitment for accomplishment of articular movements for root canal preparation with either the rotary or manual techniques is distinct. Nevertheless, the rotary instrument presented less difficulty in the generation of the joint torque in each articulation, thus, presenting a greater uniformity of joint torques.

  18. Oxidation kinetic analysis of a mixed uranium dicarbide and graphite compound

    Energy Technology Data Exchange (ETDEWEB)

    Marchand, M., E-mail: mickael.marchand@cea.fr [Commissariat à l’Energie Atomique et aux énergies alternatives, CEA, CADARACHE, DEN, DEC, SPUA/Laboratoire des Combustibles Uranium, 13108 Saint Paul-lez-Durance Cedex (France); Fiquet, O., E-mail: olivier.fiquet@cea.fr [Commissariat à l’Energie Atomique et aux énergies alternatives, CEA, CADARACHE, DEN, DEC, SPUA/Laboratoire des Combustibles Uranium, 13108 Saint Paul-lez-Durance Cedex (France); Brothier, M. [Commissariat à l’Energie Atomique et aux énergies alternatives, CEA, CADARACHE, DEN, DEC, SPUA/Laboratoire des Combustibles Uranium, 13108 Saint Paul-lez-Durance Cedex (France)

    2013-06-15

    Highlights: ► Experimental study of uranium carbides and graphite powder oxidations. ► Single rate limiting step identification by extensive kinetic analysis. ► Pseudo-steady-state validation during chemical conversion. ► Combination of TGA, TDA, XRD and gas phase chromatography results. -- Abstract: The oxidation of a mixed uranium dicarbide and graphite powder has been investigated by simultaneous thermal gravimetric (TGA) and differential thermal (DTA) analyses coupled with gas phase chromatography. For isothermal oxidation conditions with temperatures below 330 °C, only the UC{sub 2} chemical phase is progressively oxidised into U{sub 3}O{sub 8} oxides. Parabolic weight gain curves as a function of oxidation over time were obtained. A detailed kinetic study is proposed to establish a pseudo-steady-state during the oxidation process. Using an experimental method based on the sudden temperature increases, a single rate-limiting step has been validated and then modelled by a 3D diffusion law. An apparent activation energy calculated from the Arrhenius representation has been evaluated at −35 kJ/mol, thus describing the diffusion of oxygen through the oxide layer.

  19. Photoacoustic Analysis of the Penetration Kinetics of Cordia verbenacea DC in Human Skin

    Science.gov (United States)

    Carvalho, S. S.; Barja, P. R.

    2012-11-01

    Phonophoresis consists of the utilization of ultrasound radiation associated to pharmacological agents in order to enhance transdermal penetration of applied drugs. It is a widely employed resource in physiotherapy practice, normally associated with anti-inflammatory drugs, such as Acheflan. This drug was developed in Brazil from the essential oil of Cordia verbenacea DC, a native plant of the Brazilian southern coast. In previous studies, the photoacoustic (PA) technique proved effective in the study of the penetration kinetics of topically applied products and in the evaluation of drug delivery after phonophoresis application. The present work aimed to evaluate the penetration kinetics of Acheflan in human skin, employing in vivo PA measurements after massage application or phonophoresis application. Ten volunteers (aged between 18 and 30 years) took part in the study. Time evolution of the PA signal was fitted to a Boltzmann curve, S-shaped. After statistical analysis, PA measurements have shown drug penetration for both application forms, but drug delivery was more evident after phonophoresis application, with a characteristic penetration time of less than 15 min for the stratum corneum.

  20. Kinetic analysis and polymorphic phase transformation of glycine in the presence of lauric acid

    Science.gov (United States)

    Polat, Sevgi; Sayan, Perviz

    2018-01-01

    The phase transformation of β-glycine to α-glycine in a water/ethanol media was investigated in terms of its polymorphism in pure media and in the presence of an additive. Lauric acid was used as the additive, and the experiments were conducted in three different concentrations. First, the polymorphic phase transformation was continuously monitored by in-line measuring of the ultrasonic velocity. Next, the X-ray diffraction (XRD) technique was applied for the solid phase analysis of the crystals to confirm the polymorphic transformation of β-glycine to α-glycine. Based on the combination of scanning electron microscopy (SEM) and morphology analyses, it was found that not only the shape but also the size of the crystals obtained were significantly affected by the additive. The crystals obtained were further characterized by means of thermogravimetric analyzer, elemental analyzer and Fourier-transform infrared (FTIR) spectrometer. The attained thermal data were utilized to calculate the activation energy using various kinetic models based on the isoconversional method. The kinetic results revealed that the addition of lauric acid led to an increase of around 10% in the average activation energy of the glycine crystals during decomposition process. As suggested by the elemental and FTIR analyses conducted, this increase could be related to lauric acid adsorption on the crystal surface.

  1. Kinetic analysis of reverse transcriptase activity of bacterial family A DNA polymerases.

    Science.gov (United States)

    Yasukawa, Kiyoshi; Konishi, Atsushi; Shinomura, Mayu; Nagaoka, Eriko; Fujiwara, Shinsuke

    2012-10-26

    Some bacterial thermostable, wild-type or genetically engineered family A DNA polymerases have reverse transcriptase activity. However, difference in reverse transcriptase activities of family A DNA polymerases and retroviral reverse transcriptases (RTs) is unclear. In this study, comparative kinetic analysis was performed for the reverse transcriptase activities of the wild-type enzyme of family A DNA polymerase (M1pol(WT)) from Thermus thermophilus M1 and the variant enzyme of family A DNA polymerase (K4pol(L329A)), in which the mutation of Leu329→Ala is undertaken, from Thermotoga petrophila K4. In the incorporation of dTTP into poly(rA)-p(dT)(45), the reaction rates of K4pol(L329A) and M1pol(WT) exhibited a saturated profile of the Michaelis-Menten kinetics for dTTP concentrations but a substrate inhibition profile for poly(rA)-p(dT)(45) concentrations. In contrast, the reaction rates of Moloney murine leukemia virus (MMLV) RT exhibited saturated profiles for both dTTP and poly(rA)-p(dT)(45) concentrations. This suggests that high concentrations of DNA-primed RNA template decrease the efficiency of cDNA synthesis with bacterial family A DNA polymerases. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Kinetic analysis of the effects of target structure on siRNA efficiency

    Science.gov (United States)

    Chen, Jiawen; Zhang, Wenbing

    2012-12-01

    RNAi efficiency for target cleavage and protein expression is related to the target structure. Considering the RNA-induced silencing complex (RISC) as a multiple turnover enzyme, we investigated the effect of target mRNA structure on siRNA efficiency with kinetic analysis. The 4-step model was used to study the target cleavage kinetic process: hybridization nucleation at an accessible target site, RISC-mRNA hybrid elongation along with mRNA target structure melting, target cleavage, and enzyme reactivation. At this model, the terms accounting for the target accessibility, stability, and the seed and the nucleation site effects are all included. The results are in good agreement with that of experiments which show different arguments about the structure effects on siRNA efficiency. It shows that the siRNA efficiency is influenced by the integrated factors of target's accessibility, stability, and the seed effects. To study the off-target effects, a simple model of one siRNA binding to two mRNA targets was designed. By using this model, the possibility for diminishing the off-target effects by the concentration of siRNA was discussed.

  3. OCEAN THERMAL ENERGY CONVERSION (OTEC) PROGRAMMATIC ENVIRONMENTAL ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Sands, M. D.

    1980-01-01

    This programmatic environmental analysis is an initial assessment of OTEC technology considering development, demonstration and commercialization; it is concluded that the OTEC development program should continue because the development, demonstration, and commercialization on a single-plant deployment basis should not present significant environmental impacts. However, several areas within the OTEC program require further investigation in order to assess the potential for environmental impacts from OTEC operation, particularly in large-scale deployments and in defining alternatives to closed-cycle biofouling control: (1) Larger-scale deployments of OTEC clusters or parks require further investigations in order to assess optimal platform siting distances necessary to minimize adverse environmental impacts. (2) The deployment and operation of the preoperational platform (OTEC-1) and future demonstration platforms must be carefully monitored to refine environmental assessment predictions, and to provide design modifications which may mitigate or reduce environmental impacts for larger-scale operations. These platforms will provide a valuable opportunity to fully evaluate the intake and discharge configurations, biofouling control methods, and both short-term and long-term environmental effects associated with platform operations. (3) Successful development of OTEC technology to use the maximal resource capabilities and to minimize environmental effects will require a concerted environmental management program, encompassing many different disciplines and environmental specialties.

  4. Ocean Thermal Energy Conversion (OTEC) Programmatic Environmental Analysis--Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1980-01-01

    The programmatic environmental analysis is an initial assessment of Ocean Thermal Energy Conversion (OTEC) technology considering development, demonstration and commercialization. It is concluded that the OTEC development program should continue because the development, demonstration, and commercialization on a single-plant deployment basis should not present significant environmental impacts. However, several areas within the OTEC program require further investigation in order to assess the potential for environmental impacts from OTEC operation, particularly in large-scale deployments and in defining alternatives to closed-cycle biofouling control: (1) Larger-scale deployments of OTEC clusters or parks require further investigations in order to assess optimal platform siting distances necessary to minimize adverse environmental impacts. (2) The deployment and operation of the preoperational platform (OTEC-1) and future demonstration platforms must be carefully monitored to refine environmental assessment predictions, and to provide design modifications which may mitigate or reduce environmental impacts for larger-scale operations. These platforms will provide a valuable opportunity to fully evaluate the intake and discharge configurations, biofouling control methods, and both short-term and long-term environmental effects associated with platform operations. (3) Successful development of OTEC technology to use the maximal resource capabilities and to minimize environmental effects will require a concerted environmental management program, encompassing many different disciplines and environmental specialties. This volume contains these appendices: Appendix A -- Deployment Scenario; Appendix B -- OTEC Regional Characterization; and Appendix C -- Impact and Related Calculations.

  5. Environmental behavior and analysis of agricultural sulfur.

    Science.gov (United States)

    Griffith, Corey M; Woodrow, James E; Seiber, James N

    2015-11-01

    Sulfur has been widely used for centuries as a staple for pest and disease management in agriculture. Presently, it is the largest-volume pesticide in use worldwide. This review describes the sources and recovery methods for sulfur, its allotropic forms and properties and its agricultural uses, including development and potential advantages of nanosulfur as a fungicide. Chemical and microbial reactivity, interactions in soil and water and analytical methods for determination in environmental samples and foodstuffs, including inexpensive analytical methods for sulfur residues in wine, beer and other food/beverage substrates, will be reviewed. The toxicology of sulfur towards humans and agriculturally important fungi is included, with some restrictions on use to promote safety. The review concludes with areas for which more research is warranted. © 2015 Society of Chemical Industry.

  6. Regional analysis and environmental impact assessment

    International Nuclear Information System (INIS)

    Parzyck, D.C.; Brocksen, R.W.; Emanuel, W.R.

    1976-01-01

    This paper presents a number of techniques that can be used to assess environmental impacts on a regional scale. Regional methodologies have been developed which examine impacts upon aquatic and terrestrial biota in regions through consideration of changes in land use, land cover, air quality, water resource use, and water quality. Techniques used to assess long-range atmospheric transport, water resources, effects on sensitive forest and animal species, and impacts on man are presented in this paper, along with an optimization approach which serves to integrate the analytical techniques in an overall assessment framework. A brief review of the research approach and certain modeling techniques used within one regional studies program is provided. While it is not an all inclusive report on regional analyses, it does present an illustration of the types of analyses that can be performed on a regional scale

  7. Integrating health and environmental impact analysis

    DEFF Research Database (Denmark)

    Reis, S; Morris, G.; Fleming, L. E.

    2015-01-01

    . It will require outreach to political and other stakeholders including a currently largely disengaged general public. The need for an effective and robust science-policy interface has never been more pressing. Conceptual models can facilitate this by providing theoretical frameworks and supporting stakeholder......, health has been pursued as though our lives and lifestyles are disconnected from ecosystems and their component organisms. The inadequacy of the societal and public health response to obesity, health inequities, and especially global environmental and climate change now calls for an ecological approach...... a new conceptual model, the ecosystems-enriched Drivers, Pressures, State, Exposure, Effects, Actions or 'eDPSEEA' model, to address this shortcoming. The model recognizes convergence between the concept of ecosystems services which provides a human health and well-being slant to the value of ecosystems...

  8. Mass fluctuation kinetics: analysis and computation of equilibria and local dynamics.

    Science.gov (United States)

    Azunre, P; Gómez-Uribe, C; Verghese, G

    2011-11-01

    The mass fluctuation kinetics (MFK) model is a set of coupled ordinary differential equations approximating the time evolution of means and covariances of species concentrations in chemical reaction networks. It generalises classical mass action kinetics (MAK), in which fluctuations around the mean are ignored. MFK may be used to approximate stochasticity in system trajectories when stochastic simulation methods are prohibitively expensive computationally. This study presents a set of tools to aid in the analysis of systems within the MFK framework. A closed-form expression for the MFK Jacobian matrix is derived. This expression facilitates the computation of MFK equilibria and the characterisation of the dynamics of small deviations from the equilibria (i.e. local dynamics). Software developed in MATLAB to analyse systems within the MFK framework is also presented. The authors outline a homotopy continuation method that employs the Jacobian for bifurcation analysis, that is, to generate a locus of steady-state Jacobian eigenvalues corresponding to changing a chosen MFK parameter such as system volume or a rate constant. This method is applied to study the effect of small-volume stochasticity on local dynamics at equilibria in a pair of example systems, namely the formation and dissociation of an enzyme-substrate complex and a genetic oscillator. For both systems, this study reveals volume regimes where MFK provides a quantitatively and/or qualitatively correct description of system behaviour, and regimes where the MFK approximation is inaccurate. Moreover, our analysis provides evidence that decreasing volume from the MAK regime (infinite volume) has a destabilising effect on system dynamics.

  9. Extending the throughput of Biacore 4000 biosensor to accelerate kinetic analysis of antibody-antigen interaction.

    Science.gov (United States)

    Kamat, Vishal; Rafique, Ashique

    2017-08-01

    The surface plasmon resonance (SPR) biosensors are being routinely used in different stages of drug discovery and development. However, the lack of high throughput SPR biosensors continues to be a primary bottleneck for the rapid kinetic screening of large panels of monoclonal antibodies (mAbs). To further increase the throughput of the Biacore 4000 biosensor, we have developed three kinetic screening assays to characterize mAb-antigen interactions - (i) 16-mAb capture kinetic, (ii) single cycle kinetic (SCK), and (iii) parallel kinetic (PK). The performance of all three kinetic assays was evaluated by characterizing the binding of kinetically diverse human mAbs to four antigens with molecular weights of 14kD, 29kD, 38kD, and 48kD and binding affinities ranging from 130pM to 200 nM. The binding rate constants measured using all three kinetic assays were reproducible across multiple experiments and correlated with the values generated using the conventional 8-mAb capture kinetic assay on the Biacore 4000 (R 2  > 0.94). Moreover, the 16-mAb capture assay decreased experiment time and analyte consumption by 35% and 50%, respectively. This work illustrates the significance of the 16-mAb capture kinetic, SCK, and PK assays to increase the throughput of Biacore 4000 and to support rapid kinetic screening of mAbs. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Development of an inelastic stress analysis code 'KINE-T' and its evaluations

    International Nuclear Information System (INIS)

    Kobatake, K.; Takahashi, S.; Suzuki, M.

    1977-01-01

    Referring to the ASME B and PVC Code Case 1592-7, the inelastic stress analysis is required for the designs of the class 1 components in elevated temperature if the results of the elastic stress analysis and/or simplified inelastic analysis do not satisfy the requirements. Authors programmed a two-dimensional axisymmetric inelastic analysis code 'KINE-T', and carried out its evaluations and an application. This FEM code is based on the incremental method and the following: elastic-plastic constitutive equation (yield condition of von Mises; flow rule of Prandtl-Reuss; Prager's hardening rule); creep constitutive equation (equation of state approach; flow rule of von Mises; strain hardening rule); the temperature dependency of the yield function is considered; solution procedure of the assembled stiffness matrix is the 'initial stress method'. After the completion of the programming, authors compared the output with not only theoretical results but also with those of the MARC code and the ANSYS code. In order to apply the code to the practical designing, authors settled a quasi-component two-dimensional axisymmetric model and a loading cycle (500 cycles). Then, an inelastic analysis and its integrity evaluation are carried out

  11. Environmental Assessment: General Plan-Based Environmental Impact Analysis Process, Laughlin Air Force Base

    Science.gov (United States)

    2007-05-01

    BASED ENVIROMENTAL IMPACT ANALYSIS PROCESS LAUGHLIN AIR FORCE BASE, TEXAS AGENCY: 47th Flying Training Wing (FTW), Laughlin Air Force Base (AFB), Texas...in their decision-making process. The President’s Council on Environmental Quality (CEQ) has issued regulations to implement NEPA that include...Order (EO) 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-Income Populations, was issued by the President on

  12. Thermodynamic and kinetic analysis of solid-phase interaction of alkali metal carbonates with arsenic pentoxide

    International Nuclear Information System (INIS)

    Pashinkin, A.S.; Buketov, E.A.; Isabaeva, S.M.; Kasenov, B.K.

    1985-01-01

    The thermodynamic analysis of solid-phase reactions of alkali metal carbonates with arsenic pentoxide showing the possibility of formation of all arsenates at a higher than the room temperature is performed. Energetically most advantageous is formation of meta-arsenates. It is shown that temperature increase favours the reaction process. By Gibbs standard energy decrease the reactions form the Li>Na>K>Rb>Cs series. On the base of calculation data linear dependence of Gibbs standard energy in reactions on the atomic number of alkali metalis established. By the continuous weighing method the kinetics of interaction of alkali metal carbonates with arsenic pentoxide under isothermal conditions in the 450-500 deg C range is studied. Studies is the dependence of apparent energy of interaction of carbonates wih As 2 0 5 an atomic parameters of al

  13. Environmental risk assessment in GMO analysis.

    Science.gov (United States)

    Pirondini, Andrea; Marmiroli, Nelson

    2010-01-01

    Genetically modified or engineered organisms (GMOs, GEOs) are utilised in agriculture, expressing traits of interest, such as insect or herbicide resistance. Soybean, maize, cotton and oilseed rape are the GM crops with the largest acreage in the world. The distribution of GM acreage in the different countries is related with the different positions concerning labelling of GMO products: based on the principle of substantial equivalence, or rather based on the precautionary principle. The paper provides an overview on how the risks associated with release of GMO in the environments can be analysed and predicted, in view of a possible coexistence of GM and non-GM organisms in agriculture.Risk assessment procedures, both qualitative and quantitative, are compared in the context of application to GMOs considering also legislation requirements (Directive 2001/18/EC). Criteria and measurable properties to assess harm for human health and environmental safety are listed, and the possible consequences are evaluated in terms of significance.Finally, a mapping of the possible risks deriving from GMO release is reported, focusing on gene transfer to related species, horizontal gene transfer, direct and indirect effects on non target organisms, development of resistance in target organisms, and effects on biodiversity.

  14. Development of environmental sample analysis techniques for safeguards

    International Nuclear Information System (INIS)

    Magara, Masaaki; Hanzawa, Yukiko; Esaka, Fumitaka

    1999-01-01

    JAERI has been developing environmental sample analysis techniques for safeguards and preparing a clean chemistry laboratory with clean rooms. Methods to be developed are a bulk analysis and a particle analysis. In the bulk analysis, Inductively-Coupled Plasma Mass Spectrometer or Thermal Ionization Mass Spectrometer are used to measure nuclear materials after chemical treatment of sample. In the particle analysis, Electron Probe Micro Analyzer and Secondary Ion Mass Spectrometer are used for elemental analysis and isotopic analysis, respectively. The design of the clean chemistry laboratory has been carried out and construction will be completed by the end of March, 2001. (author)

  15. Kinetic analysis of lauric acid hydroxylation by human cytochrome P450 4A11.

    Science.gov (United States)

    Kim, Donghak; Cha, Gun-Su; Nagy, Leslie D; Yun, Chul-Ho; Guengerich, F Peter

    2014-10-07

    Cytochrome P450 (P450) 4A11 is the only functionally active subfamily 4A P450 in humans. P450 4A11 catalyzes mainly ω-hydroxylation of fatty acids in liver and kidney; this process is not a major degradative pathway, but at least one product, 20-hydroxyeicosatetraenoic acid, has important signaling properties. We studied catalysis by P450 4A11 and the issue of rate-limiting steps using lauric acid ω-hydroxylation, a prototypic substrate for this enzyme. Some individual reaction steps were studied using pre-steady-state kinetic approaches. Substrate and product binding and release were much faster than overall rates of catalysis. Reduction of ferric P450 4A11 (to ferrous) was rapid and not rate-limiting. Deuterium kinetic isotope effect (KIE) experiments yielded low but reproducible values (1.2-2) for 12-hydroxylation with 12-(2)H-substituted lauric acid. However, considerable "metabolic switching" to 11-hydroxylation was observed with [12-(2)H3]lauric acid. Analysis of switching results [Jones, J. P., et al. (1986) J. Am. Chem. Soc. 108, 7074-7078] and the use of tritium KIE analysis with [12-(3)H]lauric acid [Northrop, D. B. (1987) Methods Enzymol. 87, 607-625] both indicated a high intrinsic KIE (>10). Cytochrome b5 (b5) stimulated steady-state lauric acid ω-hydroxylation ∼2-fold; the apoprotein was ineffective, indicating that electron transfer is involved in the b5 enhancement. The rate of b5 reoxidation was increased in the presence of ferrous P450 mixed with O2. Collectively, the results indicate that both the transfer of an electron to the ferrous·O2 complex and C-H bond-breaking limit the rate of P450 4A11 ω-oxidation.

  16. Pyrolysis Characteristics and Kinetic Analysis of Sediment from the Dianchi Lake in China

    Directory of Open Access Journals (Sweden)

    Zhenfen Wu

    2018-01-01

    Full Text Available Pyrolysis properties and kinetic analysis of lake sediment, as well as evolution characteristics of the gaseous products at 5°C/min, 10°C/min, and 20°C/min, were investigated by TG-FTIR. Comparison to the TG and DTG curves at different heating rates, the pyrolysis process at 10°C/min could describe the sediment pyrolysis characteristics better than at 5°C/min and 20°C/min; thus the process of sediment pyrolysis could be considered as four stages. From the kinetics analysis, the nth-order chemical reaction model was suitable to describe the sediment pyrolysis reaction well. The values of n were within 2.55–3.42 and activation energy E was ranged from 15.83 KJ/mol to 57.92 KJ/mol at different heating rates. The gaseous products of H2O, CO2, CO, CH4, and SO2 and several functional groups (C-H, C=O, and C-O could be found from the IR spectrum. From the evolution characteristics with the temperature, there were two evolution peaks for CO2 and one peak for CH4 and SO2. However, the evolution of CO always increased. Besides, the evolution peak for CO2, CH4, and SO2 all shifted to the low temperature region with the decrease of heating rate. The results could provide theoretical basis for harmless treatment and resource utilization of lake sediment.

  17. Risk analysis within environmental impact assessment of proposed construction activity

    International Nuclear Information System (INIS)

    Zeleňáková, Martina; Zvijáková, Lenka

    2017-01-01

    Environmental impact assessment is an important process, prior to approval of the investment plan, providing a detailed examination of the likely and foreseeable impacts of proposed construction activity on the environment. The objective of this paper is to develop a specific methodology for the analysis and evaluation of environmental impacts of selected constructions – flood protection structures using risk analysis methods. The application of methodology designed for the process of environmental impact assessment will develop assumptions for further improvements or more effective implementation and performance of this process. The main objective of the paper is to improve the implementation of the environmental impact assessment process. Through the use of risk analysis methods in environmental impact assessment process, the set objective has been achieved. - Highlights: This paper is informed by an effort to develop research with the aim of: • Improving existing qualitative and quantitative methods for assessing the impacts • A better understanding of relations between probabilities and consequences • Methodology for the EIA of flood protection constructions based on risk analysis • Creative approaches in the search for environmentally friendly proposed activities.

  18. Kinetic analysis of ski turns based on measured ground reaction forces.

    Science.gov (United States)

    Vaverka, Frantisek; Vodickova, Sona; Elfmark, Milan

    2012-02-01

    The objective of this study was to devise a method of kinetic analysis of the ground reaction force that enables the durations and magnitudes of forces acting during the individual phases of ski turns to be described exactly. The method is based on a theoretical analysis of physical forces acting during the ski turn. Two elementary phases were defined: (1) preparing to turn (initiation) and (2) actual turning, during which the center of gravity of the skier-ski system moves along a curvilinear trajectory (steering). The starting point of the turn analysis is a dynamometric record of the resultant acting ground reaction force applied perpendicularly on the ski surface. The method was applied to six expert skiers. They completed a slalom course comprising five gates arranged on the fall line of a 26° slope at a competition speed using symmetrical carving turns (30 evaluated turns). A dynamometric measurement system was placed on the carving skis (168 cm long, radius 16 m, data were recorded at 100 Hz). MATLAB procedures were used to evaluate eight variables during each turn: five time variables and three force variables. Comparison of the turn analysis results between individuals showed that the method is useful for answering various research questions associated with ski turns.

  19. AFM stochastic analysis of surface twisted nanograin chains of iron oxide: a kinetic study

    International Nuclear Information System (INIS)

    Akhavan, O; Azimirad, R

    2009-01-01

    We have studied the stochastic parameters of surface iron oxide nanograin chains, 97 nm in diameter and 2.4 μm in length, prepared at different annealing temperatures, using atomic force microscopy (AFM) spectral analysis. In this regard, the roughness of the thin films including self-assembled twisted nanograin chains has been analysed and characterized using the height-height correlation function, the roughness exponent as well as the power spectrum density of the AFM profiles and their gradient, for the different annealing temperatures. The tip convolution effect on the stochastic parameters under study has also been investigated. The kinetics of the formation of nanograins on the film surface has been obtained using the AFM spectral analysis of the profiles and their gradient. The activation energy needed for the formation of surface nanograin chains was found to be 0.55 eV. It has been shown that the tip-surface interaction affects mainly the diffusion parameters obtained by using the surface roughness analysis of the profiles, while use of the surface roughness analysis of the gradient of the profiles results in a nearly independent tip convolution effect on the diffusion parameters. Hence, this work also provides a method for calculating the required activation energy for the formation of self-assembled nanostructures affecting the roughness of a surface.

  20. Steady state likelihood ratio sensitivity analysis for stiff kinetic Monte Carlo simulations.

    Science.gov (United States)

    Núñez, M; Vlachos, D G

    2015-01-28

    Kinetic Monte Carlo simulation is an integral tool in the study of complex physical phenomena present in applications ranging from heterogeneous catalysis to biological systems to crystal growth and atmospheric sciences. Sensitivity analysis is useful for identifying important parameters and rate-determining steps, but the finite-difference application of sensitivity analysis is computationally demanding. Techniques based on the likelihood ratio method reduce the computational cost of sensitivity analysis by obtaining all gradient information in a single run. However, we show that disparity in time scales of microscopic events, which is ubiquitous in real systems, introduces drastic statistical noise into derivative estimates for parameters affecting the fast events. In this work, the steady-state likelihood ratio sensitivity analysis is extended to singularly perturbed systems by invoking partial equilibration for fast reactions, that is, by working on the fast and slow manifolds of the chemistry. Derivatives on each time scale are computed independently and combined to the desired sensitivity coefficients to considerably reduce the noise in derivative estimates for stiff systems. The approach is demonstrated in an analytically solvable linear system.

  1. Environmental risk analysis for nanomaterials: Review and evaluation of frameworks

    DEFF Research Database (Denmark)

    Grieger, Khara Deanne; Linkov, Igor; Hansen, Steffen Foss

    2012-01-01

    In response to the challenges of conducting traditional human health and ecological risk assessment for nanomaterials (NM), a number of alternative frameworks have been proposed for NM risk analysis. This paper evaluates various risk analysis frameworks proposed for NM based on a number of criteria...... to occupational settings with minor environmental considerations, and most have not been thoroughly tested on a wide range of NM. Care should also be taken when selecting the most appropriate risk analysis strategy for a given risk context. Given this, we recommend a multi-faceted approach to assess...... the environmental risks of NM as well as increased applications and testing of the proposed frameworks for different NM....

  2. Environmental system analysis of tomato production in Ghana ...

    African Journals Online (AJOL)

    The aim of this study was to identify the most important sources of greenhouse gases, acidifying and eutrophying compounds associated with tomato production in Ghana and identify options to reduce the environmental impacts. Life Cycle Analysis (LCA) methodology was used in the analysis (Cradle to gate approach).

  3. Analysis of 129I and its Application as Environmental Tracer

    DEFF Research Database (Denmark)

    Hou, Xiaolin; Hou, Yingkun

    2012-01-01

    as an environmental tracer has highly increased in the past 10 years. Neutron activation analysis and accelerator mass spectrometry are the only techniques for measurement of 129I at environmental level. This article mainly compares these two analytical techniques for the determination of 129I at environmental level...... on the establishment of an initial 129I level in the terrestrial system are presented in this paper. A large amount of anthropogenic 129I has been released to the environment, mainly by reprocessing nuclear fuel. Anthropogenic 129I provides a good oceanographic tracer for studying the circulation and exchange of water...... mass. The speciation analysis of 129I can also be used to investigate the geochemical cycle of stable iodine. Some representative works on the environmental tracer application of 129I are summarized....

  4. Human resources in advanced environmental approaches - A case analysis

    OpenAIRE

    2008-01-01

    Abstract A weak environmental culture in organizations and deficiencies in human resources are major barriers to the implementation of environmental action processes. However, very few studies have been published in this area. The objective of this study, therefore, is to conduct an exploratory case analysis and develop some proposals based on the conclusions arrived at. We have analyzed a total of 8 factories to ensure a sufficient number of sources of information. Some factors li...

  5. Organically bound tritium analysis in environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Baglan, N. [CEA/DAM/DIF, Arpajon (France); Kim, S.B. [AECL, Chalk River Laboratories, Chalk River, ON (Canada); Cossonnet, C. [IRSN/PRP-ENV/STEME/LMRE, Orsay (France); Croudace, I.W.; Warwick, P.E. [GAU-Radioanalytical, University of Southampton, Southampton (United Kingdom); Fournier, M. [IRSN/DG/DMQ, Fontenay-aux-Roses (France); Galeriu, D. [IFIN-HH, Horia-Hulubei, Inst. Phys. and Nucl. Eng., Bucharest (Romania); Momoshima, N. [Kyushu University, Radioisotope Ctr., Fukuoka (Japan); Ansoborlo, E. [CEA/DEN/DRCP/CETAMA, Bagnols-sur-Ceze (France)

    2015-03-15

    Organically bound tritium (OBT) has become of increased interest within the last decade, with a focus on its behaviour and also its analysis, which are important to assess tritium distribution in the environment. In contrast, there are no certified reference materials and no standard analytical method through the international organization related to OBT. In order to resolve this issue, an OBT international working group was created in May 2012. Over 20 labs from around the world participated and submitted their results for the first intercomparison exercise results on potato (Sep 2013). The samples, specially-prepared potatoes, were provided in March 2013 to each participant. Technical information and results from this first exercise are discussed here for all the labs which have realised the five replicates necessary to allow a reliable statistical treatment. The results are encouraging as the increased number of participating labs did not degrade the observed dispersion of the results for a similar activity level. Therefore, the results do not seem to depend on the analytical procedure used. From this work an optimised procedure can start to be developed to deal with OBT analysis and will guide subsequent planned OBT trials by the international group.

  6. Towards a more efficient environmental policy. A socio-economic analysis of four persistent environmental problems

    International Nuclear Information System (INIS)

    2000-11-01

    For the benefit of the National Environmental Policy Plan that will be published in 2001, the Netherlands Bureau for Economic Policy Analysis analysed four persistent environmental problems. These problems are the environmental effects of the manure surplus in the agricultural sector; the climate problem; the acidification by traffic and the air traffic noise around the airport Schiphol. This study not only looks ahead, but also looks back on 30 years of environmental policy. From a welfare economic perspective an analysis is made of the efficiency and effectiveness of that policy. Several questions are answered,e.g.: how could the manure problem of such a small sector as the livestock breeding persist for so many years?; how effective were the agreements with the industry and other sectors on energy efficiency improvement?; what made the acidification policy directed on traffic so successful?; why is the noise production of air traffic still a problem whereas the number of seriously bothered houses is decreased? The answers on these questions provide information which can be useful for the formulation of the future environmental policy. This information refers to the conditions for formulating adequate policy goals, the relation between those goals and policy instruments and the differences between direct versus indirect steering. This report also gives some points of interest for tackling complex international environmental problems. refs

  7. Large-scale kinetic energy spectra from Eulerian analysis of EOLE wind data

    Science.gov (United States)

    Desbois, M.

    1975-01-01

    A data set of 56,000 winds determined from the horizontal displacements of EOLE balloons at the 200 mb level in the Southern Hemisphere during the period October 1971-February 1972 is utilized for the computation of planetary- and synoptic-scale kinetic energy space spectra. However, the random distribution of measurements in space and time presents some problems for the spectral analysis. Two different approaches are used, i.e., a harmonic analysis of daily wind values at equi-distant points obtained by space-time interpolation of the data, and a correlation method using the direct measurements. Both methods give similar results for small wavenumbers, but the second is more accurate for higher wavenumbers (k above or equal to 10). The spectra show a maximum at wavenumbers 5 and 6 due to baroclinic instability and then decrease for high wavenumbers up to wavenumber 35 (which is the limit of the analysis), according to the inverse power law k to the negative p, with p close to 3.

  8. Modal and Dynamic Analysis of a Vehicle with Kinetic Dynamic Suspension System

    Directory of Open Access Journals (Sweden)

    Bangji Zhang

    2016-01-01

    Full Text Available A novel kinetic dynamic suspension (KDS system is presented for the cooperative control of the roll and warp motion modes of off-road vehicles. The proposed KDS system consists of two hydraulic cylinders acting on the antiroll bars. Hence, the antiroll bars are not completely replaced by the hydraulic system, but both systems are installed. In this paper, the vibration analysis in terms of natural frequencies of different motion modes in frequency domain for an off-road vehicle equipped with different configurable suspension systems is studied by using the modal analysis method. The dynamic responses of the vehicle with different configurable suspension systems are investigated under different road excitations and maneuvers. The results of the modal and dynamic analysis prove that the KDS system can reduce the roll and articulation motions of the off-road vehicle without adding extra bounce stiffness and deteriorating the ride comfort. Furthermore, the roll stiffness is increased and the warp stiffness is decreased by the KDS system, which could significantly enhance handing performance and off-road capability.

  9. Novel HPC-ibuprofen conjugates: synthesis, characterization, thermal analysis and degradation kinetics

    International Nuclear Information System (INIS)

    Hussain, M.A.; Lodhi, B.A.; Abbas, K.

    2014-01-01

    Naturally occurring hydrophilic polysaccharides are advantageously used as drug carriers because they provide a mechanism to improve drug action. Hydroxypropylcellulose (HPC) is water-soluble, biocompatible and bears hydroxyl groups for drug conjugation outside the parent polymeric chains. This unique geometry allows the attachment of drug molecules with higher covalent loading. The HPC-Ibuprofen conjugates as macromolecular prodrugs were therefore synthesized employing homogenous and one pot reaction methodologies using p-toluenesulfonyl chloride in N,N-dimethylacetamide solvent at 80 degree C for 24 h under nitrogen atmosphere. The imidazole was used as a base for neutralization of acidic impurities. Present strategy appeared effective to get high yield (77-81%) and high degree of drug substitution (DS 0.88-1.40) onto the HPC polymer as determined by the acid-base titration and verified by 1H-NMR spectroscopy. The gel permeation chromatography has shown uni-modal absorption which indicates no significant degradation of polymer during reaction. Macromolecular prodrugs with different DS of ibuprofen were synthesized, purified, characterized and found soluble in organic solvents. From thermogravimetric analysis, initial, maximum and final degradation temperatures of the conjugates were calculated and compared for relative thermal stability. Thermal degradation kinetics was also studied and results have indicated that degradation of conjugates follows about first order kinetics as calculated by Kissinger model. The energy of activation was also found moderate 92.38, 99.34 and 87.34 kJ/mol as calculated using Friedman, Broido and Chang models. It was found that these novel prodrugs of ibuprofen were thermally stable therefore these may have potential pharmaceutical applications. (author)

  10. Non-Parametric Kinetic (NPK Analysis of Thermal Oxidation of Carbon Aerogels

    Directory of Open Access Journals (Sweden)

    Azadeh Seifi

    2017-05-01

    Full Text Available In recent years, much attention has been paid to aerogel materials (especially carbon aerogels due to their potential uses in energy-related applications, such as thermal energy storage and thermal protection systems. These open cell carbon-based porous materials (carbon aerogels can strongly react with oxygen at relatively low temperatures (~ 400°C. Therefore, it is necessary to evaluate the thermal performance of carbon aerogels in view of their energy-related applications at high temperatures and under thermal oxidation conditions. The objective of this paper is to study theoretically and experimentally the oxidation reaction kinetics of carbon aerogel using the non-parametric kinetic (NPK as a powerful method. For this purpose, a non-isothermal thermogravimetric analysis, at three different heating rates, was performed on three samples each with its specific pore structure, density and specific surface area. The most significant feature of this method, in comparison with the model-free isoconversional methods, is its ability to separate the functionality of the reaction rate with the degree of conversion and temperature by the direct use of thermogravimetric data. Using this method, it was observed that the Nomen-Sempere model could provide the best fit to the data, while the temperature dependence of the rate constant was best explained by a Vogel-Fulcher relationship, where the reference temperature was the onset temperature of oxidation. Moreover, it was found from the results of this work that the assumption of the Arrhenius relation for the temperature dependence of the rate constant led to over-estimation of the apparent activation energy (up to 160 kJ/mol that was considerably different from the values (up to 3.5 kJ/mol predicted by the Vogel-Fulcher relationship in isoconversional methods

  11. Cell kinetics, DNA integrity, differentiation, and lipid fingerprinting analysis of rabbit adipose-derived stem cells.

    Science.gov (United States)

    Barretto, Letícia Siqueira de Sá; Lessio, Camila; Sawaki e Nakamura, Ahy Natally; Lo Turco, Edson Guimarães; da Silva, Camila Gonzaga; Zambon, João Paulo; Gozzo, Fábio César; Pilau, Eduardo Jorge; de Almeida, Fernando Gonçalves

    2014-10-01

    Human adipose tissue has been described as a potential alternative reservoir for stem cells. Although studies have been performed in rabbits using autologous adipose-derived stem cells (ADSC), these cells have not been well characterized. The primary objectives of this study were to demonstrate the presence of adipose-derived stem cells isolated from rabbit inguinal fat pads and to characterize them through osteogenic and adipogenic in vitro differentiation and lipid fingerprinting analysis. The secondary objective was to evaluate cell behavior through growth kinetics, cell viability, and DNA integrity. Rabbit ADSCs were isolated to determine the in vitro growth kinetics and cell viability. DNA integrity was assessed by an alkaline Comet assay in passages 0 and 5. The osteogenic differentiation was evaluated by Von Kossa, and Alizarin Red S staining and adipogenic differentiation were assessed by Oil Red O staining. Lipid fingerprinting analyses of control, adipogenic, and osteogenic differentiated cells were performed by MALDI-TOF/MS. We demonstrate that rabbit ADSC have a constant growth rate at the early passages, with increased DNA fragmentation at or after passage 5. Rabbit ADSC viability was similar in passages 2 and 5 (90.7% and 86.6%, respectively), but there was a tendency to decreased cellular growth rate after passage 3. The ADSC were characterized by the expression of surface markers such as CD29 (67.4%) and CD44 (89.4%), using CD 45 (0.77%) as a negative control. ADSC from rabbits were successfully isolated form the inguinal region. These cells were capable to differentiate into osteogenic and adipogenic tissue when they were placed in inductive media. After each passage, there was a trend towards decreased cell growth. On the other hand, DNA fragmentation increased at each passage. ADSC had a different lipid profile when placed in control, adipogenic, or osteogenic media.

  12. Data management and statistical analysis for environmental assessment

    International Nuclear Information System (INIS)

    Wendelberger, J.R.; McVittie, T.I.

    1995-01-01

    Data management and statistical analysis for environmental assessment are important issues on the interface of computer science and statistics. Data collection for environmental decision making can generate large quantities of various types of data. A database/GIS system developed is described which provides efficient data storage as well as visualization tools which may be integrated into the data analysis process. FIMAD is a living database and GIS system. The system has changed and developed over time to meet the needs of the Los Alamos National Laboratory Restoration Program. The system provides a repository for data which may be accessed by different individuals for different purposes. The database structure is driven by the large amount and varied types of data required for environmental assessment. The integration of the database with the GIS system provides the foundation for powerful visualization and analysis capabilities

  13. Field Raman Spectrograph for Environmental Analysis

    International Nuclear Information System (INIS)

    Sylvia, J.M.; Haas, J.W.; Spencer, K.M.; Carrabba, M.M.; Rauh, R.D.; Forney, R.W.; Johnston, T.M.

