Comparisons of geoid models over Alaska computed with different Stokes' kernel modifications

Science.gov (United States)

Li, X.; Wang, Y.

2011-01-01

Various Stokes kernel modification methods have been developed over the years. The goal of this paper is to test the most commonly used Stokes kernel modifications numerically by using Alaska as a test area and EGM08 as a reference model. The tests show that some methods are more sensitive than others to the integration cap sizes. For instance, using the methods of Vaníček and Kleusberg or Featherstone et al. with kernel modification at degree 60, the geoid decreases by 30 cm (on average) when the cap size increases from 1° to 25°. The corresponding changes in the methods of Wong and Gore and Heck and Grüninger are only at the 1 cm level. At high modification degrees, above 360, the methods of Vaníček and Kleusberg and Featherstone et al become unstable because of numerical problems in the modification coefficients; similar conclusions have been reported by Featherstone (2003). In contrast, the methods of Wong and Gore, Heck and Grüninger and the least-squares spectral combination are stable at any modification degree, though they do not provide as good fit as the best case of the Molodenskii-type methods at the GPS/Leveling benchmarks. However, certain tests for choosing the cap size and modification degree have to be performed in advance to avoid abrupt mean geoid changes if the latter methods are applied.

Smaller sized reactors can be economically attractive

International Nuclear Information System (INIS)

Carelli, M.D.; Petrovic, B.; Mycoff, C.W.; Trucco, P.; Ricotti, M.E.; Locatelli, G.

2007-01-01

Smaller size reactors are going to be an important component of the worldwide nuclear renaissance. However, a misguided interpretation of the economy of scale would label these reactors as not economically competitive with larger plants because of their allegedly higher capital cost (dollar/kWe). Economy of scale does apply only if the considered designs are similar, which is not the case here. This paper identifies and briefly discusses the various factors which, beside size (power produced), contribute to determining the capital cost of smaller reactors and provides a preliminary evaluation for a few of these factors. When they are accounted for, in a set of realistic and comparable configurations, the final capital costs of small and large plants are practically equivalent. The Iris reactor is used as the example of smaller reactors, but the analysis and conclusions are applicable to the whole spectrum of small nuclear plants. (authors)

77 FR 2679 - Defense Federal Acquisition Regulation Supplement: Order of Application for Modifications

Science.gov (United States)

2012-01-19

... following methods: [cir] Regulations.gov : http://www.regulations.gov . Submit comments via the Federal e... contract. In order to determine the sequence of modifications to a contract or order, a method for... the numeric order of the modifications to a contract is not the order in which the changes to the...

Plasma assisted surface coating/modification processes: An emerging technology

Science.gov (United States)

Spalvins, T.

1986-01-01

A broad understanding of the numerous ion or plasma assisted surface coating/modification processes is sought. An awareness of the principles of these processes is needed before discussing in detail the ion nitriding technology. On the basis of surface modifications arising from ion or plasma energizing and interactions, it can be broadly classified as deposition of distinct overlay coatings (sputtering-dc, radio frequency, magnetron, reactive; ion plating-diode, triode) and surface property modification without forming a discrete coating (ion implantation, ion beam mixing, laser beam irradiation, ion nitriding, ion carburizing, plasma oxidation). These techniques offer a great flexibility and are capable in tailoring desirable chemical and structural surface properties independent of the bulk properties.

Plasma assisted surface coating/modification processes - An emerging technology

Science.gov (United States)

Spalvins, T.

1987-01-01

A broad understanding of the numerous ion or plasma assisted surface coating/modification processes is sought. An awareness of the principles of these processes is needed before discussing in detail the ion nitriding technology. On the basis of surface modifications arising from ion or plasma energizing and interactions, it can be broadly classified as deposition of distinct overlay coatings (sputtering-dc, radio frequency, magnetron, reactive; ion plating-diode, triode) and surface property modification without forming a discrete coating (ion implantation, ion beam mixing, laser beam irradiation, ion nitriding, ion carburizing, plasma oxidation. These techniques offer a great flexibility and are capable in tailoring desirable chemical and structural surface properties independent of the bulk properties.

Ten Indicators of Vitality in Smaller Academic Libraries

Science.gov (United States)

Pappas, David

2009-01-01

This paper provides a means of quickly ascertaining the relative health of smaller academic libraries by presenting a top ten list of vitality indicators. The list is based on an observational convenience sampling of thirty smaller academic libraries across the United States. The indicators making the list were those which appeared most often in…

Numerical simulation of microstructure of the GeSi alloy

Energy Technology Data Exchange (ETDEWEB)

Rasin, I.

2006-09-08

The goal of this work is to investigate pattern formation processes on the solid-liquid interface during the crystal growth of GeSi. GeSi crystals with cellular structure have great potential for applications in -ray and neutron optics. The interface patterns induce small quasi-periodic distortions of the microstructure called mosaicity. Existence and properties of this mosaicity are important for the application of the crystals. The properties depend on many factors; this dependence, is currently not known even not qualitatively. A better understanding of the physics near the crystal surface is therefore required, in order to optimise the growth process. There are three main physical processes in this system: phase-transition, diffusion and melt flow. Every process is described by its own set of equations. Finite difference methods and lattice kinetic methods are taken for solving these governing equations. We have developed a modification of the kinetic methods for the advectiondiffusion and extended this method for simulations of non-linear reaction diffusion equations. The phase-field method was chosen as a tool for describing the phase-transition. There are numerous works applied for different metallic alloys. An attempt to apply the method directly to simulation GeSi crystal growth showed that this method is unstable. This instability has not been observed in previous works due to the much smaller scale of simulations. We introduced a modified phase-field scheme, which enables to simulate pattern formation with the scale observed in experiment. A flow in the melt was taken in to account in the numerical model. The developed numerical model allows us to investigate pattern formation in GeSi crystals. Modelling shows that the flow near the crystal surface has impact on the patterns. The obtained patterns reproduce qualitatively and in some cases quantitatively the experimental results. (orig.)

Numerical determination of transmission probabilities in cylindrical geometry

International Nuclear Information System (INIS)

Queiroz Bogado Leite, S. de.

1989-11-01

Efficient methods for numerical calculation of transmission probabilities in cylindrical geometry are presented. Relative errors of the order of 10 -5 or smaller are obtained using analytical solutions and low order quadrature integration schemes. (author) [pt

13 CFR 107.710 - Requirement to finance smaller enterprises.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Requirement to finance smaller enterprises. 107.710 Section 107.710 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION SMALL... Small Business for Sbic Financing § 107.710 Requirement to finance smaller enterprises. Your Portfolio...

In medium modification of nucleon electromagnetic properties

International Nuclear Information System (INIS)

Khanna, F.; Rakhimov, A.; Yakhsiev, U.

1997-01-01

Since nucleons are composite objects, their internal structure is expected to be changed by nuclear environment. A Skyrme like Lagrangian is proposed to consider such effects, namely the modification of electromagnetic (EM) properties of the nucleon. The static properties and EM form factors were obtained. It was shown that the charge radius of the nucleon increased in medium and the mass and axial coupling constant are reduced. The enhancement of magnetic moment of proton is smaller than that obtained in non-topological soliton model.Obtained results may be useful in electron nucleus scattering analysis.(A.A.D.)

Numerical orbit generators of artificial earth satellites

Science.gov (United States)

Kugar, H. K.; Dasilva, W. C. C.

1984-04-01

A numerical orbit integrator containing updatings and improvements relative to the previous ones that are being utilized by the Departmento de Mecanica Espacial e Controle (DMC), of INPE, besides incorporating newer modellings resulting from the skill acquired along the time is presented. Flexibility and modularity were taken into account in order to allow future extensions and modifications. Characteristics of numerical accuracy, processing quickness, memory saving as well as utilization aspects were also considered. User's handbook, whole program listing and qualitative analysis of accuracy, processing time and orbit perturbation effects were included as well.

Experimental and Numerical analysis of Metallic Bellow for Acoustic Performance

Science.gov (United States)

Panchwadkar, Amit A.; Awasare, Pradeep J., Dr.; Ingle, Ravidra B., Dr.

2017-08-01

Noise will concern about the work environment of industry. Machinery environment has overall noise which interrupts communication between the workers. This problem of miscommunication and health hazard will make sense to go for noise attenuation. Modification in machine setup may affect the performance of it. Instead of that, Helmholtz resonator principle will be a better option for noise reduction along the transmission path. Resonator has design variables which gives resonating frequency will help us to confirm the frequency range. This paper deals with metallic bellow which behaves like inertial mass under incident sound wave. Sound wave energy is affected by hard boundary condition of resonator and bellow. Metallic bellow is used in combination with resonator to find out Transmission loss (TL). Microphone attachment with FFT analyzer will give the frequency range for numerical analysis. Numerical analysis of bellow and resonator is carried out to summarize the acoustic behavior of bellow. Bellow can be numerically analyzed to check noise attenuation for centrifugal blower. An impedance tube measurement technique is performed to validate the numerical results for assembly. Dimensional and shape modification can be done to get the acoustic performance of bellow.

Centrifugal compressor shape modification using a proposed inverse design method

International Nuclear Information System (INIS)

Niliahmadabadi, Mahdi; Poursadegh, Farzad

2013-01-01

This paper is concerned with a quasi-3D design method for the radial and axial diffusers of a centrifugal compressor on the meridional plane. The method integrates a novel inverse design algorithm, called ball-spine algorithm (BSA), and a quasi-3D analysis code. The Euler equation is solved on the meridional plane for a numerical domain, of which unknown boundaries (hub and shroud) are iteratively modified under the BSA until a prescribed pressure distribution is reached. In BSA, unknown walls are composed of a set of virtual balls that move freely along specified directions called spines. The difference between target and current pressure distributions causes the flexible boundary to deform at each modification step. In validating the quasi-3D analysis code, a full 3D Navier-Stokes code is used to analyze the existing and designed compressors numerically. Comparison of the quasi-3D analysis results with full 3D analysis results shows viable agreement. The 3D numerical analysis of the current compressor shows a huge total pressure loss on the 90 .deg. bend between the radial and axial diffusers. Geometric modification of the meridional plane causes the efficiency to improve by about 10%.

Centrifugal compressor shape modification using a proposed inverse design method

Energy Technology Data Exchange (ETDEWEB)

Niliahmadabadi, Mahdi [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Poursadegh, Farzad [Sharif University of Technology, Tehran (Iran, Islamic Republic of)

2013-03-15

This paper is concerned with a quasi-3D design method for the radial and axial diffusers of a centrifugal compressor on the meridional plane. The method integrates a novel inverse design algorithm, called ball-spine algorithm (BSA), and a quasi-3D analysis code. The Euler equation is solved on the meridional plane for a numerical domain, of which unknown boundaries (hub and shroud) are iteratively modified under the BSA until a prescribed pressure distribution is reached. In BSA, unknown walls are composed of a set of virtual balls that move freely along specified directions called spines. The difference between target and current pressure distributions causes the flexible boundary to deform at each modification step. In validating the quasi-3D analysis code, a full 3D Navier-Stokes code is used to analyze the existing and designed compressors numerically. Comparison of the quasi-3D analysis results with full 3D analysis results shows viable agreement. The 3D numerical analysis of the current compressor shows a huge total pressure loss on the 90 .deg. bend between the radial and axial diffusers. Geometric modification of the meridional plane causes the efficiency to improve by about 10%.

Influence of major-groove chemical modifications of DNA on transcription by bacterial RNA polymerases.

Science.gov (United States)

Raindlová, Veronika; Janoušková, Martina; Slavíčková, Michaela; Perlíková, Pavla; Boháčová, Soňa; Milisavljevič, Nemanja; Šanderová, Hana; Benda, Martin; Barvík, Ivan; Krásný, Libor; Hocek, Michal

2016-04-20

DNA templates containing a set of base modifications in the major groove (5-substituted pyrimidines or 7-substituted 7-deazapurines bearing H, methyl, vinyl, ethynyl or phenyl groups) were prepared by PCR using the corresponding base-modified 2'-deoxyribonucleoside triphosphates (dNTPs). The modified templates were used in an in vitro transcription assay using RNA polymerase from Bacillus subtilis and Escherichia coli Some modified nucleobases bearing smaller modifications (H, Me in 7-deazapurines) were perfectly tolerated by both enzymes, whereas bulky modifications (Ph at any nucleobase) and, surprisingly, uracil blocked transcription. Some middle-sized modifications (vinyl or ethynyl) were partly tolerated mostly by the E. colienzyme. In all cases where the transcription proceeded, full length RNA product with correct sequence was obtained indicating that the modifications of the template are not mutagenic and the inhibition is probably at the stage of initiation. The results are promising for the development of bioorthogonal reactions for artificial chemical switching of the transcription. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

A combined modification of Newton`s method for systems of nonlinear equations

Energy Technology Data Exchange (ETDEWEB)

Monteiro, M.T.; Fernandes, E.M.G.P. [Universidade do Minho, Braga (Portugal)

1996-12-31

To improve the performance of Newton`s method for the solution of systems of nonlinear equations a modification to the Newton iteration is implemented. The modified step is taken as a linear combination of Newton step and steepest descent directions. In the paper we describe how the coefficients of the combination can be generated to make effective use of the two component steps. Numerical results that show the usefulness of the combined modification are presented.

Content modification attacks on consensus seeking multi-agent system with double-integrator dynamics

Science.gov (United States)

Dong, Yimeng; Gupta, Nirupam; Chopra, Nikhil

2016-11-01

In this paper, vulnerability of a distributed consensus seeking multi-agent system (MAS) with double-integrator dynamics against edge-bound content modification cyber attacks is studied. In particular, we define a specific edge-bound content modification cyber attack called malignant content modification attack (MCoMA), which results in unbounded growth of an appropriately defined group disagreement vector. Properties of MCoMA are utilized to design detection and mitigation algorithms so as to impart resilience in the considered MAS against MCoMA. Additionally, the proposed detection mechanism is extended to detect the general edge-bound content modification attacks (not just MCoMA). Finally, the efficacies of the proposed results are illustrated through numerical simulations.

Chiral reagents in glycosylation and modification of carbohydrates.

Science.gov (United States)

Wang, Hao-Yuan; Blaszczyk, Stephanie A; Xiao, Guozhi; Tang, Weiping

2018-02-05

Carbohydrates play a significant role in numerous biological events, and the chemical synthesis of carbohydrates is vital for further studies to understand their various biological functions. Due to the structural complexity of carbohydrates, the stereoselective formation of glycosidic linkages and the site-selective modification of hydroxyl groups are very challenging and at the same time extremely important. In recent years, the rapid development of chiral reagents including both chiral auxiliaries and chiral catalysts has significantly improved the stereoselectivity for glycosylation reactions and the site-selectivity for the modification of carbohydrates. These new tools will greatly facilitate the efficient synthesis of oligosaccharides, polysaccharides, and glycoconjugates. In this tutorial review, we will summarize these advances and highlight the most recent examples.

Numeric data services and sources for the general reference librarian

CERN Document Server

Kellam, Lynda

2011-01-01

The proliferation of online access to social science statistical and numeric data sources, such as the U.S. Census Bureau's American Fact Finder, has lead to an increased interest in supporting these sources in academic libraries. Many large libraries have been able to devote staff to data services for years, and recently smaller academic libraries have recognized the need to provide numeric data services and support. This guidebook serves as a primer to developing and supporting social science statistical and numerical data sources in the academic library. It provides strategies for the estab

A status report on weather modification research in the Dakotas

Science.gov (United States)

Smith, Paul L.; Orville, Harold D.; Boe, Bruce A.; Stith, Jeffrey L.

An overview of the status of weather modification research in North and South Dakota (USA) is presented. The operational North Dakota Cloud Modification Projects has, since 1976, been seeding summer convective clouds for the dual objectives of hail suppression and rainfall enhancement. Research being carried out as part of a Federal/State cooperative program, in coordination with the operational activities, has included physical and statistical evaluation studies as well as numerical cloud modeling investigations. The statistical analyses provide some indications that the intended seeding effects are being obtained. The physical studies involve aircraft and radar observations and emphasize tracer experiments to study the transport and dispersion of seeding agents and the activation of ice nuclei. The modeling studies simulate the experiments and aid in investigation of the process involved and the effects of seeding. The 1989 North Dakota Thunderstorm Project, a major field study emphasizing physical and numerical modeling studies, is described briefly.

Numerical abilities in fish: A methodological review.

Science.gov (United States)

Agrillo, Christian; Miletto Petrazzini, Maria Elena; Bisazza, Angelo

2017-08-01

The ability to utilize numerical information can be adaptive in a number of ecological contexts including foraging, mating, parental care, and anti-predator strategies. Numerical abilities of mammals and birds have been studied both in natural conditions and in controlled laboratory conditions using a variety of approaches. During the last decade this ability was also investigated in some fish species. Here we reviewed the main methods used to study this group, highlighting the strengths and weaknesses of each of the methods used. Fish have only been studied under laboratory conditions and among the methods used with other species, only two have been systematically used in fish-spontaneous choice tests and discrimination learning procedures. In the former case, the choice between two options is observed in a biologically relevant situation and the degree of preference for the larger/smaller group is taken as a measure of the capacity to discriminate the two quantities (e.g., two shoals differing in number). In discrimination learning tasks, fish are trained to select the larger or the smaller of two sets of abstract objects, typically two-dimensional geometric figures, using food or social companions as reward. Beyond methodological differences, what emerges from the literature is a substantial similarity of the numerical abilities of fish with those of other vertebrates studied. Copyright © 2017 Elsevier B.V. All rights reserved.

Designing a Smaller Power Inverter: the Google Littlebox Challenge - Text

Science.gov (United States)

Version | Energy Systems Integration Facility | NREL Designing a Smaller Power Inverter: the Google Littlebox Challenge - Text Version er Power Inverter: the Google Littlebox Challenge - Text Version Below is the text version for the Designing a Smaller Power Inverter: the Google Littlebox

Sub-dominant cogrowth behaviour and the viability of deciding amenability numerically

OpenAIRE

Elder, Murray; Rogers, Cameron

2016-01-01

We critically analyse a recent numerical method due to the first author, Rechnitzer and van Rensburg, which attempts to detect amenability or non-amenability in a finitely generated group by numerically estimating its asymptotic cogrowth rate. We identify two potential sources of error. We then propose a modification of the method that enables it to easily compute surprisingly accurate estimates for initial terms of the cogrowth sequence.

Genetic Modification in Dedicated Bioenergy Crops and Strategies for Gene Confinement

Science.gov (United States)

Genetic modification of dedicated bioenergy crops is in its infancy; however, there are numerous advantages to the use of these tools to improve crops used for biofuels. Potential improved traits through genetic engineering (GE) include herbicide resistance, pest, drought, cold and salt tolerance, l...

Modifications of Geometric Truncation of the Scattering Phase Function

Science.gov (United States)

Radkevich, A.

2017-12-01

Phase function (PF) of light scattering on large atmospheric particles has very strong peak in forward direction constituting a challenge for accurate numerical calculations of radiance. Such accurate (and fast) evaluations are important in the problems of remote sensing of the atmosphere. Scaling transformation replaces original PF with a sum of the delta function and a new regular smooth PF. A number of methods to construct such a PF were suggested. Delta-M and delta-fit methods require evaluation of the PF moments which imposes a numerical problem if strongly anisotropic PF is given as a function of angle. Geometric truncation keeps the original PF unchanged outside the forward peak cone replacing it with a constant within the cone. This approach is designed to preserve the asymmetry parameter. It has two disadvantages: 1) PF has discontinuity at the cone; 2) the choice of the cone is subjective, no recommendations were provided on the choice of the truncation angle. This choice affects both truncation fraction and the value of the phase function within the forward cone. Both issues are addressed in this study. A simple functional form of the replacement PF is suggested. This functional form allows for a number of modifications. This study consider 3 versions providing continuous PF. The considered modifications also bear either of three properties: preserve asymmetry parameter, provide continuity of the 1st derivative of the PF, and preserve mean scattering angle. The second problem mentioned above is addressed with a heuristic approach providing unambiguous criterion of selection of the truncation angle. The approach showed good performance on liquid water and ice clouds with different particle size distributions. Suggested modifications were tested on different cloud PFs using both discrete ordinates and Monte Carlo methods. It was showed that the modifications provide better accuracy of the radiance computation compare to the original geometric truncation.

Chernobyl birds have smaller brains.

Directory of Open Access Journals (Sweden)

Anders Pape Møller

2011-02-01

Full Text Available Animals living in areas contaminated by radioactive material from Chernobyl suffer from increased oxidative stress and low levels of antioxidants. Therefore, normal development of the nervous system is jeopardized as reflected by high frequencies of developmental errors, reduced brain size and impaired cognitive abilities in humans. Alternatively, associations between psychological effects and radiation have been attributed to post-traumatic stress in humans.Here we used an extensive sample of 550 birds belonging to 48 species to test the prediction that even in the absence of post-traumatic stress, there is a negative association between relative brain size and level of background radiation. We found a negative association between brain size as reflected by external head volume and level of background radiation, independent of structural body size and body mass. The observed reduction in brain size in relation to background radiation amounted to 5% across the range of almost a factor 5,000 in radiation level. Species differed significantly in reduction in brain size with increasing background radiation, and brain size was the only morphological character that showed a negative relationship with radiation. Brain size was significantly smaller in yearlings than in older individuals.Low dose radiation can have significant effects on normal brain development as reflected by brain size and therefore potentially cognitive ability. The fact that brain size was smaller in yearlings than in older individuals implies that there was significant directional selection on brain size with individuals with larger brains experiencing a viability advantage.

Trafficking and function of the cystic fibrosis transmembrane conductance regulator: a complex network of posttranslational modifications

Science.gov (United States)

McClure, Michelle L.; Barnes, Stephen; Brodsky, Jeffrey L.

2016-01-01

Posttranslational modifications add diversity to protein function. Throughout its life cycle, the cystic fibrosis transmembrane conductance regulator (CFTR) undergoes numerous covalent posttranslational modifications (PTMs), including glycosylation, ubiquitination, sumoylation, phosphorylation, and palmitoylation. These modifications regulate key steps during protein biogenesis, such as protein folding, trafficking, stability, function, and association with protein partners and therefore may serve as targets for therapeutic manipulation. More generally, an improved understanding of molecular mechanisms that underlie CFTR PTMs may suggest novel treatment strategies for CF and perhaps other protein conformational diseases. This review provides a comprehensive summary of co- and posttranslational CFTR modifications and their significance with regard to protein biogenesis. PMID:27474090

Numerical methods for the simulation of particle generated electromagnetic fields in acclerator physics

International Nuclear Information System (INIS)

Lau, T.

2006-01-01

In this work modifications of the classical Particle-In-Cell method for the solution of the Maxwell-Vlasov equations are investigated with respect to their application in particle accelerator physics. The aim of the work is to find modifications of the method which minimize and under certain conditions even eliminate the numerical dispersion effect along the beam axis in the numerical solution of Maxwell's equations. This is achieved by the development of dedicated time-integration methods for the Finite Integration Technique and two Finite Volume Methods. The methods are theoretically investigated regarding the conservation of a discrete energy and the existence of a discrete continuity equation. Finally, some of the methods are applied to the simulation of a high frequency rf-gun. (orig.)

Condensation front modelling in a moisture separator reheater by application of SICLE numerical model

International Nuclear Information System (INIS)

Grange, J.L.; Caremoli, C.; Eddi, M.

1988-01-01

This paper presents improvements performed on SICLE numerical model in order to analyse the condensation front that occurs in the moisture separator reheaters (MSR) of nuclear power plants. Modifications of SICLE numerical model architecture and a fine modelling of reheater have allowed to correctly simulate the MSR thermohydraulic behaviour during a severe transient (plant islanding) [fr

Numerical characterization of thermo-mechanical performance of breeder pebble beds

International Nuclear Information System (INIS)

An, Zhiyong; Ying, Alice; Abdou, Mohamed

2007-01-01

A numerical approach using the discrete element method (DEM) has been applied to study the thermo-mechanical properties of ceramic breeder pebble beds. This numerical scheme is able to predict the inelastic behavior observed in a loading and unloading operation. In addition, it demonstrates that the average value of contact force increases linearly with overall pressure, but at a much faster rate, about 3.4 times the overall pressure increase rate. In this paper, the thermal creep properties of two different ceramic breeder pebble materials, Li 4 SiO 4 and Li 2 O, are also examined by the current numerical code. The difference found in the properties of candidate materials is reflected numerically in the overall strain in the pebble bed when the stress magnitude becomes smaller

Numerical characterization of thermo-mechanical performance of breeder pebble beds

International Nuclear Information System (INIS)

An, Zhiyong; Ying, Alice; Abdou, Mohamed

2008-01-01

A numerical approach using the discrete element method (DEM) has been applied to study the thermo-mechanical properties of ceramic breeder pebble beds. This numerical scheme is able to predict the inelastic behavior observed in a loading and unloading operation. In addition, it demonstrates that the average value of contact force increases linearly with overall pressure, but at a much faster rate, about 3.4 times the overall pressure increase rate. In this paper, the thermal creep properties of two different ceramic breeder pebble materials, Li 4 SiO 4 and Li 2 O, are also examined by the current numerical code. The difference found in the properties of candidate materials is reflected numerically in the overall strain in the pebble bed when the stress magnitude becomes smaller. (author)

Semiclassical anomalies of the quantum mechanical systems and their modifications for the asymptotic matching

International Nuclear Information System (INIS)

Deniz, Coskun

2011-01-01

JWKB solutions to the Initial Value Problems (IVPs) of the Time Independent Schrodinger's Equation (TISE) for the Simple Linear Potentials (SLPs) with a turning point parameter have been studied according to the turning points by graphical analysis to test the results of the JWKB solutions and suggested modifications. The anomalies happening in the classically inaccessible region where the SLP function is smaller than zero and the results of the suggested modifications, which are in consistent with the quantum mechanical theories, to remove these anomalies in this region have been presented. The origins of the anomalies and verifications of the suggested modifications showing a great success in the results have also been studied in terms of a suggested M ij =S ∼ i-1,j matrix elements made up of the JWKB expansion terms, S i-1,j (where i = 1, 2, 3 and j 1, 2). The results of the modifications for the IVPs and their application to the Bound State Problems (BSPs) with an example application of the Harmonic Oscillator (HO) have been presented and their generalization for any potential function have been discussed and classified accordingly.

Comparison between numerical and analytical results on the required rf current for stabilizing neoclassical tearing modes

Science.gov (United States)

Wang, Xiaojing; Yu, Qingquan; Zhang, Xiaodong; Zhang, Yang; Zhu, Sizheng; Wang, Xiaoguang; Wu, Bin

2018-04-01

Numerical studies on the stabilization of neoclassical tearing modes (NTMs) by electron cyclotron current drive (ECCD) have been carried out based on reduced MHD equations, focusing on the amount of the required driven current for mode stabilization and the comparison with analytical results. The dependence of the minimum driven current required for NTM stabilization on some parameters, including the bootstrap current density, radial width of the driven current, radial deviation of the driven current from the resonant surface, and the island width when applying ECCD, are studied. By fitting the numerical results, simple expressions for these dependences are obtained. Analysis based on the modified Rutherford equation (MRE) has also been carried out, and the corresponding results have the same trend as numerical ones, while a quantitative difference between them exists. This difference becomes smaller when the applied radio frequency (rf) current is smaller.

Nitric Oxide-Mediated Posttranslational Modifications: Impacts at the Synapse

Directory of Open Access Journals (Sweden)

Sophie A. Bradley

2016-01-01

Full Text Available Nitric oxide (NO is an important gasotransmitter molecule that is involved in numerous physiological processes throughout the nervous system. In addition to its involvement in physiological plasticity processes (long-term potentiation, LTP; long-term depression, LTD which can include NMDAR-mediated calcium-dependent activation of neuronal nitric oxide synthase (nNOS, new insights into physiological and pathological consequences of nitrergic signalling have recently emerged. In addition to the canonical cGMP-mediated signalling, NO is also implicated in numerous pathways involving posttranslational modifications. In this review we discuss the multiple effects of S-nitrosylation and 3-nitrotyrosination on proteins with potential modulation of function but limit the analyses to signalling involved in synaptic transmission and vesicular release. Here, crucial proteins which mediate synaptic transmission can undergo posttranslational modifications with either pre- or postsynaptic origin. During normal brain function, both pathways serve as important cellular signalling cascades that modulate a diverse array of physiological processes, including synaptic plasticity, transcriptional activity, and neuronal survival. In contrast, evidence suggests that aging and disease can induce nitrosative stress via excessive NO production. Consequently, uncontrolled S-nitrosylation/3-nitrotyrosination can occur and represent pathological features that contribute to the onset and progression of various neurodegenerative diseases, including Parkinson’s, Alzheimer’s, and Huntington’s.

Numerical simulation on dimension decrease for annular casing of one centrifugal boiler circulation pump

International Nuclear Information System (INIS)

Fan, Y Z; Zuo, Z G; Liu, S H; Wu, Y L; Sha, Y J

2012-01-01

Primary formulation derivation indicates that the dimension of one existing centrifugal boiler circulation pump casing is too large. As great manufacture cost can be saved by dimension decrease, a numerical simulation research is developed in this paper on dimension decrease for annular casing of this pump with a specific speed equaling to 189, which aims at finding an appropriately smaller dimension of the casing while hydraulic performance and strength performance will hardly be changed according to the requirements of the cooperative company. The research object is one existing centrifugal pump with a diffuser and a semi-spherical annular casing, working as the boiler circulation pump for (ultra) supercritical units in power plants. Dimension decrease, the modification method, is achieved by decreasing the existing casing's internal radius (marked as R i0 ) while keeping the wall thickness. The research analysis is based on primary formulation derivation, CFD (Computational Fluid Dynamics) simulation and FEM (Finite Element Method) simulation. Primary formulation derivation estimates that a design casing's internal radius should be less than 0.75 R i0 . CFD analysis indicates that smaller casing with 0.75 R i0 has a worse hydraulic performance when working at large flow rates and a better hydraulic performance when working at small flow rates. In consideration of hydraulic performance and dimension decrease, an appropriate casing's internal radius is determined, which equals to 0.875 R i0 . FEM analysis then confirms that modified pump casing has nearly the same strength performance as the existing pump casing. It is concluded that dimension decrease can be an economical method as well as a practical method for large pumps in engineering fields.

Numerical simulation on dimension decrease for annular casing of one centrifugal boiler circulation pump

Science.gov (United States)

Fan, Y. Z.; Zuo, Z. G.; Liu, S. H.; Wu, Y. L.; Sha, Y. J.

2012-11-01

Primary formulation derivation indicates that the dimension of one existing centrifugal boiler circulation pump casing is too large. As great manufacture cost can be saved by dimension decrease, a numerical simulation research is developed in this paper on dimension decrease for annular casing of this pump with a specific speed equaling to 189, which aims at finding an appropriately smaller dimension of the casing while hydraulic performance and strength performance will hardly be changed according to the requirements of the cooperative company. The research object is one existing centrifugal pump with a diffuser and a semi-spherical annular casing, working as the boiler circulation pump for (ultra) supercritical units in power plants. Dimension decrease, the modification method, is achieved by decreasing the existing casing's internal radius (marked as "Ri0") while keeping the wall thickness. The research analysis is based on primary formulation derivation, CFD (Computational Fluid Dynamics) simulation and FEM (Finite Element Method) simulation. Primary formulation derivation estimates that a design casing's internal radius should be less than 0.75 Ri0. CFD analysis indicates that smaller casing with 0.75 Ri0 has a worse hydraulic performance when working at large flow rates and a better hydraulic performance when working at small flow rates. In consideration of hydraulic performance and dimension decrease, an appropriate casing's internal radius is determined, which equals to 0.875 Ri0. FEM analysis then confirms that modified pump casing has nearly the same strength performance as the existing pump casing. It is concluded that dimension decrease can be an economical method as well as a practical method for large pumps in engineering fields.

Effect of Engine Modifications on Performance and Emission Characteristics of Diesel Engines with Alternative Fuels

OpenAIRE

Venkateswarlu, K.; Murthy, B.S.R

2010-01-01

Performance and emission characteristics unmodified diesel engines operating on different alternative fuels with smaller blend proportions are comparable with pure diesel operation. But with increased blend proportions due to the associated problems of vegetable oils like high viscosity and low volatility pollution levels increase which however is accompanied by operating and durability problems with the long term usage of engine. This paper discusses the necessary modifications required to o...

Modification of the Selectivity Properties of Tubular Ceramic Membranes after Alkaline Treatment

Directory of Open Access Journals (Sweden)

Patrick Dutournié

2017-11-01

Full Text Available This work focuses on the selectivity modification of ceramic membranes after a mild alkaline treatment. Filtration of pure salt-water solutions was carried out with commercial titania membranes before and after the treatment. After treatment, the rejection of NaF significantly decreased, while the rejection of NaCl and NaBr increased. Additionally, NaI and Na2SO4 remained close to zero. Pore size and electrical charge being almost unchanged, only significant modifications in the dielectric effects can explain this modification of selectivity. Therefore, the surface chemistry and the interaction (nature and magnitude with the solvent and with the species present in the solution appear to be modified by the alkaline treatment. This trend is also illustrated by discussing the electric and the dielectric properties that were numerically identified before and after treatment. The alkaline treatment significantly decreased the apparent dielectric constant of NaCl-water solution in the pore, highlighting the rejection of sodium chloride. Contrariwise, the modification of the surface chemistry increased the apparent dielectric constant of NaF-water solution by promoting fluoride transmission.

Slower gait, slower information processing and smaller prefrontal area in older adults.

NARCIS (Netherlands)

Rosano, C.; Studenski, S.A.; Aizenstein, H.J.; Boudreau, R.M.; Longstreth Jr, W.T.; Newman, A.B.

2012-01-01

BACKGROUND: Slower gait in older adults is related to smaller volume of the prefrontal area (PFAv). The pathways underlying this association have not yet been explored. Understanding slowing gait could help improve function in older age. We examine whether the association between smaller PFAv and

Smaller Cigarette Pack as a Commitment to Smoke Less? Insights from Behavioral Economics

Science.gov (United States)

Marti, Joachim; Sindelar, Jody

2015-01-01

Cigarettes are commonly sold in packs of 20 units and therefore little is known about the potential impact of pack size on consumption. Using insights from behavioral economics, we suggest that cigarette packs smaller than the standard size may help some smokers cut back and/or quit, consistent with their long-term goals. Results from an online hypothetical purchase experiment conducted in a sample of US smokers reveal that over a third of smokers are willing to pay a price premium to purchase in smaller quantities. Further, a desire to quit smoking and high self-control is associated with preference for a smaller pack. While we provide some preliminary evidence that smaller packs may be beneficial to certain types of smokers, further research should be conducted to assess whether the smaller pack size should be considered in the arsenal of tobacco control policies to help current smokers quit (JEL: I18; I12; D12) PMID:26356844

Smaller Cigarette Pack as a Commitment to Smoke Less? Insights from Behavioral Economics.

Directory of Open Access Journals (Sweden)

Joachim Marti

Full Text Available Cigarettes are commonly sold in packs of 20 units and therefore little is known about the potential impact of pack size on consumption. Using insights from behavioral economics, we suggest that cigarette packs smaller than the standard size may help some smokers cut back and/or quit, consistent with their long-term goals. Results from an online hypothetical purchase experiment conducted in a sample of US smokers reveal that over a third of smokers are willing to pay a price premium to purchase in smaller quantities. Further, a desire to quit smoking and high self-control is associated with preference for a smaller pack. While we provide some preliminary evidence that smaller packs may be beneficial to certain types of smokers, further research should be conducted to assess whether the smaller pack size should be considered in the arsenal of tobacco control policies to help current smokers quit (JEL: I18; I12; D12.

Effects of luminance contrast and its modifications on fixation behavior during free viewing of images from different categories.

Science.gov (United States)

Açik, Alper; Onat, Selim; Schumann, Frank; Einhäuser, Wolfgang; König, Peter

2009-06-01

During viewing of natural scenes, do low-level features guide attention, and if so, does this depend on higher-level features? To answer these questions, we studied the image category dependence of low-level feature modification effects. Subjects fixated contrast-modified regions often in natural scene images, while smaller but significant effects were observed for urban scenes and faces. Surprisingly, modifications in fractal images did not influence fixations. Further analysis revealed an inverse relationship between modification effects and higher-level, phase-dependent image features. We suggest that high- and mid-level features--such as edges, symmetries, and recursive patterns--guide attention if present. However, if the scene lacks such diagnostic properties, low-level features prevail. We posit a hierarchical framework, which combines aspects of bottom-up and top-down theories and is compatible with our data.

Do parents leave a smaller carbon footprint?

DEFF Research Database (Denmark)

Nordström, Leif Jonas; Shogren, Jason F.; Thunström, Linda

Do parents leave a smaller carbon footprint? While becoming a parent is transformational as one focuses more on the future, the time constraints are more binding right now. Using a unique data set that allows us to compare CO2 emissions from Swedish two-adult households with and without children......, we find becoming a Swedish parent causes a person to leave a larger carbon ootprint—due to changes in transportation patterns and food consumption choices....

