WorldWideScience

Sample records for exchange protein-ligand systems

  1. Protein-Ligand Binding Potential of Mean Force Calculations with Hamiltonian Replica Exchange on Alchemical Interaction Grids

    CERN Document Server

    Minh, David D L

    2015-01-01

    A binding potential of mean force (BPMF) is a free energy of noncovalent association in which one binding partner is flexible and the other is rigid. I have developed a method to calculate BPMFs for protein-ligand systems. The method is based on replica exchange sampling from multiple thermodynamic states at different temperatures and protein-ligand interaction strengths. Protein-ligand interactions are represented by interpolating precomputed electrostatic and van der Waals grids. Using a simple estimator for thermodynamic length, thermodynamic states are initialized at approximately equal intervals. The method is demonstrated on the Astex diverse set, a database of 85 protein-ligand complexes relevant to pharmacy or agriculture. Fifteen independent simulations of each complex were started using poses from crystallography, docking, or the lowest-energy pose observed in the other simulations. Benchmark simulations completed within three days on a single processor. Overall, protocols initialized using the ther...

  2. Quantum.Ligand.Dock: protein-ligand docking with quantum entanglement refinement on a GPU system.

    Science.gov (United States)

    Kantardjiev, Alexander A

    2012-07-01

    Quantum.Ligand.Dock (protein-ligand docking with graphic processing unit (GPU) quantum entanglement refinement on a GPU system) is an original modern method for in silico prediction of protein-ligand interactions via high-performance docking code. The main flavour of our approach is a combination of fast search with a special account for overlooked physical interactions. On the one hand, we take care of self-consistency and proton equilibria mutual effects of docking partners. On the other hand, Quantum.Ligand.Dock is the the only docking server offering such a subtle supplement to protein docking algorithms as quantum entanglement contributions. The motivation for development and proposition of the method to the community hinges upon two arguments-the fundamental importance of quantum entanglement contribution in molecular interaction and the realistic possibility to implement it by the availability of supercomputing power. The implementation of sophisticated quantum methods is made possible by parallelization at several bottlenecks on a GPU supercomputer. The high-performance implementation will be of use for large-scale virtual screening projects, structural bioinformatics, systems biology and fundamental research in understanding protein-ligand recognition. The design of the interface is focused on feasibility and ease of use. Protein and ligand molecule structures are supposed to be submitted as atomic coordinate files in PDB format. A customization section is offered for addition of user-specified charges, extra ionogenic groups with intrinsic pK(a) values or fixed ions. Final predicted complexes are ranked according to obtained scores and provided in PDB format as well as interactive visualization in a molecular viewer. Quantum.Ligand.Dock server can be accessed at http://87.116.85.141/LigandDock.html.

  3. In Silico Generation of Peptides by Replica Exchange Monte Carlo: Docking-Based Optimization of Maltose-Binding-Protein Ligands.

    Directory of Open Access Journals (Sweden)

    Anna Russo

    Full Text Available Short peptides can be designed in silico and synthesized through automated techniques, making them advantageous and versatile protein binders. A number of docking-based algorithms allow for a computational screening of peptides as binders. Here we developed ex-novo peptides targeting the maltose site of the Maltose Binding Protein, the prototypical system for the study of protein ligand recognition. We used a Monte Carlo based protocol, to computationally evolve a set of octapeptides starting from a polialanine sequence. We screened in silico the candidate peptides and characterized their binding abilities by surface plasmon resonance, fluorescence and electrospray ionization mass spectrometry assays. These experiments showed the designed binders to recognize their target with micromolar affinity. We finally discuss the obtained results in the light of further improvement in the ex-novo optimization of peptide based binders.

  4. A sequence-based dynamic ensemble learning system for protein ligand-binding site prediction

    KAUST Repository

    Chen, Peng

    2015-12-03

    Background: Proteins have the fundamental ability to selectively bind to other molecules and perform specific functions through such interactions, such as protein-ligand binding. Accurate prediction of protein residues that physically bind to ligands is important for drug design and protein docking studies. Most of the successful protein-ligand binding predictions were based on known structures. However, structural information is not largely available in practice due to the huge gap between the number of known protein sequences and that of experimentally solved structures

  5. A Sequence-Based Dynamic Ensemble Learning System for Protein Ligand-Binding Site Prediction.

    Science.gov (United States)

    Chen, Peng; Hu, ShanShan; Zhang, Jun; Gao, Xin; Li, Jinyan; Xia, Junfeng; Wang, Bing

    2016-01-01

    Proteins have the fundamental ability to selectively bind to other molecules and perform specific functions through such interactions, such as protein-ligand binding. Accurate prediction of protein residues that physically bind to ligands is important for drug design and protein docking studies. Most of the successful protein-ligand binding predictions were based on known structures. However, structural information is not largely available in practice due to the huge gap between the number of known protein sequences and that of experimentally solved structures. This paper proposes a dynamic ensemble approach to identify protein-ligand binding residues by using sequence information only. To avoid problems resulting from highly imbalanced samples between the ligand-binding sites and non ligand-binding sites, we constructed several balanced data sets and we trained a random forest classifier for each of them. We dynamically selected a subset of classifiers according to the similarity between the target protein and the proteins in the training data set. The combination of the predictions of the classifier subset to each query protein target yielded the final predictions. The ensemble of these classifiers formed a sequence-based predictor to identify protein-ligand binding sites. Experimental results on two Critical Assessment of protein Structure Prediction datasets and the ccPDB dataset demonstrated that of our proposed method compared favorably with the state-of-the-art. http://www2.ahu.edu.cn/pchen/web/LigandDSES.htm.

  6. Ideal Heat Exchange System

    Science.gov (United States)

    Tsirlin, A. M.

    2017-09-01

    The requirements with which a heat exchange system should comply in order that at certain values of the total contact surface and heat load the entropy production in it should be minimal have been determined. It has been shown that this system can serve as a standard for real systems of irreversible heat exchange. We have found the conditions for physical realizability of a heat exchange system in which heat exchange occurs by a law linear with respect to the temperature difference between contacting flows. Analogous conditions are given without deriving for the case of heat exchange by the Fourier law.

  7. The Movable Type Method Applied to Protein-Ligand Binding.

    Science.gov (United States)

    Zheng, Zheng; Ucisik, Melek N; Merz, Kenneth M

    2013-12-10

    Accurately computing the free energy for biological processes like protein folding or protein-ligand association remains a challenging problem. Both describing the complex intermolecular forces involved and sampling the requisite configuration space make understanding these processes innately difficult. Herein, we address the sampling problem using a novel methodology we term "movable type". Conceptually it can be understood by analogy with the evolution of printing and, hence, the name movable type. For example, a common approach to the study of protein-ligand complexation involves taking a database of intact drug-like molecules and exhaustively docking them into a binding pocket. This is reminiscent of early woodblock printing where each page had to be laboriously created prior to printing a book. However, printing evolved to an approach where a database of symbols (letters, numerals, etc.) was created and then assembled using a movable type system, which allowed for the creation of all possible combinations of symbols on a given page, thereby, revolutionizing the dissemination of knowledge. Our movable type (MT) method involves the identification of all atom pairs seen in protein-ligand complexes and then creating two databases: one with their associated pairwise distant dependent energies and another associated with the probability of how these pairs can combine in terms of bonds, angles, dihedrals and non-bonded interactions. Combining these two databases coupled with the principles of statistical mechanics allows us to accurately estimate binding free energies as well as the pose of a ligand in a receptor. This method, by its mathematical construction, samples all of configuration space of a selected region (the protein active site here) in one shot without resorting to brute force sampling schemes involving Monte Carlo, genetic algorithms or molecular dynamics simulations making the methodology extremely efficient. Importantly, this method explores the free

  8. Cloud computing for protein-ligand binding site comparison.

    Science.gov (United States)

    Hung, Che-Lun; Hua, Guan-Jie

    2013-01-01

    The proteome-wide analysis of protein-ligand binding sites and their interactions with ligands is important in structure-based drug design and in understanding ligand cross reactivity and toxicity. The well-known and commonly used software, SMAP, has been designed for 3D ligand binding site comparison and similarity searching of a structural proteome. SMAP can also predict drug side effects and reassign existing drugs to new indications. However, the computing scale of SMAP is limited. We have developed a high availability, high performance system that expands the comparison scale of SMAP. This cloud computing service, called Cloud-PLBS, combines the SMAP and Hadoop frameworks and is deployed on a virtual cloud computing platform. To handle the vast amount of experimental data on protein-ligand binding site pairs, Cloud-PLBS exploits the MapReduce paradigm as a management and parallelizing tool. Cloud-PLBS provides a web portal and scalability through which biologists can address a wide range of computer-intensive questions in biology and drug discovery.

  9. Cloud Computing for Protein-Ligand Binding Site Comparison

    Directory of Open Access Journals (Sweden)

    Che-Lun Hung

    2013-01-01

    Full Text Available The proteome-wide analysis of protein-ligand binding sites and their interactions with ligands is important in structure-based drug design and in understanding ligand cross reactivity and toxicity. The well-known and commonly used software, SMAP, has been designed for 3D ligand binding site comparison and similarity searching of a structural proteome. SMAP can also predict drug side effects and reassign existing drugs to new indications. However, the computing scale of SMAP is limited. We have developed a high availability, high performance system that expands the comparison scale of SMAP. This cloud computing service, called Cloud-PLBS, combines the SMAP and Hadoop frameworks and is deployed on a virtual cloud computing platform. To handle the vast amount of experimental data on protein-ligand binding site pairs, Cloud-PLBS exploits the MapReduce paradigm as a management and parallelizing tool. Cloud-PLBS provides a web portal and scalability through which biologists can address a wide range of computer-intensive questions in biology and drug discovery.

  10. Cloud Computing for Protein-Ligand Binding Site Comparison

    Science.gov (United States)

    2013-01-01

    The proteome-wide analysis of protein-ligand binding sites and their interactions with ligands is important in structure-based drug design and in understanding ligand cross reactivity and toxicity. The well-known and commonly used software, SMAP, has been designed for 3D ligand binding site comparison and similarity searching of a structural proteome. SMAP can also predict drug side effects and reassign existing drugs to new indications. However, the computing scale of SMAP is limited. We have developed a high availability, high performance system that expands the comparison scale of SMAP. This cloud computing service, called Cloud-PLBS, combines the SMAP and Hadoop frameworks and is deployed on a virtual cloud computing platform. To handle the vast amount of experimental data on protein-ligand binding site pairs, Cloud-PLBS exploits the MapReduce paradigm as a management and parallelizing tool. Cloud-PLBS provides a web portal and scalability through which biologists can address a wide range of computer-intensive questions in biology and drug discovery. PMID:23762824

  11. THERMODYNAMICS OF PROTEIN-LIGAND INTERACTIONS AND THEIR ANALYSIS

    Directory of Open Access Journals (Sweden)

    Rummi Devi Saini

    2017-11-01

    Full Text Available Physiological processes are controlled mainly by intermolecular recognition mechanisms which involve protein–protein and protein–ligand interactions with a high specificity and affinity to form a specific complex. Proteins being an important class of macromolecules in biological systems, it is important to understand their actions through binding to other molecules of proteins or ligands. In fact, the binding of low molecular weight ligands to proteins plays a significant role in regulating biological processes such as cellular metabolism and signal transmission. Therefore knowledge of the protein–ligand interactions and the knowledge of the mechanisms involved in the protein-ligand recognition and binding are key in understanding biology at molecular level which will facilitate the discovery, design, and development of drugs. In this review, the mechanisms involved in protein–ligand binding, the binding kinetics, thermodynamic concepts and binding driving forces are discussed. Thermodynamic mechanisms involved in a few important protein-ligand binding are described. Various spectroscopic, non-spectroscopic and computational method for analysis of protein–ligand binding are also discussed.

  12. Models of protein-ligand crystal structures: trust, but verify

    Science.gov (United States)

    Deller, Marc C.; Rupp, Bernhard

    2015-09-01

    X-ray crystallography provides the most accurate models of protein-ligand structures. These models serve as the foundation of many computational methods including structure prediction, molecular modelling, and structure-based drug design. The success of these computational methods ultimately depends on the quality of the underlying protein-ligand models. X-ray crystallography offers the unparalleled advantage of a clear mathematical formalism relating the experimental data to the protein-ligand model. In the case of X-ray crystallography, the primary experimental evidence is the electron density of the molecules forming the crystal. The first step in the generation of an accurate and precise crystallographic model is the interpretation of the electron density of the crystal, typically carried out by construction of an atomic model. The atomic model must then be validated for fit to the experimental electron density and also for agreement with prior expectations of stereochemistry. Stringent validation of protein-ligand models has become possible as a result of the mandatory deposition of primary diffraction data, and many computational tools are now available to aid in the validation process. Validation of protein-ligand complexes has revealed some instances of overenthusiastic interpretation of ligand density. Fundamental concepts and metrics of protein-ligand quality validation are discussed and we highlight software tools to assist in this process. It is essential that end users select high quality protein-ligand models for their computational and biological studies, and we provide an overview of how this can be achieved.

  13. The picture exchange communication system.

    Science.gov (United States)

    Bondy, A S; Frost, L A

    1998-01-01

    The Picture Exchange Communication System (PECS) was developed as a means to teach children with autism and related developmental disabilities a rapidly acquired, self-initiating, functional communication system. Its theoretical roots combine principles from applied behavior analysis and guidelines established within the field of alternative and augmentative communication. This approach has several potential advantages relative to imitation-based strategies (both vocal and gestural) and symbol selection strategies. The system begins with the exchange of simple icons but rapidly builds "sentence" structure. The system also emphasizes developing the request function prior to developing responding to simple questions and commenting. The development of requesting with a sentence structure also permits the rapid development of attributes more traditionally taught within a receptive mode. The relationship between the introduction of PECS and various other behavioral issues (i.e., social approach and behavior management) as well as its relationship to the codevelopment of speech are reviewed.

  14. Assessing protein-ligand docking for the binding of organometallic compounds to proteins.

    Science.gov (United States)

    Ortega-Carrasco, Elisabeth; Lledós, Agusti; Maréchal, Jean-Didier

    2014-01-30

    Organometallic compounds are increasingly used as molecular scaffolds in drug development projects; their structural and electronic properties offering novel opportunities in protein-ligand complementarities. Interestingly, while protein-ligand dockings have long become a spearhead in computer assisted drug design, no benchmarking nor optimization have been done for their use with organometallic compounds. Pursuing our efforts to model metal mediated recognition processes, we herein present a systematic study of the capabilities of the program GOLD to predict the interactions of protein with organometallic compounds. The study focuses on inert systems for which no alteration of the first coordination sphere of the metal occurs upon binding. Several scaffolds are used as test systems with different docking schemes and scoring functions. We conclude that ChemScore is the most robust scoring function with ASP and ChemPLP providing with good results too and GoldScore slightly underperforming. This study shows that current state-of-the-art protein-ligand docking techniques are reliable for the docking of inert organometallic compounds binding to protein. Copyright © 2013 Wiley Periodicals, Inc.

  15. Data Exchange Inventory System (DEXI)

    Data.gov (United States)

    Social Security Administration — Enterprise tool used to identify data exchanges occurring between SSA and our trading partners. DEXI contains information on both incoming and outgoing exchanges and...

  16. EPR of exchange coupled systems

    CERN Document Server

    Bencini, Alessandro

    2012-01-01

    From chemistry to solid state physics to biology, the applications of Electron Paramagnetic Resonance (EPR) are relevant to many areas. This unified treatment is based on the spin Hamiltonian approach and makes extensive use of irreducible tensor techniques to analyze systems in which two or more spins are magnetically coupled. This edition contains a new Introduction by coauthor Dante Gatteschi, a pioneer and scholar of molecular magnetism.The first two chapters review the foundations of exchange interactions, followed by examinations of the spectra of pairs and clusters, relaxation in oligon

  17. Data Exchange Inventory (DEXI) System

    Data.gov (United States)

    Social Security Administration — DEXI is an intranet application used by SSA users to track all incoming and outgoing data exchanges between SSA and our data exchange partners. Information such as...

  18. Exchanger system for anhydrite pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Penet, A.

    1980-12-01

    This paper deals with the problem of roadway behaviour affecting airways, bottom roads and top roads in advancing faces in the HBNPC area. The support work in these zones used to be undertaken manually and involved a lot of man hours. These operations are now mechanized in the form of pneumatic stowing with anhydrite. The latter is delivered by pipeline using compressed air. The 'exchanger' is a sort of branching system in the pipeline enabling the flow to be switched from the top end of the face to the bottom end and vice versa (diagram). The associated operations can be undertaken with ease. The effect the system has on costs will soon be known. (In French)

  19. Accuracy and precision of protein-ligand interaction kinetics determined from chemical shift titrations.

    Science.gov (United States)

    Markin, Craig J; Spyracopoulos, Leo

    2012-12-01

    NMR-monitored chemical shift titrations for the study of weak protein-ligand interactions represent a rich source of information regarding thermodynamic parameters such as dissociation constants (K ( D )) in the micro- to millimolar range, populations for the free and ligand-bound states, and the kinetics of interconversion between states, which are typically within the fast exchange regime on the NMR timescale. We recently developed two chemical shift titration methods wherein co-variation of the total protein and ligand concentrations gives increased precision for the K ( D ) value of a 1:1 protein-ligand interaction (Markin and Spyracopoulos in J Biomol NMR 53: 125-138, 2012). In this study, we demonstrate that classical line shape analysis applied to a single set of (1)H-(15)N 2D HSQC NMR spectra acquired using precise protein-ligand chemical shift titration methods we developed, produces accurate and precise kinetic parameters such as the off-rate (k ( off )). For experimentally determined kinetics in the fast exchange regime on the NMR timescale, k ( off ) ~ 3,000 s(-1) in this work, the accuracy of classical line shape analysis was determined to be better than 5 % by conducting quantum mechanical NMR simulations of the chemical shift titration methods with the magnetic resonance toolkit GAMMA. Using Monte Carlo simulations, the experimental precision for k ( off ) from line shape analysis of NMR spectra was determined to be 13 %, in agreement with the theoretical precision of 12 % from line shape analysis of the GAMMA simulations in the presence of noise and protein concentration errors. In addition, GAMMA simulations were employed to demonstrate that line shape analysis has the potential to provide reasonably accurate and precise k ( off ) values over a wide range, from 100 to 15,000 s(-1). The validity of line shape analysis for k ( off ) values approaching intermediate exchange (~100 s(-1)), may be facilitated by more accurate K ( D ) measurements

  20. Optimization of Electrospray Ionization by Statistical Design of Experiments and Response Surface Methodology: Protein-Ligand Equilibrium Dissociation Constant Determinations

    Science.gov (United States)

    Pedro, Liliana; Van Voorhis, Wesley C.; Quinn, Ronald J.

    2016-09-01

    Electrospray ionization mass spectrometry (ESI-MS) binding studies between proteins and ligands under native conditions require that instrumental ESI source conditions are optimized if relative solution-phase equilibrium concentrations between the protein-ligand complex and free protein are to be retained. Instrumental ESI source conditions that simultaneously maximize the relative ionization efficiency of the protein-ligand complex over free protein and minimize the protein-ligand complex dissociation during the ESI process and the transfer from atmospheric pressure to vacuum are generally specific for each protein-ligand system and should be established when an accurate equilibrium dissociation constant (KD) is to be determined via titration. In this paper, a straightforward and systematic approach for ESI source optimization is presented. The method uses statistical design of experiments (DOE) in conjunction with response surface methodology (RSM) and is demonstrated for the complexes between Plasmodium vivax guanylate kinase ( PvGK) and two ligands: 5'-guanosine monophosphate (GMP) and 5'-guanosine diphosphate (GDP). It was verified that even though the ligands are structurally similar, the most appropriate ESI conditions for KD determination by titration are different for each.

  1. Optimization of Electrospray Ionization by Statistical Design of Experiments and Response Surface Methodology: Protein-Ligand Equilibrium Dissociation Constant Determinations.

    Science.gov (United States)

    Pedro, Liliana; Van Voorhis, Wesley C; Quinn, Ronald J

    2016-09-01

    Electrospray ionization mass spectrometry (ESI-MS) binding studies between proteins and ligands under native conditions require that instrumental ESI source conditions are optimized if relative solution-phase equilibrium concentrations between the protein-ligand complex and free protein are to be retained. Instrumental ESI source conditions that simultaneously maximize the relative ionization efficiency of the protein-ligand complex over free protein and minimize the protein-ligand complex dissociation during the ESI process and the transfer from atmospheric pressure to vacuum are generally specific for each protein-ligand system and should be established when an accurate equilibrium dissociation constant (KD) is to be determined via titration. In this paper, a straightforward and systematic approach for ESI source optimization is presented. The method uses statistical design of experiments (DOE) in conjunction with response surface methodology (RSM) and is demonstrated for the complexes between Plasmodium vivax guanylate kinase (PvGK) and two ligands: 5'-guanosine monophosphate (GMP) and 5'-guanosine diphosphate (GDP). It was verified that even though the ligands are structurally similar, the most appropriate ESI conditions for KD determination by titration are different for each. Graphical Abstract ᅟ.

  2. Compact, Polyvalent Mannose Quantum Dots as Sensitive, Ratiometric FRET Probes for Multivalent Protein-Ligand Interactions.

    Science.gov (United States)

    Guo, Yuan; Sakonsinsiri, Chadamas; Nehlmeier, Inga; Fascione, Martin A; Zhang, Haiyan; Wang, Weili; Pöhlmann, Stefan; Turnbull, W Bruce; Zhou, Dejian

    2016-04-04

    A highly efficient cap-exchange approach for preparing compact, dense polyvalent mannose-capped quantum dots (QDs) has been developed. The resulting QDs have been successfully used to probe multivalent interactions of HIV/Ebola receptors DC-SIGN and DC-SIGNR (collectively termed as DC-SIGN/R) using a sensitive, ratiometric Förster resonance energy transfer (FRET) assay. The QD probes specifically bind DC-SIGN, but not its closely related receptor DC-SIGNR, which is further confirmed by its specific blocking of DC-SIGN engagement with the Ebola virus glycoprotein. Tuning the QD surface mannose valency reveals that DC-SIGN binds more efficiently to densely packed mannosides. A FRET-based thermodynamic study reveals that the binding is enthalpy-driven. This work establishes QD FRET as a rapid, sensitive technique for probing structure and thermodynamics of multivalent protein-ligand interactions.

  3. Modeling of metal interaction geometries for protein-ligand docking.

    Science.gov (United States)

    Seebeck, Birte; Reulecke, Ingo; Kämper, Andreas; Rarey, Matthias

    2008-05-15

    The accurate modeling of metal coordination geometries plays an important role for structure-based drug design applied to metalloenzymes. For the development of a new metal interaction model, we perform a statistical analysis of metal interaction geometries that are relevant to protein-ligand complexes. A total of 43,061 metal sites of the Protein Data Bank (PDB), containing amongst others magnesium, calcium, zinc, iron, manganese, copper, cadmium, cobalt, and nickel, were evaluated according to their metal coordination geometry. Based on statistical analysis, we derived a model for the automatic calculation and definition of metal interaction geometries for the purpose of molecular docking analyses. It includes the identification of the metal-coordinating ligands, the calculation of the coordination geometry and the superposition of ideal polyhedra to identify the optimal positions for free coordination sites. The new interaction model was integrated in the docking software FlexX and evaluated on a data set of 103 metalloprotein-ligand complexes, which were extracted from the PDB. In a first step, the quality of the automatic calculation of the metal coordination geometry was analyzed. In 74% of the cases, the correct prediction of the coordination geometry could be determined on the basis of the protein structure alone. Secondly, the new metal interaction model was tested in terms of predicting protein-ligand complexes. In the majority of test cases, the new interaction model resulted in an improved docking accuracy of the top ranking placements. 2007 Wiley-Liss, Inc.

  4. Lead Generation and Optimization Based on Protein-Ligand Complementarity

    Directory of Open Access Journals (Sweden)

    Koji Ogata

    2010-06-01

    Full Text Available This work proposes a computational procedure for structure-based lead generation and optimization, which relies on the complementarity of the protein-ligand interactions. This procedure takes as input the known structure of a protein-ligand complex. Retaining the positions of the ligand heavy atoms in the protein binding site it designs structurally similar compounds considering all possible combinations of atomic species (N, C, O, CH3, NH,etc. Compounds are ranked based on a score which incorporates energetic contributions evaluated using molecular mechanics force fields. This procedure was used to design new inhibitor molecules for three serine/threonine protein kinases (p38 MAP kinase, p42 MAP kinase (ERK2, and c-Jun N-terminal kinase 3 (JNK3. For each enzyme, the calculations produce a set of potential inhibitors whose scores are in agreement with IC50 data and Ki values. Furthermore, the native ligands for each protein target, scored within the five top-ranking compounds predicted by our method, one of the top-ranking compounds predicted to inhibit JNK3 was synthesized and his inhibitory activity confirmed against ATP hydrolysis. Our computational procedure is therefore deemed to be a useful tool for generating chemically diverse molecules active against known target proteins.

  5. CREDO: a protein-ligand interaction database for drug discovery.

    Science.gov (United States)

    Schreyer, Adrian; Blundell, Tom

    2009-02-01

    Harnessing data from the growing number of protein-ligand complexes in the Protein Data Bank is an important task in drug discovery. In order to benefit from the abundance of three-dimensional structures, structural data must be integrated with sequence as well as chemical data and the protein-small molecule interactions characterized structurally at the inter-atomic level. In this study, we present CREDO, a new publicly available database of protein-ligand interactions, which represents contacts as structural interaction fingerprints, implements novel features and is completely scriptable through its application programming interface. Features of CREDO include implementation of molecular shape descriptors with ultrafast shape recognition, fragmentation of ligands in the Protein Data Bank, sequence-to-structure mapping and the identification of approved drugs. Selected analyses of these key features are presented to highlight a range of potential applications of CREDO. The CREDO dataset has been released into the public domain together with the application programming interface under a Creative Commons license at http://www-cryst.bioc.cam.ac.uk/credo. We believe that the free availability and numerous features of CREDO database will be useful not only for commercial but also for academia-driven drug discovery programmes.

  6. Entropy exchange for infinite-dimensional systems.

    Science.gov (United States)

    Duan, Zhoubo; Hou, Jinchuan

    2017-02-06

    In this paper the entropy exchange for channels and states in infinite-dimensional systems are defined and studied. It is shown that, this entropy exchange depends only on the given channel and the state. An explicit expression of the entropy exchange in terms of the state and the channel is proposed. The generalized Klein's inequality, the subadditivity and the triangle inequality about the entropy including infinite entropy for the infinite-dimensional systems are established, and then, applied to compare the entropy exchange with the entropy change.

  7. Exchange fluctuation theorem for correlated quantum systems.

    Science.gov (United States)

    Jevtic, Sania; Rudolph, Terry; Jennings, David; Hirono, Yuji; Nakayama, Shojun; Murao, Mio

    2015-10-01

    We extend the exchange fluctuation theorem for energy exchange between thermal quantum systems beyond the assumption of molecular chaos, and describe the nonequilibrium exchange dynamics of correlated quantum states. The relation quantifies how the tendency for systems to equilibrate is modified in high-correlation environments. In addition, a more abstract approach leads us to a "correlation fluctuation theorem". Our results elucidate the role of measurement disturbance for such scenarios. We show a simple application by finding a semiclassical maximum work theorem in the presence of correlations. We also present a toy example of qubit-qudit heat exchange, and find that non-classical behaviour such as deterministic energy transfer and anomalous heat flow are reflected in our exchange fluctuation theorem.

  8. Development of the stock exchange information system

    Directory of Open Access Journals (Sweden)

    Miladinović Radojko

    2006-01-01

    Full Text Available The stock exchange represents the key institution for the development of capital market of any country. Thus the information system of every stock exchange must satisfy very strict international standards. The development of these systems is particularly difficult in countries in transition, due to intense economic and legal changes, lack of technical and financial resources, lack of experience and knowledge in the area of the capital market business, etc. Therefore the special software project management methodology for their realization must be clearly defined. In the development process of the Belgrade Stock Exchange (BSE information system a new software project management methodology for its realization has been defined, the application of which is illustrated through a series of different development stages of the Belgrade Stock Exchange information system. In order to make all the problems more comprehensive, only the continuous trading method is described, being the most frequently used trading method in the world.

  9. Assessment, Cleanup and Redevelopment Exchange System (ACRES)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Assessment, Cleanup and Redevelopment Exchange System (ACRES) is an online database for Brownfields Grantees to electronically submit data directly to EPA.

  10. Ion Exchange Resins Transforming Drug Delivery Systems.

    Science.gov (United States)

    Gupta, Shweta; Benien, Parul; Sahoo, P K

    2010-07-01

    Ion-exchange resins are light, porous, three-dimensional high molecular weight cross - linked matrix of hydrocarbon chains carrying positively or negatively charged sites that can attract an ion of opposite charge from the surrounding medium. There is stoichiometric exchange of mobile ions between the solid and the solution called as Ion-exchange which does not lead to any radical change in the properties and structure of the solid. Depending upon the type of Ionexchanged it can be either Cation-exchange or Anion-exchange. They are prepared in the form of granules, beads or sheets. As drug delivery systems they have received considerable attention after the 1950s due to their inertness, freedom from side effects, high drug loading capacity, ease of sterilization and the fact that their structure can be easily altered to achieve the desired drug release characteristics. Their use is revolutionizing all traditional delivery systems namely - oral, nasal, ophthalmic and parenteral. Ion- exchange resins have been used for the development of novel drug delivery systems (NDDSs), to modify the characteristics of the dosage form and various other biomedical applications. The present article deals with the varied applications of ion-exchange resins for taste making, as resinates (simple and microencapsulated or coated), Pennkinetic systems, in selective recovery of pharmaceuticals, in pH and ionic strength responsive systems, in gastro-retentive systems, in hollow fiber systems, as sigmoidal release systems, as site specific delivery systems and as inotophoretically assisted transdermal drug delivery systems. They also have an immense importance when used as disintegrants / superdisintegrants in formulation of orodispersible tablets, powder processing aids and in the dissolution and stabilization of drugs.

  11. Effect of urea on protein-ligand association.

    Science.gov (United States)

    Stepanian, Lora; Son, Ikbae; Chalikian, Tigran V

    2017-12-01

    We combine experimental and theoretical approaches to investigate the influence of a cosolvent on a ligand-protein association event. We apply fluorescence measurements to determining the affinity of the inhibitor tri-N-acetylglucosamine [(GlcNAc)3] for lysozyme at urea concentrations ranging from 0 to 8M. Notwithstanding that, at room temperature and neutral pH, lysozyme retains its native conformation up to the solubility limit of urea, the affinity of (GlcNAc)3 for the protein steadily decreases as the concentration of urea increases. We analyze the urea dependence of the binding free energy within the framework of a simplified statistical thermodynamics-based model that accounts for the excluded volume effect and direct solute-solvent interactions. The analysis reveals that the detrimental action of urea on the inhibitor-lysozyme binding originates from competition between the free energy contributions of the excluded volume effect and direct solute-solvent interactions. The free energy contribution of direct urea-solute interactions narrowly overcomes the excluded volume contribution thereby resulting in urea weakening the protein-ligand association. More broadly, the successful application of the simple model employed in this work points to the possibility of its use in quantifying the stabilizing/destabilizing action of individual cosolvents on biochemical folding and binding reactions. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Affinity-mass spectrometry approaches for elucidating structures and interactions of protein-ligand complexes.

    Science.gov (United States)

    Petre, Brînduşa Alina

    2014-01-01

    Affinity-based approaches in combination with mass spectrometry for molecular structure identification in biological complexes such as protein-protein, and protein-carbohydrate complexes have become popular in recent years. Affinity-mass spectrometry involves immobilization of a biomolecule on a chemically activated support, affinity binding of ligand(s), dissociation of the complex, and mass spectrometric analysis of the bound fraction. In this chapter the affinity-mass spectrometric methodologies will be presented for (1) identification of the epitope structures in the Abeta amyloid peptide, (2) identification of oxidative modifications in proteins such as nitration of tyrosine, (3) determination of carbohydrate recognition domains, and as (4) development of a biosensor chip-based mass spectrometric system for concomitant quantification and identification of protein-ligand complexes.

  13. A web server for analysis, comparison and prediction of protein ligand binding sites.

    Science.gov (United States)

    Singh, Harinder; Srivastava, Hemant Kumar; Raghava, Gajendra P S

    2016-03-25

    One of the major challenges in the field of system biology is to understand the interaction between a wide range of proteins and ligands. In the past, methods have been developed for predicting binding sites in a protein for a limited number of ligands. In order to address this problem, we developed a web server named 'LPIcom' to facilitate users in understanding protein-ligand interaction. Analysis, comparison and prediction modules are available in the "LPIcom' server to predict protein-ligand interacting residues for 824 ligands. Each ligand must have at least 30 protein binding sites in PDB. Analysis module of the server can identify residues preferred in interaction and binding motif for a given ligand; for example residues glycine, lysine and arginine are preferred in ATP binding sites. Comparison module of the server allows comparing protein-binding sites of multiple ligands to understand the similarity between ligands based on their binding site. This module indicates that ATP, ADP and GTP ligands are in the same cluster and thus their binding sites or interacting residues exhibit a high level of similarity. Propensity-based prediction module has been developed for predicting ligand-interacting residues in a protein for more than 800 ligands. In addition, a number of web-based tools have been integrated to facilitate users in creating web logo and two-sample between ligand interacting and non-interacting residues. In summary, this manuscript presents a web-server for analysis of ligand interacting residue. This server is available for public use from URL http://crdd.osdd.net/raghava/lpicom .

  14. AMMOS2: a web server for protein-ligand-water complexes refinement via molecular mechanics.

    Science.gov (United States)

    Labbé, Céline M; Pencheva, Tania; Jereva, Dessislava; Desvillechabrol, Dimitri; Becot, Jérôme; Villoutreix, Bruno O; Pajeva, Ilza; Miteva, Maria A

    2017-05-09

    AMMOS2 is an interactive web server for efficient computational refinement of protein-small organic molecule complexes. The AMMOS2 protocol employs atomic-level energy minimization of a large number of experimental or modeled protein-ligand complexes. The web server is based on the previously developed standalone software AMMOS (Automatic Molecular Mechanics Optimization for in silico Screening). AMMOS utilizes the physics-based force field AMMP sp4 and performs optimization of protein-ligand interactions at five levels of flexibility of the protein receptor. The new version 2 of AMMOS implemented in the AMMOS2 web server allows the users to include explicit water molecules and individual metal ions in the protein-ligand complexes during minimization. The web server provides comprehensive analysis of computed energies and interactive visualization of refined protein-ligand complexes. The ligands are ranked by the minimized binding energies allowing the users to perform additional analysis for drug discovery or chemical biology projects. The web server has been extensively tested on 21 diverse protein-ligand complexes. AMMOS2 minimization shows consistent improvement over the initial complex structures in terms of minimized protein-ligand binding energies and water positions optimization. The AMMOS2 web server is freely available without any registration requirement at the URL: http://drugmod.rpbs.univ-paris-diderot.fr/ammosHome.php. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

  15. Carbon nanotube heat-exchange systems

    Science.gov (United States)

    Hendricks, Terry Joseph; Heben, Michael J.

    2008-11-11

    A carbon nanotube heat-exchange system (10) and method for producing the same. One embodiment of the carbon nanotube heat-exchange system (10) comprises a microchannel structure (24) having an inlet end (30) and an outlet end (32), the inlet end (30) providing a cooling fluid into the microchannel structure (24) and the outlet end (32) discharging the cooling fluid from the microchannel structure (24). At least one flow path (28) is defined in the microchannel structure (24), fluidically connecting the inlet end (30) to the outlet end (32) of the microchannel structure (24). A carbon nanotube structure (26) is provided in thermal contact with the microchannel structure (24), the carbon nanotube structure (26) receiving heat from the cooling fluid in the microchannel structure (24) and dissipating the heat into an external medium (19).

  16. Heat Exchanger for Motor Vehicle Cooling System

    OpenAIRE

    Thuliez, Jean-Luc; Chevroulet, Tristan; Stoll, Daniel

    1997-01-01

    Heat exchanger for a motor vehicle cooling system including a sleeve-like meter hermetically mounted on, and surrounding, a hollow tubular chassis meter of the vehicle. The sleeve is provided with inlets and outlets communicating with the space between the sleeve and the chassis meter and vehicle coolant flows through the inlet and outlet. Air, flowing over the outside surface of the sleeve and the inside surface of the chassis meter, cools the vehicle coolant. SMH - MCC Smart, car concepts (...

  17. 40 CFR 63.104 - Heat exchange system requirements.

    Science.gov (United States)

    2010-07-01

    ... heat exchange system or at locations where the cooling water enters and exits each heat exchanger or any combination of heat exchangers. (i) For samples taken at the entrance and exit of recirculating... manufacturing process units. (iii) For samples taken at the entrance and exit of each heat exchanger or any...

  18. Influence of Sulfolane on ESI-MS Measurements of Protein-Ligand Affinities

    Science.gov (United States)

    Yao, Yuyu; Richards, Michele R.; Kitova, Elena N.; Klassen, John S.

    2016-03-01

    The results of an investigation into the influence of sulfolane, a commonly used supercharging agent, on electrospray ionization mass spectrometry (ESI-MS) measurements of protein-ligand affinities are described. Binding measurements carried out on four protein-carbohydrate complexes, lysozyme with β- d-GlcNAc-(1→4)-β- d-GlcNAc-(1→4)-β- d-GlcNAc-(1→4)- d-GlcNAc, a single chain variable fragment and α- d-Gal-(1→2)-[α- d-Abe-(1→3)]-α- d-Man-OCH3, cholera toxin B subunit homopentamer with β- d-Gal-(1→3)-β- d-GalNAc-(1→4)[α- d-Neu5Ac-(2→3)]-β- d-Gal-(1→4)-β- d-Glc, and a fragment of galectin 3 and α- l-Fuc-(1→2)-β- d-Gal-(1→3)-β- d-GlcNAc-(1→3)-β- d-Gal-(1→4)-β- d-Glc, revealed that sulfolane generally reduces the apparent (as measured by ESI-MS) protein-ligand affinities. To establish the origin of this effect, a detailed study was undertaken using the lysozyme-tetrasaccharide interaction as a model system. Measurements carried out using isothermal titration calorimetry (ITC), circular dichroism, and nuclear magnetic resonance spectroscopies reveal that sulfolane reduces the binding affinity in solution but does not cause any significant change in the higher order structure of lysozyme or to the intermolecular interactions. These observations confirm that changes to the structure of lysozyme in bulk solution are not responsible for the supercharging effect induced by sulfolane. Moreover, the agreement between the ESI-MS and ITC-derived affinities indicates that there is no dissociation of the complex during ESI or in the gas phase (i.e., in-source dissociation). This finding suggests that supercharging of lysozyme by sulfolane is not related to protein unfolding during the ESI process. Binding measurements performed using liquid sample desorption ESI-MS revealed that protein supercharging with sulfolane can be achieved without a reduction in affinity.

  19. Improved accuracy of low affinity protein-ligand equilibrium dissociation constants directly determined by electrospray ionization mass spectrometry.

    Science.gov (United States)

    Jaquillard, Lucie; Saab, Fabienne; Schoentgen, Françoise; Cadene, Martine

    2012-05-01

    There is continued interest in the determination by ESI-MS of equilibrium dissociation constants (K(D)) that accurately reflect the affinity of a protein-ligand complex in solution. Issues in the measurement of K(D) are compounded in the case of low affinity complexes. Here we present a K(D) measurement method and corresponding mathematical model dealing with both gas-phase dissociation (GPD) and aggregation. To this end, a rational mathematical correction of GPD (f(sat)) is combined with the development of an experimental protocol to deal with gas-phase aggregation. A guide to apply the method to noncovalent protein-ligand systems according to their kinetic behavior is provided. The approach is validated by comparing the K(D) values determined by this method with in-solution K(D) literature values. The influence of the type of molecular interactions and instrumental setup on f(sat) is examined as a first step towards a fine dissection of factors affecting GPD. The method can be reliably applied to a wide array of low affinity systems without the need for a reference ligand or protein.

  20. Plasma exchange in progressive systemic sclerosis

    Directory of Open Access Journals (Sweden)

    Mohammad Bagher Owlia

    2015-10-01

    Full Text Available Systemic sclerosis (SSc is an autoimmune systemic disease of unknown etiology. Present treatment modalities have limited impact on clinical/ laboratory outcomes. For the first time in our center, we used plasma exchange (PEx in a rather young woman with recent onset but progressive SSc. She is a 39-year-old woman with a recent history of skin stiffness, Raynaud’s phenomenon, nail fold capillary changes and newly diagnosis of SSc presented to us due to worsening her clinical symptoms even after initiation of routine remedies such as low dose oral prednisolone, Ca-channel blockers, azathioprine and pentoxyfylline. After obtaining written consent, interdisciplinary discussion with experts in this field and agreement we started a series of plasma exchange with FFP replacement for her. A dramatic clinical response was observed in respect to Raynaud’s phenomenon, skin stiffness, tendon rub after three sessions of PEx. Her modified Rodnan skin score (MRSS dropped from 36 (before commencement of therapy to 28 in day 4 and 18 in day 20 after 15 sessions of PEx. In conclusion PEx could significantly modify the course of SSc as observed in our case study. Elimination of culprit immune mediators/cytokines/autoantibodies could be the possible mechanism of action of PEx. 

  1. A general and fast scoring function for protein-ligand interactions: a simplified potential approach.

    Science.gov (United States)

    Muegge, I; Martin, Y C

    1999-03-11

    A fast, simplified potential-based approach is presented that estimates the protein-ligand binding affinity based on the given 3D structure of a protein-ligand complex. This general, knowledge-based approach exploits structural information of known protein-ligand complexes extracted from the Brookhaven Protein Data Bank and converts it into distance-dependent Helmholtz free interaction energies of protein-ligand atom pairs (potentials of mean force, PMF). The definition of an appropriate reference state and the introduction of a correction term accounting for the volume taken by the ligand were found to be crucial for deriving the relevant interaction potentials that treat solvation and entropic contributions implicitly. A significant correlation between experimental binding affinities and computed score was found for sets of diverse protein-ligand complexes and for sets of different ligands bound to the same target. For 77 protein-ligand complexes taken from the Brookhaven Protein Data Bank, the calculated score showed a standard deviation from observed binding affinities of 1.8 log Ki units and an R2 value of 0.61. The best results were obtained for the subset of 16 serine protease complexes with a standard deviation of 1.0 log Ki unit and an R2 value of 0.86. A set of 33 inhibitors modeled into a crystal structure of HIV-1 protease yielded a standard deviation of 0.8 log Ki units from measured inhibition constants and an R2 value of 0.74. In contrast to empirical scoring functions that show similar or sometimes better correlation with observed binding affinities, our method does not involve deriving specific parameters that fit the observed binding affinities of protein-ligand complexes of a given training set. We compared the performance of the PMF score, Böhm's score (LUDI), and the SMOG score for eight different test sets of protein-ligand complexes. It was found that for the majority of test sets the PMF score performs best. The strength of the new approach

  2. Thermal Propulsion Capture System Heat Exchanger Design

    Science.gov (United States)

    Richard, Evan M.

    2016-01-01

    One of the biggest challenges of manned spaceflight beyond low earth orbit and the moon is harmful radiation that astronauts would be exposed to on their long journey to Mars and further destinations. Using nuclear energy has the potential to be a more effective means of propulsion compared to traditional chemical engines (higher specific impulse). An upper stage nuclear engine would allow astronauts to reach their destination faster and more fuel efficiently. Testing these engines poses engineering challenges due to the need to totally capture the engine exhaust. The Thermal Propulsion Capture System is a concept for cost effectively and safely testing Nuclear Thermal Engines. Nominally, hydrogen exhausted from the engine is not radioactive, but is treated as such in case of fuel element failure. The Thermal Propulsion Capture System involves injecting liquid oxygen to convert the hydrogen exhaust into steam. The steam is then cooled and condensed into liquid water to allow for storage. The Thermal Propulsion Capture System concept for ground testing of a nuclear powered engine involves capturing the engine exhaust to be cooled and condensed before being stored. The hydrogen exhaust is injected with liquid oxygen and burned to form steam. That steam must be cooled to saturation temperatures before being condensed into liquid water. A crossflow heat exchanger using water as a working fluid will be designed to accomplish this goal. Design a cross flow heat exchanger for the Thermal Propulsion Capture System testing which: Eliminates the need for water injection cooling, Cools steam from 5800 F to saturation temperature, and Is efficient and minimizes water requirement.

  3. Physics-based scoring of protein-ligand interactions: explicit polarizability, quantum mechanics and free energies.

    Science.gov (United States)

    Bryce, Richard A

    2011-04-01

    The ability to accurately predict the interaction of a ligand with its receptor is a key limitation in computer-aided drug design approaches such as virtual screening and de novo design. In this article, we examine current strategies for a physics-based approach to scoring of protein-ligand affinity, as well as outlining recent developments in force fields and quantum chemical techniques. We also consider advances in the development and application of simulation-based free energy methods to study protein-ligand interactions. Fuelled by recent advances in computational algorithms and hardware, there is the opportunity for increased integration of physics-based scoring approaches at earlier stages in computationally guided drug discovery. Specifically, we envisage increased use of implicit solvent models and simulation-based scoring methods as tools for computing the affinities of large virtual ligand libraries. Approaches based on end point simulations and reference potentials allow the application of more advanced potential energy functions to prediction of protein-ligand binding affinities. Comprehensive evaluation of polarizable force fields and quantum mechanical (QM)/molecular mechanical and QM methods in scoring of protein-ligand interactions is required, particularly in their ability to address challenging targets such as metalloproteins and other proteins that make highly polar interactions. Finally, we anticipate increasingly quantitative free energy perturbation and thermodynamic integration methods that are practical for optimization of hits obtained from screened ligand libraries.

  4. Genetic algorithm with a crossover elitist preservation mechanism for protein-ligand docking.

    Science.gov (United States)

    Guan, Boxin; Zhang, Changsheng; Ning, Jiaxu

    2017-09-13

    Protein-ligand docking plays an important role in computer-aided pharmaceutical development. Protein-ligand docking can be defined as a search algorithm with a scoring function, whose aim is to determine the conformation of the ligand and the receptor with the lowest energy. Hence, to improve an efficient algorithm has become a very significant challenge. In this paper, a novel search algorithm based on crossover elitist preservation mechanism (CEP) for solving protein-ligand docking problems is proposed. The proposed algorithm, namely genetic algorithm with crossover elitist preservation (CEPGA), employ the CEP to keep the elite individuals of the last generation and make the crossover more efficient and robust. The performance of CEPGA is tested on sixteen molecular docking complexes from RCSB protein data bank. In comparison with GA, LGA and SODOCK in the aspects of lowest energy and highest accuracy, the results of which indicate that the CEPGA is a reliable and successful method for protein-ligand docking problems.

  5. RiverHeath: Neighborhood Loop Geothermal Exchange System

    Energy Technology Data Exchange (ETDEWEB)

    Geall, Mark [RiverHeath LLC, Appleton, WI (United States)

    2016-07-11

    The goal of the RiverHeath project is to develop a geothermal exchange system at lower capital infrastructure cost than current geothermal exchange systems. The RiverHeath system features an innovative design that incorporates use of the adjacent river through river-based heat exchange plates. The flowing water provides a tremendous amount of heat transfer. As a result, the installation cost of this geothermal exchange system is lower than more traditional vertical bore systems. Many urban areas are located along rivers and other waterways. RiverHeath will serve as a template for other projects adjacent to the water.

  6. Data Exchange Management Information System (DEMIS)

    Data.gov (United States)

    Social Security Administration — DEMIS combines a database (Operational Data Store - ODS) of data exchange-related Management Information (MI) with the agency's querying and reporting utility, the...

  7. Magnetic stability in exchange-spring and exchange bias systems after multiple switching cycles.

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, J. S.; Inomata, A.; You, C.-Y.; Pearson, J. E.; Bader, S. D.

    2001-06-01

    We have studied the magnetic stability in exchange bias and exchange spring systems prepared via epitaxial sputter deposition. The two interfacial exchange coupled systems, Fe/Cr(211) double superlattices consisting of a ferromagnetic and an antiferromagnetic Fe/Cr superlattice that are exchange coupled through a Cr spacer, and Sin-Co/Fe exchange-spring bilayer structures with ferromagnetically coupled hard Sin-Co layer and soft Fe layer, were epitaxially grown on suitably prepared Cr buffer layers to give rise to different microstructure and magnetic anisotropy. The magnetic stability was investigated using the magneto-optic Kerr effect during repeated reversal of the soft layer magnetization by field cycling up to 10{sup 7} times. For uniaxial Fe/Cr exchange biased double superlattices and exchange spring bilayers with uniaxial Sin-Co, small but rapid initial decay in the exchange bias field HE and in the remanent magnetization is observed. However, the exchange spring bilayers with biaxial and random in-plane anisotropy in the Sin-Co layer shows gradual decay in H{sub E} and without large reduction of the magnetization. The different decay behaviors are attributed to the different microstructure and spin configuration of the pinning layers.

  8. Isothermal titration calorimetry for studying protein-ligand interactions.

    Science.gov (United States)

    Damian, Luminita

    2013-01-01

    Isothermal titration calorimetry (ITC) is a biophysical technique that allows a thermodynamic characterization of an interactive system. It is a free in solution technique that requires no labeling, using heat as signal. ITC allows simultaneous determination of affinity K a, stoichiometry n, enthalpy change ΔH and calculation of free energy change ΔG and entropy change ΔS in one single experiment. It is the only technique that allows direct enthalpy change measurement. By accessing the enthalpy change, we get a step closer in estimating the driving forces that characterize the interaction of a protein with a ligand, information much needed in the drug discovery process.

  9. Intelligent transportation system (ITS) international research exchange.

    Science.gov (United States)

    2014-01-01

    ITS applications address surface transportation challenges in safety, mobility, and : sustainability that are similar in cause and impact worldwide. International ITS : exchange allows cooperating nations to benefit from each others pre-competitiv...

  10. Protein-ligand docking using FFT based sampling: D3R case study

    Science.gov (United States)

    Padhorny, Dzmitry; Hall, David R.; Mirzaei, Hanieh; Mamonov, Artem B.; Moghadasi, Mohammad; Alekseenko, Andrey; Beglov, Dmitri; Kozakov, Dima

    2017-11-01

    Fast Fourier transform (FFT) based approaches have been successful in application to modeling of relatively rigid protein-protein complexes. Recently, we have been able to adapt the FFT methodology to treatment of flexible protein-peptide interactions. Here, we report our latest attempt to expand the capabilities of the FFT approach to treatment of flexible protein-ligand interactions in application to the D3R PL-2016-1 challenge. Based on the D3R assessment, our FFT approach in conjunction with Monte Carlo minimization off-grid refinement was among the top performing methods in the challenge. The potential advantage of our method is its ability to globally sample the protein-ligand interaction landscape, which will be explored in further applications.

  11. Protein-ligand docking using FFT based sampling: D3R case study.

    Science.gov (United States)

    Padhorny, Dzmitry; Hall, David R; Mirzaei, Hanieh; Mamonov, Artem B; Moghadasi, Mohammad; Alekseenko, Andrey; Beglov, Dmitri; Kozakov, Dima

    2018-01-01

    Fast Fourier transform (FFT) based approaches have been successful in application to modeling of relatively rigid protein-protein complexes. Recently, we have been able to adapt the FFT methodology to treatment of flexible protein-peptide interactions. Here, we report our latest attempt to expand the capabilities of the FFT approach to treatment of flexible protein-ligand interactions in application to the D3R PL-2016-1 challenge. Based on the D3R assessment, our FFT approach in conjunction with Monte Carlo minimization off-grid refinement was among the top performing methods in the challenge. The potential advantage of our method is its ability to globally sample the protein-ligand interaction landscape, which will be explored in further applications.

  12. Computational Approaches to the Chemical Equilibrium Constant in Protein-ligand Binding.

    Science.gov (United States)

    Montalvo-Acosta, Joel José; Cecchini, Marco

    2016-12-01

    The physiological role played by protein-ligand recognition has motivated the development of several computational approaches to the ligand binding affinity. Some of them, termed rigorous, have a strong theoretical foundation but involve too much computation to be generally useful. Some others alleviate the computational burden by introducing strong approximations and/or empirical calibrations, which also limit their general use. Most importantly, there is no straightforward correlation between the predictive power and the level of approximation introduced. Here, we present a general framework for the quantitative interpretation of protein-ligand binding based on statistical mechanics. Within this framework, we re-derive self-consistently the fundamental equations of some popular approaches to the binding constant and pinpoint the inherent approximations. Our analysis represents a first step towards the development of variants with optimum accuracy/efficiency ratio for each stage of the drug discovery pipeline. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Surface plasmon resonance spectroscopy for characterisation of membrane protein-ligand interactions and its potential for drug discovery.

    Science.gov (United States)

    Patching, Simon G

    2014-01-01

    Surface plasmon resonance (SPR) spectroscopy is a rapidly developing technique for the study of ligand binding interactions with membrane proteins, which are the major molecular targets for validated drugs and for current and foreseeable drug discovery. SPR is label-free and capable of measuring real-time quantitative binding affinities and kinetics for membrane proteins interacting with ligand molecules using relatively small quantities of materials and has potential to be medium-throughput. The conventional SPR technique requires one binding component to be immobilised on a sensor chip whilst the other binding component in solution is flowed over the sensor surface; a binding interaction is detected using an optical method that measures small changes in refractive index at the sensor surface. This review first describes the basic SPR experiment and the challenges that have to be considered for performing SPR experiments that measure membrane protein-ligand binding interactions, most importantly having the membrane protein in a lipid or detergent environment that retains its native structure and activity. It then describes a wide-range of membrane protein systems for which ligand binding interactions have been characterised using SPR, including the major drug targets G protein-coupled receptors, and how challenges have been overcome for achieving this. Finally it describes some recent advances in SPR-based technology and future potential of the technique to screen ligand binding in the discovery of drugs. This article is part of a Special Issue entitled: Structural and biophysical characterisation of membrane protein-ligand binding. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. An interaction-motif-based scoring function for protein-ligand docking

    Directory of Open Access Journals (Sweden)

    Xie Zhong-Ru

    2010-06-01

    Full Text Available Abstract Background A good scoring function is essential for molecular docking computations. In conventional scoring functions, energy terms modeling pairwise interactions are cumulatively summed, and the best docking solution is selected. Here, we propose to transform protein-ligand interactions into three-dimensional geometric networks, from which recurring network substructures, or network motifs, are selected and used to provide probability-ranked interaction templates with which to score docking solutions. Results A novel scoring function for protein-ligand docking, MotifScore, was developed. It is non-energy-based, and docking is, instead, scored by counting the occurrences of motifs of protein-ligand interaction networks constructed using structures of protein-ligand complexes. MotifScore has been tested on a benchmark set established by others to assess its ability to identify near-native complex conformations among a set of decoys. In this benchmark test, 84% of the highest-scored docking conformations had root-mean-square deviations (rmsds below 2.0 Å from the native conformation, which is comparable with the best of several energy-based docking scoring functions. Many of the top motifs, which comprise a multitude of chemical groups that interact simultaneously and make a highly significant contribution to MotifScore, capture recurrent interacting patterns beyond pairwise interactions. Conclusions While providing quite good docking scores, MotifScore is quite different from conventional energy-based functions. MotifScore thus represents a new, network-based approach for exploring problems associated with molecular docking.

  15. PSOVina: The hybrid particle swarm optimization algorithm for protein-ligand docking.

    Science.gov (United States)

    Ng, Marcus C K; Fong, Simon; Siu, Shirley W I

    2015-06-01

    Protein-ligand docking is an essential step in modern drug discovery process. The challenge here is to accurately predict and efficiently optimize the position and orientation of ligands in the binding pocket of a target protein. In this paper, we present a new method called PSOVina which combined the particle swarm optimization (PSO) algorithm with the efficient Broyden-Fletcher-Goldfarb-Shannon (BFGS) local search method adopted in AutoDock Vina to tackle the conformational search problem in docking. Using a diverse data set of 201 protein-ligand complexes from the PDBbind database and a full set of ligands and decoys for four representative targets from the directory of useful decoys (DUD) virtual screening data set, we assessed the docking performance of PSOVina in comparison to the original Vina program. Our results showed that PSOVina achieves a remarkable execution time reduction of 51-60% without compromising the prediction accuracies in the docking and virtual screening experiments. This improvement in time efficiency makes PSOVina a better choice of a docking tool in large-scale protein-ligand docking applications. Our work lays the foundation for the future development of swarm-based algorithms in molecular docking programs. PSOVina is freely available to non-commercial users at http://cbbio.cis.umac.mo .

  16. Accounting for conformational variability in protein-ligand docking with NMR-guided rescoring.

    Science.gov (United States)

    Skjærven, Lars; Codutti, Luca; Angelini, Andrea; Grimaldi, Manuela; Latek, Dorota; Monecke, Peter; Dreyer, Matthias K; Carlomagno, Teresa

    2013-04-17

    A key component to success in structure-based drug design is reliable information on protein-ligand interactions. Recent development in NMR techniques has accelerated this process by overcoming some of the limitations of X-ray crystallography and computational protein-ligand docking. In this work we present a new scoring protocol based on NMR-derived interligand INPHARMA NOEs to guide the selection of computationally generated docking modes. We demonstrate the performance in a range of scenarios, encompassing traditionally difficult cases such as docking to homology models and ligand dependent domain rearrangements. Ambiguities associated with sparse experimental information are lifted by searching a consensus solution based on simultaneously fitting multiple ligand pairs. This study provides a previously unexplored integration between molecular modeling and experimental data, in which interligand NOEs represent the key element in the rescoring algorithm. The presented protocol should be widely applicable for protein-ligand docking also in a different context from drug design and highlights the important role of NMR-based approaches to describe intermolecular ligand-receptor interactions.

  17. Business Information Exchange System with Security, Privacy, and Anonymity

    Directory of Open Access Journals (Sweden)

    Sead Muftic

    2016-01-01

    Full Text Available Business Information Exchange is an Internet Secure Portal for secure management, distribution, sharing, and use of business e-mails, documents, and messages. It has three applications supporting three major types of information exchange systems: secure e-mail, secure instant messaging, and secure sharing of business documents. In addition to standard security services for e-mail letters, which are also applied to instant messages and documents, the system provides innovative features of privacy and full anonymity of users and their locations, actions, transactions, and exchanged resources. In this paper we describe design, implementation, and use of the system.

  18. An Electric Bus with a Battery Exchange System

    Directory of Open Access Journals (Sweden)

    Jeongyong Kim

    2015-07-01

    Full Text Available As part of the ongoing effort to be independent of petroleum resources and to be free from pollutant emission issues, various electric vehicles have been developed and tested through their integration with real world systems. In the current paper, yet another application specific EV for public transportation, an electric bus, is introduced and explained with results from the pilot test program which was carried out under real traffic conditions. The main feature of the current system is a battery exchanging mechanism mounted on the roof of the bus. The current configuration certainly requires an externally fabricated battery exchanging robot system that would complement the electric bus for a fully automated battery exchanging process. The major advantage of the current system is the quick re-charging of the electric energy through the physical battery exchange and the possible utilization of the battery exchange station as a mini scale energy storage system for grid system peak power shaving. With the total system solution approach for the public transportation system, it is fully expected to create outstanding business opportunities in number of areas such as battery suppliers, battery exchanging station management, battery leasing and many more.

  19. Wireless health data exchange for home healthcare monitoring systems.

    Science.gov (United States)

    Lee, Malrey; Gatton, Thomas M

    2010-01-01

    Ubiquitous home healthcare systems have been playing an increasingly significant role in the treatment and management of chronic diseases, such as diabetes and hypertension, but progress has been hampered by the lack of standardization in the exchange of medical health care information. In an effort to establish standardization, this paper proposes a home healthcare monitoring system data exchange scheme between the HL7 standard and the IEEE1451 standard. IEEE1451 is a standard for special sensor networks, such as industrial control and smart homes, and defines a suite of interfaces that communicate among heterogeneous networks. HL7 is the standard for medical information exchange among medical organizations and medical personnel. While it provides a flexible data exchange in health care domains, it does not provide for data exchange with sensors. Thus, it is necessary to develop a data exchange schema to convert data between the HL7 and the IEEE1451 standard. This paper proposes a schema that can exchange data between HL7 devices and the monitoring device, and conforms to the IEEE 1451 standard. The experimental results and conclusions of this approach are presented and show the feasibility of the proposed exchange schema.

  20. Wireless Health Data Exchange for Home Healthcare Monitoring Systems

    Directory of Open Access Journals (Sweden)

    Malrey Lee

    2010-04-01

    Full Text Available Ubiquitous home healthcare systems have been playing an increasingly significant role in the treatment and management of chronic diseases, such as diabetes and hypertension, but progress has been hampered by the lack of standardization in the exchange of medical health care information. In an effort to establish standardization, this paper proposes a home healthcare monitoring system data exchange scheme between the HL7 standard and the IEEE1451 standard. IEEE1451 is a standard for special sensor networks, such as industrial control and smart homes, and defines a suite of interfaces that communicate among heterogeneous networks. HL7 is the standard for medical information exchange among medical organizations and medical personnel. While it provides a flexible data exchange in health care domains, it does not provide for data exchange with sensors. Thus, it is necessary to develop a data exchange schema to convert data between the HL7 and the IEEE1451 standard. This paper proposes a schema that can exchange data between HL7 devices and the monitoring device, and conforms to the IEEE 1451 standard. The experimental results and conclusions of this approach are presented and show the feasibility of the proposed exchange schema.

  1. Forging the Basis for Developing Protein-Ligand Interaction Scoring Functions.

    Science.gov (United States)

    Liu, Zhihai; Su, Minyi; Han, Li; Liu, Jie; Yang, Qifan; Li, Yan; Wang, Renxiao

    2017-02-21

    In structure-based drug design, scoring functions are widely used for fast evaluation of protein-ligand interactions. They are often applied in combination with molecular docking and de novo design methods. Since the early 1990s, a whole spectrum of protein-ligand interaction scoring functions have been developed. Regardless of their technical difference, scoring functions all need data sets combining protein-ligand complex structures and binding affinity data for parametrization and validation. However, data sets of this kind used to be rather limited in terms of size and quality. On the other hand, standard metrics for evaluating scoring function used to be ambiguous. Scoring functions are often tested in molecular docking or even virtual screening trials, which do not directly reflect the genuine quality of scoring functions. Collectively, these underlying obstacles have impeded the invention of more advanced scoring functions. In this Account, we describe our long-lasting efforts to overcome these obstacles, which involve two related projects. On the first project, we have created the PDBbind database. It is the first database that systematically annotates the protein-ligand complexes in the Protein Data Bank (PDB) with experimental binding data. This database has been updated annually since its first public release in 2004. The latest release (version 2016) provides binding data for 16 179 biomolecular complexes in PDB. Data sets provided by PDBbind have been applied to many computational and statistical studies on protein-ligand interaction and various subjects. In particular, it has become a major data resource for scoring function development. On the second project, we have established the Comparative Assessment of Scoring Functions (CASF) benchmark for scoring function evaluation. Our key idea is to decouple the "scoring" process from the "sampling" process, so scoring functions can be tested in a relatively pure context to reflect their quality. In our

  2. NMR structure determination of protein-ligand complexes by lanthanide labeling.

    Science.gov (United States)

    Pintacuda, Guido; John, Michael; Su, Xun-Cheng; Otting, Gottfried

    2007-03-01

    The paramagnetism of lanthanide ions offers outstanding opportunities for fast determinations of the three-dimensional (3D) structures of protein-ligand complexes by nuclear magnetic resonance (NMR) spectroscopy. It is shown how the combination of pseudocontact shifts (PCSs) induced by a site-specifically bound lanthanide ion and prior knowledge of the 3D structure of the lanthanide-labeled protein can be used to achieve (i) rapid assignments of NMR spectra, (ii) structure determinations of protein-protein complexes, and (iii) identification of the binding mode of low-molecular weight compounds in complexes with proteins. Strategies for site-specific incorporation of lanthanide ions into proteins are summarized.

  3. Research on Heat Exchange Process in Aircraft Air Conditioning System

    Science.gov (United States)

    Chichindaev, A. V.

