WorldWideScience

Sample records for internal ph dynamics

  1. Biomedical PhD education - an international perspective

    DEFF Research Database (Denmark)

    Mulvany, Michael J.

    2013-01-01

    The PhD, otherwise known as the doctor of philosophy or Dr. Phil., is an internationally recognized degree, indicating that the PhD graduate has received training in research under supervision. Traditionally, the PhD was the route to an academic career, with most successful PhD graduates receiving...... tenured university positions. However, over the past 20–30 years, and particularly the past 10 years, the situation has changed dramatically. Governments in many countries have invested massively in PhD education, believing that trained researchers will contribute to the ‘knowledge society’, and thus...... increase the competitiveness of their countries in the future economies of the world. Thus, only a small fraction of PhD graduates now end up in academic research. Yet, the PhD remains a research degree, and indeed, institutions have become heavily dependent on PhD students for their research output...

  2. Dynamic international oil markets

    International Nuclear Information System (INIS)

    van der Linde, C.

    1992-01-01

    Dynamic International Oil Market Developments and Structure 1860-1990 discusses the logic of changing market structures of the international oil industry. The market structures have, in the course of time, oscillated between competition and oligopoly, as the oil market expanded, matured, stagnated, and expanded again. This book provides a dynamic interpretation of the intensifying struggle among producer, and consumer governments, and oil companies, over the distribution of economic rents and profits. In particular, it shows the shifting fortunes of the governments and companies as they try to control the recurring capacity constraints between the upstream and downstream sectors, generated by the instability of the oil market. The first part of the book examines market conditions and developments between 1860 and 1990; the second part analyzes market structures after 1945

  3. Biomedical PhD education - an international perspective

    DEFF Research Database (Denmark)

    Mulvany, Michael J.

    2013-01-01

    tenured university positions. However, over the past 20–30 years, and particularly the past 10 years, the situation has changed dramatically. Governments in many countries have invested massively in PhD education, believing that trained researchers will contribute to the ‘knowledge society’, and thus...... during their PhD studies. The purpose of this article is to explore how this seeming paradox is being addressed in biomedicine and to show that far from being inconsistent that the two aspects are in fact complementary. The article is based on the author’s experience as Head of Aarhus Graduate School...... of Health Sciences 2002–2011 and his work with graduate schools across Europe and internationally through the organization ORPHEUS....

  4. Strategies for Enhancing Nonlinear Internal Model Control of pH Processes

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Qiuping.; Rangaiah, G.P. [The National University of Singapore, Singapore (Singapore). Dept. of Chemical and Environmental Engineering

    1999-02-01

    Control of neutralization processes is very difficult due to nonlinear dynamics, different types of disturbances and modeling errors. The objective of the paper is to evaluate two strategies (augmented internal model control, AuIMC and adaptive internal model control, AdIMC) for enhancing pH control by nonlinear internal model control (NIMC). A NIMC controller is derived directly form input output linearization. The AuIMC is composed of NIMC and an additional loop through which the difference between the process and model outputs is fed back and added to the input of the controller. For the AdIMC, and adaptive law with two tuning parameters is proposed for estimating the unknown parameter. Both AuIMC and AdIMC are extensively tested via simulation for pH neutralization. The theoretical and simulation results show that both the proposed strategies can reduce the effect of modeling errors and disturbances, and thereby enhance the performance of NIMC for pH processes. (author)

  5. Dynamic regulation of gastric surface pH by luminal pH

    OpenAIRE

    Chu, Shaoyou; Tanaka, Shin; Kaunitz, Jonathan D.; Montrose, Marshall H.

    1999-01-01

    In vivo confocal imaging of the mucosal surface of rat stomach was used to measure pH noninvasively under the mucus gel layer while simultaneously imaging mucus gel thickness and tissue architecture. When tissue was superfused at pH 3, the 25 μm adjacent to the epithelial surface was relatively alkaline (pH 4.1 ± 0.1), and surface alkalinity was enhanced by topical dimethyl prostaglandin E2 (pH 4.8 ± 0.2). Luminal pH was changed from pH 3 to pH 5 to mimic the fasted-to-fed transition in intra...

  6. Constant pH Accelerated Molecular Dynamics Investigation of the pH Regulation Mechanism of Dinoflagellate Luciferase.

    Science.gov (United States)

    Donnan, Patrick H; Ngo, Phong D; Mansoorabadi, Steven O

    2018-01-23

    The bioluminescence reaction in dinoflagellates involves the oxidation of an open-chain tetrapyrrole by the enzyme dinoflagellate luciferase (LCF). The activity of LCF is tightly regulated by pH, where the enzyme is essentially inactive at pH ∼8 and optimally active at pH ∼6. Little is known about the mechanism of LCF or the structure of the active form of the enzyme, although it has been proposed that several intramolecularly conserved histidine residues in the N-terminal region are important for the pH regulation mechanism. Here, constant pH accelerated molecular dynamics was employed to gain insight into the conformational activation of LCF induced by acidification.

  7. Constant pH molecular dynamics of proteins in explicit solvent with proton tautomerism.

    Science.gov (United States)

    Goh, Garrett B; Hulbert, Benjamin S; Zhou, Huiqing; Brooks, Charles L

    2014-07-01

    pH is a ubiquitous regulator of biological activity, including protein-folding, protein-protein interactions, and enzymatic activity. Existing constant pH molecular dynamics (CPHMD) models that were developed to address questions related to the pH-dependent properties of proteins are largely based on implicit solvent models. However, implicit solvent models are known to underestimate the desolvation energy of buried charged residues, increasing the error associated with predictions that involve internal ionizable residue that are important in processes like hydrogen transport and electron transfer. Furthermore, discrete water and ions cannot be modeled in implicit solvent, which are important in systems like membrane proteins and ion channels. We report on an explicit solvent constant pH molecular dynamics framework based on multi-site λ-dynamics (CPHMD(MSλD)). In the CPHMD(MSλD) framework, we performed seamless alchemical transitions between protonation and tautomeric states using multi-site λ-dynamics, and designed novel biasing potentials to ensure that the physical end-states are predominantly sampled. We show that explicit solvent CPHMD(MSλD) simulations model realistic pH-dependent properties of proteins such as the Hen-Egg White Lysozyme (HEWL), binding domain of 2-oxoglutarate dehydrogenase (BBL) and N-terminal domain of ribosomal protein L9 (NTL9), and the pKa predictions are in excellent agreement with experimental values, with a RMSE ranging from 0.72 to 0.84 pKa units. With the recent development of the explicit solvent CPHMD(MSλD) framework for nucleic acids, accurate modeling of pH-dependent properties of both major class of biomolecules-proteins and nucleic acids is now possible. © 2013 Wiley Periodicals, Inc.

  8. Assessment of the suitability of Durafet-based sensors for pH measurement in dynamic estuarine environments

    Science.gov (United States)

    Gonski, Stephen F.; Cai, Wei-Jun; Ullman, William J.; Joesoef, Andrew; Main, Christopher R.; Pettay, D. Tye; Martz, Todd R.

    2018-01-01

    The suitability of the Honeywell Durafet to the measurement of pH in productive, high-fouling, and highly-turbid estuarine environments was investigated at the confluence of the Murderkill Estuary and Delaware Bay (Delaware, USA). Three different flow configurations of the SeapHOx sensor equipped with a Honeywell Durafet and its integrated internal (Ag/AgCl reference electrode containing a 4.5 M KCl gel liquid junction) and external (solid-state chloride ion selective electrode, Cl-ISE) reference electrodes were deployed for four periods between April 2015 and September 2016. In this environment, the Honeywell Durafet proved capable of making high-resolution and high-frequency pH measurements on the total scale between pH 6.8 and 8.4. Natural pH fluctuations of >1 pH unit were routinely captured over a range of timescales. The sensor pH collected between May and August 2016 using the most refined SeapHOx configuration exhibited good agreement with multiple sets of independently measured reference pH values. When deployed in conjunction with rigorous discrete sampling and calibration schemes, the sensor pH had a root-mean squared error ranging between 0.011 and 0.036 pH units across a wide range of salinity relative to both pHT calculated from measured dissolved inorganic carbon and total alkalinity and pHNBS measured with a glass electrode corrected to pHT at in situ conditions. The present work demonstrates the viability of the Honeywell Durafet to the measurement of pH to within the weather-level precision defined by the Global Ocean Acidification Observing Network (GOA-ON, ≤ 0.02 pH units) as a part of future estuarine CO2 chemistry studies undertaken in dynamic environments.

  9. Guidelines for dynamic international programs

    International Nuclear Information System (INIS)

    Gold, M.A.

    1993-01-01

    Matters of global concern-deforestation, global warming, biodiversity loss, sustainable development, fuelwood crises, watershed destruction, and large-scale flooding-frequently involve forests and natural resources. In the future, university students will enter a global setting that more than ever depends on a strong knowledge of international issues. USA land-grant universities are attempting to prepare students for this challenge by improving their international programs including forestry. To improve university programs, several factors will need to be addressed and are discussed, with examples, in this article: commitment of the faculty; program specialization; geographic specialization; reward systems for international contributions; international collaboration; recycled dollars within the university; active teaching programs; research; extention and outreach; language training; international faculty; travel grants; twinning relationships with sister institutions; selective in pursuit of international development assistance; and study centers. 6 refs

  10. Dynamics of International Business Research

    DEFF Research Database (Denmark)

    Kunz, Werner; Manning, Stephan; Pedersen, Torben

    2013-01-01

    This study examines the evolution of the field of international business (IB) research based on a relational cluster analysis of co-citations in the Journal of International Business Studies (JIBS) from 1982 to 2011. Particularly, we examine the changing role of theory in relation to empirical IB...... research. Based on a factor and network analysis, we identify distinct clusters of IB research and their relations over time. We show that the initial focus of IB research on issues of international expansion has shifted towards issues of governance and implementation. In this process, debates on foreign...... entry mode and culture have served as important integrating themes. At the same time, theory debates in IB have expanded from a narrow focus on explaining international expansion, to a rather heterogeneous conglomerate of approaches which have assisted increasingly differentiated empirical research. Our...

  11. Dynamics of fatty acid vesicles in response to pH stimuli

    DEFF Research Database (Denmark)

    Ikari, Keita; Sakuma, Yuka; Jimbo, Takehiro

    2015-01-01

    We investigate the dynamics of decanoic acid/decanoate (DA) vesicles in response to pH stimuli. Two types of dynamic processes induced by the micro injection of NaOH solutions are sequentially observed: deformations and topological transitions. In the deformation stage, DA vesicles show a series...

  12. Synthesis and photophysical properties of a novel terephthalic PH sensor based on internal charge transfer

    International Nuclear Information System (INIS)

    Miladinova, Polya M.

    2016-01-01

    A novel fluorescence sensing derivative of 2-aminodimethylterephthalate configured as a “fluorophore-receptor” system was synthesized and investigated. Due to the internal charge transfer, the designed fluorophore was able to act as a pH-probe via an “off-on” fluorescence sensing mechanism. The sensor activity toward protons as cations and hydroxide as anions in DMF was studied by monitoring the changes of the fluorescence intensity. Keywords: 2-aminoterephthalic derivative, ICT (internal charge transfer), pH sensor.

  13. International Students' Motivation to Pursue and Complete a Ph.D. in the U.S.

    Science.gov (United States)

    Zhou, Ji

    2015-01-01

    This study explores what motivates 19 international students to pursue a Ph.D. at a public research university in the U.S. and, more importantly, what motivates them to persist despite unsatisfying socialization. Based on value-expectancy achievement motivation theory, four motivations emerged: intrinsic interest in research, intrinsic interest in…

  14. Homogeneous plate based antibody internalization assay using pH sensor fluorescent dye.

    Science.gov (United States)

    Nath, Nidhi; Godat, Becky; Zimprich, Chad; Dwight, Stephen J; Corona, Cesear; McDougall, Mark; Urh, Marjeta

    2016-04-01

    Receptor-mediated antibody internalization is a key mechanism underlying several anti-cancer antibody therapeutics. Delivering highly toxic drugs to cancer cells, as in the case of antibody drug conjugates (ADCs), efficient removal of surface receptors from cancer cells and changing the pharmacokinetics profile of the antibody drugs are some of key ways that internalization impacts the therapeutic efficacy of the antibodies. Over the years, several techniques have been used to study antibody internalization including radiolabels, fluorescent microscopy, flow cytometry and cellular toxicity assays. While these methods allow analysis of internalization, they have limitations including a multistep process and limited throughput and are generally endpoint assays. Here, we present a new homogeneous method that enables time and concentration dependent measurements of antibody internalization. The method uses a new hydrophilic and bright pH sensor dye (pHAb dye), which is not fluorescent at neutral pH but becomes highly fluorescent at acidic pH. For receptor mediated antibody internalization studies, antibodies against receptors are conjugated with the pHAb dye and incubated with the cells expressing the receptors. Upon binding to the receptor, the dyes conjugated to the antibody are not fluorescent because of the neutral pH of the media, but upon internalization and trafficking into endosomal and lysosomal vesicles the pH drops and dyes become fluorescent. The enabling attributes of the pHAb dyes are the hydrophilic nature to minimize antibody aggregation and bright fluorescence at acidic pH which allows development of simple plate based assays using a fluorescent reader. Using two different therapeutic antibodies--Trastuzumab (anti-HER2) and Cetuximab (anti-EGFR)--we show labeling with pHAb dye using amine and thiol chemistries and impact of chemistry and dye to antibody ration on internalization. We finally present two new approaches using the pHAb dye, which will be

  15. Following the Dynamics of pH in Endosomes of Live Cells with SERS Nanosensors

    DEFF Research Database (Denmark)

    Kneipp, J.; Kneipp, Harald; Wittig, B.

    2010-01-01

    The surface enhanced Raman scattering (SERS) spectrum of a reporter molecule attached to gold or silver nanostructures, which is pH-sensitive, can deliver information on the local pH in the environment of the nanostructure. Here, we demonstrate the use of a mobile SERS nanosensor made from gold...... nanaoaggregates and 4-mercaptobenzoic acid (pMBA) attached as a reporter for monitoring changes in local pH of the cellular compartments of living NIH/3T3 cells. We show that SERS nanosensors enable the dynamics of local pH in individual live cells to be followed at subendosomal resolution in a timeline...

  16. Exploring the Internal Dynamics of Globular Clusters

    Science.gov (United States)

    Watkins, Laura L.; van der Marel, Roeland; Bellini, Andrea; Luetzgendorf, Nora; HSTPROMO Collaboration

    2018-01-01

    Exploring the Internal Dynamics of Globular ClustersThe formation histories and structural properties of globular clusters are imprinted on their internal dynamics. Energy equipartition results in velocity differences for stars of different mass, and leads to mass segregation, which results in different spatial distributions for stars of different mass. Intermediate-mass black holes significantly increase the velocity dispersions at the centres of clusters. By combining accurate measurements of their internal kinematics with state-of-the-art dynamical models, we can characterise both the velocity dispersion and mass profiles of clusters, tease apart the different effects, and understand how clusters may have formed and evolved.Using proper motions from the Hubble Space Telescope Proper Motion (HSTPROMO) Collaboration for a set of 22 Milky Way globular clusters, and our discrete dynamical modelling techniques designed to work with large, high-quality datasets, we are studying a variety of internal cluster properties. We will present the results of theoretical work on simulated clusters that demonstrates the efficacy of our approach, and preliminary results from application to real clusters.

  17. International Conference on Mathematical Fluid Dynamics

    CERN Document Server

    Suzuki, Yukihito

    2016-01-01

    This volume presents original papers ranging from an experimental study on cavitation jets to an up-to-date mathematical analysis of the Navier-Stokes equations for free boundary problems, reflecting topics featured at the International Conference on Mathematical Fluid Dynamics, Present and Future, held 11–14 November 2014 at Waseda University in Tokyo. The contributions address subjects in one- and two-phase fluid flows, including cavitation, liquid crystal flows, plasma flows, and blood flows. Written by internationally respected experts, these papers highlight the connections between mathematical, experimental, and computational fluid dynamics. The book is aimed at a wide readership in mathematics and engineering, including researchers and graduate students interested in mathematical fluid dynamics.

  18. Subtype-specific, bi-component inhibition of SK channels by low internal pH

    DEFF Research Database (Denmark)

    Peitersen, Torben; Jespersen, Thomas; Jorgensen, Nanna K

    2006-01-01

    The effects of low intracellular pH (pH(i) 6.4) on cloned small-conductance Ca2+-activated K+ channel currents of all three subtypes (SK1, SK2, and SK3) were investigated in HEK293 cells using the patch-clamp technique. In 400 nM internal Ca2+ [Ca2+]i, all subtypes were inhibited by pH(i) 6...

  19. Expanding the dynamic measurement range for polymeric nanoparticle pH sensors

    DEFF Research Database (Denmark)

    Sun, Honghao; Almdal, Kristoffer; Andresen, Thomas Lars

    2011-01-01

    Conventional optical nanoparticle pH sensors that are designed for ratiometric measurements in cells have been based on utilizing one sensor fluorophore and one reference fluorophore in each nanoparticle, which results in a relatively narrow dynamic measurement range. This results in substantial...

  20. International Conference on Dynamic Crack Propagation

    CERN Document Server

    1973-01-01

    The planning meeting for a conference on Dynamic Crack Propagation was held at M.LT. in February 1971 and attended by research workers from several industrial, governmental and academic organizations. It was felt that a more specialized meeting would provide a better opportunity for both U.S. and foreign researchers to exchange their ideas and views on dynamic fracture, a subject which is seldom emphasized in national or international fracture conferences. Dynamic crack propagation has been a concern to specialists in many fields: continuum mechanics, metallurgy, geology, polymer chemistry, orthopedics, applied mathematics, as well as structural design and testing. It impinges on a wide variety of problems such as rock breaking and earthquakes, pressure vessels and line pipes, comminution and the per­ formance of armament and ordnance, etc. Advances have been numerous, covering theories and experiments from both the microscopic and macro­ scopic points of view. Hence, the need for comparing the theoretical ...

  1. International Conference on Applications in Nonlinear Dynamics

    CERN Document Server

    Longhini, Patrick; Palacios, Antonio

    2017-01-01

    This book presents collaborative research works carried out by experimentalists and theorists around the world in the field of nonlinear dynamical systems. It provides a forum for applications of nonlinear systems while solving practical problems in science and engineering. Topics include: Applied Nonlinear Optics, Sensor, Radar & Communication Signal Processing, Nano Devices, Nonlinear Biomedical Applications, Circuits & Systems, Coupled Nonlinear Oscillator, Precision Timing Devices, Networks, and other contemporary topics in the general field of Nonlinear Science. This book provides a comprehensive report of the various research projects presented at the International Conference on Applications in Nonlinear Dynamics (ICAND 2016) held in Denver, Colorado, 2016. It can be a valuable tool for scientists and engineering interested in connecting ideas and methods in nonlinear dynamics with actual design, fabrication and implementation of engineering applications or devices.

  2. Factors Influencing the Degree Progress of International PhD Students from Africa: An Exploratory Study

    Directory of Open Access Journals (Sweden)

    Almoustapha Oumarou Soumana

    2017-05-01

    Full Text Available In recent decades some countries of the Middle East have offered facilities to attract international students to pursue their higher education within their higher education institutions. The purpose of this study is to understand the difficulties faced by these students while conducting their studies abroad, and in doing so, to broaden the awareness of the challenges they face to complete their research. The participants of this qualitative study are international PhD students studying at a Middle Eastern public university. The university has reported increasing enrollment of international students, particularly from Africa in the last few years. Data were collected using a set of semi-structured interviews that drew out information on critical incidents that characterized the kind of difficulties students had faced in their studies. The data collected was further analyzed using a qualitative software package, NVivo (QSR International, 11. Six main themes came out from the content analysis of the interviews, which are the role of the adviser, student features, funding issues, family engagement, research and psychological obstacles which provide a holistic picture of student perspectives on the factors that influence degree progress. While these students might have faced difficulties mentioned in existing literature, this study argues that the participants have indicated experiencing psychological obstacles that were not described in earlier studies, such as the state of mind they were in as a result of being worried for family members due to war or violence in their home countries, and drop in currency exchange rates and difficulties in acquiring money due to international sanctions imposed against their countries. This study provides important thoughts on the factors that impact the degree progress of international PhD students from Africa, while at the same time revealing a serious gap in the advisers’ role which can contribute to the

  3. Plasma internal inductance dynamics in a tokamak

    International Nuclear Information System (INIS)

    Romero, J.A.

    2010-01-01

    A lumped parameter model for tokamak plasma current and inductance time evolution as a function of plasma resistance, non-inductive current drive sources and boundary voltage or poloidal field coil current drive is presented. The model includes a novel formulation leading to exact equations for internal inductance and plasma current dynamics. Having in mind its application in a tokamak inductive control system, the model is expressed in state space form, the preferred choice for the design of control systems using modern control systems theory. The choice of system states allows many interesting physical quantities such as plasma current, inductance, magnetic energy, and resistive and inductive fluxes be made available as output equations. The model is derived from energy conservation theorem, and flux balance theorems, together with a first order approximation for flux diffusion dynamics. The validity of this approximation has been checked using experimental data from JET showing an excellent agreement.

  4. A Gold Nanoparticle Bio-Optical Transponder to Dynamically Monitor Intracellular pH.

    Science.gov (United States)

    Carnevale, Kate J F; Riskowski, Ryan A; Strouse, Geoffrey F

    2018-06-13

    A pH-sensitive bio-optical transponder (pH-BOT) capable of simultaneously reporting the timing of intracellular DNA cargo release from a gold nanoparticle (AuNP) and the evolving intracellular pH (pH i) during endosomal maturation is demonstrated. The pH-BOT is designed with a triple-dye-labeled duplex DNA appended to a 6.6 nm AuNP, utilizing pH-responsive fluorescein paired with DyLight405 as a surface energy transfer (SET) coupled dye pair to ratiometrically report the pH at and after cargo release. A non-SET-coupled dye, DyLight 700, is used to provide dynamic tracking throughout the experiment. The pH-BOT beacon of the cargo uptake, release, and processing was visualized using live-cell confocal fluorescent microscopy in Chinese hamster ovary cells, and it was observed that while maturation of endosomes carrying pH-BOT is slowed significantly, the pH-BOT is distributed throughout the endolysosomal system while remaining at pH ∼6. This observed decoupling of endosomal maturation from acidification lends support to those models that propose that pH alone is not sufficient to explain endosomal maturation and may enable greater insight into our understanding of the fundamental processes of biology.

  5. Charge-Neutral Constant pH Molecular Dynamics Simulations Using a Parsimonious Proton Buffer.

    Science.gov (United States)

    Donnini, Serena; Ullmann, R Thomas; Groenhof, Gerrit; Grubmüller, Helmut

    2016-03-08

    In constant pH molecular dynamics simulations, the protonation states of titratable sites can respond to changes of the pH and of their electrostatic environment. Consequently, the number of protons bound to the biomolecule, and therefore the overall charge of the system, fluctuates during the simulation. To avoid artifacts associated with a non-neutral simulation system, we introduce an approach to maintain neutrality of the simulation box in constant pH molecular dynamics simulations, while maintaining an accurate description of all protonation fluctuations. Specifically, we introduce a proton buffer that, like a buffer in experiment, can exchange protons with the biomolecule enabling its charge to fluctuate. To keep the total charge of the system constant, the uptake and release of protons by the buffer are coupled to the titration of the biomolecule with a constraint. We find that, because the fluctuation of the total charge (number of protons) of a typical biomolecule is much smaller than the number of titratable sites of the biomolecule, the number of buffer sites required to maintain overall charge neutrality without compromising the charge fluctuations of the biomolecule, is typically much smaller than the number of titratable sites, implying markedly enhanced simulation and sampling efficiency.

  6. Dynamic Nucleolar Targeting of Dengue Virus Polymerase NS5 in Response to Extracellular pH

    Science.gov (United States)

    Fraser, Johanna E.; Rawlinson, Stephen M.; Heaton, Steven M.

    2016-01-01

    ABSTRACT The nucleolar subcompartment of the nucleus is increasingly recognized as an important target of RNA viruses. Here we document for the first time the ability of dengue virus (DENV) polymerase, nonstructural protein 5 (NS5), to accumulate within the nucleolus of infected cells and to target green fluorescent protein (GFP) to the nucleolus of live transfected cells. Intriguingly, NS5 exchange between the nucleus and nucleolus is dynamically modulated by extracellular pH, responding rapidly and reversibly to pH change, in contrast to GFP alone or other nucleolar and non-nucleolar targeted protein controls. The minimal pH-sensitive nucleolar targeting region (pHNTR), sufficient to target GFP to the nucleolus in a pH-sensitive fashion, was mapped to NS5 residues 1 to 244, with mutation of key hydrophobic residues, Leu-165, Leu-167, and Val-168, abolishing pHNTR function in NS5-transfected cells, and severely attenuating DENV growth in infected cells. This is the first report of a viral protein whose nucleolar targeting ability is rapidly modulated by extracellular stimuli, suggesting that DENV has the ability to detect and respond dynamically to the extracellular environment. IMPORTANCE Infections by dengue virus (DENV) threaten 40% of the world's population yet there is no approved vaccine or antiviral therapeutic to treat infections. Understanding the molecular details that govern effective viral replication is key for the development of novel antiviral strategies. Here, we describe for the first time dynamic trafficking of DENV nonstructural protein 5 (NS5) to the subnuclear compartment, the nucleolus. We demonstrate that NS5's targeting to the nucleolus occurs in response to acidic pH, identify the key amino acid residues within NS5 that are responsible, and demonstrate that their mutation severely impairs production of infectious DENV. Overall, this study identifies a unique subcellular trafficking event and suggests that DENV is able to detect and respond

  7. Glass and antimony electrodes for long-term pH monitoring: a dynamic in vitro comparison

    NARCIS (Netherlands)

    Geus, W. P.; Smout, A. J.; Kooiman, J. C.; Lamers, C. B.; Gues, J. W.

    1995-01-01

    OBJECTIVE: To compare the performance of combined glass microelectrodes with monocrystalline and polycrystalline antimony electrodes with external reference in a 24-h dynamic in vitro study. DESIGN AND METHODS: In an artificial stomach, the pH of the contents titrated from pH1-7 and back by NaOH and

  8. Dynamical Properties of Internal Shocks Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Pe’er, Asaf; Long, Killian [Physics Department, University College Cork, Cork (Ireland); Casella, Piergiorgio [INAF, Osservatorio Astronomico di Roma, Via Frascati 33, I-00078 Monteporzio Catone (Italy)

    2017-09-01

    Internal shocks between propagating plasma shells, originally ejected at different times with different velocities, are believed to play a major role in dissipating the kinetic energy, thereby explaining the observed light curves and spectra in a large range of transient objects. Even if initially the colliding plasmas are cold, following the first collision, the plasma shells are substantially heated, implying that in a scenario of multiple collisions, most collisions take place between plasmas of non-zero temperatures. Here, we calculate the dynamical properties of plasmas resulting from a collision between arbitrarily hot plasma shells, moving at arbitrary speeds. We provide simple analytical expressions valid for both ultrarelativistic and Newtonian velocities for both hot and cold plasmas. We derive the minimum criteria required for the formation of the two-shock wave system, and show that in the relativistic limit, the minimum Lorentz factor is proportional to the square root of the ratio of the initial plasmas enthalpies. We provide basic scaling laws of synchrotron emission from both the forward and reverse-shock waves, and show how these can be used to deduce the properties of the colliding shells. Finally, we discuss the implications of these results in the study of several astronomical transients, such as X-ray binaries, radio-loud quasars, and gamma-ray bursts.

  9. 8th International Workshop on Chiral Dynamics

    CERN Document Server

    2016-01-01

    The International Workshop on Chiral Dynamics 2015, the eighth in a series which started in 1994 at MIT, and was later held in Mainz (1997), Jefferson Lab (2000 and 2012), Bonn (2003), Duke (2006) and Bern (2009), will take place in Pisa, from June 29 to July 3 2015, and will be jointly hosted by the Department of Physics of the University of Pisa and the Pisa branch of the Istituto Nazionale di Fisica Nucleare. The purpose of this workshop series is to bring physicists together who are active in this field, as well as those who are interested, to discuss and debate the most recent achievements and future developments. The workshop will have a near equal contribution from theorists and experimentalists and, as in the latest editions, a strong synergy with the lattice community will be present. Topics: Hadron structure Isospin breaking in hadronic systems Meson-meson and meson-baryon interaction Effective field theory and chiral perturbation theory Few-body physics Compton scattering and the polarizabilities o...

  10. Polymeric nanosensors for measuring the full dynamic pH range of endosomes and lysosomes in mammalian cells

    DEFF Research Database (Denmark)

    Sun, Honghao; Andresen, Thomas Lars; Benjaminsen, Rikke Vicki

    2009-01-01

    Polymer nanoparticle sensors have been constructed for studying pH in the endocytic pathway in mammalian cells. The pH sensors for fluorescence ratiometric measurements were prepared using inverse microemulsion polymerization with rhodamine as reference fluorophor and fluorescein and oregon green...... was used to introduce a net positive charge in the cationic particles. It was found that the positively charged particle sensors were internalized spontaneously by HepG2 cancer cells. These new pH nanosensors are potential tools in time resolved quantification of pH in the endocytic pathway of living cells....

  11. Total internal reflection and dynamic light scattering microscopy of gels

    Science.gov (United States)

    Gregor, Brian F.

    Two different techniques which apply optical microscopy in novel ways to the study of biological systems and materials were built and applied to several samples. The first is a system for adapting the well-known technique of dynamic light scattering (DLS) to an optical microscope. This can detect and scatter light from very small volumes, as compared to standard DLS which studies light scattering from volumes 1000x larger. The small scattering volume also allows for the observation of nonergodic dynamics in appropriate samples. Porcine gastric mucin (PGM) forms a gel at low pH which lines the epithelial cell layer and acts as a protective barrier against the acidic stomach environment. The dynamics and microscopic viscosity of PGM at different pH levels is studied using polystyrene microspheres as tracer particles. The microscopic viscosity and microrheological properties of the commercial basement membrane Matrigel are also studied with this instrument. Matrigel is frequently used to culture cells and its properties remain poorly determined. Well-characterized and purely synthetic Matrigel substitutes will need to have the correct rheological and morphological characteristics. The second instrument designed and built is a microscope which uses an interferometry technique to achieve an improvement in resolution 2.5x better in one dimension than the Abbe diffraction limit. The technique is based upon the interference of the evanescent field generated on the surface of a prism by a laser in a total internal reflection geometry. The enhanced resolution is demonstrated with fluorescent samples. Additionally. Raman imaging microscopy is demonstrated using the evanescent field in resonant and non-resonant samples, although attempts at applying the enhanced resolution technique to the Raman images were ultimately unsuccessful. Applications of this instrument include high resolution imaging of cell membranes and macroscopic structures in gels and proteins. Finally, a third

  12. A dynamic balanced scorecard for identification internal process factor

    Directory of Open Access Journals (Sweden)

    Javad sofiyabadi

    2012-08-01

    Full Text Available We present a dynamic balanced score card (BSC to investigate the strategic internal process management factors. The proposed dynamic BSC emphasizes on internal processes aspect, and using VIKOR and Shannon Entropy, determinants the internal processes, process management and improvement and all important factors are ranked. The current study first introduces dynamic BSC and examines effective factors on the process. The proposed model focuses on internal processes perspective of BSC and determines importance degree of each factor is used using VIKOR decision-making techniques.

  13. Limitations in the use of low pH extraction to distinguish internalized from cell surface-bound radiolabeled antibody

    International Nuclear Information System (INIS)

    Ong, Gaik Lin; Mattes, M. Jules

    2000-01-01

    Internalization by cells of radiolabeled protein ligands bound to the cell surface is frequently analyzed by extraction of the cells with low pH buffers. This treatment supposedly strips the ligands from the cell surface, and remaining molecules are considered to be internalized. However, we show herein that: (1) low molecular weight catabolic products that are trapped within lysosomes (residualizing radiolabels) are efficiently extracted by low pH buffers, under the same conditions used to remove cell surface-bound material, and (2) low pH treatment lyses the majority of the cells, as shown with both a nonadherent and an adherent cell line, with the release of most of a 51 Cr label. Still, low pH extraction was effective at demonstrating Ab internalization, as has been demonstrated many times. These effects of low pH treatment may be attributed to the fixative properties of these buffers. Regardless of the mechanism, these data must be taken into consideration in interpreting the results of such experiments

  14. Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique.

    Science.gov (United States)

    Khan, Md Rajibur Rahaman; Kang, Shin-Won

    2016-11-09

    In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal's pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R² is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD) of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry-Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors.

  15. Searching for "A Third Space": A Creative Pathway towards International PhD Students' Academic Acculturation

    Science.gov (United States)

    Elliot, Dely Lazarte; Baumfield, Vivienne; Reid, Kate

    2016-01-01

    Undertaking a PhD is a challenging endeavour. Pursuing a doctoral education in a "foreign" context tends to increase the demands of this intellectual venture. The nature of research-based PhD programmes, often characterised by a lack of formal curricula where academic supervision lasts several years, may add another layer of complexity.…

  16. Evolution of pH in a radwaste repository: internal reactions between concrete constituents

    International Nuclear Information System (INIS)

    Atkinson, A.; Everitt, N.M.; Guppy, R.M.

    1988-01-01

    The pH is an important characteristic of the chemical conditions within a radioactive waste repository. A high pH is particularly beneficial from a variety of points of view and this can be assured by the use of cementitious materials within the repository. Reactions between repository components which have an influence on pH have been studied in accelerated laboratory experiments. The reactions studied were those occurring in modified cements (specifically 90% pulverized fly ash/10% ordinary Portland cement and 90% blast furnace slag/10% OPC) and between aqueous calcium hydroxide and both crystalline and amorphous SiO 2 . The experiments indicate that extensive use of fuel ash leads to uncertainty in long term pH which could be as low as 9 to 10 in such cases. Experiments with crystalline calcium silicon hydrate (CSH) minerals suggest that crystallization of amorphous CSH could also lead to pH being lower than the optimum. (author)

  17. Effect of pH on the hinge region of influenza viral protein: a combined constant pH and well-tempered molecular dynamics study

    Science.gov (United States)

    Pathak, Arup Kumar

    2018-05-01

    Despite the knowledge that the influenza protein, hemagglutinin, undergoes a large conformational change at low pH during the process of fusion with the host cell, its molecular mechanism remains elusive. The present constant pH molecular dynamics (CpHMD) study identifies the residues responsible for large conformational change in acidic condition. Based on the pKa calculations, it is predicted that His-106 is much more responsible for the large conformational change than any other residues in the hinge region of hemagglutinin protein. Potential of mean force profile from well-tempered meta-dynamics (WT-MtD) simulation is also generated along the folding pathway by considering radius of gyration (R gyr) as a collective variable (CV). It is very clear from the present WT-MtD study, that the initial bending starts at that hinge region, which may trigger other conformational changes. Both the protein–protein and protein–water HB time correlation functions are monitored along the folding pathway. The protein–protein (full or hinge region) HB time correlation functions are always found to be stronger than those of the protein–water time correlation functions. The dynamical balance between protein–protein and protein–water HB interactions favors the stabilization of the folded state.

  18. Dynamic patterns and ecological impacts of declining ocean pH in a high-resolution multi-year dataset.

    Science.gov (United States)

    Wootton, J Timothy; Pfister, Catherine A; Forester, James D

    2008-12-02

    Increasing global concentrations of atmospheric CO(2) are predicted to decrease ocean pH, with potentially severe impacts on marine food webs, but empirical data documenting ocean pH over time are limited. In a high-resolution dataset spanning 8 years, pH at a north-temperate coastal site declined with increasing atmospheric CO(2) levels and varied substantially in response to biological processes and physical conditions that fluctuate over multiple time scales. Applying a method to link environmental change to species dynamics via multispecies Markov chain models reveals strong links between in situ benthic species dynamics and variation in ocean pH, with calcareous species generally performing more poorly than noncalcareous species in years with low pH. The models project the long-term consequences of these dynamic changes, which predict substantial shifts in the species dominating the habitat as a consequence of both direct effects of reduced calcification and indirect effects arising from the web of species interactions. Our results indicate that pH decline is proceeding at a more rapid rate than previously predicted in some areas, and that this decline has ecological consequences for near shore benthic ecosystems.

  19. The Road to Become a Legitimate Scholar: A Case Study of International PhD Students in Science and Engineering

    Directory of Open Access Journals (Sweden)

    Pia Bøgelund

    2015-11-01

    Full Text Available The purpose of the doctoral education process is to create and legitimize scholarly researchers. This transformation, from student to scholar, is widely discussed in the literature. However, recent rapid changes in university culture have resulted in less time for supervision, stricter completion deadlines, and a greater focus on efficiency and productivity. This has had an impact on this transition process, and this impact has not been widely studied. The aim of this article is to understand the consequences of the current trends for PhD students and the education of PhD students in general. The article is based on interviews with 14 international students from two different research programs at the Faculty of Engineering and Science at Aalborg University in Denmark. The case of international PhD students in a western setting is singled out as a challenging case for becoming a legitimate scholar, since they face the additional challenge of becoming socialised into their new foreign setting. Overall, the study concludes that the transition process of doctoral students is affected by the way different supervisors deal with current university trends and how PhD students fit or do not fit into their knowledge production practices. The study identifies matches or mismatches in a knowledge production perspective, quality of contact, and degree of independence of the PhD student as factors that influence whether a transition process can be marked as sound, troublesome, or lacking. Finally, the study identifies an overall risk of neglecting the more interdependent types of international PhD students. Suggestions are given as how to address this risk.

  20. International Conference on Dynamical Systems : Theory and Applications

    CERN Document Server

    2016-01-01

    The book is a collection of contributions devoted to analytical, numerical and experimental techniques of dynamical systems, presented at the international conference "Dynamical Systems: Theory and Applications," held in Lódz, Poland on December 7-10, 2015. The studies give deep insight into new perspectives in analysis, simulation, and optimization of dynamical systems, emphasizing directions for future research. Broadly outlined topics covered include: bifurcation and chaos in dynamical systems, asymptotic methods in nonlinear dynamics, dynamics in life sciences and bioengineering, original numerical methods of vibration analysis, control in dynamical systems, stability of dynamical systems, vibrations of lumped and continuous sytems, non-smooth systems, engineering systems and differential equations, mathematical approaches to dynamical systems, and mechatronics.

  1. International Conference on Dynamical Systems : Theory and Applications

    CERN Document Server

    2016-01-01

    The book is the second volume of a collection of contributions devoted to analytical, numerical and experimental techniques of dynamical systems, presented at the international conference "Dynamical Systems: Theory and Applications," held in Lódz, Poland on December 7-10, 2015. The studies give deep insight into new perspectives in analysis, simulation, and optimization of dynamical systems, emphasizing directions for future research. Broadly outlined topics covered include: bifurcation and chaos in dynamical systems, asymptotic methods in nonlinear dynamics, dynamics in life sciences and bioengineering, original numerical methods of vibration analysis, control in dynamical systems, stability of dynamical systems, vibrations of lumped and continuous sytems, non-smooth systems, engineering systems and differential equations, mathematical approaches to dynamical systems, and mechatronics.

  2. NASA plan for international crustal dynamics studies

    Science.gov (United States)

    1979-01-01

    The international activities being planned as part of the NASA geodynamics program are described. Methods of studying the Earth's crustal movements and deformation characteristics are discussed. The significance of the eventual formalations of earthquake predictions methods is also discussed.

  3. Internal Mass Motion for Spacecraft Dynamics and Control

    National Research Council Canada - National Science Library

    Hall, Christopher D

    2008-01-01

    We present a detailed description of the application of a noncanonical Hamiltonian formulation to the modeling, analysis, and simulation of the dynamics of gyrostat spacecraft with internal mass motion...

  4. 9th IFToMM International Conference on Rotor Dynamics

    CERN Document Server

    2015-01-01

    This book presents the proceedings of the 9th IFToMM International Conference on Rotor Dynamics. This conference is a premier global event that brings together specialists from the university and industry sectors worldwide in order to promote the exchange of knowledge, ideas, and information on the latest developments and applied technologies in the dynamics of rotating machinery. The coverage is wide ranging, including, for example, new ideas and trends in various aspects of bearing technologies, issues in the analysis of blade dynamic behavior,  condition monitoring of different rotating machines, vibration control, electromechanical and fluid-structure interactions in rotating machinery, rotor dynamics of micro, nano, and cryogenic machines, and applications of rotor dynamics in transportation engineering. Since its inception 32 years ago, the IFToMM International Conference on Rotor Dynamics has become an irreplaceable point of reference for those working in the field, and this book reflects the high qua...

  5. Effects of system net charge and electrostatic truncation on all-atom constant pH molecular dynamics

    Science.gov (United States)

    Chen, Wei; Shen, Jana K.

    2014-01-01

    Constant pH molecular dynamics offers a means to rigorously study the effects of solution pH on dynamical processes. Here we address two critical questions arising from the most recent developments of the all-atom continuous constant pH molecular dynamics (CpHMD) method: 1) What is the effect of spatial electrostatic truncation on the sampling of protonation states? 2) Is the enforcement of electrical neutrality necessary for constant pH simulations? We first examined how the generalized reaction field and force shifting schemes modify the electrostatic forces on the titration coordinates. Free energy simulations of model compounds were then carried out to delineate the errors in the deprotonation free energy and salt-bridge stability due to electrostatic truncation and system net charge. Finally, CpHMD titration of a mini-protein HP36 was used to understand the manifestation of the two types of errors in the calculated pK a values. The major finding is that enforcing charge neutrality under all pH conditions and at all time via co-titrating ions significantly improves the accuracy of protonation-state sampling. We suggest that such finding is also relevant for simulations with particle-mesh Ewald, considering the known artifacts due to charge-compensating background plasma. PMID:25142416

  6. Effects of system net charge and electrostatic truncation on all-atom constant pH molecular dynamics.

    Science.gov (United States)

    Chen, Wei; Shen, Jana K

    2014-10-15

    Constant pH molecular dynamics offers a means to rigorously study the effects of solution pH on dynamical processes. Here, we address two critical questions arising from the most recent developments of the all-atom continuous constant pH molecular dynamics (CpHMD) method: (1) What is the effect of spatial electrostatic truncation on the sampling of protonation states? (2) Is the enforcement of electrical neutrality necessary for constant pH simulations? We first examined how the generalized reaction field and force-shifting schemes modify the electrostatic forces on the titration coordinates. Free energy simulations of model compounds were then carried out to delineate the errors in the deprotonation free energy and salt-bridge stability due to electrostatic truncation and system net charge. Finally, CpHMD titration of a mini-protein HP36 was used to understand the manifestation of the two types of errors in the calculated pK(a) values. The major finding is that enforcing charge neutrality under all pH conditions and at all time via cotitrating ions significantly improves the accuracy of protonation-state sampling. We suggest that such finding is also relevant for simulations with particle mesh Ewald, considering the known artifacts due to charge-compensating background plasma. Copyright © 2014 Wiley Periodicals, Inc.

  7. XXIII International Conference on Nonlinear Dynamics of Electronic Systems

    CERN Document Server

    Stoop, Ruedi; Stramaglia, Sebastiano

    2017-01-01

    This book collects contributions to the XXIII international conference “Nonlinear dynamics of electronic systems”. Topics range from non-linearity in electronic circuits to synchronisation effects in complex networks to biological systems, neural dynamics and the complex organisation of the brain. Resting on a solid mathematical basis, these investigations address highly interdisciplinary problems in physics, engineering, biology and biochemistry.

  8. Dynamics in international market segmentation of new product growth

    NARCIS (Netherlands)

    Lemmens, A.; Croux, C.; Stremersch, S.

    2012-01-01

    Prior international segmentation studies have been static in that they have identified segments that remain stable over time. This paper shows that country segments in new product growth are intrinsically dynamic. We propose a semiparametric hidden Markov model to dynamically segment countries based

  9. International guidelines for the in vivo assessment of skin properties in non-clinical settings: part 1. pH

    Science.gov (United States)

    Stefaniak, Aleksandr B; du Plessis, Johan; John, Swen M; Eloff, Fritz; Agner, Tove; Chou, Tzu-Chieh; Nixon, Rosemary; Steiner, Markus F C; Kudla, Irena; Holness, D Linn

    2013-01-01

    Background Skin surface pH is known to influence the dissolution and partitioning of chemicals and may influence exposures that lead to skin diseases. Non-clinical environments (e.g. workplaces) are highly variable, thereby presenting unique measurement challenges that are not typically encountered in clinical settings. Hence, guidelines are needed for consistent measurement of skin surface pH in environments that are difficult to control. Methods An expert workshop was convened at the 5th International Conference on Occupational and Environmental Exposure of Skin to Chemicals to review available data on factors that could influence the determination of skin surface pH in non-clinical settings with emphasis on the workplace as a worst case scenario. Results The key elements of the guidelines are: (i) minimize, to the extent feasible, the influences of relevant endogenous (anatomical position, skin health, time of day), exogenous (hand washing, barrier creams, soaps and detergents, occlusion), environmental (seasonality), and measurement (atmospheric conditions) factors; (ii) report pH measurements results as a difference or percent change (not absolute values) using a measure of central tendency and variability; and (iii) report notable deviations from these guidelines and other relevant factors that may influence measurements. Conclusion Guidelines on the measurement and reporting of skin surface pH in non-clinical settings should promote consistency in data reporting, facilitate inter-comparison of study results, and aid in understanding and preventing occupational skin diseases. PMID:23279097

  10. Measurement of the internal pH of mast cell granules using microvolumetric fluorescence and isotopic techniques

    International Nuclear Information System (INIS)

    De Young, M.B.; Nemeth, E.F.; Scarpa, A.

    1987-01-01

    The intragranular pH of isolated mast cell granules was measured. Because of the minute amounts of isolated granules available, two techniques were developed by modifying aminoacridine fluorescence and [ 14 C]methylamine accumulation techniques to permit measurements with microliter sample volumes. Granule purity was demonstrated by electron microscopy, ruthenium red exclusion, and biochemical (histamine, mast cell granule protease) analysis. The internal pH was determined to be 5.55 +/- 0.06, indicating that the pH environment within mast cell granules is not significantly different from that of previously studied granule types (i.e., chromaffin, platelet, pancreatic islet, and pituitary granules). Collapse of the pH gradient by NH+4 was demonstrated with both techniques. No evidence of Cl-/OH- or specific cation/H+ transport was found, and major chloride permeability could not be unequivocably demonstrated. Ca 2+ and Cl- at concentrations normally present extracellularly destabilized granules in the presence of NH+4, but this phenomenon does not necessarily indicate a role for these ions in the exocytotic release of granule contents from intact cells. The pH measurement techniques developed for investigating the properties of granules in mast cells may be useful for studying other granules that can be obtained only in limited quantities

  11. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system

    Science.gov (United States)

    Raimondo, Joseph V.; Joyce, Bradley; Kay, Louise; Schlagheck, Theresa; Newey, Sarah E.; Srinivas, Shankar; Akerman, Colin J.

    2013-01-01

    Within the nervous system, intracellular Cl− and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission, and network excitability. Cl− and pH are often co-regulated, and network activity results in the movement of both Cl− and H+. Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl− and pH sensors have been described previously, these either lack ion specificity or are unsuitable for neuronal use. Here we present ClopHensorN—a new genetically-encoded ratiometric Cl− and pH sensor that is optimized for the nervous system. We demonstrate the ability of ClopHensorN to dissociate and simultaneously quantify Cl− and H+ concentrations under a variety of conditions. In addition, we establish the sensor's utility by characterizing activity-dependent ion dynamics in hippocampal neurons. PMID:24312004

  12. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system.

    Science.gov (United States)

    Raimondo, Joseph V; Joyce, Bradley; Kay, Louise; Schlagheck, Theresa; Newey, Sarah E; Srinivas, Shankar; Akerman, Colin J

    2013-01-01

    Within the nervous system, intracellular Cl(-) and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission, and network excitability. Cl(-) and pH are often co-regulated, and network activity results in the movement of both Cl(-) and H(+). Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl(-) and pH sensors have been described previously, these either lack ion specificity or are unsuitable for neuronal use. Here we present ClopHensorN-a new genetically-encoded ratiometric Cl(-) and pH sensor that is optimized for the nervous system. We demonstrate the ability of ClopHensorN to dissociate and simultaneously quantify Cl(-) and H(+) concentrations under a variety of conditions. In addition, we establish the sensor's utility by characterizing activity-dependent ion dynamics in hippocampal neurons.

  13. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system

    Directory of Open Access Journals (Sweden)

    Joseph Valentino Raimondo

    2013-11-01

    Full Text Available Within the nervous system, intracellular Cl- and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission and network excitability. Cl- and pH are often co-regulated, and network activity results in the movement of both Cl- and H+. Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl- and pH sensors have been described previously, these either lack ion specificity or are unsuitable for neuronal use. Here we present ClopHensorN - a new genetically-encoded ratiometric Cl- and pH sensor that is optimized for the nervous system. We demonstrate the ability of ClopHensorN to dissociate and simultaneously quantify Cl- and H+ concentrations under a variety of conditions. In addition, we establish the sensor’s utility by characterizing activity-dependent ion dynamics in hippocampal neurons.

  14. [Internal migration trends and regional dynamics].

    Science.gov (United States)

    Trabelsi, M

    1992-01-01

    This study concerns aspects of regional development in Tunisia. It specifically considers how economic factors affect income differentials among regions, and ways in which these in turn influence trends in internal migration. The effect of these trends on urbanization is also explored.

  15. Gender and Internal Migration dynamics in Ghana

    African Journals Online (AJOL)

    Agribotix GCS 068

    Internal migration is an inherent part of the processes of development and structural ... to rural-urban migrants by Government policies and strategies to enhance the ... Several studies globally indicate that migration is a driver of growth and an .... More recent approaches of networks theories and transnational approaches to ...

  16. Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique

    Science.gov (United States)

    Khan, Md. Rajibur Rahaman; Kang, Shin-Won

    2016-01-01

    In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal’s pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R2 is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD) of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry–Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors. PMID:27834865

  17. The experience of international nursing students studying for a PhD in the U.K: A qualitative study.

    Science.gov (United States)

    Evans, Catrin; Stevenson, Keith

    2011-06-13

    Educating nurses to doctoral level is an important means of developing nursing capacity globally. There is an international shortage of doctoral nursing programmes, hence many nurses seek their doctorates overseas. The UK is a key provider of doctoral education for international nursing students, however, very little is known about international doctoral nursing students' learning experiences during their doctoral study. This paper reports on a national study that sought to investigate the learning expectations and experiences of overseas doctoral nursing students in the UK. Semi-structured qualitative interviews were conducted in 2008/09 with 17 international doctoral nursing students representing 9 different countries from 6 different UK universities. Data were analysed thematically. All 17 interviewees were enrolled on 'traditional' 3 year PhD programmes and the majority (15/17) planned to work in higher education institutions back in their home country upon graduation. Studying for a UK PhD involved a number of significant transitions, including adjusting to a new country/culture, to new pedagogical approaches and, in some cases, to learning in a second language. Many students had expected a more structured programme of study, with a stronger emphasis on professional nursing issues as well as research - akin to the professional doctorate. Students did not always feel well integrated into their department's wider research environment, and wanted more opportunities to network with their UK peers. A good supervision relationship was perceived as the most critical element of support in a doctoral programme, but good relationships were sometimes difficult to attain due to differences in student/supervisor expectations and in approaches to supervision. The PhD was perceived as a difficult and stressful journey, but those nearing the end reflected positively on it as a life changing experience in which they had developed key professional and personal skills. Doctoral

  18. The experience of international nursing students studying for a PhD in the U.K: A qualitative study

    Directory of Open Access Journals (Sweden)

    Stevenson Keith

    2011-06-01

    Full Text Available Abstract Background Educating nurses to doctoral level is an important means of developing nursing capacity globally. There is an international shortage of doctoral nursing programmes, hence many nurses seek their doctorates overseas. The UK is a key provider of doctoral education for international nursing students, however, very little is known about international doctoral nursing students' learning experiences during their doctoral study. This paper reports on a national study that sought to investigate the learning expectations and experiences of overseas doctoral nursing students in the UK. Methods Semi-structured qualitative interviews were conducted in 2008/09 with 17 international doctoral nursing students representing 9 different countries from 6 different UK universities. Data were analysed thematically. All 17 interviewees were enrolled on 'traditional' 3 year PhD programmes and the majority (15/17 planned to work in higher education institutions back in their home country upon graduation. Results Studying for a UK PhD involved a number of significant transitions, including adjusting to a new country/culture, to new pedagogical approaches and, in some cases, to learning in a second language. Many students had expected a more structured programme of study, with a stronger emphasis on professional nursing issues as well as research - akin to the professional doctorate. Students did not always feel well integrated into their department's wider research environment, and wanted more opportunities to network with their UK peers. A good supervision relationship was perceived as the most critical element of support in a doctoral programme, but good relationships were sometimes difficult to attain due to differences in student/supervisor expectations and in approaches to supervision. The PhD was perceived as a difficult and stressful journey, but those nearing the end reflected positively on it as a life changing experience in which they had

  19. Neutron Imaging Reveals Internal Plant Hydraulic Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Jeffrey [ORNL; Bilheux, Hassina Z [ORNL; Kang, Misun [ORNL; Voisin, Sophie [ORNL; Cheng, Chu-Lin [ORNL; Horita, Jusuke [ORNL; Perfect, Edmund [ORNL

    2013-01-01

    Many terrestrial ecosystem processes are constrained by water availability and transport within the soil. Knowledge of plant water fluxes is thus critical for assessing mechanistic processes linked to biogeochemical cycles, yet resolution of root structure and xylem water transport dynamics has been a particularly daunting task for the ecologist. Through neutron imaging, we demonstrate the ability to non-invasively monitor individual root functionality and water fluxes within Zea mays L. (maize) and Panicum virgatum L. (switchgrass) seedlings growing in a sandy medium. Root structure and growth were readily imaged by neutron radiography and neutron computed tomography. Seedlings were irrigated with water or deuterium oxide and imaged through time as a growth lamp was cycled on to alter leaf demand for water. Sub-millimeter scale resolution reveals timing and magnitudes of root water uptake, redistribution within the roots, and root-shoot hydraulic linkages, relationships not well characterized by other techniques.

  20. Impact of biogeochemical processes on pH dynamics in marine systems

    NARCIS (Netherlands)

    Hagens, Mathilde

    2015-01-01

    Uptake of anthropogenic carbon dioxide (CO2) from the atmosphere has resulted in a range of changes in ocean chemistry, including the lowering of pH, collectively referred to as ocean acidification. Rates of coastal-zone acidification exceed those of the open ocean since coastal-ocean pH is

  1. Effects of Reduced pH on Macoma balthica Larvae from a System with Naturally Fluctuating pH-Dynamics.

    Directory of Open Access Journals (Sweden)

    Anna Jansson

    Full Text Available Ocean acidification is causing severe changes in the inorganic carbon balance of the oceans. The pH conditions predicted for the future oceans are, however, already regularly occurring in the Baltic Sea, and the system might thus work as an analogue for future ocean acidification scenarios. The characteristics of the Baltic Sea with low buffering capacity and large natural pH fluctuations, in combination with multiple other stressors, suggest that OA effects may be severe, but remain largely unexplored. A calcifying species potentially affected by low pH conditions is the bivalve Macoma balthica (L.. We investigated larval survival and development of M. balthica by exposing the larvae to a range of pH levels: 7.2, 7.4, 7.7 and 8.1 during 20 days in order to learn what the effects of reduced pH are on the larval biology and thus also potentially for the population dynamics of this key species. We found that even a slight pH decrease causes significant negative changes during the larval phase, both by slowing growth and by decreasing survival. The growth was slower in all reduced pH treatments compared to the control treatment. The size of 250 µm that is considered indicative to imminent settling in our system was reached by 22% of the larvae grown in control conditions after 20 days, whereas in all reduced pH treatments the size of 250 µm was reached by only 7-14%. The strong impact of ocean acidification on larvae is alarming as slowly growing individuals are exposed to higher predation risk in response to the longer time they are required to spend in the plankton, further decreasing the ecological competence of the species.

  2. 4th International Conference on Structural Nonlinear Dynamics and Diagnosis

    CERN Document Server

    2018-01-01

    This book presents contributions on the most active lines of recent advanced research in the field of nonlinear mechanics and physics selected from the 4th International Conference on Structural Nonlinear Dynamics and Diagnosis. It includes fifteen chapters by outstanding scientists, covering various aspects of applications, including road tanker dynamics and stability, simulation of abrasive wear, energy harvesting, modeling and analysis of flexoelectric nanoactuator, periodic Fermi–Pasta–Ulam problems, nonlinear stability in Hamiltonian systems, nonlinear dynamics of rotating composites, nonlinear vibrations of a shallow arch, extreme pulse dynamics in mode-locked lasers, localized structures in a photonic crystal fiber resonator, nonlinear stochastic dynamics, linearization of nonlinear resonances, treatment of a linear delay differential equation, and fractional nonlinear damping. It appeals to a wide range of experts in the field of structural nonlinear dynamics and offers researchers and engineers a...

  3. Effect of pH on the adsorption of dodecylamine on montmorillonite: Insights from experiments and molecular dynamics simulations

    Science.gov (United States)

    Peng, Chenliang; Min, Fanfei; Liu, Lingyun

    2017-12-01

    The hydrophobic aggregation in cationic surfactant suspension is an effective method to enhance the dewatering of clay-rich tailing. The solution pH can affect the adsorption behavior of cationic surfactant on clay mineral. The effect of pH on the adsorption of dodecylamine (DDA) on montmorillonite was investigated by the sedimentation test and the characterization of flocs images, contact angle, adsorption quantity, and fourier transform infrared (FTIR) spectroscopy, as well as molecular dynamics (MD) simulation. It was found that DDA ions were adsorbed on montmorillonite basal surfaces mainly by physical adsorption, including the electrostatic attraction and hydrogen bonding. A certain number of neutral DDA molecules can favor the adsorption of DDA. At pH around 8, the effect of hydrophobic modification was the best because DDA molecules and ions form compact and well-organized monolayer. The MD simulation results were in good agreement with that of contact angle, adsorption quantity and FTIR.

  4. Are international fund flows related to exchange rate dynamics?

    NARCIS (Netherlands)

    Li, Suxiao; de Haan, Jakob; Scholtens, Bert

    2018-01-01

    Employing monthly data for 53 countries between 1996 and 2015, we investigate the relationship between international fund flows and exchange rate dynamics. We find strong co-movement between funds flows (as measured with the EPFR Global data base) and bilateral real exchange rates vis-à-vis the USD.

  5. Dynamics of Receptor-Mediated Nanoparticle Internalization into Endothelial Cells

    Science.gov (United States)

    Gonzalez-Rodriguez, David; Barakat, Abdul I.

    2015-01-01

    Nanoparticles offer a promising medical tool for targeted drug delivery, for example to treat inflamed endothelial cells during the development of atherosclerosis. To inform the design of such therapeutic strategies, we develop a computational model of nanoparticle internalization into endothelial cells, where internalization is driven by receptor-ligand binding and limited by the deformation of the cell membrane and cytoplasm. We specifically consider the case of nanoparticles targeted against ICAM-1 receptors, of relevance for treating atherosclerosis. The model computes the kinetics of the internalization process, the dynamics of binding, and the distribution of stresses exerted between the nanoparticle and the cell membrane. The model predicts the existence of an optimal nanoparticle size for fastest internalization, consistent with experimental observations, as well as the role of bond characteristics, local cell mechanical properties, and external forces in the nanoparticle internalization process. PMID:25901833

  6. High-frequency dynamics of ocean pH: a multi-ecosystem comparison.

    Directory of Open Access Journals (Sweden)

    Gretchen E Hofmann

    Full Text Available The effect of Ocean Acidification (OA on marine biota is quasi-predictable at best. While perturbation studies, in the form of incubations under elevated pCO(2, reveal sensitivities and responses of individual species, one missing link in the OA story results from a chronic lack of pH data specific to a given species' natural habitat. Here, we present a compilation of continuous, high-resolution time series of upper ocean pH, collected using autonomous sensors, over a variety of ecosystems ranging from polar to tropical, open-ocean to coastal, kelp forest to coral reef. These observations reveal a continuum of month-long pH variability with standard deviations from 0.004 to 0.277 and ranges spanning 0.024 to 1.430 pH units. The nature of the observed variability was also highly site-dependent, with characteristic diel, semi-diurnal, and stochastic patterns of varying amplitudes. These biome-specific pH signatures disclose current levels of exposure to both high and low dissolved CO(2, often demonstrating that resident organisms are already experiencing pH regimes that are not predicted until 2100. Our data provide a first step toward crystallizing the biophysical link between environmental history of pH exposure and physiological resilience of marine organisms to fluctuations in seawater CO(2. Knowledge of this spatial and temporal variation in seawater chemistry allows us to improve the design of OA experiments: we can test organisms with a priori expectations of their tolerance guardrails, based on their natural range of exposure. Such hypothesis-testing will provide a deeper understanding of the effects of OA. Both intuitively simple to understand and powerfully informative, these and similar comparative time series can help guide management efforts to identify areas of marine habitat that can serve as refugia to acidification as well as areas that are particularly vulnerable to future ocean change.

  7. Symposium of the International Society of Dynamic Games

    CERN Document Server

    Haurie, Alain; Annals of the International Society of Dynamic Games

    1994-01-01

    Recent years have witnessed a surge of activity in the field of dynamic both theory and applications. Theoretical as well as practical games, in problems in zero-sum and nonzero-sum games, continuous time differential and discrete time multistage games, and deterministic and stochastic games games are currently being investigated by researchers in diverse disciplines, such as engineering, mathematics, biology, economics, management science, and political science. This surge of interest has led to the formation of the International Society of Dynamic Games (ISDG) in 1990, whose primary goal is to foster the development of advanced research and applications in the field of game theory. One important activity of the Society is to organize biannually an international symposium which aims at bringing together all those who contribute to the development of this active field of applied science. In 1992 the symposium was organized in Grimentz, Switzerland, under the supervision of an international scientific committe...

  8. Biobased, Internally pH-Sensitive Materials: Immobilized Yellow Fluorescent Protein as an Optical Sensor for Spatiotemporal Mapping of pH Inside Porous Matrices.

    Science.gov (United States)

    Consolati, Tanja; Bolivar, Juan M; Petrasek, Zdenek; Berenguer, Jose; Hidalgo, Aurelio; Guisán, Jose M; Nidetzky, Bernd

    2018-02-28

    The pH is fundamental to biological function and its measurement therefore crucial across all biosciences. Unlike homogenous bulk solution, solids often feature internal pH gradients due to partition effects and confined biochemical reactions. Thus, a full spatiotemporal mapping for pH characterization in solid materials with biological systems embedded in them is essential. In here, therefore, a fully biocompatible methodology for real-time optical sensing of pH within porous materials is presented. A genetically encoded ratiometric pH sensor, the enhanced superfolder yellow fluorescent protein (sYFP), is used to functionalize the internal surface of different materials, including natural and synthetic organic polymers as well as silica frameworks. By using controlled, tailor-made immobilization, sYFP is homogenously distributed within these materials and so enables, via self-referenced imaging analysis, pH measurements in high accuracy and with useful spatiotemporal resolution. Evolution of internal pH is monitored in consequence of a proton-releasing enzymatic reaction, the hydrolysis of penicillin by a penicillin acylase, taking place in solution or confined to the solid surface of the porous matrix. Unlike optochemical pH sensors, which often interfere with biological function, labeling with sYFP enables pH sensing without altering the immobilized enzyme's properties in any of the materials used. Fast response of sYFP to pH change permits evaluation of biochemical kinetics within the solid materials. Thus, pH sensing based on immobilized sYFP represents a broadly applicable technique to the study of biology confined to the internally heterogeneous environment of solid matrices.

  9. Dynamic response of a riser under excitation of internal waves

    Science.gov (United States)

    Lou, Min; Yu, Chenglong; Chen, Peng

    2015-12-01

    In this paper, the dynamic response of a marine riser under excitation of internal waves is studied. With the linear approximation, the governing equation of internal waves is given. Based on the rigid-lid boundary condition assumption, the equation is solved by Thompson-Haskell method. Thus the velocity field of internal waves is obtained by the continuity equation. Combined with the modified Morison formula, using finite element method, the motion equation of riser is solved in time domain with Newmark-β method. The computation programs are compiled to solve the differential equations in time domain. Then we get the numerical results, including riser displacement and transfiguration. It is observed that the internal wave will result in circular shear flow, and the first two modes have a dominant effect on dynamic response of the marine riser. In the high mode, the response diminishes rapidly. In different modes of internal waves, the deformation of riser has different shapes, and the location of maximum displacement shifts. Studies on wave parameters indicate that the wave amplitude plays a considerable role in response displacement of riser, while the wave frequency contributes little. Nevertheless, the internal waves of high wave frequency will lead to a high-frequency oscillation of riser; it possibly gives rise to fatigue crack extension and partial fatigue failure.

  10. Microbial Internal Storage Alters the Carbon Transformation in Dynamic Anaerobic Fermentation.

    Science.gov (United States)

    Ni, Bing-Jie; Batstone, Damien; Zhao, Bai-Hang; Yu, Han-Qing

    2015-08-04

    Microbial internal storage processes have been demonstrated to occur and play an important role in activated sludge systems under both aerobic and anoxic conditions when operating under dynamic conditions. High-rate anaerobic reactors are often operated at a high volumetric organic loading and a relatively dynamic profile, with large amounts of fermentable substrates. These dynamic operating conditions and high catabolic energy availability might also facilitate the formation of internal storage polymers by anaerobic microorganisms. However, so far information about storage under anaerobic conditions (e.g., anaerobic fermentation) as well as its consideration in anaerobic process modeling (e.g., IWA Anaerobic Digestion Model No. 1, ADM1) is still sparse. In this work, the accumulation of storage polymers during anaerobic fermentation was evaluated by batch experiments using anaerobic methanogenic sludge and based on mass balance analysis of carbon transformation. A new mathematical model was developed to describe microbial storage in anaerobic systems. The model was calibrated and validated by using independent data sets from two different anaerobic systems, with significant storage observed, and effectively simulated in both systems. The inclusion of the new anaerobic storage processes in the developed model allows for more successful simulation of transients due to lower accumulation of volatile fatty acids (correction for the overestimation of volatile fatty acids), which mitigates pH fluctuations. Current models such as the ADM1 cannot effectively simulate these dynamics due to a lack of anaerobic storage mechanisms.

  11. Dynamics simulation of a π-conjugated light-harvesting dendrimer II: phenylene-based dendrimer (phDG2)

    International Nuclear Information System (INIS)

    Kodama, Yasunobu; Ishii, Soh; Ohno, Kaoru

    2009-01-01

    We investigate the light-harvesting property of a π-conjugated dendrimer, phenylene-based dendrimer (phDG2), by carrying out a semi-classical Ehrenfest dynamics simulation based on the time-dependent density functional theory. Similar to our previous study of star-shaped stilbenoid phthalocyanine (SSS1Pc), phDG2 shows electron and hole transfer from the periphery to the core through a π-conjugated network when an electron is selectively excited in the periphery. The one-way electron and hole transfer occurs more easily in dendrimers with planar structure than in those with steric hindrance because π-conjugation is well maintained in the planar structure. The present results explain recent experiments by Akai et al (2005 J. Lumin. 112 449).