A numerical study to evaluate the effects of a plant canopy on the modification of thermal environment

International Nuclear Information System (INIS)

Nakano, Y.; Cho, T.

1985-01-01

It is clear that ground conditions have a large effect on the thermal environment. Plant canopies have their own characteristic types of architecture and have a great influence upon the action and reaction processes occurring between plants and their environment through the modification and interception of fluxes of radiation, heat and mass. A numerical experiment was carried out to determine the diurnal changes occurring in soil and air temperatures near the ground surface covered by a plant. The model assumed that a canopy can be mathematically condensed into a single plane and treated as a single ‘big leaf’. The stomatal resistance was estimated by using the rectangular hyperbolic relationship between stomatal resistance and irradiance. Wind velocity, potential temperature and specific humidity values of 3.6m/s, 25°C and 0.0015 were applied respectively at the upper boundary (100 m), and a temperature of 25°C was specified for the lower boundary (-0.5m). All these conditions were kept constant throughout the simulation period. The analysis was performed on the basis of irradiant data obtained in Fukuoka City (latitude 33° 38'N) on 26 th July, 1978. The temperature profiles during daylight were characterized by curves with a maximum in the canopy layer. The temperature range on the soil surface was reduced owing to the effect of shading by the leaves. These phenomena make the formation of the thermal environment on a plant canopy extremely complex. In the case presented in this paper, the type of plant canopy investigated was similar to that of a soybean field with plants 1.00 m high, but the method could easily be adapted to simulate the thermal environment of a tall canopy, such as that in a forest. (author)

Implementation Study of Smaller Learning Communities. Final Report

Science.gov (United States)

Bernstein, Lawrence; Millsap, Mary Ann; Schimmenti, Jennifer; Page, Lindsay

2008-01-01

The Smaller Learning Communities (SLC) program was established in response to growing national concerns about students too often lost and alienated in large, impersonal high schools, as well as concerns about school safety and low levels of achievement and graduation for many students. Authorized under the "Elementary and Secondary Education Act,"…

Modification of radiation damage by naturally occurring substances

International Nuclear Information System (INIS)

Prasad, K.N.

1984-01-01

The major objectives of studying the modification of radiation sensitivity have been (1) to identify a compound that will produce a differential protection or sensitization of the effect of irradiation on normal and tumor tissue, and (2) to understand more about the mechanisms of radiation damage. In spite of massive research on this particular problem since World War II, the first objective remains elusive. During this period, numerous radioprotective and radiosensitizing agents have been identified. These agents have served as important biologic tools for increasing our understanding of radiation injuries. Most of these substances are synthetic compounds and are very toxic to humans. In addition, very few of the compounds provide differential modifications of the effect of radiation on tumor and normal cells. This chapter presents objectives for identifying naturally occurring substances that modify the effect of x-radiation on mammalian cells and discusses the role of physiologic substances in modifying radiation injuries on mammalian normal and tumor cells

Structural Modifications for Torsional Vibration Control of Shafting Systems Based on Torsional Receptances

Directory of Open Access Journals (Sweden)

Zihao Liu

2016-01-01

Full Text Available Torsional vibration of shafts is a very important problem in engineering, in particular in ship engines and aeroengines. Due to their high levels of integration and complexity, it is hard to get their accurate structural data or accurate modal data. This lack of data is unhelpful to vibration control in the form of structural modifications. Besides, many parts in shaft systems are not allowed to be modified such as rotary inertia of a pump or an engine, which is designed for achieving certain functions. This paper presents a strategy for torsional vibration control of shaft systems in the form of structural modifications based on receptances, which does not need analytical or modal models of the systems under investigation. It only needs the torsional receptances of the system, which can be obtained by testing simple auxiliary structure attached to relevant locations of the shaft system and using the finite element model (FEM of the simple structure. An optimization problem is constructed to determine the required structural modifications, based on the actual requirements of modal frequencies and mode shapes. A numerical experiment is set up and the influence of several system parameters is analysed. Several scenarios of constraints in practice are considered. The numerical simulation results demonstrate the effectiveness of this method and its feasibility in solving torsional vibration problems in practice.

Numerical evaluation of high energy particle effects in magnetohydrodynamics

International Nuclear Information System (INIS)

White, R.B.; Wu, Y.

1994-03-01

The interaction of high energy ions with magnetohydrodynamic modes is analyzed. A numerical code is developed which evaluates the contribution of the high energy particles to mode stability using orbit averaging of motion in either analytic or numerically generated equilibria through Hamiltonian guiding center equations. A dispersion relation is then used to evaluate the effect of the particles on the linear mode. Generic behavior of the solutions of the dispersion relation is discussed and dominant contributions of different components of the particle distribution function are identified. Numerical convergence of Monte-Carlo simulations is analyzed. The resulting code ORBIT provides an accurate means of comparing experimental results with the predictions of kinetic magnetohydrodynamics. The method can be extended to include self consistent modification of the particle orbits by the mode, and hence the full nonlinear dynamics of the coupled system

Surface modification and properties of Bombyx mori silk fibroin films by antimicrobial peptide

International Nuclear Information System (INIS)

Bai Liqiang; Zhu Liangjun; Min Sijia; Liu Lin; Cai Yurong; Yao Juming

2008-01-01

The Bombyx mori silk fibroin films (SFFs) were modified by a Cecropin B (CB) antimicrobial peptide, (NH 2 )-NGIVKAGPAIAVLGEAAL-CONH 2 , using the carbodiimide chemistry method. In order to avoid the dissolution of films during the modification procedure, the SFFs were first treated with 60% (v/v) ethanol aqueous solution, resulting a structural transition from unstable silk I to silk II. The investigation of modification conditions showed that the surface-modified SFFs had the satisfied antimicrobial activity and durability when they were activated by EDC.HCl/NHS solution followed by a treatment in CB peptide/PBS buffer (pH 6.5 or 8) solution at ambient temperature for 2 h. Moreover, the surface-modified SFFs showed the smaller contact angle due to the hydrophilic antimicrobial peptides coupled on the film surface, which is essential for the cell adhesion and proliferation. AFM results indicated that the surface roughness of SFFs was considerably increased after the modification by the peptides. The elemental composition analysis results also suggested that the peptides were tightly coupled to the surface of SFFs. This approach may provide a new option to engineer the surface-modified implanted materials preventing the biomaterial-centered infection (BCI)

Machinability of Minor Wooden Species before and after Modification with Thermo-Vacuum Technology.

Science.gov (United States)

Sandak, Jakub; Goli, Giacomo; Cetera, Paola; Sandak, Anna; Cavalli, Alberto; Todaro, Luigi

2017-01-28

The influence of the thermal modification process on wood machinability was investigated with four minor species of low economic importance. A set of representative experimental samples was machined to the form of disks with sharp and dull tools. The resulting surface quality was visually evaluated by a team of experts according to the American standard procedure ASTM D-1666-87. The objective quantification of the surface quality was also done by means of a three dimensions (3D) surface scanner for the whole range of grain orientations. Visual assessment and 3D surface analysis showed a good agreement in terms of conclusions. The best quality of the wood surface was obtained when machining thermally modified samples. The positive effect of the material modification was apparent when cutting deodar cedar, black pine and black poplar in unfavorable conditions (i.e., against the grain). The difference was much smaller for an easy-machinability specie such as Italian alder. The use of dull tools resulted in the worst surface quality. Thermal modification has shown a very positive effect when machining with dull tools, leading to a relevant increment of the final surface smoothness.

Surface modification and properties of Bombyx mori silk fibroin films by antimicrobial peptide

Energy Technology Data Exchange (ETDEWEB)

Bai Liqiang [Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textile, Zhejiang Sci-Tech University, Xiasha Higher Education Park, Hangzhou 310018 (China); Zhu Liangjun; Min Sijia [College of Animal Sciences, Zhejiang University, Hangzhou 310029 (China); Liu Lin; Cai Yurong [Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textile, Zhejiang Sci-Tech University, Xiasha Higher Education Park, Hangzhou 310018 (China); Yao Juming [Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textile, Zhejiang Sci-Tech University, Xiasha Higher Education Park, Hangzhou 310018 (China)], E-mail: yaoj@zstu.edu.cn

2008-03-15

The Bombyx mori silk fibroin films (SFFs) were modified by a Cecropin B (CB) antimicrobial peptide, (NH{sub 2})-NGIVKAGPAIAVLGEAAL-CONH{sub 2}, using the carbodiimide chemistry method. In order to avoid the dissolution of films during the modification procedure, the SFFs were first treated with 60% (v/v) ethanol aqueous solution, resulting a structural transition from unstable silk I to silk II. The investigation of modification conditions showed that the surface-modified SFFs had the satisfied antimicrobial activity and durability when they were activated by EDC.HCl/NHS solution followed by a treatment in CB peptide/PBS buffer (pH 6.5 or 8) solution at ambient temperature for 2 h. Moreover, the surface-modified SFFs showed the smaller contact angle due to the hydrophilic antimicrobial peptides coupled on the film surface, which is essential for the cell adhesion and proliferation. AFM results indicated that the surface roughness of SFFs was considerably increased after the modification by the peptides. The elemental composition analysis results also suggested that the peptides were tightly coupled to the surface of SFFs. This approach may provide a new option to engineer the surface-modified implanted materials preventing the biomaterial-centered infection (BCI)

A Numerical Model for Trickle Bed Reactors

Science.gov (United States)

Propp, Richard M.; Colella, Phillip; Crutchfield, William Y.; Day, Marcus S.

2000-12-01

Trickle bed reactors are governed by equations of flow in porous media such as Darcy's law and the conservation of mass. Our numerical method for solving these equations is based on a total-velocity splitting, sequential formulation which leads to an implicit pressure equation and a semi-implicit mass conservation equation. We use high-resolution finite-difference methods to discretize these equations. Our solution scheme extends previous work in modeling porous media flows in two ways. First, we incorporate physical effects due to capillary pressure, a nonlinear inlet boundary condition, spatial porosity variations, and inertial effects on phase mobilities. In particular, capillary forces introduce a parabolic component into the recast evolution equation, and the inertial effects give rise to hyperbolic nonconvexity. Second, we introduce a modification of the slope-limiting algorithm to prevent our numerical method from producing spurious shocks. We present a numerical algorithm for accommodating these difficulties, show the algorithm is second-order accurate, and demonstrate its performance on a number of simplified problems relevant to trickle bed reactor modeling.

RNomics and Modomics in the halophilic archaea Haloferax volcanii: identification of RNA modification genes

Directory of Open Access Journals (Sweden)

Decatur Wayne A

2008-10-01

Full Text Available Abstract Background Naturally occurring RNAs contain numerous enzymatically altered nucleosides. Differences in RNA populations (RNomics and pattern of RNA modifications (Modomics depends on the organism analyzed and are two of the criteria that distinguish the three kingdoms of life. If the genomic sequences of the RNA molecules can be derived from whole genome sequence information, the modification profile cannot and requires or direct sequencing of the RNAs or predictive methods base on the presence or absence of the modifications genes. Results By employing a comparative genomics approach, we predicted almost all of the genes coding for the t+rRNA modification enzymes in the mesophilic moderate halophile Haloferax volcanii. These encode both guide RNAs and enzymes. Some are orthologous to previously identified genes in Archaea, Bacteria or in Saccharomyces cerevisiae, but several are original predictions. Conclusion The number of modifications in t+rRNAs in the halophilic archaeon is surprisingly low when compared with other Archaea or Bacteria, particularly the hyperthermophilic organisms. This may result from the specific lifestyle of halophiles that require high intracellular salt concentration for survival. This salt content could allow RNA to maintain its functional structural integrity with fewer modifications. We predict that the few modifications present must be particularly important for decoding, accuracy of translation or are modifications that cannot be functionally replaced by the electrostatic interactions provided by the surrounding salt-ions. This analysis also guides future experimental validation work aiming to complete the understanding of the function of RNA modifications in Archaeal translation.

Laser and chemical surface modifications of titanium grade 2 for medical application

Energy Technology Data Exchange (ETDEWEB)

Kwaśniak, P. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw (Poland); Pura, J., E-mail: jaroslawpura@gmail.com [Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw (Poland); Zwolińska, M.; Wieciński, P. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw (Poland); Skarżyński, H.; Olszewski, L. [Institute of Physiology and Pathology of Hearing, Warsaw (Poland); World Hearing Center, Kajetany (Poland); Marczak, J. [Military University of Technology, Institute of Optoelectronics, Warsaw (Poland); Garbacz, H.; Kurzydłowski, K.J. [Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw (Poland)

2015-05-01

Highlights: • DLIL technique and etching were used for functionalization of Ti grade 2 surface. • Modification was performed on semi-finished flat and curved Ti surfaces. • Modification results in periodic multimodal (micro and nano-size) Ti topography. - Abstract: The article presents combined, chemical and physical approach to titanium surface functionalization designed for biomedical applications. The topography modification has been obtained by employing the double laser beam interference technique and chemical etching. In the outcome, clean and smooth Ti surface as well as periodic striated topography with the roughness range from nano- to micrometers were created. The obtained structures were characterized in terms of shape, roughness, chemical composition, mechanical properties and microstructures. In order to achieve all information, numerous of research methods have been used: scanning electron microscopy, atomic force microscopy, optical profilometry and microhardness measurements. Demonstrated methodology can be used as an effective tool for manufacturing controlled surface structures improving the bone–implants interactions.

Coordinated action of histone modification and microRNA regulations in human genome.

Science.gov (United States)

Wang, Xuan; Zheng, Guantao; Dong, Dong

2015-10-10

Both histone modifications and microRNAs (miRNAs) play pivotal role in gene expression regulation. Although numerous studies have been devoted to explore the gene regulation by miRNA and epigenetic regulations, their coordinated actions have not been comprehensively examined. In this work, we systematically investigated the combinatorial relationship between miRNA and epigenetic regulation by taking advantage of recently published whole genome-wide histone modification data and high quality miRNA targeting data. The results showed that miRNA targets have distinct histone modification patterns compared with non-targets in their promoter regions. Based on this finding, we proposed a machine learning approach to fit predictive models on the task to discern whether a gene is targeted by a specific miRNA. We found a considerable advantage in both sensitivity and specificity in diverse human cell lines. Finally, we found that our predicted miRNA targets are consistently annotated with Gene Ontology terms. Our work is the first genome-wide investigation of the coordinated action of miRNA and histone modification regulations, which provide a guide to deeply understand the complexity of transcriptional regulation. Copyright © 2015 Elsevier B.V. All rights reserved.

Measurement of smaller colon polyp in CT colonography images using morphological image processing.

Science.gov (United States)

Manjunath, K N; Siddalingaswamy, P C; Prabhu, G K

2017-11-01

Automated measurement of the size and shape of colon polyps is one of the challenges in Computed tomography colonography (CTC). The objective of this retrospective study was to improve the sensitivity and specificity of smaller polyp measurement in CTC using image processing techniques. A domain knowledge-based method has been implemented with hybrid method of colon segmentation, morphological image processing operators for detecting the colonic structures, and the decision-making system for delineating the smaller polyp-based on a priori knowledge. The method was applied on 45 CTC dataset. The key finding was that the smaller polyps were accurately measured. In addition to 6-9 mm range, polyps of even processing. It takes [Formula: see text] min for measuring the smaller polyp in a dataset of 500 CTC images. With this method, [Formula: see text] and [Formula: see text] were achieved. The domain-based approach with morphological image processing has given good results. The smaller polyps were measured accurately which helps in making right clinical decisions. Qualitatively and quantitatively the results were acceptable when compared to the ground truth at [Formula: see text].

Simulation of a severe convective storm using a numerical model with explicitly incorporated aerosols

Science.gov (United States)

Lompar, Miloš; Ćurić, Mladjen; Romanic, Djordje

2017-09-01

Despite an important role the aerosols play in all stages of cloud lifecycle, their representation in numerical weather prediction models is often rather crude. This paper investigates the effects the explicit versus implicit inclusion of aerosols in a microphysics parameterization scheme in Weather Research and Forecasting (WRF) - Advanced Research WRF (WRF-ARW) model has on cloud dynamics and microphysics. The testbed selected for this study is a severe mesoscale convective system with supercells that struck west and central parts of Serbia in the afternoon of July 21, 2014. Numerical products of two model runs, i.e. one with aerosols explicitly (WRF-AE) included and another with aerosols implicitly (WRF-AI) assumed, are compared against precipitation measurements from surface network of rain gauges, as well as against radar and satellite observations. The WRF-AE model accurately captured the transportation of dust from the north Africa over the Mediterranean and to the Balkan region. On smaller scales, both models displaced the locations of clouds situated above west and central Serbia towards southeast and under-predicted the maximum values of composite radar reflectivity. Similar to satellite images, WRF-AE shows the mesoscale convective system as a merged cluster of cumulonimbus clouds. Both models over-predicted the precipitation amounts; WRF-AE over-predictions are particularly pronounced in the zones of light rain, while WRF-AI gave larger outliers. Unlike WRF-AI, the WRF-AE approach enables the modelling of time evolution and influx of aerosols into the cloud which could be of practical importance in weather forecasting and weather modification. Several likely causes for discrepancies between models and observations are discussed and prospects for further research in this field are outlined.

Numerical prediction of Pelton turbine efficiency

Energy Technology Data Exchange (ETDEWEB)

Jott, D; Mez' nar, P; Lipej, A, E-mail: dragicajost@turboinstitut.s [Turbointtitut, Rovtnikova 7, Ljubljana, 1210 (Slovenia)

2010-08-15

This paper presents a numerical analysis of flow in a 2 jet Pelton turbine with horizontal axis. The analysis was done for the model at several operating points in different operating regimes. The results were compared to the results of a test of the model. Analysis was performed using ANSYS CFX-12.1 computer code. A k-{omega} SST turbulent model was used. Free surface flow was modelled by two-phase homogeneous model. At first, a steady state analysis of flow in the distributor with two injectors was performed for several needle strokes. This provided us with data on flow energy losses in the distributor and the shape and velocity of jets. The second step was an unsteady analysis of the runner with jets. Torque on the shaft was then calculated from pressure distribution data. Averaged torque values are smaller than measured ones. Consequently, calculated turbine efficiency is also smaller than the measured values, the difference is about 4 %. The shape of the efficiency diagram conforms well to the measurements.

Numerical prediction of Pelton turbine efficiency

Science.gov (United States)

Jošt, D.; Mežnar, P.; Lipej, A.

2010-08-01

This paper presents a numerical analysis of flow in a 2 jet Pelton turbine with horizontal axis. The analysis was done for the model at several operating points in different operating regimes. The results were compared to the results of a test of the model. Analysis was performed using ANSYS CFX-12.1 computer code. A k-ω SST turbulent model was used. Free surface flow was modelled by two-phase homogeneous model. At first, a steady state analysis of flow in the distributor with two injectors was performed for several needle strokes. This provided us with data on flow energy losses in the distributor and the shape and velocity of jets. The second step was an unsteady analysis of the runner with jets. Torque on the shaft was then calculated from pressure distribution data. Averaged torque values are smaller than measured ones. Consequently, calculated turbine efficiency is also smaller than the measured values, the difference is about 4 %. The shape of the efficiency diagram conforms well to the measurements.

Numerical prediction of Pelton turbine efficiency

International Nuclear Information System (INIS)

Jott, D; Mez'nar, P; Lipej, A

2010-01-01

This paper presents a numerical analysis of flow in a 2 jet Pelton turbine with horizontal axis. The analysis was done for the model at several operating points in different operating regimes. The results were compared to the results of a test of the model. Analysis was performed using ANSYS CFX-12.1 computer code. A k-ω SST turbulent model was used. Free surface flow was modelled by two-phase homogeneous model. At first, a steady state analysis of flow in the distributor with two injectors was performed for several needle strokes. This provided us with data on flow energy losses in the distributor and the shape and velocity of jets. The second step was an unsteady analysis of the runner with jets. Torque on the shaft was then calculated from pressure distribution data. Averaged torque values are smaller than measured ones. Consequently, calculated turbine efficiency is also smaller than the measured values, the difference is about 4 %. The shape of the efficiency diagram conforms well to the measurements.

Desirable airfoil features for smaller-capacity straight-bladed VAWT

Energy Technology Data Exchange (ETDEWEB)

Islam, Mazharul; Ting, D.S.-K.; Fartaj, Amir

2007-05-15

In the small scale wind turbine market, the simple straight-bladed Darrieus type vertical axis wind turbine (SB-VAWT) is very attractive for its simple blade design. A detailed aerodynamic performance analysis was conducted on a smaller capacity fixed-pitch SB-VAWT. Brief analyses of the main aerodynamic challenges of this type of wind turbine were first discussed and subsequently the authors conducted further literature survey and computational analysis to shortlist aerodynamic characteristics of a desirable airfoil for a self-starting and better performing SB-VAWT. The required geometric features of the desirable airfoil to achieve the short listed characteristics were also discussed. It has been found out that conventionally used NACA symmetric airfoils are not suitable for smaller capacity SB-VAWT. Rather, it is advantageous to utilize a high-lift and low-drag asymmetric thick airfoil suitable for low speed operation typically encountered by SB-VAWT. (author)

Numerical analysis of whole-body cryotherapy chamber design improvement

Science.gov (United States)

Yerezhep, D.; Tukmakova, A. S.; Fomin, V. E.; Masalimov, A.; Asach, A. V.; Novotelnova, A. V.; Baranov, A. Yu

2018-05-01

Whole body cryotherapy is a state-of-the-art method that uses cold for treatment and prevention of diseases. The process implies the impact of cryogenic gas on a human body that implements in a special cryochamber. The temperature field in the chamber is of great importance since local integument over-cooling may occur. Numerical simulation of WBC has been carried out. Chamber design modification has been proposed in order to increase the uniformity of the internal temperature field. The results have been compared with the ones obtained for a standard chamber design. The value of temperature gradient formed in the chamber containing curved wall with certain height has been decreased almost twice in comparison with the results obtained for the standard design. The modification proposed may increase both safety and comfort of cryotherapy.

Numerical relativity reaching into post-Newtonian territory: a compact-object binary simulation spanning 350 gravitational-wave cycles

Science.gov (United States)

Scheel, Mark; Szilagyi, Bela; Blackman, Jonathan; Chu, Tony; Kidder, Lawrence; Pfeiffer, Harald; Buonanno, Alessandra; Pan, Yi; Taracchini, Andrea; SXS Collaboration

2015-04-01

We present the first numerical-relativity simulation of a compact-object binary whose gravitational waveform is long enough to cover the entire frequency band of advanced gravitational-wave detectors such as LIGO, Virgo and KAGRA, for mass ratio 7 and total mass as low as 45 . 5M⊙ . We find that effective-one-body models, either uncalibrated or calibrated against substantially shorter numerical-relativity waveforms at smaller mass ratios, reproduce our new waveform remarkably well, with a loss in detection rate due to modeling error smaller than 0 . 3 % . In contrast, post-Newtonian inspiral waveforms and existing phenomenological inspiral-merger-ringdown waveforms display much greater disagreement with our new simulation. The disagreement varies substantially depending on the specific post-Newtonian approximant used.

Trends and patterns in smaller companies: The Danish perspective

DEFF Research Database (Denmark)

Ulhøi, John Parm; Madsen, Henning

2000-01-01

This paper presents the empirical findings of a recent survey of Danish managers, with a special focus on managers in smaller companies. The survey, called the 'Danish Management Barometer', is part of a joint research programme between the Aarhus School of Business and the Danish Association...

Numerical analysis of a red blood cell flowing through a thin micropore.

Science.gov (United States)

Omori, Toshihiro; Hosaka, Haruki; Imai, Yohsuke; Yamaguchi, Takami; Ishikawa, Takuji

2014-01-01

Red blood cell (RBC) deformability plays a key role in microcirculation, especially in vessels that have diameters even smaller than the nominal cell size. In this study, we numerically investigate the dynamics of an RBC in a thin micropore. The RBC is modeled as a capsule with a thin hyperelastic membrane. In a numerical simulation, we employ a boundary element method for fluid mechanics and a finite element method for membrane mechanics. The resulting RBC deformation towards the flow direction is suppressed considerably by increased cytoplasm viscosity, whereas the gap between the cell membrane and solid wall becomes smaller with higher cytoplasm viscosity. We also measure the transit time of the RBC and find that nondimensional transit time increases nonlinearly with respect to the viscosity ratio, whereas it is invariant to the capillary number. In conclusion, cytoplasmic viscosity plays a key role in the dynamics of an RBC in a thin pore. The results of this study will be useful for designing a microfluidic device to measure cytoplasmic viscosity.

Numerical simulation of laser shock in the presence of the initial state due to welding

International Nuclear Information System (INIS)

Julan, Emricka

2014-01-01

Surface treatments as laser shock peening offer the possibility to reduce tensile stresses or to generate compressive stresses in order to prevent crack initiation or reduce crack growth rate in particular in the areas where tension weld residual stresses are present. Laser shock peening may be applied on different metallic components to prevent stress corrosion cracking of Inconel 600 and high cycle thermal fatigue of austenitic stainless steels. The main aim of the PhD thesis is to develop the numerical simulation of laser peening. In the first section, axisymmetrical and 3D numerical models for one or several pulses have been developed in Code Aster and Europlexus softwares. These models were validated by experimental tests carried out in PIMM-ENSAM laboratory. Parameters identification of Johnson-Cook constitutive law was carried out for Inconel 600 at high strain rates. Moreover a new test was proposed which allowed proving the isotropic behavior of Inconel 600 at high strain rates. A modification of the Johnson-Cook constitutive law was also proposed, to take into account in a new way the sensitivity of the law to high strain rates. The second section of the thesis concerns a study on the effect of an initial state of welding on residual stresses after application of laser peening. We could conclude that this initial state has no strong influence on final residual stresses. Finally, a qualitative study on the effect of strain hardening induced by laser peening on fatigue life of stainless steels was undertaken, which shows the advantage of laser peening on shot peening due to smaller strain hardening created by laser peening. (author)

Numerical method for solving the inverse problem of quantum scattering theory

International Nuclear Information System (INIS)

Ajrapetyan, R.G.; Puzynin, I.V.; Zhidkov, E.P.

1996-01-01

A new numerical method for solving the problem of the reconstruction of interaction potential by a phase shift given on a set of closed intervals in (l,k)-plane, satisfying certain geometrical 'Staircase Condition', is suggested. The method is based on the Variable Phase Approach and on the modification of the Continuous Analogy of the Newton Method. 22 refs., 1 fig

HIV Distal Neuropathic Pain Is Associated with Smaller Ventral Posterior Cingulate Cortex.

Science.gov (United States)

Keltner, John R; Connolly, Colm G; Vaida, Florin; Jenkinson, Mark; Fennema-Notestine, Christine; Archibald, Sarah; Akkari, Cherine; Schlein, Alexandra; Lee, Jisu; Wang, Dongzhe; Kim, Sung; Li, Han; Rennels, Austin; Miller, David J; Kesidis, George; Franklin, Donald R; Sanders, Chelsea; Corkran, Stephanie; Grant, Igor; Brown, Gregory G; Atkinson, J Hampton; Ellis, Ronald J

2017-03-01

. Despite modern antiretroviral therapy, HIV-associated neuropathy is one of the most prevalent, disabling and treatment-resistant complications of HIV disease. The presence and intensity of distal neuropathic pain is not fully explained by the degree of peripheral nerve damage. A better understanding of brain structure in HIV distal neuropathic pain may help explain why some patients with HIV neuropathy report pain while the majority does not. Previously, we reported that more intense distal neuropathic pain was associated with smaller total cerebral cortical gray matter volumes. The objective of this study was to determine which parts of the cortex are smaller. . HIV positive individuals with and without distal neuropathic pain enrolled in the multisite (N = 233) CNS HIV Antiretroviral Treatment Effects (CHARTER) study underwent structural brain magnetic resonance imaging. Voxel-based morphometry was used to investigate regional brain volumes in these structural brain images. . Left ventral posterior cingulate cortex was smaller for HIV positive individuals with versus without distal neuropathic pain (peak P  = 0.017; peak t = 5.15; MNI coordinates x = -6, y = -54, z = 20). Regional brain volumes within cortical gray matter structures typically associated with pain processing were also smaller for HIV positive individuals having higher intensity ratings of distal neuropathic pain. . The posterior cingulate is thought to be involved in inhibiting the perception of painful stimuli. Mechanistically a smaller posterior cingulate cortex structure may be related to reduced anti-nociception contributing to increased distal neuropathic pain. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Poly(3,4-ethylenedioxythiophene) (PEDOT) polymer coatings facilitate smaller neural recording electrodes

Science.gov (United States)

Ludwig, Kip A.; Langhals, Nicholas B.; Joseph, Mike D.; Richardson-Burns, Sarah M.; Hendricks, Jeffrey L.; Kipke, Daryl R.

2011-02-01

We investigated using poly(3,4-ethylenedioxythiophene) (PEDOT) to lower the impedance of small, gold recording electrodes with initial impedances outside of the effective recording range. Smaller electrode sites enable more densely packed arrays, increasing the number of input and output channels to and from the brain. Moreover, smaller electrode sizes promote smaller probe designs; decreasing the dimensions of the implanted probe has been demonstrated to decrease the inherent immune response, a known contributor to the failure of long-term implants. As expected, chronically implanted control electrodes were unable to record well-isolated unit activity, primarily as a result of a dramatically increased noise floor. Conversely, electrodes coated with PEDOT consistently recorded high-quality neural activity, and exhibited a much lower noise floor than controls. These results demonstrate that PEDOT coatings enable electrode designs 15 µm in diameter.

Dynamics of Stars, Dark Matter and the Universe

DEFF Research Database (Denmark)

Samsing, Johan Georg Mulvad

of these X-rays alone. This has implication for mass measurements which can be used for constraining the amount of matter and dark energy we have in our universe. On even smaller scales I did an interesting study on the interaction between stars and black holes. I especially looked into the interaction where...... a new model independent way of doing this which also seems promising for measuring modifications to the theory of gravity itself. On slightly smaller scales I looked into what happens when two dark matter structures merge. Numerical simulations show that a smaller fraction of the dark matter particles...

Induction of surface modification of polytetrafluoroethylene with proton ion beams

Energy Technology Data Exchange (ETDEWEB)

Noh, I S; Kim, H R; Choi, Y J; Park, H S [Seoul National Univ. of Technology, Seoul (Korea, Republic of)

2007-04-15

Cardiovascular disease is one of the leading causes of the death in the USA and developed countries. More than 570,000 artery bypass graft surgeries per USA are performed each year, though percutaneous devices have abounded in extreme cases. Based on the surgery follow-ups, large diameter expanded polytetrafluoroethylene (ePTFE) (>5 mm) are clinically employed with good results but its clinical applications in smaller vessels is still problematic due to thrombosis and neointima formation. Achievement of high patency grafts has been to some extent achieved by numerous methods of surface modification techniques, but its results are less than its initial hopes. As examples, endothelial cells coated on the luminal surface of ePTFE has demonstrated limited success after recirculation. Surface modifications of PTFE film with either argon ion beam or UV light from Xe-excimer lamp were reported to increase its interaction with vascular endothelial cell. Surface modification of poly(lactide-co-glycolide)[PLGA] is also very important in tissue engineering, in where induction of its initial high cellular adhesion and spreading is a critical step for development of tissue engineering medical products. We previously reported tissue engineering of the hybrid ePTFE scaffold by seeding smooth muscle cells and subsequently evaluation of its tissue regeneration behaviors and stabilities with circulation of pulsatile flow. To improve its tissue engineering more quickly, we here performed surface modification of ePTFE and porous PLGA scaffold and evaluated its subsequent chemical and biological properties after treating its surface with low energy ion beams. The porous ePTFE was prepared in a round shape (diameter = 1 cm) and dried after organic solvent extraction for ion beam treatment. Another porous PLGA layers (d = 1 cm, t = 1 cm with approximately 92% porosity) were fabricated and treated its surface by irradiating low energy either nitrogen or argon ion beams (1 keV, 1x1015 ions

Induction of surface modification of polytetrafluoroethylene with proton ion beams

International Nuclear Information System (INIS)

Noh, I. S.; Kim, H. R.; Choi, Y. J.; Park, H. S.

2007-04-01

Cardiovascular disease is one of the leading causes of the death in the USA and developed countries. More than 570,000 artery bypass graft surgeries per USA are performed each year, though percutaneous devices have abounded in extreme cases. Based on the surgery follow-ups, large diameter expanded polytetrafluoroethylene (ePTFE) (>5 mm) are clinically employed with good results but its clinical applications in smaller vessels is still problematic due to thrombosis and neointima formation. Achievement of high patency grafts has been to some extent achieved by numerous methods of surface modification techniques, but its results are less than its initial hopes. As examples, endothelial cells coated on the luminal surface of ePTFE has demonstrated limited success after recirculation. Surface modifications of PTFE film with either argon ion beam or UV light from Xe-excimer lamp were reported to increase its interaction with vascular endothelial cell. Surface modification of poly(lactide-co-glycolide)[PLGA] is also very important in tissue engineering, in where induction of its initial high cellular adhesion and spreading is a critical step for development of tissue engineering medical products. We previously reported tissue engineering of the hybrid ePTFE scaffold by seeding smooth muscle cells and subsequently evaluation of its tissue regeneration behaviors and stabilities with circulation of pulsatile flow. To improve its tissue engineering more quickly, we here performed surface modification of ePTFE and porous PLGA scaffold and evaluated its subsequent chemical and biological properties after treating its surface with low energy ion beams. The porous ePTFE was prepared in a round shape (diameter = 1 cm) and dried after organic solvent extraction for ion beam treatment. Another porous PLGA layers (d = 1 cm, t = 1 cm with approximately 92% porosity) were fabricated and treated its surface by irradiating low energy either nitrogen or argon ion beams (1 keV, 1x1015 ions

Iterated Crank-Nicolson method for hyperbolic and parabolic equations in numerical relativity

International Nuclear Information System (INIS)

Leiler, Gregor; Rezzolla, Luciano

2006-01-01

The iterated Crank-Nicolson is a predictor-corrector algorithm commonly used in numerical relativity for the solution of both hyperbolic and parabolic partial differential equations. We here extend the recent work on the stability of this scheme for hyperbolic equations by investigating the properties when the average between the predicted and corrected values is made with unequal weights and when the scheme is applied to a parabolic equation. We also propose a variant of the scheme in which the coefficients in the averages are swapped between two corrections leading to systematically larger amplification factors and to a smaller numerical dispersion

Flanking Magnitudes: Dissociation between Numerosity and Numerical Value in a Selective Attention Task

Science.gov (United States)

Naparstek, Sharon; Safadi, Ziad; Lichtenstein-Vidne, Limor; Henik, Avishai

2015-01-01

The current research examined whether peripherally presented numerical information can affect the speed of number processing. In 2 experiments, participants were presented with a target matrix flanked by a distractor matrix and were asked to perform a comparative judgment (i.e., decide whether the target was larger or smaller than the reference…

Validation of an elastic registration technique to estimate anatomical lung modification in Non-Small-Cell Lung Cancer Tomotherapy

International Nuclear Information System (INIS)

Faggiano, Elena; Cattaneo, Giovanni M; Ciavarro, Cristina; Dell'Oca, Italo; Persano, Diego; Calandrino, Riccardo; Rizzo, Giovanna

2011-01-01

The study of lung parenchyma anatomical modification is useful to estimate dose discrepancies during the radiation treatment of Non-Small-Cell Lung Cancer (NSCLC) patients. We propose and validate a method, based on free-form deformation and mutual information, to elastically register planning kVCT with daily MVCT images, to estimate lung parenchyma modification during Tomotherapy. We analyzed 15 registrations between the planning kVCT and 3 MVCT images for each of the 5 NSCLC patients. Image registration accuracy was evaluated by visual inspection and, quantitatively, by Correlation Coefficients (CC) and Target Registration Errors (TRE). Finally, a lung volume correspondence analysis was performed to specifically evaluate registration accuracy in lungs. Results showed that elastic registration was always satisfactory, both qualitatively and quantitatively: TRE after elastic registration (average value of 3.6 mm) remained comparable and often smaller than voxel resolution. Lung volume variations were well estimated by elastic registration (average volume and centroid errors of 1.78% and 0.87 mm, respectively). Our results demonstrate that this method is able to estimate lung deformations in thorax MVCT, with an accuracy within 3.6 mm comparable or smaller than the voxel dimension of the kVCT and MVCT images. It could be used to estimate lung parenchyma dose variations in thoracic Tomotherapy

Polysaccharides from Traditional Chinese Medicines: Extraction, Purification, Modification, and Biological Activity.

Science.gov (United States)

Chen, Yun; Yao, Fangke; Ming, Ke; Wang, Deyun; Hu, Yuanliang; Liu, Jiaguo

2016-12-13

Traditional Chinese Medicine (TCM) has been used to treat diseases in China for thousands of years. TCM compositions are complex, using as their various sources plants, animals, fungi, and minerals. Polysaccharides are one of the active and important ingredients of TCMs. Polysaccharides from TCMs exhibit a wide range of biological activities in terms of immunity- modifying, antiviral, anti-inflammatory, anti-oxidative, and anti-tumor properties. With their widespread biological activities, polysaccharides consistently attract scientist's interests, and the studies often concentrate on the extraction, purification, and biological activity of TCM polysaccharides. Currently, numerous studies have shown that the modification of polysaccharides can heighten or change the biological activities, which is a new angle of polysaccharide research. This review highlights the current knowledge of TCM polysaccharides, including their extraction, purification, modification, and biological activity, which will hopefully provide profound insights facilitating further research and development.