    2017-11-01

    Using of heat-exchanger-condenser in the air conditioning system of the airplane Tu-204 (Boeing, Airbus, Superjet 100, MS-21, etc.) for cooling the compressed air by the cold air with negative temperature exiting the turbine results in a number of operational problems. Mainly it’s frosting of the heat exchange surface, which is the cause of live-section channels frosting, resistance increasing and airflow in the system decreasing. The purpose of this work is to analyse the known freeze-up-fighting methods for heat-exchanger-condenser, description of the features of anti-icing protection and offering solutions to this problem. For the problem of optimizing the design of heat exchangers in this work used generalized criterion that describes the ratio of thermal resistances of cold and hot sections, which include: the ratio of the initial values of heat transfer agents flow state; heat exchange surface finning coefficients; factors which describes the ratio of operating parameters and finning area. By controlling the ratio of the thermal resistances can be obtained the desired temperature of the heat exchange surface, which would prevent freezing. The work presents the results of a numerical study of the effect of different combinations of regime and geometrical factors changes on reduction of the heat-exchanger-condenser freezing surface area, including using of variable ratio of thermal resistances.

  4. Induced ferro-ferromagnetic exchange bias in nanocrystalline systems

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-García, J.C.; Rivas, M.; García, J.A.

    2015-03-01

    An unusual magnetic hysteresis consisting of horizontally shifted and distorted loops appears in some Co-based nanocrystalline systems in which soft and hard ferromagnetic phases coexist. The bias field can be tuned at room temperature by premagnetising treatments. Several works attributed the origin of this effect to the dipolar interaction, while little attention has been paid to the exchange interaction contribution due to its short-range nature. In this paper the relative importance of the dipolar and exchange interactions is investigated by means of micromagnetic simulations. It is demonstrated that the exchange coupling, though a nearest-neighbour interaction, has far-reaching repercussions in the magnetic configuration, and substantially prevails over the magnetostatic interaction as the cause of the asymmetrical magnetisation reversal. The straightforward conclusion is that we are dealing with a ferro-ferromagnetic exchange bias effect. - Highlights: • Magnetic biphase nanocrystalline systems with biased hysteresis loops are presented. • Computational calculations including magnetostatic and exchange interactions have been made. • Exchange interaction largely prevails as the cause of the biasing effect. • The biasing of HL is due to exchange coupling of both ferromagnetic phases. • Assuming monodomain behaviour for the crystals allows simulating the experimental HL.

  5. The Picture Exchange Communication System: Digital Photographs versus Picture Symbols

    Science.gov (United States)

    Jonaitis, Carmen

    2011-01-01

    The Picture Exchange Communication System (PECS) is an augmentative and alternative system (AAC) used to improve and increase communication for children with Autism Spectrum Disorder (ASD) and other developmental disorders. Research addressing the efficacy of this system is increasing; however, there is limited information published that evaluates…

  6. Implementation of Medical Information Exchange System Based on EHR Standard.

    Science.gov (United States)

    Han, Soon Hwa; Lee, Min Ho; Kim, Sang Guk; Jeong, Jun Yong; Lee, Bi Na; Choi, Myeong Seon; Kim, Il Kon; Park, Woo Sung; Ha, Kyooseob; Cho, Eunyoung; Kim, Yoon; Bae, Jae Bong

    2010-12-01

    To develop effective ways of sharing patients' medical information, we developed a new medical information exchange system (MIES) based on a registry server, which enabled us to exchange different types of data generated by various systems. To assure that patient's medical information can be effectively exchanged under different system environments, we adopted the standardized data transfer methods and terminologies suggested by the Center for Interoperable Electronic Healthcare Record (CIEHR) of Korea in order to guarantee interoperability. Regarding information security, MIES followed the security guidelines suggested by the CIEHR of Korea. This study aimed to develop essential security systems for the implementation of online services, such as encryption of communication, server security, database security, protection against hacking, contents, and network security. The registry server managed information exchange as well as the registration information of the clinical document architecture (CDA) documents, and the CDA Transfer Server was used to locate and transmit the proper CDA document from the relevant repository. The CDA viewer showed the CDA documents via connection with the information systems of related hospitals. This research chooses transfer items and defines document standards that follow CDA standards, such that exchange of CDA documents between different systems became possible through ebXML. The proposed MIES was designed as an independent central registry server model in order to guarantee the essential security of patients' medical information.

  7. Knowledge-based scoring function to predict protein-ligand interactions.

    Science.gov (United States)

    Gohlke, H; Hendlich, M; Klebe, G

    2000-01-14

    The development and validation of a new knowledge-based scoring function (DrugScore) to describe the binding geometry of ligands in proteins is presented. It discriminates efficiently between well-docked ligand binding modes (root-mean-square deviation Definition of an appropriate reference state and accounting for inaccuracies inherently present in experimental data is required to achieve good predictive power. The sum of the pair preferences and the singlet preferences is calculated based on the 3D structure of protein-ligand binding modes generated by docking tools. For two test sets of 91 and 68 protein-ligand complexes, taken from the Protein Data Bank (PDB), the calculated score recognizes poses generated by FlexX deviating <2 A from the crystal structure on rank 1 in three quarters of all possible cases. Compared to FlexX, this is a substantial improvement. For ligand geometries generated by DOCK, DrugScore is superior to the "chemical scoring" implemented into this tool, while comparable results are obtained using the "energy scoring" in DOCK. None of the presently known scoring functions achieves comparable power to extract binding modes in agreement with experiment. It is fast to compute, regards implicitly solvation and entropy contributions and produces correctly the geometry of directional interactions. Small deviations in the 3D structure are tolerated and, since only contacts to non-hydrogen atoms are regarded, it is independent from assumptions of protonation states. Copyright 2000 Academic Press.

  8. A D3R prospective evaluation of machine learning for protein-ligand scoring

    Science.gov (United States)

    Sunseri, Jocelyn; Ragoza, Matthew; Collins, Jasmine; Koes, David Ryan

    2016-09-01

    We assess the performance of several machine learning-based scoring methods at protein-ligand pose prediction, virtual screening, and binding affinity prediction. The methods and the manner in which they were trained make them sufficiently diverse to evaluate the utility of various strategies for training set curation and binding pose generation, but they share a novel approach to classification in the context of protein-ligand scoring. Rather than explicitly using structural data such as affinity values or information extracted from crystal binding poses for training, we instead exploit the abundance of data available from high-throughput screening to approach the problem as one of discriminating binders from non-binders. We evaluate the performance of our various scoring methods in the 2015 D3R Grand Challenge and find that although the merits of some features of our approach remain inconclusive, our scoring methods performed comparably to a state-of-the-art scoring function that was fit to binding affinity data.

  9. Challenges, Applications, and Recent Advances of Protein-Ligand Docking in Structure-Based Drug Design

    Directory of Open Access Journals (Sweden)

    Sam Z. Grinter

    2014-07-01

    Full Text Available The docking methods used in structure-based virtual database screening offer the ability to quickly and cheaply estimate the affinity and binding mode of a ligand for the protein receptor of interest, such as a drug target. These methods can be used to enrich a database of compounds, so that more compounds that are subsequently experimentally tested are found to be pharmaceutically interesting. In addition, like all virtual screening methods used for drug design, structure-based virtual screening can focus on curated libraries of synthesizable compounds, helping to reduce the expense of subsequent experimental verification. In this review, we introduce the protein-ligand docking methods used for structure-based drug design and other biological applications. We discuss the fundamental challenges facing these methods and some of the current methodological topics of interest. We also discuss the main approaches for applying protein-ligand docking methods. We end with a discussion of the challenging aspects of evaluating or benchmarking the accuracy of docking methods for their improvement, and discuss future directions.

  10. Automated identification of protein-ligand interaction features using Inductive Logic Programming: a hexose binding case study

    Directory of Open Access Journals (Sweden)

    A Santos Jose C

    2012-07-01

    Full Text Available Abstract Background There is a need for automated methods to learn general features of the interactions of a ligand class with its diverse set of protein receptors. An appropriate machine learning approach is Inductive Logic Programming (ILP, which automatically generates comprehensible rules in addition to prediction. The development of ILP systems which can learn rules of the complexity required for studies on protein structure remains a challenge. In this work we use a new ILP system, ProGolem, and demonstrate its performance on learning features of hexose-protein interactions. Results The rules induced by ProGolem detect interactions mediated by aromatics and by planar-polar residues, in addition to less common features such as the aromatic sandwich. The rules also reveal a previously unreported dependency for residues cys and leu. They also specify interactions involving aromatic and hydrogen bonding residues. This paper shows that Inductive Logic Programming implemented in ProGolem can derive rules giving structural features of protein/ligand interactions. Several of these rules are consistent with descriptions in the literature. Conclusions In addition to confirming literature results, ProGolem’s model has a 10-fold cross-validated predictive accuracy that is superior, at the 95% confidence level, to another ILP system previously used to study protein/hexose interactions and is comparable with state-of-the-art statistical learners.

  11. Comparative field performance of three different gas exchange systems

    Directory of Open Access Journals (Sweden)

    G. F. Midgley

    1997-12-01

    Full Text Available We compared portable and continuously monitoring gas exchange systems under field conditions, using Protea glabra Thunb. as a test species. The aim was to determine if the same patterns of gas exchange and ancillary parameters could be obtained with rather different measurement systems, and whether the same interpretation and conclusions about environmental control of gas exchange could be drawn. The following systems were compared: 1, a ‘closed’ portable 1RGA manufactured by Ll-Cor (LI-6200; 2, an ‘open’ portable porometer manufactured by Walz; and 3, a continuously monitoring minicuvette system with temperature control facility, also manufactured by Walz. All three systems yielded similar diurnal curves for CO2  uptake, although absolute flux values for the minicuvette system were lower than those obtained for the portable systems. This was likely due to stem respiration and self-shading of leaves on the shoot enclosed in the minicuvette. Differences in sampling technique between the two portable systems, primarily with regard to changes in leaf orientation, resulted in some differences in absolute values of gas fluxes and ancillary parameters such as leaf temperature and leaf to air vapour pressure difference. However, data from all three systems allowed similar interpretations to be made about the environmental dependencies of gas exchange patterns. It appears that each system has certain drawbacks associated with widely varying field conditions. A combination of portable and continuous monitoring techniques would seem to be the most powerful approach to investigating the gas exchange patterns of terrestrial plants in their natural environment.

  12. Standard Data Exchanges for Distribution System Management

    Energy Technology Data Exchange (ETDEWEB)

    Thomas E. McDermott

    2007-10-05

    Databases and software tools for electric power distribution systems have not been integrated, and this leads to extra costs and restrictions imposed on utilities and other stakeholders. For example, distributed resource integration studies and modern grid technology assessments are more difficult and costly. New vendors face high market entry barriers, because it’s necessary to interface with large and customized data systems at each potential utility customer. This project promotes data and software tool integration, through a set of data translators based on a common object model. The data translators are delivered as open-source software, using appropriate Web software technologies. The parties who benefit include electric utilities (and their ratepayers), researchers at government laboratories and universities, small software companies wishing to enter the electric utility market, and parties wishing to interconnect distributed generation to a utility system.

  13. Descriptor Data Bank (DDB): A Cloud Platform for Multiperspective Modeling of Protein-Ligand Interactions.

    Science.gov (United States)

    Ashtawy, Hossam M; Mahapatra, Nihar R

    2018-01-22

    Protein-ligand (PL) interactions play a key role in many life processes such as molecular recognition, molecular binding, signal transmission, and cell metabolism. Examples of interaction forces include hydrogen bonding, hydrophobic effects, steric clashes, electrostatic contacts, and van der Waals attractions. Currently, a large number of hypotheses and perspectives to model these interaction forces are scattered throughout the literature and largely forgotten. Instead, had they been assembled and utilized collectively, they would have substantially improved the accuracy of predicting binding affinity of protein-ligand complexes. In this work, we present Descriptor Data Bank (DDB), a data-driven platform on the cloud for facilitating multiperspective modeling of PL interactions. DDB is an open-access hub for depositing, hosting, executing, and sharing descriptor extraction tools and data for a large number of interaction modeling hypotheses. The platform also implements a machine-learning (ML) toolbox for automatic descriptor filtering and analysis and scoring function (SF) fitting and prediction. The descriptor filtering module is used to filter out irrelevant and/or noisy descriptors and to produce a compact subset from all available features. We seed DDB with 16 diverse descriptor extraction tools developed in-house and collected from the literature. The tools altogether generate over 2700 descriptors that characterize (i) proteins, (ii) ligands, and (iii) protein-ligand complexes. The in-house descriptors we extract are protein-specific which are based on pairwise primary and tertiary alignment of protein structures followed by clustering and trilateration. We built and used DDB's ML library to fit SFs to the in-house descriptors and those collected from the literature. We then evaluated them on several data sets that were constructed to reflect real-world drug screening scenarios. We found that multiperspective SFs that were constructed using a large number

  14. The XChemExplorer graphical workflow tool for routine or large-scale protein-ligand structure determination.

    Science.gov (United States)

    Krojer, Tobias; Talon, Romain; Pearce, Nicholas; Collins, Patrick; Douangamath, Alice; Brandao-Neto, Jose; Dias, Alexandre; Marsden, Brian; von Delft, Frank

    2017-03-01

    XChemExplorer (XCE) is a data-management and workflow tool to support large-scale simultaneous analysis of protein-ligand complexes during structure-based ligand discovery (SBLD). The user interfaces of established crystallographic software packages such as CCP4 [Winn et al. (2011), Acta Cryst. D67, 235-242] or PHENIX [Adams et al. (2010), Acta Cryst. D66, 213-221] have entrenched the paradigm that a `project' is concerned with solving one structure. This does not hold for SBLD, where many almost identical structures need to be solved and analysed quickly in one batch of work. Functionality to track progress and annotate structures is essential. XCE provides an intuitive graphical user interface which guides the user from data processing, initial map calculation, ligand identification and refinement up until data dissemination. It provides multiple entry points depending on the need of each project, enables batch processing of multiple data sets and records metadata, progress and annotations in an SQLite database. XCE is freely available and works on any Linux and Mac OS X system, and the only dependency is to have the latest version of CCP4 installed. The design and usage of this tool are described here, and its usefulness is demonstrated in the context of fragment-screening campaigns at the Diamond Light Source. It is routinely used to analyse projects comprising 1000 data sets or more, and therefore scales well to even very large ligand-design projects.

  15. Composition of Overlapping Protein-Protein and Protein-Ligand Interfaces.

    Directory of Open Access Journals (Sweden)

    Ruzianisra Mohamed

    Full Text Available Protein-protein interactions (PPIs play a major role in many biological processes and they represent an important class of targets for therapeutic intervention. However, targeting PPIs is challenging because often no convenient natural substrates are available as starting point for small-molecule design. Here, we explored the characteristics of protein interfaces in five non-redundant datasets of 174 protein-protein (PP complexes, and 161 protein-ligand (PL complexes from the ABC database, 436 PP complexes, and 196 PL complexes from the PIBASE database and a dataset of 89 PL complexes from the Timbal database. In all cases, the small molecule ligands must bind at the respective PP interface. We observed similar amino acid frequencies in all three datasets. Remarkably, also the characteristics of PP contacts and overlapping PL contacts are highly similar.

  16. Influence of Alkylammonium Acetate Buffers on Protein-Ligand Noncovalent Interactions Using Native Mass Spectrometry

    Science.gov (United States)

    Zhuang, Xiaoyu; Gavriilidou, Agni F. M.; Zenobi, Renato

    2017-02-01

    We investigate the influence of three volatile alkylammonium acetate buffers on binding affinities for protein-ligand interactions determined by native electrospray ionization-mass spectrometry (ESI-MS). Four different types of proteins were chosen for this study. A charge-reduction effect was observed for all the cases studied, in comparison to the ions formed in ammonium acetate solution. When increasing the collision energy, the complexes of trypsin and the ligand were found to be more stable when sprayed from alkylammonium acetate buffers than from ammonium acetate. The determined dissociation constant (Kd) also exhibited a drop (up to 40%) when ammonium acetate was replaced by alkylammonium acetate buffers for the case of lysozyme and the ligand. The prospective uses of these ammonium acetate analogs in native ESI-MS are discussed in this paper as well.

  17. Protein-ligand interactions investigated by thermal shift assays (TSA) and dual polarization interferometry (DPI).

    Science.gov (United States)

    Grøftehauge, Morten K; Hajizadeh, Nelly R; Swann, Marcus J; Pohl, Ehmke

    2015-01-01

    Over the last decades, a wide range of biophysical techniques investigating protein-ligand interactions have become indispensable tools to complement high-resolution crystal structure determinations. Current approaches in solution range from high-throughput-capable methods such as thermal shift assays (TSA) to highly accurate techniques including microscale thermophoresis (MST) and isothermal titration calorimetry (ITC) that can provide a full thermodynamic description of binding events. Surface-based methods such as surface plasmon resonance (SPR) and dual polarization interferometry (DPI) allow real-time measurements and can provide kinetic parameters as well as binding constants. DPI provides additional spatial information about the binding event. Here, an account is presented of new developments and recent applications of TSA and DPI connected to crystallography.

  18. Training Paraprofessionals to Implement the Picture Exchange Communication System (PECS)

    Science.gov (United States)

    Sloman, Glenn Matthew

    2010-01-01

    Based on Skinner's "Verbal Behavior" (1957), the picture exchange communication system (PECS) was designed to teach children with autism functional verbal behavior. Much research has demonstrated the effectiveness and efficiency of PECS in building verbal behavior. However, because PECS training is typically presented in a group format and later…

  19. Data Exchange Inventory System for Telecommunications and Systems Operations (DEXI-OTSO)

    Data.gov (United States)

    Social Security Administration — This Data Exchange Inventory (DEXI) for the Office of Telecommunications and System Operations, (OTSO) Network Troubleshooting is a browser-based inventory database...

  20. Interfacial spin cluster effects in exchange bias systems

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, R., E-mail: rc548@york.ac.uk; Vallejo-Fernandez, G.; O' Grady, K. [Department of Physics, The University of York, York YO10 5DD (United Kingdom)

    2014-05-07

    In this work, the effect of exchange bias on the hysteresis loop of CoFe is observed. The evolution of the coercivities and the shift of the hysteresis loop during the annealing process has been measured for films deposited on NiCr and Cu seed layers. Through comparison of the as deposited and field annealed loops, it is clear that for an exchange biased material, the two coercivities are due to different reversal processes. This behaviour is attributed to spin clusters at the ferromagnet/antiferromagnet interface, which behave in a similar manner to a fine particle system.

  1. Exchange bias of patterned systems: Model and numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Griselda [Facultad de Fisica, P. Universidad Catolica de Chile, Casilla 306, Santiago 7820436 (Chile); Centro para el Desarrollo de la Nanociencia y la Nanotecnologia, CEDENNA, Avda. Ecuador 3493, Santiago (Chile); Kiwi, Miguel, E-mail: mkiwi@puc.c [Facultad de Fisica, P. Universidad Catolica de Chile, Casilla 306, Santiago 7820436 (Chile); Centro para el Desarrollo de la Nanociencia y la Nanotecnologia, CEDENNA, Avda. Ecuador 3493, Santiago (Chile); Mejia-Lopez, Jose; Ramirez, Ricardo [Facultad de Fisica, P. Universidad Catolica de Chile, Casilla 306, Santiago 7820436 (Chile); Centro para el Desarrollo de la Nanociencia y la Nanotecnologia, CEDENNA, Avda. Ecuador 3493, Santiago (Chile)

    2010-11-15

    The magnitude of the exchange bias field of patterned systems exhibits a notable increase in relation to the usual bilayer systems, where a continuous ferromagnetic film is deposited on an antiferromagnet insulator. Here we develop a model, and implement a Monte Carlo calculation, to interpret the experimental observations which is consistent with experimental results, on the basis of assuming a small fraction of spins pinned ferromagnetically in the antiferromagnetic interface layer.

  2. Thermal energy storage systems using fluidized bed heat exchangers

    Science.gov (United States)

    Ramanathan, V.; Weast, T. E.; Ananth, K. P.

    1980-01-01

    The viability of using fluidized bed heat exchangers (FBHX) for thermal energy storage (TES) in applications with potential for waste heat recovery was investigated. Of the candidate applications screened, cement plant rotary kilns and steel plant electric arc furnaces were identified, via the chosen selection criteria, as having the best potential for successful use of FBHX/TES system. A computer model of the FBHX/TES systems was developed and the technical feasibility of the two selected applications was verified. Economic and tradeoff evaluations in progress for final optimization of the systems and selection of the most promising system for further concept validation are described.

  3. Materials, Turbomachinery and Heat Exchangers for Supercritical CO2 Systems

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Mark; Nellis, Greg; Corradini, Michael

    2012-10-19

    The objective of this project is to produce the necessary data to evaluate the performance of the supercritical carbon dioxide cycle. The activities include a study of materials compatibility of various alloys at high temperatures, the heat transfer and pressure drop in compact heat exchanger units, and turbomachinery issues, primarily leakage rates through dynamic seals. This experimental work will serve as a test bed for model development and design calculations, and will help define further tests necessary to develop high-efficiency power conversion cycles for use on a variety of reactor designs, including the sodium fast reactor (SFR) and very high-temperature gas reactor (VHTR). The research will be broken into three separate tasks. The first task deals with the analysis of materials related to the high-temperature S-CO{sub 2} Brayton cycle. The most taxing materials issues with regard to the cycle are associated with the high temperatures in the reactor side heat exchanger and in the high-temperature turbine. The system could experience pressures as high as 20MPa and temperatures as high as 650°C. The second task deals with optimization of the heat exchangers required by the S-CO{sub 2} cycle; the S-CO{sub 2} flow passages in these heat exchangers are required whether the cycle is coupled with a VHTR or an SFR. At least three heat exchangers will be required: the pre-cooler before compression, the recuperator, and the heat exchanger that interfaces with the reactor coolant. Each of these heat exchangers is unique and must be optimized separately. The most challenging heat exchanger is likely the pre-cooler, as there is only about a 40°C temperature change but it operates close to the CO{sub 2} critical point, therefore inducing substantial changes in properties. The proposed research will focus on this most challenging component. The third task examines seal leakage through various dynamic seal designs under the conditions expected in the S-CO{sub 2} cycle

  4. Update on Modular Laser Launch System and Heat Exchanger Thruster

    Science.gov (United States)

    Kare, Jordin T.

    2011-11-01

    The heat-exchanger (HX) thruster and modular laser array provide a comparatively low-risk route to a ground-to-orbit laser launch system. Recently, the reference designs for the propulsion system, laser array, and overall launch system have evolved significantly. By combining a variable flow of dense propellant with the primary hydrogen propellant, the heat exchanger thruster can trade reduced Isp for increased thrust at liftoff, with minimal increase in tank mass. Single-mode CW fiber lasers up to 10 kW power allow a beam module to be built with off-the-shelf commercial lasers. Low-cost high-radiance laser diode arrays can deliver launch-level fluxes of 5-10 MW/m2 over tens of kilometers, sufficient to power a vehicle through the atmosphere, and high enough to hand off propulsion to a main laser array several hundred kilometers downrange. These and other enhancements enable a system design with a true single-stage vehicle in which the only component not yet demonstrated is the silicon-carbide heat exchanger itself.

  5. Thermal Analysis for Ion-Exchange Column System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Si Y.; King, William D.

    2012-12-20

    Models have been developed to simulate the thermal characteristics of crystalline silicotitanate ion exchange media fully loaded with radioactive cesium either in a column configuration or distributed within a waste storage tank. This work was conducted to support the design and operation of a waste treatment process focused on treating dissolved, high-sodium salt waste solutions for the removal of specific radionuclides. The ion exchange column will be installed inside a high level waste storage tank at the Savannah River Site. After cesium loading, the ion exchange media may be transferred to the waste tank floor for interim storage. Models were used to predict temperature profiles in these areas of the system where the cesium-loaded media is expected to lead to localized regions of elevated temperature due to radiolytic decay. Normal operating conditions and accident scenarios (including loss of solution flow, inadvertent drainage, and loss of active cooling) were evaluated for the ion exchange column using bounding conditions to establish the design safety basis. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature. In-tank modeling results revealed that an idealized hemispherical mound shape leads to the highest tank floor temperatures. In contrast, even large volumes of CST distributed in a flat layer with a cylindrical shape do not result in significant floor heating.

  6. istar: a web platform for large-scale protein-ligand docking.

    Science.gov (United States)

    Li, Hongjian; Leung, Kwong-Sak; Ballester, Pedro J; Wong, Man-Hon

    2014-01-01

    Protein-ligand docking is a key computational method in the design of starting points for the drug discovery process. We are motivated by the desire to automate large-scale docking using our popular docking engine idock and thus have developed a publicly-accessible web platform called istar. Without tedious software installation, users can submit jobs using our website. Our istar website supports 1) filtering ligands by desired molecular properties and previewing the number of ligands to dock, 2) monitoring job progress in real time, and 3) visualizing ligand conformations and outputting free energy and ligand efficiency predicted by idock, binding affinity predicted by RF-Score, putative hydrogen bonds, and supplier information for easy purchase, three useful features commonly lacked on other online docking platforms like DOCK Blaster or iScreen. We have collected 17,224,424 ligands from the All Clean subset of the ZINC database, and revamped our docking engine idock to version 2.0, further improving docking speed and accuracy, and integrating RF-Score as an alternative rescoring function. To compare idock 2.0 with the state-of-the-art AutoDock Vina 1.1.2, we have carried out a rescoring benchmark and a redocking benchmark on the 2,897 and 343 protein-ligand complexes of PDBbind v2012 refined set and CSAR NRC HiQ Set 24Sept2010 respectively, and an execution time benchmark on 12 diverse proteins and 3,000 ligands of different molecular weight. Results show that, under various scenarios, idock achieves comparable success rates while outperforming AutoDock Vina in terms of docking speed by at least 8.69 times and at most 37.51 times. When evaluated on the PDBbind v2012 core set, our istar platform combining with RF-Score manages to reproduce Pearson's correlation coefficient and Spearman's correlation coefficient of as high as 0.855 and 0.859 respectively between the experimental binding affinity and the predicted binding affinity of the docked conformation. istar

  7. Condensing Heat Exchanger Concept Developed for Space Systems

    Science.gov (United States)

    Hasan, Mohammad M.; Nayagam, Vedha

    2005-01-01

    The current system for moisture removal and humidity control for the space shuttles and the International Space Station uses a two-stage process. Water first condenses onto fins and is pulled through "slurper bars." These bars take in a two-phase mixture of air and water that is then separated by the rotary separator. A more efficient design would remove the water directly from the air without the need of an additional water separator downstream. For the Condensing Heat Exchanger for Space Systems (CHESS) project, researchers at the NASA Glenn Research Center in collaboration with NASA Johnson Space Center are designing a condensing heat exchanger that utilizes capillary forces to collect and remove water and that can operate in varying gravitational conditions including microgravity, lunar gravity, and Martian gravity.

  8. Exchange Bias Effects in Iron Oxide-Based Nanoparticle Systems

    Science.gov (United States)

    Phan, Manh-Huong; Alonso, Javier; Khurshid, Hafsa; Lampen-Kelley, Paula; Chandra, Sayan; Stojak Repa, Kristen; Nemati, Zohreh; Das, Raja; Iglesias, Óscar; Srikanth, Hariharan

    2016-01-01

    The exploration of exchange bias (EB) on the nanoscale provides a novel approach to improving the anisotropic properties of magnetic nanoparticles for prospective applications in nanospintronics and nanomedicine. However, the physical origin of EB is not fully understood. Recent advances in chemical synthesis provide a unique opportunity to explore EB in a variety of iron oxide-based nanostructures ranging from core/shell to hollow and hybrid composite nanoparticles. Experimental and atomistic Monte Carlo studies have shed light on the roles of interface and surface spins in these nanosystems. This review paper aims to provide a thorough understanding of the EB and related phenomena in iron oxide-based nanoparticle systems, knowledge of which is essential to tune the anisotropic magnetic properties of exchange-coupled nanoparticle systems for potential applications. PMID:28335349

  9. 40 CFR 63.654 - Heat exchange systems.

    Science.gov (United States)

    2010-07-01

    ... any one of the criteria in paragraphs (b)(1) through (2) of this section. (1) All heat exchangers that... any heat exchangers that are in organic HAP service as defined in this subpart). (c) The owner or... each heat exchanger exit line for each heat exchanger or group of heat exchangers in organic HAP...

  10. 40 CFR 63.1409 - Heat exchange system provisions.

    Science.gov (United States)

    2010-07-01

    ... locations where the cooling water enters and exits each heat exchanger or any combination of heat exchangers.... (iii) For samples taken at the entrance and exit of each heat exchanger or any combination of heat exchangers, the entrance is the point at which the cooling water enters the individual heat exchanger or...

  11. Modeling Of Proton Exchange Membrane Fuel Cell Systems

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh

    The objective of this doctoral thesis was to develop reliable steady-state and transient component models suitable to asses-, develop- and optimize proton exchange membrane (PEM) fuel cell systems. Several components in PEM fuel cell systems were characterized and modeled. The developed component...... cell systems. Consequences of indirectly fueling PEM stacks with hydrocarbons using reforming technology were investigated using a PEM stack model including CO poisoning kinetics and a transient Simulink steam reforming system model. Aspects regarding the optimization of PEM fuel cell systems......- and system models match experimental data from the literature. However, limited data were available for verification so further work is necessary to confirm detailed aspects of the models. It is nonetheless expected that the developed models will be useful for system modeling and optimization of PEM fuel...

  12. Specific noncovalent interactions at protein-ligand interface: implications for rational drug design.

    Science.gov (United States)

    Zhou, P; Huang, J; Tian, F

    2012-01-01

    Specific noncovalent interactions that are indicative of attractive, directional intermolecular forces have always been of key interest to medicinal chemists in their search for the "glue" that holds drugs and their targets together. With the rapid increase in the number of solved biomolecular structures as well as the performance enhancement of computer hardware and software in recent years, it is now possible to give more comprehensive insight into the geometrical characteristics and energetic landscape of certain sophisticated noncovalent interactions present at the binding interface of protein receptors and small ligands based on accumulated knowledge gaining from the combination of two quite disparate but complementary approaches: crystallographic data analysis and quantum-mechanical ab initio calculation. In this perspective, we survey massive body of published works relating to structural characterization and theoretical investigation of three kinds of strong, specific, direct, enthalpy-driven intermolecular forces, including hydrogen bond, halogen bond and salt bridge, involved in the formation of protein-ligand complex architecture in order to characterize their biological functions in conferring affinity and specificity for ligand recognition by host protein. In particular, the biomedical implications of raised knowledge are discussed with respect to potential applications in rational drug design.

  13. LiGRO: a graphical user interface for protein-ligand molecular dynamics.

    Science.gov (United States)

    Kagami, Luciano Porto; das Neves, Gustavo Machado; da Silva, Alan Wilter Sousa; Caceres, Rafael Andrade; Kawano, Daniel Fábio; Eifler-Lima, Vera Lucia

    2017-10-04

    To speed up the drug-discovery process, molecular dynamics (MD) calculations performed in GROMACS can be coupled to docking simulations for the post-screening analyses of large compound libraries. This requires generating the topology of the ligands in different software, some basic knowledge of Linux command lines, and a certain familiarity in handling the output files. LiGRO-the python-based graphical interface introduced here-was designed to overcome these protein-ligand parameterization challenges by allowing the graphical (non command line-based) control of GROMACS (MD and analysis), ACPYPE (ligand topology builder) and PLIP (protein-binder interactions monitor)-programs that can be used together to fully perform and analyze the outputs of complex MD simulations (including energy minimization and NVT/NPT equilibration). By allowing the calculation of linear interaction energies in a simple and quick fashion, LiGRO can be used in the drug-discovery pipeline to select compounds with a better protein-binding interaction profile. The design of LiGRO allows researchers to freely download and modify the software, with the source code being available under the terms of a GPLv3 license from http://www.ufrgs.br/lasomfarmacia/ligro/ .

  14. Optimizing the Heat Exchanger Network of a Steam Reforming System

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh; Korsgaard, Anders Risum; Kær, Søren Knudsen

    2004-01-01

    gas steam reformer along with gas purification reactors to generate clean hydrogen suited for a PEM stack. The temperatures in the various reactors in the fuel processing system vary from around 1000°C to the stack temperature at 80°C. Furthermore, external heating must be supplied to the endothermic...... steam reforming reaction and steam must be generated. The dependence of the temperature profiles on conversion in shift reactors for gas purification is also significant. The optimum heat integration in the system is thus imperative in order to minimize the need for hot and cold utilities. A rigorous 1D......Proton Exchange Membrane (PEM) based combined heat and power production systems are highly integrated energy systems. They may include a hydrogen production system and fuel cell stacks along with post combustion units optionally coupled with gas turbines. The considered system is based on a natural...

  15. Standards, Data Exchange and Intellectual Property Rights in Systems Biology

    DEFF Research Database (Denmark)

    van Zimmeren, Esther; Rutz, Berthold; Minssen, Timo

    2016-01-01

    assets to be formatted and described in standard ways to enable exchange and reuse of high quality data. This allows a more effective utilisation of the enormous potential that rests in “big data” analysis. Finally, SysBio is often closely linked to or provides the foundation for Synthetic Biology (Syn...... we provided a number of recommendations for a variety of stakeholders. The current article offers some deeper reflections about the interface between IPRs, standards and data exchange in Systems Biology resulting from an Expert Meeting funded by another ERA-Net, ERASysAPP. The meeting brought...... and qualitative data on biological processes and activities in much greater volumes, velocity, variety and veracity. The skilful integration of multiple heterogeneous data sets allows scientists to model and predict biological processes. SysBio’s interdisciplinary nature requires data, models and other research...

  16. A Freezable Heat Exchanger for Space Suit Radiator Systems

    Science.gov (United States)

    Nabity, James A.; Mason, Georgia R.; Copeland, Robert J.; Trevino, Luis a.

    2008-01-01

    During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut s metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment and the load from the electrical components. Although the sublimator hardware to reject this load weighs only 1.58 kg (3.48 lbm), an additional 3.6 kg (8 lbm) of water are loaded into the unit, most of which is sublimated and lost to space, thus becoming the single largest expendable during an eight-hour EVA. Using a radiator to reject heat from the astronaut during an EVA can reduce the amount of expendable water consumed in the sublimator. Radiators have no moving parts and are thus highly reliable. Past freezable radiators have been too heavy, but the weight can be greatly reduced by placing a small and freeze tolerant heat exchanger between the astronaut and radiator, instead of making the very large radiator freeze tolerant. Therefore, the key technological innovation to improve space suit radiator performance was the development of a lightweight and freezable heat exchanger that accommodates the variable heat load generated by the astronaut. Herein, we present the heat transfer performance of a newly designed heat exchanger that endured several freeze / thaw cycles without any apparent damage. The heat exchanger was also able to continuously turn down or turn up the heat rejection to follow the variable load.

  17. A microprocessor-based system for measurement of gas exchange.

    Science.gov (United States)

    Jaffe, M B; Frick, G; Wilson, D; Johnston, M; Reid, H; Foster, S; Norton, A C

    1984-10-01

    The basic physical measurements for determining gas exchange are difficult to make accurately even in a well-equipped, human-performance laboratory with experienced personnel. A fully automated system has been developed to achieve the accuracy of standard laboratory measurements. The application of this instrument extends from critical care to stress-testing. Real-time, multitasking software integrates the data collected from several transducers and analyzers and calculates up to several dozen physiological variables, which are range-checked for reasonableness. The operator is provided with user-friendly means to tailor the data-reporting and- collection functions of the system to his own needs and requirements. Because the instrument is controlled by software, the functions of calibration, measurement, timing, reporting, plotting, and data quality assurance are highly cost-effective. Extensive use of formal test procedures permits verifying all systems and data reliability; it also assures meeting the desired specifications. The ease of operation and high-quality results inherent in this system make it unsurpassed in gas-exchange measurements.

  18. Exploring the composition of protein-ligand binding sites on a large scale.

    Directory of Open Access Journals (Sweden)

    Nickolay A Khazanov

    Full Text Available The residue composition of a ligand binding site determines the interactions available for diffusion-mediated ligand binding, and understanding general composition of these sites is of great importance if we are to gain insight into the functional diversity of the proteome. Many structure-based drug design methods utilize such heuristic information for improving prediction or characterization of ligand-binding sites in proteins of unknown function. The Binding MOAD database if one of the largest curated sets of protein-ligand complexes, and provides a source of diverse, high-quality data for establishing general trends of residue composition from currently available protein structures. We present an analysis of 3,295 non-redundant proteins with 9,114 non-redundant binding sites to identify residues over-represented in binding regions versus the rest of the protein surface. The Binding MOAD database delineates biologically-relevant "valid" ligands from "invalid" small-molecule ligands bound to the protein. Invalids are present in the crystallization medium and serve no known biological function. Contacts are found to differ between these classes of ligands, indicating that residue composition of biologically relevant binding sites is distinct not only from the rest of the protein surface, but also from surface regions capable of opportunistic binding of non-functional small molecules. To confirm these trends, we perform a rigorous analysis of the variation of residue propensity with respect to the size of the dataset and the content bias inherent in structure sets obtained from a large protein structure database. The optimal size of the dataset for establishing general trends of residue propensities, as well as strategies for assessing the significance of such trends, are suggested for future studies of binding-site composition.

  19. A machine learning approach to predicting protein-ligand binding affinity with applications to molecular docking.

    Science.gov (United States)

    Ballester, Pedro J; Mitchell, John B O

    2010-05-01

    Accurately predicting the binding affinities of large sets of diverse protein-ligand complexes is an extremely challenging task. The scoring functions that attempt such computational prediction are essential for analysing the outputs of molecular docking, which in turn is an important technique for drug discovery, chemical biology and structural biology. Each scoring function assumes a predetermined theory-inspired functional form for the relationship between the variables that characterize the complex, which also include parameters fitted to experimental or simulation data and its predicted binding affinity. The inherent problem of this rigid approach is that it leads to poor predictivity for those complexes that do not conform to the modelling assumptions. Moreover, resampling strategies, such as cross-validation or bootstrapping, are still not systematically used to guard against the overfitting of calibration data in parameter estimation for scoring functions. We propose a novel scoring function (RF-Score) that circumvents the need for problematic modelling assumptions via non-parametric machine learning. In particular, Random Forest was used to implicitly capture binding effects that are hard to model explicitly. RF-Score is compared with the state of the art on the demanding PDBbind benchmark. Results show that RF-Score is a very competitive scoring function. Importantly, RF-Score's performance was shown to improve dramatically with training set size and hence the future availability of more high-quality structural and interaction data is expected to lead to improved versions of RF-Score. pedro.ballester@ebi.ac.uk; jbom@st-andrews.ac.uk Supplementary data are available at Bioinformatics online.

  20. ConsDock: A new program for the consensus analysis of protein-ligand interactions.

    Science.gov (United States)

    Paul, Nicodème; Rognan, Didier

    2002-06-01

    Protein-based virtual screening of chemical libraries is a powerful technique for identifying new molecules that may interact with a macromolecular target of interest. Because of docking and scoring limitations, it is more difficult to apply as a lead optimization method because it requires that the docking/scoring tool is able to propose as few solutions as possible and all of them with a very good accuracy for both the protein-bound orientation and the conformation of the ligand. In the present study, we present a consensus docking approach (ConsDock) that takes advantage of three widely used docking tools (Dock, FlexX, and Gold). The consensus analysis of all possible poses generated by several docking tools is performed sequentially in four steps: (i) hierarchical clustering of all poses generated by a docking tool into families represented by a leader; (ii) definition of all consensus pairs from leaders generated by different docking programs; (iii) clustering of consensus pairs into classes, represented by a mean structure; and (iv) ranking the different means starting from the most populated class of consensus pairs. When applied to a test set of 100 protein-ligand complexes from the Protein Data Bank, ConsDock significantly outperforms single docking with respect to the docking accuracy of the top-ranked pose. In 60% of the cases investigated here, ConsDock was able to rank as top solution a pose within 2 A RMSD of the X-ray structure. It can be applied as a postprocessing filter to either single- or multiple-docking programs to prioritize three-dimensional guided lead optimization from the most likely docking solution. Copyright 2002 Wiley-Liss, Inc.

  1. Consistent two-dimensional visualization of protein-ligand complex series

    Directory of Open Access Journals (Sweden)

    Stierand Katrin

    2011-06-01

    Full Text Available Abstract Background The comparative two-dimensional graphical representation of protein-ligand complex series featuring different ligands bound to the same active site offers a quick insight in their binding mode differences. In comparison to arbitrary orientations of the residue molecules in the individual complex depictions a consistent placement improves the legibility and comparability within the series. The automatic generation of such consistent layouts offers the possibility to apply it to large data sets originating from computer-aided drug design methods. Results We developed a new approach, which automatically generates a consistent layout of interacting residues for a given series of complexes. Based on the structural three-dimensional input information, a global two-dimensional layout for all residues of the complex ensemble is computed. The algorithm incorporates the three-dimensional adjacencies of the active site residues in order to find an universally valid circular arrangement of the residues around the ligand. Subsequent to a two-dimensional ligand superimposition step, a global placement for each residue is derived from the set of already placed ligands. The method generates high-quality layouts, showing mostly overlap-free solutions with molecules which are displayed as structure diagrams providing interaction information in atomic detail. Application examples document an improved legibility compared to series of diagrams whose layouts are calculated independently from each other. Conclusions The presented method extends the field of complex series visualizations. A series of molecules binding to the same protein active site is drawn in a graphically consistent way. Compared to existing approaches these drawings substantially simplify the visual analysis of large compound series.

  2. Use of the FACTS solvation model for protein-ligand docking calculations. Application to EADock.

    Science.gov (United States)

    Zoete, Vincent; Grosdidier, Aurélien; Cuendet, Michel; Michielin, Olivier

    2010-01-01

    Protein-ligand docking has made important progress during the last decade and has become a powerful tool for drug development, opening the way to virtual high throughput screening and in silico structure-based ligand design. Despite the flattering picture that has been drawn, recent publications have shown that the docking problem is far from being solved, and that more developments are still needed to achieve high successful prediction rates and accuracy. Introducing an accurate description of the solvation effect upon binding is thought to be essential to achieve this goal. In particular, EADock uses the Generalized Born Molecular Volume 2 (GBMV2) solvent model, which has been shown to reproduce accurately the desolvation energies calculated by solving the Poisson equation. Here, the implementation of the Fast Analytical Continuum Treatment of Solvation (FACTS) as an implicit solvation model in small molecules docking calculations has been assessed using the EADock docking program. Our results strongly support the use of FACTS for docking. The success rates of EADock/FACTS and EADock/GBMV2 are similar, i.e. around 75% for local docking and 65% for blind docking. However, these results come at a much lower computational cost: FACTS is 10 times faster than GBMV2 in calculating the total electrostatic energy, and allows a speed up of EADock by a factor of 4. This study also supports the EADock development strategy relying on the CHARMM package for energy calculations, which enables straightforward implementation and testing of the latest developments in the field of Molecular Modeling.

  3. Reactivation System for Proton-Exchange Membrane Fuel-Cells

    Directory of Open Access Journals (Sweden)

    Roberto Giral

    2012-07-01

    Full Text Available In recent years, Proton-Exchange Membrane Fuel Cells (PEMFCs have been the focus of very intensive researches. Manufacturers of these alternative power sources propose a rejuvenation sequence after the FC has been operating at high power for a certain period of time. These rejuvenation methods could be not appropriate for the reactivation of the FC when it has been out of operation for a long period of time or after it has been repaired. Since the developed reactivation system monitors temperature, current, and the cell voltages of the stack, it could be also useful for the diagnostic and repairing processes. The limited number of published contributions suggests that systems developing reactivation techniques are an open research field. In this paper, an automated system for reactivating PEMFCs and results of experimental testing are presented.

  4. A Spacebased Ocean Surface Exchange Data Analysis System

    Science.gov (United States)

    Tang, Wenqing; Liu, W. Timothy

    2000-01-01

    Emerging technologies have provided unprecedented opportunities to transform information into knowledge and disseminate them in a much faster, cheaper, and userfriendly mode. We have set up a system to produce and disseminate high level (gridded) ocean surface wind data from the NASA Scatterometer and European Remote Sensing missions. The data system is being expanded to produce real-time gridded ocean surface winds from an improved sensor SeaWinds on the Quikscat Mission. The wind field will be combined with hydrologic parameters from the Tropical Rain Measuring Mission to monitor evolving weather systems and natural hazard in real time. It will form the basis for spacebased Ocean Surface Exchange Data Analysis System (SOSEDAS) which will include the production of ocean surface momentum, heat, and water fluxes needed for interdisciplinary studies of ocean-atmosphere interaction. Various commercial or non-commercial software tools have been compared and selected in terms of their ability in database management, remote data accessing, graphical interface, data quality, storage needs and transfer speed, etc. Issues regarding system security and user authentication, distributed data archiving and accessing, strategy to compress large-volume geophysical and satellite data/image. and increasing transferring speed are being addressed. A simple and easy way to access information and derive knowledge from spacebased data of multiple missions is being provided. The evolving 'knowledge system' will provide relevant infrastructure to address Earth System Science, make inroads in educating an informed populace, and illuminate decision and policy making.

  5. Advanced integrated solvent extraction and ion exchange systems

    Energy Technology Data Exchange (ETDEWEB)

    Horwitz, P. [Argonne National Lab., IL (United States)

    1996-10-01

    Advanced integrated solvent extraction (SX) and ion exchange (IX) systems are a series of novel SX and IX processes that extract and recover uranium and transuranics (TRUs) (neptunium, plutonium, americium) and fission products {sup 90}Sr, {sup 99}Tc, and {sup 137}Cs from acidic high-level liquid waste and that sorb and recover {sup 90}Sr, {sup 99}Tc, and {sup 137}Cs from alkaline supernatant high-level waste. Each system is based on the use of new selective liquid extractants or chromatographic materials. The purpose of the integrated SX and IX processes is to minimize the quantity of waste that must be vitrified and buried in a deep geologic repository by producing raffinates (from SX) and effluent streams (from IX) that will meet the specifications of Class A low-level waste.

  6. Unconventional interaction forces in protein and protein-ligand systems and their impacts to drug design.

    Science.gov (United States)

    Wang, Qing-Yan; Lu, Jian; Liao, Si-Ming; Du, Qi-Shi; Huang, Ri-Bo

    2013-01-01

    In drug design and enzyme engineering, the information of interactions between receptors and ligands is crucially important. In many cases, the protein structures and drug-target complex structures are determined by a delicate balance of several weak molecular interaction types. Among these interaction forces several unconventional interactions play important roles, however, less familiar for researchers. The cation-π interaction is a unique noncovalent interaction only acting between aromatic amino acids and organic cations (protonated amino acids) and inorganic cations (proton and metallic). This article reports new study results in the interaction strength, the behaviors and the structural characters of cation-π interactions between aromatic amino acids (Phe, Tyr, and Trp) and organic and inorganic cations (Lys(+), Arg(+), H(+), H3O(+), Li(+), Na(+), K(+), Ca(2+), and Zn(2+)) in gas phase and in solutions (water, acetonitrile, and cyclohexane). Systematical research revealed that the cation-π interactions are point-to-plane (aromatic group) interactions, distance and orientationdependent, and the interaction energies change in a broad range. In gas phase the cation-π interaction energies between aromatic amino acids (Phe, Tyr, and Trp) and metallic cations (Li(+), Na(+), K(+), Ca(2+), and Zn(2+)) are in the range -12 to -160 kcal/mol, and the interaction energies of protonated amino acids (Arg(+) and Lys(+)) are in the range from -9 to -18 kcal/mol. In solutions the cation-π energies decrease with the dielectric constant ε of solvents. However, in aqueous solution the cation-π energies of H3O(+) and protonated amino acids are less affected by solvation effects. The applications of unconventional interaction forces in drug design and in protein engineering are introduced.

  7. Fabrication of Flat Plate Solar Geyser with Flat Grooved Heat Exchanger Having Special Exit System

    OpenAIRE

    Malik, Muhammad Suleman; Malik, Muhammad Arsalan; Shah, Haseeb Ali; Khan Afridi, Adnan Anwar; Asif, Muhammad

    2017-01-01

    International audience; The main objective of this paper is to introduce the concept of novel flat plate solar geyser with integrated heat exchanger and open loop passive system.The heat exchanger acts both as collector for solar radiations and as a heat exchanger its self for cold water beneath it. Contrary to the conventional flat plate solar collectors, water is in direct contact with the collector or flat grooved heat exchanger. A safety control box is installed to minimize hydraulic pres...

  8. Fundamentals for magnetic patterning by ion bombardment of exchange bias layer systems

    Science.gov (United States)

    Ehresmann, A.; Engel, D.; Weis, T.; Schindler, A.; Junk, D.; Schmalhorst, J.; Höink, V.; Sacher, M. D.; Reiss, G.

    2006-01-01

    In the present paper we investigate whether the ion bombardment induced magnetic modifications in exchange biased bilayers are stable in time, whether the direction of the exchange bias can be set to any arbitrary (in-plane) direction by the ion bombardment and whether the exchange bias field can be changed in successive bombardment steps. These three fundamental characteristics are prerequisites for ion bombardment used for an efficient, practical, and stable magnetic patterning of exchange biased layer systems.

  9. PL-PatchSurfer: A Novel Molecular Local Surface-Based Method for Exploring Protein-Ligand Interactions

    Directory of Open Access Journals (Sweden)

    Bingjie Hu

    2014-08-01

    Full Text Available Structure-based computational methods have been widely used in exploring protein-ligand interactions, including predicting the binding ligands of a given protein based on their structural complementarity. Compared to other protein and ligand representations, the advantages of a surface representation include reduced sensitivity to subtle changes in the pocket and ligand conformation and fast search speed. Here we developed a novel method named PL-PatchSurfer (Protein-Ligand PatchSurfer. PL-PatchSurfer represents the protein binding pocket and the ligand molecular surface as a combination of segmented surface patches. Each patch is characterized by its geometrical shape and the electrostatic potential, which are represented using the 3D Zernike descriptor (3DZD. We first tested PL-PatchSurfer on binding ligand prediction and found it outperformed the pocket-similarity based ligand prediction program. We then optimized the search algorithm of PL-PatchSurfer using the PDBbind dataset. Finally, we explored the utility of applying PL-PatchSurfer to a larger and more diverse dataset and showed that PL-PatchSurfer was able to provide a high early enrichment for most of the targets. To the best of our knowledge, PL-PatchSurfer is the first surface patch-based method that treats ligand complementarity at protein binding sites. We believe that using a surface patch approach to better understand protein-ligand interactions has the potential to significantly enhance the design of new ligands for a wide array of drug-targets.

  10. Compact Water Vapor Exchanger for Regenerative Life Support Systems

    Science.gov (United States)

    Izenson, Michael G.; Chen, Weibo; Anderson, Molly; Hodgson, Edward

    2012-01-01

    Thermal and environmental control systems for future exploration spacecraft must meet challenging requirements for efficient operation and conservation of resources. Regenerative CO2 removal systems are attractive for these missions because they do not use consumable CO2 absorbers. However, these systems also absorb and vent water to space along with carbon dioxide. This paper describes an innovative device designed to minimize water lost from regenerative CO2 control systems. Design studies and proof-of-concept testing have shown the feasibility of a compact, efficient membrane water vapor exchanger (WVX) that will conserve water while meeting challenging requirements for operation on future spacecraft. Compared to conventional WVX designs, the innovative membrane WVX described here has the potential for high water recovery efficiency, compact size, and very low pressure losses. The key innovation is a method for maintaining highly uniform flow channels in a WVX core built from water-permeable membranes. The proof-of-concept WVX incorporates all the key design features of a prototypical unit, except that it is relatively small scale (1/23 relative to a unit sized for a crew of six) and some components were fabricated using non-prototypical methods. The proof-of-concept WVX achieved over 90% water recovery efficiency in a compact core in good agreement with analysis models. Furthermore the overall pressure drop is very small (less than 0.5 in. H2O, total for both flow streams) and meets requirements for service in environmental control and life support systems on future spacecraft. These results show that the WVX provides very uniform flow through flow channels for both the humid and dry streams. Measurements also show that CO2 diffusion through the water-permeable membranes will have negligible effect on the CO2 partial pressure in the spacecraft atmosphere.

  11. Fault tolerance control for proton exchange membrane fuel cell systems

    Science.gov (United States)

    Wu, Xiaojuan; Zhou, Boyang

    2016-08-01

    Fault diagnosis and controller design are two important aspects to improve proton exchange membrane fuel cell (PEMFC) system durability. However, the two tasks are often separately performed. For example, many pressure and voltage controllers have been successfully built. However, these controllers are designed based on the normal operation of PEMFC. When PEMFC faces problems such as flooding or membrane drying, a controller with a specific design must be used. This paper proposes a unique scheme that simultaneously performs fault diagnosis and tolerance control for the PEMFC system. The proposed control strategy consists of a fault diagnosis, a reconfiguration mechanism and adjustable controllers. Using a back-propagation neural network, a model-based fault detection method is employed to detect the PEMFC current fault type (flooding, membrane drying or normal). According to the diagnosis results, the reconfiguration mechanism determines which backup controllers to be selected. Three nonlinear controllers based on feedback linearization approaches are respectively built to adjust the voltage and pressure difference in the case of normal, membrane drying and flooding conditions. The simulation results illustrate that the proposed fault tolerance control strategy can track the voltage and keep the pressure difference at desired levels in faulty conditions.

  12. Spatial Analysis and Quantification of the Thermodynamic Driving Forces in Protein-Ligand Binding: Binding Site Variability

    Science.gov (United States)

    Raman, E. Prabhu; MacKerell, Alexander D.

    2015-01-01

    The thermodynamic driving forces behind small molecule-protein binding are still not well understood, including the variability of those forces associated with different types of ligands in different binding pockets. To better understand these phenomena we calculate spatially resolved thermodynamic contributions of the different molecular degrees of freedom for the binding of propane and methanol to multiple pockets on the proteins Factor Xa and p38 MAP kinase. Binding thermodynamics are computed using a statistical thermodynamics based end-point method applied on a canonical ensemble comprising the protein-ligand complexes and the corresponding free states in an explicit solvent environment. Energetic and entropic contributions of water and ligand degrees of freedom computed from the configurational ensemble provides an unprecedented level of detail into the mechanisms of binding. Direct protein-ligand interaction energies play a significant role in both non-polar and polar binding, which is comparable to water reorganization energy. Loss of interactions with water upon binding strongly compensates these contributions leading to relatively small binding enthalpies. For both solutes, the entropy of water reorganization is found to favor binding in agreement with the classical view of the “hydrophobic effect”. Depending on the specifics of the binding pocket, both energy-entropy compensation and reinforcement mechanisms are observed. Notable is the ability to visualize the spatial distribution of the thermodynamic contributions to binding at atomic resolution showing significant differences in the thermodynamic contributions of water to the binding of propane versus methanol. PMID:25625202

  13. Heat exchanger optimization for geothermal district heating systems: A fuel saving approach

    Energy Technology Data Exchange (ETDEWEB)

    Dagdas, Ahmet [Department of Mechanical Engineering, Yildiz Technical University, 34349 Besiktas, Istanbul (Turkey)

    2007-05-15

    One of the most commonly used heating devices in geothermal systems is the heat exchanger. The output conditions of heat exchangers are based on several parameters. The heat transfer area is one of the most important parameters for heat exchangers in terms of economics. Although there are a lot of methods to optimize heat exchangers, the method described here is a fairly easy approach. In this paper, a counter flow heat exchanger of geothermal district heating system is considered and optimum design values, which provide maximum annual net profit, for the considered heating system are found according to fuel savings. Performance of the heat exchanger is also calculated. In the analysis, since some values are affected by local conditions, Turkey's conditions are considered. (author)

  14. 40 CFR 63.11499 - What are the standards and compliance requirements for heat exchange systems?

    Science.gov (United States)

    2010-07-01

    ... requirements for heat exchange systems? 63.11499 Section 63.11499 Protection of Environment ENVIRONMENTAL... and compliance requirements for heat exchange systems? (a) If the cooling water flow rate in your heat... part 211, you may use the physical integrity of the reactor as the surrogate indicator of heat...

  15. The Usage of Informational Gateways for Data Exchange between Personal Data Systems of Different Classes

    Directory of Open Access Journals (Sweden)

    E. I. Goncharov

    2010-03-01

    Full Text Available When personal data exchange between informational systems takes place, one must guarantee the systems are not integrating but just interacting. This task can not be accomplished by using traditional tools such as firewalls, cryptography and so on. To solve the problem we suggest deploying of informational gateway in personal data exchange process.

  16. Performance enhancement study of mobile air conditioning system using microchannel heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Zhaogang; Zhao, Yu.; Chen, Jiangping [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, No. 800, Dongchuan Road, Shanghai 200240 (China)

    2010-03-15

    In the present paper, two retrofitted compact and high efficient microchannel heat exchangers were proposed. The new microchannel heat exchangers have advantages in compactness (17.2% and 15.1% volume reduction for evaporator and condenser, respectively), weight (2.8% and 14.9% lighter for evaporator and condenser, respectively), heat transfer characteristics compared with the currently used heat exchangers in mobile air conditioning (MAC) industry. One enhanced and one baseline R134a MAC systems were established including the new microchannel heat exchangers and the traditional MAC heat exchangers, respectively. The system performances have been experimentally carried out under variable ambient conditions in psychrometric calorimeter test bench. The optimal system refrigerant charge amounts for both systems were tested and the results showed that the enhanced system with more compact heat exchangers could reduce system charge amount and the minimum effective charge amount was less than that of the baseline system. The enhanced system could supply more cooling capacity to car compartment under all test conditions because of higher performance heat exchangers. The coefficient of performance (COP) of the enhanced system was slightly lower than that of the baseline system under idle conditions but higher under all the other test conditions. Cooling capacity and COP of the enhanced system was increased by about 5% and 8% under high vehicle speed condition. (author)

  17. Using a health information exchange system for imaging information: patterns and predictors.

    Science.gov (United States)

    Vest, Joshua R; Grinspan, Zachary M; Kern, Lisa M; Campion, Thomas R; Kaushal, Rainu

    2013-01-01

    Health information exchange (HIE) systems may address the challenges that prevent easy access to patients' existing radiological information at the point of care. However, little is known about the factors associated with usage of HIE for radiology reports, nor about how reports are shared with an exchange network. We analyzed the system log files from a regional health information organization in upstate New York matched with insurance claims files using network analysis and regression modeling. The exchange network was dominated by a few key information sources. Outpatient users overall accessed 17 times more radiology reports than inpatient and ED users combined. Additionally, as the number of exchange partners increased per organization, the average number of reports exchanged by that organization also increased. Radiology reports were most likely to be accessed by physicians and other clinical users. These findings have implications for those operating and fostering exchange activity.

  18. Effects and Implications for Adoption of Brokerage System in Korea's Foreign Exchange Market

    Directory of Open Access Journals (Sweden)

    Yunjong Wang

    1999-03-01

    Full Text Available Since January 1st 1999, the South Korean government has begun to establish the understructure of the foreign exchange market in order to achieve the liberalization of foreign exchange. As one of the plans, the trade of foreign exchange which was under the monopolized mediation of the capital medium of financial settlement center will be in the charge of several commercial brokers. In the developed countries, the foreign exchange & stock system and the liberalization of foreign exchange are both widely used in a flexible way. So it is predicted that the introduction of commercial foreign exchange & stock system will bring positive effect to the enhancement of the market efficiency and the function of price both in South Korean market and overseas market, the foster of competitive power of the domestic broker and the improvement of the understructure of domestic foreign exchange market. But more importantly is that the foreign exchange market must expand the scale of its participator, bring in various relevant foreign exchange products and develop the bond market which has a close relationship with the foreign exchange market for further development.

  19. Investigation into the applicability of the centrifugal microfluidics platform for the development of protein-ligand binding assays incorporating enhanced green fluorescent protein as a fluorescent reporter.

    Science.gov (United States)

    Puckett, Libby G; Dikici, Emre; Lai, Siyi; Madou, Marc; Bachas, Leonidas G; Daunert, Sylvia

    2004-12-15

    The incorporation of a protein-ligand binding assay into a centrifugal microfluidics platform is described. The platform itself is a disc-shaped polymer substrate, upon which a series of microfluidic channels and reservoirs have been machined. Centrifugal microfluidics platforms require no internal moving parts, and fluid propulsion is achieved solely through rotation of the disc. Fluid flow is controlled by passive valves, the opening of which is dependent on the angular frequency of the rotating platform, the channel dimensions, and the physical properties of the fluid. To evaluate the effectiveness of incorporating a protein-based assay onto the centrifugal microfluidics analytical platform, a class-selective, homogeneous assay for the detection of phenothiazine antidepressants was employed. This class of drugs is known to bind to calmodulin, a calcium binding protein. Specifically, a fusion protein between calmodulin and enhanced green fluorescent protein was utilized. Calmodulin undergoes a conformational change upon binding to phenothiazines that alters the fluorescence properties of the attached fluorescent protein, which can be correlated to the concentration of the drug present. Another important aspect of this work was to study the efficacy of the platform to perform reconstitution assays. To do this, the biological reagent was dried on the platform and rehydrated to carry out the assay. The ability to prealiquot reagents on the platform should enhance its versatility and portability. The integration of protein-based assays in this platform should be useful in the design of analytical systems for high-throughput screening of pharmaceuticals and clinical diagnostics.

  20. Controlled immobilization of His-tagged proteins for protein-ligand interaction experiments using Ni²⁺-NTA layer on glass surfaces.

    Science.gov (United States)

    Cherkouk, Charaf; Rebohle, Lars; Lenk, Jens; Keller, Adrian; Ou, Xin; Laube, Markus; Neuber, Christin; Haase-Kohn, Cathleen; Skorupa, Wolfgang; Pietzsch, Jens

    2015-01-01

    Gold surfaces functionalized with nickel-nitrilotriacetic acid (Ni²⁺-NTA) as self-assembled monolayers (SAM) to immobilize histidine (His)-tagged biomolecules are broadly reported in the literature. However, the increasing demand of using microfluidic systems and biosensors takes more and more advantage on silicon technology which provides dedicated glass surfaces and substantially allows cost and resource savings. Here we present a novel method for the controlled oriented immobilization of His-tagged proteins on glass surfaces functionalized with a Ni²⁺-NTA layer. Exemplarily, the protein pattern morphology after immobilization on the Ni²⁺-NTA layer of His6-tagged soluble receptor for advanced glycation endproducts (sRAGE) was investigated and compared to non-oriented immobilization of sRAGE on amino SAM by using scanning electron microscopy (SEM). Moreover, we demonstrated interaction of immobilized sRAGE with three structurally different ligands, S100A12, S100A4, and glycated low density lipoproteins (glycLDL), by means of peak-force tapping atomic force microscopy (PF-AFM). We showed a clear discrimination of different protein-ligand orientations by differential height measurements.

  1. Model-based analysis of anion-exchanger positioning in direct methanol fuel cell systems

    Science.gov (United States)

    Kraus, Maik; Schröder, Daniel; Krewer, Ulrike

    2014-09-01

    In this work we present a model based study to investigate the presence of anion exchangers in direct methanol fuel cell (DMFC) systems. It is well known that environmental or fuel impurities lead to accumulation of harmful anions, such as chloride, in the system. However, due to DMFC anodic reaction, a carbonate system is present. These corbanate anions have to be taken into account for the anion exchanger design and placement as well as for the system operation strategy with and without anion exchanger, which is the objective of this study. For this purpose, the expected amount of harmful chloride ions in a DMFC system is estimated, and that of carbonate ions is calculated with a model of the carbonate system in a DMFC system. The predicition of durability and dimensions of an anion exchanger is based on a monovalent anion exchange model. The design of gas liquid separators in the DMFC system has a major influence on the amount of dissolved carbon dioxide, which is crucial for durability and dimension of a system integrated anion exchanger. Finally, feasible positions of anion exchanger in a DMFC system are elaborated to fulfill the needs for long term and stable DMFC operation.

  2. Inverse problem and variation method to optimize cascade heat exchange network in central heating system

    Science.gov (United States)

    Zhang, Yin; Wei, Zhiyuan; Zhang, Yinping; Wang, Xin

    2017-12-01

    Urban heating in northern China accounts for 40% of total building energy usage. In central heating systems, heat is often transferred from heat source to users by the heat network where several heat exchangers are installed at heat source, substations and terminals respectively. For given overall heating capacity and heat source temperature, increasing the terminal fluid temperature is an effective way to improve the thermal performance of such cascade heat exchange network for energy saving. In this paper, the mathematical optimization model of the cascade heat exchange network with three-stage heat exchangers in series is established. Aim at maximizing the cold fluid temperature for given hot fluid temperature and overall heating capacity, the optimal heat exchange area distribution and the medium fluids' flow rates are determined through inverse problem and variation method. The preliminary results show that the heat exchange areas should be distributed equally for each heat exchanger. It also indicates that in order to improve the thermal performance of the whole system, more heat exchange areas should be allocated to the heat exchanger where flow rate difference between two fluids is relatively small. This work is important for guiding the optimization design of practical cascade heating systems.