  12. Dust devil dynamics in the internal vortex region

    International Nuclear Information System (INIS)

    Onishchenko, O G; Pokhotelov, O A; Horton, W

    2015-01-01

    A hydrodynamic model for dust devil dynamics in the internal vortex region is analyzed. It is shown that the results concerning the growing plumes investigated by Onishchenko et al (2014) for the short time domain can be applied to the study of vortex motion in the internal region for longer times. It is demonstrated that these convective plumes in an atmosphere with weak, large-scale toroidal motion inhomogeneity in the vertical direction can be a subject for further exponential growth over time. (invited comment)

  13. Something going on in Milan: a review of the 4th International PhD Student Cancer Conference.

    Science.gov (United States)

    Segré, C

    2010-01-01

    The 4th International PhD Student Cancer Conference was held at the IFOM-IEO-Campus in Milan from 19-21 May 2010 http://www.semm.it/events_researchPast.phpThe Conference covered many topics related to cancer, from basic biology to clinical aspects of the disease. All attendees presented their research, by either giving a talk or presenting a poster. This conference is an opportunity to introduce PhD students to top cancer research institutes across Europe.THE CORE PARTICIPANTING INSTITUTES INCLUDED: European School of Molecular Medicine (SEMM)-IFOM-IEO Campus, MilanBeatson Institute for Cancer Research (BICR), GlasgowCambridge Research Institute (CRI), Cambridge, UKMRC Gray Institute of Radiation Biology (GIROB), OxfordLondon Research Institute (LRI), LondonPaterson Institute for Cancer Research (PICR), ManchesterThe Netherlands Cancer Institute (NKI), Amsterdam'You organizers have crushed all my prejudices towards Italians. Congratulations, I enjoyed the conference immensely!' Even if it might have sounded like rudeness for sure this was supposed to be a genuine compliment (at least, that's how we took it), also considering that it was told by a guy who himself was the fusion of two usually antithetical concepts: fashion style and English nationality.The year 2010 has marked an important event for Italian research in the international scientific panorama: the European School of Molecular Medicine (SEMM) had the honour to host the 4th International PhD Student Cancer Conference, which was held from 19-21 May 2010 at the IFOM-IEO-Campus (http://www.semm.it/events_researchPast.php) in Milan.The conference was attended by more than one hundred students, coming from a selection of cutting edge European institutes devoted to cancer research. The rationale behind it is the promotion of cooperation among young scientists across Europe to debate about science and to exchange ideas and experiences. But that is not all, it is also designed for PhD students to get in touch

  14. On-line monitoring of CO2 production in Lactococcus lactis during physiological pH decrease using membrane inlet mass spectrometry with dynamic pH calibration.

    Science.gov (United States)

    Andersen, Ann Zahle; Lauritsen, Frants Roager; Olsen, Lars Folke

    2005-12-20

    Monitoring CO2 production in systems, where pH is changing with time is hampered by the chemical behavior and pH-dependent volatility of this compound. In this article, we present the first method where the concentration and production rate of dissolved CO2 can be monitored directly, continuously, and quantitatively under conditions where pH changes rapidly ( approximately 2 units in 15 min). The method corrects membrane inlet mass spectrometry (MIMS) measurements of CO2 for pH dependency using on-line pH analysis and an experimentally established calibration model. It is valid within the pH range of 3.5 to 7, despite pH-dependent calibration constants that vary in a non-linear fashion with more than a factor of 3 in this interval. The method made it possible to determine the carbon dioxide production during Lactococcus lactis fermentations, where pH drops up to 3 units during the fermentation. The accuracy was approximately 5%. We used the method to investigate the effect of initial extracellular pH on carbon dioxide production during anarobic glucose fermentation by non-growing Lactocoocus lactis and demonstrated that the carbon dioxide production rate increases considerably, when the initial pH was increased from 6 to 6.8. (c) 2005 Wiley Periodicals, Inc.

  15. Bifurcation phenomena in internal dynamics of gear systems

    Directory of Open Access Journals (Sweden)

    Hortel M.

    2007-10-01

    Full Text Available The impact effects in gear mesh represent specific phenomena in the dynamic investigation of highspeed light transmission systems with kinematic couplings. They are caused of greater dynamic than static elastic deformations in meshing gear profiles. In term of internal dynamics they are influenced among others by time heteronomous stiffness functions in gear mesh and resonance tuning of stiffness level. The damping in gear mesh and in gear system is concerned significantly in the amplitude progress, greatness and phase shift of relative motion towards stiffness function alternatively towards its modify form in gear mesh. In consequence of these and another actions rise above resonance characteristics certain singular locations with jump amplitude course.

  16. 5th International Conference on Dynamics in Logistics

    CERN Document Server

    Kotzab, Herbert; Pannek, Jürgen

    2017-01-01

    These proceedings contain research papers presented at the 5th International Conference on Dynamics in Logistics, held in Bremen, Germany, February 2016. The conference is concerned with dynamic aspects of logistic processes and networks. The spectrum of topics reaches from modeling, planning and control of processes over supply chain management and maritime logistics to innovative technologies and robotic applications for cyber-physical production and logistic systems. The growing dynamic confronts the area of logistics with completely new challenges: it must become possible to describe, identify and analyze the process changes. Moreover, logistic processes and networks must be redevised to be rapidly and flexibly adaptable to continuously changing conditions. The book primarily addresses researchers and practitioners from the field of industrial engineering and logistics, but it may also be beneficial for graduate students.

  17. 4th International Conference on Dynamics in Logistics

    CERN Document Server

    Pannek, Jürgen; Thoben, Klaus-Dieter

    2016-01-01

    This contributed volume brings together research papers presented at the 4th International Conference on Dynamics in Logistics, held in Bremen, Germany in February 2014. The conference focused on the identification, analysis and description of the dynamics of logistics processes and networks. Topics covered range from the modeling and planning of processes, to innovative methods like autonomous control and knowledge management, to the latest technologies provided by radio frequency identification, mobile communication, and networking. The growing dynamic poses wholly new challenges: logistics processes and networks must be(come) able to rapidly and flexibly adapt to constantly changing conditions. The book primarily addresses the needs of researchers and practitioners from the field of logistics, but will also be beneficial for graduate students.

  18. The potential value of dynamic materials control in international safeguards

    International Nuclear Information System (INIS)

    Keepin, G.R.; Lovett, J.E.

    1979-01-01

    The difficulties inherent in conventional materials accountancy based on semi-annual or annual shutdown cleanout physical inventories have been recognized for many years. The increasing importance of international nuclear materials safeguards, coupled with the availability of advanced non-destructive measurement technology which could be installed on or near process lines, has led to the development of the concept of advanced or dynamic materials control. The potential benefits of dynamic materials control in terms of significantly improved detection capabilities (ranging from a few kilograms of plutonium down to perhaps a few hundred grams, even for large-scale bulk processing facilities), and even more dramatically improved detection timeliness (typically a few days, and potentially only a few hours, in advanced facilities), are reviewed. At least twelve major dynamic material control systems already in existence or in the process of being installed are noted, and some of the essential characteristics are discussed. Some currently unresolved questions are explored, and future prospects for the concept of dynamic material control in international safeguards are reviewed. (author)

  19. Cytoplasmic pH dynamics in maize pulvinal cells induced by gravity vector changes

    Science.gov (United States)

    Johannes, E.; Collings, D. A.; Rink, J. C.; Allen, N. S.; Brown, C. S. (Principal Investigator)

    2001-01-01

    In maize (Zea mays) and other grasses, changes in orientation of stems are perceived by pulvinal tissue, which responds to the stimulus by differential growth resulting in upward bending of the stem. The amyloplast-containing bundle sheath cells are the sites of gravity perception, although the initial steps of gravity perception and transmission remain unclear. In columella cells of Arabidopsis roots, we previously found that cytoplasmic pH (pH(c)) is a mediator in early gravitropic signaling (A.C. Scott, N.S. Allen [1999] Plant Physiol 121: 1291-1298). The question arises whether pH(c) has a more general role in signaling gravity vector changes. Using confocal ratiometric imaging and the fluorescent pH indicator carboxy seminaphtorhodafluor acetoxymethyl ester acetate, we measured pH(c) in the cells composing the maize pulvinus. When stem slices were gravistimulated and imaged on a horizontally mounted confocal microscope, pH(c) changes were only apparent within the bundle sheath cells, and not in the parenchyma cells. After turning, cytoplasmic acidification was observed at the sides of the cells, whereas the cytoplasm at the base of the cells where plastids slowly accumulated became more basic. These changes were most apparent in cells exhibiting net amyloplast sedimentation. Parenchyma cells and isolated bundle sheath cells did not show any gravity-induced pH(c) changes although all cell types responded to external stimuli in the predicted way: Propionic acid and auxin treatments induced acidification, whereas raising the external pH caused alkalinization. The results suggest that pH(c) has an important role in the early signaling pathways of maize stem gravitropism.

  20. International Symposium: “Scientific School of L.S. Vygotsky: Traditions and Innovations” and International ISCAR Summer University for PhD Students

    Directory of Open Access Journals (Sweden)

    Baykovskaya N.A.,

    2016-12-01

    Full Text Available The article represents a brief report on the work of the International Symposium: «Scientific School of L.S. Vygotsky: Traditions and Innovations» and VI th International ISCAR Summer University for PhD Students and young scholars, that were held in Moscow State University of Psychology & Education on June, 28 — July, 3 in 2016 in commemoration of the 120th anniversary of the great Russian psychologist L.S. Vygotsky. The main goals of the events organised by MSUPE include: analysis of the basic principles and the system of concepts of L.S. Vygotsky’s scientific school, discussion of the current state and the prospect for the development of the cultural-historical theory in Russia and abroad, integration of the ideas of the cultural-historical psychology and activity approach in various kinds of social and educational practices, as well as conducting research in the international scientific space. Symposium gathered the world’s leading experts and young scholars in the field of cultural-historical theory and activity approach from 19 countries, including United Kingdom, Australia, Switzerland, Greece, Brasil and USA.

  1. Fifth International Conference on the Dynamics of Information Systems

    CERN Document Server

    Walteros, Jose; Pardalos, Panos

    2014-01-01

    The contributions of this volume stem from the “Fifth International Conference on the Dynamics of Information Systems” held in Gainesville, FL in February 2013, and discuss state-of the-art  techniques in handling problems and solutions in the broad field of information systems. Dynamics of Information Systems: Computational and Mathematical Challenges presents diverse aspects of modern information systems with an emphasis on interconnected network systems and related topics, such as signal and message reconstruction, network connectivity, stochastic network analysis, cyber and computer security, community and cohesive structures in complex networks. Information systems are a vital part of modern societies. They are essential to our daily actions, including social networking, business and bank transactions, as well as sensor communications. The rapid increase in these capabilities has enabled us with more powerful systems, readily available to sense, control, disperse, and analyze information.

  2. 2nd International Conference on Dynamics of Disasters

    CERN Document Server

    Nagurney, Anna; Pardalos, Panos

    2016-01-01

    This volume results from the “Second International Conference on Dynamics of Disasters” held in Kalamata, Greece, June 29-July 2, 2015. The conference covered particular topics involved in natural and man-made disasters such as war, chemical spills, and wildfires. Papers in this volume examine the finer points of disasters through: · Critical infrastructure protection · Resiliency · Humanitarian logistic · Relief supply chains · Cooperative game theory · Dynamical systems · Decision making under risk and uncertainty · Spread of diseases · Contagion · Funding for disaster relief · Tools for emergency preparedness · Response, and risk mitigation Multi-disciplinary theories, tools, techniques and methodologies are linked with disasters from mitigation and preparedness to response and recovery. The interdisciplinary approach to problems in economics, optimization, government, management, business, humanities, engineering, medicine, mathematics, computer science, behavioral studies, emergency servi...

  3. Linear and nonlinear dynamic analysis by boundary element method. Ph.D. Thesis, 1986 Final Report

    Science.gov (United States)

    Ahmad, Shahid

    1991-01-01

    An advanced implementation of the direct boundary element method (BEM) applicable to free-vibration, periodic (steady-state) vibration and linear and nonlinear transient dynamic problems involving two and three-dimensional isotropic solids of arbitrary shape is presented. Interior, exterior, and half-space problems can all be solved by the present formulation. For the free-vibration analysis, a new real variable BEM formulation is presented which solves the free-vibration problem in the form of algebraic equations (formed from the static kernels) and needs only surface discretization. In the area of time-domain transient analysis, the BEM is well suited because it gives an implicit formulation. Although the integral formulations are elegant, because of the complexity of the formulation it has never been implemented in exact form. In the present work, linear and nonlinear time domain transient analysis for three-dimensional solids has been implemented in a general and complete manner. The formulation and implementation of the nonlinear, transient, dynamic analysis presented here is the first ever in the field of boundary element analysis. Almost all the existing formulation of BEM in dynamics use the constant variation of the variables in space and time which is very unrealistic for engineering problems and, in some cases, it leads to unacceptably inaccurate results. In the present work, linear and quadratic isoparametric boundary elements are used for discretization of geometry and functional variations in space. In addition, higher order variations in time are used. These methods of analysis are applicable to piecewise-homogeneous materials, such that not only problems of the layered media and the soil-structure interaction can be analyzed but also a large problem can be solved by the usual sub-structuring technique. The analyses have been incorporated in a versatile, general-purpose computer program. Some numerical problems are solved and, through comparisons

  4. Fermentation pH influences the physiological-state dynamics of Lactobacillus bulgaricus CFL1 during pH-controlled culture.

    Science.gov (United States)

    Rault, Aline; Bouix, Marielle; Béal, Catherine

    2009-07-01

    This study aims at better understanding the effects of fermentation pH and harvesting time on Lactobacillus bulgaricus CFL1 cellular state in order to improve knowledge of the dynamics of the physiological state and to better manage starter production. The Cinac system and multiparametric flow cytometry were used to characterize and compare the progress of the physiological events that occurred during pH 6 and pH 5 controlled cultures. Acidification activity, membrane damage, enzymatic activity, cellular depolarization, intracellular pH, and pH gradient were determined and compared during growing conditions. Strong differences in the time course of viability, membrane integrity, and acidification activity were displayed between pH 6 and pH 5 cultures. As a main result, the pH 5 control during fermentation allowed the cells to maintain a more robust physiological state, with high viability and stable acidification activity throughout growth, in opposition to a viability decrease and fluctuation of activity at pH 6. This result was mainly explained by differences in lactate concentration in the culture medium and in pH gradient value. The elevated content of the ionic lactate form at high pH values damaged membrane integrity that led to a viability decrease. In contrast, the high pH gradient observed throughout pH 5 cultures was associated with an increased energetic level that helped the cells maintain their physiological state. Such results may benefit industrial starter producers and fermented-product manufacturers by allowing them to better control the quality of their starters, before freezing or before using them for food fermentation.

  5. Charge Carrier Dynamics and pH Effect on Optical Properties of Anionic and Cationic Porphyrin-Graphene Oxide Composites

    Science.gov (United States)

    Bajjou, O.; Bakour, A.; Khenfouch, M.; Baitoul, M.; Mothudi, B.; Maaza, M.; Faulques, E.

    2018-02-01

    Composites of graphene oxide (GO) functionalized with Sn(V) tetrakis (4-pyridyl)porphyrin (SnTPyP2+) and meso-tetrakis(4-phenylsulfonic acid)porphyrin (H4TPPS4 2- ) were prepared at different pH values.Successful synthesis of water-soluble stable suspension of GO-SnTPyP2+ and GO-H4TPPS4 2-was confirmed using various spectroscopic techniques, including scanning electronic microscopy (SEM), Raman spectroscopy, and ultraviolet-visible (UV-Vis) absorption. Variation of the pH was found to strongly influence the optical properties of the GO-SnTPyP2+ and GO-H4TPPS4 2-composites, as demonstrated by the UV-Vis absorption results. Steady-state photoluminescence (PL) and time-resolved PL (TRPL) results for both composites showed PL quenching and decrease in the exciton mean lifetime, suggesting strong excited-state interactions between the different components. Moreover, charge carrier dynamics study revealed that insertion of GO into both porphyrin derivatives led to faster mean lifetime for excitons with a slight advantage in the case of the cationic porphyrin-GO composite, making it a better choice for charge separation applications thanks to the higher efficiency of charge/energy transfer interactions.

  6. Protonation-induced ultrafast torsional dynamics in 9-anthrylbenzimidazole: a pH activated molecular rotor.

    Science.gov (United States)

    Nandi, Amitabha; Kushwaha, Archana; Das, Dipanwita; Ghosh, Rajib

    2018-03-07

    We report the photophysical properties and excited state dynamics of 9-anthrylbenzimidazole (ANBI) which exhibits protonation-induced molecular rotor properties. In contrast to the highly emissive behavior of neutral ANBI, protonation of the benzimidazole group of ANBI induces efficient nonradiative deactivation by ultrafast torsional motion around the bond connecting the anthracene and benzimidazole units, as revealed by ultrafast transient absorption and fluorescence spectroscopy. Contrary to viscosity-independent fluorescence of neutral dyes, protonated ANBI is shown to display linear variation of emission yield and lifetime with solvent viscosity. The protonation-induced molecular rotor properties in the studied system are shown to be driven by enhanced charge transfer and are corroborated by quantum chemical calculations. Potential application as a microviscosity sensor of acidic regions in a heterogeneous environment by these proton-activated molecular rotor properties of ANBI is discussed.

  7. Constraint treatment techniques and parallel algorithms for multibody dynamic analysis. Ph.D. Thesis

    Science.gov (United States)

    Chiou, Jin-Chern

    1990-01-01

    Computational procedures for kinematic and dynamic analysis of three-dimensional multibody dynamic (MBD) systems are developed from the differential-algebraic equations (DAE's) viewpoint. Constraint violations during the time integration process are minimized and penalty constraint stabilization techniques and partitioning schemes are developed. The governing equations of motion, a two-stage staggered explicit-implicit numerical algorithm, are treated which takes advantage of a partitioned solution procedure. A robust and parallelizable integration algorithm is developed. This algorithm uses a two-stage staggered central difference algorithm to integrate the translational coordinates and the angular velocities. The angular orientations of bodies in MBD systems are then obtained by using an implicit algorithm via the kinematic relationship between Euler parameters and angular velocities. It is shown that the combination of the present solution procedures yields a computationally more accurate solution. To speed up the computational procedures, parallel implementation of the present constraint treatment techniques, the two-stage staggered explicit-implicit numerical algorithm was efficiently carried out. The DAE's and the constraint treatment techniques were transformed into arrowhead matrices to which Schur complement form was derived. By fully exploiting the sparse matrix structural analysis techniques, a parallel preconditioned conjugate gradient numerical algorithm is used to solve the systems equations written in Schur complement form. A software testbed was designed and implemented in both sequential and parallel computers. This testbed was used to demonstrate the robustness and efficiency of the constraint treatment techniques, the accuracy of the two-stage staggered explicit-implicit numerical algorithm, and the speed up of the Schur-complement-based parallel preconditioned conjugate gradient algorithm on a parallel computer.

  8. A computational procedure for the dynamics of flexible beams within multibody systems. Ph.D. Thesis Final Technical Report

    Science.gov (United States)

    Downer, Janice Diane

    1990-01-01

    The dynamic analysis of three dimensional elastic beams which experience large rotational and large deformational motions are examined. The beam motion is modeled using an inertial reference for the translational displacements and a body-fixed reference for the rotational quantities. Finite strain rod theories are then defined in conjunction with the beam kinematic description which accounts for the effects of stretching, bending, torsion, and transverse shear deformations. A convected coordinate representation of the Cauchy stress tensor and a conjugate strain definition is introduced to model the beam deformation. To treat the beam dynamics, a two-stage modification of the central difference algorithm is presented to integrate the translational coordinates and the angular velocity vector. The angular orientation is then obtained from the application of an implicit integration algorithm to the Euler parameter/angular velocity kinematical relation. The combined developments of the objective internal force computation with the dynamic solution procedures result in the computational preservation of total energy for undamped systems. The present methodology is also extended to model the dynamics of deployment/retrieval of the flexible members. A moving spatial grid corresponding to the configuration of a deployed rigid beam is employed as a reference for the dynamic variables. A transient integration scheme which accurately accounts for the deforming spatial grid is derived from a space-time finite element discretization of a Hamiltonian variational statement. The computational results of this general deforming finite element beam formulation are compared to reported results for a planar inverse-spaghetti problem.

  9. How internal drainage affects evaporation dynamics from soil surfaces ?

    Science.gov (United States)

    Or, D.; Lehmann, P.; Sommer, M.

    2017-12-01

    Following rainfall, infiltrated water may be redistributed internally to larger depths or lost to the atmosphere by evaporation (and by plant uptake from depths at longer time scales). A large fraction of evaporative losses from terrestrial surfaces occurs during stage1 evaporation during which phase change occurs at the wet surface supplied by capillary flow from the soil. Recent studies have shown existence of a soil-dependent characteristic length below which capillary continuity is disrupted and a drastic shift to slower stage 2 evaporation ensues. Internal drainage hastens this transition and affect evaporative losses. To predict the transition to stage 2 and associated evaporative losses, we developed an analytical solution for evaporation dynamics with concurrent internal drainage. Expectedly, evaporative losses are suppressed when drainage is considered to different degrees depending on soil type and wetness. We observe that high initial water content supports rapid drainage and thus promotes the sheltering of soil water below the evaporation depth. The solution and laboratory experiments confirm nonlinear relationship between initial water content and total evaporative losses. The concept contributes to establishing bounds on regional surface evaporation considering rainfall characteristics and soil types.

  10. Variations of internal pH in typical Italian sourdough yeasts during co-fermentation with lactobacilli

    DEFF Research Database (Denmark)

    Valmorri, Sara; Mortensen, Henrik Dam; Jespersen, Lene

    2008-01-01

    The effects of organic acids (lactic and acetic) and extracellular pH (pHex) on the intracellular pH (pHi) of Saccharomyces cerevisiae and Candida milleri during co-fermentation with lactobacilli were investigated by using Fluorescence-Ratio-Imaging-Microscopy (FRIM). Yeasts were grown in a syste...

  11. [Fluid dynamics of supercritical helium within internally cooled cabled superconductors

    International Nuclear Information System (INIS)

    Van Sciver, S.W.

    1995-01-01

    The Applied Superconductivity Center of the University of Wisconsin-Madison proposes to conduct research on low temperature helium fluid dynamics as it applies to the cooling of internally cooled cabled superconductors (ICCS). Such conductors are used in fusion reactor designs including most of the coils in ITER. The proposed work is primarily experimental involving measurements of transient and steady state pressure drop in a variety of conductor configurations. Both model and prototype conductors for actual magnet designs will be investigated. The primary goal will be to measure and model the friction factor for these complex geometries. In addition, an effort will be made to study transient processes such as heat transfer and fluid expulsion associated with quench conditions

  12. Observing and modeling nonlinear dynamics in an internal combustion engine

    International Nuclear Information System (INIS)

    Daw, C.S.; Kennel, M.B.; Finney, C.E.; Connolly, F.T.

    1998-01-01

    We propose a low-dimensional, physically motivated, nonlinear map as a model for cyclic combustion variation in spark-ignited internal combustion engines. A key feature is the interaction between stochastic, small-scale fluctuations in engine parameters and nonlinear deterministic coupling between successive engine cycles. Residual cylinder gas from each cycle alters the in-cylinder fuel-air ratio and thus the combustion efficiency in succeeding cycles. The model close-quote s simplicity allows rapid simulation of thousands of engine cycles, permitting statistical studies of cyclic-variation patterns and providing physical insight into this technologically important phenomenon. Using symbol statistics to characterize the noisy dynamics, we find good quantitative matches between our model and experimental time-series measurements. copyright 1998 The American Physical Society

  13. International Symposium on Dynamics of Ordering Processes in Condensed Matter

    CERN Document Server

    Furukawa, H

    1988-01-01

    The International Symposium on Dynamics of Ordering Processes in Condensed Matter was held at the Kansai Seminar House, Kyoto, for four days, from 27 to 30 August 1987, under the auspices of the Physical Soci­ ety of Japan. The symposium was financially supported by the four orga­ nizations and 45 companies listed on other pages in this volume. We are very grateful to all of them and particularly to the greatest sponsor, the Commemorative Association for the Japan World Exposition 1970. A total Df 22 invited lectures and 48 poster presentations were given and 110 participants attended from seven nations. An objective of the Symposium was to review and extend our present understanding of the dynamics of ordering processes in condensed matters, (for example, alloys, polymers and fluids), that are brought to an un­ stable state by sudden change of such external parameters as temperature and pressure. A second objective, no less important, was to identify new fields of science that might be investigated by sim...

  14. Ego, drives, and the dynamics of internal objects

    Directory of Open Access Journals (Sweden)

    Simon eBoag

    2014-07-01

    Full Text Available This paper addresses the relationship between the ego, id, and internal objects. While ego psychology views the ego as autonomous of the drives, a less well-known alternative position views the ego as constituted by the drives. Based on Freud’s ego-instinct account, this position has developed into a school of thought which postulates that the drives act as knowers. Given that there are multiple drives, this position proposes that personality is constituted by multiple knowers. Following on from Freud, the ego is viewed as a composite sub-set of the instinctual drives (ego-drives, whereas those drives cut off from expression form the id. The nature of the ‘self’ is developed in terms of identification and the possibility of multiple personalities is also established. This account is then extended to object-relations and the explanatory value of the ego-drive account is discussed in terms of the addressing the nature of ego-structures and the dynamic nature of internal objects. Finally, the impact of psychological conflict and the significance of repression for understanding the nature of splits within the psyche are also discussed.

  15. On the effect of subphase pH and counterions on transfer ratios and dynamic contact angles during deposition of multiple Langmuir-Blodgett monolayers

    International Nuclear Information System (INIS)

    Diaz, M. Elena; Cerro, Ramon L.

    2005-01-01

    The effects of pH and counterions on the type of deposition of Langmuir-Blodgett (LB) arachidic acid films onto hydrophobic glass slides is revisited. Unusually large differences in contact angles and transfer ratios (TR) were observed for subphase containing 10 -4 M of zinc sulfate and 2.10 -4 M of cadmium chloride, respectively, for a wide range of pH. Variations in TR occur at the same pH for different subphase cations and at different pH for the same divalent cations. These large variations in dynamic contact angles and TR as a function of pH point to the crucial role of electrical double layer forces in LB deposition phenomena. Transitions from Y- to X-type deposition are reported for pH larger or smaller than the pK A of the fatty acid-subphase salt system. Experimental results are compared with data reported in literature showing Z- to Y-transitions at pH close to the pK A of docosanoic acid monolayers

  16. Computational fluid dynamics for turbomachinery internal air systems.

    Science.gov (United States)

    Chew, John W; Hills, Nicholas J

    2007-10-15

    Considerable progress in development and application of computational fluid dynamics (CFD) for aeroengine internal flow systems has been made in recent years. CFD is regularly used in industry for assessment of air systems, and the performance of CFD for basic axisymmetric rotor/rotor and stator/rotor disc cavities with radial throughflow is largely understood and documented. Incorporation of three-dimensional geometrical features and calculation of unsteady flows are becoming commonplace. Automation of CFD, coupling with thermal models of the solid components, and extension of CFD models to include both air system and main gas path flows are current areas of development. CFD is also being used as a research tool to investigate a number of flow phenomena that are not yet fully understood. These include buoyancy-affected flows in rotating cavities, rim seal flows and mixed air/oil flows. Large eddy simulation has shown considerable promise for the buoyancy-driven flows and its use for air system flows is expected to expand in the future.

  17. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system

    OpenAIRE

    Raimondo, Joseph V.; Joyce, Bradley; Kay, Louise; Schlagheck, Theresa; Newey, Sarah E.; Srinivas, Shankar; Akerman, Colin J.

    2013-01-01

    Within the nervous system, intracellular Cl− and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission, and network excitability. Cl− and pH are often co-regulated, and network activity results in the movement of both Cl− and H+. Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl− and pH sensors have been described previously, these either l...

  18. Highly Sensitive and Wide-Dynamic-Range Multichannel Optical-Fiber pH Sensor Based on PWM Technique

    OpenAIRE

    Md. Rajibur Rahaman Khan; Shin-Won Kang

    2016-01-01

    In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal?s pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The...

  19. Dual-Ratiometric Fluorescent Nanoprobe for Visualizing the Dynamic Process of pH and Superoxide Anion Changes in Autophagy and Apoptosis.

    Science.gov (United States)

    Yang, Limin; Chen, Yuanyuan; Yu, Zhengze; Pan, Wei; Wang, Hongyu; Li, Na; Tang, Bo

    2017-08-23

    Autophagy and apoptosis are closely associated with various pathological and physiological processes in cell cycles. Investigating the dynamic changes of intracellular active molecules in autophagy and apoptosis is of great significance for clarifying their inter-relationship and regulating mechanism in many diseases. In this study, we develop a dual-ratiometric fluorescent nanoprobe for quantitatively differentiating the dynamic process of superoxide anion (O 2 •- ) and pH changes in autophagy and apoptosis in HeLa cells. A rhodamine B-loaded mesoporous silica core was used as the reference, and fluorescence probes for pH and O 2 •- measurement were doped in the outer layer shell of SiO 2 . Then, chitosan and triphenylphosphonium were modified on the surface of SiO 2 . The experimental results showed that the nanoprobe is able to simultaneously and precisely visualize the changes of mitochondrial O 2 •- and pH in HeLa cells. The kinetics data revealed that the changes of pH and O 2 •- during autophagy and apoptosis in HeLa cells were significantly different. The pH value was decreased at the early stage of apoptosis and autophagy, whereas the O 2 •- level was enhanced at the early stage of apoptosis and almost unchanged at the initial stage of autophagy. At the late stage of apoptosis and autophagy, the concentration of O 2 •- was increased, whereas the pH was decreased at the late stage of autophagy and almost unchanged at the late stage of apoptosis. We hope that the present results provide useful information for studying the effects of O 2 •- and pH in autophagy and apoptosis in various pathological conditions and diseases.

  20. Monitoring of internal pH gradients within multi-layer tablets by optical methods and EPR imaging.

    Science.gov (United States)

    Eisenächer, Friederike; Schädlich, Andreas; Mäder, Karsten

    2011-09-30

    The high variability of gastrointestinal pH is a general challenge regarding constant release from oral drug delivery systems, especially for ionisable drugs. These drugs often show a pH-dependent solubility and therewith associated intra- and inter-individual variability of emerging drug plasma levels. Several strategies have been investigated with the intention to influence the microenvironmental pH (pH(M)) within solid formulations and therefore achieve pH-independent release profiles. Because of the heterogeneity of solid systems, a precise prediction of the occurring pH(M) is rather difficult. It is therefore important to monitor the pH(M) within the formulations to achieve requested release as well as to minimise pH-dependent degradation processes of the active compound. The purpose of the current study was the analysis of pH(M) gradients within 2- and 3-layer tablets during hydration using 3 different techniques for comparison intensions, in particular a pH indicator dye, fluorescence imaging and EPR imaging. The influence of the presence or absence of pH modifying substances and of an additional lipophilic inter layer on the pH(M) was investigated as well as the variation of matrix forming excipient and buffer pH. The influence of the pH(M) on drug release was analysed as well. In addition, benchtop MRI was accomplished to gain a deeper insight on the hydration and erosion behaviour of 2- and 3-layer tablets. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Influence of pH on dynamics of microbial enhanced oil recovery processes using biosurfactant producing Pseudomonas putida: Mathematical modelling and numerical simulation.

    Science.gov (United States)

    Sivasankar, P; Suresh Kumar, G

    2017-01-01

    In present work, the influence of reservoir pH conditions on dynamics of microbial enhanced oil recovery (MEOR) processes using Pseudomonas putida was analysed numerically from the developed mathematical model for MEOR processes. Further, a new strategy to improve the MEOR performance has also been proposed. It is concluded from present study that by reversing the reservoir pH from highly acidic to low alkaline condition (pH 5-8), flow and mobility of displaced oil, displacement efficiency, and original oil in place (OOIP) recovered gets significantly enhanced, resulting from improved interfacial tension (IFT) reduction by biosurfactants. At pH 8, maximum of 26.1% of OOIP was recovered with higher displacement efficiency. The present study introduces a new strategy to increase the recovery efficiency of MEOR technique by characterizing the biosurfactants for IFT min /IFT max values for different pH conditions and subsequently, reversing the reservoir pH conditions at which the IFT min /IFT max value is minimum. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Preparation and influence of pH on the dynamic magnetic property of magnetic FeCoC films

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Hongmei; Wei, Jinwu; Zhu, Zengtai; Cao, Derang; Liu, Qingfang [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Wang, Jianbo, E-mail: wangjb@lzu.edu.cn [Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000 (China); Key Laboratory for Special Function Materials and Structural Design of the Ministry of the Education, Lanzhou University, Lanzhou 730000 (China)

    2016-07-01

    FeCoC films were successfully prepared by electrochemical deposition method in different citric acid concentrations and pH values. The morphology, structure and magnetic properties were investigated. FeCoC films deposited at different citric acid concentrations have good soft magnetic performance. As the pH value increases from 2.49 to 6.02, the atomic ratio of Fe:Co range from 0.72 to 0.95. The coercivities of the films deposited at different pH values first increase and then decrease with increasing pH. The resonance frequency of the films can be tuned by controlling the pH value, and in an appropriate pH value a wide absorption peak can be obtained. - Highlights: • We have successfully prepared FeCoC soft magnetic films by electrochemical deposition method. • The resonance frequency can be controlled by changing pH value. • A widely absorption peak will be obtained when the pH value is appropriate.

  3. NMR studies of the dynamics of high-spin nitrophorins: comparative studies of NP4 and NP2 at close to physiological pH.

    Science.gov (United States)

    Berry, Robert E; Muthu, Dhanasekaran; Yang, Fei; Walker, F Ann

    2015-01-20

    The β-barrel nitrophorin (NP) heme proteins are found in the saliva of the blood-sucking insect Rhodnius prolixus, which synthesizes and stores nitric oxide (NO) in the salivary glands. NO is bound to iron of the NPs and is released by dilution and an increase in pH when the insect spits its saliva into the tissues of a victim, to aid in obtaining a blood meal. In the adult insect, there are four nitrophorins, NP1-NP4, which have sequence similarities in two pairs, NP1 and NP4 (90% identical) and NP2 and NP3 (80% identical). The available crystal structures of NP4 have been used to propose that pH-dependent changes in the conformation of two loops between adjacent β-strands at the front opening of the protein, the A-B and G-H loops, determine the rate of NO release. At pH 7.3, NP4 releases NO 17 times faster than NP2 does. In this work, the aqua complexes of NP4 and NP2 have been investigated by nuclear magnetic resonance (NMR) relaxation measurements to probe the pico- to nanosecond and micro- to millisecond time scale motions at two pH values, 6.5 and 7.3. It is found that NP4-OH2 is fairly rigid and only residues in the loop regions show dynamics at pH 6.5; at pH 7.3, much more dynamics of the loops and most of the β-strands are observed while the α-helices remain fairly rigid. In comparison, NP2-OH2 shows much less dynamics, albeit somewhat more than that of the previously reported NP2-NO complex [Muthu, D., Berry, R. E., Zhang, H., and Walker, F. A. (2013) Biochemistry 52, 7910-7925]. The reasons for this major difference between NP4 and NP2 are discussed.

  4. Fast hydrogen elimination from the [Ru(PH3)3(CO)(H)2] and [Ru(PH3)4(H)2] complexes in the first singlet excited states: A diabatic quantum dynamics study

    International Nuclear Information System (INIS)

    Vendrell, Oriol; Moreno, Miquel; Lluch, Jose M.

    2004-01-01

    The photodissociation dynamics of [Ru(PH 3 ) 3 (CO)(H) 2 ] and cis-[Ru(PH 3 ) 4 (H) 2 ] is theoretically analyzed in the lowest two excited singlet states. Energies obtained through electronic density functional theory calculations that use the time-dependent formalism are fitted to analytical reduced two-dimensional potential energy surfaces (2D-PES). The metal-H 2 (R) and H-H (r) distances are the variables of these 2D-PES, the rest of the parameters being kept frozen at the values of the minimum energy structure in the ground electronic state. The time evolution in these 2D-PES is exactly followed by means of a fast Fourier transform algorithm applied to solve the time-dependent Schroedinger equation. A simple diabatization scheme is devised to take into account the probability of transitions between both excited states. The quantum dynamics results point out that photoelimination is almost inexistent if the H 2 fragment is to be expelled without further rearrangement of the rest of the complex. Conversely, when the geometries of the complex are optimized by keeping r and R frozen at the hydrogen elimination barrier coordinates, the new 2D-PES so obtained are highly dissociative, the H 2 fragment being expelled in less than 100 fs. Finally the picture of the whole reaction that emerges from our theoretical results is described and the main differences between both complexes are examined

  5. Solar neutrinos, helioseismology and the solar internal dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Turck-Chieze, Sylvaine [Service d' Astrophysique/IRFU/DSM/CEA, 91191 Gif sur Yvette Cedex (France); Couvidat, Sebastien, E-mail: sylvaine.turck-chieze@cea.fr, E-mail: couvidat@stanford.edu [HEPL, Stanford University, Stanford, CA 94305 (United States)

    2011-08-15

    Neutrinos are fundamental particles ubiquitous in the Universe and whose properties remain elusive despite more than 50 years of intense research activity. This review illustrates the importance of solar neutrinos in astrophysics, nuclear physics and particle physics. After a description of the historical context, we remind the reader of the noticeable properties of these particles and of the stakes of the solar neutrino puzzle. The standard solar model triggered persistent efforts in fundamental physics to predict the solar neutrino fluxes, and its constantly evolving predictions have been regularly compared with the detected neutrino signals. Anticipating that this standard model could not reproduce the internal solar dynamics, a seismic solar model was developed which enriched theoretical neutrino flux predictions with in situ observation of acoustic and gravity waves propagating in the Sun. This seismic model contributed to the stabilization of the neutrino flux predictions. This review recalls the main historical steps, from the pioneering Homestake mine experiment and the GALLEX-SAGE experiments capturing the first proton-proton neutrinos. It emphasizes the importance of the SuperKamiokande and SNO detectors. Both experiments demonstrated that the solar-emitted electron neutrinos are partially transformed into other neutrino flavors before reaching the Earth. This sustained experimental effort opens the door to neutrino astronomy, with long-base lines and underground detectors. The success of BOREXINO in detecting the {sup 7}Be neutrino signal alone instills confidence in physicists' ability to detect each neutrino source separately. It justifies the building of a new generation of detectors to measure the entire solar neutrino spectrum in greater detail, as well as supernova neutrinos. A coherent picture has emerged from neutrino physics and helioseismology. Today, new paradigms take shape in these two fields: neutrinos are massive particles, but their

  6. Modeling the dynamics of internal flooding - verification analysis

    International Nuclear Information System (INIS)

    Filipov, K.

    2011-01-01

    The results from conducted software WATERFOW's verification analysis, developed for the purposes of reactor building internal flooding analysis have been presented. For the purpose of benchmarking the integrated code MELCOR is selected. Considering the complex structure of reactor building, the sample tests were used to cover the characteristic points of the internal flooding analysis. The inapplicability of MELCOR to the internal flooding study has been proved

  7. pH and Ion Homeostasis on Plant Endomembrane Dynamics: Insights from structural models and mutants of K+/H+ antiporters.

    Science.gov (United States)

    Sze, Heven; Chanroj, Salil

    2018-04-24

    Plants remodel their cells through the dynamic endomembrane system. Intracellular pH is important for membrane trafficking, but the determinants of pH homeostasis are poorly defined in plants. Electrogenic proton (H+) pumps depend on counter-ion fluxes to establish transmembrane pH gradients at the plasma membrane and endomembranes. Vacuolar-type H+-ATPase-mediated acidification of the trans-Golgi network (TGN) is crucial for secretion and membrane recycling. Pump and counter-ion fluxes are unlikely to fine-tune pH; rather, alkali cation/H+ antiporters, which can alter pH and/or cation homeostasis locally and transiently, are prime candidates. Plants have a large family of predicted cation/H+ exchangers (CHX) of obscure function, in addition to the well-studied K+(Na+)/H+ exchangers (NHX). Here, we review the regulation of cytosolic and vacuolar pH, highlighting the similarities and distinctions of NHX and CHX members. In planta, alkalinization of the TGN or vacuole by NHXs promotes membrane trafficking, endocytosis, cell expansion, and growth. CHXs localize to endomembranes and/or the plasma membrane, contribute to male fertility, pollen tube guidance, pollen wall construction, stomatal opening, and in soybean (Glycine max), tolerance to salt stress. Three-dimensional structural models and mutagenesis of Arabidopsis thaliana genes have allowed us to infer that AtCHX17 and AtNHX1 share a global architecture and a translocation core like bacterial Na+/H+ antiporters. Yet the presence of distinct residues suggests some CHXs differ from NHXs in pH sensing and electrogenicity. How H+ pumps, counter-ion fluxes, and cation/H+ antiporters are linked with signaling and membrane trafficking to remodel membranes and cell walls awaits further investigation. {copyright, serif} 2018 American Society of Plant Biologists. All rights reserved.

  8. Modeling the dynamic volatile fatty acids profiles with pH and hydraulic retention time in an anaerobic baffled reactor during the startup period.

    Science.gov (United States)

    Shi, En; Li, Jianzheng; Leu, Shao-Yuan; Antwi, Philip

    2016-12-01

    To predict the dynamic profiles in volatile fatty acids (VFAs) with pH and hydraulic retention time (HRT) during the startup of a 4-compartment ABR, a mathematical model was constructed by introducing pH and thermodynamic inhibition functions into the biochemical processes derived from the ADM1. The calibration of inhibition parameter for propionate uptake effectively improved the prediction accuracy of VFAs. The developed model could simulate the VFAs profiles very well no matter the observable change of pH or/and HRT. The simulation results indicated that both H 2 -producing acetogenesis and methanogenesis in the ABR would be inhibited with a pH less than 4.61, and the propionate oxidation could be thermodynamically restricted even with a neutral pH. A decreased HRT would enhanced the acidogenesis and H 2 -producing acetogenesis in the first 3 compartments, but no observable increase in effluent VFAs could be found due to the synchronously enhanced methanogenesis in the last compartment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Molecular dynamics simulation of the effect of pH on the adsorption of rhodamine laser dyes on TiO2 hydroxylated surfaces

    OpenAIRE

    2009-01-01

    Abstract We have carried out a study of the adsorption, on the (101) surface of anatase TiO2, of two industrially relevant rhodamines molecules (rhodamine 6G and rhodamine 800) employing Molecular Dynamics. These theoretical studies have shown that Rhodamine 6G must adsorb on surfaces under basic conditions. Moreover, the adsorption of this molecule shows a strong dependence upon the pH of the system, i.e. under neutral conditions the adsorption energy is quite smaller, and under ...

  10. Acid dissociation constants of uridine-5 Prime -diphosphate compounds determined by {sup 31}phosphorus nuclear magnetic resonance spectroscopy and internal pH referencing

    Energy Technology Data Exchange (ETDEWEB)

    Jancan, Igor [Louisiana State University, Department of Chemistry, Baton Rouge, LA 70803 (United States); Macnaughtan, Megan A., E-mail: macnau@lsu.edu [Louisiana State University, Department of Chemistry, Baton Rouge, LA 70803 (United States)

    2012-10-24

    Highlights: Black-Right-Pointing-Pointer The first reported phosphate and imide pK{sub a} values of UDP-GlcNAc and UDP-S-GlcNAc. Black-Right-Pointing-Pointer New role for the monosaccharide in the imide pK{sub a} of uridine-5 Prime -phosphate compounds. Black-Right-Pointing-Pointer UDP-S-GlcNAc and UDP-GlcNAc have the same phosphate pK{sub a}, unlike thioyl analogs. Black-Right-Pointing-Pointer The {sup 31}P chemical shift of inorganic phosphate is a viable internal pH reference. Black-Right-Pointing-Pointer Stability of the external {sup 31}P chemical shift reference is essential. - Abstract: The acid dissociation constant (pK{sub a}) of small, biological molecules is an important physical property used for investigating enzyme mechanisms and inhibitor design. For phosphorus-containing molecules, the {sup 31}P nuclear magnetic resonance (NMR) chemical shift is sensitive to the local chemical environment, particularly to changes in the electronic state of the molecule. Taking advantage of this property, we present a {sup 31}P NMR approach that uses inorganic phosphate buffer as an internal pH reference to determine the pK{sub a} values of the imide and second diphosphate of uridine-5 Prime -diphosphate compounds, including the first reported values for UDP-GlcNAc and UDP-S-GlcNAc. New methods for using inorganic phosphate buffer as an internal pH reference, involving mathematical correction factors and careful control of the chemical shift reference sample, are illustrated. A comparison of the newly determined imide and diphosphate pK{sub a} values of UDP, UDP-GlcNAc, and UDP-S-GlcNAc with other nucleotide phosphate and thio-analogs reveals the significance of the monosaccharide and sulfur position on the pK{sub a} values.

  11. Dynamics of International Reserve Accumulation in Turkish Economy

    Directory of Open Access Journals (Sweden)

    Duygu Ayhan

    2015-05-01

    Full Text Available Many of the emerging market economies embody macroeconomic and structural vulnerabilities due to large deficits, high inflation, slowing growth and heavy reliance on short-term capital inflows. Therefore, accumulation of international reserve holdings has been frequently used by authorities to serve as an insurance against the volatility of the capital flows and strengthen the fragile nature of these economies. Turkish economy, classified as one of the most fragile of the emerging economies, has been experiencing a similar process of international reserve accumulation. The chronically high current account deficit and low savings rate boost the importance of international reserves. Thus, the aim of this paper is to investigate the determinants of international reserves in Turkey. The dataset covers the 2000-2013 period. Consequently, we find that the international reserve accumulation is mainly explained by current account balance, per capita income and past crisis experience.

  12. PH og modernismen

    DEFF Research Database (Denmark)

    Ahnfeldt-Mollerup, Merete

    2012-01-01

    Artiklen kaster et kritisk blik på Poul Henningsens samfundsanalyse og dennes sammenhæng med hans design. PH ses i en bredere national og international sammenhæng. Diskussion af designmetoder, æstetik og Bauhaus.......Artiklen kaster et kritisk blik på Poul Henningsens samfundsanalyse og dennes sammenhæng med hans design. PH ses i en bredere national og international sammenhæng. Diskussion af designmetoder, æstetik og Bauhaus....

  13. Capturing intracellular pH dynamics by coupling its molecular mechanisms within a fully tractable mathematical model.

    Directory of Open Access Journals (Sweden)

    Yann Bouret

    Full Text Available We describe the construction of a fully tractable mathematical model for intracellular pH. This work is based on coupling the kinetic equations depicting the molecular mechanisms for pumps, transporters and chemical reactions, which determine this parameter in eukaryotic cells. Thus, our system also calculates the membrane potential and the cytosolic ionic composition. Such a model required the development of a novel algebraic method that couples differential equations for slow relaxation processes to steady-state equations for fast chemical reactions. Compared to classical heuristic approaches based on fitted curves and ad hoc constants, this yields significant improvements. This model is mathematically self-consistent and allows for the first time to establish analytical solutions for steady-state pH and a reduced differential equation for pH regulation. Because of its modular structure, it can integrate any additional mechanism that will directly or indirectly affect pH. In addition, it provides mathematical clarifications for widely observed biological phenomena such as overshooting in regulatory loops. Finally, instead of including a limited set of experimental results to fit our model, we show examples of numerical calculations that are extremely consistent with the wide body of intracellular pH experimental measurements gathered by different groups in many different cellular systems.

  14. Stabilization of Rigid Body Dynamics by Internal and External Torques

    National Research Council Canada - National Science Library

    Bloch, A. M; Krishnaprasad, P. S; Marsden, J. E; Sanchez de Alvarez, G

    1990-01-01

    ...] with quadratic feedback torques for internal rotors. We show that with such torques, the equations for the rigid body with momentum wheels are Hamiltonian with respect to a Lie-Poisson bracket structure. Further...

  15. Internal and external dynamics of regional cooperation in Central Asia

    Directory of Open Access Journals (Sweden)

    Mirzokhid Rakhimov

    2010-07-01

    Challenges of the 21-century require a broader partnership and cooperation. Future prospects of multilateral regional and international cooperation in Central Asia will depend on correlations of national, regional and global interests. It is necessary first of all strong dialogs between Central Asian republics itself. Central Asian geopolitical, economic and security challenges are connected and solution could come jointly. Future regional cooperation, strong international partnership would promote more stability, economic reforms and democratization to region and beyond.

  16. Charge-leveling and proper treatment of long-range electrostatics in all-atom molecular dynamics at constant pH.

    Science.gov (United States)

    Wallace, Jason A; Shen, Jana K

    2012-11-14

    Recent development of constant pH molecular dynamics (CpHMD) methods has offered promise for adding pH-stat in molecular dynamics simulations. However, until now the working pH molecular dynamics (pHMD) implementations are dependent in part or whole on implicit-solvent models. Here we show that proper treatment of long-range electrostatics and maintaining charge neutrality of the system are critical for extending the continuous pHMD framework to the all-atom representation. The former is achieved here by adding forces to titration coordinates due to long-range electrostatics based on the generalized reaction field method, while the latter is made possible by a charge-leveling technique that couples proton titration with simultaneous ionization or neutralization of a co-ion in solution. We test the new method using the pH-replica-exchange CpHMD simulations of a series of aliphatic dicarboxylic acids with varying carbon chain length. The average absolute deviation from the experimental pK(a) values is merely 0.18 units. The results show that accounting for the forces due to extended electrostatics removes the large random noise in propagating titration coordinates, while maintaining charge neutrality of the system improves the accuracy in the calculated electrostatic interaction between ionizable sites. Thus, we believe that the way is paved for realizing pH-controlled all-atom molecular dynamics in the near future.

  17. Isolated secretion granules from parotid glands of chronically stimulated rats possess an alkaline internal pH and inward-directed H+ pump activity

    International Nuclear Information System (INIS)

    Arvan, P.; Castle, J.D.

    1986-01-01

    Secretion granules have been isolated from the parotid glands of rats that have been chronically stimulated with the β-adrenergic agonist, isoproterenol. These granules are of interest because they package a quantitatively different set of secretory proteins in comparison with granules from the normal gland. Polypeptides enriched in proline, glycine, and glutamine, which are known to have pI's >10, replace α-amylase (pI's = 6.8) as the principal content species. The internal pH of granules from the treated rats changes from 7.8 in a potassium sulfate medium to 6.9 in a choline chloride medium. The increased pH over that of normal parotid granules (∼6.8) appears to protect the change in composition of the secretory contents. Whereas normal mature parotide granules have practically negligible levels of H + pumping ATPase activity, the isolated granules from isoproterenol-treated rats undergo a time-dependent internal acidification that requires the presence of ATP and is abolished by an H + ionophore. Additionally, an inside-positive granule transmembrane potential develops after ATP addition that depends upon ATP hydrolysis. Two independent methods have been used that exclude the possibility that contaminating organelles are the source of the H + -ATPase activity. Together these data provide clear evidence for the presence of an H + pump in the membranes of parotid granules from chronically stimulated rats. However, despite the presence of H + -pump activity, fluorescence microscopy with the weak base, acridine orange, reveals that the intragranular pH in live cells is greater than that of the cytoplasm

  18. International Conference on Structural Nonlinear Dynamics and Diagnosis

    CERN Document Server

    CSNDD 2012; CSNDD 2014

    2015-01-01

    This book, which presents the peer-reviewed post-proceedings of CSNDD 2012 and CSNDD 2014, addresses the important role that relevant concepts and tools from nonlinear and complex dynamics could play in present and future engineering applications. It includes 22 chapters contributed by outstanding researchers and covering various aspects of applications, including: structural health monitoring, diagnosis and damage detection, experimental methodologies, active vibration control and smart structures, passive control of structures using nonlinear energy sinks, vibro-impact dynamic MEMS/NEMS/AFM, energy-harvesting materials and structures, and time-delayed feedback control, as well as aspects of deterministic versus stochastic dynamics and control of nonlinear phenomena in physics.  Researchers and engineers interested in the challenges posed and opportunities offered by nonlinearities in the development of passive and active control strategies, energy harvesting, novel design criteria, modeling and characteriz...

  19. Energy harvesting by dynamic unstability and internal resonance for piezoelectric beam

    Energy Technology Data Exchange (ETDEWEB)

    Lan, Chunbo; Qin, Weiyang, E-mail: 353481781@qq.com; Deng, Wangzheng [Department of Engineering Mechanics, Northwestern Polytechnical University, Xi' an 710072 (China)

    2015-08-31

    We investigated the energy harvesting of a vertical beam with tip mass under vertical excitations. We applied dynamic unstability and internal resonance to improve the efficiency of harvesting. The experiments of harmonic excitation were carried out. Results show that for the beam there exist internal resonances in the dynamically unstable and the buckling bistable cases. The dynamic unstability is a determinant for strong internal resonance or mode coupling, which can be used to create a large output from piezoelectric patches. Then, the experiments of stochastic excitation were carried out. Results prove that the internal resonance or mode coupling can transfer the excitation energy to the low order modes, mainly the first and the second one. This can bring about a large output voltage. For a stochastic excitation, it is proved that there is an optimal weight of tip mass for realizing internal resonance and producing large outputs.

  20. Support for PhD Students: The Impact of Institutional Dynamics on the Pedagogy of Learning Development

    Science.gov (United States)

    Peelo, Moira

    2013-01-01

    This paper explores one practitioner's learning development work with PhD students in a changing university context in which managerialism and financial stringency have combined. It questions how learning development practitioners can maintain their professional goals while negotiating issues arising from managerialism, financial stringency,…

  1. Conformational exchange in pseudoazurin: different kinds of microsecond to millisecond dynamics characterized by their pH and buffer dependence using 15N NMR relaxation.

    Science.gov (United States)

    Hass, Mathias A S; Vlasie, Monica D; Ubbink, Marcellus; Led, Jens J

    2009-01-13

    The dynamics of the reduced form of the blue copper protein pseudoazurin from Alcaligenes faecalis S-6 was investigated using (15)N relaxation measurements with a focus on the dynamics of the micro- to millisecond time scale. Different types of conformational exchange processes are observed in the protein on this time scale. At low pH, the protonation of the C-terminal copper-ligated histidine, His81, is observed. A comparison of the exchange rates in the presence and absence of added buffers shows that the protonation is the rate-limiting step at low buffer concentrations. This finding agrees with previous observations for other blue copper proteins, e.g., amicyanin and plastocyanin. However, in contrast to plastocyanin but similar to amicyanin, a second conformational exchange between different conformations of the protonated copper site is observed at low pH, most likely triggered by the protonation of His81. This process has been further characterized using CPMG dispersion methods and is found to occur with a rate of a few thousands per second. Finally, micro- to millisecond motions are observed in one of the loop regions and in the alpha-helical regions. These motions are unaffected by pH and are unrelated to the conformational changes in the active site of pseudoazurin.

  2. DNA fragmentation dynamics allows the assessment of cryptic sperm damage in human: Evaluation of exposure to ionizing radiation, hyperthermia, acidic pH and nitric oxide

    Energy Technology Data Exchange (ETDEWEB)

    Santiso, Rebeca; Tamayo, Maria [Laboratorio de Genetica Molecular y Radiobiologia, Centro Oncologico de Galicia, Doctor Camilo Veiras 1, 15009-A Coruna (Spain); Genetics Unit, INIBIC-Complejo Hospitalario Universitario A Coruna (CHUAC), As Xubias, 84, 15006-A Coruna (Spain); Gosalvez, Jaime [Genetics Unit, Facultad de Biologia, Universidad Autonoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049 Madrid (Spain); Johnston, Steve [School of Agriculture and Food Science, University of Queensland, Gatton 4343 (Australia); Marino, Alfonso [Servicio de Oncologia Radioterapica, Centro Oncologico de Galicia, Doctor Camilo Veiras 1, 15009-A Coruna (Spain); Fernandez, Carlos; Losada, Carlos [Servicio de Radiofisica, Centro Oncologico de Galicia, Doctor Camilo Veiras 1, 15009-A Coruna (Spain); Fernandez, Jose Luis, E-mail: Jose.Luis.Fernandez.Garcia@sergas.es [Laboratorio de Genetica Molecular y Radiobiologia, Centro Oncologico de Galicia, Doctor Camilo Veiras 1, 15009-A Coruna (Spain); Genetics Unit, INIBIC-Complejo Hospitalario Universitario A Coruna (CHUAC), As Xubias, 84, 15006-A Coruna (Spain)

    2012-06-01

    Sperm DNA fragmentation (SDF) is not a static seminal parameter, since the longevity of sperm DNA decreases progressively with time following ejaculation or thawing. While the dynamics of SDF is a species-specific characteristic, in the case of humans, there is still significant variation within patients. To evaluate the suitability of the dynamic SDF assay to assess the adverse effects of agents that cause genetic damage, fresh semen samples from different donors were exposed in vitro to (1) increasing acute doses of ionizing radiation, (2) elevated temperature (41 Degree-Sign C and 45 Degree-Sign C), (3) acidic pH (pH 4) and (4) the nitric oxide (NO) donor sodium nitroprusside (SNP). Sperm DNA fragmentation was analyzed after an incubation period of chronic (24 h), or acute (1 h) exposure to each treatment followed by incubation at 37 Degree-Sign C over a period of 24 h. SDF was assessed using the sperm chromatin dispersion (SCD) test. Dynamic SDF for each treatment was analyzed using Kaplan-Meier survival curves. All agents, except for ionizing radiation, accelerated SDF kinetics following chronic exposure over a 24 h period. Transient exposure to NO and heat but not acidic pH increased the basal (T0) level of SDF. Despite the removal of the three toxicants, the remaining sperm following acute exposure showed a decrease in their expected DNA longevity. It is concluded that the assessment of sperm DNA fragmentation dynamics is an effective methodological approach for revealing latent damage associated with toxicants that is not initially expressed following a single initial observation of SDF.

  3. Handbook of international insurance between global dynamics and local contingencies

    CERN Document Server

    Venard, Bertrand

    2007-01-01

    THE HANDBOOK OF INTERNATIONAL INSURANCE Gordon Stewart, President, Insurance Information Institute, New York, USA "The globalization of insurance markets means that understanding both international developments and local trends around the world is now fundamental for insurance executives coping with today’s complex and competitive environment. By providing such a comprehensive picture of the world’s insurance markets, this unique and necessary book becomes an essential tool for anyone seeking to operate wisely and successfully. Richard D. Phillips, Professor and Chairman, Department of Risk Management and Insurance, Georgia State University, Atlanta, USA "Comprehensive surveys, written by international experts, provide in depth descriptions and discuss recent developments of the world’s major insurance markets. Each chapter contains essential insights for insurance executives and academic researchers interested in risk management and the globalization of insurance markets." Patrick Liedtke, Secretary Ge...

  4. Internal dynamics of intense twin beams and their coherence

    Czech Academy of Sciences Publication Activity Database

    Peřina Jr., J.; Haderka, Ondřej; Allevi, A.; Bondani, M.

    2016-01-01

    Roč. 6, Feb (2016), 1-8, č. článku 22320. ISSN 2045-2322 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : dynamics of intense * twin beams * pump-depleted parametric * down-conversion * coherence Subject RIV: BH - Optics, Masers, Lasers Impact factor: 4.259, year: 2016

  5. Rotational characterization of methyl methacrylate: Internal dynamics and structure determination

    Science.gov (United States)

    Herbers, Sven; Wachsmuth, Dennis; Obenchain, Daniel A.; Grabow, Jens-Uwe

    2018-01-01

    Rotational constants, Watson's S centrifugal distortion coefficients, and internal rotation parameters of the two most stable conformers of methyl methacrylate were retrieved from the microwave spectrum. Splittings of rotational energy levels were caused by two non equivalent methyl tops. Constraining the centrifugal distortion coefficients and internal rotation parameters to the values of the main isotopologues, the rotational constants of all single substituted 13C and 18O isotopologues were determined. From these rotational constants the substitution structures and semi-empirical zero point structures of both conformers were precisely determined.

  6. An outline of military technological dynamics as restraints for acquisition, international cooperation and domestic technological development

    Directory of Open Access Journals (Sweden)

    Édison Renato Silva

    2014-12-01

    Full Text Available The expectation that technological returns from defense expenditure through acquisition, international cooperation and domestic research would further national development underappreciates the different technological dynamic of the armed services. This paper outlines the technological dynamic the stems from fighting in the air, at sea and on land, exemplifying consequences for the case of acquisition.

  7. International Workshop on Advanced Dynamics and Model Based Control of Structures and Machines

    CERN Document Server

    Belyaev, Alexander; Krommer, Michael

    2017-01-01

    The papers in this volume present and discuss the frontiers in the mechanics of controlled machines and structures. They are based on papers presented at the International Workshop on Advanced Dynamics and Model Based Control of Structures and Machines held in Vienna in September 2015. The workshop continues a series of international workshops held in Linz (2008) and St. Petersburg (2010).

  8. In situ dynamics of O2, pH, light and photosynthesis in ikaite tufa columns (Ikka Fjord, Greenland – a unique microbial habitat.

    Directory of Open Access Journals (Sweden)

    Erik Christian Løvbjerg Trampe

    2016-05-01

    Full Text Available The Ikka Fjord (SW Greenland harbors a unique microbial habitat in the form of several hundred submarine tufa columns composed of ikaite, a special hexahydrate form of calcium carbonate that precipitates when alkaline phosphate- and carbonate-enriched spring water seeping out of the sea floor meets cold seawater. While several unique heterotrophic microbes have been isolated from the tufa columns, the microbial activity and the boundary conditions for microbial growth in ikaite have remained unexplored. We present the first detailed in situ characterization of the physico-chemical microenvironment and activity of oxygenic phototrophs thriving within the ikaite columns. In situ underwater microsensor measurements of pH, temperature, and irradiance in the porous ikaite crystal matrix, revealed an extreme microenvironment characterized by low temperatures, strong light attenuation, and gradients of pH changing from pH 9 at the outer column surface to above pH 10 over the first 1-2 cm of the ikaite. This outer layer of the freshly deposited ikaite matrix contained densely pigmented yellow and green zones harboring a diverse phototrophic community dominated by diatoms and cyanobacteria, respectively, as shown by amplicon sequencing. In situ O2 measurements, as well as underwater variable chlorophyll fluorescence measurements of photosynthetic activity, demonstrated high levels of oxygenic photosynthesis in this extreme gradient environment with strong irradiance-driven O2 dynamics ranging from anoxia to hyperoxic conditions in the ikaite matrix, albeit the local formation of gas bubbles buffered the day-night dynamics of O2 in the tufa columns. The microbial phototrophs in the ikaite matrix are embedded in exopolymers forming endolithic biofilms that may interact with mineral formation and cementing of ikaite crystals.

  9. In situ Dynamics of O2, pH, Light, and Photosynthesis in Ikaite Tufa Columns (Ikka Fjord, Greenland)-A Unique Microbial Habitat.

    Science.gov (United States)

    Trampe, Erik C L; Larsen, Jens E N; Glaring, Mikkel A; Stougaard, Peter; Kühl, Michael

    2016-01-01

    The Ikka Fjord (SW Greenland) harbors a unique microbial habitat in the form of several hundred submarine tufa columns composed of ikaite, a special hexahydrate form of calcium carbonate that precipitates when alkaline phosphate- and carbonate-enriched spring water seeping out of the sea floor meets cold seawater. While several unique heterotrophic microbes have been isolated from the tufa columns, the microbial activity, and the boundary conditions for microbial growth in ikaite have remained unexplored. We present the first detailed in situ characterization of the physico-chemical microenvironment and activity of oxygenic phototrophs thriving within the ikaite columns. In situ underwater microsensor measurements of pH, temperature, and irradiance in the porous ikaite crystal matrix, revealed an extreme microenvironment characterized by low temperatures, strong light attenuation, and gradients of pH changing from pH 9 at the outer column surface to above pH 10 over the first 1-2 cm of the ikaite. This outer layer of the freshly deposited ikaite matrix contained densely pigmented yellow and green zones harboring a diverse phototrophic community dominated by diatoms and cyanobacteria, respectively, as shown by amplicon sequencing. In situ O2 measurements, as well as underwater variable chlorophyll fluorescence measurements of photosynthetic activity, demonstrated high levels of oxygenic photosynthesis in this extreme gradient environment with strong irradiance-driven O2 dynamics ranging from anoxia to hyperoxic conditions in the ikaite matrix, albeit the local formation of gas bubbles buffered the day-night dynamics of O2 in the tufa columns. The microbial phototrophs in the ikaite matrix are embedded in exopolymers forming endolithic biofilms that may interact with mineral formation and cementing of ikaite crystals.

  10. In situ Dynamics of O2, pH, Light, and Photosynthesis in Ikaite Tufa Columns (Ikka Fjord, Greenland)—A Unique Microbial Habitat

    Science.gov (United States)

    Trampe, Erik C. L.; Larsen, Jens E. N.; Glaring, Mikkel A.; Stougaard, Peter; Kühl, Michael

    2016-01-01

    The Ikka Fjord (SW Greenland) harbors a unique microbial habitat in the form of several hundred submarine tufa columns composed of ikaite, a special hexahydrate form of calcium carbonate that precipitates when alkaline phosphate- and carbonate-enriched spring water seeping out of the sea floor meets cold seawater. While several unique heterotrophic microbes have been isolated from the tufa columns, the microbial activity, and the boundary conditions for microbial growth in ikaite have remained unexplored. We present the first detailed in situ characterization of the physico-chemical microenvironment and activity of oxygenic phototrophs thriving within the ikaite columns. In situ underwater microsensor measurements of pH, temperature, and irradiance in the porous ikaite crystal matrix, revealed an extreme microenvironment characterized by low temperatures, strong light attenuation, and gradients of pH changing from pH 9 at the outer column surface to above pH 10 over the first 1–2 cm of the ikaite. This outer layer of the freshly deposited ikaite matrix contained densely pigmented yellow and green zones harboring a diverse phototrophic community dominated by diatoms and cyanobacteria, respectively, as shown by amplicon sequencing. In situ O2 measurements, as well as underwater variable chlorophyll fluorescence measurements of photosynthetic activity, demonstrated high levels of oxygenic photosynthesis in this extreme gradient environment with strong irradiance-driven O2 dynamics ranging from anoxia to hyperoxic conditions in the ikaite matrix, albeit the local formation of gas bubbles buffered the day-night dynamics of O2 in the tufa columns. The microbial phototrophs in the ikaite matrix are embedded in exopolymers forming endolithic biofilms that may interact with mineral formation and cementing of ikaite crystals. PMID:27242741

  11. International Workshop on Mathematical Modeling of Tumor-Immune Dynamics

    CERN Document Server

    Kim, Peter; Mallet, Dann

    2014-01-01

    This collection of papers offers a broad synopsis of state-of-the-art mathematical methods used in modeling the interaction between tumors and the immune system. These papers were presented at the four-day workshop on Mathematical Models of Tumor-Immune System Dynamics held in Sydney, Australia from January 7th to January 10th, 2013. The workshop brought together applied mathematicians, biologists, and clinicians actively working in the field of cancer immunology to share their current research and to increase awareness of the innovative mathematical tools that are applicable to the growing field of cancer immunology. Recent progress in cancer immunology and advances in immunotherapy suggest that the immune system plays a fundamental role in host defense against tumors and could be utilized to prevent or cure cancer. Although theoretical and experimental studies of tumor-immune system dynamics have a long history, there are still many unanswered questions about the mechanisms that govern the interaction betwe...

  12. International Trade and Macroeconomic Dynamics with Heteroegenous Firms

    OpenAIRE

    Ghironi, Fabio; Melitz, Marc J

    2004-01-01

    We develop a stochastic, general equilibrium, two-country model of trade and macroeconomic dynamics. Productivity differs across individual, monopolistically competitive firms in each country. Firms face a sunk entry cost in the domestic market and both fixed and per-unit export costs. Only relatively more productive firms export. Exogenous shocks to aggregate productivity and entry or trade costs induce firms to enter and exit both their domestic and export markets, thus altering the composi...

  13. Review of selected dynamic material control functions for international safeguards

    International Nuclear Information System (INIS)

    Lowry, L.L.