A new numerical approach for uniquely solvable exterior Riemann-Hilbert problem on region with corners

Science.gov (United States)

Zamzamir, Zamzana; Murid, Ali H. M.; Ismail, Munira

2014-06-01

Numerical solution for uniquely solvable exterior Riemann-Hilbert problem on region with corners at offcorner points has been explored by discretizing the related integral equation using Picard iteration method without any modifications to the left-hand side (LHS) and right-hand side (RHS) of the integral equation. Numerical errors for all iterations are converge to the required solution. However, for certain problems, it gives lower accuracy. Hence, this paper presents a new numerical approach for the problem by treating the generalized Neumann kernel at LHS and the function at RHS of the integral equation. Due to the existence of the corner points, Gaussian quadrature is employed which avoids the corner points during numerical integration. Numerical example on a test region is presented to demonstrate the effectiveness of this formulation.

Evaluating response modification factor (R for some types of steel structure

Directory of Open Access Journals (Sweden)

Doralba Valencia Restrepo

2008-01-01

Full Text Available Response modification factor (R, tabulated in the Colombian Design Code as NSR-98, is used in this paper for eva-luating internal member forces produced by design earthquake action on steel structures and the inconsistencies pre-sent when designing structures when 1% drift limits must be complied with. The article presents the design of 45 frames corresponding to the seismic resistance system of 5 buildings: 15 special moment frames (SMF, 15 special concentrically-braced frames (CBF and 15 eccentrically-braced frames (EBF. External loads and their combination were used in estimating internal loads and rigidity demands (1% drift were evaluated in line with NSR-98 requi-rements. Member strength requirements were evaluated by using the AISC-2005 seismic provisions for steel structu-red buildings. Modal pushover analysis was used for evaluating the response modification factor for the 45 given frames at different structural performance levels. It was found that this factor was not constant for any of the three structural systems (SMF, CBF and EBF suggested by NSR-98 and that the values of the response modification factor found in the present investigation were smaller than those tabulated in this design code governing everyday structural design. This would lead to significant errors being made in evaluating design forces, not only in the structures but in the support elements (base-plates, foundations, shear walls and any structures attached to buildings constructed in line with the seismic resistance system.

The Human Thioredoxin System: Modifications and Clinical Applications

Directory of Open Access Journals (Sweden)

Seyed Isaac Hashemy

2011-03-01

Full Text Available The thioredoxin system, comprising thioredoxin (Trx, thioredoxin reductase (TrxR and NADPH, is one of the major cellular antioxidant systems, implicated in a large and growing number of biological functions. Trx acts as an oxidoreductase via a highly conserved dithiol/disulfide motif located in the active site (-Trp-Cys-Gly-Pro-Cys-Lys-. Different factors are involved in the regulation of Trx activity, including its expression level, localization, protein-protein interactions, post-translational modifications and some chemical inhibitors. Mammalian TrxRs are selenoproteins which have a –Cys-Val-Asn-Val-Gly-Cys- N-terminal active site, as well as a C-terminal selenium-containing active site. Besides two Cys-residues in the redox-regulatory domain of cytosolic Trx (Trx1, human Trx1 has three additional Cys-residues. Post-translational modifications of human Trx1 which are involved in the regulation of its activity can happen via modification of Cys-residues including thiol oxidation, glutathionylation and S-nitrosylation or via modification of other amino acid residues such as nitration of Tyr-49. Because of the numerous functions of the thioredoxin system, its inhibition (mainly happens via the targeting TrxR can result in major cellular consequences, which are potentially pro-oxidant in nature, leading to cell death via necrosis or apoptosis if overexpression of Trx and other antioxidative enzymes can not recuperate cell response. Considering this feature, several anticancer drugs have been used which can inhibit TrxR. Elevated levels of Trx and/or TrxR have been reported in many different human malignancies, positively correlated with aggressive tumor growth and poor prognosis. Moreover, anti-oxidative and anti-apoptotic effects of Trx are reasons to study its clinical application as a drug.

Modifying a numerical algorithm for solving the matrix equation X + AX T B = C

Science.gov (United States)

Vorontsov, Yu. O.

2013-06-01

Certain modifications are proposed for a numerical algorithm solving the matrix equation X + AX T B = C. By keeping the intermediate results in storage and repeatedly using them, it is possible to reduce the total complexity of the algorithm from O( n 4) to O( n 3) arithmetic operations.

Library Homepage Design at Smaller Bachelor of Arts Institutions

Science.gov (United States)

Jones, Scott L.; Leonard, Kirsten

2011-01-01

This study examined the homepages of the libraries of 175 smaller bachelor of arts institutions, coding for the presence of 98 design elements. By reporting and examining the frequency of these features, the authors noted what is and is not common practice at these libraries. They found that only fourteen elements were present on at least half of…

Numerical simulations of comets - predictions for Comet Giacobini-Zinner

International Nuclear Information System (INIS)

Fedder, J.A.; Lyon, J.G.; Giuliani, J.L. Jr.

1986-01-01

Simulations of Comet Giacobini-Zinner's interaction with solar wind are described and results are presented. The simulations are carried out via the numerical solution of the ideal MHD equations as an initial value problem in a uniform solar wind. The calculations are performed on a Cartesian mesh centered at the comet. Results reveal that the first significant modifications of the solar wind along the ISEE/ICE trajectory will occur 100,000 km from the solar wind comet axis. 6 references

Healthcare security staffing for smaller facilities: where science meets art.

Science.gov (United States)

Warren, Bryan

2013-01-01

Obtaining effective security resourcing and staffing for smaller healthcare facilities presents many difficulties, according to the author In this article, he provides guidance to security practitioners on taking existing data and translating it into a language that administration will understand and appreciate.

Opportunities for smaller engineering companies despite globalization. Chancen kleiner Ingenieurbueros trotz Globalisierung

Energy Technology Data Exchange (ETDEWEB)

Lorentzen, P. (IPL Ingenieurbuero Peter Lorentzen, Frankfurt am Main (Germany))

1999-06-01

The trend to size is escalating into gigantism. The biggest in the branch merge to become the oversized. In view of this situation, the question which arises is what are the survival chances of the smaller players Will they all drop out of the running The answer to this question does not only concern the future order books of smaller companies, but in conjunction therewith and predominately the social security of employees, type and scope of assignments as well as the competitive situation and the consequences of all these on remuneration. (orig.)

Polysaccharides from Traditional Chinese Medicines: Extraction, Purification, Modification, and Biological Activity

Directory of Open Access Journals (Sweden)

Yun Chen

2016-12-01

Full Text Available Traditional Chinese Medicine (TCM has been used to treat diseases in China for thousands of years. TCM compositions are complex, using as their various sources plants, animals, fungi, and minerals. Polysaccharides are one of the active and important ingredients of TCMs. Polysaccharides from TCMs exhibit a wide range of biological activities in terms of immunity- modifying, antiviral, anti-inflammatory, anti-oxidative, and anti-tumor properties. With their widespread biological activities, polysaccharides consistently attract scientist's interests, and the studies often concentrate on the extraction, purification, and biological activity of TCM polysaccharides. Currently, numerous studies have shown that the modification of polysaccharides can heighten or change the biological activities, which is a new angle of polysaccharide research. This review highlights the current knowledge of TCM polysaccharides, including their extraction, purification, modification, and biological activity, which will hopefully provide profound insights facilitating further research and development.

Numerical relativity in spherical coordinates with the Einstein Toolkit

Science.gov (United States)

Mewes, Vassilios; Zlochower, Yosef; Campanelli, Manuela; Ruchlin, Ian; Etienne, Zachariah B.; Baumgarte, Thomas W.

2018-04-01

Numerical relativity codes that do not make assumptions on spatial symmetries most commonly adopt Cartesian coordinates. While these coordinates have many attractive features, spherical coordinates are much better suited to take advantage of approximate symmetries in a number of astrophysical objects, including single stars, black holes, and accretion disks. While the appearance of coordinate singularities often spoils numerical relativity simulations in spherical coordinates, especially in the absence of any symmetry assumptions, it has recently been demonstrated that these problems can be avoided if the coordinate singularities are handled analytically. This is possible with the help of a reference-metric version of the Baumgarte-Shapiro-Shibata-Nakamura formulation together with a proper rescaling of tensorial quantities. In this paper we report on an implementation of this formalism in the Einstein Toolkit. We adapt the Einstein Toolkit infrastructure, originally designed for Cartesian coordinates, to handle spherical coordinates, by providing appropriate boundary conditions at both inner and outer boundaries. We perform numerical simulations for a disturbed Kerr black hole, extract the gravitational wave signal, and demonstrate that the noise in these signals is orders of magnitude smaller when computed on spherical grids rather than Cartesian grids. With the public release of our new Einstein Toolkit thorns, our methods for numerical relativity in spherical coordinates will become available to the entire numerical relativity community.

Numerical perturbative methods in the quantum theory of physical systems

International Nuclear Information System (INIS)

Adam, G.

1980-01-01

During the last two decades, development of digital electronic computers has led to the deployment of new, distinct methods in theoretical physics. These methods, based on the advances of modern numerical analysis as well as on specific equations describing physical processes, enabled to perform precise calculations of high complexity which have completed and sometimes changed our image of many physical phenomena. Our efforts have concentrated on the development of numerical methods with such intrinsic performances as to allow a successful approach of some Key issues in present theoretical physics on smaller computation systems. The basic principle of such methods is to translate, in numerical analysis language, the theory of perturbations which is suited to numerical rather than to analytical computation. This idea has been illustrated by working out two problems which arise from the time independent Schroedinger equation in the non-relativistic approximation, within both quantum systems with a small number of particles and systems with a large number of particles, respectively. In the first case, we are led to the numerical solution of some quadratic ordinary differential equations (first section of the thesis) and in the second case, to the solution of some secular equations in the Brillouin area (second section). (author)

Numerical modeling of working of a multicellular proportional counter aimed to individual dosimetry of neutrons

International Nuclear Information System (INIS)

Bordy, J.M.; Barthe, J.; Boutruche, B.

1993-01-01

The use of a personal dosimeter imposes severe constraints, particularly for tension of polarization and tolerable dimensions. That why a numerical modeling of this detector working is an appreciable help for conception. It allows to determine quickly the influence of modification of different parameters (nature and pressure of gas, dimension of electrodes, dimension of channels, tension of polarization,...) without having to make new prototypes. The aim of this report is to give some numerical results got with a multicellular counter with a cylindrical geometry. 6 figs

Numerical Analysis of Aerodynamic Characteristics of the Finned Surfaces with Cross-inclined Fins

Directory of Open Access Journals (Sweden)

Lagutin A. E.

2016-12-01

Full Text Available This paper presents results of numerical research and analyses air-side hydraulic performance of tube bundles with cross inclined fins. The numerical simulation of the fin-tube heat exchanger was performed using the Comsol Femlab software. The results of modeling show the influence of fin inclination angle and tube pitch on hydraulic characteristics of finned surfaces. A series of numerical tests were carried out for tube bundles with different inclination angles (γ =900, 850, 650, 60, the fin pitch u=4 mm. The results indicate that tube bundles with cross inclined fins can significantly enhance the average integral value of the air flow rate in channel between fins in comparison with conventional straight fins. Aerodynamic processes on both sides of modificated channel between inclined fins were analyzed. The verification procedures for received results of numerical modeling with experimental data were performed.

Influence of microstructure modification on the circumferential creep of Zr–Nb–Sn–Fe cladding tubes

International Nuclear Information System (INIS)

Jeong, Gu Beom; Kim, In Won; Hong, Sun Ig

2016-01-01

Out-of-reactor, non-irradiated thermal creep performances and lives of annealed and stress-relieved Zr-1.02Nb-0.69Sn-0.12Fe cladding tubes were studied and compared. The creep rates of annealed Zr-1.02Nb-0.69Sn-0.12Fe cladding tubes were appreciably slower than those of stress-relieved annealed counterpart. The stress exponent increased slightly from 5.1 to 6.1 in the stress-relieved cladding to 5.3–6.3 in the annealed cladding. The creep activation energy of the annealed Zr-1.02Nb-0.69Sn-0.12Fe alloy (300–330 kJ/mol) was larger compared to that of the stress-relieved alloy (210–260 kJ/mol). The creep activation energy of annealed alloy is close to that of self-diffusion in α-Zr (336 kJ/mol). The smaller activation energy in the stress-relieved alloy is attributed to the increasing contribution of faster diffusion path such as grain boundaries and dislocations. The presence of dislocation arrays with higher dislocation density and smaller grain size in the stress-relived alloy was confirmed by TEM analysis. The creep rupture time increased dramatically in the annealed Zr–1Nb- 0.7Sn-0.1Fe alloy compared to that of stress-relieved alloy, supporting the decrease of creep rate by annealing. The creep life of Zr-1.02Nb-0.69Sn-0.12Fe claddings can be extended through microstructure modification by annealing at intermediate temperatures in which dislocation creep dominates. - Highlights: • Effect of microstructure modification on creep in Zr–Nb–Sn–Fe tubes was studied. • Creep activation energy in annealed tubes was larger than in stress-relieved tubes. • Lower dislocation density in lager grains was observed after creep in annealed tubes. • Larson–Miller parameter of annealed tube was larger than that of stress-relieved one. • Creep life of tubes was extended through microstructure modification by annealing.

Effects of Shear Fracture on In-depth Profile Modification of Weak Gels

Institute of Scientific and Technical Information of China (English)

Li Xianjie; Song Xinwang; Yue Xiang'an; Hou Jirui; Fang Lichun; Zhang Huazhen

2007-01-01

Two sand packs were filled with fine glass beads and quartz sand respectively. The characteristics of crosslinked polymer flowing through the sand packs as well as the influence of shear fracture of porous media on the in-depth profile modification of the weak gel generated from the crosslinked polymer were investigated. The results indicated that under the dynamic condition crosslinking reaction happened in both sand packs,and the weak gels in these two cases became small gel particles after water flooding. The differences were:the dynamic gelation time in the quartz sand pack was longer than that in the glass bead pack. Residual resistance factor (FRR) caused by the weak gel in the quartz sand pack was smaller than that in the glass bead pack. The weak gel became gel particles after being scoured by subsequent flood water. A weak gel with uniform apparent viscosity and sealing characteristics was generated in every part of the glass bead pack,which could not only move deeply into the sand pack but also seal the high capacity channels again when it reached the deep part. The weak gel performed in-depth profile modification in the glass bead pack,while in the quartz sand pack,the weak gel was concentrated with 100 cm from the entrance of the sand pack. When propelled by the subsequent flood water,the weak gel could move towards the deep part of the sand pack but then became tiny gel particles and could not effectively seal the high capacity channels there. The in-depth profile modification of the weak gel was very weak in the quartz sand pack. It was the shear fracture of porous media that mainly affected the properties and weakened the in-depth profile modification of the weak gel.

Evaluation of wave runup predictions from numerical and parametric models

Science.gov (United States)

Stockdon, Hilary F.; Thompson, David M.; Plant, Nathaniel G.; Long, Joseph W.

2014-01-01

Wave runup during storms is a primary driver of coastal evolution, including shoreline and dune erosion and barrier island overwash. Runup and its components, setup and swash, can be predicted from a parameterized model that was developed by comparing runup observations to offshore wave height, wave period, and local beach slope. Because observations during extreme storms are often unavailable, a numerical model is used to simulate the storm-driven runup to compare to the parameterized model and then develop an approach to improve the accuracy of the parameterization. Numerically simulated and parameterized runup were compared to observations to evaluate model accuracies. The analysis demonstrated that setup was accurately predicted by both the parameterized model and numerical simulations. Infragravity swash heights were most accurately predicted by the parameterized model. The numerical model suffered from bias and gain errors that depended on whether a one-dimensional or two-dimensional spatial domain was used. Nonetheless, all of the predictions were significantly correlated to the observations, implying that the systematic errors can be corrected. The numerical simulations did not resolve the incident-band swash motions, as expected, and the parameterized model performed best at predicting incident-band swash heights. An assimilated prediction using a weighted average of the parameterized model and the numerical simulations resulted in a reduction in prediction error variance. Finally, the numerical simulations were extended to include storm conditions that have not been previously observed. These results indicated that the parameterized predictions of setup may need modification for extreme conditions; numerical simulations can be used to extend the validity of the parameterized predictions of infragravity swash; and numerical simulations systematically underpredict incident swash, which is relatively unimportant under extreme conditions.

Numerical study of two-dimensional moist symmetric instability

Directory of Open Access Journals (Sweden)

M. Fantini

2008-06-01

Full Text Available The 2-D version of the non-hydrostatic fully compressible model MOLOCH developed at ISAC-CNR was used in idealized set-up to study the start-up and finite amplitude evolution of symmetric instability. The unstable basic state was designed by numerical integration of the equation which defines saturated equivalent potential vorticity q_e^*. We present the structure and growth rates of the linear modes both for a supersaturated initial state ("super"-linear mode and for a saturated one ("pseudo"-linear mode and the modifications induced on the base state by their finite amplitude evolution.

Concept and numerical simulations of a reactive anti-fragment armour layer

Science.gov (United States)

Hušek, Martin; Kala, Jiří; Král, Petr; Hokeš, Filip

2017-07-01

The contribution describes the concept and numerical simulation of a ballistic protective layer which is able to actively resist projectiles or smaller colliding fragments flying at high speed. The principle of the layer was designed on the basis of the action/reaction system of reactive armour which is used for the protection of armoured vehicles. As the designed ballistic layer consists of steel plates simultaneously combined with explosive material - primary explosive and secondary explosive - the technique of coupling the Finite Element Method with Smoothed Particle Hydrodynamics was used for the simulations. Certain standard situations which the ballistic layer should resist were simulated. The contribution describes the principles for the successful execution of numerical simulations, their results, and an evaluation of the functionality of the ballistic layer.

Experimental and numerical modeling research of rubber material during microwave heating process

Science.gov (United States)

Chen, Hailong; Li, Tao; Li, Kunling; Li, Qingling

2018-05-01

This paper aims to investigate the heating behaviors of block rubber by experimental and simulated method. The COMSOL Multiphysics 5.0 software was utilized in numerical simulation work. The effects of microwave frequency, power and sample size on temperature distribution are examined. The effect of frequency on temperature distribution is obvious. The maximum and minimum temperatures of block rubber increase first and then decrease with frequency increasing. The microwave heating efficiency is maximum in the microwave frequency of 2450 MHz. However, more uniform temperature distribution is presented in other microwave frequencies. The influence of microwave power on temperature distribution is also remarkable. The smaller the power, the more uniform the temperature distribution on the block rubber. The effect of power on microwave heating efficiency is not obvious. The effect of sample size on temperature distribution is evidently found. The smaller the sample size, the more uniform the temperature distribution on the block rubber. However, the smaller the sample size, the lower the microwave heating efficiency. The results can serve as references for the research on heating rubber material by microwave technology.

Modifications to POISSON

International Nuclear Information System (INIS)

Harwood, L.H.

1981-01-01

At MSU we have used the POISSON family of programs extensively for magnetic field calculations. In the presently super-saturated computer situation, reducing the run time for the program is imperative. Thus, a series of modifications have been made to POISSON to speed up convergence. Two of the modifications aim at having the first guess solution as close as possible to the final solution. The other two aim at increasing the convergence rate. In this discussion, a working knowledge of POISSON is assumed. The amount of new code and expected time saving for each modification is discussed

Modification of transition's factor in the compact surface-potential-based MOSFET model

Directory of Open Access Journals (Sweden)

Kevkić Tijana

2016-01-01

Full Text Available The modification of an important transition's factor which enables continual behavior of the surface potential in entire useful range of MOSFET operation is presented. The various modifications have been made in order to obtain an accurate and computationally efficient compact MOSFET model. The best results have been achieved by introducing the generalized logistic function (GL in fitting of considered factor. The smoothness and speed of the transition of the surface potential from the depletion to the strong inversion region can be controlled in this way. The results of the explicit model with this GL functional form for transition's factor have been verified extensively with the numerical data. A great agreement was found for a wide range of substrate doping and oxide thickness. Moreover, the proposed approach can be also applied on the case where quantum mechanical effects play important role in inversion mode.

The Underreported Use of Integrated Marketing Communication by Smaller Businesses.

Science.gov (United States)

Johnson, Ed

This research suggests integrated marketing communication (IMC) is widely used by small business. In a survey of Midwest businesses, it was found that smaller business tend to integrate their marketing communication to the same extent as do larger businesses. Their advertising, P.R., and sales promotion are as likely to present a unified message,…

Three-dimensional two-fluid numerical treatment of a reactor vessel in TRAC

International Nuclear Information System (INIS)

Liles, D.R.

1979-01-01

A three-dimensional two-fluid finite difference model has been used in TRAC (Transient Reactor Analysis Code) to represent a pressurized water reactor vessel. Mesh cells may be blocked off completely to represent large flow obstructions such as downcomer walls. The hydrodynamic volumes and flow areas may also be reduced in order to provide a porous matrix simulation of smaller scale strucuture. The finite difference equations are semi-implicit so that stability time scales are associated with material movement and not wave propagation. The block matrix structure is reduced during the implicit pass to a single element seven stripe system which is easily solved iteratively. This procedure has successfully performed numerous simulations of both full sized reactor accidents and smaller scale experments. It has proven to be a useful feature of the TRAC effort

Improved modification for in vitro labeling of red blood cells with Technetium-99m

International Nuclear Information System (INIS)

Gerson, B.; Ballinger, J.R.; Gulenchyn, K.Y.

1988-01-01

The authors have tested a modification of Brookhaven method for in vitro labeling of red blood cells (RBCs) with technetium-99m by adding an initial centrifugation step and performing the labeling on packed RBCs. This results in reproducible, high labeling efficiencies (99.3% +/- 0.4%, n = 50) after 15 min of incubation. The use of packed RBCs also results in a higher concentration of labeled RBCs (smaller bolus for injection) and less radiation exposure to the technologist. This technique has proved useful for radionuclide angiography, venography, gastrointestinal bleeding studies, and red cell mass determinations. It is particularly advantageous for RBC labeling in patients receiving chemotherapy

Adaptive cyclically dominating game on co-evolving networks: numerical and analytic results

Science.gov (United States)

Choi, Chi Wun; Xu, Chen; Hui, Pak Ming

2017-10-01

A co-evolving and adaptive Rock (R)-Paper (P)-Scissors (S) game (ARPS) in which an agent uses one of three cyclically dominating strategies is proposed and studied numerically and analytically. An agent takes adaptive actions to achieve a neighborhood to his advantage by rewiring a dissatisfying link with a probability p or switching strategy with a probability 1 - p. Numerical results revealed two phases in the steady state. An active phase for p pc has three separate clusters of agents using only R, P, and S, respectively with terminated adaptive actions. A mean-field theory based on the link densities in co-evolving network is formulated and the trinomial closure scheme is applied to obtain analytical solutions. The analytic results agree with simulation results on ARPS well. In addition, the different probabilities of winning, losing, and drawing a game among the agents are identified as the origin of the small discrepancy between analytic and simulation results. As a result of the adaptive actions, agents of higher degrees are often those being taken advantage of. Agents with a smaller (larger) degree than the mean degree have a higher (smaller) probability of winning than losing. The results are informative for future attempts on formulating more accurate theories.

Numerical modelling of random walk one-dimensional diffusion

International Nuclear Information System (INIS)

Vamos, C.; Suciu, N.; Peculea, M.

1996-01-01

The evolution of a particle which moves on a discrete one-dimensional lattice, according to a random walk low, approximates better the diffusion process smaller the steps of the spatial lattice and time are. For a sufficiently large assembly of particles one can assume that their relative frequency at lattice knots approximates the distribution function of the diffusion process. This assumption has been tested by simulating on computer two analytical solutions of the diffusion equation: the Brownian motion and the steady state linear distribution. To evaluate quantitatively the similarity between the numerical and analytical solutions we have used a norm given by the absolute value of the difference of the two solutions. Also, a diffusion coefficient at any lattice knots and moment of time has been calculated, by using the numerical solution both from the diffusion equation and the particle flux given by Fick's low. The difference between diffusion coefficient of analytical solution and the spatial lattice mean coefficient of numerical solution constitutes another quantitative indication of the similarity of the two solutions. The results obtained show that the approximation depends first on the number of particles at each knot of the spatial lattice. In conclusion, the random walk is a microscopic process of the molecular dynamics type which permits simulations precision of the diffusion processes with given precision. The numerical method presented in this work may be useful both in the analysis of real experiments and for theoretical studies

The role of interpretation in the internationalization of smaller brazilian firms

NARCIS (Netherlands)

R.W. Seifert (Ralf); J. Child (John); S.B. Rodrigues (Suzana)

2012-01-01

textabstractAbstract This study considers how decision-makers in smaller firms interpret the means and conditions of internationalization, and how different modes of interpretation are likely to inform action choices in this process. Drawing on 58 qualitative interviews with the leaders of

Economic characteristics of a smaller, simpler reactor

International Nuclear Information System (INIS)

LaBar, M.; Bowers, H.

1988-01-01

Reduced load growth and heightened concern with economic risk has led to an expressed utility preference for smaller capacity additions. The Modular High Temperature Reactor (MHTGR) plant has been developed as a small, simple plant that has limited financial risk and is economically competitive with comparatively sized coal plants. Competitive economics is achieved by the simplifications made possible in a small MHTGR, reduction in the quantity of nuclear grade construction and design standardization and certification. Assessments show the MHTGR plant to have an economic advantage over coal plants for plant sizes from 270 MWe to 1080 MWe. Financial risk is limited by small unit sizes and short lead times that allow incremental deployment. Evaluations show the MHTGR incremental deployment capability to reduce negative cash flows by almost a factor of 2 relative to that required by a single large nuclear plant

Surface modification of malachite with ethanediamine and its effect on sulfidization flotation

Science.gov (United States)

Feng, Qicheng; Zhao, Wenjuan; Wen, Shuming

2018-04-01

Ethanediamine was used to modify the mineral surface of malachite to improve its sulfidization and flotation behavior. The activation mechanism was investigated by adsorption experiments, X-ray photoelectron spectroscopy (XPS) analysis, and zeta potential measurements. Microflotation experiments showed that the flotation recovery of malachite was enhanced after the pretreatment of the mineral particles with ethanediamine prior to the addition of Na2S. Adsorption tests revealed that numerous sulfide ion species in the pulp solution were transferred onto the mineral surface through the formation of more copper sulfide species. This finding was confirmed by the results of the XPS measurements. Ethanediamine modification not only increased the contents of copper sulfide species on the malachite surface but also enhanced the reactivity of the sulfidization products. During sulfidization, Cu(II) species on the mineral surface were reduced into Cu(I) species, and the percentages of S22- and Sn2- relative to the total S increased after modification, resulting in increased surface hydrophobicity. The results of zeta potential measurements showed that the ethanediamine-modified mineral surface adsorbed with more sulfide ion species was advantageous to the attachment of xanthate species, thereby improving malachite floatability. The proposed ethanediamine modification followed by sulfidization xanthate flotation exhibits potential for industrial application.

The instanton method and its numerical implementation in fluid mechanics

Science.gov (United States)

Grafke, Tobias; Grauer, Rainer; Schäfer, Tobias

2015-08-01

A precise characterization of structures occurring in turbulent fluid flows at high Reynolds numbers is one of the last open problems of classical physics. In this review we discuss recent developments related to the application of instanton methods to turbulence. Instantons are saddle point configurations of the underlying path integrals. They are equivalent to minimizers of the related Freidlin-Wentzell action and known to be able to characterize rare events in such systems. While there is an impressive body of work concerning their analytical description, this review focuses on the question on how to compute these minimizers numerically. In a short introduction we present the relevant mathematical and physical background before we discuss the stochastic Burgers equation in detail. We present algorithms to compute instantons numerically by an efficient solution of the corresponding Euler-Lagrange equations. A second focus is the discussion of a recently developed numerical filtering technique that allows to extract instantons from direct numerical simulations. In the following we present modifications of the algorithms to make them efficient when applied to two- or three-dimensional (2D or 3D) fluid dynamical problems. We illustrate these ideas using the 2D Burgers equation and the 3D Navier-Stokes equations.

The instanton method and its numerical implementation in fluid mechanics

International Nuclear Information System (INIS)

Grafke, Tobias; Grauer, Rainer; Schäfer, Tobias

2015-01-01

A precise characterization of structures occurring in turbulent fluid flows at high Reynolds numbers is one of the last open problems of classical physics. In this review we discuss recent developments related to the application of instanton methods to turbulence. Instantons are saddle point configurations of the underlying path integrals. They are equivalent to minimizers of the related Freidlin–Wentzell action and known to be able to characterize rare events in such systems. While there is an impressive body of work concerning their analytical description, this review focuses on the question on how to compute these minimizers numerically. In a short introduction we present the relevant mathematical and physical background before we discuss the stochastic Burgers equation in detail. We present algorithms to compute instantons numerically by an efficient solution of the corresponding Euler–Lagrange equations. A second focus is the discussion of a recently developed numerical filtering technique that allows to extract instantons from direct numerical simulations. In the following we present modifications of the algorithms to make them efficient when applied to two- or three-dimensional (2D or 3D) fluid dynamical problems. We illustrate these ideas using the 2D Burgers equation and the 3D Navier–Stokes equations. (topical review)

Sensible Heat Transfer during Droplet Cooling: Experimental and Numerical Analysis

Directory of Open Access Journals (Sweden)

Emanuele Teodori

2017-06-01

Full Text Available This study presents the numerical reproduction of the entire surface temperature field resulting from a water droplet spreading on a heated surface, which is compared with experimental data. High-speed infrared thermography of the back side of the surface and high-speed images of the side view of the impinging droplet were used to infer on the solid surface temperature field and on droplet dynamics. Numerical reproduction of the phenomena was performed using OpenFOAM CFD toolbox. An enhanced volume of fluid (VOF model was further modified for this purpose. The proposed modifications include the coupling of temperature fields between the fluid and the solid regions, to account for transient heat conduction within the solid. The results evidence an extremely good agreement between the temporal evolution of the measured and simulated spreading factors of the considered droplet impacts. The numerical and experimental dimensionless surface temperature profiles within the solid surface and along the droplet radius, were also in good agreement. Most of the differences were within the experimental measurements uncertainty. The numerical results allowed relating the solid surface temperature profiles with the fluid flow. During spreading, liquid recirculation within the rim, leads to the appearance of different regions of heat transfer that can be correlated with the vorticity field within the droplet.

Genetic modification and genetic determinism

Science.gov (United States)

Resnik, David B; Vorhaus, Daniel B

2006-01-01

In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions. PMID:16800884

Genetic modification and genetic determinism

Directory of Open Access Journals (Sweden)

Vorhaus Daniel B

2006-06-01

Full Text Available Abstract In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions.

Accommodating for plant modifications

International Nuclear Information System (INIS)

Weirich, P.H.

1977-01-01

Modification to a nuclear power plant may have different causes: 1) new instructions by the authorities; 2) changes of the marginal conditions on the construction site; 3) progress in the technological development. - Examples from different plants are supposed to demonstrate how such changes influence the planning or the construction and how they are integrated in the process of preparation. A distinction can be made between modifications before the completion of the submission of the order, during the phase of preparatory planning and during the construction phase. Of great importance are especially modifications made after the beginning of the construction works, since, in general, there is little scope for technical modifications and since consequences for the time schedule are to be expected. (orig.) [de

Role of Transcription Factor Modifications in the Pathogenesis of Insulin Resistance

Directory of Open Access Journals (Sweden)

Mi-Young Kim

2012-01-01

Full Text Available Non-alcoholic fatty liver disease (NAFLD is characterized by fat accumulation in the liver not due to alcohol abuse. NAFLD is accompanied by variety of symptoms related to metabolic syndrome. Although the metabolic link between NAFLD and insulin resistance is not fully understood, it is clear that NAFLD is one of the main cause of insulin resistance. NAFLD is shown to affect the functions of other organs, including pancreas, adipose tissue, muscle and inflammatory systems. Currently efforts are being made to understand molecular mechanism of interrelationship between NAFLD and insulin resistance at the transcriptional level with specific focus on post-translational modification (PTM of transcription factors. PTM of transcription factors plays a key role in controlling numerous biological events, including cellular energy metabolism, cell-cycle progression, and organ development. Cell type- and tissue-specific reversible modifications include lysine acetylation, methylation, ubiquitination, and SUMOylation. Moreover, phosphorylation and O-GlcNAcylation on serine and threonine residues have been shown to affect protein stability, subcellular distribution, DNA-binding affinity, and transcriptional activity. PTMs of transcription factors involved in insulin-sensitive tissues confer specific adaptive mechanisms in response to internal or external stimuli. Our understanding of the interplay between these modifications and their effects on transcriptional regulation is growing. Here, we summarize the diverse roles of PTMs in insulin-sensitive tissues and their involvement in the pathogenesis of insulin resistance.

How food marketers can sell smaller portions: Consumer insights and product innovation.

Science.gov (United States)

Riis, J; Fisher, J O; Rowe, S

2016-08-01

Food portion size has been shown to be an important driver of energy intake. Despite the well acknowledged role of portion control in weight management, large portion sizes remain ubiquitous in the marketplace. Moving consumers towards consumption of smaller portion sizes will require changes in consumer behavior as well as changes in products available to consumers in a variety of settings. This special supplement presents cutting edge research aimed at understanding consumer behavior around portion size and innovations in product design that may promote the selection and consumption of smaller portion sizes. We identify further research that will be needed to translate basic behavioral findings into real world settings and to viable product development. Copyright © 2016. Published by Elsevier Ltd.

Comparison between smaller ruptured intracranial aneurysm and larger un-ruptured intracranial aneurysm: gene expression profile analysis.

Science.gov (United States)

Li, Hao; Li, Haowen; Yue, Haiyan; Wang, Wen; Yu, Lanbing; ShuoWang; Cao, Yong; Zhao, Jizong

2017-07-01

As it grows in size, an intracranial aneurysm (IA) is prone to rupture. In this study, we compared two extreme groups of IAs, ruptured IAs (RIAs) smaller than 10 mm and un-ruptured IAs (UIAs) larger than 10 mm, to investigate the genes involved in the facilitation and prevention of IA rupture. The aneurismal walls of 6 smaller saccular RIAs (size smaller than 10 mm), 6 larger saccular UIAs (size larger than 10 mm) and 12 paired control arteries were obtained during surgery. The transcription profiles of these samples were studied by microarray analysis. RT-qPCR was used to confirm the expression of the genes of interest. In addition, functional group analysis of the differentially expressed genes was performed. Between smaller RIAs and larger UIAs, 101 genes and 179 genes were significantly over-expressed, respectively. In addition, functional group analysis demonstrated that the up-regulated genes in smaller RIAs mainly participated in the cellular response to metal ions and inorganic substances, while most of the up-regulated genes in larger UIAs were involved in inflammation and extracellular matrix (ECM) organization. Moreover, compared with control arteries, inflammation was up-regulated and muscle-related biological processes were down-regulated in both smaller RIAs and larger UIAs. The genes involved in the cellular response to metal ions and inorganic substances may facilitate the rupture of IAs. In addition, the healing process, involving inflammation and ECM organization, may protect IAs from rupture.

Modification of Duval Triangle for Diagnostic Transformer Fault through a Procedure of Dissolved Gases Analysis

Directory of Open Access Journals (Sweden)

Sobhy Serry Dessouky

2016-08-01

    The evaluation is carried out on DGA data obtained from three different groups of transformers. A Matlab program was developed to automate the evaluation of  Duval Triangle graph to numerical modification, Also the fault gases can be generated due to oil decomposing effected by transformer over excitation which increasing thetransformer exciting current lead to rising the temperature inside transformer core beside the other causes.

Biomaterials modification by ion beam

International Nuclear Information System (INIS)

Zhang Tonghe; Yi Zhongzhen; Zhang Xu; Wu Yuguang

2001-01-01

Ion beam technology is one of best ways for the modification of biomaterials. The results of ion beam modification of biomaterials are given. The method and results of improved biocompatibility are indicated by ion beam technology. The future development of ion beam modification of biomaterials is discussed

Site-specific mapping of the human SUMO proteome reveals co-modification with phosphorylation

DEFF Research Database (Denmark)

Hendriks, Ivo A; Lyon, David; Young, Clifford

2017-01-01

that were co-modified by ubiquitylation, acetylation and methylation. Notably, 9% of the identified SUMOylome occurred proximal to phosphorylation, and numerous SUMOylation sites were found to be fully dependent on prior phosphorylation events. SUMO-proximal phosphorylation occurred primarily in a proline......-directed manner, and inhibition of cyclin-dependent kinases dynamically affected co-modification. Collectively, we present a comprehensive analysis of the SUMOylated proteome, uncovering the structural preferences for SUMO and providing system-wide evidence for a remarkable degree of cross-talk between...