  3. Seamless bead to microarray screening: rapid identification of the highest affinity protein ligands from large combinatorial libraries.

    Science.gov (United States)

    Astle, John M; Simpson, Levi S; Huang, Yong; Reddy, M Muralidhar; Wilson, Rosemary; Connell, Steven; Wilson, Johnnie; Kodadek, Thomas

    2010-01-29

    Several approaches have been developed for screening combinatorial libraries or collections of synthetic molecules for agonists or antagonists of protein function, each with its own advantages and limitations. In this report, we describe an experimental platform that seamlessly couples massively parallel bead-based screening of one-bead one-compound combinatorial libraries with microarray-based quantitative comparisons of the binding affinities of the many hits isolated from the bead library. Combined with other technical improvements, this technique allows the rapid identification of the best protein ligands in combinatorial libraries containing millions of compounds without the need for labor-intensive resynthesis of the hits. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  4. A Critical Review of Validation, Blind Testing, and Real- World Use of Alchemical Protein-Ligand Binding Free Energy Calculations.

    Science.gov (United States)

    Abel, Robert; Wang, Lingle; Mobley, David L; Friesner, Richard A

    2017-01-01

    Protein-ligand binding is among the most fundamental phenomena underlying all molecular biology, and a greater ability to more accurately and robustly predict the binding free energy of a small molecule ligand for its cognate protein is expected to have vast consequences for improving the efficiency of pharmaceutical drug discovery. We briefly reviewed a number of scientific and technical advances that have enabled alchemical free energy calculations to recently emerge as a preferred approach, and critically considered proper validation and effective use of these techniques. In particular, we characterized a selection bias effect which may be important in prospective free energy calculations, and introduced a strategy to improve the accuracy of the free energy predictions. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. A Comparative Assessment of Predictive Accuracies of Conventional and Machine Learning Scoring Functions for Protein-Ligand Binding Affinity Prediction.

    Science.gov (United States)

    Ashtawy, Hossam M; Mahapatra, Nihar R

    2015-01-01

    Accurately predicting the binding affinities of large diverse sets of protein-ligand complexes efficiently is a key challenge in computational biomolecular science, with applications in drug discovery, chemical biology, and structural biology. Since a scoring function (SF) is used to score, rank, and identify potential drug leads, the fidelity with which it predicts the affinity of a ligand candidate for a protein's binding site has a significant bearing on the accuracy of virtual screening. Despite intense efforts in developing conventional SFs, which are either force-field based, knowledge-based, or empirical, their limited predictive accuracy has been a major roadblock toward cost-effective drug discovery. Therefore, in this work, we explore a range of novel SFs employing different machine-learning (ML) approaches in conjunction with a variety of physicochemical and geometrical features characterizing protein-ligand complexes. We assess the scoring accuracies of these new ML SFs as well as those of conventional SFs in the context of the 2007 and 2010 PDBbind benchmark datasets on both diverse and protein-family-specific test sets. We also investigate the influence of the size of the training dataset and the type and number of features used on scoring accuracy. We find that the best performing ML SF has a Pearson correlation coefficient of 0.806 between predicted and measured binding affinities compared to 0.644 achieved by a state-of-the-art conventional SF. We also find that ML SFs benefit more than their conventional counterparts from increases in the number of features and the size of training dataset. In addition, they perform better on novel proteins that they were never trained on before.

  6. BP-Dock: a flexible docking scheme for exploring protein-ligand interactions based on unbound structures.

    Science.gov (United States)

    Bolia, Ashini; Gerek, Z Nevin; Ozkan, S Banu

    2014-03-24

    Molecular docking serves as an important tool in modeling protein-ligand interactions. However, it is still challenging to incorporate overall receptor flexibility, especially backbone flexibility, in docking due to the large conformational space that needs to be sampled. To overcome this problem, we developed a novel flexible docking approach, BP-Dock (Backbone Perturbation-Dock) that can integrate both backbone and side chain conformational changes induced by ligand binding through a multi-scale approach. In the BP-Dock method, we mimic the nature of binding-induced events as a first-order approximation by perturbing the residues along the protein chain with a small Brownian kick one at a time. The response fluctuation profile of the chain upon these perturbations is computed using the perturbation response scanning method. These response fluctuation profiles are then used to generate binding-induced multiple receptor conformations for ensemble docking. To evaluate the performance of BP-Dock, we applied our approach on a large and diverse data set using unbound structures as receptors. We also compared the BP-Dock results with bound and unbound docking, where overall receptor flexibility was not taken into account. Our results highlight the importance of modeling backbone flexibility in docking for recapitulating the experimental binding affinities, especially when an unbound structure is used. With BP-Dock, we can generate a wide range of binding site conformations realized in nature even in the absence of a ligand that can help us to improve the accuracy of unbound docking. We expect that our fast and efficient flexible docking approach may further aid in our understanding of protein-ligand interactions as well as virtual screening of novel targets for rational drug design.

  7. Fabrication of Flat Plate Solar Geyser with Flat Grooved Heat Exchanger Having Special Exit System

    OpenAIRE

    Muhammad Suleman Malik; Muhammad Arsalan Malik; Haseeb Ali Shah; Adnan Anwar khan afridi; Muhammad Asif

    2017-01-01

    The main objective of this paper is to introduce the concept of novel flat plate solar geyser with integrated heat exchanger and open loop passive system.The heat exchanger acts both as collector for solar radiations and as a heat exchanger its self for cold water beneath it. Contrary to the conventional flat plate solar collectors, water is in direct contact with the collector or flat grooved heat exchanger. A safety control box is installed to minimize hydraulic pressure of cold water rese...

  8. Fundamentals for magnetic patterning by ion bombardment of exchange bias layer systems

    Energy Technology Data Exchange (ETDEWEB)

    Ehresmann, A.; Engel, D.; Weis, T. [Institute of Physics and Centre for Interdisciplinary Nanostructure Science and Technology (CINSaT), Kassel University, Heinrich-Plett-Str. 40, 34132 Kassel (Germany); Schindler, A. [Institut fuer Festkoerperforschung, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Junk, D. [Technische Physik, Universitaet des Saarlandes, P.O. Box 151150, 66041 Saarbruecken (Germany); Schmalhorst, J.; Hoeink, V.; Sacher, M.D.; Reiss, G. [Faculty of Physics, Bielefeld University, P.O. Box 100131, 33501 Bielefeld (Germany)

    2006-01-01

    In the present paper we investigate whether the ion bombardment induced magnetic modifications in exchange biased bilayers are stable in time, whether the direction of the exchange bias can be set to any arbitrary (in-plane) direction by the ion bombardment and whether the exchange bias field can be changed in successive bombardment steps. These three fundamental characteristics are prerequisites for ion bombardment used for an efficient, practical, and stable magnetic patterning of exchange biased layer systems. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Development of a Malian food exchange system based on local ...

    African Journals Online (AJOL)

    Energy and macronutrient intakes obtained by a software-based nutritional analysis of the dietary recalls were compared with the average energy and nutrient values calculated with the exchange lists. Setting: Centre National de Lutte contre le Diabète. Subjects: Seventeen male and 40 female adults with type 2 diabetes.

  10. Design and study of the mask exchange system based on Delta parallel mechanism

    Science.gov (United States)

    Zhang, Feifan; Wang, Jianping; Zhou, Hongfei; Zhou, Zengxiang; Chu, Jiaru

    2016-07-01

    Mask exchange system is the main part of Multi-Object Broadband Imaging Echellette (MOBIE) on the Thirty Meter Telescope (TMT). The robot is one of the key parts in the mask exchange process. In view of the facts that the scheme the on-board robot is hard to meet the requirements of TMT and the traditional industrial robot is difficult to use in the Mask Exchange System (MEX). The delta parallel mechanism has much advantages such as good dynamic performance, high speed and could integrate a vision recognition system to identify the masks. The design for MEX based on off-board Delta parallel mechanism was proposed in the paper.

  11. Measuring and Modeling Component and Whole-System Carbon Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Paul Bolstad

    2006-11-01

    We measured ecosystem/atmospheric carbon exchange through a range of methods covering a range of scales. We measured carbon (C) pool and flux for a number of previously poorly quantified ecosystems, developed measurement and modeling methods, and applied these to substantially increase the accuracy and reduce uncertainty in ecosystem/atmospheric C exchange at a range of scales. It appears most upland forests are weak to strong carbon sinks, and status depends largely on disturbance history and age. Net flux from wetland ecosystems appears to be from weak sinks to moderate sources of C to the atmosphere. We found limited evidence for a positive feedback of warming/drying to increased ecosystem C emissions. We further developed multi-source integration and modeling methods, including multiple towers, to scale estimates to landscapes and larger regions.

  12. Exchange rate system and policy in the present world

    Directory of Open Access Journals (Sweden)

    Grubišić Zoran

    2005-01-01

    Full Text Available The choice of exchange rate regime is important, not only in terms of its effect on trade flows, but also with respect to inflation expectations. Countries facing disinflation may find that pegs regimes are more appropriate solution. But where the trade balance account is significantly deteriorated and growth has been sluggish, a more flexible regime might be called for. The natural classification in eighties and early nineties suggests that intermediate regimes may provide important advantages – to capture some of the benefits of both extremes while avoiding many of the costs. However today many experts predicted that exchange rate regimes would move in a "bipolar" manner to the extremes of "hard" pegs or free floats. An increasing number of countries did announce their intent to allow greater exchange rate flexibility. But, in practice, countries had a "fear of floating ". Distinction is made among advanced, emerging and other developing countries. Emerging markets have stronger links to international capital markets than do other developing economies. Thus, while non-emerging market developing economies may gain credibility through pegging their exchange rates, emerging markets find it harder to do so and could benefit from investing in "learning to float". More advanced economies with their access to international capital market are best positioned to enjoy the benefits of flexibility. It is found that the proportion of countries adopting intermediate regimes has indeed been shrinking in favor of greater flexibility or greater fixity, especially for countries more integrated with international markets. But, there is no final conclusion on the idea that intermediate regimes will dissapear.

  13. Brief Report: Randomized Test of the Efficacy of Picture Exchange Communication System on Highly Generalized Picture Exchanges in Children with ASD

    OpenAIRE

    Yoder, Paul J.; Lieberman, Rebecca G.

    2010-01-01

    A randomized control trial comparing two social-communication interventions in young children with autism examined far-transfer of the use of picture exchange to communicate. Thirty-six children were randomly assigned to one of two treatment conditions, one of which was the Picture Exchange Communication System (PECS). All children had access to picture symbols during assessments. Post-treatment measurement of the number of picture exchanges in a far-transfer, assessment context favored the P...

  14. 8 CFR 214.12 - Preliminary enrollment of schools in the Student and Exchange Visitor Information System (SEVIS).

    Science.gov (United States)

    2010-01-01

    ... Student and Exchange Visitor Information System (SEVIS). 214.12 Section 214.12 Aliens and Nationality... of schools in the Student and Exchange Visitor Information System (SEVIS). (a) Private elementary and... schools are eligible for preliminary enrollment in Student and Exchange Visitor Information System (SEVIS...

  15. Evaluating humidity recovery efficiency of currently available heat and moisture exchangers: a respiratory system model study.

    Science.gov (United States)

    Lucato, Jeanette Janaina Jaber; Adams, Alexander Bernard; Souza, Rogério; Torquato, Jamili Anbar; Carvalho, Carlos Roberto Ribeiro; Marini, John J

    2009-01-01

    To evaluate and compare the efficiency of humidification in available heat and moisture exchanger models under conditions of varying tidal volume, respiratory rate, and flow rate. Inspired gases are routinely preconditioned by heat and moisture exchangers to provide a heat and water content similar to that provided normally by the nose and upper airways. The absolute humidity of air retrieved from and returned to the ventilated patient is an important measurable outcome of the heat and moisture exchangers' humidifying performance. Eight different heat and moisture exchangers were studied using a respiratory system analog. The system included a heated chamber (acrylic glass, maintained at 37 degrees C), a preserved swine lung, a hygrometer, circuitry and a ventilator. Humidity and temperature levels were measured using eight distinct interposed heat and moisture exchangers given different tidal volumes, respiratory frequencies and flow-rate conditions. Recovery of absolute humidity (%RAH) was calculated for each setting. Increasing tidal volumes led to a reduction in %RAH for all heat and moisture exchangers while no significant effect was demonstrated in the context of varying respiratory rate or inspiratory flow. Our data indicate that heat and moisture exchangers are more efficient when used with low tidal volume ventilation. The roles of flow and respiratory rate were of lesser importance, suggesting that their adjustment has a less significant effect on the performance of heat and moisture exchangers.

  16. Data Description Exchange Services for Heterogeneous Vehicle and Spaceport Control and Monitor Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — CCT proposes an advanced data description exchange approach for space/spaceport systems that will provide a generic platform independent software capability for...

  17. RRB's SVES Input File - Post Entitlement State Verification and Exchange System (PSSVES)

    Data.gov (United States)

    Social Security Administration — Several PSSVES request files are transmitted to SSA each year for processing in the State Verification and Exchange System (SVES). This is a first step in obtaining...

  18. Gain measurements of the Ca-Xe charge exchange system. [for UV lasers

    Science.gov (United States)

    Michels, C. J.; Chubb, D. L.

    1978-01-01

    Charge-exchange-pumped Ca(+) was studied for possible positive laser gain at 370.6 and 315.9 nm using an Xe MPD arc as the Xe(+) source. The present paper describes the MPD arc, the calcium injection system, the diagnostics for gain, and spontaneous emission measurements and results. No positive gain measurements were observed. A small Xe-Ca charge exchange cross section compared to He-metal laser systems charge exchange cross sections is the most probable reason why the result was negative.

  19. Control and prevention of ice formation and accretion on heat exchangers for ventilation systems

    DEFF Research Database (Denmark)

    Rahimi, Maral; Afshari, Alireza

    2015-01-01

    In cold climates, the application of mechanical ventilation systems with heat recovery like are airto-air exchangers is used for reducing energy consumption for heating buildings by transferring heat exhausted air to supply air. However, increase efficiency of heat exchanger results in lower...... exhaust air temperatures and Ice formation on heat exchanger fins, which can cause problem and is not favourable. Therefore, prevention and control of ice formation on heat exchangers is necessary. The existing methods are divided into two different methods: active and passive ice control methods....... The active methods are e.g. bypass, recirculation, preheating. The passive methods relate to the surface characteristics of the heat exchanger fins as they have effect on ice formation in initial phase. All these methods have varying levels of success, cost, and effectiveness, which are depending on the heat...

  20. Heat and moisture exchanger: importance of humidification in anaesthesia and ventilatory breathing system.

    Science.gov (United States)

    Parmar, Vandana

    2008-08-01

    Adequate humidification is vital to maintain homeostasis of the airway. Heat and moisture exchangers conserve some of the exhaled water, heat and return them to inspired gases. Many heat and moisture exchangers also perfom bacterial/viral filtration and prevent inhalation of small particles. Heat and moisture exchangers are also called condenser humidifier, artificial nose, etc. Most of them are disposable devices with exchanging medium enclosed in a plastic housing. For adult and paediatric age group different dead space types are available. Heat and moisture exchangers are helpful during anaesthesia and ventilatory breathing system. To reduce the damage of the upper respiratory tract through cooling and dehydration inspiratory air can be heated and humidified, thus preventing the serious complications.

  1. Brief Report: Randomized Test of the Efficacy of Picture Exchange Communication System on Highly Generalized Picture Exchanges in Children with ASD

    Science.gov (United States)

    Yoder, Paul J.; Lieberman, Rebecca G.

    2010-01-01

    A randomized control trial comparing two social-communication interventions in young children with autism examined far-transfer of the use of picture exchange to communicate. Thirty-six children were randomly assigned to one of two treatment conditions, one of which was the Picture Exchange Communication System (PECS). All children had access to…

  2. Ion-exchange chromatography separation applied to mineral recycle in closed systems

    Science.gov (United States)

    Ballou, E.; Spitze, L. A.; Wong, F. W.; Wydeven, T.; Johnson, C. C.

    1981-01-01

    As part of the controlled ecological life support system (CELSS) program, a study is being made of mineral separation on ion-exchange columns. The purpose of the mineral separation step is to allow minerals to be recycled from the oxidized waste products of plants, man, and animals for hydroponic food production. In the CELSS application, relatively large quantities of minerals in a broad concentration range must be recovered by the desired system, rather than the trace quantities and very low concentrations treated in analytical applications of ion-exchange chromatography. Experiments have been carried out to assess the parameters pertinent to the scale-up of ion-exchange chromatography and to determine feasibility. Preliminary conclusions are that the column scale-up is in a reasonable size range for the CELSS application. The recycling of a suitable eluent, however, remains a major challenge to the suitability of using ion exchange chromatography in closed systems.

  3. Evaluation of a Passive Heat Exchanger Based Cooling System for Fuel Cell Applications

    Science.gov (United States)

    Colozza, Anthony J.; Burke, Kenneth A.

    2011-01-01

    Fuel cell cooling is conventionally performed with an actively controlled, dedicated coolant loop that exchanges heat with a separate external cooling loop. To simplify this system the concept of directly cooling a fuel cell utilizing a coolant loop with a regenerative heat exchanger to preheat the coolant entering the fuel cell with the coolant exiting the fuel cell was analyzed. The preheating is necessary to minimize the temperature difference across the fuel cell stack. This type of coolant system would minimize the controls needed on the coolant loop and provide a mostly passive means of cooling the fuel cell. The results indicate that an operating temperature of near or greater than 70 C is achievable with a heat exchanger effectiveness of around 90 percent. Of the heat exchanger types evaluated with the same type of fluid on the hot and cold side, a counter flow type heat exchanger would be required which has the possibility of achieving the required effectiveness. The number of heat transfer units required by the heat exchanger would be around 9 or greater. Although the analysis indicates the concept is feasible, the heat exchanger design would need to be developed and optimized for a specific fuel cell operation in order to achieve the high effectiveness value required.

  4. Real time alert system: a disease management system leveraging health information exchange.

    Science.gov (United States)

    Anand, Vibha; Sheley, Meena E; Xu, Shawn; Downs, Stephen M

    2012-01-01

    Rates of preventive and disease management services can be improved by providing automated alerts and reminders to primary care providers (PCPs) using of health information technology (HIT) tools. Using Adaptive Turnaround Documents (ATAD), an existing Health Information Exchange (HIE) infrastructure and office fax machines, we developed a Real Time Alert (RTA) system. RTA is a computerized decision support system (CDSS) that is able to deliver alerts to PCPs statewide for recommended services around the time of the patient visit. RTA is also able to capture structured clinical data from providers using existing fax technology. In this study, we evaluate RTA's performance for alerting PCPs when their patients with asthma have an emergency room visit anywhere in the state. Our results show that RTA was successfully able to deliver "just in time" patient-relevant alerts to PCPs across the state. Furthermore, of those ATADs faxed back and automatically interpreted by the RTA system, 35% reported finding the provided information helpful. The PCPs who reported finding information helpful also reported making a phone call, sending a letter or seeing the patient for follow up care. We have successfully demonstrated the feasibility of electronically exchanging important patient related information with the PCPs statewide. This is despite a lack of a link with their electronic health records. We have shown that using our ATAD technology, a PCP can be notified quickly of an important event such as a patient's asthma related emergency room admission so further follow up can happen in near real time.

  5. Proteochemometric modeling of the bioactivity spectra of HIV-1 protease inhibitors by introducing protein-ligand interaction fingerprint.

    Directory of Open Access Journals (Sweden)

    Qi Huang

    Full Text Available HIV-1 protease is one of the main therapeutic targets in HIV. However, a major problem in treatment of HIV is the rapid emergence of drug-resistant strains. It should be particularly helpful to clinical therapy of AIDS if one method can be used to predict antivirus capability of compounds for different variants. In our study, proteochemometric (PCM models were created to study the bioactivity spectra of 92 chemical compounds with 47 unique HIV-1 protease variants. In contrast to other PCM models, which used Multiplication of Ligands and Proteins Descriptors (MLPD as cross-term, one new cross-term, i.e. Protein-Ligand Interaction Fingerprint (PLIF was introduced in our modeling. With different combinations of ligand descriptors, protein descriptors and cross-terms, nine PCM models were obtained, and six of them achieved good predictive abilities (Q(2(test>0.7. These results showed that the performance of PCM models could be improved when ligand and protein descriptors were complemented by the newly introduced cross-term PLIF. Compared with the conventional cross-term MLPD, the newly introduced PLIF had a better predictive ability. Furthermore, our best model (GD & P & PLIF: Q(2(test = 0.8271 could select out those inhibitors which have a broad antiviral activity. As a conclusion, our study indicates that proteochemometric modeling with PLIF as cross-term is a potential useful way to solve the HIV-1 drug-resistant problem.

  6. Heat exchangers for cardioplegia systems: in vitro study of four different concepts.

    Science.gov (United States)

    Drummond, Mário; Novello, Waldyr Parorali; de Arruda, Antonio Celso Fonseca; Braile, Domingo Marcolino

    2003-05-01

    The aim of this work is the evaluation of four different heat exchangers used for myocardium during cardioplegic system in cardiac surgeries. Four types of shell and tube heat exchangers made of different exchange elements were constructed, as follows: stainless steel tubes, aluminium tubes, polypropylene hollow fiber, and bellows type. The evaluation was performed by in vitro tests of parameters such as heat transfer, pressure drop, and hemolysis tendency. The result has shown that all four systems tested were able to achieve the heat performance, and to offer low resistance to flow, and safety, as well as have low tendency to hemolysis. However, we can emphasize that the bellows type heat exchanger has a significant difference with regard to the other three types.

  7. Advanced Heat/Mass Exchanger Technology for Geothermal and Solar Renewable Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Greiner, Miles [Univ. of Nevada, Reno, NV (United States); Childress, Amy [Univ. of Nevada, Reno, NV (United States); Hiibel, Sage [Univ. of Nevada, Reno, NV (United States); Kim, Kwang [Univ. of Nevada, Reno, NV (United States); Park, Chanwoo [Univ. of Nevada, Reno, NV (United States); Wirtz, Richard [Univ. of Nevada, Reno, NV (United States)

    2014-12-16

    Northern Nevada has abundant geothermal and solar energy resources, and these renewable energy sources provide an ample opportunity to produce economically viable power. Heat/mass exchangers are essential components to any energy conversion system. Improvements in the heat/mass exchange process will lead to smaller, less costly (more efficient) systems. There is an emerging heat transfer technology, based on micro/nano/molecular-scale surface science that can be applied to heat/mass exchanger design. The objective is to develop and characterize unique coating materials, surface configurations and membranes capable of accommodating a 10-fold increase in heat/mass exchanger performance via phase change processes (boiling, condensation, etc.) and single phase convective heat/mass transfer.

  8. 21 CFR 26.41 - Exchange and endorsement of quality system evaluation reports.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Exchange and endorsement of quality system... DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN MEDICAL DEVICE PRODUCT EVALUATION REPORTS: UNITED STATES... endorsement of quality system evaluation reports. (a) Listed European Community (EC) conformity assessment...

  9. An Approach to Semantic Interoperability for Improved Capability Exchanges in Federations of Systems

    Science.gov (United States)

    Moschoglou, Georgios

    2013-01-01

    This study seeks an affirmative answer to the question whether a knowledge-based approach to system of systems interoperation using semantic web standards and technologies can provide the centralized control of the capability for exchanging data and services lacking in a federation of systems. Given the need to collect and share real-time…

  10. Staff exchange with Viatex-Recovery Systems, Inc.. Final project report

    Energy Technology Data Exchange (ETDEWEB)

    Jones, E.O. [Pacific Northwest Lab., Richland, WA (United States); Kensington, K.L. [Viatec, Inc., Hastings, MI (United States)

    1994-03-01

    The purpose of this industrial staff exchange is to assist the license, Viatec, Inc., in commercializing the Waste Acid Detoxification and Reclamation (WADR) process system. The process system was developed at the Pacific Northwest Laboratory (PNL) which is a DOE national laboratory. The objective of the activity is to establish a successful local business to design, build, and manufacture WARD process systems.

  11. Gold Loading on Ion Exchange Resins in Non-Ammoniacal Resin-Solution Systems

    Directory of Open Access Journals (Sweden)

    Abrar Muslim

    2010-12-01

    Full Text Available The loading of gold using strong base anion exchange resin in non-ammoniac resin-solution (NARS systems has been studied. The loading of gold onto ion exchange resins is affected by polythionate concentration, and trithionate can be used as the baseline in the system. The results also show that resin capacity on gold loading increases due to the increase in the equilibrium thiosulfate concentration in the NARS system. Gold loading performances show the need of optimization the equilibrium concentrations of thiosulfate in the NARS system. Keywords: equilibrium, gold loading, resin capacity, thiosulfate, trithionate

  12. ASN.1 notation for exchange of data in computer-based railway control systems

    Directory of Open Access Journals (Sweden)

    Zbigniew ŁUKASIK

    2009-01-01

    Full Text Available Development of railway control systems aims at computerization. In most cases these systems are Distributed Real Time Systems. However, a huge problem in their putting into practice is the lack of interface standardization in the range of data structures and information exchange methods. It results in a variety of solutions, and thus in problems concerning cooperation of systems that come from different software vendors. Specification of protocols for data exchanging applications should therefore be created with the use of generally accepted standards. One of them is ASN.1 (Abstract Syntax Notation One language, which shall be presented in this article.

  13. Dehumidification performance investigation of run-around membrane energy exchanger system

    Directory of Open Access Journals (Sweden)

    Kassai Miklos

    2016-01-01

    Full Text Available Liquid-to-air membrane energy exchanger is a novel membrane base energy exchanger, which allows both heat and moisture transfer between air and a salt solution. It uses semi-permeable membrane to eliminate entrainment of liquid desiccant as aerosols in air stream and allow simultaneous heat and moisture transfer between salt solution flow and airflow. The heat and mass transfer performance of a single liquid-to-air membrane energy exchanger is significantly dependent on two dimensionless parameters. They are the number of heat transfer units (NTU and the ratio of heat capacity rates between solution flow and air flow (Cr*. The liquid-to-air membrane energy exchangers can also be applied in a run-around membrane energy exchanger system, which is mainly comprised of two liquid-to-air membrane energy exchangers and a closed loop of aqueous desiccant solution and used as a passive energy recovery system to recover the energy (both heat and moisture from the exhaust air to precondition the supply air in air conditioning systems. In this study the dehumidification capacity of a run-around membrane energy exchanger is investigated numerically at different exhaust air temperatures and Cr* values. Increasing the exhaust air temperature or the Cr* would enhance the dehumidification capacity of the a run-around membrane energy exchanger system under Cr*≤1, but the improvement is limited. The dehumidification capacity at low Cr* is much lower than that under the optimal Cr* value (Cr*=3.2 where the maximum latent effectiveness is obtained.

  14. Nanofiltration: ion exchange system for effective surfactant removal from water solutions

    OpenAIRE

    Kowalska, I.

    2014-01-01

    A system combining nanofiltration and ion exchange for highly effective separation of anionic surfactant from water solutions was proposed. The subjects of the study were nanofiltration polyethersulfone membranes and ion-exchange resins differing in type and structure. The quality of the treated solution was affected by numerous parameters, such as quality of the feed solution, membrane cut-off, resin type, dose and the solution contact time with the resin. A properly designed purification sy...

  15. High pressure as a tool for investigating protein-ligand interactions

    Energy Technology Data Exchange (ETDEWEB)

    Marchal, S [INSERM U128, IFR 122, 1919 route de Mende, F-34293 Montpellier Cedex 5 (France); Lange, R [INSERM U128, IFR 122, 1919 route de Mende, F-34293 Montpellier Cedex 5 (France); Tortora, P [Dipartimento di Biotecnologie e Bioscienze, Universita di Milano-Bicocca, Piazza della Scienza 2, I-20126 Milan (Italy); Balny, C [INSERM U128, IFR 122, 1919 route de Mende, F-34293 Montpellier Cedex 5 (France)

    2004-04-14

    In recent years, the application of pressure on biological systems has gained increasing interest. Pressure-induced destabilization of electrostatic and hydrophobic interactions is currently exploited to study conformational protein stability and macromolecular assemblies of proteins. Due to links between severe human pathologies and ordered protein oligomerization into aggregates, which have become apparent, a better knowledge of the molecular and structural determinants that ensure the packing efficiency and stability of such complexes has taken on special importance. Here, we report the effect of pressure on the property of human ataxin-3 of aggregation. The results indicate the importance of its polyglutamine chain length in the stability and the tendency of the protein to form spheroids. Partial unfolding of the protein leading to solvent exposure of hydrophobic domains appears to be a prerequisite in the aggregation process of ataxin-3.

  16. An exchange format for use-cases of hospital information systems.

    Science.gov (United States)

    Masuda, G; Sakamoto, N; Sakai, R; Yamamoto, R

    2001-01-01

    Object-oriented software development is a powerful methodology for development of large hospital information systems. We think use-case driven approach is particularly useful for the development. In the use-cases driven approach, use-cases are documented at the first stage in the software development process and they are used through the whole steps in a variety of ways. Therefore, it is important to exchange and share the use-cases and make effective use of them through the overall lifecycle of a development process. In this paper, we propose a method of sharing and exchanging use-case models between applications, developers, and projects. We design an XML based exchange format for use-cases. We then discuss an application of the exchange format to support several software development activities. We preliminarily implemented a support system for object-oriented analysis based on the exchange format. The result shows that using the structural and semantic information in the exchange format enables the support system to assist the object-oriented analysis successfully.

  17. Amine Landscaping to Maximize Protein-Dye Fluorescence and Ultrastable Protein-Ligand Interaction.

    Science.gov (United States)

    Jacobsen, Michael T; Fairhead, Michael; Fogelstrand, Per; Howarth, Mark

    2017-08-17

    Chemical modification of proteins provides great opportunities to control and visualize living systems. The most common way to modify proteins is reaction of their abundant amines with N-hydroxysuccinimide (NHS) esters. Here we explore the impact of amine number and positioning on protein-conjugate behavior using streptavidin-biotin, a central research tool. Dye-NHS modification of streptavidin severely damaged ligand binding, necessitating development of a new streptavidin-retaining ultrastable binding after labeling. Exploring the ideal level of dye modification, we engineered a panel bearing 1-6 amines per subunit: "amine landscaping." Surprisingly, brightness increased as amine number decreased, revealing extensive quenching following conventional labeling. We ultimately selected Flavidin (fluorophore-friendly streptavidin), combining ultrastable ligand binding with increased brightness after conjugation. Flavidin enhanced fluorescent imaging, allowing more sensitive and specific cell labeling in tissues. Flavidin should have wide application in molecular detection, providing a general insight into how to optimize simultaneously the behavior of the biomolecule and the chemical probe. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  18. MODELING OF AN ADVANCED HEAT EXCHANGE UNIT WITH MICROCHANNELS FOR A COMBINED PHOTOENERGY SYSTEM

    Directory of Open Access Journals (Sweden)

    R. V. Zaitsev

    2017-06-01

    Full Text Available Purpose. Mathematical modeling of the heat exchange unit main parameters for photoenergy system based on general models with forced circulation of heat transfer fluid. Methodology. To determine the coefficient of heat transfer at a given coolant temperature and surfaces temperature necessary to determine the temperature gradient in the wall of the heat exchanger. Temperature gradients can be determined by solving the equation of energy, which depends on the distribution of the flow rate in the flow. In general, a solution of convective heat transfer fluid to flow along the plane comes to solution of the system of differential equations. Results. In the paper features of the selection of theoretical basis and mathematical modeling of thermal processes in the heat exchange unit for combination photoenergy system are presented. As a result of the simulation conducted we improve and develop high-efficiency heat exchange unit with microchannels. Testing of the proposed unit proved its high efficiency through the implementation of turbulent flow of coolant with heat transfer coefficient at 18 kW/(m2×K. Analytical testing of the heat exchanger allowed showing that heat exchanger unit provides a stable operating temperature at less than 50 °C with the coolant flow rate is less than 0.3 m/s. Originality. Novelty of the proposed heat exchanger is in the optimal design of microchannels to improve the heat transfer coefficient. Practical value. The use of this heat exchanger will improve the quality and uniformity of cooling solar panels and reduce energy costs for circulation of fluid.

  19. Regulation of protein-ligand binding affinity by hydrogen bond pairing.

    Science.gov (United States)

    Chen, Deliang; Oezguen, Numan; Urvil, Petri; Ferguson, Colin; Dann, Sara M; Savidge, Tor C

    2016-03-01

    Hydrogen (H)-bonds potentiate diverse cellular functions by facilitating molecular interactions. The mechanism and the extent to which H-bonds regulate molecular interactions are a largely unresolved problem in biology because the H-bonding process continuously competes with bulk water. This interference may significantly alter our understanding of molecular function, for example, in the elucidation of the origin of enzymatic catalytic power. We advance this concept by showing that H-bonds regulate molecular interactions via a hitherto unappreciated donor-acceptor pairing mechanism that minimizes competition with water. On the basis of theoretical and experimental correlations between H-bond pairings and their effects on ligand binding affinity, we demonstrate that H-bonds enhance receptor-ligand interactions when both the donor and acceptor have either significantly stronger or significantly weaker H-bonding capabilities than the hydrogen and oxygen atoms in water. By contrast, mixed strong-weak H-bond pairings decrease ligand binding affinity due to interference with bulk water, offering mechanistic insight into why indiscriminate strengthening of receptor-ligand H-bonds correlates poorly with experimental binding affinity. Further support for the H-bond pairing principle is provided by the discovery and optimization of lead compounds targeting dietary melamine and Clostridium difficile toxins, which are not realized by traditional drug design methods. Synergistic H-bond pairings have therefore evolved in the natural design of high-affinity binding and provide a new conceptual framework to evaluate the H-bonding process in biological systems. Our findings may also guide wider applications of competing H-bond pairings in lead compound design and in determining the origin of enzymatic catalytic power.

  20. Magnetic levitation as a platform for competitive protein-ligand binding assays.

    Science.gov (United States)

    Shapiro, Nathan D; Soh, Siowling; Mirica, Katherine A; Whitesides, George M

    2012-07-17

    This paper describes a method based on magnetic levitation (MagLev) that is capable of indirectly measuring the binding of unlabeled ligands to unlabeled protein. We demonstrate this method by measuring the affinity of unlabeled bovine carbonic anhydrase (BCA) for a variety of ligands (most of which are benzene sulfonamide derivatives). This method utilizes porous gel beads that are functionalized with a common aryl sulfonamide ligand. The beads are incubated with BCA and allowed to reach an equilibrium state in which the majority of the immobilized ligands are bound to BCA. Since the beads are less dense than the protein, protein binding to the bead increases the overall density of the bead. This change in density can be monitored using MagLev. Transferring the beads to a solution containing no protein creates a situation where net protein efflux from the bead is thermodynamically favorable. The rate at which protein leaves the bead for the solution can be calculated from the rate at which the levitation height of the bead changes. If another small molecule ligand of BCA is dissolved in the solution, the rate of protein efflux is accelerated significantly. This paper develops a reaction-diffusion (RD) model to explain both this observation, and the physical-organic chemistry that underlies it. Using this model, we calculate the dissociation constants of several unlabeled ligands from BCA, using plots of levitation height versus time. Notably, although this method requires no electricity, and only a single piece of inexpensive equipment, it can measure accurately the binding of unlabeled proteins to small molecules over a wide range of dissociation constants (K(d) values within the range from ~10 nM to 100 μM are measured easily). Assays performed using this method generally can be completed within a relatively short time period (20 min-2 h). A deficiency of this system is that it is not, in its present form, applicable to proteins with molecular weight greater

  1. Development of a Waste Water Regenerative System - Using Sphagnum Moss Ion-exchange

    Science.gov (United States)

    McKeon, M.; Wheeler, R.; Leahy, Jj

    The use of inexpensive, light weight and regenerative systems in an enclosed environment is of great importance to sustained existence in such habitats as the International Space Station, Moon or even Mars. Many systems exist which utilise various synthetic ion exchangers to complete the process of waste water clean-up. These systems do have a very good exchange rate for cations but a very low exchange rate for anions. They also have a maximum capacity before they need regeneration. This research proposes a natural alternative to these synthetic ion-exchangers that utilises one of natures greatest ion-exchangers, that of Sphagnum Moss. Sphagna can be predominantly found in the nutrient poor environment of Raised Bogs, a type of isolated wetland with characteristic low pH and little interaction with the surrounding water table. All nutrients come from precipitation. The sphagna have developed as the bog's sponges, soaking up all available nutrients (both cation & anion) from the precipitation and eventually distributing them to the surrounding flora and fauna, through the water. The goal of this research is to use this ability in the processing of waste water from systems similar to isolated microgravity environments, to produce clean water for reuse in these environments. The nutrients taken up by the sphagna will also be utilised as a growth medium for cultivar growth, such as those selected for hydroponics' systems.

  2. Compact interior heat exchangers for CO{sub 2} mobile heat pumping systems

    Energy Technology Data Exchange (ETDEWEB)

    Hafner, Armin

    2003-07-01

    The natural refrigerant carbon dioxide (CO{sub 2}) offers new possibilities for design of flexible, efficient and environmentally safe mobile heat pumping systems. As high-efficient car engines with less waste heat are developed, extra heating of the passenger compartment is needed in the cold season. A reversible transcritical CO{sub 2} system with gliding temperature heat rejection can give high air delivery temperature which results in rapid heating of the passenger compartment and rapid defogging or defrosting of windows. When operated in cooling mode, the efficiency of transcritical CO{sub 2} systems is higher compared to common (HFC) air conditioning systems, at most dominant operating conditions. Several issues were identified for the design of compact interior heat exchangers for automotive reversible CO{sub 2} heat pumping systems. Among theses issues are: (1) Refrigerant flow distribution, (2) Heat exchanger fluid flow circuiting, (3) Air temperature uniformity downstream of the heat exchanger, (4) Minimization of temperature approach, (5) Windshield flash fogging due to retained water inside the heat exchanger, (6) Internal beat conduction in heating mode operation, and (7) Refrigerant side pressure drop In order to provide a basis for understanding these issues, the author developed a calculation model and set up a test facility and investigated different prototype heat exchangers experimentally.

  3. The evolutionary synchronization of the exchange rate system in ASEAN+6

    Science.gov (United States)

    Feng, Xiaobing; Hu, Haibo; Wang, Xiaofan

    2010-12-01

    Although there are extensive researches on the behavior of the world currency network, the complexity of the Asian regional currency system is not well understood regardless of its importance. Using daily exchange rates this paper examines exchange rate co-movements in the region before and after the China exchange rate reform. It was found that the correlation between Asian currencies and the US Dollar, the previous regional key currency has become weaker and intra-Asia interactions have increased. Cross sample entropy and cross entropy approaches are also applied to examine the synchrony behavior among the Asian currencies. The study also shows that the Asian exchange rate markets featured are neither stochastic nor efficient. These findings may shed some light on the in-depth understanding of collective behaviors in a regional currency network; they will also lay a theoretical foundation for further policy formulation in Asian currency integration.

  4. Prototype solar heated hot water systems and double-walled heat exchangers. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    A collection of quarterly and monthly reports from Elcam, Inc., covering progress made from January 1, 1978, through September 30, 1978, is presented. Elcam, is developing two solar-heated hot water prototype systems and two heat exchangers. This effort consists of development, manufacture, installation, maintenance, problem resolution, and system evaluation.

  5. An Evaluation of Strategies for Training Staff to Implement the Picture Exchange Communication System

    Science.gov (United States)

    Barnes, Clarissa S.; Dunning, Johnna L.; Rehfeldt, Ruth Anne

    2011-01-01

    The picture exchange communication system (PECS) is a functional communication system frequently used with individuals diagnosed with autism spectrum disorders who experience severe language delays (Frost & Bondy, 2002). Few empirical investigations have evaluated strategies for training direct care staff how to effectively implement PECS with…

  6. The Effects of Behavioral Skills Training on Implementation of the Picture Exchange Communication System

    Science.gov (United States)

    Rosales, Rocio; Stone, Karen; Rehfeldt, Ruth Anne

    2009-01-01

    The effectiveness of a behavioral skills training (BST) package to teach the implementation of the first three phases of the picture exchange communication system (PECS) was evaluated with 3 adults who had no history teaching any functional communication system. A multiple baseline design across participants was used to evaluate the effectiveness…

  7. Constructing query-driven dynamic machine learning model with application to protein-ligand binding sites prediction.

    Science.gov (United States)

    Yu, Dong-Jun; Hu, Jun; Li, Qian-Mu; Tang, Zhen-Min; Yang, Jing-Yu; Shen, Hong-Bin

    2015-01-01

    We are facing an era with annotated biological data rapidly and continuously generated. How to effectively incorporate new annotated data into the learning step is crucial for enhancing the performance of a bioinformatics prediction model. Although machine-learning-based methods have been extensively used for dealing with various biological problems, existing approaches usually train static prediction models based on fixed training datasets. The static approaches are found having several disadvantages such as low scalability and impractical when training dataset is huge. In view of this, we propose a dynamic learning framework for constructing query-driven prediction models. The key difference between the proposed framework and the existing approaches is that the training set for the machine learning algorithm of the proposed framework is dynamically generated according to the query input, as opposed to training a general model regardless of queries in traditional static methods. Accordingly, a query-driven predictor based on the smaller set of data specifically selected from the entire annotated base dataset will be applied on the query. The new way for constructing the dynamic model enables us capable of updating the annotated base dataset flexibly and using the most relevant core subset as the training set makes the constructed model having better generalization ability on the query, showing "part could be better than all" phenomenon. According to the new framework, we have implemented a dynamic protein-ligand binding sites predictor called OSML (On-site model for ligand binding sites prediction). Computer experiments on 10 different ligand types of three hierarchically organized levels show that OSML outperforms most existing predictors. The results indicate that the current dynamic framework is a promising future direction for bridging the gap between the rapidly accumulated annotated biological data and the effective machine-learning-based predictors. OSML

  8. Work exchange between quantum systems: the spin-oscillator model.

    Science.gov (United States)

    Schröder, Heiko; Mahler, Günter

    2010-02-01

    With the development of quantum thermodynamics it has been shown that relaxation to thermal equilibrium and with it the concept of heat flux may emerge directly from quantum mechanics. This happens for a large class of quantum systems if embedded into another quantum environment. In this paper, we discuss the complementary question of the emergence of work flux from quantum mechanics. We introduce and discuss two different methods to assess the work source quality of a system, one based on the generalized factorization approximation, the other based on generalized definitions of work and heat. By means of those methods, we show that small quantum systems can, indeed, act as work reservoirs. We illustrate this behavior for a simple system consisting of a spin coupled to an oscillator and investigate the effects of two different interactions on the work source quality. One case will be shown to allow for a work source functionality of arbitrarily high quality.

  9. Recent trends in the development of heat exchangers for geothermal systems

    Science.gov (United States)

    Franco, A.; Vaccaro, M.

    2017-11-01

    The potential use of geothermal resources has been a remarkable driver for market players and companies operating in the field of geothermal energy conversion. For this reason, medium to low temperature geothermal resources have been the object of recent rise in consideration, with strong reference to the perspectives of development of Organic Rankine Cycle (ORC) technology. The main components of geothermal plants based on ORC cycle are surely the heat exchangers. A lot of different heat exchangers are required for the operation of ORC plants. Among those it is surely of major importance the Recovery Heat Exchanger (RHE, typically an evaporator), in which the operating fluid is evaporated. Also the Recuperator, in regenerative Organic Rankine Cycle, is of major interest in technology. Another important application of the heat exchangers is connected to the condensation, according to the possibility of liquid or air cooling media availability. The paper analyzes the importance of heat exchangers sizing and the connection with the operation of ORC power plants putting in evidence the real element of innovation: the consideration of the heat exchangers as central element for the optimum design of ORC systems.

  10. Respiratory dynamics of discontinuous gas exchange in the tracheal system of the desert locust, Schistocerca gregaria.

    Science.gov (United States)

    Groenewald, Berlizé; Hetz, Stefan K; Chown, Steven L; Terblanche, John S

    2012-07-01

    Gas exchange dynamics in insects is of fundamental importance to understanding evolved variation in breathing patterns, such as discontinuous gas exchange cycles (DGCs). Most insects do not rely solely on diffusion for the exchange of respiratory gases but may also make use of respiratory movements (active ventilation) to supplement gas exchange at rest. However, their temporal dynamics have not been widely investigated. Here, intratracheal pressure, V(CO2) and body movements of the desert locust Schistocerca gregaria were measured simultaneously during the DGC and revealed several important aspects of gas exchange dynamics. First, S. gregaria employs two different ventilatory strategies, one involving dorso-ventral contractions and the other longitudinal telescoping movements. Second, although a true spiracular closed (C)-phase of the DGC could be identified by means of subatmospheric intratracheal pressure recordings, some CO(2) continued to be released. Third, strong pumping actions do not necessarily lead to CO(2) release and could be used to ensure mixing of gases in the closed tracheal system, or enhance water vapour reabsorption into the haemolymph from fluid-filled tracheole tips by increasing the hydrostatic pressure or forcing fluid into the haemocoel. Finally, this work showed that the C-phase of the DGC can occur at any pressure. These results provide further insights into the mechanistic basis of insect gas exchange.

  11. Nanofiltration: ion exchange system for effective surfactant removal from water solutions

    Directory of Open Access Journals (Sweden)

    I. Kowalska

    2014-12-01

    Full Text Available A system combining nanofiltration and ion exchange for highly effective separation of anionic surfactant from water solutions was proposed. The subjects of the study were nanofiltration polyethersulfone membranes and ion-exchange resins differing in type and structure. The quality of the treated solution was affected by numerous parameters, such as quality of the feed solution, membrane cut-off, resin type, dose and the solution contact time with the resin. A properly designed purification system made it possible to reduce the concentration of anionic surfactant below 1 mg L-1 from feed solutions containing surfactant in concentrations above the CMC value.

  12. 160 C PROTON EXCHANGE MEMBRANE (PEM) FUEL CELL SYSTEM DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    L.G. Marianowski

    2001-12-21

    The objectives of this program were: (a) to develop and demonstrate a new polymer electrolyte membrane fuel cell (PEMFC) system that operates up to 160 C temperatures and at ambient pressures for stationary power applications, and (b) to determine if the GTI-molded composite graphite bipolar separator plate could provide long term operational stability at 160 C or higher. There are many reasons that fuel cell research has been receiving much attention. Fuel cells represent environmentally friendly and efficient sources of electrical power generation that could use a variety of fuel sources. The Gas Technology Institute (GTI), formerly Institute of Gas Technology (IGT), is focused on distributed energy stationary power generation systems. Currently the preferred method for hydrogen production for stationary power systems is conversion of natural gas, which has a vast distribution system in place. However, in the conversion of natural gas into a hydrogen-rich fuel, traces of carbon monoxide are produced. Carbon monoxide present in the fuel gas will in time cumulatively poison, or passivate the active platinum catalysts used in the anodes of PEMFC's operating at temperatures of 60 to 80 C. Various fuel processors have incorporated systems to reduce the carbon monoxide to levels below 10 ppm, but these require additional catalytic section(s) with sensors and controls for effective carbon monoxide control. These CO cleanup systems must also function especially well during transient load operation where CO can spike 300% or more. One way to circumvent the carbon monoxide problem is to operate the fuel cell at a higher temperature where carbon monoxide cannot easily adsorb onto the catalyst and poison it. Commercially available polymer membranes such as Nafion{trademark} are not capable of operation at temperatures sufficiently high to prevent this. Hence this project investigated a new polymer membrane alternative to Nafion{trademark} that is capable of operation at

  13. Energy exchange in systems of particles with nonreciprocal interaction

    Energy Technology Data Exchange (ETDEWEB)

    Vaulina, O. S.; Lisina, I. I., E-mail: Irina.Lisina@mail.ru; Lisin, E. A. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2015-10-15

    A model is proposed to describe the sources of additional kinetic energy and its redistribution in systems of particles with a nonreciprocal interaction. The proposed model is shown to explain the qualitative specific features of the dust particle dynamics in the sheath region of an RF discharge. Prominence is given to the systems of particles with a quasi-dipole–dipole interaction, which is similar to the interaction induced by the ion focusing effects that occur in experiments on a laboratory dusty plasma, and with the shadow interaction caused by thermophoretic forces and Le Sage’s forces.

  14. Segmented heat exchanger

    Science.gov (United States)

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  15. A Novel RFID Sensing System Using Enhanced Surface Wave Technology for Battery Exchange Stations

    OpenAIRE

    Yeong-Lin Lai; Li-Chih Chang; Tai-Hwa Liu; Yi-Chun Sung; Cheng-Lun Yin

    2014-01-01

    This paper presents a novel radio-frequency identification (RFID) sensing system using enhanced surface wave technology for battery exchange stations (BESs) of electric motorcycles. Ultrahigh-frequency (UHF) RFID technology is utilized to automatically track and manage battery and user information without manual operation. The system includes readers, enhanced surface wave leaky cable antennas (ESWLCAs), coupling cable lines (CCLs), and small radiation patches (SRPs). The RFID sensing system ...

  16. Harmonised information exchange between decentralised food composition database systems

    DEFF Research Database (Denmark)

    Pakkala, Heikki; Christensen, Tue; Martínez de Victoria, Ignacio

    2010-01-01

    to those network nodes linked to the EuroFIR Web Services that will most likely have the requested information. The retrieved FCD are compiled into a specifically designed data interchange format (the EuroFIR Food Data Transport Package) in XML, which is sent back to the EuroFIR eSearch facility......Background/Objectives: The main aim of the European Food Information Resource (EuroFIR) project is to develop and disseminate a comprehensive, coherent and validated data bank for the distribution of food composition data (FCD). This can only be accomplished by harmonising food description and data...... documentation and by the use of standardised thesauri. Subjects/Methods: The data bank is implemented through a network of local FCD storages (usually national) under the control and responsibility of the local (national) EuroFIR partner. Results: The implementation of the system based on the Euro...

  17. Large scale free energy calculations for blind predictions of protein-ligand binding: the D3R Grand Challenge 2015.

    Science.gov (United States)

    Deng, Nanjie; Flynn, William F; Xia, Junchao; Vijayan, R S K; Zhang, Baofeng; He, Peng; Mentes, Ahmet; Gallicchio, Emilio; Levy, Ronald M

    2016-09-01

    We describe binding free energy calculations in the D3R Grand Challenge 2015 for blind prediction of the binding affinities of 180 ligands to Hsp90. The present D3R challenge was built around experimental datasets involving Heat shock protein (Hsp) 90, an ATP-dependent molecular chaperone which is an important anticancer drug target. The Hsp90 ATP binding site is known to be a challenging target for accurate calculations of ligand binding affinities because of the ligand-dependent conformational changes in the binding site, the presence of ordered waters and the broad chemical diversity of ligands that can bind at this site. Our primary focus here is to distinguish binders from nonbinders. Large scale absolute binding free energy calculations that cover over 3000 protein-ligand complexes were performed using the BEDAM method starting from docked structures generated by Glide docking. Although the ligand dataset in this study resembles an intermediate to late stage lead optimization project while the BEDAM method is mainly developed for early stage virtual screening of hit molecules, the BEDAM binding free energy scoring has resulted in a moderate enrichment of ligand screening against this challenging drug target. Results show that, using a statistical mechanics based free energy method like BEDAM starting from docked poses offers better enrichment than classical docking scoring functions and rescoring methods like Prime MM-GBSA for the Hsp90 data set in this blind challenge. Importantly, among the three methods tested here, only the mean value of the BEDAM binding free energy scores is able to separate the large group of binders from the small group of nonbinders with a gap of 2.4 kcal/mol. None of the three methods that we have tested provided accurate ranking of the affinities of the 147 active compounds. We discuss the possible sources of errors in the binding free energy calculations. The study suggests that BEDAM can be used strategically to discriminate

  18. Experimental Evaluation of the Training Structure of the Picture Exchange Communication System (PECS)

    Science.gov (United States)

    Cummings, Anne R.; Carr, James E.; LeBlanc, Linda A.

    2012-01-01

    The Picture Exchange Communication System (PECS) is a picture-based alternative communication method that is widely accepted and utilized with individuals with disabilities. Although prior studies have examined the clinical efficacy of PECS, none have experimentally evaluated its manualized training structure. We experimentally evaluated the…

  19. Social-Communicative Effects of the Picture Exchange Communication System (PECS) in Autism Spectrum Disorders

    Science.gov (United States)

    Lerna, Anna; Esposito, Dalila; Conson, Massimiliano; Russo, Luigi; Massagli, Angelo

    2012-01-01

    Background: The Picture Exchange Communication System (PECS) is a common treatment choice for non-verbal children with autism. However, little empirical evidence is available on the usefulness of PECS in treating social-communication impairments in autism. Aims: To test the effects of PECS on social-communicative skills in children with autism,…

  20. Quantitative Synthesis and Component Analysis of Single-Participant Studies on the Picture Exchange Communication System

    Science.gov (United States)

    Tincani, Matt; Devis, Kathryn

    2011-01-01

    The "Picture Exchange Communication System" (PECS) has emerged as the augmentative communication intervention of choice for individuals with autism spectrum disorder (ASD), with a supporting body of single-participant studies. This report describes a meta-analysis of 16 single-participant studies on PECS with percentage of nonoverlapping data…

  1. Comparing the Picture Exchange Communication System and Sign Language Training for Children with Autism

    Science.gov (United States)

    Tincani, Matt

    2004-01-01

    This study compared the effects of Picture Exchange Communication System (PECS) and sign language training on the acquisition of mands (requests for preferred items) of students with autism. The study also examined the differential effects of each modality on students' acquisition of vocal behavior. Participants were two elementary school students…

  2. A Review of the Efficacy of the Picture Exchange Communication System Intervention

    Science.gov (United States)

    Preston, Deborah; Carter, Mark

    2009-01-01

    The Picture Exchange Communication System (PECS) is a communication program that has become widely used, especially with children with autism. This paper reports the results of a review of the empirical literature on PECS. A descriptive review is provided of the 27 studies identified, which included randomized controlled trials (RCTs), other group…

  3. The Picture Exchange Communication System (PECS): What Do the Data Say?

    Science.gov (United States)

    Sulzer-Azaroff, Beth; Hoffman, Anne O.; Horton, Catherine B.; Bondy, Andrew; Frost, Lori

    2009-01-01

    Originally designed to enable young children with autism lacking functional communication to initiate requests and to describe what they observed, the Picture Exchange Communication System (PECS) has been the subject of an ever-expanding body of research and development. Thirty-four peer-reviewed published reports on PECS are analyzed in this…

  4. A Preliminary Analysis of Teaching Improvisation with the Picture Exchange Communication System to Children with Autism

    Science.gov (United States)

    Marckel, Julie M.; Neef, Nancy A.; Ferreri, Summer J.

    2006-01-01

    Two young boys with autism who used the picture exchange communication system were taught to solve problems (improvise) by using descriptors (functions, colors, and shapes) to request desired items for which specific pictures were unavailable. The results of a multiple baseline across descriptors showed that training increased the number of…

  5. A Further Evaluation of Behavioral Skills Training for Implementation of the Picture Exchange Communication System

    Science.gov (United States)

    Homlitas, Christa; Rosales, Rocío; Candel, Lindsay

    2014-01-01

    We evaluated the effectiveness of a behavioral skills training package to teach implementation of Phases 1, 2, and 3A of the picture exchange communication system (PECS) to teachers employed at a therapeutic center for children with autism. Probes in the natural environment and follow-up were conducted with children who were assigned to work with…

  6. Understanding the Picture Exchange Communication System and Its Application in Physical Education

    Science.gov (United States)

    Green, Amanda; Sandt, Dawn

    2013-01-01

    This article presents the Picture Exchange Communication System (PECS) and its applications in physical education. The PECS is an appropriate communication intervention for students with autism who lack functional communication skills. It is often confused with other visual support strategies, so the authors delineate the six phases of PECS and…

  7. Heat exchanger modeling and identification for control of waste heat recovery systems in diesel engines

    NARCIS (Netherlands)

    Feru, E.; Willems, F.P.T.; Rojer, C.; Jager, B. de; Steinbuch, M.

    2013-01-01

    To meet future CO2 emission targets, Waste Heat Recovery systems have recently attracted much attention for automotive applications, especially for long haul trucks. This paper focuses on the development of a dynamic counter-flow heat exchanger model for control purposes. The model captures the

  8. Using the Picture Exchange Communication System with Students with Visual Impairment

    Science.gov (United States)

    Ivy, Sarah E.; Hatton, Deborah D.; Hooper, Jonathan D.

    2014-01-01

    Students with visual impairment (VI) were taught to request using the Picture Exchange Communication System (PECS) and tangible symbols. Participants were four males with additional disabilities, 5 to 11 years old, who had little to no functional vision. A functional relation between PECS Phase 1 and requesting was established using a multiple…

  9. Interoperability and models for exchange of data between information systems in public administration

    Science.gov (United States)

    Glavev, Victor

    2016-12-01

    The types of software applications used by public administrations can be divided in three main groups: document management systems, record management systems and business process systems. Each one of them generates outputs that can be used as input data to the others. This is the main reason that requires exchange of data between these three groups and well defined models that should be followed. There are also many other reasons that will be discussed in the paper. Interoperability is a key aspect when those models are implemented, especially when there are different manufactures of systems in the area of software applications used by public authorities. The report includes examples of implementation of models for exchange of data between software systems deployed in one of the biggest administration in Bulgaria.

  10. Investigation of heat exchangers for energy conversion systems of megawatt-class space power plants

    Science.gov (United States)

    Ilmov, D. N.; Mamontov, Yu. N.; Skorohodov, A. S.; Smolyarov, V. A.; Filatov, N. I.

    2016-01-01

    The specifics of operation (high temperatures in excess of 1000 K and large pressure drops of several megapascals between "hot" and "cold" coolant paths) of heat exchangers in the closed circuit of a gasturbine power converter operating in accordance with the Brayton cycle with internal heat recovery are analyzed in the context of construction of space propulsion systems. The design of a heat-exchange matrix made from doubly convex stamped plates with a specific surface relief is proposed. This design offers the opportunity to construct heat exchangers with the required parameters (strength, rigidity, weight, and dimensions) for the given operating conditions. The diagram of the working area of a test bench is presented, and the experimental techniques are outlined. The results of experimental studies of heat exchange and flow regimes in the models of heat exchangers with matrices containing 50 and 300 plates for two pairs of coolants (gas-gas and gas-liquid) are detailed. A criterion equation for the Nusselt number in the range of Reynolds numbers from 200 to 20 000 is proposed. The coefficients of hydraulic resistance for each coolant path are determined as functions of the Reynolds number. It is noted that the pressure in the water path in the "gas-liquid" series of experiments remained almost constant. This suggests that no well-developed processes of vaporization occurred within this heat-exchange matrix design even when the temperature drop between gas and water was as large as tens or hundreds of degrees. The obtained results allow one to design flight heat exchangers for various space power plants.

  11. Heat Exchanger Design Options and Tritium Transport Study for the VHTR System

    Energy Technology Data Exchange (ETDEWEB)

    Chang H. Oh; Eung S. Kim

    2008-09-01

    This report presents the results of a study conducted to consider heat exchanger options and tritium transport in a very high temperature reactor (VHTR) system for the Next Generation Nuclear Plant Project. The heat exchanger options include types, arrangements, channel patterns in printed circuit heat exchangers (PCHE), coolant flow direction, and pipe configuration in shell-and-tube designs. Study considerations include: three types of heat exchanger designs (PCHE, shell-and-tube, and helical coil); single- and two-stage unit arrangements; counter-current and cross flow configurations; and straight pipes and U-tube designs in shell-and-tube type heat exchangers. Thermal designs and simple stress analyses were performed to estimate the heat exchanger options, and the Finite Element Method was applied for more detailed calculations, especially for PCHE designs. Results of the options study show that the PCHE design has the smallest volume and heat transfer area, resulting in the least tritium permeation and greatest cost savings. It is theoretically the most reliable mechanically, leading to a longer lifetime. The two-stage heat exchanger arrangement appears to be safer and more cost effective. The recommended separation temperature between first and second stages in a serial configuration is 800oC, at which the high temperature unit is about one-half the size of the total heat exchanger core volume. Based on simplified stress analyses, the high temperature unit will need to be replaced two or three times during the plant’s lifetime. Stress analysis results recommend the off-set channel pattern configuration for the PCHE because stress reduction was estimated at up to 50% in this configuration, resulting in a longer lifetime. The tritium transport study resulted in the development of a tritium behavior analysis code using the MATLAB Simulink code. In parallel, the THYTAN code, previously performed by Ohashi and Sherman (2007) on the Peach Bottom data, was revived

  12. Detection of stratosphere troposphere exchange in cut-off low systems

    Science.gov (United States)

    Price, Jeremy D.; Vaughan, Geraint

    1994-01-01

    The Aberystwyth MST radar has been used as part of the TOASTE program to study the structure of the tropopause in cut-off-low system with an aim to identifying regions where stratosphere-troposphere exchange are taking place. Theory predicts that the vertical gradient in reflected power is proportional to the static stability of the reflecting region, and should therefore resolve tropopause structure. Comparisons of MST power profiles with radiosonde data are presented and show good agreement, revealing regions of indefinite tropopauses, where stratosphere-troposphere exchange is thought to take place. The continuous nature of MST data allows an estimation of the size of these regions.

  13. Activity systems modeling as a theoretical lens for social exchange studies

    Directory of Open Access Journals (Sweden)

    Ernest Jones

    2016-01-01

    Full Text Available The social exchange perspective seeks to acknowledge, understand and predict the dynamics of social interactions. Empirical research involving social exchange constructs have grown to be highly technical including confirmatory factor analysis to assess construct distinctiveness and structural equation modeling to assess construct causality. Each study seemingly strives to assess how underlying social exchange theoretic constructs interrelate. Yet despite this methodological depth and resultant explanatory and predictive power, a significant number of studies report findings that, once synthesized, suggest an underlying persistent threat of conceptual or construct validity brought about by a search for epistemological parsimony. Further, it is argued that a methodological approach that embraces inherent complexity such as activity systems modeling facilitates the search for simplified models while not ignoring contextual factors.

  14. Serial robot for the trajectory optimization and error compensation of TMT mask exchange system

    Science.gov (United States)

    Wang, Jianping; Zhang, Feifan; Zhou, Zengxiang; Zhai, Chao

    2015-10-01

    Mask exchange system is the main part of Multi-Object Broadband Imaging Echellette (MOBIE) on the Thirty Meter Telescope (TMT). According to the conception of the TMT mask exchange system, the pre-design was introduced in the paper which was based on IRB 140 robot. The stiffness model of IRB 140 in SolidWorks was analyzed under different gravity vectors for further error compensation. In order to find the right location and path planning, the robot and the mask cassette model was imported into MOBIE model to perform different schemes simulation. And obtained the initial installation position and routing. Based on these initial parameters, IRB 140 robot was operated to simulate the path and estimate the mask exchange time. Meanwhile, MATLAB and ADAMS software were used to perform simulation analysis and optimize the route to acquire the kinematics parameters and compare with the experiment results. After simulation and experimental research mentioned in the paper, the theoretical reference was acquired which could high efficient improve the structure of the mask exchange system parameters optimization of the path and precision of the robot position.

  15. Are there differences in health information exchange by health system type?

    Science.gov (United States)

    Opoku-Agyeman, William; Menachemi, Nir

    2016-01-01

    Despite the potential of health information exchange (HIE) to improve safety and reduce cost, hospitals have been slow to adopt HIE with only 30% of U.S. hospitals doing so in 2012. The aim of this study was to explore the relationship between different health system types and how they engage in HIE. Data on health system types and engagement in HIE activity were combined with secondary hospital characteristics. Ordinal logistic regression analyses were used to examine the relationship between a scale measuring the level of HIE engagement and health system type controlling for hospital and market characteristics. Data from 1552 hospitals were available for analyses. Overall, hospital in a health system of any kind exchanged more patient data elements (e.g., patient demographics, clinical summaries, laboratory results, medication history, and radiology report) compared with stand-alone hospitals (3.82 vs. 1.80, p difference in the exchange of patient health data. Hospital engagement in HIE is associated with health system membership. These findings will assist hospital leaders and managers to better understand how the structure and nature of their system may influence what their individual hospital can and cannot do in their decision to engage in HIE and other decisions that support the overall system objectives.