    1980-09-01

    With the development of Dynamic Special Nuclear Material Accounting and Control systems used in nuclear manufacturing and reprocessing plants, there arises the question as to how these systems affect the IAEA inspection capabilities. The systems in being and under development provide information and control for a variety of purposes important to the plant operator, the safeguards purpose being one of them. This report attempts to judge the usefulness of these dynamic systems to the IAEA and have defined 12 functions that provide essential information to it. If the information acquired by these dynamic systems is to be useful to the IAEA, the inspectors must be able to independently verify it. Some suggestions are made as to how this might be done. But, even if it should not be possible to verify all the data, the availability to the IAEA of detailed, simultaneous, and plant-wide information would tend to inhibit a plant operator from attempting to generate a floating or fictitious inventory. Suggestions are made that might be helpful in the design of future software systems, an area which has proved to be fatally deficient in some systems and difficult in all

  14. Dynamic managerial capability of technology-based international new ventures

    DEFF Research Database (Denmark)

    Altshuler, Liliya

    2014-01-01

    case study of a technology-based INV conducted over the period of 3.5 years, starting 8 years into the firm’s history. This unique design has enabled close observation of the specific events and challenges the firm has been facing after its initial success, and of the aspects in the firm’s management...... to resource availability. The study takes the dynamic capability perspective and focuses on INVs’ management, which are seen as founders and builders of the processes, rules and structures that lay the basis for long-term competitive advantage for such firms. Based on the findings, specific aspects...

  15. Dynamic International Competitiveness of Transition Economies: The Case of Poland

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Ulff-Møller

    2003-01-01

    This paper shows that the reform on the structures of the Polish economy has had an impressively fast effect on the numbers of different products this country exports to Western countries. The time path may well be described by a logistic curve. The change in the exports of this country may...... therefore be characterised by a widening, instead of a deepening in specialisation. The paper introduces a new empirical methodology to evaluate the dynamic changes in export activities of a country. The result of this new methodology is that quality competition is becoming increasingly important for Poland...

  16. Evolution of energy labelling: analysis of international dynamics

    International Nuclear Information System (INIS)

    Malandrino, Ornella; Roca, Emmanuele

    2005-01-01

    Currently there are large variety of tools that play a very important role in providing benchmarks for sustainability performance of products and guidance for consumers. The present paper analyses the most important programme related to energy labelling, a market based instrument mainly addressed to consumers, certifying that a specific product is energy efficient. Particular attention has been given to International and European Union Labels of the consumption of energy and other resources by household appliances, to the energy efficient labelling programmes for office equipment and the certification schemes of energy performance of buildings

  17. Internal Kink Mode Dynamics in High-β NSTX Plasmas

    International Nuclear Information System (INIS)

    Menard, J.E.; Bell, R.E.; Fredrickson, E.D.; Gates, D.A.; Kaye, S.M.; LeBlanc, B.P.; Medley, S.S.; Park, W.; Sabbagh, S.A.; Sontag, A.; Stutman, D.; Tritz, K.; Zhu, W.

    2004-01-01

    Saturated internal kink modes have been observed in many of the highest toroidal beta discharges of the National Spherical Torus Experiment (NSTX). These modes often cause rotation flattening in the plasma core, can degrade energy confinement, and in some cases contribute to the complete loss of plasma angular momentum and stored energy. Characteristics of the modes are measured using soft X-ray, kinetic profile, and magnetic diagnostics. Toroidal flows approaching Alfvenic speeds, island pressure peaking, and enhanced viscous and diamagnetic effects associated with high-beta may contribute to mode nonlinear stabilization. These saturation mechanisms are investigated for NSTX parameters and compared to experimental data

  18. Internal kink mode dynamics in high-β NSTX plasmas

    International Nuclear Information System (INIS)

    Menard, J.E.; Bell, R.E.; Fredrickson, E.D.; Gates, D.A.; Kaye, S.M.; LeBlanc, B.P.; Medley, S.S.; Park, W.; Sabbagh, S.A.; Sontag, A.; Zhu, W.; Stutman, D.; Tritz, K.

    2005-01-01

    Saturated internal kink modes have been observed in many of the highest toroidal beta discharges of the National Spherical Torus Experiment (NSTX). These modes often cause rotation flattening in the plasma core, can degrade energy confinement, and in some cases contribute to the complete loss of plasma angular momentum and stored energy. Characteristics of the modes are measured using soft X-ray, kinetic profile, and magnetic diagnostics. Toroidal flows approaching Alfvenic speeds, island pressure peaking, and enhanced viscous and diamagnetic effects associated with high-beta may contribute to mode non-linear stabilization. These saturation mechanisms are investigated for NSTX parameters and compared to experiment. (author)

  19. Effects of internal friction on contact formation dynamics of polymer chain

    Science.gov (United States)

    Bian, Yukun; Li, Peng; Zhao, Nanrong

    2018-04-01

    A theoretical framework is presented to study the contact formation dynamics of polymer chains, in accompany with an electron-transfer quenching. Based on a non-Markovian Smoluchowski equation supplemented with an exponential sink term, we derive the mean time of contact formation under Wilemski-Fixman approximation. Our particular attentions are paid to the effect of internal friction. We find out that internal friction induces a novel fractional viscosity dependence, which will become more remarkable as internal friction increases. Furthermore, we clarify that internal friction inevitably promotes a diffusion-controlled mechanism by slowing the chain relaxation. Finally, we apply our theory to rationalise the experimental investigation for contact formation of a single-stranded DNA. The theoretical results can reproduce the experimental data very well with quite reasonable estimation for the intrinsic parameters. Such good agreements clearly demonstrate the validity of our theory which has appropriately addressed the very role of internal friction to the relevant dynamics.

  20. PH sensor

    OpenAIRE

    Artero, C.; Nogueras Cervera, Marc; Manuel Lázaro, Antonio

    2012-01-01

    This paper presents a design of a marine instrument for the measurement of pH in seawater. The measurement system consists of a pH electrode connected to the underwater observatory OBSEA. The extracted data are useful for scientists researching ocean acidification. Peer Reviewed

  1. FOREWORD: International Summer School for Advanced Studies 'Dynamics of open nuclear systems' (PREDEAL12)

    Science.gov (United States)

    Delion, D. S.; Zamfir, N. V.; Raduta, A. R.; Gulminelli, F.

    2013-02-01

    This proceedings volume contains the invited lectures and contributions presented at the International Summer School on Nuclear Physics held at Trei Brazi, a summer resort of the Bioterra University, near the city of Predeal, Romania, on 9-20 July 2012. The long tradition of International Summer Schools on Nuclear Physics in Romania dates as far back as 1964, with the event being scheduled every two years. During this period of almost 50 years, many outstanding nuclear scientists have lectured on various topics related to nuclear physics and particle physics. This year we celebrate the 80th birthday of Aureliu Sandulescu, one of the founders of the Romanian school of theoretical nuclear physics. He was Serban Titeica's PhD student, one of Werner Heisenberg's PhD students, and he organized the first edition of this event. Aureliu Sandulescu's major contributions to the field of theoretical nuclear physics are related in particular to the prediction of cluster radioactivity, the physics of open quantum systems and the innovative technique of detecting superheavy nuclei using the double magic projectile 48Ca (Calcium), nowadays a widely used method at the JINR—Dubna and GSI—Darmstadt laboratories. The title of the event, 'Dynamics of Open Nuclear Systems', is in recognition of Aureliu Sandulescu's great personality. The lectures were attended by Romanian and foreign Master and PhD students and young researchers in nuclear physics. About 25 reputable professors and researchers in nuclear physics delivered lectures during this period. According to a well-established tradition, an interval of two hours was allotted for each lecture (including discussions). Therefore we kept a balance between the school and conference format. Two lectures were held during the morning and afternoon sessions. After lecture sessions, three or four oral contributions were given by young scientists. This was a good opportunity for them to present the results of their research in front of

  2. Occupant-vehicle dynamics and the role of the internal model

    Science.gov (United States)

    Cole, David J.

    2018-05-01

    With the increasing need to reduce time and cost of vehicle development there is increasing advantage in simulating mathematically the dynamic interaction of a vehicle and its occupant. The larger design space arising from the introduction of automated vehicles further increases the potential advantage. The aim of the paper is to outline the role of the internal model hypothesis in understanding and modelling occupant-vehicle dynamics, specifically the dynamics associated with direction and speed control of the vehicle. The internal model is the driver's or passenger's understanding of the vehicle dynamics and is thought to be employed in the perception, cognition and action processes of the brain. The internal model aids the estimation of the states of the vehicle from noisy sensory measurements. It can also be used to optimise cognitive control action by predicting the consequence of the action; thus model predictive control (MPC) theory provides a foundation for modelling the cognition process. The stretch reflex of the neuromuscular system also makes use of the prediction of the internal model. Extensions to the MPC approach are described which account for: interaction with an automated vehicle; robust control; intermittent control; and cognitive workload. Further work to extend understanding of occupant-vehicle dynamic interaction is outlined. This paper is based on a keynote presentation given by the author to the 13th International Symposium on Advanced Vehicle Control (AVEC) conference held in Munich, September 2016.

  3. Soil solution Zn and pH dynamics in non-rhizosphere soil and in the rhizosphere of Thlaspi caerulescens grown in a Zn/Cd-contaminated soil.

    Science.gov (United States)

    Luo, Y M; Christie, P; Baker, A J

    2000-07-01

    Temporal changes in soil solution properties and metal speciation were studied in non-rhizosphere soil and in the rhizosphere of the hyperaccumulator Thlaspi caerulescens J. & C. Presl (population from Prayon, Belgium) grown in a Zn- and Cd-contaminated soil. This paper focuses on soil solution Zn and pH dynamics during phytoextraction. The concentration of Zn in both non-rhizosphere and rhizosphere soil solutions decreased from 23 mg/l at the beginning to 2 mg/l at the end of the experiment (84 days after transplanting of seedlings), mainly due to chemical sorption. There was no significant difference in overall Zn concentration between the planted and the unplanted soil solutions (P > 0.05). Soil solution pH decreased initially and then increased slightly in both planted and unplanted soil zones. From 60 to 84 days after transplanting, the pH of the rhizosphere soil solution was higher than that of non-rhizosphere soil solution (P<0.05). Zn uptake by the hyperaccumulator plants was 8.8 mg per pot (each containing 1 kg oven-dry soil) on average. The data indicate that the potential of T. caerulescens to remove Zn from contaminated soil may not be related to acidification of the rhizosphere.

  4. Quantum master equation for collisional dynamics of massive particles with internal degrees of freedom

    International Nuclear Information System (INIS)

    Smirne, Andrea; Vacchini, Bassano

    2010-01-01

    We address the microscopic derivation of a quantum master equation in Lindblad form for the dynamics of a massive test particle with internal degrees of freedom, interacting through collisions with a background ideal gas. When either internal or center-of-mass degrees of freedom can be treated classically, previously established equations are obtained as special cases. If in an interferometric setup the internal degrees of freedom are not detected at the output, the equation can be recast in the form of a generalized Lindblad structure, which describes non-Markovian effects. The effect of internal degrees of freedom on center-of-mass decoherence is considered in this framework.

  5. Comparison of the Internal Dynamics of Metalloproteases Provides New Insights on Their Function and Evolution.

    Directory of Open Access Journals (Sweden)

    Henrique F Carvalho

    Full Text Available Metalloproteases have evolved in a vast number of biological systems, being one of the most diverse types of proteases and presenting a wide range of folds and catalytic metal ions. Given the increasing understanding of protein internal dynamics and its role in enzyme function, we are interested in assessing how the structural heterogeneity of metalloproteases translates into their dynamics. Therefore, the dynamical profile of the clan MA type protein thermolysin, derived from an Elastic Network Model of protein structure, was evaluated against those obtained from a set of experimental structures and molecular dynamics simulation trajectories. A close correspondence was obtained between modes derived from the coarse-grained model and the subspace of functionally-relevant motions observed experimentally, the later being shown to be encoded in the internal dynamics of the protein. This prompted the use of dynamics-based comparison methods that employ such coarse-grained models in a representative set of clan members, allowing for its quantitative description in terms of structural and dynamical variability. Although members show structural similarity, they nonetheless present distinct dynamical profiles, with no apparent correlation between structural and dynamical relatedness. However, previously unnoticed dynamical similarity was found between the relevant members Carboxypeptidase Pfu, Leishmanolysin, and Botulinum Neurotoxin Type A, despite sharing no structural similarity. Inspection of the respective alignments shows that dynamical similarity has a functional basis, namely the need for maintaining proper intermolecular interactions with the respective substrates. These results suggest that distinct selective pressure mechanisms act on metalloproteases at structural and dynamical levels through the course of their evolution. This work shows how new insights on metalloprotease function and evolution can be assessed with comparison schemes that

  6. International energy market dynamics: a modelling approach. Tome 1

    International Nuclear Information System (INIS)

    Nachet, S.

    1996-01-01

    This work is an attempt to model international energy market and reproduce the behaviour of both energy demand and supply. Energy demand was represented using sector versus source approach. For developing countries, existing link between economic and energy sectors were analysed. Energy supply is exogenous for energy sources other than oil and natural gas. For hydrocarbons, exploration-production process was modelled and produced figures as production yield, exploration effort index, etc. The model built is econometric and is solved using a software that was constructed for this purpose. We explore the energy market future using three scenarios and obtain projections by 2010 for energy demand per source and oil natural gas supply per region. Economic variables are used to produce different indicators as energy intensity, energy per capita, etc. (author). 378 refs., 26 figs., 35 tabs., 11 appends

  7. International energy market dynamics: a modelling approach. Tome 2

    International Nuclear Information System (INIS)

    Nachet, S.

    1996-01-01

    This work is an attempt to model international energy market and reproduce the behaviour of both energy demand and supply. Energy demand was represented using sector versus source approach. For developing countries, existing link between economic and energy sectors were analysed. Energy supply is exogenous for energy sources other than oil and natural gas. For hydrocarbons, exploration-production process was modelled and produced figures as production yield, exploration effort index, ect. The model build is econometric and is solved using a software that was constructed for this purpose. We explore the energy market future using three scenarios and obtain projections by 2010 for energy demand per source and oil and natural gas supply per region. Economic variables are used to produce different indicators as energy intensity, energy per capita, etc. (author). 378 refs., 26 figs., 35 tabs., 11 appends

  8. 14th International Conference on Nonequilibrium Carrier Dynamics in Semiconductors

    CERN Document Server

    Saraniti, M; Nonequilibrium Carrier Dynamics in Semiconductors

    2006-01-01

    International experts gather every two years at this established conference to discuss recent developments in theory and experiment in non-equilibrium transport phenomena. These developments have been the driving force behind the spectacular advances in semiconductor physics and devices over the last few decades. Originally known as "Hot Carriers in Semiconductors," the 14th conference in the series covered a wide spectrum of traditional topics dealing with non-equilibrium phenomena, ranging from quantum transport to optical phenomena in mesoscopic and nano-scale structures. Particular attention was given this time to emerging areas of this rapidly evolving field, with many sessions covering terahertz devices, high field transport in nitride semiconductors, spintronics, molecular electronics, and bioelectronics applications.

  9. Finite-size effects on the dynamic susceptibility of CoPhOMe single-chain molecular magnets in presence of a static magnetic field

    Science.gov (United States)

    Pini, M. G.; Rettori, A.; Bogani, L.; Lascialfari, A.; Mariani, M.; Caneschi, A.; Sessoli, R.

    2011-09-01

    The static and dynamic properties of the single-chain molecular magnet Co(hfac)2NITPhOMe (CoPhOMe) (hfac = hexafluoroacetylacetonate, NITPhOMe = 4'-methoxy-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) are investigated in the framework of the Ising model with Glauber dynamics, in order to take into account both the effect of an applied magnetic field and a finite size of the chains. For static fields of moderate intensity and short chain lengths, the approximation of a monoexponential decay of the magnetization fluctuations is found to be valid at low temperatures; for strong fields and long chains, a multiexponential decay should rather be assumed. The effect of an oscillating magnetic field, with intensity much smaller than that of the static one, is included in the theory in order to obtain the dynamic susceptibility χ(ω). We find that, for an open chain with N spins, χ(ω) can be written as a weighted sum of N frequency contributions, with a sum rule relating the frequency weights to the static susceptibility of the chain. Very good agreement is found between the theoretical dynamic susceptibility and the ac susceptibility measured in moderate static fields (Hdc≤2 kOe), where the approximation of a single dominating frequency for each segment length turns out to be valid. For static fields in this range, data for the relaxation time, τ versus Hdc, of the magnetization of CoPhOMe at low temperature are also qualitatively reproduced by theory, provided that finite-size effects are included.

  10. 12th International Conference of Dynamical Systems-Theory and Applications

    CERN Document Server

    Applied Non-Linear Dynamical Systems

    2014-01-01

    The book is a collection of contributions devoted to analytical, numerical and experimental techniques of dynamical systems, presented at the International Conference on Dynamical Systems: Theory and Applications, held in Łódź, Poland on December 2-5, 2013. The studies give deep insight into both the theory and applications of non-linear dynamical systems, emphasizing directions for future research. Topics covered include: constrained motion of mechanical systems and tracking control; diversities in the inverse dynamics; singularly perturbed ODEs with periodic coefficients; asymptotic solutions to the problem of vortex structure around a cylinder; investigation of the regular and chaotic dynamics; rare phenomena and chaos in power converters; non-holonomic constraints in wheeled robots; exotic bifurcations in non-smooth systems; micro-chaos; energy exchange of coupled oscillators; HIV dynamics; homogenous transformations with applications to off-shore slender structures; novel approaches to a qualitative s...

  11. Investigations Into Internal and External Aspects of Dynamic Agent-Environment Couplings

    Science.gov (United States)

    Dautenhahn, Kerstin

    This paper originates from my work on `social agents'. An issue which I consider important to this kind of research is the dynamic coupling of an agent with its social and non-social environment. I hypothesize `internal dynamics' inside an agent as a basic step towards understanding. The paper therefore focuses on the internal and external dynamics which couple an agent to its environment. The issue of embodiment in animals and artifacts and its relation to `social dynamics' is discussed first. I argue that embodiment is linked to a concept of a body and is not necessarily given when running a control program on robot hardware. I stress the individual characteristics of an embodied cognitive system, as well as its social embeddedness. I outline the framework of a physical-psychological state space which changes dynamically in a self-modifying way as a holistic approach towards embodied human and artificial cognition. This framework is meant to discuss internal and external dynamics of an embodied, natural or artificial agent. In order to stress the importance of a dynamic memory I introduce the concept of an `autobiographical agent'. The second part of the paper gives an example of the implementation of a physical agent, a robot, which is dynamically coupled to its environment by balancing on a seesaw. For the control of the robot a behavior-oriented approach using the dynamical systems metaphor is used. The problem is studied through building a complete and co-adapted robot-environment system. A seesaw which varies its orientation with one or two degrees of freedom is used as the artificial `habitat'. The problem of stabilizing the body axis by active motion on a seesaw is solved by using two inclination sensors and a parallel, behavior-oriented control architecture. Some experiments are described which demonstrate the exploitation of the dynamics of the robot-environment system.

  12. A quantum dynamical study of the rotation of the dihydrogen ligand in the Fe(H)2(H2)(PEtPh2)3 coordination complex

    Science.gov (United States)

    Gonzalez, Megan E.; Eckert, Juergen; Aquino, Adelia J. A.; Poirier, Bill

    2018-04-01

    Progress in the hydrogen fuel field requires a clear understanding and characterization of how materials of interest interact with hydrogen. Due to the inherently quantum mechanical nature of hydrogen nuclei, any theoretical studies of these systems must be treated quantum dynamically. One class of material that has been examined in this context are dihydrogen complexes. Since their discovery by Kubas in 1984, many such complexes have been studied both experimentally and theoretically. This particular study examines the rotational dynamics of the dihydrogen ligand in the Fe(H)2(H2)(PEtPh2)3 complex, allowing for full motion in both the rotational degrees of freedom and treating the quantum dynamics (QD) explicitly. A "gas-phase" global potential energy surface is first constructed using density functional theory with the Becke, 3-parameter, Lee-Yang-Parr functional; this is followed by an exact QD calculation of the corresponding rotation/libration states. The results provide insight into the dynamical correlation of the two rotation angles as well as a comprehensive analysis of both ground- and excited-state librational tunneling splittings. The latter was computed to be 6.914 cm-1—in excellent agreement with the experimental value of 6.4 cm-1. This work represents the first full-dimensional ab initio exact QD calculation ever performed for dihydrogen ligand rotation in a coordination complex.

  13. Internal variability of a dynamically downscaled climate over North America

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiali; Bessac, Julie; Kotamarthi, Rao; Constantinescu, Emil; Drewniak, Beth

    2017-09-08

    This study investigates the internal variability (IV) of a regional climate model, and considers the impacts of horizontal resolution and spectral nudging on the IV. A 16-member simulation ensemble was conducted using the Weather Research Forecasting model for three model configurations. Ensemble members included simulations at spatial resolutions of 50 km and 12 km without spectral nudging and simulations at a spatial resolution of 12 km with spectral nudging. All the simulations were generated over the same domain, which covered much of North America. The degree of IV was measured as the spread between the individual members of the ensemble during the integration period. The IV of the 12 km simulation with spectral nudging was also compared with a future climate change simulation projected by the same model configuration. The variables investigated focus on precipitation and near-surface air temperature. While the IVs show a clear annual cycle with larger values in summer and smaller values in winter, the seasonal IV is smaller for a 50-km spatial resolution than for a 12-km resolution when nudging is not applied. Applying a nudging technique to the 12-km simulation reduces the IV by a factor of two, and produces smaller IV than the simulation at 50 km without nudging. Applying a nudging technique also changes the geographic distributions of IV in all examined variables. The IV is much smaller than the inter-annual variability at seasonal scales for regionally averaged temperature and precipitation. The IV is also smaller than the projected changes in air-temperature for the mid- and late 21st century. However, the IV is larger than the projected changes in precipitation for the mid- and late 21st century.

  14. Internal variability of a dynamically downscaled climate over North America

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jiali; Bessac, Julie; Kotamarthi, Rao; Constantinescu, Emil; Drewniak, Beth

    2017-09-08

    This study investigates the internal variability (IV) of a regional climate model, and considers the impacts of horizontal resolution and spectral nudging on the IV. A 16-member simulation ensemble was conducted using the Weather Research Forecasting model for three model configurations. Ensemble members included simulations at spatial resolutions of 50 and 12 km without spectral nudging and simulations at a spatial resolution of 12 km with spectral nudging. All the simulations were generated over the same domain, which covered much of North America. The degree of IV was measured as the spread between the individual members of the ensemble during the integration period. The IV of the 12 km simulation with spectral nudging was also compared with a future climate change simulation projected by the same model configuration. The variables investigated focus on precipitation and near-surface air temperature. While the IVs show a clear annual cycle with larger values in summer and smaller values in winter, the seasonal IV is smaller for a 50-km spatial resolution than for a 12-km resolution when nudging is not applied. Applying a nudging technique to the 12-km simulation reduces the IV by a factor of two, and produces smaller IV than the simulation at 50 km without nudging. Applying a nudging technique also changes the geographic distributions of IV in all examined variables. The IV is much smaller than the inter-annual variability at seasonal scales for regionally averaged temperature and precipitation. The IV is also smaller than the projected changes in air-temperature for the mid- and late twenty-first century. However, the IV is larger than the projected changes in precipitation for the mid- and late twenty-first century.

  15. Internal variability of a dynamically downscaled climate over North America

    Science.gov (United States)

    Wang, Jiali; Bessac, Julie; Kotamarthi, Rao; Constantinescu, Emil; Drewniak, Beth

    2017-09-01

    This study investigates the internal variability (IV) of a regional climate model, and considers the impacts of horizontal resolution and spectral nudging on the IV. A 16-member simulation ensemble was conducted using the Weather Research Forecasting model for three model configurations. Ensemble members included simulations at spatial resolutions of 50 and 12 km without spectral nudging and simulations at a spatial resolution of 12 km with spectral nudging. All the simulations were generated over the same domain, which covered much of North America. The degree of IV was measured as the spread between the individual members of the ensemble during the integration period. The IV of the 12 km simulation with spectral nudging was also compared with a future climate change simulation projected by the same model configuration. The variables investigated focus on precipitation and near-surface air temperature. While the IVs show a clear annual cycle with larger values in summer and smaller values in winter, the seasonal IV is smaller for a 50-km spatial resolution than for a 12-km resolution when nudging is not applied. Applying a nudging technique to the 12-km simulation reduces the IV by a factor of two, and produces smaller IV than the simulation at 50 km without nudging. Applying a nudging technique also changes the geographic distributions of IV in all examined variables. The IV is much smaller than the inter-annual variability at seasonal scales for regionally averaged temperature and precipitation. The IV is also smaller than the projected changes in air-temperature for the mid- and late twenty-first century. However, the IV is larger than the projected changes in precipitation for the mid- and late twenty-first century.

  16. Internal variability of a dynamically downscaled climate over North America

    Science.gov (United States)

    Wang, Jiali; Bessac, Julie; Kotamarthi, Rao; Constantinescu, Emil; Drewniak, Beth

    2018-06-01

    This study investigates the internal variability (IV) of a regional climate model, and considers the impacts of horizontal resolution and spectral nudging on the IV. A 16-member simulation ensemble was conducted using the Weather Research Forecasting model for three model configurations. Ensemble members included simulations at spatial resolutions of 50 and 12 km without spectral nudging and simulations at a spatial resolution of 12 km with spectral nudging. All the simulations were generated over the same domain, which covered much of North America. The degree of IV was measured as the spread between the individual members of the ensemble during the integration period. The IV of the 12 km simulation with spectral nudging was also compared with a future climate change simulation projected by the same model configuration. The variables investigated focus on precipitation and near-surface air temperature. While the IVs show a clear annual cycle with larger values in summer and smaller values in winter, the seasonal IV is smaller for a 50-km spatial resolution than for a 12-km resolution when nudging is not applied. Applying a nudging technique to the 12-km simulation reduces the IV by a factor of two, and produces smaller IV than the simulation at 50 km without nudging. Applying a nudging technique also changes the geographic distributions of IV in all examined variables. The IV is much smaller than the inter-annual variability at seasonal scales for regionally averaged temperature and precipitation. The IV is also smaller than the projected changes in air-temperature for the mid- and late twenty-first century. However, the IV is larger than the projected changes in precipitation for the mid- and late twenty-first century.

  17. Dynamic and Thermodynamic Examination of a Two-Stroke Internal Combustion Engine

    OpenAIRE

    İPCİ, Duygu; KARABULUT, Halit

    2016-01-01

    In this study the combined dynamic and thermodynamic analysis of a two-stroke internal combustion engine was carried out. The variation of the heat, given to the working fluid during the heating process of the thermodynamic cycle, was modeled with the Gaussian function. The dynamic model of the piston driving mechanism was established by means of nine equations, five of them are motion equations and four of them are kinematic relations. Equations are solved by using a numerical method based o...

  18. Plant Habitat (PH)

    Science.gov (United States)

    Onate, Bryan

    2016-01-01

    The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

  19. A new approach combining different MRI methods to provide detailed view on swelling dynamics of xanthan tablets influencing drug release at different pH and ionic strength.

    Science.gov (United States)

    Mikac, Ursa; Sepe, Ana; Kristl, Julijana; Baumgartner, Sasa

    2010-08-03

    The key element in drug release from hydrophilic matrix tablets is the gel layer that regulates the penetration of water and controls drug dissolution and diffusion. We have selected magnetic resonance imaging (MRI) as the method of choice for visualizing the dynamic processes occurring during the swelling of xanthan tablets in a variety of media. The aims were (i) to develop a new method using MRI for accurate determination of penetration, swelling and erosion fronts, (ii) to investigate the effects of pH and ionic strength on swelling, and (iii) to study the influence of structural changes in xanthan gel on drug release. Two dimensional (2D) MRI and one dimensional single point imaging (SPI) of swollen xanthan tablets were recorded, together with T(2) mapping. The border between dry and hydrated glassy xanthan-the penetration front-was determined from 1D SPI signal intensity profiles. The erosion front was obtained from signal intensity profiles of 2D MR images. The swelling front, where xanthan is transformed from a glassy to a rubbery state (gel formation), was determined from T(2) profiles. Further, the new combination of MRI methods for swelling front determination enables to explain the appearance of the unusual "bright front" observed on 2D MR images in tablets swollen in HCl pH 1.2 media, which represents the position of swelling front. All six media studied, differing in pH and ionic strength, penetrate through the whole tablet in 4h+/-0.3h, but formation of the gel layer is significantly delayed. Unexpectedly, the position of the swelling front was the same, independently of the different xanthan gel structures formed under different conditions of pH and ionic strength. The position of the erosion front, on the other hand, is strongly dependent on pH and ionic strength, as reflected in different thicknesses of the gel layers. The latter are seen to be the consequence of the different hydrodynamic radii of the xanthan molecules, which affect the drug

  20. Is the Potential for International Diversification Disappearing? A Dynamic Copula Approach

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Errunza, Vihang; Jacobs, Kris

    International equity markets are characterized by nonlinear dependence and asymmetries. We propose a new dynamic asymmetric copula model to capture long-run and short-run dependence, multivariate nonnormality, and asymmetries in large cross-sections. We find that copula correlations have increased...... and nonlinear dependence. The bene…fits from international diversi…cation have reduced over time, drastically so for DMs. EMs still offer signi…cant diversi…cation bene…ts, especially during large market downturns....

  1. In vivo oxygen, temperature and pH dynamics in the female reproductive tract and their importance in human conception: a systematic review.

    Science.gov (United States)

    Ng, Ka Ying Bonnie; Mingels, Roel; Morgan, Hywel; Macklon, Nick; Cheong, Ying

    2018-01-01

    Despite advances in ART, implantation and pregnancy rates per embryo transfer still remain low. IVF laboratories strive to ensure that the process of handling gametes in vitro closely mimics the in vivo environment. However, there remains a lack of knowledge regarding the in vivo regulation and dynamic variation in biophysical parameters such as oxygen concentration, pH and temperature within the reproductive tract. To undertake a systematic review of the current understanding of the physico-chemical parameters of oxygen tension (pO2), pH and temperature within the female reproductive tract, and their potential implications in clinical and pathological processes related to fertility and those pertaining to limited reproductive capacity. A comprehensive literature search was performed using electronic databases including Medline, Embase, Cochrane Library and Pubmed to identify original and review articles addressing the biophysical parameters (pO2, pH and temperature) in the female reproductive tract of any species. The search included all studies published between 1946 and November 2015. Search terms included 'oxygen', 'pH', 'hydrogen ion concentration', 'acid base' and others terms. We also used special features and truncations to identify synonyms and broaden the search. Studies were excluded if they only assessed embryo culture conditions, fetal acid-base status, oxidative stress, outcomes of pregnancy and measurements of these parameters in non-reproductive organs. Our search generated 18 685 records and 60 articles were included. pO2 within the female reproductive tract shows cyclical variation and minute-to-minute oscillations, which may be influenced by uterine contractility, hormones, the autonomic system, cardiac pulsatility, and myometrial and smooth muscle integrity. Fine balanced control of pO2 and avoidance of overwhelming oxidative stress is crucial for embryogenesis and implantation. The pH in the female reproductive tract is graduated, with lowest pH

  2. Role of Reynolds stress and toroidal momentum transport in the dynamics of internal transport barriers

    International Nuclear Information System (INIS)

    Kim, S. S.; Jhang, Hogun; Diamond, P. H.

    2012-01-01

    We study the interplay between intrinsic rotation and internal transport barrier (ITB) dynamics through the dynamic change of the parallel Reynolds stress. Global flux-driven gyrofluid simulations are used for this study. In particular, we investigate the role of parallel velocity gradient instability (PVGI) in the ITB formation and the back transition. It is found that the excitation of PVGI is followed by a change in the Reynolds stress which drives a momentum redistribution. This significantly influences E×B shear evolution and subsequent ITB dynamics. Nonlocal interactions among fluctuations are also observed during the PVGI excitation, resulting in turbulence suppression at the ITB.

  3. Gating based on internal/external signals with dynamic correlation updates

    International Nuclear Information System (INIS)

    Wu Huanmei; Zhao Qingya; Berbeco, Ross I; Nishioka, Seiko; Shirato, Hiroki; Jiang, Steve B

    2008-01-01

    Precise localization of mobile tumor positions in real time is critical to the success of gated radiotherapy. Tumor positions are usually derived from either internal or external surrogates. Fluoroscopic gating based on internal surrogates, such as implanted fiducial markers, is accurate however requiring a large amount of imaging dose. Gating based on external surrogates, such as patient abdominal surface motion, is non-invasive however less accurate due to the uncertainty in the correlation between tumor location and external surrogates. To address these complications, we propose to investigate an approach based on hybrid gating with dynamic internal/external correlation updates. In this approach, the external signal is acquired at high frequency (such as 30 Hz) while the internal signal is sparsely acquired (such as 0.5 Hz or less). The internal signal is used to validate and update the internal/external correlation during treatment. Tumor positions are derived from the external signal based on the newly updated correlation. Two dynamic correlation updating algorithms are introduced. One is based on the motion amplitude and the other is based on the motion phase. Nine patients with synchronized internal/external motion signals are simulated retrospectively to evaluate the effectiveness of hybrid gating. The influences of different clinical conditions on hybrid gating, such as the size of gating windows, the optimal timing for internal signal acquisition and the acquisition frequency are investigated. The results demonstrate that dynamically updating the internal/external correlation in or around the gating window will reduce false positive with relatively diminished treatment efficiency. This improvement will benefit patients with mobile tumors, especially greater for early stage lung cancers, for which the tumors are less attached or freely floating in the lung.

  4. Gating based on internal/external signals with dynamic correlation updates

    Energy Technology Data Exchange (ETDEWEB)

    Wu Huanmei [Purdue School of Engineering and Technology, Indiana University School of Informatics, IUPUI, Indianapolis, IN (United States); Zhao Qingya [School of Health Sciences, Purdue University, West Lafayette, IN (United States); Berbeco, Ross I [Department of Radiation Oncology, Dana-Farber/Brigham and Womens Cancer Center and Harvard Medical School, Boston, MA (United States); Nishioka, Seiko [NTT East-Japan Sapporo Hospital, Sapporo (Japan); Shirato, Hiroki [Hokkaido University Graduate School of Medicine, Sapporo (Japan); Jiang, Steve B [Department of Radiation Oncology, School of Medicine, University of California, San Diego, CA (United States)], E-mail: hw9@iupui.edu, E-mail: sbjiang@ucsd.edu

    2008-12-21

    Precise localization of mobile tumor positions in real time is critical to the success of gated radiotherapy. Tumor positions are usually derived from either internal or external surrogates. Fluoroscopic gating based on internal surrogates, such as implanted fiducial markers, is accurate however requiring a large amount of imaging dose. Gating based on external surrogates, such as patient abdominal surface motion, is non-invasive however less accurate due to the uncertainty in the correlation between tumor location and external surrogates. To address these complications, we propose to investigate an approach based on hybrid gating with dynamic internal/external correlation updates. In this approach, the external signal is acquired at high frequency (such as 30 Hz) while the internal signal is sparsely acquired (such as 0.5 Hz or less). The internal signal is used to validate and update the internal/external correlation during treatment. Tumor positions are derived from the external signal based on the newly updated correlation. Two dynamic correlation updating algorithms are introduced. One is based on the motion amplitude and the other is based on the motion phase. Nine patients with synchronized internal/external motion signals are simulated retrospectively to evaluate the effectiveness of hybrid gating. The influences of different clinical conditions on hybrid gating, such as the size of gating windows, the optimal timing for internal signal acquisition and the acquisition frequency are investigated. The results demonstrate that dynamically updating the internal/external correlation in or around the gating window will reduce false positive with relatively diminished treatment efficiency. This improvement will benefit patients with mobile tumors, especially greater for early stage lung cancers, for which the tumors are less attached or freely floating in the lung.

  5. Simulation of the removal of NET internal components with dynamic modeling software

    International Nuclear Information System (INIS)

    Becquet, M.; Crutzen, Y.R.; Farfaletti-Casali, F.

    1989-01-01

    The replacement of the internal plasma-facing components (first-wall and blanket segments) for maintenance or at the end of their lifetime is an important aspect of the design of the next European torus (NET) and of the remote handling procedures. The first phase of development of the design software tool INVDYN (inverse dynamics) is presented, which will allow optimization of the movements of the internal segments during replacement, taking into account inertial effects and structural deformations. A first analysis of the removal of one NET internal segment provides, for a defined trajectory, the required generalized forces that must be applied on the crane system

  6. Politics and Graduate Medical Education in Internal Medicine: A Dynamic Landscape.

    Science.gov (United States)

    Wardrop, Richard M; Berkowitz, Lee R

    2017-02-01

    The promotion of change and growth within medical education is oftentimes the result of a complex mix of societal, cultural and economic forces. Graduate medical education in internal medicine is not immune to these forces. Several entities and organizations can be identified as having a major influence on internal medicine training and graduate medical education as a whole. We have reviewed how this is effectively accomplished through these entities and organizations. The result is a constantly changing and dynamic landscape for internal medicine training. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.

  7. Internal kinematics and dynamical models of dwarf spheroidal galaxies around the Milky Way

    NARCIS (Netherlands)

    Battaglia, Giuseppina; Helmi, Amina; Breddels, Maarten

    We review our current understanding of the internal dynamical properties of the dwarf spheroidal galaxies surrounding the Milky Way. These are the most dark matter dominated galaxies, and as such may be considered ideal laboratories to test the current concordance cosmological model, and in

  8. Dynamics of Context-Dependent Recall: An Examination of Internal and External Context Change

    Science.gov (United States)

    Unsworth, Nash; Spillers, Gregory J.; Brewer, Gene A.

    2012-01-01

    Retrieval dynamics in context-dependent recall were explored via manipulations of external and internal context in two experiments. Participants were tested in either the same or different context as the material was learned in and correct recalls, errors, and recall latency measures were examined. In both experiments changes in context resulted…

  9. Exploring the role of internal friction in the dynamics of unfolded proteins using simple polymer models

    Science.gov (United States)

    Cheng, Ryan R.; Hawk, Alexander T.; Makarov, Dmitrii E.

    2013-02-01

    Recent experiments showed that the reconfiguration dynamics of unfolded proteins are often adequately described by simple polymer models. In particular, the Rouse model with internal friction (RIF) captures internal friction effects as observed in single-molecule fluorescence correlation spectroscopy (FCS) studies of a number of proteins. Here we use RIF, and its non-free draining analog, Zimm model with internal friction, to explore the effect of internal friction on the rate with which intramolecular contacts can be formed within the unfolded chain. Unlike the reconfiguration times inferred from FCS experiments, which depend linearly on the solvent viscosity, the first passage times to form intramolecular contacts are shown to display a more complex viscosity dependence. We further describe scaling relationships obeyed by contact formation times in the limits of high and low internal friction. Our findings provide experimentally testable predictions that can serve as a framework for the analysis of future studies of contact formation in proteins.

  10. Study on dynamic characteristics of reduced analytical model for PWR reactor internal structures

    International Nuclear Information System (INIS)

    Yoo, Bong; Lee, Jae Han; Kim, Jong Bum; Koo, Kyeong Hoe

    1993-01-01

    The objective of this study is to establish the procedure of the reduced analytical modeling technique for the PWR reactor internal(RI) structures and to carry out the sensitivity study of the dynamic characteristics of the structures by varying the structural parameters such as the stiffness, the mass and the damping. Modeling techniques for the PWR reactor internal structures and computer programs used for the dynamic analysis of the reactor internal structures are briefly investigated. Among the many components of RI structures, the dynamic characteristics for CSB was performed. The sensitivity analysis of the dynamic characteristics for the reduced analytical model considering the variations of the stiffnesses for the lower and upper flanges of the CSB and for the RV Snubber were performed to improve the dynamic characteristics of the RI structures against the external loadings given. In order to enhance the structural design margin of the RI components, the nonlinear time history analyses were attempted for the RI reduced models to compare the structural responses between the reference model and the modified one. (Author)

  11. Origin of the Absorption Band of Bromophenol Blue in Acidic and Basic pH: Insight from a Combined Molecular Dynamics and TD-DFT/MM Study.

    Science.gov (United States)

    Chattopadhyaya, M; Murugan, N Arul; Rinkevicius, Zilvinas

    2016-09-15

    We study the linear and nonlinear optical properties of a well-known acid-base indicator, bromophenol blue (BPB), in aqueous solution by employing static and integrated approaches. In the static approach, optical properties have been calculated using time-dependent density functional theory (TD-DFT) on the fully relaxed geometries of the neutral and different unprotonated forms of BPB. Moreover, both closed and open forms of BPB were considered. In the integrated approach, the optical properties have been computed over many snapshots extracted from molecular dynamics simulation using a hybrid time-dependent density functional theory/molecular mechanics approach. The static approach suggests closed neutral ⇒ anionic interconversion as the dominant mechanism for the red shift in the absorption spectra of BPB due to a change from acidic to basic pH. It is found by employing an integrated approach that the two interconversions, namely open neutral ⇒ anionic and open neutral ⇒ dianionic, can contribute to the pH-dependent shift in the absorption spectra of BPB. Even though both static and integrated approaches reproduce the pH-dependent red shift in the absorption spectra of BPB, the latter one is suitable to determine both the spectra and spectral broadening. Finally, the computed static first hyperpolarizability for various protonated and deprotonated forms of BPB reveals that this molecule can be used as a nonlinear optical probe for pH sensing in addition to its highly exploited use as an optical probe.

  12. The dynamic interdependence of international financial markets: An empirical study on twenty-seven stock markets

    Science.gov (United States)

    Zhang, Xingwei; Zheng, Xiaolong; Zeng, Daniel Dajun

    2017-04-01

    In this paper, we aim to investigate the dynamic interdependence of international financial markets. Based on the data regarding daily returns of each market during the period 2006-2015 from Yahoo finance, we mainly focus on examining 27 markets from three continents, including Asia, America and Europe. By checking the dynamic interdependence between those markets, we find that markets from different continents have strong correlation at specific time shift. We also obtain that markets from different continents not only have a strong linkage with others at same day, but at a delay of one day, especially between Asia, Europe and Asia, America. In addition, we further analyze the time-varying influence strength between each two continents and observe that this value has abnormal changes during the financial crisis. These findings can provide us significant insights to understand the underlying dynamic interdependency of international financial markets and further help us make corresponding reasonable decisions.

  13. Simulations of ferrofluid dynamics: Rigid dipoles model versus particles with internal degrees of freedom

    International Nuclear Information System (INIS)

    Berkov, D.V.; Gorn, N.L.; Stock, D.

    2007-01-01

    For numerical studies of a ferrofluid dynamics we have developed a model which includes internal magnetic degrees of freedom of ferrofluid particles. Contrary to standard models, we take into account that the magnetocrystalline anisotropy of a ferrofluid particle material is finite, so that the particle moment is allowed to rotate with respect to the particle itself. Simulating magnetization relaxation of a ferrofluid after switching off the external field and comparing results with those obtained for rigid dipoles model, we demonstrate that for anisotropy typical for commonly used ferrofluid materials inclusion of 'magnetic' degrees of freedom is essential for a correct description of ferrofluid dynamics

  14. Self adaptive internal combustion engine control for hydrogen mixtures based on piezoelectric dynamic cylinder pressure transducers

    Energy Technology Data Exchange (ETDEWEB)

    Courteau, R.; Bose, T. K. [Universite du Quebec a Trois-Rivieres, Hydrogen Research Institute, Trois-Rivieres, PQ (Canada)

    2004-07-01

    An algorithm for self-adaptive tuning of an internal combustion engine is proposed, based on a Kalman filter operating on a few selected metrics of the dynamic pressure curve. Piezoelectric transducers are devices to monitor dynamic cylinder pressure; spark plugs with embedded piezo elements are now available to provide diagnostic engine functions. Such transducers are also capable of providing signals to the engine controller to perform auto tuning, a function that is considered very useful particularly in vehicles using alternative fuels whose characteristics frequently show variations between fill-ups. 2 refs., 2 figs.

  15. Fabrication of triple-labeled polyelectrolyte microcapsules for localized ratiometric pH sensing.

    Science.gov (United States)

    Song, Xiaoxue; Li, Huanbin; Tong, Weijun; Gao, Changyou

    2014-02-15

    Encapsulation of pH sensitive fluorophores as reporting molecules provides a powerful approach to visualize the transportation of multilayer capsules. In this study, two pH sensitive dyes (fluorescein and oregon green) and one pH insensitive dye (rhodamine B) were simultaneously labeled on the microcapsules to fabricate ratiometric pH sensors. The fluorescence of the triple-labeled microcapsule sensors was robust and nearly independent of other intracellular species. With a dynamic pH measurement range of 3.3-6.5, the microcapsules can report their localized pH at a real time. Cell culture experiments showed that the microcapsules could be internalized by RAW 246.7 cells naturally and finally accumulated in acidic organelles with a pH value of 5.08 ± 0.59 (mean ± s.d.; n=162). Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Dynamics of pH, Ferrum and Mangan, and Phosphorus on Newly Opened Paddy Soil having High Soil Organic Matter on Rice Growth

    Directory of Open Access Journals (Sweden)

    Sukristyonubowo

    2012-01-01

    Full Text Available Research had been carried out at the Research and Soil Testing Laboratory and Greenhouse of Soil ResearchInstitute, Bogor using newly opened paddy soil from Pesisir Selatan districts, West Sumatra (one year old. Totaltreatments tested were 12 which were combination of farmer rate, NPK recommendation (½×; ¾×; 1½×, strawcompost (½×; ¾×; 1½×, and dolomite. The trial was conducted using a completely randomized design with threereplications. This research had been prepared in two units, one unit for observing plant response to nutrientmanagement and another unit for incubation trial with the same treatment placed in the greenhouse. Rice cultivarused was IR-42 in accordance to the preferred varieties of local farmers. The sampling method for measuring thesolubility of Fe2+ and Mn2+, as well as the availability of PO43- was by centrifuge 50 g mud samples from theincubation pots then separated clear extract using filter paper. The observation results on dynamics of pH, Fe2+,Mn2+ and PO4-3 mainly occured in 1 to 14 days after submerging (incubation. After 14 days soil reaction had reachedthermodynamic sequence of oxidation-reduction processes, the PO43- more available and pH of the soil reached thepeak. The optimum dose of NPK fertilizer obtained 0.875 NPK or equal to 175 kg of urea, 87.5 kg of SP-36 and 87.5 kgKCl ha-1. The highest number of hills achieved from straw compost treatment 1½ organic matter (OM or 3 tons withan increase of 20%. Application of ameliorant dolomite increased the number of tillers about 2-3%, but insignificantlydifferent with no dolomite treatment.

  17. Internal Active Thermal Control System (IATCS) Sodium Bicarbonate/Carbonate Buffer in an Open Aqueous Carbon Dioxide System and Corollary Electrochemical/Chemical Reactions Relative to System pH Changes

    Science.gov (United States)

    Stegman, Thomas W.; Wilson, Mark E.; Glasscock, Brad; Holt, Mike

    2014-01-01

    The International Space Station (ISS) Internal Active Thermal Control System (IATCS) experienced a number of chemical changes driven by system absorption of CO2 which altered the coolant’s pH. The natural effects of the decrease in pH from approximately 9.2 to less than 8.4 had immediate consequences on system corrosion rates and corrosion product interactions with specified coolant constituents. The alkalinity of the system was increased through the development and implementation of a carbonate/bicarbonate buffer that would increase coolant pH to 9.0 – 10.0 and maintain pH above 9.0 in the presence of ISS cabin concentrations of CO2 up to twenty times higher than ground concentrations. This paper defines how a carbonate/bicarbonate buffer works in an open carbon dioxide system and summarizes the analyses performed on the buffer for safe and effective application in the on-orbit system. The importance of the relationship between the cabin environment and the IATCS is demonstrated as the dominant factor in understanding the system chemistry and pH trends before and after addition of the carbonate/bicarbonate buffer. The paper also documents the corollary electrochemical and chemical reactions the system has experienced and the rationale for remediation of these effects with the addition of the carbonate/bicarbonate buffer.

  18. Novel effect of interplay of internal and external noise on the dynamics of calcium oscillations

    International Nuclear Information System (INIS)

    Li Hongying; Ma Juan

    2010-01-01

    Graphical abstract: When the external noise is small (D ≤ 0.8), R goes through a maximum at an optimal system size V, indicating the occurring of internal-noise stochastic resonance (INSR), and the curves become higher with the increases of D, which shows that INSR can be enhanced by the external noise in a certain range of external noise intensity ((D ≤ 0.8). If D > 0.8, R monotonically increases and the peak disappears. When D increases further, the R curve becomes lower. Research highlights: → External noise coherence resonance (ENCR) can be suppressed by internal noise. → Internal noise stochastic resonance (INSR) can be enhanced by external noise. → When INSR occurs, the optimal system size can be regulated by the external noise. - Abstract: Using a mesoscopic stochastic model, the effect of interplay of external and internal noise on the dynamics of calcium oscillations was studied. When the system was tuned near a Hopf bifurcation point and driven by external noise or internal noise only, the existence of external noise coherence resonance (ENCR) or internal-noise stochastic resonance (INSR) was found, respectively. When both of the noises were considered, it was found that ENCR could be suppressed by internal noise, while INSR could be enhanced by external noise in a certain range of external noise intensity. It was also interesting to note that the optimal system size can be regulated by the external noise when the INSR occurs. The cell system may adapt to adjust the optimal size according to the external noise, indicating some kind of self-tuning mechanism involved in stochastic calcium dynamics.

  19. Estimation of kinematic parameters in CALIFA galaxies: no-assumption on internal dynamics

    Science.gov (United States)

    García-Lorenzo, B.; Barrera-Ballesteros, J.; CALIFA Team

    2016-06-01

    We propose a simple approach to homogeneously estimate kinematic parameters of a broad variety of galaxies (elliptical, spirals, irregulars or interacting systems). This methodology avoids the use of any kinematical model or any assumption on internal dynamics. This simple but novel approach allows us to determine: the frequency of kinematic distortions, systemic velocity, kinematic center, and kinematic position angles which are directly measured from the two dimensional-distributions of radial velocities. We test our analysis tools using the CALIFA Survey

  20. Self adaptive internal combustion engine control for hydrogen mixtures based on piezoelectric dynamic cylinder pressure transducers

    International Nuclear Information System (INIS)

    Courteau, R.; Bose, T.K.

    2004-01-01

    Piezoelectric transducers offer an effective, non-intrusive way to monitor dynamic cylinder pressure in internal combustion engines. Devices dedicated to this purpose are appearing on the market, often in the form of spark plugs with embedded piezo elements. Dynamic cylinder pressure is typically used to provide diagnostic functions, or to help map an engine after it is designed. With the advent of powerful signal processor chips, it is now possible to embed enough computing power in the engine controller to perform auto tuning based on the signals provided by such transducers. Such functionality is very useful if the fuel characteristics vary between fill ups, as is often the case with alternative fuels. We propose here an algorithm for self-adaptive tuning based on a Kalman filter operating on a few selected metrics of the dynamic pressure curve. (author)

  1. A Dynamic Approach to the Analysis of Soft Power in International Relations

    Directory of Open Access Journals (Sweden)

    Chi Zhang

    2013-12-01

    Full Text Available This article discusses soft power in international relations and the soft power of China’s foreign policy in recent years. After presenting a critique of the soft power theory developed by Joseph S. Nye, the paper provides an alternative interpretation of soft power. The author proposes a dynamic analysis of soft power in international relations, and argues that whether a power resource is soft or hard depends on the perceptions and feelings of various actors in specific situations. Due to the varying degrees of acceptance, power can be divided into hard power, soft power and bargaining power. An analysis should look at the soft or hard effectiveness of a power resource from three perspectives–horizontally, vertically and relatively. Recently, the soft power of China’s foreign policy and international behavior has mainly been manifested in multilateralism, economic diplomacy and a good-neighborly policy.

  2. Role of internal demagnetizing field for the dynamics of a surface-modulated magnonic crystal

    Science.gov (United States)

    Langer, M.; Röder, F.; Gallardo, R. A.; Schneider, T.; Stienen, S.; Gatel, C.; Hübner, R.; Bischoff, L.; Lenz, K.; Lindner, J.; Landeros, P.; Fassbender, J.

    2017-05-01

    This work aims to demonstrate and understand the key role of local demagnetizing fields in hybrid structures consisting of a continuous thin film with a stripe modulation on top. To understand the complex spin dynamics of these structures, the magnonic crystal was reconstructed in two different ways—performing micromagnetic simulations based on the structural shape as well as based on the internal demagnetizing field, which both are mapped on the nanoscale using electron holography. The simulations yield the frequency-field dependence as well as the angular dependence revealing the governing role of the internal field landscape around the backward-volume geometry. Simple rules for the propagation vector and the mode localization are formulated in order to explain the calculated mode profiles. Treating internal demagnetizing fields equivalent to anisotropies, the complex angle-dependent spin-wave behavior is described for an in-plane rotation of the external field.

  3. Dual-lifetime referencing (DLR: a powerful method for on-line measurement of internal pH in carrier-bound immobilized biocatalysts

    Directory of Open Access Journals (Sweden)

    Boniello Caterina

    2012-03-01

    Full Text Available Abstract Background Industrial-scale biocatalytic synthesis of fine chemicals occurs preferentially as continuous processes employing immobilized enzymes on insoluble porous carriers. Diffusional effects in these systems often create substrate and product concentration gradients between bulk liquid and the carrier. Moreover, some widely-used biotransformation processes induce changes in proton concentration. Unlike the bulk pH, which is usually controlled at a suitable value, the intraparticle pH of immobilized enzymes may deviate significantly from its activity and stability optima. The magnitude of the resulting pH gradient depends on the ratio of characteristic times for enzymatic reaction and on mass transfer (the latter is strongly influenced by geometrical features of the porous carrier. Design and selection of optimally performing enzyme immobilizates would therefore benefit largely from experimental studies of the intraparticle pH environment. Here, a simple and non-invasive method based on dual-lifetime referencing (DLR for pH determination in immobilized enzymes is introduced. The technique is applicable to other systems in which particles are kept in suspension by agitation. Results The DLR method employs fluorescein as pH-sensitive luminophore and Ru(II tris(4,7-diphenyl-1,10-phenantroline, abbreviated Ru(dpp, as the reference luminophore. Luminescence intensities of the two luminophores are converted into an overall phase shift suitable for pH determination in the range 5.0-8.0. Sepabeads EC-EP were labeled by physically incorporating lipophilic variants of the two luminophores into their polymeric matrix. These beads were employed as carriers for immobilization of cephalosporin C amidase (a model enzyme of industrial relevance. The luminophores did not interfere with the enzyme immobilization characteristics. Analytical intraparticle pH determination was optimized for sensitivity, reproducibility and signal stability under

  4. Molecular dynamics analysis of stabilities of the telomeric Watson-Crick duplex and the associated i-motif as a function of pH and temperature.

    Science.gov (United States)

    Panczyk, Tomasz; Wolski, Pawel

    2018-06-01

    This work deals with a molecular dynamics analysis of the protonated and deprotonated states of the natural sequence d[(CCCTAA) 3 CCCT] of the telomeric DNA forming the intercalated i-motif or paired with the sequence d[(CCCTAA) 3 CCCT] and forming the Watson-Crick (WC) duplex. By utilizing the amber force field for nucleic acids we built the i-motif and the WC duplex either with native cytosines or using their protonated forms. We studied, by applying molecular dynamics simulations, the role of hydrogen bonds between cytosines or in cytosine-guanine pairs in the stabilization of both structures in the physiological fluid. We found that hydrogen bonds exist in the case of protonated i-motif and in the standard form of the WC duplex. They, however, vanish in the case of the deprotonated i-motif and protonated form of the WC duplex. By determining potentials of mean force in the enforced unwrapping of these structures we found that the protonated i-motif is thermodynamically the most stable. Its deprotonation leads to spontaneous and observed directly in the unbiased calculations unfolding of the i-motif to the hairpin structure at normal temperature. The WC duplex is stable in its standard form and its slight destabilization is observed at the acidic pH. However, the protonated WC duplex unwraps very slowly at 310 K and its decomposition was not observed in the unbiased calculations. At higher temperatures (ca. 400 K or more) the WC duplex unwraps spontaneously. Copyright © 2018. Published by Elsevier B.V.

  5. Computational Fluid Dynamics Simulation of Hydrodynamics and Stresses in the PhEur/USP Disintegration Tester Under Fed and Fasted Fluid Characteristics.

    Science.gov (United States)

    Kindgen, Sarah; Wachtel, Herbert; Abrahamsson, Bertil; Langguth, Peter

    2015-09-01

    Disintegration of oral solid dosage forms is a prerequisite for drug dissolution and absorption and is to a large extent dependent on the pressures and hydrodynamic conditions in the solution that the dosage form is exposed to. In this work, the hydrodynamics in the PhEur/USP disintegration tester were investigated using computational fluid dynamics (CFD). Particle image velocimetry was used to validate the CFD predictions. The CFD simulations were performed with different Newtonian and non-Newtonian fluids, representing fasted and fed states. The results indicate that the current design and operating conditions of the disintegration test device, given by the pharmacopoeias, are not reproducing the in vivo situation. This holds true for the hydrodynamics in the disintegration tester that generates Reynolds numbers dissimilar to the reported in vivo situation. Also, when using homogenized US FDA meal, representing the fed state, too high viscosities and relative pressures are generated. The forces acting on the dosage form are too small for all fluids compared to the in vivo situation. The lack of peristaltic contractions, which generate hydrodynamics and shear stress in vivo, might be the major drawback of the compendial device resulting in the observed differences between predicted and in vivo measured hydrodynamics. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  6. Overcoming potential energy distortions in constrained internal coordinate molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Kandel, Saugat; Salomon-Ferrer, Romelia; Larsen, Adrien B.; Vaidehi, Nagarajan, E-mail: nvaidehi@coh.org [Division of Immunology, Beckman Research Institute of the City of Hope, Duarte, California 91010 (United States); Jain, Abhinandan, E-mail: Abhi.Jain@jpl.nasa.gov [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)

    2016-01-28

    The Internal Coordinate Molecular Dynamics (ICMD) method is an attractive molecular dynamics (MD) method for studying the dynamics of bonded systems such as proteins and polymers. It offers a simple venue for coarsening the dynamics model of a system at multiple hierarchical levels. For example, large scale protein dynamics can be studied using torsional dynamics, where large domains or helical structures can be treated as rigid bodies and the loops connecting them as flexible torsions. ICMD with such a dynamic model of the protein, combined with enhanced conformational sampling method such as temperature replica exchange, allows the sampling of large scale domain motion involving high energy barrier transitions. Once these large scale conformational transitions are sampled, all-torsion, or even all-atom, MD simulations can be carried out for the low energy conformations sampled via coarse grained ICMD to calculate the energetics of distinct conformations. Such hierarchical MD simulations can be carried out with standard all-atom forcefields without the need for compromising on the accuracy of the forces. Using constraints to treat bond lengths and bond angles as rigid can, however, distort the potential energy landscape of the system and reduce the number of dihedral transitions as well as conformational sampling. We present here a two-part solution to overcome such distortions of the potential energy landscape with ICMD models. To alleviate the intrinsic distortion that stems from the reduced phase space in torsional MD, we use the Fixman compensating potential. To additionally alleviate the extrinsic distortion that arises from the coupling between the dihedral angles and bond angles within a force field, we propose a hybrid ICMD method that allows the selective relaxing of bond angles. This hybrid ICMD method bridges the gap between all-atom MD and torsional MD. We demonstrate with examples that these methods together offer a solution to eliminate the potential

  7. What Do I Want to Be with My PhD? The Roles of Personal Values and Structural Dynamics in Shaping the Career Interests of Recent Biomedical Science PhD Graduates

    Science.gov (United States)

    Gibbs, Kenneth D., Jr.; Griffin, Kimberly A.

    2013-01-01

    Interest in faculty careers decreases as graduate training progresses; however, the process underlying career-interest formation remains poorly defined. To better understand this process and whether/how it differs across social identity (i.e., race/ethnicity, gender), we conducted focus groups with 38 biomedical scientists who received PhDs…

  8. Proceedings of the international advisory committee on 'biomolecular dynamics instrument DNA' and the workshop on 'biomolecular dynamics backscattering spectrometers'

    International Nuclear Information System (INIS)

    Arai, Masatoshi; Aizawa, Kazuya; Nakajima, Kenji; Shibata, Kaoru; Takahashi, Nobuaki

    2008-08-01

    A workshop entitled 'Biomolecular Dynamics Backscattering Spectrometers' was held on February 27th - 29th, 2008 at J-PARC Center, Japan Atomic Energy Agency. This workshop was planned to be held for aiming to realize an innovative neutron backscattering instrument, namely DNA, in the MLF and thus four leading scientists in the field of neutron backscattering instruments were invited as the International Advisory Committee (IAC member: Dr. Dan Neumann (Chair); Prof. Ferenc Mezei; Dr. Hannu Mutka; Dr. Philip Tregenna-Piggott) for DNA from institutes in the United States, France and Switzerland, where backscattering instruments are in-service. It was therefore held in the form of lecture anterior and then in the form of the committee posterior. This report includes the executive summary of the IAC and materials of the presentations in the IAC and the workshop. (author)

  9. PREFACE: International Symposium on Dynamic Deformation and Fracture of Advanced Materials (D2FAM 2013)

    Science.gov (United States)

    Silberschmidt, Vadim V.

    2013-07-01

    Intensification of manufacturing processes and expansion of usability envelopes of modern components and structures in many cases result in dynamic loading regimes that cannot be resented adequately employing quasi-static formulations of respective problems of solid mechanics. Specific features of dynamic deformation, damage and fracture processes are linked to various factors, most important among them being: a transient character of load application; complex scenarios of propagation, attenuation and reflection of stress waves in real materials, components and structures; strain-rate sensitivity of materials properties; various thermo-mechanical regimes. All these factors make both experimental characterisation and theoretical (analytical and numerical) analysis of dynamic deformation and fracture rather challenging; for instance, besides dealing with a spatial realisation of these processes, their evolution with time should be also accounted for. To meet these challenges, an International Symposium on Dynamic Deformation and Fracture of Advanced Materials D2FAM 2013 was held on 9-11 September 2013 in Loughborough, UK. Its aim was to bring together specialists in mechanics of materials, applied mathematics, physics, continuum mechanics, materials science as well as various areas of engineering to discuss advances in experimental and theoretical analysis, and numerical simulations of dynamic mechanical phenomena. Some 50 papers presented at the Symposium by researchers from 12 countries covered various topics including: high-strain-rate loading and deformation; dynamic fracture; impact and blast loading; high-speed penetration; impact fatigue; damping properties of advanced materials; thermomechanics of dynamic loading; stress waves in micro-structured materials; simulation of failure mechanisms and damage accumulation; processes in materials under dynamic loading; a response of components and structures to harsh environment. The materials discussed at D2FAM 2013

  10. Binaries traveling through a gaseous medium: dynamical drag forces and internal torques

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Salcedo, F. J. [Instituto de Astronomía, Universidad Nacional Autónoma de México, Ciudad Universitaria, Apt. Postal 70 264, C.P. 04510, Mexico City (Mexico); Chametla, Raul O., E-mail: jsanchez@astro.unam.mx [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, UP Adolfo López Mateos, Mexico City (Mexico)

    2014-10-20

    Using time-dependent linear theory, we investigate the morphology of the gravitational wake induced by a binary, whose center of mass moves at velocity V{sub cm} against a uniform background of gas. For simplicity, we assume that the components of the binary are on circular orbits about their common center of mass. The consequences of dynamical friction is twofold. First, gas dynamical friction may drag the center of mass of the binary and cause the binary to migrate. Second, drag forces also induce a braking torque, which causes the orbits of the components of the binary to shrink. We compute the drag forces acting on one component of the binary due to the gravitational interaction with its own wake. We show that the dynamical friction force responsible for decelerating the center of mass of the binary is smaller than it is in the point-mass case because of the loss of gravitational focusing. We show that the braking internal torque depends on the Mach numbers of each binary component about their center of mass, and also on the Mach number of the center of mass of the binary. In general, the internal torque decreases with increasing the velocity of the binary relative to the ambient gas cloud. However, this is not always the case. We also mention the relevance of our results to the period distribution of binaries.

  11. Waiting time distribution revealing the internal spin dynamics in a double quantum dot

    Science.gov (United States)

    Ptaszyński, Krzysztof

    2017-07-01

    Waiting time distribution and the zero-frequency full counting statistics of unidirectional electron transport through a double quantum dot molecule attached to spin-polarized leads are analyzed using the quantum master equation. The waiting time distribution exhibits a nontrivial dependence on the value of the exchange coupling between the dots and the gradient of the applied magnetic field, which reveals the oscillations between the spin states of the molecule. The zero-frequency full counting statistics, on the other hand, is independent of the aforementioned quantities, thus giving no insight into the internal dynamics. The fact that the waiting time distribution and the zero-frequency full counting statistics give a nonequivalent information is associated with two factors. Firstly, it can be explained by the sensitivity to different timescales of the dynamics of the system. Secondly, it is associated with the presence of the correlation between subsequent waiting times, which makes the renewal theory, relating the full counting statistics and the waiting time distribution, no longer applicable. The study highlights the particular usefulness of the waiting time distribution for the analysis of the internal dynamics of mesoscopic systems.

  12. The case for an internal dynamics model versus equilibrium point control in human movement.

    Science.gov (United States)

    Hinder, Mark R; Milner, Theodore E

    2003-06-15

    The equilibrium point hypothesis (EPH) was conceived as a means whereby the central nervous system could control limb movements by a relatively simple shift in equilibrium position without the need to explicitly compensate for task dynamics. Many recent studies have questioned this view with results that suggest the formation of an internal dynamics model of the specific task. However, supporters of the EPH have argued that these results are not incompatible with the EPH and that there is no reason to abandon it. In this study, we have tested one of the fundamental predictions of the EPH, namely, equifinality. Subjects learned to perform goal-directed wrist flexion movements while a motor provided assistance in proportion to the instantaneous velocity. It was found that the subjects stopped short of the target on the trials where the magnitude of the assistance was randomly decreased, compared to the preceding control trials (P = 0.003), i.e. equifinality was not achieved. This is contrary to the EPH, which predicts that final position should not be affected by external loads that depend purely on velocity. However, such effects are entirely consistent with predictions based on the formation of an internal dynamics model.

  13. Preface: Special issue featuring papers from the International Conference on Nonequilibrium Carrier Dynamics in Semiconductors

    Science.gov (United States)

    Reggiani, L.; Bordone, P.; Brunetti, R.

    2004-02-01

    The International Conference on Nonequilibrium Carrier Dynamics in Semiconductors (HCIS-13) celebrates 30 years since it first took place in Modena. Nonequilibrium dynamics of charge carriers, pioneered by the hot-electron concept, is an important issue for understanding electro-optic transport properties in semiconductor materials and structures. In these 30 years several topics have matured, and new ones have emerged thus fertilizing the field with a variety of physical problems and new ideas. The history of the conference is summarized in the opening paper `30 years of HCIS'. The future of the conference seems secure considering the continued lively interest of the participants. The conference addressed eleven major topics which constitute the backbone of the proceedings and are summarized as follows: carrier transport in low dimensional and nanostructure systems, nonequilibrium carriers in superlattices and devices, small devices and related phenomena, carrier dynamics and fluctuations, carrier quantum dynamics, coherent/incoherent carrier dynamics of optical excitations and ultra-fast optical phenomena, nonlinear optical effects, transport in organic matter, semiconductor-based spintronics, coherent dynamics in solid state systems for quantum processing and communication, novel materials and devices. Nanometric space scale and femtosecond time scale represent the ultimate domains of theoretical, experimental and practical interest. Traditional fields such as bulk properties, quantum transport, fluctuations and chaotic phenomena, etc, have received thorough and continuous attention. Emerging fields from previous conferences, such as quantum processing and communication, have been better assessed. New fields, such as spintronics and electron transport in organic matter, have appeared for the first time. One plenary talk, 11 invited talks, 230 submitted abstracts covering all these topics constituted a single-session conference. Following scientific selection

  14. Analysis and Design of International Emission Trading Markets Applying System Dynamics Techniques

    Science.gov (United States)

    Hu, Bo; Pickl, Stefan

    2010-11-01

    The design and analysis of international emission trading markets is an important actual challenge. Time-discrete models are needed to understand and optimize these procedures. We give an introduction into this scientific area and present actual modeling approaches. Furthermore, we develop a model which is embedded in a holistic problem solution. Measures for energy efficiency are characterized. The economic time-discrete "cap-and-trade" mechanism is influenced by various underlying anticipatory effects. With a systematic dynamic approach the effects can be examined. First numerical results show that fair international emissions trading can only be conducted with the use of protective export duties. Furthermore a comparatively high price which evokes emission reduction inevitably has an inhibiting effect on economic growth according to our model. As it always has been expected it is not without difficulty to find a balance between economic growth and emission reduction. It can be anticipated using our System Dynamics model simulation that substantial changes must be taken place before international emissions trading markets can contribute to global GHG emissions mitigation.