Safety of modifications at nuclear power plants - the role of minor modifications and human and organisational factors

International Nuclear Information System (INIS)

2005-01-01

Operating experience repeatedly shows that changes and modifications at nuclear power plants (NPPs) may lead to safety significant events. At the same time, modifications are necessary to ensure a safe and economic functioning of the NPPs. To ensure safety in all plant configurations it is important that modification processes are given proper attention both by the utilities and the regulators. The operability, maintainability and testability of every modification should be thoroughly assessed from different points of view to ensure that no safety problems are introduced. The OECD/NEA Committee on Safety of Nuclear Installations (CSNI) has recently addressed the issue of modifications by organising a 'Workshop on Modifications at Nuclear Power Plants Operating Experience, Safety Significance and Role of Human Factors'. This workshop was undertaken as a joint effort of the Working Group on Operating Experience (WGOE) and the Special Experts Group on Human and Organisational Factors (SEGHOF), and it was held at the OECD Headquarters in Paris on October 6 to 8, 2003. The initiative to organise the workshop was taken by the WGOE and the SEGHOF based on findings from events and incidents due to modifications at nuclear power plants in the world and weaknesses experienced in modification processes. During the workshop, the WGOE focused on the theme of 'Minor Modifications and their Safety Significance', while the SEGHOF focused on the topic 'Human and Organisational Factors in NPP Modifications'. This report is based on material collected before the workshop, the workshop proceedings, discussions of the group of experts responsible for the arrangement of the workshop, and additional material collected by a consultant. The workshop was preceded by extensive preparations, which included collection of national surveys in response to questionnaires on modifications at the NPPs. Not all of these surveys were available at the workshop, but their findings have now been included

Modification of JRR-2

International Nuclear Information System (INIS)

Miyasaka, Yasuhiko

1978-01-01

This report gives an outline of some of the main modifications carried out around the Reactor Core on the Research Reactor JRR-2, at the Tokai Research Establishment of JAERI. The JRR-2 was shut down in December 1973, to improve it in heavy water leakage from the metal packing between core tank and support ring, corrosion of the lower shielding plug, and fault in the control-rod mechanism. Main modifications were a standing seal weld at the support ring to stop heavy water leakage, replacement of the reactor top shield and improvement of the helium system. The control-rod assemblies and the refueling devices were replaced by the newly designed ones also. In addition to the modification plan, the irradiated air exhaust system was improved to reduce radioactive argon gas release through the stack. Works were completed successfully in September 1975. But a light water leakage occurred at the stand pipe below the light water tank on November 11, 1975, which was repaired in about 4 months. When considering the operation of above 5,000 hours after the modification, however, the quality of the modification work may be said to be quite satisfactory. The present report in which works to the completion are described may be valuable as a record of reactor modification which is a new experience at JAERI. (auth.)

Numerical Simulation of Transient Moisture Transfer into an Electronic Enclosure

DEFF Research Database (Denmark)

Shojaee Nasirabadi, Parizad; Jabbaribehnam, Mirmasoud; Hattel, Jesper Henri

2016-01-01

Electronic systems are sometimes exposed to harsh environmental conditions of temperature and humidity. Moisturetransfer into electronic enclosures and condensation can cause several problems such as corrosion and alteration in thermalstresses. It is therefore essential to study the local climate...... inside the enclosures to be able to protect the electronic systems.In this work, moisture transfer into a typical electronic enclosure is numerically studied using CFD. In order to reduce theCPU-time and make a way for subsequent factorial design analysis, a simplifying modification is applied in which...

A survey of Type III restriction-modification systems reveals numerous, novel epigenetic regulators controlling phase-variable regulons; phasevarions

Science.gov (United States)

Atack, John M; Yang, Yuedong; Jennings, Michael P

2018-01-01

Abstract Many bacteria utilize simple DNA sequence repeats as a mechanism to randomly switch genes on and off. This process is called phase variation. Several phase-variable N6-adenine DNA-methyltransferases from Type III restriction-modification systems have been reported in bacterial pathogens. Random switching of DNA methyltransferases changes the global DNA methylation pattern, leading to changes in gene expression. These epigenetic regulatory systems are called phasevarions — phase-variable regulons. The extent of these phase-variable genes in the bacterial kingdom is unknown. Here, we interrogated a database of restriction-modification systems, REBASE, by searching for all simple DNA sequence repeats in mod genes that encode Type III N6-adenine DNA-methyltransferases. We report that 17.4% of Type III mod genes (662/3805) contain simple sequence repeats. Of these, only one-fifth have been previously identified. The newly discovered examples are widely distributed and include many examples in opportunistic pathogens as well as in environmental species. In many cases, multiple phasevarions exist in one genome, with examples of up to 4 independent phasevarions in some species. We found several new types of phase-variable mod genes, including the first example of a phase-variable methyltransferase in pathogenic Escherichia coli. Phasevarions are a common epigenetic regulation contingency strategy used by both pathogenic and non-pathogenic bacteria. PMID:29554328

Experimental investigation of the material surface modification in microsecond plasma opening switch

Energy Technology Data Exchange (ETDEWEB)

Bystritskij, V; Grigor` ev, S; Kharlov, A; Sinebryukhov, A [Russian Academy of Sciences, Tomsk (Russian Federation). Institute of Electrophysics; Burkov, P [Russian Academy of Scinces, Tomsk (Russian Federation). Institute of Strength Physics and Materials Control; Grigorev, V; Koval, T [Institute of Nuclear Physics, Tomsk (Russian Federation)

1997-12-31

The paper is devoted to the investigations of the material surface modification by high power ion beam generated in microsecond plasma opening switch (MPOS). Various types of steels were investigated: stainless steel 17-4PH, carbon steel C1020, pure iron. For all these materials, the optimal regimes for irradiation were defined. A significant increase in microhardness (1.5 to 2-fold) was obtained for these materials. Numerical calculations and theoretical estimations of the ion beam-matter interaction were also performed. The advantages and problems of this approach are discussed. (author). 8 figs., 3 refs.

Permit application modifications

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-11-01

This document contains the Permit Application Modifications for the Y-12 Industrial Landfill V site on the Oak Ridge Reservation. These modifications include the assessment of stability of the proposed Landfill V under static and loading conditions. Analyses performed include the general slope stability, veneer stability of the bottom liner and cover system, and a liquefaction potential assessment of the foundation soils.

Permit application modifications

International Nuclear Information System (INIS)

1995-11-01

This document contains the Permit Application Modifications for the Y-12 Industrial Landfill V site on the Oak Ridge Reservation. These modifications include the assessment of stability of the proposed Landfill V under static and loading conditions. Analyses performed include the general slope stability, veneer stability of the bottom liner and cover system, and a liquefaction potential assessment of the foundation soils

Modification to the accelerator of the NBI-1B ion source for improving the injection efficiency

International Nuclear Information System (INIS)

Kim, T. S.; Jeong, S. H.; Chang, D. H.; In, S. R.; Park, M.; Jung, B. K.; Lee, K. W.; Wang, S. J.; Bae, Y. S.; Park, H. T.; Kim, J. S.; Cho, W.; Choi, D. J.

2016-01-01

Minimizing power loss of a neutral beam imposes modification of the accelerator of the ion source for further improvement of the beam optics. The beam optics can be improved by focusing beamlets. The injection efficiencies by the steering of ion beamlets are investigated numerically to find the optimum modification of the accelerator design of the NBI-1B ion source. The beam power loss was reduced by aperture displacement of three edge beamlets arrays considering power loadings on the beamline components. Successful testing and operation of the ion source at 60 keV/84% of injection efficiency led to the possibility of enhancing the system capability to a 2.4 MW power level at 100 keV/1.9 μP

Genetic Modification of the Lung Directed Toward Treatment of Human Disease.

Science.gov (United States)

Sondhi, Dolan; Stiles, Katie M; De, Bishnu P; Crystal, Ronald G

2017-01-01

Genetic modification therapy is a promising therapeutic strategy for many diseases of the lung intractable to other treatments. Lung gene therapy has been the subject of numerous preclinical animal experiments and human clinical trials, for targets including genetic diseases such as cystic fibrosis and α1-antitrypsin deficiency, complex disorders such as asthma, allergy, and lung cancer, infections such as respiratory syncytial virus (RSV) and Pseudomonas, as well as pulmonary arterial hypertension, transplant rejection, and lung injury. A variety of viral and non-viral vectors have been employed to overcome the many physical barriers to gene transfer imposed by lung anatomy and natural defenses. Beyond the treatment of lung diseases, the lung has the potential to be used as a metabolic factory for generating proteins for delivery to the circulation for treatment of systemic diseases. Although much has been learned through a myriad of experiments about the development of genetic modification of the lung, more work is still needed to improve the delivery vehicles and to overcome challenges such as entry barriers, persistent expression, specific cell targeting, and circumventing host anti-vector responses.

Field-based dynamic light scattering microscopy: theory and numerical analysis.

Science.gov (United States)

Joo, Chulmin; de Boer, Johannes F

2013-11-01

We present a theoretical framework for field-based dynamic light scattering microscopy based on a spectral-domain optical coherence phase microscopy (SD-OCPM) platform. SD-OCPM is an interferometric microscope capable of quantitative measurement of amplitude and phase of scattered light with high phase stability. Field-based dynamic light scattering (F-DLS) analysis allows for direct evaluation of complex-valued field autocorrelation function and measurement of localized diffusive and directional dynamic properties of biological and material samples with high spatial resolution. In order to gain insight into the information provided by F-DLS microscopy, theoretical and numerical analyses are performed to evaluate the effect of numerical aperture of the imaging optics. We demonstrate that sharp focusing of fields affects the measured diffusive and transport velocity, which leads to smaller values for the dynamic properties in the sample. An approach for accurately determining the dynamic properties of the samples is discussed.

Behavior Modification in Coaching.

Science.gov (United States)

Lynch, Annette Rutt; Stillman, Stephen M.

1979-01-01

An example of behavior modification used in athletic coaching is presented. The case study involves a member of a women's basketball team and details the use of behavior modification for both weight reduction and skill improvement. (JMF)

Numerical design and test on an assembled structure of a bolted joint with viscoelastic damping

Science.gov (United States)

Hammami, Chaima; Balmes, Etienne; Guskov, Mikhail

2016-03-01

Mechanical assemblies are subjected to many dynamic loads and modifications are often needed to achieve acceptable vibration levels. While modifications on mass and stiffness are well mastered, damping modifications are still considered difficult to design. The paper presents a case study on the design of a bolted connection containing a viscoelastic damping layer. The notion of junction coupling level is introduced to ensure that sufficient energy is present in the joints to allow damping. Static performance is then addressed and it is shown that localization of metallic contact can be used to meet objectives, while allowing the presence of viscoelastic materials. Numerical prediction of damping then illustrates difficulties in optimizing for robustness. Modal test results of three configurations of an assembled structure, inspired by aeronautic fuselages, are then compared to analyze the performance of the design. While validity of the approach is confirmed, the effect of geometric imperfections is shown and stresses the need for robust design.

Six-dimensional localized black holes: Numerical solutions

International Nuclear Information System (INIS)

Kudoh, Hideaki

2004-01-01

To test the strong-gravity regime in Randall-Sundrum braneworlds, we consider black holes bound to a brane. In a previous paper, we studied numerical solutions of localized black holes whose horizon radii are smaller than the AdS curvature radius. In this paper, we improve the numerical method and discuss properties of the six-dimensional (6D) localized black holes whose horizon radii are larger than the AdS curvature radius. At a horizon temperature T≅1/2πl, the thermodynamics of the localized black hole undergo a transition with its character changing from a 6D Schwarzschild black hole type to a 6D black string type. The specific heat of the localized black holes is negative, and the entropy is greater than or nearly equal to that of the 6D black strings with the same thermodynamic mass. The large localized black holes show flattened horizon geometries, and the intrinsic curvature of the horizon four-geometry becomes negative near the brane. Our results indicate that the recovery mechanism of lower-dimensional Einstein gravity on the brane works even in the presence of the black holes

The Beam Break-Up Numerical Simulator

International Nuclear Information System (INIS)

Travish, G.A.

1989-11-01

Beam Break-Up (BBU) is a severe constraint in accelerator design, limiting beam current and quality. The control of BBU has become the focus of much research in the design of the next generation collider, recirculating and linear induction accelerators and advanced accelerators. Determining the effect on BBU of modifications to cavities, the focusing elements or the beam is frequently beyond the ability of current analytic models. A computer code was written to address this problem. The Beam Break-Up Numerical Simulator (BBUNS) was designed to numerically solve for beam break-up (BBU) due to an arbitrary transverse wakefield. BBUNS was developed to be as user friendly as possible on the Cray computer series. The user is able to control all aspects of input and output by using a single command file. In addition, the wakefield is specified by the user and read in as a table. The program can model energy variations along and within the beam, focusing magnetic field profiles can be specified, and the graphical output can be tailored. In this note we discuss BBUNS, its structure and application. Included are detailed instructions, examples and a sample session of BBUNS. This program is available for distribution. 50 refs., 18 figs., 5 tabs

Glucose oxidase stabilization against thermal inactivation using high hydrostatic pressure and hydrophobic modification.

Science.gov (United States)

Halalipour, Ali; Duff, Michael R; Howell, Elizabeth E; Reyes-De-Corcuera, José I

2017-03-01

High hydrostatic pressure (HHP) stabilized glucose oxidase (GOx) against thermal inactivation. The apparent first-order kinetics of inactivation of GOx were investigated at 0.1-300 MPa and 58.8-80.0°C. At 240 MPa and 74.5°C, GOx inactivated at a rate 50 times slower than at atmospheric pressure at the same temperature. The apparent activation energy of inactivation at 300 MPa was 281.0 ± 17.4 kJ mol -1 or 1.3-fold smaller than for the inactivation at atmospheric pressure (378.1 ± 25.6 kJ mol -1 ). The stabilizing effect of HHP was greatest at 74.5°C, where the activation volume of 57.0 ± 12.0 cm 3  mol -1 was highest compared to all other studied temperatures. Positive apparent activation volumes for all the treatment temperatures confirmed that HHP favors GOx stabilization. A second approach to increase GOx stability involved crosslinking with N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC) and either aniline or benzoate. The modified enzyme remained fully active with only slight increases in K M (1.3-1.9-fold increases for aniline and benzoate modification, respectively). The thermal stability of GOx increased by 8°C with aniline modification, while it decreased by 0.9°C upon modification with benzoate. Biotechnol. Bioeng. 2017;114: 516-525. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Smaller Brains and Optic Lobes in Reproductive Workers of the Ant Harpegnathos

Science.gov (United States)

Gronenberg, Wulfila; Liebig, Jürgen

Most animals show long-term modifications of their behavior which often reflect an adaptation to seasonal variations (e.g., hibernation) or result from changes in the animal's internal state (e.g., estrous cycle or sexual maturity). Such modifications may substantially affect the nervous system [1, 2]. A particularly striking behavioral change can occur in workers of the ant Harpegnathos. A few young workers in the colony may become reproductives and are thus confined to their dark nest chambers, whereas most workers spend their lives as foragers, employing acute vision when hunting prey. This behavioral difference coincides with a marked decrease in brain volume and with an even stronger reduction in the large visual brain centers. Instead of maintaining superfluous brain functions, these ants reduce brain matter which is expensive to support.

Smaller hippocampal volume as a vulnerability factor for the persistence of post-traumatic stress disorder.

Science.gov (United States)

van Rooij, S J H; Kennis, M; Sjouwerman, R; van den Heuvel, M P; Kahn, R S; Geuze, E

2015-10-01

Smaller hippocampal volume has often been observed in patients with post-traumatic stress disorder (PTSD). However, there is no consensus whether this is a result of stress/trauma exposure, or constitutes a vulnerability factor for the development of PTSD. Second, it is unclear whether hippocampal volume normalizes with successful treatment of PTSD, or whether a smaller hippocampus is a risk factor for the persistence of PTSD. Magnetic resonance imaging (MRI) scans and clinical interviews were collected from 47 war veterans with PTSD, 25 healthy war veterans (combat controls) and 25 healthy non-military controls. All veterans were scanned a second time with a 6- to 8-month interval, during which PTSD patients received trauma-focused therapy. Based on post-treatment PTSD symptoms, patients were divided into a PTSD group who was in remission (n = 22) and a group in whom PTSD symptoms persisted (n = 22). MRI data were analysed with Freesurfer. Smaller left hippocampal volume was observed in PTSD patients compared with both control groups. Hippocampal volume of the combat controls did not differ from healthy controls. Second, pre- and post-treatment analyses of the PTSD patients and combat controls revealed reduced (left) hippocampal volume only in the persistent patients at both time points. Importantly, hippocampal volume did not change with treatment. Our findings suggest that a smaller (left) hippocampus is not the result of stress/trauma exposure. Furthermore, hippocampal volume does not increase with successful treatment. Instead, we demonstrate for the first time that a smaller (left) hippocampus constitutes a risk factor for the persistence of PTSD.

Numerical investigation of FAST powder consolidation of Al2O3 and additive free β-SiC

International Nuclear Information System (INIS)

Allen, J B; Cornwell, C F; Carlson, T; Marsh, C P

2015-01-01

In this work we examine ceramic synthesis through powder consolidation and the field assisted sintering technique. In particular, we investigate the sintering of Al 2 O 3 and additive free β−SiC from both an experimental and numerical perspective. For the numerical model, the continuum theory of sintering model is employed, and the densification mechanisms corresponding to power law creep and grain boundary diffusion are considered. Experiments are used for comparison and validation purposes. The results indicate that in general, the densification kinetics simulated by the numerical model compare favorably with the experimental results. Parametric studies involving initial grain size, heating rate, and applied stress are also examined using the numerical model, and confirm many of the expected results from previous research, including increased densification due to higher heating rates, smaller grain sizes, and increased applied loading conditions. (paper)

Numerical investigations on axial and radial blade rubs in turbo-machinery

Science.gov (United States)

Abdelrhman, Ahmed M.; Tang, Eric Sang Sung; Salman Leong, M.; Al-Qrimli, Haidar F.; Rajamohan, G.

2017-07-01

In the recent years, the clearance between the rotor blades and stator/casing had been getting smaller and smaller prior improving the aerodynamic efficiency of the turbomachines as demand in the engineering field. Due to the clearance reduction between the blade tip and the rotor casing and between rotor blades and stator blades, axial and radial blade rubbing could be occurred, especially at high speed resulting into complex nonlinear vibrations. The primary aim of this study is to address the blade axial rubbing phenomenon using numerical analysis of rotor system. A comparison between rubbing caused impacts of axial and radial blade rubbing and rubbing forces are also aims of this study. Tow rotor models (rotor-stator and rotor casing models) has been designed and sketched using SOILDSWORKS software. ANSYS software has been used for the simulation and the numerical analysis. The rubbing conditions were simulated at speed range of 1000rpm, 1500rpm and 2000rpm. Analysis results for axial blade rubbing showed the appearance of blade passing frequency and its multiple frequencies (lx, 2x 3x etc.) and these frequencies will more excited with increasing the rotational speed. Also, it has been observed that when the rotating speed increased, the rubbing force and the harmonics frequencies in x, y and z-direction become higher and severe. The comparison study showed that axial blade rub is more dangerous and would generate a higher vibration impacts and higher blade rubbing force than radial blade rub.

Chemical surface reactions by click chemistry: coumarin dye modification of 11-bromoundecyltrichlorosilane monolayers

International Nuclear Information System (INIS)

Haensch, Claudia; Hoeppener, Stephanie; Schubert, Ulrich S

2008-01-01

The functionalization of surfaces and the ability to tailor their properties with desired physico-chemical functions is an important field of research with a broad spectrum of applications. These applications range from the modification of wetting properties, over the alteration of optical properties, to the fabrication of molecular electronic devices. In each of these fields, it is of specific importance to be able to control the quality of the layers with high precision. The present study demonstrates an approach that utilizes the 1,3-dipolar cycloaddition of terminal acetylenes to prepare triazole-terminated monolayers on different substrates. The characterization of the precursor monolayers, the optimization of the chemical surface reactions as well as the clicking of a fluorescent dye molecule on such azide-terminated monolayers was carried out. A coumarin 343 derivative was utilized to discuss the aspects of the functionalization approach. Based on this approach, a number of potential surface reactions, facilitated via the acetylene-substituted functional molecules, for a broad range of applications is at hand, thus leading to numerous possibilities where surface modifications are concerned. These modifications can be applied on non-structured surfaces of silicon or glass or can be used on structured surfaces. Various possibilities are discussed

Marketing healthcare: lessons for smaller hospitals.

Science.gov (United States)

Chowdhary, N R

2000-02-01

Recently, I have noted ubiquitous trends that lead me to conclude that we are on the brink of a fundamental change in the structure of healthcare delivery. Hospitals are changing. The hospital, that enduring and pervasive organization, which for decades has delivered the vast majority of acute care services is being re-conceptualized. Administrators and executives in today's hospitals are beginning to recognize the disaffection of constituents and the necessity to change from placing their own agenda or that of their profession over the needs of the customer. A lesson that is increasingly being heeded, particularly by the leading hospitals, is that a belief in one's own importance or a feeling of invulnerability represents an anachronistic stance. No hospital today can afford to retain a view that it is more important than the patients it serves, or that it is invulnerable. The external pressures are already clear--the actors, factors and forces in the external environment are forcing hospitals to re-evaluate efficiency, effectiveness and delivery arrangements. The rise to prominence of the outcomes movement is part of this trend. The present study was an attempt to assess the practices and trends in the modern smaller hospitals as a part of their strategy to match the competitive pressures.

Particle-in-cell numerical simulations of a cylindrical Hall thruster with permanent magnets

Science.gov (United States)

Miranda, Rodrigo A.; Martins, Alexandre A.; Ferreira, José L.

2017-10-01

The cylindrical Hall thruster (CHT) is a propulsion device that offers high propellant utilization and performance at smaller dimensions and lower power levels than traditional Hall thrusters. In this paper we present first results of a numerical model of a CHT. This model solves particle and field dynamics self-consistently using a particle-in-cell approach. We describe a number of techniques applied to reduce the execution time of the numerical simulations. The specific impulse and thrust computed from our simulations are in agreement with laboratory experiments. This simplified model will allow for a detailed analysis of different thruster operational parameters and obtain an optimal configuration to be implemented at the Plasma Physics Laboratory at the University of Brasília.

13 CFR 120.215 - What interest rates apply to smaller loans?

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false What interest rates apply to... BUSINESS LOANS Policies Specific to 7(a) Loans Maturities; Interest Rates; Loan and Guarantee Amounts § 120.215 What interest rates apply to smaller loans? For a loan over $25,000 but not exceeding $50,000, the...

Free surface modelling with two-fluid model and reduced numerical diffusion of the interface

International Nuclear Information System (INIS)

Strubelj, Luka; Tiselj, Izrok

2008-01-01

Full text of publication follows: The free surface flows are successfully modelled with one of existing free surface models, such as: level set method, volume of fluid method (with/without surface reconstruction), front tracking, two-fluid model (two momentum equations) with modified interphase force and others. The main disadvantage of two-fluid model used for simulations of free surface flows is numerical diffusion of the interface, which can be significantly reduced using the method presented in this paper. Several techniques for reduction of numerical diffusion of the interface have been implemented in the volume of fluid model and are based on modified numerical schemes for advection of volume fraction near the interface. The same approach could be used also for two-fluid method, but according to our experience more successful reduction of numerical diffusion of the interface can be achieved with conservative level set method. Within the conservative level set method, continuity equation for volume fraction is solved and after that the numerical diffusion of the interface is reduced in such a way that the thickness of the interface is kept constant during the simulation. Reduction of the interface diffusion can be also called interface sharpening. In present paper the two-fluid model with interface sharpening is validated on Rayleigh-Taylor instability. Under assumptions of isothermal and incompressible flow of two immiscible fluids, we simulated a system with the fluid of higher density located above the fluid of smaller density in two dimensions. Due to gravity in the system, fluid with higher density moves below the fluid with smaller density. Initial condition is not a flat interface between the fluids, but a sine wave with small amplitude, which develops into a mushroom-like structure. Mushroom-like structure in simulation of Rayleigh-Taylor instability later develops to small droplets as result of numerical dispersion of interface (interface sharpening

Restricted numerical range: A versatile tool in the theory of quantum information

Science.gov (United States)

Gawron, Piotr; Puchała, Zbigniew; Miszczak, Jarosław Adam; Skowronek, Łukasz; Życzkowski, Karol

2010-10-01

Numerical range of a Hermitian operator X is defined as the set of all possible expectation values of this observable among a normalized quantum state. We analyze a modification of this definition in which the expectation value is taken among a certain subset of the set of all quantum states. One considers, for instance, the set of real states, the set of product states, separable states, or the set of maximally entangled states. We show exemplary applications of these algebraic tools in the theory of quantum information: analysis of k-positive maps and entanglement witnesses, as well as study of the minimal output entropy of a quantum channel. Product numerical range of a unitary operator is used to solve the problem of local distinguishability of a family of two unitary gates.

Numerical calculation procedure for criticality parameters of the two-zone reflected reactor with flat central zone

International Nuclear Information System (INIS)

Bosevski, T.; Strugar, P.

1966-10-01

In determining the criticality parameters of a two-zone reactor with flat central zone one encounters a numerical problem requiring the solution of a system of two non-linear equations. To solve them the Newton method, which proved convenient, was used n this work. By comparing our results with those reported one obtains about 5% smaller values of both the radius of the flat zone and of the radial buckling of the outer zone. This discrepancy probably results from some approximations used in solving the same system of equations used in solving the same system of equations where the procedure form was applied, whereas the calculation time is by one order of magnitude smaller

Prostate cancer: The main risk and protective factors-Epigenetic modifications.

Science.gov (United States)

Adjakly, Mawussi; Ngollo, Marjolaine; Dagdemir, Aslihan; Judes, Gaëlle; Pajon, Amaury; Karsli-Ceppioglu, Seher; Penault-Llorca, Frédérique; Boiteux, Jean-Paul; Bignon, Yves-Jean; Guy, Laurent; Bernard-Gallon, Dominique

2015-02-01

With 13 million new cases worldwide every year, prostate cancer is as a very real public health concern. Prostate cancer is common in over-50s men and the sixth-leading cause of cancer-related death in men worldwide. Like all cancers, prostate cancer is multifactorial - there are non-modifiable risk factors like heredity, ethnicity and geographic location, but also modifiable risk factors such as diet. Diet-cancer linkages have risen to prominence in the last few years, with accruing epidemiological data pointing to between-population incidence differentials in numerous cancers. Indeed, there are correlations between fat-rich diet and risk of hormone-dependent cancers like prostate cancer and breast cancer. Diet is a risk factor for prostate cancer, but certain micronutrients in specific diets are considered protective factors against prostate cancer. Examples include tomato lycopene, green tea epigallocatechin gallate, and soy phytoestrogens. These micronutrients are thought to exert cancer-protective effects via anti-oxidant pathways and inhibition of cell proliferation. Here, we focus in on the effects of phytoestrogens, and chiefly genistein and daidzein, which are the best-researched to date. Soy phytoestrogens are nonsteroid molecules whose structural similarity lends them the ability to mimic the effects of 17ß-estradiol. On top of anti-oxidant effects, there is evidence that soy phytoestrogens can modulate the epigenetic modifications found in prostate cancer. We also studied the impact of phytoestrogens on epigenetic modifications in prostate cancer, with special focus on DNA methylation, miRNA-mediated regulation and histone modifications. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

DNA modification study of major depressive disorder: beyond locus-by-locus comparisons.

Science.gov (United States)

Oh, Gabriel; Wang, Sun-Chong; Pal, Mrinal; Chen, Zheng Fei; Khare, Tarang; Tochigi, Mamoru; Ng, Catherine; Yang, Yeqing A; Kwan, Andrew; Kaminsky, Zachary A; Mill, Jonathan; Gunasinghe, Cerisse; Tackett, Jennifer L; Gottesman, Irving I; Willemsen, Gonneke; de Geus, Eco J C; Vink, Jacqueline M; Slagboom, P Eline; Wray, Naomi R; Heath, Andrew C; Montgomery, Grant W; Turecki, Gustavo; Martin, Nicholas G; Boomsma, Dorret I; McGuffin, Peter; Kustra, Rafal; Petronis, Art

2015-02-01

Major depressive disorder (MDD) exhibits numerous clinical and molecular features that are consistent with putative epigenetic misregulation. Despite growing interest in epigenetic studies of psychiatric diseases, the methodologies guiding such studies have not been well defined. We performed DNA modification analysis in white blood cells from monozygotic twins discordant for MDD, in brain prefrontal cortex, and germline (sperm) samples from affected individuals and control subjects (total N = 304) using 8.1K CpG island microarrays and fine mapping. In addition to the traditional locus-by-locus comparisons, we explored the potential of new analytical approaches in epigenomic studies. In the microarray experiment, we detected a number of nominally significant DNA modification differences in MDD and validated selected targets using bisulfite pyrosequencing. Some MDD epigenetic changes, however, overlapped across brain, blood, and sperm more often than expected by chance. We also demonstrated that stratification for disease severity and age may increase the statistical power of epimutation detection. Finally, a series of new analytical approaches, such as DNA modification networks and machine-learning algorithms using binary and quantitative depression phenotypes, provided additional insights on the epigenetic contributions to MDD. Mapping epigenetic differences in MDD (and other psychiatric diseases) is a complex task. However, combining traditional and innovative analytical strategies may lead to identification of disease-specific etiopathogenic epimutations. Copyright © 2015 Society of Biological Psychiatry. All rights reserved.

Numerical Study of Natural Supercavitation Influenced by Rheological Properties of Turbulent Drag-Reducing Additives

Directory of Open Access Journals (Sweden)

Chen-Xing Jiang

2014-08-01

Full Text Available Natural supercavitations in water and turbulent drag-reducing solution were numerically simulated using unsteady Reynolds averaged Navier-Stokes (RANS scheme with mixture-multiphase model. The Cross viscosity equation was adopted to represent the fluid property of aqueous solution of drag-reducing additives. The characteristics of natural supercavity configuration and overall resistance of the navigating body were presented, respectively. The numerical simulation results indicated that, at the same cavitation number, the length and diameter of supercavity in drag-reducing solution are larger than those in water, and the drag coefficient of navigating body in solution is smaller than that in water; the surface tension plays an important role in incepting and maintaining the cavity. Turbulent drag-reducing additives have the potential in enhancement of supercavitation, drag reduction, and decrease of turbulent vortex structures. Numerical simulation results are consistent with the available experimental data.

Plant Sterols: Chemical and Enzymatic Structural Modifications and Effects on Their Cholesterol-Lowering Activity.

Science.gov (United States)

He, Wen-Sen; Zhu, Hanyue; Chen, Zhen-Yu

2018-03-28

Plant sterols have attracted increasing attention due to their excellent cholesterol-lowering activity. However, free plant sterols have some characteristics of low oil solubility, water insolubility, high melting point, and low bioavailability, which greatly limit their application in foods. Numerous studies have been undertaken to modify their chemical structures to improve their chemical and physical properties in meeting the needs of various applications. The present review is to summarize the literature and update the progress on structural modifications of plant sterols in the following aspects: (i) synthesis of plant sterol esters by esterification and transesterification with hydrophobic fatty acids and triacylglycerols to improve their oil solubility, (ii) synthesis of plant sterol derivatives by coupling with various hydrophilic moieties to enhance their water solubility, and (iii) mechanisms by which plant sterols reduce plasma cholesterol and the effect of structural modifications on plasma cholesterol-lowering activity of plant sterols.

The management of modifications

International Nuclear Information System (INIS)

Bernard, C.

1992-01-01

Description of the management methods of modifications at EDF. To maintain safety standards of the nuclear power station the 'Direction de l'Equipment' and the 'Direction du Parc en Exploitation' have jointly fixed the modalities of management for all modifications and recorded them in a 'Practical Guide'

Areal variation and chemical modification of weathered shale infiltration characteristics

International Nuclear Information System (INIS)

Luxmoore, R.J.; Spalding, B.P.; Munro, I.M.

1981-01-01

Spatial variability of infiltration into a weathered shale subsoil was evaluated at a site proximal to one used for shallow land burial of low-level radioactive waste at Oak Ridge National Laboratory. Double-ring infiltometers were installed at 48 locations on a 2- by 2-m grid after the removal of 1 to 2 m of soil (Litz-Sequoia association, Typic Hapludults). Infiltration rates were measured before and during the 0- to 20- and 239- to 259-day periods following treatment with solutions of NaOH, KOH, NaF, NaAlO 2 , and Na 2 SiO 3 at rates of 151 equivalents/m 2 . None of these chemical treatments significantly altered infiltration rate, indicating that chemical modification of soil exchange properties may be achieved without inducing hydrologic disturbance in these subsoils. A semivariogram analysis of infiltration data showed that areal variability was random; any spatial patterning must therefore occur at a smaller scale than 2 m

Numerical simulation of two-phase flow in horizontal interconnected subchannels

International Nuclear Information System (INIS)

Shourki, M.; Carver, M.B.; Tahir, A.

1985-01-01

Different subchannel computer codes have been successfully used for the thermal-hydraulic analysis of coolant flow in vertical fuel channels. None of these methods, however, is suitable for two-phase flow in horizontal fuel channels, such as those of the CANDU nuclear reactors, due to the lack of appropriate constitutive relationships that can correctly account for the gravity separation effects. A transverse vapor drift model that accounts for the combined effect of gravity separation and turbulent diffusion has been incorporated into the existing subchannel computer code SAGA. Although the basic structure of the code remains similar to SAGA III, some modifications in both the mathematical formulation and numerical solution have been incorporated. These modifications resulted in significant improvements in the code's ability to model horizontal two-phase subchannel flow. The new version of the code was tested and found to be capable of simulating the complex exchange phenomenon between adjacent horizontal subchannels caused by the interaction of turbulent diffusion, pressure gradient, and gravity-induced cross flows. The code predictions were compared with experimental data obtained from two different sources and showed good agreement

Smaller superior temporal gyrus volume specificity in schizotypal personality disorder

Science.gov (United States)

Goldstein, Kim E.; Hazlett, Erin A.; New, Antonia S.; Haznedar, M. Mehmet; Newmark, Randall E.; Zelmanova, Yuliya; Passarelli, Vincent; Weinstein, Shauna R.; Canfield, Emily L.; Meyerson, David A.; Tang, Cheuk Y.; Buchsbaum, Monte S.; Siever, Larry J.

2009-01-01

Background Superior temporal gyrus (STG/BA22) volume is reduced in schizophrenia and to a milder degree in schizotypal personality disorder (SPD), representing a less severe disorder in the schizophrenia-spectrum. SPD and Borderline personality disorder (BPD) are severe personality disorders characterized by social and cognitive dysfunction. However, while SPD is characterized by social withdrawal/anhedonia, BPD is marked by hyper-reactivity to interpersonal stimuli and hyper-emotionality. This is the first morphometric study to directly compare SPD and BPD patients in temporal volume. Methods We compared three age-gender- and education-matched groups: 27 unmedicated SPD individuals with no BPD traits, 52 unmedicated BPD individuals with no SPD traits, and 45 healthy controls. We examined gray matter volume of frontal and temporal lobe Brodmann areas (BAs), and dorsal/ventral amygdala from 3T magnetic resonance imaging. Results In the STG, an auditory association area reported to be dysfunctional in SPD and BPD, the SPD patients had significantly smaller volume than healthy controls and BPD patients. No group differences were found between BPD patients and controls. Smaller BA22 volume was associated with greater symptom severity in SPD patients. Reduced STG volume may be an important endophenotype for schizophrenia-spectrum disorders. SPD is distinct from BPD in terms of STG volume abnormalities which may reflect different underlying pathophysiological mechanisms and could help discriminate between them. PMID:19473820

Human Rights and Behavior Modification

Science.gov (United States)

Roos, Philip

1974-01-01

Criticisms of behavior modification, which charge that it violates ethical and legal principles, are discussed and reasons are presented to explain behavior modification's susceptibility to attack. (GW)

Absence of evidence or evidence of absence: reflecting on therapeutic implementations of attentional bias modification.

Science.gov (United States)

Clarke, Patrick J F; Notebaert, Lies; MacLeod, Colin

2014-01-15

Attentional bias modification (ABM) represents one of a number of cognitive bias modification techniques which are beginning to show promise as therapeutic interventions for emotional pathology. Numerous studies with both clinical and non-clinical populations have now demonstrated that ABM can reduce emotional vulnerability. However, some recent studies have failed to achieve change in either selective attention or emotional vulnerability using ABM methodologies, including a recent randomised controlled trial by Carlbring et al. Some have sought to represent such absence of evidence as a sound basis not to further pursue ABM as an online intervention. While these findings obviously raise questions about the specific conditions under which ABM procedures will produce therapeutic benefits, we suggest that the failure of some studies to modify selective attention does not challenge the theoretical and empirical basis of ABM. The present paper seeks to put these ABM failures in perspective within the broader context of attentional bias modification research. In doing so it is apparent that the current findings and future prospects of ABM are in fact very promising, suggesting that more research in this area is warranted, not less.