  16. Effects of Picture Exchange Communication System on Communication and Behavioral Anomalies in Autism

    OpenAIRE

    Malhotra, Shahzadi; Rajender, Gaurav; Bhatia, Manjeet S.; Singh, Tej B.

    2010-01-01

    Communication skills deficits and stereotyped behaviors are frequently found among people with pervasive developmental disabilities like autism. These communication and behavioral oddities of autism are often considered to be difficult to treat and are challenging. Picture exchange communication system (PECS) is a six-phase picture system based on applied behavior analysis and is specially designed to overcome these communication difficulties in children with autism by encouraging the child t...

  17. Application of an open circuit indirect calorimetry system for gaseous exchange measurements in small ruminant nutrition

    OpenAIRE

    CRISCIONI FERREIRA, PATRICIA FABIOLA

    2016-01-01

    [EN] The main objective of this Thesis was to study the energy metabolism in small ruminants under different nutrition sceneries. As methodology we utilized indirect calorimetry instead of direct calorimetry or feeding trials. Within indirect calorimetry we worked with a portable open circuit gas exchange system with a head hood. This open circuit respiration system permitted completed the whole energy balance and evaluate the efficiency of utilization of the energy of the diet for different ...

  18. Natural convection heat exchangers for solar water heating systems. Technical progress report, October 1, 1995--November 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, J.H.

    1998-06-01

    The goals of this project are: (1) to develop guidelines for the design and use of thermosypohon side-arm heat exchangers in solar domestic water heating systems, and (2) to establish appropriate modeling and testing criteria for evaluating the performance of systems using this type of heat exchanger.

  19. The strategic use of standardized information exchange technology in a university health system.

    Science.gov (United States)

    Cheng, Po-Hsun; Chen, Heng-Shuen; Lai, Feipei; Lai, Jin-Shin

    2010-04-01

    This article illustrates a Web-based health information system that is comprised of specific information exchange standards related to health information for healthcare services in National Taiwan University Health System. Through multidisciplinary teamwork, medical and informatics experts collaborated and studied on system scope definition, standard selection challenges, system implementation barriers, system management outcomes, and further expandability of other systems. After user requirement analysis and prototyping, from 2005 to 2008, an online clinical decision support system with multiple functions of reminding and information push was implemented. It was to replace its original legacy systems and serve among the main hospital and three branches of 180-200 clinics and 7,500-8,000 patient visits per day. To evaluate the effectiveness of this system, user surveys were performed, which revealed that the average score of user satisfaction increased from 2.80 to 3.18 on a 4-point scale. Among the items, especially e-learning for training service, courtesy communications for system requests, and courtesy communications for system operations showed statistically significant improvement. From this study, the authors concluded that standardized information exchange technologies can be used to create a brand new enterprise value and steadily obtain more competitive advantages for a prestige healthcare system.

  20. Enabling Data Exchange in Two-Agent Interactive Systems Under Privacy Constraints

    Science.gov (United States)

    Belmega, E. Veronica; Sankar, Lalitha; Poor, H. Vincent

    2015-10-01

    Data collecting agents in large networks, such as the electric power system, need to share information (measurements) for estimating the system state in a distributed manner. However, privacy concerns may limit or prevent this exchange leading to a tradeoff between state estimation fidelity and privacy (referred to as competitive privacy). This paper builds upon a recent information-theoretic result (using mutual information to measure privacy and mean-squared error to measure fidelity) that quantifies the region of achievable distortion-leakage tuples in a two-agent network. The objective of this paper is to study centralized and decentralized mechanisms that can enable and sustain non-trivial data exchanges among the agents. A centralized mechanism determines the data sharing policies that optimize a network-wide objective function combining the fidelities and leakages at both agents. Using common-goal games and best-response analysis, the optimal policies allow for distributed implementation. In contrast, in the decentralized setting, repeated discounted games are shown to naturally enable data exchange without any central control nor economic incentives. The effect of repetition is modeled by a time-averaged payoff function at each agent which combines its fidelity and leakage at each interaction stage. For both approaches, it is shown that non-trivial data exchange can be sustained for specific fidelity ranges even when privacy is a limiting factor.

  1. Pressure Pump Power Control in the Primary Circuit of the Heat Exchange System

    Directory of Open Access Journals (Sweden)

    Shilin Aleksandr

    2017-01-01

    Full Text Available In this paper we consider the problem of speed in hot water systems where highly efficient plate heat exchanger is used. Especially marked the problem which is connected with long transition drive of constant speed exceeding the time of the heat exchanger accumulative tank emptying more than twice. As a regulating element in the heat exchange system there was proposed to use asynchronous electric drive of pressure pump in the primary circuit of the heat exchanger. For correct use of such electric drive we solved the problem of control object mathematical model synthesis, which has non-linear properties, in particular, the transfer coefficient of the circuit can vary in more than 6 times. At the same time there was revealed the dependence of the transfer coefficient on the motor speed, which must be considered in the controller synthesis. In conclusion we suggested the solutions of regulators synthesis tasks with customizable settings for speed and switchable structure between relay λ and PI regulators.

  2. Setting up a large set of protein-ligand PDB complexes for the development and validation of knowledge-based docking algorithms.

    Science.gov (United States)

    Diago, Luis A; Morell, Persy; Aguilera, Longendri; Moreno, Ernesto

    2007-08-25

    The number of algorithms available to predict ligand-protein interactions is large and ever-increasing. The number of test cases used to validate these methods is usually small and problem dependent. Recently, several databases have been released for further understanding of protein-ligand interactions, having the Protein Data Bank as backend support. Nevertheless, it appears to be difficult to test docking methods on a large variety of complexes. In this paper we report the development of a new database of protein-ligand complexes tailored for testing of docking algorithms. Using a new definition of molecular contact, small ligands contained in the 2005 PDB edition were identified and processed. The database was enriched in molecular properties. In particular, an automated typing of ligand atoms was performed. A filtering procedure was applied to select a non-redundant dataset of complexes. Data mining was performed to obtain information on the frequencies of different types of atomic contacts. Docking simulations were run with the program DOCK. We compiled a large database of small ligand-protein complexes, enriched with different calculated properties, that currently contains more than 6000 non-redundant structures. As an example to demonstrate the value of the new database, we derived a new set of chemical matching rules to be used in the context of the program DOCK, based on contact frequencies between ligand atoms and points representing the protein surface, and proved their enhanced efficiency with respect to the default set of rules included in that program. The new database constitutes a valuable resource for the development of knowledge-based docking algorithms and for testing docking programs on large sets of protein-ligand complexes. The new chemical matching rules proposed in this work significantly increase the success rate in DOCKing simulations. The database developed in this work is available at http://cimlcsext.cim.sld.cu:8080/screeningbrowser/.

  3. Setting up a large set of protein-ligand PDB complexes for the development and validation of knowledge-based docking algorithms

    Directory of Open Access Journals (Sweden)

    Aguilera Longendri

    2007-08-01

    Full Text Available Abstract Background The number of algorithms available to predict ligand-protein interactions is large and ever-increasing. The number of test cases used to validate these methods is usually small and problem dependent. Recently, several databases have been released for further understanding of protein-ligand interactions, having the Protein Data Bank as backend support. Nevertheless, it appears to be difficult to test docking methods on a large variety of complexes. In this paper we report the development of a new database of protein-ligand complexes tailored for testing of docking algorithms. Methods Using a new definition of molecular contact, small ligands contained in the 2005 PDB edition were identified and processed. The database was enriched in molecular properties. In particular, an automated typing of ligand atoms was performed. A filtering procedure was applied to select a non-redundant dataset of complexes. Data mining was performed to obtain information on the frequencies of different types of atomic contacts. Docking simulations were run with the program DOCK. Results We compiled a large database of small ligand-protein complexes, enriched with different calculated properties, that currently contains more than 6000 non-redundant structures. As an example to demonstrate the value of the new database, we derived a new set of chemical matching rules to be used in the context of the program DOCK, based on contact frequencies between ligand atoms and points representing the protein surface, and proved their enhanced efficiency with respect to the default set of rules included in that program. Conclusion The new database constitutes a valuable resource for the development of knowledge-based docking algorithms and for testing docking programs on large sets of protein-ligand complexes. The new chemical matching rules proposed in this work significantly increase the success rate in DOCKing simulations. The database developed in this work is

  4. CONAN-The cruncher of local exchange coefficients for strongly interacting confined systems in one dimension

    Science.gov (United States)

    Loft, N. J. S.; Kristensen, L. B.; Thomsen, A. E.; Volosniev, A. G.; Zinner, N. T.

    2016-12-01

    We consider a one-dimensional system of particles with strong zero-range interactions. This system can be mapped onto a spin chain of the Heisenberg type with exchange coefficients that depend on the external trap. In this paper, we present an algorithm that can be used to compute these exchange coefficients. We introduce an open source code CONAN (Coefficients of One-dimensional N-Atom Networks) which is based on this algorithm. CONAN works with arbitrary external potentials and we have tested its reliability for system sizes up to around 35 particles. As illustrative examples, we consider a harmonic trap and a box trap with a superimposed asymmetric tilted potential. For these examples, the computation time typically scales with the number of particles as O(N 3.5 ± 0.4) . Computation times are around 10 s for N = 10 particles and less than 10 min for N = 20 particles.

  5. Grating exchange system of independent mirror supported by floating rotary stage

    Science.gov (United States)

    Zhang, Jianhuan; Tao, Jin; Liu, Yan; Nan, Yan

    2015-10-01

    The performance of The Grating Exchange System can satisfy the Thirty Meter Telescope - TMT for astronomical observation WFOS index requirements and satisfy the requirement of accuracy in the grating exchange. It is used to install in the MOBIE and a key device of MOBIE. The Wide Field Optical Spectrograph (WFOS) is one of the three first-light observing capabilities selected by the TMT Science Advisory Committee. The Multi-Object Broadband Imaging Echellette (MOBIE) instrument design concept has been developed to address the WFOS requirements as described in the TMT Science-Based Requirements Document (SRD). The Grating Exchange System uses a new type of separate movement way of three grating devices and a mirror device. Three grating devices with a mirror are able to achieve independence movement. This kind of grating exchange system can effectively solve the problem that the volume of the grating change system is too large and that the installed space of MOBIE instruments is too limit. This system adopts the good stability, high precision of rotary stage - a kind of using air bearing (Air bearing is famous for its ultra-high precision, and can meet the optical accuracy requirement) and rotation positioning feedback gauge turntable to support grating device. And with a kind of device which can carry greater weight bracket fixed on the MOBIE instrument, with two sets of servo motor control rotary stage and the mirror device respectively. And we use the control program to realize the need of exercising of the grating device and the mirror device. Using the stress strain analysis software--SolidWorks for stress and strain analysis of this structure. And then checking the structure of the rationality and feasibility. And prove that this system can realize the positioning precision under different working conditions can meet the requirements of imaging optical grating diffraction efficiency and error by the calculation and optical performance analysis.

  6. Experimental study on the effects of the number of heat exchanger modules on thermal characteristics in a premixed combustion system

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Byeonghun; Lee, Chang-Eon [Inha University, Incheon (Korea, Republic of); Kum, Sung Min [Halla University, Wonju (Korea, Republic of); Lee, Seungro [Chonbuk National University, Jeonju (Korea, Republic of)

    2016-01-15

    The effects of the number of heat exchanger modules on thermal characteristics were experimentally studied in a premixed combustion system with a cross-flow staggered-tube heat exchanger. The various heat exchanger modules, from 4 to 8, combined with a premixed burner were tested to investigate the performance of the heat exchanger through the surface area of the heat exchanger at various equivalence ratios. Additionally, the performance of the heat exchanger was analyzed by applying entropy generation theory to the heat exchanger system. As a result, although the heat transfer rate increases with the increase of the equivalence ratio, the NOx and CO concentrations also increase due to the increasing flame temperature. In addition, the entropy generation increases with an increase of the equivalence ratio. Furthermore, the heat transfer rate and the effectiveness are increased with the increase of the number of the heat exchanger modules. Also, the effectiveness is sharply increased when the number of the heat exchanger modules is increased from 4 to 5. Consequently, the optimal operating conditions regarding pollutant emission, effectiveness and entropy generation in this experimental range are 0.85 for the equivalence ratio and 8 for the number of heat exchanger modules.

  7. Continual Energy Management System of Proton Exchange Membrane Fuel Cell Hybrid Power Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Ren Yuan

    2016-01-01

    Full Text Available Current research status in energy management of Proton Exchange Membrane (PEM fuel cell hybrid power electric vehicles are first described in this paper, and then build the PEMFC/ lithium-ion battery/ ultra-capacitor hybrid system model. The paper analysis the key factors of the continuous power available in PEM fuel cell hybrid power electric vehicle and hybrid power system working status under different driving modes. In the end this paper gives the working flow chart of the hybrid power system and concludes the three items of the system performance analysis.

  8. Heat transfer analysis of underground U-type heat exchanger of ground source heat pump system.

    Science.gov (United States)

    Pei, Guihong; Zhang, Liyin

    2016-01-01

    Ground source heat pumps is a building energy conservation technique. The underground buried pipe heat exchanging system of a ground source heat pump (GSHP) is the basis for the normal operation of an entire heat pump system. Computational-fluid-dynamics (CFD) numerical simulation software, ANSYS-FLUENT17.0 have been performed the calculations under the working conditions of a continuous and intermittent operation over 7 days on a GSHP with a single-well, single-U and double-U heat exchanger and the impact of single-U and double-U buried heat pipes on the surrounding rock-soil temperature field and the impact of intermittent operation and continuous operation on the outlet water temperature. The influence on the rock-soil temperature is approximately 13 % higher for the double-U heat exchanger than that of the single-U heat exchanger. The extracted energy of the intermittent operation is 36.44 kw·h higher than that of the continuous mode, although the running time is lower than that of continuous mode, over the course of 7 days. The thermal interference loss and quantity of heat exchanged for unit well depths at steady-state condition of 2.5 De, 3 De, 4 De, 4.5 De, 5 De, 5.5 De and 6 De of sidetube spacing are detailed in this work. The simulation results of seven working conditions are compared. It is recommended that the side-tube spacing of double-U underground pipes shall be greater than or equal to five times of outer diameter (borehole diameter: 180 mm).

  9. Thermal stability of magnetic nanostructures in ion-bombardment-modified exchange-bias systems

    Science.gov (United States)

    Höink, V.; Sacher, M. D.; Schmalhorst, J.; Reiss, G.; Engel, D.; Weis, T.; Ehresmann, A.

    2006-06-01

    In magnetic bilayer systems consisting of a ferromagnet and an antiferromagnet the strength and direction of the exchange bias coupling can be set by ion bombardment in an external magnetic field. Magnetic nanostructures with a laterally varying exchange bias direction can be produced by local ion bombardment (ion bombardment induced magnetic patterning). We have investigated the thermal stability of these magnetic nanostructures by in situ x-ray photoemission electron microscopy while heating the samples above their blocking temperature. The investigations have been done at a 10.4μm×10.4μm large checkered pattern with a minimum size of the magnetic patterns of 800nm×800nm on a field cooled MnIr/CoFe stack and a pattern with 1.6μm wide lines with a periodicity of 5μm on an as-prepared MnIr/Co stack. The temperature dependence of the magnetization pattern can be explained by the temperature dependence of the exchange bias interaction, the exchange interaction energy, and the stray field energy. No substantial change of the thermal stability of magnetic patterns in remanence by the ion bombardment was found.

  10. Building a national electronic medical record exchange system - experiences in Taiwan.

    Science.gov (United States)

    Li, Yu-Chuan Jack; Yen, Ju-Chuan; Chiu, Wen-Ta; Jian, Wen-Shan; Syed-Abdul, Shabbir; Hsu, Min-Huei

    2015-08-01

    There are currently 501 hospitals and about 20,000 clinics in Taiwan. The National Health Insurance (NHI) system, which is operated by the NHI Administration, uses a single-payer system and covers 99.9% of the nation's total population of 23,000,000. Taiwan's NHI provides people with a high degree of freedom in choosing their medical care options. However, there is the potential concern that the available medical resources will be overused. The number of doctor consultations per person per year is about 15. Duplication of laboratory tests and prescriptions are not rare either. Building an electronic medical record exchange system is a good method of solving these problems and of improving continuity in health care. In November 2009, Taiwan's Executive Yuan passed the 'Plan for accelerating the implementation of electronic medical record systems in medical institutions' (2010-2012; a 3-year plan). According to this plan, a patient can, at any hospital in Taiwan, by using his/her health insurance IC card and physician's medical professional IC card, upon signing a written agreement, retrieve all important medical records for the past 6 months from other participating hospitals. The focus of this plan is to establish the National Electronic Medical Record Exchange Centre (EEC). A hospital's information system will be connected to the EEC through an electronic medical record (EMR) gateway. The hospital will convert the medical records for the past 6 months in its EMR system into standardized files and save them on the EMR gateway. The most important functions of the EEC are to generate an index of all the XML files on the EMR gateways of all hospitals, and to provide search and retrieval services for hospitals and clinics. The EEC provides four standard inter-institution EMR retrieval services covering medical imaging reports, laboratory test reports, discharge summaries, and outpatient records. In this system, we adopted the Health Level 7 (HL7) Clinical Document

  11. The Picture Exchange Communication System and his application of child with autism spectrum disorder

    OpenAIRE

    Kozlová, Veronika

    2011-01-01

    The bachelor thesis with title "The Picture Exchange Communication System and his application of child with autism spectrum disorder", deals with problems in communication of the children with autism spectrum disorders. One of the goals of the thesis is to submit a comprehensive overview of the essential knowledge of autism, history of autism, typical triad of symptoms (characteristic features of children with autism), etiology, and dividing autism by the adaptability. Another goal is to intr...

  12. A Preliminary Analysis of Teaching Improvisation with the Picture Exchange Communication System to Children with Autism

    OpenAIRE

    Marckel, Julie M; Neef, Nancy A; Ferreri, Summer J

    2006-01-01

    Two young boys with autism who used the picture exchange communication system were taught to solve problems (improvise) by using descriptors (functions, colors, and shapes) to request desired items for which specific pictures were unavailable. The results of a multiple baseline across descriptors showed that training increased the number of improvised requests, and that these skills generalized to novel items, and across settings and listeners in the natural environment.

  13. Factors influencing intentions to use social recommender systems: a social exchange perspective.

    Science.gov (United States)

    Chang, Tsung-Sheng; Hsiao, Wei-Hung

    2013-05-01

    This study employs the perspective of social exchange theory and seeks to understand users' intentions to use social recommender systems (SRS) through three psychological factors: trust, shared values, and reputation. We use structural equation modeling to analyze 221 valid questionnaires. The results show that trust has a direct positive influence on the intention to use SRS, followed by shared values, whereas reputation has an indirect influence on SRS use. We further discuss specific recommendations concerning these factors for developing SRS.

  14. A Generic Data Exchange System for Friend-to-Friend Networks

    OpenAIRE

    Soler, Cyril

    2017-01-01

    Decentralized private networks (a.k.a. darknets) guaranty privacy and concealment of information against global observers. Although a significant number of decentralized data distribution systems ex- ist, most of them target peer-to-peer architectures where any pair of nodes can exchange data using a temporary encrypted connection. Little has been done to achieve the same confidentiality in static darknet architectures, also known as “Friend-to-Friend” net- works, in which participants form a...

  15. Exchange Network

    Science.gov (United States)

    The Environmental Information Exchange Network (EIEN) is an Internet-based system used by state, tribal and territorial partners to securely share environmental and health information with one another and EPA.

  16. Replica exchange molecular simulation of Lennard-Jones particles in a two-dimensional confined system

    Science.gov (United States)

    Doi, Hideo; Yasuoka, Kenji

    2017-05-01

    Confined systems exhibit interesting properties that are applied to the fields of lubrication, adhesion and nanotechnology. The replica exchange molecular simulation method was applied to calculate the phase equilibrium points of Lennard-Jones particles in a two-dimensional confined system. The liquid-solid phase equilibrium points and the solid structure with a dependency of the slit width were determined and the order parameter of the solid structure was analyzed. Such confined systems are shown to be favorable for manipulation of the phase equilibrium points.

  17. Analysis and Perspective from the Complex Aerospace Systems Exchange (CASE) 2013

    Science.gov (United States)

    Jones, Kennie H.; Parker, Peter A.; Detweiler, Kurt N.; McGowan, Anna-Maria R.; Dress, David A.; Kimmel, William M.

    2014-01-01

    NASA Langley Research Center embedded four rapporteurs at the Complex Aerospace Systems Exchange (CASE) held in August 2013 with the objective to capture the essence of the conference presentations and discussions. CASE was established to provide a discussion forum among chief engineers, program managers, and systems engineers on challenges in the engineering of complex aerospace systems. The meeting consists of invited presentations and panels from industry, academia, and government followed by discussions among attendees. This report presents the major and reoccurring themes captured throughout the meeting and provides analysis and insights to further the CASE mission.

  18. Replica exchange molecular simulation of Lennard–Jones particles in a two-dimensional confined system

    Directory of Open Access Journals (Sweden)

    Hideo Doi

    2017-05-01

    Full Text Available Confined systems exhibit interesting properties that are applied to the fields of lubrication, adhesion and nanotechnology. The replica exchange molecular simulation method was applied to calculate the phase equilibrium points of Lennard–Jones particles in a two-dimensional confined system. The liquid–solid phase equilibrium points and the solid structure with a dependency of the slit width were determined and the order parameter of the solid structure was analyzed. Such confined systems are shown to be favorable for manipulation of the phase equilibrium points.

  19. Development of a system using the library of the Genie spectroscopy software and exchange of samples

    Energy Technology Data Exchange (ETDEWEB)

    Lapolli, Andre L.; Munita, Casimiro S., E-mail: alapolli@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    One the great difficulties in using the NAA method is in regards to the time that the operator spends exchanging the samples after each measurement. It becomes a big problem in routine analyses when various chemical elements are determined and then each sample must be measured at different decay times. The application of the automatic sample exchanger reduces the time analysis by several hours and reduces the tedious manual operation. Then, the effective use of NAA depends on the availability of a suitable automatic sample changer. There are some systems that are sold commercially, however many laboratories can not acquire them because they are costly. This paper presents altered programs the G2KNAA.REX, which created a screen making possible automatic or manual acquisitions by calling the old program NAAACQ.rex for the procurement manual and the new program NAAACQ2.rex for automatic requisitions. In conclusion, as can be seen in the program lines, the synchronization to automation, which unites the three systems (the computer, the Canberra Set, the sample exchanger) is done in a timely manner. The system was tested and is functioning in a satisfactory manner. (author)

  20. Photolithography and Fluorescence Correlation Spectroscopy used to examine the rates of exchange in reverse micelle systems

    Science.gov (United States)

    Norris, Zach; Mawson, Cara; Johnson, Kyron; Kessler, Sarah; Rebecca, Anne; Wolf, Nathan; Lim, Michael; Nucci, Nathaniel

    Reverse micelles are molecular complexes that encapsulate a nanoscale pool of water in a surfactant shell dissolved in non-polar solvent. These complexes have a wide range of applications, and in all cases, the degree to which reverse micelles (RM) exchange their contents is relevant for their use. Despite its importance, this aspect of RM behavior is poorly understood. Photolithography is employed here to create micro and nano scale fluidic systems in which mixing rates can be precisely measured using fluorescence correlation spectroscopy (FCS). Micro-channel patterns are etched using reactive ion etching process into a layer of silicon dioxide on crystalline silicon substrates. Solutions containing mixtures of reverse micelles, proteins, and fluorophores are placed into reservoirs in the patterns, while diffusion and exchange between RMs is monitored using a FCS system built from a modified confocal Raman spectrometer. Using this approach, the diffusion and exchange rates for RM systems are measured as a function of the components of the RM mixture. Funding provided by Rowan University.

  1. Combined quantum mechanics/molecular mechanics (QM/MM) simulations for protein-ligand complexes: free energies of binding of water molecules in influenza neuraminidase.

    Science.gov (United States)

    Woods, Christopher J; Shaw, Katherine E; Mulholland, Adrian J

    2015-01-22

    The applicability of combined quantum mechanics/molecular mechanics (QM/MM) methods for the calculation of absolute binding free energies of conserved water molecules in protein/ligand complexes is demonstrated. Here, we apply QM/MM Monte Carlo simulations to investigate binding of water molecules to influenza neuraminidase. We investigate five different complexes, including those with the drugs oseltamivir and peramivir. We investigate water molecules in two different environments, one more hydrophobic and one hydrophilic. We calculate the free-energy change for perturbation of a QM to MM representation of the bound water molecule. The calculations are performed at the BLYP/aVDZ (QM) and TIP4P (MM) levels of theory, which we have previously demonstrated to be consistent with one another for QM/MM modeling. The results show that the QM to MM perturbation is significant in both environments (greater than 1 kcal mol(-1)) and larger in the more hydrophilic site. Comparison with the same perturbation in bulk water shows that this makes a contribution to binding. The results quantify how electronic polarization differences in different environments affect binding affinity and also demonstrate that extensive, converged QM/MM free-energy simulations, with good levels of QM theory, are now practical for protein/ligand complexes.

  2. Risk management and market efficiency on the Midwest Independent System Operator electricity exchange

    Science.gov (United States)

    Jones, Kevin

    Midwest Independent Transmission System Operator, Inc. (MISO) is a non-profit regional transmission organization (RTO) that oversees electricity production and transmission across thirteen states and one Canadian province. MISO also operates an electronic exchange for buying and selling electricity for each of its five regional hubs. MISO oversees two types of markets. The forward market, which is referred to as the day-ahead (DA) market, allows market participants to place demand bids and supply offers on electricity to be delivered at a specified hour the following day. The equilibrium price, known as the locational marginal price (LMP), is determined by MISO after receiving sale offers and purchase bids from market participants. MISO also coordinates a spot market, which is known as the real-time (RT) market. Traders in the real-time market must submit bids and offers by thirty minutes prior to the hour for which the trade will be executed. After receiving purchase and sale offers for a given hour in the real time market, MISO then determines the LMP for that particular hour. The existence of the DA and RT markets allows producers and retailers to hedge against the large fluctuations that are common in electricity prices. Hedge ratios on the MISO exchange are estimated using various techniques. No hedge ratio technique examined consistently outperforms the unhedged portfolio in terms of variance reduction. Consequently, none of the hedge ratio methods in this study meet the general interpretation of FASB guidelines for a highly effective hedge. One of the major goals of deregulation is to bring about competition and increased efficiency in electricity markets. Previous research suggests that electricity exchanges may not be weak-form market efficient. A simple moving average trading rule is found to produce statistically and economically significant profits on the MISO exchange. This could call the long-term survivability of the MISO exchange into question.

  3. Time dependency of psychotherapeutic exchanges: the contribution of the theory of dynamic systems in analyzing process.

    Science.gov (United States)

    Salvatore, Sergio; Tschacher, Wolfgang

    2012-01-01

    This paper provides a general framework for the use of Theory of Dynamic Systems (TDS) in the field of psychotherapy research. Psychotherapy is inherently dynamic, namely a function of time. Consequently, the improvement of construct validity and clinical relevance of psychotherapy process research require the development of models of investigation allowing dynamic mappings of clinical exchange. Thus, TDS becomes a significant theoretical and methodological reference. The paper focuses two topics. First, the main concepts of TDS are briefly introduced together with a basic typology of approaches developed within this domain. Second, we propose a repertoire of investigation strategies that can be used to capture the dynamic nature of clinical exchange. In this way we intend to highlight the feasibility and utility of strategies of analysis informed by TDS.

  4. Time dependency of psychotherapeutic exchanges: The contribution of the Theory of Dynamic Systems in analyzing process

    Directory of Open Access Journals (Sweden)

    Sergio eSalvatore

    2012-07-01

    Full Text Available This paper provides a general framework for the use of TDS in the field of psychotherapy research. Psychotherapy is inherently dynamic, namely a function of time. Consequently, the improvement of construct validity and clinical relevance of psychotherapy process research require the development of models of investigation allowing dynamic mappings of clinical exchange. Thus, the Theory of Dynamic Systems (TDS becomes a significant theoretical and methodological reference. The paper focuses two topics. First, the main concepts of TDS are briefly introduced together with a basic typology of approaches developed within this domain. Second, we propose a repertoire of investigation strategies that can be used to capture the dynamic nature of clinical exchange. In this way we intend to highlight the feasibility and utility of strategies of analysis informed by TDS.

  5. Fault diagnosis for the heat exchanger of the aircraft environmental control system based on the strong tracking filter.

    Science.gov (United States)

    Ma, Jian; Lu, Chen; Liu, Hongmei

    2015-01-01

    The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system's efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger.

  6. Fault diagnosis for the heat exchanger of the aircraft environmental control system based on the strong tracking filter.

    Directory of Open Access Journals (Sweden)

    Jian Ma

    Full Text Available The aircraft environmental control system (ECS is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system's efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger.

  7. Two-Phase Cryogenic Heat Exchanger for the Thermodynamic Vent System

    Science.gov (United States)

    Christie, Robert J.

    2011-01-01

    A two-phase cryogenic heat exchanger for a thermodynamic vent system was designed and analyzed, and the predicted performance was compared with test results. A method for determining the required size of the Joule-Thomson device was also developed. Numerous sensitivity studies were performed to show that the design was robust and possessed a comfortable capacity margin. The comparison with the test results showed very similar heat extraction performance for similar inlet conditions. It was also shown that estimates for Joule- Thomson device flow rates and exit quality can vary significantly and these need to be accommodated for with a robust system design.

  8. Control of Advanced Reactor-Coupled Heat Exchanger System: Incorporation of Reactor Dynamics in System Response to Load Disturbances

    Directory of Open Access Journals (Sweden)

    Isaac Skavdahl

    2016-12-01

    Full Text Available Alternative control schemes for an Advanced High Temperature Reactor system consisting of a reactor, an intermediate heat exchanger, and a secondary heat exchanger (SHX are presented in this paper. One scheme is designed to control the cold outlet temperature of the SHX (Tco and the hot outlet temperature of the intermediate heat exchanger (Tho2 by manipulating the hot-side flow rates of the heat exchangers (Fh/Fh2 responding to the flow rate and temperature disturbances. The flow rate disturbances typically require a larger manipulation of the flow rates than temperature disturbances. An alternate strategy examines the control of the cold outlet temperature of the SHX (Tco only, since this temperature provides the driving force for energy production in the power conversion unit or the process application. The control can be achieved by three options: (1 flow rate manipulation; (2 reactor power manipulation; or (3 a combination of the two. The first option has a quicker response but requires a large flow rate change. The second option is the slowest but does not involve any change in the flow rates of streams. The third option appears preferable as it has an intermediate response time and requires only a minimal flow rate change.

  9. Improvement of an automated protein crystal exchange system PAM for high-throughput data collection

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, Masahiko, E-mail: masahiko.hiraki@kek.jp; Yamada, Yusuke; Chavas, Leonard M. G. [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Wakatsuki, Soichi [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); SLAC National Accelerator Laboratory, 2575 Sand Hill Road, MS 69, Menlo Park, CA 94025-7015 (United States); Stanford University, Beckman Center B105, Stanford, CA 94305-5126 (United States); Matsugaki, Naohiro [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2013-11-01

    A special liquid-nitrogen Dewar with double capacity for the sample-exchange robot has been created at AR-NE3A at the Photon Factory, allowing continuous fully automated data collection. In this work, this new system is described and the stability of its calibration is discussed. Photon Factory Automated Mounting system (PAM) protein crystal exchange systems are available at the following Photon Factory macromolecular beamlines: BL-1A, BL-5A, BL-17A, AR-NW12A and AR-NE3A. The beamline AR-NE3A has been constructed for high-throughput macromolecular crystallography and is dedicated to structure-based drug design. The PAM liquid-nitrogen Dewar can store a maximum of three SSRL cassettes. Therefore, users have to interrupt their experiments and replace the cassettes when using four or more of them during their beam time. As a result of investigation, four or more cassettes were used in AR-NE3A alone. For continuous automated data collection, the size of the liquid-nitrogen Dewar for the AR-NE3A PAM was increased, doubling the capacity. In order to check the calibration with the new Dewar and the cassette stand, calibration experiments were repeatedly performed. Compared with the current system, the parameters of the novel system are shown to be stable.

  10. Development of two-grating spectrometer for the charge exchange spectroscopy system on KSTAR

    Science.gov (United States)

    Lee, Hyungho; Song, Eun-ji; Park, Young-dong; Oh, Soo-ghee; Ko, Won-Ha

    2011-06-01

    The charge exchange spectroscopy (CES) system on Korea Superconducting Tokamak Advanced Research (KSTAR) was installed last year and had been applied to measure the C VI ion temperature and rotation velocity profiles. The ion temperature and rotation velocity profiles had been estimated from the C VI 5290.5 Å (n = 8-7) charge-exchange spectrum signal measured by a Czerny-Turner type spectrometer and a thinned back-illuminated charge coupled device (CCD) camera. However, the Czerny-Turner type spectrometer used for the KSTAR CES system showed so low signal to noise ratio for KSTAR plasmas in the 2010 experimental campaign that the time resolution of the CES system had been limited to 100 ms due to the increased exposure time of the attached CCD camera. Then, new two-grating spectrometer had been developed in order to improve the time resolution of the CES system. The spectrometer consists of two gratings (1200 g/mm and 1800 g/mm each) with additive configuration, concave mirrors (f = 50 cm), and a cylindrical lens (f = 50 cm). The time resolution of the CES system increases by a factor of 2-4 with the two-grating spectrometer. The C VI ion temperature and rotation velocity profiles obtained by the two-grating spectrometer are compared to those by Czerny-Turner type spectrometer in this paper.

  11. Modelling gradient elution of bioactive multicomponent systems in non-linear ion-exchange chromatography.

    Science.gov (United States)

    Wiesel, A; Schmidt-Traub, H; Lenz, J; Strube, J

    2003-07-18

    A theoretical framework for the ion-exchange behaviour of bioactive substances in non-linear ion-exchange chromatogaphy is described. The aim of the study was the creation of a model basis to support a process design for production-scale ion-exchange chromatography. The theory can be applied to a whole variety of biological substances, such as amino acids, polysaccharides, peptides and proteins and either isocratic or gradient elution can be carried out. The influence of the eluent concentration on the ion-exchange as well as on the characteristic charge was considered. Experimental measurements showed a strong non-linear ion-exchange equilibrium with a transition from a Langmuir-type to a sigmoidal isotherm at higher eluent concentrations. Hereby, the compound binds to the surface though it is not ionic. Therefore, the model considered the possibility of ion-exchange as well as adsorption. A simplified distribution of the counter-ions based on the Gouy-Chapman theory with a discrete distribution of the counter-ions was used. The theory was extended by a selectivity in the double layer to allow specific adsorption. Calculations of adsorption-elution cycles showed, in agreement with the experimental observations, the development of non-linear elution profiles with a desorption fronting. As a result, the column loading and the eluent concentration were varied. The effect of contaminants, in this case sodium ions, was investigated and included in the model. Finally, the model was extended to multicomponent systems to investigate the effect of side components on the retention behaviour. The development of the characteristic elution profiles and the effect of the column loading on the separation are discussed. Calculated concentration profiles along the column at discrete time steps were used to reveal the influence of side components and the underlying separation mechanism. The simulations provided a new insight into the phenomena involved in biochromatography and make

  12. Rapid RNA Exchange in Aqueous Two-Phase System and Coacervate Droplets

    Science.gov (United States)

    Jia, Tony Z.; Hentrich, Christian; Szostak, Jack W.

    2014-02-01

    Compartmentalization in a prebiotic setting is an important aspect of early cell formation and is crucial for the development of an artificial protocell system that effectively couples genotype and phenotype. Aqueous two-phase systems (ATPSs) and complex coacervates are phase separation phenomena that lead to the selective partitioning of biomolecules and have recently been proposed as membrane-free protocell models. We show in this study through fluorescence recovery after photobleaching (FRAP) microscopy that despite the ability of such systems to effectively concentrate RNA, there is a high rate of RNA exchange between phases in dextran/polyethylene glycol ATPS and ATP/poly-L-lysine coacervate droplets. In contrast to fatty acid vesicles, these systems would not allow effective segregation and consequent evolution of RNA, thus rendering these systems ineffective as model protocells.

  13. Study of heat exchange in cooling systems of heat-stressed structures

    Science.gov (United States)

    Vikulin, A. V.; Yaroslavtsev, N. L.; Zemlyanaya, V. A.

    2017-01-01

    Increasing working parameters of the cycle of gas-turbine engines, complicating design of gas-turbine plants, as well as growing aerodynamic, thermal, static, and dynamic loads, necessitate the development of promising cooling systems for heat-stressed structures. This work is devoted to an experimental study of heat exchange in ducts equipped with systems of inclined and cross walls (fins). It has been found that an increase in the Reynolds number Re from 3000 to 20000 leads to a decrease in the heat exchange, which is characterized by the relative Nusselt number overline{Nu}, by 19-30% at the angle of inclination of the walls φ = 0, 40°, 50°, and 90° if the length of the walls x w is comparable to the spacing b s and by 12-15% at φ = 30° and 90° if x w ≫ b s. If cross walls are used in cooling ducts, the length of the walls x w plays the governing role; an increase in this characteristic from 1.22 × 10-3 to 3.14 × 10-3 m leads to an increase in the intensity of heat exchange by 30-40% and to a decrease in the capacity of the entire system of the walls. It has been shown that, on surfaces with wavy fins, the intensity of heat exchange is closest to that determined in the models under study. For example, values of the Colborne criterion StPr2/3 for ducts equipped with wavy fins and for the models under study differ only slightly (by 2-20% depending on the value of the angle φ). However, the difference for surfaces with short plate fins and ducts equipped with inclined walls is high (30-40%). This is due to the design features of these surfaces and to the severe effect of the inlet portion on heat exchange, since the surfaces are characterized by a higher ratio of the duct length to the hydraulic diameter L/d h at small fin thicknesses ((0.1-0.15) × 10-3 m). The experimental results can be used in developing designs of nozzle and rotor blades of high-temperature gas turbines in gas-turbine engines and plants.

  14. Fault Diagnosis for the Heat Exchanger of the Aircraft Environmental Control System Based on the Strong Tracking Filter

    Science.gov (United States)

    Ma, Jian; Lu, Chen; Liu, Hongmei

    2015-01-01

    The aircraft environmental control system (ECS) is a critical aircraft system, which provides the appropriate environmental conditions to ensure the safe transport of air passengers and equipment. The functionality and reliability of ECS have received increasing attention in recent years. The heat exchanger is a particularly significant component of the ECS, because its failure decreases the system’s efficiency, which can lead to catastrophic consequences. Fault diagnosis of the heat exchanger is necessary to prevent risks. However, two problems hinder the implementation of the heat exchanger fault diagnosis in practice. First, the actual measured parameter of the heat exchanger cannot effectively reflect the fault occurrence, whereas the heat exchanger faults are usually depicted by utilizing the corresponding fault-related state parameters that cannot be measured directly. Second, both the traditional Extended Kalman Filter (EKF) and the EKF-based Double Model Filter have certain disadvantages, such as sensitivity to modeling errors and difficulties in selection of initialization values. To solve the aforementioned problems, this paper presents a fault-related parameter adaptive estimation method based on strong tracking filter (STF) and Modified Bayes classification algorithm for fault detection and failure mode classification of the heat exchanger, respectively. Heat exchanger fault simulation is conducted to generate fault data, through which the proposed methods are validated. The results demonstrate that the proposed methods are capable of providing accurate, stable, and rapid fault diagnosis of the heat exchanger. PMID:25823010

  15. European radiological emergency information exchange systems developed at EC-JRC/IES: current status future developments

    Energy Technology Data Exchange (ETDEWEB)

    De Cort, M.; Vries, G. de; Galmarini, S. [European Comission, Ispra (Italy). Inst. for Environment and Sustainability

    2003-07-01

    Shortly after the Chernobyl accident the European Commission initiated various activities with the scope to make early notification and reliable radiological information available to the EU member states in case of nuclear accidents. JRC-IES/REM in Ispra, Italy, is responsible for the scientific and technical development of three closely related projects that should be a source of valuable information to support decision support in European during major radiological accidents: ECURIE (European Community Urgent Radiological Information Exchange) notifies the competent authorities and continuously informs them about the current status of the accident and its consequences; EURDEP (European Radiological Data Exchange Platform) makes radiological monitoring data from most European countries available in real-time. Currently 23 European countries exchange on a daily basis gamma dose-rates; ENSEMBLE produces a comprehensive overview and comparison of the contamination predictions calculated by world-leading long-range dispersion models. Starting from the legal background these information systems are further described in detail, with an emphasis on their current status, our experience and the planned future developments. (orig.)

  16. Molecular recognition in a diverse set of protein-ligand interactions studied with molecular dynamics simulations and end-point free energy calculations.

    Science.gov (United States)

    Wang, Bo; Li, Liwei; Hurley, Thomas D; Meroueh, Samy O

    2013-10-28

    End-point free energy calculations using MM-GBSA and MM-PBSA provide a detailed understanding of molecular recognition in protein-ligand interactions. The binding free energy can be used to rank-order protein-ligand structures in virtual screening for compound or target identification. Here, we carry out free energy calculations for a diverse set of 11 proteins bound to 14 small molecules using extensive explicit-solvent MD simulations. The structure of these complexes was previously solved by crystallography and their binding studied with isothermal titration calorimetry (ITC) data enabling direct comparison to the MM-GBSA and MM-PBSA calculations. Four MM-GBSA and three MM-PBSA calculations reproduced the ITC free energy within 1 kcal·mol(-1) highlighting the challenges in reproducing the absolute free energy from end-point free energy calculations. MM-GBSA exhibited better rank-ordering with a Spearman ρ of 0.68 compared to 0.40 for MM-PBSA with dielectric constant (ε = 1). An increase in ε resulted in significantly better rank-ordering for MM-PBSA (ρ = 0.91 for ε = 10), but larger ε significantly reduced the contributions of electrostatics, suggesting that the improvement is due to the nonpolar and entropy components, rather than a better representation of the electrostatics. The SVRKB scoring function applied to MD snapshots resulted in excellent rank-ordering (ρ = 0.81). Calculations of the configurational entropy using normal-mode analysis led to free energies that correlated significantly better to the ITC free energy than the MD-based quasi-harmonic approach, but the computed entropies showed no correlation with the ITC entropy. When the adaptation energy is taken into consideration by running separate simulations for complex, apo, and ligand (MM-PBSAADAPT), there is less agreement with the ITC data for the individual free energies, but remarkably good rank-ordering is observed (ρ = 0.89). Interestingly, filtering MD snapshots by prescoring

  17. Alkaline Exchange Membrane (AEM) for High-Efficiency Fuel Cells, Electrolyzers and Regenerative Fuel Cell Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop an alkaline exchange membrane (AEM)for use as a polymer electrolyte in both fuel cell and electrolyzer systems.  The ultimate goal in AEM development is...

  18. Active heat exchange system development for latent heat thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Alario, J.; Kosson, R.; Haslett, R.

    1980-01-01

    The selection and evaluation phase of a program to develop active heat exchange concepts for latent heat thermal energy storage systems applicable to the utility industry is described. An evaluation of suitable storage media with melting points in the temperature range of interest (250 to 400/sup 0/C) limited the candidates to molten salts from the chloride, hydroxide and nitrate families, based on high storage capacity, good corrosion characteristics and availability in large quantities at reasonable cost. The specific salt recommended for laboratory tests was a chloride eutectic (20.5KCl-24.5NaCl-55.0MgCl/sub 2/% by wt), with a nominal melting point of 385/sup 0/C. Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application (300 MW/sub t/ storage for 6 hours). Two concepts were selected for hardware development: a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which has been nickel plated to decrease adhesion forces. In addition to improving performance by providing a nearly constant heat transfer rate during discharge, these active heat exchanger concepts were estimated to cost at least 25% less than the passive tube-shell design.

  19. Experimental evaluation of an adaptive Joule–Thomson cooling system including silicon-microfabricated heat exchanger and microvalve components

    OpenAIRE

    Zhu, Weibin; Park, Jong M.; White, Michael J.; Nellis, Gregory F.; Gianchandani, Yogesh B.

    2011-01-01

    This article reports the evaluation of a Joule–Thomson (JT) cooling system that combines two custom micromachined components—a Si/glass-stack recuperative heat exchanger and a piezoelectrically actuated expansion microvalve. With the microvalve controlling the flow rate, this system can modulate cooling to accommodate varying refrigeration loads. The perforated plate Si/glass heat exchanger is fabricated with a stack of alternating silicon plates and Pyrex glass spacers. The microvalve utiliz...

  20. A Novel RFID Sensing System Using Enhanced Surface Wave Technology for Battery Exchange Stations

    Directory of Open Access Journals (Sweden)

    Yeong-Lin Lai

    2014-01-01

    Full Text Available This paper presents a novel radio-frequency identification (RFID sensing system using enhanced surface wave technology for battery exchange stations (BESs of electric motorcycles. Ultrahigh-frequency (UHF RFID technology is utilized to automatically track and manage battery and user information without manual operation. The system includes readers, enhanced surface wave leaky cable antennas (ESWLCAs, coupling cable lines (CCLs, and small radiation patches (SRPs. The RFID sensing system overcomes the electromagnetic interference in the metallic environment of a BES cabinet. The developed RFID sensing system can effectively increase the efficiency of BES operation and promote the development of electric vehicles which solve the problem of air pollution as well as protect the environment of the Earth.

  1. Technology and Policy Challenges in the Adoption and Operation of Health Information Exchange Systems.

    Science.gov (United States)

    Ji, Hyerim; Yoo, Sooyoung; Heo, Eun-Young; Hwang, Hee; Kim, Jeong-Whun

    2017-10-01

    This study aimed to identify problems and issues that arise with the implementation of online health information exchange (HIE) systems in a medical environment and to identify solutions to facilitate the successful operation of future HIE systems in primary care clinics and hospitals. In this study, the issues that arose during the establishment and operation of an HIE system in a hospital were identified so that they could be addressed to enable the successful establishment and operation of a standard-based HIE system. After the issues were identified, they were reviewed and categorized by a group of experts that included medical information system experts, doctors, medical information standard experts, and HIE researchers. Then, solutions for the identified problems were derived based on the system development, operation, and improvement carried out during this work. Twenty-one issues were identified during the implementation and operation of an online HIE system. These issues were then divided into four categories: system architecture and standards, documents and data items, consent of HIE, and usability. We offer technical and policy recommendations for various stakeholders based on the experiences of operating and improving the online HIE system in the medical field. The issues and solutions identified in this study regarding the implementation and operate of an online HIE system can provide valuable insight for planners to enable them to successfully design and operate such systems at a national level in the future. In addition, policy support from governments is needed.

  2. Observability and Estimation of Distributed Space Systems via Local Information-Exchange Networks

    Science.gov (United States)

    Fathpour, Nanaz; Hadaegh, Fred Y.; Mesbahi, Mehran; Rahmani, Amirreza

    2011-01-01

    Spacecraft formation flying involves the coordination of states among multiple spacecraft through relative sensing, inter-spacecraft communication, and control. Most existing formation-flying estimation algorithms can only be supported via highly centralized, all-to-all, static relative sensing. New algorithms are proposed that are scalable, modular, and robust to variations in the topology and link characteristics of the formation exchange network. These distributed algorithms rely on a local information exchange network, relaxing the assumptions on existing algorithms. Distributed space systems rely on a signal transmission network among multiple spacecraft for their operation. Control and coordination among multiple spacecraft in a formation is facilitated via a network of relative sensing and interspacecraft communications. Guidance, navigation, and control rely on the sensing network. This network becomes more complex the more spacecraft are added, or as mission requirements become more complex. The observability of a formation state was observed by a set of local observations from a particular node in the formation. Formation observability can be parameterized in terms of the matrices appearing in the formation dynamics and observation matrices. An agreement protocol was used as a mechanism for observing formation states from local measurements. An agreement protocol is essentially an unforced dynamic system whose trajectory is governed by the interconnection geometry and initial condition of each node, with a goal of reaching a common value of interest. The observability of the interconnected system depends on the geometry of the network, as well as the position of the observer relative to the topology. For the first time, critical GN&C (guidance, navigation, and control estimation) subsystems are synthesized by bringing the contribution of the spacecraft information-exchange network to the forefront of algorithmic analysis and design. The result is a

  3. Effects on Communicative Requesting and Speech Development of the Picture Exchange Communication System in Children with Characteristics of Autism

    Science.gov (United States)

    Ganz, Jennifer B.; Simpson, Richard L.

    2004-01-01

    Few studies on augmentative and alternative communication (AAC) systems have addressed the potential for such systems to impact word utterances in children with autism spectrum disorders (ASD). The Picture Exchange Communication System (PECS) is an AAC system designed specifically to minimize difficulties with communication skills experienced by…

  4. A gas-exchange system for assessing plant performance in response to environmental stress

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, G.E. Jr; Tingey, D.T.

    1979-10-01

    Anthropogenic stresses are increasingly common as environmental factors affecting the performance of plants in both natural and agro-ecosystems. There is a need to determine how these stresses may influence vital physiological processes in plants. This report documents the design, construction and performance of a whole-plant, gas-exchange system that can accurately monitor gas flux (e.g., carbon dioxide, water vapor, pollutants) between plants and the atmospheric environment. From these data, rates of key physiological processes--photosynthesis, transpiration, gaseous uptake and emission--can be assessed. Example studies are reported on the uptake of sulfur dioxide by plants and emissions of monoterpenes from plants.

  5. Formula study for plate heat exchanger in the central heating regulation of the indirect connection hot water heating system

    Directory of Open Access Journals (Sweden)

    Minghui CUI

    2016-10-01

    Full Text Available Plate heat exchanger has unique advantages and becomes dominant heat exchange equipment in heating engineering, but there is no heating regulation formula of plate exchanger applied in central heating regulation of indirect connection hot water heating. This paper analyzes the condition that the heating user's system adopts quality regulation method and the hot water network system adopts quality-flow regulation method, and obtains the regulation formulas of plate exchanger applied in central heating regulation of indirect connection hot water heating used for the above two systems. Empirical calculation shows that the formula can be applied to the quality regulation and the mass flow regulation of the different flow optimization adjustment coefficient, and it is an all-round formula.

  6. Quantifying the Pathway and Predicting Spontaneous Emulsification during Material Exchange in a Two Phase Liquid System.

    Science.gov (United States)

    Spooner, Stephen; Rahnama, Alireza; Warnett, Jason M; Williams, Mark A; Li, Zushu; Sridhar, Seetharaman

    2017-10-30

    Kinetic restriction of a thermodynamically favourable equilibrium is a common theme in materials processing. The interfacial instability in systems where rate of material exchange is far greater than the mass transfer through respective bulk phases is of specific interest when tracking the transient interfacial area, a parameter integral to short processing times for productivity streamlining in all manufacturing where interfacial reaction occurs. This is even more pertinent in high-temperature systems for energy and cost savings. Here the quantified physical pathway of interfacial area change due to material exchange in liquid metal-molten oxide systems is presented. In addition the predicted growth regime and emulsification behaviour in relation to interfacial tension as modelled using phase-field methodology is shown. The observed in-situ emulsification behaviour links quantitatively the geometry of perturbations as a validation method for the development of simulating the phenomena. Thus a method is presented to both predict and engineer the formation of micro emulsions to a desired specification.

  7. Lack of Agreement Between Gas Exchange Variables Measured by Two Metabolic Systems

    Science.gov (United States)

    Jakovljevic, Djordje G.; Nunan, David; Donovan, Gay; Hodges, Lynette D.; Sandercock, Gavin R. H.; Brodie, David A.

    2008-01-01

    The purpose of this study was to assess the agreement and consistency between gas exchange variables measured by two online metabolic systems during an incremental exercise test. After obtaining local ethics approval and informed consent, 15 healthy subjects performed an incremental exercise test to volitional fatigue using the Bruce protocol. The Innocor (Innovision, Denmark) and CardiO2 (Medical Graphics, USA) systems were placed in series, with the Innocor mouthpiece attached to the pneumotach of the CardiO2. Metabolic data were analysed during the last 30 seconds of each stage and at peak exercise. There were non- significant differences (p > 0.05) between the two systems in estimation of oxygen consumption (VO2) and in minute ventilation (VE). Mean Cronbach’s alpha for VO2 and VE were 0.88 and 0.92. The Bland-Altman analysis revealed that limits of agreement were -0.52 to 0.55 l.min-1 for VO2, and -8.74 to 10.66 l.min-1 for VE. Carbon dioxide production (VCO2) and consequently respiratory exchange ratio (RER) measured by the Innocor were significantly lower (p < 0.05) through all stages. The CardiO2 measured fraction of expired carbon dioxide (FeCO2) significantly higher (p < 0.05). The limits of agreement for VO2 and VE are wide and unacceptable in cardio-pulmonary exercise testing. The Innocor reported VCO2 systematically lower. Therefore the Innocor and CardiO2 metabolic systems cannot be used interchangeably without affecting the diagnosis of an individual patient. Results from the present study support previous suggestion that considerable care is needed when comparing metabolic data obtained from different automated metabolic systems. Key pointsThere is general concern regarding the limited knowledge available about the accuracy of a number of commercially available systems.Demonstrated limits of agreement between key gas exchange variables (oxygen consumption and minute ventilation) as measured by the two metabolic systems were wide and unacceptable

  8. A general technique to rank protein-ligand binding affinities and determine allosteric versus direct binding site competition in compound mixtures.

    Science.gov (United States)

    Annis, D Allen; Nazef, Naim; Chuang, Cheng-Chi; Scott, Margaret Porter; Nash, Huw M

    2004-12-01

    To realize the full potential of combinatorial chemistry-based drug discovery, generic and efficient tools must be developed that apply the strengths of diversity-oriented chemical synthesis to the identification and optimization of lead compounds for disease-associated protein targets. We report an affinity selection-mass spectrometry (AS-MS) method for protein-ligand affinity ranking and the classification of ligands by binding site. The method incorporates the following steps: (1) an affinity selection stage, where protein-binding compounds are selected from pools of ligands in the presence of varying concentrations of a competitor ligand, (2) a first chromatography stage to separate unbound ligands from protein-ligand complexes, and (3) a second chromatography stage to dissociate the ligands from the complexes for identification and quantification by MS. The ability of the competitor ligand to displace a target-bound library member, as measured by MS, reveals the binding site classification and affinity ranking of the mixture components. The technique requires no radiolabel incorporation or direct biochemical assay, no modification or immobilization of the compounds or target protein, and all reaction components, including any buffers or cofactors required for protein stability, are free in solution. We demonstrate the method for several compounds of wide structural variety against representatives of the most important protein classes in contemporary drug discovery, including novel ATP-competitive and allosteric inhibitors of the Akt-1 (PKB) and Zap-70 kinases, and previously undisclosed antagonists of the M(2) muscarinic acetylcholine receptor, a G-protein coupled receptor (GPCR). The theoretical basis of the technique is analyzed mathematically, allowing quantitative estimation of binding affinities and, in the case of allosteric interaction, absolute determination of binding cooperativity. The method is readily applicable to high-throughput screening hit

  9. Modelling shelf-ocean exchange and its biogeochemical consequences in coastal upwelling systems

    DEFF Research Database (Denmark)

    Muchamad, Al Azhar

    The biogeochemical cycles of organic carbon, nutrients, oxygen, and sulfur in the oceans have been suggested to dominantly occur across the shelf–ocean transition over the continental margin, although this zone represents only a small percentage of the global ocean area. Coastal upwelling zones...... in eastern boundary upwelling systems is an example of the most productive ocean waters over continental margins where intense supply of nutrients occur from deeper ocean waters. Interesting questions arise related to the biogeochemical cycles in such upwelling systems; such as 1) how the recently observed...... these questions centering on shelf–ocean exchange and biogeochemical cycle in the coastal upwelling systems under oxic and anoxic conditions. Firstly, I developed a new biogeochemical model which resolves coupling between cycles of the elements nitrogen, oxygen, phosphate, and sulfur by considering several key...

  10. A MODEL OF HETEROGENEOUS DISTRIBUTED SYSTEM FOR FOREIGN EXCHANGE PORTFOLIO ANALYSIS

    Directory of Open Access Journals (Sweden)

    Dragutin Kermek

    2006-06-01

    Full Text Available The paper investigates the design of heterogeneous distributed system for foreign exchange portfolio analysis. The proposed model includes few separated and dislocated but connected parts through distributed mechanisms. Making system distributed brings new perspectives to performance busting where software based load balancer gets very important role. Desired system should spread over multiple, heterogeneous platforms in order to fulfil open platform goal. Building such a model incorporates different patterns from GOF design patterns, business patterns, J2EE patterns, integration patterns, enterprise patterns, distributed design patterns to Web services patterns. The authors try to find as much as possible appropriate patterns for planned tasks in order to capture best modelling and programming practices.

  11. A new hybrid ion exchanger: Effect of system parameters on the adsorption of vanadium (V)

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Bong-Yeol [Nonwovens Cooperative Research Center, College of Textiles, North Carolina State University, Raleigh, NC 27695-8301 (United States); Lee, Chang-Soo [School of Applied Chemistry and Biological Engineering, College of Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Hwang, Taek-Sung, E-mail: tshwang@cnu.ac.kr [School of Applied Chemistry and Biological Engineering, College of Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2009-07-15

    The hybrid ion exchanger consisted of PONF-g-GMA anion fibrous exchanger and IRA-96 bead-type anion exchanger was developed by combining different types of layers with hot-melt adhesive. Its ion exchange capacity and the pressure drop with flow rate of water were measured and the adsorption of vanadium (V) ions on the hybrid ion exchanger was evaluated with various process parameters such as pH, initial concentration, and temperature. It was observed that the adsorption kinetics of vanadium (V) ions on the hybrid ion exchanger could be analyzed with pseudo-second-order model.

  12. High Level Waste System Impacts from Small Column Ion Exchange Implementation

    Energy Technology Data Exchange (ETDEWEB)

    McCabe, D. J.; Hamm, L. L.; Aleman, S. E.; Peeler, D. K.; Herman, C. C.; Edwards, T. B.

    2005-08-18

    The objective of this task is to identify potential waste streams that could be treated with the Small Column Ion Exchange (SCIX) and perform an initial assessment of the impact of doing so on the High-Level Waste (HLW) system. Design of the SCIX system has been performed as a backup technology for decontamination of High-Level Waste (HLW) at the Savannah River Site (SRS). The SCIX consists of three modules which can be placed in risers inside underground HLW storage tanks. The pump and filter module and the ion exchange module are used to filter and decontaminate the aqueous tank wastes for disposition in Saltstone. The ion exchange module contains Crystalline Silicotitanate (CST in its engineered granular form is referred to as IONSIV{reg_sign} IE-911), and is selective for removal of cesium ions. After the IE-911 is loaded with Cs-137, it is removed and the column is refilled with a fresh batch. The grinder module is used to size-reduce the cesium-loaded IE-911 to make it compatible with the sludge vitrification system in the Defense Waste Processing Facility (DWPF). If installed at the SRS, this SCIX would need to operate within the current constraints of the larger HLW storage, retrieval, treatment, and disposal system. Although the equipment has been physically designed to comply with system requirements, there is also a need to identify which waste streams could be treated, how it could be implemented in the tank farms, and when this system could be incorporated into the HLW flowsheet and planning. This document summarizes a preliminary examination of the tentative HLW retrieval plans, facility schedules, decontamination factor targets, and vitrified waste form compatibility, with recommendations for a more detailed study later. The examination was based upon four batches of salt solution from the currently planned disposition pathway to treatment in the SCIX. Because of differences in capabilities between the SRS baseline and SCIX, these four batches were

  13. Development of Laboratory Experimental System to Clarify Solar Wind Charge Exchange Mechanism with TES Microcalorimeter

    Science.gov (United States)

    Enoki, T.; Ishisaki, Y.; Akamatsu, H.; Ezoe, Y.; Ohashi, T.; Kanda, T.; Ishida, T.; Tanuma, H.; Ohashi, H.; Shinozaki, K.; Mitsuda, K.

    2012-06-01

    Significant fraction of the cosmic diffuse soft X-ray emission (0.1-1 keV) is caused by the Solar Wind Charge eXchange (SWCX) process between the solar wind ion (C q+, N q+, O q+ etc.) and the interplanetary neutral matter. It is difficult to identify spectral features of SWCX with the spectral resolution of existing X-ray astronomy satellites. We are developing a laboratory experimental system with transition edge sensor (TES) X-ray microcalorimeters, in order to clarify the SWCX mechanism. This experiment is designed to measure Charge eXchange (CX) X-rays using Electron Cyclotron Resonance Ion Source (ECRIS) that generates multi-charged ions. Emission lines (OVIII: 2p→1s; 654 eV) by CX between O8+ and neutral He atom is aimed to be measured with energy resolution better than 10 eV. The TES microcalorimeter is cooled by a double-stage adiabatic demagnetization refrigerator (DADR), however, our TES microcalorimeter are not working potentially due to magnetic field contamination. This paper reports our experimental system, present results, and future prospects.

  14. Exchange Perturbation Theory for Multiatomic Electron System and Its Application to Spin Arrangement in Manganite Chains

    Directory of Open Access Journals (Sweden)

    E. V. Orlenko

    2011-01-01

    Full Text Available A new methodology of binding energy calculation with respect to different spin arrangements for a multiatomic electron system is developed from the first principle in the frame of the exchange perturbation theory (EPT. We developed EPT formalism in the general form of the Rayleigh-Srchödinger expansion with a symmetric Hamiltonian, taking into account an exchange and nonadditive contributions of a superexchange interaction. The expressions of all corrections to the energy and wave function were reduced to the nonsymmetric Hamiltonian form. The EPT method is extended for the case of degeneracy in the total spin of a system. As an example of the application of the developed EPT formalism for the degeneracy case, spin arrangements were considered for the key ⟨Mn⟩–O–⟨Mn⟩ (⟨Mn⟩: Mn3+ or Mn4+ fragments in manganites. In ⟨Mn⟩–O–⟨Mn⟩ for La1/3Ca2/3MnO3 are in good agreement the obtained estimations of Heisenberg parameter and binding energy with the available experimental data.

  15. Assessing the value of cooperation and information exchange in large water resources systems by agent-based optimization

    Science.gov (United States)

    Giuliani, M.; Castelletti, A.

    2013-07-01

    Many large-scale water resources systems, especially in transboundary contexts, are characterized by the presence of several and conflicting interests and managed by multiple, institutionally independent decision makers. These systems are often studied adopting a centralized approach based on the assumption of full cooperation and information exchange among the involved parties. Such a perspective is conceptually interesting to quantify the best achievable performance but might have little practical impact given the real political and institutional setting. In this work, we propose a novel decision-analytic framework based on multiagent systems to model and analyze different levels of cooperation and information exchange among multiple decision makers. The Zambezi River basin is used as a case study. According to the proposed agent-based optimization approach, each agent represents a decision maker, whose decisions are defined by an explicit optimization problem considering only the agent's local interests. The economic value of information exchange is estimated comparing a noncooperative setting, where agents act independently, with the first basic level of cooperation, i.e., coordination, characterized by full information exchange. The economic value of cooperation is also estimated by comparison with the ideal, fully cooperative management of the system. Results show that coordination, obtained with complete information exchange, allows the downstream agents to better adapt to the upstream behaviors. The impact of information exchange depends on the objective considered, and we show coordination to be particularly beneficial to environmental interests.

  16. Enhanced exchange anisotropy in IrMn/CoFeB systems and its correlation with uncompensated interfacial spins

    DEFF Research Database (Denmark)

    Du, Yuqing; Pan, Genhua; Moate, Roy

    2010-01-01

    Bottom pinned exchange bias systems of IrMn/CoFe and IrMn/CoFeB on CoFe seed layers were studied. Enhanced exchange anisotropy has been observed for IrMn/CoFeB samples annealed at 350 °C. The ferromagnetic and antiferromagnetic layers of both samples are polycrystalline and textured {110......} for the CoFe and CoFeB, and {111} for IrMn. Results demonstrated that the enhanced exchange anisotropy in the IrMn/CoFeB system is closely associated with the increased uncompensated interfacial spins as evidenced by the enhanced Mn x-ray magnetic circular dichroism (XMCD) signal strength. A quantitative...... correlation between the Mn XMCD signal and the exchange anisotropy constant Jk was observed....