    1998-01-01

    The widespread contamination found across the US Department of Energy (DOE) complex has received considerable attention from the government and public alike. A massive site characterization and cleanup effort has been underway for several years and is expected to continue for several decades more. The scope of the cleanup effort ranges from soil excavation and treatment to complete dismantling and decontamination of whole buildings. To its credit, DOE has supported research and development of new technologies to speed up and reduce the cost of this effort. One area in particular has been the development of portable instrumentation that can be used to perform analytical measurements in the field. This approach provides timely data to decision makers and eliminates the expense, delays, and uncertainties of sample preservation, transport, storage, and laboratory analysis. In this program, we have developed and demonstrated in the field a transportable, high performance Raman spectrograph that can be used to detect and identify contaminants in a variety of scenarios. With no moving parts, the spectrograph is rugged and can perform many Raman measurements in situ with flexible fiber optic sampling probes. The instrument operates under computer control and a software package has been developed to collect and process spectral data. A collection of Raman spectra for 200 contaminants of DOE importance has been compiled in a searchable format to assist in the identification of unknown contaminants in the field

  14. Analysis of mercury in environmental samples

    International Nuclear Information System (INIS)

    Schoester, F.S.

    1992-01-01

    The possibility to determine mercury in sub-ppm levels in biological samples has been studied through neutron activation analysis , using as standards aliquots of mercury nitrate solution, deposited on treated cellulose with thio acetamide and ammonia. Sample and standards were irradiated simultaneously in quartz ampoules during 8 hours at a flux of 5 x 10 13 n/cm 2 s and were counted in a hyper pure germanium detector after 4 weeks of decay. Corrections were made for the interference of 75 Se in the 279 keV photopeak used in the determination. The results obtained for the reference materials IAEA-H-8(horse kidney), IAEA-M A-A2(fish flesh) and IAEA-M A-A-1(cope pod homogenate) were (0.91±0.07), (0.56±0.02) and (0.17±0.02) ppm, versus certified values of (0.91±0.08), (0.47±0.02) and (0.28±0.01) ppm respectively. (EMR). 54 refs., 8 app

  15. A kinetic analysis of manual wheelchair propulsion during start-up on select indoor and outdoor surfaces

    NARCIS (Netherlands)

    Koontz, AM; Cooper, RA; Boninger, ML; Yang, YS; Impink, BG; van der Woude, LHV

    2005-01-01

    The objective of this study was to conduct a kinetic analysis of manual wheelchair propulsion during start-LIP on select indoor and Outdoor surfaces. Eleven manual wheelchairs were fitted with a SMART(Wheel) and their users were asked to Push on a Course consisting of high- and low-pile carpet,

  16. Analysis of thermoluminescence kinetics of Mg2SiO4:Tb compounds employing an interactive model

    International Nuclear Information System (INIS)

    Marcazzo, J.; Prokic, M.; Santiago, M.; Molina, P.; Caselli, E.

    2009-01-01

    The kinetics involved in the thermoluminescence (TL) of Mg 2 SiO 4 :Tb compounds has been investigated by unfolding glow curves employing both the General Order model and a model that takes into account interactions among traps. The dependence of the glow curve shape on dose is only correctly described if interaction among traps is included in the analysis.

  17. Sensitivity analysis of autotrophic N removal by a granule based bioreactor: Influence of mass transfer versus microbial kinetics

    DEFF Research Database (Denmark)

    Vangsgaard, Anna Katrine; Mauricio Iglesias, Miguel; Gernaey, Krist

    2012-01-01

    A comprehensive and global sensitivity analysis was conducted under a range of operating conditions. The relative importance of mass transfer resistance versus kinetic parameters was studied and found to depend on the operating regime as follows: Operating under the optimal loading ratio of 1.90 ...

  18. Direct dynamic kinetic analysis and computer simulation of growth of Clostridium perfringens in cooked turkey during cooling

    Science.gov (United States)

    This research applied a new one-step methodology to directly construct a tertiary model for describing the growth of C. perfringens in cooked turkey meat under dynamically cooling conditions. The kinetic parameters of the growth models were determined by numerical analysis and optimization using mu...

  19. Environmental risk analysis of hazardous material rail transportation.

    Science.gov (United States)

    Saat, Mohd Rapik; Werth, Charles J; Schaeffer, David; Yoon, Hongkyu; Barkan, Christopher P L

    2014-01-15

    An important aspect of railroad environmental risk management involves tank car transportation of hazardous materials. This paper describes a quantitative, environmental risk analysis of rail transportation of a group of light, non-aqueous-phase liquid (LNAPL) chemicals commonly transported by rail in North America. The Hazardous Materials Transportation Environmental Consequence Model (HMTECM) was used in conjunction with a geographic information system (GIS) analysis of environmental characteristics to develop probabilistic estimates of exposure to different spill scenarios along the North American rail network. The risk analysis incorporated the estimated clean-up cost developed using the HMTECM, route-specific probability distributions of soil type and depth to groundwater, annual traffic volume, railcar accident rate, and tank car safety features, to estimate the nationwide annual risk of transporting each product. The annual risk per car-mile (car-km) and per ton-mile (ton-km) was also calculated to enable comparison between chemicals and to provide information on the risk cost associated with shipments of these products. The analysis and the methodology provide a quantitative approach that will enable more effective management of the environmental risk of transporting hazardous materials. Published by Elsevier B.V.

  20. Evolution of inhibitor-resistant natural mutant forms of HIV-1 protease probed by pre-steady state kinetic analysis.

    Science.gov (United States)

    Zakharova, Maria Yu; Kuznetsova, Alexandra A; Kaliberda, Elena N; Dronina, Maria A; Kolesnikov, Alexander V; Kozyr, Arina V; Smirnov, Ivan V; Rumsh, Lev D; Fedorova, Olga S; Knorre, Dmitry G; Gabibov, Alexander G; Kuznetsov, Nikita A

    2017-11-01

    Pre-steady state kinetic analysis of mechanistic features of substrate binding and processing is crucial for insight into the evolution of inhibitor-resistant forms of HIV-1 protease. These data may provide a correct vector for rational drug design assuming possible intrinsic dynamic effects. These data should also give some clues to the molecular mechanism of protease action and resistance to inhibitors. Here we report pre-steady state kinetics of the interaction of wild type or mutant forms of HIV-1 protease with a FRET-labeled peptide. The three-stage "minimal" kinetic scheme with first and second reversible steps of substrate binding and with following irreversible peptide cleavage step adequately described experimental data. For the first time, a set of "elementary" kinetic parameters of wild type HIV-1 protease and its natural mutant inhibitor-resistant forms MDR-HM, ANAM-11 and prDRV4 were compared. Inhibitors of the first and second generation were used to estimate the inhibitory effects on HIV-1 protease activity. The resulting set of kinetic data supported that the mutant forms are kinetically unaffected by inhibitors of the first generation, proving their functional resistance to these compounds. The second generation inhibitor darunavir inhibited mutant forms MDR-HM and ANAM-11, but was ineffective against prDRV4. Our kinetic data revealed that these inhibitors induced different conformational changes in the enzyme and, thereby they have different mode of binding in the enzyme active site. These data confirmed hypothesis that the driving force of the inhibitor-resistance evolution is disruption of enzyme-inhibitor complex by changing of the contact network in the inhibitor binding site. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  1. Fuzzy Clustering Analysis in Environmental Impact Assessment--A Complement Tool to Environmental Quality Index.

    Science.gov (United States)

    Kung, Hsiang-Te; And Others

    1993-01-01

    In spite of rapid progress achieved in the methodological research underlying environmental impact assessment (EIA), the problem of weighting various parameters has not yet been solved. This paper presents a new approach, fuzzy clustering analysis, which is illustrated with an EIA case study on Baoshan-Wusong District in Shanghai, China. (Author)

  2. Entropy Analysis of Kinetic Flux Vector Splitting Schemes for the Compressible Euler Equations

    Science.gov (United States)

    Shiuhong, Lui; Xu, Jun

    1999-01-01

    Flux Vector Splitting (FVS) scheme is one group of approximate Riemann solvers for the compressible Euler equations. In this paper, the discretized entropy condition of the Kinetic Flux Vector Splitting (KFVS) scheme based on the gas-kinetic theory is proved. The proof of the entropy condition involves the entropy definition difference between the distinguishable and indistinguishable particles.

  3. Kinetic analysis of the thermal isomerisation pathways in an asymmetric double azobenzene switch

    NARCIS (Netherlands)

    Robertus, Jort; Reker, Siebren F.; Pijper, Thomas C.; Deuzeman, Albert; Browne, Wesley R.; Feringa, Ben L.

    2012-01-01

    Here we report a photochemical and kinetic study of the thermal relaxation reaction of a double azobenzene system, in which two azobenzene photochromic units are connected via a phenyl ring. Upon UV irradiation, three thermally unstable isomers are formed. Kinetic studies using arrayed H-1-NMR

  4. Machine vision analysis for industrial beet color change kinetics and total soluble solid content

    Science.gov (United States)

    A machine vision system (MVS) for the measurement of color change kinetics in crushed industrial beet to evaluate the total soluble solid content (°Brix) was developed in this study. It is expected that higher the °Brix faster the color change and modeling this color change kinetics helps in assessi...

  5. Diffusive transport of organic vapors in the unsaturated zone with kinetically-controlled volatilization and dissolution: analytical model and analysis

    Science.gov (United States)

    Zaidel, Jacob; Russo, David

    1994-12-01

    Kinetically-controlled volatilization and dissolution of nonaqueous-phase liquids (NAPL's) in the unsaturated (vadose) zone are a more general model as compared to the usually used local equilibrium model of mass transfer. This paper presents a one-dimensional vertical model of kinetically-controlled diffusive transport of organic vapors pertinent to pollution caused by a relatively long, ground surface-originating, mainly horizontally-spread leak of NAPL, the volatile compound of which undergoes sorption and degradation in the soil. Analytical solutions of this model are applicable to homogeneous soils with ground surface fully open to the atmosphere. Application of the solutions to several examples demonstrates the role of kinetically-controlled volatilization and dissolution at both early and advanced stages of the transport process. Asymptotic analysis of the outlined solutions is employed in order to examine the depletion of the contaminant source.

  6. Sum over Histories Representation for Kinetic Sensitivity Analysis: How Chemical Pathways Change When Reaction Rate Coefficients Are Varied.

    Science.gov (United States)

    Bai, Shirong; Davis, Michael J; Skodje, Rex T

    2015-11-12

    The sensitivity of kinetic observables is analyzed using a newly developed sum over histories representation of chemical kinetics. In the sum over histories representation, the concentrations of the chemical species are decomposed into the sum of probabilities for chemical pathways that follow molecules from reactants to products or intermediates. Unlike static flux methods for reaction path analysis, the sum over histories approach includes the explicit time dependence of the pathway probabilities. Using the sum over histories representation, the sensitivity of an observable with respect to a kinetic parameter such as a rate coefficient is then analyzed in terms of how that parameter affects the chemical pathway probabilities. The method is illustrated for species concentration target functions in H2 combustion where the rate coefficients are allowed to vary over their associated uncertainty ranges. It is found that large sensitivities are often associated with rate limiting steps along important chemical pathways or by reactions that control the branching of reactive flux.

  7. Application of multicriteria decision analysis in environmental decision making.

    Science.gov (United States)

    Kiker, Gregory A; Bridges, Todd S; Varghese, Arun; Seager, P Thomas P; Linkov, Igor

    2005-04-01

    Decision making in environmental projects can be complex and seemingly intractable, principally because of the inherent trade-offs between sociopolitical, environmental, ecological, and economic factors. The selection of appropriate remedial and abatement strategies for contaminated sites, land use planning, and regulatory processes often involves multiple additional criteria such as the distribution of costs and benefits, environmental impacts for different populations, safety, ecological risk, or human values. Some of these criteria cannot be easily condensed into a monetary value, partly because environmental concerns often involve ethical and moral principles that may not be related to any economic use or value. Furthermore, even if it were possible to aggregate multiple criteria rankings into a common unit, this approach would not always be desirable because the ability to track conflicting stakeholder preferences may be lost in the process. Consequently, selecting from among many different alternatives often involves making trade-offs that fail to satisfy 1 or more stakeholder groups. Nevertheless, considerable research in the area of multicriteria decision analysis (MCDA) has made available practical methods for applying scientific decision theoretical approaches to complex multicriteria problems. This paper presents a review of the available literature and provides recommendations for applying MCDA techniques in environmental projects. A generalized framework for decision analysis is proposed to highlight the fundamental ingredients for more structured and tractable environmental decision making.

  8. Ash contents of foodstuff samples in environmental radioactivity analysis

    International Nuclear Information System (INIS)

    Oikawa, Shinji; Ohta, Hiroshi; Hayano, Kazuhiko; Nonaka, Nobuhiro

    2004-01-01

    Statistical data of the ash content in various environmental samples obtained from an environmental radioactivity survey project commissioned by the Japanese government of Science and Technology Agency (at present Ministry of Education, Culture, Sports, Sciences and Technology) during the past 10 years are expressed for establishing a standard of ash content in environmental samples based on radioactivity analysis. The ash content for some kinds of environmental samples such as dietary food, milk, Japanese radish, spinach, fish, green tea and potato was reviewed in the light of statistical and stochastic viewpoints. For all of the samples reviewed in this paper, the coefficient of variation varied from 4.7% for milk to 36.3% for cabbage. Dietary food and milk samples were reviewed more than 1900 and 1400 samples, respectively. Especially, ash content of dietary food depended mainly on the dietary culture reflected on the period. However it showed an almost invariant distribution within 18.7% of coefficient of variation during the past 10 years. Pretreatment of environmental samples especially ashing processes are important from the viewpoint on environmental radioactivity analysis, which is one of the especial fields in analytical chemistry. Statistical reviewed data obtained in this paper may be useful for sample preparation. (author)

  9. Quantitative analysis of ibuprofen in pharmaceuticals and human control serum using kinetic spectrophotometry

    Directory of Open Access Journals (Sweden)

    SNEZANA S. MITIC

    2008-08-01

    Full Text Available The aim of this work was to develop a new kinetic spectrophoto-metric method for the determination of ibuprofen in pharmaceutical for-mulations. Ibuprofen was determined in an acidic ethanolic medium by monitoring the rate of appearance of 1-nitroso-2-naphthol, resulting from the displacement by ibuprofen of Co(III from the tris(1-nitroso-2-naptholatocobalt(III complex. The optimum operating conditions regarding reagent concentrations and temperature were established. The tangent method was adopted for constructing the calibration curve, which was found to be linear over the concentration range 0.21–1.44 and 1.44–2.06 µg ml-1. The optimized conditions yielded a theoretical detection limit of 0.03 µg ml-1 based on the 3.3 S0 criterion. The interference effects of the usual excipients of powdery drugs, foreign ions and amino acids on the reaction rate were studied in order to assess the selectivity of the method. The developed procedure was successfully applied for the rapid determination of ibuprofen in commercial pharmaceutical formulations and human control serum. The unique features of this procedure are that the determination can be performed at room temperature and the analysis time is short. The newly developed method is simple, inexpensive and efficient for use in the analysis of a large number of samples.

  10. Thermal analysis and kinetics of coal during oxy-fuel combustion

    Science.gov (United States)

    Kosowska-Golachowska, Monika

    2017-08-01

    The pyrolysis and oxy-fuel combustion characteristics of Polish bituminous coal were studied using non-isothermal thermogravimetric analysis. Pyrolysis tests showed that the mass loss profiles were almost similar up to 870°C in both N2 and CO2 atmospheres, while further mass loss occurred in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Replacement of N2 in the combustion environment by CO2 delayed the combustion of bituminous coal. At elevated oxygen levels, TG/DTG profiles shifted through lower temperature zone, ignition and burnout temperatures decreased and mass loss rate significantly increased and complete combustion was achieved at lower temperatures and shorter times. Kinetic analysis for the tested coal was performed using Kissinger-Akahira-Sunose (KAS) method. The activation energies of bituminous coal combustion at the similar oxygen content in oxy-fuel with that of air were higher than that in air atmosphere. The results indicated that, with O2 concentration increasing, the activation energies decreased.

  11. Comparative Kinetic Analysis of Closed-Ended and Open-Ended Porous Sensors

    Science.gov (United States)

    Zhao, Yiliang; Gaur, Girija; Mernaugh, Raymond L.; Laibinis, Paul E.; Weiss, Sharon M.

    2016-09-01

    Efficient mass transport through porous networks is essential for achieving rapid response times in sensing applications utilizing porous materials. In this work, we show that open-ended porous membranes can overcome diffusion challenges experienced by closed-ended porous materials in a microfluidic environment. A theoretical model including both transport and reaction kinetics is employed to study the influence of flow velocity, bulk analyte concentration, analyte diffusivity, and adsorption rate on the performance of open-ended and closed-ended porous sensors integrated with flow cells. The analysis shows that open-ended pores enable analyte flow through the pores and greatly reduce the response time and analyte consumption for detecting large molecules with slow diffusivities compared with closed-ended pores for which analytes largely flow over the pores. Experimental confirmation of the results was carried out with open- and closed-ended porous silicon (PSi) microcavities fabricated in flow-through and flow-over sensor configurations, respectively. The adsorption behavior of small analytes onto the inner surfaces of closed-ended and open-ended PSi membrane microcavities was similar. However, for large analytes, PSi membranes in a flow-through scheme showed significant improvement in response times due to more efficient convective transport of analytes. The experimental results and theoretical analysis provide quantitative estimates of the benefits offered by open-ended porous membranes for different analyte systems.

  12. A Sensitivity Analysis Approach to Identify Key Environmental Performance Factors

    Directory of Open Access Journals (Sweden)

    Xi Yu

    2014-01-01

    Full Text Available Life cycle assessment (LCA is widely used in design phase to reduce the product’s environmental impacts through the whole product life cycle (PLC during the last two decades. The traditional LCA is restricted to assessing the environmental impacts of a product and the results cannot reflect the effects of changes within the life cycle. In order to improve the quality of ecodesign, it is a growing need to develop an approach which can reflect the changes between the design parameters and product’s environmental impacts. A sensitivity analysis approach based on LCA and ecodesign is proposed in this paper. The key environmental performance factors which have significant influence on the products’ environmental impacts can be identified by analyzing the relationship between environmental impacts and the design parameters. Users without much environmental knowledge can use this approach to determine which design parameter should be first considered when (redesigning a product. A printed circuit board (PCB case study is conducted; eight design parameters are chosen to be analyzed by our approach. The result shows that the carbon dioxide emission during the PCB manufacture is highly sensitive to the area of PCB panel.

  13. New trends in sample preparation techniques for environmental analysis.

    Science.gov (United States)

    Ribeiro, Cláudia; Ribeiro, Ana Rita; Maia, Alexandra S; Gonçalves, Virgínia M F; Tiritan, Maria Elizabeth

    2014-01-01

    Environmental samples include a wide variety of complex matrices, with low concentrations of analytes and presence of several interferences. Sample preparation is a critical step and the main source of uncertainties in the analysis of environmental samples, and it is usually laborious, high cost, time consuming, and polluting. In this context, there is increasing interest in developing faster, cost-effective, and environmentally friendly sample preparation techniques. Recently, new methods have been developed and optimized in order to miniaturize extraction steps, to reduce solvent consumption or become solventless, and to automate systems. This review attempts to present an overview of the fundamentals, procedure, and application of the most recently developed sample preparation techniques for the extraction, cleanup, and concentration of organic pollutants from environmental samples. These techniques include: solid phase microextraction, on-line solid phase extraction, microextraction by packed sorbent, dispersive liquid-liquid microextraction, and QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe).

  14. Analysis of the environmental impact generated by nuclear activities

    International Nuclear Information System (INIS)

    Lazar, Roxana Elena; Dumitrescu, Maria

    2000-01-01

    Assessment of environmental impact represents one of the most formalized examples of interdisciplinary approach. After more then a century from the introduction of the concept of environmental impact assessment, this undertaking still represents an amalgamation of mini-studies based on pre-determined approaches rather than a genuine integrated document. This work presents the most important and adequate techniques of analysis of environmental impact generated by nuclear activities starting from identification of the events causing negative effects upon environment (by using checking list, the matrices and the cause-effect diagram) and radiation dose determination up to the decision making process. To preserve environment integrity the human factor should be re-evaluated as well as its active participation in formation and settling of an real environmental culture

  15. Environmental pressures from European consumption and production. A study in integrated environmental and economic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Watson, D. [Copenhagen Resource Institute, Copenhagen (Denmark); Fernandez, J.A.; Wittmer, D. [Wuppertal Institute, Wuppertal (Germany); Gravgaerd Pedersen, O. [Statistics Denmark, Copenhagen (Denmark); European Topic Centre on Sustainable Consumption and Production, Copenhagen (Denmark)

    2013-03-15

    Environmental pressures from European consumption and production shows how economic and environmental data can be integrated to analyse environmental performance and material efficiency of whole economies as well as their individual elements. The analyses presented in the report provide policy makers with a tool to target economic incentives and information campaigns, encouraging a shift to more sustainable production and consumption patterns in order to reduce Europe's global footprint. The report discusses two analytical approaches. The production-based method considers direct environmental pressures caused by European industries and service providers - for example, the extraction of material resources by the mining and quarrying sector, air pollutants from power stations, greenhouse gas emissions from agriculture and so on. The consumption-based method focuses on the indirect environmental pressures caused by European consumers. In this approach, the direct production-related pressures are attributed to broad groups of products and services, also taking into account pressures that are embodied in goods imported into the EU. Using Environmentally Extended Input Output Analysis (EE-IOA) it is possible to estimate the environmental pressures ultimately generated by individual product groups and also by European consumption as a whole. Four types of environmental pressures are considered by the report: raw material use, greenhouse gas emissions, acidifying air emissions, and air pollutants leading to harmful ground-level ozone. However, the method has the potential to assess many other types of environmental pressure including land use, water use, waste generation and energy use. Thanks to the conceptual consistency between the system of national economic accounts and environmental accounts, data on environmental pressures is directly comparable to economic expenditure. Policy makers can thus see which sectors have been most successful in decoupling

  16. WATERSHED SELECTION FOR ENVIRONMENTAL REHABILITATION USING MULTICRITERIA ANALYSIS

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo da Silva Francisco

    2009-10-01

    Full Text Available The Anhumas creek watershed, in the region of Campinas, São Paulo State, Brazil, is degraded also as a result of unplanned land use of its riparian zones, considered Permanent Preservation Areas (APP. Therefore, river flow is unstable, promoting frequent flood damages, besides the lack of several environmental functions of its APPs. Environmental recovery of a degraded area requires a comprehensive effort, often multidisciplinary. Multicriterial analysis is a tool which allows gathering a diversity of attributes of the studied subject, weighing and valuating them, helping in the decision making effort. This work aims to apply two methods of multicriteria analysis to optimize the selection of a watershed for an environmental recovery study of APPs in the Anhumas watershed. The Anhumas watershed was divided in 7 sub-basins aiming the selection of one of those to implement an environmental planning study and to establish and rank areas that should be prioritized for recovery. Thirteen environmental criteria were selected for application of multicriteria analysis using the methods of Compromise Programming (PC and Cooperative Game Theory (CGT. Relevance of each criterion to the analysis was given by a questionnaire answered by specialists. Basin selection results showed no difference neither between PC and CGT nor between mean or mode used to standardize weights given by specialists. Multicriteria analysis was effective, but allowed enough flexibility for the decision maker (DM to adjust undesired analysis distortions. After DM adjustments, the priority basins were ranked as basins 4 > 7 > 5 > 6 > 2 > 3 > 1. Important procedures when carrying out such an analysis were to avoid conceptual overlapping among different criteria, to implement appropriate value judgment for each criterion and to use decision maker expertise to supplement weights obtained with specialists.

  17. Kinetic modelling and meta-analysis of the B. subtilis SigA regulatory network during spore germination and outgrowth.

    Science.gov (United States)

    Ramaniuk, O; Černý, M; Krásný, L; Vohradský, J

    2017-08-01

    This study describes the meta-analysis and kinetic modelling of gene expression control by sigma factor SigA of Bacillus subtilis during germination and outgrowth based on microarray data from 14 time points. The analysis computationally models the direct interaction among SigA, SigA-controlled sigma factor genes (sigM, sigH, sigD, sigX), and their target genes. Of the >800 known genes in the SigA regulon, as extracted from databases, 311 genes were analysed, and 190 were confirmed by the kinetic model as being controlled by SigA. For the remaining genes, alternative regulators satisfying kinetic constraints were suggested. The kinetic analysis suggested another 214 genes as potential SigA targets. The modelling was able to (i) create a particular SigA-controlled gene expression network that is active under the conditions for which the expression time series was obtained, and where SigA is the dominant regulator, (ii) suggest new potential SigA target genes, and (iii) find other possible regulators of a given gene or suggest a new mechanism of its control by identifying a matching profile of unknown regulator(s). Selected predicted regulatory interactions were experimentally tested, thus validating the model. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Effect of exercise on kinetic gait analysis of dogs afflicted by osteoarthritis.

    Science.gov (United States)

    Beraud, R; Moreau, M; Lussier, B

    2010-01-01

    To evaluate the effects of moderate exercise on kinetic gait analysis using a force platform in dogs with hindlimb lameness due to osteoarthritis (OA). Ten control dogs (Control) and 10 dogs presented with chronic and stable hindlimb lameness (OA) were recruited. Dogs were subjected to force platform gait analysis to determine baseline data. They were thereafter trotted for a distance of 1.2 km on a short leash, lead by the same handler at a gait convenient for each of them (ranging from slow to fast trot), after which the gait analysis was immediately repeated to determine post-exercise values. Peak and impulse of the vertical and braking / propulsion forces were analysed using a linear model for repeated measures and Bonferroni sequential correction. In the Control group, the differences between baseline and post-exercise data were not significant. Conversely, post-exercise peak (p = 0.020) and impulse (p = 0.009) values of the vertical force, as well as the peak of the propulsion force (p = 0.009) values were significantly lower than baseline in the OA group. This study demonstrates the significant effect of a moderate amount of exercise in exacerbating hindlimb lameness in dogs clinically afflicted by OA. It is suggested that: 1) exercise should be considered as a potential factor of variation in future force platform gait analyses and an effort should be made to limit bias in data recording; and 2) an exercise-based protocol could be added to the standard force platform gait analysis to potentially increase its sensitivity in the detection of lame dogs.

  19. Improving estimation of kinetic parameters in dynamic force spectroscopy using cluster analysis

    Science.gov (United States)

    Yen, Chi-Fu; Sivasankar, Sanjeevi

    2018-03-01

    Dynamic Force Spectroscopy (DFS) is a widely used technique to characterize the dissociation kinetics and interaction energy landscape of receptor-ligand complexes with single-molecule resolution. In an Atomic Force Microscope (AFM)-based DFS experiment, receptor-ligand complexes, sandwiched between an AFM tip and substrate, are ruptured at different stress rates by varying the speed at which the AFM-tip and substrate are pulled away from each other. The rupture events are grouped according to their pulling speeds, and the mean force and loading rate of each group are calculated. These data are subsequently fit to established models, and energy landscape parameters such as the intrinsic off-rate (koff) and the width of the potential energy barrier (xβ) are extracted. However, due to large uncertainties in determining mean forces and loading rates of the groups, errors in the estimated koff and xβ can be substantial. Here, we demonstrate that the accuracy of fitted parameters in a DFS experiment can be dramatically improved by sorting rupture events into groups using cluster analysis instead of sorting them according to their pulling speeds. We test different clustering algorithms including Gaussian mixture, logistic regression, and K-means clustering, under conditions that closely mimic DFS experiments. Using Monte Carlo simulations, we benchmark the performance of these clustering algorithms over a wide range of koff and xβ, under different levels of thermal noise, and as a function of both the number of unbinding events and the number of pulling speeds. Our results demonstrate that cluster analysis, particularly K-means clustering, is very effective in improving the accuracy of parameter estimation, particularly when the number of unbinding events are limited and not well separated into distinct groups. Cluster analysis is easy to implement, and our performance benchmarks serve as a guide in choosing an appropriate method for DFS data analysis.

  20. Integrated Analysis of Contractile Kinetics, Force Generation, and Electrical Activity in Single Human Stem Cell-Derived Cardiomyocytes

    Directory of Open Access Journals (Sweden)

    Jan David Kijlstra

    2015-12-01

    Full Text Available The quantitative analysis of cardiomyocyte function is essential for stem cell-based approaches for the in vitro study of human cardiac physiology and pathophysiology. We present a method to comprehensively assess the function of single human pluripotent stem cell-derived cardiomyocyte (hPSC-CMs through simultaneous quantitative analysis of contraction kinetics, force generation, and electrical activity. We demonstrate that statistical analysis of movies of contracting hPSC-CMs can be used to quantify changes in cellular morphology over time and compute contractile kinetics. Using a biomechanical model that incorporates substrate stiffness, we calculate cardiomyocyte force generation at single-cell resolution and validate this approach with conventional traction force microscopy. The addition of fluorescent calcium indicators or membrane potential dyes allows the simultaneous analysis of contractility and calcium handling or action potential morphology. Accordingly, our approach has the potential for broad application in the study of cardiac disease, drug discovery, and cardiotoxicity screening.

  1. Toluene combustion: reaction paths, thermochemical properties, and kinetic analysis for the methylphenyl radical + O2 reaction.

    Science.gov (United States)

    da Silva, Gabriel; Chen, Chiung-Chu; Bozzelli, Joseph W

    2007-09-06

    Aromatic compounds such as toluene and xylene are major components of many fuels. Accurate kinetic mechanisms for the combustion of toluene are, however, incomplete, as they do not accurately model experimental results such as strain rates and ignition times and consistently underpredict conversion. Current kinetic mechanisms for toluene combustion neglect the reactions of the methylphenyl radicals, and we believe that this is responsible, in part, for the shortcomings of these models. We also demonstrate how methylphenyl radical formation is important in the combustion and pyrolysis of other alkyl-substituted aromatic compounds such as xylene and trimethylbenzene. We have studied the oxidation reactions of the methylphenyl radicals with O2 using computational ab initio and density functional theory methods. A detailed reaction submechanism is presented for the 2-methylphenyl radical + O2 system, with 16 intermediates and products. For each species, enthalpies of formation are calculated using the computational methods G3 and G3B3, with isodesmic work reactions used to minimize computational errors. Transition states are calculated at the G3B3 level, yielding high-pressure limit elementary rate constants as a function of temperature. For the barrierless methylphenyl + O2 and methylphenoxy + O association reactions, rate constants are determined from variational transition state theory. Multichannel, multifrequency quantum Rice-Ramsperger-Kassel (qRRK) theory, with master equation analysis for falloff, provides rate constants as a function of temperature and pressure from 800 to 2400 K and 1 x 10(-4) to 1 x 10(3) atm. Analysis of our results shows that the dominant pathways for reaction of the three isomeric methylphenyl radicals is formation of methyloxepinoxy radicals and subsequent ring opening to methyl-dioxo-hexadienyl radicals. The next most important reaction pathway involves formation of methylphenoxy radicals + O in a chain branching process. At lower

  2. Characterizing the Estrogenic Potential of 1060 Environmental Chemicals by Assessing Growth Kinetics in T47D Cells

    Science.gov (United States)

    In order to detect environmental chemicals that pose a risk of endocrine disruption, high-throughput screening (HTS) tests capable of testing thousands of environmental chemicals are needed. Alteration of estrogen signaling has been implicated in a variety of adverse health effec...

  3. Guidebook in using Cost Benefit Analysis and strategic environmental assessment for environmental planning in China

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Environmental planning in China may benefit from greater use of Cost Benefit Analysis (CBA) and Strategic Environmental Assessment (SEA) methodologies. We provide guidance on using these methodologies. Part I and II show the principles behind the methodologies as well as their theoretical structure. Part III demonstrates the methodologies in action in a range of different good practice examples. The case studies and theoretical expositions are intended to teach by way of example as well as by understanding the principles, and to help planners use the methodologies as correctly as possible.(auth)

  4. Sampling and chemical analysis in environmental samples around Nuclear Power Plants and some environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Woo; Han, Man Jung; Cho, Seong Won; Cho, Hong Jun; Oh, Hyeon Kyun; Lee, Jeong Min; Chang, Jae Sook [KORTIC, Taejon (Korea, Republic of)

    2002-12-15

    Twelve kinds of environmental samples such as soil, seawater, underground water, etc. around Nuclear Power Plants(NPPs) were collected. Tritium chemical analysis was tried for the samples of rain water, pine-needle, air, seawater, underground water, chinese cabbage, a grain of rice and milk sampled around NPPs, and surface seawater and rain water sampled over the country. Strontium in the soil that sere sampled at 60 point of district in Korea were analyzed. Tritium were sampled at 60 point of district in Korea were analyzed. Tritium were analyzed in 21 samples of surface seawater around the Korea peninsular that were supplied from KFRDI(National Fisheries Research and Development Institute). Sampling and chemical analysis environmental samples around Kori, Woolsung, Youngkwang, Wooljin Npps and Taeduk science town for tritium and strontium analysis was managed according to plans. Succeed to KINS after all samples were tried.

  5. Environmental risk analysis of hazardous material rail transportation

    International Nuclear Information System (INIS)

    Saat, Mohd Rapik; Werth, Charles J.; Schaeffer, David; Yoon, Hongkyu; Barkan, Christopher P.L.

    2014-01-01

    Highlights: • Comprehensive, nationwide risk assessment of hazardous material rail transportation. • Application of a novel environmental (i.e. soil and groundwater) consequence model. • Cleanup cost and total shipment distance are the most significant risk factors. • Annual risk varies from $20,000 to $560,000 for different products. • Provides information on the risk cost associated with specific product shipments. -- Abstract: An important aspect of railroad environmental risk management involves tank car transportation of hazardous materials. This paper describes a quantitative, environmental risk analysis of rail transportation of a group of light, non-aqueous-phase liquid (LNAPL) chemicals commonly transported by rail in North America. The Hazardous Materials Transportation Environmental Consequence Model (HMTECM) was used in conjunction with a geographic information system (GIS) analysis of environmental characteristics to develop probabilistic estimates of exposure to different spill scenarios along the North American rail network. The risk analysis incorporated the estimated clean-up cost developed using the HMTECM, route-specific probability distributions of soil type and depth to groundwater, annual traffic volume, railcar accident rate, and tank car safety features, to estimate the nationwide annual risk of transporting each product. The annual risk per car-mile (car-km) and per ton-mile (ton-km) was also calculated to enable comparison between chemicals and to provide information on the risk cost associated with shipments of these products. The analysis and the methodology provide a quantitative approach that will enable more effective management of the environmental risk of transporting hazardous materials

  6. Kinetic analysis of IgG antibodies to beta-amyloid oligomers with surface plasmon resonance.

    Science.gov (United States)

    Crisostomo, Amanda C; Dang, Loan; Digambaranath, Jyothi L; Klaver, Andrea C; Loeffler, David A; Payne, Jeremiah J; Smith, Lynnae M; Yokom, Adam L; Finke, John M

    2015-07-15

    Surface plasmon resonance was used to investigate the kinetics, affinity, and specificity of binding between anti-Aβ (beta-amyloid) IgG antibodies and oligomeric Aβ. Two factors were needed to accurately characterize the IgG binding kinetics. First, a bivalent model was necessary to properly fit the kinetic association and dissociation sensograms. Second, a high concentration of IgG was necessary to overcome a significant mass transport limitation that existed regardless of oligomer density on the sensor surface. Using high IgG concentrations and bivalent fits, consistent kinetic parameters were found at varying sensor surface ligand densities. A comparison of binding specificity, affinity, and kinetic flux between monoclonal and natural human anti-Aβ IgG antibodies revealed the following findings. First, monoclonal antibodies 6E10 and 4G8 single-site binding affinity is similar between Aβ oligomers and monomers. Second, natural human anti-Aβ IgG binding readily binds Aβ oligomers but does not bind monomers. Third, natural human anti-Aβ IgG binds Aβ oligomers with a higher affinity and kinetic flux than 6E10 and 4G8. Both the current analytical methodology and antibody binding profiles are important for advances in antibody drug development and kinetic biomarker applications for Alzheimer's disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Using multicriteria analysis to develop environmental flow scenarios ...

    African Journals Online (AJOL)

    DRIFT is an interactive, holistic approach for advising on environmental flows for rivers. The DRIFT methodology, together with multicriteria analysis (MCA), can be used to provide flow scenarios and descriptive summaries of their consequences in terms of the condition of the river ecosystem, for examination and ...

  8. Rainfall analysis for environmental applications in Maiduguri, Nigeria

    African Journals Online (AJOL)

    The F- and t-tests on the series showed consistency and stability of the variance and mean, respectively. It is therefore, concluded that the rainfall data can be used for further analysis and storm sewage facility design. Keywords: rainfall, trend, stationary, homogeneous, consistent. Global Journal of Environmental Sciences ...

  9. Environmental Impact and Hazards Analysis Critical Control Point ...

    African Journals Online (AJOL)

    Tsire is a local meat delicacy (kebab) in northern Nigeria, which has become popular and widely acceptable throughout the country and even beyond. Three production sites of tsire were evaluated for the environmental impact and hazard analysis critical control point (HACCP) on the microbiological and chemical qualities ...

  10. Environmental/Economic Analysis and Recycling of Wastes from Air ...

    African Journals Online (AJOL)

    Environmental and economic analysis was performed on the wastes from Air Liquid Nigeria Ltd. The company's waste water, spent oil, noise and air pollutants were examined. Results show no serious adverse impact on the ambient air quality. There was serious noise pollution problem around the factory hall and generator ...

  11. Photon-by-Photon Hidden Markov Model Analysis for Microsecond Single-Molecule FRET Kinetics.

    Science.gov (United States)

    Pirchi, Menahem; Tsukanov, Roman; Khamis, Rashid; Tomov, Toma E; Berger, Yaron; Khara, Dinesh C; Volkov, Hadas; Haran, Gilad; Nir, Eyal

    2016-12-29

    The function of biological macromolecules involves large-scale conformational dynamics spanning multiple time scales, from microseconds to seconds. Such conformational motions, which may involve whole domains or subunits of a protein, play a key role in allosteric regulation. There is an urgent need for experimental methods to probe the fastest of these motions. Single-molecule fluorescence experiments can in principle be used for observing such dynamics, but there is a lack of analysis methods that can extract the maximum amount of information from the data, down to the microsecond time scale. To address this issue, we introduce H 2 MM, a maximum likelihood estimation algorithm for photon-by-photon analysis of single-molecule fluorescence resonance energy transfer (FRET) experiments. H 2 MM is based on analytical estimators for model parameters, derived using the Baum-Welch algorithm. An efficient and effective method for the calculation of these estimators is introduced. H 2 MM is shown to accurately retrieve the reaction times from ∼1 s to ∼10 μs and even faster when applied to simulations of freely diffusing molecules. We further apply this algorithm to single-molecule FRET data collected from Holliday junction molecules and show that at low magnesium concentrations their kinetics are as fast as ∼10 4 s -1 . The new algorithm is particularly suitable for experiments on freely diffusing individual molecules and is readily incorporated into existing analysis packages. It paves the way for the broad application of single-molecule fluorescence to study ultrafast functional dynamics of biomolecules.

  12. High resolution gas chromatography in dedicated petrochemical and environmental analysis

    International Nuclear Information System (INIS)

    Nijs, R. De

    1990-01-01

    Turn key systems dedicated and designed for a special application in petrochemical as well as environmental analysis are used already for many years. However, the use of high resolution gas chromatography columns in this type of equipment is only performed recently. In petrochemistry, examples of this type of systems are analyzers for light hydrocarbons, inerts and oxygenates in petrochemical streams and natural gas. In environmental monitoring analyzers for hydrocarbons and halogenated hydrocarbons in air or waste water and surface water are of importance. The use of capillary gas chromatography columns in this kind of application is resulting, when compared with packed columns, in improved separation power, a higher speed of analysis and in most cases a lower detection limit. Because of the high separation power of capillary columns, when compared with packed columns, the amount of columns needed to obtain a certain separation is less and so the analysis is simplified, becoming more reliable. For environmental analysis the use of high resolution columns in combination with thermal desorption could trap techniques in the analysis of volatile organic compound (VOC) in air results in information on ppb or even ppt level pollution of hydrocarbon and halogenated hydrocarbons. For the analysis of VOC's in water purge and trap techniques are used in combination with high resolution gas chromatography. Applications and results obtained with above mentioned equipment will be discussed. Special attention will be given to the incorporation of high resolution chromatography in this type of equipment

  13. Environmental metabolomics: a SWOT analysis (strengths, weaknesses, opportunities, and threats).

    Science.gov (United States)

    Miller, Marion G

    2007-02-01

    Metabolomic approaches have the potential to make an exceptional contribution to understanding how chemicals and other environmental stressors can affect both human and environmental health. However, the application of metabolomics to environmental exposures, although getting underway, has not yet been extensively explored. This review will use a SWOT analysis model to discuss some of the strengths, weaknesses, opportunities, and threats that are apparent to an investigator venturing into this relatively new field. SWOT has been used extensively in business settings to uncover new outlooks and identify problems that would impede progress. The field of environmental metabolomics provides great opportunities for discovery, and this is recognized by a high level of interest in potential applications. However, understanding the biological consequence of environmental exposures can be confounded by inter- and intra-individual differences. Metabolomic profiles can yield a plethora of data, the interpretation of which is complex and still being evaluated and researched. The development of the field will depend on the availability of technologies for data handling and that permit ready access metabolomic databases. Understanding the relevance of metabolomic endpoints to organism health vs adaptation vs variation is an important step in understanding what constitutes a substantive environmental threat. Metabolomic applications in reproductive research are discussed. Overall, the development of a comprehensive mechanistic-based interpretation of metabolomic changes offers the possibility of providing information that will significantly contribute to the protection of human health and the environment.