  15. Output Tracking for Systems with Non-Hyperbolic and Near Non-Hyperbolic Internal Dynamics: Helicopter Hover Control

    Science.gov (United States)

    Devasia, Santosh

    1996-01-01

    A technique to achieve output tracking for nonminimum phase linear systems with non-hyperbolic and near non-hyperbolic internal dynamics is presented. This approach integrates stable inversion techniques, that achieve exact-tracking, with approximation techniques, that modify the internal dynamics to achieve desirable performance. Such modification of the internal dynamics is used (1) to remove non-hyperbolicity which an obstruction to applying stable inversion techniques and (2) to reduce large pre-actuation time needed to apply stable inversion for near non-hyperbolic cases. The method is applied to an example helicopter hover control problem with near non-hyperbolic internal dynamic for illustrating the trade-off between exact tracking and reduction of pre-actuation time.

  16. PREFACE: 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19)

    Science.gov (United States)

    González, T.; Martín-Martínez, M. J.; Mateos, J.

    2015-10-01

    The 19th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON'19) was held at the Hospedería Fonseca (Universidad de Salamanca, Spain), on 29 June - 2 July, 2015, and was organized by the Electronics Area from the University of Salamanca. The Conference is held biannually and covers the recent progress in the field of electron dynamics in solid-state materials and devices. This was the 19th meeting of the international conference series formerly named Hot Carriers in Semiconductors (HCIS), first held in Modena in 1973. In the edition of 1997 in Berlin the name of the conference changed to International Conference on Nonequilibrium Carrier Dynamics in Semiconductors, keeping the same acronym, HCIS; and finally in the edition of Montpellier in 2009 the name was again changed to the current one, International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (EDISON). The latest editions took place in Santa Barbara, USA, in 2011 and Matsue, Japan, in 2013. Research work on electron dynamics involves quite different disciplines, and requires both fundamental and technological scientific efforts. Attendees to the conference come mostly from academic institutions, belonging to both theoretical and experimental groups working in a variety of fields, such as solid-state physics, electronics, optics, electrical engineering, material science, laser physics, etc. In this framework, events like the EDISON conference become a basic channel for the progress in the field. Here, researchers working in different areas can meet, present their latest advances and exchange their ideas. The program of EDISON'19 included 13 invited papers, 61 oral contributions and 73 posters. These contributions originated from scientists in more than 30 different countries. The Conference gathered 140 participants, coming from 24 different countries, most from Europe, but also with a significant participation

  17. Dynamic changes of intramural hematoma in patients with acute spontaneous internal carotid artery dissection.

    Science.gov (United States)

    Heldner, Mirjam R; Nedelcheva, Mila; Yan, Xin; Slotboom, Johannes; Mathier, Etienne; Hulliger, Justine; Verma, Rajeev K; Sturzenegger, Matthias; Jung, Simon; Bernasconi, Corrado; Arnold, Marcel; Wiest, Roland; Fischer, Urs

    2015-08-01

    We prospectively investigated temporal and spatial evolution of intramural hematomas in patients with acute spontaneous internal carotid artery dissection using repeated magnetic resonance imaging over six-months. The aim of the present study was to assess dynamic changes of intramural hematoma in patients with acute spontaneous internal carotid artery dissection at multiple follow-up time-points with T1w, PD/T2w, and magnetic resonance angiography. We performed serial multiparametric magnetic resonance imaging in 10 patients with spontaneous internal carotid artery dissection on admission, at days 1, 3, 7-14 and at months 1·5, 3, and 6. We calculated the volume and extension of the hyperintense intramural hematoma using T1w and PD/T2w fat suppressed sequences and assessed the degree of stenosis due to the hematoma using magnetic resonance angiography. Mean interval from symptom onset to first magnetic resonance imaging was two-days (SD 2·7). Two patients presented with ischemic stroke, three with transient ischemic attacks, and five with pain and local symptoms only. Nine patients had a transient increase of the intramural hematoma volume, mainly up to day 10 after symptom onset. Fifty percent had a transient increase in the degree of the internal carotid artery stenosis on MRA, one resulting in a temporary occlusion. Lesions older than one-week were predominantly characterized by a shift from iso- to hyperintese signal on T2w images. At three-month follow-up, intramural hematoma was no longer detectable in 80% of patients and had completely resolved in all patients after six-months. Spatial and temporal dynamics of intramural hematomas after spontaneous internal carotid artery dissection showed an early volume increase with concomitant progression of the internal carotid artery stenosis in 5 of 10 patients. Although spontaneous internal carotid artery dissection overall carries a good prognosis with spontaneous hematoma resorption in all our patients, early

  18. The Discursive Dynamics in Teacher Education: Authoritative Discourse or Internally Persuasive Discourse?

    Directory of Open Access Journals (Sweden)

    Maria Otilia Guimarães Ninin

    2014-06-01

    Full Text Available This article, based on the socio-cultural-historical theoretical perspective, discusses the activity in which individuals engage as constitutive of the social roles they occupy. It aims to trigger discussion of discursive dynamics in the context of critical-collaborative teacher education, focusing on internally persuasive and authoritative discourse (BAKHTIN, 1981 and their co-occurrence in situations of negotiation of meanings. This distinction is relevant because it is possible to understand different argumentative enunciations or not, conducted by educators in training, which approach or distance themselves from those cast by their trainers or isolated voices of theoretical practice, indicating possibilities of creation or reduction of dialogic expansion. From the emphasis on internally persuasive discourse, this article highlights the critical - collaborative argumentation role in training educators. Examples selected from a corpus of research collected in public school in São Paulo subsidize the discussion supported by Bakhtin (1981 and Vygotsky (1998; 2001.

  19. Dynamic response of a system with internal heat sources cooled by a flowing incompressible fluid

    International Nuclear Information System (INIS)

    Georgescu, R.; Dobrescu, C.

    1975-01-01

    The paper investigates the dynamic temperature response of an incompressible fluid which cools a duct with internal heat sources sinusoidally oscillated. The analytical results utilise the Laplace transformation technique. The experimental and calculated results are obtained by transfer function approach. Comparison of the calculated with the experimental data indicates agreement from 6 to 24 percent for the amplitude and up to 30 degree for the phase-shift. All the calculated data are below the experimental ones. The analytical method of transfer function approach presents interest and may be utilized for the initial calculations giving good results for flow rates above 1000 kg per hour

  20. Analysis of the fluid-structure dynamic interaction of reactor pressure vessel internals during blowdown

    International Nuclear Information System (INIS)

    Schlechtendahl, E.G.; Krieg, R.; Schumann, U.

    1977-01-01

    The loadings on reactor internal structures (in particular the core barrel) induced during a PWR-blowdown must not result in excessive stresses and strains. The deformations are strongly influenced by the coupling of fluid and structure dynamics and it is necessary, therefore, to develop and apply new coupled analysis tools. In this paper a survey is given over work currently in progress in the Nuclear Research Center Karlsruhe and the Los Alamos Scientific Laboratory which aim towards 'best estimate codes'. The new methods will be verified by means of the HDR-blowdown tests and other experiments. The results of several scoping calculations are presented and illustrated by movie films. (orig.) [de

  1. A Dynamic Programming Model for Internal Attack Detection in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Qiong Shi

    2017-01-01

    Full Text Available Internal attack is a crucial security problem of WSN (wireless sensor network. In this paper, we focus on the internal attack detection which is an important way to locate attacks. We propose a state transition model, based on the continuous time Markov chain (CTMC, to study the behaviors of the sensors in a WSN under internal attack. Then we conduct the internal attack detection model as the epidemiological model. In this model, we explore the detection rate as the rate of a compromised state transition to a response state. By using the Bellman equation, the utility for the state transitions of a sensor can be written in standard forms of dynamic programming. It reveals a natural way to find the optimal detection rate that is by maximizing the total utility of the compromised state of the node (the sum of current utility and future utility. In particular, we encapsulate the current state, survivability, availability, and energy consumption of the WSN into an information set. We conduct extensive experiments and the results show the effectiveness of our solutions.

  2. Dynamic Thermodynamics with Internal Energy, Volume, and Amount of Moles as States : Application to Liquefied Gas Tank

    NARCIS (Netherlands)

    Arendsen, A. R. J.; Versteeg, G. F.

    2009-01-01

    Dynamic models for process design, optimization, and control usually solve a set of heat and/or mass balances as a function of time and/or position in the process. To obtain more robust dynamic models and to minimize the amount of assumptions, internal energy, volume, and amount of moles are chosen

  3. PhD students and integrative research

    NARCIS (Netherlands)

    Fry, G.; Tress, B.; Tress, G.

    2006-01-01

    The training of PhD students is currently very dynamic and varies widely from place to place. We present some examples of this variation and comment on how it may affect the way PhD students cope with integrative studies. Our focus is on the training needs of PhD students studying integrative

  4. International and Domestic Business Cycles as Dynamics of a Network of Networks

    Science.gov (United States)

    Ikeda, Yuichi; Iyetomi, Hiroshi; Aoyama, Hideaki; Yoshikawa, Hiroshi

    2014-03-01

    Synchronization in business cycles has attracted economists and physicists as self-organization in the time domain. From a different point of view, international and domestic business cycles are also interesting as dynamics of a network of networks or a multi-level network. In this paper, we analyze the Indices of Industrial Production monthly time-series in Japan from January 1988 to December 2007 to develop a deeper understanding of domestic business cycles. The frequency entrainment and the partial phase locking were observed for the 16 sectors to be direct evidence of synchronization. We also showed that the information of the economic shock is carried by the phase time-series. The common shock and individual shocks are separated using phase time-series. The former dominates the economic recession in all of 1992, 1998 and 2001. In addition to the above analysis, we analyze the quarterly GDP time series for Australia, Canada, France, Italy, the United Kingdom, and the United States from Q2 1960 to Q1 2010 in order to clarify its origin. We find frequency entrainment and partial phase locking. Furthermore, a coupled limit-cycle oscillator model is developed to explain the mechanism of synchronization. In this model, the interaction due to international trade is interpreted as the origin of the synchronization. The obtained results suggest that the business cycle may be described as a dynamics of the multi-level coupled oscillators exposed to random individual shocks.

  5. Smooth Adaptive Internal Model Control Based on U Model for Nonlinear Systems with Dynamic Uncertainties

    Directory of Open Access Journals (Sweden)

    Li Zhao

    2016-01-01

    Full Text Available An improved smooth adaptive internal model control based on U model control method is presented to simplify modeling structure and parameter identification for a class of uncertain dynamic systems with unknown model parameters and bounded external disturbances. Differing from traditional adaptive methods, the proposed controller can simplify the identification of time-varying parameters in presence of bounded external disturbances. Combining the small gain theorem and the virtual equivalent system theory, learning rate of smooth adaptive internal model controller has been analyzed and the closed-loop virtual equivalent system based on discrete U model has been constructed as well. The convergence of this virtual equivalent system is proved, which further shows the convergence of the complex closed-loop discrete U model system. Finally, simulation and experimental results on a typical nonlinear dynamic system verified the feasibility of the proposed algorithm. The proposed method is shown to have lighter identification burden and higher control accuracy than the traditional adaptive controller.

  6. Internal exposure dynamics drive the Adverse Outcome Pathways of synthetic glucocorticoids in fish

    Science.gov (United States)

    Margiotta-Casaluci, Luigi; Owen, Stewart F.; Huerta, Belinda; Rodríguez-Mozaz, Sara; Kugathas, Subramanian; Barceló, Damià; Rand-Weaver, Mariann; Sumpter, John P.

    2016-02-01

    The Adverse Outcome Pathway (AOP) framework represents a valuable conceptual tool to systematically integrate existing toxicological knowledge from a mechanistic perspective to facilitate predictions of chemical-induced effects across species. However, its application for decision-making requires the transition from qualitative to quantitative AOP (qAOP). Here we used a fish model and the synthetic glucocorticoid beclomethasone dipropionate (BDP) to investigate the role of chemical-specific properties, pharmacokinetics, and internal exposure dynamics in the development of qAOPs. We generated a qAOP network based on drug plasma concentrations and focused on immunodepression, skin androgenisation, disruption of gluconeogenesis and reproductive performance. We showed that internal exposure dynamics and chemical-specific properties influence the development of qAOPs and their predictive power. Comparing the effects of two different glucocorticoids, we highlight how relatively similar in vitro hazard-based indicators can lead to different in vivo risk. This discrepancy can be predicted by their different uptake potential, pharmacokinetic (PK) and pharmacodynamic (PD) profiles. We recommend that the development phase of qAOPs should include the application of species-species uptake and physiologically-based PK/PD models. This integration will significantly enhance the predictive power, enabling a more accurate assessment of the risk and the reliable transferability of qAOPs across chemicals.

  7. Separation Dynamics of Controlled Internal Flow in an Adverse Pressure Gradient

    Science.gov (United States)

    Peterson, C. J.; Vukasinovic, B.; Glezer, A.

    2017-11-01

    The effects of fluidic actuation on the dynamic evolution of aggressive internal flow separation is investigated at speeds up to M = 0.4 within a constant-width diffuser branching off of a primary flow duct. It is shown that a spanwise array of fluidic actuators upstream of the separation actively controls the flow constriction (and losses) within the diffuser and consequently the local pressure gradient at its entrance. The effectiveness of the actuation, as may be measured by the increased flow rate that is diverted through the diffuser, scales with its flow rate coefficient. In the presence of actuation (0.7% mass fraction), the mass flow rate in the primary duct increases by 10% while the fraction of the diverted mass flow rate in the diffuser increases by more than 45%. The flow dynamics near separation in the absence and presence of actuation are characterized using high speed particle image velocimetry and analyzed using proper orthogonal and spectral decompositions. In particular, the spectral contents of the incipient boundary layer separation are compared in the absence and presence of actuation with emphasis on the changes in local dynamics near separation as the characteristic cross stream scale of the boundary layer increases with separation delay.

  8. Internal models of limb dynamics and the encoding of limb state

    Science.gov (United States)

    Hwang, Eun Jung; Shadmehr, Reza

    2005-09-01

    Studies of reaching suggest that humans adapt to novel arm dynamics by building internal models that transform planned sensory states of the limb, e.g., desired limb position and its derivatives, into motor commands, e.g., joint torques. Earlier work modeled this computation via a population of basis elements and used system identification techniques to estimate the tuning properties of the bases from the patterns of generalization. Here we hypothesized that the neural representation of planned sensory states in the internal model might resemble the signals from the peripheral sensors. These sensors normally encode the limb's actual sensory state in which movement errors occurred. We developed a set of equations based on properties of muscle spindles that estimated spindle discharge as a function of the limb's state during reaching and drawing of circles. We then implemented a simulation of a two-link arm that learned to move in various force fields using these spindle-like bases. The system produced a pattern of adaptation and generalization that accounted for a wide range of previously reported behavioral results. In particular, the bases showed gain-field interactions between encoding of limb position and velocity, very similar to the gain fields inferred from behavioral studies. The poor sensitivity of the bases to limb acceleration predicted behavioral results that were confirmed by experiment. We suggest that the internal model of limb dynamics is computed by the brain with neurons that encode the state of the limb in a manner similar to that expected of muscle spindle afferents.

  9. Examining the Dynamic Structure of Daily Internalizing and Externalizing Behavior at Multiple Levels of Analysis

    Directory of Open Access Journals (Sweden)

    Aidan G.C. Wright

    2015-12-01

    Full Text Available Psychiatric diagnostic covariation suggests that the underlying structure of psychopathology is not one of circumscribed disorders. Quantitative modeling of individual differences in diagnostic patterns has uncovered several broad domains of mental disorder liability, of which the Internalizing and Externalizing spectra have garnered the greatest support. These dimensions have generally been estimated from lifetime or past-year comorbidity patters, which are distal from the covariation of symptoms and maladaptive behavior that ebb and flow in daily life. In this study, structural models are applied to daily diary data (Median = 94 days of maladaptive behaviors collected from a sample (N = 101 of individuals diagnosed with personality disorders. Using multilevel and unified structural equation modeling, between-person, within-person, and person-specific structures were estimated from 16 behaviors that are encompassed by the Internalizing and Externalizing spectra. At the between-person level (i.e., individual differences in average endorsement across days we found support for a two-factor Internalizing-Externalizing model, which exhibits significant associations with corresponding diagnostic spectra. At the within-person level (i.e., dynamic covariation among daily behavior pooled across individuals we found support for a more differentiated, four-factor, Negative Affect-Detachment-Hostility-Impulsivity structure. Finally, we demonstrate that the person-specific structures of associations between these four domains are highly idiosyncratic.

  10. The mechanism of electron gating in proton pumping cytochrome c oxidase: the effect of pH and temperature on internal electron transfer.

    Science.gov (United States)

    Brzezinski, P; Malmström, B G

    1987-10-29

    Electron-transfer reactions following flash photolysis of the mixed-valence cytochrome oxidase-CO complex have been measured at 445, 598 and 830 nm between pH 5.2 and 9.0 in the temperature range of 0-25 degrees C. There is a rapid electron transfer from the cytochrome a3-CuB pair to CuA (time constant: 14200 s-1), which is followed by a slower electron transfer to cytochrome a. Both the rate and the amplitude of the rapid phase are independent of pH, and the rate in the direction from CuA to cytochrome a3-CuB is practically independent of temperature. The second phase depends strongly on pH due to the titration of an acid-base group with pKa = 7.6. The equilibrium at pH 7.4 corresponds to reduction potentials of 225 and 345 mV for cytochrome a and a3, respectively, from which it is concluded that the enzyme is in a different conformation compared to the fully oxidized form. The results have been used to suggest a series of reaction steps in a cycle of the oxidase as a proton pump. Application of the electron-transfer theory to the temperature-dependence data suggests a mechanism for electron gating in the pump. Reduction of both cytochrome a and CuA leads to a conformational change, which changes the structure of cytochrome a3-CuB in such a way that the reorganizational barrier for electron transfer is removed and the driving force is increased.

  11. Estimating Rheological Parameters of Anhydrite from Folded Evaporite sequences: Implications for Internal Dynamics of Salt Structure

    Science.gov (United States)

    Adamuszek, Marta; Dabrowski, Marcin; Schmalholz, Stefan M.; Urai, Janos L.; Raith, Alexander

    2015-04-01

    Salt structures have been identified as a potential target for hydrocarbon, CO2, or radioactive waste storage. The most suitable locations for magazines are considered in the thick and relatively homogeneous rock salt layers. However, salt structures often consist of the evaporite sequence including rock salt intercalated with other rock types e.g.: anhydrite, gypsum, potassium and magnesium salt, calcite, dolomite, or shale. The presence of such heterogeneities causes a serious disturbance in the structure management. Detailed analysis of the internal architecture and internal dynamics of the salt structure are crucial for evaluating them as suitable repositories and also their long-term stability. The goal of this study is to analyse the influence of the presence of anhydrite layers on the internal dynamics of salt structures. Anhydrite is a common rock in evaporite sequences. Its physical and mechanical properties strongly differ from the properties of rock salt. The density of anhydrite is much higher than the density of salt, thus anhydrite is likely to sink in salt causing the disturbance of the surrounding structures. This suggestion was the starting point to the discussion about the long-term stability of the magazines in salt structures [1]. However, the other important parameter that has to be taken into account is the viscosity of anhydrite. The high viscosity ratio between salt and anhydrite can restrain the layer from sinking. The rheological behaviour of anhydrite has been studied in laboratory experiments [2], but the results only provide information about the short-term behaviour. The long-term behaviour can be best predicted using indirect methods e.g. based on the analysis of natural structures that developed over geological time scale. One of the most promising are fold structures, the shape of which is very sensitive to the rheological parameters of the deforming materials. Folds can develop in mechanically stratified materials during layer

  12. International Collaboration and Spatial Dynamics of US Patenting in Central and Eastern Europe 1981-2010

    Science.gov (United States)

    Lengyel, Balázs; Leskó, Mariann

    2016-01-01

    How did post-socialist transition and a parallel shift in international labor division restructure regional innovation systems in Central and Eastern Europe? This question is increasingly important, because current EU innovation policy is combined with regional development in Smart Specialization Strategies; however, spatial trends of innovation in Central and Eastern Europe are not fully understood which might lead to less than perfectly efficient policy. In this paper we describe the spatial dynamics of inventor activity in the Czech Republic, Hungary, Poland and Slovakia between 1981 and 2010 –a period that covers both the late socialist era and the post-socialist transition. Cleaning and analyzing the publicly available data from the United States Patent and Trademark Office we illustrate that Central and Eastern European patents made in international co-operations with partners outside the region receive more citations than those Central and Eastern European patents that lack international co-operation. Furthermore, the technological portfolio of the former patents has become increasingly independent from the technological portfolio of the latter class. A town-level analysis of the applicant-inventor ties reveals that inventors have started to work for foreign assignees in those towns where no innovation activity had been recorded before. However, the positive effect does not last long and patenting seems to be only periodic in the majority of these towns. Therefore, innovation policy in Central and Eastern European countries, as well as in other less developed regions, shall foster synergies between international and domestic collaborations in order to decrease regional disparities in patenting. PMID:27846288

  13. International Collaboration and Spatial Dynamics of US Patenting in Central and Eastern Europe 1981-2010.

    Science.gov (United States)

    Lengyel, Balázs; Leskó, Mariann

    2016-01-01

    How did post-socialist transition and a parallel shift in international labor division restructure regional innovation systems in Central and Eastern Europe? This question is increasingly important, because current EU innovation policy is combined with regional development in Smart Specialization Strategies; however, spatial trends of innovation in Central and Eastern Europe are not fully understood which might lead to less than perfectly efficient policy. In this paper we describe the spatial dynamics of inventor activity in the Czech Republic, Hungary, Poland and Slovakia between 1981 and 2010 -a period that covers both the late socialist era and the post-socialist transition. Cleaning and analyzing the publicly available data from the United States Patent and Trademark Office we illustrate that Central and Eastern European patents made in international co-operations with partners outside the region receive more citations than those Central and Eastern European patents that lack international co-operation. Furthermore, the technological portfolio of the former patents has become increasingly independent from the technological portfolio of the latter class. A town-level analysis of the applicant-inventor ties reveals that inventors have started to work for foreign assignees in those towns where no innovation activity had been recorded before. However, the positive effect does not last long and patenting seems to be only periodic in the majority of these towns. Therefore, innovation policy in Central and Eastern European countries, as well as in other less developed regions, shall foster synergies between international and domestic collaborations in order to decrease regional disparities in patenting.

  14. Spinal motor control system incorporates an internal model of limb dynamics.

    Science.gov (United States)

    Shimansky, Y P

    2000-10-01

    The existence and utilization of an internal representation of the controlled object is one of the most important features of the functioning of neural motor control systems. This study demonstrates that this property already exists at the level of the spinal motor control system (SMCS), which is capable of generating motor patterns for reflex rhythmic movements, such as locomotion and scratching, without the aid of the peripheral afferent feedback, but substantially modifies the generated activity in response to peripheral afferent stimuli. The SMCS is presented as an optimal control system whose optimality requires that it incorporate an internal model (IM) of the controlled object's dynamics. A novel functional mechanism for the integration of peripheral sensory signals with the corresponding predictive output from the IM, the summation of information precision (SIP) is proposed. In contrast to other models in which the correction of the internal representation of the controlled object's state is based on the calculation of a mismatch between the internal and external information sources, the SIP mechanism merges the information from these sources in order to optimize the precision of the controlled object's state estimate. It is demonstrated, based on scratching in decerebrate cats as an example of the spinal control of goal-directed movements, that the results of computer modeling agree with the experimental observations related to the SMCS's reactions to phasic and tonic peripheral afferent stimuli. It is also shown that the functional requirements imposed by the mathematical model of the SMCS comply with the current knowledge about the related properties of spinal neuronal circuitry. The crucial role of the spinal presynaptic inhibition mechanism in the neuronal implementation of SIP is elucidated. Important differences between the IM and a state predictor employed for compensating for a neural reflex time delay are discussed.

  15. Book of abstracts of International Conference on Nuclear Structure and Dynamics 2009

    International Nuclear Information System (INIS)

    Prepolec, L.; Niksic, T.

    2009-01-01

    Following the long tradition of nuclear physics conferences organized by our two institutes, e.g. the Adriatic International Conference and Europhysics Study Conferences, this meeting will provide a broad discussion forum on recent experimental and theoretical advances in the physics of nuclear structure and reactions. The main focus will be on the following topics: Nuclear structure and reactions far from stability; Exotic modes of excitation and decays; Collective phenomena and symmetries; Ab initio, cluster model, and shell-model approaches; Nuclear energy density functionals; Heavy-ion reactions at near-barrier energies; Dynamics of light-ion reactions; Nuclear reactions of astrophysical interest; Weak-interaction processes. This booklet contains the abstracts of contributions which will be presented at the Conference, either as invited and contributed talks, or oral poster presentations

  16. Recombination dynamics and internal quantum efficiency in InGaN

    International Nuclear Information System (INIS)

    Murotani, Hideaki; Andoh, Hiroya; Tsukamoto, Takehiko; Sugiura, Toko; Yamada, Yoichi; Tabata, Takuya; Honda, Yoshio; Yamaguchi, Masahito; Amano, Hiroshi

    2014-01-01

    Recombination dynamics and internal quantum efficiency (IQE) of green luminescent InGaN nanowires with different crystalline qualities have been studied by means photoluminescence (PL) and time-resolved PL spectroscopy. Temperature- and excitation-power-density-dependent PL spectroscopy enabled to evaluate the IQE as a function of excitation power density. The shape of the efficiency curves at low temperature strongly depended on the magnitude of nonradiative recombination processes. This leads to the misestimation of the IQE in the lower quality nanowire. In addition, the PL decay curves were well described by a double exponential function both at 6 and 300 K. The PL decay time of the faster component was affected by nonradiative recombination processes even at low temperature. This indicated that the radiative recombination lifetime cannot be estimated from the PL decay time in the lower quality nanowire. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. THE IMPACT OF THE ECONOMIC CRISIS ON THE DYNAMIC OF INTERNATIONAL FDI

    Directory of Open Access Journals (Sweden)

    Lenuţa Carp

    2012-03-01

    Full Text Available FDI flows are internationally recognized for the benefits they generate (technological transfer, know – how, industrial reorganization, raising the number of working places. Foreign capitals increased significantly under the impact of globalization and accelerated the interdependencies between economies up to 2007, but, in the current crisis, the dynamic of FDI flows was affected in a negative manner, both in developed economies and in the developing ones. The aim of this paper is to reveal and analyze the evolution of FDI flows in the period 2007 – 2010, emphasizing the strong impact that economic crisis exerts. The results of the analysis presents the descending trend up to 2009, since 2010 being noticed a slight recovery which continued in the first trimester of 2011 and according to the forecasts will continue in the future.

  18. Influence of an Internally-Generated QBO on Modeled Stratospheric Dynamics and Ozone

    Science.gov (United States)

    Hurwitz, M. M.; Newman, P. A.; Song, I. S.

    2011-01-01

    A GEOS V2 CCM simulation with an internally generated quasi-biennial oscillation (QBO) signal is compared to an otherwise identical simulation without a QBO. In a present-day climate, inclusion of the modeled QBO makes a significant difference to stratospheric dynamics and ozone throughout the year. The QBO enhances variability in the tropics, as expected, but also in the polar stratosphere in some seasons. The modeled QBO also affects the mean stratospheric climate. Because tropical zonal winds in the baseline simulation are generally easterly, there is a relative increase in zonal wind magnitudes in tropical lower and middle stratosphere in the QBO simulation. Extra-tropical differences between the QBO and 'no QBO' simulations thus reflect a bias toward the westerly phase of the QBO: a relative strengthening and poleward shifting the polar stratospheric jets, and a reduction in Arctic lower stratospheric ozone.

  19. Internal friction studies on dynamic strain aging in P91 ferritic steel

    International Nuclear Information System (INIS)

    Zhou, Hongwei; Fang, Junfei; Chen, Yan; Yang, Lei; Zhang, Hui; Lu, Yun; He, Yizhu

    2016-01-01

    The temperature of dynamic strain aging (DSA) regime in P91 steel is between 523 K and 773 K. The activation energy (Q) for onset of DSA is 73 kJ/mol, while that for finale of DSA is 202 kJ/mol. Two main Internal friction (IF) speaks were observed, Snoek and SKK with the activation energy of 67.9 kJ/mol and 121 kJ/mol, respectively. IF shows that activation energy of 73 kJ/mol is equal to that of C atom body diffusion in α-Fe, and 202 kJ/mol is equal to binding energy between C atoms and moving dislocations. These results confirm that the mechanism of DSA can be explained by the diffusion of C atoms and pinning between C and moving dislocation. These investigations indicate that DSA in P91 steel is resulted from C atom diffusion, instead of Cr or Mo atoms.

  20. A dynamic mathematical test of international property securities bubbles and crashes

    Science.gov (United States)

    Hui, Eddie C. M.; Zheng, Xian; Wang, Hui

    2010-04-01

    This study investigates property securities bubbles and crashes by using a dynamic mathematical methodology developed from the previous research (Watanabe et al. 2007a, b [31,32]). The improved model is used to detect the bubble and crash periods in five international countries/cities (namely, United States, United Kingdom, Japan, Hong Kong and Singapore) from Jan, 2000 to Oct, 2008. By this model definition, we are able to detect the beginning of each bubble period even before it bursts. Meanwhile, the empirical results show that most of property securities markets experienced bubble periods between 2003 and 2007, and crashes happened in Apr 2008 triggered by the Subprime Mortgage Crisis of US. In contrast, Japan suffered the shortest bubble period and no evidence has documented the existence of crash there.

  1. INTERNAL DYNAMICS WITHIN HADHRAMI ARABS IN INDONESIA: From Social Hierarchy to Islamic Doctrine

    Directory of Open Access Journals (Sweden)

    Syamsul Rijal

    2017-07-01

    Full Text Available This paper examines the current landscape of Hadhrami Arab Community in Indonesia. It aims to understand the internal fissures that affect the cohesion within the community. Some scholars contended that the conflicts taking place within the Hadhrami community are due to the Yemeni traditional stratification and nationalist orientation during colonial era. However, they do not include in their analysis the contemporary state of Hadhramis in Indonesia. This paper focuses on the contemporary era and argues that doctrinal contest and competition for religious authority have dominated the dynamics of conflict within Indonesian Hadhrami community. The paper will touch on the debates on the notion of Shi’ism among the so-called sayyids and Salafism among the followers of Al-Irsyad Al-Islamiyyah. It suggests that it is through these two currents of thought that the Hadhrami community in Indonesia not only exercise their power and authority, but also shape and transform their very identity.

  2. Computational fluid dynamics applied to flows in an internal combustion engine

    Science.gov (United States)

    Griffin, M. D.; Diwakar, R.; Anderson, J. D., Jr.; Jones, E.

    1978-01-01

    The reported investigation is a continuation of studies conducted by Diwakar et al. (1976) and Griffin et al. (1976), who reported the first computational fluid dynamic results for the two-dimensional flowfield for all four strokes of a reciprocating internal combustion (IC) engine cycle. An analysis of rectangular and cylindrical three-dimensional engine models is performed. The working fluid is assumed to be inviscid air of constant specific heats. Calculations are carried out of a four-stroke IC engine flowfield wherein detailed finite-rate chemical combustion of a gasoline-air mixture is included. The calculations remain basically inviscid, except that in some instances thermal conduction is included to allow a more realistic model of the localized sparking of the mixture. All the results of the investigation are obtained by means of an explicity time-dependent finite-difference technique, using a high-speed digital computer.

  3. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    Energy Technology Data Exchange (ETDEWEB)

    Othman, M. N. K., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Zuradzman, M. Razlan, E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Hazry, D., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Khairunizam, Wan, E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Shahriman, A. B., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Yaacob, S., E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my; Ahmed, S. Faiz, E-mail: najibkhir86@gmail.com, E-mail: zuradzman@unimap.edu.my, E-mail: hazry@unimap.edu.my, E-mail: khairunizam@unimap.edu.my, E-mail: shahriman@unimap.edu.my, E-mail: s.yaacob@unimap.edu.my, E-mail: syedfaiz@unimap.edu.my, E-mail: abadal@unimap.edu.my [Centre of Excellence for Unmanned Aerial Systems, Universiti Malaysia Perlis, 01000 Kangar, Perlis (Malaysia); and others

    2014-12-04

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  4. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    Science.gov (United States)

    Othman, M. N. K.; Zuradzman, M. Razlan; Hazry, D.; Khairunizam, Wan; Shahriman, A. B.; Yaacob, S.; Ahmed, S. Faiz; Hussain, Abadalsalam T.

    2014-12-01

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  5. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    International Nuclear Information System (INIS)

    Othman, M. N. K.; Zuradzman, M. Razlan; Hazry, D.; Khairunizam, Wan; Shahriman, A. B.; Yaacob, S.; Ahmed, S. Faiz

    2014-01-01

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity

  6. International Conference on Computer Modelling of Seas and Coastal Regions and Boundary Elements and Fluid Dynamics

    CERN Document Server

    Partridge, P; Boundary Elements in Fluid Dynamics

    1992-01-01

    This book Boundary Elements in Fluid Dynamics is the second volume of the two volume proceedings of the International Conference on Computer Modelling of Seas and Coastal Regions and Boundary Elements and Fluid Dynamics, held in Southampton, U.K., in April 1992. The Boundary Element Method (BEM) is now fully established as an ac­ curate and successful technique for solving engineering problems in a wide range of fields. The success of the method is due to its advantages in data reduction, as only the boundary of the region is modelled. Thus moving boundaries may be more easily handled, which is not the case if domain methods are used. In addition, the method is easily able to model regions to extending to infinity. Fluid mechanics is traditionally one of the most challenging areas of engi­ neering, the simulation of fluid motion, particularly in three dimensions, is always a serious test for any numerical method, and is an area in which BEM analysis may be used taking full advantage of its special character...

  7. Predictable Internal Brain Dynamics in EEG and Its Relation to Conscious States

    Directory of Open Access Journals (Sweden)

    Jaewook eYoo

    2014-06-01

    Full Text Available Consciousness is a complex and multi-faceted phenomenon defying scientific explanation. Part of the reason why this is the case is due to its subjective nature. In our previous computational experiments, to avoid such a subjective trap, we took a strategy to investigate objective necessary conditions of consciousness. Our basic hypothesis was that predictive internal dynamics serves as such a condition. This is in line with theories of consciousness that treat retention (memory, protention (anticipation, and primary impression as the tripartite temporal structure of consciousness. To test our hypothesis, we analyzed publicly available sleep and awake electroencephalogram (EEG data. Our results show that EEG signals from awake or rapid eye movement (REM sleep states have more predictable dynamics compared to those from slow-wave sleep (SWS. Since awakeness and REM sleep are associated with conscious states and SWS with unconscious or less consciousness states, these results support our hypothesis. The results suggest an intricate relationship among prediction, consciousness, and time, with potential applications to time perception and neurorobotics.

  8. Dynamic Oil Consumption Measurement of Internal Combustion Engines using Laser Spectroscopy.

    Science.gov (United States)

    Sellmeier, Stefan; Alonso, Eduardo; Boesl, Ulrich

    2014-01-07

    A new approach has been developed to measure dynamic consumption of lubricant oil in an internal combustion engine. It is based on the already known technique where sulfur is used as a natural tracer of the engine oil. Since ejection of motor oil in gaseous form into the exhaust is by far the main source of engine oil consumption, detection of sulfur in the exhaust emission is a valuable way to measure engine oil consumption in a dynamic way. In earlier approaches, this is done by converting all sulfur containing chemical components into SO2 by thermal pyrolysis in a high temperature furnace at atmospheric pressure. The so-formed SO2 then is detected by broadband-UV-induced fluorescence or mass spectrometric methods. The challenge is to reach the necessary detection limit of 50 ppb. The new approach presented here includes sulfur conversion in a low-pressure discharge cell and laser-induced fluorescence with wavelength and fluorescence lifetime selection. A limit of detection down to 10 ppb at a temporal resolution in the time scale of few seconds is reached. Extensive, promising studies have been performed at a real engine test bench. Future developments of a compact, mobile device based on these improvements are discussed.

  9. Vestibular stimulation interferes with the dynamics of an internal representation of gravity.

    Science.gov (United States)

    De Sá Teixeira, Nuno Alexandre; Hecht, Heiko; Diaz Artiles, Ana; Seyedmadani, Kimia; Sherwood, David P; Young, Laurence R

    2017-11-01

    The remembered vanishing location of a moving target has been found to be displaced downward in the direction of gravity (representational gravity) and more so with increasing retention intervals, suggesting that the visual spatial updating recruits an internal model of gravity. Despite being consistently linked with gravity, few inquiries have been made about the role of vestibular information in these trends. Previous experiments with static tilting of observers' bodies suggest that under conflicting cues between the idiotropic vector and vestibular signals, the dynamic drift in memory is reduced to a constant displacement along the body's main axis. The present experiment aims to replicate and extend these outcomes while keeping the observers' bodies unchanged in relation to physical gravity by varying the gravito-inertial acceleration using a short-radius centrifuge. Observers were shown, while accelerated to varying degrees, targets moving along several directions and were required to indicate the perceived vanishing location after a variable interval. Increases of the gravito-inertial force (up to 1.4G), orthogonal to the idiotropic vector, did not affect the direction of representational gravity, but significantly disrupted its time course. The role and functioning of an internal model of gravity for spatial perception and orientation are discussed in light of the results.

  10. Internal and External Dynamics in Language: Evidence from Verb Regularity in a Historical Corpus of English

    Science.gov (United States)

    Cuskley, Christine F.; Pugliese, Martina; Castellano, Claudio; Colaiori, Francesca; Loreto, Vittorio; Tria, Francesca

    2014-01-01

    Human languages are rule governed, but almost invariably these rules have exceptions in the form of irregularities. Since rules in language are efficient and productive, the persistence of irregularity is an anomaly. How does irregularity linger in the face of internal (endogenous) and external (exogenous) pressures to conform to a rule? Here we address this problem by taking a detailed look at simple past tense verbs in the Corpus of Historical American English. The data show that the language is open, with many new verbs entering. At the same time, existing verbs might tend to regularize or irregularize as a consequence of internal dynamics, but overall, the amount of irregularity sustained by the language stays roughly constant over time. Despite continuous vocabulary growth, and presumably, an attendant increase in expressive power, there is no corresponding growth in irregularity. We analyze the set of irregulars, showing they may adhere to a set of minority rules, allowing for increased stability of irregularity over time. These findings contribute to the debate on how language systems become rule governed, and how and why they sustain exceptions to rules, providing insight into the interplay between the emergence and maintenance of rules and exceptions in language. PMID:25084006

  11. Examining the Dynamic Structure of Daily Internalizing and Externalizing Behavior at Multiple Levels of Analysis

    Science.gov (United States)

    Wright, Aidan G. C.; Beltz, Adriene M.; Gates, Kathleen M.; Molenaar, Peter C. M.; Simms, Leonard J.

    2015-01-01

    Psychiatric diagnostic covariation suggests that the underlying structure of psychopathology is not one of circumscribed disorders. Quantitative modeling of individual differences in diagnostic patterns has uncovered several broad domains of mental disorder liability, of which the Internalizing and Externalizing spectra have garnered the greatest support. These dimensions have generally been estimated from lifetime or past-year comorbidity patters, which are distal from the covariation of symptoms and maladaptive behavior that ebb and flow in daily life. In this study, structural models are applied to daily diary data (Median = 94 days) of maladaptive behaviors collected from a sample (N = 101) of individuals diagnosed with personality disorders (PDs). Using multilevel and unified structural equation modeling, between-person, within-person, and person-specific structures were estimated from 16 behaviors that are encompassed by the Internalizing and Externalizing spectra. At the between-person level (i.e., individual differences in average endorsement across days) we found support for a two-factor Internalizing–Externalizing model, which exhibits significant associations with corresponding diagnostic spectra. At the within-person level (i.e., dynamic covariation among daily behavior pooled across individuals) we found support for a more differentiated, four-factor, Negative Affect-Detachment-Hostility-Disinhibition structure. Finally, we demonstrate that the person-specific structures of associations between these four domains are highly idiosyncratic. PMID:26732546

  12. The dynamics of hepcidin-ferroportin internalization and consequences of a novel ferroportin disease mutation.

    Science.gov (United States)

    Wallace, Daniel F; McDonald, Cameron J; Ostini, Lesa; Iser, David; Tuckfield, Annabel; Subramaniam, V Nathan

    2017-10-01

    The hepcidin-ferroportin axis underlies the pathophysiology of many iron-associated disorders and is a key target for the development of therapeutics for treating iron-associated disorders. The aims of this study were to investigate the dynamics of hepcidin-mediated ferroportin internalization and the consequences of a novel disease-causing mutation on ferroportin function. Specific reagents for ferroportin are limited; we developed and characterized antibodies against the largest extracellular loop of ferroportin and developed a novel cell-based assay for studying hepcidin-ferroportin function. We show that hepcidin-mediated ferroportin internalization is a rapid process and could be induced using low concentrations of hepcidin. Targeted next-generation sequencing utilizing an iron metabolism gene panel developed in our group identified a novel ferroportin p.D84E variant in a patient with iron overload. Wild-type and mutant ferroportin constructs were generated, transfected into HEK293 cells and analysed using an all-in-one flow-cytometry-based assay to study the effects on hepcidin-mediated internalization and iron transport. Consistent with the classical phenotype of ferroportin disease, the p.D84E mutation results in an inability to transport iron and hepcidin insensitivity. These results validate a recently proposed 3D-structural model of ferroportin and highlight the significance of this variant in the structure and function of ferroportin. Our novel ferroportin antibody and assay will be valuable tools for investigating the regulation of hepcidin/ferroportin function and the development of novel approaches for the therapeutic modulation of iron homeostasis. © 2017 Wiley Periodicals, Inc.

  13. Internal Bleeding

    Science.gov (United States)

    ... Fractures (Part II) Additional Content Medical News Internal Bleeding By Amy H. Kaji, MD, PhD, Associate Professor, ... Emergency First Aid Priorities Cardiac Arrest Choking Internal Bleeding Severed or Constricted Limbs or Digits Soft-Tissue ...

  14. Internal migration of Canadian immigrants, 1993–2004: Evidence from the Survey of Labour and Income Dynamics

    OpenAIRE

    Karen M. King; K. Bruce Newbold

    2011-01-01

    Combining the 1993, 1996, and 1999 six-year panels of the Survey of Labour and Income Dynamics Master Files, the purpose of the paper is twofold. First, it examines the migration and distribution patterns of the foreign-born across Census Metropolitan Areas (CMAs). Second, it examines how internal migration modeling results may differ whether pre- and post-migration measures are used. Results suggest that internal migration of the foreign-born generally does not increase their dispersion acr...

  15. Ultrafast internal rotational dynamics of the azido group in (4S)-azidoproline: Chemical exchange 2DIR spectroscopic investigations

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kyung-Koo; Park, Kwang-Hee; Joo, Cheonik; Kwon, Hyeok-Jun; Han, Hogyu [Department of Chemistry, Korea University, Seoul 136-701 (Korea, Republic of); Ha, Jeong-Hyon [Multidimensional Spectroscopy Laboratory, Korea Basic Science Institute, Seoul 136-713 (Korea, Republic of); Park, Sungnam, E-mail: spark8@korea.ac.kr [Department of Chemistry, Korea University, Seoul 136-701 (Korea, Republic of); Multidimensional Spectroscopy Laboratory, Korea Basic Science Institute, Seoul 136-713 (Korea, Republic of); Cho, Minhaeng, E-mail: mcho@korea.ac.kr [Department of Chemistry, Korea University, Seoul 136-701 (Korea, Republic of); Multidimensional Spectroscopy Laboratory, Korea Basic Science Institute, Seoul 136-713 (Korea, Republic of); Research Institute for Natural Sciences, Korea University, Seoul 136-713 (Korea, Republic of)

    2012-03-02

    Graphical abstract: Internal rotational dynamics of the azido group in SA (Ac-(4S)-Azp-NHMe) was studied in real time by using ultrafast 2DIR spectroscopic method. The time constant of the internal rotation around the C{sup {gamma}}-N{sup {delta}} bond in SA was determined to be {tau}{sub ir} = 5.1 ps, which is found to be much faster than that around the C-C bond in ethane. Highlights: Black-Right-Pointing-Pointer Femtosecond two-dimensional IR spectroscopy of internal rotational dynamics. Black-Right-Pointing-Pointer Stereo-electronic effects of azido group in azido-derivatized proline peptide. Black-Right-Pointing-Pointer The timescale of the azido group internal rotation is about 5.1 ps. - Abstract: The azido group in 4-azidoproline (Azp) derivative, SA (Ac-(4S)-Azp-NHMe), can form an intramolecular electrostatic interaction with the backbone peptide in the s-trans and C{sup {gamma}}-endo conformations of SA. As a result, the azido group exists as two forms, bound and free, which are defined by the presence and absence of such interaction, respectively. The bound and free azido forms are spectrally resolved in the azido IR spectrum of SA in CHCl{sub 3}. Using the two-dimensional infrared (2DIR) and polarization-controlled IR pump-probe methods, we investigated the internal rotational and orientational relaxation dynamics of the azido group and determined the internal rotational time constant of the azido group to be 5.1 ps. The internal rotational motion is found to be responsible for the early part of the orientational relaxation of the azido group in SA. Thus, the femtosecond 2DIR spectroscopy is shown to be an ideal tool for studying ultrafast conformational dynamics of SA.

  16. Attributing Asymmetric Productivity Responses to Internal Ecosystem Dynamics and External Drivers Using Probabilistic Models

    Science.gov (United States)

    Parolari, A.; Goulden, M.

    2017-12-01

    A major challenge to interpreting asymmetric changes in ecosystem productivity is the attribution of these changes to external climate forcing or to internal ecophysiological processes that respond to these drivers (e.g., photosynthesis response to drying soil). For example, positive asymmetry in productivity can result from either positive skewness in the distribution of annual rainfall amount or from negative curvature in the productivity response to annual rainfall. To analyze the relative influences of climate and ecosystem dynamics on both positive and negative asymmetry in multi-year ANPP experiments, we use a multi-scale coupled ecosystem water-carbon model to interpret field experimental results that span gradients of rainfall skewness and ANPP response curvature. The model integrates rainfall variability, soil moisture dynamics, and net carbon assimilation from the daily to inter-annual scales. From the underlying physical basis of the model, we compute the joint probability distribution of the minimum and maximum ANPP for an annual ANPP experiment of N years. The distribution is used to estimate the likelihood that either positive or negative asymmetry will be observed in an experiment, given the annual rainfall distribution and the ANPP response curve. We estimate the total asymmetry as the mode of this joint distribution and the relative contribution attributable to rainfall skewness as the mode for a linear ANPP response curve. Applied to data from several long-term ANPP experiments, we find that there is a wide range of observed ANPP asymmetry (positive and negative) and a spectrum of contributions from internal and external factors. We identify the soil water holding capacity relative to the mean rain event depth as a critical ecosystem characteristic that controls the non-linearity of the ANPP response and positive curvature at high rainfall. Further, the seasonal distribution of rainfall is shown to control the presence or absence of negative

  17. Three Levels of Push-Pull Dynamics among Chinese International Students' Decision to Study Abroad in the Canadian Context

    Science.gov (United States)

    Chen, Jun Mian

    2017-01-01

    The extant literature on student migration flows generally focus on the traditional push-pull factors of migration at the individual level. Such a tendency excludes the broader levels affecting international student mobility. This paper proposes a hybrid of three levels of push-pull dynamics (micro-individual decision-making, meso-academic…

  18. Ph3CCOOSnPh3.Ph3PO AND Ph3CCOOSnPh3.Ph3AsO: SYNTHESIS AND INFRARED STUDY

    Directory of Open Access Journals (Sweden)

    ABDOU MBAYE

    2014-08-01

    Full Text Available The mixture of ethanolic solutions of Ph3CCOOSnPh3 and Ph3PO or Ph3AsO gives Ph3CCOOSnPh3.Ph3PO and Ph3CCOOSnPh3.Ph3AsO adducts which have been characterized by infrared spectroscopy. A discrete structure is suggested for both, the environment around the tin centre being trigonal bipyramidal, the triphenylacetate anion behaving as a mondentate ligand.

  19. Dynamics of a Pipeline under the Action of Internal Shock Pressure

    Science.gov (United States)

    Il'gamov, M. A.

    2017-11-01

    The static and dynamic bending of a pipeline in the vertical plane under the action of its own weight is considered with regard to the interaction of the internal pressure with the curvature of the axial line and the axisymmetric deformation. The pressure consists of a constant and timevarying parts and is assumed to be uniformly distributed over the entire span between the supports. The pipeline reaction to the stepwise increase in the pressure is analyzed in the case where it is possible to determine the exact solution of the problem. The initial stage of bending determined by the smallness of elastic forces as compared to the inertial forces is introduced into the consideration. At this stage, the solution is sought in the form of power series and the law of pressure variation can be arbitrary. This solution provides initial conditions for determining the further process. The duration of the inertial stage is compared with the times of sharp changes of the pressure and the shock waves in fluids. The structure parameters are determined in the case where the shock pressure is accepted only by the inertial forces in the pipeline.

  20. Modelling of the dynamical behaviour of LWR internals by homogeneization methods

    International Nuclear Information System (INIS)

    Brochard, D.; Lepareux, M.; Gibert, R.J.; Delaigue, D.; Planchard, J.

    1987-01-01

    The upper plenum of the internals of PWR, the steam generator bundle, the nuclear reactor core, may be schematically represented by a beam bundle immersed in a fluid. The dynamical study of such a system needs to take into account fluid structure interaction. A refined modelisation at the scale of the tubes can be used but leads to a very important size of problem difficult to solve even on the biggest computers. The homogeneization method allows to have an approximation of the fluid structure interaction for the global behaviour of the bundle. It consists in replacing the heterogeneous physical medium (tubes and fluid) by an equivalent homogeneous medium whose characteristics are determined from the resolution of a set of problems on the elementary cell. The aim of this paper is to present the main steps of the determination of this equivalent medium in the case of small displacements (acoustic behaviour of the fluid) and in using displacement variables for both fluid and tubes. Then some precisions about the implementation of this method in computer codes will be given. (orig.)

  1. 11th International Conference on Clustering Aspects of Nuclear Structure and Dynamics

    International Nuclear Information System (INIS)

    2017-01-01

    Preface The 11 th edition of the International Conference on Clustering Aspects of Nuclear Structure and Dynamics (CLUSTER‘16) was held in Napoli, Italy, on May 23-27 2016. All the Conference Sessions took place in the magnificent Complesso Monumentale dei Ss. Marcellino e Festo , located in the Historical Centre of Naples. This is one of the most prestigious building complexes of the Federico II University of Naples, the main home institution of the organizers, together with the Istituto Nazionale di Fisica Nucleare (Naples division). This building is 500 years old; in the XVIII century, it was reshaped by Luigi Vanvitelli, a famous architect of the pre-Neoclassical period in Italy, designer of the prestigious Royal Palace in the near town of Caserta. The site of Plenary Sessions was the Church of Ss. Marcellino e Festo , where all the participants were surrounded by the Baroque frescoes by Belisario Corenzio and, among the others, the paintings of Battistello Caracciolo, Massimo Stanzione, Giuseppe Simonelli and Francesco De Mura, important artists of the late Baroque period in South Italy. The sites of Parallel Sessions were two halls in the arcade of the S. Marcellino cloister: this gave the opportunity to the participants to enjoy the beauty of the architecture of the cloister with its fountains, gardens, sculptures. As organizers of the Conference, our main aims were: (1) to provide an excellent programme, with the expectation to be a reference point for the Nuclear Cluster Physics in the next four years; (2) to assure a very relaxing stay to the participants, allowing them to explore the bounty of artistic, and also culinary, masterpieces that Naples offers to its guests. The first point was assured by all the conveners that, with their excellent talks, gave a very precise and complete overview of the most recent achievements on Nuclear Cluster Physics, both from the experimental and theoretical point of view. We are indebted with the International

  2. A molecular dynamics analysis of internal friction effects on the plasticity of Zr65Cu35 metallic glass

    International Nuclear Information System (INIS)

    Feng, Shidong; Qi, Li; Zhao, Fengli; Pan, Shaopeng; Li, Gong; Ma, Mingzhen; Liu, Riping

    2015-01-01

    Highlights: • Effects of internal friction on plasticity is investigated at the atomic level. • The simulations allow reproduction of images of internal friction evolution. • The simulation results are in good agreement with experiments and theories. • This simulation can predict the deformation mode with different internal friction. - Abstract: The effects of internal friction (IF) on Zr 65 Cu 35 metallic glass plasticity are investigated through molecular dynamics simulations. Results show that the Voronoi polyhedron 〈0, 3, 6, 3〉 increases as IF increases, thereby effectively inhibiting localized deformation and improving metallic glass plasticity. The simulations allow reproduction of images of IF evolution in metallic glasses subjected to isothermal annealing at 730 K and 850 K respectively, which can help explain the experimental observations. IF could be adjusted by selecting suitable annealing temperatures and cooling rates. The results of this work provide a strong foundation for future metallic glass designs

  3. Radio scintillations observed during atmospheric occultations of Voyager: Internal gravity waves at Titan and magnetic field orientations at Jupiter and Saturn. Ph.D. Thesis

    Science.gov (United States)

    Hinson, D. P.

    1983-01-01

    The refractive index of planetary atmospheres at microwave frequencies is discussed. Physical models proposed for the refractive irregularities in the ionosphere and neutral atmosphere serve to characterize the atmospheric scattering structures, and are used subsequently to compute theoretical scintillation spectra for comparison with the Voyager occultation measurements. A technique for systematically analyzing and interpreting the signal fluctuations observed during planetary occultations is presented and applied to process the dual-wavelength data from the Voyager radio occultations by Jupiter, Saturn, and Titan. Results concerning the plasma irregularities in the upper ionospheres of Jupiter and Saturn are reported. The measured orientation of the irregularities is used to infer the magnetic field direction at several locations in the ionospheres of these two planets; the occultation measurements conflict with the predictions of Jovian magnetic field models, but generally confirm current models of Saturn's field. Wave parameters, including the vertical fluxes of energy and momentum, are estimated, and the source of the internal gravity waves discovered in Titan's upper atmosphere is considered.

  4. A study on the change in dynamic characteristics of reactor internals

    International Nuclear Information System (INIS)

    Kim, Tae Ryong; Jung, Seung Ho; Park, Jin Ho; Park, Jin Suk; Jeong, Keong Hoon

    1993-12-01

    An experimental and analytical studies were performed to establish the relationship between in-air dynamic characteristics of reactor internals and in-water ones by using a scaled-down model which consists of CSB (flexible) and RPV (rigid) models. The experimental results show that the natural frequencies of the CSB model in water are remarkably lowered than those in air, and the normalized natural frequency (in-water frequency/in-air frequency) of the CSB model exists between in-phase mode and out-of-phase mode values of the flexible-to-flexible co-axial cylindrical structure which has the same dimensions as the scaled-down model. The normalized frequency increases to asymptotically reach the in-phase mode frequency of the flexible co-axial cylindrical structure as circumferential mode number (n) increases, while decreases to come near of the out-of-phase mode value as the circumferential mode number decreases. The support condition change for the CSB model in waster made the frequency of 1st axial mode (pure beam mode) shifted into lower value without any effect on the other modes. The changing trend of the natural frequencies and the mode shapes resulted from the finite element analysis by using the ANSYS code shows good agreement with the experimental results both in air and in water cases. In addition, a theoretical study was also performed by simplifying the scaled-down model as flexible-to-rigid co-axial cylindrical structure. It is found that the in-air natural frequencies shows good agreement with both the experimental and finite element analysis results, while the in-water frequencies reveals rather discrepancies. (Author)

  5. The Traumatogenic Dynamics of Internalized Stigma of Mental Illness Among Arab American, Muslim, and Refugee Clients.

    Science.gov (United States)

    Kira, Ibrahim A; Lewandowski, Linda; Ashby, Jeffrey S; Templin, Thomas; Ramaswamy, Vidya; Mohanesh, Jamal

    2014-07-01

    Understanding the dynamics of mental health stigma through existing frameworks, especially in minorities with higher stigma, is problematic. There is a need to reconceptualize stigma, particularly in highly traumatized groups. The current study examines the validity of a new development-based trauma framework that conceptualizes stigma as a type III chronic trauma that contributes to negative mental health effects. This framework proposes that public stigma is a unique chronic traumatic stress that mediates the effects of similar trauma types in mental health patients. To test this proposition, this study explores the relationships between internalized stigma of mental illness (ISMI), different trauma types, and posttrauma spectrum disorders. ISMI, posttraumatic stress disorder, other posttrauma spectrum disorders, and cumulative trauma measures were administered to a sample of 399 mental health patients that included Arab (82%), Muslim (84%), and refugee (31%), as well as American patients (18%). Age in the sample ranged from 18 to 76 years (M = 39.66, SD = 11.45), with 53.5% males. Hierarchical multiple regression, t tests, and path analyses were conducted. Results indicated that ISMI predicted posttraumatic stress disorder and other posttrauma spectrum disorders after controlling for cumulative trauma. ISMI was associated with other chronic collective identity traumas. While Arab Americans, Muslims, and refugees had higher ISMI scores than other Americans, the elevated chronic trauma levels of these groups were significant predictors of these differences. The results provide evidence to support ISMI traumatology model. Implications of the results for treating victims of ISMI, especially Arab Americans, Muslims and refugees are discussed. © The Author(s) 2014.

  6. Proceedings of the International Symposium on Dynamics of Fluids in Fractured Rocks: Concepts and Recent Advances

    Energy Technology Data Exchange (ETDEWEB)

    Faybishenko, B. (ed.)

    1999-02-01

    This publication contains extended abstracts of papers presented at the International Symposium ''Dynamics of Fluids in Fractured Rocks: Concepts and Recent Advances'' held at Ernest Orlando Lawrence Berkeley National Laboratory on February 10-12, 1999. This Symposium is organized in Honor of the 80th Birthday of Paul A. Witherspoon, who initiated some of the early investigations on flow and transport in fractured rocks at the University of California, Berkeley, and at Lawrence Berkeley National Laboratory. He is a key figure in the development of basic concepts, modeling, and field measurements of fluid flow and contaminant transport in fractured rock systems. The technical problems of assessing fluid flow, radionuclide transport, site characterization, modeling, and performance assessment in fractured rocks remain the most challenging aspects of subsurface flow and transport investigations. An understanding of these important aspects of hydrogeology is needed to assess disposal of nu clear wastes, development of geothermal resources, production of oil and gas resources, and remediation of contaminated sites. These Proceedings of more than 100 papers from 12 countries discuss recent scientific and practical developments and the status of our understanding of fluid flow and radionuclide transport in fractured rocks. The main topics of the papers are: Theoretical studies of fluid flow in fractured rocks; Multi-phase flow and reactive chemical transport in fractured rocks; Fracture/matrix interactions; Hydrogeological and transport testing; Fracture flow models; Vadose zone studies; Isotopic studies of flow in fractured systems; Fractures in geothermal systems; Remediation and colloid transport in fractured systems; and Nuclear waste disposal in fractured rocks.

  7. Internal cycling, not external loading, decides the nutrient limitation in eutrophic lake: A dynamic model with temporal Bayesian hierarchical inference.

    Science.gov (United States)

    Wu, Zhen; Liu, Yong; Liang, Zhongyao; Wu, Sifeng; Guo, Huaicheng

    2017-06-01

    Lake eutrophication is associated with excessive anthropogenic nutrients (mainly nitrogen (N) and phosphorus (P)) and unobserved internal nutrient cycling. Despite the advances in understanding the role of external loadings, the contribution of internal nutrient cycling is still an open question. A dynamic mass-balance model was developed to simulate and measure the contributions of internal cycling and external loading. It was based on the temporal Bayesian Hierarchical Framework (BHM), where we explored the seasonal patterns in the dynamics of nutrient cycling processes and the limitation of N and P on phytoplankton growth in hyper-eutrophic Lake Dianchi, China. The dynamic patterns of the five state variables (Chla, TP, ammonia, nitrate and organic N) were simulated based on the model. Five parameters (algae growth rate, sediment exchange rate of N and P, nitrification rate and denitrification rate) were estimated based on BHM. The model provided a good fit to observations. Our model results highlighted the role of internal cycling of N and P in Lake Dianchi. The internal cycling processes contributed more than external loading to the N and P changes in the water column. Further insights into the nutrient limitation analysis indicated that the sediment exchange of P determined the P limitation. Allowing for the contribution of denitrification to N removal, N was the more limiting nutrient in most of the time, however, P was the more important nutrient for eutrophication management. For Lake Dianchi, it would not be possible to recover solely by reducing the external watershed nutrient load; the mechanisms of internal cycling should also be considered as an approach to inhibit the release of sediments and to enhance denitrification. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Dynamic analysis of electron density in the course of the internal motion of molecular system

    International Nuclear Information System (INIS)

    Tachibana, A.; Hori, K.; Asai, Y.; Yamabe, T.

    1984-01-01

    The general dynamic aspect of electron density of a molecular system is studied on the basis of the general equation of the electron orbital which is formulated for the dynamic study of electronic motion. The newly defined electron orbital incorporates the dynamics of molecular vibration into the electronic structures. In this scheme, the change of electron distribution caused by excitation of vibrational state is defined as the ''dynamic electron transfer.'' The dynamic electron density is found to have the remarkable ''additive'' property. The time-dependent aspect of the dynamic electron redistribution is also analyzed on the basis of the ''coherent state.'' The new method relates the classical vibrational amplitude to the quantum number of the vibrational state. As a preliminary application of the present treatment, the dynamic electron densities of H 2 , HD, HT, HF, and HCl molecules are calculated by use of ab initio molecular orbital method

  9. Internal Migration of Canadian Immigrants, 1993-2004: Evidence from the Survey of Labour and Income Dynamics

    Directory of Open Access Journals (Sweden)

    K. Bruce Newbold

    2011-01-01

    Full Text Available Combining the 1993, 1996, and 1999 six-year panels of the Survey of Labour and Income Dynamics Master Files, the purpose of the paper is twofold. First, it examines the migration and distribution patterns of the foreign-born across Census Metropolitan Areas (CMAs. Second, it examines how internal migration modeling results may differ whether pre- and post-migration measures are used. Results suggest that internal migration of the foreign-born generally does not increase their dispersion across Canada, with the foreign-born primarily choosing one of the three immigrant gateway cities of Toronto, Montreal and Vancouver, or moving to other relatively large CMAs.

  10. The impact of seasonal changes in stratification on the dynamics of internal waves in the Sea of Okhotsk

    Directory of Open Access Journals (Sweden)

    Oxana E. Kurkina

    2017-11-01

    Full Text Available The properties and dynamics of internal waves in the ocean crucially depend on the vertical structure of water masses. We present detailed analysis of the impact of spatial and seasonal variations in the density-driven stratification in the Sea of Okhotsk on the properties of the classic kinematic and nonlinear parameters of internal waves in this water body. The resulting maps of the phase speed of long internal waves and coefficients at various terms of the underlying Gardner’s equation make it possible to rapidly determine the main properties of internal solitary waves in the region and to choose an adequate set of parameters of the relevant numerical models. It is shown that the phase speed of long internal waves almost does not depend on the particular season. The coefficient at the quadratic term of the underlying evolution equation is predominantly negative in summer and winter and therefore internal solitons usually have negative polarity. Numerical simulations of the formation of internal solitons and solibores indicate that seasonal variations in the coefficient at the cubic term of Gardner’s equation lead to substantial variations in the shape of solibores.

  11. [Differences in dynamics of insulin and insulin-like growth I (IGF-I) receptors internalization in isolated rat hepatocytes].

    Science.gov (United States)

    Kolychev, A P; Ternovskaya, E E; Arsenieva, A V; Shapkina, E V

    2013-01-01

    Insulin and IGF-I are two related peptides performing in the mammalian body functionally different roles of the metabolic and growth hormones, respectively. Internalization of the insulin-receptor complex (IRC) is the most important chain of mechanism of the action of hormone. To elucidate differences in the main stages of internalization of the two related hormones, the internalization dynamics of 125I-insulin and 125I-IGF-I was traced in isolated rat hepatocytes at 37 and 12 degrees C. There were established marked differences in the process of internalization of labeled hormones, which is stimulated by insulin and IGF-I. At 37 degrees C the insulin-stimulated internalization, unlike the process initiated by IGF-I, did not reach the maximal level for 1 h of incubation. However, essential differences in the internalization course of these two related peptide were obvious at the temperature of 12 degrees C. The internalization level of insulin receptors at 12 degrees C decreased by one third in spite of a significant increase of the insulin receptor binding on the hepatocytes plasma membrane. At 12 degrees C a slight decrease of the proportion of intracellular 125I-IGF-I correlated with a decrease in the 125I-IGF-I binding to receptors on the cell membrane. Internalization of IGF-I receptors was not affected by low temperature, as neither its level, nor the rate changed at 12 degrees C. The paradoxical decrease of the insulin-stimulated internalization at low temperature seems to represent a peculiar "inhibition mechanism" of immersion of IRC into the cell, which leads to accumulation of the complexes on the cell surface and possibly to a readjustment of the insulin biological activity. The resistance of internalization of the IGF-I receptor to cold seems to be related to the more ancient origin of this mechanism in the poikilothermal vertebrates.

  12. A review of a method for dynamic load distribution, dynamical modeling, and explicit internal force control when two manipulators mutually lift and transport a rigid body object

    International Nuclear Information System (INIS)

    Unseren, M.A.

    1997-01-01

    The paper reviews a method for modeling and controlling two serial link manipulators which mutually lift and transport a rigid body object in a three dimensional workspace. A new vector variable is introduced which parameterizes the internal contact force controlled degrees of freedom. A technique for dynamically distributing the payload between the manipulators is suggested which yields a family of solutions for the contact forces and torques the manipulators impart to the object. A set of rigid body kinematic constraints which restrict the values of the joint velocities of both manipulators is derived. A rigid body dynamical model for the closed chain system is first developed in the joint space. The model is obtained by generalizing the previous methods for deriving the model. The joint velocity and acceleration variables in the model are expressed in terms of independent pseudovariables. The pseudospace model is transformed to obtain reduced order equations of motion and a separate set of equations governing the internal components of the contact forces and torques. A theoretic control architecture is suggested which explicitly decouples the two sets of equations comprising the model. The controller enables the designer to develop independent, non-interacting control laws for the position control and internal force control of the system

  13. A review of a method for dynamic load distribution, dynamical modeling, and explicit internal force control when two manipulators mutually lift and transport a rigid body object

    Energy Technology Data Exchange (ETDEWEB)

    Unseren, M.A.

    1997-04-20

    The paper reviews a method for modeling and controlling two serial link manipulators which mutually lift and transport a rigid body object in a three dimensional workspace. A new vector variable is introduced which parameterizes the internal contact force controlled degrees of freedom. A technique for dynamically distributing the payload between the manipulators is suggested which yields a family of solutions for the contact forces and torques the manipulators impart to the object. A set of rigid body kinematic constraints which restrict the values of the joint velocities of both manipulators is derived. A rigid body dynamical model for the closed chain system is first developed in the joint space. The model is obtained by generalizing the previous methods for deriving the model. The joint velocity and acceleration variables in the model are expressed in terms of independent pseudovariables. The pseudospace model is transformed to obtain reduced order equations of motion and a separate set of equations governing the internal components of the contact forces and torques. A theoretic control architecture is suggested which explicitly decouples the two sets of equations comprising the model. The controller enables the designer to develop independent, non-interacting control laws for the position control and internal force control of the system.