  17. LACK OF AGREEMENT BETWEEN GAS EXCHANGE VARIABLES MEASURED BY TWO METABOLIC SYSTEMS

    Directory of Open Access Journals (Sweden)

    DjordjeG. Jakovljevic

    2008-03-01

    Full Text Available The purpose of this study was to assess the agreement and consistency between gas exchange variables measured by two online metabolic systems during an incremental exercise test. After obtaining local ethics approval and informed consent, 15 healthy subjects performed an incremental exercise test to volitional fatigue using the Bruce protocol. The Innocor (Innovision, Denmark and CardiO2 (Medical Graphics, USA systems were placed in series, with the Innocor mouthpiece attached to the pneumotach of the CardiO2. Metabolic data were analysed during the last 30 seconds of each stage and at peak exercise. There were non- significant differences (p > 0.05 between the two systems in estimation of oxygen consumption (VO2 and in minute ventilation (VE. Mean Cronbach's alpha for VO2 and VE were 0.88 and 0.92. The Bland-Altman analysis revealed that limits of agreement were -0.52 to 0.55 l.min-1 for VO2, and -8.74 to 10.66 l.min-1 for VE. Carbon dioxide production (VCO2 and consequently respiratory exchange ratio (RER measured by the Innocor were significantly lower (p < 0.05 through all stages. The CardiO2 measured fraction of expired carbon dioxide (FeCO2 significantly higher (p < 0.05. The limits of agreement for VO2 and VE are wide and unacceptable in cardio-pulmonary exercise testing. The Innocor reported VCO2 systematically lower. Therefore the Innocor and CardiO2 metabolic systems cannot be used interchangeably without affecting the diagnosis of an individual patient. Results from the present study support previous suggestion that considerable care is needed when comparing metabolic data obtained from different automated metabolic systems.

  18. Characterization and control of the microbial community affiliated with copper or aluminum heat exchangers of HVAC systems.

    Science.gov (United States)

    Schmidt, Michael G; Attaway, Hubert H; Terzieva, Silva; Marshall, Anna; Steed, Lisa L; Salzberg, Deborah; Hamoodi, Hameed A; Khan, Jamil A; Feigley, Charles E; Michels, Harold T

    2012-08-01

    Microbial growth in heating ventilation and air-conditioning (HVAC) systems with the subsequent contamination of indoor air is of increasing concern. Microbes and the subsequent biofilms grow easily within heat exchangers. A comparative study where heat exchangers fabricated from antimicrobial copper were evaluated for their ability to limit microbial growth was conducted using a full-scale HVAC system under conditions of normal flow rates using single-pass outside air. Resident bacterial and fungal populations were quantitatively assessed by removing triplicate sets of coupons from each exchanger commencing the fourth week after their installation for the next 30 weeks. The intrinsic biofilm associated with each coupon was extracted and characterized using selective and differential media. The predominant organisms isolated from aluminum exchangers were species of Methylobacterium of which at least three colony morphologies and 11 distinct PFGE patterns we found; of the few bacteria isolated from the copper exchangers, the majority were species of Bacillus. The concentrations and type of bacteria recovered from the control, aluminum, exchangers were found to be dependent on the type of plating media used and were 11,411-47,257 CFU cm(-2) per coupon surface. The concentration of fungi was found to average 378 CFU cm(-2). Significantly lower concentrations of bacteria, 3 CFU cm(-2), and fungi, 1 CFU cm(-2), were recovered from copper exchangers regardless of the plating media used. Commonly used aluminum heat exchangers developed stable, mixed, bacterial/fungal biofilms in excess of 47,000 organisms per cm(2) within 4 weeks of operation, whereas the antimicrobial properties of metallic copper were able to limit the microbial load affiliated with the copper heat exchangers to levels 99.97 % lower during the same time period.

  19. Spin polarization and exchange-correlation effects in transport properties of two-dimensional electron systems in silicon

    Science.gov (United States)

    Dolgopolov, V. T.; Shashkin, A. A.; Kravchenko, S. V.

    2017-08-01

    We show that the parallel magnetic field-induced increase in the critical electron density for the Anderson transition in a strongly interacting two-dimensional electron system is caused by the effects of exchange and correlations. If the transition occurs when electron spins are only partially polarized, additional increase in the magnetic field is necessary to achieve the full spin polarization in the insulating state due to the exchange effects.

  20. Protein-stimulated exchange of phosphatidylcholine between intact erythrocytes and various membrane systems

    NARCIS (Netherlands)

    Meer, G. van; Lange, L.G.; Kamp, J.A.F. op den; Deenen, L.L.M. van

    1980-01-01

    Phosphatidylcholine specific exchange protein from beef liver was found to catalyze the exchange of phosphatidylcholine between intact rat and human erythrocytes and various artificial membranes. Both multilamellar liposomes and single bilayer vesicles prepared from egg lecithin, cholesterol and

  1. Impact of the picture exchange communication system: effects on communication and collateral effects on maladaptive behaviors.

    Science.gov (United States)

    Ganz, Jennifer B; Parker, Richard; Benson, Joanne

    2009-12-01

    Many children with autism require intensive instruction in the use of augmentative or alternative communication systems, such as the Picture Exchange Communication System (PECS). This study investigated the use of PECS with three young boys with autism to determine the impact of PECS training on use of pictures for requesting, use of intelligible words, and maladaptive behaviors. A multiple baseline-probe design with a staggered start was implemented. Results indicated that all of the participants quickly learned to make requests using pictures and that two used intelligible speech following PECS instruction; maladaptive behaviors were variable throughout baseline and intervention phases. Although all of the participants improved in at least one dependent variable, there remain questions regarding who is best suited for PECS and similar interventions.

  2. On-line fault diagnostic system for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Riascos, Luis Alberto M. [Federal University of ABC, r. Santa Adelia 166, CEP 09210-170, Santo Andre, Sao Paulo (Brazil); Simoes, Marcelo G. [Colorado School of Mines, 1500 Illinois St, 80401 Golden, CO (United States); Miyagi, Paulo E. [Escola Politecnica, University of Sao Paulo, Av. Prof. Mello Moraes 2231, CEP 05508-900, Sao Paulo (Brazil)

    2008-01-03

    In this paper, a supervisor system, able to diagnose different types of faults during the operation of a proton exchange membrane fuel cell is introduced. The diagnosis is developed by applying Bayesian networks, which qualify and quantify the cause-effect relationship among the variables of the process. The fault diagnosis is based on the on-line monitoring of variables easy to measure in the machine such as voltage, electric current, and temperature. The equipment is a fuel cell system which can operate even when a fault occurs. The fault effects are based on experiments on the fault tolerant fuel cell, which are reproduced in a fuel cell model. A database of fault records is constructed from the fuel cell model, improving the generation time and avoiding permanent damage to the equipment. (author)

  3. On-line fault diagnostic system for proton exchange membrane fuel cells

    Science.gov (United States)

    Riascos, Luis Alberto M.; Simoes, Marcelo G.; Miyagi, Paulo E.

    In this paper, a supervisor system, able to diagnose different types of faults during the operation of a proton exchange membrane fuel cell is introduced. The diagnosis is developed by applying Bayesian networks, which qualify and quantify the cause-effect relationship among the variables of the process. The fault diagnosis is based on the on-line monitoring of variables easy to measure in the machine such as voltage, electric current, and temperature. The equipment is a fuel cell system which can operate even when a fault occurs. The fault effects are based on experiments on the fault tolerant fuel cell, which are reproduced in a fuel cell model. A database of fault records is constructed from the fuel cell model, improving the generation time and avoiding permanent damage to the equipment.

  4. Arctic decadal variability: An auto-oscillatory system of heat and fresh water exchange

    Science.gov (United States)

    Dukhovskoy, Dmitry S.; Johnson, Mark A.; Proshutinsky, Andrey

    2004-02-01

    This paper presents a mechanism of decadal variability in the Artic Ocean-GIN Sea (Greenland, Iceland and Norwegian Seas) atmosphere-ice-ocean system. We hypothesize that Arctic variability is regulated by heat and freshwater exchange between the Arctic Ocean and the GIN Sea. The interaction between basins is weak during anticyclonic circulation regimes (low AO/NAO) and strong during cyclonic circulation regimes (high AO/NAO). Regime shifts are controlled by the system itself through oceanic and atmospheric gradients (dynamic height and surface air temperature) that increase during the anticyclonic regime and decrease during the cyclonic regime. This conceptual mechanism for Arctic decadal variability has been reproduced in a model experiment. Both model results and observational data support the suggested mechanism.

  5. The Influence of Organizational Systems on Information Exchange in Long-Term Care Facilities: An Institutional Ethnography.

    Science.gov (United States)

    Caspar, Sienna; Ratner, Pamela A; Phinney, Alison; MacKinnon, Karen

    2016-06-01

    Person-centered care is heavily dependent on effective information exchange among health care team members. We explored the organizational systems that influence resident care attendants' (RCAs) access to care information in long-term care (LTC) settings. We conducted an institutional ethnography in three LTC facilities. Investigative methods included naturalistic observations, in-depth interviews, and textual analysis. Practical access to texts containing individualized care-related information (e.g., care plans) was dependent on job classification. Regulated health care professionals accessed these texts daily. RCAs lacked practical access to these texts and primarily received and shared information orally. Microsystems of care, based on information exchange formats, emerged. Organizational systems mandated written exchange of information and did not formally support an oral exchange. Thus, oral information exchanges were largely dependent on the quality of workplace relationships. Formal systems are needed to support structured oral information exchange within and between the microsystems of care found in LTC. © The Author(s) 2016.

  6. Secure Data Exchange in Environmental Health Monitoring System through Wireless Sensor Network

    Directory of Open Access Journals (Sweden)

    Amang Sudarsono

    2016-04-01

    Full Text Available Recently, disseminating latest sensory information regarding the status of environmental health in the surroundings of human life is one of very important circumstances which must be known by everyone. These circumstances should be accessible at anytime and anywhere by everyone through any type of end-user devices, both fixed and mobile devices, i.e., Desktop PCs, Laptop PCs, and Smartphones. Wireless Sensor Network (WSN is one of the networks which deals with data sensors distribution from sensor nodes to the gateway node toward a Data Center Server. However, there is a big possibility for many adversaries to intercept and even manipulate data sensors crossing the network. Hence, a secure data sensor exchange in the system would be strongly desirable. In this research, we propose an environmental health conditions monitoring system through WSN and its implementation with considering secure data sensor exchange within the network and secure data sensor access. This work may contribute to support a part of smart cities and take in part the Internet of Thing (IoT technology. In our proposed system, we collect some environmental health information such as temperature, humidity, luminosity, noise, carbon monoxide (CO and carbon dioxide (CO2 from sensor nodes. We keep the confidentiality and integrity of transmitted data sensors propagating through IEEE802.15.4-based communication toward a gateway node. Further, the collected data sensors in the gateway are synchronized to the Data Center Server through a secure TCP/IP connection for permanently storing. At anytime and anywhere, only legitimated users who successfully pass-through an attribute-based authentication system are able to access the data sensors.

  7. Health information exchange system usage patterns in three communities: practice sites, users, patients, and data.

    Science.gov (United States)

    Campion, Thomas R; Edwards, Alison M; Johnson, Stephen B; Kaushal, Rainu

    2013-09-01

    Public and private organizations are implementing systems for query-based health information exchange (HIE), the electronic aggregation of patient data from multiple institutions. However, existing studies of query-based HIE system usage have addressed a limited number of settings. Our goal was to quantify the breadth and depth of usage of a query-based HIE system implemented across multiple communities with diverse care settings and patient populations. We performed a cross-sectional study in three communities in New York State using system access log files from January 2009 to May 2011 to measure usage patterns of a query-based HIE web portal system with respect to practice sites, users, patients, and data. System access occurred from 60% (n=200) of practice sites registered to use the system in Community A, 59% (n=156) in Community B, and 82% (n=28) in Community C. In Communities A and B, users were primarily non-clinical staff in outpatient settings, while in Community C inpatient physicians were the main users. Across communities, proportions of patients whose data were accessed varied with 5% (n=11,263) in Community A, 60% (n=212,586) in Community B, and 1% (n=1107) in Community C. In Community B, users updated patient consent through the HIE portal, whereas in the other communities, users updated patient consent through a separate system. Across communities, users most frequently accessed only patient summary data displayed by default followed by detailed laboratory and radiology data. This study is among the first to illustrate large-scale usage of a query-based HIE system implemented across multiple communities. Patient summary data displayed by default may be an important feature of query-based HIE systems. User role, practice site type, and patient consent workflow may affect patterns of query-based HIE web portal system usage in the communities studied and elsewhere. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  8. Feasibility and design studies for heat recovery from a refrigeration system with a Canopus heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, S.C.; Singh, M. [Indian Inst. of Tech., New Delhi (India). Centre of Energy Studies

    1995-10-01

    This paper presents an investigation of the feasibility of heat recovery from the condenser of a vapour compression refrigeration (VCR) system through a Canopus heat exchanger (CHE) between the compressor and condenser components. The presence of the CHE makes it possible to recover the superheat of the discharged vapour and utilize it for increasing the temperature of the external fluid (water) removing heat from the condenser. The effects of the operating temperatures in the condenser and evaporator for different inlet water temperatures and mass flow rates on the heat recovery output and its distribution over the condenser and CHE (the fraction of the condenser heat available through the CHE), available outlet water temperature and heat recovery factor have all been studied and optimum operating parameters for feasible heat recovery have been ascertained. The parametric results obtained for different working fluids, such as R-22, R-12, R-717 and R-500, have been presented. It is found that, in general, a heat recovery factor of the order of 2.0 and 40% of condenser heat can be recovered through the Canopus heat exchanger for a typical set of operating conditions. (Author)

  9. Derivatization patterns among starch chain populations assessed by ion-exchange chromatography: a model system approach.

    Science.gov (United States)

    Hong, Jung Sun; Huber, Kerry C

    2015-05-20

    Reaction patterns of wheat starch derivatized with a fluorescent probe (model reaction system) were investigated over the course of a reaction period (0.5, 4, 12, or 24h). Debranched derivatives were fractionated into three populations (Unbound, Bound-1, Bound-2) based on charge density via anion-exchange chromatography, with each ion-exchanged fraction further analyzed by size-exclusion chromatography (refractive index [RI] and fluorescence [FL] detection) to assess proportions and patterns of reaction on amylose (AM) and amylopectin (AP) long (LC), medium (MC), and short (SC) branch chains. Approximately 11-12% of the total chains accounted for 63-75% of the FL recovered in the two bound fractions. FL peaks representing AM, AP-LC, AP-MC, AP-SC, and intermediate material (eluted with AM based on molecular size, but reacted more akin to AP-LC) were monitored over the reaction period. Fractionation behaviors varied amongst starch chains, attributable to the impact of the granule structure on molecular reaction patterns. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Resonant electronic excitation energy transfer by exchange mechanism in the quantum dot system

    Science.gov (United States)

    Chikalova-Luzina, O. P.; Samosvat, D. M.; Vyatkin, V. M.; Zegrya, G. G.

    2017-11-01

    A microscopic theory of nonradiative resonance energy transfer between spherical A3B5 semiconductor quantum dots by the exchange mechanism is suggested. The interdot Coulomb interaction is taken into consideration. It is assumed that the quantum dot-donor and the quantum dot-acceptor are made from the same A3B5 compound and are embedded in the matrix of another material that produces potential barriers for electrons and holes. The dependences of the energy transfer rate on the quantum-dot system parameters are found in the frame of the Kane model that provides the most adequate description of the real spectra of A3B5 semiconductors. The analytical treatment is carried out with using the density matrix method, which enabled us to perform an energy transfer analysis both in the weak-interaction approximation and in the strong-interaction approximation. The numerical calculations showed the saturation of the energy transfer rate at the distances between the donor and the acceptor approaching the contact one. The contributions of the exchange and direct Coulomb intractions can be of the same order at the small distances and can have the same value in the saturation range.

  11. Computational fluid dynamics simulation of an earth-air heat exchanger for ventilation system

    Science.gov (United States)

    Raczkowski, Andrzej; Suchorab, Zbigniew; Czechowska-Kosacka, Aneta

    2017-07-01

    Directive 2010/31/EU (EPBD Recast) obligates European Union members to improve energetic performance of the buildings. One of the crucial standards of energy-saving buildings are the passive houses, which are characterized by annual maximum space heating below 15 kWh/(m2.a) and the use of the specific primary energy for all domestic applications (also heating, hot water production and electricity) below 120 kWh/(m2.a). To achieve this standard there should be applied the solutions based on ground energy acquisition. One of them is the earth-air heat exchanger (EAHC) for ventilation systems. The article presents numerical simulations conducted by solving partial differential equations for three dimensional heat transfer. For the simulations it was applied Computational Fluid Dynamics (CFD) technique. The efficiency of EAHC was considered under different values of external temperature during the winter period (from -24 to -8 °C). Obtained results prove linear correlation with calculations of EAHC according to standards of the Polish National Energy Conservation Agency (NAPE). The slope of regression between outlet temperatures calculated with CFD model and NAPE standards, equals 0.59 which means, that according the CFD model, the efficiency of the exchanger is lower.

  12. Conceptual Design of a Condensing Heat Exchanger for Space Systems Using Porous Media

    Science.gov (United States)

    Hasan, Mohammad M.; Khan, Lutful I.; Nayagam, Vedha; Balasubramaniam, Ramaswamy

    2006-01-01

    Condensing heat exchangers are used in many space applications in the thermal and humidity control systems. In the International Space Station (ISS), humidity control is achieved by using a water cooled fin surface over which the moist air condenses, followed by "slurper bars" that take in both the condensate and air into a rotary separator and separates the water from air. The use of a cooled porous substrate as the condensing surface provides and attractive alternative that combines both heat removal as well as liquid/gas separation into a single unit. By selecting the pore sizes of the porous substrate a gravity independent operation may also be possible with this concept. Condensation of vapor into and on the porous surface from the flowing air and the removal of condensate from the porous substrate are the critical processes involved in the proposed concept. This paper describes some preliminary results of the proposed condensate withdrawal process and discusses the on-going design and development work of a porous media based condensing heat exchanger at the NASA Glenn Research Center in collaboration with NASA Johnson Space Center.

  13. New chiral ligand exchange capillary electrophoresis system with chiral amino amide ionic liquids as ligands.

    Science.gov (United States)

    Jiang, Junfang; Mu, Xiaoyu; Qiao, Juan; Su, Yuan; Qi, Li

    2017-12-01

    Using chiral amino amide ionic liquids as the ligands, a new chiral ligand exchange capillary electrophoresis method with Cu(II) as the central ion was constructed for enantioseparation of labeled D,L-amino acids. The effects of key parameters, including pH value of the running buffer, the ratio of Cu(II) to chiral amino amide ionic liquids, the concentration of complexes based on Cu(II)-chiral amino amide ionic liquids were investigated. It has been observed that eight pairs of labeled D,L-amino acids could be baseline-separated with a running buffer of 15.0mM ammonium acetate, 10.0mM Cu(II) and 20.0mML-phenylalaninamide based ionic liquid at pH 5.0. The quantitation of D,L-amino acids was conducted and good linearity (r2 ≥ 0.964) was obtained. Furthermore, an assay for determining the enantiomeric purity of D,L-amino acids was developed and the possible enantiorecognition mechanism was discussed briefly. The results indicated that the chiral amino amide ionic liquids could play the role of ligands in chiral ligand exchange capillary electrophoresis system and exhibit great potential in chiral analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. The study of the mobile compressor unit heat losses recovery system waste heat exchanger thermal insulation types influence on the operational efficiency

    Science.gov (United States)

    Yusha, V. L.; Chernov, G. I.; Kalashnikov, A. M.

    2017-08-01

    The paper examines the mobile compressor unit (MCU) heat losses recovery system waste heat exchanger prototype external thermal insulation types influence on the operational efficiency. The study is conducted by means of the numerical method through the modellingof the heat exchange processes carried out in the waste heat exchanger in ANSUS. Thermaflex, mineral wool, penofol, water and air were applied as the heat exchanger external insulation. The study results showed the waste heat exchanger external thermal insulationexistence or absence to have a significant impact on the heat exchanger operational efficiency.

  15. DESIGN OF A COMPACT HEAT EXCHANGER FOR HEAT RECUPERATION FROM A HIGH TEMPERATURE ELECTROLYSIS SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    G. K. Housley; J.E. O' Brien; G.L. Hawkes

    2008-11-01

    Design details of a compact heat exchanger and supporting hardware for heat recuperation in a high-temperature electrolysis application are presented. The recuperative heat exchanger uses a vacuum-brazed plate-fin design and operates between 300 and 800°C. It includes corrugated inserts for enhancement of heat transfer coefficients and extended heat transfer surface area. Two recuperative heat exchangers are required per each four-stack electrolysis module. The heat exchangers are mated to a base manifold unit that distributes the inlet and outlet flows to and from the four electrolysis stacks. Results of heat exchanger design calculations and assembly details are also presented.

  16. Potential for Small Unmanned Aircraft Systems Applications for Identifying Groundwater-Surface Water Exchange in a Meandering River Reach

    Science.gov (United States)

    Pai, H.; Malenda, H. F.; Briggs, M. A.; Singha, K.; González-Pinzón, R.; Gooseff, M. N.; Tyler, S. W.

    2017-12-01

    The exchange of groundwater and surface water (GW-SW), including dissolved constituents and energy, represents a critical yet challenging characterization problem for hydrogeologists and stream ecologists. Here we describe the use of a suite of high spatial resolution remote sensing techniques, collected using a small unmanned aircraft system (sUAS), to provide novel and complementary data to analyze GW-SW exchange. sUAS provided centimeter-scale resolution topography and water surface elevations, which are often drivers of exchange along the river corridor. Additionally, sUAS-based vegetation imagery, vegetation-top elevation, and normalized difference vegetation index mapping indicated GW-SW exchange patterns that are difficult to characterize from the land surface and may not be resolved from coarser satellite-based imagery. We combined these data with estimates of sediment hydraulic conductivity to provide a direct estimate of GW "shortcutting" through meander necks, which was corroborated by temperature data at the riverbed interface.

  17. Internal heat exchange in an ejector-compression solar refrigeration system with R142b

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Joge I; Estrada, Claudio A; Best, Roberto [Centro de Investigacion en Energia, UNAM, Temixco, Morelos (Mexico); Dorantes Ruben, J [Departamento de Energia, UNAM Azcapotzalco, Mexico, D.F. (Mexico)

    2000-07-01

    One way to use more efficiently the actual energy transfer in the ejector-compression system, is the use of heat exchangers between some of the components. The inclusion of two heat exchangers, preheater and precooler, is considered in a basic ejector-compression refrigeration system with refrigerant 142b. This study accounts for the energy and exergy efficiencies. COP and {epsilon}, according to parameter variations such as ejector efficiency, generation temperature with different superheating, condensation temperature and heat exchangers effectiveness. As known, the most important parameters in ejector-compression system analysis are the entrain-ment ratio U and system efficiencies COP and {epsilon}. The highest system COP and {epsilon}, as the entrainment ratio U, correspond to the highest exchangers effectiveness, highest superheating generator temperatures, highest ejector efficiency and lowest condenser temperature. For the COP and {epsilon} ratios, their maxima correspond to the same independent variables aforementioned for one of the higher superheating generator temperatures. In this case, this result indicates that the exergy efficiency {epsilon} does not contradict the information given by energy efficiency COP. So, to select correctly and optimum design condition, is enough to employ the COP ratio, which maximum value for the data shown corresponds to a superheating generator temperature of about 110 Celsius degrees, that can only be reached by evacuated tubular collectors or CPC solar concentrators. [Spanish] Una forma de usar mas eficientemente la transferencia real de energia en el sistema eyector-compresion es el uso de intercambiadores de calor entre algunos de los componentes. La inclusion de dos intercambiadores de calor precalentador y pre-enfriador se considera en un sistema de refrigeracion eyector-compresion con refrigerante 142b. Este estudio toma en cuenta las eficiencias de energia y exergia, COP y {epsilon}, de acuerdo con las variaciones

  18. Observations on gas exchange and element recycle within a gas-closed algal-mouse system

    Science.gov (United States)

    Smernoff, D. T.; Wharton, R. A., Jr.; Averner, M. M.

    1986-01-01

    Life support systems based on bioregeneration rely on the control and manipulation of organisms. Algae are potentially useful for a variety of Closed Ecological Life Support System (CELSS) functions including the revitalization of atmospheres, production of food and for nitrogen fixation. The results of experiments conducted with a gas-closed algal-mouse system designed to investigate gas exchange phenomena under varying algal environmental conditions, and the ability of algae to utilize oxidized mouse solid waste are reported. Inherent instabilities exist between the uptake and release of carbon dioxide (CO2) and oxygen (O2) by the mouse and algae in a gas-closed system. Variations in light intensity and cell density alter the photosynthetic rate of the algae and enable short-term steady-state concentrations of atmospheric CO2 and O2. Different nitrogen sources (urea and nitrate) result in different algal assimilatory quotients (AQ). Combinations of photosynthetic rate and AQ ratio manipulations were examined for their potential in stabilizing atmospheric gas concentrations in the gas-closed algal-mouse system.

  19. Enthalpy analysis and Heat Exchanger Sizing of an Air-cooled Proton Exchange Membrane Fuel Cell System

    DEFF Research Database (Denmark)

    Gao, Xin; Berning, Torsten; Kær, Søren Knudsen

    the warmer exhaust air is used to pre-heat and also humidify the incoming colder and dryer air stream using an enthalpy wheel. It is important to thermodynamically understand such a fuel cell system, and in this work the enthalpy streams and the humidity stream are followed throughout the fuel cell system...... simulations have been carried out to better understand the distribution of the reactant air over the fuel cell stack and the resulting temperature distribution across the stack. These results suggest that the humidifying function of the current enthalpy wheel is negligible and a smaller enthalpy wheel...

  20. Anonymous three-party password-authenticated key exchange scheme for Telecare Medical Information Systems.

    Directory of Open Access Journals (Sweden)

    Qi Xie

    Full Text Available Telecare Medical Information Systems (TMIS provide an effective way to enhance the medical process between doctors, nurses and patients. For enhancing the security and privacy of TMIS, it is important while challenging to enhance the TMIS so that a patient and a doctor can perform mutual authentication and session key establishment using a third-party medical server while the privacy of the patient can be ensured. In this paper, we propose an anonymous three-party password-authenticated key exchange (3PAKE protocol for TMIS. The protocol is based on the efficient elliptic curve cryptosystem. For security, we apply the pi calculus based formal verification tool ProVerif to show that our 3PAKE protocol for TMIS can provide anonymity for patient and doctor while at the same time achieves mutual authentication and session key security. The proposed scheme is secure and efficient, and can be used in TMIS.

  1. Anonymous three-party password-authenticated key exchange scheme for Telecare Medical Information Systems.

    Science.gov (United States)

    Xie, Qi; Hu, Bin; Dong, Na; Wong, Duncan S

    2014-01-01

    Telecare Medical Information Systems (TMIS) provide an effective way to enhance the medical process between doctors, nurses and patients. For enhancing the security and privacy of TMIS, it is important while challenging to enhance the TMIS so that a patient and a doctor can perform mutual authentication and session key establishment using a third-party medical server while the privacy of the patient can be ensured. In this paper, we propose an anonymous three-party password-authenticated key exchange (3PAKE) protocol for TMIS. The protocol is based on the efficient elliptic curve cryptosystem. For security, we apply the pi calculus based formal verification tool ProVerif to show that our 3PAKE protocol for TMIS can provide anonymity for patient and doctor while at the same time achieves mutual authentication and session key security. The proposed scheme is secure and efficient, and can be used in TMIS.

  2. Active heat exchange: System development for latent heat thermal energy storage

    Science.gov (United States)

    Alario, J.; Haslett, R.

    1981-03-01

    An active heat exchange method in a latent heat (salt) thermal energy storage system that prevents a low conductivity solid salt layer from forming on heat transfer surfaces was developed. An evaluation of suitable media with melting points in the temperature range of interest (250 to 400 C) limited the candidates to molten salts from the chloride, hydroxide, and nitrate families, based on high storage capacity, good corrosion characteristics, and availability in large quantities at reasonable cost. The specific salt recommended for laboratory tests was a choride eutectic (20.5KCl, 24.5NaCl, 55.0MgCl2 percent by wt.), with a nominal melting point of 385 C.

  3. Health and Environment Linked for Information Exchange in Atlanta (HELIX-Atlanta): A Pilot Tracking System

    Science.gov (United States)

    Rickman, Doug; Shire, J.; Qualters, J.; Mitchell, K.; Pollard, S.; Rao, R.; Kajumba, N.; Quattrochi, D.; Estes, M., Jr.; Meyer, P.; hide

    2009-01-01

    Objectives. To provide an overview of four environmental public health surveillance projects developed by CDC and its partners for the Health and Environment Linked for Information Exchange, Atlanta (HELIX-Atlanta) and to illustrate common issues and challenges encountered in developing an environmental public health tracking system. Methods. HELIX-Atlanta, initiated in October 2003 to develop data linkage and analysis methods that can be used by the National Environmental Public Health Tracking Network (Tracking Network), conducted four projects. We highlight the projects' work, assess attainment of the HELIX-Atlanta goals and discuss three surveillance attributes. Results. Among the major challenges was the complexity of analytic issues which required multidiscipline teams with technical expertise. This expertise and the data resided across multiple organizations. Conclusions:Establishing formal procedures for sharing data, defining data analysis standards and automating analyses, and committing staff with appropriate expertise is needed to support wide implementation of environmental public health tracking.

  4. Down-Hole Heat Exchangers: Modelling of a Low-Enthalpy Geothermal System for District Heating

    Directory of Open Access Journals (Sweden)

    M. Carlini

    2012-01-01

    Full Text Available In order to face the growing energy demands, renewable energy sources can provide an alternative to fossil fuels. Thus, low-enthalpy geothermal plants may play a fundamental role in those areas—such as the Province of Viterbo—where shallow groundwater basins occur and conventional geothermal plants cannot be developed. This may lead to being fuelled by locally available sources. The aim of the present paper is to exploit the heat coming from a low-enthalpy geothermal system. The experimental plant consists in a down-hole heat exchanger for civil purposes and can supply thermal needs by district heating. An implementation in MATLAB environment is provided in order to develop a mathematical model. As a consequence, the amount of withdrawable heat can be successfully calculated.

  5. CFD Modeling of Flow and Ion Exchange Kinetics in a Rotating Bed Reactor System

    DEFF Research Database (Denmark)

    Larsson, Hilde Kristina; Schjøtt Andersen, Patrick Alexander; Byström, Emil

    2017-01-01

    A rotating bed reactor (RBR) has been modeled using computational fluid dynamics (CFD). The flow pattern in the RBR was investigated and the flow through the porous material in it was quantified. A simplified geometry representing the more complex RBR geometry was introduced and the simplified...... model was able to reproduce the main characteristics of the flow. Alternating reactor shapes were investigated, and it was concluded that the use of baffles has a very large impact on the flows through the porous material. The simulations suggested, therefore, that even faster reaction rates could...... be achieved by making the baffles deeper. Two-phase simulations were performed, which managed to reproduce the deflection of the gas–liquid interface in an unbaffled system. A chemical reaction was implemented in the model, describing the ion-exchange phenomena in the porous material using four different...

  6. Deliberative dialogues as a strategy for system-level knowledge translation and exchange.

    Science.gov (United States)

    Boyko, Jennifer A; Lavis, John N; Dobbins, Maureen

    2014-05-01

    We undertook a case study in order to explore deliberative dialogue as a system-level knowledge translation and exchange (KTE) strategy and to describe the design features and intended effects of this dialogue. Our data included observations made during the dialogue, evaluations completed by dialogue participants and interviews. We placed these data in the context of our broader experience. We learned that (a) all the design elements we examined could be maintained in future dialogues, but organizers of dialogues that address similar issues and take place in similar contexts should consider the relative importance of these features and (b) the intended effects of a deliberative dialogue that addresses a low-priority policy issue are mainly apparent at the individual level among dialogue participants. Further research is required to explore the key features and intended effects of deliberative dialogues used to address other issues or in different contexts. Copyright © 2014 Longwoods Publishing.

  7. Patients' Data Management System Protected by Identity-Based Authentication and Key Exchange.

    Science.gov (United States)

    Rivero-García, Alexandra; Santos-González, Iván; Hernández-Goya, Candelaria; Caballero-Gil, Pino; Yung, Moti

    2017-03-31

    A secure and distributed framework for the management of patients' information in emergency and hospitalization services is proposed here in order to seek improvements in efficiency and security in this important area. In particular, confidentiality protection, mutual authentication, and automatic identification of patients are provided. The proposed system is based on two types of devices: Near Field Communication (NFC) wristbands assigned to patients, and mobile devices assigned to medical staff. Two other main elements of the system are an intermediate server to manage the involved data, and a second server with a private key generator to define the information required to protect communications. An identity-based authentication and key exchange scheme is essential to provide confidential communication and mutual authentication between the medical staff and the private key generator through an intermediate server. The identification of patients is carried out through a keyed-hash message authentication code. Thanks to the combination of the aforementioned tools, a secure alternative mobile health (mHealth) scheme for managing patients' data is defined for emergency and hospitalization services. Different parts of the proposed system have been implemented, including mobile application, intermediate server, private key generator and communication channels. Apart from that, several simulations have been performed, and, compared with the current system, significant improvements in efficiency have been observed.

  8. A system dynamics evaluation model: implementation of health information exchange for public health reporting.

    Science.gov (United States)

    Merrill, Jacqueline A; Deegan, Michael; Wilson, Rosalind V; Kaushal, Rainu; Fredericks, Kimberly

    2013-06-01

    To evaluate the complex dynamics involved in implementing electronic health information exchange (HIE) for public health reporting at a state health department, and to identify policy implications to inform similar implementations. Qualitative data were collected over 8 months from seven experts at New York State Department of Health who implemented web services and protocols for querying, receipt, and validation of electronic data supplied by regional health information organizations. Extensive project documentation was also collected. During group meetings experts described the implementation process and created reference modes and causal diagrams that the evaluation team used to build a preliminary model. System dynamics modeling techniques were applied iteratively to build causal loop diagrams representing the implementation. The diagrams were validated iteratively by individual experts followed by group review online, and through confirmatory review of documents and artifacts. Three casual loop diagrams captured well-recognized system dynamics: Sliding Goals, Project Rework, and Maturity of Resources. The findings were associated with specific policies that address funding, leadership, ensuring expertise, planning for rework, communication, and timeline management. This evaluation illustrates the value of a qualitative approach to system dynamics modeling. As a tool for strategic thinking on complicated and intense processes, qualitative models can be produced with fewer resources than a full simulation, yet still provide insights that are timely and relevant. System dynamics techniques clarified endogenous and exogenous factors at play in a highly complex technology implementation, which may inform other states engaged in implementing HIE supported by federal Health Information Technology for Economic and Clinical Health (HITECH) legislation.

  9. Design and simulation of a hybrid ventilation system with earth-air heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Athienitis, A.K.; Zhao, M. [Concordia Univ., Centre for Building Studies, Montreal, PQ (Canada). Dept. of Building, Civil and Environmental Engineering; Roy, M. [Martin Roy and Associes Group Conseil Inc., Montreal, PQ (Canada)

    2005-07-01

    A simulation study was conducted during the design phase of a new circus building in Montreal which includes a hybrid ventilation system through which fresh air is supplied from an earth-air heat exchanger (EAHE). The EAHE has the potential to satisfy the cooling needs of the building and can also be used to preheat fresh air, thereby satisfying one-third or more of the building's heating needs. Another feature of the building is that it uses displacement ventilation by which the air is supplied at low velocities through large diffusers behind the top level seats or under the seats. In this study, computational fluid dynamics (CFD) simulations were carried out to help size the supply and return units of the heating, ventilating and air conditioning (HVAC) system, as well as the exhaust chimney. The primary objective of the CFD simulation was to determine the maximum velocity and temperature in the seated area to ensure thermal comfort. CFD simulation predictions were found to be in good agreement with preliminary measurements taken in the building. In order to monitor the operation of the system over the next year, the underground ducts were equipped with temperature sensors at several depths into the soil. The energy efficiency of the hybrid HVAC system will be assessed and the velocity and temperature distribution in the theatre will be examined under various operating and energy load conditions. 8 refs., 6 figs.

  10. Patients’ Data Management System Protected by Identity-Based Authentication and Key Exchange

    Directory of Open Access Journals (Sweden)

    Alexandra Rivero-García

    2017-03-01

    Full Text Available A secure and distributed framework for the management of patients’ information in emergency and hospitalization services is proposed here in order to seek improvements in efficiency and security in this important area. In particular, confidentiality protection, mutual authentication, and automatic identification of patients are provided. The proposed system is based on two types of devices: Near Field Communication (NFC wristbands assigned to patients, and mobile devices assigned to medical staff. Two other main elements of the system are an intermediate server to manage the involved data, and a second server with a private key generator to define the information required to protect communications. An identity-based authentication and key exchange scheme is essential to provide confidential communication and mutual authentication between the medical staff and the private key generator through an intermediate server. The identification of patients is carried out through a keyed-hash message authentication code. Thanks to the combination of the aforementioned tools, a secure alternative mobile health (mHealth scheme for managing patients’ data is defined for emergency and hospitalization services. Different parts of the proposed system have been implemented, including mobile application, intermediate server, private key generator and communication channels. Apart from that, several simulations have been performed, and, compared with the current system, significant improvements in efficiency have been observed.

  11. Patients’ Data Management System Protected by Identity-Based Authentication and Key Exchange

    Science.gov (United States)

    Rivero-García, Alexandra; Santos-González, Iván; Hernández-Goya, Candelaria; Caballero-Gil, Pino; Yung, Moti

    2017-01-01

    A secure and distributed framework for the management of patients’ information in emergency and hospitalization services is proposed here in order to seek improvements in efficiency and security in this important area. In particular, confidentiality protection, mutual authentication, and automatic identification of patients are provided. The proposed system is based on two types of devices: Near Field Communication (NFC) wristbands assigned to patients, and mobile devices assigned to medical staff. Two other main elements of the system are an intermediate server to manage the involved data, and a second server with a private key generator to define the information required to protect communications. An identity-based authentication and key exchange scheme is essential to provide confidential communication and mutual authentication between the medical staff and the private key generator through an intermediate server. The identification of patients is carried out through a keyed-hash message authentication code. Thanks to the combination of the aforementioned tools, a secure alternative mobile health (mHealth) scheme for managing patients’ data is defined for emergency and hospitalization services. Different parts of the proposed system have been implemented, including mobile application, intermediate server, private key generator and communication channels. Apart from that, several simulations have been performed, and, compared with the current system, significant improvements in efficiency have been observed. PMID:28362328

  12. A high-altitude balloon platform to measure regional carbon dioxide exchange from agricultural systems

    Science.gov (United States)

    Potosnak, M. J.; Pocs, M.; Bouche, A.; Roberts, K.; Goedde, C.; Beck-Winchatz, B.

    2014-12-01

    Biosphere-atmosphere exchanges of carbon dioxide are an important component of the global carbon cycle, and understanding current exchanges is crucial for predicting future uptake of anthropogenic carbon dioxide. Agricultural systems in the Midwestern United States cover a large area and have the potential to influence the future carbon budget of the United States. Biosphere-atmosphere exchanges of carbon dioxide are typically measured at the ecosystem level using the eddy covariance technique that covers a relatively small spatial area. Top-down approaches using a global network of carbon dioxide concentration measurements provide relatively coarse spatial information. High altitude balloons (HABs) are an inexpensive platform for sounding the vertical structure and composition of the atmosphere that can bridge the spatial gap between these two other techniques. The HAB platform will also complement new satellite measurements of carbon dioxide from the Orbiting Carbon Observatory-2. In the first-generation approach of the HAB technique, a single balloon is launched, and a vertical profile of carbon dioxide is recorded during the balloon's ascent. The balloon bursts between 11 and 14 km altitude, and a second profile of carbon dioxide is obtained during the descent. The difference in carbon dioxide concentration is computed as a function of altitude, which is converted to a molar difference by accounting for the temperature and pressure profile of the atmosphere, and then a flux is obtained by summing the molar differences and dividing by the time difference between ascent and descent. The second-generation approach uses two balloons and compares their ascent profiles. This is an improvement, since the balloon can travel 100 km due to the strength of the jet stream, making it difficult to compare ascent and descent profiles. The technique works best on days with a well-developed convective boundary layer. During peak growing season, uptake rates of -30 to -50

  13. Novel wireless sensor system for dynamic characterization of borehole heat exchangers.

    Science.gov (United States)

    Martos, Julio; Montero, Álvaro; Torres, José; Soret, Jesús; Martínez, Guillermo; García-Olcina, Raimundo

    2011-01-01

    The design and field test of a novel sensor system based in autonomous wireless sensors to measure the temperature of the heat transfer fluid along a borehole heat exchanger (BHE) is presented. The system, by means of two special valves, inserts and extracts miniaturized wireless sensors inside the pipes of the borehole, which are carried by the thermal fluid. Each sensor is embedded in a small sphere of just 25 mm diameter and 8 gr weight, containing a transceiver, a microcontroller, a temperature sensor and a power supply. A wireless data processing unit transmits to the sensors the acquisition configuration before the measurements, and also downloads the temperature data measured by the sensor along its way through the BHE U-tube. This sensor system is intended to improve the conventional thermal response test (TRT) and it allows the collection of information about the thermal characteristics of the geological structure of subsurface and its influence in borehole thermal behaviour, which in turn, facilitates the implementation of TRTs in a more cost-effective and reliable way.

  14. Vapor Compression and Thermoelectric Heat Pump Heat Exchangers for a Condensate Distillation System: Design and Experiment

    Science.gov (United States)

    Erickson, Lisa R.; Ungar, Eugene K.

    2013-01-01

    Maximizing the reuse of wastewater while minimizing the use of consumables is critical in long duration space exploration. One of the more promising methods of reclaiming urine is the distillation/condensation process used in the cascade distillation system (CDS). This system accepts a mixture of urine and toxic stabilizing agents, heats it to vaporize the water and condenses and cools the resulting water vapor. The CDS wastewater flow requires heating and its condensate flow requires cooling. Performing the heating and cooling processes separately requires two separate units, each of which would require large amounts of electrical power. By heating the wastewater and cooling the condensate in a single heat pump unit, mass, volume, and power efficiencies can be obtained. The present work describes and compares two competing heat pump methodologies that meet the needs of the CDS: 1) a series of mini compressor vapor compression cycles and 2) a thermoelectric heat exchanger. In the paper, the system level requirements are outlined, the designs of the two heat pumps are described in detail, and the results of heat pump performance tests are provided. A summary is provided of the heat pump mass, volume and power trades and a selection recommendation is made.

  15. A review of fault tolerant control strategies applied to proton exchange membrane fuel cell systems

    Science.gov (United States)

    Dijoux, Etienne; Steiner, Nadia Yousfi; Benne, Michel; Péra, Marie-Cécile; Pérez, Brigitte Grondin

    2017-08-01

    Fuel cells are powerful systems for power generation. They have a good efficiency and do not generate greenhouse gases. This technology involves a lot of scientific fields, which leads to the appearance of strongly inter-dependent parameters. This makes the system particularly hard to control and increases fault's occurrence frequency. These two issues call for the necessity to maintain the system performance at the expected level, even in faulty operating conditions. It is called ;fault tolerant control; (FTC). The present paper aims to give the state of the art of FTC applied to the proton exchange membrane fuel cell (PEMFC). The FTC approach is composed of two parts. First, a diagnosis part allows the identification and the isolation of a fault; it requires a good a priori knowledge of all the possible faults. Then, a control part allows an optimal control strategy to find the best operating point to recover/mitigate the fault; it requires the knowledge of the degradation phenomena and their mitigation strategies.

  16. Manipulation of Superparamagnetic Beads on Patterned Exchange-Bias Layer Systems for Biosensing Applications.

    Science.gov (United States)

    Ehresmann, Arno; Koch, Iris; Holzinger, Dennis

    2015-11-13

    A technology platform based on a remotely controlled and stepwise transport of an array arrangement of superparamagnetic beads (SPB) for efficient molecular uptake, delivery and accumulation in the context of highly specific and sensitive analyte molecule detection for the application in lab-on-a-chip devices is presented. The near-surface transport of SPBs is realized via the dynamic transformation of the SPBs' magnetic potential energy landscape above a magnetically stripe patterned Exchange-Bias (EB) thin film layer systems due to the application of sub-mT external magnetic field pulses. In this concept, the SPB velocity is dramatically influenced by the magnitude and gradient of the magnetic field landscape (MFL) above the magnetically stripe patterned EB substrate, the SPB to substrate distance, the magnetic properties of both the SPBs and the EB layer system, respectively, as well as by the properties of the external magnetic field pulses and the surrounding fluid. The focus of this review is laid on the specific MFL design in EB layer systems via light-ion bombardment induced magnetic patterning (IBMP). A numerical approach is introduced for the theoretical description of the MFL in comparison to experimental characterization via scanning Hall probe microscopy. The SPB transport mechanism will be outlined in terms of the dynamic interplay between the EB substrate's MFL and the pulse scheme of the external magnetic field.

  17. Novel Wireless Sensor System for Dynamic Characterization of Borehole Heat Exchangers

    Directory of Open Access Journals (Sweden)

    Raimundo García-Olcina

    2011-07-01

    Full Text Available The design and field test of a novel sensor system based in autonomous wireless sensors to measure the temperature of the heat transfer fluid along a borehole heat exchanger (BHE is presented. The system, by means of two specials valves, inserts and extracts miniaturized wireless sensors inside the pipes of the borehole, which are carried by the thermal fluid. Each sensor is embedded in a small sphere of just 25 mm diameter and 8 gr weight, containing a transceiver, a microcontroller, a temperature sensor and a power supply. A wireless data processing unit transmits to the sensors the acquisition configuration before the measurements, and also downloads the temperature data measured by the sensor along its way through the BHE U-tube. This sensor system is intended to improve the conventional thermal response test (TRT and it allows the collection of information about the thermal characteristics of the geological structure of subsurface and its influence in borehole thermal behaviour, which in turn, facilitates the implementation of TRTs in a more cost-effective and reliable way.

  18. Investigation of protein-ligand and protein-protein interactions in type II non-ribosomal peptide synthetases

    OpenAIRE

    Jaremko, Matt J.

    2017-01-01

    Non-ribosomal peptide synthetases (NRPSs) are responsible for the biosynthesis of many pharmaceutically relavant compounds. Type II NRPSs are an emerging subfamily of NRPSs that form hybrid pathways with type I fatty acid synthases (FAS), polyketide synthases (PKS), type I NRPSs, or others. The type II NRPSs commonly contain tailoring enzymes that generate unique substrate modifications, such as dehydrogenations and halogenation. Unlike type I NRPSs, the type II systems consists of standalone...

  19. Numerical calculation of protein-ligand binding rates through solution of the Smoluchowski equation using smooth particle hydrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Wenxiao; Daily, Michael D.; Baker, Nathan A.

    2015-12-01

    We demonstrate the accuracy and effectiveness of a Lagrangian particle-based method, smoothed particle hydrodynamics (SPH), to study diffusion in biomolecular systems by numerically solving the time-dependent Smoluchowski equation for continuum diffusion. The numerical method is first verified in simple systems and then applied to the calculation of ligand binding to an acetylcholinesterase monomer. Unlike previous studies, a reactive Robin boundary condition (BC), rather than the absolute absorbing (Dirichlet) boundary condition, is considered on the reactive boundaries. This new boundary condition treatment allows for the analysis of enzymes with "imperfect" reaction rates. Rates for inhibitor binding to mAChE are calculated at various ionic strengths and compared with experiment and other numerical methods. We find that imposition of the Robin BC improves agreement between calculated and experimental reaction rates. Although this initial application focuses on a single monomer system, our new method provides a framework to explore broader applications of SPH in larger-scale biomolecular complexes by taking advantage of its Lagrangian particle-based nature.

  20. Convex-PL: a novel knowledge-based potential for protein-ligand interactions deduced from structural databases using convex optimization

    Science.gov (United States)

    Kadukova, Maria; Grudinin, Sergei

    2017-10-01

    We present a novel optimization approach to train a free-shape distance-dependent protein-ligand scoring function called Convex-PL. We do not impose any functional form of the scoring function. Instead, we decompose it into a polynomial basis and deduce the expansion coefficients from the structural knowledge base using a convex formulation of the optimization problem. Also, for the training set we do not generate false poses with molecular docking packages, but use constant RMSD rigid-body deformations of the ligands inside the binding pockets. This allows the obtained scoring function to be generally applicable to scoring of structural ensembles generated with different docking methods. We assess the Convex-PL scoring function using data from D3R Grand Challenge 2 submissions and the docking test of the CASF 2013 study. We demonstrate that our results outperform the other 20 methods previously assessed in CASF 2013. The method is available at http://team.inria.fr/nano-d/software/Convex-PL/.

  1. Quantifying protein-ligand interactions by direct electrospray ionization-MS analysis: evidence of nonuniform response factors induced by high molecular weight molecules and complexes.

    Science.gov (United States)

    Lin, Hong; Kitova, Elena N; Klassen, John S

    2013-10-01

    The deleterious effects of high molecular weight (MW) solute (polymers and noncovalent assemblies) on protein-ligand (PL) affinity measurements carried out using the direct electrospray ionization mass spectrometry (ESI-MS) assay are described. The presence of high MW solute, that do not interact with the protein (P) or ligand (L) of interest, is shown to result in a decrease in the abundance (Ab) ratio (R) of ligand-bound to free protein ions (i.e., Ab(PL)/Ab(P)) measured for protein-carbohydrate complexes. This effect, which can reduce the apparent association constant by more than 60%, is found to be more pronounced as the differences in the surface properties of P and PL become more significant. It is proposed that the decrease in R reflects a reduction in the number of available surface sites in the ESI droplets upon introduction of large solute and increased competition between P and the more hydrophilic PL for these sites. That a similar decrease in R is observed upon introduction of surfactants to solution provides qualitative support for this hypothesis.

  2. Combined Approach of Patch-Surfer and PL-PatchSurfer for Protein-Ligand Binding Prediction in CSAR 2013 and 2014.

    Science.gov (United States)

    Zhu, Xiaolei; Shin, Woong-Hee; Kim, Hyungrae; Kihara, Daisuke

    2016-06-27

    The Community Structure-Activity Resource (CSAR) benchmark exercise provides a unique opportunity for researchers to objectively evaluate the performance of protein-ligand docking methods. Patch-Surfer and PL-PatchSurfer, molecular surface-based methods for predicting binding ligands of proteins developed in our group, were tested on both CSAR 2013 and 2014 benchmark exercises in combination with an empirical scoring function-based method, AutoDock, while we only participated in CSAR 2013 using Patch-Surfer. The prediction results for Phase 1 task in CSAR 2013 showed that Patch-Surfer was able to rank all the four designed binding proteins within top ranks, outperforming AutoDock Vina. In Phase 2 of 2013, PL-PatchSurfer correctly selected the correct ligand pose for two target proteins. PL-PatchSurfer performed reasonably well in ranking ligands according to their binding affinity and in selecting near-native ligand poses in 2013 Phase 3 and 2014 Phase 1, respectively, although AutoDock Vina showed better performance. Lastly, in the 2014 Phase 2 exercise, the PL-PatchSurfer scores computed for ligands to target protein pairs correlated well with their pIC50 values, which was better or comparable to results by other participants. Overall, our methods showed fairly good performance in CSAR 2013 and 2014. Unique characteristics of the methods are discussed in comparison with AutoDock.

  3. Ranking docking poses by graph matching of protein-ligand interactions: lessons learned from the D3R Grand Challenge 2

    Science.gov (United States)

    da Silva Figueiredo Celestino Gomes, Priscila; Da Silva, Franck; Bret, Guillaume; Rognan, Didier

    2017-08-01

    A novel docking challenge has been set by the Drug Design Data Resource (D3R) in order to predict the pose and affinity ranking of a set of Farnesoid X receptor (FXR) agonists, prior to the public release of their bound X-ray structures and potencies. In a first phase, 36 agonists were docked to 26 Protein Data Bank (PDB) structures of the FXR receptor, and next rescored using the in-house developed GRIM method. GRIM aligns protein-ligand interaction patterns of docked poses to those of available PDB templates for the target protein, and rescore poses by a graph matching method. In agreement with results obtained during the previous 2015 docking challenge, we clearly show that GRIM rescoring improves the overall quality of top-ranked poses by prioritizing interaction patterns already visited in the PDB. Importantly, this challenge enables us to refine the applicability domain of the method by better defining the conditions of its success. We notably show that rescoring apolar ligands in hydrophobic pockets leads to frequent GRIM failures. In the second phase, 102 FXR agonists were ranked by decreasing affinity according to the Gibbs free energy of the corresponding GRIM-selected poses, computed by the HYDE scoring function. Interestingly, this fast and simple rescoring scheme provided the third most accurate ranking method among 57 contributions. Although the obtained ranking is still unsuitable for hit to lead optimization, the GRIM-HYDE scoring scheme is accurate and fast enough to post-process virtual screening data.

  4. Severe Acute Respiratory Syndrome-Coronavirus Papain-Like Novel Protease Inhibitors: Design, Synthesis, Protein-Ligand X-ray Structure and Biological Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Arun K.; Takayama, Jun; Rao, Kalapala Venkateswar; Ratia, Kiira; Chaudhuri, Rima; Mulhearn, Debbie C.; Lee, Hyun; Nichols, Daniel B.; Baliji, Surendranath; Baker, Susan C.; Johnson, Michael E.; Mesecar, Andrew D. (Purdue); (UC); (UIC)

    2012-02-21

    The design, synthesis, X-ray crystal structure, molecular modeling, and biological evaluation of a series of new generation SARS-CoV PLpro inhibitors are described. A new lead compound 3 (6577871) was identified via high-throughput screening of a diverse chemical library. Subsequently, we carried out lead optimization and structure-activity studies to provide a series of improved inhibitors that show potent PLpro inhibition and antiviral activity against SARS-CoV infected Vero E6 cells. Interestingly, the (S)-Me inhibitor 15h (enzyme IC{sub 50} = 0.56 {mu}M; antiviral EC{sub 50} = 9.1 {mu}M) and the corresponding (R)-Me 15g (IC{sub 50} = 0.32 {mu}M; antiviral EC{sub 50} = 9.1 {mu}M) are the most potent compounds in this series, with nearly equivalent enzymatic inhibition and antiviral activity. A protein-ligand X-ray structure of 15g-bound SARS-CoV PLpro and a corresponding model of 15h docked to PLpro provide intriguing molecular insight into the ligand-binding site interactions.

  5. Convex-PL: a novel knowledge-based potential for protein-ligand interactions deduced from structural databases using convex optimization

    Science.gov (United States)

    Kadukova, Maria; Grudinin, Sergei

    2017-09-01

    We present a novel optimization approach to train a free-shape distance-dependent protein-ligand scoring function called Convex-PL. We do not impose any functional form of the scoring function. Instead, we decompose it into a polynomial basis and deduce the expansion coefficients from the structural knowledge base using a convex formulation of the optimization problem. Also, for the training set we do not generate false poses with molecular docking packages, but use constant RMSD rigid-body deformations of the ligands inside the binding pockets. This allows the obtained scoring function to be generally applicable to scoring of structural ensembles generated with different docking methods. We assess the Convex-PL scoring function using data from D3R Grand Challenge 2 submissions and the docking test of the CASF 2013 study. We demonstrate that our results outperform the other 20 methods previously assessed in CASF 2013. The method is available at http://team.inria.fr/nano-d/software/Convex-PL/.

  6. On the mathematic simulation of the energy efficiency for heat exchangers with the systems of impingement plane-parallel jets

    Directory of Open Access Journals (Sweden)

    Haritonova Larisa

    2017-01-01

    Full Text Available The article gives the analytical generalization of the data on the energy efficiency for heat exchangers with the flat heat exchange surface to which systems of impact plane parallel jets are sent. Functional relations of specific power consumption (per unit of area, which were obtained for the first time using the techniques of the similarity law, for moving a heat carrier are shown with regard to design and operation factors. The regression equations representing a mathematical model of the process enable to carry out an analysis of various factors impact on the parameter to be determined. The obtained results can be used to optimize or to create the calculation techniques for new highly-efficient heat exchange devices with jet plane -parallel impingement systems and also to reduce power consumption for moving a heat carrier.

  7. Heat Exchanger/Humidifier Trade Study and Conceptual Design for the Constellation Space Suit Portable Life Support System Ventilation Subsystem

    Science.gov (United States)

    Paul, Heather L.; Sompayrac, Robert; Conger, Bruce; Chamberlain, Mateo

    2009-01-01

    As development of the Constellation Space Suit Element progresses, designing the most effective and efficient life support systems is critical. The baseline schematic analysis for the Portable Life Support System (PLSS) indicates that the ventilation loop will need some method of heat exchange and humidification prior to entering the helmet. A trade study was initiated to identify the challenges associated with conditioning the spacesuit breathing gas stream for temperature and water vapor control, to survey technological literature and resources on heat exchanger and humidifiers to provide solutions to the problems of conditioning the spacesuit breathing gas stream, and to propose potential candidate technologies to perform the heat exchanger and humidifier functions. This paper summarizes the results of this trade study and also describes the conceptual designs that NASA developed to address these issues.

  8. The development of a Patient-Identification-Oriented Nursing Shift Exchange Support System using wireless RFID PDA techniques.

    Science.gov (United States)

    Huang, Pin-Jen; She, Chien-Cheng; Chang, Polun

    2005-01-01

    The objectives of this study were to technically testing the feasibility of combining RFID and PDA technologies in nursing care and to develop a support system for the nursing shift exchange, which featured with "Positive Patient Identification" and "Point of Care" for patient's safety and security. The most challenging part for the future work would be to embed the system into the real workflow. Future study would be to examine the practical effectiveness of the system.

  9. The Development of a Patient-Identification-Oriented Nursing Shift Exchange Support System Using Wireless RFID PDA Techniques

    OpenAIRE

    Huang, Pin-Jen; She, Chien-Cheng; Chang, Polun

    2005-01-01

    The objectives of this study were to technically testing the feasibility of combining RFID and PDA technologies in nursing care and to develop a support system for the nursing shift exchange, which featured with “Positive Patient Identification” and “Point of Care” for patient’s safety and security. The most challenging part for the future work would be to embed the system into the real workflow. Future study would be to examine the practical effectiveness of the system....

  10. Creating a Global Stock Exchange: Does the Present National System Have a Future?

    Science.gov (United States)

    Warner-Allen, Charles

    Sovereignty and national pride throw up potentially the biggest obstacles in the path of a global stock exchange, being all the more insurmountable because of their bases in emotional politics as opposed to economic logic. A global stock exchange could come about if New York, London and Tokyo could consolidate their current baton-passing activity…

  11. Pairwise additivity of energy components in protein-ligand binding: The HIV II protease-Indinavir case

    Science.gov (United States)

    Ucisik, Melek N.; Dashti, Danial S.; Faver, John C.; Merz, Kenneth M.

    2011-08-01

    An energy expansion (binding energy decomposition into n-body interaction terms for n ≥ 2) to express the receptor-ligand binding energy for the fragmented HIV II protease-Indinavir system is described to address the role of cooperativity in ligand binding. The outcome of this energy expansion is compared to the total receptor-ligand binding energy at the Hartree-Fock, density functional theory, and semiempirical levels of theory. We find that the sum of the pairwise interaction energies approximates the total binding energy to ˜82% for HF and to >95% for both the M06-L density functional and PM6-DH2 semiempirical method. The contribution of the three-body interactions amounts to 18.7%, 3.8%, and 1.4% for HF, M06-L, and PM6-DH2, respectively. We find that the expansion can be safely truncated after n = 3. That is, the contribution of the interactions involving more than three parties to the total binding energy of Indinavir to the HIV II protease receptor is negligible. Overall, we find that the two-body terms represent a good approximation to the total binding energy of the system, which points to pairwise additivity in the present case. This basic principle of pairwise additivity is utilized in fragment-based drug design approaches and our results support its continued use. The present results can also aid in the validation of non-bonded terms contained within common force fields and in the correction of systematic errors in physics-based score functions.

  12. General Systems Theory, Systems Analysis, and Regional Planning: An Introductory Bibliography. Exchange Bibliography No. 164.

    Science.gov (United States)

    Williams, Hugh E.

    This bibliography suggests a number of introductory readings that will enable regional and urban planners to understand the systems approach. The main focus of the research study that gave rise to this review of the literature was on establishing ways in which decisionmakers in regional planning could be helped in making their choices. The…

  13. Effects of picture exchange communication system on communication and behavioral anomalies in autism.

    Science.gov (United States)

    Malhotra, Shahzadi; Rajender, Gaurav; Bhatia, Manjeet S; Singh, Tej B

    2010-07-01

    Communication skills deficits and stereotyped behaviors are frequently found among people with pervasive developmental disabilities like autism. These communication and behavioral oddities of autism are often considered to be difficult to treat and are challenging. Picture exchange communication system (PECS) is a six-phase picture system based on applied behavior analysis and is specially designed to overcome these communication difficulties in children with autism by encouraging the child to be the communication initiator. The present paper throws light on the process of using PECS along with other traditional behavioral approaches in managing communication deficits and behavioral stereotypies in a seven-year-old male child diagnosed as having childhood autism. The identified target behaviors of repeated head turning, flapping his hands, poor communication skills were assessed using various rating scales including visual analogue scale as per clinician observation and parental reports and managed using PECS as an adjunct to traditional behavioral techniques of contingency management, differential reinforcement, task direction and reprimand. Outcome was assessed using same tools after thirty-two sessions of interventions spread over three months. Significant improvements of around 60% were observed in the target behaviors.

  14. Use of subirrigation for water stress imposition in a semi-continuous CO2-exchange system

    Directory of Open Access Journals (Sweden)

    Rhuanito Soranz Ferrarezi

    2015-08-01

    Full Text Available The objectives of this work were to evaluate the effects of distinct moisture contents to trigger subirrigation on salvia photosynthesis and plant growth, and to verify the feasibility of subirrigation use in water stress imposition research in this crop. We evaluated two substrate volumetric water contents (VWC as treatments (0.2 and 0.4 m3 m-3 to trigger subirrigation, with 4 replications. Each replication was composed of 10 plants. An automated semi-continuous multi-chamber crop CO2-exchange system was used, with capacitance soil moisture sensors for continuous moisture monitoring. Manual subirrigation with nutrient solution was performed when VWC dropped below the thresholds. In both treatments, the values of net photosynthesis, daily carbon gain and carbon use efficiency reduced over time, from 2 to 1.1 μmol s-1 from 2.2 to 1 μmol d-1 from 0.7 to 0.45 mol mol-1, respectively, in both soil moisture treatments. Total shoot dry mass (p=0.0129, shoot height in the tip of the highest flower (p<0.0001 and total leaf area (p=0.0007 were statistically higher at 0.4 m3 m-3 treatment. The subirrigation system was not efficient to impose water stress, due to excessive variation on VWC values after each irrigation event in both treatments. Higher soil moisture promoted positive plant growth responses in salvia cultivated by subirrigation.

  15. Water Phase Change Heat Exchanger System Level Analysis for Low Lunar Orbit

    Science.gov (United States)

    Navarro, Moses; Ungar, Eugene; Sheth, Rubik; Hansen, Scott

    2016-01-01

    In low Lunar orbit (LLO) the thermal environment is cyclic - extremely cold in the eclipse and as warm as room temperature near the subsolar point. Phase change material heat exchangers (PCHXs) are the best option for long term missions in these environments. The Orion spacecraft will use a n-pentadecane wax PCHX for its envisioned mission to LLO. Using water as a PCM material is attractive because its higher heat of fusion and greater density result in a lighter, more compact PCHX. To assess the use of a water PCHX for a human spacecraft in a circular LLO, a system level analysis was performed for the Orion spacecraft. Three cases were evaluated: 1) A one-to-one replacement of the wax PCHX on the internal thermal control loop with a water PCHX (including the appropriate control modifications), 2) reducing the radiator return setpoint temperature below Orion's value to enhance PCHX freezing, and 3) placing the water PCM on the external loop. The model showed that the water PCHX could not be used as a drop-in replacement for the wax PCHX. It did not freeze fully during the eclipse owing to its low freezing point. To obtain equivalent performance, 40% more radiator area than the Orion baseline was required. The study shows that, although water PCHXs are attractive at a component level, system level effects mean that they are not the best choice for LLO.