High-resolution study of photoinduced modification in fused silica produced by a tightly focused femtosecond laser beam in the presence of aberrations

International Nuclear Information System (INIS)

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

2005-01-01

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

Modification of the RTMTRACE program for numerical simulation of particle dynamics at racetrack microtrons with account of space charge forces

International Nuclear Information System (INIS)

Surma, I.V.; Shvedunov, V.I.

1993-01-01

The paper presents modification results of the program for simulation of particle dynamics in cyclic accelerators with RTMTRACE linear gap. The program was modified with regard for the effect of space charge effect on particle dynamics. Calculation results of particle dynamics in 1 MeV energy continuous-duty accelerator with 10 kw beam were used to develop continuous powerful commercial accelerator. 3 refs., 2 figs

Behavior Modification in the Classroom

Science.gov (United States)

Whitman, Mryon; Whitman, Joan

1971-01-01

This article presents the theoretical rationale for behavior modification, principally through its comparison with traditional psychotherapies, and suggests some behavior modification techniques for the classroom management of maladaptive behavior. (Author)

Smaller socioeconomic inequalities in health among women: the role of employment status

NARCIS (Netherlands)

Stronks, K.; van de Mheen, H.; van den Bos, J.; Mackenbach, J. P.

1995-01-01

Socioeconomic inequalities in health are smaller among women than among men. In this paper, it is hypothesized that this is due to a gender difference in employment status. We used data from the baseline of a Dutch longitudinal study. The socioeconomic indicators were educational level of the

Numerical modeling of thermal regime in inland water bodies with field measurement data

Science.gov (United States)

Gladskikh, D.; Sergeev, D.; Baydakov, G.; Soustova, I.; Troitskaya, Yu.

2018-01-01

Modification of the program complex LAKE, which is intended to compute the thermal regimes of inland water bodies, and the results of its validation in accordance with the parameters of lake part of Gorky water reservoir are reviewed in the research. The modification caused changing the procedure of input temperature profile assignment and parameterization of surface stress on air-water boundary in accordance with the consideration of wind influence on mixing process. Also the innovation consists in combined methods of gathering meteorological parameters from files of global meteorological reanalysis and data of hydrometeorological station. Temperature profiles carried out with CTD-probe during expeditions in the period 2014-2017 were used for validation of the model. The comparison between the real data and the numerical results and its assessment based on time and temperature dependences in control points, correspondence of the forms of the profiles and standard deviation for all performed realizations are provided. It is demonstrated that the model reproduces the results of field measurement data for all observed conditions and seasons. The numerical results for the regimes with strong mixing are in the best quantitative and qualitative agreement with the real profiles. The accuracy of the forecast for the ones with strong stratification near the surface is lower but all specificities of the forms are correctly reproduced.

MODIFICATION OF PAPERMAKING GRADE FILLERS: A BRIEF REVIEW

Directory of Open Access Journals (Sweden)

Jing Shen

2009-08-01

Full Text Available The use of fillers in paper products can provide cost and energy savings, improved paper properties, increased productivities, and specifically desired paper functionalities. There are many problems associated with the use of fillers, such as unsuitability of calcium carbonate fillers in acid papermaking, negative effects of filler loading on paper strength, sizing, and retention, and tendencies of fillers to cause abrasion and dusting. In order to solve these problems and to make better use of fillers, many methods have been proposed, among which filler modification has been a hot topic. The available technologies of filler modification mainly include modification with inorganic substances, modification with natural polymers or their derivatives, modification with water-soluble synthetic polymers, modification with surfactants, modification with polymer latexes, hydrophobic modification, cationic modification, surface nano-structuring, physical modification by compressing, calcination or grinding, and modification for use in functional papers. The methods of filler modification can provide improved acid tolerant and optical properties of fillers, enhanced fiber-filler bonding, improved filler retention and filler sizabilities, alleviated filler abrasiveness, improved filler dispersability, and functionalization of filled papers. Filler modification has been an indispensable way to accelerate the development of high filler technology in papermaking, which is likely to create additional benefits to papermaking industry in the future.

Glutamine methylation in histone H2A is an RNA-polymerase-I-dedicated modification

Science.gov (United States)

Tessarz, Peter; Santos-Rosa, Helena; Robson, Sam C.; Sylvestersen, Kathrine B.; Nelson, Christopher J.; Nielsen, Michael L.; Kouzarides, Tony

2014-01-01

Nucleosomes are decorated with numerous post-translational modifications capable of influencing many DNA processes. Here we describe a new class of histone modification, methylation of glutamine, occurring on yeast histone H2A at position 105 (Q105) and human H2A at Q104. We identify Nop1 as the methyltransferase in yeast and demonstrate that fibrillarin is the orthologue enzyme in human cells. Glutamine methylation of H2A is restricted to the nucleolus. Global analysis in yeast, using an H2AQ105me-specific antibody, shows that this modification is exclusively enriched over the 35S ribosomal DNA transcriptional unit. We show that the Q105 residue is part of the binding site for the histone chaperone FACT (facilitator of chromatin transcription) complex. Methylation of Q105 or its substitution to alanine disrupts binding to FACT in vitro. A yeast strain mutated at Q105 shows reduced histone incorporation and increased transcription at the ribosomal DNA locus. These features are phenocopied by mutations in FACT complex components. Together these data identify glutamine methylation of H2A as the first histone epigenetic mark dedicated to a specific RNA polymerase and define its function as a regulator of FACT interaction with nucleosomes.

Influence of biases in numerical magnitude allocation on human prosocial decision making.

Science.gov (United States)

Arshad, Qadeer; Nigmatullina, Yuliya; Siddiqui, Shuaib; Franka, Mustafa; Mediratta, Saniya; Ramachandaran, Sanjeev; Lobo, Rhannon; Malhotra, Paresh A; Roberts, R E; Bronstein, Adolfo M

2017-12-01

Over the past decade neuroscientific research has attempted to probe the neurobiological underpinnings of human prosocial decision making. Such research has almost ubiquitously employed tasks such as the dictator game or similar variations (i.e., ultimatum game). Considering the explicit numerical nature of such tasks, it is surprising that the influence of numerical cognition on decision making during task performance remains unknown. While performing these tasks, participants typically tend to anchor on a 50:50 split that necessitates an explicit numerical judgement (i.e., number-pair bisection). Accordingly, we hypothesize that the decision-making process during the dictator game recruits overlapping cognitive processes to those known to be engaged during number-pair bisection. We observed that biases in numerical magnitude allocation correlated with the formulation of decisions during the dictator game. That is, intrinsic biases toward smaller numerical magnitudes were associated with the formulation of less favorable decisions, whereas biases toward larger magnitudes were associated with more favorable choices. We proceeded to corroborate this relationship by subliminally and systematically inducing biases in numerical magnitude toward either higher or lower numbers using a visuo-vestibular stimulation paradigm. Such subliminal alterations in numerical magnitude allocation led to proportional and corresponding changes to an individual's decision making during the dictator game. Critically, no relationship was observed between neither intrinsic nor induced biases in numerical magnitude on decision making when assessed using a nonnumerical-based prosocial questionnaire. Our findings demonstrate numerical influences on decisions formulated during the dictator game and highlight the necessity to control for confounds associated with numerical cognition in human decision-making paradigms. NEW & NOTEWORTHY We demonstrate that intrinsic biases in numerical magnitude

Numerical Analysis of Magnetic Sail Spacecraft

International Nuclear Information System (INIS)

Sasaki, Daisuke; Yamakawa, Hiroshi; Usui, Hideyuki; Funaki, Ikkoh; Kojima, Hirotsugu

2008-01-01

To capture the kinetic energy of the solar wind by creating a large magnetosphere around the spacecraft, magneto-plasma sail injects a plasma jet into a strong magnetic field produced by an electromagnet onboard the spacecraft. The aim of this paper is to investigate the effect of the IMF (interplanetary magnetic field) on the magnetosphere of magneto-plasma sail. First, using an axi-symmetric two-dimensional MHD code, we numerically confirm the magnetic field inflation, and the formation of a magnetosphere by the interaction between the solar wind and the magnetic field. The expansion of an artificial magnetosphere by the plasma injection is then simulated, and we show that the magnetosphere is formed by the interaction between the solar wind and the magnetic field expanded by the plasma jet from the spacecraft. This simulation indicates the size of the artificial magnetosphere becomes smaller when applying the IMF.

EXTENDED SCALING LAWS IN NUMERICAL SIMULATIONS OF MAGNETOHYDRODYNAMIC TURBULENCE

International Nuclear Information System (INIS)

Mason, Joanne; Cattaneo, Fausto; Perez, Jean Carlos; Boldyrev, Stanislav

2011-01-01

Magnetized turbulence is ubiquitous in astrophysical systems, where it notoriously spans a broad range of spatial scales. Phenomenological theories of MHD turbulence describe the self-similar dynamics of turbulent fluctuations in the inertial range of scales. Numerical simulations serve to guide and test these theories. However, the computational power that is currently available restricts the simulations to Reynolds numbers that are significantly smaller than those in astrophysical settings. In order to increase computational efficiency and, therefore, probe a larger range of scales, one often takes into account the fundamental anisotropy of field-guided MHD turbulence, with gradients being much slower in the field-parallel direction. The simulations are then optimized by employing the reduced MHD equations and relaxing the field-parallel numerical resolution. In this work we explore a different possibility. We propose that there exist certain quantities that are remarkably stable with respect to the Reynolds number. As an illustration, we study the alignment angle between the magnetic and velocity fluctuations in MHD turbulence, measured as the ratio of two specially constructed structure functions. We find that the scaling of this ratio can be extended surprisingly well into the regime of relatively low Reynolds number. However, the extended scaling easily becomes spoiled when the dissipation range in the simulations is underresolved. Thus, taking the numerical optimization methods too far can lead to spurious numerical effects and erroneous representation of the physics of MHD turbulence, which in turn can affect our ability to identify correctly the physical mechanisms that are operating in astrophysical systems.

The effects of NACA 0012 airfoil modification on aerodynamic performance improvement and obtaining high lift coefficient and post-stall airfoil

Science.gov (United States)

Sogukpinar, Haci

2018-02-01

In this study, aerodynamic performances of NACA 0012 airfoils with distinct modification are numerically investigated to obtain high lift coefficient and post-stall airfoils. NACA 0012 airfoil is divided into two part thought chord line then suction sides kept fixed and by changing the thickness of the pressure side new types of airfoil are created. Numerical experiments are then conducted by varying thickness of NACA 0012 from lower surface and different relative thicknesses asymmetrical airfoils are modified and NACA 0012-10, 0012-08, 0012-07, 0012-06, 0012-04, 0012-03, 0012-02, 0012-01 are created and simulated by using COMSOL software.

Smaller Is More Personal, and the Personal Gets Results. The Editor Reflects.

Science.gov (United States)

Erb, Tom

2001-01-01

Summarizes growing body of evidence relating small school size at elementary and middle grades to positive student outcomes. Notes that positive outcomes associated with small size relate to teacher commitment and effectiveness as well as student attachment, persistence, and performance. Concludes that smaller, more intimate schools are better…

Electrostatic bio-manipulation for the modification of cellular functions

International Nuclear Information System (INIS)

Washizu, Masao

2013-01-01

The use of electrostatic field effects, including field-induced reversible-breakdown of the membrane and dielectrophoresis (DEP), in microfabricated structures are investigated. With the use of field constriction created by a micro-orifice whose diameter is smaller than the cells, controlled magnitude of pulsed voltage can be applied across the cell membrane regardless of the cell size, shape or orientation. As a result, the breakdown occurs reproducibly and with minimal invasiveness. The breakdown is used for two purposes, electroporation by which foreign substances can be fed into cells, and electrofusion which creates genetic and/or cytoplasmic mixture among two cells. When GFP plasmid is fed into MSC cell, the gene expression started within 2 hours, and finally observed in more than 50% of cells. For cell fusion, several ten percent fusion yield is achieved for most cell types, with the colony formation in several percents. Timing-controlled feeding foreign substances or mixing cellular contents, with high-yield and low-invasiveness, is expected to bring about a new technology for both genetic and epigenetic modifications of cellular functions, in such field as regenerative medicine.

A Numerical Estimation of a RFID Reader Field and SAR inside a Blood Bag at UHF

Directory of Open Access Journals (Sweden)

Alessandro Fanti

2016-11-01

Full Text Available In this paper, the effects of UHF electromagnetic fields produced by a RFID reader on a blood bag are evaluated numerically in several configurations. The results of the simulation, field level and distribution, specific absorption rate (SAR, and heating time show that an exposure to a typical reader field leads to a temperature increase smaller than 0.1 C and to a SAR smaller than 1 W/kg. As a consequence, no adverse biological effects occur during a typical UHF RFID reading cycle on a blood bag. Therefore, the blood contained in a bag traced using UHF-RFID is as safe as those traced using barcodes. The proposed analysis supports the use of UHF RFID in the blood transfusion supply chain.

Numerical analysis of laser ablation and damage in glass with multiple picosecond laser pulses.

Science.gov (United States)

Sun, Mingying; Eppelt, Urs; Russ, Simone; Hartmann, Claudia; Siebert, Christof; Zhu, Jianqiang; Schulz, Wolfgang

2013-04-08

This study presents a novel numerical model for laser ablation and laser damage in glass including beam propagation and nonlinear absorption of multiple incident ultrashort laser pulses. The laser ablation and damage in the glass cutting process with a picosecond pulsed laser was studied. The numerical results were in good agreement with our experimental observations, thereby revealing the damage mechanism induced by laser ablation. Beam propagation effects such as interference, diffraction and refraction, play a major role in the evolution of the crater structure and the damage region. There are three different damage regions, a thin layer and two different kinds of spikes. Moreover, the electronic damage mechanism was verified and distinguished from heat modification using the experimental results with different pulse spatial overlaps.

Developmental specialization of the left parietal cortex for the semantic representation of Arabic numerals: An fMR-adaptation study

Directory of Open Access Journals (Sweden)

Stephan E. Vogel

2015-04-01

Full Text Available The way the human brain constructs representations of numerical symbols is poorly understood. While increasing evidence from neuroimaging studies has indicated that the intraparietal sulcus (IPS becomes increasingly specialized for symbolic numerical magnitude representation over developmental time, the extent to which these changes are associated with age-related differences in symbolic numerical magnitude representation or with developmental changes in non-numerical processes, such as response selection, remains to be uncovered. To address these outstanding questions we investigated developmental changes in the cortical representation of symbolic numerical magnitude in 6- to 14-year-old children using a passive functional magnetic resonance imaging adaptation design, thereby mitigating the influence of response selection. A single-digit Arabic numeral was repeatedly presented on a computer screen and interspersed with the presentation of novel digits deviating as a function of numerical ratio (smaller/larger number. Results demonstrated a correlation between age and numerical ratio in the left IPS, suggesting an age-related increase in the extent to which numerical symbols are represented in the left IPS. Brain activation of the right IPS was modulated by numerical ratio but did not correlate with age, indicating hemispheric differences in IPS engagement during the development of symbolic numerical representation.

Modifications to Replacement Costs System

International Nuclear Information System (INIS)

Godec, M.

1989-01-01

The purpose of this memorandum is to document the improvements and modifications made to the Replacement Costs of Crude Oil (REPCO) Supply Analysis System. While some of this work was performed under our previous support contract to DOE/ASFE, we are presenting all modifications and improvements are presented here for completeness. The memo primarily documents revisions made to the Lower-48 Onshore Model. Revisions and modifications made to other components and models in the REPCO system which are documented elsewhere are only highlighted in this memo. Generally, the modifications made to the Lower-48 Onshore Model reflect changes that have occurred in domestic drilling, oil field costs, and reserves since 1982, the date of the most recent available data used for the original Replacement Costs report, published in 1985

Airfoil-Wake Modification with Gurney Flap at Low Reynolds Number

Science.gov (United States)

Gopalakrishnan Meena, Muralikrishnan; Taira, Kunihiko; Asai, Keisuke

2018-04-01

The complex wake modifications produced by a Gurney flap on symmetric NACA airfoils at low Reynolds number are investigated. Two-dimensional incompressible flows over NACA 0000 (flat plate), 0006, 0012 and 0018 airfoils at a Reynolds number of $Re = 1000$ are analyzed numerically to examine the flow modifications generated by the flaps for achieving lift enhancement. While high lift can be attained by the Gurney flap on airfoils at high angles of attack, highly unsteady nature of the aerodynamic forces are also observed. Analysis of the wake structures along with the lift spectra reveals four characteristic wake modes (steady, 2S, P and 2P), influencing the aerodynamic performance. The effects of the flap over wide range of angles of attack and flap heights are considered to identify the occurrence of these wake modes, and are encapsulated in a wake classification diagram. Companion three-dimensional simulations are also performed to examine the influence of three-dimensionality on the wake regimes. The spanwise instabilities that appear for higher angles of attack are found to suppress the emergence of the 2P mode. The use of the wake classification diagram as a guidance for Gurney flap selection at different operating conditions to achieve the required aerodynamic performance is discussed.

A Compact Numerical Implementation for Solving Stokes Equations Using Matrix-vector Operations

KAUST Repository

Zhang, Tao; Salama, Amgad; Sun, Shuyu; Zhong, Hua

2015-01-01

In this work, a numerical scheme is implemented to solve Stokes equations based on cell-centered finite difference over staggered grid. In this scheme, all the difference operations have been vectorized thereby eliminating loops. This is particularly important when using programming languages that require interpretations, e.g., MATLAB and Python. Using this scheme, the execution time becomes significantly smaller compared with non-vectorized operations and also become comparable with those languages that require no repeated interpretations like FORTRAN, C, etc. This technique has also been applied to Navier-Stokes equations under laminar flow conditions.

A Compact Numerical Implementation for Solving Stokes Equations Using Matrix-vector Operations

KAUST Repository

Zhang, Tao

2015-06-01

In this work, a numerical scheme is implemented to solve Stokes equations based on cell-centered finite difference over staggered grid. In this scheme, all the difference operations have been vectorized thereby eliminating loops. This is particularly important when using programming languages that require interpretations, e.g., MATLAB and Python. Using this scheme, the execution time becomes significantly smaller compared with non-vectorized operations and also become comparable with those languages that require no repeated interpretations like FORTRAN, C, etc. This technique has also been applied to Navier-Stokes equations under laminar flow conditions.

Value-impact assessment of safety-related modifications

International Nuclear Information System (INIS)

Knowles, W.M.C.; Dinnie, K.S.; Gordon, C.W.

1992-01-01

Like other nuclear utilities, Ontario Hydro, as part of its risk management activities, continually assesses the safety of its nuclear operations. In addition, new regulatory requirements are being applied to the older nuclear power plants. Both of these result in proposed plant modifications designed to reduce the risk to the public. However, modifications to an operating plant can have serious economic effects, and the resources, both financial and personnel, required for the implementation of these modifications are limited. Thus, all potential benefits and effects of a proposed modification must be thoroughly investigated to judge whether the modification is beneficial. Ontario Hydro has begun to use comprehensive value-impact assessments, utilizing plant-specific probabilistic risk assessments (PRAs), as tools to provide an informed basis for judgments on the benefit of safety-related modifications. The results from value-impact assessments can also be used to prioritize the implementation of these modifications

On topological modifications of Newton's law

International Nuclear Information System (INIS)

Floratos, E.G.; Leontaris, G.K.

2012-01-01

Recent cosmological data for very large distances challenge the validity of the standard cosmological model. Motivated by the observed spatial flatness the accelerating expansion and the various anisotropies with preferred axes in the universe we examine the consequences of the simple hypothesis that the three-dimensional space has a global R 2 × S 1 topology. We take the radius of the compactification to be the observed cosmological scale beyond which the accelerated expansion starts. We derive the induced corrections to the Newton's gravitational potential and we find that for distances smaller than the S 1 radius the leading 1/r-term is corrected by convergent power series of multipole form in the polar angle making explicit the induced anisotropy by the compactified third dimension. On the other hand, for distances larger than the compactification scale the asymptotic behavior of the potential exhibits a logarithmic dependence with exponentially small corrections. The change of Newton's force from 1/r 2 to 1/r behavior implies a weakening of the deceleration for the expanding universe. Such topologies can also be created locally by standard Newtonian axially symmetric mass distributions with periodicity along the symmetry axis. In such cases we can use our results to obtain measurable modifications of Newtonian orbits for small distances and flat rotation spectra, for large distances at the galactic level

Use of the deterministic safety analyses in support to the NPP Krsko modification

International Nuclear Information System (INIS)

Feretic, D.; Cavlina, N.; Debrecin, N.; Grgic, D.; Bajs, T.; Spalj, S.

2004-01-01

The ultimate goal of the safety analysis is to verify that Nuclear Power Plant (NPP) meets safety and operational requirements. To this aim it is necessary to demonstrate that plant safety has not been deteriorated in the case of the modifications to the plant Systems, Structures and Components (SSC) or changes to the plant procedures. In addition, safety analyses are needed in the case of reassessment of an existing plant. The reasons for reassessment may be different, e.g. due to the changes in the methodology and assumptions used in the original design, if the original design basis or acceptance criteria may no longer be adequate, if the safety analysis tools used may have been superseded by more sophisticated methods or if the original design basis may no longer be met. The operation of the NPP Krsko has experienced numerous changes from the original design for the majority of the reasons that have been mentioned before. On the other side, the application of the large best-estimate thermalhydraulic codes has evolved to the wide spread support in the operation of the NPP: compliance with the regulatory goals, support to the PSA studies, analysis of the operational transients, plant modifications studies, equipment qualification, training of the operators, preparation of the operating procedures, etc. This trend has been followed at the Faculty of Electrical Engineering Zagreb (FER) and applied to the on-going needs due to the modifications and changes at NPP Krsko. In this paper, an overview of the deterministic safety analyses performed at FER in the support to the NPP Krsko modifications and changes is presented.(author)

Modification of Sr on 4004 Aluminum Alloy

Science.gov (United States)

Guo, Erjun; Cao, Guojian; Feng, Yicheng; Wang, Liping; Wang, Guojun; Lv, Xinyu

2013-05-01

As a brazing foil, 4004 Al alloy has good welding performance. However, the high Si content decreases the plasticity of the alloy. To improve the plasticity of 4004 Al alloy and subsequently improve the productivity of 4004 Al foil or 434 composite foil, 4004 Al alloy was modified by Al-10%Sr master alloy. Modification effects of an additional amount of Sr, modification temperature, and holding time on 4004 aluminum alloy were studied by orthogonal design. The results showed that the greatest impact parameter of 4004 aluminum alloy modification was the additional amount of Sr, followed by holding time and modification temperature. The optimum modification parameters obtained by orthogonal design were as follows: Sr addition of 0.04%, holding time of 60 min, and modification temperature of 760°C. The effect of Sr addition on modification was analyzed in detail based on orthogonal results. With increasing of Sr addition, elongation of 4004 alloy increased at first, and decreased after reaching the maximum value.

Chemical Modifications of Starch: Microwave Effect

Directory of Open Access Journals (Sweden)

Kamila Lewicka

2015-01-01

Full Text Available This paper presents basic methods of starch chemical modification, the effect of microwave radiation on the modification process, and the physicochemical properties of starch. It has been shown that the modifications contribute to improvement of the material performance and likewise to significant improvement of its mechanical properties. As a result, more and more extensive use of starch is possible in various industries. In addition, methods of oxidized starch and starch esters preparation are discussed. Properties of microwave radiation and its impact on starch (with particular regard to modifications described in literature are characterized.

Plant Proteins Are Smaller Because They Are Encoded by Fewer Exons than Animal Proteins.

Science.gov (United States)

Ramírez-Sánchez, Obed; Pérez-Rodríguez, Paulino; Delaye, Luis; Tiessen, Axel

2016-12-01

Protein size is an important biochemical feature since longer proteins can harbor more domains and therefore can display more biological functionalities than shorter proteins. We found remarkable differences in protein length, exon structure, and domain count among different phylogenetic lineages. While eukaryotic proteins have an average size of 472 amino acid residues (aa), average protein sizes in plant genomes are smaller than those of animals and fungi. Proteins unique to plants are ∼81aa shorter than plant proteins conserved among other eukaryotic lineages. The smaller average size of plant proteins could neither be explained by endosymbiosis nor subcellular compartmentation nor exon size, but rather due to exon number. Metazoan proteins are encoded on average by ∼10 exons of small size [∼176 nucleotides (nt)]. Streptophyta have on average only ∼5.7 exons of medium size (∼230nt). Multicellular species code for large proteins by increasing the exon number, while most unicellular organisms employ rather larger exons (>400nt). Among subcellular compartments, membrane proteins are the largest (∼520aa), whereas the smallest proteins correspond to the gene ontology group of ribosome (∼240aa). Plant genes are encoded by half the number of exons and also contain fewer domains than animal proteins on average. Interestingly, endosymbiotic proteins that migrated to the plant nucleus became larger than their cyanobacterial orthologs. We thus conclude that plants have proteins larger than bacteria but smaller than animals or fungi. Compared to the average of eukaryotic species, plants have ∼34% more but ∼20% smaller proteins. This suggests that photosynthetic organisms are unique and deserve therefore special attention with regard to the evolutionary forces acting on their genomes and proteomes. Copyright © 2016 The Authors. Production and hosting by Elsevier Ltd.. All rights reserved.

Plant Proteins Are Smaller Because They Are Encoded by Fewer Exons than Animal Proteins

Directory of Open Access Journals (Sweden)

Obed Ramírez-Sánchez

2016-12-01

Full Text Available Protein size is an important biochemical feature since longer proteins can harbor more domains and therefore can display more biological functionalities than shorter proteins. We found remarkable differences in protein length, exon structure, and domain count among different phylogenetic lineages. While eukaryotic proteins have an average size of 472 amino acid residues (aa, average protein sizes in plant genomes are smaller than those of animals and fungi. Proteins unique to plants are ∼81 aa shorter than plant proteins conserved among other eukaryotic lineages. The smaller average size of plant proteins could neither be explained by endosymbiosis nor subcellular compartmentation nor exon size, but rather due to exon number. Metazoan proteins are encoded on average by ∼10 exons of small size [∼176 nucleotides (nt]. Streptophyta have on average only ∼5.7 exons of medium size (∼230 nt. Multicellular species code for large proteins by increasing the exon number, while most unicellular organisms employ rather larger exons (>400 nt. Among subcellular compartments, membrane proteins are the largest (∼520 aa, whereas the smallest proteins correspond to the gene ontology group of ribosome (∼240 aa. Plant genes are encoded by half the number of exons and also contain fewer domains than animal proteins on average. Interestingly, endosymbiotic proteins that migrated to the plant nucleus became larger than their cyanobacterial orthologs. We thus conclude that plants have proteins larger than bacteria but smaller than animals or fungi. Compared to the average of eukaryotic species, plants have ∼34% more but ∼20% smaller proteins. This suggests that photosynthetic organisms are unique and deserve therefore special attention with regard to the evolutionary forces acting on their genomes and proteomes.

Modification Semantics in Now-Relative Databases

DEFF Research Database (Denmark)

Torp, Kristian; Jensen, Christian Søndergaard; Snodgrass, R. T.

2004-01-01

Most real-world databases record time-varying information. In such databases, the notion of ??the current time,?? or NOW, occurs naturally and prominently. For example, when capturing the past states of a relation using begin and end time columns, tuples that are part of the current state have some...... past time as their begin time and NOW as their end time. While the semantics of such variable databases has been described in detail and is well understood, the modification of variable databases remains unexplored. This paper defines the semantics of modifications involving the variable NOW. More...... specifically,  the problems with modifications in the presence of NOW are explored, illustrating that the main problems are with modifications of tuples that reach into the future. The paper defines the semantics of modifications?including insertions, deletions, and updates?of databases without NOW, with NOW...

Order of Magnitude Smaller Limit on the Electron's Electron Dipole Moment

Science.gov (United States)

Gabrielse, Gerald

2014-05-01

Proposed extensions to the Standard Model of particle physics typically predict that the electron would naturally have a small but potentially measurable electric dipole moment (EDM). The Standard Model, known to be incomplete, instead predicts that the electron EDM is much too small to measure. The ACME collaboration used the enormous electric field that electrons experience within a ThO molecule, the unique structure of this molecule, and a cryogenic buffer gas beam of molecules to search for an electron EDM. The new search was sensitive enough to detect an EDM that is ten times smaller than the previously measured upper limit - well within the range of predictions from various proposed extensions to the Standard Model. We did not detect such an EDM, however. Instead, we set a new upper limit on the electron EDM at a 90% confidence limit, | de | < 8 . 7 × 10-29 , making use of the effective electric field calculated for ThO. The new limit stringently constrains the parameters of proposed extensions to the Standard Model to values that predict an electron EDM smaller than the new limit. The TeV energy scale being probed is comparable to that being investigated at CERN's Large Hadron Collider (LHC). Supported by the AMO program of the NSF.

Evidence for smaller right amygdala volumes in posttraumatic stress disorder following childhood trauma

NARCIS (Netherlands)

Veer, I.M.; Oei, N.Y.L.; van Buchem, M.A.; Spinhoven, Ph.; Elzinga, B.M.; Rombouts, S.A.R.B.

2015-01-01

Hippocampus and amygdala volumes in posttraumatic stress disorder (PTSD) related to childhood trauma are relatively understudied, albeit the potential importance to the disorder. Whereas some studies reported smaller hippocampal volumes, little evidence was found for abnormal amygdala volumes. Here

Experimental and Numerical Study of Water Entry Supercavity Influenced by Turbulent Drag-Reducing Additives

Directory of Open Access Journals (Sweden)

Chen-Xing Jiang

2014-04-01

Full Text Available The configurational and dynamic characteristics of water entry supercavities influenced by turbulent drag-reducing additives were studied through supercavitating projectile approach, experimentally and numerically. The projectile was projected vertically into water and aqueous solution of CTAC with weight concentrations of 100, 500, and 1000 ppm, respectively, using a pneumatic nail gun. The trajectories of the projectile and the supercavity configuration were recorded by a high-speed CCD camera. Besides, water entry supercavities in water and CTAC solution were numerically simulated based on unsteady RANS scheme, together with application of VOF multiphase model. The Cross viscosity model was adopted to represent the fluid property of CTAC solution. It was obtained that the numerical simulation results are in consistence with experimental data. Numerical and experimental results all show that the length and diameter of supercavity in drag-reducing solution are larger than those in water, and the drag coefficient is smaller than that in water; the maintaining time of supercavity is longer in solution as well. The surface tension plays an important role in maintaining the cavity. Turbulent drag-reducing additives have the potential in enhancement of supercavitation and drag reduction.

Functional anthology of intrinsic disorder. 3. Ligands, post-translational modifications, and diseases associated with intrinsically disordered proteins.

Science.gov (United States)

Xie, Hongbo; Vucetic, Slobodan; Iakoucheva, Lilia M; Oldfield, Christopher J; Dunker, A Keith; Obradovic, Zoran; Uversky, Vladimir N

2007-05-01

Currently, the understanding of the relationships between function, amino acid sequence, and protein structure continues to represent one of the major challenges of the modern protein science. As many as 50% of eukaryotic proteins are likely to contain functionally important long disordered regions. Many proteins are wholly disordered but still possess numerous biologically important functions. However, the number of experimentally confirmed disordered proteins with known biological functions is substantially smaller than their actual number in nature. Therefore, there is a crucial need for novel bionformatics approaches that allow projection of the current knowledge from a few experimentally verified examples to much larger groups of known and potential proteins. The elaboration of a bioinformatics tool for the analysis of functional diversity of intrinsically disordered proteins and application of this data mining tool to >200 000 proteins from the Swiss-Prot database, each annotated with at least one of the 875 functional keywords, was described in the first paper of this series (Xie, H.; Vucetic, S.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V.N. Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions. J. Proteome Res. 2007, 5, 1882-1898). Using this tool, we have found that out of the 710 Swiss-Prot functional keywords associated with at least 20 proteins, 262 were strongly positively correlated with long intrinsically disordered regions, and 302 were strongly negatively correlated. Illustrative examples of functional disorder or order were found for the vast majority of keywords showing strongest positive or negative correlation with intrinsic disorder, respectively. Some 80 Swiss-Prot keywords associated with disorder- and order-driven biological processes and protein functions were described in the first paper (see above). The second paper of the series was

Single- and dual-wavelength laser pulses induced modification in 10×(Al/Ti)/Si multilayer system

Energy Technology Data Exchange (ETDEWEB)

Salatić, B. [University of Belgrade, Institute of Physics Belgrade, Pregrevica 118, 11080 Belgrade (Serbia); Petrović, S., E-mail: spetro@vinca.rs [University of Belgrade, Institute of Nuclear Science-Vinča, POB 522, 11001 Belgrade (Serbia); Peruško, D. [University of Belgrade, Institute of Nuclear Science-Vinča, POB 522, 11001 Belgrade (Serbia); Čekada, M.; Panjan, P. [Jožef Stefan Institute, Jamova 39, 1000 Ljubljana (Slovenia); Pantelić, D.; Jelenković, B. [University of Belgrade, Institute of Physics Belgrade, Pregrevica 118, 11080 Belgrade (Serbia)

2016-01-01

Graphical abstract: - Highlights: • Experimental and numerical study of laser-induced ablation and micro-sized crater formation. • Dual-wavelength pulses induce creation of wider and deeper craters due to synergies of two processes. • Sunflower-like structure formed by dual-wavelength pulses at low irradiance. • Numerical model of nanosecond pulsed laser ablation for complex (Al/Ti)/Si system has been developed. - Abstract: The surface morphology of the ablation craters created in the multilayer 10×(Al/Ti)/Si system by nanosecond laser pulses at single- and dual wavelength has been studied experimentally and numerically. A complex multilayer thin film including ten (Al/Ti) bilayers deposited by ion sputtering on Si(1 0 0) substrate to a total thickness of 260 nm were illuminated at different laser irradiance in the range 0.25–3.5 × 10{sup 9} W cm{sup −2}. Single pulse laser irradiation was done at normal incidence in air, with the single wavelength, either at 532 nm or 1064 nm or with both laser light simultaneously in the ratio of 1:10 for energy per pulse between second harmonic and 1064 nm. Most of the absorbed laser energy was rapidly transformed into heat, producing intensive modifications of composition and morphology on the sample surface. The results show an increase in surface roughness, formation of specific nanostructures, appearance of hydrodynamic features and ablation of surface material with crater formation. Applying a small fraction (10%) of the second harmonic in dual-wavelength pulses, a modification of the 10×(Al/Ti)/Si system by a single laser pulse was reflected in the formation of wider and/or deeper craters. Numerical calculations show that the main physical mechanism in ablation process is normal evaporation without phase explosion. The calculated and experimental results agree relatively well for the whole irradiance range, what makes the model applicable to complex Al/Ti multilayer systems.

Miniaturized inertial impactor for personal airborne particulate monitoring: Numerical model

Science.gov (United States)

Cortelezzi, Luca; Pasini, Silvia; Bianchi, Elena; Dubini, Gabriele

2017-11-01

The rising level of fine particle matter's (PM10, PM2.5 and PM1) pollution in the world has increased the interest in developing portable personal air-qualitity monitoring systems. To answer this need, we conceived a miniaturized inertial impactor. The development of such an impactor becomes more challenging as the diameter of the particles to be collected becomes smaller, since the velocities required to induce the impact of finer particulate matter become higher. To overcome these challenges, we modeled numerically the fluid dynamics and particles transport within the impactor. Our simulations show that the fluid flow within the impactor becomes unstable as the Reynolds number is increased to capture finer particles. Furthermore, the onset of these instabilities depends not only on the Reynolds number but also on the geometry of the impactor. The unsteady flow within the impactor influences the trajectories of the particles to be collected, especially the smaller particles. The particles trajectories shows that the impaction location varies substantially as the Reynolds number increases and, consequently, the efficiency of the impactor deteriorates. Finally, we optimize the design of our impactor to maximize its collection efficiency. CARIPLO Fundation - project MINUTE (Grant No. 2011-2118).

SYNCHRONIZATION OF HETEROGENEOUS OSCILLATORS UNDER NETWORK MODIFICATIONS: PERTURBATION AND OPTIMIZATION OF THE SYNCHRONY ALIGNMENT FUNCTION

Science.gov (United States)

Taylor, Dane; Skardal, Per Sebastian; Sun, Jie

2016-01-01

Synchronization is central to many complex systems in engineering physics (e.g., the power-grid, Josephson junction circuits, and electro-chemical oscillators) and biology (e.g., neuronal, circadian, and cardiac rhythms). Despite these widespread applications—for which proper functionality depends sensitively on the extent of synchronization—there remains a lack of understanding for how systems can best evolve and adapt to enhance or inhibit synchronization. We study how network modifications affect the synchronization properties of network-coupled dynamical systems that have heterogeneous node dynamics (e.g., phase oscillators with non-identical frequencies), which is often the case for real-world systems. Our approach relies on a synchrony alignment function (SAF) that quantifies the interplay between heterogeneity of the network and of the oscillators and provides an objective measure for a system’s ability to synchronize. We conduct a spectral perturbation analysis of the SAF for structural network modifications including the addition and removal of edges, which subsequently ranks the edges according to their importance to synchronization. Based on this analysis, we develop gradient-descent algorithms to efficiently solve optimization problems that aim to maximize phase synchronization via network modifications. We support these and other results with numerical experiments. PMID:27872501

Modification of Gaussian Elimination to the Complex Seismic Data

International Nuclear Information System (INIS)

Smaglichenko, Tatyana A.