  14. Conserving Coherence and Storing Energy during Internal Conversion: Photoinduced Dynamics of cis- and trans-Azobenzene Radical Cations

    KAUST Repository

    Munkerup, Kristin

    2017-10-24

    Light harvesting via energy storage in azobenzene has been a key topic for decades, and the process of energy distribution over the molecular degrees of freedom following photoexcitation remains to be understood. Dynamics of a photoexcited system can exhibit high degrees of non-ergodicity when it is driven by just a few degrees of freedom. Typically, an internal conversion leads to the loss of such localization of dynamics, as the intramolecular energy becomes statistically redistributed over all molecular degrees of freedom. Here, we present a unique case where the excitation energy remains localized even subsequent to internal conversion. Strong-field ionization is used to prepare cis- and trans-azobenzene radical cations on the D1 surface with little excess energy, at the equilibrium neutral geometry. These D1 ions are preferably formed because in this case D1 and D0 switch place in the presence of the strong laser field. The post-ionization dynamics is dictated by the potential energy landscape. The D1 surface is steep downhill along the cis/trans isomerization coordinate and towards a common minimum shared by the two isomers in the region of D1/D0 conical intersection. Coherent cis/trans torsional motion along this coordinate is manifested in the ion transients by a cosine modulation. In this scenario, D0 becomes populated with molecules that are energized mainly along the cis-trans isomerization coordinate, with the kinetic energy above the cis-trans inter-conversion barrier. These activated azobenzene molecules easily cycle back and forth along the D0 surface, and give rise to several periods of modulated signal before coherence is lost. This persistent localization of the internal energy during internal conversion is provided by the steep downhill potential energy surface, small initial internal energy content, and a strong hole-lone pair interaction that drives the molecule along the cis-trans isomerization coordinate to facilitate the transition between

  15. A dynamic model and an experimental study for the internal air and soil temperatures in an innovative greenhouse

    International Nuclear Information System (INIS)

    Joudi, Khalid A.; Farhan, Ammar A.

    2015-01-01

    Highlights: • Simulation model for internal Greenhouse temperature including soil reflectance. • Greenhouse soil heat exchange affects internal temperature by approximately 12%. • Solar air heaters as greenhouse roof maintain better internal temperature year round. - Abstract: An innovative greenhouse which integrates a conventional greenhouse with roof mounted solar air heaters is used in this investigation. This design reduces the solar radiation incoming to the greenhouse in summer which reduced the load and cost of greenhouse cooling and provides a means of solar heating. Experimental measurements of the internal air and internal soil sub-layer temperatures in the greenhouse, without crops, were performed in Baghdad University, Baghdad, Iraq (33.3 °N, 44.4 °E). Measurements were recorded for clear and partly cloudy winter days. A dynamic model was developed to predict the all internal temperatures of the greenhouse. This model includes soil surface heat exchange with the greenhouse air which was found to give a more accurate prediction of the internal temperatures. Soil surface heat exchange has a positive contribution to the internal environment. The input parameters of the model were the measured meteorological conditions and the thermo-physical properties of the greenhouse components which include the cover, inside air, and soil. Comparisons between the predicted and measured results show good agreement. Also, results show that soil sub-layers inside the greenhouse at 50 cm depth are the best place for heat storage elements. The integrated system rendered maximum differences between ambient and internal air temperatures of 16 °C in February and 10 °C in June without operating any heating or cooling system

  16. The internal processes and behavioral dynamics of hospital boards: an exploration of differences between high- and low-performing hospitals.

    Science.gov (United States)

    Kane, Nancy M; Clark, Jonathan R; Rivenson, Howard L

    2009-01-01

    Nonprofit hospital boards are under increasing pressure to improve financial, clinical, and charitable and community benefit performance. Most research on board effectiveness focuses on variables measuring board structure and attributes associated with competing ideal models of board roles. However, the results do not provide clear evidence that one role is superior to another and suggest that in practice boards pursue hybrid roles. Board dynamics and processes have received less attention from researchers, but emerging theoretical frameworks highlight them as key to effective corporate governance. We explored differences in board processes and behavioral dynamics between financially high- and low-performing hospitals, with the goal of developing a better understanding of the best board practices in nonprofit hospitals. A comparative case study approach allowed for in-depth, qualitative assessments of how the internal workings of boards differ between low- and high-performing facilities. Boards of hospitals with strong financial performance exhibited behavioral dynamics and internal processes that differed in important ways from those of hospitals with poor financial performance. Boards need to actively attend to key processes and foster positive group dynamics in decision making to be more effective in governing hospitals.

  17. Behavior of beta-Amyloid 1-16 at the Air-Water Interface at Varying pH by Nonlinear Spectroscopy and Molecular Dynamics Simulations

    Czech Academy of Sciences Publication Activity Database

    Miller, A. E.; Petersen, P. B.; Hollars, C. H.; Saykally, R. J.; Heyda, Jan; Jungwirth, Pavel

    2011-01-01

    Roč. 115, č. 23 (2011), s. 5873-5880 ISSN 1089-5639 R&D Projects: GA MŠk LC512; GA ČR GA203/08/0114 Grant - others:NSF(US) 0650950 Institutional research plan: CEZ:AV0Z40550506 Keywords : beta-amyloid * air /water interface * SHG spectroscopy * molecular dynamics Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.946, year: 2011

  18. Molecular dynamics simulation of a piston driven shock wave in a hard sphere gas. Final Contractor ReportPh.D. Thesis

    Science.gov (United States)

    Woo, Myeung-Jouh; Greber, Isaac

    1995-01-01

    Molecular dynamics simulation is used to study the piston driven shock wave at Mach 1.5, 3, and 10. A shock tube, whose shape is a circular cylinder, is filled with hard sphere molecules having a Maxwellian thermal velocity distribution and zero mean velocity. The piston moves and a shock wave is generated. All collisions are specular, including those between the molecules and the computational boundaries, so that the shock development is entirely causal, with no imposed statistics. The structure of the generated shock is examined in detail, and the wave speed; profiles of density, velocity, and temperature; and shock thickness are determined. The results are compared with published results of other methods, especially the direct simulation Monte-Carlo method. Property profiles are similar to those generated by direct simulation Monte-Carlo method. The shock wave thicknesses are smaller than the direct simulation Monte-Carlo results, but larger than those of the other methods. Simulation of a shock wave, which is one-dimensional, is a severe test of the molecular dynamics method, which is always three-dimensional. A major challenge of the thesis is to examine the capability of the molecular dynamics methods by choosing a difficult task.

  19. Internal motion time scales of a small, highly stable and disulfide-rich protein: A 15N, 13C NMR and molecular dynamics study

    International Nuclear Information System (INIS)

    Guenneugues, Marc; Gilquin, Bernard; Wolff, Nicolas; Menez, Andre; Zinn-Justin, Sophie

    1999-01-01

    Motions of the backbone CαHα and threonine CβHβ bonds of toxin α were investigated using natural abundance 13C NMR and molecular dynamics. Measurement of the 13C longitudinal and transverse relaxation rates employed ACCORDION techniques together with coherence selection by pulsed field gradients and sensitivity enhancement through the use of preservation of equivalent pathway, thus allowing a considerable reduction of the required spectrometer time. 13C R1, R2, 1H → 13C NOE were obtained, as well as the variations of R1ρ(90 deg.) as a function of the rf field strength. These data were compared to those recorded by 1H and 15N NMR on a labelled sample of the toxin [Guenneugues et al. (1997) Biochemistry, 36, 16097-16108]. Both sets of data showed that picosecond to nanosecond time scale motions are well correlated to the secondary structure of the protein. This was further reinforced by the analysis of a 1 ns molecular dynamics simulation in water. Several CαHα and threonine CβHβ experimentally exhibit fast motions with a correlation time longer than 500 ps, that cannot be sampled along the simulation. In addition, the backbone exhibits motions on the microsecond to millisecond time scale on more than half of its length. Thus, toxin α, a highly stable protein (Tm=75 deg. C at acidic pH) containing 61 amino acids and 4 disulfides, shows important internal motions on time scales ranging from 0.1-0.5 ps, to 10-100 ps, 1 ns, and about 30 μs to 10 ms

  20. Effect of bidirectional internal flow on fluid–structure interaction dynamics of conveying marine riser model subject to shear current

    Directory of Open Access Journals (Sweden)

    Zheng-Shou Chen

    2012-03-01

    Full Text Available This article presents a numerical investigation concerning the effect of two kinds of axially progressing internal flows (namely, upward and downward on fluid–structure interaction (FSI dynamics about a marine riser model which is subject to external shear current. The CAE technology behind the current research is a proposed FSI solution, which combines structural analysis software with CFD technology together. Efficiency validation for the CFD software was carried out first. It has been proved that the result from numerical simulations agrees well with the observation from relating model test cases in which the fluidity of internal flow is ignorable. After verifying the numerical code accuracy, simulations are conducted to study the vibration response that attributes to the internal progressive flow. It is found that the existence of internal flow does play an important role in determining the vibration mode (/dominant frequency and the magnitude of instantaneous vibration amplitude. Since asymmetric curvature along the riser span emerges in the case of external shear current, the centrifugal and Coriolis accelerations owing to up- and downward internal progressive flows play different roles in determining the fluid–structure interaction response. The discrepancy between them becomes distinct, when the velocity ratio of internal flow against external shear current is relatively high.

  1. Internal Innovation and Informational Dynamics within Small and Medium Beef Cattle Farm Enterprises

    OpenAIRE

    Noble, Chris

    2011-01-01

    The internal knowledge capabilities of small and medium beef cattle farm enterprises are examined using information economics to gain an understanding of how these organisations approach innovation. Enterprises are viewed as being embedded in the wider industry and are subject to both external and internal influences. However the discussion here is focused on internal activities in order to consider how enterprise specific knowledge is constructed allowing innovation to occur. Innovation is a...

  2. Global monitoring of dynamic information systems a case study in the international supply chain

    NARCIS (Netherlands)

    Pruksasri, P.; Berg, J. van den; Hofman, W.J.

    2014-01-01

    Global information systems are becoming more complex and dynamic everyday: huge amounts of data and messages through those systems show dynamically changing traffic patterns. Because of this, diagnosing when sub-systems are not working properly is difficult. System failures or errors in information

  3. Around the Fishing Net: Leadership Dynamics for Change in an American International School

    Science.gov (United States)

    Murakami-Ramalho, Elizabeth; Benham, Maenette

    2010-01-01

    This study explored the active involvement of school and community members investing in leadership dynamics for change, especially considering the increasingly globalized world and the importance of preparing globally minded citizens. To explore how educators and leaders work to foster dynamic learning experiences in a highly mobile global…

  4. 13th International Conference on Motion and Vibration Control (MOVIC 2016) and the 12th International Conference on Recent Advances in Structural Dynamics (RASD 2016)

    International Nuclear Information System (INIS)

    2016-01-01

    This volume contains the papers presented at the Thirteenth International Conference on Motion and Vibration Control (MoViC), together with the Twelfth International Conference on Recent Advances in Structural Dynamics (RASD). MoViC is an event that started in Yokohama, Japan in 1992 and has been organised every two years alternating between Japan, USA and Europe. The eleven previous RASD conferences have been held every three years or so since 1980 primarily in Southampton, UK. The idea of joining the two conferences came quite naturally because of the common ground of the two conferences and the chances of cross-pollination between two otherwise separate research groups. This joint conference is devoted to theoretical, numerical and experimental developments in motion/vibration/structural dynamics, their control and application to all types of structures and dynamical systems. The conference reflects the state-of-the- art in these topics, and is an excellent opportunity to exchange scientific, technical and experimental ideas. The Conference Proceedings include over 250 papers by authors from over 20 countries, forty technical sessions and five plenary presentations. The five invited speakers are Professor Roger Goodall (Loughborough University, UK) presenting “Motion and vibration control for railway vehicles”, Professor Takeshi Mizuno (Saitama University, Japan) presenting “Recent advances in magnetic suspension technology”, Professor Kevin Murphy (University of Louisville, USA) presenting “Dynamics of Passive Balancing Rings for Rotating Systems”, Professor David Wagg (University of Sheffield, UK) presenting “Reducing vibrations in structures using structural control”, and Professor Kon-Well Wang (University of Michigan, USA) presenting “From Muscles to Plants - Nature-Inspired Adaptive Metastructures for Structural Dynamics Enhancement”. I would like to thank members of the Organising Committee for their help, over the last year or so, in

  5. International trade in services developments in light of dynamic developments in competitive environment

    Directory of Open Access Journals (Sweden)

    Anna Olefir

    2008-06-01

    Full Text Available The paper analyses theoretical grounds for determining «services», key peculiarities of international trade in services and its discrepancies from trade in goods, and determines the modern trends of development of this form of international trade according to the main types of services.

  6. International

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    This rubric reports on 10 short notes about international economical facts about nuclear power: Electricite de France (EdF) and its assistance and management contracts with Eastern Europe countries (Poland, Hungary, Bulgaria); Transnuclear Inc. company (a 100% Cogema daughter company) acquired the US Vectra Technologies company; the construction of the Khumo nuclear power plant in Northern Korea plays in favour of the reconciliation between Northern and Southern Korea; the delivery of two VVER 1000 Russian reactors to China; the enforcement of the cooperation agreement between Euratom and Argentina; Japan requested for the financing of a Russian fast breeder reactor; Russia has planned to sell a floating barge-type nuclear power plant to Indonesia; the control of the Swedish reactor vessels of Sydkraft AB company committed to Tractebel (Belgium); the renewal of the nuclear cooperation agreement between Swiss and USA; the call for bids from the Turkish TEAS electric power company for the building of the Akkuyu nuclear power plant answered by three candidates: Atomic Energy of Canada Limited (AECL), Westinghouse (US) and the French-German NPI company. (J.S.)

  7. A study of quadrupole dynamics: quantification of classical motion chaos, and new features of the coherent states model. Resume of Ph.D thesis

    International Nuclear Information System (INIS)

    Baran, V.

    1995-01-01

    This resume of the Ph.D. thesis has three main parts. In the first part a fourth order quadrupole boson Hamiltonian is semi classically treated through a time-dependent variational principle (TDVP), the variational states being of coherent type for the boson operators b 20 + and 1/√2 (b 22 + + b 2-2 + ). The static ground state is studied as a function of the parameters involved in the model Hamiltonian. Linearizing the classical equations of motion one obtains the RPA approach for the many boson correlations. There are two RPA roots which describe the beta and gamma vibrations, respectively. Several quantization procedures for both small and large amplitude regimes are discussed. The quantized Hamiltonians are compared with some others which were previously obtained by using different methods. A special attention is paid to the quantal states associated to some of the peaks appearing in the Fourier spectrum of the classical action density. Some of the quantal states exhibit a pronounced anharmonic structure. Therefore the procedure may be used for a unified description of small and large amplitude regimes. In the next part the semiclassical foundations of the Coherent State Model are established using the formalism elaborated in the previous section. In the third part the semiclassical treatment through a time-dependent variational principle (TDVP) of the fourth order quadrupole boson Hamiltonian H is continued. In the parameter space of H there are regions, conventionally called as 'nuclear phases', determining specific static properties. Several ground states corresponding to different equilibrium shapes are found as static solutions of classical equations of motion. The non-integrable system may follow a chaotic trajectory. The mechanism of destroying the tori bearing regular orbits and the onset of chaos may depend on nuclear phase. The regular and chaotic motions are analyzed in terms of Poincare sections and Lyapunov largest exponent. Specific features of

  8. Modeling the lubrication, dynamics, and effects of piston dynamic tilt of twin-land oil control rings in internal combustion engines

    Energy Technology Data Exchange (ETDEWEB)

    Tian, T.; Wong, V.W.

    2000-01-01

    A theoretical model was developed to study the lubrication, friction, dynamics, and oil transport of twin-land oil control rings (TLOCR) in internal combustion engines. A mixed lubrication model with consideration of shear-thinning effects of multigrade oils was used to describe the lubrication between the running surfaces of the two lands and the liner. Oil squeezing and asperity contact were both considered for the interaction between the flanks of the TLOCR and the ring groove. Then, the moments and axial forces from TLOCR/liner lubrication and TLOCR/groove interaction were coupled into the dynamic equations of the TLOCR. Furthermore, effects of piston dynamic tilt were considered in a quasi three-dimensional manner so that the behaviors of the TLOCR at different circumferential location could be studied. As a first step, variation of the third land pressure was neglected. The model predictions were illustrated via an SI engine. One important finding is that around thrust and anti-thrust sides, the difference between the minimum oil film thickness of two lands can be as high as several micrometers due to piston dynamic tilt. As a result, at thrust and anti-thrust sides, significant oil can pass under one land of the TLOCR along the bore, although the other land perfectly seals the bore. Then, the capabilities of the model were further explained by studying the effects of ring tension and torsional resistance on the lubrication and oil transport between the lands and the liner. The effects of oil film thickness on the flanks of the ring groove on the dynamics of the TLOCR were also studied. Friction results show that boundary lubrication contributes significantly to the total friction of the TLOCR.

  9. A "continuity-index" for assessing ice-sheet dynamics from radar-sounded internal layers

    DEFF Research Database (Denmark)

    Karlsson, Nanna Bjørnholt; Rippin, David; Bingham, Robert G.

    2012-01-01

    Radio-echo sounding (RES) of polar icesheets reveals extensive internal layering. The degree of continuity of internal layering holds critical information about the ice-flow field, but previous analyses of this parameter have been limited to qualitative classifications. Here we present a new...... further support that the main trunk and tributaries are unlikely to have undergone substantial migration since the deposition of the internal layering. Significantly, our new method for analyzing internallayers is readily transferable across RES datasets, offering promise for data-led assessments of past...

  10. In Vitro-In Vivo Predictive Dissolution-Permeation-Absorption Dynamics of Highly Permeable Drug Extended-Release Tablets via Drug Dissolution/Absorption Simulating System and pH Alteration.

    Science.gov (United States)

    Li, Zi-Qiang; Tian, Shuang; Gu, Hui; Wu, Zeng-Guang; Nyagblordzro, Makafui; Feng, Guo; He, Xin

    2018-05-01

    Each of dissolution and permeation may be a rate-limiting factor in the absorption of oral drug delivery. But the current dissolution test rarely took into consideration of the permeation property. Drug dissolution/absorption simulating system (DDASS) valuably gave an insight into the combination of drug dissolution and permeation processes happening in human gastrointestinal tract. The simulated gastric/intestinal fluid of DDASS was improved in this study to realize the influence of dynamic pH change on the complete oral dosage form. To assess the effectiveness of DDASS, six high-permeability drugs were chosen as model drugs, including theophylline (pK a1  = 3.50, pK a2  = 8.60), diclofenac (pK a  = 4.15), isosorbide 5-mononitrate (pK a  = 7.00), sinomenine (pK a  = 7.98), alfuzosin (pK a  = 8.13), and metoprolol (pK a  = 9.70). A general elution and permeation relationship of their commercially available extended-release tablets was assessed as well as the relationship between the cumulative permeation and the apparent permeability. The correlations between DDASS elution and USP apparatus 2 (USP2) dissolution and also between DDASS permeation and beagle dog absorption were developed to estimate the predictability of DDASS. As a result, the common elution-dissolution relationship was established regardless of some variance in the characteristic behavior between DDASS and USP2 for drugs dependent on the pH for dissolution. Level A in vitro-in vivo correlation between DDASS permeation and dog absorption was developed for drugs with different pKa. The improved DDASS will be a promising tool to provide a screening method on the predictive dissolution-permeation-absorption dynamics of solid drug dosage forms in the early-phase formulation development.

  11. Dynamical and quasi-static multi-physical models of a diesel internal combustion engine using Energetic Macroscopic Representation

    International Nuclear Information System (INIS)

    Horrein, L.; Bouscayrol, A.; Cheng, Y.; El Fassi, M.

    2015-01-01

    Highlights: • Internal Combustion Engine (ICE) dynamical and static models. • Organization of ICE model using Energetic Macroscopic Representation. • Description of the distribution of the chemical, thermal and mechanical power. • Implementation of the ICE model in a global vehicle model. - Abstract: In the simulation of new vehicles, the Internal Combustion Engine (ICE) is generally modeled by a static map. This model yields the mechanical power and the fuel consumption. But some studies require the heat energy from the ICE to be considered (i.e. waste heat recovery, thermal regulation of the cabin). A dynamical multi-physical model of a diesel engine is developed to consider its heat energy. This model is organized using Energetic Macroscopic Representation (EMR) in order to be interconnected to other various models of vehicle subsystems. An experimental validation is provided. Moreover a multi-physical quasi-static model is also derived. According to different modeling aims, a comparison of the dynamical and the quasi-static model is discussed in the case of the simulation of a thermal vehicle. These multi-physical models with different simulation time consumption provide good basis for studying the effects of the thermal energy on the vehicle behaviors, including the possibilities of waste heat recovery

  12. Change of conformation and internal dynamics of supercoiled DNA upon binding of Escherichia coli single-strand binding protein

    International Nuclear Information System (INIS)

    Langowski, J.; Benight, A.S.; Fujimoto, B.S.; Schurr, J.M.; Schomburg, U.

    1985-01-01

    The influence of Escherichia coli single-strand binding (SSB) protein on the conformation and internal dynamics of pBR322 and pUC8 supercoiled DNAs has been investigated by using dynamic light scattering at 632.8 and 351.1 nm and time-resolved fluorescence polarization anisotropy of intercalated ethidium. SSB protein binds to both DNAs up to a stoichiometry that is sufficient to almost completely relax the superhelical turns. Upon saturation binding, the translational diffusion coefficients (D 0 ) of both DNAs decrease by approximately 20%. Apparent diffusion coefficients (D/sub app/) obtained from dynamic light scattering display the well-known increase with K 2 (K = scattering vector), leveling off toward a plateau value (D/sub plat/) at high K 2 . For both DNAs, the difference D/sub plat/ - D 0 increases upon relaxation of supercoils by SSB protein, which indicates a corresponding enhancement of the subunit mobilities in internal motions. Fluorescence polarization anisotropy measurements on free and complexed pBR322 DNA indicate a (predominantly) uniform torsional rigidity for the saturated DNA/SSB protein complex that is significantly reduced compared to the free DNA. These observations are all consistent with the notion that binding of SSB protein is accompanied by a gradual loss of supercoils and saturates when the superhelical twist is largely removed

  13. Development of international labor migration in the dynamics of globalization processes

    Directory of Open Access Journals (Sweden)

    Rubinskaya Eteri, D.

    2015-03-01

    Full Text Available The current characteristics of international migration caused by the qualitative changes that occur in the global economy under influence of increasing globalization. The paper attempts to suggest periodization of the global economy development and to identify features of international labor migration occurred under the influence of deep changes in the world economy. During this period, the author identifies three stages in the formation of globalization, the transition criterion from one to other is the degree of world economy changes under the influence of the productive forces development and the major social and political transformations resulted in qualitative changes in the processes of international labor migration. At the same time in the context of globalization the place and role of international labor migration changes in the global economy system: migration becomes a means of promoting the globalization of countries and regions, the most important factor of demographic development and economic growth.

  14. Neglected chaos in international stock markets: Bayesian analysis of the joint return-volatility dynamical system

    Science.gov (United States)

    Tsionas, Mike G.; Michaelides, Panayotis G.

    2017-09-01

    We use a novel Bayesian inference procedure for the Lyapunov exponent in the dynamical system of returns and their unobserved volatility. In the dynamical system, computation of largest Lyapunov exponent by traditional methods is impossible as the stochastic nature has to be taken explicitly into account due to unobserved volatility. We apply the new techniques to daily stock return data for a group of six countries, namely USA, UK, Switzerland, Netherlands, Germany and France, from 2003 to 2014, by means of Sequential Monte Carlo for Bayesian inference. The evidence points to the direction that there is indeed noisy chaos both before and after the recent financial crisis. However, when a much simpler model is examined where the interaction between returns and volatility is not taken into consideration jointly, the hypothesis of chaotic dynamics does not receive much support by the data ("neglected chaos").

  15. International conference on dynamical systems and game theory in honor of Mauricio Peixoto and David Rand

    CERN Document Server

    Peixoto, Mauricio Matos; Rand, David A J; Dynamics, Games and Science I

    2011-01-01

    "Dynamics, Games and Science I and II" are a selection of surveys and research articles written by leading researchers in mathematics and its applications to the sciences. The majority of the contributions are on dynamical systems and game theory, focusing either on some of their most fundamental and theoretical developments or on their applications to modeling in biology, economics, engineering, finances and psychology. The aim of these books is to present cutting-edge research in these areas that can encourage graduate students and researchers in mathematics to develop them further

  16. Glitches as probes of neutron star internal structure and dynamics: Effects of the superfluid-superconducting core

    Science.gov (United States)

    Gügercinoğlu, Erbil

    2017-12-01

    Glitches, sudden spin-up of pulsars with subsequent recovery, provide us with a unique opportunity to investigate various physical processes, including the crust-core coupling, distribution of reservoir angular momentum within different internal layers, spin-up in neutral and charged superfluids and constraining the equation of state of the neutron star (NS) matter. In this work, depending on the dynamic interaction between the vortex lines and the nuclei in the inner crust, and between the vortex lines and the magnetic flux tubes in the outer core, various types of relaxation behavior are obtained and confronted with the observations. It is shown that the glitches have strong potential to deduce information about the cooling behavior and interior magnetic field configuration of NSs. Some implications of the relative importance of the external spin-down torques and the superfluid internal torques for recently observed unusual glitches are also discussed.

  17. Dynamic functional coupling of high resolution EEG potentials related to unilateral internally triggered one-digit movements.

    Science.gov (United States)

    Urbano, A; Babiloni, C; Onorati, P; Babiloni, F

    1998-06-01

    Between-electrode cross-covariances of delta (0-3 Hz)- and theta (4-7 Hz)-filtered high resolution EEG potentials related to preparation, initiation. and execution of human unilateral internally triggered one-digit movements were computed to investigate statistical dynamic coupling between these potentials. Significant (P planning, starting, and performance of unilateral movement. The involvement of these cortical areas is supported by the observation that averaged spatially enhanced delta- and theta-bandpassed potentials were computed from the scalp regions where task-related electrical activation of primary sensorimotor areas and supplementary motor area was roughly represented.

  18. Pectins, Hemicelluloses and Celluloses Show Specific Dynamics in the Internal and External Surfaces of Grape Berry Skin During Ripening.

    Science.gov (United States)

    Fasoli, Marianna; Dell'Anna, Rossana; Dal Santo, Silvia; Balestrini, Raffaella; Sanson, Andrea; Pezzotti, Mario; Monti, Francesca; Zenoni, Sara

    2016-06-01

    Grapevine berry skin is a complex structure that contributes to the final size and shape of the fruit and affects its quality traits. The organization of cell wall polysaccharides in situ and their modification during ripening are largely uncharacterized. The polymer structure of Corvina berry skin, its evolution during ripening and related modifying genes were determined by combing mid-infrared micro-spectroscopy and multivariate statistical analysis with transcript profiling and immunohistochemistry. Spectra were acquired in situ using a surface-sensitive technique on internal and external sides of the skin without previous sample pre-treatment, allowing comparison of the related cell wall polymer dynamics. The external surface featured cuticle-related bands; the internal surface showed more adsorbed water. Application of surface-specific normalization revealed the major molecular changes related to hemicelluloses and pectins in the internal surface and to cellulose and pectins in the external surface and that they occur between mid-ripening and full ripening in both sides of the skin. Transcript profiling of cell wall-modifying genes indicated a general suppression of cell wall metabolism during ripening. Genes related to pectin metabolism-a β-galactosidase, a pectin(methyl)esterase and a pectate lyase-and a xyloglucan endotransglucosylase/hydrolase, involved in hemicellulose modification, showed enhanced expression. In agreement with Fourier transform infrared spectroscopy, patterns due to pectin methyl esterification provided new insights into the relationship between pectin modifications and the associated transcript profile during skin ripening. This study proposes an original description of polymer dynamics in grape berries during ripening, highlighting differences between the internal and external sides of the skin. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For

  19. The world network of scientific collaborations between cities: domestic or international dynamics?

    Energy Technology Data Exchange (ETDEWEB)

    Maisonobe, M.; Eckert, D.; Grossetti, M.; Jégou, L.; Milard, B.

    2016-07-01

    Earlier publication (Grossetti et al., 2014) has established that we are attending a decreasing concentration of scientific activities within “world-cities”. Given that more and more cities and countries are contributing to the world production of knowledge, this article analyzes the evolution of the world network of collaborations both at the domestic and international levels during the 2000s. Using data from the Science Citation Index Expanded, scientific authors’ addresses are geo-localized and grouped by urban areas. Our data suggests that interurban collaborations within countries have increased together with international linkages. In most countries, domestic collaborations have increased faster than international collaborations. Even among the top collaborating cities, sometimes referred to as “world cities”, the share of domestic collaborations is gaining momentum. Our results suggest that, contrary to common beliefs about the globalization process, national systems of research have been strengthening during the 2000s. (Author)

  20. The dynamics of tax havens: An analysis from an international and domestic perspective

    OpenAIRE

    Kolade, Deborah

    2017-01-01

    2017 dissertation for Master of Law in International Business Law. Selected by academic staff as a good example of a masters level dissertation. Since the occurrence of history’s biggest data leak known as Panama Papers, more\\ud focus has been placed upon offshore dealings and tax havens. With no clear\\ud definition on what tax haven is, this research will be exploring the usage of tax\\ud haven internationally whilst paying particular attention to the United Kingdom,\\ud it’s perspectives and ...

  1. Internal sub-sonic burning during an explosion viewed via dynamic X-ray radiography

    Science.gov (United States)

    Smilowitz, L.; Henson, B. F.; Oschwald, D.; Suvorova, N.; Remelius, D.

    2017-10-01

    We observe internal convective and conductive burn front propagation and solid consumption subsequent to thermal ignition for plastic bonded formulations of the solid organic secondary explosives octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine and 1,3,5-triamino-2,4,6-trinitrobenzene. This work describes x-ray radiographic diagnostics enabling the study of solid density in a fully encased explosive during internal burning subsequent to ignition. The result of this study is the ability to directly observe and measure rates of energy release during a thermal explosion.

  2. Rule of Law Dynamics in an Era of International and Transnational Governance

    NARCIS (Netherlands)

    Zürn, M.; Nollkaemper, A.; Peerenboom, R.

    2011-01-01

    The international and transnational nature of modern governance presents major challenges for the rule of law promotion agenda, at a time when the less than stellar results of traditional state-oriented rule of law promotion have led to increased doubts about the wisdom and feasibility of the

  3. Dynamism and the erosion of procedural safeguards in international governance of terrorism

    NARCIS (Netherlands)

    N.T. Ali (Nathanael)

    2015-01-01

    markdownabstractAbstract Contemporary international governance of terrorism reflects a conceptualisation of terrorism as a global public problem that both affects and needs to be responded to by all sectors of global society. Consequently, counter-terrorism has taken the form of proactive risk

  4. Analysis of Leadership Dynamics in Educational Settings during Times of External and Internal Change

    Science.gov (United States)

    Jäppinen, Aini-Kristiina

    2017-01-01

    Background: The article concerns the tensions that can arise during demanding external, and consequential internal changes and considers how educational leadership is able to respond to them. Leadership is here understood as a collaborative endeavour, producing shared sense-making in situations of tension. Purpose: The main research question was:…

  5. DREISS: Using State-Space Models to Infer the Dynamics of Gene Expression Driven by External and Internal Regulatory Networks

    Science.gov (United States)

    Gerstein, Mark

    2016-01-01

    Gene expression is controlled by the combinatorial effects of regulatory factors from different biological subsystems such as general transcription factors (TFs), cellular growth factors and microRNAs. A subsystem’s gene expression may be controlled by its internal regulatory factors, exclusively, or by external subsystems, or by both. It is thus useful to distinguish the degree to which a subsystem is regulated internally or externally–e.g., how non-conserved, species-specific TFs affect the expression of conserved, cross-species genes during evolution. We developed a computational method (DREISS, dreiss.gerteinlab.org) for analyzing the Dynamics of gene expression driven by Regulatory networks, both External and Internal based on State Space models. Given a subsystem, the “state” and “control” in the model refer to its own (internal) and another subsystem’s (external) gene expression levels. The state at a given time is determined by the state and control at a previous time. Because typical time-series data do not have enough samples to fully estimate the model’s parameters, DREISS uses dimensionality reduction, and identifies canonical temporal expression trajectories (e.g., degradation, growth and oscillation) representing the regulatory effects emanating from various subsystems. To demonstrate capabilities of DREISS, we study the regulatory effects of evolutionarily conserved vs. divergent TFs across distant species. In particular, we applied DREISS to the time-series gene expression datasets of C. elegans and D. melanogaster during their embryonic development. We analyzed the expression dynamics of the conserved, orthologous genes (orthologs), seeing the degree to which these can be accounted for by orthologous (internal) versus species-specific (external) TFs. We found that between two species, the orthologs have matched, internally driven expression patterns but very different externally driven ones. This is particularly true for genes with

  6. DREISS: Using State-Space Models to Infer the Dynamics of Gene Expression Driven by External and Internal Regulatory Networks.

    Directory of Open Access Journals (Sweden)

    Daifeng Wang

    2016-10-01

    Full Text Available Gene expression is controlled by the combinatorial effects of regulatory factors from different biological subsystems such as general transcription factors (TFs, cellular growth factors and microRNAs. A subsystem's gene expression may be controlled by its internal regulatory factors, exclusively, or by external subsystems, or by both. It is thus useful to distinguish the degree to which a subsystem is regulated internally or externally-e.g., how non-conserved, species-specific TFs affect the expression of conserved, cross-species genes during evolution. We developed a computational method (DREISS, dreiss.gerteinlab.org for analyzing the Dynamics of gene expression driven by Regulatory networks, both External and Internal based on State Space models. Given a subsystem, the "state" and "control" in the model refer to its own (internal and another subsystem's (external gene expression levels. The state at a given time is determined by the state and control at a previous time. Because typical time-series data do not have enough samples to fully estimate the model's parameters, DREISS uses dimensionality reduction, and identifies canonical temporal expression trajectories (e.g., degradation, growth and oscillation representing the regulatory effects emanating from various subsystems. To demonstrate capabilities of DREISS, we study the regulatory effects of evolutionarily conserved vs. divergent TFs across distant species. In particular, we applied DREISS to the time-series gene expression datasets of C. elegans and D. melanogaster during their embryonic development. We analyzed the expression dynamics of the conserved, orthologous genes (orthologs, seeing the degree to which these can be accounted for by orthologous (internal versus species-specific (external TFs. We found that between two species, the orthologs have matched, internally driven expression patterns but very different externally driven ones. This is particularly true for genes with

  7. The dynamic interaction between combustible renewables and waste consumption and international tourism: the case of Tunisia.

    Science.gov (United States)

    Ben Jebli, Mehdi; Ben Youssef, Slim; Apergis, Nicholas

    2015-08-01

    This paper employs the autoregressive distributed lag (ARDL) bounds methodological approach to investigate the relationship between economic growth, combustible renewables and waste consumption, carbon dioxide (CO2) emissions, and international tourism for the case of Tunisia spanning the period 1990-2010. The results from the Fisher statistic of both the Wald test and the Johansen test confirm the presence of a long-run relationship among the variables under investigation. The stability of estimated parameters has been tested, while Granger causality tests recommend a short-run unidirectional causality running from economic growth and combustible renewables and waste consumption to CO2 emissions, a bidirectional causality between economic growth and combustible renewables and waste consumption and unidirectional causality running from economic growth and combustible renewables and waste consumption to international tourism. In the long-run, the error correction terms confirm the presence of bidirectional causality relationships between economic growth, CO2 emissions, combustible renewables and waste consumption, and international tourism. Our long-run estimates show that combustible renewables and waste consumption increases international tourism, and both renewables and waste consumption and international tourism increase CO2 emissions and output. We recommend that (i) Tunisia should use more combustible renewables and waste energy as this eliminates wastes from touristic zones and increases the number of tourist arrivals, leading to economic growth, and (ii) a fraction of this economic growth generated by the increase in combustible renewables and waste consumption should be invested in clean renewable energy production (i.e., solar, wind, geothermal) and energy efficiency projects.

  8. Effects of changes in nutrient loading and composition on hypoxia dynamics and internal nutrient cycling of a stratified coastal lagoon

    Science.gov (United States)

    Zhu, Yafei; McCowan, Andrew; Cook, Perran L. M.

    2017-10-01

    The effects of changes in catchment nutrient loading and composition on the phytoplankton dynamics, development of hypoxia and internal nutrient dynamics in a stratified coastal lagoon system (the Gippsland Lakes) were investigated using a 3-D coupled hydrodynamic biogeochemical water quality model. The study showed that primary production was equally sensitive to changed dissolved inorganic and particulate organic nitrogen loads, highlighting the need for a better understanding of particulate organic matter bioavailability. Stratification and sediment carbon enrichment were the main drivers for the hypoxia and subsequent sediment phosphorus release in Lake King. High primary production stimulated by large nitrogen loading brought on by a winter flood contributed almost all the sediment carbon deposition (as opposed to catchment loads), which was ultimately responsible for summer bottom-water hypoxia. Interestingly, internal recycling of phosphorus was more sensitive to changed nitrogen loads than total phosphorus loads, highlighting the potential importance of nitrogen loads exerting a control over systems that become phosphorus limited (such as during summer nitrogen-fixing blooms of cyanobacteria). Therefore, the current study highlighted the need to reduce both total nitrogen and total phosphorus for water quality improvement in estuarine systems.

  9. Effects of changes in nutrient loading and composition on hypoxia dynamics and internal nutrient cycling of a stratified coastal lagoon

    Directory of Open Access Journals (Sweden)

    Y. Zhu

    2017-10-01

    Full Text Available The effects of changes in catchment nutrient loading and composition on the phytoplankton dynamics, development of hypoxia and internal nutrient dynamics in a stratified coastal lagoon system (the Gippsland Lakes were investigated using a 3-D coupled hydrodynamic biogeochemical water quality model. The study showed that primary production was equally sensitive to changed dissolved inorganic and particulate organic nitrogen loads, highlighting the need for a better understanding of particulate organic matter bioavailability. Stratification and sediment carbon enrichment were the main drivers for the hypoxia and subsequent sediment phosphorus release in Lake King. High primary production stimulated by large nitrogen loading brought on by a winter flood contributed almost all the sediment carbon deposition (as opposed to catchment loads, which was ultimately responsible for summer bottom-water hypoxia. Interestingly, internal recycling of phosphorus was more sensitive to changed nitrogen loads than total phosphorus loads, highlighting the potential importance of nitrogen loads exerting a control over systems that become phosphorus limited (such as during summer nitrogen-fixing blooms of cyanobacteria. Therefore, the current study highlighted the need to reduce both total nitrogen and total phosphorus for water quality improvement in estuarine systems.

  10. Internal Migration, Regional Labour Market Dynamics and Implications for German East-West Disparities – Results from a Panel VAR

    DEFF Research Database (Denmark)

    Alecke, Björn; Mitze, Timo; Untiedt, Gerhard

    This paper analyses the causal linkages between regional labour market variables and internal migration flows among German states between 1991–2006. We adopt a Panel VAR approach to identify the feedback effects among the variables and analyse the dynamic properties of the system through impulser......This paper analyses the causal linkages between regional labour market variables and internal migration flows among German states between 1991–2006. We adopt a Panel VAR approach to identify the feedback effects among the variables and analyse the dynamic properties of the system through...... impulseresponse functions.We also use the model to track the evolution of the particular East-West migration since re-unification aiming to shed more light on the East German “empirical puzzle”, characterized by lower migration responses than expected from the regional labour market position relative to the West......:That is, along with a second wave of East-West movements around 2001 net flows out of East Germany were much higher than expected after controlling for its weak labour market and macroeconomic performance. Since this second wave is also accompanied by a gradual fading out of economic distortions...

  11. Evaluation of Internal Friction versus Plastic Deformations Effects in Impact Dynamics Problems of Robotic Elements

    Directory of Open Access Journals (Sweden)

    Stelian Alaci

    2014-06-01

    Full Text Available The dynamical behavior study of robotic systems is obtained using multibody dynamics method. The joints met in robots are modeled in different manners. In a robotic joint the energy is lost via hysteretic work and plastic deformation work. The paper presents a comparative study for the results obtained by integration of the equations defining two limit models which describe the impact between two robot parts, modeled by the centric collision between two spheres with loss of energy. The motion equations characteristic for the two models are integrated and for a tangible situation, are presented comparatively, for different values of the coefficient of restitution, the time dependencies of impacting force between the two bodies as well as the hysteresis loops. Finally, an evaluation of the lost work during impact, for the whole range of coefficients of restitution, is completed, together with characteristic parameters of collision: approaching period, complete contact time, maximum approaching and plastic imprint.

  12. Exhaust Gas Temperature Measurements in Diagnostics of Turbocharged Marine Internal Combustion Engines Part II Dynamic Measurements

    Directory of Open Access Journals (Sweden)

    Korczewski Zbigniew

    2016-01-01

    Full Text Available The second part of the article describes the technology of marine engine diagnostics making use of dynamic measurements of the exhaust gas temperature. Little-known achievements of Prof. S. Rutkowski of the Naval College in Gdynia (now: Polish Naval Academy in this area are presented. A novel approach is proposed which consists in the use of the measured exhaust gas temperature dynamics for qualitative and quantitative assessment of the enthalpy flux of successive pressure pulses of the exhaust gas supplying the marine engine turbocompressor. General design assumptions are presented for the measuring and diagnostic system which makes use of a sheathed thermocouple installed in the engine exhaust gas manifold. The corrected thermal inertia of the thermocouple enables to reproduce a real time-history of exhaust gas temperature changes.

  13. Structural criteria for extreme dynamic internal pressure loadings of vessels and closure heads

    International Nuclear Information System (INIS)

    Bitner, J.L.

    1985-01-01

    The criteria protect against tensile plastic instability and local ductile rupture failure modes. To minimize the number of critical areas that may need more rigorous analytical methods, a screening criterion for limiting the membrane, bending and local stresses is defined. The stresses for this criterion are calculated from either simple and economical elastic dynamic or equivalent static methods. For the critical areas that remain, a strain-based criterion for strains derived from dynamic, inelastic methods is given. To assure that the criteria are properly applied, guidelines are outlined for controlling methods for deriving stresses and strains, for selecting appropriate material properties and for addressing specific dominating parameters that affect the validity of the analysis. The application of the criteria to a complex liquid metal fast breeder reactor vessel and closure head and the subsequent experimental verification of the results by several scale model experiments are summarized. (orig./HP)

  14. On the internal stability of non-linear dynamic inversion: application to flight control

    Czech Academy of Sciences Publication Activity Database

    Alam, M.; Čelikovský, Sergej

    2017-01-01

    Roč. 11, č. 12 (2017), s. 1849-1861 ISSN 1751-8644 R&D Projects: GA ČR(CZ) GA17-04682S Institutional support: RVO:67985556 Keywords : flight control * non-linear dynamic inversion * stability Subject RIV: BC - Control Systems Theory OBOR OECD: Automation and control systems Impact factor: 2.536, year: 2016 http://library.utia.cas.cz/separaty/2017/TR/celikovsky-0476150.pdf

  15. A Dynamic Model of Internally-Driven Corporate Social Responsibility and Enlightened Profit Maximization

    OpenAIRE

    F. Balboni

    2009-01-01

    The aim of this paper is to contribute to the analysis of Corporate Social Responsibility (CSR) from an economic perspective, in two ways. Firstly, introducing a new definition and a new framework of analysis, which can account for both the externallydriven and the internallydriven view of CSR. Secondly, developing a dynamic model of internallydriven CSR – which draws inspiration from the literature on renewable resources – to show that, under certain circumstances, an enlightened profit‐maxi...

  16. Markov switching mean-variance frontier dynamics: theory and international evidence

    OpenAIRE

    M. Guidolin; F. Ria

    2010-01-01

    It is well-known that regime switching models are able to capture the presence of rich non-linear patterns in the joint distribution of asset returns. After reviewing key concepts and technical issues related to specifying, estimating, and using multivariate Markov switching models in financial applications, in this paper we map the presence of regimes in means, variances, and covariances of asset returns into explicit dynamics of the Markowitz mean-variance frontier. In particular, we show b...

  17. Global-scale equatorial Rossby waves as an essential component of solar internal dynamics

    Science.gov (United States)

    Löptien, Björn; Gizon, Laurent; Birch, Aaron C.; Schou, Jesper; Proxauf, Bastian; Duvall, Thomas L.; Bogart, Richard S.; Christensen, Ulrich R.

    2018-05-01

    The Sun’s complex dynamics is controlled by buoyancy and rotation in the convection zone. Large-scale flows are dominated by vortical motions1 and appear to be weaker than expected in the solar interior2. One possibility is that waves of vorticity due to the Coriolis force, known as Rossby waves3 or r modes4, remove energy from convection at the largest scales5. However, the presence of these waves in the Sun is still debated. Here, we unambiguously discover and characterize retrograde-propagating vorticity waves in the shallow subsurface layers of the Sun at azimuthal wavenumbers below 15, with the dispersion relation of textbook sectoral Rossby waves. The waves have lifetimes of several months, well-defined mode frequencies below twice the solar rotational frequency, and eigenfunctions of vorticity that peak at the equator. Rossby waves have nearly as much vorticity as the convection at the same scales, thus they are an essential component of solar dynamics. We observe a transition from turbulence-like to wave-like dynamics around the Rhines scale6 of angular wavenumber of approximately 20. This transition might provide an explanation for the puzzling deficit of kinetic energy at the largest spatial scales.

  18. The spatiotemporal dynamic analysis of the implied market information and characteristics of the correlation coefficient matrix of the international crude oil price returns

    International Nuclear Information System (INIS)

    Tian, Lixin; Ding, Zhenqi; Zhen, Zaili; Wang, Minggang

    2016-01-01

    The international crude oil market plays a crucial role in economies, and the studies of the correlation, risk and synchronization of the international crude oil market have important implications for the security and stability of the country, avoidance of business risk and people's daily lives. We investigate the information and characteristics of the international crude oil market (1999-2015) based on the random matrix theory (RMT). Firstly, we identify richer information in the largest eigenvalues deviating from RMT predictions for the international crude oil market; the international crude oil market can be roughly divided into ten different periods by the methods of eigenvectors and characteristic combination, and the implied market information of the correlation coefficient matrix is advanced. Secondly, we study the characteristics of the international crude oil market by the methods of system risk entropy, dynamic synchronous ratio, dynamic non-synchronous ratio and dynamic clustering algorithm. The results show that the international crude oil market is full of risk. The synchronization of the international crude oil market is very strong, and WTI and Brent occupy a very important position in the international crude oil market. (orig.)

  19. The spatiotemporal dynamic analysis of the implied market information and characteristics of the correlation coefficient matrix of the international crude oil price returns

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Lixin [Jiangsu University, Energy Development and Environmental Protection Strategy Research Center, Zhenjiang, Jiangsu (China); Nanjing Normal University, School of Mathematical Sciences, Nanjing, Jiangsu (China); Ding, Zhenqi; Zhen, Zaili [Jiangsu University, Energy Development and Environmental Protection Strategy Research Center, Zhenjiang, Jiangsu (China); Wang, Minggang [Nanjing Normal University, School of Mathematical Sciences, Nanjing, Jiangsu (China)

    2016-08-15

    The international crude oil market plays a crucial role in economies, and the studies of the correlation, risk and synchronization of the international crude oil market have important implications for the security and stability of the country, avoidance of business risk and people's daily lives. We investigate the information and characteristics of the international crude oil market (1999-2015) based on the random matrix theory (RMT). Firstly, we identify richer information in the largest eigenvalues deviating from RMT predictions for the international crude oil market; the international crude oil market can be roughly divided into ten different periods by the methods of eigenvectors and characteristic combination, and the implied market information of the correlation coefficient matrix is advanced. Secondly, we study the characteristics of the international crude oil market by the methods of system risk entropy, dynamic synchronous ratio, dynamic non-synchronous ratio and dynamic clustering algorithm. The results show that the international crude oil market is full of risk. The synchronization of the international crude oil market is very strong, and WTI and Brent occupy a very important position in the international crude oil market. (orig.)

  20. 'Wildlife 2001: Populations', an International Conference on Population Dynamics and Management of Vertebrates

    CERN Document Server

    Barrett, Reginald

    1992-01-01

    In 1984, a conference called Wildlife 2000: Modeling habitat relationships of terrestrial vertebrates, was held at Stanford Sierra Camp at Fallen Leaf Lake in the Sierra Nevada Mountains of California. The conference was well-received, and the published volume (Verner, J. , M. L. Morrison, and C. J. Ralph, editors. 1986. Wildlife 2000: modeling habitat relationships of terrestrial vertebrates, University of Wisconsin Press, Madison, Wisconsin, USA) proved to be a landmark publication that received a book award by The Wildlife Society. Wildlife 2001: populations was a followup conference with emphasis on the other major biological field of wildlife conservation and management, populations. It was held on July 29-31, 1991, at the Oakland Airport Hilton Hotel in Oakland, California, in accordance with our intent that this conference have a much stronger international representation than did Wildlife 2000. The goal of the conference was to bring together an international group of specialists to address the state ...

  1. Dynamic characterization of external and internal mass transport in heterotrophic biofilms from microsensors measurements.

    Science.gov (United States)

    Guimerà, Xavier; Dorado, Antonio David; Bonsfills, Anna; Gabriel, Gemma; Gabriel, David; Gamisans, Xavier

    2016-10-01

    Knowledge of mass transport mechanisms in biofilm-based technologies such as biofilters is essential to improve bioreactors performance by preventing mass transport limitation. External and internal mass transport in biofilms was characterized in heterotrophic biofilms grown on a flat plate bioreactor. Mass transport resistance through the liquid-biofilm interphase and diffusion within biofilms were quantified by in situ measurements using microsensors with a high spatial resolution (mass transport coefficients. The sensitivity of external and internal mass transport resistances to flow conditions within the range of typical fluid velocities over biofilms (Reynolds numbers between 0.5 and 7) was assessed. Estimated external mass transfer coefficients at different liquid phase flow velocities showed discrepancies with studies considering laminar conditions in the diffusive boundary layer near the liquid-biofilm interphase. The correlation of effective diffusivity with flow velocities showed that the heterogeneous structure of biofilms defines the transport mechanisms inside biofilms. Internal mass transport was driven by diffusion through cell clusters and aggregates at Re below 2.8. Conversely, mass transport was driven by advection within pores, voids and water channels at Re above 5.6. Between both flow velocities, mass transport occurred by a combination of advection and diffusion. Effective diffusivities estimated at different biofilm densities showed a linear increase of mass transport resistance due to a porosity decrease up to biofilm densities of 50 g VSS·L(-1). Mass transport was strongly limited at higher biofilm densities. Internal mass transport results were used to propose an empirical correlation to assess the effective diffusivity within biofilms considering the influence of hydrodynamics and biofilm density. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. The dynamic interaction between combustible renewables and waste consumption and international tourism: The case of Tunisia

    OpenAIRE

    Ben Jebli, Mehdi; Ben Youssef, Slim; Apergis, Nicholas

    2014-01-01

    This paper employs the Autoregressive Distributed Lag (ARDL) bounds methodological approach to investigate the relationship between economic growth, combustible renewables and waste consumption, carbon dioxide (CO2) emissions and international tourism for the case of Tunisia spanning the period 1990-2010. The results from the Fisher statistic of both the Wald-test and the Johansen test confirm the presence of a long-run relationship among the variables under investigation. The stability of es...

  3. ANALYSING ROMANIAN INDUSTRIAL COMPETITIVENESS REGARDING THE RECENT DYNAMICS OF THE INTERNATIONAL INDUSTRIAL TRADE BALANCE

    OpenAIRE

    Felea Adrian Ioan

    2015-01-01

    The industry remains the most important sector of the national economy, although in the other member states the services have a more important share of GDP. In this context, the level of industrial competitiveness is essential for the national competitiveness. This is a characteristic feature for Romania, where the industry has an important share in the GDP, in comparison with the other member states. The international trade balance is an important indicator for measuring the economic competi...

  4. A dynamic approach to assess international competitiveness of Vietnam's garment and textile industry.

    Science.gov (United States)

    Vu, Huong Thanh; Pham, Lam Cat

    2016-01-01

    Garment and textile (G&T) industry has been playing as a driving force for the socio-economic development of Vietnam. With the international integration process and rising challenges from the global market, there is a need to examine international competitiveness of Vietnam's G&T industry to find out what Vietnam should focus on to enhance its position in the global market place. This paper, by using the Generalized Double Diamond Model (GDDM), analyzed international competitiveness of Vietnam's G&T industry and compared it with China. The results showed that Vietnam was less competitive than China in all four attributes of the GDDM. The lowest competitiveness of Vietnam in comparison with China was Related and Supporting industries, followed by Factor Conditions. Therefore, the paper argued that although Vietnam should improve all of the four attributes in the long term, Vietnam must put a high priority on developing Related and Supporting Industries and then enhance Factor Conditions while maintaining its strengths over China in terms of G&T export growths and favorable business context.

  5. NATO Advanced Study Institute on International Summer School on Chaotic Dynamics and Transport in Classical and Quantum Systems

    CERN Document Server

    Collet, P; Métens, S; Neishtadt, A; Zaslavsky, G; Chaotic Dynamics and Transport in Classical and Quantum Systems

    2005-01-01

    This book offers a modern updated review on the most important activities in today dynamical systems and statistical mechanics by some of the best experts in the domain. It gives a contemporary and pedagogical view on theories of classical and quantum chaos and complexity in hamiltonian and ergodic systems and their applications to anomalous transport in fluids, plasmas, oceans and atom-optic devices and to control of chaotic transport. The book is issued from lecture notes of the International Summer School on "Chaotic Dynamics and Transport in Classical and Quantum Systems" held in Cargèse (Corsica) 18th to the 30th August 2003. It reflects the spirit of the School to provide lectures at the post-doctoral level on basic concepts and tools. The first part concerns ergodicity and mixing, complexity and entropy functions, SRB measures, fractal dimensions and bifurcations in hamiltonian systems. Then, models of dynamical evolutions of transport processes in classical and quantum systems have been largely expla...

  6. Dynamics of seizure of animal products in international baggage on Airport of Brasilia (AIB-PJK/SBBR.

    Directory of Open Access Journals (Sweden)

    Cristiano Barros de Melo

    2016-09-01

    Full Text Available ABSTRACT. de Melo C.B., Fino T.C.M., Schwingel F.F., Santiago M.T., de Barros L.F.R., McManus C. & Sá M.E.P. [Dynamics of seizure of animal products in international baggage on Airport of Brasilia (AIB-PJK/SBBR.] Dinâmica da apreensão de produtos de origem animal em bagagens internacionais no Aeroporto de Brasília (AIB-PJK/SBBR. Revista Brasileira de Medicina Veterinária, 38(3:265-276, 2016. Universidade de Brasília, PPGCA, Campus Universitário Darcy Ribeiro, ICC Sul, Asa Norte, Brasília, DF 70910-900, Brasil. E-mail: cristianomelo@unb.br The risk of introducing infectious agents increases as the volume of imported products rises. The illegal entry of animal products (POA brought in international passenger baggage is a factor that makes up the risk assessment and that grows proportionally to the intensification of international transit passengers. They evaluated the data on seizures of animal products intercepted in international baggage passengers in Airport of Brasilia (AIB-PJK/SBBR between the years 2010 and 2012. The analysis of the dynamics of these seizures considered the POA category, origin, airline and months more frequently and also verified the correlation between these variables. According to retrospective analysis, nearly eight tons of POA were seized from 52 countries throughout the study period. The results showed Portugal (p <0.0001 as the source of passengers who had higher frequency and quantity of seizures, and, added to other European origins, totaled 84.3% of seizures. The months of July, August and September stood out for the highest number of seizures and greater movement of international passengers. The increase in the number of seizures accompanied by a rise in the percentage of inspected passengers (r=0.69, emphasizing the importance of airport surveillance. According to the calculation of relative risk, passengers from African and South American countries showed greater magnitude of risk to bring animal

  7. Kinematics and Dynamics Analysis of a 3-DOF Upper-Limb Exoskeleton with an Internally Rotated Elbow Joint

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2018-03-01

    Full Text Available The contradiction between self-weight and load capacity of a power-assisted upper-limb exoskeleton for material hanging is unresolved. In this paper, a non-anthropomorphic 3-degree of freedom (DOF upper-limb exoskeleton with an internally rotated elbow joint is proposed based on an anthropomorphic 5-DOF upper-limb exoskeleton for power-assisted activity. The proposed 3-DOF upper-limb exoskeleton contains a 2-DOF shoulder joint and a 1-DOF internally rotated elbow joint. The structural parameters of the 3-DOF upper-limb exoskeleton were determined, and the differences and singularities of the two exoskeletons were analyzed. The workspace, the joint torques and the power consumption of two exoskeletons were analyzed by kinematics and dynamics, and an exoskeleton prototype experiment was performed. The results showed that, compared with a typical anthropomorphic upper-limb exoskeleton, the non-anthropomorphic 3-DOF upper-limb exoskeleton had the same actual workspace; eliminated singularities within the workspace; improved the elbow joint force situation; and the maximum elbow joint torque, elbow external-flexion/internal-extension and shoulder flexion/extension power consumption were significantly reduced. The proposed non-anthropomorphic 3-DOF upper-limb exoskeleton can be applied to a power-assisted upper-limb exoskeleton in industrial settings.

  8. A New Approach for Studying Nonlinear Dynamic Response of a Thin Plate with Internal Resonance in a Fractional Viscoelastic Medium

    Directory of Open Access Journals (Sweden)

    Yury A. Rossikhin

    2015-01-01

    Full Text Available In the previous analysis, the dynamic behaviour of a nonlinear plate embedded into a fractional derivative viscoelastic medium has been studied by the method of multiple time scales under the conditions of the internal resonances two-to-one and one-to-one, as well as the internal combinational resonances for the case when the linear parts of nonlinear equations of motion occur to be coupled. A new approach proposed in this paper allows one to uncouple the linear parts of equations of motion of the plate, while the same method, the method of multiple time scales, has been utilized for solving nonlinear equations. The influence of viscosity on the energy exchange mechanism between interacting nonlinear modes has been analyzed. It has been shown that for some internal resonances there exist such particular cases when it is possible to obtain two first integrals, namely, the energy integral and the stream function, which allows one to reduce the problem to the calculation of elliptic integrals. The new approach enables one to solve the problems of vibrations of thin bodies more efficiently.

  9. Nonlinear dynamics; Proceedings of the International Conference, New York, NY, December 17-21, 1979

    Science.gov (United States)

    Helleman, R. H. G.

    1980-01-01

    Papers were presented on turbulence, ergodic and integrable behavior, chaotic maps and flows, chemical and fully developed turbulence, and strange attractors. Specific attention was given to measures describing a turbulent flow, stochastization and collapse of vortex systems, a subharmonic route to turbulent convection, and weakly nonlinear turbulence in a rotating convection layer. The Korteweg-de Vries and Hill equations, plasma transport in three dimensions, a horseshoe in the dynamics of a forced beam, and the explosion of strange attractors exhibited by Duffing's equation were also considered.

  10. Sixth International Symposium on Bifurcations and Instabilities in Fluid Dynamics (BIFD2015)

    DEFF Research Database (Denmark)

    Bar-Yoseph, P. Z.; Brøns, Morten; Gelfgat, A.

    2016-01-01

    dynamics and remain a challenge for experimental, theoretical and computational studies. Examples of prototypical hydrodynamic instabilities are the Rayleigh–Bénard, Taylor–Couette, Bénard–Marangoni, Rayleigh–Taylor, and Kelvin–Helmholtz instabilities. A fundamental understanding of bifurcation patterns...... diseases, such as atherosclerotic and vulnerable plaques, abdominal aortic aneurisms, carotid artery disease, and pulmonary embolisms and implications for vascular interventions such as grafting and stenting. The collection of papers in this issue is a selection of the presentations given at the Sixth...

  11. Dynamic International Competitiveness of Transition Economies. What do trade figures tell us? The case of Poland

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Ulff-Møller

    This paper shows that the reform on the structures of the Polish economy has had an impressively fast effect on the numbers of different products this country exports to Western countries. The time path may well be described by a logistic curve. The change in the exports of this country may...... therefore be characterised by a widening, instead of a deepening in specialisation. The paper introduces a new empirical methodology to evaluate the dynamic changes in export activities of a country. The result of this new methodology is that quality competition is becoming increasingly important for Poland...

  12. The dynamics in the international commercial changes in globalization terms-Comparison situation

    Directory of Open Access Journals (Sweden)

    Ph. D. Ion Gr. Ionescu

    2010-05-01

    Full Text Available The bigest weight of commercial changing of the country analysis have the manufactured products like: automobiles and industrial utilities, informatic products, ways of transportation,chimical products, thextile and footwear, this have 80% from total exports and 76% from total import. This fact is the consequence of recession of the working divizion , of speciality in industrial product, on branch and sub branch, on the type of products and subansanble of an morale abrasion for the product majority.The products of base have a low ponder in the exports and imports of this countries, they present a commercial balance and pasive for the raw metals and fuel, as the export of alimentary products, this country plais a role very important.So if it’s affected by the period of crisis, the international trade it has an important role in the sustain of economic growth of them. The sustain of this project are convinced that the introduction of the new coin will have positive feedback for the worldwide economy, confronted now with one of the most sedate crisis. And the european economy it will have, only to win from the project and the investitors can drop the unsure marketing from other continents for the investment in a stable region. With all of this the growth ot the european economy can be late, however, makes it doubt the succes of the „euro” project. The International Monetary Fond have seen that the eleven european countries that adopted euro at the 1st of January 2006, a growth of the Intern Brute Porduct (IBP of 2,4% (same as for European Union, 2,6% in spring with 0,4% less then 2005, the growth that classifies as „solid and continuous”.

  13. The extensive international use of commercial computational fluid dynamics (CFD) codes

    International Nuclear Information System (INIS)

    Hartmut Wider

    2005-01-01

    What are the main reasons for the extensive international success of commercial CFD codes? This is due to their ability to calculate the fine structures of the investigated processes due to their versatility, their numerical stability and that they can guarantee the proper solution in most cases. This was made possible by the constantly increasing computer power at an ever more affordable prize. Furthermore it is much more efficient to have researchers use a CFD code rather than to develop a similar code system due to the time consuming nature of this activity and the high probability of hidden coding errors. The centralized development and upgrading makes these reliable CFD codes possible and affordable. However, the CFD companies' developments are naturally concentrated on the most profitable areas, and thus, if one works in a 'non-priority' field one cannot use them. Moreover, the prize of renting CFD codes, applications to complex systems such as whole nuclear reactors and the need to teach students gives the development of self-made codes still plenty of room. But CFD codes can model detailed aspects of large systems and subroutines generated by users can be added. Since there are only a few heavily used CFD codes such as FLUENT, STAR-CD, ANSYS CFX, these are used in many countries. Also international training courses are given and the news bulletins of these codes help to spread the news on further developments. A larger number of international codes would increase the competition but would at the same time make it harder to select the most appropriate CFD code for a given problem. Examples will be presented of uses of CFD codes as more detailed system codes for the decay heat removal from reactors, the application to aerosol physics and the application to heavy metal fluids using different turbulence models. (author)

  14. 3rd International Conference on Dynamics, Games and Science & 7th Berkeley Bioeconomy Conference

    CERN Document Server

    Zilberman, David

    2017-01-01

    The concepts and techniques presented in this volume originated from the fields of dynamics, statistics, control theory, computer science and informatics, and are applied to novel and innovative real-world applications. Over the past few decades, the use of dynamic systems, control theory, computing, data mining, machine learning and simulation has gained the attention of numerous researchers from all over the world. Admirable scientific projects using both model-free and model-based methods coevolved at today’s research centers and are introduced in conferences around the world, yielding new scientific advances and helping to solve important real-world problems. One important area of progress is the bioeconomy, where advances in the life sciences are used to produce new products in a sustainable and clean manner. In this book, scientists from all over the world share their latest insights and important findings in the field.  The majority of the contributed papers for this volume were written by particip...

  15. Kink dynamics in a parametric ϕ 6 system: a model with controllably many internal modes

    Science.gov (United States)

    Demirkaya, A.; Decker, R.; Kevrekidis, P. G.; Christov, I. C.; Saxena, A.

    2017-12-01

    We explore a variant of the ϕ 6 model originally proposed in Phys. Rev. D 12 (1975) 1606 as a prototypical, so-called, "bag" model in which domain walls play the role of quarks within hadrons. We examine the steady state of the model, namely an apparent bound state of two kink structures. We explore its linearization, and we find that, as a function of a parameter controlling the curvature of the potential, an effectively arbitrary number of internal modes may arise in the point spectrum of the linearization about the domain wall profile. We explore some of the key characteristics of kink-antikink collisions, such as the critical velocity and the multi-bounce windows, and how they depend on the principal parameter of the model. We find that the critical velocity exhibits a non-monotonic dependence on the parameter controlling the curvature of the potential. For the multi-bounce windows, we find that their range and complexity decrease as the relevant parameter decreases (and as the number of internal modes in the model increases). We use a modified collective coordinates method [in the spirit of recent works such as Phys. Rev. D 94 (2016) 085008] in order to capture the relevant phenomenology in a semi-analytical manner.

  16. The Dynamics of Daylighting at a Residential College Building with the Internal Courtyard Arrangement

    Directory of Open Access Journals (Sweden)

    Adi Ainurzaman Jamaludin

    2015-11-01

    Full Text Available Dayasari residential college building was designed with the internal courtyard that allows for numerous implementations of bioclimatic design strategies, especially on daylighting. The field measurement was conducted at eight unoccupied student rooms, selected as samples to represent ten scenarios and orientations that concerned with the level of radiation and penetration of sunlight. This study reveals the contribution of the internal courtyard in the residential college which allows the daylight penetration at the corridor areas and interior of the rooms through the transom over the entrance door, up to ten hours daily. Different amounts of daylight were measured in specific room scenarios to suggest on the most comfortable indoor living space. The recorded mean value for indoor varied from 37 to 286 lux, while in the corridor area 192 to 3,848 lux. However, the use of the large overhangs over the windows, wall openings in the room and trees with large canopy in the landscape setting should critically justify when the adequacy of daylight was drastically reduced in certain rooms.

  17. Dynamics of the international coffee market and instrumental in price formation

    Directory of Open Access Journals (Sweden)

    Ricardo Candéa Sá Barreto

    2016-12-01

    Full Text Available This study's main general objective of studying the behavior of coffee beans on the international market. Empirical analysis uses econometric tool as a model of simultaneous equations using least squares in a three-stage annual data base extending over the period 1964 / 65-2014 / 15. The results suggest that the factors that affect the production of coffee beans are the actual prices and the planted area. However, demand is affected by the growth of the world economy. The price simulations for the period 2014/15 - 2020/21 indicate that a yearly growth (GDP of 2.1% there is a tendency of small high price to 3.6% moderate rise in the price of coffee until 2018/19 and a stronger growth trend of prices from 2019/20 and a growth of 4.7% a high coffee prices trend in grain on the international market. Thus the tendency of the projections 3 and the key market factors continue to favor the maintenance of current high coffee prices. For the full period 1964/65 to 2014/15 there is a moderate relationship between coffee prices and the stock. It follows that the results obtained with the scenarios developed in this work can be useful to rethink measures to recover income from coffee producing countries

  18. MO-F-CAMPUS-J-03: Sorting 2D Dynamic MR Images Using Internal Respiratory Signal for 4D MRI

    International Nuclear Information System (INIS)

    Wen, Z; Hui, C; Beddar, S; Stemkens, B; Tijssen, R; Berg, C van den

    2015-01-01

    Purpose: To develop a novel algorithm to extract internal respiratory signal (IRS) for sorting dynamic magnetic resonance (MR) images in order to achieve four-dimensional (4D) MR imaging. Methods: Dynamic MR images were obtained with the balanced steady state free precession by acquiring each two-dimensional sagittal slice repeatedly for more than one breathing cycle. To generate a robust IRS, we used 5 different representative internal respiratory surrogates in both the image space (body area) and the Fourier space (the first two low-frequency phase components in the anterior-posterior direction, and the first two low-frequency phase components in the superior-inferior direction). A clustering algorithm was then used to search for a group of similar individual internal signals, which was then used to formulate the final IRS. A phantom study and a volunteer study were performed to demonstrate the effectiveness of this algorithm. The IRS was compared to the signal from the respiratory bellows. Results: The IRS computed by our algorithm matched well with the bellows signal in both the phantom and the volunteer studies. On average, the normalized cross correlation between the IRS and the bellows signal was 0.97 in the phantom study and 0.87 in the volunteer study, respectively. The average difference between the end inspiration times in the IRS and bellows signal was 0.18 s in the phantom study and 0.14 s in the volunteer study, respectively. 4D images sorted based on the IRS showed minimal mismatched artifacts, and the motion of the anatomy was coherent with the respiratory phases. Conclusion: A novel algorithm was developed to generate IRS from dynamic MR images to achieve 4D MR imaging. The performance of the IRS was comparable to that of the bellows signal. It can be easily implemented into the clinic and potentially could replace the use of external respiratory surrogates. This research was partially funded by the the Center for Radiation Oncology Research from

  19. Dynamic Establishment of Weight of Enterprise’s Internal Function Based on AHP and QFD

    Directory of Open Access Journals (Sweden)

    He Pei

    2017-01-01

    Full Text Available Modern enterprise management strives to become effective and pragmatic, usually, KPI is the most essential key indicator for the enterprise examination department. However, because the supporting and bearing roles of KPI for different departments are different, no a rather scientific quantification for the weight between them is available, unbalanced examination weights between indicators and departments usually exists. Here, it is with balanced score card to breakdown enterprise’s key tasks, card the performance indicators supporting enterprise’s key tasks, and utilize AHP and QFD method to dynamically establish a standard for measuring each department’s indicators so as to provide a basis for enterprise’s scientific examination.