  16. Construction of Exchange-Correlation Potentials for Strongly Interacting One-Dimensional Systems

    Science.gov (United States)

    Silva, J. Wildon O.; Vieira, Daniel

    2017-08-01

    One-dimensional (1D) systems are useful laboratories aiming further improvement of electronic structure calculations. In order to simulate electron-electron interactions, two types of expressions are commonly considered: soft-Coulomb and exponential. For both cases, in the context of density-functional theory (DFT), 1D systems can be employed to gain insight into the ingredients accurate exchange-correlation (XC) density functionals must incorporate. A question of major interest is the treatment of strongly interacting situations, one of the main modern challenges for DFT. In this manuscript, we propose a generalization of preexisting XC potentials which can be applied to investigate the transition from weak to strong interactions. Specifically, we employ the intriguing behavior of electrons confined in one dimension: the spin-charge separation, for which spin and charge are decoupled to form two independent quasiparticles, spinons, and chargons. By means of Friedel oscillations, our results indicate it is possible to reproduce the weak-strong interaction transition by using a simple strategy we name, from previous works, spin-charge separation correction (SCSC). In addition, SCSC also yields good results in reproducing the constancy of the highest occupied Kohn-Sham eigenvalues upon fractional electron charges.

  17. Control of proton exchange membrane fuel cell system breathing based on maximum net power control strategy

    Science.gov (United States)

    Li, Qi; Chen, Weirong; Liu, Zhixiang; Guo, Ai; Liu, Shukui

    2013-11-01

    In order to achieve the maximum net power, the analysis for the maximum net power characterization of a proton exchange membrane fuel cell (PEMFC) system is carried out. A maximum net power control (MNPC) strategy based on an implicit generalized predictive control (IGPC) and a reference governor is proposed to keep optimal oxygen excess ratio (OER) trajectory. The IGPC based on an effective informed adaptive particle swarm optimization (EIA-PSO) algorithm is developed to solve the predictive control law and reduce the computational complexity in the rolling optimization process. The simulations of three conditional tests are implemented and the results demonstrate that the proposed strategy can track the optimal OER trajectory, reduce the parasitic power and maximize the output net power. The comprehensive comparisons based on three conditional tests verify that the MNPC-IGPC has better robust performance in the presence of large disturbances, time delay and various noises. The experimental comparison with internal control system of Ballard 1.2 kW Nexa Power Module testifies the validity of the MNPC-IGPC for increasing the net power. Hence, this proposed strategy can provide better behavior to guarantee optimal OER trajectory and the maximum net power even though the disturbances and uncertainties occur.

  18. Tuning of PID Controllers for Quadcopter System using Cultural Exchange Imperialist Competitive Algorithm

    Directory of Open Access Journals (Sweden)

    Nizar Hadi Abbas

    2018-02-01

    Full Text Available Quadrotors are coming up as an attractive platform for unmanned aerial vehicle (UAV research, due to the simplicity of their structure and maintenance, their ability to hover, and their vertical take-off and landing (VTOL capability. With the vast advancements in small-size sensors, actuators, and processors, researchers are now focusing on developing mini UAV’s to be used in both research and commercial applications. This work presents a detailed mathematical nonlinear dynamic model of the quadrotor which is formulated using the Newton-Euler method. Although the quadrotor is a 6 DOF under-actuated system, the derived rotational subsystem is fully actuated, while the translational subsystem is under-actuated. The derivation of the mathematical model was followed by the development of the controller to control the altitude, attitude, heading and position of the quadrotor in space, which is, based on the linear Proportional-Derivative- Integral (PID controller; thus, a simplified version of the model is obtained. The gains of the controllers will be tuned using optimization techniques to improve the system's dynamic response. The standard Imperialist Competitive Algorithm (ICA was applied to tune the PID parameters and then it was compared to Cultural Exchange Imperialist Competitive algorithm (CEICA tuning, and the results show improvement in the proposed algorithm. The objective function results were enhanced by (23.91% in the CEICA compared with ICA.

  19. An Experimental Seismic Data and Parameter Exchange System for Tsunami Warning Systems

    Science.gov (United States)

    Hoffmann, T. L.; Hanka, W.; Saul, J.; Weber, B.; Becker, J.; Heinloo, A.; Hoffmann, M.

    2009-12-01

    For several years GFZ Potsdam is operating a global earthquake monitoring system. Since the beginning of 2008, this system is also used as an experimental seismic background data center for two different regional Tsunami Warning Systems (TWS), the IOTWS (Indian Ocean) and the interim NEAMTWS (NE Atlantic and Mediterranean). The SeisComP3 (SC3) software, developed within the GITEWS (German Indian Ocean Tsunami Early Warning System) project, capable to acquire, archive and process real-time data feeds, was extended for export and import of individual processing results within the two clusters of connected SC3 systems. Therefore not only real-time waveform data are routed to the attached warning centers through GFZ but also processing results. While the current experimental NEAMTWS cluster consists of SC3 systems in six designated national warning centers in Europe, the IOTWS cluster presently includes seven centers, with another three likely to join in 2009/10. For NEAMTWS purposes, the GFZ virtual real-time seismic network (GEOFON Extended Virtual Network -GEVN) in Europe was substantially extended by adding many stations from Western European countries optimizing the station distribution. In parallel to the data collection over the Internet, a GFZ VSAT hub for secured data collection of the EuroMED GEOFON and NEAMTWS backbone network stations became operational and first data links were established through this backbone. For the Southeast Asia region, a VSAT hub has been established in Jakarta already in 2006, with some other partner networks connecting to this backbone via the Internet. Since its establishment, the experimental system has had the opportunity to prove its performance in a number of relevant earthquakes. Reliable solutions derived from a minimum of 25 stations were very promising in terms of speed. For important events, automatic alerts were released and disseminated by emails and SMS. Manually verified solutions are added as soon as they become

  20. Design, Development, and Testing of a Water Vapor Exchanger for Spacecraft Life Support Systems

    Science.gov (United States)

    Izenson, Michael G.; Micka, Daniel J.; Chepko, Ariane B.; Rule, Kyle C.; Anderson, Molly S.

    2016-01-01

    Thermal and environmental control systems for future exploration spacecraft must meet challenging requirements for efficient operation and conservation of resources. Maximizing the use of regenerative systems and conserving water are critical considerations. This paper describes the design, development, and testing of an innovative water vapor exchanger (WVX) that can minimize the amount of water absorbed in, and vented from, regenerative CO2 removal systems. Key design requirements for the WVX are high air flow capacity (suitable for a crew of six), very high water recovery, and very low pressure losses. We developed fabrication and assembly methods that enable high-efficiency mass transfer in a uniform and stable array of Nafion tubes. We also developed analysis and design methods to compute mass transfer and pressure losses. We built and tested subscale units sized for flow rates of 2 and 5 cu ft/min (3.4–8.5 cu m/hr). Durability testing demonstrated that a stable core geometry was sustained over many humid/dry cycles. Pressure losses were very low (less than 0.5 in. H2O (125 Pa) total) and met requirements at prototypical flow rates. We measured water recovery efficiency across a range of flow rates and humidity levels that simulate the range of possible cabin conditions. We measured water recovery efficiencies in the range of 80 to 90%, with the best efficiency at lower flow rates and higher cabin humidity levels. We compared performance of the WVX with similar units built using an unstructured Nafion tube bundle. The WVX achieves higher water recovery efficiency with nearly an order of magnitude lower pressure drop than unstructured tube bundles. These results show that the WVX provides uniform flow through flow channels for both the humid and dry streams and can meet requirements for service on future exploration spacecraft. The WVX technology will be best suited for long-duration exploration vehicles that require regenerative CO2 removal systems while

  1. Modelling, simulation and control of a proton exchange membrane fuel cell (PEMFC) power system

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dabbagh, Ahmad W.; Lu, Lixuan; Mazza, Antonio [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, Oshawa, ON L1H 7K4 (Canada)

    2010-05-15

    Fuel cell power systems are emerging as promising means of electrical power generation on account of the associated clean electricity generation process, as well as their suitability for use in a wide range of applications. During the design stage, the development of a computer model for simulating the behaviour of a system under development can facilitate the experimentation and testing of that system's performance. Since the electrical power output of a fuel cell stack is seldom at a suitable fixed voltage, conditioning circuits and their associated controllers must be incorporated in the design of the fuel cell power system. This paper presents a MATLAB/Simulink model that simulates the behaviour of a Proton Exchange Membrane Fuel Cell (PEMFC), conditioning circuits and their controllers. The computer modelling of the PEMFC was based on adopted mathematical models that describe the fuel cell's operational voltage, while accounting for the irreversibilities associated with the fuel cell stack. The conditioning circuits that are included in the Simulink model are a DC-DC converter and DC-AC inverter circuits. These circuits are the commonly utilized power electronics circuits for regulating and conditioning the output voltage from a fuel cell stack. The modelling of the circuits is based on relationships that govern the output voltage behaviour with respect to their input voltages, switching duty cycle and efficiency. In addition, this paper describes a Fuzzy Logic Controller (FLC) design that is aimed at regulating the conditioning circuits to provide and maintain suitable electrical power for a wide range of applications. The model presented demonstrates the use of the FLC in conjunction with the PEMFC Simulink model and that it is the basis for more in-depth analytical models. (author)

  2. ReFlexIn: a flexible receptor protein-ligand docking scheme evaluated on HIV-1 protease.

    Directory of Open Access Journals (Sweden)

    Simon Leis

    Full Text Available For many targets of pharmaceutical importance conformational changes of the receptor protein are relevant during the ligand binding process. A new docking approach, ReFlexIn (Receptor Flexibility by Interpolation, that combines receptor flexibility with the computationally efficient potential grid representation of receptor molecules has been evaluated on the retroviral HIV-1 (Human Immunodeficiency Virus 1 protease system. An approximate inclusion of receptor flexibility is achieved by using interpolation between grid representations of individual receptor conformations. For the retroviral protease the method was tested on an ensemble of protease structures crystallized in the presence of different ligands and on a set of structures obtained from morphing between the unbound and a ligand-bound protease structure. Docking was performed on ligands known to bind to the protease and several non-binders. For the binders the ReFlexIn method yielded in almost all cases ligand placements in similar or closer agreement with experiment than docking to any of the ensemble members without degrading the discrimination with respect to non-binders. The improved docking performance compared to docking to rigid receptors allows for systematic virtual screening applications at very small additional computational cost.

  3. Overview on R&D and design activities for the ITER core charge exchange spectroscopy diagnostic system

    NARCIS (Netherlands)

    Biel, W.; Baross, T.; Bourauel, P.; Dunai, D.; Durkut, M.; Erdei, G.; Hawkes, N.; Hellermann, M. von; Hogenbirk, A.; Jaspers, R.; Kiss, G.; Klinkhamer, J.F.F.; Koning, J.F.; Kotov, V.; Krasikov, Y.; Krimmer, A.; Lischtschenko, O.; Litnovsky, A.; Marchuk, O.; Neubauer, O.; Offermanns, G.; Panin, A.; Patel, K.; Pokol, G.; Schrader, M.; Snijders, B.; Szabo, V.; Valk, N.J.C. van der; Voinchet, R.; Wolters, J.; Zoletnik, S.

    2011-01-01

    The ITER core charge exchange recombination spectroscopy (core CXRS) diagnostic system is designed to provide experimental access to various measurement quantities in the ITER core plasma such as ion densities, temperatures and velocities. The implementation of the approved CXRS diagnostic principle

  4. Brief Report: Increasing Communication Skills for an Elementary-Aged Student with Autism Using the Picture Exchange Communication System.

    Science.gov (United States)

    Kravits, Tamara R.; Kamps, Debra M.; Kemmerer, Katie; Potucek, Jessica

    2002-01-01

    Effects of the Picture Exchange Communication System on the spontaneous communication skills and social interactions of a 6-year-old girl with autism across her home and school environments were evaluated. Results indicated increases in spontaneous language, increases in intelligible verbalizations in two of three settings, and changes in peer…

  5. Teaching Children with Autism to Engage in Peer-Directed Mands Using a Picture Exchange Communication System

    Science.gov (United States)

    Paden, Amber R.; Kodak, Tiffany; Fisher, Wayne W.; Gawley-Bullington, Elizabeth M.; Bouxsein, Kelly J.

    2012-01-01

    We evaluated differential reinforcement of alternative behavior (DRA) plus prompting to increase peer-directed mands for preferred items using a picture exchange communication system (PECS). Two nonvocal individuals with autism participated. Independent mands with a peer increased with the implementation of DRA plus prompting for both…

  6. Comparative Efficacy of the Picture Exchange Communication System (PECS) versus a Speech-Generating Device: Effects on Requesting Skills

    Science.gov (United States)

    Boesch, Miriam C.; Wendt, Oliver; Subramanian, Anu; Hsu, Ning

    2013-01-01

    An experimental, single-subject research study investigated the comparative efficacy of the Picture Exchange Communication System (PECS) versus a speech-generating device (SGD) in developing requesting skills for three elementary-age children with severe autism and little to no functional speech. Results demonstrated increases in requesting…

  7. Augmentative and Alternative Communication in Autism: A Comparison of the Picture Exchange Communication System and Speech-Output Technology

    Science.gov (United States)

    Boesch, Miriam Chacon

    2011-01-01

    The purpose of this comparative efficacy study was to investigate the Picture Exchange Communication System (PECS) and a speech-generating device (SGD) in developing requesting skills, social-communicative behavior, and speech for three elementary-age children with severe autism and little to no functional speech. Requesting was selected as the…

  8. A Pilot Evaluation Study of the Picture Exchange Communication System (PECS) for Children with Autistic Spectrum Disorders.

    Science.gov (United States)

    Magiati, Iliana; Howlin, Patricia

    2003-01-01

    A study evaluated the effects of training 47 teachers of children with autism in the use of the Picture Exchange Communication System (PECS). Following training, significant, rapid increases were recorded in the level of PECS attained by the students (n=34), in students' PECS vocabulary, and in students' use of PECS. (Contains references.) (CR)

  9. Effects of Iconicity on Requesting with the Picture Exchange Communication System in Children with Autism Spectrum Disorder

    Science.gov (United States)

    Angermeier, Katie; Schlosser, Ralf W.; Luiselli, James K.; Harrington, Caroline; Carter, Beth

    2008-01-01

    Research on graphic symbol learning suggests that symbols with a greater visual resemblance to their referents (greater iconicity) are more easily learned. The iconicity hypothesis has not yet been explored within the intervention protocol of the Picture Exchange Communication System (PECS). Within the PECS protocol, participants do not point to a…

  10. Picture Exchange Communication System with Individuals with Developmental Disabilities: A Meta-Analysis of Single Subject Studies

    Science.gov (United States)

    Hart, Stephanie L.; Banda, Devender R.

    2010-01-01

    Picture Exchange Communication System (PECS) is a picture-based communication strategy used to teach communication skills to persons with developmental disabilities including autism. This article systematically reviews 13 published single-subject studies to examine the effectiveness of PECS, the effects of PECS on speech and problem behaviors,…

  11. The Picture Exchange Communication System: Effects on Manding and Speech Development for School-Aged Children with Autism

    Science.gov (United States)

    Tincani, Matt; Crozier, Shannon; Alazett, Shannon

    2006-01-01

    We examined the effects of the Picture Exchange Communication System (PECS; Frost & Bondy, 2002) on the manding (requesting) and speech development of school-aged children with autism. In study 1, two participants, Damian and Bob, were taught PECS within a delayed multiple baseline design. Both participants demonstrated increased levels of manding…

  12. Two-phase plate-fin heat exchanger modeling for waste heat recovery systems in diesel engines

    NARCIS (Netherlands)

    Feru, E.; de Jager, B.; Willems, F.; Steinbuch, M.

    2014-01-01

    This paper presents the modeling and model validation for a modular two-phase heat exchanger that recovers energy in heavy-duty diesel engines. The model is developed for temperature and vapor quality prediction and for control design of the waste heat recovery system. In the studied waste heat

  13. Researches Regarding the Efficiency of Water to Air Heat Exchanger with Heat Pipes for the Mechanical Ventilation System

    OpenAIRE

    Andrei Burlacu; Theodor Mateescu

    2007-01-01

    The present paper proposes the analysis of the efficiency of water to air heat exchanger with heat pipes for the mechanical ventilation system. The performed study is based on the necessity of the unconventional energy forms capitalization, increasing of the energy efficiency and the energy consumption decrease in concordance with the sustainable development concept.

  14. Researches Regarding the Efficiency of Water to Air Heat Exchanger with Heat Pipes for the Mechanical Ventilation System

    Directory of Open Access Journals (Sweden)

    Andrei Burlacu

    2007-01-01

    Full Text Available The present paper proposes the analysis of the efficiency of water to air heat exchanger with heat pipes for the mechanical ventilation system. The performed study is based on the necessity of the unconventional energy forms capitalization, increasing of the energy efficiency and the energy consumption decrease in concordance with the sustainable development concept.

  15. Analysis of leakage in IRGA's leaf chambers of open gas exchange systems: quantification and its effects in photosynthesis parameterization

    National Research Council Canada - National Science Library

    J. Flexas; A. Díaz-Espejo; J. A. Berry; J. Cifre; J. Galmés; R. Kaldenhoff; H. Medrano; M. Ribas-Carbó

    2007-01-01

    ... Ci. A quantitative analysis of CO2 leakage in the chamber of a portable open gas exchange system (Li-6400, LI-COR Inc., NE, USA) was performed. In an empty chamber, the measured CO2 leakage was similar to that calculated using the manufacturer's equations...

  16. A Novel Ion Exchange System to Purify Mixed ISS Waste Water Brines for Chemical Production and Enhanced Water Recovery

    Science.gov (United States)

    Lunn, Griffin; Spencer, LaShelle; Ruby, Anna-Maria; McCaskill, Andrew

    2014-01-01

    Current International Space Station water recovery regimes produce a sizable portion of waste water brine. This brine is highly toxic and water recovery is poor: a highly wasteful proposition. With new biological techniques that do not require waste water chemical pretreatment, the resulting brine would be chromium-free and nitrate rich which can allow possible fertilizer recovery for future plant systems. Using a system of ion exchange resins we can remove hardness, sulfate, phosphate and nitrate from these brines to leave only sodium and potassium chloride. At this point modern chlor-alkali cells can be utilized to produce a low salt stream as well as an acid and base stream. The first stream can be used to gain higher water recovery through recycle to the water separation stage while the last two streams can be used to regenerate the ion exchange beds used here, as well as other ion exchange beds in the ISS. Conveniently these waste products from ion exchange regeneration would be suitable as plant fertilizer. In this report we go over the performance of state of the art resins designed for high selectivity of target ions under brine conditions. Using ersatz ISS waste water we can evaluate the performance of specific resins and calculate mass balances to determine resin effectiveness and process viability. If this system is feasible then we will be one step closer to closed loop environmental control and life support systems (ECLSS) for current or future applications.

  17. Abnormal swimming behavior and increased deformities in rainbow trout Oncorhynchus mykiss cultured in low exchange water recirculation aquaculture systems

    Science.gov (United States)

    Two studies were conducted to determine if accumulating water quality parameters would negatively impact rainbow trout Oncorhynchus mykiss health and welfare within water recirculation aquaculture systems (WRAS) that were operated at low and near-zero water exchange, with and without ozonation, and ...

  18. Effect of Moisture Exchange on Interface Formation in the Repair System Studied by X-ray Absorption

    Directory of Open Access Journals (Sweden)

    Mladena Lukovic

    2015-12-01

    Full Text Available In concrete repair systems, material properties of the repair material and the interface are greatly influenced by the moisture exchange between the repair material and the substrate. If the substrate is dry, it can absorb water from the repair material and reduce its effective water-to-cement ratio (w/c. This further affects the hydration rate of cement based material. In addition to the change in hydration rate, void content at the interface between the two materials is also affected. In this research, the influence of moisture exchange on the void content in the repair system as a function of initial saturation level of the substrate is investigated. Repair systems with varying level of substrate saturation are made. Moisture exchange in these repair systems as a function of time is monitored by the X-ray absorption technique. After a specified curing age (3 d, the internal microstructure of the repair systems was captured by micro-computed X-ray tomography (CT-scanning. From reconstructed images, different phases in the repair system (repair material, substrate, voids can be distinguished. In order to quantify the void content, voids were thresholded and their percentage was calculated. It was found that significantly more voids form when the substrate is dry prior to application of the repair material. Air, initially filling voids and pores of the dry substrate, is being released due to the moisture exchange. As a result, air voids remain entrapped in the repair material close to the interface. These voids are found to form as a continuation of pre-existing surface voids in the substrate. Knowledge about moisture exchange and its effects provides engineers with the basis for recommendations about substrate preconditioning in practice.

  19. Analysis and Test of a Proton Exchange Membrane Fuel Cell Power System for Space Power Applications

    Science.gov (United States)

    Vasquez, Arturo; Varanauski, Donald; Clark, Robert, Jr.

    2000-01-01

    An effort is underway to develop a prototype Proton Exchange Membrane (PEM) Fuel Cell breadboard system for fuhlre space applications. This prototype will be used to develop a comprehensive design basis for a space-rated PEM fuel cell powerplant. The prototype system includes reactant pressure regulators, ejector-based reactant pumps, a 4-kW fuel cell stack and cooling system, and a passive, membranebased oxygen / water separator. A computer model is being developed concurrently to analytically predict fluid flow in the oxidant reactant system. Fuel cells have historically played an important role in human-rated spacecraft. The Gemini and Apollo spacecraft used fuel cells for vehicle electrical power. The Space Shuttle currently uses three Alkaline Fuel Cell Powerplants (AFCP) to generate all of the vehicle's 15-20kW electrical power. Engineers at the Johnson Space Center have leveraged off the development effort ongoing in the commercial arena to develop PEM fuel cel ls for terrestrial uses. The prototype design originated from efforts to develop a PEM fuel cell replacement for the current Space Shuttle AFCP' s. In order to improve on the life and an already excellent hi storical record of reliability and safety, three subsystems were focused on. These were the fuel cell stack itself, the reactant circulation devices, and reactant / product water separator. PEM fuel cell stack performance is already demonstrating the potential for greater than four times the useful life of the current Shuttle's AFCP. Reactant pumping for product water removal has historically been accomplished with mechanical pumps. Ejectors offer an effective means of reactant pumping as well as the potential for weight reduction, control simplification, and long life. Centrifugal water separation is used on the current AFCP. A passive, membrane-based water separator offers compatibility with the micro-gravity environment of space, and the potential for control simplification, elimination of

  20. Mass exchange in an experimental new-generation life support system model based on biological regeneration of environment

    Science.gov (United States)

    Tikhomirov, A. A.; Ushakova, S. A.; Manukovsky, N. S.; Lisovsky, G. M.; Kudenko, Yu. A.; Kovalev, V. S.; Gubanov, V. G.; Barkhatov, Yu. V.; Gribovskaya, I. V.; Zolotukhin, I. G.; Gros, J. B.; Lasseur, Ch.

    An experimental model of a biological life support system was used to evaluate qualitative and quantitative parameters of the internal mass exchange. The photosynthesizing unit included the higher plant component (wheat and radish), and the heterotrophic unit consisted of a soil-like substrate, California warms, mushrooms and microbial microflora. The gas mass exchange involved evolution of oxygen by the photosynthesizing component and its uptake by the heterotroph component along with the formation and maintaining of the SLS structure, growth of mushrooms and California worms, human respiration, and some other processes. Human presence in the system in the form of "virtual human" that at regular intervals took part in the respirative gas exchange during the experiment. Experimental data demonstrated good oxygen/carbon dioxide balance, and the closure of the cycles of these gases was almost complete. The water cycle was nearly 100% closed. The main components in the water mass exchange were transpiration water and the watering solution with mineral elements. Human consumption of the edible plant biomass (grains and roots) was simulated by processing these products by a unique physicochemical method of oxidizing them to inorganic mineral compounds, which were then returned into the system and fully assimilated by the plants. The oxidation was achieved by "wet combustion" of organic biomass, using hydrogen peroxide following a special procedure, which does not require high temperature and pressure. Hydrogen peroxide is produced from the water inside the system. The closure of the cycle was estimated for individual elements and compounds. Stoichiometric proportions are given for the main components included in the experimental model of the system. Approaches to the mathematical modeling of the cycling processes are discussed, using the data of the experimental model. Nitrogen, as a representative of biogmic elements, shows an almost 100% closure of the cycle inside

  1. New counter flow heat exchanger designed for ventilation systems in cold climates

    DEFF Research Database (Denmark)

    Kragh, Jesper; Rose, Jørgen; Nielsen, Toke Rammer

    2007-01-01

    that the heat exchanger is capable of continuously defrosting itself at outside air temperatures well below the freezing point while still maintaining a very high efficiency. Further analysis and development of a detailed simulation model of a counter flow air-to-air heat exchanger will be described in future...... drop. Preheating the inlet air (outdoor air) to a temperature above 0 degrees C before it enters the exchanger is one solution often used to solve the problem, however, this method reduces the energy saving potential significantly. To minimize the energy cost, a more efficient way to solve the freezing...

  2. Ion exchange system design for removal of heavy metals from acid mine drainage wastewater

    Directory of Open Access Journals (Sweden)

    R. S. Sapkal

    2010-11-01

    Full Text Available This paper discusses the methodology used to determine the optimal ion-exchange column size to process all separate batchesof feeds from acid mine drainage wastewater.The optimal design ensures the best utilization of resin material and therefore results in a minimum amount of spent resins.Ion exchanger materials have been studied for removing heavy metals from a metal bearing wastes. For the current treatment,a facility has been designed for the removal of heavy metals from the acid mine drainage (AMD waste by the ion-exchange technology.

  3. Performance Expectations of Closed-Brayton-Cycle Heat Exchangers in 100-kWe Nuclear Space Power Systems

    Science.gov (United States)

    Barrett, Michael J.

    2003-01-01

    Performance expectations of closed-Brayton-cycle heat exchangers to be used in 100-kWe nuclear space power systems were forecast. Proposed cycle state points for a system supporting a mission to three of Jupiter s moons required effectiveness values for the heat-source exchanger, recuperator and rejection exchanger (gas cooler) of 0.98,0.95 and 0.97, respectively. Performance parameters such as number of thermal units (Nm), equivalent thermal conductance (UA), and entropy generation numbers (Ns) varied from 11 to 19,23 to 39 kWK, and 0.019 to 0.023 for some standard heat exchanger configurations. Pressure-loss contributions to entropy generation were significant; the largest frictional contribution was 114% of the heat-transfer irreversibility. Using conventional recuperator designs, the 0.95 effectiveness proved difficult to achieve without exceeding other performance targets; a metallic, plate-fin counterflow solution called for 15% more mass and 33% higher pressure-loss than the target values. Two types of gas-coolers showed promise. Single-pass counterflow and multipass cross-counterflow arrangements both met the 0.97 effectiveness requirement. Potential reliability-related advantages of the cross-countefflow design were noted. Cycle modifications, enhanced heat transfer techniques and incorporation of advanced materials were suggested options to reduce system development risk. Carbon-carbon sheeting or foam proved an attractive option to improve overall performance.

  4. Tuning the ferromagnetic-antiferromagnetic interfaces of granular Co-CoO exchange bias systems by annealing

    Energy Technology Data Exchange (ETDEWEB)

    Menéndez, E., E-mail: Enric.MenendezDalmau@fys.kuleuven.be; Modarresi, H.; Pereira, L. M. C.; Temst, K.; Vantomme, A. [Instituut voor Kern- en Stralingsfysica, KU Leuven, Celestijnenlaan 200 D, BE-3001 Leuven (Belgium); Dias, T. [Instituut voor Kern- en Stralingsfysica, KU Leuven, Celestijnenlaan 200 D, BE-3001 Leuven (Belgium); Instituto de Física, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, 91501-970 Rio Grande do Sul (Brazil); Geshev, J. [Instituto de Física, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, 91501-970 Rio Grande do Sul (Brazil)

    2014-04-07

    The low-temperature magnetic behavior of granular Co-CoO exchange bias systems, prepared by oxygen ion implantation in Co thin films and subsequent annealing, is addressed. The thermal activation effects lead to an O migration which results in virtually pure Co areas embedded in a structurally relaxed and nearly stoichiometric CoO phase. This yields decreased training and exchange bias shifts, while the blocking temperature significantly increases, coming close to the Néel temperature of bulk CoO for samples implanted to a fluence above 1 × 10{sup 17} ions/cm{sup 2} (15% O). The dependence of the exchange bias shift on the pristine O-implanted content is analogous to that of the antiferromagnetic thickness in most ferromagnetic/antiferromagnetic systems (i.e., an increase in the exchange bias shift up to a maximum followed by a decrease until a steady state is reached), suggesting that, after annealing, the enriched Co areas might be rather similar in size for samples implanted above 1 × 10{sup 17} ions/cm{sup 2}, whereas the corresponding CoO counterparts become enlarged with pristine O content (i.e., effect of the antiferromagnet size). This study demonstrates that the magnetic properties of granular Co-CoO systems can be tailored by controllably modifying the local microstructure through annealing treatments.

  5. Prospect: A Picture Exchange Communication System (PECS)-based Instant Messaging Application for Autism Spectrum Condition

    Science.gov (United States)

    Raja, Pravind; Zainuri Saringat, Mohd; Mustapha, Aida; Zainal, Abidah

    2017-08-01

    Autism Spectrum Disorder (ASC) has widely gained the common attention from the public especially autistic communities. Individuals with ASC are said to have poor verbal skills and this affects them in carrying out their daily basis which they are afraid to expose themselves to the world due to their problems. ASC is diagnosed among children ranging from ages 5-12 years old and they suffer from the abnormal functioning of the brain which in turn causes lack of development activities. Thus, studies have shown that diagrammatic approaches help children with ASC to overcome their issues and improvise their visual and verbal skills. Picture Exchange Communication System or PECS consists of a series of illustrated cards and each cards has its own illustration with a caption on it. These children will understand the cards and they can compile several other cards to form sentences. This paper presents a mobile application called the Prospect, which has been developed using the agile development model for digital representation of PECS. The application is hoped to enhance the learning process and a better yielding results.

  6. Computational Fluid Dynamic Modeling of Horizontal Air-Ground Heat Exchangers (HAGHE for HVAC Systems

    Directory of Open Access Journals (Sweden)

    Paolo Maria Congedo

    2014-12-01

    Full Text Available In order to satisfy the requirements of Directive 2010/31/EU for Zero Energy Buildings (ZEB, innovative solutions were investigated for building HVAC systems. Horizontal air-ground heat exchangers (HAGHE offer a significant contribution in reducing energy consumption for ventilation, using the thermal energy stored underground, in order to pre-heat or pre-cool the ventilation air, in winter and summer, respectively. This is particularly interesting in applications for industrial, commercial and education buildings where keeping the indoor air quality under control is extremely important. Experimental measurements show that, throughout the year, the outside air temperature fluctuations are mitigated at sufficient ground depth (about 3 m because of the high thermal inertia of the soil, the ground temperature is relatively constant and instead higher than that of the outside air in winter and lower in summer. The study aims to numerically investigate the behavior of HAGHE by varying the air flow rate and soil conductivity in unsteady conditions by using annual weather data of South-East Italy. The analysis shows that, in warm climates, the HAGHE brings a real advantage for only a few hours daily in winter, while it shows significant benefits in the summer for the cooling of ventilation air up to several temperature degrees, already by a short pipe.

  7. Using adaptive neuro fuzzy inference system (ANFIS) for proton exchange membrane fuel cell (PEMFC) performance modeling

    Energy Technology Data Exchange (ETDEWEB)

    Rezazadeh, S.; Mirzaee, I. [Urmia Univ., Urmia (Iran, Islamic Republic of); Mehrabi, M. [University of Pretoria, Pretoria (South Africa)

    2012-11-15

    In this paper, an adaptive neuro fuzzy inference system (ANFIS) is used for modeling proton exchange membrane fuel cell (PEMFC) performance using some numerically investigated and compared with those to experimental results for training and test data. In this way, current density I (A/cm{sup 2}) is modeled to the variation of pressure at the cathode side P{sup C} (atm), voltage V (V), membrane thickness (mm), Anode transfer coefficient {alpha}{sup an}, relative humidity of inlet fuel RH{sup a} and relative humidity of inlet air RH{sup c} which are defined as input (design) variables. Then, we divided these data into train and test sections to do modeling. We instructed ANFIS network by 80% of numerical validated data. 20% of primary data which had been considered for testing the appropriateness of the models was entered ANFIS network models and results were compared by three statistical criterions. Considering the results, it is obvious that our proposed modeling by ANFIS is efficient and valid and it can be expanded for more general states.

  8. Thermal modeling of a greenhouse integrated to an aquifer coupled cavity flow heat exchanger system

    Energy Technology Data Exchange (ETDEWEB)

    Sethi, V.P. [Department of Mechanical Engineering, Punjab Agricultural University, Ludhiana 141 008, Punjab (India); Sharma, S.K. [Energy Research Centre, Panjab University, Chandigarh 160 017, Punjab (India)

    2007-06-15

    A thermal model is developed for heating and cooling of an agricultural greenhouse integrated with an aquifer coupled cavity flow heat exchanger system (ACCFHES). The ACCFHES works on the principal of utilizing deep aquifer water available at the ground surface through an irrigation tube well already installed in every agricultural field at constant year-round temperature of 24 C. The analysis is based on the energy balance equations for different components of the greenhouse. Using the derived analytical expressions, a computer program is developed in C{sup ++} for computing the hourly greenhouse plant and room air temperature for various design and climatic parameters. Experimental validation of the developed model is carried out using the measured plant and room air temperature data of the greenhouse (in which capsicum is grown) for the winter and summer conditions of the year 2004-2005 at Chandigarh (31 N and 78 E), Punjab, India. It is observed that the predicted and measured values are in close agreement. Greenhouse room air and plant temperature is maintained 6-7 K and 5-6 K below ambient, respectively for an extreme summer day and 7-8 K and 5-6 K above ambient, respectively for an extreme winter night. Finally, parametric studies are conducted to observe the effect of various operating parameters such as mass of the plant, area of the plant, mass flow rate of the circulating air and area of the ACCFHES on the greenhouse room air and plant temperature. (author)

  9. Methane exchange at the peatland forest floor - automatic chamber system exposes the dynamics of small fluxes

    Science.gov (United States)

    Korkiakoski, Mika; Tuovinen, Juha-Pekka; Aurela, Mika; Koskinen, Markku; Minkkinen, Kari; Ojanen, Paavo; Penttilä, Timo; Rainne, Juuso; Laurila, Tuomas; Lohila, Annalea

    2017-04-01

    We measured methane (CH4) exchange rates with automatic chambers at the forest floor of a nutrient-rich drained peatland in 2011-2013. The fen, located in southern Finland, was drained for forestry in 1969 and the tree stand is now a mixture of Scots pine, Norway spruce, and pubescent birch. Our measurement system consisted of six transparent chambers and stainless steel frames, positioned on a number of different field and moss layer compositions. Gas concentrations were measured with an online cavity ring-down spectroscopy gas analyzer. Fluxes were calculated with both linear and exponential regression. The use of linear regression resulted in systematically smaller CH4 fluxes by 10-45 % as compared to exponential regression. However, the use of exponential regression with small fluxes ( low fluxes and that higher fluxes are then recalculated using exponential regression. The exponential flux was clearly affected by the length of the fitting period when this period was < 190 s, but stabilized with longer periods. Thus, we also recommend the use of a fitting period of several minutes to stabilize the results and decrease the flux detection limit. There were clear seasonal dynamics in the CH4 flux: the forest floor acted as a CH4 sink particularly from early summer until the end of the year, while in late winter the flux was very small and fluctuated around zero. However, the magnitude of fluxes was relatively small throughout the year, ranging mainly from -130 to +100 µg CH4 m-2 h-1. CH4 emission peaks were observed occasionally, mostly in summer during heavy rainfall events. Diurnal variation, showing a lower CH4 uptake rate during the daytime, was observed in all of the chambers, mainly in the summer and late spring, particularly in dry conditions. It was attributed more to changes in wind speed than air or soil temperature, which suggest that physical rather than biological phenomena are responsible for the observed variation. The annual net CH4 exchange

  10. DOE-EPSCoR. Exchange interactions in epitaxial intermetallic layered systems

    Energy Technology Data Exchange (ETDEWEB)

    LeClair, Patrick R. [Univ. of Alabama, Tuscaloosa, AL (United States); Gary, Mankey J. [Univ. of Alabama, Tuscaloosa, AL (United States)

    2015-05-25

    The goal of this research is to develop a fundamental understanding of the exchange interactions in epitaxial intermetallic alloy thin films and multilayers, including films and multilayers of Fe-Pt, Co-Pt and Fe-P-Rh alloys deposited on MgO and Al2O3 substrates. Our prior results have revealed that these materials have a rich variety of ferromagnetic, paramagnetic and antiferromagnetic phases which are sensitive functions of composition, substrate symmetry and layer thickness. Epitaxial antiferromagnetic films of FePt alloys exhibit a different phase diagram than bulk alloys. The antiferromagnetism of these materials has both spin ordering transitions and spin orienting transitions. The objectives include the study of exchange-inversion materials and the interface of these materials with ferromagnets. Our aim is to formulate a complete understanding of the magnetic ordering in these materials, as well as developing an understanding of how the spin structure is modified through contact with a ferromagnetic material at the interface. The ultimate goal is to develop the ability to tune the phase diagram of the materials to produce layered structures with tunable magnetic properties. The alloy systems that we will study have a degree of complexity and richness of magnetic phases that requires the use of the advanced tools offered by the DOE-operated national laboratory facilities, such as neutron and x-ray scattering to measure spin ordering, spin orientations, and element-specific magnetic moments. We plan to contribute to DOE’s mission of producing “Materials by Design” with properties determined by alloy composition and crystal structure. We have developed the methods for fabricating and have performed neutron diffraction experiments on some of the most interesting phases, and our work will serve to answer questions raised about the element-specific magnetizations using the magnetic x-ray dichroism techniques and interface magnetism in layered structures

  11. Resolution exchange simulation.

    Science.gov (United States)

    Lyman, Edward; Ytreberg, F Marty; Zuckerman, Daniel M

    2006-01-20

    We extend replica-exchange simulation in two ways and apply our approaches to biomolecules. The first generalization permits exchange simulation between models of differing resolution--i.e., between detailed and coarse-grained models. Such "resolution exchange" can be applied to molecular systems or spin systems. The second extension is to "pseudoexchange" simulations, which require little CPU usage for most levels of the exchange ladder and also substantially reduce the need for overlap between levels. Pseudoexchanges can be used in either replica or resolution exchange simulations. We perform efficient, converged simulations of a 50-atom peptide to illustrate the new approaches.

  12. Heat exchanger selection and design analyses for metal hydride heat pump systems

    DEFF Research Database (Denmark)

    Mazzucco, Andrea; Voskuilen, Tyler G.; Waters, Essene L.

    2016-01-01

    This study presents a design analysis for the development of highly efficient heat exchangers within stationary metal hydride heat pumps. The design constraints and selected performance criteria are applied to three representative heat exchangers. The proposed thermal model can be applied to select...... the most efficient heat exchanger design and provides outcomes generally valid in a pre-design stage. Heat transfer effectiveness is the principal performance parameter guiding the selection analysis, the results of which appear to be mildly (up to 13%) affected by the specific Nusselt correlation used....... The thermo-physical properties of the heat transfer medium and geometrical parameters are varied in the sensitivity analysis, suggesting that the length of independent tubes is the physical parameter that influences the performance of the heat exchangers the most. The practical operative regions for each...

  13. Data Description Exchange Services for Heterogeneous Vehicle and Spaceport Control and Monitor Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — CCT has designed and prototyped, as part of the Phase-1 SBIR, a generic platform independent software capability for exchange of semantic control and monitoring...

  14. Direct-hydrogen-fueled proton-exchange-membrane fuel cell system for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Oei, D.; Adams, J.A.; Kinnelly, A.A. [and others

    1997-07-01

    In partial fulfillment of the U.S. Department of Energy Contract No. DE-ACO2-94CE50389, {open_quotes}Direct Hydrogen-Fueled Proton-Exchange-Membrane (PEM) Fuel Cell System for Transportation Applications{close_quotes}, this conceptual vehicle design report addresses the design and packaging of battery augmented fuel cell powertrain vehicles. This report supplements the {open_quotes}Conceptual Vehicle Design Report - Pure Fuel Cell Powertrain Vehicle{close_quotes} and includes a cost study of the fuel cell power system. The three classes of vehicles considered in this design and packaging exercise are the same vehicle classes that were studied in the previous report: the Aspire, representing the small vehicle class; the AIV (Aluminum Intensive Vehicle) Sable, representing the mid-size vehicle; and the E-150 Econoline, representing the van-size class. A preliminary PEM fuel cell power system manufacturing cost study is also presented. As in the case of the previous report concerning the {open_quotes}Pure Fuel Cell Powertrain Vehicle{close_quotes}, the same assumptions are made for the fuel cell power system. These assumptions are fuel cell system power densities of 0.33 kW/ka and 0.33 kW/l, platinum catalyst loading of less than or equal to 0.25 mg/cm{sup 2} total, and hydrogen tanks containing compressed gaseous hydrogen under 340 atm (5000 psia) pressure. The batteries considered for power augmentation of the fuel cell vehicle are based on the Ford Hybrid Electric Vehicle (HEV) program. These are state-of-the-art high power lead acid batteries with power densities ranging from 0.8 kW/kg to 2 kW/kg. The results reported here show that battery augmentation provides the fuel cell vehicle with a power source to meet instant high power demand for acceleration and start-up. Based on the assumptions made in this report, the packaging of the battery augmented fuel cell vehicle appears to be as feasible as the packaging of the pure fuel cell powered vehicle.

  15. Comparing the Net Ecosystem Exchange of Two Cropping Systems for Dairy Feed Production

    Science.gov (United States)

    Sulaiman, M. F.; Wagner-Riddle, C.; Brown, S. E.

    2015-12-01

    A three-year study was conducted from 2012 to 2014 to determine the net CO2 fluxes from corn and hay, the two main feed crops used in dairy production. The aim of this study is to better understand the net ecosystem exchange (NEE) in annual and perennial cropping systems used in dairy production to benefit greenhouse gas emission model developments and the life cycle analysis of dairy production. The study was conducted on two 4-ha plots where one plot was a 5-year old hayfield and the other plot was planted in a continuous cycle corn. All plots were continuously monitored using the flux-gradient method deployed with a tunable diode laser trace gas analyzer and sonic anemometers. All plots received dairy manure as fertilizer applied according to common practice. The cumulative NEE for the three years of the study was -873.15 g C m-2 for corn and -409.36 g C m-2 for hay. Differences in respiration between the two cropping systems was found to be the larger factor compared to differences in gross ecosystem production (GEP) that resulted in the contrasting cumulative NEE where cumulative respiration for the three years for hay was 3094.23 g C m-2 as opposed to 2078.11 g C m-2 for corn. Cumulative GEP for the three years was 3503.60 and 2951.31 g C m-2 for hay and corn respectively. Inter-annual and inter-crop variability of the NEE, GEP and respiration will be discussed in relation to biomass production, climatic conditions and crop physiological characteristics.

  16. Challenges of Executive Information Systems in listed Johannesburg Stock Exchange companies

    Directory of Open Access Journals (Sweden)

    Elmarie Papageorgiou

    2011-03-01

    Full Text Available Background: The widespread use of Executive Information Systems (EISs as a management information tool was noted in listed Johannesburg Stock Exchange (JSE companies. The digital business environment exposed executives to so much data that data need to be converted into useful information that is organised and summarised.Objectives: The purpose of this study is to establish and to determine the existence, and to what extent EISs exist in all levels of management and to identify the challenges companies experienced in listed JSE companies. Therefore the problem exists that EIS-users at all levels of management are unaware of the challenges of EISs and that EISs can be used as a tool to analyse their businesses’ performance and competitiveness.Method: A mixed method was used; both quantitative and qualitative in nature. Questionnaires were sent to 334 listed JSE companies and 13 interviews were conducted with users of EISs in all levels of management.Results: The results of the study demonstrate that the majority of respondents of the questionnaire have an EIS or plan to implement an EIS. The results further revealed the respondents’ positive attitude towards EISs as it is an excellent management information tool that adds strategic value to their business, that is critical for real-time decision-making, solves problems and creates a competitive edge. From the results it is evident that there is a need for an EIS to be ‘everybody’s information system’. The results of the interviews demonstrate that an EIS is a seamless reliable system necessary for proper timeous decision-making. The respondents to the questionnaire and the interviewees indicated that they understood the value of EISs as a useful part of their company.Conclusion: The study adds value to the awareness and understanding of EISs that creates a business environment in which business and management can enhance sustainability and strategic competitiveness.

  17. Seasonal and interannual variability of the water exchange in the Turkish Straits System estimated by modelling

    Directory of Open Access Journals (Sweden)

    V. MADERICH

    2015-07-01

    Full Text Available A chain of simple linked models is used to simulate the seasonal and interannual variability of the Turkish Straits System. This chain includes two-layer hydraulic models of the Bosphorus and Dardanelles straits simulating the exchange in terms of level and density difference along each strait, and a one-dimensional area averaged layered model of the Marmara Sea. The chain of models is complemented also by the similar layered model of the Black Sea proper and by a one-layer Azov Sea model with the Kerch Strait. This linked chain of models is used to study the seasonal and interannual variability of the system in the period 1970-2009. The salinity of the Black Sea water flowing into the Aegean Sea increases by approximately 1.7 times through entrainment from the lower layer. The flow entering into the lower layer of the Dardanelles Strait from the Aegean Sea is reduced by nearly 80% when it reaches the Black Sea. In the seasonal scale, a maximal transport in the upper layer and minimal transport in the bottom layer are during winter/spring for the Bosphorus and in spring for the Dardanelles Strait, whereas minimal transport in upper layer and maximal undercurrent are during the summer for the Bosphorus Strait and autumn for the Dardanelles Strait. The increase of freshwater flux into the Black Sea in interannual time scales (41 m3s-1 per year is accompanied by a more than twofold growth of the Dardanelles outflow to the North Aegean (102 m3s-1 per year.

  18. Unlocking Chain Exchange in Highly Amphiphilic Block Polymer Micellar Systems: Influence of Agitation.

    Science.gov (United States)

    Murphy, Ryan P; Kelley, Elizabeth G; Rogers, Simon A; Sullivan, Millicent O; Epps, Thomas H

    2014-11-18

    Chain exchange between block polymer micelles in highly selective solvents, such as water, is well-known to be arrested under quiescent conditions, yet this work demonstrates that simple agitation methods can induce rapid chain exchange in these solvents. Aqueous solutions containing either pure poly(butadiene-b-ethylene oxide) or pure poly(butadiene-b-ethylene oxide-d4) micelles were combined and then subjected to agitation by vortex mixing, concentric cylinder Couette flow, or nitrogen gas sparging. Subsequently, the extent of chain exchange between micelles was quantified using small angle neutron scattering. Rapid vortex mixing induced chain exchange within minutes, as evidenced by a monotonic decrease in scattered intensity, whereas Couette flow and sparging did not lead to measurable chain exchange over the examined time scale of hours. The linear kinetics with respect to agitation time suggested a surface-limited exchange process at the air-water interface. These findings demonstrate the strong influence of processing conditions on block polymer solution assemblies.

  19. Determination of γ-hydroxybutyrate in human urine samples by ion exclusion and ion exchange two-dimensional chromatography system.

    Science.gov (United States)

    Liu, Junwei; Deng, Zhifen; Zhu, Zuoyi; Wang, Yong; Wang, Guoqing; Sun, Yu-An; Zhu, Yan

    2017-12-15

    A two-dimensional ion chromatography system was developed for the determination of γ-hydroxybutyrate (GHB) in human urine samples. Ion exclusion chromatography was used in the first dimensional separation for elimination of urine matrices and detection of GHB above 10mgL-1, ion exchange chromatography was used in the second dimensional separation via column-switching technique for detection of GHB above 0.08mgL-1. Under the optimized chromatographic conditions, the ion exclusion and ion exchange chromatography separation system exhibited satisfactory repeatability (RSDion chromatography system was convenient and practical for the determination of GHB in human urine samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Experimental evaluation of an adaptive Joule-Thomson cooling system including silicon-microfabricated heat exchanger and microvalve components.

    Science.gov (United States)

    Zhu, Weibin; Park, Jong M; White, Michael J; Nellis, Gregory F; Gianchandani, Yogesh B

    2011-03-01

    This article reports the evaluation of a Joule-Thomson (JT) cooling system that combines two custom micromachined components-a Si/glass-stack recuperative heat exchanger and a piezoelectrically actuated expansion microvalve. With the microvalve controlling the flow rate, this system can modulate cooling to accommodate varying refrigeration loads. The perforated plate Si/glass heat exchanger is fabricated with a stack of alternating silicon plates and Pyrex glass spacers. The microvalve utilizes a lead zirconate titanate actuator to push a Si micromachined valve seat against a glass plate, thus modulating the flow passing through the gap between the valve seat and the glass plate. The fabricated heat exchanger has a footprint of 1 × 1 cm(2) and a length of 35 mm. The size of the micromachined piezoelectrically actuated valve is about 1 × 1 × 1 cm(3). In JT cooling tests, the temperature of the system was successfully controlled by adjusting the input voltage of the microvalve. When the valve was fully opened (at an input voltage of -30 V), the system cooled down to a temperature as low as 254.5 K at 430 kPa pressure difference between inlet and outlet at steady state and 234 K at 710 kPa in a transient state. The system provided cooling powers of 75 mW at 255 K and 150 mW at 258 K. Parasitic heat loads at 255 K are estimated at approximately 700 mW.

  1. Solid State Joining of High Temperature Alloy Tubes for USC and Heat-Exchanger Systems

    Energy Technology Data Exchange (ETDEWEB)

    Bimal Kad

    2011-12-31

    The principal objective of this project was to develop materials enabling joining technologies for use in forward looking heat-exchanger fabrication in Brayton cycle HIPPS, IGCC, FutureGen concepts capable of operating at temperatures in excess of 1000{degree}C as well as conventional technology upgrades via Ultra Super-Critical (USC) Rankine-cycle boilers capable of operating at 760{degree}C (1400F)/38.5MPa (5500psi) steam, while still using coal as the principal fossil fuel. The underlying mission in Rankine, Brayton or Brayton-Rankine, or IGCC combined cycle heat engine is a steady quest to improving operating efficiency while mitigating global environmental concerns. There has been a progressive move to higher overall cycle efficiencies, and in the case of fossil fuels this has accelerated recently in part because of concerns about greenhouse gas emissions, notably CO{sub 2}. For a heat engine, the overall efficiency is closely related to the difference between the highest temperature in the cycle and the lowest temperature. In most cases, efficiency gains are prompted by an increase in the high temperature, and this in turn has led to increasing demands on the materials of construction used in the high temperature end of the systems. Our migration to new advanced Ni-base and Oxide Dispersion Strengthened (ODS) alloys poses significant fabrication challenges, as these materials are not readily weldable or the weld performs poorly in the high temperature creep regime. Thus the joining challenge is two-fold to a) devise appropriate joining methodologies for similar/dissimilar Ni-base and ODS alloys while b) preserving the near baseline creep performance in the welded region. Our program focus is on solid state joining of similar and dissimilar metals/alloys for heat exchanger components currently under consideration for the USC, HIPPS and IGCC power systems. The emphasis is to manipulate the joining methods and variables available to optimize joint creep

  2. Predicting progress in Picture Exchange Communication System (PECS) use by children with autism.

    Science.gov (United States)

    Pasco, Greg; Tohill, Christina

    2011-01-01

    The Picture Exchange Communication System (PECS) is a widely used communication intervention for non-verbal children with autism spectrum disorder. Findings for the benefits of PECS have almost universally been positive, although there is very limited information about the characteristics of PECS users that determine the amount of progress that they are likely to make. To explore the utility of using children's developmental age to predict the subsequent degree of progress using PECS. In a retrospective study, 23 non-verbal 5- and 6-year-old children with autism spectrum disorder attending a special school were assessed to determine their highest level of PECS ability. They were then allocated to one of two groups depending on whether or not they had mastered PECS phase III. All participants had been assessed using the Psycho-Educational Profile-Revised (PEP-R) on entry to the school and before being introduced to PECS. Total developmental age scores were examined to determine whether they accurately predicted membership of the two PECS ability groups. All the 16 children who had mastered PECS phase III had total developmental age scores of 16 months or above, whilst six of the seven children who had not progressed beyond phase III scored below 16 months--the other child had a score of 16 months. The assessment of the developmental level of potential PECS users may provide valuable predictive information for speech-and-language therapists and other professionals in relation to the likely degree of progress and in setting realistic and achievable targets. © 2010 Royal College of Speech & Language Therapists.

  3. Social-communicative effects of the Picture Exchange Communication System (PECS) in autism spectrum disorders.

    Science.gov (United States)

    Lerna, Anna; Esposito, Dalila; Conson, Massimiliano; Russo, Luigi; Massagli, Angelo

    2012-01-01

    The Picture Exchange Communication System (PECS) is a common treatment choice for non-verbal children with autism. However, little empirical evidence is available on the usefulness of PECS in treating social-communication impairments in autism. To test the effects of PECS on social-communicative skills in children with autism, concurrently taking into account standardized psychometric data, standardized functional assessment of adaptive behaviour, and information on social-communicative variables coded in an unstructured setting. Eighteen preschool children (mean age = 38.78 months) were assigned to two intervention approaches, i.e. PECS and Conventional Language Therapy (CLT). Both PECS (Phases I-IV) and CLT were delivered three times per week, in 30-min sessions, for 6 months. Outcome measures were the following: Autism Diagnostic Observation Schedule (ADOS) domain scores for Communication and Reciprocal Social Interaction; Language and Personal-Social subscales of the Griffiths' Mental Developmental Scales (GMDS); Communication and Social Abilities domains of the Vineland Adaptive Behavior Scales (VABS); and several social-communicative variables coded in an unstructured setting. Results demonstrated that the two groups did not differ at Time 1 (pre-treatment assessment), whereas at Time 2 (post-test) the PECS group showed a significant improvement with respect to the CLT group on the VABS social domain score and on almost all the social-communicative abilities coded in the unstructured setting (i.e. joint attention, request, initiation, cooperative play, but not eye contact). These findings showed that PECS intervention (Phases I-IV) can improve social-communicative skills in children with autism. This improvement is especially evident in standardized measures of adaptive behaviour and measures derived from the observation of children in an unstructured setting. © 2012 Royal College of Speech and Language Therapists.

  4. A classification system of intraocular lens dislocation sites under operating microscopy, and the surgical techniques and outcomes of exchange surgery.

    Science.gov (United States)

    Hayashi, Ken; Ogawa, Soichiro; Manabe, Shin-Ichi; Hirata, Akira; Yoshimura, Koichi

    2016-03-01

    The aim of this study was to examine the recent status of intraocular lens (IOL) dislocation according to a classification system based on vertical dislocation position, as well as the surgical techniques and outcomes of IOL exchange surgery. The medical records of 230 eyes from 214 consecutive patients who experienced IOL dislocation and underwent exchange surgery between 2006 and 2014 were reviewed. Vertical dislocation sites observed preoperatively under operating microscopy were examined, along with the surgical techniques and outcomes of IOL exchange. Dislocation sites included (1) the anterior chamber (12.2 %), (2) pseudophakodonesis (19.1 %), (3) the anterior vitreous cavity (47.4 %), (4) trap door-like dislocation (dangling in the peripheral vitreous cavity; 16.1 %), and (5) the retinal surface (5.2 %). The IOL retained in the anterior segment was moved onto the iris by pulling it up through the limbal side ports with an anterior vitrectomy (67.8 %), or by pushing it up from the pars plana with an anterior vitrectomy (26.5 %), while the IOL dropped on the retina was lifting it up from the retina after pars plana vitrectomy (5.7 %). Mean uncorrected and distance-corrected visual acuity significantly improved postoperatively (p system, approximately 95 % of dislocated IOLs were retained in the anterior segment, and these IOLs were exchanged using an anterior approach through limbal incisions with an anterior vitrectomy. Visual acuity improved significantly, and serious complications were uncommon, probably because the IOL exchange techniques were standardized and simplified without pars plana vitrectomy.

  5. Optimal design of the first stage of the plate-fin heat exchanger for the EAST cryogenic system

    Science.gov (United States)

    Qingfeng, JIANG; Zhigang, ZHU; Qiyong, ZHANG; Ming, ZHUANG; Xiaofei, LU

    2018-03-01

    The size of the heat exchanger is an important factor determining the dimensions of the cold box in helium cryogenic systems. In this paper, a counter-flow multi-stream plate-fin heat exchanger is optimized by means of a spatial interpolation method coupled with a hybrid genetic algorithm. Compared with empirical correlations, this spatial interpolation algorithm based on a kriging model can be adopted to more precisely predict the Colburn heat transfer factors and Fanning friction factors of offset-strip fins. Moreover, strict computational fluid dynamics simulations can be carried out to predict the heat transfer and friction performance in the absence of reliable experimental data. Within the constraints of heat exchange requirements, maximum allowable pressure drop, existing manufacturing techniques and structural strength, a mathematical model of an optimized design with discrete and continuous variables based on a hybrid genetic algorithm is established in order to minimize the volume. The results show that for the first-stage heat exchanger in the EAST refrigerator, the structural size could be decreased from the original 2.200 × 0.600 × 0.627 (m3) to the optimized 1.854 × 0.420 × 0.340 (m3), with a large reduction in volume. The current work demonstrates that the proposed method could be a useful tool to achieve optimization in an actual engineering project during the practical design process.

  6. Potential for Small Unmanned Aircraft Systems applications for identifying groundwater-surface water exchange in a meandering river reach

    Science.gov (United States)

    Pai, H.; Malenda, H.; Briggs, Martin; Singha, K.; González-Pinzón, R.; Gooseff, M.; Tyler, S.W.; ,

    2017-01-01

    The exchange of groundwater and surface water (GW-SW), including dissolved constituents and energy, represents a critical yet challenging characterization problem for hydrogeologists and stream ecologists. Here, we describe the use of a suite of high spatial-resolution remote-sensing techniques, collected using a small unmanned aircraft system (sUAS), to provide novel and complementary data to analyze GW-SW exchange. sUAS provided centimeter-scale resolution topography and water surface elevations, which are often drivers of exchange along the river corridor. Additionally, sUAS-based vegetation imagery, vegetation-top elevation, and normalized difference vegetation index (NDVI) mapping indicated GW-SW exchange patterns that are difficult to characterize from the land surface and may not be resolved from coarser satellite-based imagery. We combined these data with estimates of sediment hydraulic conductivity to provide a direct estimate of GW “shortcutting” through meander necks, which was corroborated by temperature data at the riverbed interface.

  7. EU enlargement and new member countries' involvement in the exchange rates system

    Directory of Open Access Journals (Sweden)

    Vlatka Bilas

    2005-08-01

    Full Text Available For each country, joining the union is a unique process, considering advantages and disadvantages which a country can thus obtain. In order to fulfill conditions for the EU accession, transition countries must achieve different convergence criteria. Expansion of the EU brings along many challenges including coordination of policies and conducting a common monetary policy. After joining the EU new members are expected to have a minimum of two years of participation in the Exchange Rate Mechanism 2 before accepting euro. ERM2 can be a flexible and efficient framework for the determination of a appropriate level of irrevocable exchange rate fixing according to euro, as well as for achieving macroeconomic stability. Even though, considering demands for complete abolition of capital controls and high capital mobility, fixed exchange rate with fluctuation margins of ±15% is to become sensitive to the capital movements and speculative attacks.

  8. Adaptively Compressed Exchange Operator

    CERN Document Server

    Lin, Lin

    2016-01-01

    The Fock exchange operator plays a central role in modern quantum chemistry. The large computational cost associated with the Fock exchange operator hinders Hartree-Fock calculations and Kohn-Sham density functional theory calculations with hybrid exchange-correlation functionals, even for systems consisting of hundreds of atoms. We develop the adaptively compressed exchange operator (ACE) formulation, which greatly reduces the computational cost associated with the Fock exchange operator without loss of accuracy. The ACE formulation does not depend on the size of the band gap, and thus can be applied to insulating, semiconducting as well as metallic systems. In an iterative framework for solving Hartree-Fock-like systems, the ACE formulation only requires moderate modification of the code, and can be potentially beneficial for all electronic structure software packages involving exchange calculations. Numerical results indicate that the ACE formulation can become advantageous even for small systems with tens...

  9. Nanometer-size magnetic domains and coherent magnetization reversal in a giant exchange-bias system

    DEFF Research Database (Denmark)

    Dufour, C.; Fitzsimmons, M. R.; Borchers, J. A.

    2011-01-01

    The role of magnetic domains and domain walls in exchange bias has stimulated much contemporary deliberation. Here we present compelling evidence obtained with small-angle scattering of unpolarized- and polarized-neutron beams that magnetization reversal occurs via formation of 10-100s nm......-sized magnetic domains in an exchange-biased DyFe2/YFe2 superlattice. The reversal mechanism is observed to involve rotation of magnetization in and out of the sample plane. Remarkably, the domains are arranged in a quasiperiodic manner in the plane of the sample. The length scale of domain formation is similar...

  10. Heat transfer characteristics of various kinds of ground heat exchangers for ground source heat pump system

    Science.gov (United States)

    Miyara, A.; Kariya, K.; Ali, Md. H.; Selamat, S. B.; Jalaluddin

    2017-01-01

    Three kinds of vertical-type ground heat exchangers, U-tube; double-tube; multi-tube, and two kinds of horizontal-type ground heat exchangers, standing Slinky; reclined Slinky, were experimentally and numerically investigated in order to clarify their heat transfer characteristics. Experiments and simulations were carried out under two operation conditions which are continuous operation mode and discontinuous operation mode and effects of temperature recovery and thermal storage on the heat transfer rate were shown. Differences of the heat transfer rate between standing Slinky and reclined Slinky were also indicated.

  11. The generalisation effects of picture exchange communication system (pecs) training for children with autism and language delay

    OpenAIRE

    Yoon, Jung ae

    2017-01-01

    The Picture Exchange Communication System (PECS) has been widely used in intervention programs to develop functional communication for children who have no or little vocal communication. Studies have shown that PECS training is effective in developing communication and social interaction (Carr & Felce, 2006; Ganz, Simpson, & Corbin-Newsome, 2007) for children with autism. However, most research on the effectiveness of PECS has been limited in several ways. Firstly, few studies have evaluated ...

  12. Verifier-based three-party authentication schemes using extended chaotic maps for data exchange in telecare medicine information systems.

    Science.gov (United States)

    Lee, Tian-Fu

    2014-12-01

    Telecare medicine information systems provide a communicating platform for accessing remote medical resources through public networks, and help health care workers and medical personnel to rapidly making correct clinical decisions and treatments. An authentication scheme for data exchange in telecare medicine information systems enables legal users in hospitals and medical institutes to establish a secure channel and exchange electronic medical records or electronic health records securely and efficiently. This investigation develops an efficient and secure verified-based three-party authentication scheme by using extended chaotic maps for data exchange in telecare medicine information systems. The proposed scheme does not require server's public keys and avoids time-consuming modular exponential computations and scalar multiplications on elliptic curve used in previous related approaches. Additionally, the proposed scheme is proven secure in the random oracle model, and realizes the lower bounds of messages and rounds in communications. Compared to related verified-based approaches, the proposed scheme not only possesses higher security, but also has lower computational cost and fewer transmissions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  13. Barter exchanges

    DEFF Research Database (Denmark)

    Sudzina, Frantisek

    Although barter is often perceived as something that proceeded money, barter is still used. The focus of the paper is on barter exchanges. Barter exchanges are used both in developing countries as well as in developed countries (including the U.S.). They are used by both organizations...... and individuals. They usually allow to exchange good but some include also services. Some exchanges allow only for bi-directional barter, i.e. when only two parties are involved in the exchange. But probably most of the barter exchanges use barter money; this makes it easier to exchange goods and services...

  14. Multiply Controlled Verbal Operants: An Analysis and Extension to the Picture Exchange Communication System

    Science.gov (United States)

    Bondy, A.; Tincani, M.; Frost, L.