2011-01-01

A method for solution of large and sparse systems with complex seismic observations has been developed by revising of the classical Gaussian elimination. The observation matrix is divided into a set of smaller cells that can be determined based on clusters of a seismic activity. Reliable inversion solutions with minimum error rating are selected within each cell, then solutions that are non-stable with respect to the same unknown are rejected After the final sifting the found unknowns are eliminated from the initial system with subsequent decreasing of its size. A numerical example is provided to demonstrate how the method can be applied to a real data set (a case study of the Nagano fault area, Central Japan). Results of processing of a huge volume of data and their importance for the Earthquake Early Warning (EEW) system are briefly discussed.

Wake flow behaviour behind a smaller cylinder oscillating in the wake of an upstream stationary cylinder

Energy Technology Data Exchange (ETDEWEB)

Gao, Yangyang; Sun, Zhilin [Ocean College, Zhejiang University, Hangzhou 310058 (China); Tan, Danielle S [Maritime Research Centre, Nanyang Technological University, Singapore 639798 (Singapore); Yu, Dingyong [College of Engineering, Ocean University of China, 266100 (China); Tan, Soon Keat, E-mail: yygao@zju.edu.cn [Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 639798 (Singapore)

2014-04-01

The flow patterns around a cylinder oscillating freely in the wake of a larger cylinder upstream were investigated using the particle image velocimetry technique. The upstream cylinder was fixed at both ends while the downstream smaller cylinder was held by springs such that it was free to oscillate in the transverse direction. The flow patterns, amplitudes of oscillation and vortex shedding frequencies were compared with those of a single cylinder. In the presence of the upstream cylinder, the three parameters characterizing the oscillation response of the smaller cylinder—amplitude of oscillation, vortex shedding frequency and Reynolds stresses—were greatly reduced. While their magnitude increased with gap ratio, these three parameters were still smaller than the corresponding magnitudes for a single oscillating cylinder. The peak values of turbulence statistics such as Reynolds shear stress and normal stress behind the oscillating downstream cylinder were similarly reduced, and increased with gap ratios. (paper)

Numerical simulation and analysis of confined turbulent buoyant jet with variable source

KAUST Repository

El-Amin, Mohamed

2016-01-23

In this work, experimental and numerical investigations are undertaken for confined buoyant turbulent jet with varying inlet temperatures. Results of the experimental work and numerical simulations for the problem under consideration are presented. Four cases of different variable inlet temperatures and different flow rates are considered. The realizable k-ɛ turbulence model is used to model the turbulent flow. Comparisons show good agreements between simulated and measured results. The average deviation of the simulated temperature by realizable k-ɛ turbulent model and the measured temperature is within 2%. The results indicate that temperatures along the vertical axis vary, generally, in nonlinear fashion as opposed to the approximately linear variation that was observed for the constant inlet temperature that was done in a previous work. Furthermore, thermal stratification exits, particularly closer to the entrance region. Further away from the entrance region the variation in temperatures becomes relatively smaller. The stratification is observed since the start of the experiment and continues during the whole course. Numerical experiments for constant, monotone increasing and monotone decreasing of inlet temperature are done to show its effect on the buoyancy force in terms of Richardson number.

Numerical simulation and analysis of confined turbulent buoyant jet with variable source

KAUST Repository

El-Amin, Mohamed; Al-Ghamdi, Abdulmajeed; Salama, Amgad; Sun, Shuyu

2016-01-01

In this work, experimental and numerical investigations are undertaken for confined buoyant turbulent jet with varying inlet temperatures. Results of the experimental work and numerical simulations for the problem under consideration are presented. Four cases of different variable inlet temperatures and different flow rates are considered. The realizable k-ɛ turbulence model is used to model the turbulent flow. Comparisons show good agreements between simulated and measured results. The average deviation of the simulated temperature by realizable k-ɛ turbulent model and the measured temperature is within 2%. The results indicate that temperatures along the vertical axis vary, generally, in nonlinear fashion as opposed to the approximately linear variation that was observed for the constant inlet temperature that was done in a previous work. Furthermore, thermal stratification exits, particularly closer to the entrance region. Further away from the entrance region the variation in temperatures becomes relatively smaller. The stratification is observed since the start of the experiment and continues during the whole course. Numerical experiments for constant, monotone increasing and monotone decreasing of inlet temperature are done to show its effect on the buoyancy force in terms of Richardson number.

Numerical simulation of two-phase flow in horizontal interconnected subchannels

International Nuclear Information System (INIS)

Shoukri, M.; Tahir, A.; Carver, M.B.

1983-01-01

Different subchannel computer codes have been successfully used for the thermal-hydraulic analysis of coolant flow in vertical fuel channels. However, none of these methods is suitable for two-phase flow in horizontal fuel channels, such as those of the CANDU nuclear reactors, due to the lack of appropriate constitutive relationships that can correctly account for the gravity separation effects. This paper describes the incorporation of a transverse vapour drift model which accounts for the combined effect of gravity separation and turbulent diffusion into the existing subchannel computer code SAGA. Although the basic structure of the code remains similar to SAGA III some modifications in both the mathematical formulation and numerical solution have been incorporated. These modifications resulted in significant improvements in the code's ability in modelling horizontal two-phase subchannel flow. The new version of the code was tested and found to be capable of simulating the complex exchange phenomenon between adjacent horizontal subchannels caused by the interaction of turbulent diffusion, pressure gradient as well as gravity induced cross flows. The code predictions were compared with experimental data obtained from two different sources and showed good agreement

Epigenetic Modifications and Diabetic Retinopathy

Directory of Open Access Journals (Sweden)

Renu A. Kowluru

2013-01-01

Full Text Available Diabetic retinopathy remains one of the most debilitating chronic complications, but despite extensive research in the field, the exact mechanism(s responsible for how retina is damaged in diabetes remains ambiguous. Many metabolic pathways have been implicated in its development, and genes associated with these pathways are altered. Diabetic environment also facilitates epigenetics modifications, which can alter the gene expression without permanent changes in DNA sequence. The role of epigenetics in diabetic retinopathy is now an emerging area, and recent work has shown that genes encoding mitochondrial superoxide dismutase (Sod2 and matrix metalloproteinase-9 (MMP-9 are epigenetically modified, activates of epigenetic modification enzymes, histone lysine demethylase 1 (LSD1, and DNA methyltransferase are increased, and the micro RNAs responsible for regulating nuclear transcriptional factor and VEGF are upregulated. With the growing evidence of epigenetic modifications in diabetic retinopathy, better understanding of these modifications has potential to identify novel targets to inhibit this devastating disease. Fortunately, the inhibitors and mimics targeted towards histone modification, DNA methylation, and miRNAs are now being tried for cancer and other chronic diseases, and better understanding of the role of epigenetics in diabetic retinopathy will open the door for their possible use in combating this blinding disease.

NUMERICAL ANALYSIS OF THE CRITICAL STATE OF THIN-WALLED STRUCTURE WITH Z-PROFILE CROSS SECTION

Directory of Open Access Journals (Sweden)

Patryk Różyło

2017-03-01

Full Text Available The object of the study was the thin-walled profile with Z-shaped cross section made of the carbon-epoxy composite. Material model was prepared based on the implemented orthotropic properties. The purpose of study was to determine the value of the critical load at which buckling occurs, the form of buckling and operating characteristics in critical condition. In order to achieve this numerical analysis were carried out. Additionally, the effects of the modification in arrangement of layers of the laminate to the stability and strength of thin-walled composite structures was presented. Numerical studies were carried out using commercial simulation software - ABAQUS®. Within the FEM research, both forms of buckling and the associated critical load, dependent on the configuration the layers of the composite were achieved. Analysis of the obtained results, allowed the evaluation of the structure's work in relation to the level of energy consumption or rigidity estimation. In the paper only numerical simulations of the critical state were conducted.

Accuracy requirements for the calculation of gravitational waveforms from coalescing compact binaries in numerical relativity

International Nuclear Information System (INIS)

Miller, Mark

2005-01-01

I discuss the accuracy requirements on numerical relativity calculations of inspiraling compact object binaries whose extracted gravitational waveforms are to be used as templates for matched filtering signal extraction and physical parameter estimation in modern interferometric gravitational wave detectors. Using a post-Newtonian point particle model for the premerger phase of the binary inspiral, I calculate the maximum allowable errors for the mass and relative velocity and positions of the binary during numerical simulations of the binary inspiral. These maximum allowable errors are compared to the errors of state-of-the-art numerical simulations of multiple-orbit binary neutron star calculations in full general relativity, and are found to be smaller by several orders of magnitude. A post-Newtonian model for the error of these numerical simulations suggests that adaptive mesh refinement coupled with second-order accurate finite difference codes will not be able to robustly obtain the accuracy required for reliable gravitational wave extraction on Terabyte-scale computers. I conclude that higher-order methods (higher-order finite difference methods and/or spectral methods) combined with adaptive mesh refinement and/or multipatch technology will be needed for robustly accurate gravitational wave extraction from numerical relativity calculations of binary coalescence scenarios

Perceived state of self during motion can differentially modulate numerical magnitude allocation.

Science.gov (United States)

Arshad, Q; Nigmatullina, Y; Roberts, R E; Goga, U; Pikovsky, M; Khan, S; Lobo, R; Flury, A-S; Pettorossi, V E; Cohen-Kadosh, R; Malhotra, P A; Bronstein, A M

2016-09-01

Although a direct relationship between numerical allocation and spatial attention has been proposed, recent research suggests that these processes are not directly coupled. In keeping with this, spatial attention shifts induced either via visual or vestibular motion can modulate numerical allocation in some circumstances but not in others. In addition to shifting spatial attention, visual or vestibular motion paradigms also (i) elicit compensatory eye movements which themselves can influence numerical processing and (ii) alter the perceptual state of 'self', inducing changes in bodily self-consciousness impacting upon cognitive mechanisms. Thus, the precise mechanism by which motion modulates numerical allocation remains unknown. We sought to investigate the influence that different perceptual experiences of motion have upon numerical magnitude allocation while controlling for both eye movements and task-related effects. We first used optokinetic visual motion stimulation (OKS) to elicit the perceptual experience of either 'visual world' or 'self'-motion during which eye movements were identical. In a second experiment, we used a vestibular protocol examining the effects of perceived and subliminal angular rotations in darkness, which also provoked identical eye movements. We observed that during the perceptual experience of 'visual world' motion, rightward OKS-biased judgments towards smaller numbers, whereas leftward OKS-biased judgments towards larger numbers. During the perceptual experience of 'self-motion', judgments were biased towards larger numbers irrespective of the OKS direction. Contrastingly, vestibular motion perception was found not to modulate numerical magnitude allocation, nor was there any differential modulation when comparing 'perceived' vs. 'subliminal' rotations. We provide a novel demonstration that numerical magnitude allocation can be differentially modulated by the perceptual state of self during visual but not vestibular mediated motion

Modification of the CEBAF transport dipoles for energy upgrade considerations

International Nuclear Information System (INIS)

D. Bullard; L. Harwood; T. Hiatt; J. Karn; E. Martin; W. Oren; C. Rode; K. Sullivan; R. Wines; M. Wiseman

1999-01-01

The CEBAF accelerator at the Thomas Jefferson National Accelerator Facility contains 415 resistive dipoles in the recirculation arcs and transport lines. These dipoles were originally designed and magnetically mapped to support the operation of the accelerator at 6 GeV. Recent interests in upgrading the CEBAF energy beyond 6 GeV prompted a study into operating the dipoles beyond their design limits. Finite element modeling was performed to quantify saturation effects at higher currents and to test simple modifications to improve magnetic performance. For confirmation, various steps were prototyped and magnetically measured. Measurement results agreed with finite element models and showed that saturation could be reduced to manageable levels. It was found that the most populous dipole families could be modified to reach twice their design field with minimal cost and effort. At these higher fields, the magnets operate at a reasonable thermal state with minimal saturation losses a nd little degradation in field quality. Work continues on studying the smaller population of dipoles to determine their performance at higher fields

Numerical solution of modified differential equations based on symmetry preservation.

Science.gov (United States)

Ozbenli, Ersin; Vedula, Prakash

2017-12-01

In this paper, we propose a method to construct invariant finite-difference schemes for solution of partial differential equations (PDEs) via consideration of modified forms of the underlying PDEs. The invariant schemes, which preserve Lie symmetries, are obtained based on the method of equivariant moving frames. While it is often difficult to construct invariant numerical schemes for PDEs due to complicated symmetry groups associated with cumbersome discrete variable transformations, we note that symmetries associated with more convenient transformations can often be obtained by appropriately modifying the original PDEs. In some cases, modifications to the original PDEs are also found to be useful in order to avoid trivial solutions that might arise from particular selections of moving frames. In our proposed method, modified forms of PDEs can be obtained either by addition of perturbation terms to the original PDEs or through defect correction procedures. These additional terms, whose primary purpose is to enable symmetries with more convenient transformations, are then removed from the system by considering moving frames for which these specific terms go to zero. Further, we explore selection of appropriate moving frames that result in improvement in accuracy of invariant numerical schemes based on modified PDEs. The proposed method is tested using the linear advection equation (in one- and two-dimensions) and the inviscid Burgers' equation. Results obtained for these tests cases indicate that numerical schemes derived from the proposed method perform significantly better than existing schemes not only by virtue of improvement in numerical accuracy but also due to preservation of qualitative properties or symmetries of the underlying differential equations.

Proteomic analysis of post-translational modifications

DEFF Research Database (Denmark)

Mann, Matthias; Jensen, Ole N

2003-01-01

Post-translational modifications modulate the activity of most eukaryote proteins. Analysis of these modifications presents formidable challenges but their determination generates indispensable insight into biological function. Strategies developed to characterize individual proteins are now...... systematically applied to protein populations. The combination of function- or structure-based purification of modified 'subproteomes', such as phosphorylated proteins or modified membrane proteins, with mass spectrometry is proving particularly successful. To map modification sites in molecular detail, novel...

Chemical Modifications of Starch: Microwave Effect

OpenAIRE

Lewicka, Kamila; Siemion, Przemysław; Kurcok, Piotr

2015-01-01

This paper presents basic methods of starch chemical modification, the effect of microwave radiation on the modification process, and the physicochemical properties of starch. It has been shown that the modifications contribute to improvement of the material performance and likewise to significant improvement of its mechanical properties. As a result, more and more extensive use of starch is possible in various industries. In addition, methods of oxidized starch and starch esters preparation ...

Smaller genitals at school age in boys whose mothers were exposed to non-persistent pesticides in early pregnancy

DEFF Research Database (Denmark)

Veje, Christine Wohlfahrt; Andersen, H R; Jensen, Tina Kold

2012-01-01

. The effects were associated with the maternal exposure levels, so that high-exposed boys had smaller genitals than medium-exposed boys, who had smaller genitals than those who were unexposed. Boys of mothers in the high exposure group (n = 23) had 24.7% smaller testes (95% CI: -62.2; -10.1) and 9.4% shorter...... penile length (95% CI: -16.8; -1.1) compared with the unexposed. The testicular volume and penile length at school age could be tracked to measures from the same boys made at 3 months, e.g. those that had small testes at school age also had small testes at 3 months. Pituitary and testicular hormone serum...

The surface modification of polystyrene

International Nuclear Information System (INIS)

Tremlett, C.

2000-03-01

Polymers have ideal bulk properties for many applications. However, adhesion to many polymers is poor without surface pretreatment. This can result, for example, in peeling paint and printing, adhesive joint failure and bio-incompatibility. In applications such as painting, printing, adhesive bonding and biocompatibility, various cleaning or surface chemical modifications may be employed. A commodity polymer where pretreatment is sometimes needed is polystyrene. This project investigated, in detail, the effects of a novel method of modification namely mediated electrochemical oxidation (MEO), as a mode of surface modification on polystyrene and a comparison was made with other polymers. The resulting modification was investigated using a range of surface analysis techniques to obtain complementary information. These included, X-ray photoelectron spectroscopy, contact angles, static secondary ion mass spectrometry, atomic force microscopy, chemical derivatization, scanning electron microscopy, attenuated total reflection Fourier Transform infrared spectroscopy and composite lap shear joint testing. It has been shown that MEO modifies the surface of polystyrene introduced oxygen mainly as hydroxyl groups, and a small number of carbonyl groups, that are positioned only on the backbone hydrocarbon chain. This modification improved adhesion, was stable and samples could be stored in aqueous media. The resulting hydroxylation was further derivatized using an amino acid to provide a specialised surface. This was very different from the multiple oxygen functionalities introduced in the comparison studies by UV/ozone and plasma treatments. (author)

Gamma irradiating elm billets reduces their attractancy to the smaller elm bark beetle, Scolytus multistriatus (Marsham)

International Nuclear Information System (INIS)

French, J.R.J.; Robinson, P.J.

1982-01-01

Irradiating elm billets with gamma rays had a significant effect in reducing the attractancy of these billets to inflight adults of the smaller elm bark beetle Scolytus multistriatus (Marsham). The temperature at which the fresh billets were stored prior to the beetle exposure had little effect. Irradiated billets, irrespective of storage temperature, had significantly fewer holes than the freshly cut billets. There were significant differences associated with the location of the billets in the field, but these differences were smaller than those associated with irradiation. (orig.) [de

Application of radiation technology in starch modification

International Nuclear Information System (INIS)

Chen Huiyuan; Peng Zhigang; Ding Zhongmin; Lu Jiajiu

2007-01-01

In order to commercialize the radiation modification of starch, corn starch was irradiated with different dose of 60 Co gamma radiations. Some basic physical and chemical properties of the resulted modified starch paste were measured with emphasis on the viscosity stability and tensile strength. The results indicate that irradiation of corn starch with a dose of 4-10 kGy can decrease its viscosity to 5-14 mPa·s, and the tensile strength can meet the standard set up for textile paste. In comparison with chemical modification for starch, radiation modification is simpler in technology, more convenient in operation, more stable in modification quality, and easier to control. The mechanism of radiation modification of starch was also discussed. (authors)

Numerical relativity

International Nuclear Information System (INIS)

Piran, T.

1982-01-01

There are many recent developments in numerical relativity, but there remain important unsolved theoretical and practical problems. The author reviews existing numerical approaches to solution of the exact Einstein equations. A framework for classification and comparison of different numerical schemes is presented. Recent numerical codes are compared using this framework. The discussion focuses on new developments and on currently open questions, excluding a review of numerical techniques. (Auth.)

Modification of Spalart-Allmaras model with consideration of turbulence energy backscatter using velocity helicity

International Nuclear Information System (INIS)

Liu, Yangwei; Lu, Lipeng; Fang, Le; Gao, Feng

2011-01-01

The correlation between the velocity helicity and the energy backscatter is proved in a DNS case of 256 3 -grid homogeneous isotropic decaying turbulence. The helicity is then proposed to be employed to improve turbulence models and SGS models. Then Spalart-Allmaras turbulence model (SA) is modified with the helicity to take account of the energy backscatter, which is significant in the region of corner separation in compressors. By comparing the numerical results with experiments, it can be concluded that the modification for SA model with helicity can appropriately represent the energy backscatter, and greatly improves the predictive accuracy for simulating the corner separation flow in compressors. -- Highlights: → We study the relativity between the velocity helicity and the energy backscatter. → Spalart-Allmaras turbulence model is modified with the velocity helicity. → The modified model is employed to simulate corner separation in compressor cascade. → The modification can greatly improve the accuracy for predicting corner separation. → The helicity can represent the energy backscatter in turbulence and SGS models.

Knowledge acquisition for the internationalization of the smaller firm:Content and sources

OpenAIRE

Harris, Simon; Fletcher, Margaret

2012-01-01

Internationalization process research emphasizes accumulated experience and networks as sources of knowledge for internationalization. Our understanding, however, as to what this knowledge is in practice for smaller firms, the challenges they face in acquiring it, and how they address those challenges is limited. Integrating organizational learning concepts with our theoretical understanding of the small firm internationalization process, we develop a new framework for understanding knowledge...

Detection of smaller Jc region and damage in YBCO coated conductors by using permanent magnet method

International Nuclear Information System (INIS)

Hattori, K.; Saito, A.; Takano, Y.; Suzuki, T.; Yamada, H.; Takayama, T.; Kamitani, A.; Ohshima, S.

2011-01-01

We developed a non-destructive method for measuring the critical current density (J c ) in YBCO-coated conductors by using a permanent magnet (Sm 2 Co 17 ). J c could be determined from the repulsive force (F r ) generated between a permanent magnet and a coated conductor where shielding current flows. We also examined the influence of damage to the film on the J c distribution. The measured F r when the permanent magnet approached the cut part was smaller than that of the undamaged area. We developed a non-destructive method for measuring the critical current density (J c ) in YBCO-coated conductors by using a permanent magnet (Sm 2 Co 17 ). J c could be determined from the repulsive force (F r ) generated between a permanent magnet and a coated conductor where shielding current flows. We tried to detect a smaller J c region in the coated conductor by using the system. The J c distribution could be determined without influence from the thick copper film on YBCO thin film. We also examined the influence of damage to the film on the J c distribution. The surface of the coated conductors was cut by using a knife. The measured F r when the permanent magnet approached the cut part was smaller than that of the undamaged area. This J c measurement technique will be useful for detecting smaller J c regions and defects in coated conductors.

Scalability on LHS (Latin Hypercube Sampling) samples for use in uncertainty analysis of large numerical models

International Nuclear Information System (INIS)

Baron, Jorge H.; Nunez Mac Leod, J.E.

2000-01-01

The present paper deals with the utilization of advanced sampling statistical methods to perform uncertainty and sensitivity analysis on numerical models. Such models may represent physical phenomena, logical structures (such as boolean expressions) or other systems, and various of their intrinsic parameters and/or input variables are usually treated as random variables simultaneously. In the present paper a simple method to scale-up Latin Hypercube Sampling (LHS) samples is presented, starting with a small sample and duplicating its size at each step, making it possible to use the already run numerical model results with the smaller sample. The method does not distort the statistical properties of the random variables and does not add any bias to the samples. The results is a significant reduction in numerical models running time can be achieved (by re-using the previously run samples), keeping all the advantages of LHS, until an acceptable representation level is achieved in the output variables. (author)

Modification of the grain structure of austenitic welds for improved ultrasonic inspectability

International Nuclear Information System (INIS)

Wagner, S.; Dugan, S.; Stubenrauch, S.; Jacobs, O.

2012-01-01

Austenitic stainless steel welds, which are widely used for example in nuclear power plants and chemical installations, present major challenges for ultrasonic inspection due to the grain structure of the weld. Large grains in combination with the elastic anisotropy of the material lead to increased scattering and affect sound wave propagation in the weld. This results in a reduced signal-to-noise ratio, and complicates the interpretation of signals and the localization of defects. The aim of this project is to influence grain growth in the weld during the welding process to produce smaller grains, in order to improve sound propagation through the weld, thus improving inspectability. Metallographic sections of the first test welds have shown that a modification of the grain structure can be achieved by influencing the grain growth with magnetic fields. For further optimization, test blocks for ultrasonic testing were manufactured to study sound propagation through the weld and detectability of test flaws.

Pragmatic Graph Rewriting Modifications

OpenAIRE

Rodgers, Peter; Vidal, Natalia

1999-01-01

We present new pragmatic constructs for easing programming in visual graph rewriting programming languages. The first is a modification to the rewriting process for nodes the host graph, where nodes specified as 'Once Only' in the LHS of a rewrite match at most once with a corresponding node in the host graph. This reduces the previously common use of tags to indicate the progress of matching in the graph. The second modification controls the application of LHS graphs, where those specified a...

Drug Addiction and DNA Modifications.

Science.gov (United States)

Brown, Amber N; Feng, Jian

2017-01-01

Drug addiction is a complex disorder which can be influenced by both genetic and environmental factors. Research has shown that epigenetic modifications can translate environmental signals into changes in gene expression, suggesting that epigenetic changes may underlie the causes and possibly treatment of substance use disorders. This chapter will focus on epigenetic modifications to DNA, which include DNA methylation and several recently defined additional DNA epigenetic changes. We will discuss the functions of DNA modifications and methods for detecting them, followed by a description of the research investigating the function and consequences of drug-induced changes in DNA methylation patterns. Understanding these epigenetic changes may provide us translational tools for the diagnosis and treatment of addiction in the future.

Methodological guidelines for developing accident modification functions

DEFF Research Database (Denmark)

Elvik, Rune

2015-01-01

This paper proposes methodological guidelines for developing accident modification functions. An accident modification function is a mathematical function describing systematic variation in the effects of road safety measures. The paper describes ten guidelines. An example is given of how to use...... limitations in developing accident modification functions are the small number of good evaluation studies and the often huge variation in estimates of effect. It is therefore still not possible to develop accident modification functions for very many road safety measures. © 2015 Elsevier Ltd. All rights...... the guidelines. The importance of exploratory analysis and an iterative approach in developing accident modification functions is stressed. The example shows that strict compliance with all the guidelines may be difficult, but represents a level of stringency that should be strived for. Currently the main...

What Research Tells Us about the Impact and Challenges of Smaller Learning Communities

Science.gov (United States)

Levine, Thomas H.

2010-01-01

In the United States, considerable financial and human resources have been devoted to breaking some large high schools into smaller learning communities (SLCs). This article reviews research that compares SLCs to comprehensive high schools on a variety of measures. Extant research neither supports nor refutes the promise of SLCs to improve…

Identifying generalized Fitzhugh-Nagumo equation from a numerical solution of Hodgkin-Huxley model

Directory of Open Access Journals (Sweden)

Nikola V. Georgiev

2003-01-01

Full Text Available An analytic time series in the form of numerical solution (in an appropriate finite time interval of the Hodgkin-Huxley current clamped (HHCC system of four differential equations, well known in the neurophysiology as an exact empirical model of excitation of a giant axon of Loligo, is presented. Then we search for a second-order differential equation of generalized Fitzhugh-Nagumo (GFN type, having as a solution the given single component (action potential of the numerical solution. The given time series is used as a basis for reconstructing orders, powers, and coefficients of the polynomial right-hand sides of GFN equation approximately governing the process of action potential. For this purpose, a new geometrical method for determining phase space dimension of the unknown dynamical system (GFN equation and a specific modification of least squares method for identifying unknown coefficients are developed and applied.

Functional Anthology of Intrinsic Disorder. III. Ligands, Postranslational Modifications and Diseases Associated with Intrinsically Disordered Proteins

Science.gov (United States)

Xie, Hongbo; Vucetic, Slobodan; Iakoucheva, Lilia M.; Oldfield, Christopher J.; Dunker, A. Keith; Obradovic, Zoran; Uversky, Vladimir N.

2008-01-01

Currently, the understanding of the relationships between function, amino acid sequence and protein structure continues to represent one of the major challenges of the modern protein science. As much as 50% of eukaryotic proteins are likely to contain functionally important long disordered regions. Many proteins are wholly disordered but still possess numerous biologically important functions. However, the number of experimentally confirmed disordered proteins with known biological functions is substantially smaller than their actual number in nature. Therefore, there is a crucial need for novel bioinformatics approaches that allow projection of the current knowledge from a few experimentally verified examples to much larger groups of known and potential proteins. The elaboration of a bioinformatics tool for the analysis of functional diversity of intrinsically disordered proteins and application of this data mining tool to >200,000 proteins from Swiss-Prot database, each annotated with at least one of the 875 functional keywords was described in the first paper of this series (Xie H., Vucetic S., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic Z., Uversky V.N. (2006) Functional anthology of intrinsic disorder. I. Biological processes and functions of proteins with long disordered regions. J. Proteome Res.). Using this tool, we have found that out of the 711 Swiss-Prot functional keywords associated with at least 20 proteins, 262 were strongly positively correlated with long intrinsically disordered regions, and 302 were strongly negatively correlated. Illustrative examples of functional disorder or order were found for the vast majority of keywords showing strongest positive or negative correlation with intrinsic disorder, respectively. Some 80 Swiss-Prot keywords associated with disorder- and order-driven biological processes and protein functions were described in the first paper (Xie H., Vucetic S., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic

High proportion of smaller ranged hummingbird species coincides with ecological specialization across the Americas

DEFF Research Database (Denmark)

Sonne, Jesper; Martín González, Ana M.; Maruyama, Pietro K.

2016-01-01

Ecological communities that experience stable climate conditions have been speculated to preserve more specialized interspecific associations and have higher proportions of smaller ranged species (SRS). Thus, areas with disproportionally large numbers of SRS are expected to coincide geographicall...

A new numerical modelling method for deformation behaviour of metallic porous materials using X-ray computed microtomography

Energy Technology Data Exchange (ETDEWEB)

Doroszko, M., E-mail: m.doroszko@pb.edu.pl; Seweryn, A., E-mail: a.seweryn@pb.edu.pl

2017-03-24

Microtomographic devices have limited imaging accuracy and are often insufficient for proper mapping of small details of real objects (e.g. elements of material mesostructures). This paper describes a new method developed to compensate the effect of X-ray computed microtomography (micro-CT) inaccuracy in numerical modelling of the deformation process of porous sintered 316 L steel. The method involves modification of microtomographic images where the pore shapes are separated. The modification consists of the reconstruction of fissures and small pores omitted by micro-CT scanning due to the limited accuracy of the measuring device. It enables proper modelling of the tensile deformation process of porous materials. In addition, the proposed approach is compared to methods described in the available literature. As a result of numerical calculations, stress and strain distributions were obtained in deformed sintered 316 L steel. Based on the results, macroscopic stress-strain curves were received. Maximum principal stress distributions obtained by the proposed calculation model, indicated specific locations, where the stress reached a critical value, and fracture initiation occurred. These are bridges with small cross sections and notches in the shape of pores. Based on calculation results, the influence of the deformation mechanism of the material porous mesostructures on their properties at the macroscale is described.

A new numerical modelling method for deformation behaviour of metallic porous materials using X-ray computed microtomography

International Nuclear Information System (INIS)

Doroszko, M.; Seweryn, A.

2017-01-01

Microtomographic devices have limited imaging accuracy and are often insufficient for proper mapping of small details of real objects (e.g. elements of material mesostructures). This paper describes a new method developed to compensate the effect of X-ray computed microtomography (micro-CT) inaccuracy in numerical modelling of the deformation process of porous sintered 316 L steel. The method involves modification of microtomographic images where the pore shapes are separated. The modification consists of the reconstruction of fissures and small pores omitted by micro-CT scanning due to the limited accuracy of the measuring device. It enables proper modelling of the tensile deformation process of porous materials. In addition, the proposed approach is compared to methods described in the available literature. As a result of numerical calculations, stress and strain distributions were obtained in deformed sintered 316 L steel. Based on the results, macroscopic stress-strain curves were received. Maximum principal stress distributions obtained by the proposed calculation model, indicated specific locations, where the stress reached a critical value, and fracture initiation occurred. These are bridges with small cross sections and notches in the shape of pores. Based on calculation results, the influence of the deformation mechanism of the material porous mesostructures on their properties at the macroscale is described.

Effects of a lighter, smaller football on Acute match injuries in adolescent female football

DEFF Research Database (Denmark)

Zebis, Mette K.; Thorborg, Kristian; Andersen, Lars L.

2018-01-01

BACKGROUND: The high injury incidence during match-play in female adolescent football is a major concern. In football, males and females play matches with the same football size. No studies have investigated the effect of football size on injury incidence in female adolescent football. Thus......, the aim of the present study was to investigate the effects of introducing a lighter, smaller football on the injury pattern in female adolescent football. METHODS We conducted a pilot cluster randomized controlled trial including 26 football teams representing 346 adolescent female football players (age...... 15-18 years). The teams were randomized to a new lighter, smaller football (INT, N.=12 teams) or a traditional FIFA size 5 football (CON, N.=14 teams) during a full match-season. Acute time-loss injuries and football-exposure during match-play were reported weekly by text-message questions...

Numerical relativity

CERN Document Server

Shibata, Masaru

2016-01-01

This book is composed of two parts: First part describes basics in numerical relativity, that is, the formulations and methods for a solution of Einstein's equation and general relativistic matter field equations. This part will be helpful for beginners of numerical relativity who would like to understand the content of numerical relativity and its background. The second part focuses on the application of numerical relativity. A wide variety of scientific numerical results are introduced focusing in particular on the merger of binary neutron stars and black holes.

Numerical analysis

CERN Document Server

Khabaza, I M

1960-01-01

Numerical Analysis is an elementary introduction to numerical analysis, its applications, limitations, and pitfalls. Methods suitable for digital computers are emphasized, but some desk computations are also described. Topics covered range from the use of digital computers in numerical work to errors in computations using desk machines, finite difference methods, and numerical solution of ordinary differential equations. This book is comprised of eight chapters and begins with an overview of the importance of digital computers in numerical analysis, followed by a discussion on errors in comput

The computational nature of memory modification.

Science.gov (United States)

Gershman, Samuel J; Monfils, Marie-H; Norman, Kenneth A; Niv, Yael

2017-03-15

Retrieving a memory can modify its influence on subsequent behavior. We develop a computational theory of memory modification, according to which modification of a memory trace occurs through classical associative learning, but which memory trace is eligible for modification depends on a structure learning mechanism that discovers the units of association by segmenting the stream of experience into statistically distinct clusters (latent causes). New memories are formed when the structure learning mechanism infers that a new latent cause underlies current sensory observations. By the same token, old memories are modified when old and new sensory observations are inferred to have been generated by the same latent cause. We derive this framework from probabilistic principles, and present a computational implementation. Simulations demonstrate that our model can reproduce the major experimental findings from studies of memory modification in the Pavlovian conditioning literature.

Modifications to nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2004-01-01

This Safety Guide was prepared under the IAEA's programme for safety standards for nuclear power plants. It supplements Section 7 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation, which establishes the safety requirements for the modification of nuclear power plants. Reasons for carrying out modifications to nuclear power plants may include: (1) maintaining or strengthening existing safety provisions and thus maintaining consistency with or improving on the current design. (2) recovering from plant faults. (3) improving the thermal performance or increasing the power rating of the plant. (4) increasing the maintainability of the plant, reducing the radiation exposure of personnel or reducing the costs of plant maintenance. And (5) extending the design life of the plant. Most modifications, made on the basis of operating experience, are intended to improve on the design or to improve operational performance and flexibility. Some are rendered necessary by new regulatory requirements, ageing of the plant or obsolescence of equipment. However, the benefits of regularly updating the plant design can be jeopardized if modifications are not kept under rigorous control throughout the lifetime of the plant. The need to reduce costs and improve efficiency, in combination with changes to the structure of the electricity generation sector of the economy in many countries, has led many companies to make changes in the structure of the operating organization for nuclear power plants. Whatever the reason for such organizational changes, consideration should be given to the effects of those changes with the aim of ensuring that they would have no impacts that would compromise the safety of the plant. The objective of this Safety Guide is to provide guidance and recommendations on controlling activities relating to modifications at nuclear power plants in order to reduce risk and to ensure that the configuration of the plant is at all times under

Modifications to nuclear power plants. Safety guide

International Nuclear Information System (INIS)

2007-01-01

This Safety Guide was prepared under the IAEA's programme for safety standards for nuclear power plants. It supplements Section 7 of the Safety Requirements publication on Safety of Nuclear Power Plants: Operation, which establishes the safety requirements for the modification of nuclear power plants. Reasons for carrying out modifications to nuclear power plants may include: (1) maintaining or strengthening existing safety provisions and thus maintaining consistency with or improving on the current design. (2) recovering from plant faults. (3) improving the thermal performance or increasing the power rating of the plant. (4) increasing the maintainability of the plant, reducing the radiation exposure of personnel or reducing the costs of plant maintenance. And (5) extending the design life of the plant. Most modifications, made on the basis of operating experience, are intended to improve on the design or to improve operational performance and flexibility. Some are rendered necessary by new regulatory requirements, ageing of the plant or obsolescence of equipment. However, the benefits of regularly updating the plant design can be jeopardized if modifications are not kept under rigorous control throughout the lifetime of the plant. The need to reduce costs and improve efficiency, in combination with changes to the structure of the electricity generation sector of the economy in many countries, has led many companies to make changes in the structure of the operating organization for nuclear power plants. Whatever the reason for such organizational changes, consideration should be given to the effects of those changes with the aim of ensuring that they would have no impacts that would compromise the safety of the plant. The objective of this Safety Guide is to provide guidance and recommendations on controlling activities relating to modifications at nuclear power plants in order to reduce risk and to ensure that the configuration of the plant is at all times under

Energy conservation potential of surface modification technologies

Energy Technology Data Exchange (ETDEWEB)

Le, H.K.; Horne, D.M.; Silberglitt, R.S.

1985-09-01

This report assesses the energy conservation impact of surface modification technologies on the metalworking industries. The energy conservation impact of surface modification technologies on the metalworking industries is assessed by estimating their friction and wear tribological sinks and the subsequent reduction in these sinks when surface modified tools are used. Ion implantation, coatings, and laser and electron beam surface modifications are considered.