  20. Analysis of heat release dynamics in an internal combustion engine using multifractals and wavelets

    International Nuclear Information System (INIS)

    Sen, A.K.; Litak, G.; Finney, C.E.A.; Daw, C.S.; Wagner, R.M.

    2010-01-01

    In this paper we analyze data from previously reported experimental measurements of cycle-to-cycle combustion variations in a lean-fueled, multi-cylinder spark-ignition (SI) engine. We characterize the changes in the observed combustion dynamics with as-fed fuel-air ratio using conventional histograms and statistical moments, and we further characterize the shifts in combustion complexity in terms of multifractals and wavelet decomposition. Changes in the conventional statistics and multifractal structure indicate trends with fuel-air ratio that parallel earlier reported observations. Wavelet decompositions reveal persistent, non-stochastic oscillation modes at higher fuel-air ratios that were not obvious in previous analyses. Recognition of these long-time-scale, non-stochastic oscillations is expected to be useful for improving modelling and control of engine combustion variations and multi-cylinder balancing.

  1. Proceedings of the 20th International Symposium on Space Flight Dynamics

    Science.gov (United States)

    Woodard, Mark (Editor); Stengle, Tom (Editor)

    2007-01-01

    Topics include: Measuring Image Navigation and Registration Performance at the 3-Sigma Level Using Platinum Quality Landmarks; Flight Dynamics Performances of the MetOp A Satellite during the First Months of Operations; Visual Navigation - SARE Mission; Determining a Method of Enabling and Disabling the Integral Torque in the SDO Science and Inertial Mode Controllers; Guaranteeing Pointing Performance of the SDO Sun-Pointing Controllers in Light of Nonlinear Effects; SDO Delta H Mode Design and Analysis; Observing Mode Attitude Controller for the Lunar Reconnaissance Orbiter; Broken-Plane Maneuver Applications for Earth to Mars Trajectories; ExoMars Mission Analysis and Design - Launch, Cruise and Arrival Analyses; Mars Reconnaissance Orbiter Aerobraking Daily Operations and Collision Avoidance; Mars Reconnaissance Orbiter Interplanetary Cruise Navigation; Motion Parameters Determination of the SC and Phobos in the Project Phobos-Grunt; GRAS NRT Precise Orbit Determination: Operational Experience; Orbit Determination of LEO Satellites for a Single Pass through a Radar: Comparison of Methods; Orbit Determination System for Low Earth Orbit Satellites; Precise Orbit Determination for ALOS; Anti-Collision Function Design and Performances of the CNES Formation Flying Experiment on the PRISMA Mission; CNES Approaching Guidance Experiment within FFIORD; Maneuver Recovery Analysis for the Magnetospheric Multiscale Mission; SIMBOL-X: A Formation Flying Mission on HEO for Exploring the Universe; Spaceborne Autonomous and Ground Based Relative Orbit Control for the TerraSAR-X/TanDEM-X Formation; First In-Orbit Experience of TerraSAR-X Flight Dynamics Operations; Automated Target Planning for FUSE Using the SOVA Algorithm; Space Technology 5 Post-Launch Ground Attitude Estimation Experience; Standardizing Navigation Data: A Status Update; and A Study into the Method of Precise Orbit Determination of a HEO Orbiter by GPS and Accelerometer.

  2. Internal models of target motion: expected dynamics overrides measured kinematics in timing manual interceptions.

    Science.gov (United States)

    Zago, Myrka; Bosco, Gianfranco; Maffei, Vincenzo; Iosa, Marco; Ivanenko, Yuri P; Lacquaniti, Francesco

    2004-04-01

    Prevailing views on how we time the interception of a moving object assume that the visual inputs are informationally sufficient to estimate the time-to-contact from the object's kinematics. Here we present evidence in favor of a different view: the brain makes the best estimate about target motion based on measured kinematics and an a priori guess about the causes of motion. According to this theory, a predictive model is used to extrapolate time-to-contact from expected dynamics (kinetics). We projected a virtual target moving vertically downward on a wide screen with different randomized laws of motion. In the first series of experiments, subjects were asked to intercept this target by punching a real ball that fell hidden behind the screen and arrived in synchrony with the visual target. Subjects systematically timed their motor responses consistent with the assumption of gravity effects on an object's mass, even when the visual target did not accelerate. With training, the gravity model was not switched off but adapted to nonaccelerating targets by shifting the time of motor activation. In the second series of experiments, there was no real ball falling behind the screen. Instead the subjects were required to intercept the visual target by clicking a mousebutton. In this case, subjects timed their responses consistent with the assumption of uniform motion in the absence of forces, even when the target actually accelerated. Overall, the results are in accord with the theory that motor responses evoked by visual kinematics are modulated by a prior of the target dynamics. The prior appears surprisingly resistant to modifications based on performance errors.

  3. Inferring internal properties of Earth's core dynamics and their evolution from surface observations and a numerical geodynamo model

    Directory of Open Access Journals (Sweden)

    J. Aubert

    2011-10-01

    Full Text Available Over the past decades, direct three-dimensional numerical modelling has been successfully used to reproduce the main features of the geodynamo. Here we report on efforts to solve the associated inverse problem, aiming at inferring the underlying properties of the system from the sole knowledge of surface observations and the first principle dynamical equations describing the convective dynamo. To this end we rely on twin experiments. A reference model time sequence is first produced and used to generate synthetic data, restricted here to the large-scale component of the magnetic field and its rate of change at the outer boundary. Starting from a different initial condition, a second sequence is next run and attempts are made to recover the internal magnetic, velocity and buoyancy anomaly fields from the sparse surficial data. In order to reduce the vast underdetermination of this problem, we use stochastic inversion, a linear estimation method determining the most likely internal state compatible with the observations and some prior knowledge, and we also implement a sequential evolution algorithm in order to invert time-dependent surface observations. The prior is the multivariate statistics of the numerical model, which are directly computed from a large number of snapshots stored during a preliminary direct run. The statistics display strong correlation between different harmonic degrees of the surface observations and internal fields, provided they share the same harmonic order, a natural consequence of the linear coupling of the governing dynamical equations and of the leading influence of the Coriolis force. Synthetic experiments performed with a weakly nonlinear model yield an excellent quantitative retrieval of the internal structure. In contrast, the use of a strongly nonlinear (and more realistic model results in less accurate static estimations, which in turn fail to constrain the unobserved small scales in the time integration of the

  4. Dynamics of Professional and Communicative Tolerance in Educating International Relations Specialists

    Directory of Open Access Journals (Sweden)

    Alexander L. Temnitskiy

    2014-01-01

    Full Text Available Under the conditions of the accelerated development of Russian economics, commercial sector and due to a great number of international private companies we can see the intensified problem of tolerance of future diplomats, international specialists, regarding to the system, its the main components such as political, economic, military. It is supposed, that in the modern student environment of future diplomats we can notice the exaltation of values of individual pragmatism and increasing the lack of sociality by deciding of questions about their present and future professional activity. Sociological researches carried out among the students of faculty of international affairs in 2002, 2007 and 2012 review different factors of professional and communicative tolerance. The author of this article markes and diagnoses the materially - pragmatic and art-substantial values of the chosen profession and it's given an interpretation of value orientations content on the categories of employment after the university graduation. Students' estimations define the personal competents of government employee, which are necessary for the successful carrier in the system of MFA of Russia. The interpretation and the real content of communicative tolerance levels are reviewed in the article. The ethnic component of communicative tolerance is studied separately. In conclusion of the article we can define the role of material differentiation of students in the context of communicative tolerance. According to the analyse it is confuted the initial supposition about the glorification of individual pragmatic values and shortage of social responsibility in the student environment. It was found out, that in the communicative tolerance the level of empathy in the personal contact is keeping to be prevalent and stable according to different years of survey. However, it is deduced, the occurred for 10 years the growth of students material welfare didn't contribute to the growth

  5. Dynamic estimator for determining operating conditions in an internal combustion engine

    Science.gov (United States)

    Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob

    2016-01-05

    Methods and systems are provided for estimating engine performance information for a combustion cycle of an internal combustion engine. Estimated performance information for a previous combustion cycle is retrieved from memory. The estimated performance information includes an estimated value of at least one engine performance variable. Actuator settings applied to engine actuators are also received. The performance information for the current combustion cycle is then estimated based, at least in part, on the estimated performance information for the previous combustion cycle and the actuator settings applied during the previous combustion cycle. The estimated performance information for the current combustion cycle is then stored to the memory to be used in estimating performance information for a subsequent combustion cycle.

  6. Nonlinear dynamics of mini-satellite respinup by weak internal controllable torques

    Energy Technology Data Exchange (ETDEWEB)

    Somov, Yevgeny, E-mail: e-somov@mail.ru [Samara State Technical University, Department for Guidance, Navigation and Control, 244 Molodogvardeyskaya Str., Samara 443100 (Russian Federation)

    2014-12-10

    Contemporary space engineering advanced new problem before theoretical mechanics and motion control theory: a spacecraft directed respinup by the weak restricted control internal forces. The paper presents some results on this problem, which is very actual for energy supply of information mini-satellites (for communication, geodesy, radio- and opto-electronic observation of the Earth et al.) with electro-reaction plasma thrusters and gyro moment cluster based on the reaction wheels or the control moment gyros. The solution achieved is based on the methods for synthesis of nonlinear robust control and on rigorous analytical proof for the required spacecraft rotation stability by Lyapunov function method. These results were verified by a computer simulation of strongly nonlinear oscillatory processes at respinuping of a flexible spacecraft.

  7. International evidence on crude oil price dynamics. Applications of ARIMA-GARCH models

    International Nuclear Information System (INIS)

    Mohammadi, Hassan; Su, Lixian

    2010-01-01

    We examine the usefulness of several ARIMA-GARCH models for modeling and forecasting the conditional mean and volatility of weekly crude oil spot prices in eleven international markets over the 1/2/1997-10/3/2009 period. In particular, we investigate the out-of-sample forecasting performance of four volatility models - GARCH, EGARCH and APARCH and FIGARCH over January 2009 to October 2009. Forecasting results are somewhat mixed, but in most cases, the APARCH model outperforms the others. Also, conditional standard deviation captures the volatility in oil returns better than the traditional conditional variance. Finally, shocks to conditional volatility dissipate at an exponential rate, which is consistent with the covariance-stationary GARCH models than the slow hyperbolic rate implied by the FIGARCH alternative. (author)

  8. Nonlinear dynamics of mini-satellite respinup by weak internal controllable torques

    Science.gov (United States)

    Somov, Yevgeny

    2014-12-01

    Contemporary space engineering advanced new problem before theoretical mechanics and motion control theory: a spacecraft directed respinup by the weak restricted control internal forces. The paper presents some results on this problem, which is very actual for energy supply of information mini-satellites (for communication, geodesy, radio- and opto-electronic observation of the Earth et al.) with electro-reaction plasma thrusters and gyro moment cluster based on the reaction wheels or the control moment gyros. The solution achieved is based on the methods for synthesis of nonlinear robust control and on rigorous analytical proof for the required spacecraft rotation stability by Lyapunov function method. These results were verified by a computer simulation of strongly nonlinear oscillatory processes at respinuping of a flexible spacecraft.

  9. Fluid dynamic modeling of junctions in internal combustion engine inlet and exhaust systems

    Science.gov (United States)

    Chalet, David; Chesse, Pascal

    2010-10-01

    The modeling of inlet and exhaust systems of internal combustion engine is very important in order to evaluate the engine performance. This paper presents new pressure losses models which can be included in a one dimensional engine simulation code. In a first part, a CFD analysis is made in order to show the importance of the density in the modeling approach. Then, the CFD code is used, as a numerical test bench, for the pressure losses models development. These coefficients depend on the geometrical characteristics of the junction and an experimental validation is made with the use of a shock tube test bench. All the models are then included in the engine simulation code of the laboratory. The numerical calculation of unsteady compressible flow, in each pipe of the inlet and exhaust systems, is made and the calculated engine torque is compared with experimental measurements.

  10. Beyond the internal dynamics of organizational responses to conflicting institutional demands

    Directory of Open Access Journals (Sweden)

    Viviana Gutiérrez‐Rincón

    2014-10-01

    Full Text Available This paper presents some reflections on strategic response models, in particular the models proposed by Pache, Santos and Oliver, and it evaluates their complementarity and differences, especially regarding the interactions between decision making and the possible strategic responses to institutional demands. It is argued that the theoretical contributions of Pache and Santos can be categorized under the dimension of utility, because they can enhance the potential to operationalize and test the model. However, the reflections made in this paper not only highlight the need to take into account other external and internal factors for the study of strategic responses, but also the integration of different linkages of the decision process with strategic responses to institutional demands.

  11. The broadband microwave spectra of the monoterpenoids thymol and carvacrol: Conformational landscape and internal dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, D.; Shubert, V. A. [Max Planck Institute for the Structure and Dynamics of Matter, Hamburg (Germany); The Center for Free-Electron Laser Science, Hamburg (Germany); Giuliano, B. M. [Center for Astrobiology, INTA-CSIC, Torrejón de Ardoz, Madrid (Spain); Schnell, M., E-mail: melanie.schnell@mpsd.mpg.de [Max Planck Institute for the Structure and Dynamics of Matter, Hamburg (Germany); The Center for Free-Electron Laser Science, Hamburg (Germany); The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Hamburg (Germany)

    2014-07-21

    The rotational spectra of the monoterpenoids thymol and carvacrol are reported in the frequency range 2–8.5 GHz, obtained with broadband Fourier-transform microwave spectroscopy. For carvacrol four different conformations were identified in the cold conditions of the molecular jet, whereas only three conformations were observed for thymol. The rotational constants and other molecular parameters are reported and compared with quantum chemical calculations. For both molecules, line splittings due to methyl group internal rotation were observed and the resulting barrier heights could be determined. The experimental barrier heights, 4.0863(25) kJ/mol for trans-carvacrol-A, 4.4024(16) kJ/mol for trans-carvacrol-B, and 0.3699(11) kJ/mol for trans-thymol-A, are compared with similar molecules.

  12. The broadband microwave spectra of the monoterpenoids thymol and carvacrol: Conformational landscape and internal dynamics

    International Nuclear Information System (INIS)

    Schmitz, D.; Shubert, V. A.; Giuliano, B. M.; Schnell, M.

    2014-01-01

    The rotational spectra of the monoterpenoids thymol and carvacrol are reported in the frequency range 2–8.5 GHz, obtained with broadband Fourier-transform microwave spectroscopy. For carvacrol four different conformations were identified in the cold conditions of the molecular jet, whereas only three conformations were observed for thymol. The rotational constants and other molecular parameters are reported and compared with quantum chemical calculations. For both molecules, line splittings due to methyl group internal rotation were observed and the resulting barrier heights could be determined. The experimental barrier heights, 4.0863(25) kJ/mol for trans-carvacrol-A, 4.4024(16) kJ/mol for trans-carvacrol-B, and 0.3699(11) kJ/mol for trans-thymol-A, are compared with similar molecules

  13. Proceedings of the 2nd international advisory committee on biomolecular dynamics instrument DNA in MLF at J-PARC

    International Nuclear Information System (INIS)

    Arai, Masatoshi; Aizawa, Kazuya; Nakajima, Kenji; Shibata, Kaoru; Takahashi, Nobuaki

    2009-07-01

    The 2nd International Advisory Committee on the 'Biomolecular Dynamics Backscattering Spectrometer DNA' was held on November 12th - 13th, 2008 at J-PARC Center, Japan Atomic Energy Agency. This IAC has been organized for aiming to realize an innovative neutron backscattering instrument in the Materials and Life Science Experimental Facility (MLF) at the J-PARC and therefore four leading scientists in the field of neutron backscattering instruments has been selected as the member (Dr. Dan Neumann (Chair); Prof. Ferenc Mezei; Dr. Hannu Mutka; Dr. Philip Tregenna-Piggott), and the 1st IAC had been held on February 27th - 29th, 2008. This report includes the executive summary and materials of the presentations in the 2nd IAC. (author)

  14. Poloidal rotation dynamics, radial electric field, and neoclassical theory in the jet internal-transport-barrier region.

    Science.gov (United States)

    Crombé, K; Andrew, Y; Brix, M; Giroud, C; Hacquin, S; Hawkes, N C; Murari, A; Nave, M F F; Ongena, J; Parail, V; Van Oost, G; Voitsekhovitch, I; Zastrow, K-D

    2005-10-07

    Results from the first measurements of a core plasma poloidal rotation velocity (upsilontheta) across internal transport barriers (ITB) on JET are presented. The spatial and temporal evolution of the ITB can be followed along with the upsilontheta radial profiles, providing a very clear link between the location of the steepest region of the ion temperature gradient and localized spin-up of upsilontheta. The upsilontheta measurements are an order of magnitude higher than the neoclassical predictions for thermal particles in the ITB region, contrary to the close agreement found between the determined and predicted particle and heat transport coefficients [K.-D. Zastrow, Plasma Phys. Controlled Fusion 46, B255 (2004)]. These results have significant implications for the understanding of transport barrier dynamics due to their large impact on the measured radial electric field profile.

  15. Asymmetric learning by doing and dynamically efficient policy: implications for domestic and international emissions permit trading of allocating permits usefully

    International Nuclear Information System (INIS)

    Read, Peter

    2000-01-01

    Learning by doing leads to cost reductions as suppliers move down the 'experience curve'. This results in a beneficial supply side inter-temporal externality that, for dynamic efficiency, requires a higher incentive for abatement innovations than the penalty on emissions. This effect can be achieved by a dedicated emissions tax or by a proportionate abatement obligation or by allocating permits usefully. The latter arrangement is compatible with the effective cap on emissions that is secured by an emissions trading scheme. Each of the three possibilities results in a reduced loss of international competitivity in policy-committed regions, in less 'leakage, and in more technology transfer. Implications for trading in emissions permits and in project-related credits are discussed. (Author)

  16. The dynamics of fauna and population of birds in agricultural landscapes on the border of Kazan International Airport

    Science.gov (United States)

    Bespalov, A. F.; Belyaev, A. N.

    2018-01-01

    The dynamics of fauna and population of birds from agricultural lands near Kazan International Airport has been studied for one year. A total of 60 bird species have been registered, of which 26 species must be considered as highly dangerous to flying aircraft. With regard to seasonal activity, the nesting period (April - June) is the most hazardous, since it is characterized by maximum species richness and total population density of birds, as well as their high species diversity. Furthermore, a serious danger is posed by the period of postnesting nomadic movements and the onset of migrations (July - September) when the species diversity turns out to be the highest and the total population density begins to decrease. It has been recommended based on the obtained results that the current crops should be replaced by cultivars that will be less attractive to birds. In spring and autumn, certain bird hazing and frightening measures must be taken on a more regular basis.

  17. 2nd International Symposium "Atomic Cluster Collisions : Structure and Dynamics from the Nuclear to the Biological Scale"

    CERN Document Server

    Solov'yov, Andrey; ISACC 2007; Latest advances in atomic cluster collisions

    2008-01-01

    This book presents a 'snapshot' of the most recent and significant advances in the field of cluster physics. It is a comprehensive review based on contributions by the participants of the 2nd International Symposium on Atomic Cluster Collisions (ISACC 2007) held in July 19-23, 2007 at GSI, Darmstadt, Germany. The purpose of the Symposium is to promote the growth and exchange of scientific information on the structure and properties of nuclear, atomic, molecular, biological and complex cluster systems studied by means of photonic, electronic, heavy particle and atomic collisions. Particular attention is devoted to dynamic phenomena, many-body effects taking place in cluster systems of a different nature - these include problems of fusion and fission, fragmentation, collective electron excitations, phase transitions, etc.Both the experimental and theoretical aspects of cluster physics, uniquely placed between nuclear physics on the one hand and atomic, molecular and solid state physics on the other, are discuss...

  18. Dynamic effects on the acceptance of hydrogen technologies - an international comparison

    International Nuclear Information System (INIS)

    Heinz, Boris; Erdmann, Georg

    2008-01-01

    Social acceptance plays an important role for the future hydrogen economy and a broad market launch of hydrogen technologies. Neglecting the aspect of public acceptance and attitude may become a serious obstacle for the establishment of a mass market infrastructure. With a standardized questionnaire and a standardized procedure, personal interviews were conducted with at least 300 persons in Amsterdam, Barcelona, Berlin, Hamburg, London, Luxembourg, Madrid and Reykjavik, in total with 3352 persons. Thus the dynamics of the public attitude toward hydrogen were analyzed, whereby the possibility of setbacks and accidents was taken into consideration. Whereas 68% of the interviewed persons would be supportive of the aforementioned technologies, an amount of 31% was determined to be volatile. An amount of 77% stated that they would use a hydrogen bus instead of a conventional one if they could choose, but an amount of 21% was indifferent. It will be shown how these amounts can affect the balance of acceptance and how stable the acceptance of hydrogen technologies can be considered in the evaluated six countries. (author)

  19. Internal representation of task rules by recurrent dynamics: the importance of the diversity of neural responses

    Directory of Open Access Journals (Sweden)

    Mattia Rigotti

    2010-10-01

    Full Text Available Neural activity of behaving animals, especially in the prefrontal cortex, is highly heterogeneous, with selective responses to diverse aspects of the executed task. We propose a general model of recurrent neural networks that perform complex rule-based tasks, and we show that the diversity of neuronal responses plays a fundamental role when the behavioral responses are context dependent. Specifically, we found that when the inner mental states encoding the task rules are represented by stable patterns of neural activity (attractors of the neural dynamics, the neurons must be selective for combinations of sensory stimuli and inner mental states. Such mixed selectivity is easily obtained by neurons that connect with random synaptic strengths both to the recurrent network and to neurons encoding sensory inputs. The number of randomly connected neurons needed to solve a task is on average only three times as large as the number of neurons needed in a network designed ad hoc. Moreover, the number of needed neurons grows only linearly with the number of task-relevant events and mental states, provided that each neuron responds to a large proportion of events (dense/distributed coding. A biologically realistic implementation of the model captures several aspects of the activity recorded from monkeys performing context dependent tasks. Our findings explain the importance of the diversity of neural responses and provide us with simple and general principles for designing attractor neural networks that perform complex computation.

  20. Reorganization of personal identity in the context of motivational dynamics and internal dialogical activity.

    Science.gov (United States)

    Batory, Anna

    2014-08-01

    Identity is constantly constructed and reconstructed. It may be assumed that there are six fundamental motivational goals according to which it is organized: self-esteem, self-efficacy, continuity, distinctiveness, belonging, and meaning (Vignoles, 2011). Moreover, identity is shaped by its dialogical nature (Hermans, 2003; van Halen & Janssen, 2004). The longitudinal study was conducted to examine both the motivational and the dialogical basis of identity structure dynamics. The results showed that the more the identity element was connected with a sense of continuity and the more dialogical it was, the greater the perceived centrality of this element was after two months. Furthermore, the more the identity element satisfied the self-esteem and belonging motives, the more positive was the affect ascribed to it. In the behavioral domain of identity, participants more strongly manifested those identity aspects that were earlier rated as more dialogical and satisfying the motive of belonging. The results showed that the motivational underpinnings of identity along with its dialogical nature explain changes in identity structure. © 2014 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  1. A study of internal energy relaxation in shocks using molecular dynamics based models

    International Nuclear Information System (INIS)

    Li, Zheng; Parsons, Neal; Levin, Deborah A.

    2015-01-01

    Recent potential energy surfaces (PESs) for the N 2 + N and N 2 + N 2 systems are used in molecular dynamics (MD) to simulate rates of vibrational and rotational relaxations for conditions that occur in hypersonic flows. For both chemical systems, it is found that the rotational relaxation number increases with the translational temperature and decreases as the rotational temperature approaches the translational temperature. The vibrational relaxation number is observed to decrease with translational temperature and approaches the rotational relaxation number in the high temperature region. The rotational and vibrational relaxation numbers are generally larger in the N 2 + N 2 system. MD-quasi-classical trajectory (QCT) with the PESs is also used to calculate the V-T transition cross sections, the collision cross section, and the dissociation cross section for each collision pair. Direct simulation Monte Carlo (DSMC) results for hypersonic flow over a blunt body with the total collision cross section from MD/QCT simulations, Larsen-Borgnakke with new relaxation numbers, and the N 2 dissociation rate from MD/QCT show a profile with a decreased translational temperature and a rotational temperature close to vibrational temperature. The results demonstrate that many of the physical models employed in DSMC should be revised as fundamental potential energy surfaces suitable for high temperature conditions become available

  2. Internal stress evolution in Fe laths deformed at low temperature analysed by dislocation dynamics simulations

    International Nuclear Information System (INIS)

    Chaussidon, Julien; Fivel, Marc; Robertson, Christian; Marini, Bernard

    2010-01-01

    Stress evolution in Fe laths undergoing plastic deformation is investigated using three-dimensional dislocation dynamics simulations adapted to body centred cubic crystals, in the ductile to brittle transition temperature range. The selected boundary conditions, applied stress tensor and initial dislocation structures account for the realistic microstructure observed in bainitic steels. The effective stress field projected in the three different {1 0 0}cleavage planes is calculated for two different temperatures (50 and 200 K) and presented quantitatively, in the form of stress/frequency diagrams. It is shown that plastic activity tends to relax the stress acting in certain cleavage planes (the (0 1 0) and (0 0 1) planes) while, at the same time, amplifying the stress acting in other cleavage planes (the (1 0 0) planes). The selective stress amplification in the latter planes depends on the applied load direction, in combination with the limited set of available slip systems and the lath geometry. In the examined configuration, this selection effect is more pronounced with decreasing temperature, emphasizing the role of thermally activated plasticity on deformation-induced stress concentrations

  3. Self adaptive internal combustion engine control for hydrogen mixtures using piezoelectric transducers for dynamic cylinder pressure monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Courteau, R.; Bose, T.K. [Quebec Univ., Trois-Rivieres, PQ (Canada). Institut de recherche sur l' hydrogene

    2004-07-01

    Hydrogen internal combustion engine research at the Hydrogen Research Institute includes the following infrastructure: a 20 square metre test cell, an engine preparation room, a 150 hp dynamometer, exhaust gas analysers and a hydrogen supply. The goal of the research is to develop internal combustion engine technologies that can use hydrogen as a fuel without knocking, backfires, excessive engine wear, and with low emissions. As well as hydrogen, fuels such as biogas are also investigated. Technologies under investigation include adaptive control algorithms, as well as advanced sensors and actuators. The latter include piezolelectrics, optical fibres, nitrogen oxide detectors, and chemical composition detectors. Developments include microprocessor-controlled injection and ignition control systems for both single cylinder and multicylinder engines. Research on the influence of fuel composition on best ignition timing is presented. There is also dynamic cylinder pressure monitoring to prevent knocking make engine state assessments and perform engine calibration. Piezoelectric cylinder pressure sensors are employed, either integrated with the spark plugs, or stand-alone, inserted through separate holes through the cylinder head. tabs, figs.

  4. Influence of different breathing maneuvers on internal and external organ motion: Use of fiducial markers in dynamic MRI

    International Nuclear Information System (INIS)

    Plathow, Christian; Zimmermann, Hendrik; Fink, Christian; Umathum, Reiner; Schoebinger, Max; Huber, Peter; Zuna, Ivan; Debus, Juergen; Schlegel, Wolfgang; Meinzer, Hans-Peter; Semmler, Wolfhard; Kauczor, Hans-Ulrich; Bock, Michael

    2005-01-01

    Purpose: To investigate, with dynamic magnetic resonance imaging (dMRI) and a fiducial marker, the influence of different breathing maneuvers on internal organ and external chest wall motion. Methods and materials: Lung and chest wall motion of 16 healthy subjects (13 male, 3 female) were examined with real-time trueFISP (true fast imaging with steady-state precession) dMRI and a small inductively coupled marker coil on either the abdomen or thorax. Three different breathing maneuvers were performed (predominantly 'abdominal breathing,' 'thoracic breathing,' and unspecific 'normal breathing'). The craniocaudal (CC), anteroposterior (AP), and mediolateral (ML) lung distances were correlated (linear regression coefficient) with marker coil position during forced and quiet breathing. Results: Differences of the CC distance between maximum forced inspiration and expiration were significant between abdominal and thoracic breathing (p < 0.05). The correlation between CC distance and coil position was best for forced abdominal breathing and a marker coil in the abdominal position (r 0.89 ± 0.04); for AP and ML distance, forced thoracic breathing and a coil in the thoracic position was best (r = 0.84 ± 0.03 and 0.82 ± 0.03, respectively). In quiet breathing, a lower correlation was found. Conclusion: A fiducial marker coil external to the thorax in combination with dMRI is a new technique to yield quantitative information on the correlation of internal organ and external chest wall motion. Correlations are highly dependent on the breathing maneuver

  5. Internal dynamics and emittance growth in space-charge-dominated beams

    International Nuclear Information System (INIS)

    Anderson, O.A.

    1987-01-01

    Previous analytical studies have related transverse rms emittance growth in nonuniform beams to changes in the beam density profile, but the time evolution of the process has not been analyzed. Our new approach analyzes the internal motion of the beam and from this obtains the explicit time dependence of the rms emittance. It is shown to reach its peak value explosively in about one quarter of a plasma period. The subsequent behavior depends on the uniformity of the initial density profile. We derive a uniformity criterion that determines whether or not the emittance oscillates periodically and present examples of density profiles for which the emittance returns to its initial value and then continues to oscillate. We discuss a class of continuous initial profiles that lead to discontinuous shocklike behavior (with partial irreversibility of the oscillations) and a class of segmented profiles for which the emittance jumps to its maximum value in one fourth of a plasma period and remains at that value with essentially no further change. (author)

  6. Computational Fluid Dynamics Ventilation Study for the Human Powered Centrifuge at the International Space Station

    Science.gov (United States)

    Son, Chang H.

    2012-01-01

    The Human Powered Centrifuge (HPC) is a facility that is planned to be installed on board the International Space Station (ISS) to enable crew exercises under the artificial gravity conditions. The HPC equipment includes a "bicycle" for long-term exercises of a crewmember that provides power for rotation of HPC at a speed of 30 rpm. The crewmember exercising vigorously on the centrifuge generates the amount of carbon dioxide of about two times higher than a crewmember in ordinary conditions. The goal of the study is to analyze the airflow and carbon dioxide distribution within Pressurized Multipurpose Module (PMM) cabin when HPC is operating. A full unsteady formulation is used for airflow and CO2 transport CFD-based modeling with the so-called sliding mesh concept when the HPC equipment with the adjacent Bay 4 cabin volume is considered in the rotating reference frame while the rest of the cabin volume is considered in the stationary reference frame. The rotating part of the computational domain includes also a human body model. Localized effects of carbon dioxide dispersion are examined. Strong influence of the rotating HPC equipment on the CO2 distribution detected is discussed.

  7. Microwave heating device for internal heating convection experiments, applied to Earth's mantle dynamics.

    Science.gov (United States)

    Surducan, E; Surducan, V; Limare, A; Neamtu, C; Di Giuseppe, E

    2014-12-01

    We report the design, construction, and performances of a microwave (MW) heating device for laboratory experiments with non-contact, homogeneous internal heating. The device generates MW radiation at 2.47 GHz from a commercial magnetron supplied by a pulsed current inverter using proprietary, feedback based command and control hardware and software. Specially designed MW launchers direct the MW radiation into the sample through a MW homogenizer, devised to even the MW power distribution into the sample's volume. An adjustable MW circuit adapts the MW generator to the load (i.e., the sample) placed in the experiment chamber. Dedicated heatsinks maintain the MW circuits at constant temperature throughout the experiment. Openings for laser scanning for image acquisition with a CCD camera and for the cooling circuits are protected by special MW filters. The performances of the device are analyzed in terms of heating uniformity, long term output power stability, and load matching. The device is used for small scale experiments simulating Earth's mantle convection. The 30 × 30 × 5 cm(3) convection tank is filled with a water‑based viscous fluid. A uniform and constant temperature is maintained at the upper boundary by an aluminum heat exchanger and adiabatic conditions apply at the tank base. We characterize the geometry of the convective regime as well as its bulk thermal evolution by measuring the velocity field by Particle Image Velocimetry and the temperature field by using Thermochromic Liquid Crystals.

  8. Microwave heating device for internal heating convection experiments, applied to Earth's mantle dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Surducan, E.; Surducan, V.; Neamtu, C., E-mail: camelia.neamtu@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies (INCDTIM), 67-103 Donat St., 400293, Cluj‑Napoca (Romania); Limare, A.; Di Giuseppe, E. [Institut de Physique du Globe de Paris (IPGP), Univ. Paris Diderot, UMR CNRS 7154, 1 rue Jussieu, 75005, Paris (France)

    2014-12-15

    We report the design, construction, and performances of a microwave (MW) heating device for laboratory experiments with non-contact, homogeneous internal heating. The device generates MW radiation at 2.47 GHz from a commercial magnetron supplied by a pulsed current inverter using proprietary, feedback based command and control hardware and software. Specially designed MW launchers direct the MW radiation into the sample through a MW homogenizer, devised to even the MW power distribution into the sample's volume. An adjustable MW circuit adapts the MW generator to the load (i.e., the sample) placed in the experiment chamber. Dedicated heatsinks maintain the MW circuits at constant temperature throughout the experiment. Openings for laser scanning for image acquisition with a CCD camera and for the cooling circuits are protected by special MW filters. The performances of the device are analyzed in terms of heating uniformity, long term output power stability, and load matching. The device is used for small scale experiments simulating Earth's mantle convection. The 30 × 30 × 5 cm{sup 3} convection tank is filled with a water‑based viscous fluid. A uniform and constant temperature is maintained at the upper boundary by an aluminum heat exchanger and adiabatic conditions apply at the tank base. We characterize the geometry of the convective regime as well as its bulk thermal evolution by measuring the velocity field by Particle Image Velocimetry and the temperature field by using Thermochromic Liquid Crystals.

  9. EU internal energy market policy: new dynamics in the Brussels policy game?

    Energy Technology Data Exchange (ETDEWEB)

    Eikeland, Per Ove

    2008-11-15

    The paper analyses the September 2007 European Commission proposal for a third internal energy policy package. It asks if the proposal reflected fundamental changes in the Brussels policy game from 2003, when the existing legislation had been adopted. A multi-level governance approach has inspired this check of alternative propositions. We find that the proposal was primarily the result of greater will on the part of the Commission to pressure unwilling member-state governments. There is also strong evidence that the Commission pursued a new form of multi-level game, pressing non-state agents directly to change the political game at the national level. Our study finally discusses whether different network approaches would add explanatory power to our study, acknowledging that agents working in larger networks could have greater thrust on the Commission. The main conclusion is that EU policy networks have become less stable and more issue-specific, making policy predictions less certain than before. (author).refs.,tab

  10. Analysis of internal shading degree to a prototype of dynamics photovoltaic greenhouse through simulation software

    Directory of Open Access Journals (Sweden)

    Alvaro Marucci

    2015-12-01

    Full Text Available In recent years the use of photovoltaic panels as cover materials for greenhouses developed a great interest due to the state’s incentives obtainable by such applications. Shading caused by these elements inside the structure appears to be often too much for the normal development of agricultural activity. In this study it was analyzed the behaviour of shading caused by the photovoltaic panels inside a prototype of dynamic photovoltaic greenhouse whose particularity lies in the possibility of rotation of the panels along the longitudinal axis. The panels’ rotation allows varying shading degree in function of some parameters such as latitude and the different solar angles. In order to avoid any reflection losses due to imperfect inclination of the photovoltaic panels, 24 highly reflective aluminium mirrors were prepared with the objective of recovering the portion of solar radiation otherwise lost by reflection. For the study it was used the simulation software Autodesk® Ecotect® Analysis which allows to analyse the path of the shadows during the day and throughout the year for any latitude considered. For this study it was analyzed shading with the panels in a horizontal position. It was also analyzed the evolution of the percentage of shading simulating different latitudes. The results obtained show a great variation of the shading degree inside the structure during a single day and during the year. We can conclude that integrating this analysis with the energy balance it is possible to study the behaviour of photovoltaic greenhouses in order to integrate the energy production from renewable energy sources and agricultural production.

  11. The evolution of young HII regions. I. Continuum emission and internal dynamics

    Science.gov (United States)

    Klaassen, P. D.; Johnston, K. G.; Urquhart, J. S.; Mottram, J. C.; Peters, T.; Kuiper, R.; Beuther, H.; van der Tak, F. F. S.; Goddi, C.

    2018-04-01

    Context. High-mass stars form in much richer environments than those associated with isolated low-mass stars, and once they reach a certain mass, produce ionised (HII) regions. The formation of these pockets of ionised gas are unique to the formation of high-mass stars (M > 8 M⊙), and present an excellent opportunity to study the final stages of accretion, which could include accretion through the HII region itself. Aim. This study of the dynamics of the gas on both sides of these ionisation boundaries in very young HII regions aims to quantify the relationship between the HII regions and their immediate environments. Methods: We present high-resolution ( 0.5″) ALMA observations of nine HII regions selected from the red MSX source survey with compact radio emission and bolometric luminosities greater than 104 L⊙. We focus on the initial presentation of the data, including initial results from the radio recombination line H29α, some complementary molecules, and the 256 GHz continuum emission. Results: Of the six (out of nine) regions with H29α detections, two appear to have cometary morphologies with velocity gradients across them, and two appear more spherical with velocity gradients suggestive of infalling ionised gas. The remaining two were either observed at low resolution or had signals that were too weak to draw robust conclusions. We also present a description of the interactions between the ionised and molecular gas (as traced by CS (J = 5 - 4)), often (but not always) finding the HII region had cleared its immediate vicinity of molecules. Conclusions: Of our sample of nine, the observations of the two clusters expected to have the youngest HII regions (from previous radio observations) are suggestive of having infalling motions in the H29α emission, which could be indicative of late stage accretion onto the stars despite the presence of an HII region. Table A.2 is also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130

  12. PREFACE: 10th International Conference on Clustering Aspects of Nuclear Structure and Dynamics (CLUSTER'12)

    Science.gov (United States)

    Lovas, R. G.; Dombrádi, Zs; Kiss, G. G.; Kruppa, A. T.; Lévai, G.

    2013-04-01

    , but we had some invited talks even in the parallel sessions. Written versions of 86 talks have been submitted. Quite a number of the speakers have modified the title of their talk in the written version. To keep the correspondence between the Programme list and the written papers, we have accordingly changed the titles in the Programme list as well. The papers are arranged according to their subjects, without regard to whether they were delivered in a plenary or in a parallel session. There was a talk classified wrongly; this is now classified correctly. In the Programme list and in the list of the papers submitted the names are those of the speakers. You can read in the Opening Address that, by ruling of the organizing institution, no members of the Debrecen Institute of Nuclear Research were selected as invited speakers and no contributions were accepted from them. We doubted the wisdom of this rigour ourselves, and I think the criticism we received for it is justifiable. The success of a conference depends primarily on the speakers. In retrospect, we can say that this conference was extremely successful, and that is owing to the great many wonderful talks delivered. This reflects very well on the present status of the field as well as on the work of the International Advisory Board, which proposed the list of excellent speakers. The Japanese dominance characteristic of all cluster conferences has only been complained about by some of the Japanese who came to Europe primarily to learn things that they could not learn at home. We would like to express our gratitude to our sponsors: the Hungarian Academy of Sciences the Paks Nuclear Power Ltd HMP Logic Ltd International Workshop for Theoretical Physics(Budapest) We were also supported indirectly by a JSPS-MTA bilateral cooperation project, which made it possible for five Japanese colleagues to participate. It just remains to be announced that the next, number 11 in this series of conferences, will be held in Naples in

  13. Probing Ligand Exchange in the P450 Enzyme CYP121 from Mycobacterium tuberculosis: Dynamic Equilibrium of the Distal Heme Ligand as a Function of pH and Temperature.

    Science.gov (United States)

    Fielding, Andrew J; Dornevil, Kednerlin; Ma, Li; Davis, Ian; Liu, Aimin

    2017-12-06

    CYP121 is a cytochrome P450 enzyme from Mycobacterium tuberculosis that catalyzes the formation of a C-C bond between the aromatic groups of its cyclodityrosine substrate (cYY). The crystal structure of CYP121 in complex with cYY reveals that the solvent-derived ligand remains bound to the ferric ion in the enzyme-substrate complex. Whereas in the generally accepted P450 mechanism, binding of the primary substrate in the active-site triggers the release of the solvent-derived ligand, priming the metal center for reduction and subsequent O 2 binding. Here we employed sodium cyanide to probe the metal-ligand exchange of the enzyme and the enzyme-substrate complex. The cyano adducts were characterized by UV-vis, EPR, and ENDOR spectroscopies and X-ray crystallography. A 100-fold increase in the affinity of cyanide binding to the enzyme-substrate complex over the ligand-free enzyme was observed. The crystal structure of the [CYP121(cYY)CN] ternary complex showed a rearrangement of the substrate in the active-site, when compared to the structure of the binary [CYP121(cYY)] complex. Transient kinetic studies showed that cYY binding resulted in a lower second-order rate constant (k on (CN) ) but a much more stable cyanide adduct with 3 orders of magnitude slower k off (CN) rate. A dynamic equilibrium between multiple high- and low-spin species for both the enzyme and enzyme-substrate complex was also observed, which is sensitive to changes in both pH and temperature. Our data reveal the chemical and physical properties of the solvent-derived ligand of the enzyme, which will help to understand the initial steps of the catalytic mechanism.

  14. Dynamics

    CERN Document Server

    Goodman, Lawrence E

    2001-01-01

    Beginning text presents complete theoretical treatment of mechanical model systems and deals with technological applications. Topics include introduction to calculus of vectors, particle motion, dynamics of particle systems and plane rigid bodies, technical applications in plane motions, theory of mechanical vibrations, and more. Exercises and answers appear in each chapter.

  15. Effect of two mouthwashes on salivary ph.

    Science.gov (United States)

    Belardinelli, Paola A; Morelatto, Rosana A; Benavidez, Tomás E; Baruzzi, Ana M; López de Blanc, Silvia A

    2014-01-01

    To analyze the effect of two mouthwashes on salivary pH and correlate it with age, buffer capacity and saliva flow rate in healthy volunteers, a crossover phase IV clinical study involving three age-based groups was designed. Two commercial mouthwashes (MW), Cool Mint ListerineR (MWa) and Periobacter R (MWb) were used. The unstimulated saliva of each individual was first characterized by measuring flow rate, pH, and buffer capacity. Salivary pH was evaluated before rinsing with a given MW, immediately after rinsing, 5 minutes later, and then every 10 min (at 15, 25, 35 min) until the baseline pH was recovered. Paired t-test, ANOVA with a randomized block design, and Pearson correlation tests were used. Averages were 0.63 mL/min, 7.06, and 0.87 for flow rate, pH, and buffer capacity, respectively. An immediate significant increase in salivary pH was observed after rinsing, reaching average values of 7.24 (MWb) and 7.30 (MWa), which declined to an almost stable value 15 minutes. The great increase in salivary pH, after MW use shows that saliva is a dynamic system, and that the organism is capable of responding to a stimulus with changes in its composition. It is thus evident that pH of the external agent alone is not a good indicator for its erosive potential because biological systems tend to neutralize it. The results of this study enhance the importance of in vivo measurements and reinforce the concept of the protective action of saliva.

  16. Shenzhen International Low Carbon City in Development: Practice of Low Carbon Planning Technology Strategy Based on Dynamic Demands

    Institute of Scientific and Technical Information of China (English)

    Yu; Han; Li; Caige

    2016-01-01

    Targeted at the dynamic demands in the rapid urban construction, the planning technology strategy of the Shenzhen International Low Carbon City studies the fl exible index model based on carbon emission evaluation, and adopts rolling development and micro-circulation construction mode to achieve quick returns with small investment. Meanwhile, it also evaluates the application of low carbon technology and gives feedback in time, so as to constantly optimize and complete the low carbon city planning. In detail, it involves industrial planning, ecological restoration, transport planning, energy resource planning, architectural design, etc., for which appropriate approaches are selected according to the principle of rolling development of unit cells and based on different requirements of different stages. The quick-response and fl exible technology system can help the low carbon city to choose an appropriate technology strategy in line with its own characteristics in the start-up stage and rapid development, thus realizing the sustainable leap-forward development and providing reference for other similar regions.

  17. Shenzhen International Low Carbon City in Development: Practice of Low Carbon Planning Technology Strategy Based on Dynamic Demands

    Institute of Scientific and Technical Information of China (English)

    Yu Han; Li Caige

    2016-01-01

    Targeted at the dynamic demands in the rapid urban construction,the planning technology strategy of the Shenzhen International Low Carbon City studies the flexible index model based on carbon emission evaluation,and adopts rolling development and micro-circulation construction mode to achieve quick returns with small investment.Meanwhile,it also evaluates the application of low carbon technology and gives feedback in time,so as to constantly optimize and complete the low carbon city planning.In detail,it involves industrial planning,ecological restoration,transport planning,energy resource planning,architectural design,etc.,for which appropriate approaches are selected according to the principle of rolling development of unit cells and based on different requirements of different stages.The quick-response and flexible technology system can help the low carbon city to choose an appropriate technology strategy in line with its own characteristics in the start-up stage and rapid development,thus realizing the sustainable leap-forward development and providing reference for other similar regions.

  18. Simultaneous determination of arterial input function of the internal carotid and middle cerebral arteries for dynamic susceptibility contrast MRI

    International Nuclear Information System (INIS)

    Scholdei, R.; Wenz, F.; Fuss, M.; Essig, M.; Knopp, M.V.

    1999-01-01

    Purpose: The determination of the arterial input function (AIF) is necessary for absolute quantification of the regional cerebral blood volume and blood flow using dynamic susceptibility contrast MRI. The suitability of different vessels (ICA-internal carotid artery, MCA-middle cerebral artery) for AIF determination was compared in this study. Methods: A standard 1.5 T MR system and a simultaneous dual FLASH sequence (TR/TE1/TE2/α=32/15/25/10 ) were used to follow a bolus of contrast agent. Slice I was chosen to cut the ICA perpendicularly. Slice II included the MCA. Seventeen data sets from ten subjects were evaluated. Results: The number of AIF-relevant pixels, the area under the AIF and the maximum concentration were all lower when the AIF was determined from the MCA compared to the ICA. Additionally, the mean transit time (MTT) and the time to maximum concentration (TTM) were longer in the MCA, complicating the computerized identification of AIF-relevant pixels. Data from one subject, who was examined five times, demonstrated that the intraindividual variance of the measured parameters was markedly lower than the interpersonal variance. Conclusions: It appears to be advantageous to measure the AIF in the ICA rather than the MCA. (orig.) [de

  19. Observation Platform for Dynamic Biomedical and Biotechnology Experiments Using the International Space Station (ISS) Light Microscopy Module (LMM)

    Science.gov (United States)

    Kurk, Michael A. (Andy)

    2015-01-01

    Techshot, Inc., has developed an observation platform for the LMM on the ISS that will enable biomedical and biotechnology experiments. The LMM Dynamic Stage consists of an electronics module and the first two of a planned suite of experiment modules. Specimens and reagent solutions can be injected into a small, hollow microscope slide-the heart of the innovation-via a combination of small reservoirs, pumps, and valves. A life science experiment module allows investigators to load up to two different fluids for on-orbit, real-time image cytometry. Fluids can be changed to initiate a process, fix biological samples, or retrieve suspended cells. A colloid science experiment module conducts microparticle and nanoparticle tests for investigation of colloid self-assembly phenomena. This module includes a hollow glass slide and heating elements for the creation of a thermal gradient from one end of the slide to the other. The electronics module supports both experiment modules and contains a unique illuminator/condenser for bright and dark field and phase contrast illumination, power supplies for two piezoelectric pumps, and controller boards for pumps and valves. This observation platform safely contains internal fluids and will greatly accelerate the research and development (R&D) cycle of numerous experiments, products, and services aboard the ISS.

  20. Regulation of intracellular pH in cnidarians: response to acidosis in Anemonia viridis.

    Science.gov (United States)

    Laurent, Julien; Venn, Alexander; Tambutté, Éric; Ganot, Philippe; Allemand, Denis; Tambutté, Sylvie

    2014-02-01

    The regulation of intracellular pH (pHi) is a fundamental aspect of cell physiology that has received little attention in studies of the phylum Cnidaria, which includes ecologically important sea anemones and reef-building corals. Like all organisms, cnidarians must maintain pH homeostasis to counterbalance reductions in pHi, which can arise because of changes in either intrinsic or extrinsic parameters. Corals and sea anemones face natural daily changes in internal fluids, where the extracellular pH can range from 8.9 during the day to 7.4 at night. Furthermore, cnidarians are likely to experience future CO₂-driven declines in seawater pH, a process known as ocean acidification. Here, we carried out the first mechanistic investigation to determine how cnidarian pHi regulation responds to decreases in extracellular and intracellular pH. Using the anemone Anemonia viridis, we employed confocal live cell imaging and a pH-sensitive dye to track the dynamics of pHi after intracellular acidosis induced by acute exposure to decreases in seawater pH and NH₄Cl prepulses. The investigation was conducted on cells that contained intracellular symbiotic algae (Symbiodinium sp.) and on symbiont-free endoderm cells. Experiments using inhibitors and Na⁺-free seawater indicate a potential role of Na⁺/H⁺ plasma membrane exchangers (NHEs) in mediating pHi recovery following intracellular acidosis in both cell types. We also measured the buffering capacity of cells, and obtained values between 20.8 and 43.8 mM per pH unit, which are comparable to those in other invertebrates. Our findings provide the first steps towards a better understanding of acid-base regulation in these basal metazoans, for which information on cell physiology is extremely limited. © 2013 FEBS.

  1. Internal tides and sediment dynamics in the deep sea-Evidence from radioactive Th-234/U-238 disequilibria

    International Nuclear Information System (INIS)

    Turnewitsch, R.; Turnewitsch, R.; Waniek, J.J.; Reyss, J.L.; Nycander, J.; Lampitt, R.S.

    2008-01-01

    Residual flow, baro-tropic tides and internal (baro-clinic) tides interact in a number of ways with kilometer-scale sea floor topography such as abyssal hills and sea mounts. Because of their likely impact on vertical mixing such interactions are potentially important for ocean circulation and the mechanisms and the geometry of these interactions are a matter of ongoing studies. In addition, very little is known about how these interactions are reflected in the sedimentary record. This multi-year study investigates if flow/topography interactions are reflected in distributional patterns of the natural short-lived (half-life: 24.1 d) particulate-matter tracer 234 Th relative to its conservative (non-particle-reactive) and very long-lived parent nuclide 238 U. The sampling sites were downstream of, or surrounded by, fields of short sea mounts and, therefore, very likely to be influenced by nearby flow/topography interactions. At the sampling sites between about 200 and 1000 m above the sea floor recurrent 'fossil' disequilibria were detected. 'Fossil' disequilibria are defined by clearly detectable 234 Th/ 238 U disequilibria (total 234 Th radioactivity ≤ 238 U radioactivity, indicating a history of intense particulate 234 Th scavenging and particulate-matter settling from the sampled parcel of water) and conspicuously low particle-associated 234 Th activities. 'Fossil' disequilibria were centered at levels in the water column that correspond to the average height of the short sea mounts near the sampling sites. This suggests the 'fossil' disequilibria are formed on the sea mount slopes. Moreover, the magnitude of the 'fossil' disequilibria suggests that the slopes of the short sea mounts in the study region are characterized by particularly vigorous fluid dynamics. Since 'fossil' disequilibria already occurred at ∼ O (1-10 km) away from the sea mount slopes it is likely that these vigorous fluid dynamics rapidly decay away from the slopes on scales of O (1-10 km

  2. An under-active or over-active internal world? An exploration of parallel dynamics within psyche and soma, and the difficulty of internal regulation, in patients with Chronic Fatigue Syndrome and Myalgic Encephalomyelitis.

    Science.gov (United States)

    Driver, Christine

    2005-04-01

    This paper explores the dynamics brought into analytic work when there is a symmetric fusion between psyche and soma within the patient. It will consider how such a fusion may emerge from reverberations between physical constitution and a lack of maternal attunement, containment and reflective function. I will describe the work with a patient, Jane, who was diagnosed with Myalgic Encephalomyelitis (ME) during the course of her analysis. The dynamic of her physical symptoms within the analytic work, and the impact of her internal affects and internal 'objects' within the transference and countertransference, indicated a difficulty in finding an homeostatic balance resulting in overactivity and underactivity at both somatic and psychological levels. Using the clinical work with Jane this paper will also examine the interrelationship between mother-infant attachment, an inadequate internalized maternal reflective function, affect dysregulation, unconscious fusion, the lack of psyche-soma differentiation and the impact of the latter in relation to internal regulation systems, or lack of, in patients with Chronic Fatigue Syndrome (CFS) and Myalgic Encephalomyelitis (ME). I will draw on similar work carried out by Holland (1997), Simpson (1997) and Simpson et al. (1997). The paper will also employ the concept of the reflective function (Fonagy 2001; Knox 2003), and consider Matte-Blanco's (1999) concepts of generalization and unconscious symmetry in relation to the patient's internal world. I go on to consider how analysis provides a point outside the 'fusion' that can enable the 'deadlock' to be broken.

  3. PhD Dissertations

    OpenAIRE

    Redazione Reti Medievali (a cura di)

    2010-01-01

    Report of PhD Dissertations.Anna Airò La scrittura delle regole. Politica e istituzioni a Taranto nel Quattrocento, Tesi di dottorato di ricerca in Storia medievale, Università degli studi di Firenze, 2005 Pasquale Arfé La Clavis Physicae II (316-529) di Honorius Augustodunensis. Studio ed edizione critica, Tesi di dottorato in Storia della filosofia medievale, Università degli Studi di Napoli "L'Orientale", 2005 Alessandro Azzimonti Scrittura agiografica e strutture di potere nell'Italia c...

  4. Protein Internal Dynamics Associated With Pre-System Glass Transition Temperature Endothermic Events: Investigation of Insulin and Human Growth Hormone by Solid State Hydrogen/Deuterium Exchange.

    Science.gov (United States)

    Fang, Rui; Grobelny, Pawel J; Bogner, Robin H; Pikal, Michael J

    2016-11-01

    Lyophilized proteins are generally stored below their glass transition temperature (T g ) to maintain long-term stability. Some proteins in the (pure) solid state showed a distinct endotherm at a temperature well below the glass transition, designated as a pre-T g endotherm. The pre-T g endothermic event has been linked with a transition in protein internal mobility. The aim of this study was to investigate the internal dynamics of 2 proteins, insulin and human growth hormone (hGH), both of which exhibit the pre-T g endothermic event with onsets at 50°C-60°C. Solid state hydrogen/deuterium (H/D) exchange of both proteins was characterized by Fourier transform infrared spectroscopy over a temperature range from 30°C to 80°C. A distinct sigmoidal transition in the extent of H/D exchange had a midpoint of 56.1 ± 1.2°C for insulin and 61.7 ± 0.9°C for hGH, suggesting a transition to greater mobility in the protein molecules at these temperatures. The data support the hypothesis that the pre-T g event is related to a transition in internal protein mobility associated with the protein dynamical temperature. Exceeding the protein dynamical temperature is expected to activate protein internal motion and therefore may have stability consequences. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  5. The internal model: A study of the relative contribution of proprioception and visual information to failure detection in dynamic systems. [sensitivity of operators versus monitors to failures

    Science.gov (United States)

    Kessel, C.; Wickens, C. D.

    1978-01-01

    The development of the internal model as it pertains to the detection of step changes in the order of control dynamics is investigated for two modes of participation: whether the subjects are actively controlling those dynamics or are monitoring an autopilot controlling them. A transfer of training design was used to evaluate the relative contribution of proprioception and visual information to the overall accuracy of the internal model. Sixteen subjects either tracked or monitored the system dynamics as a 2-dimensional pursuit display under single task conditions and concurrently with a sub-critical tracking task at two difficulty levels. Detection performance was faster and more accurate in the manual as opposed to the autopilot mode. The concurrent tracking task produced a decrement in detection performance for all conditions though this was more marked for the manual mode. The development of an internal model in the manual mode transferred positively to the automatic mode producing enhanced detection performance. There was no transfer from the internal model developed in the automatic mode to the manual mode.

  6. Conformation and dynamics of nucleotides in bulges and symmetric internal loops in duplex DNA studied by EPR and fluorescence spectroscopies

    International Nuclear Information System (INIS)

    Cekan, Pavol; Sigurdsson, Snorri Th.

    2012-01-01

    Highlights: ► Bulges and loops were studied by both EPR and fluorescence spectroscopies using the probe Ç/Ç f . ► One-base bulge was in a temperature-dependent equilibrium between looped-out and stacked states. ► Bases in two- and three-base bulges were stacked at all temperatures, resulting in DNA bending. ► Bases were stacked in symmetrical two- to five-base internal loops, according to EPR data. ► Unexpectedly high fluorescence for the smaller loops indicated local structural perturbations. -- Abstract: The dynamics and conformation of base bulges and internal loops in duplex DNA were studied using the bifunctional spectroscopic probe Ç, which becomes fluorescent (Ç f ) upon reduction of the nitroxide functional group, along with EPR and fluorescence spectroscopies. A one-base bulge was in a conformational equilibrium between looped-out and stacked states, the former favored at higher temperature and the latter at lower temperature. Stacking of bulge bases was favored in two- and three-base bulges, independent of temperature, resulting in DNA bending as evidenced by increased fluorescence of Ç f . EPR spectra of Ç-labeled three-, four- and five-base symmetrical interior DNA bulges at 20 °C showed low mobility, indicating that the spin-label was stacked within the loop. The spin-label mobility at 37 °C increased as the loops became larger. A considerable variation in fluorescence between different loops was observed, as well as a temperature-dependence within constructs. Fluorescence unexpectedly increased as the size of the loop decreased at 2 °C. Fluorescence of the smallest loops, where a single T·T mismatch was located between the stem region and the probe, was even larger than for the single strand, indicating a considerable local structural deformation of these loops from regular B-DNA. These results show the value of combining EPR and fluorescence spectroscopy to study non-helical regions of nucleic acids.

  7. Esophageal pH monitoring

    Science.gov (United States)

    pH monitoring - esophageal; Esophageal acidity test ... Esophageal pH monitoring is used to check how much stomach acid is entering the esophagus. It also checks how well the acid is cleared downward into the ...

  8. DYNAMICS OF HIGHGER MENTAL FUNCTION IN PATIENTS WITH OBLITERATING LESIONS OF INTERNAL CAROTID ARTERIES IN SURGICAL BRAIN REVASCUL

    Directory of Open Access Journals (Sweden)

    R. A. Vinogradov

    2017-01-01

    Full Text Available Obliterating atherosclerosis of internal carotid arteries is one of the main causes of ischemic stroke and discirculatory encephalopathy. It causes up to 40% of ischemic disorders of cerebral circulation. Currently, the strategy for stroke prevention is determined by the intensive development of surgical methods of treatment, primarily methods for managing lesions of brachiocephalic arteries. Based on the results of a number of international multicenter randomized studies, indications for reconstructive operations for BCA, tactics for managing patients in the postoperative period were formulated. A number of patients with atherosclerotic lesions of brachiocephalic arteries have reduced cognitive functions. The aim of the study is to compare cognitive functions (CF in patients who underwent different surgical approaches in the treatment of obliterating atherosclerotic lesion of internal carotid arteries (ICA.MATERIAL AND METHODS. We studied higher mental functions (HMFs in 116 patients with obliterating unilateral or bilateral lesion of ICA. The study of cognitive functions (MF was performed prior to carotid endarterectomy (CE, group 1, n=73 and transluminal balloon angioplasty of ICAs (TBA of ICA, group 2, n=43, and on days 5–7 and 30–31 after cerebral revascularization (CR. To assess the overall severity of cognitive impairment, the summary indicators of main screening neuropsychological tests were used: MMSE; MoCA; Frontal Assessment Battery (FAB; Beck Depression Inventory and Hamilton Depression Rating Scale.RESULTS. Results Neuropsychologic disorders were reavealed in 98% of patients prior to surgery. An initially comparable condition of HMF in groups with CE and TBA of ICA was revealed. MMSE2 revealed a significant improvement in the results in group 1 both in comparison with the initial data (p<0.05 and in comparison with the results of the second test of group 2. The results of MMSE1 and MMSE2 in group 2 did not show significant

  9. Coral calcifying fluid pH is modulated by seawater carbonate chemistry not solely seawater pH.

    Science.gov (United States)

    Comeau, S; Tambutté, E; Carpenter, R C; Edmunds, P J; Evensen, N R; Allemand, D; Ferrier-Pagès, C; Tambutté, S; Venn, A A

    2017-01-25

    Reef coral calcification depends on regulation of pH in the internal calcifying fluid (CF) in which the coral skeleton forms. However, little is known about calcifying fluid pH (pH CF ) regulation, despite its importance in determining the response of corals to ocean acidification. Here, we investigate pH CF in the coral Stylophora pistillata in seawater maintained at constant pH with manipulated carbonate chemistry to alter dissolved inorganic carbon (DIC) concentration, and therefore total alkalinity (A T ). We also investigate the intracellular pH of calcifying cells, photosynthesis, respiration and calcification rates under the same conditions. Our results show that despite constant pH in the surrounding seawater, pH CF is sensitive to shifts in carbonate chemistry associated with changes in [DIC] and [A T ], revealing that seawater pH is not the sole driver of pH CF Notably, when we synthesize our results with published data, we identify linear relationships of pH CF with the seawater [DIC]/[H + ] ratio, [A T ]/ [H + ] ratio and [[Formula: see text

  10. International Symposium on Spacecraft Ground Control and Flight Dynamics, SCD1, Sao Jose dos Campos, Brazil, Feb. 7-11, 1994

    Science.gov (United States)

    Rozenfeld, Pawel; Kuga, Helio Koiti; Orlando, Valcir

    An international symposium on spacecraft flight dynamics and ground control systems produced 85 papers in the areas of attitude determination and control, orbit control, satellite constellation strategies, stationkeeping, spacecraft maneuvering, orbit determination, astrodynamics, ground command and control systems, and mission operations. Several papers included discussions on the application of artificial intelligence, neural networks, expert systems, and ion propulsion. For individual titles, see A95-89098 through A95-89182.

  11. Level and dynamics of internal dose from 137Cs and 90Sr formation in connection with ecological diversity of polluted agrogenoses of Ukraine

    International Nuclear Information System (INIS)

    Kravets, A.P.; Grodzinsky, D.M.; Pavlenko, Yu.A.

    2004-01-01

    The purpose of our calculations was estimation of quantitative influence of ecological diversity on levels and dynamics of internal doses formation from long-lived radionuclide such as 137 Cs and 90 Sr. Our estimations have radioecological nature that is they are based on registration of natural mechanisms of agricultural products pollution. It has been realized on the basis of three-module ecological model of assessment of radiological consequences (EMARC) of use of polluted agrocenoses

  12. Peptide-targeted delivery of a pH sensor for quantitative measurements of intraglycosomal pH in live Trypanosoma brucei.

    Science.gov (United States)

    Lin, Sheng; Morris, Meredith T; Ackroyd, P Christine; Morris, James C; Christensen, Kenneth A

    2013-05-28

    Studies of dynamic changes in organelles of protozoan parasite Trypanosoma brucei have been limited, in part because of the difficulty of targeting analytical probes to specific subcellular compartments. Here we demonstrate application of a ratiometric probe for pH quantification in T. brucei glycosomes. The probe consists of a peptide encoding the peroxisomal targeting sequence (F-PTS1, acetyl-CKGGAKL) coupled to fluorescein, which responds to pH. When incubated with living parasites, the probe is internalized within vesicular structures that colocalize with a glycosomal marker. Inhibition of uptake of F-PTS1 at 4 °C and pulse-chase colocalization with fluorescent dextran suggested that the probe is initially taken up by non-receptor-mediated endocytosis but is subsequently transported separately from dextran and localized within glycosomes, prior to the final fusion of labeled glycosomes and lysosomes as part of glycosomal turnover. Intraorganellar measurements and pH calibration with F-PTS1 in T. brucei glycosomes indicate that the resting glycosomal pH under physiological conditions is 7.4 ± 0.2. However, incubation in glucose-depleted buffer triggered mild acidification of the glycosome over a period of 20 min, with a final observed pH of 6.8 ± 0.3. This glycosomal acidification was reversed by reintroduction of glucose. Coupling of ratiometric fluorescent sensors and reporters to PTS peptides offers an invaluable tool for monitoring in situ glycosomal response(s) to changing environmental conditions and could be applied to additional kinetoplastid parasites.

  13. Short-Term Therapeutic Efficacy of the Isobar TTL Dynamic Internal Fixation System for the Treatment of Lumbar Degenerative Disc Diseases.