  14. Environmental management in sugar-energy sector: a comparative analysis

    Directory of Open Access Journals (Sweden)

    Andréia Marize Rodrigues

    2014-11-01

    Full Text Available With the rise of the environmental variable in the business environment, companies started to give greater attention to strategies and practices focused on the rational use of natural resources and minimize the environmental impacts of their business operations. Many productive sectors stood out in the reflections on production and the environment, as is the case of the sugar energy industry, which constitutes a sector with a highly demanding industrial activity of natural resources, whether as sources of inputs as depositories of waste production. Thus, the aim of this paper is a comparative analysis of environmental practices of two sugar energy plants, both from the point of view of their operational strategy and regarding the suitability of the disposal of waste generated by the industrial area. It was concluded that, although many practices adopted by businesses are analogous, one of the studied plants have distinctive environmental performance, because of the increased attention given to the implementation of environmental practices and especially the inclusion of the environmental variable in their strategies.

  15. Proof-of-Concept Oil Shale Facility Environmental Analysis Program

    Energy Technology Data Exchange (ETDEWEB)

    1990-11-01

    The objectives of the Project are to demonstrate: (1) the Modified In- Situ (MIS) shale oil extraction process and (2) the application of CFBC technology using oil shale, coal and waste gas streams as fuels. The project will focus on evaluating and improving the efficiency and environmental performance of these technologies. The project will be modest by commercial standards. A 17-retort MIS system is planned in which two retorts will be processed simultaneously. Production of 1206-barrels per calendar day of raw shale oil and 46-megawatts of electricity is anticipated. West Virginia University coordinated an Environmental Analysis Program for the Project. Experts from around the country were retained by WVU to prepare individual sections of the report. These experts were exposed to all of OOSI`s archives and toured Tract C-b and Logan Wash. Their findings were incorporated into this report. In summary, no environmental obstacles were revealed that would preclude proceeding with the Project. One of the most important objectives of the Project was to verify the environmental acceptability of the technologies being employed. Consequently, special attention will be given to monitoring environmental factors and providing state of the art mitigation measures. Extensive environmental and socioeconomic background information has been compiled for the Tract over the last 15 years and permits were obtained for the large scale operations contemplated in the late 1970`s and early 1980`s. Those permits have been reviewed and are being modified so that all required permits can be obtained in a timely manner.

  16. INSTRUMENTATION AND BIOMECHANICAL MODEL FOR KINEMATIC AND KINETIC ANALYSIS OF UPPER LIMBS DURING GAIT WITH CRUTCHES

    Directory of Open Access Journals (Sweden)

    Enrique Pérez-Rizo

    2013-11-01

    Full Text Available The goal of this study was to develop a three-dimensional kinematic and kinetic model of the right upper extremity and a Lofstrand crutch in order to analyze joint displacements and loads during crutch-assisted gait. A Lofstrand crutch was instrumented with a six-component load cell to measure forces and moments at the crutch tip. The crutch and the right upper extremity of a subject were instrumented with markers to obtain kinematic data. A biomechanical model based on rigid bodies was implemented in biomechanical analysis software. To demonstrate the functionality of the model, a pilot test was conducted on one healthy individual during Lofstrand crutch-assisted gait. The shoulder extended during the support phase and flexed in the swing phase, the elbow flexed during the swing, and the wrist remained in extension throughout the cycle. In the shoulder and elbow joints, the predominant reaction forces were upward, whereas the internal force moments were flexion and extension, respectively. This tool will be useful when it comes to identifying risk factors for joint pathology associated with pattern gait, aid design or crutch overuse.

  17. Qualitative and kinetic analysis of torrefaction of lignocellulosic biomass using DSC-TGA-FTIR

    Directory of Open Access Journals (Sweden)

    Bimal Acharya

    2015-11-01

    Full Text Available Torrefaction is a thermochemical conversion technique to improve the fuel properties of lignocellulosic biomass by treating at temperature 200 ℃-300 ℃ in the minimum oxygen environment for a reasonable residence time. In this study, thermal decomposition and thermal activities of miscanthus and wheat straw during the torrefaction at 200 ℃, 275 ℃, and 300 ℃ in a nitrogen environment for 45 minutes of residence time are analyzed in a simultaneous thermogravimetric analyzer (micro TGA with a differential scanning calorimetry (DSC, and a macro-TGA. The output of the micro TGA is fed into the Fourier transform infrared spectrometry (FTIR and qualitative analysis of the gaseous product is carried out. The composition of different gas products during the torrefaction of biomass are compared critically and kinetics were analyzed. It is found that the weight loss due to degradation of initial biomass in second stage (torrefaction process is a much faster conversion process than the weight loss process in the first stage (drying process. The weight loss of biomass increases with increase in the residence time and torrefaction treatment temperatures. The yield after torrefaction is a solid bio-coal product. The torrefied product were less reactive and has nearly 25% better heating value than the raw biomass. Between the two feedstocks studied, torrefied miscanthus proved to be a more stable fuel than the torrefied wheat straw. The major gaseous components observed during torrefaction are water, carbon dioxide, carbon monoxide, 1,2-Dibromethylene.

  18. Kinetic and thermodynamic analysis of Bradyrhizobium japonicum PutA-membrane associations.

    Science.gov (United States)

    Zhang, Weimin; Krishnan, Navasona; Becker, Donald F

    2006-01-01

    In Escherichia coli, proline induces tight membrane binding of the PutA flavoenzyme and transforms PutA from a transcriptional repressor to a membrane-associated proline catabolic enzyme. In other gram-negative bacteria such as Bradyrhizobium japonicum, PutA lacks DNA binding activity and functions only as a proline catabolic enzyme. Here, we characterize the membrane binding properties of PutA from B. japonicum (BjPutA) to address whether proline regulates BjPutA-lipid binding similar to Escherichia coli PutA (EcPutA). Surface plasmon resonance (SPR) kinetic measurements of BjPutA-lipid binding show BjPutA forms a complex with lipids in the absence and presence of proline with similar dissociation constant (K(D)) values of 2.5 and 1.7nM, respectively. SPR experiments using differently charged lipid bilayers indicate BjPutA selectively binds negatively charged lipids, which contrasts with the charge independent membrane binding of EcPutA. Analysis of BjPutA-lipid binding by isothermal titration calorimetry at 25 degrees C revealed an endothermic binding reaction that is entropically driven. This work shows that BjPutA-membrane associations vary significantly from EcPutA.

  19. Kinetic analysis of the vasodilator and ganglionic blocking actions of N-acetylprocainamide.

    Science.gov (United States)

    Eudeikis, J R; Henthorn, T K; Lertora, J J; Atkinson, A J; Chao, G C; Kushner, W

    1982-01-01

    The hypotensive effects of N-acetylprocainamide (NAPA) were studied in anesthetized dogs and in a normal subject. In dogs, intravenous NAPA infusions reduced mean arterial pressure and the pressor response of the isolated, perfused gracilis muscle vascular bed to preganglionic, but not postganglionic, sympathetic stimulation. The kinetics of these effects were correlated with NAPA pharmacokinetics. The time course of NAPA concentrations in a hypothetical biophase was characterized, and the relationship between NAPA biophase concentrations and the intensity of the effects was determined. From these results, it was estimated that peak effects would occur in dogs 6.6 min after intravenous bolus injection of NAPA, and that biophase NAPA concentration would lower mean arterial pressure 0.39 mm Hg/microgram/ml and would attenuate by 0.224 mm Hg/microgram/ml the gracilis muscle vascular bed pressor response to preganglionic stimulation. In the normal subject, a similar analysis indicated that maximal hypotension would occur 8.0 min after intravenous NAPA injection, and that blood pressure would fall 0.40 mm Hg/microgram/ml relative to biophase NAPA concentrations. These results suggest that blood pressure should be monitored for at least 10 min after patients receive and intravenous NAPA injection, and that repeated NAPA doses probably should not be administered more frequently.

  20. Integrated kinematics-kinetics-plantar pressure data analysis: a useful tool for characterizing diabetic foot biomechanics.

    Science.gov (United States)

    Sawacha, Zimi; Guarneri, Gabriella; Cristoferi, Giuseppe; Guiotto, Annamaria; Avogaro, Angelo; Cobelli, Claudio

    2012-05-01

    The fundamental cause of lower-extremity complications in diabetes is chronic hyperglycemia leading to diabetic foot ulcer pathology. While the relationship between abnormal plantar pressure distribution and plantar ulcers has been widely investigated, little is known about the role of shear stress. Moreover, the mutual relationship among plantar pressure, shear stress, and abnormal kinematics in the etiology of diabetic foot has not been established. This lack of knowledge is determined by the lack of commercially available instruments which allow such a complex analysis. This study aims to develop a method for the simultaneous assessment of kinematics, kinetics, and plantar pressure on foot subareas of diabetic subjects by means of combining three commercial systems. Data were collected during gait on 24 patients (12 controls and 12 diabetic neuropathics) with a motion capture system synchronized with two force plates and two baropodometric systems. A four segment three-dimensional foot kinematics model was adopted for the subsegment angles estimation together with a three segment model for the plantar sub-area definition during gait. The neuropathic group exhibited significantly excessive plantar pressure, ground reaction forces on each direction, and a reduced loading surface on the midfoot subsegment (p<0.04). Furthermore the same subsegment displayed excessive dorsiflexion, external rotation, and eversion (p<0.05). Initial results showed that this methodology may enable a more appropriate characterization of patients at risk of foot ulcerations, and help planning prevention programs. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Synthesis and characterization of cement slurries additives with epoxy resins - kinetics, thermodynamic and calorimetric analysis

    International Nuclear Information System (INIS)

    Tavares, A.M.G.; Andrade Junior, M.A.S.; Cestari, A.R.; Vieira, E.F.S.

    2010-01-01

    Cement has been used in the world, presenting a wide versatility. However, due to its chemical nature, it is subject to several types of chemical damages, especially for agents of acidic nature. With the purpose of increase its life-time, new cement slurries have been modified with the addition of specific additives. The objective of this work is to modify cement slurries with epoxy resins, which promote higher resistance of those materials in relation to acid attacks. Three cement slurries were synthesized with epoxy resins and a standard slurries, which was composed by cement and water. After 30 days of hydration, the samples were characterized by XDR, FTIR and thermal analysis (TG and DSC). The hydration processes of the cement slurries were studied by heat-conduction microcalorimetry. A kinetic study of HCl interaction with the new slurries were performed by the batch methodology at 25, 35, 45 e 55 deg C. It was verified that the addition of the polymers delayed the processes of hydration of the slurries, decreasing the flow of heat released as a function of the amount of added resin and, increased the resistance of those slurries to the acid attack. (author)

  2. Comparative kinetic analysis of89 Sr,60 Co and65 Zn Uptake by human bone powder

    International Nuclear Information System (INIS)

    Abdel-Fatah, A.T.A.; Essa, M.W.A.; Mohamed, S.A.; Molokhia, M.K.

    1990-01-01

    Human bone powder samples were prepared from recent femurs. The Bone particles range between 30 and 40 MU in diameter. One portion of this powder was prepared fat-free (FFB), the second portion as protein-free (PFB) and the last portion was left as raw bone powder-(RB). The sequence of uptake of 89 Sr by these types of bone powder is : FFB > RB > PFB, while that of 60 Co and 65 Zn is: PFB > FFB > RB. Kinetic analysis of the uptake curves of the 3 isotopes indicated that these processes proceed in 3 distinct steps; very fast initial, moderate intermediate and slow last step. The obtained rates of uptake indicated that : (1) the uptake by PEB is faster in its third step than the other types, (2) the most predominant step in case of 89 Sr and 60 Co is the third step (ion exchange step) while in case of 65 Zn it is the first step (physical adsorption), (3) defatenisation or deproteinisation, in general, inhances the uptake process

  3. Kinetic analysis of interaction between N atoms and O-covered Ru(0001)

    Science.gov (United States)

    Kang, Kai; Kleyn, A. W.; Gleeson, M. A.

    2015-10-01

    Eley-Rideal (ER) reactions involving neutral atoms heavier than hydrogen reacting with adsorbed atoms of similar mass were first observed in recent molecular beam experiments by Zaharia et al. [Phys. Rev. Lett. 113, 053201 (2014)]. Through analysis of two types of measurements, they obtained different estimations for the N-O ER reaction cross section, one of which is unexpectedly high. This was qualitatively accounted for by invoking a secondary effect whereby the presence of N adatoms on the surface acted to "shield" O adatoms from prompt recombinative desorption. We apply a rate equation model that includes two ER processes involving different adsorbed species (N-Oad and N-Nad) and an N-adsorption process to the full-beam exposure subset of the experimental data in order to study the reaction kinetics. Values for the individual reaction cross sections are derived. The measured N2 response can be well described by the model, but it is insufficient to completely describe the NO response. Modeling of different exposures is used to evaluate the qualitative picture presented by Zaharia et al.

  4. Heterogeneous dissolution kinetics as a method of the granulometric analysis of polydispersed solids

    International Nuclear Information System (INIS)

    Melichar, F.; Pourova, D.; Simova, L.; Zvonickova, J.

    1976-05-01

    The principles of determining the granulometric composition of polydisperse solids from kinetic data on the solubilities thereof are given in the theoretical part of the report. The conditions are stated under which characteristic curves (equations) may be determined. These equations define the relationship between the dissolved polydisperse fraction and the relative decrease of the characteristic size of the polydisperse particles. The characteristic curves are specific for the given granulometric polydispersion state. The experimentally determined characteristic curves, which are expressed analytically by means of an equivalent function, are analyzed using three independent methods, which make it possible to determine the granulometric composition of the dissolved polydispersion: the method of the ''reversed geometrical model'', the Akselrud model method, the granulometric atlas method. The granulometric compositions determined by these methods are compared and discussed. The methods proposed may be considered as further applicable methods in the granulometric particle analysis within the size range of 1 to 700 μm defining predominantly the granulometric spectrum of the primary dispersion, i.e. the deagglomerated particles. (author)

  5. Kinetic analysis and chemical modification studies of nicotinate phosphoribosyltransferase from yeast

    International Nuclear Information System (INIS)

    Hess, S.L.

    1988-01-01

    Nicotinate phosphoribosyltransferase (NaPRTase) from Baker's yeast catalyzes the formation of nicotinate mononucleotide (NaMN) and pyrophosphate from phosphoribosyl α-1-pyrophosphate and nicotinate, concomitant with ATP hydrolysis. Using purified NaPRTase, initial velocity measurements were performed varying one substrate concentration at different fixed levels of the second substrate and maintaining the third substrate constant. Subsequently, an exchange of label was observed between ATP and [ 14 C]-ADP. This rate of exchange was inhibited by PRibPP and pyrophosphate. Incubations of NaPRTase with pyridoxal 5'-phosphate followed by sodium borohydride reduction led to inactivation of the enzyme. Pyridoxal was a less effective inhibitor than pyridoxal 5'-phosphate. The inactivation of the enzyme by pyridoxal 5'-phosphate was reversible upon flow dialysis, whereas reduction of the enzyme-pyridoxal complex with sodium borohydride rendered the inhibition irreversible. The presence of ATP or PRibPP, with or with Mg 2+ , provided protection against this inactivation, while a kinetic analysis revealed the inhibition to be competitive, and noncompetitive, respectively. One mole of [ 3 H]-pyridoxal phosphate was required to completely inactivate the enzyme, which was reduced in the presence of MgATP and MgPRibPP to 0.2 and 0.6, respectively. No incorporation of pyridoxal 5'-phosphate was observed in the combination of both of the two substrates

  6. Research on the Combustion Characteristics and Kinetic Analysis of the Recycling Dust for a COREX Furnace

    Directory of Open Access Journals (Sweden)

    Haiyang Wang

    2017-02-01

    Full Text Available Thermogravimetric analysis of recycling dust (RD from the melter gasifier of COREX, coke1 (C-1, coke2 (C-2 and coal char (CC under 70% oxygen atmosphere was carried out using thermal balance. The chemical composition and physical structure of the samples were investigated. The characteristic temperatures and comprehensive combustion characteristic indexes were calculated and kinetic parameters during the combustion process were calculated as well using a distributed activation energy model (DAEM. The results show that the carbon in the recycling dust originates from unconsumed CC and coke fines, and the average stacking height of carbon in RD is larger than that of C-1, C-2 and CC. The conversion curves of RD are different from those of C-1, C-2 and CC, and there are two peaks in the RD conversion rate curves. The combustion profiles of RD moves to a higher temperature zone with increasing heating rates. The average activation energies of their combustion process for RD, C-1, C-2 and CC range from 191.84 kJ/mol to 128.31 kJ/mol. The activation energy for recycling dust increases as the fractional conversion increases, but the value for C-1, C-2 and CC decreases with increasing conversion, indicating different combustion mechanisms.

  7. An improved kinetic model for the acetone-butanol-ethanol pathway of Clostridium acetobutylicum and model-based perturbation analysis

    Science.gov (United States)

    2011-01-01

    Background Comprehensive kinetic models of microbial metabolism can enhance the understanding of system dynamics and regulatory mechanisms, which is helpful in optimizing microbial production of industrial chemicals. Clostridium acetobutylicum produces solvents (acetone-butanol–ethanol, ABE) through the ABE pathway. To systematically assess the potential of increased production of solvents, kinetic modeling has been applied to analyze the dynamics of this pathway and make predictive simulations. Up to date, only one kinetic model for C. acetobutylicum supported by experiment has been reported as far as we know. But this model did not integrate the metabolic regulatory effects of transcriptional control and other complex factors. It also left out the information of some key intermediates (e.g. butyryl-phosphate). Results We have developed an improved kinetic model featured with the incorporation of butyryl-phosphate, inclusion of net effects of complex metabolic regulations, and quantification of endogenous enzyme activity variations caused by these regulations. The simulation results of our model are more consistent with published experimental data than the previous model, especially in terms of reflecting the kinetics of butyryl-phosphate and butyrate. Through parameter perturbation analysis, it was found that butyrate kinase has large and positive influence on butanol production while CoA transferase has negative effect on butanol production, suggesting that butyrate kinase has more efficiency in converting butyrate to butanol than CoA transferase. Conclusions Our improved kinetic model of the ABE process has more capacity in approaching real circumstances, providing much more insight in the regulatory mechanisms and potential key points for optimization of solvent productions. Moreover, the modeling strategy can be extended to other biological processes. PMID:21689471

  8. Quantitative kinetic and structural analysis of geopolymers. Part 2. Thermodynamics of sodium silicate activation of metakaolin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zuhua, E-mail: zuhua.zhang2@usq.edu.au [Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba, QLD 4350 (Australia); Provis, John L. [Department of Materials Science and Engineering, The University of Sheffield, Mappin St, Sheffield S1 3JD (United Kingdom); Wang, Hao; Bullen, Frank [Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba, QLD 4350 (Australia); Reid, Andrew [Halok Pty Ltd. West End, QLD 4101 (Australia)

    2013-08-10

    Highlights: • ICC is confirmed again to be useful in studying the thermodynamics of geopolymerization. • Na-silicate activation of metakaolin at 25 °C processes an extent of ∼0.20, far from the final structure. • Na/Al has a more pronounced influence on the reaction extent of metakaolin than do temperature and Si/Al ratio. • ICC is expected to be a powerful technique in quantifying the reactivity of various aluminosilicate precursors. - Abstract: The paper describes the outcomes of a study using isothermal conduction calorimetry (ICC) to characterize the geopolymerization kinetics of metakaolin activated with sodium silicate. Two exothermic peaks are observed in the calorimetric curves for all systems reacting within the temperature range 20–40 °C. The peaks are assigned to the dissolution of metakaolin, and the formation of geopolymeric gels with disordered structure, respectively. Compared with the use of NaOH solution to activate metakaolin, the presence of soluble silicate in the activator hinders the reorganization of the local structure of geopolymeric gels and also suppresses the formation of zeolites or zeolite precursors. The ICC data are used via a thermochemical model to quantify the reaction kinetics of geopolymerization, by assuming that the geopolymeric gels have an analcime-like local structure and taking into account the speciation of the silicate monomers and dimers in the activator. Decreasing the modulus from 1.6 to 1.0 increases the fractional reaction extent from 0.12 to 0.26 after 72 h at 25 °C. When the modulus is 1.2, increasing the reaction temperature from 20 °C to 35 °C results in an improved reaction extent from 0.24 to 0.35. The rapid polymerization that occurs at 40 °C appears to hinder the further reaction of MK and consequently results in a lower reaction extent than at 35 °C. Combined with the findings from previous analysis of systems where NaOH was used to activate MK, the concentration of available Na

  9. MRI kinetics with volumetric analysis in correlation with hormonal receptor subtypes and histologic grade of invasive breast cancers.

    Science.gov (United States)

    Leong, Lester Chee Hao; Gombos, Eva C; Jagadeesan, Jayender; Fook-Chong, Stephanie Man Chung

    2015-03-01

    OBJECTIVE. The aim of this study was to assess whether computer-assisted detection-processed MRI kinetics data can provide further information on the biologic aggressiveness of breast tumors. MATERIALS AND METHODS. We identified 194 newly diagnosed invasive breast cancers presenting as masses on contrast-enhanced MRI by a HIPAA-compliant pathology database search. Computer-assisted detection-derived data for the mean and median peak signal intensity percentage increase, most suspicious kinetic curve patterns, and volumetric analysis of the different kinetic patterns by mean percentage tumor volume were compared against the different hormonal receptor (estrogen-receptor [ER], progesterone-receptor [PR], ERRB2 (HER2/neu), and triple-receptor expressivity) and histologic grade subgroups, which were used as indicators of tumor aggressiveness. RESULTS. The means and medians of the peak signal intensity percentage increase were higher in ER-negative, PR-negative, and triple-negative (all p ≤ 0.001), and grade 3 tumors (p = 0.011). Volumetric analysis showed higher mean percentage volume of rapid initial enhancement in biologically more aggressive ER-negative, PR-negative, and triple-negative tumors compared with ER-positive (64% vs 53.6%, p = 0.013), PR-positive (65.4% vs 52.5%, p = 0.001), and nontriple-negative tumors (65.3% vs 54.6%, p = 0.028), respectively. A higher mean percentage volume of rapid washout component was seen in ERRB2-positive tumors compared with ERRB2-negative tumors (27.5% vs 17.9%, p = 0.020). CONCLUSION. Peak signal intensity percentage increase and volume analysis of the different kinetic patterns of breast tumors showed correlation with hormonal receptor and histologic grade indicators of cancer aggressiveness. Computer-assisted detection-derived MRI kinetics data have the potential to further characterize the aggressiveness of an invasive cancer.

  10. Kinetic analysis of batch ethanol acetylation in isothermal non-stationary multiphase systems by lyophilized mycelium of Aspergillus oryzae

    Directory of Open Access Journals (Sweden)

    Emilio Palazzi

    2011-03-01

    Full Text Available A relatively complex network of reactions has been investigated, using as a network model the isothermal batch esterification of acetic acid with ethanol in n-heptane catalyzed by lyophilized mycelium of Aspergillus oryzae. The kinetic analysis was firstly carried out on the whole system, without any simplification, by means of the well-known integral method. Owing to the poor results obtained by this way, we developed an alternative approach, combining initial rates and integral analysis and reducing the number of empirical parameters to be determined by the use of equilibrium data. All the values of the parameters calculated according to this "composite" approach to kinetic analysis well correlate with experimental data.

  11. The Environmental Scenario Generator (ESG: a distributed environmental data archive analysis tool

    Directory of Open Access Journals (Sweden)

    E A Kihn

    2006-01-01

    Full Text Available The Environmental Scenario Generator (ESG is a network distributed software system designed to allow a user to interact with archives of environmental data for the purpose of scenario extraction, data analysis and integration with existing models that require environmental input. The ESG uses fuzzy-logic based search tools to allow a user to look for specific environmental scenarios in vast archives by specifying the search in human linguistic terms. For example, the user can specify a scenario such as a "cloud free week" or "high winds and low pressure" and then search relevant archives available across the network to get a list of matching events. The ESG hooks to existing archives of data by providing a simple communication framework and an efficient data model for exchanging data. Once data has been delivered by the distributed archives in the ESG data model, it can easily be accessed by the visualization, integration and analysis components to meet specific user requests. The ESG implementation provides a framework which can be taken as a pattern applicable to other distributed archive systems.

  12. Environmental and safety envelope analysis for inertial fusion applications

    International Nuclear Information System (INIS)

    Freiwald, J.G.; Pendergrass, J.H.; Frank, T.G.

    1980-01-01

    This paper describes an envelope analysis concept and a generic process flow model which together can be used to identify and isolate plant functions and provide for detailed mass- and energy-balance bookkeeping for environmental and safety studies. Los Alamos Scientific Laboratory's (LASL) two laser fusion power plant concepts were analyzed with this approach. Samples of the detailed tables of material flow rates into and out of an envelope are presented in this paper. The tritium and lithium inventories and air activation were identified as having important potential environmental problems and safety risks

  13. TXRF analysis of soils and sediments to assess environmental contamination.

    Science.gov (United States)

    Bilo, Fabjola; Borgese, Laura; Cazzago, Davide; Zacco, Annalisa; Bontempi, Elza; Guarneri, Rita; Bernardello, Marco; Attuati, Silvia; Lazo, Pranvera; Depero, Laura E

    2014-12-01

    Total reflection x-ray fluorescence spectroscopy (TXRF) is proposed for the elemental chemical analysis of crustal environmental samples, such as sediments and soils. A comparative study of TXRF with respect to flame atomic absorption spectroscopy and inductively coupled plasma optical emission spectroscopy was performed. Microwave acid digestion and suspension preparation methods are evaluated. A good agreement was found among the results obtained with different spectroscopic techniques and sample preparation methods for Cr, Mn, Fe, Ni, Cu, and Zn. We demonstrated that TXRF is suitable for the assessment of environmental contamination phenomena, even if the errors for Pb, As, V, and Ba are ingent.

  14. Combination Of Static And Dynami,C Stereophotogrammetry For The Kinetic Analysis Of Human Locomotion: Preliminary Results

    Science.gov (United States)

    Schaer, Alex R.; Sheffer, Daniel B.; Jones, D.; Meier, G.; Baumann, Juerg U.

    1989-04-01

    For a deeper understanding of the complexity of human walking movement not only a kinematic analysis , but also a comprehensive three-dimensional biomechanical model of the human body is required to detail the kinetic activities. This research combined static stereophotogrammetric determination of body segment mass parameters with three-dimensional gait analysis by cinephotography, direct linear transformation and two force plates. A method of combining the two independent analyses by defining the anatomical axes of each segment is shown. Practical problems arising in dynamic and stereometric analysis are demonstrated. Power spectra of a normal and a matched subject with spastic diplegia were calculated for a proper design of the kinematic analysis.

  15. Analysis in environmental radioactivity around Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Woo; Han, Man Jung; Cho, Seong Won; Cho, Hong Jun; Oh, Hyeon Kyun; Lee, Jeong Min; Chang, Jae Sook [KORTIC, Taejon (Korea, Republic of)

    2003-12-15

    Twelve kinds of environmental samples such as soil, seawater, underground water, etc. around Nuclear Power Plants(NPPs) were collected. Tritium chemical analysis was tried for the samples of rain water, pine-needle, air, seawater, underground water, chinese cabbage, again of rice and milk sampled around NPPs, and surface seawater and rain water sampled over the country. Strontium in the soil that were sampled at 60 point of district in Korea were analyzed. Tritium were analyzed in 21 samples of surface seawater around the Korea peninsular that were supplied form KFRDI(National Fisheries Research and Development Institute). Sampling and chemical analysis environmental samples around Kori, Woolsung, Youngkwang, Wooljin NPPs and Taeduk science town for tritium and strontium analysis was managed according to plans. Succeed to KINS after all samples were tried.

  16. Environmental cost/benefit analysis for fusion power plants

    International Nuclear Information System (INIS)

    Young, J.R.

    1976-11-01

    This document presents a cost/benefit analysis of use of fusion power plants early in the 21st century. The first section describes the general formulation of the analysis. Included are the selection of the alternatives to the fusion reactor, selection of the power system cases to be compared, and a general comparison of the environmental effects of the selected alternatives. The second section compares the cumulative environmental effects from 2010 to 2040 for the primary cases of the power system with and without fusion reactors. The third section briefly illustrates the potential economic benefits if fusion reactors produce electricity at a lower unit cost than LMFBRs can. The fourth section summarizes the cost/benefit analysis

  17. New portable micro gas chromatograph for environmental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Overton, E.B.; Carney, K.R.; Dharmasena, H.P.; Mainga, A.M.; Ehrmann, U. [Louisiana State Univ., Baton Rouge, LA (United States). Inst. for Environmental Studies

    1994-12-31

    Efforts directed at developing a truly portable method for the analysis of semivolatile compounds have led to the construction and testing of a new generation of micro-GC instrumentation. Building on the successful application of microbore GC columns for in-field analysis of volatile organic compounds, the instrument development group at the LSU-Institute for Environmental Studies has developed a hand portable GC capable of analyzing samples containing compounds with retention indices (100% dimethylpolysiloxane column) up to at least 2,000 in less than 4 minutes, using less than 50 watts (peak) of electrical power. In addition to the ability to analyze semivolatile compounds, the chromatograph is capable of analyzing volatile organics competitively with the most sophisticated of the current commercial portable GCs. The presentation will evaluate chromatographic performance of the instrument at its latest stage of development and demonstrate some applications to environmental analysis using the prototype instrument.

  18. Kinetic analysis of guanosine 5'-O-(3-thiotriphosphate) effects on phosphatidylinositol turnover in NRK cell homogenates

    International Nuclear Information System (INIS)

    Chahwala, S.B.; Fleischman, L.F.; Cantley, L.

    1987-01-01

    Addition of the guanine nucleotide analogue guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) to [ 3 H]inositol-labeled NRK cell homogenates resulted in rapid breakdown of cellular polyphosphoinositides. GTP gamma S stimulated phospholipase C, resulting in a more than 4-fold increase in the hydrolysis rates of phosphatidylinositol 4-phosphate (PIP) and phosphatidylinositol 4,5-bis(phosphate) (PIP2). No significant effect of GTP gamma S on direct phosphatidylinositol (PI) hydrolysis was detected. There was an increase in water-soluble inositols, with inositol tris(phosphate) (IP3) levels increasing at least 10 times over the decrease seen in PIP2, indicating that PIP kinase activity was also accelerated following GTP gamma S addition. Inositol 1,4,5-tris(phosphate) peaked rapidly after GTP gamma S addition (less than 2 min) while inositol 1,3,4-tris-(phosphate) was produced more slowly and leveled off after approximately 10 min. The differential equations describing conversion between intermediates in the PI turnover pathway were solved and fitted to data obtained from both [ 3 H]inositol and [ 32 P]phosphate fluxes by nonlinear least-squares analysis. GTP gamma S effects on the pseudo-first-order rate constants for the lipase, kinase, and phosphatase steps were determined from the analysis. From these measurements it can be estimated that, in the presence of GTP gamma S and calcium buffered to 130 nM, hydrolysis of PIP2 accounts for at least 10 times as much diacylglycerol as direct PI breakdown despite the 100-fold excess of PI over PIP2. From the kinetic model it is predicted that small changes in the activities of PI and PIP kinases can have large but different effects on the level of IP3 and diacylglycerol following GTP gamma S addition. These results argue that regulation of PI and PIP kinases may be important for determining both cellular IP3 and diacylglycerol levels

  19. Biodegradation of hydrocarbon mixtures in surface waters at environmentally relevant levels - Effect of inoculum origin on kinetics and sequence of degradation.

    Science.gov (United States)

    Birch, Heidi; Hammershøj, Rikke; Comber, Mike; Mayer, Philipp

    2017-10-01

    Biodegradation is a dominant removal process for many organic pollutants, and biodegradation tests serve as tools for assessing their environmental fate within regulatory risk assessment. In simulation tests, the inoculum is not standardized, varying in microbial quantity and quality, thereby potentially impacting the observed biodegradation kinetics. In this study we investigated the effect of inoculum origin on the biodegradation kinetics of hydrocarbons for five inocula from surface waters varying in urbanization and thus expected pre-exposure to petroleum hydrocarbons. A new biodegradation method for testing mixtures of hydrophobic chemicals at trace concentrations was demonstrated: Aqueous solutions containing 9 hydrocarbons were generated by passive dosing and diluted with surface water resulting in test systems containing native microorganisms exposed to test substances at ng-μg/L levels. Automated Headspace Solid Phase Microextraction coupled to GC-MS was applied directly to these test systems to determine substrate depletion relative to abiotic controls. Lag phases were generally less than 8 days. First order rate constants were within one order of magnitude for each hydrocarbon in four of the five waters but lower in water from a rural lake. The sequence of degradation between the 9 hydrocarbons showed similar patterns in the five waters indicating the potential for using selected hydrocarbons for benchmarking between biodegradation tests. Degradation half-times were shorter than or within one order of magnitude of BioHCwin predictions for 8 of 9 hydrocarbons. These results showed that location choice is important for biodegradation kinetics and can provide a relevant input to aquatic exposure and fate models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Environmental accounting in Spain: structured review process and theoretical analysis

    Directory of Open Access Journals (Sweden)

    Fabricia Silva da Rosa

    2012-12-01

    Full Text Available One way to perceive and understand the level of development of environmental accounting is to study the main features of its publications. Thus, the purpose of this paper is to identify and analyze the profile of Spanish publications in accounting journals. To this end, 15 journals were selected and analyzed 74 articles in the period 2001 to 2010. The results show that the peak years of publication are 2001, 2003 and 2006, and authors with more articles in the sample are Moneva Abadía, Larrinaga González, Fernández Cuesta and Archel Domench. In terms of methodology, the works of review, case studies and content analysis, addressing standardization issues, fundamentals of environmental accounting, environmental sustainability indicators and reporting.

  1. Analysis of Environmental Law Enforcement Mechanism Based on Economic Principle

    Science.gov (United States)

    Cao, Hongjun; Shao, Haohao; Cai, Xuesen

    2017-11-01

    Strengthening and improving the environmental law enforcement mechanism is an important way to protect the ecological environment. This paper is based on economical principles, we did analysis of the marginal management costs by using Pigou means and the marginal transaction costs by using Coase means vary with the quantity growth of pollutant discharge Enterprises. We analyzed all this information, then we got the conclusion as follows. In the process of strengthening the environmental law enforcement mechanism, firstly, we should fully mobilize all aspects of environmental law enforcement, such as legislative bodies and law enforcement agencies, public welfare organizations, television, newspapers, enterprises, people and so on, they need to form a reasonable and organic structure system; then we should use various management means, such as government regulation, legal sanctions, fines, persuasion and denounce, they also need to form an organic structural system.

  2. Kinetic analysis of platelet-derived growth factor receptor/phosphoinositide 3-kinase/Akt signaling in fibroblasts.

    Science.gov (United States)

    Park, Chang Shin; Schneider, Ian C; Haugh, Jason M

    2003-09-26

    Isoforms of the serine-threonine kinase Akt coordinate multiple cell survival pathways in response to stimuli such as platelet-derived growth factor (PDGF). Activation of Akt is a multistep process, which relies on the production of 3'-phosphorylated phosphoinositide (PI) lipids by PI 3-kinases. To quantitatively assess the kinetics of PDGF receptor/PI 3-kinase/Akt signaling in fibroblasts, a systematic study of this pathway was performed, and a mechanistic mathematical model that describes its operation was formulated. We find that PDGF receptor phosphorylation exhibits positive cooperativity with respect to PDGF concentration, and its kinetics are quantitatively consistent with a mechanism in which receptor dimerization is initially mediated by the association of two 1:1 PDGF/PDGF receptor complexes. Receptor phosphorylation is transient at high concentrations of PDGF, consistent with the loss of activated receptors upon endocytosis. By comparison, Akt activation responds to lower PDGF concentrations and exhibits more sustained kinetics. Further analysis and modeling suggest that the pathway is saturated at the level of PI 3-kinase activation, and that the p110alpha catalytic subunit of PI 3-kinase contributes most to PDGF-stimulated 3'-PI production. Thus, at high concentrations of PDGF the kinetics of 3'-PI production are limited by the turnover rate of these lipids, while the Akt response is additionally influenced by the rate of Akt deactivation.

  3. Environmental impact analysis with the airspace concept evaluation system

    Science.gov (United States)

    Augustine, Stephen; Capozzi, Brian; DiFelici, John; Graham, Michael; Thompson, Terry; Miraflor, Raymond M. C.

    2005-01-01

    The National Aeronautics and Space Administration (NASA) Ames Research Center has developed the Airspace Concept Evaluation System (ACES), which is a fast-time simulation tool for evaluating Air Traffic Management (ATM) systems. This paper describes linking a capability to ACES which can analyze the environmental impact of proposed future ATM systems. This provides the ability to quickly evaluate metrics associated with environmental impacts of aviation for inclusion in multi-dimensional cost-benefit analysis of concepts for evolution of the National Airspace System (NAS) over the next several decades. The methodology used here may be summarized as follows: 1) Standard Federal Aviation Administration (FAA) noise and emissions-inventory models, the Noise Impact Routing System (NIRS) and the Emissions and Dispersion Modeling System (EDMS), respectively, are linked to ACES simulation outputs; 2) appropriate modifications are made to ACES outputs to incorporate all information needed by the environmental models (e.g., specific airframe and engine data); 3) noise and emissions calculations are performed for all traffic and airports in the study area for each of several scenarios, as simulated by ACES; and 4) impacts of future scenarios are compared to the current NAS baseline scenario. This paper also provides the results of initial end-to-end, proof-of-concept runs of the integrated ACES and environmental-modeling capability. These preliminary results demonstrate that if no growth is likely to be impeded by significant environmental impacts that could negatively affect communities throughout the nation.

  4. Environmental costs and reverse logistics: a systemic analysis

    Directory of Open Access Journals (Sweden)

    Paula de Souza

    2013-08-01

    Full Text Available This article aims to analyze the articles most relevant to the themes inherent environmental costs from the perspective of reverse logistics, identifying gaps for these two approaches through systemic analysis. In order to achieve the purpose of this article, the intervention instrument used was ProKnow-C (Knowledge Process Development - Constructivist. The application of this methodology resulted in gross bank of articles, comprising 1225 items obtained from four international databases: Science Direct, ISI Web of Science, Scopus and Wiley Online Library. The raw bank was filtered in relation to redundancy, the alignment of the title and the scientific relevance. The filtering had resulted in a set of 15 articles aligned with two axes of research. The analysis of the selected articles identified the most cited article and the author most cited, concluding that the issue environmental costs associated with reverse logistics is studied by several authors and universities. Moreover, it was found that the keyword most presented in the articles was reverse logistics. The analysis of 1117 references of the 15 articles has shown the most cited articles, as well as the most countrast journals and academic relevance of authors and their selected articles. A systemic analysis of the 15 selected articles showed that the two lines of research are related mainly to issues of environmental sustainability, competitiveness and business efficiency.

  5. A Critical View on In Vitro Analysis of P-glycoprotein (P-gp) Transport Kinetics

    DEFF Research Database (Denmark)

    Saaby, Lasse; Brodin, Birger

    2017-01-01

    Transport proteins expressed in the different barriers of the human body can have great implications on absorption, distribution, and excretion of drug compounds. Inhibition or saturation of a transporter can potentially alter these absorbtion, distribution, metabolism and elimination properties ......-gp transport kinetics and aims at providing a critical evaluation of the application of steady-state Michaelis-Menten analysis of kinetic parameters for substrate/P-gp interactions....... mediate efflux of drug compounds and may also be a potential site for drug-drug interactions. Consequently, there is a need to be able to predict the saturation and inhibition of P-gp and other transporters in vivo. For this purpose, Michaelis-Menten steady-state analysis has been applied to estimate...