Histone modifications: Cycling with chromosomal replication

DEFF Research Database (Denmark)

Thon, Genevieve

2008-01-01

Histone modifications tend to be lost during chromosome duplication. Several recent studies suggest that the RNA interference pathway becomes active during the weakened transcriptional repression occurring at centromeres in S phase, resulting in the re-establishment of histone modifications...

Modification of equivalent photon approximation (EPA) for resolved photon processes

International Nuclear Information System (INIS)

Drees, M.; Godbole, R.M.

1995-05-01

The authors propose a modification of the equivalent photon approximation (EPA) for processes which involve the parton content of the photon, to take into account the suppression of the photonic parton fluxes due to the virtuality of the photon. They present simple, physically motivated ansaetze to model this suppression and show that even though the parton content of the electron no longer factorizes into an electron flux function and photon structure function, it is still possible to express it as a single integral. They also show that for the TRISTAN (transposable ring intersecting storage accelerators in Nippon) experiments its effects can be numerically of the same size as that of the NLO corrections. Further, it is discussed a possible measurements at HERA (hadron electron ring an large), which can be provide an experimental handle on the effect the authors model through their ansaetze

Tandem affinity purification of histones, coupled to mass spectrometry, identifies associated proteins and new sites of post-translational modification in Saccharomyces cerevisiae.

Science.gov (United States)

Valero, M Luz; Sendra, Ramon; Pamblanco, Mercè

2016-03-16

Histones and their post-translational modifications contribute to regulating fundamental biological processes in all eukaryotic cells. We have applied a conventional tandem affinity purification strategy to histones H3 and H4 of the yeast Saccharomyces cerevisiae. Mass spectrometry analysis of the co-purified proteins revealed multiple associated proteins, including core histones, which indicates that tagged histones may be incorporated to the nucleosome particle. Among the many other co-isolated proteins there are histone chaperones, elements of chromatin remodeling, of nucleosome assembly/disassembly, and of histone modification complexes. The histone chaperone Rtt106p, two members of chromatin assembly FACT complex and Psh1p, an ubiquitin ligase, were the most abundant proteins obtained with both H3-TAP and H4-TAP, regardless of the cell extraction medium stringency. Our mass spectrometry analyses have also revealed numerous novel post-translational modifications, including 30 new chemical modifications in histones, mainly by ubiquitination. We have discovered not only new sites of ubiquitination but that, besides lysine, also serine and threonine residues are targets of ubiquitination on yeast histones. Our results show the standard tandem affinity purification procedure is suitable for application to yeast histones, in order to isolate and characterize histone-binding proteins and post-translational modifications, avoiding the bias caused by histone purification from a chromatin-enriched fraction. Copyright © 2016 Elsevier B.V. All rights reserved.

A nerve stimulation method to selectively recruit smaller motor-units in rat skeletal muscle

NARCIS (Netherlands)

van Bolhuis, A.I.; Holsheimer, J.; Savelsberg, H.H.C.M.

2001-01-01

Electrical stimulation of peripheral nerve results in a motor-unit recruitment order opposite to that attained by natural neural control, i.e. from large, fast-fatiguing to progressively smaller, fatigue-resistant motor-units. Yet animal studies involving physiological exercise protocols of low

Calculation about a modification to the toroidal magnetic field of the Tokamak Novillo. Part I

International Nuclear Information System (INIS)

Chavez A, E.; Melendez L, L.; Colunga S, S.; Valencia A, R.; Lopez C, R.; Gaytan G, E.

1991-07-01

The charged particles that constitute the plasma in the tokamaks are located in magnetic fields that determine its behavior. The poloidal magnetic field of the plasma current and the toroidal magnetic field of the tokamak possess relatively big gradients, which produce drifts on these particles. These drifts are largely the cause of the continuous lost of particles and of energy of the confinement region. In this work the results of numerical calculations of a modification to the 'traditional' toroidal magnetic field that one waits it diminishes the drifts by gradient and improve the confinement properties of the tokamaks. (Author)

75 FR 41529 - Petitions for Modification

Science.gov (United States)

2010-07-16

... application of existing mandatory safety standards published in Title 30 of the Code of Federal Regulations... DEPARTMENT OF LABOR Mine Safety and Health Administration Petitions for Modification AGENCY: Mine Safety and Health Administration (MSHA), Labor. ACTION: Notice of petitions for modification of existing...

75 FR 29784 - Petitions for Modification

Science.gov (United States)

2010-05-27

... application of existing mandatory safety standards published in Title 30 of the Code of Federal Regulations... DEPARTMENT OF LABOR Mine Safety and Health Administration Petitions for Modification AGENCY: Mine Safety and Health Administration (MSHA), Labor. ACTION: Notice of petitions for modification of existing...

75 FR 34486 - Petitions for Modification

Science.gov (United States)

2010-06-17

... application of existing mandatory safety standards published in Title 30 of the Code of Federal Regulations... DEPARTMENT OF LABOR Mine Safety and Health Administration Petitions for Modification AGENCY: Mine Safety and Health Administration (MSHA), Labor. ACTION: Notice of petitions for modification of existing...

Numerical analysis of boosting scheme for scalable NMR quantum computation

International Nuclear Information System (INIS)

SaiToh, Akira; Kitagawa, Masahiro

2005-01-01

Among initialization schemes for ensemble quantum computation beginning at thermal equilibrium, the scheme proposed by Schulman and Vazirani [in Proceedings of the 31st ACM Symposium on Theory of Computing (STOC'99) (ACM Press, New York, 1999), pp. 322-329] is known for the simple quantum circuit to redistribute the biases (polarizations) of qubits and small time complexity. However, our numerical simulation shows that the number of qubits initialized by the scheme is rather smaller than expected from the von Neumann entropy because of an increase in the sum of the binary entropies of individual qubits, which indicates a growth in the total classical correlation. This result--namely, that there is such a significant growth in the total binary entropy--disagrees with that of their analysis

The Application of Systemic Safety for Smaller Nuclear Installations

International Nuclear Information System (INIS)

Ward, J.

2016-01-01

This paper will provide an outline of ARPANSA’s approach to systemic safety as applied to smaller hazard nuclear installations. It will describe ARPANSA’s effort to enable licence holders to better understand the principles of systemic safety so that they may make improvements for themselves. In regard to human and organizational factors, inspections are more often used to highlight areas where performance can be improved to meet best practice rather than strictly as a compliance tool. This takes account of a graded, risk informed approach and is undertaken in a collaborative way that places a premium on openness, clarity, reliability and efficiency. The paper will discuss the challenges faced by the approach, and how ARPANSA is currently managing these. It will describe ARPANSA’s regulatory guidance and inspection processes. The significant stages in ARPANSA development of the systemic approach are provided briefly in the following paragraphs.

Improvement of D.I. diesel engine combustion using numerical simulation; Chokufun diesel kikan no nensho kaizen shuho. Suchi kaiseki ni yoru torikumi

Energy Technology Data Exchange (ETDEWEB)

Minami, T.; Adachi, T.; Isyii, Y. [Isuzu Motors Ltd., Tokyo (Japan)

1999-04-01

For the purpose of improving DI diesel engine combustion, it is important to predict air flow of intake and exhaust manifold, intake port flow, combustion chamber swirl and fuel spray combustion. This paper describes the application of numerical simulation to the engines, the analysis of phenomena and a problem of simulation model modification. (author)

Post-Translational Modifications of TRP Channels

Directory of Open Access Journals (Sweden)

Olaf Voolstra

2014-04-01

Full Text Available Transient receptor potential (TRP channels constitute an ancient family of cation channels that have been found in many eukaryotic organisms from yeast to human. TRP channels exert a multitude of physiological functions ranging from Ca2+ homeostasis in the kidney to pain reception and vision. These channels are activated by a wide range of stimuli and undergo covalent post-translational modifications that affect and modulate their subcellular targeting, their biophysical properties, or channel gating. These modifications include N-linked glycosylation, protein phosphorylation, and covalent attachment of chemicals that reversibly bind to specific cysteine residues. The latter modification represents an unusual activation mechanism of ligand-gated ion channels that is in contrast to the lock-and-key paradigm of receptor activation by its agonists. In this review, we summarize the post-translational modifications identified on TRP channels and, when available, explain their physiological role.

Does attentional training improve numerical processing in developmental dyscalculia?

Science.gov (United States)

Ashkenazi, Sarit; Henik, Avishai

2012-01-01

Recently, a deficit in attention was found in those with pure developmental dyscalculia (DD). Accordingly, the present study aimed to examine the influence of attentional training on attention abilities, basic numerical abilities, and arithmetic in participants who were diagnosed as having DD. Nine university students diagnosed as having DD (IQ and reading abilities in the normal range and no indication of attention-deficit hyperactivity disorder) and nine matched controls participated in attentional training (i.e., video game training). First, training modulated the orienting system; after training, the size of the validity effect (i.e., effect of valid vs. invalid) decreased. This effect was comparable in the two groups. Training modulated abnormalities in the attention systems of those with DD, that is, it reduced their enlarged congruity effect (i.e., faster responding when flanking arrows pointed to the same location as a center arrow). Second, in relation to the enumeration task, training reduced the reaction time of the DD group in the subitizing range but did not change their smaller-than-normal subitizing range. Finally, training improved performance in addition problems in both the DD and control groups. These results imply that attentional training does improve most of the attentional deficits of those with DD. In contrast, training did not improve the abnormalities of the DD group in arithmetic or basic numerical processing. Thus, in contrast to the domain-general hypothesis, the deficits in attention among those with DD and the deficits in numerical processing appear to originate from different sources.

Induction heating to trigger the nickel surface modification by in situ generated 4-carboxybenzene diazonium

Science.gov (United States)

Arrotin, Bastien; Jacques, Amory; Devillers, Sébastien; Delhalle, Joseph; Mekhalif, Zineb

2016-05-01

Nickel is commonly used in numerous applications and is one of the few materials that present strong ferromagnetic properties. These make it a suitable material for induction heating which can be used to activate the grafting of organic species such as diazonium salts onto the material. Diazonium compounds are often used for the modification of metals and alloys thanks to their easy chemical reduction onto the substrates and the possibility to apply a one-step in situ generation process of the diazonium species. This work focuses on the grafting of 4-aminocarboxybenzene on nickel substrates in the context of a spontaneous grafting conducted either at room temperature or by thermal assistance through conventional heating and induction heating. These modifications are also carried out with the goal of maintaining the oxides layer as much as possible unaffected. The benefits of using induction heating with respect to conventional heating are an increase of the grafting rate, a better control of the reaction and a slighter impact on the oxides layer.

New algorithm for detecting smaller retinal blood vessels in fundus images

Science.gov (United States)

LeAnder, Robert; Bidari, Praveen I.; Mohammed, Tauseef A.; Das, Moumita; Umbaugh, Scott E.

2010-03-01

About 4.1 million Americans suffer from diabetic retinopathy. To help automatically diagnose various stages of the disease, a new blood-vessel-segmentation algorithm based on spatial high-pass filtering was developed to automatically segment blood vessels, including the smaller ones, with low noise. Methods: Image database: Forty, 584 x 565-pixel images were collected from the DRIVE image database. Preprocessing: Green-band extraction was used to obtain better contrast, which facilitated better visualization of retinal blood vessels. A spatial highpass filter of mask-size 11 was applied. A histogram stretch was performed to enhance contrast. A median filter was applied to mitigate noise. At this point, the gray-scale image was converted to a binary image using a binary thresholding operation. Then, a NOT operation was performed by gray-level value inversion between 0 and 255. Postprocessing: The resulting image was AND-ed with its corresponding ring mask to remove the outer-ring (lens-edge) artifact. At this point, the above algorithm steps had extracted most of the major and minor vessels, with some intersections and bifurcations missing. Vessel segments were reintegrated using the Hough transform. Results: After applying the Hough transform, both the average peak SNR and the RMS error improved by 10%. Pratt's Figure of Merit (PFM) was decreased by 6%. Those averages were better than [1] by 10-30%. Conclusions: The new algorithm successfully preserved the details of smaller blood vessels and should prove successful as a segmentation step for automatically identifying diseases that affect retinal blood vessels.

Modifications at operating nuclear power plants

International Nuclear Information System (INIS)

Duffy, T.J.; Gazda, P.A.

1985-01-01

Modifications at operating nuclear power plants offer the structural engineer many challenges in the areas of scheduling of work, field adjustments, and engineering staff planning. The scheduling of structural modification work for operating nuclear power plants is normally closely tied to planned or unplanned outages of the plant. Coordination between the structural engineering effort, the operating plant staff, and the contractor who will be performing the modifications is essential to ensure that all work can be completed within the allotted time. Due to the inaccessibility of some areas in operating nuclear power plants or the short time available to perform the structural engineering in the case of an unscheduled outrage, field verification of a design is not always possible prior to initiating the construction of the modification. This requires the structural engineer to work closely with the contractor to promptly resolve problems due to unanticipated interferences or material procurement problems that may arise during the course of construction. The engineering staff planning for structural modifications at an operating nuclear power plant must be flexible enough to permit rapid response to the common ''fire drills,'' but controlled enough to ensure technically correct designs and to minimize the expenditure of man-hours and the resulting engineering cost

A comparison of etched-geometry and overgrown silicon permeable base transistors by two-dimensional numerical simulations

Science.gov (United States)

Vojak, B. A.; Alley, G. D.

1983-08-01

Two-dimensional numerical simulations are used to compare etched geometry and overgrown Si permeable base transistors (PTBs), considering both the etched collector and etched emitter biasing conditions made possible by the asymmetry of the etched structure. In PTB devices, the two-dimensional nature of the depletion region near the Schottky contact base grating results in a smaller electron barrier and, therefore, a larger collector current in the etched than in the overgrown structure. The parasitic feedback effects which result at high base-to-emitter bias levels lead to a deviation from the square-law behavior found in the collector characteristics of the overgrown PBT. These structures also have lower device capacitances and smaller transconductances at high base-to-emitter voltages. As a result, overgrown and etched structures have comparable predicted maximum values of the small signal unity short-circuit current gain frequency and maximum oscillation frequency.

On the modification of the Efimov spectrum in a finite cubic box

International Nuclear Information System (INIS)

Kreuzer, S.; Hammer, H.W.

2010-01-01

Three particles with large scattering length display a universal spectrum of three-body bound states called ''Efimov trimers''. We calculate the modification of the Efimov trimers of three identical bosons in a finite cubic box and compute the dependence of their energies on the box size using effective field theory. Previous calculations for positive scattering length that were perturbative in the finite-volume energy shift are extended to arbitrarily large shifts and negative scattering lengths. The renormalization of the effective field theory in the finite volume is explicitly verified. We investigate the effects of partial-wave mixing and study the behavior of shallow trimers near the dimer energy. Moreover, we provide numerical evidence for universal scaling of the finite-volume corrections. (orig.)

Numerical modeling and design of a disk-type rotating permanent magnet induction pump

Energy Technology Data Exchange (ETDEWEB)

Koroteeva, E., E-mail: koroteeva@physics.msu.ru [Institute of Physics of University of Latvia, Salaspils 2169 (Latvia); Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Ščepanskis, M. [Laboratory for Mathematical Modelling of Environmental and Technological Processes, University of Latvia, Rīga 1002 (Latvia); Bucenieks, I.; Platacis, E. [Institute of Physics of University of Latvia, Salaspils 2169 (Latvia)

2016-05-15

Highlights: • The design and performance of a disk-type induction pump are described. • A 3D numerical model based on an iterative coupling between EM and hydrodynamic solvers is developed. • The model is verified by comparing with the experiments in a Pb-Bi loop facility. • The suggestions are given to estimate the pump performance in a Pb-Li loop at high pressures. - Abstract: Electromagnetic induction pumps with rotating permanent magnets appear to be the most promising devices to transport liquid metals in high-temperature applications. Here we present a numerical methodology to simulate the operation of one particular modification of these types of pumps: a disk-type induction pump. The numerical model allows for the calculation and analysis of the flow parameters, including the pressure–flow rate characteristics of the pump. The simulations are based on an iterative fully coupled scheme for electromagnetic and hydrodynamic solvers. The developed model is verified by comparing with experimental data obtained using a Pb-Bi loop test facility, for pressures up to 4 bar and flow rates up to 9 kg/s. The verified model is then expanded to higher pressures, beyond the limits of the experimental loop. Based on the numerical simulations, suggestions are given to extrapolate experimental data to higher (industrially important) pressure ranges. Using the numerical model and analytical estimation, the pump performance for the Pb-Li loop is also examined, and the ability of the designed pump to develop pressure heads over 6 bar and to provide flow rates over 15 kg/s is shown.

Use of numerical modeling in design for co-firing biomass in wall-fired burners

DEFF Research Database (Denmark)

Yin, Chungen; Rosendahl, Lasse Aistrup; Kær, Søren Knudsen

2004-01-01

modification to the motion and reaction due to their non-sphericity. The simulation results show a big difference between the two cases and indicate it is very significant to take into account the non-sphericity of biomass particles in order to model biomass combustion more accurately. Methods to improve...... of numerical modeling. The models currently used to predict solid fuel combustion rely on a spherical particle shape assumption, which may deviate a lot from reality for big biomass particles. A sphere gives a minimum in terms of the surface-area-to-volume ratio, which impacts significantly both motion...... and reaction of a particle. To better understand biomass combustion and thus improve the design for co-firing biomass in wall-fired burners, non-sphericity of biomass particles is considered. To ease comparison, two cases are numerically studied in a 10m long gas/biomass co-fired burner model. (1) The biomass...

Standard approach to plant modifications

International Nuclear Information System (INIS)

Mecredy, R.C.

1988-01-01

Organizational and management approaches to the design, installation, and turnover of nuclear plant modifications have changed dramatically in the last 10 to 15 yr. In response to these changes, organizational and individual responsibilities have been defined and management systems have been established at Rochester Gas and Electric (RG and E) Corporation to ensure that high-quality plant modifications are installed in a timely manner that satisfies user needs at minimal cost

Trends and patterns in contemporary management in smaller companies: The Danish perspective

OpenAIRE

Ulhøi, John Parm; Madsen, Henning

2001-01-01

This paper reports empirical findings from a recent survey of Danish managers with a special focus on managers from smaller companies. The survey has been initiated in Denmark and it is called the 'Danish Management Barometer'. The project is a joint research program between the Aarhus School of Business and the Danish Association of Managers and Executives. It is based on a structured, pre-tested questionnaire send out to 1500 pre-notified managers in Denmark aiming at establishing a...

Efficient reanalysis of structures by a direct modification method. [local stiffness modifications of large structures

Science.gov (United States)

Raibstein, A. I.; Kalev, I.; Pipano, A.

1976-01-01

A procedure for the local stiffness modifications of large structures is described. It enables structural modifications without an a priori definition of the changes in the original structure and without loss of efficiency due to multiple loading conditions. The solution procedure, implemented in NASTRAN, involved the decomposed stiffness matrix and the displacement vectors of the original structure. It solves the modified structure exactly, irrespective of the magnitude of the stiffness changes. In order to investigate the efficiency of the present procedure and to test its applicability within a design environment, several real and large structures were solved. The results of the efficiency studies indicate that the break-even point of the procedure varies between 8% and 60% stiffness modifications, depending upon the structure's characteristics and the options employed.

The computational nature of memory modification

Science.gov (United States)

Gershman, Samuel J; Monfils, Marie-H; Norman, Kenneth A; Niv, Yael

2017-01-01

Retrieving a memory can modify its influence on subsequent behavior. We develop a computational theory of memory modification, according to which modification of a memory trace occurs through classical associative learning, but which memory trace is eligible for modification depends on a structure learning mechanism that discovers the units of association by segmenting the stream of experience into statistically distinct clusters (latent causes). New memories are formed when the structure learning mechanism infers that a new latent cause underlies current sensory observations. By the same token, old memories are modified when old and new sensory observations are inferred to have been generated by the same latent cause. We derive this framework from probabilistic principles, and present a computational implementation. Simulations demonstrate that our model can reproduce the major experimental findings from studies of memory modification in the Pavlovian conditioning literature. DOI: http://dx.doi.org/10.7554/eLife.23763.001 PMID:28294944

Numerical analysis of the spacer grids' compression strength

International Nuclear Information System (INIS)

Schettino, C.F.M.; Gouvea, J.P.; Medeiros, N.

2013-01-01

Among the components of the fuel assembly, the spacer grids play an important structural role during the energy generation process, mainly for their requirement to have enough structural strength to withstand lateral impact loads, due to fuel assembly shipping/handling and due to forces outcome from postulated accidents (earthquake and LOCA). This requirement ensures a proper geometry for cooling and for guide thimble straightness in the fuel assembly. In this way, the understanding of the macroscopic mechanical behavior of this component becomes essential even to any subsequent geometrical modifications to optimize the flue assemblies' structural behavior. In the present work, three-dimensional finite element models destined to provide consistent predictions of 16X16-type spacer grids lateral strength were proposed. Firstly, buckling tests based on results available in the literature were performed to establish a methodology for spacer grid finite element-based modeling. The, by considering a spacer grid interesting geometry and some possible variations associated to its fabrication, tolerance, the proposed numerical models were submitted to compression conditions to calculate the buckling force. Also, these models were validated for comparison with experimental buckling load results. Comparison of buckling predictions combined to observations of actual and simulated deformed spacer grids geometries permitted to verify the consistency and applicability of the proposed models. Thus, these numerical results show a good agreement between the and the experimental results. (author)

Numerical models for prestressing tendons in containment structures

International Nuclear Information System (INIS)

Kwak, Hyo-Gyoung; Kim, Jae Hong

2006-01-01

Two modified stress-strain relations for bonded and unbonded internal tendons are proposed. The proposed relations can simulate the post-cracking behavior and tension stiffening effect in prestressed concrete containment structures. In the case of the bonded tendon, tensile forces between adjacent cracks are transmitted from a bonded tendon to concrete by bond forces. Therefore, the constitutive law of a bonded tendon stiffened by grout needs to be determined from the bond-slip relationship. On the other hand, a stress increase beyond the effective prestress in an unbonded tendon is not section-dependent but member-dependent. It means that the tendon stress unequivocally represents a uniform distribution along the length when the friction loss is excluded. Thus, using a strain reduction factor, the modified stress-strain curve of an unbonded tendon is derived by successive iterations. In advance, the prediction of cracking behavior and ultimate resisting capacity of prestressed concrete containment structures using the introduced numerical models are succeeded, and the need for the consideration of many influencing factors such as the tension stiffening effect, plastic hinge length and modification of stress-strain relation of tendon is emphasized. Finally, the developed numerical models are applied to prestressed concrete containment structures to verify the efficiency and applicability in simulating the structural behavior with bonded and/or unbonded tendons

23 CFR 630.110 - Modification of original agreement.

Science.gov (United States)

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Modification of original agreement. 630.110 Section 630... OPERATIONS PRECONSTRUCTION PROCEDURES Project Authorization and Agreements § 630.110 Modification of original agreement. (a) When changes are needed to the original project agreement, a modification of agreement shall...

Surface modification of ceramics. Ceramics no hyomen kaishitsu

Energy Technology Data Exchange (ETDEWEB)

Hioki, T. (Toyota Central Research and Development Labs., Inc., Nagoya (Japan))

1993-07-05

Surface modification of ceramics and some study results using in implantation in surface modification are introduced. The mechanical properties (strength, fracture toughness, flaw resistance) of ceramics was improved and crack was repaired using surface modification by ion implantation. It is predicted that friction and wear properties are considerably affected because the hardness of ceramics is changed by ion implantation. Cementing and metalization are effective as methods for interface modification and the improvement of the adhesion power of the interface between metal and ceramic is their example. It was revealed that the improvement of mechanical properties of ceramics was achieved if appropriate surface modification was carried out. The market of ceramics mechanical parts is still small, therefore, the present situation is that the field of activities for surface modification of ceramics is also narrow. However, it is thought that in future, ceramics use may be promoted surely in the field like medicine and mechatronics. 8 refs., 4 figs.

Structural dynamic modification

Indian Academy of Sciences (India)

and stiffness matrices) andaor modal parameters, in order to acquire some ... For the above reasons, another modification approach is presented here ... The data necessary to solve the direct problem are dynamic behaviour of the original.

Investigating MCTS Modifications in General Video Game Playing

DEFF Research Database (Denmark)

Frydenberg, Frederik; Andersen, Kasper; Risi, Sebastian

2015-01-01

-style video games. This paper investigates of how well these modifications perform in general video game playing using the general video game AI (GVG-AI) framework and introduces a new MCTS modification called UCT reverse penalty that penalizes the MCTS controller for exploring recently visited children......While Monte Carlo tree search (MCTS) methods have shown promise in a variety of different board games, more complex video games still present significant challenges. Recently, several modifications to the core MCTS algorithm have been proposed with the hope to increase its effectiveness on arcade....... The results of our experiments show that a combination of two MCTS modifications can improve the performance of the vanilla MCTS controller, but the effectiveness of the modifications highly depends on the particular game being played....

Minimal modification to tribimaximal mixing

International Nuclear Information System (INIS)

He Xiaogang; Zee, A.

2011-01-01

We explore some ways of minimally modifying the neutrino mixing matrix from tribimaximal, characterized by introducing at most one mixing angle and a CP violating phase thus extending our earlier work. One minimal modification, motivated to some extent by group theoretic considerations, is a simple case with the elements V α2 of the second column in the mixing matrix equal to 1/√(3). Modifications by keeping one of the columns or one of the rows unchanged from tribimaximal mixing all belong to the class of minimal modification. Some of the cases have interesting experimentally testable consequences. In particular, the T2K and MINOS collaborations have recently reported indications of a nonzero θ 13 . For the cases we consider, the new data sharply constrain the CP violating phase angle δ, with δ close to 0 (in some cases) and π disfavored.

Numerical Investigation of Liquid Carryover in T-Junction with Different Diameter Ratios

Science.gov (United States)

Pao, William; Sam, Ban; Saieed, Ahmed; Tran, Cong Minh

2018-03-01

In offshore Malaysia, T-junction is installed at the production header as a compact separator to tap produced gas from reservoir as fuel gas for power generation. However, excessive liquid carryover in T-junction presents a serious operational issue because it trips the whole production platform. The primary objective of present study is to numerically investigate the liquid carryover due to formation of slug, subsequently its liquid carryover at different diameter ratio. The analyses were carried out on a model with 0.0254 m (1 inch) diameter horizontal main arm and a vertically upward side arm using Volume of Fluid Method. Three different sides to main arm diameter ratio of 1.0, 0.5 and 0.3 were investigated with different gas and liquid superficial velocities. The results showed that, while the general trend is true that smaller diameter ratio T-junction has lesser liquid take off capacity, it has a very high frequency of low liquid carryover threshold. In other words, under slug flow, smaller diameter ratio T-junction is constantly transporting liquid even though at a lesser volume in comparison to regular T-junction.

Disassembling and modification of RA-3

International Nuclear Information System (INIS)

Tarizzo, R.D.

1990-01-01

The objective of this paper is to describe the partial disassembling and modification of RA-3, called the Modernization Project. It comprises all the technical and administrative steps directly related with this task. The improvement of RA-3 is a result of the lack of 90% enriched uranium obliging a change over to 20% enriched uranium. This brought about design modifications both in fuel elements and the reactor. The presentation of documents for the licensing authority as well as are detailed separately. The modernization project was divided in 25 tasks: 1) changing fuel element support table, 2) changing heat exchanger, 3) repairing of cooling towers, 4) repairing of primary circuit valves, 5) repairing of irradiation channels, 6) construction of a new sampler, 7) changing tangential channel, 8) cleaning and disassembling of reactor (inside), 9) changing continuous demineralizer (ion exchange column), 10) detection of failure in fuel elements, 11) modification of nuclear instrumentation, 12) modification of conventional instrumentation, 13) modification of electrical system, 14) changing telemanipulators, 15) construction of mechanism bridge, 16) changing a primary circuit valve when the heat exchanger is changed too, 17) painting ground floor, hall floor, and pump room floor with epoxy resin levelling, 18) installation of fire alarm system, 19) radioactive liquid discharge, 20) modification of secondary circuit (This task involves: a) installation of a third secondary pump, b) extension of this piping, c) installation of two 12 inch valves to the present cooling towers pools independent, d) installation of filtering system), 21) optimization hot water bed, 22) changing detector support table, 23) removal, decontamination and reinstallation of shielding, 25) changing pneumatic system

Duration and numerical estimation in right brain-damaged patients with and without neglect: Lack of support for a mental time line.

Science.gov (United States)

Masson, Nicolas; Pesenti, Mauro; Dormal, Valérie

2016-08-01

Previous studies have shown that left neglect patients are impaired when they have to orient their attention leftward relative to a standard in numerical comparison tasks. This finding has been accounted for by the idea that numerical magnitudes are represented along a spatial continuum oriented from left to right with small magnitudes on the left and large magnitudes on the right. Similarly, it has been proposed that duration could be represented along a mental time line that shares the properties of the number continuum. By comparing directly duration and numerosity processing, this study investigates whether or not the performance of neglect patients supports the hypothesis of a mental time line. Twenty-two right brain-damaged patients (11 with and 11 without left neglect), as well as 11 age-matched healthy controls, had to judge whether a single dot presented visually lasted shorter or longer than 500 ms and whether a sequence of flashed dots was smaller or larger than 5. Digit spans were also assessed to measure verbal working memory capacities. In duration comparison, no spatial-duration bias was found in neglect patients. Moreover, a significant correlation between verbal working memory and duration performance was observed in right brain-damaged patients, irrespective of the presence or absence of neglect. In numerical comparison, only neglect patients showed an enhanced distance effect for numerical magnitude smaller than the standard. These results do not support the hypothesis of the existence of a mental continuum oriented from left to right for duration. We discuss an alternative account to explain the duration impairment observed in right brain-damaged patients. © 2015 The British Psychological Society.

Modification degrees at specific sites on heparan sulphate: an approach to measure chemical modifications on biological molecules with stable isotope labelling

Science.gov (United States)

Wu, Zhengliang L.; Lech, Miroslaw

2005-01-01

Chemical modification of biological molecules is a general mechanism for cellular regulation. A quantitative approach has been developed to measure the extent of modification on HS (heparan sulphates). Sulphation on HS by sulphotransferases leads to variable sulphation levels, which allows cells to tune their affinities to various extracellular proteins, including growth factors. With stable isotope labelling and HPLC-coupled MS, modification degrees at various O-sulphation sites could be determined. A bovine kidney HS sample was first saturated in vitro with 34S by an OST (O-sulphotransferase), then digested with nitrous acid and analysed with HPLC-coupled MS. The 34S-labelled oligosaccharides were identified based on their unique isotope clusters. The modification degrees at the sulphotransferase recognition sites were obtained by calculating the intensities of isotopic peaks in the isotope clusters. The modification degrees at 3-OST-1 and 6-OST-1 sites were examined in detail. This approach can also be used to study other types of chemical modifications on biological molecules. PMID:15743272

Epigenetic Modifications: Therapeutic Potential in Cancer

Directory of Open Access Journals (Sweden)

Manisha Sachan

2015-08-01

Full Text Available Epigenetic modifications and alterations in chromatin structure and function contribute to the cumulative changes observed as normal cells undergo malignant transformation. These modifications and enzymes (DNA methyltransferases, histone deacetylases, histone methyltransferases, and demethylases related to them have been deeply studied to develop new drugs, epigenome-targeted therapies and new diagnostic tools. Epigenetic modifiers aim to restore normal epigenetic modification patterns through the inhibition of epigenetic modifier enzymes. Four of them (azacitidine, decitabine, vorinostat and romidepsin are approved by the U.S. Food and Drug Administration. This article provides an overview about the known functional roles of epigenetic enzymes in cancer development.

14 CFR 21.9 - Replacement and modification articles.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

An Investigation of Higher-Order Thinking Skills in Smaller Learning Community Social Studies Classrooms

Science.gov (United States)

Fischer, Christopher; Bol, Linda; Pribesh, Shana

2011-01-01

This study investigated the extent to which higher-order thinking skills are promoted in social studies classes in high schools that are implementing smaller learning communities (SLCs). Data collection in this mixed-methods study included classroom observations and in-depth interviews. Findings indicated that higher-order thinking was rarely…

Honors Programs at Smaller Colleges. 3rd Edition. National Collegiate Honors Council Monograph Series

Science.gov (United States)

Schuman, Samuel

2011-01-01

This monograph focuses upon areas of special concern to those working with honors at smaller colleges and universities: mission, recruitment, facilities, administration, budget, and curriculum. In each area, the author makes some general suggestions about overall operating principles, note specific issues that can lead to difficulties, and suggest…

Modification of metallic corrosion by ion implantation

International Nuclear Information System (INIS)

Clayton, C.R.

1981-01-01

This review will consider some of the properties of surface alloys, formed by ion implantation, which are effective in modifying corrosion behaviour. Examples will be given of the modification of the corrosion behaviour of pure metals, steels and other engineering alloys, resulting from implantation with metals and metalloids. Emphasis will be given to the modification of anodic processes produced by ion implantation since a review will be given elsewhere in the proceedings concerning the modification of cathodic processes. (orig.)

Less Daily Computer Use is Related to Smaller Hippocampal Volumes in Cognitively Intact Elderly.

Science.gov (United States)

Silbert, Lisa C; Dodge, Hiroko H; Lahna, David; Promjunyakul, Nutta-On; Austin, Daniel; Mattek, Nora; Erten-Lyons, Deniz; Kaye, Jeffrey A

2016-01-01

Computer use is becoming a common activity in the daily life of older individuals and declines over time in those with mild cognitive impairment (MCI). The relationship between daily computer use (DCU) and imaging markers of neurodegeneration is unknown. The objective of this study was to examine the relationship between average DCU and volumetric markers of neurodegeneration on brain MRI. Cognitively intact volunteers enrolled in the Intelligent Systems for Assessing Aging Change study underwent MRI. Total in-home computer use per day was calculated using mouse movement detection and averaged over a one-month period surrounding the MRI. Spearman's rank order correlation (univariate analysis) and linear regression models (multivariate analysis) examined hippocampal, gray matter (GM), white matter hyperintensity (WMH), and ventricular cerebral spinal fluid (vCSF) volumes in relation to DCU. A voxel-based morphometry analysis identified relationships between regional GM density and DCU. Twenty-seven cognitively intact participants used their computer for 51.3 minutes per day on average. Less DCU was associated with smaller hippocampal volumes (r = 0.48, p = 0.01), but not total GM, WMH, or vCSF volumes. After adjusting for age, education, and gender, less DCU remained associated with smaller hippocampal volume (p = 0.01). Voxel-wise analysis demonstrated that less daily computer use was associated with decreased GM density in the bilateral hippocampi and temporal lobes. Less daily computer use is associated with smaller brain volume in regions that are integral to memory function and known to be involved early with Alzheimer's pathology and conversion to dementia. Continuous monitoring of daily computer use may detect signs of preclinical neurodegeneration in older individuals at risk for dementia.

Approaching the Post-Newtonian Regime with Numerical Relativity: A Compact-Object Binary Simulation Spanning 350 Gravitational-Wave Cycles.

Science.gov (United States)

Szilágyi, Béla; Blackman, Jonathan; Buonanno, Alessandra; Taracchini, Andrea; Pfeiffer, Harald P; Scheel, Mark A; Chu, Tony; Kidder, Lawrence E; Pan, Yi

2015-07-17

We present the first numerical-relativity simulation of a compact-object binary whose gravitational waveform is long enough to cover the entire frequency band of advanced gravitational-wave detectors, such as LIGO, Virgo, and KAGRA, for mass ratio 7 and total mass as low as 45.5M_{⊙}. We find that effective-one-body models, either uncalibrated or calibrated against substantially shorter numerical-relativity waveforms at smaller mass ratios, reproduce our new waveform remarkably well, with a negligible loss in detection rate due to modeling error. In contrast, post-Newtonian inspiral waveforms and existing calibrated phenomenological inspiral-merger-ringdown waveforms display greater disagreement with our new simulation. The disagreement varies substantially depending on the specific post-Newtonian approximant used.