    Science.gov (United States)

    Qian, Jiale; Bao, Zhaohua; Li, Xuefeng; Zou, Jun; Yang, Huilin

    2016-07-01

    At present, posterior interbody fusion surgery with pedicle internal fixation is the gold standard for the treatment of lumbar degenerative disc diseases. However, an increasing number of studies have shown that because fused lumbar vertebrae lose their physiological activity, the compensatory range of motion (ROM) of the adjacent levels increases. To address this issue, dynamic internal fixation systems have been developed. Our goal was to investigate the short-term therapeutic efficacy of the Isobar TTL dynamic internal fixation system for the treatment of lumbar degenerative disc diseases and its effect on the ROM of the surgical segments. Retrospective Evaluation. Tertiary hospital setting in China. Twenty-four lumbar degenerative disc disease patients who underwent posterior lumbar decompression and single-segment Isobar TTL dynamic internal fixation at our hospital between January 2013 and July 2014 were retrospectively analyzed. The preoperative and one month, 3 month, and 12 month postoperative visual analog scale (VAS) pain scores, Japanese Orthopedic Association (JOA) scores, and Oswestry Disability Index (ODI) scores were observed and recorded to assess the clinical therapeutic effect; the lumbar ROM was measured preoperatively and at the last follow-up to evaluate the preservation of functional movement in the dynamically stabilized segment. All patients underwent the operation successfully without complications during hospitalization and were followed for 12 to 27 months, with an average of 18 months. The patients' preoperative and one month, 3 month, and 12 month postoperative VAS scores were 6.42 ± 0.72, 1.71 ± 0.86, 1.38 ± 0.65, and 1.37 ± 0.58, respectively, and their JOA scores were 9.54 ± 1.89, 21.21 ± 1.98, 22.50 ± 1.47, and 23.46 ± 1.32, respectively. The preoperative ODI score was 42.04 ± 2.63; the one month, 3 month, and 12 month postoperative ODI scores were 22.79 ± 1.61, 18.63 ± 1.61, and 15.08 ± 1.21, respectively. These

  14. PhD Dissertations

    Directory of Open Access Journals (Sweden)

    Redazione Reti Medievali (a cura di

    2004-06-01

    Full Text Available Report of PhD Dissertations. Francesco Barone Istituzioni, società ed economia a Catania nel tardo medioevo (XIV-XV secolo, Tesi di dottorato in Storia medievale (XVI ciclo, Università degli Studi di Firenze, 2004   Laura Berti Ceroni Il territorio e le strutture di Cesarea e Classe tra tarda antichità e alto medioevo in rapporto con Ravenna, Tesi di dottorato di ricerca in Storia e Informatica, Università degli studi di Bologna, 2002-2003.   Marco Bicchierai Poppi dalla signoria dei conti Guidi al vicariato del Casentino (1360-1480, Tesi di dottorato in Storia medievale (XIV ciclo, Università degli Studi di Firenze, 2004   Emanuela Garimberti Spatiosa ad habitandum loca. Luoghi e identità nella Historia Langobardorum di Paolo Diacono, Tesi di dottorato in Storia medievale (XV ciclo, Università degli Studi di Bologna, 2004   Lorenzo Tanzini Sistemi normativi e pratiche istituzionali a Firenze dalla fine del XIII all’inizio del XV secolo, Tesi di dottorato di ricerca in Storia medievale (XVI ciclo, Università degli Studi di Firenze, 2004   Stefania Tarquini Pellegrinaggio e asseto urbano di Roma, Tesi di dottorato di ricerca in Storia dei centri, delle vie e della cultura dei pellegrinaggi nel Medioevo euro mediterraneo (XV ciclo, Università degli studi di Lecce, 2003

  15. PhD Dissertations

    Directory of Open Access Journals (Sweden)

    Redazione Reti Medievali (a cura di

    2010-06-01

    Full Text Available Report of PhD dissertations. Andrea Brugnoli Una storia locale: l’organizzazione del territorio veronese nel medioevo: trasformazioni della realtà e schemi notarili (IX-metà XII secolo, Tesi di dottorato di ricerca in Scienze Storiche e Antropologiche (XXII ciclo, Università degli Studi di Verona, 2010   Luca Filangieri Famiglie e gruppi dirigenti a Genova (secoli XII-metà XIII, Tesi di dottorato di ricerca in Storia medievale (XXII ciclo, Università degli Studi di Firenze, 2010   Jakub Kujawi ski Wernakularna kolekcja historiograficzna z rękopisu francuskiego nr 688 z Biblioteki Narodowej w Paryżu. Studium źródłoznawcze (La raccolta dei volgarizzamenti delle opere storiografiche nel manoscritto francese 688 della Biblioteca Nazionale di Parigi, Tesi di dottorato, Università “Adam Mickiewicz”, Facoltà di Storia, Pozna, a.a. 2009/2010   Marta Longhi I signori “de Radicata”. Strategie di affermazione familiare e patrimoniale nel Piemonte dei secoli XII-XIV, Tesi di dottorato di ricerca in Istituzioni, Società, Religioni dal Tardo Antico alla fine del Medioevo (XX ciclo, Università di Torino, 2008

  16. PhD Dissertations

    Directory of Open Access Journals (Sweden)

    Redazione Reti Medievali (a cura di

    2003-06-01

    Full Text Available Reporto of PhD Dissertations.   Mario Dalle Carbonare Società, potere e clientele nell’Irlanda altomedievale (secoli V-IX, Tesi di dottorato di ricerca in Storia sociale europea, Università "Ca' Foscari" di Venezia, 2003 Vieri Mazzoni La legislazione antighibellina e la politica oligarchica della Parte Guelfa di Firenze nel secondo Trecento (1347-1378, Tesi di dottorato di ricerca in Storia Medievale (ciclo XII, Università degli Studi di Firenze   Alma Poloni Pisa dalle origini del movimento popolare alla discesa di Ludovico il Bavaro. I gruppi dirigenti cittadini tra continuità e trasformazione, Tesi di dottorato di ricerca in Storia dell'Europa nel medioevo, Università degli studi di Pisa, 2003   Andrea Puglia Potere marchionale, amministrazione del territorio, società locali dalla morte di Ugo di Tuscia a Guelfo VI di Baviera (1001-1160, Tesi di dottorato di ricerca in Storia medievale, Università degli studi di Milano, 2003

  17. NMR Spectroscopy and Molecular Dynamics Simulation of r(CCGCUGCGG)2 Reveal a Dynamic UU Internal Loop Found in Myotonic Dystrophy Type 1†

    Science.gov (United States)

    Parkesh, Raman; Fountain, Matthew; Disney, Matthew D.

    2011-01-01

    The NMR structure of an RNA with a copy of the 5′CUG/3′GUC motif found in the triplet repeating disorder myotonic dystrophy type 1 (DM1) is disclosed. The lowest energy conformation of the UU pair is a single hydrogen bonded structure; however, the UU protons undergo exchange indicating structural dynamics. Molecular dynamics simulations show that the single hydrogen bonded structure is the most populated one but the UU pair interconverts between 0, 1, and 2 hydrogen bonded pairs. These studies have implications for the recognition of the DM1 RNA by small molecules and proteins. PMID:21204525

  18. The Formation and Spatiotemporal Progress of the pH Wave Induced by the Temperature Gradient in the Thin-Layer H2O2-Na2S2O3-H2SO4-CuSO4 Dynamical System.

    Science.gov (United States)

    Jędrusiak, Mikołaj; Orlik, Marek

    2016-03-31

    The H2O2-S2O3(2-)-H(+)-Cu(2+) dynamical system exhibits sustained oscillations under flow conditions but reveals only a single initial peak of the indicator electrode potential and pH variation under batch isothermal conditions. Thus, in the latter case, there is no possibility of the coupling of the oscillations and diffusion which could lead to formation of sustained spatiotemporal patterns in this process. However, in the inhomogeneous temperature field, due to dependence of the local reaction kinetics on temperature, spatial inhomogeneities of pH distribution can develop which, in the presence of an appropriate indicator, thymol blue, manifest themselves as the color front traveling along the quasi-one-dimensional reactor. In this work, we describe the experimental conditions under which the above-mentioned phenomena can be observed and present their numerical model based on thermokinetic coupling and spatial coordinate introduced to earlier isothermal homogeneous kinetic mechanism.

  19. Conserving Coherence and Storing Energy during Internal Conversion: Photoinduced Dynamics of cis- and trans-Azobenzene Radical Cations

    KAUST Repository

    Munkerup, Kristin; Romanov, Dmitri A.; Bohinski, Timothy; Stephansen, Anne B.; Levis, Robert J.; Sø lling, Theis Ivan

    2017-01-01

    Light harvesting via energy storage in azobenzene has been a key topic for decades, and the process of energy distribution over the molecular degrees of freedom following photoexcitation remains to be understood. Dynamics of a photoexcited system

  20. Influence of forced internal air circulation on airflow distribution and heat transfer in a gas double-dynamic solid-state fermentation bioreactor.

    Science.gov (United States)

    Chen, Hongzhang; Qin, Lanzhi; Li, Hongqiang

    2014-02-01

    Internal air circulation affects the temperature field distribution in a gas double-dynamic solid-state fermentation bioreactor (GDSFB). To enhance heat transfer through strengthening internal air circulation in a GDSFB, we put an air distribution plate (ADP) into the bioreactor and studied the effects of forced internal air circulation on airflow, heat transfer, and cellulase activity of Trichoderma viride L3. Results showed that ADP could help form a steady and uniform airflow distribution, and with gas-guide tubes, air reversal was formed inside the bioreactor, thus resulting in a smaller temperature difference between medium and air by enhancing convective heat transfer inside the bioreactor. Using an ADP of 5.35 % aperture ratio caused a 1 °C decrease in the average temperature difference during the solid-state fermentation process of T. viride L3. Meanwhile, the cellulase activity of T. viride L3 increased by 13.5 %. The best heat-transfer effect was attained when using an ADP of 5.35 % aperture ratio and setting the fan power to 125 V (4.81 W) in the gas double-dynamic solid-state fermentation (GDSF) process. An option of suitable aperture ratio and fan power may be conducive to ADPs' industrial amplification.

  1. Quantum-dynamical Modeling of the Rydberg to Valence Excited-State Internal Conversion in Cyclobutanone and Cyclopentanone

    Directory of Open Access Journals (Sweden)

    Møller K. B.

    2013-03-01

    Full Text Available In this paper we present 4-state, 5-dimensional Vibronic Coupling Hamiltonians for cyclobutanone and cyclopentanone. Wave packet calculations using these Hamiltonians reveal that for cyclobutanone the (n,3s to (n,π* internal conversion involves direct motion in nuclear modes coupling the two states leading to fast population transfer. For cyclopentanone, internal vibrational energy redistribution is a bottleneck for activating reactive nuclear modes leading to slower population transfer.

  2. Quantum-dynamical Modeling of the Rydberg to Valence Excited-State Internal Conversion in Cyclobutanone and Cyclopentanone

    DEFF Research Database (Denmark)

    Kuhlman, T. S.; Sauer, Stephan P. A.; Solling, T. I.

    2013-01-01

    In this paper we present 4-state, 5-dimensional Vibronic Coupling Hamiltonians for cyclobutanone and cyclopentanone. Wave packet calculations using these Hamiltonians reveal that for cyclobutanone the (n,3s) to (n,π*) internal conversion involves direct motion in nuclear modes coupling the two st...... states leading to fast population transfer. For cyclopentanone, internal vibrational energy redistribution is a bottleneck for activating reactive nuclear modes leading to slower population transfer....

  3. Next Generation Qualification: Nanometrics T120PH Seismometer Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, Bion J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Slad, George William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-01

    Sandia National Laboratories has tested and evaluated three seismometers, the Trillium 120PH, manufactured by Nanometrics. These seismometers measure broadband ground velocity using a UVW configuration with feedback control in a mechanically levelled borehole package. The purpose of the seismometer evaluation was to determine a measured sensitivity, response, self- noise, dynamic range, and self-calibration ability. The Nanometrics Trillium 120PH seismometers are being evaluated for the U.S. Air Force as part of their Next Generation Qualification effort.

  4. THE BIOENERGETICS OF AMMONIA AND HYDROXYLAMINE OXIDATION IN NITROSOMONAS-EUROPAEA AT ACID AND ALKALINE PH

    NARCIS (Netherlands)

    FRIJLINK, MJ; ABEE, T; LAANBROEK, HJ; DEBOER, W; KONINGS, WN

    Autotrophic ammonia oxidizers depend on alkaline or neutral conditions for optimal activity. Below pH 7 growth and metabolic activity decrease dramatically. Actively oxidizing cells of Nitrosomonas europaea do not maintain a constant internal pH when the external pH is varied from 5 to 8. Studies of

  5. Intracellular pH distribution as a cell health indicator in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Aabo, Thomas; Glückstad, Jesper; Siegumfeldt, Henrik

    2011-01-01

    .d.(pHint)) to describe the internal pH distributions. The cellular pH distributional response to external stress such as heat has not previously been determined. In this study, the intracellular pH (pHi) and the s.d.(pHint) of Saccharomyces cerevisiae cells exposed to supralethal temperatures were measured using...

  6. A PhD is a PhD is a PhD

    OpenAIRE

    Ostrow, Deborah Anne

    2017-01-01

    A PhD is a PhD is a PhD is a practice-based project that interrogates the process of an artist undertaking PhD research under established criteria. It consists of an exegesis, an original screenplay, and a digital film made for online viewing, with images drawn from a range of documentaries and films found on YouTube. They have been dissected, re-assembled and then re-embedded to YouTube. The source material covers topics such as medicalization of madness, the conspicuous appropriation of uni...

  7. A review of a method for dynamic load distribution, dynamic modeling, and explicit internal force control when two serial link manipulators mutually lift and transport a rigid body object

    International Nuclear Information System (INIS)

    Unseren, M.A.

    1997-09-01

    The report reviews a method for modeling and controlling two serial link manipulators which mutually lift and transport a rigid body object in a three dimensional workspace. A new vector variable is introduced which parameterizes the internal contact force controlled degrees of freedom. A technique for dynamically distributing the payload between the manipulators is suggested which yields a family of solutions for the contact forces and torques the manipulators impart to the object. A set of rigid body kinematic constraints which restricts the values of the joint velocities of both manipulators is derived. A rigid body dynamical model for the closed chain system is first developed in the joint space. The model is obtained by generalizing the previous methods for deriving the model. The joint velocity and acceleration variables in the model are expressed in terms of independent pseudovariables. The pseudospace model is transformed to obtain reduced order equations of motion and a separate set of equations governing the internal components of the contact forces and torques. A theoretic control architecture is suggested which explicitly decouples the two sets of equations comprising the model. The controller enables the designer to develop independent, non-interacting control laws for the position control and internal force control of the system

  8. A review of a method for dynamic load distribution, dynamic modeling, and explicit internal force control when two serial link manipulators mutually lift and transport a rigid body object

    Energy Technology Data Exchange (ETDEWEB)

    Unseren, M.A.

    1997-09-01

    The report reviews a method for modeling and controlling two serial link manipulators which mutually lift and transport a rigid body object in a three dimensional workspace. A new vector variable is introduced which parameterizes the internal contact force controlled degrees of freedom. A technique for dynamically distributing the payload between the manipulators is suggested which yields a family of solutions for the contact forces and torques the manipulators impart to the object. A set of rigid body kinematic constraints which restricts the values of the joint velocities of both manipulators is derived. A rigid body dynamical model for the closed chain system is first developed in the joint space. The model is obtained by generalizing the previous methods for deriving the model. The joint velocity and acceleration variables in the model are expressed in terms of independent pseudovariables. The pseudospace model is transformed to obtain reduced order equations of motion and a separate set of equations governing the internal components of the contact forces and torques. A theoretic control architecture is suggested which explicitly decouples the two sets of equations comprising the model. The controller enables the designer to develop independent, non-interacting control laws for the position control and internal force control of the system.

  9. The pH Game.

    Science.gov (United States)

    Chemecology, 1996

    1996-01-01

    Describes a game that can be used to teach students about the acidity of liquids and substances around their school and enable them to understand what pH levels tell us about the environment. Students collect samples and measure the pH of water, soil, plants, and other natural material. (DDR)

  10. Estabilidade aeróbia, pH e dinâmica de desenvolvimento de microrganismos da cana-de-açúcar in natura hidrolisada com cal virgem Aerobic stability, pH and development dynamic of microorganisms on fresh sugarcane hydrolyzed with whitewash

    Directory of Open Access Journals (Sweden)

    F.N. Domingues

    2011-04-01

    Full Text Available Objetivou-se com este trabalho avaliar o efeito da adição de cal virgem e dos tempos após a aplicação sobre a estabilidade aeróbia e o crescimento de microrganismos (leveduras e fungos na cana-de-açúcar in natura. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições. Avaliaram-se a estabilidade aeróbia (temperatura, a dinâmica de desenvolvimento de leveduras e fungos e o pH, em um esquema de parcelas subdivididas, com cinco doses de cal (0; 0,5; 1,0; 1,5 e 2,0% e cinco tempos após aplicação (0, 24, 48, 72, 96 horas. Houve efeito significativo das doses de cal para todos os parâmetros avaliados. A cana que não foi tratada com cal (0% apresentou quebra da estabilidade no menor intervalo de tempo. Os valores de pH aumentaram gradativamente de acordo com a dose de cal aplicada e diminuíram com o tempo após aplicação. Houve aumento numérico na contagem de leveduras até as 72 horas após a aplicação da cal, independentemente da dose, e os valores tenderam a estabilizar no tempo de 96 horas pós-tratamento. Não houve efeito significativo das doses de cal sobre o desenvolvimento dos fungos. A aplicação de cal virgem é eficaz no controle do crescimento de leveduras e aumenta a estabilidade aeróbia da cana-de-açúcar in natura.The objective of this work was to evaluate the effect of whitewash addition and the times after application on aerobic stability and growth of microorganisms (fungi and yeasts in fresh sugarcane. It was used a completely randomized experimental design, with four replications. Aerobic stability (temperature and the concentrations of yeast and fungus and pH were evaluated in a split-splot scheme with five doses of whitewash (0; 0.5; 1.0; 1.5 and 2.0% and five times after treatment (0, 24, 48, 72 and 96 hours. There was a significant effect of doses of whitewash for all evaluated parameters. The sugarcane which was not treated with whitewash (0.0% showed a break in

  11. Experimental investigation of the fluid dynamic efficiency of a high performance multi-valve internal combustion engine during the intake phase: Influence of valve-valve interference phenomena

    Directory of Open Access Journals (Sweden)

    Algieri Angelo

    2013-01-01

    Full Text Available The purpose of the present work is the analysis of the fluid dynamic behavior of a high performance internal combustion engine during the intake phase. In particular, a four-valve spark-ignition engine has been characterized at the steady flow rig. Dimensionless discharge coefficients have been used to define the global fluid dynamic efficiency of the intake system, while the Laser Doppler Anemometry (LDA technique has been employed to evaluate the mean flow in the valve curtain area and to characterise the interference phenomena between the two intake valves. The investigation has shown the significant influence of the valve lift on the volumetric efficiency of the intake apparatus. Moreover, the experimental analysis has highlighted that the valve-valve interference phenomena have a relevant impact on the head breathability, on the flow development within the combustion chamber and on the velocity standard deviations.

  12. A model of turbocharger radial turbines appropriate to be used in zero- and one-dimensional gas dynamics codes for internal combustion engines modelling

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, J.R.; Arnau, F.J.; Dolz, V.; Tiseira, A. [CMT-Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Cervello, C. [Conselleria de Cultura, Educacion y Deporte, Generalitat Valenciana (Spain)

    2008-12-15

    The paper presents a model of fixed and variable geometry turbines. The aim of this model is to provide an efficient boundary condition to model turbocharged internal combustion engines with zero- and one-dimensional gas dynamic codes. The model is based from its very conception on the measured characteristics of the turbine. Nevertheless, it is capable of extrapolating operating conditions that differ from those included in the turbine maps, since the engines usually work within these zones. The presented model has been implemented in a one-dimensional gas dynamic code and has been used to calculate unsteady operating conditions for several turbines. The results obtained have been compared with success against pressure-time histories measured upstream and downstream of the turbine during on-engine operation. (author)

  13. Development and validation of the International Hidradenitis Suppurativa Severity Score System (IHS4), a novel dynamic scoring system to assess HS severity

    DEFF Research Database (Denmark)

    Zouboulis, C C; Tzellos, T; Kyrgidis, A

    2017-01-01

    BACKGROUND: A validated tool for the dynamic severity assessment of hidradenitis suppurativa/acne inversa (HS) is lacking. OBJECTIVES: To develop and validate a novel dynamic scoring system to assess the severity of HS. METHODS: A Delphi voting procedure was conducted among the members......, as well as examination for correlation (Spearman's rho) and agreement (Cohen's kappa) with existing scores, were engaged to recognize the variables for a new International HS4 (IHS4) that was established by a second Delphi round. RESULTS: Consensus HS4 was based on number of skin lesions, number of skin....... Three candidate scores were presented to the second Delphi round. The resulting IHS4 score is arrived at by the number of nodules (multiplied by 1) plus the number of abscesses (multiplied by 2) plus the number of draining tunnels (multiplied by 4). A total score of 3 or less signifies mild, 4...

  14. A model of turbocharger radial turbines appropriate to be used in zero- and one-dimensional gas dynamics codes for internal combustion engines modelling

    International Nuclear Information System (INIS)

    Serrano, J.R.; Arnau, F.J.; Dolz, V.; Tiseira, A.; Cervello, C.

    2008-01-01

    The paper presents a model of fixed and variable geometry turbines. The aim of this model is to provide an efficient boundary condition to model turbocharged internal combustion engines with zero- and one-dimensional gas dynamic codes. The model is based from its very conception on the measured characteristics of the turbine. Nevertheless, it is capable of extrapolating operating conditions that differ from those included in the turbine maps, since the engines usually work within these zones. The presented model has been implemented in a one-dimensional gas dynamic code and has been used to calculate unsteady operating conditions for several turbines. The results obtained have been compared with success against pressure-time histories measured upstream and downstream of the turbine during on-engine operation

  15. Acid skim milk gels: The gelation process as affected by preheated pH

    NARCIS (Netherlands)

    Lakemond, C.M.M.; Vliet, van T.

    2008-01-01

    The effect of preheating milk (10 min 80 [degree sign]C) at pH values from 6.20 to 6.90 on formation of acid skim milk gels was studied by dynamic oscillation measurements. Up to pH 6.65 a higher pH of heating (pHheating) resulted in a higher G'. Since below pH 4.9 the development of

  16. Multi-mode-multi-state quantum dynamics of key five-membered heterocycles: spectroscopy and ultrafast internal conversion

    International Nuclear Information System (INIS)

    Koeppel, H.; Gromov, E.V.; Trofimov, A.B.

    2004-01-01

    The multi-mode and multi-state vibronic interactions in the heterocyclic molecules furan, pyrrole, thiophene and their radical cations are investigated theoretically, employing a linear vibronic coupling scheme. The underlying system parameters are determined from large-scale ab initio computations. Previous time-independent dynamical calculations on the radical cations are extended by wave-packet propagations (using the MCTDH method) confirming the strong nonadiabatic coupling effects. For the singlet excited states of furan and thiophene quantum dynamical calculations are presented which go beyond the two-state approximation frequently applied in the literature. The characteristic spectral structures are well reproduced, especially in the case of furan. The implications of these results on the photochemical reaction dynamics of these species are discussed

  17. Dynamics of data flows on the low-activated vanadium alloy for thermonuclear power engineering (analysis of four international data bases)

    International Nuclear Information System (INIS)

    Shepelev, A.G.; Kurilo, Yu.P.; Krivchenko, O.V.

    2015-01-01

    The paper presents the results of scientometric analysis of data flows in the International Data Bases SCOPUS, INSPEC, INIS, MSCI over a period since 1971 to 2014 on low-activated vanadium alloys suitable for operation as structural materials under extremely hard conditions in the future fusion reactors. The data on the dynamics of publications and contributions in them from the scientists of different countries have been obtained. The types and languages of publications have been identified. The analysis shows that investigations on the low-activated vanadium alloys are of current importance

  18. Influence of internal thermal mass on the indoor thermal dynamics and integration of phase change materials in furniture for building energy storage

    DEFF Research Database (Denmark)

    Johra, Hicham; Heiselberg, Per Kvols

    2017-01-01

    The increasing share of intermittent renewable energy on the grid encourages researchers to develop demand-side management strategies. Passive heat storage in the indoor space is a promising solution to improve the building energy flexibility. It relies on an accurate control of the transient...... building temperature. However, many of the current numerical models for building energy systems assume empty rooms and do not account entirely for the internal thermal inertia of objects like furniture. This review article points out that such assumption is not valid for dynamic calculations...

  19. Estimation of error in maximal intensity projection-based internal target volume of lung tumors: a simulation and comparison study using dynamic magnetic resonance imaging.

    Science.gov (United States)

    Cai, Jing; Read, Paul W; Baisden, Joseph M; Larner, James M; Benedict, Stanley H; Sheng, Ke

    2007-11-01

    To evaluate the error in four-dimensional computed tomography (4D-CT) maximal intensity projection (MIP)-based lung tumor internal target volume determination using a simulation method based on dynamic magnetic resonance imaging (dMRI). Eight healthy volunteers and six lung tumor patients underwent a 5-min MRI scan in the sagittal plane to acquire dynamic images of lung motion. A MATLAB program was written to generate re-sorted dMRI using 4D-CT acquisition methods (RedCAM) by segmenting and rebinning the MRI scans. The maximal intensity projection images were generated from RedCAM and dMRI, and the errors in the MIP-based internal target area (ITA) from RedCAM (epsilon), compared with those from dMRI, were determined and correlated with the subjects' respiratory variability (nu). Maximal intensity projection-based ITAs from RedCAM were comparatively smaller than those from dMRI in both phantom studies (epsilon = -21.64% +/- 8.23%) and lung tumor patient studies (epsilon = -20.31% +/- 11.36%). The errors in MIP-based ITA from RedCAM correlated linearly (epsilon = -5.13nu - 6.71, r(2) = 0.76) with the subjects' respiratory variability. Because of the low temporal resolution and retrospective re-sorting, 4D-CT might not accurately depict the excursion of a moving tumor. Using a 4D-CT MIP image to define the internal target volume might therefore cause underdosing and an increased risk of subsequent treatment failure. Patient-specific respiratory variability might also be a useful predictor of the 4D-CT-induced error in MIP-based internal target volume determination.

  20. Dynamical analysis of a PWR internals using super-elements in an integrated 3-D model model. Part 2: dynamical tests and seismic analysis

    International Nuclear Information System (INIS)

    Jesus Miranda, C.A. de.

    1992-01-01

    The results of the test analysis (frequencies) for the isolated super-elements and for the developed 3-D model of the internals core support structures of a PWR research reactor are presented. Once certified of the model effectiveness for this type of analysis the seismic spectral analysis was performed. From the results can be seen that the structures are rigid for this load, isolated or together with the other in the 3-D model, and there are no impacts among them during the earthquake (OBE). (author)

  1. Kinematics and Dynamics Analysis of a 3-DOF Upper-Limb Exoskeleton with an Internally Rotated Elbow Joint

    OpenAIRE

    Xin Wang; Qiuzhi Song; Xiaoguang Wang; Pengzhan Liu

    2018-01-01

    The contradiction between self-weight and load capacity of a power-assisted upper-limb exoskeleton for material hanging is unresolved. In this paper, a non-anthropomorphic 3-degree of freedom (DOF) upper-limb exoskeleton with an internally rotated elbow joint is proposed based on an anthropomorphic 5-DOF upper-limb exoskeleton for power-assisted activity. The proposed 3-DOF upper-limb exoskeleton contains a 2-DOF shoulder joint and a 1-DOF internally rotated elbow joint. The structural parame...

  2. The dynamics of immunologic reactions in rats affected by repeated external γ-irradiation and internal irradiation with radionuclides

    International Nuclear Information System (INIS)

    Shubik, V.M.; Livshits, R.E.

    1975-01-01

    Nonspecific factors of immunity and formation of autoantibodies in rats exposed to comparable doses of repeated external γ-irradiation and of internal irradiation with Cs 137 , Sr 90 and I 131 chronically administered to animals have been studied comparatively. No essential variations have been found in changes induced in the immunologic reactions by chronic external and even internal γ-irradiation. Certain peculiarities have been revealed in the character of changes in the immunologic reactions depending on biophysical properties of the radionuclides used in the experiments

  3. Internal migration of Canadian immigrants, 1993–2004: Evidence from the Survey of Labour and Income Dynamics

    Directory of Open Access Journals (Sweden)

    Karen M. King

    2011-12-01

    migration modeling results may differ when pre- and post-migration measures are used. Results suggest that internal migration of the foreign-born generally does not increase their dispersion across Canada, with the foreign-born primarily choosing one of the three immigrant gateway cities of Toronto, Montreal, and Vancouver, or moving to other relatively large CMAs.

  4. Study of the Career Intern Program. Final Technical Report--Task C: Program Dynamics: Structure, Function, and Interrelationships.

    Science.gov (United States)

    Fetterman, David M.

    A study identified causal linkages and basic interrelationships among components of the Career Intern Program (CIP) and observed outcomes. (The CIP is an alternative high school designed to enable disadvantaged and alienated dropouts or potential dropouts to earn regular high school diplomas, to prepare them for meaningful employment or…

  5. Dynamics of clinical semiotics in children with pathological tortuosity of internal carotid arteries in remote period after surgical management.

    Science.gov (United States)

    Shoĭkhet, Ya N; Khorev, N G; Kulikova, N I; Beller, A V; Kulikov, V P; Miller, V E

    2010-01-01

    The present study enrolling a total of eighty-eight 4-to-16-year-old children and adolescents was aimed at detailed elaboration and formalization of clinical signs of the internal carotid artery pathological kinking syndrome. To achieve these objectives, the authors carried out a comparative analysis of clinical manifestations of the disease in the surgically treated subjects (constituting the Surgery Group comprising 43 children and adolescents) and non-operated patients (making up the Comparison Group consisting of 45 age- and gender-matched subjects). There were no baseline differences in the incidence rate of clinical syndromes and symptoms between the groups of the would-be operated and conservatively treated patients. Also studied were the remote outcomes (1-to-12-year follow up) of surgical correction for pathological tortuosity of the internal carotid artery. The incidence rate of regression of neurological symptomatology along different clinical signs after surgery was shown to vary within a wide range from 11.6% to 96.3%. Resection of the proximal portion of the internal carotid artery with re-implantation into the old ostium turned out to be clinically effective in 90.0% of cases, with the haemodynamic efficacy amounting to 83.3%. Arteriolysis of the internal carotid artery rendered a clinical effect in 75% of cases, with a haemodynamical effect thereof equalling 25.0%. The decision as to the type of a surgical intervention to perform was primarily made based on the findings of angiography of the internal carotid artery. The operation of arteriolysis did not lead to deterioration of the child's condition.

  6. Molecular dynamics investigation of ferrous-ferric electron transfer in a hydrolyzing aqueous solution: Calculation of the pH dependence of the diabatic transfer barrier and the potential of mean force

    International Nuclear Information System (INIS)

    Rustad, James R.; Rosso, Kevin M.; Felmy, Andrew R.

    2004-01-01

    We present a molecular model for ferrous-ferric electron transfer in an aqueous solution that accounts for electronic polarizability and exhibits spontaneous cation hydrolysis. An extended Lagrangian technique is introduced for carrying out calculations of electron-transfer barriers in polarizable systems. The model predicts that the diabatic barrier to electron transfer increases with increasing pH, due to stabilization of the Fe 3+ by fluctuations in the number of hydroxide ions in its first coordination sphere, in much the same way as the barrier would increase with increasing dielectric constant in the Marcus theory. We have also calculated the effect of pH on the potential of mean force between two hydrolyzing ions in aqueous solution. As expected, increasing pH reduces the potential of mean force between the ferrous and ferric ions in the model system. The magnitudes of the predicted increase in diabatic transfer barrier and the predicted decrease in the potential of mean force nearly cancel each other at the canonical transfer distance of 0.55 nm. Even though hydrolysis is allowed in our calculations, the distribution of reorganization energies has only one maximum and is Gaussian to an excellent approximation, giving a harmonic free energy surface in the reorganization energy F(ΔE) with a single minimum. There is thus a surprising amount of overlap in electron-transfer reorganization energies for Fe 2+ -Fe(H 2 O) 6 3+ , Fe 2+ -Fe(OH)(H 2 O) 5 2+ , and Fe 2+ -Fe(OH) 2 (H 2 O) + couples, indicating that fluctuations in hydrolysis state can be viewed on a continuum with other solvent contributions to the reorganization energy. There appears to be little justification for thinking of the transfer rate as arising from the contributions of different hydrolysis states. Electronic structure calculations indicate that Fe(H 2 O) 6 2+ -Fe(OH) n (H 2 O) 6-n (3-n)+ complexes interacting through H 3 O 2 - bridges do not have large electronic couplings

  7. Dynamics of internal waves on the Southeast Florida shelf: Implications for cross-shelf exchange and turbulent mixing on a barrier reef system

    Science.gov (United States)

    Davis, Kristen Alexis

    The dynamics of internal waves shoaling on the Southeast Florida shelf and the resulting stratified turbulence in the shelf bottom boundary layer are investigated using observational studies completed during the summers of 2003-2005. This work is driven by a desire to understand the effects of internal wave-driven flow and the shoreward transport of cool, nutrient-rich water masses on cross-shelf exchange, vertical mixing, and mass transfer to benthic reef organisms. Shelf sea internal wave fields are typically highly variable and dominated by wind and tidal forces. However, this is not necessarily true for outer shelf regions or very narrow shelves where remote physical processes originating over the slope or deep ocean may exert a strong influence on the internal wave climate. During the summers of 2003 and 2004 observational studies were conducted to examine the effects of a western boundary current (the Florida Current), tides, and wind on the mean currents and internal wave field on the outer Southeast Florida shelf. We present evidence that suggests that the Florida Current plays as large a role in the determination of the high frequency internal wave field as tidal forces. These observations and analyses show that it is necessary to include the forcing from the Florida Current meanders and instabilities in order to predict accurately the episodic nature of the internal wave field on the Southeast Florida shelf. Deep ocean and continental shelf processes intersect at the shelf edge and influence the exchange of water masses and their associated characteristics including heat, nutrients, sediment, and larvae across the shelf. Thus, the dynamics of cross-shelf circulation have important consequences for organisms living on the shelf. In the second phase of this work, we investigate physical mechanisms controlling the exchange of water masses during the summer season across the Southeast Florida shelf. A time series of cross-shelf transport from May to August

  8. A dynamic Thurstonian item response theory of motive expression in the picture story exercise: solving the internal consistency paradox of the PSE.

    Science.gov (United States)

    Lang, Jonas W B

    2014-07-01

    The measurement of implicit or unconscious motives using the picture story exercise (PSE) has long been a target of debate in the psychological literature. Most debates have centered on the apparent paradox that PSE measures of implicit motives typically show low internal consistency reliability on common indices like Cronbach's alpha but nevertheless predict behavioral outcomes. I describe a dynamic Thurstonian item response theory (IRT) model that builds on dynamic system theories of motivation, theorizing on the PSE response process, and recent advancements in Thurstonian IRT modeling of choice data. To assess the models' capability to explain the internal consistency paradox, I first fitted the model to archival data (Gurin, Veroff, & Feld, 1957) and then simulated data based on bias-corrected model estimates from the real data. Simulation results revealed that the average squared correlation reliability for the motives in the Thurstonian IRT model was .74 and that Cronbach's alpha values were similar to the real data (value of extant evidence from motivational research using PSE motive measures. (c) 2014 APA, all rights reserved.

  9. Limited and time-delayed internal resource allocation generates oscillations and chaos in the dynamics of citrus crops

    International Nuclear Information System (INIS)

    Ye, Xujun; Sakai, Kenshi

    2013-01-01

    Alternate bearing or masting is a yield variability phenomenon in perennial crops. The complex dynamics in this phenomenon have stimulated much ecological research. Motivated by data from an eight-year experiment with forty-eight individual trees, we explored the mechanism inherent to these dynamics in Satsuma mandarin (Citrus unshiu Marc.). By integrating high-resolution imaging technology, we found that the canopy structure and reproduction output of individual citrus crops are mutually dependent on each other. Furthermore, it was revealed that the mature leaves in early season contribute their energy to the fruiting of the current growing season, whereas the younger leaves show a delayed contribution to the next growing season. We thus hypothesized that the annual yield variability might be caused by the limited and time-delayed resource allocation in individual plants. A novel lattice model based on this hypothesis demonstrates that this pattern of resource allocation will generate oscillations and chaos in citrus yield

  10. Non-orthogonal internally contracted multi-configurational perturbation theory (NICPT): Dynamic electron correlation for large, compact active spaces

    Science.gov (United States)

    Kähler, Sven; Olsen, Jeppe

    2017-11-01

    A computational method is presented for systems that require high-level treatments of static and dynamic electron correlation but cannot be treated using conventional complete active space self-consistent field-based methods due to the required size of the active space. Our method introduces an efficient algorithm for perturbative dynamic correlation corrections for compact non-orthogonal MCSCF calculations. In the algorithm, biorthonormal expansions of orbitals and CI-wave functions are used to reduce the scaling of the performance determining step from quadratic to linear in the number of configurations. We describe a hierarchy of configuration spaces that can be chosen for the active space. Potential curves for the nitrogen molecule and the chromium dimer are compared for different configuration spaces. Already the most compact spaces yield qualitatively correct potentials that with increasing size of configuration spaces systematically approach complete active space results.

  11. Limited and time-delayed internal resource allocation generates oscillations and chaos in the dynamics of citrus crops

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Xujun, E-mail: yexujun@cc.hirosaki-u.ac.jp [College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058 (China); Faculty of Agriculture and Life Sciences, Hirosaki University, Aomori 036-8561 (Japan); Sakai, Kenshi, E-mail: ken@cc.tuat.ac.jp [Environmental and Agricultural Engineering Department, Tokyo University of Agriculture and Technology, Tokyo 183-8509 (Japan)

    2013-12-15

    Alternate bearing or masting is a yield variability phenomenon in perennial crops. The complex dynamics in this phenomenon have stimulated much ecological research. Motivated by data from an eight-year experiment with forty-eight individual trees, we explored the mechanism inherent to these dynamics in Satsuma mandarin (Citrus unshiu Marc.). By integrating high-resolution imaging technology, we found that the canopy structure and reproduction output of individual citrus crops are mutually dependent on each other. Furthermore, it was revealed that the mature leaves in early season contribute their energy to the fruiting of the current growing season, whereas the younger leaves show a delayed contribution to the next growing season. We thus hypothesized that the annual yield variability might be caused by the limited and time-delayed resource allocation in individual plants. A novel lattice model based on this hypothesis demonstrates that this pattern of resource allocation will generate oscillations and chaos in citrus yield.

  12. Urine pH test

    Science.gov (United States)

    ... urine test Male urinary tract References Bose A, Monk RD, Bushinsky DA. Kidney stones. In: Melmed S, Polonsky ... and its influence on urine pH. J Am Diet Assoc . 1995;95(7):791-797. PMID: 7797810 ...

  13. Exercise and Pulmonary Hypertension (PH)

    Science.gov (United States)

    ... Situations Find a Doctor PH Care Centers PHA Classroom PHA Registry Insurance Guide Specialty Pharmacy Other Resources ... no published data in the medical literature regarding routine exercise in patients with PAH. However, there are ...

  14. Nonlinear response of a post-tensioned concrete structure to static and dynamic internal-pressure loads

    International Nuclear Information System (INIS)

    Butler, T.A.; Bennett, J.G.

    1981-01-01

    A nonlinear finite element model of a nuclear power plant containment building was developed to determine its ultimate pressure capability under quasistatic and impulsive dynamic loads. The ADINA finite element computer code was used to develop the model because of its capability to handle concrete cracking and crushing. Results indicate that, even though excessive concrete cracking occurs, failure is ultimately caused by rupture of post-tensioning tendons

  15. Overview study of the analytical analysis of the internal dynamics of nonlinear time heteronymous planetary differential systems

    Czech Academy of Sciences Publication Activity Database

    Hortel, Milan; Škuderová, Alena

    2016-01-01

    Roč. 821, č. 2016 (2016), s. 213-220 ISSN 1662-7482. [Engineering Mechanics 2015. Svratka, 11.05.2015-14.05.2015] R&D Projects: GA TA ČR(CZ) TA04011656 Institutional support: RVO:61388998 Keywords : nonlinear dynamics * time heteronymous systems * damping in gear mesh Subject RIV: JT - Propulsion, Motors ; Fuels http://www.scientific.net/AMM.821.213

  16. PhEDEx Data Service

    International Nuclear Information System (INIS)

    Egeland, Ricky; Wildish, Tony; Huang, Chih-Hao

    2010-01-01

    The PhEDEx Data Service provides access to information from the central PhEDEx database, as well as certificate-authenticated managerial operations such as requesting the transfer or deletion of data. The Data Service is integrated with the 'SiteDB' service for fine-grained access control, providing a safe and secure environment for operations. A plug-in architecture allows server-side modules to be developed rapidly and easily by anyone familiar with the schema, and can automatically return the data in a variety of formats for use by different client technologies. Using HTTP access via the Data Service instead of direct database connections makes it possible to build monitoring web-pages with complex drill-down operations, suitable for debugging or presentation from many aspects. This will form the basis of the new PhEDEx website in the near future, as well as providing access to PhEDEx information and certificate-authenticated services for other CMS dataflow and workflow management tools such as CRAB, WMCore, DBS and the dashboard. A PhEDEx command-line client tool provides one-stop access to all the functions of the PhEDEx Data Service interactively, for use in simple scripts that do not access the service directly. The client tool provides certificate-authenticated access to managerial functions, so all the functions of the PhEDEx Data Service are available to it. The tool can be expanded by plug-ins which can combine or extend the client-side manipulation of data from the Data Service, providing a powerful environment for manipulating data within PhEDEx.

  17. Programmable pH buffers

    Science.gov (United States)

    Gough, Dara Van; Huber, Dale L.; Bunker, Bruce C.; Roberts, Mark E.

    2017-01-24

    A programmable pH buffer comprises a copolymer that changes pK.sub.a at a lower critical solution temperature (LCST) in water. The copolymer comprises a thermally programmable polymer that undergoes a hydrophobic-to-hydrophilic phase change at the LCST and an electrolytic polymer that exhibits acid-base properties that are responsive to the phase change. The programmable pH buffer can be used to sequester CO.sub.2 into water.

  18. Painleve analysis for a forced Korteveg-de Vries equation arisen in fluid dynamics of internal solitary waves

    Directory of Open Access Journals (Sweden)

    Zhang Sheng

    2015-01-01

    Full Text Available In this paper, Painleve analysis is used to test the Painleve integrability of a forced variable-coefficient extended Korteveg-de Vries equation which can describe the weakly-non-linear long internal solitary waves in the fluid with continuous stratification on density. The obtained results show that the equation is integrable under certain conditions. By virtue of the truncated Painleve expansion, a pair of new exact solutions to the equation is obtained.

  19. The Local Structure of Globalization. The Network Dynamics of Foreign Direct Investments in the International Electricity Industry

    Science.gov (United States)

    Koskinen, Johan; Lomi, Alessandro

    2013-05-01

    We study the evolution of the network of foreign direct investment (FDI) in the international electricity industry during the period 1994-2003. We assume that the ties in the network of investment relations between countries are created and deleted in continuous time, according to a conditional Gibbs distribution. This assumption allows us to take simultaneously into account the aggregate predictions of the well-established gravity model of international trade as well as local dependencies between network ties connecting the countries in our sample. According to the modified version of the gravity model that we specify, the probability of observing an investment tie between two countries depends on the mass of the economies involved, their physical distance, and the tendency of the network to self-organize into local configurations of network ties. While the limiting distribution of the data generating process is an exponential random graph model, we do not assume the system to be in equilibrium. We find evidence of the effects of the standard gravity model of international trade on evolution of the global FDI network. However, we also provide evidence of significant dyadic and extra-dyadic dependencies between investment ties that are typically ignored in available research. We show that local dependencies between national electricity industries are sufficient for explaining global properties of the network of foreign direct investments. We also show, however, that network dependencies vary significantly over time giving rise to a time-heterogeneous localized process of network evolution.

  20. Dynamic analysis of double-row self-aligning ball bearings due to applied loads, internal clearance, surface waviness and number of balls

    Science.gov (United States)

    Zhuo, Yaobin; Zhou, Xiaojun; Yang, Chenlong

    2014-11-01

    In this paper, a three degrees of freedom (dof) model was established for a double-row self-aligning ball bearing (SABB) system, and was applied to study the dynamic behavior of the system during starting process and constant speed rotating process. A mathematical model was developed concerning stiffness and damping characteristics of the bearing, as well as three-dimensional applied load, rotor centrifugal force, etc. Balls and races were all considered as nonlinear springs, and the contact force between ball and race was calculated based on classic Hertzian elastic contact deformation theory and deformation compatibility theory. The changes of each ball's contact force and loaded angle of each row were taken into account. In order to solve the nonlinear dynamical equilibrium equations of the system, these equations were rewritten as differential equations and the fourth order Runge-Kutta method was used to solve the equations iteratively. In order to verify accuracy of the dynamical model and correctness of the numerical solution method, a kind of SABB-BRF30 was chosen for case studies. The effects of several important governing parameters, such as radial and axial applied loads, normal internal, inner and outer races waviness, and number of balls were investigated. These parametric studies led to a complete characterization of the shaft-bearing system vibration transmission. The research provided a theoretical reference for new type bearing design, shaft-bearing system kinetic analysis, optimal design, etc.

  1. Pre-study of dynamic loads on the internals caused by a large pipe break in a BWR; Foerstudie av stroemningsinducerade laster paa interndelar vid brott i huvudcirkulationskretsarna i BWR

    Energy Technology Data Exchange (ETDEWEB)

    Marcinkiewicz, Jerzy; Lindgren, Anders [Det Norske Veritas Nuclear Technology AB, Stockholm (Sweden)

    2002-12-01

    Det Norske Veritas Nuclear Technology has performed a literature study of dynamic load on a BWR (Boiling Water Reactor) internals caused by a large pipe break. The goal of the study was to improve the knowledge about the physics of phenomena occurring in the RPV (Reactor Pressure Vessel) after pipe break in the main circulation system and also to make a review of calculation methods, models and computer programs including their capabilities when calculating the dynamic loads. The report presents description of relevant parts of a BWR, initial and boundary conditions, and phenomena determining the loads - rapid depressurization and propagation of pressure wave (including none-equilibrium). Furthermore, the report generally describes possible methodologies for calculating the dynamic loads on internals after the pipe break and the experiences from calculations the dynamic loads with different methods (computer programs) including comparisons with experimental data. Fluid-Structure Interaction methodology and its importance for calculation of dynamic loads on reactor internals is discussed based on experimental data. A very intensive research program for studying and calculating the dynamic loads on internals after pipe breaks has been performed in USA and Germany during the seventies and the eighties. Several computer programs have been developed and a number of large-scale experiments have been performed to calibrate the calculation methods. In spite of the fact that all experiments were performed for PWR several experiences should be valid also for BWR. These experiences, connected mainly to capabilities of computer programs calculating dynamic loads, are discussed in the report.

  2. A feasibility study of dynamic stress analysis inside a running internal combustion engine using synchrotron X-ray beams.

    Science.gov (United States)

    Baimpas, Nikolaos; Drakopoulos, Michael; Connolley, Thomas; Song, Xu; Pandazaras, Costas; Korsunsky, Alexander M

    2013-03-01

    The present investigation establishes the feasibility of using synchrotron-generated X-ray beams for time-resolved in situ imaging and diffraction of the interior components of an internal combustion engine during its operation. The demonstration experiment was carried out on beamline I12 (JEEP) at Diamond Light Source, UK. The external hutch of the JEEP instrument is a large-scale engineering test bed for complex in situ processing and simulation experiments. The hutch incorporates a large capacity translation and rotation table and a selection of detectors for monochromatic and white-beam diffraction and imaging. These capabilities were used to record X-ray movies of a motorcycle internal combustion engine running at 1850 r.p.m. and to measure strain inside the connecting rod via stroboscopic X-ray diffraction measurement. The high penetrating ability and high flux of the X-ray beam at JEEP allowed the observation of inlet and outlet valve motion, as well as that of the piston, connecting rod and the timing chain within the engine. Finally, the dynamic internal strain within the moving connecting rod was evaluated with an accuracy of ~50 × 10(-6).

  3. Communication between the Zinc and Nickel Sites in Dimeric HypA: Metal Recognition and pH Sensing

    International Nuclear Information System (INIS)

    Herbst, R.; Perovic, I.; Martin-Diaconescu, V.; O'Brien, K.; Chivers, P.; Sondej Pochapsky, S.; Pochapsky, T.; Maroney, M.

    2010-01-01

    Helicobacter pylori, a pathogen that colonizes the human stomach, requires the nickel-containing metalloenzymes urease and NiFe-hydrogenase to survive this low pH environment. The maturation of both enzymes depends on the metallochaperone, HypA. HypA contains two metal sites, an intrinsic zinc site and a low-affinity nickel binding site. X-ray absorption spectroscopy (XAS) shows that the structure of the intrinsic zinc site of HypA is dynamic and able to sense both nickel loading and pH changes. At pH 6.3, an internal pH that occurs during acid shock, the zinc site undergoes unprecedented ligand substitutions to convert from a Zn(Cys) 4 site to a Zn(His) 2 (Cys) 2 site. NMR spectroscopy shows that binding of Ni(II) to HypA results in paramagnetic broadening of resonances near the N-terminus. NOEs between the β-CH 2 protons of Zn cysteinyl ligands are consistent with a strand-swapped HypA dimer. Addition of nickel causes resonances from the zinc binding motif and other regions to double, indicating more than one conformation can exist in solution. Although the structure of the high-spin, 5-6 coordinate Ni(II) site is relatively unaffected by pH, the nickel binding stoichiometry is decreased from one per monomer to one per dimer at pH = 6.3. Mutation of any cysteine residue in the zinc binding motif results in a zinc site structure similar to that found for holo-WT-HypA at low pH and is unperturbed by the addition of nickel. Mutation of the histidines that flank the CXXC motifs results in a zinc site structure that is similar to holo-WT-HypA at neutral pH (Zn(Cys) 4 ) and is no longer responsive to nickel binding or pH changes. Using an in vitro urease activity assay, it is shown that the recombinant protein is sufficient for recovery of urease activity in cell lysate from a HypA deletion mutant, and that mutations in the zinc-binding motif result in a decrease in recovered urease activity. The results are interpreted in terms of a model wherein HypA controls the

  4. Communication between the Zinc and Nickel Sites in Dimeric HypA: Metal Recognition and pH Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Herbst, R.; Perovic, I; Martin-Diaconescu, V; O’Brien, K; Chivers, P; Sondej Pochapsky, S; Pochapsky, T; Maroney, M

    2010-01-01

    Helicobacter pylori, a pathogen that colonizes the human stomach, requires the nickel-containing metalloenzymes urease and NiFe-hydrogenase to survive this low pH environment. The maturation of both enzymes depends on the metallochaperone, HypA. HypA contains two metal sites, an intrinsic zinc site and a low-affinity nickel binding site. X-ray absorption spectroscopy (XAS) shows that the structure of the intrinsic zinc site of HypA is dynamic and able to sense both nickel loading and pH changes. At pH 6.3, an internal pH that occurs during acid shock, the zinc site undergoes unprecedented ligand substitutions to convert from a Zn(Cys){sub 4} site to a Zn(His){sub 2}(Cys){sub 2} site. NMR spectroscopy shows that binding of Ni(II) to HypA results in paramagnetic broadening of resonances near the N-terminus. NOEs between the {beta}-CH{sub 2} protons of Zn cysteinyl ligands are consistent with a strand-swapped HypA dimer. Addition of nickel causes resonances from the zinc binding motif and other regions to double, indicating more than one conformation can exist in solution. Although the structure of the high-spin, 5-6 coordinate Ni(II) site is relatively unaffected by pH, the nickel binding stoichiometry is decreased from one per monomer to one per dimer at pH = 6.3. Mutation of any cysteine residue in the zinc binding motif results in a zinc site structure similar to that found for holo-WT-HypA at low pH and is unperturbed by the addition of nickel. Mutation of the histidines that flank the CXXC motifs results in a zinc site structure that is similar to holo-WT-HypA at neutral pH (Zn(Cys){sub 4}) and is no longer responsive to nickel binding or pH changes. Using an in vitro urease activity assay, it is shown that the recombinant protein is sufficient for recovery of urease activity in cell lysate from a HypA deletion mutant, and that mutations in the zinc-binding motif result in a decrease in recovered urease activity. The results are interpreted in terms of a model

  5. Development and verification of coupled fluid-structural dynamic codes for stress analysis of reactor vessel internals under blowdown loading

    International Nuclear Information System (INIS)

    Krieg, R.; Schlechtendahl, E.G.

    1977-01-01

    YAQUIR has been applied to large PWR blowdown problems and compared with LECK results. The structural model of CYLDY2 and the fluid model of YAQUIR have been coupled in the code STRUYA. First tests with the fluid dynamic systems code FLUST have been successful. The incompressible fluid version of the 3D coupled code FLUX for HDR-geometry was checked against some analytical test cases and was used for evaluation of the eigenfrequencies of the coupled system. Several test cases were run with the two phase flow code SOLA-DF with satisfactory results. Remarkable agreement was found between YAQUIR results and experimental data obtained from shallow water analogy experiments. A test for investigation of nonequilibrium twophase flow dynamics has been specified in some detail. The test is to be performed early 1978 in the water loop of the IRB. Good agreement was found between the natural frequency predictions for the core barrel obtained from CYLDY2 and STRUDL/DYNAL. Work started on improvement of the beam mode treatment in CYLDY2. The name of this modified version will be CYLDY3. The fluiddynamic code SING1, based on an advanced singularity method and applicable to a broad class of highly transient, incompressible 3D-problems with negligible viscosity has been developed and tested. It will be used in connection with the planned laboratory experiments in order to investigate the effect of the core structure on the blowdown process. Coupling of SING1 with structural dynamics is on the way. (orig./RW) [de

  6. A new approach combining different MRI methods to provide detailed view on 2 swelling dynamics of xanthan tablets influencing drug release at different pH and 3 ionic strength

    OpenAIRE

    Sepe, Ana; Mikac, Urška; Baumgartner, Saša; Kristl, Julijana

    2015-01-01

    The key element in drug release from hydrophilic matrix tablets is the gel layer that regulates the penetration of water and controls drug dissolution and diffusion. We have selected magnetic resonance imaging (MRI) as the method of choice for visualizing the dynamic processes occurring during the swelling of xanthan tablets in a variety of media. The aims were (i) to develop a new method using MRI for accurate determination of penetration, swelling and erosion fronts, (ii) to investigate the...

  7. Hegemons, Leaders and Followers: A Game-Theoretic Approach to the Postwar Dynamics of International Political Economy

    Directory of Open Access Journals (Sweden)

    Kjell Hausken

    2015-08-01

    Full Text Available The article introduces the concept of hegemony to leadership theory, which has developed mainly as a critique of hegemonic stability theory. We argue that it makes sense to combine the two theories by introducing the concept of 'size' into neoliberal thinking about International Political Economy. We accept the neo-institutional hypothesis that a hegemon is not needed to provide public goods, and demonstrate with non-cooperative games how multiple leaders may jointly provide public goods. A game-theoretic model is developed illustrating with Nash equilibria the conditions under which a hegemon rationally switches from hegemony to leadership. It also shows why followers rationally switch from free-riding in their consumption of the public goods to taking part in leading, in the sense of contributing to covering the cost of the production of the public goods. The emergence of joint leadership leads to multiple equilibria in the sense of allowing for multiple stable leadership constellations. The actors are in a mixed-motive or coordination game where they have different preferences for the equilibria, and thus different preferences for which strategies to choose, and for who is to take part in covering the cost of the production of the public goods. Two aspects of joint leadership 'after hegemony' are treated, namely coercive and benevolent leadership on the one hand, and collective action in the sense of joint leadership on the other hand. Finally, future leadership constellations and the quest for international order are discussed.

  8. Evaluating nanoparticle sensor design for intracellular pH measurements.

    Science.gov (United States)

    Benjaminsen, Rikke V; Sun, Honghao; Henriksen, Jonas R; Christensen, Nynne M; Almdal, Kristoffer; Andresen, Thomas L

    2011-07-26

    Particle-based nanosensors have over the past decade been designed for optical fluorescent-based ratiometric measurements of pH in living cells. However, quantitative and time-resolved intracellular measurements of pH in endosomes and lysosomes using particle nanosensors are challenging, and there is a need to improve measurement methodology. In the present paper, we have successfully carried out time-resolved pH measurements in endosomes and lyosomes in living cells using nanoparticle sensors and show the importance of sensor choice for successful quantification. We have studied two nanoparticle-based sensor systems that are internalized by endocytosis and elucidated important factors in nanosensor design that should be considered in future development of new sensors. From our experiments it is clear that it is highly important to use sensors that have a broad measurement range, as erroneous quantification of pH is an unfortunate result when measuring pH too close to the limit of the sensitive range of the sensors. Triple-labeled nanosensors with a pH measurement range of 3.2-7.0, which was synthesized by adding two pH-sensitive fluorophores with different pK(a) to each sensor, seem to be a solution to some of the earlier problems found when measuring pH in the endosome-lysosome pathway.

  9. Dynamic light scattering and X-ray photoelectron spectroscopy characterization of PEGylated polymer nanocarriers: internal structure and surface properties.

    Science.gov (United States)

    Celasco, Edvige; Valente, Ilaria; Marchisio, Daniele L; Barresi, Antonello A

    2014-07-22

    In this work, nanospheres and nanocapsules are precipitated in confined impinging jet mixers through solvent displacement and characterized. Acetone and water are used as the solvent and antisolvent, respectively, together with polymethoxypolyethylene glycol cyanoacrylate-co-hexadecylcyanoacrylate and Miglyol as the copolymer and oil, respectively. Characterization is performed with dynamic light scattering, with electrophoretic measurements, and for the first time with X-ray photoelectron spectroscopy. Results show that the presence of polyethylene glycol chains seems to be more pronounced on the surface of nanospheres than on that of nanocapsules. The thickness of the copolymer layer in nanocapsules ranges from 1 to 10 nm, depending on the value of the oil:copolymer mass ratio. Fast dilution is confirmed to have a positive effect in suppressing aggregation but can induce further copolymer precipitation.

  10. Effect of pH on structure, function, and stability of mitochondrial carbonic anhydrase VA.

    Science.gov (United States)

    Idrees, Danish; Shahbaaz, Mohd; Bisetty, Krishna; Islam, Asimul; Ahmad, Faizan; Hassan, Md Imtaiyaz

    2017-02-01

    Mitochondrial carbonic anhydrase VA (CAVA) catalyzes the hydration of carbon dioxide to produce proton and bicarbonate which is primarily expressed in the mitochondrial matrix of liver, and involved in numerous physiological processes including lipogenesis, insulin secretion from pancreatic cells, ureagenesis, gluconeogenesis, and neuronal transmission. To understand the effect of pH on the structure, function, and stability of CAVA, we employed spectroscopic techniques such as circular dichroism, fluorescence, and absorbance measurements in wide range of pH (from pH 2.0 to pH 11.5). CAVA showed an aggregation at acidic pH range from pH 2.0 to pH 5.0. However, it remains stable and maintains its secondary structure in the pH range, pH 7.0-pH 11.5. Furthermore, this enzyme has an appreciable activity at more than pH 7.0 (7.0 < pH ≤ 11.5) with maximum activity at pH 9.0. The maximal values of k cat and k cat /K m at pH 9.0 are 3.7 × 10 6  s -1 and 5.5 × 10 7  M -1  s -1 , respectively. However, this enzyme loses its activity in the acidic pH range. We further performed 20-ns molecular dynamics simulation of CAVA to see the dynamics at different pH values. An excellent agreement was observed between in silico and in vitro studies. This study provides an insight into the activity of CAVA in the pH range of subcellular environment.

  11. Dynamical analysis of a PWR internals using super-elements in an integrated 3-D model model. Part 1: model description and static tests

    International Nuclear Information System (INIS)

    Jesus Miranda, C.A. de.

    1992-01-01

    An integrated 3-D model of a research PWR reactor core support internals structures was developed for its dynamic analyses. The static tests for the validation of the model are presented. There are about 90 super-elements with, approximately, 85000 degrees of freedom (DoF), 8200 masters DoF, 12000 elements with about 8400 thin shell elements. A DEC VAX computer 11/785 model and the ANSYS program were used. If impacts occurs the spectral seismic analysis will be changed to a non-linear one with direct integration of the displacement pulse derived from the seismic accelerogram. This last will be obtained from the seismic acceleration response spectra. (author)

  12. From e+e- to Heavy Ion Collisions - Proceedings of the XXX International Symposium on Multiparticle Dynamics

    Science.gov (United States)

    Csörgő, Tamás Hegyi, Sándor Kittel, Wolfram

    The Table of Contents for the book is as follows: * Preface * QCD IN MULTIPARTICLE PRODUCTION * QCD and multiparticle production - The status of the perturbative cascade * Test of QCD predictions for multiparticle production at LEP * Multijet final states in e+e- annihilation * Tests of QCD in two photon physics at LEP * Interplay between perturbative and non-perturbative QCD in three-jet events * QCD and hadronic final states at the LHC * Transverse energy and minijets in high energy collisions * Multiparticle production at RHIC and LHC: A classical point of view * High energy interaction with the nucleus in the perturbative QCD with Nc → ∞ * DIFFRACTIVE PRODUCTION AND SMALL-x * Introduction to low-x physics and diffraction * Low-x physics at HERA * Diffractive structure functions at the Tevatron * What is the experimental evidence for the BFKL Pomeron? * Self-organized criticality in gluon systems and its consequences * Scale anomaly and dipole scattering in QCD * Pomeron and AdS/CFT correspondence for QCD * INTERPLAY BETWEEN SOFT AND HARD PHENOMENA * Inclusive jet cross sections and BFKL dynamics searches in dijet cross sections * Soft and hard interactions in p bar{p} Collisions at √ s = 1800 and 630 GeV * Recent results on particle production from OPAL * New results on αs and optimized scales * Preliminary results of the standard model Higgs boson search at LEP 2 in 2000 * Ways to go between hard and soft QCD * Alternative scenarios for fragmentation of a gluonic Lund String * A simultaneous measurement of the QCD colour charges and the strong coupling from LEP multijet data * Branching processes and Koenigs function * Soft and hard QCD dynamics in J/ψ hadroproduction * HADRONIC FINAL STATES IN 1+1, 1+h AND h+h REACTIONS * Universality in hadron production in electron-positron, lepton-hadron and hadron-hadron reactions * Search for gluonic mesons in gluon jets * Vector-to-pseudoscalar and meson-to-baryon ratios in hadronic Z decays at LEP

  13. Commentary: PhDs in biochemistry education-5 years later.

    Science.gov (United States)

    Offerdahl, Erika G; Momsen, Jennifer L; Osgood, Marcy

    2014-01-01

    In this commentary, the discussion of PhDs in biochemistry education research is expanded to explore a number of diverse pathways leading to a competitive research program in biochemistry education research. © 2013 by The International Union of Biochemistry and Molecular Biology.

  14. A computational fluid dynamics analysis on stratified scavenging system of medium capacity two-stroke internal combustion engines

    Directory of Open Access Journals (Sweden)

    Pitta Srinivasa Rao

    2008-01-01

    Full Text Available The main objective of the present work is to make a computational study of stratified scavenging system in two-stroke medium capacity engines to reduce or to curb the emissions from the two-stroke engines. The 3-D flows within the cylinder are simulated using computational fluid dynamics and the code Fluent 6. Flow structures in the transfer ports and the exhaust port are predicted without the stratification and with the stratification, and are well predicted. The total pressure and velocity map from computation provided comprehensive information on the scavenging and stratification phenomenon. Analysis is carried out for the transfer ports flow and the extra port in the transfer port along with the exhaust port when the piston is moving from the top dead center to the bottom dead center, as the ports are closed, half open, three forth open, and full port opening. An unstructured cell is adopted for meshing the geometry created in CATIA software. Flow is simulated by solving governing equations namely conservation of mass momentum and energy using SIMPLE algorithm. Turbulence is modeled by high Reynolds number version k-e model. Experimental measurements are made for validating the numerical prediction. Good agreement is observed between predicted result and experimental data; that the stratification had significantly reduced the emissions and fuel economy is achieved.

  15. A Nonlinear Dynamic Subscale Model for Partially Resolved Numerical Simulation (PRNS)/Very Large Eddy Simulation (VLES) of Internal Non-Reacting Flows

    Science.gov (United States)

    Shih, Tsan-Hsing; Liu, nan-Suey

    2010-01-01

    A brief introduction of the temporal filter based partially resolved numerical simulation/very large eddy simulation approach (PRNS/VLES) and its distinct features are presented. A nonlinear dynamic subscale model and its advantages over the linear subscale eddy viscosity model are described. In addition, a guideline for conducting a PRNS/VLES simulation is provided. Results are presented for three turbulent internal flows. The first one is the turbulent pipe flow at low and high Reynolds numbers to illustrate the basic features of PRNS/VLES; the second one is the swirling turbulent flow in a LM6000 single injector to further demonstrate the differences in the calculated flow fields resulting from the nonlinear model versus the pure eddy viscosity model; the third one is a more complex turbulent flow generated in a single-element lean direct injection (LDI) combustor, the calculated result has demonstrated that the current PRNS/VLES approach is capable of capturing the dynamically important, unsteady turbulent structures while using a relatively coarse grid.

  16. Ca2+-associated triphasic pH changes in mitochondria during brown adipocyte activation.

    Science.gov (United States)

    Hou, Yanyan; Kitaguchi, Tetsuya; Kriszt, Rókus; Tseng, Yu-Hua; Raghunath, Michael; Suzuki, Madoka

    2017-08-01

    Brown adipocytes (BAs) are endowed with a high metabolic capacity for energy expenditure due to their high mitochondria content. While mitochondrial pH is dynamically regulated in response to stimulation and, in return, affects various metabolic processes, how mitochondrial pH is regulated during adrenergic stimulation-induced thermogenesis is unknown. We aimed to reveal the spatial and temporal dynamics of mitochondrial pH in stimulated BAs and the mechanisms behind the dynamic pH changes. A mitochondrial targeted pH-sensitive protein, mito-pHluorin, was constructed and transfected to BAs. Transfected BAs were stimulated by an adrenergic agonist, isoproterenol. The pH changes in mitochondria were characterized by dual-color imaging with indicators that monitor mitochondrial membrane potential and heat production. The mechanisms of pH changes were studied by examining the involvement of electron transport chain (ETC) activity and Ca 2+ profiles in mitochondria and the intracellular Ca 2+ store, the endoplasmic reticulum (ER). A triphasic mitochondrial pH change in BAs upon adrenergic stimulation was revealed. In comparison to a thermosensitive dye, we reveal that phases 1 and 2 of the pH increase precede thermogenesis, while phase 3, characterized by a pH decrease, occurs during thermogenesis. The mechanism of pH increase is partially related to ETC. In addition, the pH increase occurs concurrently with an increase in mitochondrial Ca 2+ . This Ca 2+ increase is contributed to by an influx from the ER, and it is further involved in mitochondrial pH regulation. We demonstrate that an increase in mitochondrial pH is implicated as an early event in adrenergically stimulated BAs. We further suggest that this pH increase may play a role in the potentiation of thermogenesis.

  17. Paulette Gray, Ph.D.

    Science.gov (United States)

    Paulette S. Gray, Ph.D. is the Director for the Division of Extramural Activities (DEA). As the director of the division, she is responsible for the overall scientific, fiscal, and administrative management of the division, including broad strategic planning, development, implementation, and evaluation.

  18. pH in Action

    NARCIS (Netherlands)

    Tijskens, L.M.M.; Biekman, E.S.A.

    2001-01-01

    Based on fundamental chemical relations, well-established in chemical engineering and chemical technology over almost a century, the effects of pH in food and agricultural products will be deduced for different situations and processes. Based on simple equilibria and dissociation of water, salts,

  19. Neuronal pH regulation

    DEFF Research Database (Denmark)

    Vorstrup, S; Jensen, K E; Thomsen, C

    1989-01-01

    The intracellular pH in the brain was studied in six healthy volunteers before and immediately after the administration of 2 g of acetazolamide. Phosphorus-31 nuclear magnetic resonance spectroscopy by a 1.5 tesla whole-body scanner was used. The chemical shift between the inorganic phosphate...

  20. Microwave spectrum, dipole moment, and internal dynamics of the methyl fluoride-carbonyl sulfide weakly bound complex.

    Science.gov (United States)

    Serafin, Michal M; Peebles, Sean A

    2008-02-21

    Rotational spectra for the normal and four isotopically substituted species of the 1:1 complex between methyl fluoride (H3CF) and carbonyl sulfide (OCS) have been measured using Fourier-transform microwave spectroscopy in the 5-16 GHz frequency region. The observed spectra fit well to a semirigid Watson Hamiltonian, and an analysis of the rotational constants has allowed a structure to be determined for this complex. The dipole moment vectors of the H3CF and OCS monomers are aligned approximately antiparallel with a C...C separation of 3.75(3) A and with an ab plane of symmetry. The values of the Pcc planar moments were found to be considerably different from the expected rigid values for all isotopologues. An estimate of approximately 14.5(50) cm-1 for the internal rotation barrier of the CH3 group with respect to the framework of the complex has been made using the Pcc values for the H3CF-OCS and D3CF-OCS isotopic species. Two structures, very close in energy and approximately related by a 60 degrees rotation about the C3 axis of the methyl fluoride, were identified by ab initio calculations at the MP2/6-311++G(2d,2p) level and provide reasonable agreement with the experimental rotational constants and dipole moment components.