  6. Detectable states, cycle fluxes, and motility scaling of molecular motor kinesin: An integrative kinetic graph theory analysis

    Science.gov (United States)

    Ren, Jie

    2017-12-01

    The process by which a kinesin motor couples its ATPase activity with concerted mechanical hand-over-hand steps is a foremost topic of molecular motor physics. Two major routes toward elucidating kinesin mechanisms are the motility performance characterization of velocity and run length, and single-molecular state detection experiments. However, these two sets of experimental approaches are largely uncoupled to date. Here, we introduce an integrative motility state analysis based on a theorized kinetic graph theory for kinesin, which, on one hand, is validated by a wealth of accumulated motility data, and, on the other hand, allows for rigorous quantification of state occurrences and chemomechanical cycling probabilities. An interesting linear scaling for kinesin motility performance across species is discussed as well. An integrative kinetic graph theory analysis provides a powerful tool to bridge motility and state characterization experiments, so as to forge a unified effort for the elucidation of the working mechanisms of molecular motors.

  7. Cost-benefit analysis for design of environmentally conscious manufacturing

    International Nuclear Information System (INIS)

    Matysiak, L.M.

    1993-01-01

    In recent years, much attention has been focused on reducing the environmental impacts of products and manufacturing processes. Concerned about rising compliance costs and stringent regulatory requirements, companies are carefully evaluating the environmental impacts of their products. In response, designers, engineers, and managers are beginning to use life-cycle analysis, design for environment techniques, and environmentally conscious manufacturing (ECM) as tools to help them to not only do what is best for the environment, but also to do what is best for their company. These tools are also a useful aid in evaluating the trade-offs that may exist between different product and process alternatives. However, how does one choose the optimal solution from these various product and process alternatives? Cost versus benefit analysis is an effective tool that can be used to evaluate various manufacturing alternatives and to choose a solution that is both cost effective and environmentally compatible. Many companies are beginning to use cost benefit analyses as a means to justify product or process modifications that result in a benefit to the environment

  8. Image Restoration and Analysis of Influenza Virions Binding to Membrane Receptors Reveal Adhesion-Strengthening Kinetics.

    Directory of Open Access Journals (Sweden)

    Donald W Lee

    Full Text Available With the development of single-particle tracking (SPT microscopy and host membrane mimics called supported lipid bilayers (SLBs, stochastic virus-membrane binding interactions can be studied in depth while maintaining control over host receptor type and concentration. However, several experimental design challenges and quantitative image analysis limitations prevent the widespread use of this approach. One main challenge of SPT studies is the low signal-to-noise ratio of SPT videos, which is sometimes inevitable due to small particle sizes, low quantum yield of fluorescent dyes, and photobleaching. These situations could render current particle tracking software to yield biased binding kinetic data caused by intermittent tracking error. Hence, we developed an effective image restoration algorithm for SPT applications called STAWASP that reveals particles with a signal-to-noise ratio of 2.2 while preserving particle features. We tested our improvements to the SPT binding assay experiment and imaging procedures by monitoring X31 influenza virus binding to α2,3 sialic acid glycolipids. Our interests lie in how slight changes to the peripheral oligosaccharide structures can affect the binding rate and residence times of viruses. We were able to detect viruses binding weakly to a glycolipid called GM3, which was undetected via assays such as surface plasmon resonance. The binding rate was around 28 folds higher when the virus bound to a different glycolipid called GD1a, which has a sialic acid group extending further away from the bilayer surface than GM3. The improved imaging allowed us to obtain binding residence time distributions that reflect an adhesion-strengthening mechanism via multivalent bonds. We empirically fitted these distributions using a time-dependent unbinding rate parameter, koff, which diverges from standard treatment of koff as a constant. We further explain how to convert these models to fit ensemble-averaged binding data

  9. Stepwise binding of tylosin and erythromycin to Escherichia coli ribosomes, characterized by kinetic and footprinting analysis.

    Science.gov (United States)

    Petropoulos, Alexandros D; Kouvela, Ekaterini C; Dinos, George P; Kalpaxis, Dimitrios L

    2008-02-22

    Erythromycin and tylosin are 14- and 16-membered lactone ring macrolides, respectively. The current work shows by means of kinetic and chemical footprinting analysis that both antibiotics bind to Escherichia coli ribosomes in a two-step process. The first step established rapidly, involves a low-affinity binding site placed at the entrance of the exit tunnel in the large ribosomal subunit, where macrolides bind primarily through their hydrophobic portions. Subsequently, slow conformational changes mediated by the antibiotic hydrophilic portion push the drugs deeper into the tunnel, in a high-affinity site. Compared with erythromycin, tylosin shifts to the high-affinity site more rapidly, due to the interaction of the mycinose sugar of the drug with the loop of H35 in domain II of 23 S rRNA. Consistently, mutations of nucleosides U2609 and U754 implicated in the high-affinity site reduce the shift of tylosin to this site and destabilize, respectively, the final drug-ribosome complex. The weak interaction between tylosin and the ribosome is Mg2+ independent, unlike the tight binding. In contrast, both interactions between erythromycin and the ribosome are reduced by increasing concentrations of Mg2+ ions. Polyamines attenuate erythromycin affinity for the ribosome at both sequential steps of binding. In contrast, polyamines facilitate the initial binding of tylosin, but exert a detrimental, more pronounced, effect on the drug accommodation at its final position. Our results emphasize the role of the particular interactions that side chains of tylosin and erythromycin establish with 23 S rRNA, which govern the exact binding process of each drug and its response to the ionic environment.

  10. Analysis of the kinetics of the fragile fracture process in Mo monocrystals in quasi-relaxation

    International Nuclear Information System (INIS)

    Tamayo Meza, Pedro; Bautista Godinez, Eric Gustavo; Yermishkin, Viacheslav

    2008-01-01

    The method of quasi-relaxation, generally known as the force relaxation method, has been widely applied in the study of elementary dislocational processes. It is essential for the study and analysis of thermoactivated mechanisms, for the determination of the energy of interaction between dislocations and inclusions, in the definition of the dislocational constants, to predict the development of creep, and even for the study of fracture kinetics. For the first time the use of the quasi-relaxation method for evaluating the fragile fracture tendency was presented in the work. However, as usually carried out, the use of mass specimens and the development of a considerable plastic deformation in the vertex of the crack-notch sample limits the possibilities for this method. Many studies analyze the theoretical aspects of the fracture process, and the obtention of reliable quantitative information about the behavior of the dislocation based on an analytical description of the process, and how and when it influences the conditions under which the final catastrophic fracture occurs. This work proposes a new method to analyze the effect of a tension concentrator on the surface of Mo monocrystal specimens. The relaxation of the force and the increase in the crack opening is related to the development of the plastic zone in its vertex with the help of the Irwin correction. During the relaxation, the crack-groove grows until it attains the length of the plastic zone. Specimens with and without force concentrators were tested in quasi-relaxation. The cracks appearing under these conditions are analyzed using a scanning electron microscopy (SEM). The crack appearing in the specimens under load conditions, whose development produced heavy force relaxation, allowed the force relaxation value to be defined and compared in the specimens with and without tension concentrators (au)

  11. Electron kinetics dependence on gas pressure in laser-induced oxygen plasma experiment: Theoretical analysis

    Science.gov (United States)

    Gamal, Yosr E. E.-D.; Abdellatif, Galila

    2017-08-01

    A study is performed to investigate the dependency of threshold intensity on gas pressure observed in the measurements of the breakdown of molecular oxygen that carried out by Phuoc (2000) [1]. In this experiment, the breakdown was induced by 532 nm laser radiation of pulse width 5.5 ns and spot size of 8.5 μm, in oxygen over a wide pressure range (190-3000 Torr). The analysis aimed to explore the electron kinetic reliance on gas pressure for the separate contribution of each of the gain and loss processes encountered in this study. The investigation is based on an electron cascade model applied previously in Gamal and Omar (2001) [2] and Gaabour et al. (2013) [3]. This model solves numerically a differential equation designates the time evolution of the electron energy distribution, and a set of rate equations that describe the change of excited states population. The numerical examination of the electron energy distribution function and its parameters revealed that photo-ionization of the excited molecules plays a significant role in enhancing the electron density growth rate over the whole tested gas pressure range. This process is off set by diffusion of electrons out of the focal volume in the low-pressure regime. At atmospheric pressure electron, collisional processes dominate and act mainly to populate the excited states. Hence photo-ionization becomes efficient and compete with the encountered loss processes (electron diffusion, vibrational excitation of the ground state molecules as well as two body attachments). At high pressures ( 3000 Torr) three body attachments are found to be the primary cause of losses which deplete the electron density and hence results in the slow decrease of the threshold intensity.

  12. Characterizing the Growth Kinetics in Estrogen Responsive T47D Cells After Exposure to 2000 Environmental Chemicals

    Science.gov (United States)

    There is a need to develop high-throughput screening (HTS) tests capable of testing thousands of environmental chemicals for endocrine disrupting potential. The estrogen signaling pathway is a known xenobiotic target that has been implicated in a variety of adverse health effects...

  13. Risk analysis and priority setting for environmental policy

    International Nuclear Information System (INIS)

    Travis, C.C.

    1991-01-01

    There is a growing realization that the demand for funding to correct our nation's environmental problems will soon outstrip available resources. In the hazardous waste area alone, the estimated cost of remediating Superfund sites ranges from $32 billion to $80 billion. Numerous other areas of competing for these same financial resources. These include ozone depletion, global warming, the protection of endangered species and wetlands, toxic air pollution, carcinogenic pesticides, and urban smog. In response to this imbalance in the supply and demand for national funds, several political constituencies are calling for the use of risk assessment as a tool in the prioritization of research and budget needs. Comparative risk analysis offers a logical framework in which to organize information about complex environmental problems. Risk analysis allows policy analysts to make resource allocation decisions on the basis of scientific judgement rather than political expediency

  14. Digital gamma-gamma coincidence HPGe system for environmental analysis

    DEFF Research Database (Denmark)

    Markovic, Nikola; Roos, Per; Nielsen, Sven Poul

    2017-01-01

    The performance of a new gamma-gamma coincidence spectrometer system for environmental samples analysis at the Center for Nuclear Technologies of the Technical University of Denmark (DTU) is reported. Nutech Coincidence Low Energy Germanium Sandwich (NUCLeGeS) system consists of two HPGe detector...... in a surface laboratory with a digital acquisition system used to collect the data in time-stamped list mode with 10. ns time resolution. The spectrometer is used in both anticoincidence and coincidence modes....

  15. Instrumental neutron activation analysis in environmental studies of trace elements

    International Nuclear Information System (INIS)

    Salmon, L.

    1975-06-01

    The application of a routine instrumental nuclear method is described in relation to environmental surveys and studies. A working rather than formal review is made of the techniques applied with particular reference to the data processing methods involved. The elements measured by instrumental activation analysis were: Ag, Al, As, Au, Ba, Br, Ca, Ce, Cl, Cd, Co, Cr, Cs, Cu, Fe, Hg, I, In, La, Mn, Na, Ni, Pb, Rb, Sb, Sc, Se, Th, Ti, U, V, W, Zn. (author)

  16. Use of the environmental resource management and analysis system at the Fernald Environmental Management Project

    International Nuclear Information System (INIS)

    Erjavec, J.L.

    1992-01-01

    In the past, hazardous waste site characterization and remediation using computer-based technologies has been a difficult and time-consuming process because of the need to analyze data using non-interfaced computer and software environments. The Environmental Resource Management and Analysis System (ERMA) was developed as an innovative approach to the management, analyses and depiction of data collected during a hazardous site remediation. A modular, multi-disciplined software package, ERMA integrates an environmental database management system with variety of Geographic Information System technologies. ERMA capabilities include spatial analysis, three-dimensional subsurface geologic interpretation and modeling, terrain modeling, and groundwater flow and contaminant transport modeling. ERMA's data management is provided through a set of user-modifiable, graphic interface tools that permit complex data queries, data modification and reporting. An ERMA prototype has been implemented at the Fernald Environmental Management Project (a Department of Energy cleanup site) using groundwater monitoring and elevation data collected over the last few years. ERMA has enabled the precision posting of data from the 853 groundwater monitoring wells at the site. Data from these wells have ben used to define the piezometric surface of the Great Miami Aquifer and correlate it with the uranium concentration contours of an identified groundwater plume. Using spatial query capabilities, radioactive sampling results from monitoring wells have been compared to contour maps defining the extent of the plume to determine the validity of those maps and the need for additional well locations

  17. Transuranium analysis methodologies for biological and environmental samples

    International Nuclear Information System (INIS)

    Wessman, R.A.; Lee, K.D.; Curry, B.; Leventhal, L.

    1978-01-01

    Analytical procedures for the most abundant transuranium nuclides in the environment (i.e., plutonium and, to a lesser extent, americium) are available. There is a lack of procedures for doing sequential analysis for Np, Pu, Am, and Cm in environmental samples, primarily because of current emphasis on Pu and Am. Reprocessing requirements and waste disposal connected with the fuel cycle indicate that neptunium and curium must be considered in environmental radioactive assessments. Therefore it was necessary to develop procedures that determine all four of these radionuclides in the environment. The state of the art of transuranium analysis methodology as applied to environmental samples is discussed relative to different sample sources, such as soil, vegetation, air, water, and animals. Isotope-dilution analysis with 243 Am ( 239 Np) and 236 Pu or 242 Pu radionuclide tracers is used. Americium and curium are analyzed as a group, with 243 Am as the tracer. Sequential extraction procedures employing bis(2-ethyl-hexyl)orthophosphoric acid (HDEHP) were found to result in lower yields and higher Am--Cm fractionation than ion-exchange methods

  18. Assessment of Background Parenchymal Enhancement and Lesion Kinetics in Breast MRI of BRCA 1/2 Mutation Carriers Compared to Matched Controls Using Quantitative Kinetic Analysis.

    Science.gov (United States)

    Lewin, Alana A; Kim, Sungheon Gene; Babb, James S; Melsaether, Amy N; McKellop, Jason; Moccaldi, Melanie; Klautau Leite, Ana Paula; Moy, Linda

    2016-03-01

    To investigate whether quantitative kinetic analysis of lesions and background parenchyma in breast magnetic resonance imaging can elucidate differences between BRCA carriers and sporadic controls with high risk for breast cancer. Fifty-nine BRCA and 59 control cases (49 benign, 10 malignant) were examined in this study. Principal component analysis was applied for quantitative analysis of dynamic signal in background parenchyma (B) and lesion (L) in terms of initial enhancement ratio (IER) and delayed enhancement ratio (DER). Control B-IER, B-DER, L-IER, and L-DER were higher than BRCA cases in all women and in women with benign lesions; statistically significant differences in B-IER and B-DER (all women: P = 0.02 and P = 0.02, respectively; benign only: P = 0.005 and P = 0.005, respectively). In the control cohort, B-IER and B-DER were higher in the premenopausal women than in the postmenopausal women (P = 0.013 and 0.003, respectively), but not in the BRCA cohort; this led to significant differences in B-IER and B-DER between the control and the BRCA groups in the premenopausal women (P = 0.01 and 0.01, respectively) but not in the postmenopausal women. Results suggest possible differences in the vascular properties of background parenchyma between BRCA carriers and noncarriers and its association with menopausal status. Copyright © 2015 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

  19. Stochastic kinetics

    International Nuclear Information System (INIS)

    Colombino, A.; Mosiello, R.; Norelli, F.; Jorio, V.M.; Pacilio, N.

    1975-01-01

    A nuclear system kinetics is formulated according to a stochastic approach. The detailed probability balance equations are written for the probability of finding the mixed population of neutrons and detected neutrons, i.e. detectrons, at a given level for a given instant of time. Equations are integrated in search of a probability profile: a series of cases is analyzed through a progressive criterium. It tends to take into account an increasing number of physical processes within the chosen model. The most important contribution is that solutions interpret analytically experimental conditions of equilibrium (moise analysis) and non equilibrium (pulsed neutron measurements, source drop technique, start up procedures)

  20. Proof-of-Concept Oil Shale Facility Environmental Analysis Program

    Energy Technology Data Exchange (ETDEWEB)

    1990-11-01

    The objectives of the Project are to demonstrate: (1) the Modified In- Situ (MIS) shale oil extraction process and (2) the application of CFBC technology using oil shale, coal and waste gas streams as fuels. The project will focus on evaluating and improving the efficiency and environmental performance of these technologies. The project will be modest by commercial standards. A 17-retort MIS system is planned in which two retorts will be processed simultaneously. Production of 1206-barrels per calendar day of raw shale oil and 46-megawatts of electricity is anticipated. West Virginia University coordinated an Environmental Analysis Program for the Project. Experts from around the country were retained by WVU to prepare individual sections of the report. These experts were exposed to all of OOSI's archives and toured Tract C-b and Logan Wash. Their findings were incorporated into this report. In summary, no environmental obstacles were revealed that would preclude proceeding with the Project. One of the most important objectives of the Project was to verify the environmental acceptability of the technologies being employed. Consequently, special attention will be given to monitoring environmental factors and providing state of the art mitigation measures. Extensive environmental and socioeconomic background information has been compiled for the Tract over the last 15 years and permits were obtained for the large scale operations contemplated in the late 1970's and early 1980's. Those permits have been reviewed and are being modified so that all required permits can be obtained in a timely manner.

  1. Environmental impact analysis for the main accidental sequences of ignitor

    International Nuclear Information System (INIS)

    Carpignano, A.; Francabandiera, S.; Vella, R.; Zucchetti, M.

    1996-01-01

    A safety analysis study has been applied to the Ignitor machine using Probabilistic Safety Assessment. The main initiating events have been identified, and accident sequences have been studied by means of traditional methods such as Failure Mode and Effect Analysis (FMEA), Fault Trees (FT) and Event Trees (ET). The consequences of the radioactive environmental releases have been assessed in terms of Effective Dose Equivalent (EDEs) to the Most Exposed Individuals (MEI) of the chosen site, by means of a population dose code. Results point out the low enviromental impact of the machine. 13 refs., 1 fig., 3 tabs

  2. Kinetics analysis of two-stage austenitization in supermartensitic stainless steel

    DEFF Research Database (Denmark)

    Nießen, Frank; Villa, Matteo; Hald, John

    2017-01-01

    The martensite-to-austenite transformation in X4CrNiMo16-5-1 supermartensitic stainless steel was followed in-situ during isochronal heating at 2, 6 and 18 K min−1 applying energy-dispersive synchrotron X-ray diffraction at the BESSY II facility. Austenitization occurred in two stages, separated...... by a temperature region in which the transformation was strongly decelerated. The region of limited transformation was more concise and occurred at higher austenite phase fractions and temperatures for higher heating rates. The two-step kinetics was reproduced by kinetics modeling in DICTRA. The model indicates...

  3. An optimum analysis sequence for environmental gamma-ray spectrometry

    International Nuclear Information System (INIS)

    De la Torre, F.; Rios M, C.; Ruvalcaba A, M. G.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L.

    2010-10-01

    This work aims to obtain an optimum analysis sequence for environmental gamma-ray spectroscopy by means of Genie 2000 (Canberra). Twenty different analysis sequences were customized using different peak area percentages and different algorithms for: 1) peak finding, and 2) peak area determination, and with or without the use of a library -based on evaluated nuclear data- of common gamma-ray emitters in environmental samples. The use of an optimum analysis sequence with certified nuclear information avoids the problems originated by the significant variations in out-of-date nuclear parameters of commercial software libraries. Interference-free gamma ray energies with absolute emission probabilities greater than 3.75% were included in the customized library. The gamma-ray spectroscopy system (based on a Ge Re-3522 Canberra detector) was calibrated both in energy and shape by means of the IAEA-2002 reference spectra for software intercomparison. To test the performance of the analysis sequences, the IAEA-2002 reference spectrum was used. The z-score and the reduced χ 2 criteria were used to determine the optimum analysis sequence. The results show an appreciable variation in the peak area determinations and their corresponding uncertainties. Particularly, the combination of second derivative peak locate with simple peak area integration algorithms provides the greater accuracy. Lower accuracy comes from the combination of library directed peak locate algorithm and Genie's Gamma-M peak area determination. (Author)

  4. An optimum analysis sequence for environmental gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    De la Torre, F.; Rios M, C.; Ruvalcaba A, M. G.; Mireles G, F.; Saucedo A, S.; Davila R, I.; Pinedo, J. L., E-mail: fta777@hotmail.co [Universidad Autonoma de Zacatecas, Centro Regional de Estudis Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2010-10-15

    This work aims to obtain an optimum analysis sequence for environmental gamma-ray spectroscopy by means of Genie 2000 (Canberra). Twenty different analysis sequences were customized using different peak area percentages and different algorithms for: 1) peak finding, and 2) peak area determination, and with or without the use of a library -based on evaluated nuclear data- of common gamma-ray emitters in environmental samples. The use of an optimum analysis sequence with certified nuclear information avoids the problems originated by the significant variations in out-of-date nuclear parameters of commercial software libraries. Interference-free gamma ray energies with absolute emission probabilities greater than 3.75% were included in the customized library. The gamma-ray spectroscopy system (based on a Ge Re-3522 Canberra detector) was calibrated both in energy and shape by means of the IAEA-2002 reference spectra for software intercomparison. To test the performance of the analysis sequences, the IAEA-2002 reference spectrum was used. The z-score and the reduced {chi}{sup 2} criteria were used to determine the optimum analysis sequence. The results show an appreciable variation in the peak area determinations and their corresponding uncertainties. Particularly, the combination of second derivative peak locate with simple peak area integration algorithms provides the greater accuracy. Lower accuracy comes from the combination of library directed peak locate algorithm and Genie's Gamma-M peak area determination. (Author)

  5. Kinetic analysis of the inhibition of the drug efflux protein AcrB using surface plasmon resonance.

    Science.gov (United States)

    Mowla, Rumana; Wang, Yinhu; Ma, Shutao; Venter, Henrietta

    2018-04-01

    Multidrug efflux protein complexes such as AcrAB-TolC from Escherichia coli are paramount in multidrug resistance in Gram-negative bacteria and are also implicated in other processes such as virulence and biofilm formation. Hence efflux pump inhibition, as a means to reverse antimicrobial resistance in clinically relevant pathogens, has gained increased momentum over the past two decades. Significant advances in the structural and functional analysis of AcrB have informed the selection of efflux pump inhibitors (EPIs). However, an accurate method to determine the kinetics of efflux pump inhibition was lacking. In this study we standardised and optimised surface plasmon resonance (SPR) to probe the binding kinetics of substrates and inhibitors to AcrB. The SPR method was also combined with a fluorescence drug binding method by which affinity of two fluorescent AcrB substrates were determined using the same conditions and controls as for SPR. Comparison of the results from the fluorescent assay to those of the SPR assay showed excellent correlation and provided validation for the methods and conditions used for SPR. The kinetic parameters of substrate (doxorubicin, novobiocin and minocycline) binding to AcrB were subsequently determined. Lastly, the kinetics of inhibition of AcrB were probed for two established inhibitors (phenylalanine arginyl β-naphthylamide and 1-1-naphthylmethyl-piperazine) and three novel EPIs: 4-isobutoxy-2-naphthamide (A2), 4-isopentyloxy-2-naphthamide (A3) and 4-benzyloxy-2-naphthamide (A9) have also been probed. The kinetic data obtained could be correlated with inhibitor efficacy and mechanism of action. This study is the first step in the quantitative analysis of the kinetics of inhibition of the clinically important RND-class of multidrug efflux pumps and will allow the design of improved and more potent inhibitors of drug efflux pumps. This article is part of a Special Issue entitled: Beyond the Structure-Function Horizon of Membrane

  6. A Critical View on In Vitro Analysis of P-glycoprotein (P-gp) Transport Kinetics.

    Science.gov (United States)

    Saaby, Lasse; Brodin, Birger

    2017-09-01

    Transport proteins expressed in the different barriers of the human body can have great implications on absorption, distribution, and excretion of drug compounds. Inhibition or saturation of a transporter can potentially alter these absorbtion, distribution, metabolism and elimination properties and thereby also the pharmacokinetic profile and bioavailability of drug compounds. P-glycoprotein (P-gp, ABCB1) is an efflux transporter which is present in most of the barriers of the body, including the small intestine, the blood-brain barrier, the liver, and the kidney. In all these tissues, P-gp may mediate efflux of drug compounds and may also be a potential site for drug-drug interactions. Consequently, there is a need to be able to predict the saturation and inhibition of P-gp and other transporters in vivo. For this purpose, Michaelis-Menten steady-state analysis has been applied to estimate kinetic parameters, such as K m and V max , for carrier-mediated transport, whereas half-maximal inhibitor concentration (IC 50 ) and the disassociation constant for an inhibitor/P-gp complex (K i ) have been determined to estimate P-gp inhibition. This review addresses in vitro methods commonly used to study P-gp transport kinetics and aims at providing a critical evaluation of the application of steady-state Michaelis-Menten analysis of kinetic parameters for substrate/P-gp interactions. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  7. Combination of Markov state models and kinetic networks for the analysis of molecular dynamics simulations of peptide folding.

    Science.gov (United States)

    Radford, Isolde H; Fersht, Alan R; Settanni, Giovanni

    2011-06-09

    Atomistic molecular dynamics simulations of the TZ1 beta-hairpin peptide have been carried out using an implicit model for the solvent. The trajectories have been analyzed using a Markov state model defined on the projections along two significant observables and a kinetic network approach. The Markov state model allowed for an unbiased identification of the metastable states of the system, and provided the basis for commitment probability calculations performed on the kinetic network. The kinetic network analysis served to extract the main transition state for folding of the peptide and to validate the results from the Markov state analysis. The combination of the two techniques allowed for a consistent and concise characterization of the dynamics of the peptide. The slowest relaxation process identified is the exchange between variably folded and denatured species, and the second slowest process is the exchange between two different subsets of the denatured state which could not be otherwise identified by simple inspection of the projected trajectory. The third slowest process is the exchange between a fully native and a partially folded intermediate state characterized by a native turn with a proximal backbone H-bond, and frayed side-chain packing and termini. The transition state for the main folding reaction is similar to the intermediate state, although a more native like side-chain packing is observed.

  8. Thermolysis of (1R,2R)-1,2-dideuteriocyclobutane. An application of vibrational circular dichroism to kinetic analysis

    International Nuclear Information System (INIS)

    Chickos, J.S.; Annamalai, A.; Keiderling, T.A.

    1986-01-01

    The relative rates of geometric isomerization to racemization have been studied for the title compound by using a combination of infrared (IR) and vibrational circular dichroism (VCD) spectroscopies, respectively. The results are interpreted with a kinetic and mechanistic scheme which parallels that used by Berson, Pedersen, and Carpenter on a similar study of chiral cyclopropane-d 2 thermolysis. Relative rates of isomerization to stereomutation of 1.5 +/- 0.4 were obtained which can be interpreted to be consistent with a mechanism best described by random methylene rotation in tetramethylene-d 2 . This is the first application of VCD to kinetic analysis, and the advantages of IR techniques over the more usually employed UV spectroscopies to this type of basic mechanistic problem are illustrated

  9. Estimation of particle size and initial growth kinetics of asphaltene particles using spectral analysis of reservoir fluid

    Energy Technology Data Exchange (ETDEWEB)

    Jamaluddin, A.; Joshi, N.; Mullins, O. [Schlumberger Canada Ltd., Calgary, AB (Canada); Creek, J. [Chevron Canada Resources, Calgary, AB (Canada); McFadden, J. [BHD Petroleum, Calgary, AB (Canada)

    2002-06-01

    One of the challenges facing heavy oil reservoir management and production operations is to minimize the impact of asphaltene deposition, the most aromatic and heaviest fraction of a crude oil. A study was conducted in which both fixed wavelength near infrared (NIR) and variable wavelength spectral analysis methods were applied to two individual crude oil samples obtained from one reservoir. The objective was to assess asphaltene properties. The samples were collected using 2 different sampling chambers and techniques. Both were homogenized and treated identically. The macroscopic properties of both samples were similar, but the microscopic asphaltene particle properties varied significantly in the asphaltene particle size, as did the formation kinetics between the 2 samples. The paper also presented estimates of asphaltene particle size and initial growth kinetics from the acquired data. The properties were used to determine the basic differences between fluid samples collected using different techniques. 14 refs., 1 tab., 9 figs.

  10. Determination of kinetic parameters in the pyrolysis operation and thermal behavior of Prosopis juliflora using thermogravimetric analysis.

    Science.gov (United States)

    Chandrasekaran, Arunkumar; Ramachandran, Sethumadhavan; Subbiah, Senthilmurugan

    2017-06-01

    This paper deals with the pyrolysis of Prosopis juliflora fuelwood using thermogravimetric analysis to determine the kinetic parameters at six different heating rates of 2, 5, 10, 15, 20 and 25°C/min. The activation energy of pyrolysis was calculated using different methods, namely Kissinger, Kissinger-Akahira-Sunose, Ozawa-Flynn-Wall and Friedman model and corresponding calculated activation energy were found to be 164.6, 204, 203.2, and 219.3kJ/mol, respectively for each method. The three-pseudo component model was applied to calculate the following three kinetic parameters: activation energy, pre-exponential factor and order of reaction. The experimental results were validated with model prediction for all the six heating rates. The three-pseudo component model is able to predict experimental results much accurately while considering variable order reaction model (n≠1). Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Development and Sensitivity Analysis of a Fully Kinetic Model of Sequential Reductive Dechlorination in Groundwater

    DEFF Research Database (Denmark)

    Malaguerra, Flavio; Chambon, Julie Claire Claudia; Bjerg, Poul Løgstrup

    2011-01-01

    been modeled using modified Michaelis–Menten kinetics and has been implemented in the geochemical code PHREEQC. The model have been calibrated using a Shuffled Complex Evolution Metropolis algorithm to observations of chlorinated solvents, organic acids, and H2 concentrations in laboratory batch...

  12. A kinetic analysis of the tumor-associated galactopyranosyl- (1→3 ...

    Indian Academy of Sciences (India)

    WINTEC

    synthesized by chemical methods and was functionalized suitably for immobilization onto a carboxy- methylated sensor chip. ... lectin interaction was compared with the kinetic rates of the interaction of a galactopyranosyl-(1→4)-β-. D-galactopyranoside ...... based drug discovery (Wiley-VCH Weinheim). 3. Hakomori S 1991 ...

  13. Tyrosinase kinetics in epidermal melanocytes: analysis of DAG-PKC-dependent signaling pathway

    Science.gov (United States)

    Stolnitz, Mikhail M.; Peshkova, Anna Y.

    2001-05-01

    Tyrosinase is the key enzyme of melanogenesis with unusual enzyme kinetics. Protein kinase C plays an important role in regulating of tyrosinase activity. In the paper the mathematical model of PKC-DAG-dependent signal transduction pathway for UV-radiation is presented.

  14. Kinetic analysis of nitric oxide reduction using biogas as reburning fuel

    African Journals Online (AJOL)

    STORAGESEVER

    2009-05-18

    May 18, 2009 ... 2007; Guo and Smallwood, 2007; Giles et al., 2006; Shoji et al.,. 2005). Consequently, Miller and Bowman's mechanism is selected as the calculation dynamics model. The kinetic numeration is carried out in the PSR environment of Sandia National Laboratory. Reactions mainly referring to nitrogen species ...

  15. Kinetic and thermodynamic analysis of ultra-high pressure and heat ...

    African Journals Online (AJOL)

    Purpose: To undertake comparative kinetic and thermodynamic analyses of the interaction of bovine serum albumin (BSA) with IgG pre-treated with ultra-high pressure (UHP) and moderate heat. Methods: BSA solutions were processed at 100 – 600 MPa and 25 – 40 °C. We applied an optical biosensor based on surface ...

  16. Nano-desorption electrospray and kinetic method in chiral analysis of clinical samples

    Czech Academy of Sciences Publication Activity Database

    Ranc, V.; Havlíček, Vladimír; Bednář, P.; Lemr, Karel

    2008-01-01

    Roč. 14, č. 6 (2008), s. 411-417 ISSN 1469-0667 R&D Projects: GA MŠk LC545; GA ČR GA203/07/0765 Institutional research plan: CEZ:AV0Z50200510 Keywords : nano-desorption electrospray * mass spectrometry * kinetic method Subject RIV: EE - Microbiology, Virology Impact factor: 1.167, year: 2008

  17. Optimization and kinetic analysis on the sulfuric acid - Catalyzed depolymerization of wheat straw.

    Science.gov (United States)

    Wu, Qian-Qian; Ma, Yu-Long; Chang, Xuan; Sun, Yong-Gang

    2015-09-20

    The objectives of this work were to optimize the experimental condition and to study the kinetic behavior of wheat straw depolymerization with sulfuric acid (2 wt%, 3 wt%, and 4 wt%) at different temperatures (120°C, 130°C, and 140°C). The two-fraction kinetic model was obtained for the prediction of the generations of product and by-product during depolymerization. The kinetic parameters of the two-fraction model were analyzed using an Arrhenius-type equation. Applying the kinetic two-fraction model, the optimum condition for wheat straw depolymerization was 3 wt% H2SO4 at 130°C for 75 min, which yielded a high concentration of fermentable sugars (xylose 8.934 g/L, glucose 1.363 g/L, and arabinose 1.203 g/L) and low concentrations of microbial inhibitors (furfural 0.526 g/L and acetic acid 1.192 g/L). These results suggest that the model obtained in this study can satisfactorily describe the formation of degradation products and the depolymerization mechanism of wheat straw. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Analysis on reduced chemical kinetic model of N-heptane for HCCI combustion. Paper no. IGEC-1-072

    International Nuclear Information System (INIS)

    Yao, M.; Zheng, Z.

    2005-01-01

    Because of high complexity coupled with multidimensional fluid dynamics, it is difficult to apply detailed chemical kinetic model to simulate practical engines. A reduced model of n-heptane has been developed on the basic of detailed mechanism by sensitivity analysis and reaction path analysis of every stage of combustion. The new reduced mechanism consists of 35 species and 41 reactions, and it is effective in engine condition. The results show that it gives predictions similar to the detailed model in ignition timing, in-cylinder temperature and pressure. Furthermore, the reduced mechanism can be used to simulate boundary condition of partial combustion in good agreement with the detailed mechanism. (author)

  19. Kinetic analysis on photocatalytic degradation of gaseous acetaldehyde, ammonia and hydrogen sulfide on nanosized porous TiO2 films

    Directory of Open Access Journals (Sweden)

    Iis Sopyan

    2007-01-01

    Full Text Available The characteristics of the UV illumination-assisted degradation of gaseous acetaldehyde, hydrogen sulfide, and ammonia on highly active nanostructured-anatase and rutile films were investigated. It was found that the anatase film showed a higher photocatalytic activity than the counterpart did, however, the magnitude of difference in the photocatalytic activity of both films decreased in the order ammonia>acetaldehyde>hydrogen sulfide. To elucidate the reasons for the observation, the adsorption characteristics and the kinetics of photocatalytic degradation of the three reactants on both films were analyzed. The adsorption analysis examined using a simple Langmuir isotherm, showed that adsorbability on both films decreased in the order ammonia>acetaldehyde>hydrogen sulfide, which can be explained in terms of the decreasing electron-donor capacity. Acetaldehyde and ammonia adsorbed more strongly and with higher coverage on anatase film (1.2 and 5.6 molecules/nm2, respectively than on rutile (0.6 and 4.7 molecules/nm2, respectively. Conversely, hydrogen sulfide molecules adsorbed more strongly on rutile film (0.7 molecules/nm2 than on anatase (0.4 molecules/nm2. Exposure to UV light illumination brought about the photocatalytic oxidation of the three gases in contact with both TiO2 films, and the decrease in concentration were measured, and their kinetics are analyzed in terms of the Langmuir–Hinshelwood kinetic model. From the kinetic analysis, it was found that the anatase film showed the photocatalytic activities that were factors of ~8 and ~5 higher than the rutile film for the degradation of gaseous ammonia and acetaldehyde, respectively. However, the activity was only a factor of ~1.5 higher for the photodegradation of hydrogen sulfide. These observations are systematically explained by the charge separation efficiency and the adsorption characteristics of each catalyst as well as by the physical and electrochemical properties of each

  20. 32 CFR 989.12 - AF Form 813, Request for Environmental Impact Analysis.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false AF Form 813, Request for Environmental Impact... FORCE ENVIRONMENTAL PROTECTION ENVIRONMENTAL IMPACT ANALYSIS PROCESS (EIAP) § 989.12 AF Form 813, Request for Environmental Impact Analysis. The Air Force uses AF Form 813 to document the need for...

  1. Environmental pressure group strength and air pollution. An empirical analysis

    International Nuclear Information System (INIS)

    Binder, Seth; Neumayer, Eric

    2005-01-01

    There is an established theoretical and empirical case-study literature arguing that environmental pressure groups have a real impact on pollution levels. Our original contribution to this literature is to provide the first systematic quantitative test of the strength of environmental non-governmental organizations (ENGOs) on air pollution levels. We find that ENGO strength exerts a statistically significant impact on sulfur dioxide, smoke and heavy particulates concentration levels in a cross-country time-series regression analysis. This result holds true both for ordinary least squares and random-effects estimation. It is robust to controlling for the potential endogeneity of ENGO strength with the help of instrumental variables. The effect is also substantively important. Strengthening ENGOs represents an important strategy by which aid donors, foundations, international organizations and other stakeholders can try to achieve lower pollution levels around the world

  2. Application of ion chemistry to environmental trace gas analysis

    International Nuclear Information System (INIS)

    Hansel, A.; Wisthaler, A.

    2001-01-01

    Full text: In Werner Lindingers laboratory we have developed a mass spectrometric technique, named proton-transfer-reaction mass-spectrometry (PTR-MS), which utilizes positive ion chemistry to measure trace neutral concentrations in air. During the last few years PTR-MS has been used in food research, in medical applications, and in environmental applications to gain gas phase information of volatile organic compounds (VOCs) at parts per trillion (pptv) levels. The real time method relies on proton transfer reactions between H 3 O + primary ions and organic trace gases (VOCs) which have a higher proton affinity than water molecules. Organic trace gases such as hydrocarbons, carbonyls, alcohols, acetonitrile, and others can be monitored on-line. In this lecture we will discuss the mass spectrometric method and present recent results gained in the field of environmental trace gas analysis. (author)

  3. Performance Test of Alpha Spectrometry for Environmental Radioactivity Analysis

    International Nuclear Information System (INIS)

    Choi, Jung Youn; Yoon, Jong-Ho; Han, Ki-Tek; Ahn, Gil Hoon

    2015-01-01

    Environmental samples are analyzed by various methods such as, ICP-MS (inductively coupled plasma mass spectrometry), AMS (accelerator mass spectrometry) TIMS (thermal ionization mass spectrometry), HRGS (high resolution gamma spectrometry) and alpha /beta particle analysis. In this study, we will described the result of performance test using alpha spectrometry for analyzing environmental samples. Measurement data of the U activity using SRM based on extraction chromatography with UTEVA resin. It should be effective way to separate of uranium isotope for the measurement of alpha spectrometry. But, the result of this measurement data is higher than another recovery data. Also concentration of U data is lack of consistency. We leave out of consideration many effect of factors about influence in the experiment process. In the future work, we will try to reduce the step of experiment process and reflect the uncertainty factors

  4. Social Cost Benefit Analysis for Environmental Policy-Making

    International Nuclear Information System (INIS)

    De Zeeuw, A.; In t Veld, R.; Van Soest, D.; Meuleman, L.; Hoogewoning, P.

    2008-01-01

    Review of the theoretical literature and the current debate on the valuation of environmental goods and services, on the discounting of future benefits and costs, and on how social cost benefit analysis (SCBAs) can be integrated in the policy and decision making process. It is concluded that SCBA can be a good decision support method in environmental policy-making if it is transparent and if all impacts are taken into account. Furthermore, the SCBA process should be participative, and politicians must be prepared to take responsibility for the assumptions behind the SCBA, including the assumptions on valuation and on the discount rate. Such a political role makes each SCBA a unique product of a politically responsible actor, and makes it possible for other stakeholders to have calculated an alternative SCBA based on their own assumptions. This Background Study also contains the proceedings of the international SCBA conference organised by RMNO on 16-17 January 2008

  5. Analysis of the Environmental Impact on Remanufacturing Wind Turbines

    Science.gov (United States)

    Sosa Skrainka, Manuel R.