    2004-01-01

    This paper presents Skinner's (1957) analysis of verbal behavior as a framework for understanding language acquisition in children with autism. We describe Skinner's analysis of pure and impure verbal operants and illustrate how this analysis may be applied to the design of communication training programs. The picture exchange communication system…

  15. The Effectiveness of the Picture Exchange Communication System (PECS) for Children with Autism Spectrum Disorder (ASD): A South African Pilot Study

    Science.gov (United States)

    Travis, Julia; Geiger, Martha

    2010-01-01

    This study investigated the effects of introducing the Picture Exchange Communication System (PECS) on the frequency of requesting and commenting and the length of verbal utterances of two children with autism spectrum disorder (ASD) who presented with some spoken language, but limited use of language in communicative exchanges. A mixed research…

  16. The Impact of Coastal Phytoplankton Blooms on Ocean-Atmosphere Thermal Energy Exchange: Evidence from a Two-Way Coupled Numerical Modeling System

    Science.gov (United States)

    2012-12-25

    Phytoplankton Blooms on Ocean-Atmosphere Thermal Energy Exchange: Evidence from a Two-Way Coupled Numerical Modeling System 5a. CONTRACT NUMBER... phytoplankton stocks in a coastal embayment may impact thermal energy exchange processes. Monterey Bay simulations parameterizing solar shortwave transparency...in the surface ocean as an invariant oligotrophic oceanic water type estimate consistently colder sea surface temperature (SST) than simulations

  17. Efficiency Analysis of the Main Components of a Vertical Closed-Loop System in a Borehole Heat Exchanger

    Directory of Open Access Journals (Sweden)

    Cristina Sáez Blázquez

    2017-02-01

    Full Text Available In vertical closed-loop systems, it is common to use single or double U-tube heat exchangers separated by longitudinal spacers. In addition, the helical-shaped pipe is another configuration that requires lower drilling lengths but it is less used. The aim of the present research is to study the influence of these components on the total efficiency of a borehole heat exchanger (BHE. Thus, the differences between using single/double U-tubes (with or without spacers and helical pipes are analysed in terms of efficiency. Through different laboratory tests, a small vertical closed-loop system was simulated in order to analyse all these possible configurations. The grouting materials and the temperatures of the ground were modified at the same time in these tests. Regarding the heat exchange process between the ground and the heat carrier fluid, it must be highlighted that the best results were obtained for the helical-shaped pipe configuration. Some of the improvements offered by this heat exchanger typology with respect to the vertical configuration is that a lower drilling depth is required even it requires a larger diameter. This leads to significant economic savings in the performing drilling process. Finally, it is also worth noting the importance of using spacers in vertical U-tubes and that no improvements have been found regarding the use of single or double configuration of U-tubes. Thanks to the laboratory results derived from this study it is possible to establish the optimum behaviour pattern for the entire vertical closed-loop systems.

  18. Formula study for plate heat exchanger in the central heating regulation of the indirect connection hot water heating system

    National Research Council Canada - National Science Library

    Minghui CUI; Dezhi MENG; Chengming NI

    2016-01-01

    Plate heat exchanger has unique advantages and becomes dominant heat exchange equipment in heating engineering, but there is no heating regulation formula of plate exchanger applied in central heating...

  19. Modeling and Validation of Sodium Plugging for Heat Exchangers in Sodium-cooled Fast Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    Ferroni, Paolo [Westinghouse Electric Company LLC, Cranberry Township, PA (United States). Global Technology Development; Tatli, Emre [Westinghouse Electric Company LLC, Cranberry Township, PA (United States); Czerniak, Luke [Westinghouse Electric Company LLC, Cranberry Township, PA (United States); Sienicki, James J. [Argonne National Lab. (ANL), Argonne, IL (United States); Chien, Hual-Te [Argonne National Lab. (ANL), Argonne, IL (United States); Yoichi, Momozaki [Argonne National Lab. (ANL), Argonne, IL (United States); Bakhtiari, Sasan [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-06-29

    The project “Modeling and Validation of Sodium Plugging for Heat Exchangers in Sodium-cooled Fast Reactor Systems” was conducted jointly by Westinghouse Electric Company (Westinghouse) and Argonne National Laboratory (ANL), over the period October 1, 2013- March 31, 2016. The project’s motivation was the need to provide designers of Sodium Fast Reactors (SFRs) with a validated, state-of-the-art computational tool for the prediction of sodium oxide (Na2O) deposition in small-diameter sodium heat exchanger (HX) channels, such as those in the diffusion bonded HXs proposed for SFRs coupled with a supercritical CO2 (sCO2) Brayton cycle power conversion system. In SFRs, Na2O deposition can potentially occur following accidental air ingress in the intermediate heat transport system (IHTS) sodium and simultaneous failure of the IHTS sodium cold trap. In this scenario, oxygen can travel through the IHTS loop and reach the coldest regions, represented by the cold end of the sodium channels of the HXs, where Na2O precipitation may initiate and continue. In addition to deteriorating HX heat transfer and pressure drop performance, Na2O deposition can lead to channel plugging especially when the size of the sodium channels is small, which is the case for diffusion bonded HXs whose sodium channel hydraulic diameter is generally below 5 mm. Sodium oxide melts at a high temperature well above the sodium melting temperature such that removal of a solid plug such as through dissolution by pure sodium could take a lengthy time. The Sodium Plugging Phenomena Loop (SPPL) was developed at ANL, prior to this project, for investigating Na2O deposition phenomena within sodium channels that are prototypical of the diffusion bonded HX channels envisioned for SFR-sCO2 systems. In this project, a Computational Fluid Dynamic (CFD) model capable of simulating the thermal-hydraulics of the SPPL test

  20. Application of the Hubbard model to Cp*(2)Yb(bipy), a model system for strong exchange coupling in lanthanide systems.

    Science.gov (United States)

    Lukens, Wayne W; Magnani, Nicola; Booth, Corwin H

    2012-10-01

    Exchange coupling is quantified in lanthanide (Ln) single-molecule magnets (SMMs) containing a bridging N(2)(3-) radical ligand and between [Cp*(2)Yb](+) and bipy(•-) in Cp*(2)Yb(bipy), where Cp* is pentamethylcyclopentadienyl and bipy is 2,2'-bipyridyl. In the case of these lanthanide SMMs, the magnitude of exchange coupling between the Ln ion and the bridging N(2)(3-), 2J, is very similar to the barrier to magnetic relaxation, U(eff). A molecular version of the Hubbard model is applied to systems in which unpaired electrons on magnetic metal ions have direct overlap with unpaired electrons residing on ligands. The Hubbard model explicitly addresses electron correlation, which is essential for understanding the magnetic behavior of these complexes. This model is applied quantitatively to Cp*(2)Yb(bipy) to explain its very strong exchange coupling, 2J = -0.11 eV (-920 cm(-1)). The model is also used to explain the presence of strong exchange coupling in Ln SMMs in which the lanthanide spins are coupled via bridging N(2)(3-) radical ligands. The results suggest that increasing the magnetic coupling in lanthanide clusters could lead to an increase in the blocking temperatures of exchange-coupled lanthanide SMMs, suggesting routes to rational design of future lanthanide SMMs.

  1. A whole-plant chamber system for parallel gas exchange measurements of Arabidopsis and other herbaceous species.

    Science.gov (United States)

    Kölling, Katharina; George, Gavin M; Künzli, Roland; Flütsch, Patrick; Zeeman, Samuel C

    2015-01-01

    Photosynthetic assimilation of carbon is a defining feature of the plant kingdom. The fixation of large amounts of carbon dioxide supports the synthesis of carbohydrates, which make up the bulk of plant biomass. Exact measurements of carbon assimilation rates are therefore crucial due to their impact on the plants metabolism, growth and reproductive success. Commercially available single-leaf cuvettes allow the detailed analysis of many photosynthetic parameters, including gas exchange, of a selected leaf area. However, these cuvettes can be difficult to use with small herbaceous plants such as Arabidopsis thaliana or plants having delicate or textured leaves. Furthermore, data from single leaves can be difficult to scale-up for a plant shoot with a complex architecture and tissues in different physiological states. Therefore, we constructed a versatile system-EGES-1-to simultaneously measure gas exchange in the whole shoots of multiple individual plants. Our system was designed to be able record data continuously over several days. The EGES-1 system yielded comparable measurements for eight plants for up to 6 days in stable, physiologically realistic conditions. The chambers seals have negligible permeability to carbon dioxide and the system is designed so as to detect any bulk-flow air leaks. We show that the system can be used to monitor plant responses to changing environmental conditions, such as changes in illumination or stress treatments, and to compare plants with phenotypically severe mutations. By incorporating interchangeable lids, the system could be used to measure photosynthetic gas exchange in several genera such as Arabidopsis, Nicotiana, Pisum, Lotus and Mesembryanthemum. EGES-1 can be introduced into a variety of growth facilities and measure gas exchange in the shoots diverse plant species grown in different growth media. It is ideal for comparing photosynthetic carbon assimilation of wild-type and mutant plants and/or plants undergoing

  2. Plasma FITC-dextran exchange between the primary and secondary circulatory systems in the Atlantic cod, Gadus Morhua

    DEFF Research Database (Denmark)

    Fischer, Claes; Steffensen, John Fleng

    2008-01-01

    Fluorescein isothiocyanate dextran (FITC-dextran) exchange between the primary (PCS) and secondary (SCS) circulatory systems in the Atlantic cod, Gadus morhua (Linnaeus, 1752), were studied using 20-kDa (n = 4) and 500-kDa (n = 4) FITC-dextran. In order to give a qualitative perspective...... of the injected 500-kDa FITC-dextran was also examined, and it was observed that of the 500-kDa FITC-dextran lost from the primary and secondary vascular systems, 63.0 +/- 9.2% could be recovered from the liver....

  3. Thermal stratification in vertical mantle heat-exchangers with application to solar domestic hot-water systems

    DEFF Research Database (Denmark)

    Knudsen, Søren; Furbo, Simon

    2004-01-01

    Experimental and numerical investigations of vertical mantle heat exchangers for solar domestic hot water (SDHW) systems have been carried out. Two different inlet positions are investigated. Experiments based on typical operation conditions are carried out to investigate how the thermal...... stratification is affected by different positions of the mantle inlet. The heat transfer between the solar collector fluid in the mantle and the domestic water in the tank is analysed by CFD-simulations. Furthermore, side-by-side laboratory tests have been carried out with SDHW systems with different mantle...

  4. 78 FR 69910 - Joint Industry Plan; BATS Exchange, Inc., BATS-Y Exchange, Inc., BOX Options Exchange LLC, C2...

    Science.gov (United States)

    2013-11-21

    ... COMMISSION Joint Industry Plan; BATS Exchange, Inc., BATS-Y Exchange, Inc., BOX Options Exchange LLC, C2... LLC, NYSE Arca, Inc. and Topaz Exchange, LLC; Notice of Filing of Proposed National Market System Plan... and Exchange Commission (``Commission'') the proposed National Market System (``NMS'') Plan Governing...

  5. Development of a hot heat exchanger and a cleaning system for a 35 kW hermetic four cylinder Stirling engine for solid biomass fuels

    DEFF Research Database (Denmark)

    Carlsen, Henrik; Marinitsch, Gerald; Schöch, Martin

    2005-01-01

    been operated for more than 9,000 hours. Operating experiences gained from these plants formed the basis for the further development of this technology. The experiences showed that the efficiency of the Stirling hot gas heat exchanger and of the hot gas heat exchanger cleaning system have to be further...... optimised. Within the scope of a RD&D project, a new hot gas heat exchanger and a new cleaning system have been developed and optimised in cooperation of the AUSTRIAN BIOENERGY CENTRE GmbH, the Technical University of Denmark, MAWERA Holzfeuerungsanlagen GmbH, Austria, and BIOS BIOENERGIESYSTEME Gmb......H, Austria. The new design of the Stirling hot gas heat exchanger has been developed in order to optimise the performance of the engine and simplify the geometry. In this respect, an equal distribution of the heat transfer across each tube in the hot gas heat exchanger, the reduction of the internal Helium...

  6. Characterization of protein/ligand interactions by {sup 1}H/{sup 3}H exchange: application to the hAsf{sup 1}/ histone H{sup 3} complex; Caracterisation des interactions proteine / ligand par echange {sup 1}H/{sup 3}H: application au complexe entre la proteine hAsf{sup 1} et l'histone H{sup 3}

    Energy Technology Data Exchange (ETDEWEB)

    Mousseau, G

    2007-05-15

    In the first chapter will be exposed the main current methods of identification to high debit of the interactions protein-protein. Then the methods allowing to characterize the surfaces of interaction or to determine the structures of the complexes will be listed by discussing the main advantages and the inconveniences. Our approach of characterization of the zones of interaction protein-protein is a method of 'foot-printing' 1, based on the identification and radicals' quantification formed on the residues of proteins accessible to the water. The second chapter will so discuss the development of this method of radical identification using the atom of tritium as radioactive label. Our approach will finally be validated in the third chapter by applying it to the characterization of amino acids involved in the interaction enter the human protein anti silencing factor 1 (hAsf11-156) and a fragment of the histone H{sup 3}. (N.C.)

  7. Patient Privacy, Consent, and Identity Management in Health Information Exchange: Issues for the Military Health System

    Science.gov (United States)

    2013-01-01

    Graham Nixon, Jennifer Teal, Mike Davis, Robert Smith, Linda Fischetti, David Parker, Zachary Gillen, and John Mattison, “The Department of...April 8, 2011. 74 Patient Privacy, Consent, and Identity Management Dimitropoulos, Linda L., Shaun J. Grannis, Alison K. Banger, and David H...Goldstein, Melissa M., and Alison L. Rein, Consumer Consent Options for Electronic Health Information Exchange: Policy Considerations and Analysis, March 23

  8. COMPUTER PROGRAM FOR CALCULATION MICROCHANNEL HEAT EXCHANGERS FOR AIR CONDITIONING SYSTEMS

    Directory of Open Access Journals (Sweden)

    Olga V. Olshevska

    2016-08-01

    Full Text Available Creating a computer program to calculate microchannel air condensers to reduce design time and carrying out variant calculations. Software packages for thermophysical properties of the working substance and the coolant, the correlation equation for calculating heat transfer, aerodynamics and hydrodynamics, the thermodynamic equations for the irreversible losses and their minimization in the heat exchanger were used in the process of creating. Borland Delphi 7 is used for creating software package.

  9. Experimental evaluation of an adaptive Joule–Thomson cooling system including silicon-microfabricated heat exchanger and microvalve components

    Science.gov (United States)

    Zhu, Weibin; Park, Jong M.; White, Michael J.; Nellis, Gregory F.; Gianchandani, Yogesh B.

    2011-01-01

    This article reports the evaluation of a Joule–Thomson (JT) cooling system that combines two custom micromachined components—a Si/glass-stack recuperative heat exchanger and a piezoelectrically actuated expansion microvalve. With the microvalve controlling the flow rate, this system can modulate cooling to accommodate varying refrigeration loads. The perforated plate Si/glass heat exchanger is fabricated with a stack of alternating silicon plates and Pyrex glass spacers. The microvalve utilizes a lead zirconate titanate actuator to push a Si micromachined valve seat against a glass plate, thus modulating the flow passing through the gap between the valve seat and the glass plate. The fabricated heat exchanger has a footprint of 1×1 cm2 and a length of 35 mm. The size of the micromachined piezoelectrically actuated valve is about 1×1×1 cm3. In JT cooling tests, the temperature of the system was successfully controlled by adjusting the input voltage of the microvalve. When the valve was fully opened (at an input voltage of −30 V), the system cooled down to a temperature as low as 254.5 K at 430 kPa pressure difference between inlet and outlet at steady state and 234 K at 710 kPa in a transient state. The system provided cooling powers of 75 mW at 255 K and 150 mW at 258 K. Parasitic heat loads at 255 K are estimated at approximately 700 mW. PMID:21552354

  10. Active heat exchange system development for latent heat thermal energy storage

    Science.gov (United States)

    Alario, J.; Kosson, R.; Haslett, R.

    1980-01-01

    Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application (300 MW sub t storage for 6 hours). Two concepts were selected for hardware development: (1) a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and (2) a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which was nickel plated to decrease adhesion forces. In addition to improving performance by providing a nearly constant transfer rate during discharge, these active heat exchanger concepts were estimated to cost at least 25% less than the passive tube-shell design.

  11. High Temperature Heat Exchanger Design and Fabrication for Systems with Large Pressure Differentials

    Energy Technology Data Exchange (ETDEWEB)

    Chordia, Lalit [Thar Energy, LLC, Pittsburgh, PA (United States); Portnoff, Marc A. [Thar Energy, LLC, Pittsburgh, PA (United States); Green, Ed [Thar Energy, LLC, Pittsburgh, PA (United States)

    2017-03-31

    The project’s main purpose was to design, build and test a compact heat exchanger for supercritical carbon dioxide (sCO2) power cycle recuperators. The compact recuperator is required to operate at high temperature and high pressure differentials, 169 bar (~2,500 psi), between streams of sCO2. Additional project tasks included building a hot air-to-sCO2 Heater heat exchanger (HX) and design, build and operate a test loop to characterize the recuperator and heater heat exchangers. A novel counter-current microtube recuperator was built to meet the high temperature high differential pressure criteria and tested. The compact HX design also incorporated a number of features that optimize material use, improved reliability and reduced cost. The air-to-sCO2 Heater HX utilized a cross flow, counter-current, micro-tubular design. This compact HX design was incorporated into the test loop and exceeded design expectations. The test loop design to characterize the prototype Brayton power cycle HXs was assembled, commissioned and operated during the program. Both the prototype recuperator and Heater HXs were characterized. Measured results for the recuperator confirmed the predictions of the heat transfer models developed during the project. Heater HX data analysis is ongoing.

  12. pH Transitions in ion-exchange systems: role in the development of a cation-exchange process for a recombinant protein.

    Science.gov (United States)

    Ghose, Sanchayita; McNerney, Thomas M; Hubbard, Brian

    2002-01-01

    Unexpected transient changes in effluent pH can occur during ion-exchange chromatography. Such changes can occur even if a column that is equilibrated with a buffer receives another solution in the same buffer and of the same pH but of a different salt concentration. An attempt is made to understand the basis for this phenomenon and apply it to the process purification of a recombinant protein on a strong cation-exchange resin. Incomplete column equilibration was eliminated as a possible cause of these effects. Various buffering species and various salt ions were studied at different solution concentrations to investigate pH transitions on strong cation-exchange resins. A further comparison was made between cation-exchange resins with different backbone chemistries. On the basis of these studies, a mechanism is proposed for these phenomena based on competitive equilibria between ions from the buffer salts and H(+)/OH(-) ions. In addition to the equilibria between these ions and the functional groups on the resins, charged groups on the resin backbone were also found to contribute to transient pH changes. The results from this study were applied to the cation-exchange step for a recombinant protein that was sensitive to pH excursions to help maintain activity of the protein during the purification process.

  13. Performance of water source heat pump system using high-density polyethylene tube heat exchanger wound with square copper wire

    Directory of Open Access Journals (Sweden)

    Xin Wen Zhang

    2015-07-01

    Full Text Available Surface water source heat pump system is an energy-efficient heat pump system. Surface water heat exchanger is an important part of heat pump system that can affect the performance of the system. In order to enhance the performance of the system, the overall heat transfer coefficient (U value of the water exchanger using a 32A square copper coiled high-density polyethylene tube was researched. Comparative experiments were conducted between the performance of the coiled high-density polyethylene tube and the 32A smooth high-density polyethylene tube. At the same time, the coefficient of performance of the heat pump was investigated. According to the result, the U value of the coiled tube was 18% higher than that of the smooth tube in natural convection and 19% higher in forced convection. The coefficient of performance of the heat pump with the coiled tube is higher than that with the smooth tube. The economic evaluation of the coiled tube was also investigated.

  14. The effect of a heat and moisture exchanger on gas flow in a Mapleson F breathing system during inhalational induction.

    Science.gov (United States)

    Da Fonseca, J M; Wheeler, D W; Pook, J A

    2000-06-01

    Heat and moisture exchangers (HMEs) humidify, warm and filter inspired gas, protecting patients and apparatus during anaesthesia. Their incorporation into paediatric anaesthetic breathing systems is recommended. We experienced delays in inhalational induction whilst using a Mapleson F breathing system with an HME. We have demonstrated that the HME significantly alters gas flow within the breathing system. Approximately half of the fresh gas flow is delivered to the patient, the remainder being wasted into the expiratory limb of the breathing system. We suggest that the HME should be removed from the Mapleson F breathing system until inhalational induction is complete, or that the reservoir bag is completely occluded until an effective seal is obtained with the mask.

  15. Screening protein-ligand interactions using {sup 1}H NMR techniques for detecting the ligand; Mapeamento das interacoes proteina-ligante atraves de tecnicas de RMN de {sup 1}H utilizando deteccao do ligante

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Isis Martins; Marsaioli, Anita Jocelyne [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Organica]. E-mail: anita@iqm.unicamp.br

    2007-07-01

    NMR is a valuable screening tool for the binding of ligands to proteins providing structural information on both protein and ligands and is thus largely applied to drug-discovery. Among the recent NMR techniques to probe weak binding protein-ligand complexes we have critically evaluated the advantages and disadvantages of STD (Saturation Transfer Difference), WaterLOGSY (Water Ligand Observation with Gradient Spectroscopy), NOE pumping and DOSY-NOESY (Diffusion-Ordered NOESY) using a mixture of BSA (bovine serum albumin) plus salicylic acid, caffeine, citric acid, adipic acid and D-glucose. (author)

  16. Microplate Heat Exchanger Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a microplate heat exchanger for cryogenic cooling systems used for continuous flow distributed cooling systems, large focal plane arrays, multiple cooling...

  17. An integrated healthcare information system for end-to-end standardized exchange and homogeneous management of digital ECG formats.

    Science.gov (United States)

    Trigo, Jesús Daniel; Martínez, Ignacio; Alesanco, Alvaro; Kollmann, Alexander; Escayola, Javier; Hayn, Dieter; Schreier, Günter; García, José

    2012-07-01

    This paper investigates the application of the enterprise information system (EIS) paradigm to standardized cardiovascular condition monitoring. There are many specifications in cardiology, particularly in the ECG standardization arena. The existence of ECG formats, however, does not guarantee the implementation of homogeneous, standardized solutions for ECG management. In fact, hospital management services need to cope with various ECG formats and, moreover, several different visualization applications. This heterogeneity hampers the normalization of integrated, standardized healthcare information systems, hence the need for finding an appropriate combination of ECG formats and a suitable EIS-based software architecture that enables standardized exchange and homogeneous management of ECG formats. Determining such a combination is one objective of this paper. The second aim is to design and develop the integrated healthcare information system that satisfies the requirements posed by the previous determination. The ECG formats selected include ISO/IEEE11073, Standard Communications Protocol for Computer-Assisted Electrocardiography, and an ECG ontology. The EIS-enabling techniques and technologies selected include web services, simple object access protocol, extensible markup language, or business process execution language. Such a selection ensures the standardized exchange of ECGs within, or across, healthcare information systems while providing modularity and accessibility.

  18. Impacts of intra-day rescheduling of unit commitment and cross border exchange on operational costs in European power systems

    Energy Technology Data Exchange (ETDEWEB)

    Meibom, Peter [Technical Univ. of Denmark (DTU), Roskilde (Denmark). Risoe National Lab. for Sustainable Energy; Weber, Christoph [Duisburg-Essen Univ., Essen (Germany). Chair for Management Sciences and Energy Economics

    2009-07-01

    The Wilmar Planning tool was used to study market rule parameters directly influencing the functioning of the internal European electricity market. These parameters are the efficiency of the cross-border allocation mechanism (spatial dimension) and the flexibility in time that is offered by the markets (time dimension). Simulations were carried out for a European power system covering 25 countries and two target years (2020 and 2030) characterized by installed wind power capacity, electricity demand, available interconnector capacity and energy economic boundary conditions. Four model runs for each target year were carried out investigating the consequences of having different degrees of market integration between countries and having different amounts of well functioning intra-day power markets for the operation of the European power market in terms of system costs and CO{sub 2} emissions. Model results show large system cost increases connected with fixing unit commitment of slow units day-ahead, and smaller but still significant system cost increases with fixing cross-border exchange day-ahead. Cross-border exchange of reserves induced very small costs savings due to model limitations. (orig.)

  19. A Bayesian network fault diagnostic system for proton exchange membrane fuel cells

    Science.gov (United States)

    Riascos, Luis Alberto M.; Simoes, Marcelo G.; Miyagi, Paulo E.

    This paper considers the effects of different types of faults on a proton exchange membrane fuel cell model (PEMFC). Using databases (which record the fault effects) and probabilistic methods (such as the Bayesian-Score and Markov Chain Monte Carlo), a graphical-probabilistic structure for fault diagnosis is constructed. The graphical model defines the cause-effect relationship among the variables, and the probabilistic method captures the numerical dependence among these variables. Finally, the Bayesian network (i.e. the graphical-probabilistic structure) is used to execute the diagnosis of fault causes in the PEMFC model based on the effects observed.

  20. A Bayesian network fault diagnostic system for proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Riascos, Luis Alberto M. [Federal University of ABC, r. Santa Adelia, 166, CEP 09210-170, Santo Andre, SP (Brazil); Simoes, Marcelo G. [Colorado School of Mines, 1500 Illinois Street, 80401, Golden, CO (United States); Miyagi, Paulo E. [Escola Politecnica, University of Sao Paulo, Av. Prof. Mello Moraes, 2231, CEP 05508-900, Sao Paulo (Brazil)

    2007-02-25

    This paper considers the effects of different types of faults on a proton exchange membrane fuel cell model (PEMFC). Using databases (which record the fault effects) and probabilistic methods (such as the Bayesian-Score and Markov Chain Monte Carlo), a graphical-probabilistic structure for fault diagnosis is constructed. The graphical model defines the cause-effect relationship among the variables, and the probabilistic method captures the numerical dependence among these variables. Finally, the Bayesian network (i.e. the graphical-probabilistic structure) is used to execute the diagnosis of fault causes in the PEMFC model based on the effects observed. (author)

  1. Modification of the saturation magnetization of exchange bias thin film systems upon light-ion bombardment.

    Science.gov (United States)

    Huckfeldt, Henning; Gaul, Alexander; David Müglich, Nicolas; Holzinger, Dennis; Nissen, Dennis; Albrecht, Manfred; Emmrich, Daniel; Beyer, André; Gölzhäuser, Armin; Ehresmann, Arno

    2017-03-29

    The magnetic modification of exchange bias materials by 'ion bombardment induced magnetic patterning' has been established more than a decade ago. To understand these experimental findings several theoretical models were introduced. Few investigations, however, did focus on magnetic property modifications caused by effects of ion bombardment in the ferromagnetic layer. In the present study, the structural changes occurring under ion bombardment were investigated by Monte-Carlo simulations and in experiments. A strong reduction of the saturation magnetization scaling linearly with increasing ion doses is observed and our findings suggest that it is correlated to the swelling of the layer material based on helium implantation and vacancy creation.

  2. Experimental results with a natural gas cogeneration system using a polymer exchange membrane fuel cell

    Science.gov (United States)

    Radulescu, Mihai; Lottin, Olivier; Feidt, Michel; Lombard, Christophe; Noc, David Le; Doze, Stéphane Le

    This paper reports experimental results of an investigation of five identical CHP (combined heat and power) units using PEMFC (proton exchange membrane fuel cell) and running on natural gas. The natural gas is reformed locally to produce hydrogen. The net electric power is 4.5 kWe and the installations are designed for low temperature heat recovery (6 kW at 60 °C). The performances of the CHP units are analyzed in terms of electrical, thermal and total efficiencies. The electrical efficiency is low and it is shown that this is due mostly to the reforming process and to electric losses, while fuel cell performances are fully satisfying.

  3. Hydrogeologic controls on chemical transport at Malibu Lagoon, CA: Implications for land to sea exchange in coastal lagoon systems

    Directory of Open Access Journals (Sweden)

    N. Dimova

    2017-06-01

    New hydrological insights for the region: Nearshore lagoons that are seasonally disconnected from the coastal ocean occupy about 10% of coastal areas worldwide. Lagoon systems often are poorly flushed and thus sensitive to nutrient over-enrichment that can lead to eutrophication, oxygen depletion, and/or pervasive algal blooms. This sensitivity is exacerbated in lagoons that are intermittently closed to surface water exchange with the sea and occur in populous coastal areas. Such estuarine systems are disconnected from the sea during most of the year by wave-built barriers, but during the rainy season these berms can breach, enabling direct water exchange. Using naturally-occurring 222Rn as groundwater tracer, we estimate that groundwater discharge to Malibu Lagoon during open berm conditions was one order of magnitude higher (21 ± 17 cm/day than during closed berm conditions (1.8 ± 1.4 cm/day. The SGD (submarine groundwater discharge into nearshore coastal waters at the SurferRider and Colony Malibu was 4.2 cm/day on average. The exported total dissolved nitrogen (TDN through the berm during closed berm was 1.6 × 10−3 mol/day, whereas during open berm (exported by the Creek was 3.5 × 103 mol/day. Although these evaluations are specific to the collection campaigns the 2009 and 2010 hydro years, these two distinct hydrologic scenarios play an important role in the seasonality and geochemical impact of land/sea exchange, and highlight the sensitivity of such systems to future impacts such as sea level rise and increasing coastal populations.

  4. El sistema de comunicación a través de pictogramas o picture exchange communication system (PECS)

    OpenAIRE

    Garrachón Ugarte, Mireia

    2017-01-01

    Con este Trabajo de Fin de Grado (TFG) quiero dar a conocer la importancia de uno de los sistemas de comunicación que tenemos hoy en nuestra sociedad, el Picture Exchange Communication System o Sistema De Comunicación por Intercambio de Imágenes (PECS). Es un sistema que se basa en el intercambio de pictogramas y ayuda a los niños/as a comunicarse en su entorno social. Este sistema es un recurso para aquellos niños/as que presentan trastornos en el desarrollo, para los que tienen trastorno...

  5. An evaluation of multiple-schedule variations to reduce high-rate requests in the picture exchange communication system.

    Science.gov (United States)

    Landa, Robin; Hanley, Gregory P

    2016-06-01

    Using procedures similar to those of Tiger, Hanley, and Heal (2006), we compared two multiple-schedule variations (S+/S- and S+ only) to treat high-rate requests for edible items in the Picture Exchange Communication System (PECS). Two individuals with autism participated, after they showed persistent requests for edible items after PECS training. Stimulus control was achieved only with the multiple schedule that involved presentation of a discriminative stimulus during reinforcement components and its removal during extinction components (S+ only). Discriminated requests were maintained for the 1 participant who experienced schedule thinning. © 2016 Society for the Experimental Analysis of Behavior.

  6. Patterns of exchange of forensic DNA data in the European Union through the Prüm system.

    Science.gov (United States)

    Santos, Filipe; Machado, Helena

    2017-07-01

    This paper presents a study of the 5-year operation (2011-2015) of the transnational exchange of forensic DNA data between Member States of the European Union (EU) for the purpose of combating cross-border crime and terrorism within the so-called Prüm system. This first systematisation of the full official statistical dataset provides an overall assessment of the match figures and patterns of operation of the Prüm system for DNA exchange. These figures and patterns are analysed in terms of the differentiated contributions by participating EU Member States. The data suggest a trend for West and Central European countries to concentrate the majority of Prüm matches, while DNA databases of Eastern European countries tend to contribute with profiles of people that match stains in other countries. In view of the necessary transparency and accountability of the Prüm system, more extensive and informative statistics would be an important contribution to the assessment of its functioning and societal benefits. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Active heat exchange system development for latent heat thermal energy storage

    Science.gov (United States)

    Alario, J.; Haslett, R.

    1980-03-01

    Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application. Two concepts selected for hardware development are a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which has been nickel plated to decrease adhesion forces. Suitable phase change material (PCM) storage media with melting points in the temperature range of interest (250 C to 400 C) were investigated. The specific salt recommended for laboratory tests was a chloride eutectic (20.5KCl-24/5 NaCl-55.0MgCl 2% by wt.), with a nominal melting point of 385 C.

  8. Characterization of the outer membrane receptor ShuA from the heme uptake system of Shigella dysenteriae. Substrate specificity and identification of the heme protein ligands.

    Science.gov (United States)

    Burkhard, Kimberly A; Wilks, Angela

    2007-05-18

    Shigella dysenteriae, like many bacterial pathogens, has evolved outer membrane receptor-mediated pathways for the uptake and utilization of heme as an iron source. As a first step toward understanding the mechanism of heme uptake we have undertaken a site-directed mutagenesis, spectroscopic, and kinetic analysis of the outer membrane receptor ShuA of S. dysenteriae. Purification of the outer membrane receptor gave a single band of molecular mass 73 kDa on SDS-PAGE. Initial spectroscopic analysis of the protein in either detergent micelles or lipid bicelles revealed residual heme bound to the receptor, with a Soret maximum at 413 nm. Titration of the protein with exogenous heme gave a Soret peak at 437 nm in detergent micelles, and 402 nm in lipid bicelles. However, transfer of heme from hemoglobin yields a Soret maximum at 413 nm identical to that of the isolated protein. Further spectroscopic and kinetic analysis revealed that hemoglobin in the oxidized state is the most likely physiological substrate for ShuA. In addition, mutation of the conserved histidines, H86A or H420A, resulted in a loss of the ability of the receptor to efficiently extract heme from hemoglobin. In contrast the double mutant H86A/H420A was unable to extract heme from hemoglobin. These findings taken together confirm that both His-86 and His-420 are essential for substrate recognition, heme coordination, and transfer. Furthermore, the full-length TonB was shown to form a 1:1 complex with either apo-ShuA H86A/H420A or the wild-type ShuA. These observations provide a basis for future studies on the coordination and transport of heme by the TonB-dependent outer membrane receptors.

  9. Water quality monitoring system for determination of ionic nutrients by ion-exclusion chromatography with spectrophotometric detection on cation- and anion-exchange resin columns using water eluent.

    Science.gov (United States)

    Kozaki, Daisuke; Nakatani, Nobutake; Mori, Masanobu; Nakagoshi, Nobukazu; Tanaka, Kazuhiko

    2012-07-01

    A unified ion-exclusion chromatography (IEC) system for monitoring anionic and cationic nutrients like NH4+, NO2-, NO3-, phosphate ion, silicate ion and HCO3- was developed and applied to several environmental waters. The IEC system consisted of four IEC methodologies, including the IEC with ultraviolet (UV) form connected with detection at 210 nm for determining NH4+ on anion-exchange separation column in OH anion-exchange UV-conversion column in I- form in tandem, the IEC with UV-detection at 210 nm for determining simultaneously NO3- and NO3- on cation-exchange separation column in H+ form, the IEC with UV-detection at 210 nm for determining HCO3- on cation-exchange separation column in H+ form connected with anion-exchange UV-conversion column in I- form in tandem, and the IEC with visible-detection based on molybdenum-blue reaction for determining simultaneously silicate and phosphate ions on cation-exchange separation column in H+ form. These IEC systems were combined through three manually-driven 6-port column selection valves to select each separation column to determine selectively the ionic nutrients. Using this sequential water quality monitoring system, the analytical performances such as calibration linearity, reproducibility, detection limit and recovery were also tested under the optimized chromatographic conditions. This novel water quality monitoring system has been applied successfully for the determination of the ionic eutrophication components in sub-urban river waters.

  10. Development of next generation micro-CHP system: Based on high temperature proton exchange membrane fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Arsalis, A.

    2012-01-15

    Novel proposals for the modeling and operation of a micro-CHP (combined-heat-and-power) residential system based on HT-PEMFC (High Temperature-Proton Exchange Membrane Fuel Cell) technology are described and analyzed to investigate the technical feasibility of such systems. The proposed systems must provide electricity, hot water, and space heating for an average single-family household in Denmark. A complete fuel processing subsystem, with all necessary BOP (balance-of-plant) components, is modeled and coupled to the fuel cell stack subsystem. The research project is divided into five main study topics: (a) Modeling, simulation and validation of the system in LabVIEW environment to provide the ability of Data Acquisition of actual components, and thereby more realistic design in the future; (b) Modeling, parametric study, and sensitivity analysis of the system in EES (Engineering Equation Solver). The parametric study is conducted to determine the most viable system/component design based on maximizing total system efficiency; (c) An improved operational strategy is formulated and applied in an attempt to minimize operational implications, experienced when using conventional operational strategies; (d) Application of a GA (Genetic Algorithm) optimization strategy. The objective function of the single-objective optimization strategy is the net electrical efficiency of the micro-CHP system. The implemented optimization procedure attempts to maximize the objective function by variation of nine decision variables; (e) The micro-CHP system is optimized by formulating and applying a process integration methodology. The methodology involves system optimization targeting in net electrical efficiency maximization. Subsequently a MINLP (Mixed Integer Non-Linear Programming) problem optimization strategy is applied to minimize the annual cost of the HEN (Heat Exchanger Network). The results obtained throughout this research work indicate the high potential of the proposed

  11. Methane Exchange in a Coastal Fen in the First Year after Flooding - A Systems Shift

    Science.gov (United States)

    Hahn, Juliane; Köhler, Stefan; Glatzel, Stephan; Jurasinski, Gerald

    2015-01-01

    Background Peatland restoration can have several objectives, for example re-establishing the natural habitat, supporting unique biodiversity attributes or re-initiating key biogeochemical processes, which can ultimately lead to a reduction in greenhouse gas (GHG) emissions. Every restoration measure, however, is itself a disturbance to the ecosystem. Methods Here, we examine an ecosystem shift in a coastal fen at the southern Baltic Sea which was rewetted by flooding. The analyses are based on one year of bi-weekly closed chamber measurements of methane fluxes gathered at spots located in different vegetation stands. During measurement campaigns, we recorded data on water levels, peat temperatures, and chemical properties of peat water. In addition we analyzed the first 20 cm of peat before and after flooding for dry bulk density (DBD), content of organic matter and total amounts of carbon (C), nitrogen (N), sulfur (S), and other nutrients. Results Rewetting turned the site from a summer dry fen into a shallow lake with water levels up to 0.60 m. We observed a substantial die-back of vegetation, especially in stands of sedges (Carex acutiformis Ehrh). Concentrations of total organic carbon and nitrogen in the peat water, as well as dry bulk density and concentrations of C, N and S in the peat increased. In the first year after rewetting, the average annual exchange of methane amounted to 0.26 ± 0.06 kg m-2. This is equivalent to a 190-times increase in methane compared to pre-flooding conditions. Highest methane fluxes occurred in sedge stands which suffered from the heaviest die-back. None of the recorded environmental variables showed consistent relationships with the amounts of methane exchanged. Conclusions Our results suggest that rewetting projects should be monitored not only with regard to vegetation development but also with respect to biogeochemical conditions. Further, high methane emissions that likely occur directly after rewetting by flooding should

  12. Methane Exchange in a Coastal Fen in the First Year after Flooding--A Systems Shift.

    Directory of Open Access Journals (Sweden)

    Juliane Hahn

    Full Text Available Peatland restoration can have several objectives, for example re-establishing the natural habitat, supporting unique biodiversity attributes or re-initiating key biogeochemical processes, which can ultimately lead to a reduction in greenhouse gas (GHG emissions. Every restoration measure, however, is itself a disturbance to the ecosystem.Here, we examine an ecosystem shift in a coastal fen at the southern Baltic Sea which was rewetted by flooding. The analyses are based on one year of bi-weekly closed chamber measurements of methane fluxes gathered at spots located in different vegetation stands. During measurement campaigns, we recorded data on water levels, peat temperatures, and chemical properties of peat water. In addition we analyzed the first 20 cm of peat before and after flooding for dry bulk density (DBD, content of organic matter and total amounts of carbon (C, nitrogen (N, sulfur (S, and other nutrients.Rewetting turned the site from a summer dry fen into a shallow lake with water levels up to 0.60 m. We observed a substantial die-back of vegetation, especially in stands of sedges (Carex acutiformis Ehrh. Concentrations of total organic carbon and nitrogen in the peat water, as well as dry bulk density and concentrations of C, N and S in the peat increased. In the first year after rewetting, the average annual exchange of methane amounted to 0.26 ± 0.06 kg m-2. This is equivalent to a 190-times increase in methane compared to pre-flooding conditions. Highest methane fluxes occurred in sedge stands which suffered from the heaviest die-back. None of the recorded environmental variables showed consistent relationships with the amounts of methane exchanged.Our results suggest that rewetting projects should be monitored not only with regard to vegetation development but also with respect to biogeochemical conditions. Further, high methane emissions that likely occur directly after rewetting by flooding should be considered when

  13. Elevated atmospheric carbon dioxide effects on soybean and sorghum gas exchange in conventional and no-tillage systems.

    Science.gov (United States)

    Prior, S A; Runion, G B; Rogers, H H; Arriaga, F J

    2010-01-01

    Increasing atmospheric CO(2) concentration has led to concerns about potential effects on production agriculture. In the fall of 1997, a study was initiated to compare the response of two crop management systems (conventional tillage and no-tillage) to elevated CO(2). The study used a split-plot design replicated three times with two management systems as main plots and two atmospheric CO(2) levels (ambient and twice ambient) as split plots using open-top chambers on a Decatur silt loam soil (clayey, kaolinitic, thermic Rhodic Paleudults). The conventional system was a grain sorghum [Sorghum bicolor (L.) Moench.] and soybean [Glycine max (L.) Merr.] rotation with winter fallow and spring tillage practices. In the no-tillage system, sorghum and soybean were rotated, and three cover crops were used [crimson clover (Trifolium incarnatum L.), sunn hemp (Crotalaria juncea L.), and wheat (Triticum aestivum L.)]. Over multiple growing seasons, the effect of management and CO(2) concentration on leaf-level gas exchange during row crop (soybean in 1999, 2001, and 2003; sorghum in 2000, 2002, and 2004) reproductive growth were evaluated. Treatment effects were fairly consistent across years. In general, higher photosynthetic rates were observed under CO(2) enrichment (more so with soybean) regardless of residue management practice. Elevated CO(2) led to decreases in stomatal conductance and transpiration, which resulted in increased water use efficiency. The effects of management system on gas exchange measurements were infrequently significant, as were interactions of CO(2) and management. These results suggest that better soil moisture conservation and high rates of photosynthesis can occur in both tillage systems in CO(2)-enriched environments during reproductive growth.

  14. Plasma-exchange in the treatment of systemic rheumatic diseases: past and present experience

    Directory of Open Access Journals (Sweden)

    P. Marson

    2011-06-01

    Full Text Available La terapia con plasma-exchange (PEx è stata utilizzata sin dagli anni Settanta per la cura di molteplici malattie, nella cui patogenesi fattori umorali si riteneva potessero giocare un ruolo di rilievo. Questa modalità di trattamento comporta la rimozione di autoanticorpi, immunocomplessi circolanti, molecole di adesione, citochine, chemochine ed altri mediatori solubili implicati nello sviluppo del danno tissutale (1. Nel 1993 l’American Society of Apheresis (ASFA ha per la prima volta pubblicato un elenco di applicazioni cliniche delle diverse tecniche di aferesi terapeutica, fra le quali di gran lunga la più utilizzata era, allora come oggi, il PEx (2. Questo elenco comprendeva malattie autoimmuni, malattie ematologiche ed oncologiche, disordini metabolici, malattie neurologiche e malattie renali. Fra le malattie autoimmuni figuravano molte forme morbose di pertinenza reumatologica...

  15. Impact of Seasonal Heat Accumulation on Operation of Geothermal Heat Pump System with Vertical Ground Heat Exchanger

    Science.gov (United States)

    Timofeev, D. V.; Malyavina, E. G.

    2017-11-01

    The subject of the investigation was to find out the influence of heat pump operation in summer on its function in winter. For this purpose a mathematical model of a ground coupled heat pump system has been developed and programmed. The mathematical model of a system ground heat exchanger uses the finite difference method to describe the heat transfer in soil and the analytical method to specify the heat transfer in the U-tubes heat exchanger. The thermal diffusivity by the heat transfer in the soil changes during gradual freezing of the pore moisture and thus slows soil freezing. The mathematical model of a heat pump includes the description of a scroll compressor and the simplified descriptions of the evaporator and condenser. The analysis showed that heating during the cold season and cooling in the warm season affect the average heat transfer medium temperature in the soil loop in the winter season. It has been also showed that the degree of this effect depends on the clay content in the soil.

  16. Determination of Minimum Data Set (MSD) in Echocardiography Reporting System to Exchange with Iran’s Electronic Health Record (EHR) System

    Science.gov (United States)

    Mahmoudvand, Zahra; Kamkar, Mehran; Shahmoradi, Leila; Nejad, Ahmadreza Farzaneh

    2016-01-01

    Background: Determination of minimum data set (MDS) in echocardiography reports is necessary for documentation and putting information in a standard way, and leads to the enhancement of electrocardiographic studies through having access to precise and perfect reports and also to the development of a standard database for electrocardiographic reports. Aim: to determine the minimum data set of echocardiography reporting system to exchange with Iran’s electronic health record (EHR) system. Methods: First, a list of minimum data set was prepared after reviewing texts and studying cardiac patients’ records. Then, to determine the content validity of the prepared MDS, the expert views of 10 cardiologists and 10 health information management (HIM) specialists were obtained; to estimate the reliability of the set, test-retest method was employed. Finally, the data were analyzed using SPSS software. Results: The highest degree of consensus was found for the following MDSs: patient’s name and family name (5), accepting doctor’s name and family name, familial death records due to cardiac disorders, the image identification code, mitral valve, aortic valve, tricuspid valve, pulmonary valve, left ventricle, hole, atrium valve, Doppler examination of ventricular and atrial movement models and diagnoses with an average of. Conclusions: To prepare a model of echocardiography reporting system to exchange with EHR system, creation a standard data set is the vital point. Therefore, based on the research findings, the minimum reporting system data to exchange with Iran’s electronic health record system include information on entity, management, medical record, carried-out acts, and the main content of the echocardiography report, which the planners of reporting system should consider. PMID:27147803

  17. Scientific Verification Test of Orbitec Deployable Vegetable Production System for Salad Crop Growth on ISS- Gas Exchange System design and function

    Science.gov (United States)

    Eldemire, Ashleigh

    2007-01-01

    The ability to produce and maintain salad crops during long term missions would be a great benefit to NASA; the renewable food supply would save cargo space, weight and money. The ambient conditions of previous ground controlled crop plant experiments do not reflect the microgravity and high CO2 concentrations present during orbit. It has been established that microgravity does not considerably alter plant growth. (Monje, Stutte, Chapman, 2005). To support plants in a space-craft environment efficient and effective lighting and containment units are necessary. Three lighting systems were previously evaluated for radish growth in ambient air; fluorescent lamps in an Orbitec Biomass Production System Educational (BPSE), a combination of red, blue, and green LED's in a Deployable Vegetable Production System (Veggie), and a combination of red and blue LED's in a Veggie. When mass measurements compared the entire possible growing area vs. power consumed by the respective units, the Veggies clearly exceeded the BPSE indicating that the LED units were a more resource efficient means of growing radishes under ambient conditions in comparison with fluorescent lighting. To evaluate the most productive light treatment system for a long term space mission a more closely simulated ISS environment is necessary. To induce a CO2 dense atmosphere inside the Veggie's and BPSE a gas exchange system has been developed to maintain a range of 1000-1200 ppm CO2 during a 21-day light treatment experiment. This report details the design and function of the gas exchange system. The rehabilitation, trouble shooting, maintenance and testing of the gas exchange system have been my major assignments. I have also contributed to the planting, daily measurements and harvesting of the radish crops 21-day light treatment verification test.

  18. A Generalized Adsorption Rate Model Based on the Limiting-Component Constraint in Ion-Exchange Chromatographic Separation for Multicomponent Systems

    DEFF Research Database (Denmark)

    In species exchange processes (e.g., ion-exchange chromatography column), conventional adsorption rate models describe mass transfer (or exchange) between phases, assuming the existence of a counterpart species. In contrast, the adsorption models may not be useful in an inert environment (or...... inactive zone) where adsorption/desorption cannot take place because of lack of counterpart species. In packed-bed chromatography described as a distributed dynamic system, a wide range of concentrations including zero-concentrations can be distributed over the column length and the concentration profiles...... such that conventional LDF (linear driving force) type models are extended to inactive zones without loosing their generality. Based on a limiting component constraint, an exchange probability kernel is developed for multi-component systems. The LDF-type model with the kernel is continuous with time and axial direction...

  19. CO{sub 2}-C{sub 3}H{sub 8} cascade refrigeration-heat pump system: Heat exchanger inventory optimization and its numerical verification

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, Souvik [Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Mukhopadhyay, S. [School of Mechanical Engineering, Maurice J. Zucrow Laboratories, Purdue University, 500 Allison Road, West Lafayette, IN 47907-2014 (United States); Sarkar, J. [Department of Mechanical Engineering, Institute of Technology-BHU, Varanasi 221005 (India)

    2008-11-15

    This article presents an analytical study on the performance of a cascade refrigeration-heat pump system based on a model incorporating both internal and external irreversibilities. It further explores the optimum allocation of heat exchanger inventories in cascade refrigeration cycles for the maximization of performance and minimization of system cost. In a novel attempt, a CO{sub 2}-propane cascade system, lately showing good promise as a future solution, has been numerically simulated comprehensively incorporating precision property routines for the working fluids and this numerical model subsequently has been employed for validation of the proposed analytical model. It has been established that the total system heat exchanger inventory should be optimally divided in the ratio of a factor K between the gas cooler and the evaporator heat exchangers for maximal system output and minimal mechanical power requirement for a specified total heat exchanger inventory. It can also be construed that a similar allocation is recommended for minimization of total heat exchanger inventory with specified total system output. A strong assertion of all the analytical model results has been exhibited through a completely independent numerical system simulation. (author)

  20. Method of uranium reclamation from aqueous systems by reactive ion exchange. [US DOE patent application; anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands

    Science.gov (United States)

    Maya, L.

    1981-11-05

    A reactive ion exchange method for separation and recovery of values of uranium, neptunium, plutonium, or americium from substantially neutral aqueous systems of said metals comprises contacting said system with an effective amount of a basic anion exchange resin of copolymerized divinyl-benzene and styrene having quarternary ammonium groups and bicarbonate ligands to achieve nearly 100% sorption of said actinyl ion onto said resin and an aqueous system practically free of said actinyl ions. The method is operational over an extensive range of concentrations from about 10/sup -6/ M to 1.0 M actinyl ion and a pH range of about 4 to 7. The method has particulr application to treatment of waste streams from Purex-type nuclear fuel reprocessing facilities and hydrometallurgical processes involving U, Np, P, or Am.

  1. [An economic organisation analysis of the need for the exchange of information between the European health systems].

    Science.gov (United States)

    Kainzinger, F; Brüggenjürgen, B; Willich, S N

    2009-02-01

    Demographic development and technological progress are rapidly changing the existing health systems in Europe. As a result, increasingly more complex and heterogeneous structures are emerging, which clearly differ in each of the European member state. From a company's point of view these continuously changing frameworks are leading to an increasing non-transparency regarding the structures and processes within the healthcare systems themselves. The goal is to design a suitable solution to overcome the obstacles within the information exchange process between the individual European health systems. Theoretic-deductive analysis was used for the design of an organisational structure that enables information transparency between the individual European health systems. Incorporation of an economic perspective was implemented under consideration of the theory for the building of the new institutional economics. The operational organisation analysis proves that the matrix project organisation with a function- and project-related decision system is the theoretically optimal organisational form. The organisation model derived from the theoretical analysis offers an organisation variant that guarantees an optimal processing of tasks pertaining to European health systems. This could result in the closing of an existing supply gap in the knowledge market for health systems. The evaluation of enterprise practice and the comparison with existing departments in enterprises can be explored in further research work.

  2. Removal of isopropyl alcohol and methanol in ultrapure water production system using a 185 nm ultraviolet and ion exchange system.

    Science.gov (United States)

    Choi, Jeongyun; Kim, Jong-Oh; Chung, Jinwook

    2016-08-01

    The oxidation of low-molecular-weight (LMW) compounds, including isopropyl alcohol (IPA) and methanol in ultrapure water (UPW) production system was evaluated using the continuously operating 185 nm total organic carbon (TOC) reduction UV and ion exchange system. The initial concentration of compounds was in the range of tens of ppb which was the general feed condition of UV system located after 2 pass reverse osmosis (RO) in the UPW production system. UV irradiation transformed the compounds to less oxidative products that were ultimately converted to CO2. The ion exchange system then removed carboxyl-containing organic acids generated by UV oxidation. It means that the oxidation efficiency of organic compounds by UV irradiation can be accurately measured by the summation of the final product (CO2) and the by-product containing carboxyl functional group. The removal efficiency of LMW compounds decreased when either the initial TOC concentration increased or the UV intensity was reduced. Finally, the insertion of a baffle into the UV oxidation system was found to enhance solution turbulence and improve the oxidation efficiency. Copyright © 2016. Published by Elsevier Ltd.

  3. Ligand exchange in ionic systems and its effect on silver nucleation and growth.

    Science.gov (United States)

    Abbott, Andrew P; Azam, Muhammad; Frisch, Gero; Hartley, Jennifer; Ryder, Karl S; Saleem, Saima

    2013-10-28

    The electrodeposition of metals from ionic solutions is intrinsically linked to the reactivity of the solute ions. When metal salts dissolve, the exchange of the anion with the molecular and ionic components from solution affects the speciation and therefore the characteristics of metal reduction. This study investigates the nucleation mechanism, deposition kinetics, metal speciation and diffusion coefficients of silver salts dissolved in Deep Eutectic Solvents. The electrochemical reduction of AgCl, AgNO3 and Ag2O is studied in 1 : 2 choline chloride : ethylene glycol and 1 : 2 choline chloride : urea. Cyclic voltammetry is used to evaluate electrochemical kinetics. Detailed analysis of chronoamperometric data shows that silver deposits form via multiple 3D nucleation with mass transport controlled hemispherical growth. The nucleation mechanism was found to be potential dependent, varying from progressive to instantaneous as the reduction potential becomes more cathodic. Diffusion coefficients are determined using three different methods. Trends are rationalised in terms of solvent viscosity and silver speciation analysis with EXAFS. The morphology of electroreduced silver is investigated with scanning electron microscopy and shows that deposits from the urea based liquid form more dense morphologies than those from the ethylene glycol based liquid.

  4. APEX user`s guide - (Argonne production, expansion, and exchange model for electrical systems), version 3.0

    Energy Technology Data Exchange (ETDEWEB)

    VanKuiken, J.C.; Veselka, T.D.; Guziel, K.A.; Blodgett, D.W.; Hamilton, S.; Kavicky, J.A.; Koritarov, V.S.; North, M.J.; Novickas, A.A.; Paprockas, K.R. [and others

    1994-11-01

    This report describes operating procedures and background documentation for the Argonne Production, Expansion, and Exchange Model for Electrical Systems (APEX). This modeling system was developed to provide the U.S. Department of Energy, Division of Fossil Energy, Office of Coal and Electricity with in-house capabilities for addressing policy options that affect electrical utilities. To meet this objective, Argonne National Laboratory developed a menu-driven programming package that enables the user to develop and conduct simulations of production costs, system reliability, spot market network flows, and optimal system capacity expansion. The APEX system consists of three basic simulation components, supported by various databases and data management software. The components include (1) the investigation of Costs and Reliability in Utility Systems (ICARUS) model, (2) the Spot Market Network (SMN) model, and (3) the Production and Capacity Expansion (PACE) model. The ICARUS model provides generating-unit-level production-cost and reliability simulations with explicit recognition of planned and unplanned outages. The SMN model addresses optimal network flows with recognition of marginal costs, wheeling charges, and transmission constraints. The PACE model determines long-term (e.g., longer than 10 years) capacity expansion schedules on the basis of candidate expansion technologies and load growth estimates. In addition, the Automated Data Assembly Package (ADAP) and case management features simplify user-input requirements. The ADAP, ICARUS, and SMN modules are described in detail. The PACE module is expected to be addressed in a future publication.

  5. Comparing net ecosystem carbon dioxide exchange at adjacent commercial bioenergy and conventional cropping systems in Lincolnshire, United Kingdom

    Science.gov (United States)

    Morrison, Ross; Brooks, Milo; Evans, Jonathan; Finch, Jon; Rowe, Rebecca; Rylett, Daniel; McNamara, Niall

    2016-04-01

    The conversion of agricultural land to bioenergy plantations represents one option in the national and global effort to reduce greenhouse gas emissions whilst meeting future energy demand. Despite an increase in the area of (e.g. perennial) bioenergy crops in the United Kingdom and elsewhere, the biophysical and biogeochemical impacts of large scale conversion of arable and other land cover types to bioenergy cropping systems remain poorly characterised and uncertain. Here, the results of four years of eddy covariance (EC) flux measurements of net ecosystem CO2 exchange (NEE) obtained at a commercial farm in Lincolnshire, United Kingdom (UK) are reported. CO2 flux measurements are presented and compared for arable crops (winter wheat, oilseed rape, spring barely) and plantations of the perennial biofuel crops Miscanthus x. giganteus (C4) and short rotation coppice (SRC) willow (Salix sp.,C3). Ecosystem light and temperature response functions were used to analyse and compare temporal trends and spatial variations in NEE across the three land covers. All three crops were net in situ sinks for atmospheric CO2 but were characterised by large temporal and between site variability in NEE. Environmental and biological controls driving the spatial and temporal variations in CO2 exchange processes, as well as the influences of land management, will be analysed and discussed.

  6. Technical complications during veno-venous extracorporeal membrane oxygenation and their relevance predicting a system-exchange--retrospective analysis of 265 cases.

    Directory of Open Access Journals (Sweden)

    Matthias Lubnow

    Full Text Available OBJECTIVES: Technical complications are a known hazard in veno-venous extracorporeal membrane oxygenation (vvECMO. Identifying these complications and predictive factors indicating a developing system-exchange was the goal of the study. METHODS: Retrospective study on prospectively collected data of technical complications including 265 adult patients (Regensburg ECMO Registry, 2009-2013 with acute respiratory failure treated with vvECMO. Alterations in blood flow resistance, gas transfer capability, hemolysis, coagulation and hemostasis parameters were evaluated in conjunction with a system-exchange in all patients with at least one exchange (n = 83. RESULTS: Values presented as median (interquartile range. Patient age was 50(36-60 years, the SOFA score 11(8-14.3 and the Murray lung injury Score 3.33(3.3-3.7. Cumulative ECMO support time 3411 days, 9(6-15 days per patient. Mechanical failure of the blood pump (n = 5, MO (n = 2 or cannula (n = 1 accounted for 10% of the exchanges. Acute clot formation within the pump head (visible clots, increase in plasma free hemoglobin (frHb, serum lactate dehydrogenase (LDH, n = 13 and MO (increase in pressure drop across the MO, n = 16 required an urgent system-exchange, of which nearly 50% could be foreseen by measuring the parameters mentioned below. Reasons for an elective system-exchange were worsening of gas transfer capability (n = 10 and device-related coagulation disorders (n = 32, either local fibrinolysis in the MO due to clot formation (increased D-dimers [DD], decreased platelet count; n = 24, or device-induced hyperfibrinolysis (increased DD, decreased fibrinogen [FG], decreased platelet count, diffuse bleeding tendency; n = 8, which could be reversed after system-exchange. Four MOs were exchanged due to suspicion of infection. CONCLUSIONS: The majority of ECMO system-exchanges could be predicted by regular inspection of the complete ECMO circuit, evaluation of gas exchange, pressure drop

  7. LIMITING POSSIBILITIES OF RESOURCE EXCHANGE PROCESS IN COMPLEX OPEN MICROECONOMIC SYSTEM

    Directory of Open Access Journals (Sweden)

    Serghey A. Amelkin

    2004-06-01

    Full Text Available A problem on extreme performance of microeconomic system with several firms is considered. Each firm aspires to increase the profit. Flows of the good between the firms determine the structure of the system. So, sequential structure corresponds to intermediaries (dealers operating in the market, parallel structure corresponds to competition in the market. The system at issue is an open economic system because of presence of external flows from the sources described by a distribution of the value of the good. The problem is solved for the basic structures: maximal profit and corresponding prices are found for each firm.

  8. Optimization of Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Ivan Catton

    2010-10-01

    The objective of this research is to develop tools to design and optimize heat exchangers (HE) and compact heat exchangers (CHE) for intermediate loop heat transport systems found in the very high temperature reator (VHTR) and other Generation IV designs by addressing heat transfer surface augmentation and conjugate modeling. To optimize heat exchanger, a fast running model must be created that will allow for multiple designs to be compared quickly. To model a heat exchanger, volume averaging theory, VAT, is used. VAT allows for the conservation of mass, momentum and energy to be solved for point by point in a 3 dimensional computer model of a heat exchanger. The end product of this project is a computer code that can predict an optimal configuration for a heat exchanger given only a few constraints (input fluids, size, cost, etc.). As VAT computer code can be used to model characteristics )pumping power, temperatures, and cost) of heat exchangers more quickly than traditional CFD or experiment, optimization of every geometric parameter simultaneously can be made. Using design of experiment, DOE and genetric algorithms, GE, to optimize the results of the computer code will improve heat exchanger disign.

  9. Chief Information Officer's Role in Adopting an Interoperable Electronic Health Record System for Medical Data Exchange

    Science.gov (United States)

    Akpabio, Akpabio Enebong Ema

    2013-01-01

    Despite huge growth in hospital technology systems, there remains a dearth of literature examining health care administrator's perceptions of the efficacy of interoperable EHR systems. A qualitative research methodology was used in this multiple-case study to investigate the application of diffusion of innovations theory and the technology…

  10. Estimation of membrane hydration status for standby proton exchange membrane fuel cell systems by impedance measurement

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Rugholt, Mark; Nielsen, Morten Busk

    2014-01-01

    Fuel cells are getting growing interest in both backup systems and electric vehicles. Although these systems are characterized by long periods of inactivity, they must be able to start at any instant in the shortest time. However, the membrane of which PEMFCs are made tends to dry out when not in...

  11. Barcoded materials based on photoluminescent hybrid system of lanthanide ions-doped metal organic framework and silica via ion exchange.

    Science.gov (United States)

    Shen, Xiang; Yan, Bing

    2016-04-15

    A multicolored photoluminescent hybrid system based on lanthanide ions-doped metal organic frameworks/silica composite host has potential in display and barcode applications. By controlling the stoichiometry of the lanthanides via cation exchange, proportional various lanthanide ions are successfully introduced into metal organic frameworks, whose emission intensity is correspondingly proportional to its amount. The resulting luminescent barcodes depend on the lanthanide ions ratios and compositions. Subsequently, the lanthanide ions located in the channels of metal organic frameworks are protected from any interaction with the environment after the modification of silica on the surface. The optical and thermal stability of the hybrid materials are improved for technological application. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. The Common Alerting Protocol (CAP) and Emergency Data Exchange Language (EDXL) - Application in Early Warning Systems for Natural Hazard

    Science.gov (United States)

    Lendholt, Matthias; Hammitzsch, Martin; Wächter, Joachim

    2010-05-01

    The Common Alerting Protocol (CAP) [1] is an XML-based data format for exchanging public warnings and emergencies between alerting technologies. In conjunction with the Emergency Data Exchange Language (EDXL) Distribution Element (-DE) [2] these data formats can be used for warning message dissemination in early warning systems for natural hazards. Application took place in the DEWS (Distance Early Warning System) [3] project where CAP serves as central message format containing both human readable warnings and structured data for automatic processing by message receivers. In particular the spatial reference capabilities are of paramount importance both in CAP and EDXL. Affected areas are addressable via geo codes like HASC (Hierarchical Administrative Subdivision Codes) [4] or UN/LOCODE [5] but also with arbitrary polygons that can be directly generated out of GML [6]. For each affected area standardized criticality values (urgency, severity and certainty) have to be set but also application specific key-value-pairs like estimated time of arrival or maximum inundation height can be specified. This enables - together with multilingualism, message aggregation and message conversion for different dissemination channels - the generation of user-specific tailored warning messages. [1] CAP, http://www.oasis-emergency.org/cap [2] EDXL-DE, http://docs.oasis-open.org/emergency/edxl-de/v1.0/EDXL-DE_Spec_v1.0.pdf [3] DEWS, http://www.dews-online.org [4] HASC, "Administrative Subdivisions of Countries: A Comprehensive World Reference, 1900 Through 1998" ISBN 0-7864-0729-8 [5] UN/LOCODE, http://www.unece.org/cefact/codesfortrade/codes_index.htm [6] GML, http://www.opengeospatial.org/standards/gml

  13. A nitrogen removal system to limit water exchange for recirculating freshwater aquarium using DHS-USB reactor.

    Science.gov (United States)

    Adlin, Nur; Matsuura, Norihisa; Ohta, Yuki; Hirakata, Yuga; Maki, Shinya; Hatamoto, Masashi; Yamaguchi, Takashi

    2017-06-13

    This study proposes a biological nitrogen removal system for freshwater aquaria consisting of a down-flow hanging sponge (DHS) and an up-flow sludge blanket (USB). DHS-USB systems can perform nitrification and denitrification simultaneously, reducing ammonia (NH3) and nitrate (NO3(-)) toxicity in the water. The performance of the system was evaluated using on-site fresh water aquaria at ambient temperature (23-34°C) over 192 days. NH3 and nitrite (NO2(-)) were maintained at a detection limit of 0.01 mg N L(-1) and NO3(-) was maintained below 10 mg N L(-1), despite limited water exchange. The 16S rRNA gene of microorganisms from the sludge retained in the bioreactors was sequenced to identify the microbial communities present. Microbial community analysis revealed that ammonia oxidizing archaea (AOA), Ca. Nitrososphaera and Nitrosopumilus, played an important role in nitrification in the DHS reactor, while denitrifying bacteria Thauera played an important role in denitrification in the USB reactor. The proposed DHS-USB system is a promising technological advancement in the development of lower maintenance aquaria.