  1. International cooperative research with Japan for the establishment of cooperation structure and technology for dynamic neutron radiography using HANARO

    International Nuclear Information System (INIS)

    Lim, I. C.; Sim, C. M.; Lee, B. H.; Choi, Y. S.; Baek, W. P.; Cha, J. E.; Yoon, B. J.; Chu, I. C.

    2007-07-01

    DNR is the technique to obtain radiography image continuously using a imaging system and Japan is the leading country in this field. Considering that no research has been performed to obtain quantitative parameters using DNR in Korea, it was necessary to establish a cooperative structure with Japanese experts and to develop the DNR technique throughout this project. The objectives of the project were to conduct 4 cooperative experiments using the HANARO BNCT facility and to establish a relationship with Japanese experts which makes it possible to maintain continuous communication. 4 experiments such as the void fraction and flow pattern measurement in a channel simulating HANARO fuel channel, observation of flow field in Pb/Bi field and the observation of cavity in a diesel engine nozzle were successfully completed. Also, the continuos communication and cooperation between the experts of two countries will be made. In this sense, this project is believed as a model project to use the mega research facility such as HANARO for the international cooperation

  2. Electron internal transport barrier formation and dynamics in the plasma core of the TJ-II stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Estrada, T [Laboratorio Nacional de Fusion por Confinamiento Magnetico, Asociacion Euratom-CIEMAT, 28040 Madrid (Spain); Krupnik, L [Institute of Plasma Physics, NSC ' KIPT' , Kharkov (Ukraine); Dreval, N [Institute of Plasma Physics, NSC ' KIPT' , Kharkov (Ukraine); Melnikov, A [Institute of Nuclear Fusion, RRC ' Kurchatov Institute' , Moscow, Russia (Russian Federation); Khrebtov, S M [Institute of Plasma Physics, NSC ' KIPT' , Kharkov (Ukraine); Hidalgo, C [Laboratorio Nacional de Fusion por Confinamiento Magnetico, Asociacion Euratom-CIEMAT, 28040 Madrid (Spain); Milligen, B van [Laboratorio Nacional de Fusion por Confinamiento Magnetico, Asociacion Euratom-CIEMAT, 28040 Madrid (Spain); Castejon, F [Laboratorio Nacional de Fusion por Confinamiento Magnetico, Asociacion Euratom-CIEMAT, 28040 Madrid (Spain); AscasIbar, E [Laboratorio Nacional de Fusion por Confinamiento Magnetico, Asociacion Euratom-CIEMAT, 28040 Madrid (Spain); Eliseev, L [Institute of Nuclear Fusion, RRC ' Kurchatov Institute' , Moscow, Russia (Russian Federation); Chmyga, A A [Institute of Plasma Physics, NSC ' KIPT' , Kharkov (Ukraine); Komarov, A D [Institute of Plasma Physics, NSC ' KIPT' , Kharkov (Ukraine); Kozachok, A S [Institute of Plasma Physics, NSC ' KIPT' , Kharkov (Ukraine); Tereshin, V [Institute of Plasma Physics, NSC ' KIPT' , Kharkov (Ukraine)

    2004-01-01

    The influence of magnetic topology on the formation of electron internal transport barriers (e-ITBs) has been studied experimentally in electron cyclotron heated plasmas in the stellarator TJ-II. e-ITB formation is characterized by an increase in core electron temperature and plasma potential. The positive radial electric field increases by a factor of 3 in the central plasma region when an e-ITB forms. The experiments reported demonstrate that the formation of an e-ITB depends on the magnetic configuration. Calculations of the modification of the rotational transform due to plasma current lead to the interpretation that the formation of an e-ITB can be triggered by positioning a low order rational surface close to the plasma core region. In configurations without any central low order rational, no barrier is formed for any accessible value of heating power. Different mechanisms associated with neoclassical/turbulent bifurcations and kinetic effects are put forward to explain the impact of magnetic topology on radial electric fields and confinement.

  3. Dynamic behavior of transport in normal and reversed shear plasmas with internal barriers in JT-60U

    International Nuclear Information System (INIS)

    Neudatchin, Sergi V.; Takizuka, Tomonori; Shirai, Hiroshi; Fujita, Takaaki; Isayama, Akihiko; Kamada, Yutaka; Koide, Yoshihiko

    2001-12-01

    Transport evolution in normal shear (NrS) and reversed shear (RS) JT-60U tokamak plasmas with internal transport barrier (ITB) is described as a combination of various fast and slow time scale processes. Abrupt in time (ms time scale) and wide in space (∼0.3 of minor radius) variations of electron and ion heat diffusivities χ e,i (δχ e,i ), which are called ITB-events and seen as simultaneous rise and decay of electron and ion temperatures in two spatial zones, are found for weak ITBs in both NrS and RS plasmas. Profiles of δχ e in RS plasmas with strong ITBs are usually localized near ITB foot inside smaller space region. The maximum of the heat flux variation is located near position of the minimum of safety factor in various RS plasmas, and variation is extended in positive shear region. Inward and outward heat pulse propagations created by the jump of χ e and the sawtooth-like crash are analyzed. Small values of χ e and the absence of heat pinch are found inside strong ITBs. Another non-local abrupt variations of χ e inside most of the plasma volume, including significant part of weak ITB inside RS zone of RS plasmas, are seen at the ELM-induced H-L transition and the L-H recovery. (author)

  4. A PROSPECTIVE STUDY ON FUNCTIONAL OUTCOME OF HUMERUS SHAFT FRACTURES TREATED WITH OPEN REDUCTION AND INTERNAL FIXATION WITH DYNAMIC COMPRESSION PLATE AND SCREWS

    Directory of Open Access Journals (Sweden)

    Vidyadhar S. Donimath

    2017-12-01

    Full Text Available BACKGROUND Fracture of the humerus shaft accounts to 3% to 5% of all fractures. Majority of the fractures are unstable due to distraction force of the gravity in the upper limb and strong muscle contraction leading to displacement. Internal fixation and early mobilisation is more stressed on than splinting and prolonged immobilisation to allow earlier mobilisation and rapid return to work. The aim of the study was to study the union rates and the functional outcome and complications associated with shaft humerus fractures in KIMS Hospital. MATERIALS AND METHODS A prospective study which was carried out from October 2015 to September 2017 in Karnataka Institute of Medical Sciences, Hubballi, Karnataka State, India. In this study period, 25 cases of fracture shaft of the humerus were treated by open reduction and internal fixation using DCP. Skeletally mature patients with fresh humerus diaphysis fractures were included in the study. Pathological fractures and Tscherne grade 2 and above, Gustilo Anderson type2 and above were excluded from the study. RESULTS In our series of 25 cases, there were 21 men and 4 women with average age of 42.5 years. Sixteen (64% cases were due to RTA and with predominance of right side. Transverse fractures were most common that is 15 (60% patients. Eleven (31% cases were having associated injuries. 92% of the fractures united with good to excellent outcome. There were 2 (8% cases of non-union due to infection and comminution. CONCLUSION Open reduction and internal fixation with dynamic compression plate is still the standard treatment of choice for fracture shaft of humerus achieving excellent to good functional outcome.

  5. Internal Dynamics and Ionization States of the Macrophage Migration Inhibitory Factor: Comparison Between Wild-Type and Mutant Forms

    International Nuclear Information System (INIS)

    Soares, T A.; Lins, R D.; Straatsma, TP; Briggs, J M.

    2002-01-01

    The macrophage migration inhibitory factor (MIF) is a cytokine which shares a common structural architecture and catalytic strategy with three isomerases: 4-oxalocrotonate tautomerase, 5-carboxymethyl-2-hydroxymuconate isomerase and D-dopachrome tautomerase. A highly conserved N-terminal proline acts as a base/acid during the proton transfer reaction catalyzed by these enzymes. Such unusual catalytic strategy appears to be possible only due to the N-terminal proline pKa be shifted to 5.0-6.0 units. Mutations of this residue result in a significant decrease of the catalytic activity of MIF. Two hypotheses have been proposed to explain the catalytic inefficiency of MIF: the lower basicity of primary amines with regard to secondary ones and the increased flexibility resulting from the replacement of a proline by residues like glycine. To investigate that, we have performed molecular dynamics simulations of MIF-wt and its mutant P1G as well as calculated the protonation properties of sever al mutant forms. It has been found that the N-terminal glycine does not show larger fluctuations compared to proline, but the former residue is more exposed to the solvent throughout the simulations. The apparent pKa of these residues displays very little change (as expected from the structural rigidity of MIF) and is not significantly affected by the surrounding ionizable residues. Instead, the hydrophobic character of the active site seems to be the main factor in determining the pKa of the N-terminal residue and the catalytic efficiency of MIF

  6. Effects of a strong magnetic field on internal gravity waves: trapping, phase mixing, reflection and dynamical chaos

    Science.gov (United States)

    Loi, Shyeh Tjing; Papaloizou, John C. B.

    2018-04-01

    The spectrum of oscillation modes of a star provides information not only about its material properties (e.g. mean density), but also its symmetries. Spherical symmetry can be broken by rotation and/or magnetic fields. It has been postulated that strong magnetic fields in the cores of some red giants are responsible for their anomalously weak dipole mode amplitudes (the "dipole dichotomy" problem), but a detailed understanding of how gravity waves interact with strong fields is thus far lacking. In this work, we attack the problem through a variety of analytical and numerical techniques, applied to a localised region centred on a null line of a confined axisymmetric magnetic field which is approximated as being cylindrically symmetric. We uncover a rich variety of phenomena that manifest when the field strength exceeds a critical value, beyond which the symmetry is drastically broken by the Lorentz force. When this threshold is reached, the spatial structure of the g-modes becomes heavily altered. The dynamics of wave packet propagation transitions from regular to chaotic, which is expected to fundamentally change the organisation of the mode spectrum. In addition, depending on their frequency and the orientation of field lines with respect to the stratification, waves impinging on different parts of the magnetised region are found to undergo either reflection or trapping. Trapping regions provide an avenue for energy loss through Alfvén wave phase mixing. Our results may find application in various astrophysical contexts, including the dipole dichotomy problem, the solar interior, and compact star oscillations.

  7. 3D simulation of the influence of internal mixing dynamics on the propagation of river plumes in Lake Constance

    Science.gov (United States)

    Pflugbeil, Thomas; Pöschke, Franziska; Noffke, Anna; Winde, Vera; Wolf, Thomas

    2017-04-01

    Lake Constance is one of most important drinking water resources in southern Germany. Furthermore, the lake and its catchment is a meaningful natural habitat as well as economical and cultural area. In this context, sustainable development and conservation of the lake ecosystem and drinking water quality is of high importance. However, anthropogenic pressures (e.g. waste water, land use, industry in catchment area) on the lake itself and its external inflows are high. The project "SeeZeichen" (ReWaM-project cluster by BMBF, funding number 02WRM1365) is investigating different immission pathways (groundwater, river, superficial inputs) and their impact on the water quality of Lake Constance. The investigation includes the direct inflow areas as well as the lake-wide context. The present simulation study investigates the mixing dynamics of Lake Constance and its impacts on river inflows and vice versa. It considers different seasonal (mixing and stratification periods), hydrological (flood events, average and low discharge) and transport conditions (sediment loads). The simulations are focused on two rivers: The River Alpenrhein delivers about 60 % of water and material input into Lake Constance. The River Schussen was chosen since it is highly anthropogenic influenced. For this purpose, a high-resolution three-dimensional hydrodynamic model of the Lake Constance is set up with Delft3D-Flow model system. The model is calibrated and validated with long term data sets of water levels, discharges and temperatures. The model results will be analysed for residence times of river water within the lake and particle distributions to evaluate potential impacts of river plume water constituents on the general water quality of the lake.

  8. 6th International RILEM PhD Workshop

    CERN Document Server

    Gulikers, Joost; Polder, Rob

    2015-01-01

    This book presents key advances in the modeling of reinforcement corrosion and concrete durability. It also examines various further aspects of reinforcement corrosion and concrete durability, striking a balance between modeling and testing. Particular attention is paid to innovative treatments for avoiding deterioration, and to methods for modeling performance in a real environment. Some basic aspects related to non-destructive testing techniques are also discussed. Deterioration-related topics addressed in the book include the basis for modeling alkali-silica reactions, chloride diffusion and the development of concrete microstructure; measurement-related topics include cathodic protection, polarization resistance and resistivity. A combined approach using the AFM technique and polarization measurements is examined, and the relation between cracking and corrosion and the treatment of concrete with hydrophobes or innovative products such as hydrotalcite is also discussed.

  9. The Paramecium germline genome provides a niche for intragenic parasitic DNA: evolutionary dynamics of internal eliminated sequences.

    Science.gov (United States)

    Arnaiz, Olivier; Mathy, Nathalie; Baudry, Céline; Malinsky, Sophie; Aury, Jean-Marc; Denby Wilkes, Cyril; Garnier, Olivier; Labadie, Karine; Lauderdale, Benjamin E; Le Mouël, Anne; Marmignon, Antoine; Nowacki, Mariusz; Poulain, Julie; Prajer, Malgorzata; Wincker, Patrick; Meyer, Eric; Duharcourt, Sandra; Duret, Laurent; Bétermier, Mireille; Sperling, Linda

    2012-01-01

    Insertions of parasitic DNA within coding sequences are usually deleterious and are generally counter-selected during evolution. Thanks to nuclear dimorphism, ciliates provide unique models to study the fate of such insertions. Their germline genome undergoes extensive rearrangements during development of a new somatic macronucleus from the germline micronucleus following sexual events. In Paramecium, these rearrangements include precise excision of unique-copy Internal Eliminated Sequences (IES) from the somatic DNA, requiring the activity of a domesticated piggyBac transposase, PiggyMac. We have sequenced Paramecium tetraurelia germline DNA, establishing a genome-wide catalogue of -45,000 IESs, in order to gain insight into their evolutionary origin and excision mechanism. We obtained direct evidence that PiggyMac is required for excision of all IESs. Homology with known P. tetraurelia Tc1/mariner transposons, described here, indicates that at least a fraction of IESs derive from these elements. Most IES insertions occurred before a recent whole-genome duplication that preceded diversification of the P. aurelia species complex, but IES invasion of the Paramecium genome appears to be an ongoing process. Once inserted, IESs decay rapidly by accumulation of deletions and point substitutions. Over 90% of the IESs are shorter than 150 bp and present a remarkable size distribution with a -10 bp periodicity, corresponding to the helical repeat of double-stranded DNA and suggesting DNA loop formation during assembly of a transpososome-like excision complex. IESs are equally frequent within and between coding sequences; however, excision is not 100% efficient and there is selective pressure against IES insertions, in particular within highly expressed genes. We discuss the possibility that ancient domestication of a piggyBac transposase favored subsequent propagation of transposons throughout the germline by allowing insertions in coding sequences, a fraction of the

  10. The Paramecium germline genome provides a niche for intragenic parasitic DNA: evolutionary dynamics of internal eliminated sequences.

    Directory of Open Access Journals (Sweden)

    Olivier Arnaiz

    Full Text Available Insertions of parasitic DNA within coding sequences are usually deleterious and are generally counter-selected during evolution. Thanks to nuclear dimorphism, ciliates provide unique models to study the fate of such insertions. Their germline genome undergoes extensive rearrangements during development of a new somatic macronucleus from the germline micronucleus following sexual events. In Paramecium, these rearrangements include precise excision of unique-copy Internal Eliminated Sequences (IES from the somatic DNA, requiring the activity of a domesticated piggyBac transposase, PiggyMac. We have sequenced Paramecium tetraurelia germline DNA, establishing a genome-wide catalogue of -45,000 IESs, in order to gain insight into their evolutionary origin and excision mechanism. We obtained direct evidence that PiggyMac is required for excision of all IESs. Homology with known P. tetraurelia Tc1/mariner transposons, described here, indicates that at least a fraction of IESs derive from these elements. Most IES insertions occurred before a recent whole-genome duplication that preceded diversification of the P. aurelia species complex, but IES invasion of the Paramecium genome appears to be an ongoing process. Once inserted, IESs decay rapidly by accumulation of deletions and point substitutions. Over 90% of the IESs are shorter than 150 bp and present a remarkable size distribution with a -10 bp periodicity, corresponding to the helical repeat of double-stranded DNA and suggesting DNA loop formation during assembly of a transpososome-like excision complex. IESs are equally frequent within and between coding sequences; however, excision is not 100% efficient and there is selective pressure against IES insertions, in particular within highly expressed genes. We discuss the possibility that ancient domestication of a piggyBac transposase favored subsequent propagation of transposons throughout the germline by allowing insertions in coding sequences, a

  11. Proton dynamics in cancer.

    Science.gov (United States)

    Huber, Veronica; De Milito, Angelo; Harguindey, Salvador; Reshkin, Stephan J; Wahl, Miriam L; Rauch, Cyril; Chiesi, Antonio; Pouysségur, Jacques; Gatenby, Robert A; Rivoltini, Licia; Fais, Stefano

    2010-06-15

    Cancer remains a leading cause of death in the world today. Despite decades of research to identify novel therapeutic approaches, durable regressions of metastatic disease are still scanty and survival benefits often negligible. While the current strategy is mostly converging on target-therapies aimed at selectively affecting altered molecular pathways in tumor cells, evidences are in parallel pointing to cell metabolism as a potential Achilles' heel of cancer, to be disrupted for achieving therapeutic benefit. Critical differences in the metabolism of tumor versus normal cells, which include abnormal glycolysis, high lactic acid production, protons accumulation and reversed intra-extracellular pH gradients, make tumor site a hostile microenvironment where only cancer cells can proliferate and survive. Inhibiting these pathways by blocking proton pumps and transporters may deprive cancer cells of a key mechanism of detoxification and thus represent a novel strategy for a pleiotropic and multifaceted suppression of cancer cell growth.Research groups scattered all over the world have recently started to investigate various aspects of proton dynamics in cancer cells with quite encouraging preliminary results. The intent of unifying investigators involved in this research line led to the formation of the "International Society for Proton Dynamics in Cancer" (ISPDC) in January 2010. This is the manifesto of the newly formed society where both basic and clinical investigators are called to foster translational research and stimulate interdisciplinary collaboration for the development of more specific and less toxic therapeutic strategies based on proton dynamics in tumor cell biology.

  12. Proton dynamics in cancer

    Directory of Open Access Journals (Sweden)

    Pouysségur Jacques

    2010-06-01

    Full Text Available Abstract Cancer remains a leading cause of death in the world today. Despite decades of research to identify novel therapeutic approaches, durable regressions of metastatic disease are still scanty and survival benefits often negligible. While the current strategy is mostly converging on target-therapies aimed at selectively affecting altered molecular pathways in tumor cells, evidences are in parallel pointing to cell metabolism as a potential Achilles' heel of cancer, to be disrupted for achieving therapeutic benefit. Critical differences in the metabolism of tumor versus normal cells, which include abnormal glycolysis, high lactic acid production, protons accumulation and reversed intra-extracellular pH gradients, make tumor site a hostile microenvironment where only cancer cells can proliferate and survive. Inhibiting these pathways by blocking proton pumps and transporters may deprive cancer cells of a key mechanism of detoxification and thus represent a novel strategy for a pleiotropic and multifaceted suppression of cancer cell growth. Research groups scattered all over the world have recently started to investigate various aspects of proton dynamics in cancer cells with quite encouraging preliminary results. The intent of unifying investigators involved in this research line led to the formation of the "International Society for Proton Dynamics in Cancer" (ISPDC in January 2010. This is the manifesto of the newly formed society where both basic and clinical investigators are called to foster translational research and stimulate interdisciplinary collaboration for the development of more specific and less toxic therapeutic strategies based on proton dynamics in tumor cell biology.

  13. Industrial PhD report: Sustainable Innovation

    DEFF Research Database (Denmark)

    Olesen, Gitte Gylling Hammershøj

    2011-01-01

    Erhvervs PhD rapport udarbejdet i tilknytning til Erhvervs PhD kurset der er obligatorisk for Erhvervs PhD studerende. Rapporten omhandler relationer melllem den akademiske verden og industrien i sammenhæng med PhD projektet, betragtet og analyseret gennem teori om bæredygtig innovation....

  14. International Humanitarian Award.

    Science.gov (United States)

    2017-12-01

    The International Humanitarian Award recognizes extraordinary humanitarian services and activism by psychologists, including professional and volunteer work conducted primarily in the field with underserved populations. Award recipients are psychologists who, by their extraordinary service at a difficult time, improve the lives and contribute to the well-being of people in a large or small geographic area anywhere in the world. The 2017 recipient of the APA International Humanitarian Award was selected by the 2016 Committee on International Relations in Psychology (CIRP). The members of the 2016 CIRP were Melissa Morgan Consoli, PhD, and Arpana G. Inman, PhD (Co-chairs); Rehman Abdulrehman, PhD; Gonzalo Bacigalupe, EdD; Frederic Bemak, EdD; Brigitte Khoury, PhD; Susan Nolan, PhD; Nancy Sidun, PsyD; and Danny Wedding, PhD. Dr. Morgan Consoli, Dr. Inman, Dr. Nolan, and Doctor Sidun were members of the subcommittee for the 2017 award. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. Identification of a molecular pH sensor in coral.

    Science.gov (United States)

    Barott, Katie L; Barron, Megan E; Tresguerres, Martin

    2017-11-15

    Maintaining stable intracellular pH (pHi) is essential for homeostasis, and requires the ability to both sense pH changes that may result from internal and external sources, and to regulate downstream compensatory pH pathways. Here we identified the cAMP-producing enzyme soluble adenylyl cyclase (sAC) as the first molecular pH sensor in corals. sAC protein was detected throughout coral tissues, including those involved in symbiosis and calcification. Application of a sAC-specific inhibitor caused significant and reversible pHi acidosis in isolated coral cells under both dark and light conditions, indicating sAC is essential for sensing and regulating pHi perturbations caused by respiration and photosynthesis. Furthermore, pHi regulation during external acidification was also dependent on sAC activity. Thus, sAC is a sensor and regulator of pH disturbances from both metabolic and external origin in corals. Since sAC is present in all coral cell types, and the cAMP pathway can regulate virtually every aspect of cell physiology through post-translational modifications of proteins, sAC is likely to trigger multiple homeostatic mechanisms in response to pH disturbances. This is also the first evidence that sAC modulates pHi in any non-mammalian animal. Since corals are basal metazoans, our results indicate this function is evolutionarily conserved across animals. © 2017 The Author(s).

  16. Long term reduction of Caesium and Strontium transfer factors from soil in foodstuff and dynamics of internal doses for a russian population after the Chernobyl accident

    International Nuclear Information System (INIS)

    Shutov, V.N.; Bruk, J.Ja.; Travnikova, I.G.; Balonov, M.I.

    2002-01-01

    The model of the formation of the internal doses for the population living on the territory contaminated after the Chernobyl accident is described. Model parameters were obtained on the base of natural measurements results implemented in the different terms after the accident. The data on the caesium radionuclides content in the bodies of the inhabitants measurements were priority for the internal exposure dose estimation. In the case of the absence of such information, the results of the radionuclides content in the food products analysis or the data on the soil types prevailing in the areas of settlements, were used for the calculations. The data were obtained during 1986-2001 as a result of monitoring of contaminated areas in Russia that considerably differ in their soil and climate conditions, the levels of 1 37C s and 9 0S r surface activity on soil and types of countermeasures applied. A summary of effective half-lives (T 1/2 ) of 1 37C s and 9 0S r aggregated transfer factors (Tag) from soil into agricultural and natural products observed after the Chernobyl fallout is given. The short term decrease of 1 37C s Tag from soil into milk and beef during two months after fallout were observed - T 1/2 varied from 13 d to 36 d in depend on the part of dry and wet fallout. The studies between autumn 1986 and 1991 suggest a decrease in the 1 37C s Tag with T 1/2 /2 =1-2 years. From 5-6 years after deposition onwards T 1/2 /2 of 1 37 Cs and 9 0S r Tag's in the range of 8 to 21 years were observed. Effective half-lives of 1 37C s Tag's for foods from semi-natural ecosystems (mushrooms, berries, game, fish) are longer (up to tens years). On at least for some natural products the decrease seems to be only to radioactive decay. Comparison of the data on the dynamics of 1 37C s content in agricultural and natural food products indicates that the contribution of the latter in the internal dose of population grows with each year after fallout, and can reach in the remote

  17. Dynamic Analysis of Coolant Channel and Its Internals of Indian 540 MWe PHWR Reactor

    Directory of Open Access Journals (Sweden)

    A. Rama Rao

    2008-04-01

    Full Text Available The horizontal coolant channel is one of the important parts of primary heat transport system in PHWR type of reactors. There are in all 392 channels in the core of Indian 540 MWe reactor. Each channel houses 13 natural uranium fuel bundles and shielding and sealing plugs one each on either side of the channel. The heavy water coolant flows through the coolant channel and carries the nuclear heat to outside the core for steam generation and power production in the turbo-generator. India has commissioned one 540 MWe PHWR reactor in September 2005 and another similar unit will be going into operation very shortly. For a complete dynamic study of the channel and its internals under the influence of high coolant flow, experimental and modeling studies have been carried out. A good correlation has been achieved between the results of experimental and analytical models. The operating life of a typical coolant channel typically ranges from 10 to 15 full-power years. Towards the end of its operating life, its health monitoring becomes an important activity. Vibration diagnosis plays an important role as a tool for life management of coolant. Through the study of dynamic characteristics of the coolant channel under simulated loading condition, an attempt has been made to develop a diagnostics to monitor the health of the coolant channel over its operating life. A study has been also carried out to characterize the fuel vibration under different flow condition.

  18. Cyclical Dynamics Of The «External» And «Internal» Environments Of Business-Organizations In Gr-Management

    Directory of Open Access Journals (Sweden)

    A. A. Degtyarev

    2018-01-01

    Full Text Available Within current conditions large business seeks to more actively influence processes of public state policy formulation and implementation connected with regulation of the economy and allocation of public resources. To ensure growing and systemic influence on the processes of government decision making, corporations promote economic interests by creating systems of controlled communications and relations with state bodies (SB. This field of professional activity identified as «GR» (Government Relations is a specific type of management activity, specific cross-sectoral (cross-area management of interactions between business companies (and other non-state actors and the state authorities, located at the crossing of three basic sectors of governance (government, business and social (nonprofit organizations. Professional functions on establishing and maintaining relations between business and government are conducted by GR-departments of large companies, specialized consulting firms and business associations. The complexity of those activities for business organizations proceeds from its specific location at the intersection of two environments (sectors: internal (in-house and external (political and public ones. This means that GR-specialist tries to consider the interests of these counterparties and identify points of intersection, where common interests can develop into business cooperation, and this may also contribute to the constructive involvement of business in shaping public policy. During such activities GR-specialist regularly faces the practical problems of frequent temporary error (“temporal asynchrony” and low level of spatial contingency (“spatial incongruence” between the “sectoral (environmental” types of managerial dynamics and their autonomous rhythms and paces, special sectoral functioning and development strategies, deployed within each of these sectors (industry business strategy vs public policy area and specific

  19. A ph sensor based on a flexible substrate

    Science.gov (United States)

    Huang, Wen-Ding

    implanted inside the esophagus. Our pH electrode can monitor the pH changes of gastric juice in real time when the reflux happening in the esophagus. Our micro flexible pH sensor performed clear responses in each distinct pH reflux episode quickly and accurately comparing with the other commercial pH monitoring system. For the food freshness monitoring applications, we used the flexible pH sensor as a freshness indicator to monitor the pH changing profile during the food spoilage procedure. The sensor was then embedded with radio frequency identification (RFID) based passive telemetry enabling remote monitoring of food freshness. In the result, our pH-wireless RFID system presented 633Hz/pH of the sensitivity in the frequency calibration. The calibration of stability and dynamical response of the RFID system were also demonstrated before the test on food freshness monitoring. Finally, a white fish meat for long term spoilage procedure monitoring was applied and tested by using our wireless IrOx pH sensing system. Our RFID pH sensing module is able to monitor, collect and transmit the pH information continuously for 18 hours during the food spoilage procedure. In this dissertation, a micro size of IrOx/AgCl pH sensor was fabricated on a flexible substrate. The physical properties of the IrO x thin film was verified in the work. The different sensing capability such as the sensitivity, stability, reversibility, response time, repeatability, selectivity, and temperature dependence was then demonstrated in this work. After the different in-vitro tests, the pH sensor were embedded with our passive RFID circuitry for the in-vivo GERD diagnosis and food freshness monitoring application. Our wireless pH sensing system was able to deliver the accurate and quick pH sensing data wirelessly. In conclusion, our deformable IrOx pH electrodes have been demonstrated with the advantages of accommodating and conforming sensors in small spaces or curved surfaces. This miniature IrOx pH sensor

  20. Effects of the international soybean trade on the dynamics of Gross Primary Productivity in soybean-producing regions in China and Brazil

    Science.gov (United States)

    Viña, A.; Silva, R. F. B. D.; Yang, H.; Liu, J.

    2017-12-01

    The international trade of agricultural commodities, such as soybean, is driven by a series of pull and push factors linked to market demand. These in turn fluctuate based on changes in economic affluence, infrastructure development, and socioeconomic homogenization, among others, in both sending and receiving systems. While many studies have analyzed some of these push/pull factors and their environmental effects in either sending or receiving systems, few studies have assessed these effects simultaneously in both sending and receiving systems. This study evaluates the effects of the soybean trade between Brazil and China on the spatio-temporal patterns of gross primary productivity (GPP) in both sending and receiving systems. The GPP is a measure of the amount of biomass produced through photosynthesis across space and through time. This metric is directly related with the amount of carbon that is sequestered from the atmosphere, and thus is related with the impacts of land use/cover dynamics on global climate change. The spatio-temporal patterns of both GPP and land use/cover were evaluated simultaneously in two soybean-producing regions (state of Mato Grosso in Brazil, and Heilongjiang province in China) through the use of surface reflectance data acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA's Terra satellite, combined with a production efficiency model (PEM) entirely based on remotely sensed data. Results from this analysis provide new insights on the consequences of the international trade at local/regional scales, and allow assessing how changes in market demand for agricultural commodities may generate drastic environmental effects in both sending and receiving systems, with global implications on carbon sequestration and thus on climate change.

  1. Alkaline pH sensor molecules.

    Science.gov (United States)

    Murayama, Takashi; Maruyama, Ichiro N

    2015-11-01

    Animals can survive only within a narrow pH range. This requires continual monitoring of environmental and body-fluid pH. Although a variety of acidic pH sensor molecules have been reported, alkaline pH sensor function is not well understood. This Review describes neuronal alkaline pH sensors, grouped according to whether they monitor extracellular or intracellular alkaline pH. Extracellular sensors include the receptor-type guanylyl cyclase, the insulin receptor-related receptor, ligand-gated Cl- channels, connexin hemichannels, two-pore-domain K+ channels, and transient receptor potential (TRP) channels. Intracellular sensors include TRP channels and gap junction channels. Identification of molecular mechanisms underlying alkaline pH sensing is crucial for understanding how animals respond to environmental alkaline pH and how body-fluid pH is maintained within a narrow range. © 2015 Wiley Periodicals, Inc.

  2. The dynamics of security provision in the aftermath of war : How international efforts to contribute to security in post-settlement countries relate to national and local perceptions and practices of security

    NARCIS (Netherlands)

    Willems, R.C.

    2013-01-01

    This thesis is based on field research in eastern Democratic Republic of the Congo, Burundi and South Sudan and looks at the dynamics of security provisioning in post-settlement contexts. A particular focus is on international security interventions, which are constituted by Disarmament,

  3. A networked pathway to the PhD: The African-Norwegian case of ...

    African Journals Online (AJOL)

    How do PhD students become socialised into the professional world of academic work? This article pays attention to a 'networked' support pathway towards a PhD. The network constitutes an international research collaboration through a programme called Productive Learning Cultures (PLC) (2002-2011) between Norway ...

  4. Low pH Cements

    International Nuclear Information System (INIS)

    Savage, David; Benbow, Steven

    2007-05-01

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit ≤ 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio ≤ 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  5. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit {<=} 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio {<=} 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  6. Proceedings of the ICTSS 2012 PhD Workshop - Preface

    DEFF Research Database (Denmark)

    Nielsen, Brian; Weise, Carsten

    2012-01-01

    and their thesis work and receive constructive feedback from experts in the field as well as from peers. Also it is an opportunity for researchers to get an insight into new research topics in the field. Ph.D. students at any stage of their doctoral studies may participate. Seven abstracts were submitted......This technical report contains the proceedings of the Ph.D. Workshop held in conjunction with the The 24th IFIP Int. Conference on Testing Software and Systems (ICTSS'12) in Aalborg, Denmark, November 19, 2012. The well‐established ICTSS series of international conferences addresses the conceptual......, theoretic, and practical challenges of testing software systems, including communication protocols, services, distributed platforms, middleware, embedded systems, and security infrastructures. The aims of the ICTSS Doctoral Workshop is to provide a forum for PhD students to present preliminary results...

  7. Prevalence and Associated Factors of Secondhand Smoke Exposure among Internal Chinese Migrant Women of Reproductive Age: Evidence from China's Labor-Force Dynamic Survey.

    Science.gov (United States)

    Gong, Xiao; Luo, Xiaofeng; Ling, Li

    2016-04-01

    Secondhand smoke (SHS) is a major risk factor for poor health outcomes among women in China, where proportionately few women smoke. This is especially the case as it pertains to women's reproductive health, specifically migrant women who are exposed to SHS more than the population at large. There are several factors which may increase migrant women's risk of SHS exposure. This paper aims to investigate the prevalence and associated factors of SHS exposure among internal Chinese migrant women of reproductive age. The data used were derived from the 2014 Chinese Labor Dynamic Survey, a national representative panel survey. The age-adjusted rate of SHS exposure of women of reproductive age with migration experience was of 43.46% (95% CI: 40.73%-46.40%), higher than those without migration experience (35.28% (95% CI: 33.66%-36.97%)). Multivariate analysis showed that participants with a marital status of "Widowed" had statistically lower exposure rates, while those with a status of "Cohabitation" had statistically higher exposure. Those with an undergraduate degree or above had statistically lower SHS exposure. Those with increasing levels of social support, and those who currently smoke or drink alcohol, had statistically higher SHS exposure. Participants' different work-places had an effect on their SHS exposure, with outdoor workers statistically more exposed. Our findings suggest that urgent tobacco control measures should be taken to reduce smoking prevalence and SHS exposure. Specific attention should be paid to protecting migrant women of reproductive age from SHS.

  8. Estimation of electric fields and currents from International Magnetospheric Study magnetometer data for the CDAW 6 intervals: Implications for substorm dynamics

    International Nuclear Information System (INIS)

    Kamide, Y.; Baumjohann, W.

    1985-01-01

    Using a recently developed numerical scheme combined with International Magnetospheric Study magnetometer data and the Rice University Ionospheric conductivity model as input, the global distribution of the key ionospheric parameters is estimated for the Coordinated Data Analysis Workshop (CDAW) 6 intervals. These outputs include ionospheric electric fields and currents, field-aligned currents and Joule heat production rate at high latitudes, and are compiled in the form of a color movie film, which demonstrates dynamics of substorm changes of the three-dimensional current system as well as of the associated potential pattern. The present paper gives, on the basis of the space-time distribution of the key parameters, the substorm time frame that can be referenced to in terms of the substorm phases when discussing some other magnetospheric and ionospheric records. The distinction between ''substorm expansion'' and ''enhanced convection'' current systems is presented on the basis of the conventional equivalent current and potential patterns and ''true'' ionospheric currents. Although the auroral electrojets flow rather contiguously throughout the dark sector, there are several separate source regions of Joule heating from the electrojet currents. This indicates that the relative importance of the ionospheric conductivity and the electric field in the ionospheric currents varies considerably depending upon latitude and local time. A possible difference in the generation mechanisms of isolated and continuous substorm activity is also discussed to some extent in the light of the two CDAW 6 intervals

  9. Engineering a pH responsive pore forming protein.

    Science.gov (United States)

    Kisovec, Matic; Rezelj, Saša; Knap, Primož; Cajnko, Miša Mojca; Caserman, Simon; Flašker, Ajda; Žnidaršič, Nada; Repič, Matej; Mavri, Janez; Ruan, Yi; Scheuring, Simon; Podobnik, Marjetka; Anderluh, Gregor

    2017-02-08

    Listeriolysin O (LLO) is a cytolysin capable of forming pores in cholesterol-rich lipid membranes of host cells. It is conveniently suited for engineering a pH-governed responsiveness, due to a pH sensor identified in its structure that was shown before to affect its stability. Here we introduced a new level of control of its hemolytic activity by making a variant with hemolytic activity that was pH-dependent. Based on detailed structural analysis coupled with molecular dynamics and mutational analysis, we found that the bulky side chain of Tyr406 allosterically affects the pH sensor. Molecular dynamics simulation further suggested which other amino acid residues may also allosterically influence the pH-sensor. LLO was engineered to the point where it can, in a pH-regulated manner, perforate artificial and cellular membranes. The single mutant Tyr406Ala bound to membranes and oligomerized similarly to the wild-type LLO, however, the final membrane insertion step was pH-affected by the introduced mutation. We show that the mutant toxin can be activated at the surface of artificial membranes or living cells by a single wash with slightly acidic pH buffer. Y406A mutant has a high potential in development of novel nanobiotechnological applications such as controlled release of substances or as a sensor of environmental pH.

  10. Engineering a pH responsive pore forming protein

    Science.gov (United States)

    Kisovec, Matic; Rezelj, Saša; Knap, Primož; Cajnko, Miša Mojca; Caserman, Simon; Flašker, Ajda; Žnidaršič, Nada; Repič, Matej; Mavri, Janez; Ruan, Yi; Scheuring, Simon; Podobnik, Marjetka; Anderluh, Gregor

    2017-02-01

    Listeriolysin O (LLO) is a cytolysin capable of forming pores in cholesterol-rich lipid membranes of host cells. It is conveniently suited for engineering a pH-governed responsiveness, due to a pH sensor identified in its structure that was shown before to affect its stability. Here we introduced a new level of control of its hemolytic activity by making a variant with hemolytic activity that was pH-dependent. Based on detailed structural analysis coupled with molecular dynamics and mutational analysis, we found that the bulky side chain of Tyr406 allosterically affects the pH sensor. Molecular dynamics simulation further suggested which other amino acid residues may also allosterically influence the pH-sensor. LLO was engineered to the point where it can, in a pH-regulated manner, perforate artificial and cellular membranes. The single mutant Tyr406Ala bound to membranes and oligomerized similarly to the wild-type LLO, however, the final membrane insertion step was pH-affected by the introduced mutation. We show that the mutant toxin can be activated at the surface of artificial membranes or living cells by a single wash with slightly acidic pH buffer. Y406A mutant has a high potential in development of novel nanobiotechnological applications such as controlled release of substances or as a sensor of environmental pH.

  11. Graphite Screen-Printed Electrodes Applied for the Accurate and Reagentless Sensing of pH.

    Science.gov (United States)

    Galdino, Flávia E; Smith, Jamie P; Kwamou, Sophie I; Kampouris, Dimitrios K; Iniesta, Jesus; Smith, Graham C; Bonacin, Juliano A; Banks, Craig E

    2015-12-01

    A reagentless pH sensor based upon disposable and economical graphite screen-printed electrodes (GSPEs) is demonstrated for the first time. The voltammetric pH sensor utilizes GSPEs which are chemically pretreated to form surface immobilized oxygenated species that, when their redox behavior is monitored, give a Nernstian response over a large pH range (1-13). An excellent experimental correlation is observed between the voltammetric potential and pH over the entire pH range of 1-13 providing a simple approach with which to monitor solution pH. Such a linear response over this dynamic pH range is not usually expected but rather deviation from linearity is encountered at alkaline pH values; absence of this has previously been attributed to a change in the pKa value of surface immobilized groups from that of solution phase species. This non-deviation, which is observed here in the case of our facile produced reagentless pH sensor and also reported in the literature for pH sensitive compounds immobilized upon carbon electrodes/surfaces, where a linear response is observed over the entire pH range, is explained alternatively for the first time. The performance of the GSPE pH sensor is also directly compared with a glass pH probe and applied to the measurement of pH in "real" unbuffered samples where an excellent correlation between the two protocols is observed validating the proposed GSPE pH sensor.

  12. Intracellular pH and 42.00 C heat response of CHO cells cultured at pH 6.6

    International Nuclear Information System (INIS)

    Cook, J.A.; Fox, M.H.

    1987-01-01

    The authors previously reported that cells under chronic low pH (6.6) conditions have altered thermotolerance. They further characterized both the doubling time (t/sub d/) and the internal pH (pH/sub 1/) of CHO cells continuously cultured at pH 6.6 for times greater than one year. The following differences were noted: 1) A t/sub d/ of 16 hr compared to a t/sub d/ of 12 hr for cells at normal pH (7.3) and a t/sub d/ of 25 hr for the acute low pH cells (pH = 6.6; incubation time = 4 hr). 2) A pH/sub i/ 0.1-0.15 pH units > normal cells and 0.3 pH units > acute low pH cells. 3) Survival at 42.0 0 C which differed from both normal and acute low pH cells. The chronic culture was still quite sensitive to 42.0 0 C treatments during the first 5 hr, but developed tolerance at a higher level than cells under acute low pH conditions. The pH/sub i/ of the chronic culture responded to 42.0 0 C heating in a manner similar to that for acute low pH cells. Whether this culture represents a normal response to long term low pH exposure, or was the response of a mutant population is at the present unknown

  13. Fetal scalp pH testing

    Science.gov (United States)

    Fetal scalp blood; Scalp pH testing; Fetal blood testing - scalp; Fetal distress - fetal scalp testing; Labor - fetal scalp testing ... a baby. In these cases, testing the scalp pH can help the doctor decide whether the fetus ...

  14. Acid loading test (pH)

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003615.htm Acid loading test (pH) To use the sharing features on this page, please enable JavaScript. The acid loading test (pH) measures the ability of the ...

  15. Traceability of pH to the Mole

    Directory of Open Access Journals (Sweden)

    Maria Filomena Camões

    2015-08-01

    Full Text Available Free acidity of aqueous solutions was initially defined in 1909 by Søren Peter Lauritz Sørensen as pH = −lgcH+ (c/mol·dm−3 or m/mol·kg−1 of the free hydrogen ions in solution, H+ soon (1910 was changed to pH = paH+ = −lgaH+, integrating the new concepts of activity, ai and activity coefficient γi, for the ionic species i under concern, H+ in this case; it is ai = −lg(miγi. Since individual ions do not exist alone in solution, primary pH values cannot be assigned solely by experimental measurements, requiring extra thermodynamic model assumptions for the activity coefficient, γH+, which has put pH in a unique situation of not being fully traceable to the International System of Units (SI. Also the concept of activity is often not felt to be as perceptible as that of concentration which may present difficulties, namely with the interpretation of data. pH measurements on unknown samples rely on calibration of the measuring setup with adequate reference pH buffers. In this work, the assignment of pH values to buffers closely matching the samples, e.g., seawater, is revisited. An approach is presented to assess the quantity pmH+ = −lgmH+ profiting from the fact that, contrary to single ion activity coefficients, mean activity coefficients,   can be assessed based on experimentally assessed quantities alone, γExp ±, thus ensuring traceability to the mole, the SI base unit for amount of substance. Compatibility between γExp ± and mean activity coefficient calculated by means of Pitzer model equations, γPtz ±, validates the model for its intended use.

  16. pH sensor calibration procedure

    OpenAIRE

    Artero Delgado, Carola; Nogueras Cervera, Marc; Manuel Lázaro, Antonio; Prat Tasias, Jordi; Prat Farran, Joana d'Arc

    2013-01-01

    This paper describes the calibration of pH sensor located at the OBSEA marine Observatory. This instrument is based on an industrial pH electrode that is connected to a CTD instrument (Conductivity, Temperature, and Depth ). The calibration of the pH sensor has been done using a high precision spectrophotometer pH meter from Institute of Marine Sciences (ICM), and in this way it has been obtained a numerical function for the p H sensor propor...

  17. TAPERED OPTICAL FIBRES FOR LOCAL pH DETECTION

    Czech Academy of Sciences Publication Activity Database

    Martan, Tomáš; Pospíšilová, Marie; Aubrecht, Jan; Mrázek, Jan; Podrazký, Ondřej; Kašík, Ivan; Matějec, Vlastimil

    2010-01-01

    Roč. 206, č. 1 (2010), 0120171-0120172 ISSN 1742-6588. [8th International Workshop on Information Optics (WIO' 09). Paris, 20.07.2009-24.07.2009] R&D Projects: GA ČR(CZ) GP102/08/P639 Institutional research plan: CEZ:AV0Z20670512 Keywords : optical planar sensor * fluorescence * pH Subject RIV: JB - Sensor s, Measurment, Regulation

  18. Spectrally-resolved internal quantum efficiency and carrier dynamics of semipolar (10\\bar{1}1) core-shell triangular nanostripe GaN/InGaN LEDs

    Science.gov (United States)

    Okur, Serdal; Rishinaramangalam, Ashwin K.; Mishkat-Ul-Masabih, Saadat; Nami, Mohsen; Liu, Sheng; Brener, Igal; Brueck, Steven R. J.; Feezell, Daniel F.

    2018-06-01

    We investigate the spectrally resolved internal quantum efficiency (IQE) and carrier dynamics in semipolar (10\\bar{1}1) core–shell triangular nanostripe light-emitting diodes (TLEDs) using temperature-dependent photoluminescence (TDPL) and time-resolved photoluminescence (TRPL) at various excitation energy densities. Using electroluminescence, photoluminescence, and cathodoluminescence measurements, we verify the origins of the broad emission spectra from the nanostructures and confirm that localized regions of high-indium-content InGaN exist along the apex of the nanostructures. Spectrally resolved IQE measurements are then performed, with the spectra integrated from 400–450 nm and 450–500 nm to obtain the IQE of the QWs mainly near the sidewalls and apex of the TLEDs, respectively. TDPL and TRPL are used to decouple the radiative and non-radiative carrier lifetimes for different regions of the emission spectra. We observe that the IQE is higher for the spectral region between 450 nm and 500 nm compared to the IQE between 400 and 450 nm. This result is in contrast to the typical observation that the IQE of planar GaN-based LEDs is lower for longer wavelengths (i.e., higher indium contents). We also observe a longer non-radiative recombination lifetime for the longer wavelength portion of the spectrum. Several explanations are proposed for the improved IQE and longer non-radiative lifetime observed near the apex of the nanostructures. The results show that nanostructures may be leveraged to design more efficient green LEDs, potentially addressing a long-standing challenge in GaN-based materials.

  19. Three-Dimensional Sediment Dynamics in Well-Mixed Estuaries: Importance of the Internally Generated Overtide, Spatial Settling Lag, and Gravitational Circulation

    Science.gov (United States)

    Wei, Xiaoyan; Kumar, Mohit; Schuttelaars, Henk M.

    2018-02-01

    To investigate the dominant sediment transport and trapping mechanisms, a semi-analytical three-dimensional model is developed resolving the dynamic effects of salt intrusion on sediment in well-mixed estuaries in morphodynamic equilibrium. As a study case, a schematized estuary with a converging width and a channel-shoal structure representative for the Delaware estuary is considered. When neglecting Coriolis effects, sediment downstream of the estuarine turbidity maximum (ETM) is imported into the estuary through the deeper channel and exported over the shoals. Within the ETM region, sediment is transported seaward through the deeper channel and transported landward over the shoals. The largest contribution to the cross-sectionally integrated seaward residual sediment transport is attributed to the advection of tidally averaged sediment concentrations by river-induced flow and tidal return flow. This contribution is mainly balanced by the residual landward sediment transport due to temporal correlations between the suspended sediment concentrations and velocities at the M2 tidal frequency. The M2 sediment concentration mainly results from spatial settling lag effects and asymmetric bed shear stresses due to interactions of M2 bottom velocities and the internally generated M4 tidal velocities, as well as the salinity-induced residual currents. Residual advection of tidally averaged sediment concentrations also plays an important role in the landward sediment transport. Including Coriolis effects hardly changes the cross-sectionally integrated sediment balance, but results in a landward (seaward) sediment transport on the right (left) side of the estuary looking seaward, consistent with observations from literature. The sediment transport/trapping mechanisms change significantly when varying the settling velocity and river discharge.

  20. Hemodynamic vascular biomarkers for initiation of paraclinoid internal carotid artery aneurysms using patient-specific computational fluid dynamic simulation based on magnetic resonance imaging.

    Science.gov (United States)

    Watanabe, Tomoya; Isoda, Haruo; Takehara, Yasuo; Terada, Masaki; Naito, Takehiro; Kosugi, Takafumi; Onishi, Yuki; Tanoi, Chiharu; Izumi, Takashi

    2018-05-01

    We performed computational fluid dynamics (CFD) for patients with and without paraclinoid internal carotid artery (ICA) aneurysms to evaluate the distribution of vascular biomarkers at the aneurysm initiation sites of the paraclinoid ICA. This study included 35 patients who were followed up for aneurysms using 3D time of flight (TOF) magnetic resonance angiography (MRA) and 3D cine phase-contrast MR imaging. Fifteen affected ICAs were included in group A with the 15 unaffected contralateral ICAs in group B. Thirty-three out of 40 paraclinoid ICAs free of aneurysms and arteriosclerotic lesions were included in group C. We deleted the aneurysms in group A based on the 3D TOF MRA dataset. We performed CFD based on MR data set and obtained wall shear stress (WSS), its derivatives, and streamlines. We qualitatively evaluated their distributions at and near the intracranial aneurysm initiation site among three groups. We also calculated and compared the normalized highest (nh-) WSS and nh-spatial WSS gradient (SWSSG) around the paraclinoid ICA among three groups. High WSS and SWSSG distribution were observed at and near the aneurysm initiation site in group A. High WSS and SWSSG were also observed at similar locations in group B and group C. However, nh-WSS and nh-SWSSG were significantly higher in group A than in group C, and nh-SWSSG was significantly higher in group A than in group B. Our findings indicated that nh-WSS and nh-SWSSG were good biomarkers for aneurysm initiation in the paraclinoid ICA.

  1. Hyperpolarized Amino Acid Derivatives as Multivalent Magnetic Resonance pH Sensor Molecules.

    Science.gov (United States)

    Hundshammer, Christian; Düwel, Stephan; Ruseckas, David; Topping, Geoffrey; Dzien, Piotr; Müller, Christoph; Feuerecker, Benedikt; Hövener, Jan B; Haase, Axel; Schwaiger, Markus; Glaser, Steffen J; Schilling, Franz

    2018-02-15

    pH is a tightly regulated physiological parameter that is often altered in diseased states like cancer. The development of biosensors that can be used to non-invasively image pH with hyperpolarized (HP) magnetic resonance spectroscopic imaging has therefore recently gained tremendous interest. However, most of the known HP-sensors have only individually and not comprehensively been analyzed for their biocompatibility, their pH sensitivity under physiological conditions, and the effects of chemical derivatization on their logarithmic acid dissociation constant (p K a ). Proteinogenic amino acids are biocompatible, can be hyperpolarized and have at least two pH sensitive moieties. However, they do not exhibit a pH sensitivity in the physiologically relevant pH range. Here, we developed a systematic approach to tailor the p K a of molecules using modifications of carbon chain length and derivatization rendering these molecules interesting for pH biosensing. Notably, we identified several derivatives such as [1- 13 C]serine amide and [1- 13 C]-2,3-diaminopropionic acid as novel pH sensors. They bear several spin-1/2 nuclei ( 13 C, 15 N, 31 P) with high sensitivity up to 4.8 ppm/pH and we show that 13 C spins can be hyperpolarized with dissolution dynamic polarization (DNP). Our findings elucidate the molecular mechanisms of chemical shift pH sensors that might help to design tailored probes for specific pH in vivo imaging applications.

  2. International Trade. International Business

    OpenAIRE

    Мохнюк, А. М.; Mokhniuk, A. M.

    2015-01-01

    Work programme of the study course “International Trade. International Business” was prepared in accordance with educational and vocational training program for bachelors of training direction 6.030601 “Management”.

  3. Improvement of the Performance of an Electrocoagulation Process System Using Fuzzy Control of pH.

    Science.gov (United States)

    Demirci, Yavuz; Pekel, Lutfiye Canan; Altinten, Ayla; Alpbaz, Mustafa

    2015-12-01

    The removal efficiencies of electrocoagulation (EC) systems are highly dependent on the initial value of pH. If an EC system has an acidic influent, the pH of the effluent increases during the treatment process; conversely, if such a system has an alkaline influent, the pH of the effluent decreases during the treatment process. Thus, changes in the pH of the wastewater affect the efficiency of the EC process. In this study, we investigated the dynamic effects of pH. To evaluate approaches for preventing increases in the pH of the system, the MATLAB/Simulink program was used to develop and evaluate an on-line computer-based system for pH control. The aim of this work was to study Proportional-Integral-Derivative (PID) control and fuzzy control of the pH of a real textile wastewater purification process using EC. The performances and dynamic behaviors of these two control systems were evaluated based on determinations of COD, colour, and turbidity removal efficiencies.

  4. A comparison of exogenous and endogenous CEST MRI methods for evaluating in vivo pH.

    Science.gov (United States)

    Lindeman, Leila R; Randtke, Edward A; High, Rachel A; Jones, Kyle M; Howison, Christine M; Pagel, Mark D

    2018-05-01

    Extracellular pH (pHe) is an important biomarker for cancer cell metabolism. Acido-chemical exchange saturation transfer (CEST) MRI uses the contrast agent iopamidol to create spatial maps of pHe. Measurements of amide proton transfer exchange rates (k ex ) from endogenous CEST MRI were compared to pHe measurements by exogenous acido-CEST MRI to determine whether endogenous k ex could be used as a proxy for pHe measurements. Spatial maps of pHe and k ex were obtained using exogenous acidoCEST MRI and an endogenous CEST MRI analyzed with the omega plot method, respectively, to evaluate mouse kidney, a flank tumor model, and a spontaneous lung tumor model. The pHe and k ex results were evaluated using pixelwise comparisons. The k ex values obtained from endogenous CEST measurements did not correlate with the pHe results from exogenous CEST measurements. The k ex measurements were limited to fewer pixels and had a limited dynamic range relative to pHe measurements. Measurements of k ex with endogenous CEST MRI cannot substitute for pHe measurements with acidoCEST MRI. Whereas endogenous CEST MRI may still have good utility for evaluating some specific pathologies, exogenous acido-CEST MRI is more appropriate when evaluating pathologies based on pHe values. Magn Reson Med 79:2766-2772, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  5. pH distribution in human tumors

    International Nuclear Information System (INIS)

    Thistlethwaite, A.J.; Leeper, D.B.; Moylan, D.J.; Nerlinger, R.E.

    1984-01-01

    pH distribution in human tumors is being determined to evaluate this parameter as a prognostic indicator of hyperthermia response. pH is measured by a modified glass pH electrode (21g, model MI 408, Microelectrodes, Inc., Londonderry, NH) inserted through an 18g open-ended Angiocath. Eight tumors have been evaluated to date; and of those, 3 were also assayed after the first heat treatment coincident with determination of blood flow. Tumors were between 2-5 cm, of various histologies, and of primary, recurrent, or metastatic origin. 2-4 measurements were made per tumor. Pretreatment readings were between 6.4 and 7.2 pH units. As tumor blood flow increased after 1 hr heating (41.5 - 43 0 ) pH rose 0.1 - 0.3 units. Normal rat muscle yields pH readings of 7.35 - 7.45. Although there was considerable heterogeneity of pH within tumors, accuracy and drift were not a problem. 5-15 min were required for pH stabilization after catheter insertion and <5 min after electrode insertion. A saline wheal was used for anesthesia to preclude modification of pH by anesthetics. Patient tolerance has not been a problems. This study suggests that human tumor tissue has a preponderance of areas more acidic than normal tissue. This may serve to sensitize tumor cells to hyperthermia and provide a prognostic indicator of tumor response

  6. A hybrid total internal reflection fluorescence and optical tweezers microscope to study cell adhesion and membrane protein dynamics of single living cells

    NARCIS (Netherlands)

    Snijder-van As, M.I.; Rieger, B.; Joosten, B.; Subramaniam, Vinod; Figdor, Carl; Kanger, Johannes S.

    2009-01-01

    The dynamics of cell surface membrane proteins plays an important role in cell–cell interactions. The onset of the interaction is typically not precisely controlled by current techniques, making especially difficult the visualization of early-stage dynamics. We have developed a novel method where

  7. Dynamic Assessment of Writing: The Impact of Implicit/Explicit Mediations on L2 Learners' Internalization of Writing Skills and Strategies

    Science.gov (United States)

    Alavi, Sayyed Mohammad; Taghizadeh, Mahboubeh

    2014-01-01

    Dynamic assessment is a procedure in which development is simultaneously assessed and improved with regard to the individual's or group's Zone of Proximal Development (ZPD; Lantolf & Poehner, 2004). This study aimed to follow dynamic assessment and investigate the impact of three types of implicit and explicit feedback on the essay writing of…

  8. Functional and rheological properties of proteins in frozen turkey breast meat with different ultimate pH.

    Science.gov (United States)

    Chan, J T Y; Omana, D A; Betti, M

    2011-05-01

    Functional and rheological properties of proteins from frozen turkey breast meat with different ultimate pH at 24 h postmortem (pH(24)) have been studied. Sixteen breast fillets from Hybrid Tom turkeys were initially selected based on lightness (L*) values for each color group (pale, normal, and dark), with a total of 48 breast fillets. Further selection of 8 breast samples was made within each class of meat according to the pH(24). The average L* and pH values of the samples were within the following range: pale (L* >52; pH ≤5.7), normal (46 meat, respectively. Ultimate pH did not cause major changes in the emulsifying and foaming properties of the extracted sarcoplasmic and myofibrillar proteins. An SDS-PAGE profile of proteins from low and normal pH meat was similar, which revealed that the extent of protein denaturation was the same. Low pH meat had the lowest water-holding capacity compared with normal and high pH meat as shown by the increase in cooking loss, which can be explained by factors other than protein denaturation. Gel strength analysis and folding test revealed that gel-forming ability was better for high pH meat compared with low and normal pH meat.Dynamic viscoelastic behavior showed that myosin denaturation temperature was independent of pH(24). Normal and high pH meat had similar hardness, springiness, and chewiness values as revealed by texture profile analysis. The results from this study indicate that high pH meat had similar or better functional properties than normal pH meat. Therefore, high pH meat is suitable for further processed products, whereas low pH meat may need additional treatment or ingredient formulations to improve its functionality.

  9. Meta-Cresol Purple Reference Material® (RM) for Seawater pH Measurements

    Science.gov (United States)

    Easley, R. A.; Waters, J. F.; Place, B. J.; Pratt, K. W.

    2016-02-01

    The pH of seawater is a fundamental quantity that governs the carbon dioxide - carbonate system in the world's oceans. High quality pH measurements for long-term monitoring, shipboard studies, and shorter-term biological studies (mesocosm and field experiments) can be ensured through a reference material (RM) that is compatible with existing procedures and which is traceable to primary pH measurement metrology. High-precision spectrophotometric measurements of seawater pH using an indicator dye such as meta-cresol purple (mCP) are well established. However, traceability of these measurements to the International System of Units (SI) additionally requires characterizing the spectrophotometric pH response of the dye in multiple artificial seawater buffers that themselves are benchmarked via primary pH (Harned cell) measurements at a range of pH, salinity, and temperature. NIST is currently developing such a mCP pH RM using this approach. This material will also incorporate new procedures developed at NIST for assessing the purity and homogeneity of the mCP reagent itself. The resulting mCP will provide long-term (years) stability and ease of shipment compared to artificial seawater pH buffers. These efforts will provide the oceanographic user community with a NIST issued mCP (RM), characterized as to its molar absorptivity values and acid dissociation constants (pKa), with uncertainties that comply with the Guide to the Expression of Uncertainty in Measurement (GUM).

  10. In vivo measurement of cytosolic and mitochondrial pH using a pH-sensitive GFP derivative in Saccharomyces cerevisiae reveals a relation between intracellular pH and growth

    NARCIS (Netherlands)

    Orij, R.; Postmus, J.; ter Beek, A.; Brul, S.; Smits, G.J.

    2009-01-01

    The specific pH values of cellular compartments affect virtually all biochemical processes, including enzyme activity, protein folding and redox state. Accurate, sensitive and compartment-specific measurements of intracellular pH (pHi) dynamics in living cells are therefore crucial to the

  11. Physical and mechanical properties of cast 17-4 PH stainless steel

    International Nuclear Information System (INIS)

    Rack, H.J.

    1981-02-01

    The physical and mechanical properties of an overaged 17-4 PH stainless steel casting have been examined. The tensile and compressive properties of cast 17-4 PH are only influenced to a slight degree by changing test temperature and strain rate. However, both the Charpy impact energy and dynamic fracture toughness exhibit a tough-to-brittle transition with decreasing temperature - this transition being related to a change in fracture mode from ductile, dimple to cleavage-like. Finally, although the overaged 17-4 PH casting had a relatively low room temperature Charpy impact energy when compared to wrought 17-4 PH, its fracture toughness was at least comparable to that of wrought 17-4 PH. This observation suggests that prior correlations between Charpy impact energies and fracture toughness, as derived from wrought materials, must be approached with caution when applied to cast alloys

  12. Coaching af ph.d.-studerende

    DEFF Research Database (Denmark)

    Godskesen, Mirjam Irene

    Rapporten danner grundlag for at etablere et koncept for ph.d.-coaching. Erfaringerne fra et 2-årigt projekt om ph.d.-coaching i SCKK regi beskrives. De centrale temaer er tilrettelæggelse af den individuelle coaching, typiske temaer i coachingen og arbejdsdeling mellem coach og vejleder. Der er...

  13. Salivary pH: A diagnostic biomarker

    Directory of Open Access Journals (Sweden)

    Sharmila Baliga

    2013-01-01

    Full Text Available Objectives: Saliva contains a variety of host defense factors. It influences calculus formation and periodontal disease. Different studies have been done to find exact correlation of salivary biomarkers with periodontal disease. With a multitude of biomarkers and complexities in their determination, the salivary pH may be tried to be used as a quick chairside test. The aim of this study was to analyze the pH of saliva and determine its relevance to the severity of periodontal disease. Study Design: The study population consisted of 300 patients. They were divided into three groups of 100 patients each: Group A had clinically healthy gingiva, Group B who had generalized chronic gingivitis and Group C who had generalized chronic periodontitis. The randomized unstimulated saliva from each patient was collected and pH was tested. Data was analyzed statistically using analysis of variance technique. Results: The salivary pH was more alkaline for patients with generalized chronic gingivitis as compared with the control group (P = 0.001 whereas patients with generalized chronic periodontitis had more acidic pH as compared with the control group (P = 0.001. Conclusion: These results indicate a significant change in the pH depending on the severity of the periodontal condition. The salivary pH shows significant changes and thus relevance to the severity of periodontal disease. Salivary pH may thus be used as a quick chairside diagnostic biomarker.

  14. Salivary pH: A diagnostic biomarker.

    Science.gov (United States)

    Baliga, Sharmila; Muglikar, Sangeeta; Kale, Rahul

    2013-07-01

    Saliva contains a variety of host defense factors. It influences calculus formation and periodontal disease. Different studies have been done to find exact correlation of salivary biomarkers with periodontal disease. With a multitude of biomarkers and complexities in their determination, the salivary pH may be tried to be used as a quick chairside test. The aim of this study was to analyze the pH of saliva and determine its relevance to the severity of periodontal disease. The study population consisted of 300 patients. They were divided into three groups of 100 patients each: Group A had clinically healthy gingiva, Group B who had generalized chronic gingivitis and Group C who had generalized chronic periodontitis. The randomized unstimulated saliva from each patient was collected and pH was tested. Data was analyzed statistically using analysis of variance technique. The salivary pH was more alkaline for patients with generalized chronic gingivitis as compared with the control group (P = 0.001) whereas patients with generalized chronic periodontitis had more acidic pH as compared with the control group (P = 0.001). These results indicate a significant change in the pH depending on the severity of the periodontal condition. The salivary pH shows significant changes and thus relevance to the severity of periodontal disease. Salivary pH may thus be used as a quick chairside diagnostic biomarker.

  15. Ph og børnenes rum

    DEFF Research Database (Denmark)

    de Coninck-Smith, Ning

    2008-01-01

    Arkiteten og kulturkritikeren PH tegnede to bygninger til børn, nemlig fabriksbørnehaven ved Dehns Vaskeri fra 1948 og det ombyggede børnehjem Mindet fra 1954. Bidraget diskuterer PH's særlige greb om arkitektur til børn og placerer det ind i samtidens diskussion om børn, deres udvikling og behov....

  16. PER PhDs & Bachelor's Degrees

    Science.gov (United States)

    White, Susan C.

    2017-01-01

    Recently, the editor remarked to me that physics departments that offered a PhD with a specialization in Physics Education Research (PER) seemed to graduate more bachelor's degree recipients than those physics PhD departments that did not have the specialization. I was not convinced. That led to quite a bit of discussion between us. He compiled a…

  17. Urbanism PhD Research 2008 - 2010

    NARCIS (Netherlands)

    Smit, M.; Van der Hoeven, F.D.; Brand, N.; Van der Burg, L.; Çal??kan, O.; Tan, E.R.; Wang, C.Y.; Zhou, J.

    2009-01-01

    To ensure the quality of the Ph.D. research the Department introduced a special procedure for periodic evaluation: after a period of nine months the potential Ph.D. candidates are asked to present their research design, theoretical framework and methodological approach to the members of the

  18. (ajst) the influence of ph and adsorbent

    African Journals Online (AJOL)

    goethite sorbed a little more metal ion than the natural goethite. This was attributed ... was greatly governed by pH with nearly 100% adsorption of Pb occurring at initial pH of 5. Generally, Pb was ... extensively study and applied for the removal of heavy .... Goethite has variable surface charge characteristics, which gave it a ...

  19. On Calibration of pH Meters

    Directory of Open Access Journals (Sweden)

    Da-Ming Zhu

    2005-04-01

    Full Text Available The calibration of pH meters including the pH glass electrode, ISE electrodes,buffers, and the general background for calibration are reviewed. Understanding of basicconcepts of pH, pOH, and electrode mechanism is emphasized. New concepts of pH, pOH,as well as critical examination of activity, and activity coefficients are given. Theemergence of new solid state pH electrodes and replacement of the salt bridge with aconducting wire have opened up a new horizon for pH measurements. A pH buffer solutionwith a conducting wire may be used as a stable reference electrode. The misleadingunlimited linear Nernstian slope should be discarded. Calibration curves with 3 nonlinearportions for the entire 0—14 pH range due to the isoelectric point change effect areexplained. The potential measurement with stirring or unstirring and effects by double layer(DL and triple layer (TL will be discussed.

  20. A Flexible Optical pH Sensor Based on Polysulfone Membranes Coated with pH-Responsive Polyaniline Nanofibers.

    Science.gov (United States)

    Abu-Thabit, Nedal; Umar, Yunusa; Ratemi, Elaref; Ahmad, Ayman; Ahmad Abuilaiwi, Faraj

    2016-06-27

    A new optical pH sensor based on polysulfone (PSU) and polyaniline (PANI) was developed. A transparent and flexible PSU membrane was employed as a support. The electrically conductive and pH-responsive PANI was deposited onto the membrane surface by in situ chemical oxidative polymerization (COP). The absorption spectra of the PANI-coated PSU membranes exhibited sensitivity to pH changes in the range of 4-12, which allowed for designing a dual wavelength pH optical sensor. The performance of the membranes was assessed by measuring their response starting from high pH and going down to low pH, and vice versa. It was found that it is necessary to precondition the sensor layers before each measurement due to the slight hysteresis observed during forward and backward pH titrations. PSU membranes with polyaniline coating thicknesses in the range of ≈100-200 nm exhibited fast response times of pH sensor was characterized by a sigmoidal response (R² = 0.997) which allows for pH determination over a wide dynamic range. All membranes were stable for a period of more than six months when stored in 1 M HCl solution. The reproducibility of the fabricated optical pH sensors was found to be pH sensor was tested and the obtained pH values were compared with the results obtained using a pH meter device.