    To deliver clean energy the use of wind turbines is essential. In June 2011 there was an installed wind capacity equivalent to 211,000MW world-wide (WWEA, 2011). By the end of the year 2009 the U.S. had 35,100MW of wind energy installed capacity to generate electricity (AWEA, 2010). This industry has grown in recent years and is expected to grow even more in the future. The environmental impacts that will arise from the increased number of wind turbines and their end-of-life should be addressed, as large amounts of resources will be required to satisfy the current and future market demands for wind turbines. Since future 10MW wind turbines are expected to be as heavy as 1000 tons each, the study of the environmental response of profitable retirement strategies, such as remanufacturing for these machines, must be considered. Because of the increased number of wind turbines and the materials used, this study provides a comparison between the environmental impacts from remanufacturing the components installed inside the nacelle of multi-megawatt wind turbines and wind turbines manufactured using new components. The study methodology is the following: • Describe the life-cycle and the materials and processes employed for the manufacture and remanufacturing for components inside the nacelle. • Identify remanufacturing alternatives for the components inside the nacelle at the end of the expected life-time service of wind turbines. • Evaluate the environmental impacts from the remanufactured components and compare the results with the impacts of the manufacturing of new components using SimaPro. • Conduct sensitivity analysis over the critical parameters of the life cycle assessment • Propose the most environmentally friendly options for the retirement of each major component of wind turbines. After an analysis of the scenarios the goal of the study is to evaluate remanufacturing as an end-of-life option from an environmental perspective for commercial multi

  6. Use of activation analysis of hair in environmental protection

    International Nuclear Information System (INIS)

    Obrusnik, I.

    1982-01-01

    Human hair is very suitable for use in environmental control monitoring because trace elements concentrate in it at higher levels than in most other organs. Unlike in other biological materials, the trace element contents in hair can be determined by instrumental neutron activation analysis (INAA), as the interference by 24 Na can be eliminated by appropriate washing of hair, e.g., using the procedure recommended by IAEA. The methods of sampling, washing and sample analysis using INAA and neutron activation analysis with radiochemical separation are described including the recommended way of the presentation of results. The results are presented of analyses for trace elements in hair from both little and highly polluted areas. (Ha)

  7. Kinetic Typography

    DEFF Research Database (Denmark)

    van Leeuwen, Theo; Djonov, Emilia

    2014-01-01

    After discussing broad cultural drivers behind the development of kinetic typography, the chapter outlines an approach to analysing kinetic typography which is based on Halliday's theory of transitivity, as applied by Kress and Van Leeuwen to visual images....

  8. Kinetic Typography

    DEFF Research Database (Denmark)

    van Leeuwen, Theo; Djonov, Emilia

    2014-01-01

    After discussing broad cultural drivers behind the development of kinetic typography, the chapter outlines an approach to analysing kinetic typography which is based on Halliday's theory of transitivity, as applied by Kress and Van Leeuwen to visual images.......After discussing broad cultural drivers behind the development of kinetic typography, the chapter outlines an approach to analysing kinetic typography which is based on Halliday's theory of transitivity, as applied by Kress and Van Leeuwen to visual images....

  9. Neutron activation analysis as analytical tool of environmental issue

    International Nuclear Information System (INIS)

    Otoshi, Tsunehiko

    2004-01-01

    Neutron activation analysis (NAA) ia applicable to the sample of wide range of research fields, such as material science, biology, geochemistry and so on. However, respecting the advantages of NAA, a sample with small amounts or a precious sample is the most suitable samples for NAA, because NAA is capable of trace analysis and non-destructive determination. In this paper, among these fields, NAA of atmospheric particulate matter (PM) sample is discussed emphasizing on the use of obtained data as an analytical tool of environmental issue. Concentration of PM in air is usually very low, and it is not easy to get vast amount of sample even using a high volume air sampling devise. Therefore, high sensitive NAA is suitable to determine elements in PM samples. Main components of PM is crust oriented silicate, and so on in rural/remote area, and carbonic materials and heavy metals are concentrated in PM in urban area, because of automobile exhaust and other anthropogenic emission source. Elemental pattern of PM reflects a condition of air around the monitoring site. Trends of air pollution can be traced by periodical monitoring of PM by NAA method. Elemental concentrations in air change by season. For example, crustal elements increase in dry season, and sea salts components increase their concentration when wind direction from sea is dominant. Elements that emitted from anthropogenic sources are mainly contained in fine portion of PM, and increase their concentration during winter season, when emission from heating system is high and air is stable. For further analysis and understanding of environmental issues, indicator elements for various emission sources, and elemental concentration ratios of some environmental samples and source portion assignment techniques are useful. (author)

  10. Comparative evaluation of thermal oxidative decomposition for oil-plant residues via thermogravimetric analysis: Thermal conversion characteristics, kinetics, and thermodynamics.

    Science.gov (United States)

    Chen, Jianbiao; Wang, Yanhong; Lang, Xuemei; Ren, Xiu'e; Fan, Shuanshi

    2017-11-01

    Thermal oxidative decomposition characteristics, kinetics, and thermodynamics of rape straw (RS), rapeseed meal (RM), camellia seed shell (CS), and camellia seed meal (CM) were evaluated via thermogravimetric analysis (TGA). TG-DTG-DSC curves demonstrated that the combustion of oil-plant residues proceeded in three stages, including dehydration, release and combustion of organic volatiles, and chars oxidation. As revealed by combustion characteristic parameters, the ignition, burnout, and comprehensive combustion performance of residues were quite distinct from each other, and were improved by increasing heating rate. The kinetic parameters were determined by Coats-Redfern approach. The results showed that the most possible combustion mechanisms were order reaction models. The existence of kinetic compensation effect was clearly observed. The thermodynamic parameters (ΔH, ΔG, ΔS) at peak temperatures were calculated through the activated complex theory. With the combustion proceeding, the variation trends of ΔH, ΔG, and ΔS for RS (RM) similar to those for CS (CM). Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Thermogravimetric Analysis of Modified Hematite by Methane (CH{sub 4}) for Chemical-Looping Combustion: A Global Kinetics Mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Monazam, Esmail R; Breault, Ronald W; Siriwardane, Ranjani; Miller, Duane D

    2013-10-01

    Iron oxide (Fe{sub 2}O{sub 3}) or in its natural form (hematite) is a potential material to capture CO{sub 2} through the chemical-looping combustion (CLC) process. It is known that magnesium (Mg) is an effective methyl cleaving catalyst and as such it has been combined with hematite to assess any possible enhancement to the kinetic rate for the reduction of Fe{sub 2}O{sub 3} with methane. Therefore, in order to evaluate its effectiveness as a hematite additive, the behaviors of Mg-modified hematite samples (hematite –5% Mg(OH){sub 2}) have been analyzed with regard to assessing any enhancement to the kinetic rate process. The Mg-modified hematite was prepared by hydrothermal synthesis. The reactivity experiments were conducted in a thermogravimetric analyzer (TGA) using continuous stream of CH{sub 4} (5, 10, and 20%) at temperatures ranging from 700 to 825 {degrees}C over ten reduction cycles. The mass spectroscopy analysis of product gas indicated the presence of CO{sub 2}, H{sub 2}O, H{sub 2} and CO in the gaseous product. The kinetic data at reduction step obtained by isothermal experiments could be well fitted by two parallel rate equations. The modified hematite samples showed higher reactivity as compared to unmodified hematite samples during reduction at all investigated temperatures.

  12. Photocatalytic degradation kinetics and mechanism of environmental pharmaceuticals in aqueous suspension of TiO{sub 2}: A case of {beta}-blockers

    Energy Technology Data Exchange (ETDEWEB)

    Yang Hai [State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Kehua Street, Tianhe District, Guangzhou 510640 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); An Taicheng, E-mail: antc99@gig.ac.cn [State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Kehua Street, Tianhe District, Guangzhou 510640 (China); Li Guiying [State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Kehua Street, Tianhe District, Guangzhou 510640 (China); Song Weihua; Cooper, William J. [Urban Water Research Center, Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697-2175 (United States); Luo Haiying [State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Resources Utilization and Protection, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Kehua Street, Tianhe District, Guangzhou 510640 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Guangzhou Product Quality Supervision and Testing Institute, National Centre for Quality Supervision and Testing of Processed Food (Guangzhou), Guangzhou 510110 (China); Guo Xindong [Guangzhou Product Quality Supervision and Testing Institute, National Centre for Quality Supervision and Testing of Processed Food (Guangzhou), Guangzhou 510110 (China)

    2010-07-15

    This study investigated the photocatalytic degradation of three {beta}-blockers in TiO{sub 2} suspensions. The disappearance of the compounds followed pseudo-first-order kinetics according to the Langmuir-Hinshelwood model and the rate constants were 0.075, 0.072 and 0.182 min{sup -1} for atenolol, metoprolol and propranolol, respectively. After 240 min irradiation, the reaction intermediates were completely mineralized to CO{sub 2} and the nitrogen was predominantly as NH{sub 4}{sup +}. The influence of initial pH and {beta}-blocker concentration on the kinetics was also studied. From adsorption studies it appears that the photocatalytic degradation occurred mainly on the surface of TiO{sub 2}. Further studies indicated that surface reaction with {center_dot}OH radical was principally responsible for the degradation of these three {beta}-blockers. The major degradation intermediates were identified by HPLC/MS analysis. Cleavage of the side chain and the addition of the hydroxyl group to the parent compounds were found to be the two main degradation pathways for all three {beta}-blockers.

  13. Performance Analysis of an Environmental Adaptive CFAR Detector

    Directory of Open Access Journals (Sweden)

    Sung Won Hong

    2014-01-01

    Full Text Available The constant false alarm rate (CFAR is a detection algorithm that is generally used in radar or sonar systems, but its performance depends greatly on the environment. This means that the detection performance cannot be satisfied with only a single CFAR detector. This paper evaluates mathematically a proposed environmental adaptive (EA CFAR detector. The proposed CFAR detector selects an optimal CFAR detector depending on the environment. Computer simulations validate the mathematical analysis and robustness of the detector in homogeneous and nonhomogeneous backgrounds.

  14. Digital gamma-gamma coincidence HPGe system for environmental analysis.

    Science.gov (United States)

    Marković, Nikola; Roos, Per; Nielsen, Sven Poul

    2017-08-01

    The performance of a new gamma-gamma coincidence spectrometer system for environmental samples analysis at the Center for Nuclear Technologies of the Technical University of Denmark (DTU) is reported. Nutech Coincidence Low Energy Germanium Sandwich (NUCLeGeS) system consists of two HPGe detectors in a surface laboratory with a digital acquisition system used to collect the data in time-stamped list mode with 10ns time resolution. The spectrometer is used in both anticoincidence and coincidence modes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Multicriteria decision analysis: Overview and implications for environmental decision making

    Science.gov (United States)

    Hermans, Caroline M.; Erickson, Jon D.; Erickson, Jon D.; Messner, Frank; Ring, Irene

    2007-01-01

    Environmental decision making involving multiple stakeholders can benefit from the use of a formal process to structure stakeholder interactions, leading to more successful outcomes than traditional discursive decision processes. There are many tools available to handle complex decision making. Here we illustrate the use of a multicriteria decision analysis (MCDA) outranking tool (PROMETHEE) to facilitate decision making at the watershed scale, involving multiple stakeholders, multiple criteria, and multiple objectives. We compare various MCDA methods and their theoretical underpinnings, examining methods that most realistically model complex decision problems in ways that are understandable and transparent to stakeholders.

  16. Nonactivation interaction techniques in the analysis of environmental samples

    International Nuclear Information System (INIS)

    Tolgyessy, J.

    1986-01-01

    Nonactivation interaction analytical methods are based on the interaction processes of nuclear and X-ray radiation with a sample, leading to their absorption and backscattering, to the ionization of gases or excitation of fluorescent X-ray by radiation, but not to the activation of determined elements. From the point of view of environmental analysis, the most useful nonactivation interaction techniques are X-ray fluorescence by photon or charged particle excitation, ionization of gases by nuclear radiation, elastic scattering of charged particles and backscattering of beta radiation. The significant advantage of these methods is that they are nondestructive. (author)

  17. Extracting the basal extracellular dopamine concentrations from the evoked responses: re-analysis of the dopamine kinetics.

    Science.gov (United States)

    Chen, Kevin C; Budygin, Evgeny A

    2007-08-15

    Fast-scan cyclic voltammetry in conjunction with carbon fiber microelectrode has been used to study dopamine (DA) release and uptake mechanisms in rat brains because of the smaller size of the electrode and the subsecond resolution. Current voltammetry data were analyzed by a DA kinetic model assuming a zero baseline, which is in conflict with existing microdialysis findings and a recent claim of the striatal extracellular DA concentration at micromolar levels. This work applied a new analysis approach based on a modified DA kinetic model to analyze the kinetics of electrically evoked DA overflow in the caudate-putamen of anesthetized rats. The DA uptake parameters were fitted from the electrical stimulation phase, and subsequently used to calculate theoretical DA uptake rates. Comparison of the theoretical uptake rates with experimental clearance rates allows for the study of the tonic DA release process following electrical stimulations. Analyses of DA voltammetry data suggest that the locally averaged basal level of extracellular DA in the rat striatum might be confined between 95 and 220 nM. The disparate time scales in the clearance kinetics of endogenous and exogenous DA were investigated. Long-distance diffusion could only partially explain the slow clearance time course of exogenous DA. Model simulations and parameter analyses on evoked DA responses indicate that suppression of the nonevoked DA release process immediately following electrical stimulation cannot completely account for the rapid clearance of the electrically evoked DA. Inconsistency in the measured uptake strengths in the literature studying endogenous and exogenous DA remains to be investigated in the future.

  18. Analysis and simulation of phase transformation kinetics of zeolite A from amorphous phases

    Energy Technology Data Exchange (ETDEWEB)

    Marui, Yukiko; Matsuoka, Masakuni; Uchida, Hirohisa; Takiyama, Hiroshi [Tokyo Univ. of Agriculture and Technology, Koganei, Tokyo (Japan)

    2003-05-01

    Experiments on transformation rates of zeolite A from amorphous phases at different feed rates to alter the particle size of the amorphous phases were carried out to analyze the kinetics of the transformation, and were analyzed by performing simulation of the transformation. A clear dependence of the induction time for nucleation of zeolite A crystals on the surface area of the amorphous phase was recognized, indicating that the nucleation of zeolite A was heterogeneous and the nucleation rate was almost proportional to the size of the amorphous particles. From the simulation, the mechanism of the transformation was found to be heterogeneous nucleation of zeolite A crystals on the surface of amorphous particles followed by solution mediated phase transformation, and the transformation kinetics were well reproduced at different feed rates. (author)

  19. Physicochemical analysis and nonisothermal kinetic study of sertraline-lactose binary mixtures.

    Science.gov (United States)

    Ghaderi, Faranak; Nemati, Mahboob; Siahi-Shadbad, Mohammad Reza; Valizadeh, Hadi; Monajjemzadeh, Farnaz

    2017-07-01

    In the present study the physicochemical stability of sertraline with lactose was evaluated in drug-excipient binary mixtures. Different physicochemical methods such as differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy, and mass spectrometry were applied to confirm the incompatibility. The final aim of this study was to evaluate the kinetic parameters using a fast and sensitive DSC method. Solid-state kinetic parameters were derived from nonisothermally stressed physical mixtures using different thermal models such as Friedman, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose. Overall, the instability of sertraline with lactose was successfully evaluated. Further confirmation was made by tracking the Maillard reaction product of sertraline and lactose by mass spectrometry. DSC scans provided important information about the stability of sertraline in solid-state condition and also revealed the related thermokinetic parameters in order to understand the nature of the chemical instability. Copyright © 2016. Published by Elsevier B.V.

  20. Thermochemistry and micro-kinetic analysis of methanol synthesis on ZnO (0001)

    DEFF Research Database (Denmark)

    Medford, Andrew James; Sehested, Jens; Rossmeisl, Jan

    2014-01-01

    DFT calculations using the RPBE and BEEF-vdW functionals. The energies obtained from the two functionals are compared and it is determined that the BEEF-vdW functional is more appropriate for the reaction. The BEEF-vdW energetics are used to construct surface phase diagrams as a function of CO, H2O......, and H2 chemical potentials. The computed binding energies along with activation barriers from literature are used as inputs for a mean-field micro-kinetic model for methanol synthesis including the CO and CO2 hydrogenation routes and the water–gas shift reaction. The kinetic model is used to investigate...... the methanol synthesis rate as a function of temperature and pressure. The results show qualitative agreement with experiment and yield information on the optimal working conditions of ZnO catalysts....

  1. Analysis and simulation of phase transformation kinetics of zeolite A from amorphous phases

    CERN Document Server

    Marui, Y; Uchida, H; Takiyama, H

    2003-01-01

    Experiments on transformation rates of zeolite A from amorphous phases at different feed rates to alter the particle size of the amorphous phases were carried out to analyze the kinetics of the transformation, and were analyzed by performing simulation of the transformation. A clear dependence of the induction time for nucleation of zeolite A crystals on the surface area of the amorphous phase was recognized, indicating that the nucleation of zeolite A was heterogeneous and the nucleation rate was almost proportional to the size of the amorphous particles. From the simulation, the mechanism of the transformation was found to be heterogeneous nucleation of zeolite A crystals on the surface of amorphous particles followed by solution mediated phase transformation, and the transformation kinetics were well reproduced at different feed rates. (author)

  2. Kinetics of the Thermal Degradation of Granulated Scrap Tyres: a Model-free Analysis

    Directory of Open Access Journals (Sweden)

    Félix A. LÓPEZ

    2013-12-01

    Full Text Available Pyrolysis is a technology with a promising future in the recycling of scrap tyres. This paper determines the thermal decomposition behaviour and kinetics of granulated scrap tyres (GST by examining the thermogravimetric/derivative thermogravimetric (TGA/DTG data obtained during their pyrolysis in an inert atmosphere at different heating rates. The model-free methods of Friedman, Flynn-Wall-Ozawa and Coats-Redfern were used to determine the reaction kinetics from the DTG data. The apparent activation energy and pre-exponential factor for the degradation of GST were calculated. A comparison with the results obtained by other authors was made.DOI: http://dx.doi.org/10.5755/j01.ms.19.4.2947

  3. Model-free method for isothermal and non-isothermal decomposition kinetics analysis of PET sample

    International Nuclear Information System (INIS)

    Saha, B.; Maiti, A.K.; Ghoshal, A.K.

    2006-01-01

    Pyrolysis, one possible alternative to recover valuable products from waste plastics, has recently been the subject of renewed interest. In the present study, the isoconversion methods, i.e., Vyazovkin model-free approach is applied to study non-isothermal decomposition kinetics of waste PET samples using various temperature integral approximations such as Coats and Redfern, Gorbachev, and Agrawal and Sivasubramanian approximation and direct integration (recursive adaptive Simpson quadrature scheme) to analyze the decomposition kinetics. The results show that activation energy (E α ) is a weak but increasing function of conversion (α) in case of non-isothermal decomposition and strong and decreasing function of conversion in case of isothermal decomposition. This indicates possible existence of nucleation, nuclei growth and gas diffusion mechanism during non-isothermal pyrolysis and nucleation and gas diffusion mechanism during isothermal pyrolysis. Optimum E α dependencies on α obtained for non-isothermal data showed similar nature for all the types of temperature integral approximations

  4. Kinetic analysis of the reactions of hypobromous acid with protein components

    DEFF Research Database (Denmark)

    Pattison, David I; Davies, Michael Jonathan

    2004-01-01

    are more, and Cys and Met much less, important targets for HOBr than HOCl. Kinetic models have been developed to predict the targets of HOX attack on proteins and free amino acids. Overall, these results shed light on the mechanisms of cell damage induced by HOX and indicate, for example, that the 3-chloro......Hypohalous acids (HOX, X = Cl, Br) are produced by activated neutrophils, monocytes, eosinophils, and possibly macrophages. These oxidants react readily with biological molecules, with amino acids and proteins being major targets. Elevated levels of halogenated Tyr residues have been detected...... in proteins isolated from patients with atherosclerosis, asthma, and cystic fibrosis, implicating the production of HOX in these diseases. The quantitative significance of these findings requires knowledge of the kinetics of reaction of HOX with protein targets, and such data have not been previously...

  5. Present status of neutron activation analysis in environmental research

    International Nuclear Information System (INIS)

    Steinnes, E.

    1984-01-01

    Neutron activation analysis, in spite of its many advantageous features, is less widely used than some alternative trace element techniques, and has been losing ground during the last decade. In the environmental field however there are still many problems which can be solved in a better way by the contribution of NAA. The combination of multi-element capability and high accuracy is of great importance in many studies related to atmospheric trace elements. Also in aquatic studies NAA still has a significant role to play. Applications to soils, sediments, and plant material have so far been limited, but there is a place for further development. The scope of NAA in environmental research may be extended by further use of pre-irradiation separations. NAA is particularly important in the certification of analytical reference materials in the environmental field. In future applications of NAA an appropriate combination with other analytical techniques will often be a requisite for success. The general future of NAA is dependent on the availability of nuclear reactors, radiochemical laboratoties and appropriate competence. 21 references

  6. Comparative environmental analysis of waste brominated plastic thermal treatments.

    Science.gov (United States)

    Bientinesi, M; Petarca, L

    2009-03-01

    The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of "fossil fuels" and "climate change". Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste.

  7. Comparative environmental analysis of waste brominated plastic thermal treatments

    International Nuclear Information System (INIS)

    Bientinesi, M.; Petarca, L.

    2009-01-01

    The aim of this research activity is to investigate the environmental impact of different thermal treatments of waste electric and electronic equipment (WEEE), applying a life cycle assessment methodology. Two scenarios were assessed, which both allow the recovery of bromine: (A) the co-combustion of WEEE and green waste in a municipal solid waste combustion plant, and (B) the staged-gasification of WEEE and combustion of produced syngas in gas turbines. Mass and energy balances on the two scenarios were set and the analysis of the life cycle inventory and the life cycle impact assessment were conducted. Two impact assessment methods (Ecoindicator 99 and Impact 2002+) were slightly modified and then used with both scenarios. The results showed that scenario B (staged-gasification) had a potentially smaller environmental impact than scenario A (co-combustion). In particular, the thermal treatment of staged-gasification was more energy efficient than co-combustion, and therefore scenario B performed better than scenario A, mainly in the impact categories of 'fossil fuels' and 'climate change'. Moreover, the results showed that scenario B allows a higher recovery of bromine than scenario A; however, Br recovery leads to environmental benefits for both the scenarios. Finally the study demonstrates that WEEE thermal treatment for energy and matter recovery is an eco-efficient way to dispose of this kind of waste

  8. Kinetics Analysis of Synthesis Reaction of Struvite With Air-Flow Continous Vertical Reactors

    Science.gov (United States)

    Edahwati, L.; Sutiyono, S.; Muryanto, S.; Jamari, J.; Bayuseno, dan A. P.

    2018-01-01

    Kinetics reaction is a knowledge about a rate of chemical reaction. The differential of the reaction rate can be determined from the reactant material or the formed material. The reaction mechanism of a reactor may include a stage of reaction occurring sequentially during the process of converting the reactants into products. In the determination of reaction kinetics, the order of reaction and the rate constant reaction must be recognized. This study was carried out using air as a stirrer as a medium in the vertical reactor for crystallization of struvite. Stirring is one of the important aspects in struvite crystallization process. Struvite crystals or magnesium ammonium phosphate hexahydrates (MgNH4PO4·6H2O) is commonly formed in reversible reactions and can be generated as an orthorhombic crystal. Air is selected as a stirrer on the existing flow pattern in the reactor determining the reaction kinetics of the crystal from the solution. The experimental study was conducted by mixing an equimolar solution of 0.03 M NH4OH, MgCl2 and H3PO4 with a ratio of 1: 1: 1. The crystallization process of the mixed solution was observed in an inside reactor at the flow rate ranges of 16-38 ml/min and the temperature of 30°C was selected in the study. The air inlet rate was kept constant at 0.25 liters/min. The pH solution was adjusted to be 8, 9 and 10 by dropping wisely of 1 N KOH solution. The crystallization kinetics was examined until the steady state of the reaction was reached. The precipitates were filtered and dried at a temperature for subsequent material characterization, including Scanning Electron Microscope (SEM) and XRD (X-Ray diffraction) method. The results show that higher flow rate leads to less mass of struvite.

  9. Kinetic modeling and process analysis for Desmodesmus sp. lutein photo-production

    OpenAIRE

    del Rio-Chanona, Ehecatl Antonio; Ahmed, Nur rashid; Zhang, Dongda; Lu, Yinghua; Jing, Keju

    2017-01-01

    Lutein is a high-value bioproduct synthesized by microalga Desmodesmus sp. In the current study two aspects of this process are thoroughly investigated: identifying the complex effects of light intensity and nitrate concentration on bio- mass growth and lutein synthesis, and constructing an accurate kinetic model capable of simulating the entire biopro- cess dynamic performance, neither of which has been previously addressed. Three original contributions are presented here. First, it is found...

  10. Kinetic analysis of tubulin assembly in the presence of the microtubule-associated protein TOGp

    OpenAIRE

    Bonfils, Claude; Bec, Nicole; Lacroix, Benjamin; Harricane, Marie-Cécile; Larroque, Christian

    2006-01-01

    International audience; The microtubule-associated protein TOGp, which belongs to a widely distributed protein family from yeasts to humans, is highly expressed in human tumors and brain tissue. From purified components we have determined the effect of TOGp on thermally induced tubulin association in vitro in the presence of 1 mm GTP and 3.4 m glycerol. Physicochemical parameters describing the mechanism of tubulin polymerization were deduced from the kinetic curves by application of the clas...

  11. Kinetic analysis of polyoxometalate (POM) oxidation of non-phenolic lignin model compound

    Science.gov (United States)

    Tomoya Yokoyama; Hou-min Chang; Ira A. Weinstock; Richard S. Reiner; John F. Kadla

    2003-01-01

    Kinetic and reaction mechanism of non-phenolic lignin model compounds under anaerobic polyoxometalate (POM), Na5(+1.9)[SiV1(-0.1)MoW10(+0.1) 40], bleaching conditions were examined. Analyses using a syringyl type model, 1-(3,4,5-trimethoxyphenyl)ethanol (1), a guaiacyl type, 1-(3,4- imethoxyphenyl)ethanol (2), and 1- (4-ethoxy-3,5-dimethoxyphenyl)ethanol (3) suggest...

  12. Environmental Systems Research and Analysis FY 2000 Annual Report

    Energy Technology Data Exchange (ETDEWEB)

    David L. Miller; Castle, Peter Myer; Steven J. Piet

    2001-01-01

    The Environmental Systems Research (ESR) Program, a part of the Environmental Systems Research and Analysis (ESRA) Program, was implemented to enhance and augment the technical capabilities of the INEEL. Strengthening the Technical capabilities of the INEEL will provide the technical base to serve effectively as the Environmental Management Laboratory for the Office of Environmental Management (EM). This is a progress report for the third year of the ESR Program (FY 2000). A report of activities is presented for the five ESR research investment areas: (1) Transport Aspects of Selective Mass Transport Agents, (2) Chemistry of Environmental Surfaces, (3) Materials Dynamics, (4) Characterization Science, and (5) Computational Simulation of Mechanical and Chemical Systems. In addition to the five technical areas, the report describes activities in the Science and Technology Foundations element of the program, e.g., interfaces between ESR and the EM Science Program (EMSP) and the EM Focus Areas. The five research areas are subdivided into 18 research projects. FY 2000 research in these 18 projects has resulted in more than 50 technical papers that are in print, in press, in review, or in preparation. Additionally, more than 100 presentations were made at professional society meetings nationally and internationally. Work supported by this program was in part responsible for one of our researchers, Dr. Mason Harrup, receiving the Department of Energy’s “Bright Light” and “Energy at 23” awards. Significant accomplishments were achieved. Non-Destructive Assay hardware and software was deployed at the INEEL, enhancing the quality and efficiency of TRU waste characterization for shipment. The advanced tensiometer has been employed at numerous sites around the complex to determine hydrologic gradients in variably saturated vadose zones. An ion trap, secondary ion mass spectrometer (IT-SIMS) was designed and fabricated to deploy at the INEEL site to measure the

  13. Kinetic study of hydrogen-material interactions in nickel base alloy 600 and stainless steel 316L through coupled experimental and numerical analysis

    International Nuclear Information System (INIS)

    Hurley, Caitlin-Mae

    2015-01-01

    In France all of the nuclear power plant facilities in service today are pressurized water reactors (PWR). Some parts of the PWR in contact with the primary circuit medium, such as the steam generator tubes (fabricated in nickel base alloy A600) and some reactor core internal components (fabricated in stainless steel 316L), can fall victim to environmental degradation phenomena such as stress corrosion cracking (SCC). In the late 1950's, H. Coriou observed experimentally and predicted this type of cracking in alloys traditionally renowned for their SCC resistance (A600). Just some 20 to 30 years later his predictions became a reality. Since then, numerous studies have focused on the description and comprehension of the SCC phenomenon in primary water under reactor operating conditions. In view of reactor lifetime extension, it has become both critical and strategic to be capable of simulating SCC phenomenon in order to optimize construction materials, operating conditions, etc. and to understand the critical parameters in order to limit the damage done by SCC. This study focuses on the role hydrogen plays in SCC phenomenon and in particular H-material interactions. Hydrogen, from primary medium in the form of dissolved H gas or H from the water, can be absorbed by the alloy during the oxidation process taking place under reactor operating conditions. Once absorbed, hydrogen may be transported across the material, diffusing in the interstitial sites of the crystallographic structure and interacting with local defects, such as dislocations, precipitates, vacancies, etc. The presence of these [local defect] sites can slow the hydrogen transport and may provoke local H accumulation in the alloy. This accumulation could modify the local mechanical properties of the material and favor premature rupture. It is therefore essential to identify the nature of these H-material interactions, specifically the rate of H diffusion and hydrogen trapping kinetics at these

  14. The solution of the neutron point kinetics equation with stochastic extension: an analysis of two moments

    International Nuclear Information System (INIS)

    Silva, Milena Wollmann da; Vilhena, Marco Tullio M.B.; Bodmann, Bardo Ernst J.; Vasques, Richard

    2015-01-01

    The neutron point kinetics equation, which models the time-dependent behavior of nuclear reactors, is often used to understand the dynamics of nuclear reactor operations. It consists of a system of coupled differential equations that models the interaction between (i) the neutron population; and (II) the concentration of the delayed neutron precursors, which are radioactive isotopes formed in the fission process that decay through neutron emission. These equations are deterministic in nature, and therefore can provide only average values of the modeled populations. However, the actual dynamical process is stochastic: the neutron density and the delayed neutron precursor concentrations vary randomly with time. To address this stochastic behavior, Hayes and Allen have generalized the standard deterministic point kinetics equation. They derived a system of stochastic differential equations that can accurately model the random behavior of the neutron density and the precursor concentrations in a point reactor. Due to the stiffness of these equations, this system was numerically implemented using a stochastic piecewise constant approximation method (Stochastic PCA). Here, we present a study of the influence of stochastic fluctuations on the results of the neutron point kinetics equation. We reproduce the stochastic formulation introduced by Hayes and Allen and compute Monte Carlo numerical results for examples with constant and time-dependent reactivity, comparing these results with stochastic and deterministic methods found in the literature. Moreover, we introduce a modified version of the stochastic method to obtain a non-stiff solution, analogue to a previously derived deterministic approach. (author)

  15. Useful multivariate kinetic analysis: Size determination based on cystein-induced aggregation of gold nanoparticles.

    Science.gov (United States)

    Rabbani, Faride; Hormozi Nezhad, Mohammad Reza; Abdollahi, Hamid

    2013-11-01

    This study describes spectrometric monitored kinetic processes to determine the size of citrate-capped Au nanoparticles (Au NPs) based on aggregation induced by l-cysteine (l-Cys) as a molecular linker. The Au NPs association process is thoroughly dependent on pH, concentration and size of nanoparticles. Size dependency of aggregation inspirits to determine the average diameters of Au NPs. For this aim the procedure is achieved in aqueous medium at pH 7 (phosphate buffer), and multivariate data including kinetic spectra of Au NPs are collected during aggregation process. Subsequently partial least squares (PLS) modeling is carried out analyzing the obtained data. The model is built on the basis of relation between the kinetics behavior of aggregation and different Au NPs sizes. Training the model was performed using latent variables (LVs) of the original data. The analytical performance of the model was characterized by relative standard error. The proposed method was applied to determination of size in unknown samples. The predicted sizes of unknown samples that obtained by the introduced method are interestingly in agreement with the sizes measured by Transmission Electron Microscopy (TEM) images and Dynamic Light Scattering (DLS) measurement. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Kinetic analysis on the two-step processes of AOB and NOB in aerobic nitrifying granules.

    Science.gov (United States)

    Fang, Fang; Ni, Bing-Jie; Li, Xiao-Yan; Sheng, Guo-Ping; Yu, Han-Qing

    2009-07-01

    Complete granulation of nitrifying sludge was achieved in a sequencing batch reactor. For the granular sludge, batch experiments were conducted to characterize the kinetic features of ammonia oxidizers (AOB) and nitrite oxidizers (NOB) in the granules using the respirometric method. A two-step nitrification model was established to determine the kinetic parameters of both AOB and NOB. In addition to nitrification reactions, the new model also took into account biomass maintenance and mass transfer through the granules. The yield coefficient, maximum specific growth rate, and affinity constant for ammonium for AOB were 0.21 g chemical oxygen demand (COD) g(-1) N, 0.09 h(-1), and 9.1 mg N L(-1), respectively, whereas the corresponding values for NOB were 0.05 g COD g(-1) N, 0.11 h(-1), and 4.85 mg N L(-1), respectively. The model developed in this study performed well in simulating the oxygen uptake rate and nitrogen conversion kinetics and in predicting the oxygen consumption of the AOB and NOB in aerobic granules.

  17. Kinetic analysis of Yersinia pestis DNA adenine methyltransferase activity using a hemimethylated molecular break light oligonucleotide.

    Directory of Open Access Journals (Sweden)

    Robert J Wood

    Full Text Available BACKGROUND: DNA adenine methylation plays an important role in several critical bacterial processes including mismatch repair, the timing of DNA replication and the transcriptional control of gene expression. The dependence of bacterial virulence on DNA adenine methyltransferase (Dam has led to the proposal that selective Dam inhibitors might function as broad spectrum antibiotics. METHODOLOGY/PRINCIPAL FINDINGS: Herein we report the expression and purification of Yersinia pestis Dam and the development of a continuous fluorescence based assay for DNA adenine methyltransferase activity that is suitable for determining the kinetic parameters of the enzyme and for high throughput screening against potential Dam inhibitors. The assay utilised a hemimethylated break light oligonucleotide substrate containing a GATC methylation site. When this substrate was fully methylated by Dam, it became a substrate for the restriction enzyme DpnI, resulting in separation of fluorophore (fluorescein and quencher (dabcyl and therefore an increase in fluorescence. The assays were monitored in real time using a fluorescence microplate reader in 96 well format and were used for the kinetic characterisation of Yersinia pestis Dam, its substrates and the known Dam inhibitor, S-adenosylhomocysteine. The assay has been validated for high throughput screening, giving a Z-factor of 0.71+/-0.07 indicating that it is a sensitive assay for the identification of inhibitors. CONCLUSIONS/SIGNIFICANCE: The assay is therefore suitable for high throughput screening for inhibitors of DNA adenine methyltransferases and the kinetic characterisation of the inhibition.

  18. The solution of the neutron point kinetics equation with stochastic extension: an analysis of two moments

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Milena Wollmann da; Vilhena, Marco Tullio M.B.; Bodmann, Bardo Ernst J.; Vasques, Richard, E-mail: milena.wollmann@ufrgs.br, E-mail: vilhena@mat.ufrgs.br, E-mail: bardobodmann@ufrgs.br, E-mail: richard.vasques@fulbrightmail.org [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica

    2015-07-01

    The neutron point kinetics equation, which models the time-dependent behavior of nuclear reactors, is often used to understand the dynamics of nuclear reactor operations. It consists of a system of coupled differential equations that models the interaction between (i) the neutron population; and (II) the concentration of the delayed neutron precursors, which are radioactive isotopes formed in the fission process that decay through neutron emission. These equations are deterministic in nature, and therefore can provide only average values of the modeled populations. However, the actual dynamical process is stochastic: the neutron density and the delayed neutron precursor concentrations vary randomly with time. To address this stochastic behavior, Hayes and Allen have generalized the standard deterministic point kinetics equation. They derived a system of stochastic differential equations that can accurately model the random behavior of the neutron density and the precursor concentrations in a point reactor. Due to the stiffness of these equations, this system was numerically implemented using a stochastic piecewise constant approximation method (Stochastic PCA). Here, we present a study of the influence of stochastic fluctuations on the results of the neutron point kinetics equation. We reproduce the stochastic formulation introduced by Hayes and Allen and compute Monte Carlo numerical results for examples with constant and time-dependent reactivity, comparing these results with stochastic and deterministic methods found in the literature. Moreover, we introduce a modified version of the stochastic method to obtain a non-stiff solution, analogue to a previously derived deterministic approach. (author)

  19. Dual-Mode Measurement and Theoretical Analysis of Evaporation Kinetics of Binary Mixtures

    Science.gov (United States)

    Song, Hanyu; He, Chi-Ruei; Basdeo, Carl; Li, Ji-Qin; Ye, Dezhuang; Kalonia, Devendra; Li, Si-Yu; Fan, Tai-Hsi

    Theoretical and experimental investigations are presented for the precision measurement of evaporation kinetics of binary mixtures using a quartz crystal resonator. A thin layer of light alcohol mixture including a volatile (methanol) and a much less volatile (1-butanol) components is deployed on top of the resonator. The normal or acoustic mode is to detect the moving liquid-vapor interface due to evaporation with a great spatial precision on the order of microns, and simultaneously the shear mode is used for in-situ detection of point viscosity or concentration of the mixture near the resonator. A one-dimensional theoretical model is developed to describe the underlying mass transfer and interfacial transport phenomena. Along with the modeling results, the transient evaporation kinetics, moving interface, and the stratification of viscosity of the liquid mixture during evaporation are simultaneously measured by the impedance response of the shear and longitudinal waves emitted from the resonator. The system can be used to characterize complicated evaporation kinetics involving multi-component fuels. American Chemical Society Petroleum Research Fund, NSF CMMI-0952646.

  20. Computer system for environmental sample analysis and data storage and analysis

    International Nuclear Information System (INIS)

    Brauer, F.P.; Fager, J.E.

    1976-01-01

    A mini-computer based environmental sample analysis and data storage system has been developed. The system is used for analytical data acquisition, computation, storage of analytical results, and tabulation of selected or derived results for data analysis, interpretation and reporting. This paper discussed the structure, performance and applications of the system

  1. Environmental analysis and zoning for an urban park management purpose

    Directory of Open Access Journals (Sweden)

    Elisabete Maria Zanin

    2005-07-01

    Full Text Available Environmental analysis and zoning were carried out for management purpose of the Longines Malinowski Municipal Park (LMMP. With an area of 24.85 ha, this urban park includes a patch of sub-tropical humid forest, completely surrounded by residential and commercial areas in the City of Erechim, Rio Grande do Sul State,Brazil. Landscape features derived from aerophotogrametric maps, based on the use of Geographical Information Systems (GIS-IDRISI, resulted in several thematic maps, through which a proposal of environmental zoning was perfomed, observing the definition of five zones of use. The environmental diagnosis identified several types of activities potentially harmful to the biodiversity of the LMMP and city's environmental quality. The implementation of a management plan would be essential to maintain and preseve this urban park, aiming to ensure its participation in the urban quality of life.Foram realizados a análise e o zoneamento ambiental com a finalidade do manejo do Parque Municipal Longines Malinowski (PMLM. Com 24,85 ha, este parque urbano inclui um fragmento de floresta sub-tropical úmida, completamente cercado por áreas residenciais e comerciais na cidade de Erechim, Rio Grande do Sul. As características da paisagem, obtidas de cartas aerofotogramétricas, com base no uso de Sistemas de Informações Geográficas (SIG-IDRISI, resultaram em diversas cartas temáticas, pelas quais foi efetuada uma proposta do zoneamento ambiental, observando a definição de cinco zonas de uso. O diagnóstico ambiental identificou diversos tipos de atividades potencialmente prejudiciais à biodiversidade do PMLM e à qualidade ambiental da cidade. A implementação de um plano de manejo é essencial à manutenção e à conservação deste parque urbano, assegurando sua participação na qualidade de vida urbana.

  2. Green tide to green fuels: TG–FTIR analysis and kinetic study of Ulva prolifera pyrolysis

    International Nuclear Information System (INIS)

    Ceylan, Selim; Goldfarb, Jillian L.