  14. Impact factors on the long-term sustainability of Borehole Heat Exchanger coupled Ground Source Heat Pump System

    Science.gov (United States)

    Shao, Haibing; Hein, Philipp; Görke, Uwe-Jens; Bucher, Anke; Kolditz, Olaf

    2016-04-01

    In recent years, Ground Source Heat Pump System (GSHPS) has been recognized as an efficient technology to utilize shallow geothermal energy. Along with its wide application, some GSHPS are experiencing a gradual decrease in Borehole Heat Exchanger (BHE) outflow temperatures and thus have to be turned off after couple of years' operation. A comprehensive numerical investigation was then performed to model the flow and heat transport processes in and around the BHE, together with the dynamic change of heat pump efficiency. The model parameters were based on the soil temperature and surface weather condition in the Leipzig area. Different scenarios were modelled for a service life of 30 years, to reveal the evolution of BHE outflow and surrounding soil temperatures. It is found that lateral groundwater flow and using BHE for cooling will be beneficial to the energy recovery, along with the efficiency improvement of the heat pump. In comparison to other factors, the soil heat capacity and thermal conductivity are considered to have minor impact on the long-term sustainability of the system. Furthermore, the application of thermally enhanced grout material will improve the sustainability and efficiency. In contrast, it is very likely that undersized systems and improper grouting are the causes of strong system degradation.

  15. High Efficiency, High Temperature Foam Core Heat Exchanger for Fission Surface Power Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fission-based power systems are anticipated for various planetary surface human base applications with power levels of 30?100+ kWe. The development of high...

  16. High Efficiency, High Temperature Foam Core Heat Exchanger for Fission Surface Power Systems, Phase II Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fission-based power systems with power levels of 30 to ≥100 kWe will be needed for planetary surface bases. Development of high temperature, high efficiency...

  17. Protein-ligand interfaces are polarized: discovery of a strong trend for intermolecular hydrogen bonds to favor donors on the protein side with implications for predicting and designing ligand complexes.

    Science.gov (United States)

    Raschka, Sebastian; Wolf, Alex J; Bemister-Buffington, Joseph; Kuhn, Leslie A

    2018-02-12

    Understanding how proteins encode ligand specificity is fascinating and similar in importance to deciphering the genetic code. For protein-ligand recognition, the combination of an almost infinite variety of interfacial shapes and patterns of chemical groups makes the problem especially challenging. Here we analyze data across non-homologous proteins in complex with small biological ligands to address observations made in our inhibitor discovery projects: that proteins favor donating H-bonds to ligands and avoid using groups with both H-bond donor and acceptor capacity. The resulting clear and significant chemical group matching preferences elucidate the code for protein-native ligand binding, similar to the dominant patterns found in nucleic acid base-pairing. On average, 90% of the keto and carboxylate oxygens occurring in the biological ligands formed direct H-bonds to the protein. A two-fold preference was found for protein atoms to act as H-bond donors and ligand atoms to act as acceptors, and 76% of all intermolecular H-bonds involved an amine donor. Together, the tight chemical and geometric constraints associated with satisfying donor groups generate a hydrogen-bonding lock that can be matched only by ligands bearing the right acceptor-rich key. Measuring an index of H-bond preference based on the observed chemical trends proved sufficient to predict other protein-ligand complexes and can be used to guide molecular design. The resulting Hbind and Protein Recognition Index software packages are being made available for rigorously defining intermolecular H-bonds and measuring the extent to which H-bonding patterns in a given complex match the preference key.

  18. Proton exchange membrane fuel cell systems engineering at Vickers Shipbuilding and Engineering Limited (VSEL)

    Science.gov (United States)

    Seymour, C. M.

    1992-01-01

    A project, jointly funded by VSEL and CJB Developments Limited, is aimed at the development of complete power generation systems based on PEM fuel cell technology. Potential markets for such systems are seen as being very broadly based, ranging from military land and marine systems through to commercial on-site power generation and transport. From the outset the project was applications driven, the intent being to identify market requirements, in terms of system specifications and to use these to produce development targets. The two companies have based their work on the Ballard PEM stack and have focused their efforts on the development of supporting systems. This benefits all three companies as it allows Ballard to obtain applications information on which to base future research and VSEL/CJBD are able to capitalise on the advanced development of the Ballard stack. Current work is focused on the production of a 20 kW, methanol fuelled, power generation system demonstrator, although work is also in hand to address a wider range of fuels including natural gas. The demonstrator, when complete, will be used to indicate the potential benefits of such systems and to act as a design aid for the applications phase of the project. Preliminary work on this next phase is already in hand, with studies to assess both systems and fuel cell stack design requirements for specific applications and to generate concept designs. Work to date has concentrated on the development of a methanol reformer, suitable for integration into a fuel cell system and on extensive testing and evaluation of the Ballard fuel cell stacks. This testing has covered a wide range of operating parameters, including different fuel and oxidant combinations. The effect of contaminants on the performance and life of the fuel cells is also under evaluation. PEM fuel cells still require a great deal of further development if they are to gain widespread commercial acceptance. A recent study conducted by VSEL in

  19. Closed and continuous algae cultivation system for food production and gas exchange in CELSS

    Science.gov (United States)

    Oguchi, Mitsuo; Otsubo, Koji; Nitta, Keiji; Shimada, Atsuhiro; Fujii, Shigeo; Koyano, Takashi; Miki, Keizaburo

    In CELSS (Controlled Ecological Life Support System), utilization of photosynthetic algae is an effective means for obtaining food and oxygen at the same time. We have chosen Spirulina, a blue-green alga, and have studied possibilities of algae utilization. We have developed an advanced algae cultivation system, which is able to produce algae continuously in a closed condition. Major features of the new system are as follows. o (1)In order to maintain homogeneous culture conditions, the cultivator was designed so as to cause a swirl on medium circulation. (2)Oxygen gas separation and carbon dioxide supply are conducted by a newly designed membrane module. (3)Algae mass and medium are separated by a specially designed harvester. (4)Cultivation conditions, such as pH, temperature, algae growth rate, light intensity and quanlity of generated oxygen gas are controlled by a computer system and the data are automatically recorded. This equipment is a primary model for ground experiments in order to obtain some design data for space use. A feasibility of algae cultivation in a closed condition is discussed on the basis of data obtained by use of this new system.

  20. Oxygen isotope exchange kinetics of mineral pairs in closed and open systems: Applications to problems of hydrothermal alteration of igneous rocks and Precambrian iron formations

    Science.gov (United States)

    Gregory, R.T.; Criss, R.E.; Taylor, H.P.

    1989-01-01

    The systematics of stable-isotope exchange between minerals and fluids are examined in the context of modal mineralogical variations and mass-balance considerations, both in closed and in open systems. On mineral-pair ??18O plots, samples from terranes that have exchanged with large amounts of fluid typically map out steep positively-sloped non-equilibrium arrays. Analytical models are derived to explain these effects; these models allow for different exchange rates between the various minerals and the external fluids, as well as different fluid fluxes. The steep arrays are adequately modelled by calculated isochron lines that involve the whole family of possible exchange trajectories. These isochrons have initially-steep near-vertical positive slopes that rotate toward a 45?? equilibrium slope as the exchange process proceeds to completion. The actual data-point array is thus analogous to the hand of an "isotopic clock" that measures the duration of the hydrothermal episode. The dimensionless ratio of the volumetric fluid flux to the kinetic rate parameter ( u k) determines the shape of each individual exchange trajectory. In a fluid-buffered system ( u k ??? 1), the solutions to the equations: (1) are independent of the mole fractions of the solid phases; (2) correspond to Taylor's open-system water/rock equation; and (3) yield straight-line isochrons that have slopes that approach 1 f, where f is the fraction reacted of the more sluggishly exchanging mineral. The isochrons for this simple exchange model are closely congruent with the isochrons calculated for all of the more complex models, thereby simplifying the application of theory to actual hydrothermal systems in nature. In all of the models an order of magnitude of time (in units of kt) separates steep non-equilibrium arrays (e.g., slope ??? 10) from arrays approaching an equilibrium slope of unity on a ??-?? diagram. Because we know the approximate lifetimes of many hydrothermal systems from geologic and

  1. A general model of resource production and exchange in systems of interdependent specialists.

    Energy Technology Data Exchange (ETDEWEB)

    Conrad, Stephen Hamilton; Finley, Patrick D.; Beyeler, Walter Eugene; Brown, Theresa Jean; Glass, Robert John, Jr.; Breen, Peter; Kuypers, Marshall; Norton, Matthew David; Quach, Tu-Thach; Antognoli, Matthew; Mitchell, Michael David

    2011-11-01

    Infrastructures are networks of dynamically interacting systems designed for the flow of information, energy, and materials. Under certain circumstances, disturbances from a targeted attack or natural disasters can cause cascading failures within and between infrastructures that result in significant service losses and long recovery times. Reliable interdependency models that can capture such multi-network cascading do not exist. The research reported here has extended Sandia's infrastructure modeling capabilities by: (1) addressing interdependencies among networks, (2) incorporating adaptive behavioral models into the network models, and (3) providing mechanisms for evaluating vulnerability to targeted attack and unforeseen disruptions. We have applied these capabilities to evaluate the robustness of various systems, and to identify factors that control the scale and duration of disruption. This capability lays the foundation for developing advanced system security solutions that encompass both external shocks and internal dynamics.

  2. MatDB Online - A Standards-Based System for Preserving, Managing, and Exchanging Engineering Materials Test Data

    Directory of Open Access Journals (Sweden)

    TSP Austin

    2012-11-01

    Full Text Available With ICT Standards playing a key role in support of research and development in many disciplines, the European Commission Institute for Energy and Transport is keen to promote the development and adoption of ICT Standards for engineering data. In this respect, its MatDB Online facility is a Standards-based system for preserving, managing, and exchanging engineering materials test data. While MatDB Online has evolved over more than 30 years to incorporate the latest innovations in data preservation and exchange, such as XML-based data transfer and data citation using digital object identifiers, it continues to rely on a robust data model developed more than 30 years ago through the joint efforts of the National Research Institute for Metals (the predecessor to NIMS, the National Institute for Materials Science, the European Commission Joint Research Centre, and the National Institute of Standards and Technology. While this data model has endured over many years, there is no corresponding Standard. Similarly, related efforts by the engineering materials community to deliver a Standard representation for engineering materials, such as MatML, have failed to be ratified. In consequence of the continued absence of a Standard representation for engineering materials data, there is no common mechanism for preserving and exchanging materials data and no formal means of maintaining a data model to support advances in materials technology, such as the emergence of nanomaterials. It is for these reasons that the European Commission Institute for Energy and Transport is supporting SERES, a CEN Workshop on Standards for Electronic Reporting in the Engineering Sector. As one of more than thirty organisations supporting the SERES Workshop, the Institute for Energy and Transport will make the MatDB XML schema available as one of several resources that will be taken into consideration when the prenormative Standard for representing engineering materials data is

  3. A Web-based computer system supporting information access, exchange and management during building processes

    DEFF Research Database (Denmark)

    Sørensen, Lars Schiøtt

    1998-01-01

    During the last two decades, a number of research efforts have been made in the field of computing systmes related to the building construction industry. Most of the projects have focused on a part of the entire design process and have typically been limited to a specific domain. This paper prese...... presents a newly developed computer system based on the World Wide Web on the Internet. The focus is on the simplicity of the systems structure and on an intuitive and user friendly interface...

  4. Dynamic Simulation of a Proton Exchange Membrane Fuel Cell System For Automotive Applications

    DEFF Research Database (Denmark)

    Rabbani, Raja Abid; Rokni, Masoud

    2012-01-01

    are implemented into the code and are based on adopted mathematical models describing the voltages and current densities and their dependence on operating pressures, temperatures and stoichiometric ratios of the reactant gases. As a result, this model can predict both steady and transient states. The model...... and operating conditions. Simulation results for system start-up and variable loads are discussed. Results for system efficiency, auxiliary power consumption, feed flow effects and water crossover are presented. Transitory effects of liquid water saturation at cathode are also determined. This study can provide...

  5. The Power of STEP for the Exchange of Engineering Information between CA(X) Systems

    DEFF Research Database (Denmark)

    Sørensen, Torben; Conrad, Finn

    1999-01-01

    to the neutral Product Data Technology by use of the open systems' architecture. The initial release of STEP, consisting of twelve essential parts, has been approved and published (in 1994) as an International Standard. The introduction of STEP based software and its application in industry is thus on the verge...... components and systems we need to describe, e.g. additional CFD information and CACSD information that are not provided by STEP in its initial release. Fortunately, the methodologies provided by STEP enable us to write our own additional dedicated information resources as needed, and even map these dedicated...

  6. Overview on R and D and design activities for the ITER core charge exchange spectroscopy diagnostic system

    Energy Technology Data Exchange (ETDEWEB)

    Biel, W., E-mail: w.biel@fz-juelich.de [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany); Baross, T. [KFKI RMKI, EURATOM Association, PO Box 49, H-1521 Budapest (Hungary); Bourauel, P. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany); Dunai, D. [KFKI RMKI, EURATOM Association, PO Box 49, H-1521 Budapest (Hungary); Durkut, M. [TNO Science and Industry, Partner in ITER-NL, P.O. Box 155, 2600 AD Delft (Netherlands); Erdei, G. [BME, EURATOM Association, PO Box 91, H-1521 Budapest (Hungary); Hawkes, N. [Association EURATOM/CCFE, OX14 3DB Abingdon (United Kingdom); Hellermann, M. von [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, partner in the Trilateral Euregio Cluster and ITER-NL, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Hogenbirk, A. [Nuclear Research and Consultancy Group V.o.F., Petten (Netherlands); Jaspers, R. [Department of Applied Physics, Eindhoven University of Technology (Netherlands); Kiss, G. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany); Klinkhamer, F. [TNO Science and Industry, Partner in ITER-NL, P.O. Box 155, 2600 AD Delft (Netherlands); Koning, J.F. [FOM-Institute for Plasma Physics Rijnhuizen, Association EURATOM-FOM, partner in the Trilateral Euregio Cluster and ITER-NL, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands); Kotov, V.; Krasikov, Y.; Krimmer, A. [Institut fuer Energieforschung - Plasmaphysik, Forschungszentrum Juelich Gmbh, Association EURATOM-FZJ, member of Trilateral Euregio Cluster, 52425 Juelich (Germany)

    2011-10-15

    The ITER core charge exchange recombination spectroscopy (core CXRS) diagnostic system is designed to provide experimental access to various measurement quantities in the ITER core plasma such as ion densities, temperatures and velocities. The implementation of the approved CXRS diagnostic principle on ITER faces significant challenges: First, a comparatively low CXRS signal intensity is expected, together with a high noise level due to bremsstrahlung, while the requested measurement accuracy and stability for the core CXRS system go far beyond the level commonly achieved in present-day fusion experiments. Second, the lifetime of the first mirror surface is limited due to either erosion by fast particle bombardment or deposition of impurities. Finally, the hostile technical environment on ITER imposes challenging boundary conditions for the diagnostic integration and operation, including high neutron loads, electro-magnetic loads, seismic events and a limited access for maintenance. A brief overview on the R and D and design activities for the core CXRS system is presented here, while the details are described in parallel papers.

  7. Web-based documentation system with exchange of DICOM RT for multicenter clinical studies in particle therapy

    Science.gov (United States)

    Kessel, Kerstin A.; Bougatf, Nina; Bohn, Christian; Engelmann, Uwe; Oetzel, Dieter; Bendl, Rolf; Debus, Jürgen; Combs, Stephanie E.

    2012-02-01

    Conducting clinical studies is rather difficult because of the large variety of voluminous datasets, different documentation styles, and various information systems, especially in radiation oncology. In this paper, we describe our development of a web-based documentation system with first approaches of automatic statistical analyses for transnational and multicenter clinical studies in particle therapy. It is possible to have immediate access to all patient information and exchange, store, process, and visualize text data, all types of DICOM images, especially DICOM RT, and any other multimedia data. Accessing the documentation system and submitting clinical data is possible for internal and external users (e.g. referring physicians from abroad, who are seeking the new technique of particle therapy for their patients). Thereby, security and privacy protection is ensured with the encrypted https protocol, client certificates, and an application gateway. Furthermore, all data can be pseudonymized. Integrated into the existing hospital environment, patient data is imported via various interfaces over HL7-messages and DICOM. Several further features replace manual input wherever possible and ensure data quality and entirety. With a form generator, studies can be individually designed to fit specific needs. By including all treated patients (also non-study patients), we gain the possibility for overall large-scale, retrospective analyses. Having recently begun documentation of our first six clinical studies, it has become apparent that the benefits lie in the simplification of research work, better study analyses quality and ultimately, the improvement of treatment concepts by evaluating the effectiveness of particle therapy.

  8. Compact Design of 10 kW Proton Exchange Membrane Fuel Cell Stack Systems with Microcontroller Units

    Directory of Open Access Journals (Sweden)

    Hsiaokang Ma

    2014-04-01

    Full Text Available In this study, fuel, oxidant supply and cooling systems with microcontroller units (MCU are developed in a compact design to fit two 5 kW proton exchange membrane fuel cell (PEMFC stacks. At the initial stage, the testing facility of the system has a large volume (2.0 m × 2.0 m × 1.5 m with a longer pipeline and excessive control sensors for safe testing. After recognizing the performance and stability of stack, the system is redesigned to fit in a limited space (0.4 m × 0.5 m × 0.8 m. Furthermore, the stack performance is studied under different hydrogen recycling modes. Then, two similar 5 kW stacks are directly coupled with diodes to obtain a higher power output and safe operation. The result shows that the efficiency of the 5 kW stack is 43.46% with a purge period of 2 min with hydrogen recycling and that the hydrogen utilization rate µf is 66.31%. In addition, the maximum power output of the twin-coupled module (a power module with two stacks in electrical cascade/parallel arrangement is 9.52 kW.

  9. Nature's Heat Exchangers.

    Science.gov (United States)

    Barnes, George

    1991-01-01

    Discusses the heat-transfer systems of different animals. Systems include heat conduction into the ground, heat transferred by convection, heat exchange in lizards, fish and polar animals, the carotid rete system, electromagnetic radiation from animals and people, and plant and animal fiber optics. (MDH)

  10. Heat Exchange in “Human body - Thermal protection - Environment” System

    Science.gov (United States)

    Khromova, I. V.

    2017-11-01

    This article is devoted to the issues of simulation and calculation of thermal processes in the system called “Human body – Thermal protection - Environment” under low temperature conditions. It considers internal heat sources and convective heat transfer between calculated elements. Overall this is important for the Heat Transfer Theory. The article introduces complex heat transfer calculation method and local thermophysical parameters calculation method in the system called «Human body – Thermal protection – Environment», considering passive and active thermal protections, thermophysical and geometric properties of calculated elements in a wide range of environmental parameters (water, air). It also includes research on the influence that thermal resistance of modern materials, used in special protective clothes development, has on heat transfer in the system “Human body – Thermal protection – Environment”. Analysis of the obtained results allows adding of the computer research data to experiments and optimizing of individual life-support system elements, which are intended to protect human body from exposure to external factors.

  11. Towards a reference ontology of complex economic exchanges for Accounting Information Systems

    NARCIS (Netherlands)

    Blums, Ivar; Weigand, Hans; Matthes, Flores; Mendling, Jan; Rinderle-Ma, Stefanie

    Although the field of Accounting Information Systems (AIS) has a long tradition, there is still a lack of a widely adopted conceptualization. The Unified Foundational Ontology (UFO) and its Services sub- ontology (UFO-S) are regarded as grounding the engineering of a reference ontology for AIS. The

  12. Yield and gas exchange ability of sweetpotato plants cultured in a hydroponic system

    Science.gov (United States)

    Kitaya, Y.; Hirai, H.; Saiful Islam, A. F. M.; Yamamoto, M.

    Life support of crews in space is greatly dependent on the amounts of food atmospheric O 2 and clean water produced by plants Therefore the space farming systems with scheduling of crop production obtaining high yields with a rapid turnover rate converting atmospheric CO 2 to O 2 and purifying water should be established with employing suitable plant species and varieties and precisely controlling environmental variables around plants grown at a high density in a limited space In this study three sweetpotato varieties were cultured in a newly developed hydroponic system and the yield the photosynthetic rate and the transpiration rate were compared on the earth as a fundamental study for establishing the space farming systems The varieties were Elegant summer Koukei 14 and Beniazuma The hydroponic system mainly consisted of water channels and rockwool boards A growing space for roots was made between the rockwool board and nutrient solution in the water channel Storage roots were developed on the lower surface of the rockwool plates Fresh weights of the storage roots were 1 6 1 2 and 0 6 kg plant for Koukei 14 Elegant summer and Beniazuma respectively grown for five months from June to October under the sun light in Osaka Japan Koukei 14 and Elegant summer produced greater total phytomass than Beniazuma There were positive correlations among the total phytomass the net photosynthetic rate and the transpiration rate Young stems and leaves as well as storage roots of Elegant summer are edible Therefore Elegant-summer

  13. Fluidized bed heat exchangers to prevent fouling in ice slurry systems and industrial crystallizers

    NARCIS (Netherlands)

    Pronk, P.

    2006-01-01

    Ozon layer depletion and global warming by synthetic refrigerants forces refrigeration industries to switch over to natural but hazardous refrigerants like ammonia and hydrocarbons. A promising technology to safely use the latter refrigerants is the application of indirect refrigeration systems with

  14. 18 CFR 301.4 - Exchange Period Average System Cost determination.

    Science.gov (United States)

    2010-04-01

    ... Accounts in the Appendix 1. Bonneville will use Global Insight as the source of data for the escalation... Regional Dialogue High Water Mark contracts. For Consumer-owned Utilities that elect to execute Regional Dialogue CHWM contracts, Bonneville will use the following approach: (1) Use the RHWM System Resources as...

  15. Design and fabrication of a 3-D printable counter-low/precipitation heat exchanger for use with a novel off-grid solid state refrigeration system

    Science.gov (United States)

    Ryan, Sean Thomas

    Off-grid refrigeration technologies are currently limited to either vapor-compression cycles driven by photovoltaics or solar thermal absorption cycles. Rebound Technologies has recently developed a novel off-grid refrigeration system called Sunchill(TM) for agricultural applications in humid environments in the developing world. The Sunchill(TM) refrigeration system utilizes the daily high and low temperatures to drive a 24 hour refrigeration cycle. Cooling is provided by the dissolution of an endothermic salt, sodium carbonate decahydrate. Once the salt is solvated and cooling is delivered to freshly harvest crops, the system is "recharged" in a multi-step process that relies on a solar collector, an air-gap membrane unit and a heat exchanger. The heat exchanger, which is the focus of this thesis, is required to remove 36.6 MJ of heat over a twelve hour period in order to "recharge" the system. The heat exchanger is also required to transfer heat from a fresh water stream to a cold brine solution to generate the cold water necessary to submerse and cool harvested crops. To provide a sustainable technology to the target community, the feasibility of fabricating the heat exchanger via the low cost 3-D printing method of fused filament fabrication (FFF) was examined. This thesis presents the design, development, and manufacturing considerations that were performed in support of developing a waterproof, counter-flow, 3-D printable heat exchanger. Initial geometries and performance were modeled by constructing a linear thermal resistance network with truncating temperatures of 30°C (saturated brine temperature) and 18°C (average daily low temperature). The required surface area of the heat exchanger was found to be 20.46 m2 to remove the required 36.6 MJ of heat. Iterative print tests were conducted to arrive at the wall thickness, hexagon shape, and double wall structure of the heat exchanger. A laboratory-scale heat exchanger was fabricated using a Lulzbot Taz 4

  16. An Experimental Seismic Data and Parameter Exchange System for Interim NEAMTWS

    Science.gov (United States)

    Hanka, W.; Hoffmann, T.; Weber, B.; Heinloo, A.; Hoffmann, M.; Müller-Wrana, T.; Saul, J.

    2009-04-01

    In 2008 GFZ Potsdam has started to operate its global earthquake monitoring system as an experimental seismic background data centre for the interim NEAMTWS (NE Atlantic and Mediterranean Tsunami Warning System). The SeisComP3 (SC3) software, developed within the GITEWS (German Indian Ocean Tsunami Early Warning System) project was extended to test the export and import of individual processing results within a cluster of SC3 systems. The initiated NEAMTWS SC3 cluster consists presently of the 24/7 seismic services at IMP, IGN, LDG/EMSC and KOERI, whereas INGV and NOA are still pending. The GFZ virtual real-time seismic network (GEOFON Extended Virtual Network - GEVN) was substantially extended by many stations from Western European countries optimizing the station distribution for NEAMTWS purposes. To amend the public seismic network (VEBSN - Virtual European Broadband Seismic Network) some attached centres provided additional private stations for NEAMTWS usage. In parallel to the data collection by Internet the GFZ VSAT hub for the secured data collection of the EuroMED GEOFON and NEAMTWS backbone network stations became operational and the first data links were established. In 2008 the experimental system could already prove its performance since a number of relevant earthquakes have happened in NEAMTWS area. The results are very promising in terms of speed as the automatic alerts (reliable solutions based on a minimum of 25 stations and disseminated by emails and SMS) were issued between 2 1/2 and 4 minutes for Greece and 5 minutes for Iceland. They are also promising in terms of accuracy since epicenter coordinates, depth and magnitude estimates were sufficiently accurate from the very beginning, usually don't differ substantially from the final solutions and provide a good starting point for the operations of the interim NEAMTWS. However, although an automatic seismic system is a good first step, 24/7 manned RTWCs are mandatory for regular manual verification

  17. Towards Standardized Patient Data Exchange: Integrating a FHIR Based API for the Open Medical Record System.

    Science.gov (United States)

    Kasthurirathne, Suranga N; Mamlin, Burke; Grieve, Grahame; Biondich, Paul

    2015-01-01

    Interoperability is essential to address limitations caused by the ad hoc implementation of clinical information systems and the distributed nature of modern medical care. The HL7 V2 and V3 standards have played a significant role in ensuring interoperability for healthcare. FHIR is a next generation standard created to address fundamental limitations in HL7 V2 and V3. FHIR is particularly relevant to OpenMRS, an Open Source Medical Record System widely used across emerging economies. FHIR has the potential to allow OpenMRS to move away from a bespoke, application specific API to a standards based API. We describe efforts to design and implement a FHIR based API for the OpenMRS platform. Lessons learned from this effort were used to define long term plans to transition from the legacy OpenMRS API to a FHIR based API that greatly reduces the learning curve for developers and helps enhance adhernce to standards.

  18. A Message Exchange Protocol in Command and Control Systems Integration, using the JC3IEDM

    Science.gov (United States)

    2014-06-01

    Foster City, CA, USA (1998). Erl, T. SOA Design Patterns , Prentice Hall Service-Oriented Computing Series (2009). Hohpe, G. and Woolf, B...Control, Communications, and Computer Systems, Joint Chiefs of Staf. USA, 1st October 1996 edition. • Erl, T., 2009. SOA Design Patterns , Prentice...19 June, 2014 in Alexandria, VA. U.S. Government or Federal Rights License 14. ABSTRACT A Joint Operation scenario can be described as a

  19. Fire Suppression M and S Validation (Status and Challenges), Systems Fire Protection Information Exchange

    Science.gov (United States)

    2015-10-14

    SYSTEMS ENGINEERING and TECHNOLOGY SYMPOSIUM Outline • Introduction • Physics being solved • Reduced Chemical Kinetics : – Complete description of...Future Work UNCLASSIFIED: Distribution A. Authorized for Public Release; distribution is unlimited 2 Introduction • Develop a Computational Fluid...rate Kinetics •14 Species & 12 reactionsCombustion Model •Participating Media Discrete Ordinate Method •WSG model for CO2, H2O and SootRadiation Model

  20. Modelling of Thermal Behavior of Borehole Heat Exchangers of Geothermal Heat Pump Heating Systems

    Directory of Open Access Journals (Sweden)

    Gornov V.F.

    2016-01-01

    Full Text Available This article reports results of comparing the accuracy of the software package “INSOLAR.GSHP.12”, modeling non-steady thermal behavior of geothermal heat pump heating systems (GHCS and of the similar model “conventional” using finite difference methods for solving spatial non-steady problems of heat conductivity. The software package is based on the method of formulating mathematical models of thermal behavior of ground low-grade heat collection systems developed by INSOLAR group of companies. Equations of mathematical model of spatial non-steady thermal behavior of ground mass of low-grade heat collection system obtained by the developed method have been solved analytically that significantly reduced computing time spent by the software complex “INSOLAR.GSHP.12” for calculations. The method allows to turn aside difficulties associated with information uncertainty of mathematical models of the ground thermal behavior and approximation of external factors affecting the ground. Use of experimentally obtained information about the ground natural thermal behavior in the software package allows to partially take into account the whole complex of factors (such as availability of groundwater, their velocity and thermal behavior, structure and arrangement of ground layers, the Earth’s thermal background, precipitation, phase transformations of moisture in the pore space, and more, significantly influencing the formation of thermal behavior of the ground mass of a low-grade geothermal heat collection system. Numerical experiments presented in the article confirmed the high convergence of the results obtained through the software package “INSOLAR.GSHP.12” with solutions obtained by conventional finite-difference methods.

  1. Development of an Eddy Covariance System for Air-Sea Carbon Dioxide Exchange

    Science.gov (United States)

    Miller, S. D.; Marandino, C. A.; McCormick, C.; Saltzman, E. S.

    2006-12-01

    We are developing a ship-based system to measure the air-sea pCO2 gradient and air-sea turbulent flux of CO2 over the ocean. The eddy covariance flux system uses off-the-shelf instruments to measure the turbulent wind vector (Campbell Scientific CSAT3 sonic anemometer), platform motion (Systron Donner Motion Pak II), and carbon dioxide molar density (LiCor 7000 Infrared Gas Analyzer). Two major sources of uncertainty in calculated fluxes are the effect of water vapor fluctuations on air density fluctuations (the WPL effect, Webb, Pearman and Leuning. 1980), and a spurious CO2 signal due to the sensitivity of the gas analyzer to platform motion (McGillis et al., 1998). Two flux systems were deployed side-by-side on a cruise from Manzanillo, Mexico to Puntas Arenas, Chile, in January 2006. Results from the cruise are presented, with a focus on our attempts to reduce biases in the calculated air-sea CO2 flux due to the WPL effect and the motion sensitivity of the gas analyzer.

  2. Demonstration of Regenerable, Large-Scale Ion Exchange System Using WBA Resin in Rialto, CA

    Science.gov (United States)

    2012-12-01

    contactors 201-A, B, C, D, E, F Liqui-cel G533 14"X28" membrane contactor . X50 fiber, epoxy potting, PVC vessel with nylon end caps, 2" ANSI...at operating pressures. Excess dissolved CO2 is removed to reduce post-treatment costs using Liqui-Cell membranes designed for degassing liquids...carbon dioxide from the groundwater feed can be accomplished using membrane treatment systems or stripping towers. Both methods are straightforward and

  3. Mapserver – Information Flow Management Software for The Border Guard Distributed Data Exchange System

    Directory of Open Access Journals (Sweden)

    Blok Marek

    2016-09-01

    Full Text Available In this paper the architecture of the software designed for management of position and identification data of floating and flying objects in Maritime areas controlled by Polish Border Guard is presented. The software was designed for managing information stored in a distributed system with two variants of the software, one for a mobile device installed on a vessel, an airplane or a car and second for a central server. The details of implementation of all functionalities of the MapServer in both, mobile and central, versions are briefly presented on the basis of information flow diagrams.

  4. Thermal and water management of low temperature Proton Exchange Membrane Fuel Cell in fork-lift truck power system

    DEFF Research Database (Denmark)

    Hosseinzadeh, Elham; Rokni, Masoud; Rabbani, Raja Abid

    2013-01-01

    A general zero-dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model has been developed for forklift truck application. The balance of plant (BOP) comprises of a compressor, an air humidifier, a set of heat exchangers and a recirculation pump. Water and thermal management of the fuel cell...

  5. Expert Advisor (EA) Evaluation System Using Web-based ELECTRE Method in Foreign Exchange (Forex) Market

    Science.gov (United States)

    Satibi; Widodo, Catur Edi; Farikhin

    2018-02-01

    This research aims to optimize forex trading profit automatically using EA but its still keep considering accuracy and drawdown levels. The evaluation system will classify EA performance based on trading market sessions (Sydney, Tokyo, London and New York) to determine the right EA to be used in certain market sessions. This evaluation system is a web-based ELECTRE methods that interact in real-time with EA through web service and are able to present real-time charts performance dashboard using web socket protocol communications. Web applications are programmed using NodeJs. In the testing period, all EAs had been simulated 24 hours in all market sessions for three months, the best EA is valued by its profit, accuracy and drawdown criteria that calculated using web-based ELECTRE method. The ideas of this research are to compare the best EA on testing period with collaboration performances of each best classified EA by market sessions. This research uses three months historical data of EUR/USD as testing period and other 3 months as validation period. As a result, performance of collaboration four best EA classified by market sessions can increase profits percentage consistently in testing and validation periods and keep securing accuracy and drawdown levels.

  6. First System-Wide Estimates of Air-Water Exchange of Carbon Dioxide in the Chesapeake Bay

    Science.gov (United States)

    Najjar, R.; Herrmann, M.; Menendez, A.; Goldberger, S.

    2016-12-01

    Estuaries are estimated to play an uncertain but potentially important role in the global carbon cycle via the evasion of CO2 to the atmosphere. Global estimates are uncertain due to limited data availability and the extreme heterogeneity of coastal systems. Notably, the air-water CO2 flux for the largest estuary in the United States, the Chesapeake Bay, is yet unknown. Here we provide the first system-level CO2 gas exchange estimates for the main stem of the Chesapeake Bay using pH and alkalinity data from the Chesapeake Bay Program. Errors are propagated based on errors in pH measurement and alkalinity-salinity relationships. Estimates are made at monthly resolution from 1985 to 2013 for eight segments of the Bay. We find the main stem to be a net source of CO2 to the atmosphere, outgassing from 1.9 to 2.6 mol m-2 yr-1 over the study period, with the range encompassing a variety of quality control procedures. Outgassing is greatest in the fall and winter and in the oligohaline and polyhaline portions of the Bay.

  7. In-Frame and Unmarked Gene Deletions in Burkholderia cenocepacia via an Allelic Exchange System Compatible with Gateway Technology

    Science.gov (United States)

    Fazli, Mustafa; Harrison, Joe J.; Gambino, Michela; Givskov, Michael

    2015-01-01

    Burkholderia cenocepacia is an emerging opportunistic pathogen causing life-threatening infections in immunocompromised individuals and in patients with cystic fibrosis, which are often difficult, if not impossible, to treat. Understanding the genetic basis of virulence in this emerging pathogen is important for the development of novel treatment regimes. Generation of deletion mutations in genes predicted to encode virulence determinants is fundamental to investigating the mechanisms of pathogenesis. However, there is a lack of appropriate selectable and counterselectable markers for use in B. cenocepacia, making its genetic manipulation problematic. Here we describe a Gateway-compatible allelic exchange system based on the counterselectable pheS gene and the I-SceI homing endonuclease. This system provides efficiency in cloning homology regions of target genes and allows the generation of precise and unmarked gene deletions in B. cenocepacia. As a proof of concept, we demonstrate its utility by deleting the Bcam1349 gene, encoding a cyclic di-GMP (c-di-GMP)-responsive regulator protein important for biofilm formation. PMID:25795676

  8. Modeling of a data exchange process in the Automatic Process Control System on the base of the universal SCADA-system

    Science.gov (United States)

    Topolskiy, D.; Topolskiy, N.; Solomin, E.; Topolskaya, I.

    2016-04-01

    In the present paper the authors discuss some ways of solving energy saving problems in mechanical engineering. In authors' opinion one of the ways of solving this problem is integrated modernization of power engineering objects of mechanical engineering companies, which should be intended for the energy supply control efficiency increase and electric energy commercial accounting improvement. The author have proposed the usage of digital current and voltage transformers for these purposes. To check the compliance of this equipment with the IEC 61850 International Standard, we have built a mathematic model of the data exchange process between measuring transformers and a universal SCADA-system. The results of modeling show that the discussed equipment corresponds to the mentioned Standard requirements and the usage of the universal SCADA-system for these purposes is preferable and economically reasonable. In modeling the authors have used the following software: MasterScada, Master OPC_DI_61850, OPNET.

  9. Comparing the Picture Exchange Communication System and the iPad™ for Communication of Students with Autism Spectrum Disorder and Developmental Delay

    Science.gov (United States)

    Hill, Doris Adams; Flores, Margaret M.

    2014-01-01

    Both picture exchange, a low-tech picturebased communication system, and technologybased interventions, such as the iPad™ with communication application, are emerging treatments for students with autism spectrum disorder (ASD), according to the National Autism Center (2009). Recently, investigations regarding the use of the Apple iPad™ to…

  10. The Use of Video Modeling with the Picture Exchange Communication System to Increase Independent Communicative Initiations in Preschoolers with Autism and Developmental Delays

    Science.gov (United States)

    Cihak, David F.; Smith, Catherine C.; Cornett, Ashlee; Coleman, Mari Beth

    2012-01-01

    The use of video modeling (VM) procedures in conjunction with the picture exchange communication system (PECS) to increase independent communicative initiations in preschool-age students was evaluated in this study. The four participants were 3-year-old children with limited communication skills prior to the intervention. Two of the students had…

  11. Effectiveness of the Picture Exchange Communication System (PECS) on Communication and Speech for Children with Autism Spectrum Disorders: A Meta-Analysis

    Science.gov (United States)

    Flippin, Michelle; Reszka, Stephanie; Watson, Linda R.

    2010-01-01

    Purpose: The Picture Exchange Communication System (PECS) is a popular communication-training program for young children with autism spectrum disorders (ASD). This meta-analysis reviews the current empirical evidence for PECS in affecting communication and speech outcomes for children with ASD. Method: A systematic review of the literature on PECS…

  12. The Effectiveness of Picture Exchange Communication System (PECS) Training for Teachers of Children with Autism: A Pragmatic, Group Randomised Controlled Trial

    Science.gov (United States)

    Howlin, Patricia; Gordon, R. Kate; Pasco, Greg; Wade, Angie; Charman, Tony

    2007-01-01

    Objective: To assess the effectiveness of expert training and consultancy for teachers of children with autism spectrum disorder in the use of the Picture Exchange Communication System (PECS). Method: Design: Group randomised, controlled trial (3 groups: immediate treatment, delayed treatment, no treatment). Participants: 84 elementary school…

  13. A Review and Analysis of the Picture Exchange Communication System (PECS) for Individuals With Autism Spectrum Disorders Using a Paradigm of Communication Competence

    Science.gov (United States)

    Ostryn, Cheryl; Wolfe, Pamela S.; Rusch, Frank R.

    2008-01-01

    Research related to the use of the Picture Exchange Communication System (PECS) with individuals having autism spectrum disorders (ASDs) was examined using a communication competence paradigm detailed by J. C. Light (1988, 1989, 2003). Communication components were operationalized based on skills identified in ASD research. A review was conducted…

  14. Picture Exchange Communication System and Pals: A Peer-Mediated Augmentative and Alternative Communication Intervention for Minimally Verbal Preschoolers with Autism

    Science.gov (United States)

    Thiemann-Bourque, Kathy; Brady, Nancy; McGuff, Sara; Strump, Keenan; Naylor, Amy

    2016-01-01

    Purpose: This study was conducted to investigate the effectiveness of a social intervention that integrates peer-mediated approaches and the Picture Exchange Communication System (PECS). Method: Effects were evaluated using a series of A-B designs replicated across 4 children with severe autism and limited verbal skills. Seven peers without…

  15. Teaching Young People Who Are Blind and Have Autism to Make Requests Using a Variation on the Picture Exchange Communication System with Tactile Symbols: A Preliminary Investigation

    Science.gov (United States)

    Lund, Shelley K.; Troha, Jeanette M.

    2008-01-01

    This study used a single-subject multiple baseline across participants design to evaluate the effectiveness of a modified picture exchange communication system (PECS) teaching protocol with tactile symbols. Three students (two male, one female) aged 12-17 years who had autism and were blind participated in the study. The instructional program…

  16. Effects of Mother-Implemented Picture Exchange Communication System (PECS) Training on Independent Communicative Behaviors of Young Children with Autism Spectrum Disorders

    Science.gov (United States)

    Park, Ju Hee; Alber-Morgan, Sheila R.; Cannella-Malone, Helen

    2011-01-01

    This study examined the effects of mother-implemented Picture Exchange Communication System (PECS) training on the independent communication of three young children with autism spectrum disorders. Three mothers were trained to teach their child PECS Phases 1 through 3B, which they did with high integrity. Moreover, all three children successfully…

  17. The Effects of Mother-Implemented Picture Exchange Communication System Training on Spontaneous Communicative Behaviors of Young Children with Autism Spectrum Disorders

    Science.gov (United States)

    Park, Ju Hee

    2010-01-01

    The current study examined whether mothers could be taught to implement the picture exchange communication system (PECS) training with their child and investigated the effects of the mother-implemented PECS training on the spontaneous communication of young children with autism spectrum disorders. Three mothers were trained to teach their child…

  18. The Impact of the Picture Exchange Communication System on Requesting and Speech Development in Preschoolers with Autism Spectrum Disorders and Similar Characteristics

    Science.gov (United States)

    Ganz, Jennifer B.; Simpson, Richard L.; Corbin-Newsome, Jawanda

    2008-01-01

    By definition children with autism spectrum disorders (ASD) experience difficulty understanding and using language. Accordingly, visual and picture-based strategies such as the Picture Exchange Communication System (PECS) show promise in ameliorating speech and language deficits. This study reports the results of a multiple baseline across…

  19. The impact of water exchange rate and treatment processes on water-borne hormones in recirculation aquaculture systems containing sexually maturing Atlantic salmon Salmo salar

    Science.gov (United States)

    A controlled seven-month study was conducted in six replicated water recirculation aquaculture systems (WRAS) to assess post-smolt Atlantic salmon (Salmo salar) performance in relation to WRAS water exchange rate. Unexpectedly high numbers of precocious sexually mature fish were observed in all WRAS...

  20. Development and Validation of a Simple Analytical Model of the Proton Exchange Membrane Fuel Cell (Pemfc) in a Fork-Lift Truck Power System

    DEFF Research Database (Denmark)

    Hosseinzadeh, Elham; Rokni, Masoud

    2013-01-01

    overpotentials in the cells. Moreover, it is zero-dimensional and is assumed to be steady state. The system includes a compressor, an air humidifier, a set of heat exchangers, and a stack that together build up the anode circuit, the cathode circuit, and the cooling loop. Several issues are discussed: water...

  1. Effects of the Picture Exchange Communication System (PECS) on Maladaptive Behavior in Children with Autism Spectrum Disorders (ASD): A Review of the Literature

    Science.gov (United States)

    Battaglia, Dana; McDonald, Mary E.

    2015-01-01

    This paper provides an overview of the literature investigating the functional relationship between the use of the Picture Exchange Communication System (PECS) and maladaptive behavior (i.e., aggression, tantrums) in individuals with autism spectrum disorders (ASD). Digital searches were conducted to identify single subject design studies…

  2. Effectiveness of the Picture Exchange Communication System as a Functional Communication Intervention for Individuals with Autism Spectrum Disorders: A Practice-Based Research Synthesis

    Science.gov (United States)

    Tien, Kai-Chien

    2008-01-01

    This research synthesis verifies the effectiveness of the Picture Exchange Communication System (PECS) for improving the functional communication skills of individuals with autism spectrum disorders (ASD). The research synthesis was focused on the degree to which variations in PECS training are associated with variations in functional…

  3. Effectiveness of Combining Tangible Symbols with the Picture Exchange Communication System to Teach Requesting Skills to Children with Multiple Disabilities Including Visual Impairment

    Science.gov (United States)

    Ali, Emad; MacFarland, Stephanie Z.; Umbreit, John

    2011-01-01

    The Picture Exchange Communication System (PECS) is an augmentative and alternative communication (AAC) program used to teach functional requesting and commenting skills to people with disabilities (Bondy & Frost, 1993; Frost & Bondy, 2002). In this study, tangible symbols were added to PECS in teaching requesting to four students (ages 7-14) with…

  4. The Effectiveness of Combining Tangible Symbols with the Picture Exchange Communication System to Teach Requesting Skills to Children with Multiple Disabilities Including Visual Impairment

    Science.gov (United States)

    Ali, Emad

    2009-01-01

    The Picture Exchange Communication System (PECS) is an augmentative and alternative communication program (Frost & Bondy, 2002). Although PECS has been effectively used to teach functional requesting skills for children with autism, mental retardation, visual impairment, and physical disabilities (e.g., Anderson, Moore, & Bourne, 2007; Chambers &…

  5. A general halide-to-anion switch for imidazolium-based ionic liquids and oligocationic systems using anion exchange resins (A- form).

    Science.gov (United States)

    Alcalde, Ermitas; Dinarès, Immaculada; Ibáñez, Anna; Mesquida, Neus

    2011-03-21

    Further studies on the application of an AER (A(-) form) method broadened the anion exchange scope of representative ionic liquids and bis(imidazolium) systems. Depending on the hydrophobicity nature of the targeted imidazolium species and counteranions, different organic solvents were used to swap halides for assorted anions, proceeding in excellent to quantitative yields.

  6. The Atmospheric Chemistry and Canopy Exchange Simulation System (ACCESS: model description and application to a temperate deciduous forest canopy

    Directory of Open Access Journals (Sweden)

    R. D. Saylor

    2013-01-01

    Full Text Available Forest canopies are primary emission sources of biogenic volatile organic compounds (BVOCs and have the potential to significantly influence the formation and distribution of secondary organic aerosol (SOA mass. Biogenically-derived SOA formed as a result of emissions from the widespread forests across the globe may affect air quality in populated areas, degrade atmospheric visibility, and affect climate through direct and indirect forcings. In an effort to better understand the formation of SOA mass from forest emissions, a 1-D column model of the multiphase physical and chemical processes occurring within and just above a vegetative canopy is being developed. An initial, gas-phase-only version of this model, the Atmospheric Chemistry and Canopy Exchange Simulation System (ACCESS, includes processes accounting for the emission of BVOCs from the canopy, turbulent vertical transport within and above the canopy and throughout the height of the planetary boundary layer (PBL, near-explicit representation of chemical transformations, mixing with the background atmosphere and bi-directional exchange between the atmosphere and canopy and the atmosphere and forest floor. The model formulation of ACCESS is described in detail and results are presented for an initial application of the modeling system to Walker Branch Watershed, an isoprene-emission-dominated forest canopy in the southeastern United States which has been the focal point for previous chemical and micrometeorological studies. Model results of isoprene profiles and fluxes are found to be consistent with previous measurements made at the simulated site and with other measurements made in and above mixed deciduous forests in the southeastern United States. Sensitivity experiments are presented which explore how canopy concentrations and fluxes of gas-phase precursors of SOA are affected by background anthropogenic nitrogen oxides (NOx. Results from these experiments suggest that the

  7. Anthropology, organ transplantation and the immune system: resituating commodity and gift exchange.

    Science.gov (United States)

    Kierans, Ciara

    2011-11-01

    This article reflects on contributions from medical anthropology to our understanding of the bio-social and bio-political implications of renal transplantation. Taking up the idea of transplantation as a 'complex', a vast assemblage of people, places, practices and procedures which intersect medical, social and cultural domains, I point to a reliance in the anthropological literature on overly pre-determined conceptual frameworks, organised around a distinct polarisation between organ giving and receiving, where one side (supply) takes analytical, and indeed moral, precedence over the other (receipt). These frameworks tend to fail us when it comes to thinking about the wider social, cultural and political implications of transplant technologies. In an attempt to offer a less polarised view, I draw attention to the material and symbolic role of the immune system in transplantation and the ways in which it simultaneously shapes opportunities for procurement and the lived realities of recipiency. This helps us see the many complex ways in which suffering and inequality are constituted all along the variegated chains of supply and demand that are internal to, and made possible by, transplantation practices themselves. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Challenges of Executive Information Systems in listed Johannesburg Stock Exchange companies

    Directory of Open Access Journals (Sweden)

    Elmarie Papageorgiou

    2011-09-01

    Objectives: The purpose of this study is to establish and to determine the existence, and to what extent EISs exist in all levels of management and to identify the challenges companies experienced in listed JSE companies. Therefore the problem exists that EIS-users at all levels of management are unaware of the challenges of EISs and that EISs can be used as a tool to analyse their businesses’ performance and competitiveness. Method: A mixed method was used; both quantitative and qualitative in nature. Questionnaires were sent to 334 listed JSE companies and 13 interviews were conducted with users of EISs in all levels of management. Results: The results of the study demonstrate that the majority of respondents of the questionnaire have an EIS or plan to implement an EIS. The results further revealed the respondents’ positive attitude towards EISs as it is an excellent management information tool that adds strategic value to their business, that is critical for real-time decision-making, solves problems and creates a competitive edge. From the results it is evident that there is a need for an EIS to be ‘everybody’s information system’. The results of the interviews demonstrate that an EIS is a seamless reliable system necessary for proper timeous decision-making. The respondents to the questionnaire and the interviewees indicated that they understood the value of EISs as a useful part of their company. Conclusion: The study adds value to the awareness and understanding of EISs that creates a business environment in which business and management can enhance sustainability and strategic competitiveness.

  9. Hydrogen exchange

    DEFF Research Database (Denmark)

    Jensen, Pernille Foged; Rand, Kasper Dyrberg

    2016-01-01

    Hydrogen exchange (HX) monitored by mass spectrometry (MS) is a powerful analytical method for investigation of protein conformation and dynamics. HX-MS monitors isotopic exchange of hydrogen in protein backbone amides and thus serves as a sensitive method for probing protein conformation...... and dynamics along the entire protein backbone. This chapter describes the exchange of backbone amide hydrogen which is highly quenchable as it is strongly dependent on the pH and temperature. The HX rates of backbone amide hydrogen are sensitive and very useful probes of protein conformation......, as they are distributed along the polypeptide backbone and form the fundamental hydrogen-bonding networks of basic secondary structure. The effect of pressure on HX in unstructured polypeptides (poly-dl-lysine and oxidatively unfolded ribonuclease A) and native folded proteins (lysozyme and ribonuclease A) was evaluated...

  10. Selection of words for implementation of the Picture Exchange Communication System - PECS in non-verbal autistic children.

    Science.gov (United States)

    Ferreira, Carine; Bevilacqua, Monica; Ishihara, Mariana; Fiori, Aline; Armonia, Aline; Perissinoto, Jacy; Tamanaha, Ana Carina

    2017-03-09

    It is known that some autistic individuals are considered non-verbal, since they are unable to use verbal language and barely use gestures to compensate for the absence of speech. Therefore, these individuals' ability to communicate may benefit from the use of the Picture Exchange Communication System - PECS. The objective of this study was to verify the most frequently used words in the implementation of PECS in autistic children, and on a complementary basis, to analyze the correlation between the frequency of these words and the rate of maladaptive behaviors. This is a cross-sectional study. The sample was composed of 31 autistic children, twenty-five boys and six girls, aged between 5 and 10 years old. To identify the most frequently used words in the initial period of implementation of PECS, the Vocabulary Selection Worksheet was used. And to measure the rate of maladaptive behaviors, we applied the Autism Behavior Checklist (ABC). There was a significant prevalence of items in the category "food", followed by "activities" and "beverages". There was no correlation between the total amount of items identified by the families and the rate of maladaptive behaviors. The categories of words most mentioned by the families could be identified, and it was confirmed that the level of maladaptive behaviors did not interfere directly in the preparation of the vocabulary selection worksheet for the children studied.

  11. Use of a Picture Exchange Communication System for preventive procedures in individuals with autism spectrum disorder: pilot study.

    Science.gov (United States)

    Zink, Adriana Gledys; Diniz, Michele Baffi; Rodrigues Dos Santos, Maria Teresa Botti; Guaré, Renata Oliveira

    2016-09-01

    The aim of the present study was to evaluate the use of the Picture Exchange Communication System (PECS) in individuals with autism spectrum disorder (ASD) in order to facilitate patient-professional communication during preventive procedures. In this study, 26 patients with ASD, between 5 and 19 years of age (10±3.3 y), were divided into two groups: G1 (n = 13) with no previous experience of dental treatment, and G2 (n = 13), with such previous experience. The initial approach followed the principles of the Son-Rise Program®. The seven PECSs presented the routine of the dental office: "room," "ground," "chair," "dentist," "mouth," "low," and "triple." Each PEC was used up to three times in order to acquire the skill proposed. It was verified that G2 required a greater number of times to achieve the acceptance of PECS "ground," "dentist," "mouth," and "triple" (p communication during preventive procedures, including for ASD patients with previous dental experience. © 2016 Special Care Dentistry Association and Wiley Periodicals, Inc.

  12. Experience of Treatments of Amanita phalloides-Induced Fulminant Liver Failure with Molecular Adsorbent Recirculating System and Therapeutic Plasma Exchange.

    Science.gov (United States)

    Zhang, Jicheng; Zhang, Ying; Peng, Zhiyong; Maberry, Donald; Feng, Xueqiang; Bian, Pengfei; Ma, Wenjuan; Wang, Chunting; Qin, Chengyong

    2014-01-01

    Ingestion of the mushroom containing Amanita phalloides can induce fulminant liver failure and death. There are no specific antidotes. Blood purifications, such as molecular adsorbent recirculating system (MARS) and therapeutic plasma exchange (TPE), are potential therapies. However, the extent to which these technologies avert the deleterious effects of amatoxins remains controversial; the optimal intensity, duration, and initiation criteria have not been determined yet. This study aimed to retrospectively observe the effects of MARS and TPE on nine patients with A. phalloides-induced fulminant liver failure. The survival rate for the nine patients was 66.7%. Both TPE and MARS might remove toxins and improve liver functions. However, a single session of TPE produced immediately greater improvements in alanine aminotransferase (-60% vs. -16.3%), aspartate aminotransferase (-47.6% vs. -15.4%), and total bilirubin (-37.3% vs. -17.1%) (compared with the values of pretreatment, all p < 0.05) than MARS compared with MARS. Early intervention may be more effective than delayed therapy. Additionally, the presence of severe liver failure and renal failure indicated worse outcome. Although these findings are promising, additional case-controlled, randomized studies are required to confirm our results.

  13. Analysis of the control structures for an integrated ethanol processor for proton exchange membrane fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Biset, S.; Nieto Deglioumini, L.; Basualdo, M. [GIAIP-CIFASIS (UTN-FRRo-CONICET-UPCAM-UNR), BV. 27 de Febrero 210 Bis, S2000EZP Rosario (Argentina); Garcia, V.M.; Serra, M. [Institut de Robotica i Informatica Industrial, C. Llorens i Artigas 4-6, 08028 Barcelona (Spain)

    2009-07-01

    The aim of this work is to investigate which would be a good preliminary plantwide control structure for the process of Hydrogen production from bioethanol to be used in a proton exchange membrane (PEM) accounting only steady-state information. The objective is to keep the process under optimal operation point, that is doing energy integration to achieve the maximum efficiency. Ethanol, produced from renewable feedstocks, feeds a fuel processor investigated for steam reforming, followed by high- and low-temperature shift reactors and preferential oxidation, which are coupled to a polymeric fuel cell. Applying steady-state simulation techniques and using thermodynamic models the performance of the complete system with two different control structures have been evaluated for the most typical perturbations. A sensitivity analysis for the key process variables together with the rigorous operability requirements for the fuel cell are taking into account for defining acceptable plantwide control structure. This is the first work showing an alternative control structure applied to this kind of process. (author)

  14. On controllability and system constraints of the linear models of proton exchange membrane and solid oxide fuel cells

    Science.gov (United States)

    Radisavljevic, Verica

    2011-10-01

    In this paper we first show that the linear models of proton exchange membrane (polymer electrolyte membrane, PEM) and solid oxide (SO) fuel cells, commonly used in power and energy literature, are not controllable. The source of uncontrollability is the equation for pressure of the water vapor that is only affected by the fuel cell current, which in fact is a disturbance in this system and cannot be controlled by the given model inputs: inlet molar flow rates of hydrogen and oxygen. Being uncontrollable these models are not good candidates for studying control of dynamic processes in PEM and SO fuel cells. However, due to their simplicity, they can be used in hybrid configurations with other energy producing devices such as photovoltaic (solar) cells, wind turbine, micro gas turbine, battery (ultra capacitor) to demonstrate some other phenomena, but not for control purposes unless the hybrid models formed in such hybrid configurations are controllable. Testing controllability of such hybrid models is mandatory. Secondly, we introduce some algebraic constraints that follow from the model dynamics and the Nernst open-loop fuel cell voltage formula. These constraints must be satisfied in simulation of considered fuel cell modes, for example, via MATLAB/Simulink or any other computer software package.

  15. Using executive information systems as a business management tool in listed Johannesburg Stock Exchange (JSE companies: An exploratory study

    Directory of Open Access Journals (Sweden)

    Elmarie Papageorgiou

    2010-12-01

    Full Text Available Purpose: The aim of the study is to investigate the extent and use of Executive Information Systems (EISs as a business management tool in listed Johannesburg Stock Exchange (JSE companies. Problem: This study is important in order to establish the existence of EISs in these companies and whether it is being used as a business management tool to analyse and measure companies' performances. Research Methodolog:The research methods were both quantitative and qualitative in nature and are based on the literature study, questionnaire and interviews. Findings and conclusion: The findings of the study provide evidence that companies with an EIS or planning to implement an EIS view it as an excellent business management tool. This tool has built-in features, is critical for real-time decision-making, solves problems and creates a competitive edge. Value of the research: The value of the study adds to the current understanding and awareness of EISs. EISs create an environment in which business and management can enhance sustainability and strategic competitiveness.

  16. Beneficial phosphate recovery from reverse osmosis (RO) concentrate of an integrated membrane system using polymeric ligand exchanger (PLE).

    Science.gov (United States)

    Kumar, Manish; Badruzzaman, Mohammad; Adham, Samer; Oppenheimer, Joan

    2007-05-01

    Phosphorus (P) discharge to surface water is a major environmental problem. Wastewater treatment is targeted towards removal of this nutrient to prevent degradation of surface water. Integrated membrane systems (IMS) are increasingly being considered for wastewater reclamation, and provide excellent removal of P compounds. However, reverse osmosis (RO), which forms an integral part of these IMSs, concentrates most dissolved substances including P-species such as phosphates in the RO waste stream. In this study, removal of phosphate from this stream using polymeric ligand exchange (PLE) resins was investigated. Further, the possibility of phosphate recovery through struvite (MgNH(4)PO(4).6H(2)O) precipitation was tested. Struvite has been promoted as a slow release fertilizer in recent years. This study demonstrates that PLEs can be successfully used to remove phosphate from RO-concentrate, and to recover more than 85% of the adsorbed phosphorus from the exhausted media and precipitated as a beneficial product (struvite). The approach, presented in this study, suggests advantages of providing economic benefit from a waste product (RO) while avoiding phosphorus discharge to the environment.

  17. Using executive information systems as a business management tool in listed Johannesburg Stock Exchange (JSE companies: An exploratory study

    Directory of Open Access Journals (Sweden)

    Elmarie Papageorgiou

    2010-12-01

    Full Text Available Purpose: The aim of the study is to investigate the extent and use of Executive Information Systems (EISs as a business management tool in listed Johannesburg Stock Exchange (JSE companies. Problem: This study is important in order to establish the existence of EISs in these companies and whether it is being used as a business management tool to analyse and measure companies' performances.Research Methodolog:The research methods were both quantitative and qualitative in nature and are based on the literature study, questionnaire and interviews. Findings and conclusion: The findings of the study provide evidence that companies with an EIS or planning to implement an EIS view it as an excellent business management tool. This tool has built-in features, is critical for real-time decision-making, solves problems and creates a competitive edge. Value of the research: The value of the study adds to the current understanding and awareness of EISs. EISs create an environment in which business and management can enhance sustainability and strategic competitiveness.

  18. Mastering Microsoft Exchange Server 2013

    CERN Document Server

    Elfassy, David

    2013-01-01

    The bestselling guide to Exchange Server, fully updated for the newest version Microsoft Exchange Server 2013 is touted as a solution for lowering the total cost of ownership, whether deployed on-premises or in the cloud. Like the earlier editions, this comprehensive guide covers every aspect of installing, configuring, and managing this multifaceted collaboration system. It offers Windows systems administrators and consultants a complete tutorial and reference, ideal for anyone installing Exchange Server for the first time or those migrating from an earlier Exchange Server version.Microsoft

  19. Exchange bias in sputtered FeNi/FeMn systems: Effect of short low-temperature heat treatments

    Energy Technology Data Exchange (ETDEWEB)

    Savin, Peter, E-mail: peter.savin@urfu.ru [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Guzmán, Jorge [Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain); Lepalovskij, Vladimir [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Svalov, Andrey; Kurlyandskaya, Galina [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Departamento de Electricidad y Electrónica, Universidad del País Vasco (UPV/EHU), 48940 Leioa, Vizcaya (Spain); Asenjo, Agustina [Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain); Vas’kovskiy, Vladimir [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Vazquez, Manuel [Department of Magnetism and Magnetic Nanomaterials, Laboratory of Magnetic Sensors, Ural Federal University, 620002 Ekaterinburg (Russian Federation); Instituto de Ciencia de Materiales de Madrid-CSIC, 28049 Madrid (Spain)

    2016-03-15

    Short (5 min) post-deposition thermal treatments under magnetic field at low temperature (up to 200 °C) performed in exchange-coupled FeNi(40 nm)/FeMn(20 nm) bilayer thin films prepared by magnetron sputtering are shown to be effective to significantly modify their exchange field (from around 40 Oe down to 27 Oe) between FeNi and FeMn layers. A similar exchange field decrease was observed for the first deposited FeNi layer of the FeNi(40 nm)/FeMn(20 nm)/FeNi(40 nm) trilayer films after the same thermal treatments. The exchange field value for the second FeNi layer was not substantially changed. The X-ray diffraction patterns indicates that such a heat treatment has no effect on the grain size and crystalline texture of the films, while atomic force microscope studies reveal an increase of the surface roughness after the treatment which is more noticeable in the case of the trilayer film. Analysis of the experimental results leads us to conclude that the variations of the exchange field after heat treatment are likely caused by a modification of interfacial roughness and/or interfacial magnetic structure, but unlikely by the changes in the microstructure and/or changes of composition of the antiferromagnetic FeMn layer. - Highlights: • FeNi/FeMn bilayers and FeNi/FeMn/FeNi trilayers were prepared by magnetron sputtering. • Post-deposition heat treatments at the temperatures below 200 °C during 5 min were made. • Annealing reduces the exchange field for the first FeNi layer in trilayers. • The exchange field value for the second FeNi layer was not substantially changed. • Exchange field changes are most likely caused by a modification of interface roughness.

  20. Exchange Options

    NARCIS (Netherlands)

    Jamshidian, F.

    2007-01-01

    The contract is described and market examples given. Essential theoretical developments are introduced and cited chronologically. The principles and techniques of hedging and unique pricing are illustrated for the two simplest nontrivial examples: the classical Black-Scholes/Merton/Margrabe exchange