    2015-01-01

    Highlights: • Distributed Activation Energy Model applied to Ulva prolifera pyrolysis. • Model and experimental data in good agreement to predict activation energy. • Ulva prolifera shows relatively low activation energy compared to other macroalgae. • Evolved gas analysis shows CO 2 emission decreasing with temperature. • Methane evolution increases with temperature, peaks at 800 °C. - Abstract: The world grapples with identifying renewable replacements for fossil fuels. Ulva prolifera, a macroalgae species that has caused green tides in China and Europe, represents a possible source of renewable energy. Given its low lipid content, thermochemical conversion techniques such as pyrolysis may be more suitable than biochemical techniques. We apply the Distributed Activation Energy Model to determine the activation energy of pyrolysis of U. prolifera from thermogravimetric data with combined evolved gas analysis via FTIR. Correlation coefficients for the DAEM were greater than 0.98 at each conversion; the apparent activation energy ranged from 130 to 152 kJ/mol, in good accord with the literature. Three stages of decomposition were noted over the entire temperature range; below 110 °C mass loss due to moisture removal. The largest stage of pyrolysis occurred between 190 and 400 °C with peak mass loss conversion rates up to 8.1 wt% per minute at 20 °C/min. The concentration of CO 2 in the evolved gas peaked along with mass loss rate at 242.7 °C. Stage III of pyrolysis saw a slow mass loss rate and a significant amount of methane from the macroalgae. Given its low energy, nutrient, land and maintenance requirements to grow, tolerance to a variety of environmental conditions, and low pyrolysis activation energies (as compared to other macroalgae), thermochemical conversion via pyrolysis is a viable way to extract energy from this seaweed species

  3. [Application of microfluidics in aquatic environmental pollution analysis].

    Science.gov (United States)

    Wang, Hu; Wei, Jun-Feng; Zheng, Guo-Xia

    2014-04-01

    Recently, a new type of chip technology, microfluidics, has received global attention for its rapid analysis speed, low reagent consumption, small size and simple operation, etc. Based on a micro-channel network and supported by a Micro-Electro-Mechanic System (MEMS), this technology integrates all the functions of a laboratory into one small piece of chip, which is called "lab on the chip". This paper presented a brief introduction about microfluidics and its representative developments. Future prospects in the aspects of instrument miniaturization, system integration, chip materials, and detection techniques, as well as the implementation of microfluidics in aquatic environmental pollutant analysis were thoroughly discussed. Some problems faced now were put forward. With the rapid progress in the microfluidics, a universal low-cost microchip capable of high speed multi-channel detection and integrated with many kinds of detection methods would be the research focus in the future.

  4. Radioactive kryptonates in the analysis of environmental samples

    International Nuclear Information System (INIS)

    Tolgyessy, J.

    1986-01-01

    The term ''radioactive Kryptonates'' is used for substances into which atoms or ions of the radioactive nuclide 85 Kr are incorporated. The basis of the use of radioactive Kryptonates in analytical chemistry is that during a chemical reaction the crystalline lattice of the kryptonated carrier is destroyed, the carrier consumed, and the radioactive krypton released (radio-release method). Analysis can be made with a calibration curve or by comparison with a standard. Radio-release methods with the aid of radioactive Kryptonates as analytical reagents are very useful for the analysis of environmental samples, e.g. for the determination of air pollutants (ozone, sulphur dioxide, fluorine, hydrogen fluoride, mercury); and water pollutants (oxygen, dichromate, vanadium, hydrochloric acid, sulphur dioxide). (author)

  5. 2004 Power marketing program. Final environmental impact statement. Volume 1 - summary and environmental analysis

    International Nuclear Information System (INIS)

    1997-02-01

    The Sierra Nevada Region proposes to develop a plan to allocate power within its marketing areas of California and Nevada. Five alternatives were analyzed based on the possible range of operations of the Central Valley Project (CVP) hydroelectric system, levels of power purchases, and customer group allocations. Scheduling of the hydropower generating plants is the key difference across the alternatives. The peaking, preferred, renewables, and no-action alternatives are based on scheduling to emphasize peaking power. The baseload alternative assumes steady water releases. The analysis found no significant impacts overall. However, peaking operations tend to result in the greatest benefits and least negative effects to resources where impacts could be quantified. The peaking alternative was selected as the environmentally preferred alternative. The peaking alternative would add up to 317 MW of load-carrying capacity during August compared to taking no action. The preferred alternative results in up to a 262-MW gain and the baseload alternative results in a loss of 581 MW in comparison to the no-action alternative. Although it is not possible to determine where or when any lost capacity would be made up, building replacement capacity would result in land-use impacts and the use of natural and financial resources. The baseload alternative would result in more stable pool fluctuation within regulating reservoirs, which may benefit resident fish, recreation, and cultural resources; but these effects would be minor and could not be quantified. Environmental impacts within the CVP are limited to fluctuations in the regulating reservoirs. Changes in allocations to customer groups result in negligible regional economic effects. The renewables alternative is similar in CVP operation to the peaking alternative and melds 50 MW of renewables with CVP hydropower. Its environmental impacts vary, depending on the presence of biomass in the resource mix. 84 refs., 44 figs., 27 tabs

  6. Environmental impact analysis (EIA) concerning lodgepole pine forestry in Sweden

    International Nuclear Information System (INIS)

    Andersson, Bengt; Rosvall, Ola; Engelmark, Ola; Sjoeberg, Kjell

    1999-01-01

    This report presents an analysis of the ecological consequences of forestry with Canadian lodgepole pine introduced into Sweden. The report includes a compilation of present knowledge in the area, research priorities, and proposed measures for dealing with the negative environmental consequences that could arise. The point of departure of the analysis is a description of the properties of lodgepole pine, including species-specific characteristics of the tree, and changes in stand environment and silvicultural management practices that can be expected. The report describes the dispersal capacity of lodgepole pine in its new Swedish environment and the effects of host-parasite interactions. Thereafter, ecological effects on the capacity of the soil for sustainable production and on biological diversity at various scales (tree, stand, landscape) are analysed. Lodgepole pine forestry is also considered in relation to current laws and regulations as well as national and international environmental goals. At the end of the report, a strategy is proposed for handling the inevitable uncertainties associated with the introduction of exotic species 111 refs, 14 figs

  7. Draft Waste Management Programmatic Environmental Impact Statement for managing treatment, storage, and disposal of radioactive and hazardous waste. Volume 3, Appendix A: Public response to revised NOI, Appendix B: Environmental restoration, Appendix C, Environmental impact analysis methods, Appendix D, Risk

    International Nuclear Information System (INIS)

    1995-08-01

    Volume three contains appendices for the following: Public comments do DOE's proposed revisions to the scope of the waste management programmatic environmental impact statement; Environmental restoration sensitivity analysis; Environmental impacts analysis methods; and Waste management facility human health risk estimates

  8. Environmental systems analysis of biogas systems; Miljoeanalys av biogassystem

    Energy Technology Data Exchange (ETDEWEB)

    Boerjesson, Paal; Berglund, Maria

    2003-05-01

    The purpose of this study is to analyse various biogas systems from an environmental point of view. The analyses are based on a systems analysis approach and an energy perspective. Biogas systems included are based on various combinations of substrates and final use of the biogas (heat, power and transportation fuel). The overall aims are to calculate fuel cycle emissions, quantify indirect environmental effects when various reference systems are replaced (e.g. current systems for waste treatment, agricultural production and energy generation), and to present data, calculations and results in a clear and transparent way, making the study useful for other environmental systems analyses. A general conclusion is that the environmental impact from biogas systems can vary significantly due to such factors as which substrate, energy service and reference system are chosen, and if indirect environmental effects and the need of systems enlargement are considered. The introduction of biogas systems normally leads to a reduced contribution of greenhouse gases, with some exceptions such as when biogas is used for heat and the alternative is combustion of the biomass. Biogas from manure seems to result in particularly large reductions due to indirect benefits in the form of reduced leakage of methane compared with conventional methods for handling and storing manure. A prerequisite is, however, that the losses of methane are small or that methane is combusted and thus converted into carbon dioxide. This study shows that the losses of methane can be up to 8-26%, due to what kind of biogas system is studied, before the contribution of greenhouse gases exceeds the contribution from reference systems based on fossil fuels. The contribution of emissions that leads to eutrophication and acidification is almost always reduced when biogas systems are introduced. The indirect environmental benefits could be significant for biogas based on sugar beet tops when leaving the beet tops at

  9. Study of Non-Isothermal Decomposition and Kinetic Analysis of 2,4-Dihydroxybenzoic Acid- Melamine-Formaldehyde Copolymer

    Directory of Open Access Journals (Sweden)

    S. S. Butoliya

    2010-01-01

    Full Text Available A copolymer (2,4-DHBAMF synthesized by the condensation of 2,4-dihydroxybenzoic acid and melamine with formaldehyde in the presence of acid catalyst using varied molar proportions of the reactants. A composition of the copolymer has been determined by elemental analysis. The number average molecular weight has been determined by conductometric titration in non-aqueous medium. The copolymer has been characterized by UV-Visible, IR and 1H NMR spectral analysis. Thermogravimetric analysis was carried out to study the decomposition and various kinetic parameters. Freeman Carroll and Sharp Wentworth methods have been applied for the calculation of kinetic parameters while the data from Freeman Carroll method have been used to determine various thermodynamic parameters such as order of reaction, energy of activation, frequency factor, entropy change, free energy change and apparent entropy change. The results indicate that given copolymer have potential as matrix resin for long term applications at temperature up to 350 °C.

  10. Removal of methylene blue from aqueous solution with magnetite loaded multi-wall carbon nanotube: Kinetic, isotherm and mechanism analysis

    International Nuclear Information System (INIS)

    Ai, Lunhong; Zhang, Chunying; Liao, Fang; Wang, Yao; Li, Ming; Meng, Lanying; Jiang, Jing

    2011-01-01

    Highlights: ► M-MWCNTs were synthesized by a facile one-pot solvothermal method and used as an efficient adsorbent for removing toxic dye from aqueous solution. ► The adsorption process was characterized by kinetics and isotherm analysis. ► FTIR analysis was employed to investigate the interactions between M-MWCNTs and dye. - Abstract: In this study, we have demonstrated the efficient removal of cationic dye, methylene blue (MB), from aqueous solution with the one-pot solvothermal synthesized magnetite-loaded multi-walled carbon nanotubes (M-MWCNTs). The as-prepared M-MWCNTs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The effects of contact time, initial dye concentration, and solution pH on the adsorption of MB onto M-MWCNTs were systematically studied. It was shown that the MB adsorption was pH-dependent. Adsorption kinetics was best described by the pseudo-second-order model. Equilibrium data were well fitted to the Langmuir isotherm model, yielding maximum monolayer adsorption capacity of 48.06 mg g −1 . FTIR analysis suggested that the adsorption mechanism was possibly attributed to the electrostatic attraction and π–π stacking interactions between MWCNTs and MB.

  11. Kinetic bed therapy to prevent nosocomial pneumonia in mechanically ventilated patients: a systematic review and meta-analysis.

    Science.gov (United States)

    Delaney, Anthony; Gray, Hilary; Laupland, Kevin B; Zuege, Danny J

    2006-01-01

    Nosocomial pneumonia is the most important infectious complication in patients admitted to intensive care units. Kinetic bed therapy may reduce the incidence of nosocomial pneumonia in mechanically ventilated patients. The objective of this study was to investigate whether kinetic bed therapy reduces the incidence of nosocomial pneumonia and improves outcomes in critically ill mechanically ventilated patients. We searched Medline, EMBASE, CINAHL, CENTRAL, and AMED for studies, as well as reviewed abstracts of conference proceedings, bibliographies of included studies and review articles and contacted the manufacturers of medical beds. Studies included were randomized or pseudo-randomized clinical trials of kinetic bed therapy compared to standard manual turning in critically ill mechanically ventilated adult patients. Two reviewers independently applied the study selection criteria and extracted data regarding study validity, type of bed used, intensity of kinetic therapy, and population under investigation. Outcomes assessed included the incidence of nosocomial pneumonia, mortality, duration of ventilation, and intensive care unit and hospital length of stay. Fifteen prospective clinical trials were identified, which included a total of 1,169 participants. No trial met all the validity criteria. There was a significant reduction in the incidence of nosocomial pneumonia (pooled odds ratio (OR) 0.38, 95% confidence interval (CI) 0.28 to 0.53), but no reduction in mortality (pooled OR 0.96, 95%CI 0.66 to 1.14), duration of mechanical ventilation (pooled standardized mean difference (SMD) -0.14 days, 95%CI, -0.29 to 0.02), duration of intensive care unit stay (pooled SMD -0.064 days, 95% CI, -0.21 to 0.086) or duration of hospital stay (pooled SMD 0.05 days, 95% CI -0.18 to 0.27). While kinetic bed therapy has been purported to reduce the incidence of nosocomial pneumonia in mechanically ventilated patients, the overall body of evidence is insufficient to support this

  12. A combined kinematic and kinetic analysis at the residuum/socket interface of a knee-disarticulation amputee.

    Science.gov (United States)

    Tang, Jinghua; McGrath, Michael; Hale, Nick; Jiang, Liudi; Bader, Dan; Laszczak, Piotr; Moser, David; Zahedi, Saeed

    2017-11-01

    The bespoke interface between a lower limb residuum and a prosthetic socket is critical for an amputee's comfort and overall rehabilitation outcomes. Analysis of interface kinematics and kinetics is important to gain full understanding of the interface biomechanics, which could aid clinical socket fit, rehabilitation and amputee care. This pilot study aims to investigate the dynamic correlation between kinematic movement and kinetic stresses at the interface during walking tests on different terrains. One male, knee disarticulation amputee participated in the study. He was asked to walk on both a level surface and a 5° ramped surface. The movement between the residuum and the socket was evaluated by the angular and axial couplings, based on the outputs from a 3D motion capture system. The corresponding kinetic stresses at anterior-proximal (AP), posterior-proximal (PP) and anterior-distal (AD) locations of the residuum were measured, using individual stress sensors. Approximately 8° of angular coupling and up to 32 mm of axial coupling were measured when walking on different terrains. The direction of the angular coupling shows strong correlation with the pressure difference between the PP and AP sensors. Higher pressure was obtained at the PP location than the AP location during stance phase, associated with the direction of the angular coupling. A strong correlation between axial coupling length, L, and longitudinal shear was also evident at the PP and AD locations i.e. the shortening of L corresponds to the increase of shear in the proximal direction. Although different terrains did not affect these correlations in principle, interface kinematic and kinetic values suggested that gait changes can induce modifications to the interface biomechanics. It is envisaged that the reported techniques could be potentially used to provide combined kinematics and kinetics for the understanding of biomechanics at the residuum/socket interface, which may play an important

  13. Kinetic Analysis of Drug Release from Compounded Slow-release Capsules of Liothyronine Sodium (T3).

    Science.gov (United States)

    Bakhteyar, Hamid; Cassone, Clayton; Kohan, Hamed Gilzad; Sani, Shabnam N

    2017-01-01

    The purpose of this study was to formulate extemporaneously compounded Liothyronine Sodium (T3) slow-release capsules and to evaluate their in vitro drug release performance. Twenty-one formulations containing T3 (7.5 µg) with various compositions of two different grades of Methocel E4M and K100M premium (30% to 90%), and/or SimpleCap/Lactose (10% to 70%) were examined. Quality assessment of the capsules was conducted by standard quality control criteria of the United States Pharmacopeia (i.e., weight variation, content uniformity) to ensure their compliance. The dissolution release profile of the formulations was evaluated using United States Pharmacopeia Apparatus type II (paddle method) at a speed of 50 rpm and temperature of 37°C in phosphate buffered saline media ( pH = 7.2 to 7.4). Aliquots from the media were taken periodically up to 24 hours and analyzed using a validated enzyme-linked immunosorbent assay method. The cumulative percentage of drug release for each formulation was fitted to eleven major release kinetic equations to determine the best-fit model of drug release, as well as the mechanism of release. Assay sensitivity was as low as 1 ng/mL and the optimal calibration range was found to be between 0 ng/mL and 7.5 ng/mL, which corresponded well with the average physiological plasma concentrations of T3. Liothyronine sodium with either SimpleCap (100%) or Methocel E4M (100%) exhibited slowrelease kinetic patterns of Peppas and Zero Order, respectively. The formulation with SimpleCap (100%) had a higher percentage of drug release (as compared to 100% Methocel E4M) within the first four hours; this formulation released 80% of the drug within 12 hours when the release was plateaued thereafter. The formulation with 30% Methocel E4M and 70% SimpleCap released 100% of the drug within the initial 12 hours and exhibited a Zero Order slow-release kinetic pattern. In general, the release kinetic rate of the formulations containing Methocel K100M appeared to

  14. Mechanistic insight into sono-enzymatic degradation of organic pollutants with kinetic and thermodynamic analysis.

    Science.gov (United States)

    Malani, Ritesh S; Khanna, Swati; Chakma, Sankar; Moholkar, Vijayanand S

    2014-07-01

    In this paper, we have attempted to get a physical insight into process of sono-enzymatic treatment for degradation of recalcitrant organic pollutants. Decolourization of an azo dye has been used as model reaction with different experimental protocols that alter characteristics of ultrasound and cavitation phenomena in the system. Experimental data is analyzed to determine kinetic and thermodynamic parameters of decolorization process. The trends observed in kinetic and thermodynamic parameters of decolourization are essentially manifestations of the dominating mechanism of the decolorization of the textile dye (or nature of prevalent chemical reaction in the system), viz. either molecular reaction due to enzyme or radical reaction due to transient cavitation. The activation energy for sonochemical protocol is negative, which indicates instantaneity of the radical reactions. The frequency factor is also low, which is attributed to high instability of radicals. For enzymatic and sono-enzymatic protocols, activation energy is positive with higher frequency factor. Enthalpy change for sonochemical protocol is negative, while that for enzymatic and sono-enzymatic protocols is positive. The net entropy change for sonochemical protocol is more negative than enzymatic or sono-enzymatic protocol due to differences in prevalent chemical mechanism of dye decolorization. Due to inverse variations of frequency factor and activation energy, marginal rise in reaction kinetics is seen for sono-enzymatic protocol, as compared to enzymatic treatment alone. Due to inverse variations of enthalpy and entropy change, net Gibbs energy change in all experimental protocols shows little variation indicating synergism of the mechanism of ultrasound and enzyme. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Heterodimer Binding Scaffolds Recognition via the Analysis of Kinetically Hot Residues.

    Science.gov (United States)

    Perišić, Ognjen

    2018-03-16

    Physical interactions between proteins are often difficult to decipher. The aim of this paper is to present an algorithm that is designed to recognize binding patches and supporting structural scaffolds of interacting heterodimer proteins using the Gaussian Network Model (GNM). The recognition is based on the (self) adjustable identification of kinetically hot residues and their connection to possible binding scaffolds. The kinetically hot residues are residues with the lowest entropy, i.e., the highest contribution to the weighted sum of the fastest modes per chain extracted via GNM. The algorithm adjusts the number of fast modes in the GNM's weighted sum calculation using the ratio of predicted and expected numbers of target residues (contact and the neighboring first-layer residues). This approach produces very good results when applied to dimers with high protein sequence length ratios. The protocol's ability to recognize near native decoys was compared to the ability of the residue-level statistical potential of Lu and Skolnick using the Sternberg and Vakser decoy dimers sets. The statistical potential produced better overall results, but in a number of cases its predicting ability was comparable, or even inferior, to the prediction ability of the adjustable GNM approach. The results presented in this paper suggest that in heterodimers at least one protein has interacting scaffold determined by the immovable, kinetically hot residues. In many cases, interacting proteins (especially if being of noticeably different sizes) either behave as a rigid lock and key or, presumably, exhibit the opposite dynamic behavior. While the binding surface of one protein is rigid and stable, its partner's interacting scaffold is more flexible and adaptable.

  16. Concentration dependent switch in the kinetic pathway of lysozyme fibrillation: Spectroscopic and microscopic analysis

    Science.gov (United States)

    Kiran Kumar, E.; Prasad, Deepak Kumar; Prakash Prabhu, N.

    2017-08-01

    Formation of amyloid fibrils is found to be a general tendency of many proteins. Investigating the kinetic mechanisms and structural features of the intermediates and the final fibrillar state is essential to understand their role in amyloid diseases. Lysozyme, a notable model protein for amyloidogenic studies, readily formed fibrils in vitro at neutral pH in the presence of urea. It, however, showed two different kinetic pathways under varying urea concentrations when probed with thioflavin T (ThT) fluorescence. In 2 M urea, lysozyme followed a nucleation-dependent fibril formation pathway which was not altered by varying the protein concentration from 2 mg/ml to 8 mg/ml. In 4 M urea, the protein exhibited concentration dependent change in the mechanism. At lower protein concentrations, lysozyme formed fibrils without any detectable nuclei (nucleation-independent polymerization pathway). When the concentration of the protein was increased above 3 mg/ml, the protein followed nucleation-dependent polymerization pathway as observed in the case of 2 M urea condition. This was further verified using microscopic images of the fibrils. The kinetic parameters such as lag time, elongation rate, and fibrillation half-time, which were derived from ThT fluorescence changes, showed linear dependency against the initial protein concentration suggested that under the nucleation-dependent pathway conditions, the protein followed primary-nucleation mechanism without any significant secondary nucleation events. The results also suggested that the differences in the initial protein conformation might alter the mechanism of fibrillation; however, at the higher protein concentrations lysozyme shifted to nucleation-dependent pathway.

  17. Gyro-kinetic analysis of micro-instabilities in negative shear tokamaks

    International Nuclear Information System (INIS)

    Idomura, Yasuhiro

    2001-01-01

    In order to study linear and nonlinear properties of micro-instabilities in negative shear tokamaks, a gyro-kinetic integral eigenvalue code and a gyro-kinetic finite element particle-in-cell (PIC) code are developed. Linear calculations show that both the slab ion temperature gradient driven (ITG) mode and the slab electron temperature gradient driven (ETG) mode become strongly unstable around the q min -surface, where q min is the minimum value of a safety factor q. Both modes have three types of branches in the negative shear configuration: a single mode-rational surface mode, a double mode-rational surface mode, and a non-resonant mode. The ETG turbulence in a slab configuration modeling the negative shear tokamak is studies using a gyro-kinetic finite element PIC code. It is found that quasi-steady E r x B zonal flows are generated in finite magnetic shear regions in both sides of the q min -surface, where the electron thermal transport is reduced substantially. Stability analyses of the electrostatic Kelvin-Helmholtz (K-H) mode show that the quasi-steady E r x B zonal flow profile is closely related to the q-profile or the magnetic shear, which has a stabilizing effect on the K-H mode. By changing the q-profile to reduce the magnetic shear, the K-H mode becomes unstable for the quasi-steady E r x B zonal flows, and the E r x B zonal flows disappear in the weak magnetic shear region. Numerical results show a possibility of controlling E r x B zonal flows with the magnetic shear, through the stability of the K-H mode. (author)

  18. Second Law Analysis for a Variable Viscosity Reactive Couette Flow under Arrhenius Kinetics

    Directory of Open Access Journals (Sweden)

    N. S. Kobo

    2010-01-01

    Full Text Available This study investigates the inherent irreversibility associated with the Couette flow of a reacting variable viscosity combustible material under Arrhenius kinetics. The nonlinear equations of momentum and energy governing the flow system are solved both analytically using a perturbation method and numerically using the standard Newton Raphson shooting method along with a fourth-order Runge Kutta integration algorithm to obtain the velocity and temperature distributions which essentially expedite to obtain expressions for volumetric entropy generation numbers, irreversibility distribution ratio, and the Bejan number in the flow field.

  19. Inhibition of tyrosinase by 4H-chromene analogs: Synthesis, kinetic studies, and computational analysis.

    Science.gov (United States)

    Brasil, Edikarlos M; Canavieira, Luciana M; Cardoso, Érica T C; Silva, Edilene O; Lameira, Jerônimo; Nascimento, José L M; Eifler-Lima, Vera L; Macchi, Barbarella M; Sriram, Dharmarajan; Bernhardt, Paul V; Silva, José Rogério Araújo; Williams, Craig M; Alves, Cláudio N

    2017-11-01

    Inhibition of mushroom tyrosinase was observed with synthetic dihydropyrano[3,2-b]chromenediones. Among them, DHPC04 displayed the most potent tyrosinase inhibitory activity with a K i value of 4 μm, comparable to the reference standard inhibitor kojic acid. A kinetic study suggested that these synthetic heterocyclic compounds behave as competitive inhibitors for the L-DOPA binding site of the enzyme. Furthermore, molecular modeling provided important insight into the mechanism of binding interactions with the tyrosinase copper active site. © 2017 John Wiley & Sons A/S.

  20. Application of a fluorescent cobalamin analogue for analysis of the binding kinetics. A study employing recombinant human transcobalamin and intrinsic factor

    DEFF Research Database (Denmark)

    Fedosov, Sergey N; Grissom, Charles B; Fedosova, Natalya U

    2006-01-01

    facilitated detailed kinetic analysis of Cbl binding. We found that TC had the same affinity for CBC and Cbl (K(d) = 5 x 10(-15) m), whereas interaction of CBC with the highly specific protein IF was more complex. For instance, CBC behaved normally in the partial reactions CBC + IF(30) and CBC + IF(20) when...... in the kinetic studies, moreover, it seems to be applicable for imaging purposes in vivo....

  1. A study on the environmental impacts analysis with life cycle analysis of NPPs

    International Nuclear Information System (INIS)

    This Life Cycle Analysis (LCA) work was accomplished based on the ISO-14040 framework goal and scope definition, including life cycle inventory analysis, and life cycle impact assessment. For the selection of impact categories, resource use, global affairs, local affairs, and nuclear specific affair were considered. It was unexpected that environmental burdens are generally heavier in an electricity generation process than in upper stream and fabrication processes, except ODP and ETPs. It has been normally thought that environmental burden in upper steam would be heavier than those in other processes. This misconception could have originated from the ambiguous thought for end-of-pipe emissions and life cycle inventories

  2. Temperature-Dependent Growth Modeling of Environmental and Clinical Legionella pneumophila Multilocus Variable-Number Tandem-Repeat Analysis (MLVA) Genotypes.

    Science.gov (United States)

    Sharaby, Yehonatan; Rodríguez-Martínez, Sarah; Oks, Olga; Pecellin, Marina; Mizrahi, Hila; Peretz, Avi; Brettar, Ingrid; Höfle, Manfred G; Halpern, Malka

    2017-04-15

    Legionella pneumophila causes waterborne infections resulting in severe pneumonia. High-resolution genotyping of L. pneumophila isolates can be achieved by multiple-locus variable-number tandem-repeat analysis (MLVA). Recently, we found that different MLVA genotypes of L. pneumophila dominated different sites in a small drinking-water network, with a genotype-related temperature and abundance regime. The present study focuses on understanding the temperature-dependent growth kinetics of the genotypes that dominated the water network. Our aim was to model mathematically the influence of temperature on the growth kinetics of different environmental and clinical L. pneumophila genotypes and to compare it with the influence of their ecological niches. Environmental strains showed a distinct temperature preference, with significant differences among the growth kinetics of the three studied genotypes (Gt4, Gt6, and Gt15). Gt4 strains exhibited superior growth at lower temperatures (25 and 30°C), while Gt15 strains appeared to be best adapted to relatively higher temperatures (42 and 45°C). The temperature-dependent growth traits of the environmental genotypes were consistent with their distribution and temperature preferences in the water network. Clinical isolates exhibited significantly higher growth rates and reached higher maximal cell densities at 37°C and 42°C than the environmental strains. Further research on the growth preferences of L. pneumophila clinical and environmental genotypes will result in a better understanding of their ecological niches in drinking-water systems as well as in the human body. IMPORTANCE Legionella pneumophila is a waterborne pathogen that threatens humans in developed countries. The bacteria inhabit natural and man-made freshwater environments. Here we demonstrate that different environmental L. pneumophila genotypes have different temperature-dependent growth kinetics. Moreover, Legionella strains that belong to the same species

  3. VKTA Rossendorf: Laboratory for Environmental and Radionuclide Analysis

    International Nuclear Information System (INIS)

    Koehler, M.; Knappik, R.; Fiola, K.

    2015-01-01

    The VKTA (Nuclear Engineering and Analytics Inc.) is charged by the Free State of Saxony with the decommissioning and waste management of the nuclear installations at the research site Dresden-Rossendorf. This task includes the safe management and disposal of fissile material and radioactive wastes. The acquired expertise and our solution-oriented way of working are the basis for a varied range of services especially the environmental and radionuclide analyzes. The Laboratory for Environmental and Radionuclide Analysis is accredited according to DIN EN ISO/IEC 17025 and provides a sound range of analytical and metrological services including their coordination and management. The personnel and the rooms, measuring and technical equipment are particularly designed for our special field, the measuring of radioactivity. We are focussed on measuring artificial and natural radionuclides in a wide range of activity and in different sample matrices (e.g., urine, faeces, metals, soil, concrete, food, liquids). With the flexible accreditation of the radionuclide analytics the Laboratory is able to react shortly to changing requirements in decommissioning, environmental monitoring and radiation protection. Essential chemical and radiochemical methods are e.g.: · Alpha particle spectrometry, · Liquid scintillation counting, · gamma ray spectrometry, including Ultra-Low-Level, · High-resolution ICP-MS, · Chromatographic methods such as ion chromatography, gas chromatography, HPLC, · Electrochemical measuring methods such as potentiometry, voltammetry. The Laboratory offers analytical services to the research site Dresden-Rossendorf and national and international customers adapting its analytical procedures to the special needs of customers. The presentation demonstrates on the basis of examples the work of Laboratory within the scope of decommissioning of nuclear facilities, especially at a research site, from radiological preliminary investigation to declaration of

  4. Simultaneity modeling analysis of the environmental Kuznets curve hypothesis

    International Nuclear Information System (INIS)

    Ben Youssef, Adel; Hammoudeh, Shawkat; Omri, Anis

    2016-01-01

    The environmental Kuznets curve (EKC) hypothesis has been recognized in the environmental economics literature since the 1990's. Various statistical tests have been used on time series, cross section and panel data related to single and groups of countries to validate this hypothesis. In the literature, the validation has always been conducted by using a single equation. However, since both the environment and income variables are endogenous, the estimation of a single equation model when simultaneity exists produces inconsistent and biased estimates. Therefore, we formulate simultaneous two-equation models to investigate the EKC hypothesis for fifty-six countries, using annual panel data from 1990 to 2012, with the end year is determined by data availability for the panel. To make the panel data analysis more homogeneous, we investigate this issue for a three income-based panels (namely, high-, middle-, and low-income panels) given several explanatory variables. Our results indicate that there exists a bidirectional causality between economic growth and pollution emissions in the overall panels. We also find that the relationship is nonlinear and has an inverted U-shape for all the considered panels. Policy implications are provided. - Highlights: • We have given a new look for the validity of the EKC hypothesis. • We formulate two-simultaneous equation models to validate this hypothesis for fifty-six countries. • We find a bidirectional causality between economic growth and pollution emissions. • We also discover an inverted U-shaped between environmental degradation and economic growth. • This relationship varies at different stages of economic development.

  5. Initial Northwest Power Act Power Sales Contracts : Final Environmental Impact Statement. Volume 1, Environmental Analysis.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1992-01-01

    This is volume 1 of the final environmental impact statement of the Bonneville Power Administration Information is included on the following: Purpose of and need for action; alternatives including the proposed action; affected environment; and environmental consequences.

  6. Environmental Impact Analysis Process. Environmental Assessment for Combat Survivor/Evader Locator System Testing and Deployment

    National Research Council Canada - National Science Library

    1998-01-01

    This environmental assessment (EA) analyzes the potential environmental issues associated with the Developmental Testing and Operational Assessment of 35 production CSEL radios by DoD personnel at various existing DoD facilities...

  7. Kinetic Analysis of Weakly ionized Plasmas in presence of collecting walls

    Science.gov (United States)

    Gonzalez, J.; Donoso, J. M.

    2018-02-01

    Description of plasmas in contact with a wall able to collecting or emitting charged particles is a research topic of great importance. This situation arises in a great variety of phenomena such as the characterization of plasmas by means of electric probes, in the surface treatment of materials and in the service-life of coatings in electric thrusters. In particular, in this work we devote attention to the dynamics of an argon weakly ionized plasma in the presence of a collecting wall. It is proposed a kinetic model in a 1D1V planar phase-space geometry. The model accounts for the electric field coupled to the system by solving the associated Poisson’s equation. To solve numerically the resulting non-linear system of equations, the Propagator Integral Method is used in conjunction with a slabbing method. On each interrelating plasma slab the integral advancing scheme operates in velocity space, in such a way that the all the species dynamics dominating the system evolution are kinetically described.

  8. Performance analysis and acceleration of explicit integration for large kinetic networks using batched GPU computations

    Energy Technology Data Exchange (ETDEWEB)

    Shyles, Daniel [University of Tennessee (UT); Dongarra, Jack J. [University of Tennessee, Knoxville (UTK); Guidry, Mike W. [ORNL; Tomov, Stanimire Z. [ORNL; Billings, Jay Jay [ORNL; Brock, Benjamin A. [ORNL; Haidar Ahmad, Azzam A. [ORNL

    2016-09-01

    Abstract—We demonstrate the systematic implementation of recently-developed fast explicit kinetic integration algorithms that solve efficiently N coupled ordinary differential equations (subject to initial conditions) on modern GPUs. We take representative test cases (Type Ia supernova explosions) and demonstrate two or more orders of magnitude increase in efficiency for solving such systems (of realistic thermonuclear networks coupled to fluid dynamics). This implies that important coupled, multiphysics problems in various scientific and technical disciplines that were intractable, or could be simulated only with highly schematic kinetic networks, are now computationally feasible. As examples of such applications we present the computational techniques developed for our ongoing deployment of these new methods on modern GPU accelerators. We show that similarly to many other scientific applications, ranging from national security to medical advances, the computation can be split into many independent computational tasks, each of relatively small-size. As the size of each individual task does not provide sufficient parallelism for the underlying hardware, especially for accelerators, these tasks must be computed concurrently as a single routine, that we call batched routine, in order to saturate the hardware with enough work.

  9. Kinetic analysis of [11C]vorozole binding in the human brain with positron emission tomography.

    Science.gov (United States)

    Logan, Jean; Kim, Sung Won; Pareto, Deborah; Telang, Frank; Wang, Gene-Jack; Fowler, Joanna S; Biegon, Anat

    2014-01-01

    Using positron emission tomography, we investigated the kinetics of [11C]vorozole ([11C]VOR), a radiotracer for the enzyme aromatase that catalyzes the last step in estrogen biosynthesis. Six subjects were scanned under baseline conditions followed by retest 2 weeks later. The retest was followed by a blocking study with 2.5 mg of the aromatase inhibitor letrozole. The binding potential (BP(A)ND) was estimated from a Lassen plot using the total tissue distribution volume (VT) for baseline and blocked. for the thalamus was found to be 15 times higher than that for the cerebellum. From the letrozole studies, we found that [11C]VOR exhibits a slow binding compartment (small k4) that has a nonspecific and a blockable component. Because of the sensitivity of VT to variations in k4, a common value was used for the four highest binding regions. We also considered the tissue uptake to plasma ratio for 60 to 90 minutes as an outcome measure. Using the ratio method, the difference between the highest and lowest was 2.4 compared to 3.5 for the VT. The ratio method underestimates the high regions but is less variable and may be more suitable for patient studies. Because of its kinetics and distribution, this tracer is not a candidate for a bolus infusion or reference tissue methods.

  10. Kinetic analysis and modelling of combined high-pressure-temperature inactivation of the yeast Zygosaccharomyces bailii.

    Science.gov (United States)

    Reyns, K M; Soontjens, C C; Cornelis, K; Weemaes, C A; Hendrickx, M E; Michiels, C W

    2000-06-01

    Eight foodborne yeasts were screened for sensitivity to high-pressure (HP) inactivation under a limited number of pressure-temperature combinations. The most resistant strains were Zygoascus hellenicus and Zygosaccharomyces bailii. The latter was taken for a detailed study of inactivation kinetics over a wide range of pressures (120-320 MPa) and temperatures (-5 to 45 degrees C). Isobaric and isothermal inactivation experiments were conducted in Tris-HCl buffer pH 6.5 for 48 different combinations of pressure and temperature. Inactivation was biphasic, with a first phase encompassing four to six decades and being described by first-order kinetics, followed by a tailing phase. Decimal reduction times (D) were calculated for the first-order inactivation phase and their temperature and pressure dependence was described. At constant temperature, D decreased with increasing pressure as expected. At constant pressure, D showed a maximum at around 20 degrees C, and decreased both at lower and at higher temperatures. A mathematical expression was developed to describe accurately the inactivation of Z. bailii as a function of pressure and temperature under the experimental conditions employed. A limited number of experiments in buffer at low pH (3-6) suggest that the model is, in principle, applicable at low pH. In apple and orange juice however, higher inactivation than predicted by the model was achieved.

  11. A kinetic study of pyrolysis and combustion of microalgae Chlorella vulgaris using thermo-gravimetric analysis.

    Science.gov (United States)

    Agrawal, Ankit; Chakraborty, Saikat

    2013-01-01

    This work uses thermo-gravimetric, differential thermo-gravimetric and differential thermal analyses to evaluate the kinetics of pyrolysis (in inert/N(2) atmosphere) and (oxidative) combustion of microalgae Chlorella vulgaris by heating from 50 to 800 °C at heating rates of 5-40 °C/min. This study shows that combustion produces higher biomass conversion than pyrolysis, and that three stages of decomposition occur in both cases, of which, the second one--consisting of two temperature zones--is the main stage of devolatization. Proteins and carbohydrates are decomposed in the first of the two zones at activation energies of 51 and 45 kJ/mol for pyrolysis and combustion, respectively, while lipids are decomposed in its second zone at higher activation energies of 64 and 63 kJ/mol, respectively. The kinetic expressions of the reaction rates in the two zones for pyrolysis and combustion have been obtained and it has been shown that increased heating rates result in faster and higher conversion. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Degradation Kinetics of Atorvastatin under Stress Conditions and Chemical Analysis by HPLC

    Directory of Open Access Journals (Sweden)

    Romanélia Spessemille Valotto

    2013-01-01

    Full Text Available Atorvastatin is an antilipemic drug belonging to the statins class, whose reference drug is Pfizer’s Lipitor®. It is used to reduce the levels of lipoproteins rich in cholesterol and reduce the risk of coronary artery disease. It is well-known that calcium atorvastatin (ATV, C66H68CaF2N4O10•3H2O, presents polymorphism. The drug in question is commonly sought after by pharmaceutical industries that produce generic drugs, due to the fact that the drug has a high value price, it is consumed globally, and its patent expired in late 2010. Many questions concerning this drug’s pharmaceutical scope demonstrate its importance regarding stability studies and the identification of degradation products of drugs and pharmaceutical formulations. ATV has been found to degrade under acid and basic conditions, including a first order kinetic degradation under acid conditions, as compared to a zero order kinetic degradation under basic conditions, which tends to be less stable when studied within acid mediums. The rate constant (k for degradation in acid medium was 1.88 × 10−2 s−1 (first order, while for basic medium k = 2.35 × 10−4 mol L−1 s−1 (zero order, demonstrating a lower stability of the drug within acid mediums.

  13. Kinetic parameter estimation and fluctuation analysis of CO at SnO2 single nanowires.

    Science.gov (United States)

    Tulzer, Gerhard; Baumgartner, Stefan; Brunet, Elise; Mutinati, Giorgio C; Steinhauer, Stephan; Köck, Anton; Barbano, Paolo E; Heitzinger, Clemens

    2013-08-09

    In this work, we present calculated numerical values for the kinetic parameters governing adsorption/desorption processes of carbon monoxide at tin dioxide single-nanowire gas sensors. The response of such sensors to pulses of 50 ppm carbon monoxide in nitrogen is investigated at different temperatures to extract the desired information. A rate-equation approach is used to model the reaction kinetics, which results in the problem of determining coefficients in a coupled system of nonlinear ordinary differential equations. The numerical values are computed by inverse-modeling techniques and are then used to simulate the sensor response. With our model, the dynamic response of the sensor due to the gas-surface interaction can be studied in order to find the optimal setup for detection, which is an important step towards selectivity of these devices. We additionally investigate the noise in the current through the nanowire and its changes due to the presence of carbon monoxide in the sensor environment. Here, we propose the use of a wavelet transform to decompose the signal and analyze the noise in the experimental data. This method indicates that some fluctuations are specific for the gas species investigated here.

  14. Kinetic parameter estimation and fluctuation analysis of CO at SnO 2 single nanowires

    KAUST Repository

    Tulzer, Gerhard

    2013-07-12

    In this work, we present calculated numerical values for the kinetic parameters governing adsorption/desorption processes of carbon monoxide at tin dioxide single-nanowire gas sensors. The response of such sensors to pulses of 50 ppm carbon monoxide in nitrogen is investigated at different temperatures to extract the desired information. A rate-equation approach is used to model the reaction kinetics, which results in the problem of determining coefficients in a coupled system of nonlinear ordinary differential equations. The numerical values are computed by inverse-modeling techniques and are then used to simulate the sensor response. With our model, the dynamic response of the sensor due to the gas-surface interaction can be studied in order to find the optimal setup for detection, which is an important step towards selectivity of these devices. We additionally investigate the noise in the current through the nanowire and its changes due to the presence of carbon monoxide in the sensor environment. Here, we propose the use of a wavelet transform to decompose the signal and analyze the noise in the experimental data. This method indicates that some fluctuations are specific for the gas species investigated here. © 2013 IOP Publishing Ltd.

  15. [Enzyme kinetic analysis of Oncomelania hupensis exposed to active ingredient of Buddleja lindleyana (AIBL)].

    Science.gov (United States)

    Bang-Xing, Han; Jun, Chen

    2016-07-01

    To analyze the enzyme kinetics of active ingredient of Buddleja lindleyana (AIBL) against Oncomelania hupensis , the intermediate host of Schistosoma japonicum . O . hupensis snails were placed in 1 000 ml of 3.55 mg/L AIBL solution for 24, 48 h and 72 h, respectively, and the enzyme kinetics of alanine aminotransferase (GPT) was determined by Reitman-Frankel assay, lactate dehydrogenase (LDH) by the chemical inhibition lactic acid substrate method, alkaline phosphatase (AKP) by the disodium phenyl phosphate colorimetric method, acetylcholine esterase (AChE) and malate dehydrogenas (MDH) by ELISA, and succinate dehydrogenase (SDH) by the phenazine methyl sulfate reaction method (PMS) in the soft tissues of O. hupensis before and after AIBL treatment. Following exposure to 3.55 mg/L AIBL solution for 24 h, the GPT, LDH, and AKP activities significantly improved in the soft tissues of O. hupensis , while the SDH and MDH activities were significantly lowered in the head-foot and liver. However, AIBL treatment did not cause significant effect on AChE activity in O. hupensis . AIBL causes significant damages to O. hupensis liver and can efficiently act on anaerobic and aerobic respiration loci, which will hinder energy metabolism, and cause inadequate energy supply in cells used for normal secretion, eventually leading to O. hupensis death.

  16. Evolution of Enzyme Kinetic Mechanisms.

    Science.gov (United States)

    Ulusu, Nuriye Nuray

    2015-06-01

    This review paper discusses the reciprocal kinetic behaviours of enzymes and the evolution of structure-function dichotomy. Kinetic mechanisms have evolved in response to alterations in ecological and metabolic conditions. The kinetic mechanisms of single-substrate mono-substrate enzyme reactions are easier to understand and much simpler than those of bi-bi substrate enzyme reactions. The increasing complexities of kinetic mechanisms, as well as the increasing number of enzyme subunits, can be used to shed light on the evolution of kinetic mechanisms. Enzymes with heterogeneous kinetic mechanisms attempt to achieve specific products to subsist. In many organisms, kinetic mechanisms have evolved to aid survival in response to changing environmental factors. Enzyme promiscuity is defined as adaptation to changing environmental conditions, such as the introduction of a toxin or a new carbon source. Enzyme promiscuity is defined as adaptation to changing environmental conditions, such as the introduction of a toxin or a new carbon source. Enzymes with broad substrate specificity and promiscuous properties are believed to be more evolved than single-substrate enzymes. This group of enzymes can adapt to changing environmental substrate conditions and adjust catalysing mechanisms according to the substrate's properties, and their kinetic mechanisms have evolved in response to substrate variability.

  17. Structural and kinetic analysis of the unnatural fusion protein 4-coumaroyl-CoA ligase::stilbene synthase

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yechun; Yi, Hankuil; Wang, Melissa; Yu, Oliver; Jez, Joseph M. (WU); (Danforth)

    2012-10-24

    To increase the biochemical efficiency of biosynthetic systems, metabolic engineers have explored different approaches for organizing enzymes, including the generation of unnatural fusion proteins. Previous work aimed at improving the biosynthesis of resveratrol, a stilbene associated a range of health-promoting activities, in yeast used an unnatural engineered fusion protein of Arabidopsis thaliana (thale cress) 4-coumaroyl-CoA ligase (At4CL1) and Vitis vinifera (grape) stilbene synthase (VvSTS) to increase resveratrol levels 15-fold relative to yeast expressing the individual enzymes. Here we present the crystallographic and biochemical analysis of the 4CL::STS fusion protein. Determination of the X-ray crystal structure of 4CL::STS provides the first molecular view of an artificial didomain adenylation/ketosynthase fusion protein. Comparison of the steady-state kinetic properties of At4CL1, VvSTS, and 4CL::STS demonstrates that the fusion protein improves catalytic efficiency of either reaction less than 3-fold. Structural and kinetic analysis suggests that colocalization of the two enzyme active sites within 70 {angstrom} of each other provides the basis for enhanced in vivo synthesis of resveratrol.

  18. Carbon Dioxide Adsorption in Nanopores of Coconut Shell Chars for Pore Characterization and the Analysis of Adsorption Kinetics

    Directory of Open Access Journals (Sweden)

    Chaiyot Tangsathitkulchai

    2016-01-01

    Full Text Available The uptake data of CO2 adsorption at 273 K by coconut shell chars prepared at various carbonization temperatures from 250 to 550°C were used for characterizing pore texture of chars as well as the analysis of CO2 adsorption kinetics. The equilibrium isotherms were used to determine the porous texture of chars, employing the DR equation and GCMC simulation. It was found that all the test chars contain micropores of a size range from 0.8 to 2.2 nm with the pore size distribution becoming wider for char prepared at a higher carbonization temperature. Porous properties of chars, including surface area, total pore volume, and the average pore size, appear to increase with an increasing carbonization temperature. The analysis of CO2 uptake during the transient measurement of isotherms revealed that the kinetics of CO2 adsorption is governed by the internal diffusional transport of the adsorptive molecules. The effective pore diffusivity characterizing this transport process increases with increasing CO2 loading and passes through a maximum at a certain loading. This maximum pore diffusivity shifts to a higher value as the carbonization temperature is increased. A semiempirical equation was developed to correlate the effective pore diffusivity of CO2 with the equilibrium adsorption loading and its predictive capability is satisfactory.

  19. Comparative study of binding constants from Love wave surface acoustic wave and surface plasmon resonance biosensors using kinetic analysis.

    Science.gov (United States)

    Lee, Sangdae; Kim, Yong-Il; Kim, Ki-Bok

    2013-11-01

    Biosensors are used in a variety of fields for early diagnosis of diseases, measurement of toxic contaminants, quick detection of pathogens, and separation of specific proteins or DNA. In this study, we fabricated and evaluated the capability of a high sensitivity Love wave surface acoustic wave (SAW) biosensor. The experimental setup was composed of the fabricated 155-MHz Love wave SAW biosensor, a signal measurement system, a liquid flow system, and a temperature-control system. Subsequently, we measured the lower limit of detection (LOD) of the 155-MHz Love wave SAW biosensor, and calculated the association and dissociation constants between protein G and anti-mouse IgG using kinetic analysis. We compared these results with those obtained using a commercial surface plasmon resonance (SPR) biosensor. We found that the LOD of the SAW biosensor for anti-mouse IgG and mouse IgG was 0.5 and 1 microg/ml, respectively, and the resultant equilibrium association and dissociation constants were similar to the corresponding values obtaining using the commercial SPR biosensor. Thus, we conclude that the fabricated 155-MHz Love wave SAW biosensor exhibited the high sensitivity of the commercial SPR biosensor and was able to analyze the binding properties of the ligand and receptor by kinetic analysis similarly to the commercial SPR biosensor.

  20. Enzyme kinetics, inhibitors, mutagenesis and electron paramagnetic resonance analysis of dual-affinity nitrate reductase in unicellular N(2)-fixing cyanobacterium Cyanothece sp. PCC 8801.

    Science.gov (United States)

    Wang, Tung-Hei; Chen, Yung-Han; Huang, Jine-Yung; Liu, Kang-Cheng; Ke, Shyue-Chu; Chu, Hsiu-An

    2011-11-01

    The assimilatory nitrate reductase (NarB) of N(2)-fixing cyanobacterium Cyanothece sp. PCC 8801 is a monomeric enzyme with dual affinity for substrate nitrate. We purified the recombinant NarB of Cyanothece sp. PCC 8801 and further investigated it by enzyme kinetics analysis, site-directed mutagenesis, inhibitor kinetics analysis, and electron paramagnetic resonance (EPR) spectroscopy. The NarB showed 2 kinetic regimes at pH 10.5 or 8 and electron-donor conditions methyl viologen or ferredoxin (Fd). Fd-dependent NR assay revealed NarB with very high affinity for nitrate (K(m)1, ∼1μM; K(m)2, ∼270μM). Metal analysis and EPR results showed that NarB contains a Mo cofactor and a [4Fe-4S] cluster. In addition, the R352A mutation on the proposed nitrate-binding site of NarB greatly altered both high- and low-affinity kinetic components. Furthermore, the effect of azide on the NarB of Cyanothece sp. PCC 8801 was more complex than that on the NarB of Synechococcus sp. PCC 7942 with its single kinetic regime. With 1mM azide, the kinetics of the wild-type NarB was transformed from 2 kinetic regimes to hyperbolic kinetics, and its activity was enhanced significantly under medium nitrate concentrations. Moreover, EPR results also suggested a structural difference between the two NarBs. Taken together, our results show that the NarB of Cyanothece sp. PCC 8801 contains only a single Mo-catalytic center, and we rule out that the enzyme has 2 independent, distinct catalytic sites. In addition, the NarB of Cyanothece sp. PCC 8801 may have a regulatory nitrate-binding site. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  1. Situated student learning and spatial informational analysis for environmental problems

    Science.gov (United States)

    Olsen, Timothy Paul

    Ninth and tenth grade high school Biology student research teams used spatial information analysis tools to site a prairie restoration plot on a 55 acre campus during a four-week environment unit. Students made use of innovative technological practices by applying geographic information systems (GIS) approaches to solving environmental and land use problems. Student learning was facilitated by starting with the students' initial conceptions of computing, local landscape and biological environment, and then by guiding them through a problem-based science project process. The project curriculum was framed by the perspective of legitimate peripheral participation (Lave & Wenger, 1991) where students were provided with learning opportunities designed to allow them to act like GIS practitioners. Sociocultural lenses for learning were employed to create accounts of human mental processes that recognize the essential relationship between these processes and their cultural, historical, and institutional settings (Jacob, 1997; Wertsch, 1991). This research investigated how student groups' meaning-making actions were mediated by GIS tools on the periphery of a scientific community of practice. Research observations focused on supporting interpretations of learners' socially constructed actions and the iterative building of assertions from multiple sources. These included the artifacts students produced, the tools they used, the cultural contexts that constrained their activity, and how people begin to adopt ways of speaking (speech genres) of the referent community to negotiate meanings and roles. Students gathered field observations and interpreted attributes of landscape entities from the GIS data to advocate for an environmental decision. However, even while gaining proficiencies with GIS tools, most students did not begin to appropriate roles from the GIS community of practice. Students continued to negotiate their project actions simply as school exercises motivated by

  2. Small-scale wind power design, analysis, and environmental impacts

    CERN Document Server

    Abraham, John P

    2014-01-01

    In today's world, clean and robust energy sources are being sought to provide power to residences, commercial operations, and manufacturing enterprises. Among the most appealing energy sources is wind power-with its high reliability and low environmental impact. Wind power's rapid penetration into markets throughout the world has taken many forms, and this book discusses the types of wind power, as well as the appropriate decisions that need to be made regarding wind power design, testing, installation, and analysis. Inside, the authors detail the design of various small-wind systems including horizontal-axis wind turbines (HAWTs) and vertical-axis wind turbines (VAWTs). The design of wind turbines takes advantage of many avenues of investigation, all of which are included in the book. Analytical methods that have been developed over the past few decades are major methods used for design. Alternatively, experimentation (typically using scaled models in wind tunnels) and numerical simulation (using modern comp...

  3. Environmental Quality Information Analysis Center multi-year plan

    International Nuclear Information System (INIS)

    Rivera, R.G.; Das, S.; Walsh, T.E.

    1992-09-01

    An information analysis center (IAC) is a federal resource that provides technical information for a specific technology field. An IAC links an expert technical staff with an experienced information specialist group, supported by in-house or external data bases to provide technical information and maintain a corporate knowledge in a technical area. An IAC promotes the rapid transfer of technology among its users and provides assistance in adopting new technology and predicting and assessing emerging technology. This document outlines the concept, requirements, and proposed development of an Environmental Quality IAC (EQIAC). An EQIAC network is composed of several nodes, each of which has specific technology capabilities. This document outlines strategic and operational objectives for the phased development of one such node of an EQIAC network

  4. Formalization of an environmental model using formal concept analysis - FCA

    Science.gov (United States)

    Bourdon-García, Rubén D.; Burgos-Salcedo, Javier D.

    2016-08-01

    Nowadays, there is a huge necessity to generate novel strategies for social-ecological systems analyses for resolving global sustainability problems. This paper has as main purpose the application of the formal concept analysis to formalize the theory of Augusto Ángel Maya, who without a doubt, was one of the most important environmental philosophers in South America; Ángel Maya proposed and established that Ecosystem-Culture relations, instead Human-Nature ones, are determinants in our understanding and management of natural resources. Based on this, a concept lattice, formal concepts, subconcept-superconcept relations, partially ordered sets, supremum and infimum of the lattice and implications between attributes (Duquenne-Guigues base), were determined for the ecosystem-culture relations.

  5. Kinetic sculpture

    OpenAIRE

    Joneta Witabora; Jonata Witabora

    2014-01-01

    Kinetic Sculpture was born from a long process of searching new approach in sculpture. The artists tried to escape from 'static' paradigm and tried to implement movement into their works: a sculpture that is mobile. Movement is always a fascinating phenomenon to eyes. Kinetic sculpture strength lies in its unique character in combining science and art. Kinetic Sculptures are really interesting pieces of art. It succeeds to fascinate human everytime. 

  6. Environmental Metagenomics: The Data Assembly and Data Analysis Perspectives

    Science.gov (United States)

    Kumar, Vinay; Maitra, S. S.; Shukla, Rohit Nandan

    2015-01-01

    Novel gene finding is one of the emerging fields in the environmental research. In the past decades the research was focused mainly on the discovery of microorganisms which were capable of degrading a particular compound. A lot of methods are available in literature about the cultivation and screening of these novel microorganisms. All of these methods are efficient for screening of microbes which can be cultivated in the laboratory. Microorganisms which live in extreme conditions like hot springs, frozen glaciers, acid mine drainage, etc. cannot be cultivated in the laboratory, this is because of incomplete knowledge about their growth requirements like temperature, nutrients and their mutual dependence on each other. The microbes that can be cultivated correspond only to less than 1 % of the total microbes which are present in the earth. Rest of the 99 % of uncultivated majority remains inaccessible. Metagenomics transcends the culture requirements of microbes. In metagenomics DNA is directly extracted from the environmental samples such as soil, seawater, acid mine drainage etc., followed by construction and screening of metagenomic library. With the ongoing research, a huge amount of metagenomic data is accumulating. Understanding this data is an essential step to extract novel genes of industrial importance. Various bioinformatics tools have been designed to analyze and annotate the data produced from the metagenome. The Bio-informatic requirements of metagenomics data analysis are different in theory and practice. This paper reviews the tools that are available for metagenomic data analysis and the capability such tools—what they can do and their web availability.

  7. Application of positive matrix factor analysis in heterogeneous kinetics studies: an improvement to the mixed-phase relative rates technique

    Science.gov (United States)

    Liu, Y.; Li, S.-M.; Liggio, J.

    2014-03-01

    The mixed-phase relative rate approach for determining aerosol particle organic component heterogeneous reaction kinetics and OH uptake coefficients to particles is often performed utilizing mass spectral tracers as a proxy for particle phase reactant concentration. However, this approach may be influenced by signal contaminations from oxidation products during the experiment. In the current study, the mixed-phase relative rates technique has been improved by combining a Positive Matrix Factor (PMF) analysis with electron ionization Aerosol Mass Spectrometry, thereby removing the influence of m / z fragments from reaction products on the reactant signals. To demonstrate the advantages of this approach, the heterogeneous reaction between OH radicals and citric acid (CA) was investigated using a photochemical flow tube coupled to a compact time-of-flight aerosol mass spectrometer (C-ToF-AMS). The measured heterogeneous rate constant (k2) of citric acid toward OH was (3.31 ± 0.29) × 10-12 cm3 molecule-1 s-1 at 298 K and (30 ± 3)% RH and was ∼7.7 times greater than previously reported results utilizing individual m / z fragments. This phenomenon was further confirmed for particulate-phase organophosphates (TPhP, TDCPP, and TEHP), leading to k2 values significantly larger than previously reported. The results suggest that heterogeneous kinetics can be significantly underestimated when a non-molecular ion peak is used as the tracer. Finally, the results suggest that the heterogeneous lifetime of organic aerosol in models can be overestimated due to underestimated OH uptake coefficients, and that it may be necessary to revisit the heterogeneous kinetic data of organic aerosol components which were derived in the context of the relative rates technique.

  8. Kinetic Modeling of ABCG2 Transporter Heterogeneity: A Quantitative, Single-Cell Analysis of the Side Population Assay.

    Directory of Open Access Journals (Sweden)

    Adam F Prasanphanich

    2016-11-01

    Full Text Available The side population (SP assay, a technique used in cancer and stem cell research, assesses the activity of ABC transporters on Hoechst staining in the presence and absence of transporter inhibition, identifying SP and non-SP cell (NSP subpopulations by differential staining intensity. The interpretation of the assay is complicated because the transporter-mediated mechanisms fail to account for cell-to-cell variability within a population or adequately control the direct role of transporter activity on staining intensity. We hypothesized that differences in dye kinetics at the single-cell level, such as ABCG2 transporter-mediated efflux and DNA binding, are responsible for the differential cell staining that demarcates SP/NSP identity. We report changes in A549 phenotype during time in culture and with TGFβ treatment that correlate with SP size. Clonal expansion of individually sorted cells re-established both SP and NSPs, indicating that SP membership is dynamic. To assess the validity of a purely kinetics-based interpretation of SP/NSP identity, we developed a computational approach that simulated cell staining within a heterogeneous cell population; this exercise allowed for the direct inference of the role of transporter activity and inhibition on cell staining. Our simulated SP assay yielded appropriate SP responses for kinetic scenarios in which high transporter activity existed in a portion of the cells and little differential staining occurred in the majority of the population. With our approach for single-cell analysis, we observed SP and NSP cells at both ends of a transporter activity continuum, demonstrating that features of transporter activity as well as DNA content are determinants of SP/NSP identity.

  9. Kinetic analysis of DAF-FM activation by NO: toward calibration of a NO-sensitive fluorescent dye.

    Science.gov (United States)

    Namin, Shabnam M; Nofallah, Sara; Joshi, Mahesh S; Kavallieratos, Konstantinos; Tsoukias, Nikolaos M

    2013-01-15

    Nitric oxide (NO) research in biomedicine has been hampered by the absence of a method that will allow quantitative measurement of NO in biological tissues with high sensitivity and selectivity, and with adequate spatial and temporal resolution. 4-amino-5-methylamino-2',7'-difluorofluorescein (DAF-FM) is a NO sensitive fluorescence probe that has been used widely for qualitative assessment of cellular NO production. However, calibration of the fluorescent signal and quantification of NO concentration in cells and tissues using fluorescent probes, have provided significant challenge. In this study we utilize a combination of mathematical modeling and experimentation to elucidate the kinetics of NO/DAF-FM reaction in solution. Modeling and experiments suggest that the slope of fluorescent intensity (FI) can be related to NO concentration according to the equation: ddtFI=2αk(1)NO(2)O(2)DAF-FMkNO+DAF-FM where α is a proportionality coefficient that relates FI to unit concentration of activated DAF-FM, k(1) is the NO oxidation rate constant, and k was estimated to be 4.3±0.6. The FI slope exhibits saturation kinetics with DAF-FM concentration. Interestingly, the effective half-maximum constant (EC(50)) increases proportionally to NO concentration. This result is not in agreement with the proposition that N(2)O(3) is the NO oxidation byproduct that activates DAF-FM. Kinetic analysis suggests that the reactive intermediate should exhibit NO-dependent consumption and thus NO(2)() is a more likely candidate. The derived rate law can be used for the calibration of DAF-FM fluorescence and the quantification of NO concentration in biological tissues. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Kinetic Modeling of ABCG2 Transporter Heterogeneity: A Quantitative, Single-Cell Analysis of the Side Population Assay

    Science.gov (United States)

    Prasanphanich, Adam F.; White, Douglas E.; Gran, Margaret A.

    2016-01-01

    The side population (SP) assay, a technique used in cancer and stem cell research, assesses the activity of ABC transporters on Hoechst staining in the presence and absence of transporter inhibition, identifying SP and non-SP cell (NSP) subpopulations by differential staining intensity. The interpretation of the assay is complicated because the transporter-mediated mechanisms fail to account for cell-to-cell variability within a population or adequately control the direct role of transporter activity on staining intensity. We hypothesized that differences in dye kinetics at the single-cell level, such as ABCG2 transporter-mediated efflux and DNA binding, are responsible for the differential cell staining that demarcates SP/NSP identity. We report changes in A549 phenotype during time in culture and with TGFβ treatment that correlate with SP size. Clonal expansion of individually sorted cells re-established both SP and NSPs, indicating that SP membership is dynamic. To assess the validity of a purely kinetics-based interpretation of SP/NSP identity, we developed a computational approach that simulated cell staining within a heterogeneous cell population; this exercise allowed for the direct inference of the role of transporter activity and inhibition on cell staining. Our simulated SP assay yielded appropriate SP responses for kinetic scenarios in which high transporter activity existed in a portion of the cells and little differential staining occurred in the majority of the population. With our approach for single-cell analysis, we observed SP and NSP cells at both ends of a transporter activity continuum, demonstrating that features of transporter activity as well as DNA content are determinants of SP/NSP identity. PMID:27851764

  11. Fully integrated analysis of reactor kinetics, thermalhydraulics and the reactor control system in the MAPLE-X10 research reactor

    International Nuclear Information System (INIS)

    Shim, S.Y.; Carlson, P.A.; Baxter, D.K.

    1992-01-01

    A prototype research reactor, designated MAPLE-X10 (Multipurpose Applied Physics Lattice Experimental - X 10MW), is currently being built at AECL's Chalk River Laboratories. The CATHENA (Canadian Algorithm for Thermalhydraulic Network Analysis) two-fluid code was used in the safety analysis of the reactor to determine the adequacy of core cooling during postulated reactivity and loss-of-forced-flow transients. The system responses to a postulated transient are predicted including the feedback between reactor kinetics, thermalhydrauilcs and the reactor control systems. This paper describes the MAPLE-X10 reactor and the modelling methodology used. Sample simulations of postulated loss-of-heat-sink and loss-of-regulation transients are presented. (author)

  12. Relating the environmental impact of consumption to household expenditures : An input-output analysis

    NARCIS (Netherlands)

    Kerkhof, Annemarie C.; Nonhebel, Sanderine; Moll, Henri C.

    2009-01-01

    In this paper we evaluate the relationships between household expenditures and the environmental impact categories climate change, acidification, eutrophication and smog formation, by combining household expenditures with environmentally extended input–output analysis. Expenditure elasticities are

  13. Retrospektive analysis of theory and practice of environmental approach in urban planning

    OpenAIRE

    Skripal, Elena

    2013-01-01

    Research describes the history of theory and practice of environmental urban development. Presents a historical analysis of domestic and foreign experience in urban environmental planning (from ancient times to the XXI century).

  14. SVD-aided pseudo principal-component analysis: A new method to speed up and improve determination of the optimum kinetic model from time-resolved data

    Energy Technology Data Exchange (ETDEWEB)

    Oang, Key Young; Yang, Cheolhee; Muniyappan, Srinivasan; Kim, Jeongho; Ihee, Hyotcherl

    2017-07-01

    Determination of the optimum kinetic model is an essential prerequisite for characterizing dynamics and mechanism of a reaction. Here, we propose a simple method, termed as singular value decomposition-aided pseudo principal-component analysis (SAPPA), to facilitate determination of the optimum kinetic model from time-resolved data by bypassing any need to examine candidate kinetic models. We demonstrate the wide applicability of SAPPA by examining three different sets of experimental time-resolved data and show that SAPPA can efficiently determine the optimum kinetic model. In addition, the results of SAPPA for both time-resolved X-ray solution scattering (TRXSS) and transient absorption (TA) data of the same protein reveal that global structural changes of protein, which is probed by TRXSS, may occur more slowly than local structural changes around the chromophore, which is probed by TA spectroscopy.

  15. Photoelectric Franck-Hertz experiment and its kinetic analysis by Monte Carlo simulation.

    Science.gov (United States)

    Magyar, Péter; Korolov, Ihor; Donkó, Zoltán

    2012-05-01

    The electrical characteristics of a photoelectric Franck-Hertz cell are measured in argon gas over a wide range of pressure, covering conditions where elastic collisions play an important role, as well as conditions where ionization becomes significant. Photoelectron pulses are induced by the fourth harmonic UV light of a diode-pumped Nd:YAG laser. The electron kinetics, which is far more complex compared to the naive picture of the Franck-Hertz experiment, is analyzed via Monte Carlo simulation. The computations provide the electrical characteristics of the cell, the energy and velocity distribution functions, and the transport parameters of the electrons, as well as the rate coefficients of different elementary processes. A good agreement is obtained between the cell's measured and calculated electrical characteristics, the peculiarities of which are understood by the simulation studies.

  16. Source-jerk analysis using a semi-explicit inverse kinetic technique

    International Nuclear Information System (INIS)

    Spriggs, G.D.; Pederson, R.A.

    1985-01-01

    A method is proposed for measuring the effective reproduction factor, k, in subcritical systems. The method uses the transient response of a subcritical system to the sudden removal of an extraneous neutron source (i.e., a source jerk). The response is analyzed using an inverse kinetic technique that least-squares fits the exact analytical solution corresponding to a source-jerk transient as derived from the point-reactor model. It has been found that the technique can provide an accurate means of measuring k in systems that are close to critical (i.e., 0.95 < k < 1.0). As a system becomes more subcritical (i.e., k << 1.0) spatial effects can introduce significant biases depending on the source and detector positions. However, methods are available that can correct for these biases and, hence, can allow measuring subcriticality in systems with k as low as 0.5. 12 refs., 3 figs

  17. Source-jerk analysis using a semi-explicit inverse kinetic technique

    International Nuclear Information System (INIS)

    Spriggs, G.D.; Pederson, R.A.

    1985-01-01

    A method is proposed for measuring the effective reproduction factor, k, in subcritical systems. The method uses the transient responses of a subcritical system to the sudden removal of an extraneous neutron source (i.e., a source jerk). The response is analyzed using an inverse kinetic technique that least-squares fits the exact analytical solution corresponding to a source-jerk transient as derived from the point-reactor model. It has been found that the technique can provide an accurate means of measuring k in systems that are close to critical (i.e., 0.95 < k < 1.0). As a system becomes more subcritical (i.e., k << 1.0) spatial effects can introduce significant biases depending on the source and detector positions. However, methods are available that can correct for these biases and, hence, can allow measuring subcriticality in systems with k as low as 0.5

  18. Nutrient Removal from Wastewater using Microalgae: A Kinetic Evaluation and Lipid Analysis.

    Science.gov (United States)

    2017-09-15

    The objective of this study was to examine the performance of mixed microalgal bioreactors in treating three differenttypes of wastewaters - kitchen wastewater (KWW), palm oil mill effluent (POME), and pharmaceutical wastewater (PWW) in semi-continuous mode and to analyze the lipid content in the harvested algal biomass. The reactors were monitored for total nitrogen and phosphate removal at eight solid retention times (SRTs) - 2, 4, 6, 8, 10, 12, 14, and 16 days. The nutrient uptake kinetic parameters were quantified using linearized Michaelis-Menten and Monod models at steady-state conditions. The nutrient removal efficiency and lipid production were found to be higher in KWW when compared with the other wastewaters. Saturated fatty acids (C16:0, C18:0, and C18:1) accounted for more than 60% of the algal fatty acids for all the wastewaters. The lipid is, therefore, considered suitable for synthesizing biodiesel.

  19. Kinetic and thermodynamic analysis of the fate of sulphur compounds in gasification products

    Energy Technology Data Exchange (ETDEWEB)

    Melita Jazbec; Karina Sendt; Brian S. Haynes [University of Sydney, Sydney, NSW (Australia). Department of Chemical Engineering J01

    2004-11-01

    Synthesis gas produced from gasification of coal contains sulphur compounds that need to be removed before the gas can be further processed. For the sulphur removal process, it is normally assumed that all sulphur is present as hydrogen sulphide (H{sub 2}S) with minor amounts of carbonyl sulphide (OCS). This paper examines the equilibrium composition of a raw synthesis gas from a Texaco gasifier, and how the composition changes kinetically as the gas is cooled. It is confirmed that H{sub 2}S should always be the dominant sulphur species in cold syngas, with about 5% of sulphur appearing as OCS. Higher temperatures, and very high cooling rates can cause significant conversion of the sulphur to elemental S{sub 2}. 21 refs., 8 figs., 4 tabs.

  20. Kinetic magnetic resonance imaging analysis of lumbar segmental motion at levels adjacent to disc herniation.

    Science.gov (United States)

    Lao, Lifeng; Daubs, Michael D; Takahashi, Shinji; Lord, Elizabeth L; Cohen, Jeremiah R; Zhong, Guibin; Wang, Jeffrey C

    2016-01-01

    A retrospective radiographic study was carried out to analyze the effect of lumbar disc herniation on the kinetic motion of adjacent segments. A total of 162 patients with low back pain or radicular pain in the lower limbs without a prior history of surgery were evaluated using kinetic magnetic resonance imaging. Translational motion, angular variation, and disc height were measured at each segment from L1-L2 to L5-S1. Other factors including the degree of disc degeneration, age, gender, and vertebral segment location were analyzed to determine any predisposing risk factors for segmental instability adjacent to disc herniations. Spinal levels above the disc herniation exhibited, on average, a 6.4 % increase in translational motion per mm of disc herniation (P = 0.496) and a 21.4 % increase in angular motion per mm herniation (P = 0.447). Levels below the herniation demonstrated a 5.2 % increase in translational motion per mm of disc herniation (P = 0.428) and a decrease of 10.7 % in angular motion per mm (P = 0.726). The degree of disc degeneration had no significant correlation with adjacent level motion. Similarly, disc herniation was not significantly correlated with disc height at adjacent levels, although there was a significant relationship between gender and adjacent segment disc height. Although disc height, translational motion, and angular variation are significantly affected at the level of a disc herniation, no significant changes are apparent in adjacent segments. Our results indicate that herniated discs have no effect on range of motion at adjacent levels regardless of the degree of disc degeneration or the size of disc herniation, suggesting that the natural progression of disc degeneration and adjacent segment disease may be separate, unrelated processes within the lumbar spine.

  1. A combined spectroscopic and plasma chemical kinetic analysis of ionospheric samarium releases

    Science.gov (United States)

    Holmes, Jeffrey M.; Dressler, Rainer A.; Pedersen, Todd R.; Caton, Ronald G.; Miller, Daniel

    2017-05-01

    Two rocket-borne releases of samarium vapor in the upper atmosphere occurred in May 2013, as part of the Metal Oxide Space Clouds experiment. The releases were characterized by a combination of optical and RF diagnostic instruments located at the Roi-Namur launch site and surrounding islands and atolls. The evolution of the optical spectrum of the solar-illuminated cloud was recorded with a spectrograph covering a 400-800 nm spectral range. The spectra exhibit two distinct spectral regions centered at 496 and 636 nm within which the relative intensities change insignificantly. The ratio between the integrated intensities within these regions, however, changes with time, suggesting that they are associated with different species. With the help of an equilibrium plasma spectral model we attribute the region centered at 496 nm to neutral samarium atoms (Sm I radiance) and features peaking at 649 nm to a molecular species. No evidence for structure due to Sm+ (Sm II) is identified. The persistence of the Sm I radiance suggests a high dissociative recombination rate for the chemi-ionization product, SmO+. A one-dimensional plasma chemical kinetic model of the evolution of the density ratio NSmO/NSm(t) demonstrates that the molecular feature peaking at 649 nm can be attributed to SmO radiance. SmO+ radiance is not identified. By adjusting the Sm vapor mass of the chemical kinetic model input to match the evolution of the total electron density determined by ionosonde data, we conclude that less than 5% of the payload samarium was vaporized.

  2. Kinetic analysis of in vitro production of wild-type Spodoptera frugiperda nucleopolyhedrovirus

    Directory of Open Access Journals (Sweden)

    Andréa Farias de Almeida

    2010-04-01

    Full Text Available In this study, the kinetic behavior of Sf9 and Sf21 cells used in the production of a baculovirus biopesticide to control the pest of corn Spodoptera frugiperda was analyzed. Kinetic variables such as maximum specific growth rate, cell productivity, mean rate of infection, as well as the mean rate of occlusion body production were determined during the infection of these cell-lines with the extracellular virus of the S. frugiperda nucleopolyhedrovirus (SfMNPV. The Sf9 cell-line resulted in better viral production results (5.0 x 10(8 OB/mL than the Sf21 cell-line (2.5 x 10(8 OB/mL.Neste trabalho, analisou-se o comportamento cinético das células Sf9 e Sf21 utilizadas na produção de biopesticida para o controle de Spodoptera frugiperda. Variáveis cinéticas, como velocidade específica máxima de crescimento, produtividade em células, velocidade média de infecção e a velocidade média de produção de OB foram determinadas durante a infecção destas linhagens com o vírus extracelular do nucleopoliedrovirus de S. frugiperda. A linhagem Sf9 resultou em melhores resultados de produção do baculovírus (5 x 10(8 OB/mL, quando comparada à linhagem Sf21 (2,5 x 10(8 OB/mL e outras linhagens da literatura.

  3. Structural and kinetic analysis of Schistosoma mansoni Adenylosuccinate Lyase (SmADSL).

    Science.gov (United States)

    Romanello, Larissa; Serrão, Vitor Hugo Balasco; Torini, Juliana Roberta; Bird, Louise E; Nettleship, Joanne E; Rada, Heather; Reddivari, Yamini; Owens, Ray J; DeMarco, Ricardo; Brandão-Neto, José; Pereira, Humberto D'Muniz

    2017-06-01

    Schistosoma mansoni is the parasite responsible for schistosomiasis, a disease that affects about 218 million people worldwide. Currently, both direct treatment and disease control initiatives rely on chemotherapy using a single drug, praziquantel. Concerns over the possibility of resistance developing to praziquantel, have stimulated efforts to develop new drugs for the treatment of schistosomiasis. Schistosomes do not have the de novo purine biosynthetic pathway, and instead depend entirely on the purine salvage pathway to supply its need for purines. The purine salvage pathway has been reported as a potential target for developing new drugs against schistosomiasis. Adenylosuccinate lyase (SmADSL) is an enzyme in this pathway, which cleaves adenylosuccinate (ADS) into adenosine 5'-monophosphate (AMP) and fumarate. SmADSL kinetic characterization was performed by isothermal titration calorimetry (ITC) using both ADS and SAICAR as substrates. Structures of SmADSL in Apo form and in complex with AMP were elucidated by x-ray crystallography revealing a highly conserved tetrameric structure required for their function since the active sites are formed from residues of three different subunits. The active sites are also highly conserved between species and it is difficult to identify a potent species-specific inhibitor for the development of new therapeutic agents. In contrast, several mutagenesis studies have demonstrated the importance of dimeric interface residues in the stability of the quaternary structure of the enzyme. The lower conservation of these residues between SmADSL and human ADSL could be used to lead the development of anti-schistosomiasis drugs based on disruption of subunit interfaces. These structures and kinetics data add another layer of information to Schistosoma mansoni purine salvage pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Mixed methods analysis of urban environmental stewardship networks

    Science.gov (United States)

    James J.T. Connolly; Erika S. Svendsen; Dana R. Fisher; Lindsay K. Campbell

    2015-01-01

    While mixed methods approaches to research have been accepted practice within the social sciences for several decades (Tashakkori and Teddlie 2003), the rising demand for cross-disciplinary analyses of socio-environmental processes has necessitated a renewed examination of this approach within environmental studies. Urban environmental stewardship is one area where it...

  5. 15 CFR 970.204 - Environmental and use conflict analysis.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS OF THE ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES... environmental impact statement (EIS) on the issuance of an exploration license, the application must include information for use in preparing NOAA's EIS on the environmental impacts of the activities proposed by the...

  6. Analysis of residuals from enzyme kinetic and protein folding experiments in the presence of correlated experimental noise.

    Science.gov (United States)

    Kuzmic, Petr; Lorenz, Thorsten; Reinstein, Jochen

    2009-12-01

    Experimental data from continuous enzyme assays or protein folding experiments often contain hundreds, or even thousands, of densely spaced data points. When the sampling interval is extremely short, the experimental data points might not be statistically independent. The resulting neighborhood correlation invalidates important theoretical assumptions of nonlinear regression analysis. As a consequence, certain goodness-of-fit criteria, such as the runs-of-signs test and the autocorrelation function, might indicate a systematic lack of fit even if the experiment does agree very well with the underlying theoretical model. A solution to this problem is to analyze only a subset of the residuals of fit, such that any excessive neighborhood correlation is eliminated. Substrate kinetics of the HIV protease and the unfolding kinetics of UMP/CMP kinase, a globular protein from Dictyostelium discoideum, serve as two illustrative examples. A suitable data-reduction algorithm has been incorporated into software DYNAFIT [P. Kuzmic, Anal. Biochem. 237 (1996) 260-273], freely available to all academic researchers from http://www.biokin.com.

  7. Kinetic and thermodynamic analysis for lipase-catalyzed hydrolytic resolution of (R,S)-alcohols though their azolyl carbamates.

    Science.gov (United States)

    Cheng, Ya-Ling; Wu, An-Chi; Wang, Pei-Yun; Tsai, Shau-Wei

    2012-08-01

    A new approach to the lipase-catalyzed hydrolytic resolution of (R,S)-azolyl carbamates for obtaining chiral azolyl carbamates and alcohol is described. With (R,S)-1-phenylethyl azolyl carbamates as the model substrates, the best reaction condition of using (R,S)-1-phenylethyl 4-bromopyrazole carbamate (1) as the substrate in water-saturated diisopropyl ether at 45 °C is selected. The kinetic constants, and hence enantiomeric ratio of 124, are then estimated from the kinetic analysis by considering the alcohol inhibition effect, with which theoretical time-course conversions for both enantiomers are numerically solved and agree with the experimental data. The thermodynamic parameters -ΔΔH and -ΔΔS satisfying a linear enthalpy-entropy compensation relationship of -ΔΔS = -38.84 + 3.29(-ΔΔH) are further estimated. An extension of the resolution platform to (R,S)-4-bromopyrazole carbamates derived from other (R,S)-alcohols (4, 5, 7) is also addressed.

  8. Thermodynamic analysis and kinetic modelling of dioxin formation and emissions from power boilers firing salt-laden hog fuel.

    Science.gov (United States)

    Duo, Wenli; Leclerc, Denys

    2007-04-01

    Both organic chlorine (e.g. PVC) and inorganic chlorides (e.g. NaCl) can be significant chlorine sources for dioxin and furan (PCDD/F) formation in combustion processes. This paper presents a thermodynamic analysis of high temperature salt chemistry. Its influence on PCDD/F formation in power boilers burning salt-laden wood waste is examined through the relationships between Cl2, HCl, NaCl(g) and NaCl(c). These analyses show that while HCl is a product of combustion of PVC-laden municipal solid waste, NaCl can be converted to HCl in hog fuel boilers by reactions with SO2 or alumino-silicate materials. Cl2 is a strong chlorinating agent for PCDD/F formation. HCl can be oxidized to Cl2 by O2, and Cl2 can be reduced back to HCl by SO2. The presence of sulphur at low concentrations thus enhances PCDD/F formation by increasing HCl concentrations. At high concentrations, sulphur inhibits de novo formation of PCDD/Fs through Cl2 reduction by excess SO2. The effect of NH3, CO and NOx on PCDD/F formation is also discussed. A semi-empirical kinetic model is proposed. This model considers both precursor and de novo formation mechanisms. A simplified version is used as a stack emission model. The kinetic model indicates that stack dioxin emissions will increase linearly with decreasing electrostatic precipitator (ESP) efficiency and exponentially with increasing ESP temperature.

  9. 3D gait analysis in patients with hereditary spastic paraparesis and spastic diplegia: a kinematic, kinetic and EMG comparison.

    Science.gov (United States)

    Piccinini, Luigi; Cimolin, Veronica; D'Angelo, Maria Grazia; Turconi, Anna Carla; Crivellini, Marcello; Galli, Manuela

    2011-03-01

    The predominant clinical feature of patients with Hereditary Spastic Paraparesis (HSP) is gait disturbance owing to spasticity and weakness of the lower limbs; the spasticity in early-onset disease (infancy or childhood) often cannot be distinguished from mild form of spastic diplegia (SD). The aim of this study was to quantify the gait strategy in HSP and SD children, focusing on the differences between groups as concerns functional limitation during gait. 9 HSP and 16 SD children were evaluated using Gait Analysis; kinematic and kinetic parameters and EMG pattern during walking were identified and calculated to compare the two gait strategies. The results revealed that these two pathologies are characterised by different gait strategies. In particular we found that knee joint, in terms of kinematics and kinetics, and rectus femoris pattern represent discriminatory aspects in order to compare and differentiate gait patterns of HSP and SD children. The findings strongly support the issue that HSP and SD patients need individualised therapeutical program, either neurosurgical or pharmacological treatment, based on the quantification of gait deficiencies and in order to address the peculiarity of their motor limitations and to prevent the onset of compensatory strategies. Copyright © 2010 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

  10. Computational analysis of interfacial attachment kinetics and transport phenomena during liquid phase epitaxy of mercury cadmium telluride

    Energy Technology Data Exchange (ETDEWEB)

    Rasin, Igal; Brandon, Simon [Dept. of Chemical Engineering, Technion, Haifa 32000 (Israel); Ben Dov, Anne; Grimberg, Ilana; Klin, Olga; Weiss, Eliezer [SCD-Semi-Conductor Devices, P.O. Box 2250/99, Haifa 31021 (Israel)

    2010-07-01

    Deposition of mercury cadmium telluride (MCT) thin films, on lattice matched cadmium zinc telluride substrates, is often achieved via Liquid Phase Epitaxy (LPE). The yield and quality of these films, required for the production of infrared detector devices, is to a large extent limited by lack of knowledge regarding details of physical phenomena underlying the deposition process. Improving the understanding of these phenomena and their impact on the quality of the resultant films is therefore an important goal which can be achieved through relevant computational and/or experimental studies. We present a combined computational and experimental effort aimed at elucidating physical phenomena underlying the LPE of MCT via a slider growth process. The focus of the presentation will be results generated by a time-dependent three-dimensional model of mass transport, fluid flow, and interfacial attachment kinetics, which we have developed and applied in the analysis of this LPE process. These results, combined with experimental analyses, lead to an improved understanding of the role of different transport and kinetic phenomena underlying this growth process.

  11. Participatory Environmental Valuation: A Comparative Analysis of Four Case Studies

    Directory of Open Access Journals (Sweden)

    Leslie Carnoye

    2015-07-01

    Full Text Available The valuation of multiple ecosystem services requires the design of valuation processes able to integrate different dimensions of value and to cope with complexity. Following the “value-articulating institution” framework, we note that three core problems arise: the cognitive, normative and composition problems. Combining valuation methods, such as contingent valuation and multicriteria analysis, with participatory and deliberative techniques is increasingly promoted as a means to address those fundamental problems. However, the quality and legitimacy of the valuation process then becomes dependent on how participation is framed. We note that numerous issues need to be taken into account, such as the roles assumed by participants, the differences in contribution among participants, the level of participatory impact and the level of democratization of the decision-making process. This paper proposes a detailed qualitative analysis of four case studies, each of them having implemented a specific valuation method in a participatory process. We analyze how those cases were handled in each of the dimensions considered and offer our conclusions about the added values and remaining challenges related to participatory environmental valuation.

  12. Analysis of environmental friendliness of DUPIC fuel cycle

    International Nuclear Information System (INIS)

    Ko, Won Il; Kim, Ho Dong

    2001-07-01

    Some properties of irradiated DUPIC fuels are compared with those of other fuel cycles. It was indicated that the toxicity of the DUPIC option based on 1 GWe-yr is much smaller than those of other fuel cycle options, and is just about half the order of magnitude of other fuel cycles. From the activity analysis of 99 Tc and 237 Np, which are important to the long-term transport of fission products stored in geologic media, the DUPIC option, was being contained only about half of those other options. It was found from the actinide content estimation that the MOX option has the lowest plutonium arising based on 1 GWe-year and followed by the DUPIC option. However, fissile Pu content generated in the DUPIC fuel was the lowest among the fuel cycle options. From the analysis of radiation barrier in proliferation resistance aspect, the fresh DUPIC fuel can play a radiation barrier part, better than CANDU spent fuels as well as fresh MOX fuel. It is indicated that the DUPIC fuel cycle has the excellent resistance to proliferation, compared with an existing reprocessing option and CANDU once-through option. In conclusions, DUPIC fuel cycle would have good properties on environmental effect and proliferation resistance, compared to other fuel cycle cases

  13. Application of Environmental Input-Output Analysis for Corporate and Product Environmental Footprints—Learnings from Three Cases

    DEFF Research Database (Denmark)

    Kjær, Louise Laumann; Høst-Madsen, Niels Karim Høst-Madsen; Schmidt, Jannick H.

    2015-01-01

    An increasing number of companies are expanding their environmental impact reduction targets and strategies to include their supply chains or whole product life cycles. In this paper, we demonstrate and evaluate an approach, where we used a hybrid Environmental Input-Output (EIO) database...... 2, the approach was used as basis for an Environmental Profit and Loss account for the healthcare company, Novo Nordisk A/S. Case study 3 used the approach for life cycle assessment of a tanker ship. We conclude that EIO-based analyses offer a holistic view of environmental performance, provide...... a foundation for decision-making within reasonable time and cost, and for companies with a large upstream environmental footprint, the analysis supports advancing their sustainability agenda to include supply chain impacts. However, there are implications when going from screening to implementing the results...

  14. Free Radical Addition Polymerization Kinetics without Steady-State Approximations: A Numerical Analysis for the Polymer, Physical, or Advanced Organic Chemistry Course

    Science.gov (United States)

    Iler, H. Darrell; Brown, Amber; Landis, Amanda; Schimke, Greg; Peters, George

    2014-01-01

    A numerical analysis of the free radical addition polymerization system is described that provides those teaching polymer, physical, or advanced organic chemistry courses the opportunity to introduce students to numerical methods in the context of a simple but mathematically stiff chemical kinetic system. Numerical analysis can lead students to an…

  15. Kinetic approach

    Indian Academy of Sciences (India)

    Collapse of a Bose gas: Kinetic approach ... Thermodynamical, statistical and static properties of condensates; Ultracold and trapped gases; matter waves. ... of a harmonically trapped attractively interacting Bose gas below the condensation point by introducing a kinetic approach within the Hartee-Fock approximation.

  16. Environmental Correlation Analysis for Genes Associated with Protection against Malaria.

    Science.gov (United States)

    Mackinnon, Margaret J; Ndila, Carolyne; Uyoga, Sophie; Macharia, Alex; Snow, Robert W; Band, Gavin; Rautanen, Anna; Rockett, Kirk A; Kwiatkowski, Dominic P; Williams, Thomas N

    2016-05-01

    Genome-wide searches for loci involved in human resistance to malaria are currently being conducted on a large scale in Africa using case-control studies. Here, we explore the utility of an alternative approach-"environmental correlation analysis, ECA," which tests for clines in allele frequencies across a gradient of an environmental selection pressure-to identify genes that have historically protected against death from malaria. We collected genotype data from 12,425 newborns on 57 candidate malaria resistance loci and 9,756 single nucleotide polymorphisms (SNPs) selected at random from across the genome, and examined their allele frequencies for geographic correlations with long-term malaria prevalence data based on 84,042 individuals living under different historical selection pressures from malaria in coastal Kenya. None of the 57 candidate SNPs showed significant (P < 0.05) correlations in allele frequency with local malaria transmission intensity after adjusting for population structure and multiple testing. In contrast, two of the random SNPs that had highly significant correlations (P < 0.01) were in genes previously linked to malaria resistance, namely, CDH13, encoding cadherin 13, and HS3ST3B1, encoding heparan sulfate 3-O-sulfotransferase 3B1. Both proteins play a role in glycoprotein-mediated cell-cell adhesion which has been widely implicated in cerebral malaria, the most life-threatening form of this disease. Other top genes, including CTNND2 which encodes δ-catenin, a molecular partner to cadherin, were significantly enriched in cadherin-mediated pathways affecting inflammation of the brain vascular endothelium. These results demonstrate the utility of ECA in the discovery of novel genes and pathways affecting infectious disease. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  17. Green roof valuation: a probabilistic economic analysis of environmental benefits.

    Science.gov (United States)

    Clark, Corrie; Adriaens, Peter; Talbot, F Brian

    2008-03-15

    Green (vegetated) roofs have gained global acceptance as a technologythat has the potential to help mitigate the multifaceted, complex environmental problems of urban centers. While policies that encourage green roofs exist atthe local and regional level, installation costs remain at a premium and deter investment in this technology. The objective of this paper is to quantitatively integrate the range of stormwater, energy, and air pollution benefits of green roofs into an economic model that captures the building-specific scale. Currently, green roofs are primarily valued on increased roof longevity, reduced stormwater runoff, and decreased building energy consumption. Proper valuation of these benefits can reduce the present value of a green roof if investors look beyond the upfront capital costs. Net present value (NPV) analysis comparing a conventional roof system to an extensive green roof system demonstrates that at the end of the green roof lifetime the NPV for the green roof is between 20.3 and 25.2% less than the NPV for the conventional roof over 40 years. The additional upfront investment is recovered at the time when a conventional roof would be replaced. Increasing evidence suggests that green roofs may play a significant role in urban air quality improvement For example, uptake of N0x is estimated to range from $1683 to $6383 per metric ton of NOx reduction. These benefits were included in this study, and results translate to an annual benefit of $895-3392 for a 2000 square meter vegetated roof. Improved air quality leads to a mean NPV for the green roof that is 24.5-40.2% less than the mean conventional roof NPV. Through innovative policies, the inclusion of air pollution mitigation and the reduction of municipal stormwater infrastructure costs in economic valuation of environmental benefits of green roofs can reduce the cost gap that currently hinders U.S. investment in green roof technology.

  18. Socio-environmental health analysis in Nogales, Sonora, Mexico

    Science.gov (United States)

    Norman, Laura M.; Caldeira, Felipe; Callegary, James; Gray, Floyd; O’ Rourke, Mary Kay; Meranza, Veronica; Van Rijn, Saskia

    2012-01-01

    In Nogales, Sonora, Mexico, some neighborhoods, or colonias, have intermittent delivery of water through pipes from the city of Nogales’s municipal water-delivery system while other areas lack piped water and rely on water delivered by truck or pipas. This research examined how lifestyles, water quality, and potential disease response, such as diarrhea, differs seasonally from a colonia with access to piped water as opposed to one using alternative water-delivery systems. Water samples were collected from taps or spigots at homes in two Nogales colonias. One colonia reflected high socio-environmental conditions where residents are supplied with municipal piped water (Colonia Lomas de Fatima); the second colonia reflected low socio-environmental conditions, lacking access to piped water and served by pipas (Colonia Luis Donaldo Colosio). A survey was developed and implemented to characterize perceptions of water quality, health impacts, and quality of life. Water samples were analyzed for microbial and inorganic water-quality parameters known to impact human health including, Escherichia coli (E. coli), total coliform bacteria, arsenic, and lead. A total of 21 households agreed to participate in the study (14 in Colosio and 7 in Fatima). In both colonias metal concentrations from water samples were all well below the United States Environmental Protection Agency’s (US EPA’s) maximum contaminant levels. E. coli concentrations exceeded the US EPA’s drinking-water standard in Colosio but not Fatima. Total coliform bacteria were present in over 50 % of households in both colonias. Microbial contamination was significantly higher in the summer than in the winter in both colonias. Resulting analysis suggests that residents in colonias without piped water are at a greater risk of gastrointestinal illness from consumption of compromised drinking water. Our survey corroborated reports of gastrointestinal illness in the summer months but not in the winter. Chloride

  19. Kinetics Parameters of VVER-1000 Core with 3 MOX Lead Test Assemblies To Be Used for Accident Analysis Codes

    International Nuclear Information System (INIS)

    Pavlovitchev, A.M.

    2000-01-01

    The present work is a part of Joint U.S./Russian Project with Weapons-Grade Plutonium Disposition in VVER Reactor and presents the neutronics calculations of kinetics parameters of VVER-1000 core with 3 introduced MOX LTAs. MOX LTA design has been studied in [1] for two options of MOX LTA: 100% plutonium and of ''island'' type. As a result, zoning i.e. fissile plutonium enrichments in different plutonium zones, has been defined. VVER-1000 core with 3 introduced MOX LTAs of chosen design has been calculated in [2]. In present work, the neutronics data for transient analysis codes (RELAP [3]) has been obtained using the codes chain of RRC ''Kurchatov Institute'' [5] that is to be used for exploitation neutronics calculations of VVER. Nowadays the 3D assembly-by-assembly code BIPR-7A and 2D pin-by-pin code PERMAK-A, both with the neutronics constants prepared by the cell code TVS-M, are the base elements of this chain. It should be reminded that in [6] TVS-M was used only for the constants calculations of MOX FAs. In current calculations the code TVS-M has been used both for UOX and MOX fuel constants. Besides, the volume of presented information has been increased and additional explications have been included. The results for the reference uranium core [4] are presented in Chapter 2. The results for the core with 3 MOX LTAs are presented in Chapter 3. The conservatism that is connected with neutronics parameters and that must be taken into account during transient analysis calculations, is discussed in Chapter 4. The conservative parameters values are considered to be used in 1-point core kinetics models of accident analysis codes

  20. CFD analysis of the dynamic behaviour of a fuel rod subchannel in a supercritical water reactor with point kinetics

    International Nuclear Information System (INIS)

    Ampomah-Amoako, Emmanuel; Akaho, Edward H.K.; Nyarko, Benjamin J.B.; Ambrosini, Walter

    2013-01-01

    Highlights: • The analysis of flow stability of nuclear fuel subchannels with supercritical water is presented. • The results obtained by a CFD code are compared with those of a system code. • The model includes also heat conduction in the fuel rod and point neutron kinetics. - Abstract: The paper presents the analysis by a CFD code of coupled neutronic–thermal hydraulic instabilities in a subchannel slice belonging to a square lattice assembly. The work represents a further phase in the assessment of the suitability of CFD codes for studies of flow stability of supercritical fluids; the research started in previous work with the analysis of bare 2D circular pipes and already addressed 3D subchannel slices with no allowance for heat conduction or neutronic effects. In the present phase, a more realistic system is considered, dealing with a slice of a fuel assembly subchannel containing the regions of the pellet, the gap and the cladding and including also the effect of inlet and outlet throttling. The adopted neutronic model is a point kinetics one, including six delayed neutron groups with global Doppler and fluid density feedbacks. The response of the model to perturbations applied starting from a steady-state condition at the rated power is compared with that of a similar model developed for a 1D system code. Upward, horizontal and downward flow orientations are addressed making use of a uniform power profile and changing relevant parameters as the gap equivalent conductance and the density reactivity coefficient. A bottom-peaked power profile is also considered in the case of vertical upward flow. Though the adopted model can still be considered simple in comparison with actual details of fuel assemblies, the obtained results demonstrate the potential of the adopted methodology for more accurate analyses to be made with larger computational resources

  1. Heparin kinetics

    International Nuclear Information System (INIS)

    Swart, C.A.M. de.

    1983-01-01

    The author has studied the kinetics of heparin and heparin fractions after intravenous administration in humans and in this thesis the results of this study are reported. Basic knowledge about the physico-chemical properties of heparin and its interactions with proteins resulting in anticoagulant and lipolytic effects are discussed in a review (chapter II), which also comprises some clinical aspects of heparin therapy. In chapter III the kinetics of the anticoagulant effect are described after intravenous administration of five commercial heparin preparations. A mathematical model is presented that fits best to these kinetics. The kinetics of the anticoagulant and lipolytic effects after intravenous injection of various 35 S-radiolabelled heparin fractions and their relationship with the disappearance of the radiolabel are described in chapter IV. Chapter V gives a description of the kinetics of two radiolabels after injection of in vitro formed complexes consisting of purified, 125 I-radiolabelled antithrombin III and various 35 S-radiolabelled heparin fractions. (Auth.)

  2. Automatic flow analysis method to determine traces of Mn²⁺ in sea and drinking waters by a kinetic catalytic process using LWCC-spectrophotometric detection.

    Science.gov (United States)

    Chaparro, Laura; Ferrer, Laura; Leal, Luz O; Cerdà, Víctor

    2016-02-01

    A new automatic kinetic catalytic method has been developed for the measurement of Mn(2+) in drinking and seawater samples. The method is based on the catalytic effect of Mn(2+) on the oxidation of tiron by hydrogen peroxide in presence of Pb(2+) as an activator. The optimum conditions were obtained at pH 10 with 0.019 mol L(-1) 2'2 bipyridyl, 0.005 mol L(-1) tiron and 0.38 mol L(-1) hydrogen peroxide. Flow system is based on multisyringe flow injection analysis (MSFIA) coupled with a lab-on-valve (LOV) device exploiting on line spectrophotometric detection by a Liquid Waveguide Capillary Cell (LWCC), 1m optical length and performed at 445 nm. Under the optimized conditions by a multivariate approach, the method allowed the measurement of Mn(2+) in a range of 0.03-35 µg L(-1) with a detection limit of 0.010 µg L(-1), attaining a repeatability of 1.4% RSD. The method was satisfactorily applied to the determination of Mn(2+) in environmental water samples. The reliability of method was also verified by determining the manganese content of the certified standard reference seawater sample, CASS-4. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Using Remote Sensing Products for Environmental Analysis in South America

    Directory of Open Access Journals (Sweden)

    Fabrício Brito Silva

    2011-09-01

    Full Text Available Land cover plays a major role in many biogeochemical models that represent processes and connections with terrestrial systems; hence, it is a key component for public decisions in ecosystems management. The advance of remote sensing technology, combined with the emergence of new operational products, offers alternatives to improve the accuracy of environmental monitoring and analysis. This work uses the GLOBCOVER, the Vegetation Continuous Field (VCF, MODIS Fire Radiative Power (FRP and the Tropical Rainfall Measuring Mission (TRMM remotely sensed databases to analyze the biomass burning distribution, the land use and land cover characteristics and the percent of tree cover in South America during the years 2000 to 2005. Initially, GLOBCOVER was assessed based on VCF product, and subsequently used for quantitative analysis of the spatial distribution of the South America fires with the fire radiative power (FRP. The results show that GLOBCOVER has a tendency to overestimate forest classes and to underestimate urban and mangroves areas. The fire quantification based on GLOBCOVER product shows that the highest incidence of fires can be observed in the arc of deforestation, located in the Amazon forest border, with vegetation cover composed mainly of broadleaved evergreen or semi-deciduous forest. A time series analysis of FRP database indicates that biomass burning occurs mainly in areas of broadleaved evergreen or semi-deciduous forest and in Brazilian Cerrado associated with grassland management, agricultural land clearing and with the deforestation of Amazon tropical rainforest. Also, variations in FRP intensity and spread can be attributed to rainfall anomalies, such as in 2004, when South America had a positive anomaly rainfall.

  4. Intermediate modeling between kinetic equations and hydrodynamic limits: derivation, analysis and simulations

    International Nuclear Information System (INIS)

    Parisot, M.

    2011-01-01

    This work is dedicated study of a problem resulting from plasma physics: the thermal transfer of electrons in a plasma close to equilibrium Maxwellian. Firstly, a dimensional study of the Vlasov-Fokker-Planck-Maxwell system is performed, allowing one hand to identify a physically relevant parameter of scale and also to define mathematically the contours of validity domain. The asymptotic regime called Spitzer-Harm is studied for a relatively general class of collision operator. The following part of this work is devoted to the derivation and study of the hydrodynamic limit of the system of Vlasov-Maxwell-Landau outside the strictly asymptotic. A model proposed by Schurtz and Nicolais located in this context and analyzed. The particularity of this model lies in the application of a delocalization operation in the heat flux. The link with non-local models of Luciani and Mora is established as well as mathematics properties as the principle of maximum and entropy dissipation. Then a formal derivation from the Vlasov equations with a simplified collision operator, is proposed. The derivation, inspired by the recent work of D. Levermore, involves decomposition methods according to the spherical harmonics and methods of closing called diffusion methods. A hierarchy of intermediate models between the kinetic equations and the hydrodynamic limit is described. In particular a new hydrodynamic system integro-differential by nature, is proposed. The Schurtz and Nicolai model appears as a simplification of the system resulting from the derivation, assuming a steady flow of heat. The above results are then generalized to account for the internal energy dependence which appears naturally in the equation establishment. The existence and uniqueness of the solution of the nonstationary system are established in a simplified framework. The last part is devoted was the implementation of a specific numerical scheme to solve these models. We propose a finite volume approach can be

  5. Acceleration and sensitivity analysis of lattice kinetic Monte Carlo simulations using parallel processing and rate constant rescaling.

    Science.gov (United States)

    Núñez, M; Robie, T; Vlachos, D G

    2017-10-28

    Kinetic Monte Carlo (KMC) simulation provides insights into catalytic reactions unobtainable with either experiments or mean-field microkinetic models. Sensitivity analysis of KMC models assesses the robustness of the predictions to parametric perturbations and identifies rate determining steps in a chemical reaction network. Stiffness in the chemical reaction network, a ubiquitous feature, demands lengthy run times for KMC models and renders efficient sensitivity analysis based on the likelihood ratio method unusable. We address the challenge of efficiently conducting KMC simulations and performing accurate sensitivity analysis in systems with unknown time scales by employing two acceleration techniques: rate constant rescaling and parallel processing. We develop statistical criteria that ensure sufficient sampling of non-equilibrium steady state conditions. Our approach provides the twofold benefit of accelerating the simulation itself and enabling likelihood ratio sensitivity analysis, which provides further speedup relative to finite difference sensitivity analysis. As a result, the likelihood ratio method can be applied to real chemistry. We apply our methodology to the water-gas shift reaction on Pt(111).

  6. Acceleration and sensitivity analysis of lattice kinetic Monte Carlo simulations using parallel processing and rate constant rescaling

    Science.gov (United States)

    Núñez, M.; Robie, T.; Vlachos, D. G.

    2017-10-01

    Kinetic Monte Carlo (KMC) simulation provides insights into catalytic reactions unobtainable with either experiments or mean-field microkinetic models. Sensitivity analysis of KMC models assesses the robustness of the predictions to parametric perturbations and identifies rate determining steps in a chemical reaction network. Stiffness in the chemical reaction network, a ubiquitous feature, demands lengthy run times for KMC models and renders efficient sensitivity analysis based on the likelihood ratio method unusable. We address the challenge of efficiently conducting KMC simulations and performing accurate sensitivity analysis in systems with unknown time scales by employing two acceleration techniques: rate constant rescaling and parallel processing. We develop statistical criteria that ensure sufficient sampling of non-equilibrium steady state conditions. Our approach provides the twofold benefit of accelerating the simulation itself and enabling likelihood ratio sensitivity analysis, which provides further speedup relative to finite difference sensitivity analysis. As a result, the likelihood ratio method can be applied to real chemistry. We apply our methodology to the water-gas shift reaction on Pt(111).

  7. Sonodegradation of cyanidin-3-glucosylrutinoside: degradation kinetic analysis and its impact on antioxidant capacity in vitro.

    Science.gov (United States)

    Sun, Jianxia; Li, Xinghua; Lin, Xinyu; Mei, Zhouxiong; Li, Yitao; Ding, Lijun; Bai, Weibin

    2017-03-01

    As an alternative preservation method for thermal treatment, ultrasound comprises a novel non-thermal processing technology that can significantly avoid undesirable nutritional changes. However, the recent literature indicates that anthocyanin degradation occurs when ultrasound is applied in juice at high amplitude parameters. Such work has mainly focussed on the effect of ultrasound on stability, the antioxidant capacity of cyanidin-3-glucosylrutinoside (Cy-3-glc-rut) and the correlation between anthocyanin degradation and ·OH generation in a simulated system. The spectral intensities of Cy-3-glc-rut at 518 and 282 nm decreased with increasing ultrasound power and treatment time. The degradation of Cy-3-glc-rut was consistent with first-order reaction kinetics (r 2  > 0.9000) and there was a good linear correlation between anthocyanin degradation and hydroxyl radical formation induced by ultrasound (r 2  = 0.9258). Moreover, a decrease in the antioxidant activity of Cy-3-glc-rut after ultrasound evaluated by the 1,1-diphenyl-2-picrylhydrazyl and ferric reducing antioxidant power methods was observed. Overall, the results of the present study show that ultrasound will accelerate the degradation of Cy-3-glc-rut with the growth of power over time. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Combustion characteristics and kinetic analysis of pulverized coal under different pressure grades

    Directory of Open Access Journals (Sweden)

    Qiwei ZUO

    2016-02-01

    Full Text Available By using thermo gravimetric balance, experimental research on combustion characteristics and dynamics parameters of the typical coal injection from some domestic steelworks are conducted with non-isothermal method. The combustion characteristic parameters of the sample pulverized coal such as ignition temperature, peak temperature at maximum weight loss rate, burnout temperature, general burn exponent(S, and maximum combustion rate are studied under pressure grades of 0.1, 1.1, 2.1, 3.1 and 4.1 MPa, the activation energy (E and pre-exponential factor in the combustion process are calculated. The results show that when the pressure increases from 0.1 to 4.1 MPa, ignition temperature decreases by 85.7 K at most, peak temperature at maximum weight loss rate decreases by 249.3 K at most, burnout temperature decreases by 375 K at most, maximum weight loss rate increases by 10 times, and S increases by 33.6 times at most. It is also shown that there exists a kinetic complementation between E and ln A from the view point of dynamics, and the critical pressure of pulverized coal reaction control requirement and combustion mode transform is 3.1 MPa for the pulverized coal.

  9. Design and kinetic analysis of piezoelectric energy harvesters with self-adjusting resonant frequency

    Science.gov (United States)

    Yu-Jen, Wang; Tsung-Yi, Chuang; Jui-Hsin, Yu

    2017-09-01

    Vibration-based energy harvesters have been developed as power sources for wireless sensor networks. Because the vibration frequency of the environment is varied with surrounding conditions, how to design an adaptive energy harvester is a practical topic. This paper proposes a design for a piezoelectric energy harvester possessing the ability to self-adjust its resonant frequency in rotational environments. The effective length of a trapezoidal cantilever is extended by centrifugal force from a rotating wheel to vary its area moment of inertia. The analytical solution for the natural frequency of the piezoelectric energy harvester was derived from the parameter design process, which could specify a structure approaching resonance at any wheel rotating frequency. The kinetic equation and electrical damping induced by power generation were derived from a Lagrange method and a mechanical-electrical coupling model, respectively. An energy harvester with adequate parameters can generate power at a wide range of car speeds. The output power of an experimental prototype composed of piezoelectric thin films and connected to a 3.3 MΩ external resistor was approximately 70-140 μW at wheel speeds ranging from 200 to 700 RPM. These results demonstrate that the proposed piezoelectric energy harvester can be applied as a power source for the wireless tire pressure monitoring sensor.

  10. Kinetic Analysis of Biomarkers in a Cohort of US Patients With Ebola Virus Disease

    Science.gov (United States)

    McElroy, Anita K.; Harmon, Jessica R.; Flietstra, Timothy D.; Campbell, Shelley; Mehta, Aneesh K.; Kraft, Colleen S.; Lyon, Marshall G.; Varkey, Jay B.; Ribner, Bruce S.; Kratochvil, Christopher J.; Iwen, Peter C.; Smith, Philip W.; Ahmed, Rafi; Nichol, Stuart T.; Spiropoulou, Christina F.

    2016-01-01

    Background. Ebola virus (EBOV) infection causes a severe and often fatal disease. Despite the fact that more than 30 000 individuals have acquired Ebola virus disease (EVD), the medical and scientific community still does not have a clear understanding of the mechanisms by which EBOV causes such severe disease. Methods. In this study, 54 biomarkers in plasma samples serially collected from 7 patients with EVD were analyzed in an attempt to define the kinetics of inflammatory modulators. Two clinical disease groups were defined (moderate and severe) based on the need for clinical support. Biomarkers were evaluated for correlation with viremia and clinical disease in an effort to identify pathways that could be useful targets of therapeutic intervention. Results. Patients with severe disease had higher viremia than those with moderate disease. Several biomarkers of immune activation and control were significantly elevated in patients with moderate disease. A series of pro-inflammatory cytokines and chemokines were significantly elevated in patients with severe disease. Conclusions. Biomarkers that were associated with severe EVD were proinflammatory and indicative of endothelial or coagulation cascade dysfunction, as has been seen historically in patients with fatal outcomes. In contrast, biomarkers that were associated with moderate EVD were suggestive of a strong interferon response and control of both innate and adaptive responses. Therefore, clinical interventions that modulate the phenotype and magnitude of immune activation may be beneficial in treating EVD. PMID:27353663

  11. Kinetic and catalytic analysis of mesoporous Co3O4 on the oxidation of morin

    Science.gov (United States)

    Xaba, Morena. S.; Meijboom, Reinout

    2017-11-01

    Herein we report on the synthesis, characterization and catalytic evaluation of mesoporous cobalt oxides on the oxidation of morin. These mesoporous cobalt oxides were synthesized using an inverse surfactant micelle method, they are connected, well-defined with intra-particle voids. These materials were calcined to different final heating temperatures of 150, 250, 350, 450 and 550 °C, and each mesoporous cobalt oxide catalyst showed unique physical properties and catalytic behavior. Morin oxidation was used as a model reaction in the presence of hydrogen peroxide to evaluate the kinetic and catalytic activity of calcined mesoporous cobalt oxides. The adsorption-desorption equilibrium rate constants of morin and hydrogen peroxide were found to be inversely proportional to the crystallite size of the mesoporous cobalt oxide, and the characteristic path length in which the mass transfer takes place was found to be directly proportional to the crystallite size. The materials were characterized using powder X-Ray Diffraction (p-XRD), N2-sorption isotherms (BET), hydrogen temperature programmed reduction (H2-TPR) and High Resolution-Transmission Electron Microscopy (HR-TEM). UV-vis spectrophotometry was used to monitor the time-resolved absorbance of morin at λmax = 410 nm. The surface reaction in this system is described in terms of the well-established Langmuir-Hinshelwood model. The thermodynamic parameters, EA, ΔH#, ΔS# and ΔG# were calculated and catalyst recycling and reusability is demonstrated.

  12. Steady state kinetic analysis of substrate specificity of glycoside hydrolases from families 13 and 38

    DEFF Research Database (Denmark)

    Nielsen, Jonas Willum

    and lysosomes of glycans originating from e.g. terminally misfolded proteins. A divalent metal ion typically resides in the active site, and is essential for enzyme activity. Recently, the α-mannosidase II from Sulfolobus solfataricus (ManA) was purified and characterized as a Zn2+-containing enzyme, but also...... displayed metal ion promiscuity. The present thesis (Manuscript 1) describes the steady state kinetics of ManA in complex with various activating divalent metal ions and substrates. The Co2+-enzyme was superior on both para-nitrophenyl-α-Dmannoside and on 1,2-, 1,3-, 1,4- and 1,6-α-mannobiose. On para......-nitrophenyl-α-Dmannoside the Co2+ substituted ManA displayed a 6-fold higher kcat/KM compared to ManA substituted with Cd2+ and Zn2+. On the α-mannobioses the difference was even more pronounced, with the Co2+substituted ManA being the only metal ion enzyme complex, which allowed the determination of individual KM and kcat...

  13. Animal manure phosphorus characterization by sequential chemical fractionation, release kinetics and 31P-NMR analysis

    Directory of Open Access Journals (Sweden)

    Tales Tiecher

    2014-10-01

    Full Text Available Phosphate release kinetics from manures are of global interest because sustainable plant nutrition with phosphate will be a major concern in the future. Although information on the bioavailability and chemical composition of P present in manure used as fertilizer are important to understand its dynamics in the soil, such studies are still scarce. Therefore, P extraction was evaluated in this study by sequential chemical fractionation, desorption with anion-cation exchange resin and 31P nuclear magnetic resonance (31P-NMR spectroscopy to assess the P forms in three different dry manure types (i.e. poultry, cattle and swine manure. All three methods showed that the P forms in poultry, cattle and swine dry manures are mostly inorganic and highly bioavailable. The estimated P pools showed that organic and recalcitrant P forms were negligible and highly dependent on the Ca:P ratio in manures. The results obtained here showed that the extraction of P with these three different methods allows a better understanding and complete characterization of the P pools present in the manures.

  14. Adsorption of 4-chlorophenol from aqueous solutions by xad-4 resin: Isotherm, kinetic, and thermodynamic analysis

    International Nuclear Information System (INIS)

    Bilgili, M. Sinan

    2006-01-01

    Removal of 4-chlorophenol (4-CP) from synthetic aqueous solutions through adsorption on Amberlite XAD-4 resin, a non-ionic macroreticular resins, under batch equilibrium experimental conditions at 298, 308 and 318 K was investigated. It is necessary to propose a suitable model to a better understanding on the mechanism of 4-CP adsorption. For this purpose, Langmiur, Freundlich, Toth, and Redlich-Peterson (RP) isotherm models were compared. The two and three parameters in the adopted adsorption isotherm models were determined by the help of MATLAB package program. It was determined that best fitted adsorption isotherm models were obtained to be in the order: Redlich-Peterson > Langmuir > Toth > Freundlich isotherms. The pseudo-second-order kinetic model provided the best correlation to the experimental results. Results of the intra-particle diffusion model show that the pore diffusion is not the only rate limiting step. The lower correlation of the data to the Bangham's equation also represents that the diffusion of the adsorbate into pores of the sorbent is not the only rate-controlling step. The thermodynamic constants of adsorption phenomena; ΔG o , ΔH o , and ΔS o were found as -4.17 (at 298 K) kJ/mol, -42.01 kJ/mol, and -0.127 kJ/(mol K), respectively. The results showed that adsorption of 4-CP on Amberlite XAD-4, a nonionic polymeric resin was exothermic and spontaneous

  15. Response to glucose and lipid infusions in sepsis: a kinetic analysis

    International Nuclear Information System (INIS)

    Shaw, J.H.; Wolfe, R.R.

    1985-01-01

    The kinetics and oxidation of glucose and free fatty acid (FFA) metabolism were assessed in control and Escherichia coli septicemic dogs by using primed, constant infusions of U- 14 C-glucose and 1,2, 13 C-palmitic acid. In the controls, the infusion of glucose suppressed endogenous glucose production completely, whereas, in the septic dogs, only a 30% suppression of glucose production occurred. The ability of the septic dogs to oxidize endogenous or exogenous glucose was decreased significantly. The basal rate of appearance of FFA was significantly higher in the septic dogs, but their ability to oxidize FFA was comparable to that of the control dogs; therefore, the basal rate of FFA oxidation was higher in the septic dogs. These studies indicate that septic dogs have a decreased capacity to oxidize glucose, but that they retain their ability to oxidize long-chain fatty acids. Because the rate of lipolysis was increased in sepsis, lipid was the predominate energy substrate in this septic model

  16. Exploratory Analysis of Kinetic Solubility Measurements of a Small Molecule Library

    Science.gov (United States)

    Guha, Rajarshi; Dexheimer, Thomas S.; Kestranek, Aimee N.; Jadhav, Ajit; Chervenak, Andrew M.; Ford, Michael G.; Simeonov, Anton; Roth, Gregory P.; Thomas, Craig J.

    2011-01-01

    Kinetic solubility measurements using prototypical assay buffer conditions are presented for a ~58,000 member library of small molecules. Analyses of the data based upon physical and calculated properties of each individual molecule were performed and resulting trends were considered in the context of commonly held opinions of how physicochemical properties influence aqueous solubility. We further analyze the data using a decision tree model for solubility prediction and via a multi-dimensional assessment of physicochemical relationships to solubility in the context of specific ‘rule-breakers’ relative to common dogma. The role of solubility as a determinant of assay outcome is also considered based upon each compound’s cross-assay activity score for a collection of publicly available screening results. Further, the role of solubility as a governing factor for colloidal aggregation formation within a specified assay setting is examined and considered as a possible cause of a high cross-assay activity score. The results of this solubility profile should aid chemists during library design and optimization efforts and represents a useful training set for computational solubility prediction. PMID:21640593

  17. Simulation of the process kinetics and analysis of physicochemical properties in the freeze drying of kale

    Science.gov (United States)

    Dziki, Dariusz; Polak, Renata; Rudy, Stanisław; Krzykowski, Andrzej; Gawlik-Dziki, Urszula; Różyło, Renata; Miś, Antoni; Combrzyński, Maciej

    2018-01-01

    Investigations were performed to study the freeze-drying process of kale (Brassica oleracea L. var acephala). The process of freeze-drying was performed at temperatures of 20, 40, and 60°C for whole pieces of leaves and for pulped leaves. The kinetics of the freeze-drying of both kale leaves and kale pulp were best described by the Page model. The increasing freeze-drying temperature from 20 to 60°C induced an approximately two-fold decrease in the drying time. Freeze-drying significantly increased the value of the lightness, delta Chroma, and browning index of kale, and had little influence on the hue angle. The highest increase in the lightness and delta Chroma was observed for whole leaves freeze-dried at 20°C. An increase in the drying temperature brought about a slight decrease in the lightness, delta Chroma and the total colour difference. Pulping decreased the lightness and hue angle, and increased browning index. Freeze-drying engendered a slight decrease in the total phenolics content and antioxidant activity, in comparison to fresh leaves. The temperature of the process and pulping had little influence on the total phenolics content and antioxidant activity of dried kale, but significantly decreased the contents of chlorophyll a and chlorophyll b.

  18. A kinematic and kinetic analysis of drop landings in military boots.

    Science.gov (United States)

    Oliver, G D; Stone, A J; Booker, J M; Plummer, H A

    2011-09-01

    The purpose of this study was to examine knee valgus in drop landings during three different footwear conditions and to examine the ground reaction forces exhibited during the drop landing in the three different footwear conditions. Sixteen male and female Reserve Officer Training Corps (ROTC) university undergraduate cadets (21 +/- 3 yrs, 79 +/- 12 kg, and 172 +/- 10 cm) volunteered to participate in the study. Kinematic data were collected while participants performed drop landings in three conditions: bare feet, tennis shoes, and issued military boots. Significant differences among footwear for ground reaction forces (bare feet: 1646 +/- 359%, tennis shoe: 1880 +/- 379%, boot: 1833 +/- 438%; p knee valgus among footwear. Though footwear conditions did not affect knee valgus, they did affect ground reaction forces. Participants in this study had yet to receive any military training on how to land properly from a specified height. Further research should be completed to analyze the kinematics and kinetics of the lower extremity during different landing strategies implemented by trained military personnel in order to better understand injury mechanisms of drop landings in this population. It is likely that injury prevention landing techniques would be beneficial if these were employed by the military and not just in the sporting community.

  19. Bacterial Expression and Kinetic Analysis of Carboxylesterase 001D from Helicoverpa armigera

    Directory of Open Access Journals (Sweden)

    Yongqiang Li

    2016-04-01

    Full Text Available Carboxylesterasesare an important class of detoxification enzymes involved in insecticide resistance in insects. A subgroup of Helicoverpa armigera esterases, known as Clade 001, was implicated in organophosphate and pyrethroid insecticide resistance due to their overabundance in resistant strains. In this work, a novel carboxylesterasegene 001D of H. armigera from China was cloned, which has an open reading frame of 1665 nucleotides encoding 554 amino acid residues. We used a series of fusion proteins to successfully express carboxylesterase 001D in Escherichia coli. Three different fusion proteins were generated and tested. The enzyme kinetic assay towards 1-naphthyl acetate showed all three purified fusion proteins are active with a Kcat between 0.35 and 2.29 s−1, and a Km between 7.61 and 19.72 μM. The HPLC assay showed all three purified fusion proteins had low but measurable hydrolase activity towards β-cypermethrin and fenvalerate insecticides (specific activities ranging from 0.13 to 0.67 μM·min−1·(μM−1·protein. The enzyme was stable up to 40 °C and at pH 6.0–11.0. The results imply that carboxylesterase 001D is involved in detoxification, and this moderate insecticide hydrolysis may suggest that overexpression of the gene to enhance insecticide sequestration is necessary to allow carboxylesterases to confer resistance to these insecticides in H. armigera.

  20. Adsorption of reactive dye from an aqueous solution by chitosan: isotherm, kinetic and thermodynamic analysis

    International Nuclear Information System (INIS)

    Annadurai, Gurusamy; Ling, L.Y.; Lee, J.-F.

    2008-01-01

    The adsorption of Remazol black 13 (Reactive) dye onto chitosan in aqueous solutions was investigated. Experiments were carried out as function of contact time, initial dye concentration (100-300 mg/L), particle size (0.177, 0.384, 1.651 mm), pH (6.7-9.0), and temperature (30-60 deg. C). The equilibrium adsorption data of reactive dye on chitosan were analyzed by Langmuir and Freundlich models. The maximum adsorption capacity (q m ) has been found to be 91.47-130.0 mg/g. The amino group nature of the chitosan provided reasonable dye removal capability. The kinetics of reactive dye adsorption nicely followed the pseudo-first and second-order rate expression which demonstrates that intraparticle diffusion plays a significant role in the adsorption mechanism. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy and entropy of adsorption. The positive value of the enthalpy change (0.212 kJ/mol) indicated that the adsorption is endothermic process. The results indicate that chitosan is suitable as adsorbent material for adsorption of reactive dye form aqueous solutions