Numerical simulations of a family of the coupled viscous Burgers, equation using the lattice Boltzmann method

International Nuclear Information System (INIS)

He, Y B; Tang, X H

2016-01-01

In this paper, in order to extend the lattice Boltzmann method (LBM) to deal with more nonlinear systems, a one-dimensional and five-velocity lattice Boltzmann scheme with an amending function for a family of the coupled viscous Burgers’ equation (CVBE) is proposed. With the Taylor and Chapman–Enskog expansion, a family of the CVBE is recovered correctly from the lattice Boltzmann equation through selecting the equilibrium distribution functions and amending functions properly. The method is applied to some test examples with an analytical solution. The results are compared with those obtained by the finite difference method (FDM); it is shown that the numerical solutions agree well with the analytical solutions and the errors obtained by the present method are smaller than the FDM. Furthermore, some problems without analytical solutions are numerically studied by the present method and the FDM. The results show that the numerical solutions of the LBM are in good agreement with those obtained by the FDM, which can validate the effectiveness and stability of the LBM. (paper: classical statistical mechanics, equilibrium and non-equilibrium)

A numerical study of adaptive space and time discretisations for Gross–Pitaevskii equations

Science.gov (United States)

Thalhammer, Mechthild; Abhau, Jochen

2012-01-01

As a basic principle, benefits of adaptive discretisations are an improved balance between required accuracy and efficiency as well as an enhancement of the reliability of numerical computations. In this work, the capacity of locally adaptive space and time discretisations for the numerical solution of low-dimensional nonlinear Schrödinger equations is investigated. The considered model equation is related to the time-dependent Gross–Pitaevskii equation arising in the description of Bose–Einstein condensates in dilute gases. The performance of the Fourier-pseudo spectral method constrained to uniform meshes versus the locally adaptive finite element method and of higher-order exponential operator splitting methods with variable time stepsizes is studied. Numerical experiments confirm that a local time stepsize control based on a posteriori local error estimators or embedded splitting pairs, respectively, is effective in different situations with an enhancement either in efficiency or reliability. As expected, adaptive time-splitting schemes combined with fast Fourier transform techniques are favourable regarding accuracy and efficiency when applied to Gross–Pitaevskii equations with a defocusing nonlinearity and a mildly varying regular solution. However, the numerical solution of nonlinear Schrödinger equations in the semi-classical regime becomes a demanding task. Due to the highly oscillatory and nonlinear nature of the problem, the spatial mesh size and the time increments need to be of the size of the decisive parameter 0Fourier pseudo-spectral and the finite element method. Nevertheless, for smaller parameter values locally adaptive time discretisations facilitate to determine the time stepsizes sufficiently small in order that the numerical approximation captures correctly the behaviour of the analytical solution. Further illustrations for Gross–Pitaevskii equations with a focusing nonlinearity or a sharp Gaussian as initial condition, respectively

Media bias under direct and indirect government control: when is the bias smaller?

OpenAIRE

Abhra Roy

2015-01-01

We present an analytical framework to compare media bias under direct and indirect government control. In this context, we show that direct control can lead to a smaller bias and higher welfare than indirect control. We further show that the size of the advertising market affects media bias only under direct control. Media bias, under indirect control, is not affected by the size of the advertising market.

A numerical study of the effects of design parameters on the acoustics noise of a high efficiency propeller

Science.gov (United States)

Yang, Liu; Huang, Jun; Yi, Mingxu; Zhang, Chaopu; Xiao, Qian

2017-11-01

A numerical study of a high efficiency propeller in the aerodynamic noise generation is carried out. Based on RANS, three-dimensional numerical simulation is performed to obtain the aerodynamic performance of the propeller. The result of the aerodynamic analysis is given as input of the acoustic calculation. The sound is calculated using the Farassat 1A, which is derived from Ffowcs Williams-Hawkings equation, and compared with the data of wind tunnel. The propeller is modified for noise reduction by changing its geometrical parameters such as diameter, chord width and pitch angle. The trend of variation between aerodynamic analysis data and acoustic calculation result are compared and discussed for different modification tasks. Meaningful conclusions are drawn on the noise reduction of propeller.

75 FR 37779 - Office of Elementary and Secondary Education; Smaller Learning Communities Program; Notice...

Science.gov (United States)

2010-06-30

... DEPARTMENT OF EDUCATION [CFDA No. 84.215L] Office of Elementary and Secondary Education; Smaller...-Marshall, U.S. Department of Education, 400 Maryland Avenue, SW., room 3E308, Washington, DC 20202-6200..., in text or Adobe Portable Document Format (PDF) on the Internet at the following site: http://www.ed...

Modification of Alumina and Spinel Inclusions by Calcium in Liquid Steel

Science.gov (United States)

Verma, Neerav

2011-12-01

samples were characterized for inclusion shape, size and chemistry through scanning electron microscopy (SEM). Automated inclusion analysis tools (like ASCAT [59, 91, 92], INCA-GSR [126]; Please refer section 6.4., page number 68) were employed to generate statistical information of the inclusions. Thermodynamic database software FACTSAGE [62] was used to determine thermochemistry of reactions, ternary phase diagrams (Ca-Al-S and Ca-Al-Mg systems). The compositions of the inclusions were tracked before and after calcium treatment to determine the effectiveness of calcium treatment. Extraction of inclusions through dissolution of iron in bromine-methanol solution was employed to reveal 3-D geometry of inclusions and analyze inclusions through EDS (Energy-dispersive X-ray spectroscopy) without any matrix effects. Various industrial samples were also analyzed to confirm the feasibility of various reaction mechanisms deduced through experiments. Successful modification of alumina and spinel inclusions by calcium was demonstrated [85, 86]. It was observed that these modification mechanisms proceed through transient phase (CaO, CaS) formation. In the case of spinels, preferential reduction of MgO part was also observed during calcium modification of spinels. The magnesium after MgO reduction by calcium can enter back into the melt or leave the melt in vapor form. The inclusion area fraction decreased after calcium treatment, but the inclusion concentration (number of inclusions per cm2) increased because inclusions shifted to a smaller size distribution after calcium treatment. Severe matrix effects during EDS analysis of inclusions were observed, due to which inclusion composition analyses can be significantly affected. *Please refer to dissertation for footnotes.

TWO MODIFICATIONS OF SCALERS FOR RATE STUDIES

Energy Technology Data Exchange (ETDEWEB)

Hodgson, T. S.; Gordon, B. E.

1964-04-15

Two simple modifications to nuclear scalers have been developed. The first involves an automatic stepping switch which permits a single scaler to be actuated by up to four Geiger counters in sequence and to record the time to reach a preset count for each. The second modification is designed to pick a pulse off a conventional scaler when a preset count has been reached and to use the pulse to actuate a recorder. Both modifications considerably extend the utility of conventional scalers.

Experimental and numerical investigation of gas side particulate fouling onto heat exchanger tubes

International Nuclear Information System (INIS)

Bailer, Frederic

1998-01-01

This work deals with gas side particulate fouling onto heat exchanger tubes. An experimental and numerical investigation was carried out. By means of a new testing loop designed for this study, the deposit kinetics were obtained in dust-controlled conditions at the beginning of the fouling process. Experimental results pointed out the existence of various transport regimes: for sub-micronic particles, convective diffusion augmented by thermophoresis in the presence of a temperature gradient governs the particle deposition; inertial impaction controls the super-micronic particles deposition: in the intermediate granulometric range, combined action of particle inertia and thermophoresis must be considered. Moreover, measurements on an other testing loop using a more concentrated aerosol allowed us to point out the modification of the mechanisms with time and the influence of the deposit shape. A numerical model predicting the particle deposition, based on the TRIO software and an Eulerian-Lagrangian approach, was developed and validated against experimental results from the literature and from our study. Numerical approach gave us an accurate understanding of the phenomena by means of local parameters computations. In this way, the different mechanisms which control particulate deposition onto heat exchangers tubes were identified and modelled, especially before the onset of the inertial impaction. (author) [fr

Modifications of the Weibull distribution: A review

International Nuclear Information System (INIS)

Almalki, Saad J.; Nadarajah, Saralees

2014-01-01

It is well known that the Weibull distribution is the most popular and the most widely used distribution in reliability and in analysis of lifetime data. Unfortunately, its hazard function cannot exhibit non-monotonic shapes like the bathtub shape or the unimodal shape. Since 1958, the Weibull distribution has been modified by many researchers to allow for non-monotonic hazard functions. This paper gives an extensive review of some discrete and continuous versions of the modifications of the Weibull distribution. - Highlights: • A comprehensive review of known discrete modifications and generalizations of the Weibull distribution. • A comprehensive review of known continuous modifications and generalizations of the Weibull distribution. • Over 110 references on modifications/generalizations of the Weibull distribution. • More than 55% of the cited references appeared in the last 5 years

Tailored HIV-1 vectors for genetic modification of primary human dendritic cells and monocytes.

Science.gov (United States)

Durand, Stéphanie; Nguyen, Xuan-Nhi; Turpin, Jocelyn; Cordeil, Stephanie; Nazaret, Nicolas; Croze, Séverine; Mahieux, Renaud; Lachuer, Joël; Legras-Lachuer, Catherine; Cimarelli, Andrea

2013-01-01

Monocyte-derived dendritic cells (MDDCs) play a key role in the regulation of the immune system and are the target of numerous gene therapy applications. The genetic modification of MDDCs is possible with human immunodeficiency virus type 1 (HIV-1)-derived lentiviral vectors (LVs) but requires high viral doses to bypass their natural resistance to viral infection, and this in turn affects their physiological properties. To date, a single viral protein is able to counter this restrictive phenotype, Vpx, a protein derived from members of the HIV-2/simian immunodeficiency virus SM lineage that counters at least two restriction factors present in myeloid cells. By tagging Vpx with a short heterologous membrane-targeting domain, we have obtained HIV-1 LVs incorporating high levels of this protein (HIV-1-Src-Vpx). These vectors efficiently transduce differentiated MDDCs and monocytes either as previously purified populations or as populations within unsorted peripheral blood mononuclear cells (PBMCs). In addition, these vectors can be efficiently pseudotyped with receptor-specific envelopes, further restricting their cellular tropism almost uniquely to MDDCs. Compared to conventional HIV-1 LVs, these novel vectors allow for an efficient genetic modification of MDDCs and, more importantly, do not cause their maturation or affect their survival, which are unwanted side effects of the transduction process. This study describes HIV-1-Src-Vpx LVs as a novel potent tool for the genetic modification of differentiated MDDCs and of circulating monocyte precursors with strong potential for a wide range of gene therapy applications.

Evaluation of pain relief sufficiency using the Cumulative Analgesic Consumption Score (CACS) and its modification (MACS).

Science.gov (United States)

Frank, Alexander Harald Ralf; Groene, Philipp; von Ehrlich-Treuenstätt, Viktor; Heiliger, Christian; Werner, Jens; Karcz, Konrad

2017-12-01

Postoperative pain is one of the major complications in general and bariatric surgery, associated with ongoing problems such as ileus, pneumonia and prolonged mobilization. In this study, patients undergoing bariatric surgery were analyzed according to their postoperative pain relief regime. In one group patients were treated with a patient-controlled analgesia (PCA) device, while the other group was treated with oral and intravenous analgesic medication. The aim of this study was to analyze which postoperative pain relief therapy would be more appropriate. We chose the Cumulative Analgesic Consumption Score (CACS) and Numeric Rating Scale (NRS) for pain measurement. For better comparison, we performed a modification of CACS according to PCA treatment. We observed better pain relief in the PCA group. Furthermore, we observed an advantage of treatment with laxatives in patients treated with PCA. In conclusion, PCA devices are appropriate instruments for postoperative pain relief in bariatric patients. CACS is a practical tool for postoperative pain measurement, describing individual pain sensation more objectively, although holding further potential in modification.

Numerical study on aerodynamics of banked wing in ground effect

Directory of Open Access Journals (Sweden)

Qing Jia

2016-03-01

Full Text Available Unlike conventional airplane, a WIG craft experiences righting moment and adverse yaw moment in banked turning in ground effect. Numerical simulations are carried out to study the aerodynamics of banked wing in ground effect. Configurations of rectangular wing and delta wing are considered, and performance of endplates and ailerons during banking are also studied. The study shows that righting moment increase nonlinearly with heeling angle, and endplates enhance the righting. The asymmetric aerodynamic distribution along span of wing with heeling angle introduces adverse yaw moment. Heeling in ground effect with small ground clearance increases the vertical aerodynamic force and makes WIG craft climb. Deflections of ailerons introduce lift decrease and a light pitching motion. Delta wing shows advantage in banked turning for smaller righting moment and adverse yaw moment during banking.

Numerical solution of stiff systems of ordinary differential equations with applications to electronic circuits

Science.gov (United States)

Rosenbaum, J. S.

1971-01-01

Systems of ordinary differential equations in which the magnitudes of the eigenvalues (or time constants) vary greatly are commonly called stiff. Such systems of equations arise in nuclear reactor kinetics, the flow of chemically reacting gas, dynamics, control theory, circuit analysis and other fields. The research reported develops an A-stable numerical integration technique for solving stiff systems of ordinary differential equations. The method, which is called the generalized trapezoidal rule, is a modification of the trapezoidal rule. However, the method is computationally more efficient than the trapezoidal rule when the solution of the almost-discontinuous segments is being calculated.

Three Sisters Dam modifications and performance

Energy Technology Data Exchange (ETDEWEB)

Courage, L.J.R. [Monenco AGRA Inc., Calgary, AB (Canada)

1995-12-31

Recent modifications and maintenance carried out at the Three Sisters Dam, in the Alberta Rockies south of the town of Canmore, were described. A detailed account was given of the dam`s geological setting, its abnormally high leakage through the foundation and its sinkhole activity. Results of studies aimed at finding the cause of leakage and sinkhole occurrences were reviewed. Modifications made to the dam since 1951 were detailed, as were modifications to handle probable maximum flood levels. Three approaches for estimating failure probabilities after identification of failure modes were described. The overall conclusion was that based on constant leakage, no settlement in the dam, penstocks, or the powerhouse since construction, the Three Sisters Dam was stable. 1 ref.

Numerical study on channel size effect for proton exchange membrane fuel cell with serpentine flow field

International Nuclear Information System (INIS)

Wang Xiaodong; Yan Weimon; Duan Yuanyuan; Weng Fangbor; Jung Guobin; Lee Chiyuan

2010-01-01

This work numerically investigates the effect of the channel size on the cell performance of proton exchange membrane (PEM) fuel cells with serpentine flow fields using a three-dimensional, two-phase model. The local current densities in the PEM, oxygen mass flow rates and liquid water concentrations at the interface of the cathode gas diffusion layer and catalyst layer were analyzed to understand the channel size effect. The predictions show that smaller channel sizes enhance liquid water removal and increase oxygen transport to the porous layers, which improve cell performance. Additionally, smaller channel sizes also provide more uniform current density distributions in the cell. However, as the channel size decreases, the total pressure drops across the cell increases, which leads to more pump work. With taking into account the pressure losses, the optimal cell performance occurs for a cell with a flow channel cross-sectional area of 0.535 x 0.535 mm 2 .

Investigating the effects of in utero benzene exposure on epigenetic modifications in maternal and fetal CD-1 mice

International Nuclear Information System (INIS)

Philbrook, Nicola A.; Winn, Louise M.

2015-01-01

Exposure to the ubiquitous environmental pollutant benzene is positively correlated with leukemia in adults and may be associated with childhood leukemia following in utero exposure. While numerous studies implicate oxidative stress and DNA damage as playing a role in benzene-mediated carcinogenicity, emerging evidence suggests that alterations in epigenetic regulations may be involved. The present study aimed to determine whether DNA methylation and/or various histone modifications were altered following in utero benzene exposure in CD-1 mice. Global DNA methylation and promoter-specific methylation of the tumor suppressor gene, p15, were assessed. Additionally, levels of acetylated histones H3, H4, and H3K56, as well as methylated histones H3K9 and H3K27 were assessed by Western blotting. A significant decrease in global DNA methylation of maternal bone marrow was observed following benzene exposure; however no effect on global DNA methylation was detected in fetal livers. Additionally, no effect of benzene exposure was observed on p15 promoter methylation or any measured histone modifications in both maternal bone marrow and fetal livers. These results suggest that the methodology used in the present study did not reveal alterations in DNA methylation and histone modifications following in utero exposure to benzene; however further experimentation investigating these modifications at the whole genome/epigenome level, as well as at later stages of benzene-induced carcinogenesis, are warranted. - Highlights: • Benzene exposure in pregnant mice decreased global DNA methylation in maternal bone marrow. • Benzene exposure in pregnant mice had no effect on global DNA methylation in fetal livers. • No effect of benzene exposure was observed on p15 promoter methylation. • No effect of benzene on measured histone modifications in both maternal bone marrow and fetal livers was observed.

Investigating the effects of in utero benzene exposure on epigenetic modifications in maternal and fetal CD-1 mice

Energy Technology Data Exchange (ETDEWEB)

Philbrook, Nicola A. [Department of Biomedical and Molecular Sciences, Graduate Program in Pharmacology and Toxicology, Queen' s University, Kingston, ON K7L3N6 (Canada); Winn, Louise M., E-mail: winnl@queensu.ca [Department of Biomedical and Molecular Sciences, Graduate Program in Pharmacology and Toxicology, Queen' s University, Kingston, ON K7L3N6 (Canada); School of Environmental Studies, Queen' s University, Kingston, ON K7L3N6 (Canada)

2015-11-15

Exposure to the ubiquitous environmental pollutant benzene is positively correlated with leukemia in adults and may be associated with childhood leukemia following in utero exposure. While numerous studies implicate oxidative stress and DNA damage as playing a role in benzene-mediated carcinogenicity, emerging evidence suggests that alterations in epigenetic regulations may be involved. The present study aimed to determine whether DNA methylation and/or various histone modifications were altered following in utero benzene exposure in CD-1 mice. Global DNA methylation and promoter-specific methylation of the tumor suppressor gene, p15, were assessed. Additionally, levels of acetylated histones H3, H4, and H3K56, as well as methylated histones H3K9 and H3K27 were assessed by Western blotting. A significant decrease in global DNA methylation of maternal bone marrow was observed following benzene exposure; however no effect on global DNA methylation was detected in fetal livers. Additionally, no effect of benzene exposure was observed on p15 promoter methylation or any measured histone modifications in both maternal bone marrow and fetal livers. These results suggest that the methodology used in the present study did not reveal alterations in DNA methylation and histone modifications following in utero exposure to benzene; however further experimentation investigating these modifications at the whole genome/epigenome level, as well as at later stages of benzene-induced carcinogenesis, are warranted. - Highlights: • Benzene exposure in pregnant mice decreased global DNA methylation in maternal bone marrow. • Benzene exposure in pregnant mice had no effect on global DNA methylation in fetal livers. • No effect of benzene exposure was observed on p15 promoter methylation. • No effect of benzene on measured histone modifications in both maternal bone marrow and fetal livers was observed.

Experimental and numerical study of Bondura® 6.6 PIN joints

Science.gov (United States)

Berkani, I.; Karlsen, Ø.; Lemu, H. G.

2017-12-01

Pin joints are widely used in heavy-duty machinery such as aircrafts, cranes and offshore drilling equipment to transfer multi-dimensional shear forces. Their strength and service life depend on the clamping force in the contact region that is provided by interference fits. Though the interference fits provide full contact at the pin-hole interface under pretension loads, the contact interface reduces when the pin is subjected to an external load and hence a smaller contact surface leads to dramatic increase of the contact stress. The PIN joint of Bondura® Technology, investigated in this study, is an innovative solution intended to reduce the slack at the contact surface of the pin joint of heavy-duty machinery by using tapered sleeves on each end of the PIN. The study is aimed to better understand the contact pressure build-up and stress distribution in the supporting contact surface under pre-loading of the joint and the influence of temperature difference between part assembly and operation conditions. Numerical simulation using finite element method and diverse experimental tests were conducted. The numerical simulation and the test results, particularly the tests conducted with lubricated joints, show good conformance.

Microscopic mechanism of amino silicone oil modification and modification effect with different amino group contents based on molecular dynamics simulation

Science.gov (United States)

He, Liping; Li, Wenjun; Chen, Dachuan; Yuan, Jianmin; Lu, Gang; Zhou, Dianwu

2018-05-01

The microscopic mechanism of amino silicone oil (ASO) modification of natural fiber was investigated for the first time using molecular dynamics (MD) simulation at the atomic and molecular levels. The MD simulation results indicated that the ASO molecular interacted with the cellulose molecular within the natural fiber, mainly by intermolecular forces of Nsbnd Hsbnd O and Osbnd Hsbnd N hydrogen bonds and the molecular chain of ASO absorbed onto the natural fiber in a selective orientation, i.e., the hydrophobic alkyl groups (sbnd CnH2n+1) project outward and the polar amino groups (sbnd NH2) point to the surface of natural fiber. Consequently, the ASO modification changed the surface characteristic of natural fiber from hydrophilic to hydrophobic. Furthermore, the modification effects of the ASO modification layer with different amino group contents (m:n ratio) were also evaluated in this study by calculating the binding energy between the ASO modifier and natural fiber, and the cohesive energy density and free volume of the ASO modification layer. The results showed that the binding energy reached a maximum when the m:n ratio of ASO was of 8:4, suggesting that a good bonding strength was achieved at this m:n ratio. It was also found that the cohesive energy density enhanced with the increase in the amino group content, and the higher the cohesive energy density, the easier the formation of the ASO modification layer. However, the fraction free volume decreased with the increase in the amino group content. This is good for improving the water-proof property of natural fiber. The present work can provide an effective method for predicting the modification effects and designing the optimized m:n ratio of ASO modification.

MEG evidence for conceptual combination but not numeral quantification in the left anterior temporal lobe during language production

Directory of Open Access Journals (Sweden)

Paul eDel Prato

2014-06-01

Full Text Available The left anterior temporal lobe (LATL has risen as a leading candidate for a brain locus of composition in language; yet the computational details of its function are unknown. Although most literature discusses it as a combinatory region in very general terms, it has also been proposed to reflect the more specific function of conceptual combination, which in the classic use of this term mainly pertains to the combination of open class words with obvious conceptual contributions. We aimed to distinguish between these two possibilities by contrasting plural nouns in contexts where they were either preceded by a color modifier (red cups, eliciting conceptual combination, or by a number word (two cups, eliciting numeral quantification but no conceptual combination. This contrast was chosen because within a production task, it allows the manipulation of composition type while keeping the physical stimulus constant: a display of two red cups can be named as two cups or red cups depending on the task instruction. These utterances were compared to productions of two-word number and color lists, intended as noncombinatory control conditions. MEG activity was recorded during the planning for production, prior to motion artifacts. As expected on the basis of comprehension studies, color modification elicited increased LATL activity as compared to color lists, demonstrating that this basic combinatory effect is strongly crossmodal. However, numeral quantification did not elicit a parallel effect, suggesting that the function of the LATL is (i semantic and not syntactic (given that both color modification and numeral quantification involve syntactic composition and (ii corresponds more closely to the classical psychological notion of conceptual combination as opposed to a more general semantic combinatory function.

Use of precracked Charpy and smaller specimens to establish the master curve

International Nuclear Information System (INIS)

Sokolov, M.A.; McCabe, D.E.; Nanstad, R.K.; Davidov, Y.A.

1997-01-01

The current provisions used in the U.S. Code of Federal Regulations for the determination of the fracture toughness of reactor pressure vessel steels employs an assumption that there is a direct correlation between K Ic lower-bound toughness and the Charpy V-notch transition curve. Such correlations are subject to scatter from both approaches which weakens the reliability of fracture mechanics-based analyses. In this study, precracked Charpy and smaller size specimens are used in three-point static bend testing to develop fracture mechanics based K k values. The testing is performed under carefully controlled conditions such that the values can be used to predict the fracture toughness performance of large specimens. The concept of a universal transition curve (master curve) is applied. Data scatter that is characteristic of commercial grade steels and their weldments is handled by Weibull statistical modeling. The master curve is developed to describe the median K Jc fracture toughness for 1T size compact specimens. Size effects are modeled using weakest-link theory and are studied for different specimen geometries. It is shown that precracked Charpy specimens when tested within their confined validity limits follow the weakest-link size-adjustment trend and predict the fracture toughness of larger specimens. Specimens of smaller than Charpy sizes (5 mm thick) exhibit some disparities in results relative to weakest-link size adjustment prediction suggesting that application of such adjustment to very small specimens may have some limitations

Radiocarbon evidence for a smaller oceanic carbon dioxide sink than previously believed

Science.gov (United States)

Hesshaimer, Vago; Heimann, Martin; Levin, Ingeborg

1994-07-01

RADIOCARBON produced naturally in the upper atmosphere or arti-ficially during nuclear weapons testing is the main tracer used to validate models of oceanic carbon cycling, in particular the exchange of carbon dioxide with the atmosphere1-3 and the mixing parameters within the ocean itself4-7. Here we test the overall consistency of exchange fluxes between all relevant compartments in a simple model of the global carbon cycle, using measurements of the long-term tropospheric CO2 concentration8 and radiocarbon composition9-12, the bomb 14C inventory in the stratosphere13,14 and a compilation of bomb detonation dates and strengths15. We find that to balance the budget, we must invoke an extra source to account for 25% of the generally accepted uptake of bomb 14C by the oceans3. The strength of this source decreases from 1970 onwards, with a characteristic timescale similar to that of the ocean uptake. Significant radiocarbon transport from the remote high stratosphere and significantly reduced uptake of bomb 14C by the biosphere can both be ruled out by observational constraints. We therefore conclude that the global oceanic bomb 14C inventory should be revised downwards. A smaller oceanic bomb 14C inventory also implies a smaller oceanic radiocarbon penetration depth16, which in turn implies that the oceans take up 25% less anthropogenic CO2 than had previously been believed.

Numerical analysis

CERN Document Server

Rao, G Shanker

2006-01-01

About the Book: This book provides an introduction to Numerical Analysis for the students of Mathematics and Engineering. The book is designed in accordance with the common core syllabus of Numerical Analysis of Universities of Andhra Pradesh and also the syllabus prescribed in most of the Indian Universities. Salient features: Approximate and Numerical Solutions of Algebraic and Transcendental Equation Interpolation of Functions Numerical Differentiation and Integration and Numerical Solution of Ordinary Differential Equations The last three chapters deal with Curve Fitting, Eigen Values and Eigen Vectors of a Matrix and Regression Analysis. Each chapter is supplemented with a number of worked-out examples as well as number of problems to be solved by the students. This would help in the better understanding of the subject. Contents: Errors Solution of Algebraic and Transcendental Equations Finite Differences Interpolation with Equal Intervals Interpolation with Unequal Int...

Posttranslational Modification Biology of Glutamate Receptors and Drug Addiction

Directory of Open Access Journals (Sweden)

Li-Min eMao

2011-03-01

Full Text Available Posttranslational covalent modifications of glutamate receptors remain a hot topic. Early studies have established that this family of receptors, including almost all ionotropic and metabotropic glutamate receptor subtypes, undergoes active phosphorylation at serine, threonine, or tyrosine residues on their intracellular domains. Recent evidence identifies several glutamate receptor subtypes to be direct substrates for palmitoylation at cysteine residues. Other modifications such as ubiquitination and sumoylation at lysine residues also occur to certain glutamate receptors. These modifications are dynamic and reversible in nature and are regulatable by changing synaptic inputs. The regulated modifications significantly impact the receptor in many ways, including interrelated changes in biochemistry (synthesis, subunit assembling and protein-protein interactions, subcellular redistribution (trafficking, endocytosis, synaptic delivery and clustering, and physiology, usually associated with changes in synaptic plasticity. Glutamate receptors are enriched in the striatum and cooperate closely with dopamine to regulate striatal signaling. Emerging evidence shows that modification processes of striatal glutamate receptors are sensitive to addictive drugs, such as psychostimulants (cocaine and amphetamines. Altered modifications are believed to be directly linked to enduring receptor/synaptic plasticity and drug-seeking. This review summarizes several major types of modifications of glutamate receptors and analyzes the role of these modifications in striatal signaling and in the pathogenesis of psychostimulant addiction.

Sequence tagging reveals unexpected modifications in toxicoproteomics

Science.gov (United States)

Dasari, Surendra; Chambers, Matthew C.; Codreanu, Simona G.; Liebler, Daniel C.; Collins, Ben C.; Pennington, Stephen R.; Gallagher, William M.; Tabb, David L.

2010-01-01

Toxicoproteomic samples are rich in posttranslational modifications (PTMs) of proteins. Identifying these modifications via standard database searching can incur significant performance penalties. Here we describe the latest developments in TagRecon, an algorithm that leverages inferred sequence tags to identify modified peptides in toxicoproteomic data sets. TagRecon identifies known modifications more effectively than the MyriMatch database search engine. TagRecon outperformed state of the art software in recognizing unanticipated modifications from LTQ, Orbitrap, and QTOF data sets. We developed user-friendly software for detecting persistent mass shifts from samples. We follow a three-step strategy for detecting unanticipated PTMs in samples. First, we identify the proteins present in the sample with a standard database search. Next, identified proteins are interrogated for unexpected PTMs with a sequence tag-based search. Finally, additional evidence is gathered for the detected mass shifts with a refinement search. Application of this technology on toxicoproteomic data sets revealed unintended cross-reactions between proteins and sample processing reagents. Twenty five proteins in rat liver showed signs of oxidative stress when exposed to potentially toxic drugs. These results demonstrate the value of mining toxicoproteomic data sets for modifications. PMID:21214251

On the genetic modification of psychology, personality, and behavior.

Science.gov (United States)

Neitzke, Alex B

2012-12-01

I argue that the use of heritable modifications for psychology, personality, and behavior should be limited to the reversal or prevention of relatively unambiguous instances of pathology or likely harm (e.g. sociopathy). Most of the likely modifications of psychological personality would not be of this nature, however, and parents therefore should not have the freedom to make such modifications to future children. I argue by examining the viewpoints of both the individual and society. For individuals, modifications would interfere with their capacity for self-determination in a way that undermines the very concept of self-determination. I argue that modification of psychology and personality is unlike present parenting in morally significant ways. For society, modification offers a medium for power to manipulate the makeup of persons and populations, possibly causing biological harm to the species and altering our conceptions of social responsibility.

Ion bombardment modification of surfaces

International Nuclear Information System (INIS)

Auciello, O.

1984-01-01

Ion bombardment-induced modification of surfaces may be considered one of the significant scientific and technological developments of the last two decades. The understanding acquired concerning the underlying mechanisms of several phenomena occurring during ion-surface interactions has led to applications within different modern technologies. These include microelectronics, surface acoustical and optical technologies, solar energy conversion, thin film technology, ion implantation metallurgy, nuclear track technology, thermonuclear fusion, vacuum technology, cold welding technology, biomedicine (implantology). It has become clear that information on many relevant advances, regarding ion bombardment modification of surfaces is dispersed among journals involving fields sometimes not clearly related. This may result, in some cases, in a loss of the type of interdisciplinary exchange of ideas, which has proved to be so fruitful for the advancement of science and technology. This book has been planned in an attempt to collect at least some of today's relevant information about the experimental and theoretical knowledge related to surface modification and its application to technology. (Auth.)

Pretreatment and Membrane Hydrophilic Modification to Reduce Membrane Fouling

Directory of Open Access Journals (Sweden)

Huaqiang Chu

2013-09-01

Full Text Available The application of low pressure membranes (microfiltration/ultrafiltration has undergone accelerated development for drinking water production. However, the major obstacle encountered in its popularization is membrane fouling caused by natural organic matter (NOM. This paper firstly summarizes the two factors causing the organic membrane fouling, including molecular weight (MW and hydrophilicity/hydrophobicity of NOM, and then presents a brief introduction of the methods which can prevent membrane fouling such as pretreatment of the feed water (e.g., coagulation, adsorption, and pre-oxidation and membrane hydrophilic modification (e.g., plasma modification, irradiation grafting modification, surface coating modification, blend modification, etc.. Perspectives of further research are also discussed.

Fluid cognitive ability is associated with greater exposure and smaller reactions to daily stressors.

Science.gov (United States)

Stawski, Robert S; Almeida, David M; Lachman, Margie E; Tun, Patricia A; Rosnick, Christopher B

2010-06-01

The authors of this study investigated whether fluid cognitive ability predicts exposure and emotional reactivity to daily stressors. A national sample of adults from the Midlife in the United States study and the National Study of Daily Experiences (N = 1,202) who had a mean age of 57 years (SD = 12; 56% women, 44% men) completed positive and negative mood reports as well as a stressor diary on 8 consecutive evenings via telephone. Participants also completed a telephone-based battery of tests measuring fluid cognitive ability. Higher levels of fluid cognitive ability were associated with greater exposure to work- and home-related overload stressors. Possessing higher levels of fluid cognitive ability was associated with smaller stressor-related increases in negative mood, primarily for interpersonal tensions and network stressors, and smaller stressor-related decreases in positive mood for interpersonal tensions. Furthermore, fluid cognitive ability was unrelated to subjective severity ratings of the stressors reported. Discussion focuses on the role of fluid cognitive ability in daily stress processes. (c) 2010 APA, all rights reserved).

Numerical analysis of dynamic behavior of pre-stressed shape memory alloy concrete beam-column joints

Science.gov (United States)

Yan, S.; Xiao, Z. F.; Lin, M. Y.; Niu, J.

2018-04-01

Beam-column joints are important parts of a main frame structure. Mechanical properties of beam-column joints have a great influence on dynamic performances of the frame structure. Shape memory alloy (SMA) as a new type of intelligent metal materials has wide applications in civil engineering. The paper aims at proposing a novel beam-column joint reinforced with pre-stressed SMA tendons to increase its dynamic performance. Based on the finite element analysis (FEA) software ABAQUS, a numerical simulation for 6 beam-column scaled models considering different SMA reinforcement ratios and pre-stress levels was performed, focusing on bearing capacities, energy-dissipation and self-centering capacities, etc. These models were numerically tested under a pseudo-static load on the beam end, companying a constant vertical compressive load on the top of the column. The numerical results show that the proposed SMA-reinforced joint has a significantly increased bearing capacity and a good self-centering capability after unloading even though the energy-dissipation capacity becomes smaller due the less residual deformation. The concept and mechanism of the novel joint can be used as an important reference for civil engineering applications.

Transport of particles by surface waves: a modification of the classical bouncer model

International Nuclear Information System (INIS)

Ragulskis, M; Sanjuan, M A F

2008-01-01

We consider a ball under the influence of gravity on a platform. A propagating surface wave travels on the surface of the platform, while the platform remains motionless. This is a modification of the classical bouncing ball problem and describes the transport of particles by surface waves. Phase and velocity maps cannot be expressed in an explicit form owing to implicit formulations, and no formal analytical analysis is possible. Numerical analysis shows that the transition to chaos is produced via a period doubling route, which is a common property for classical bouncers. The bouncing process can be sensitive to the initial conditions, which can build the ground for control techniques that can dramatically increase the effectiveness of particle transport in practical applications

A numerical study of adaptive space and time discretisations for Gross-Pitaevskii equations.

Science.gov (United States)

Thalhammer, Mechthild; Abhau, Jochen

2012-08-15

As a basic principle, benefits of adaptive discretisations are an improved balance between required accuracy and efficiency as well as an enhancement of the reliability of numerical computations. In this work, the capacity of locally adaptive space and time discretisations for the numerical solution of low-dimensional nonlinear Schrödinger equations is investigated. The considered model equation is related to the time-dependent Gross-Pitaevskii equation arising in the description of Bose-Einstein condensates in dilute gases. The performance of the Fourier-pseudo spectral method constrained to uniform meshes versus the locally adaptive finite element method and of higher-order exponential operator splitting methods with variable time stepsizes is studied. Numerical experiments confirm that a local time stepsize control based on a posteriori local error estimators or embedded splitting pairs, respectively, is effective in different situations with an enhancement either in efficiency or reliability. As expected, adaptive time-splitting schemes combined with fast Fourier transform techniques are favourable regarding accuracy and efficiency when applied to Gross-Pitaevskii equations with a defocusing nonlinearity and a mildly varying regular solution. However, the numerical solution of nonlinear Schrödinger equations in the semi-classical regime becomes a demanding task. Due to the highly oscillatory and nonlinear nature of the problem, the spatial mesh size and the time increments need to be of the size of the decisive parameter [Formula: see text], especially when it is desired to capture correctly the quantitative behaviour of the wave function itself. The required high resolution in space constricts the feasibility of numerical computations for both, the Fourier pseudo-spectral and the finite element method. Nevertheless, for smaller parameter values locally adaptive time discretisations facilitate to determine the time stepsizes sufficiently small in order that

Lower Lip Reconstruction after Wide Excision of a Malignancy with Barrel-Shaped Excision or the Webster Modification of the Bernard Operation

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Hyung Joon Seo

2013-01-01

Full Text Available BackgroundBecause there are numerous methods for reconstruction of the lower lip, it is not easy to choose the optimal method. In choosing the surgical method for lower lip reconstruction, we obtained acceptable outcomes based on our treatment strategy, which included either a barrel-shaped excision or the Webster modification of the Bernard operation. We report on the surgical outcomes based on our treatment strategy.MethodsThis study included 26 patients who underwent lower lip reconstructive surgery from September 1996 to September 2010. The operation was done using either a barrel-shaped excision or the Webster modification, considering the location of the defect, the size of the defect, and the amount of residual tissue on the lateral side of the vermilion after excision.ResultsIn our series, 3 patients underwent a single barrel-shaped excision, and nine patients underwent a double barrel-shaped excision. In addition, the unilateral Webster modification was performed on in 6 patients, and there were eight cases of bilateral Webster modification. All of the patients except one were satisfied with the postoperative shape of the lip. In one case both recurrence and dehiscence occurred. One patient had a good postoperative lip shape, but had difficulty wearing a denture, and also underwent commissuroplasty. Furthermore, there were two patients who complained of drooling, and 4 with paresthesia.ConclusionsA soft tissue defect resulting from wide excision of a lower lip malignancy can be successfully reconstructed using only one of two surgical methods: the barrel-shaped excision or the Webster modification of the Bernard operation.

Automated Polarimetry with Smaller Aperture Telescopes: The ROVOR Observatory

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Joseph Moody

2017-10-01

Full Text Available To better understand possible blazar jet mechanisms and morphologies, brighter prototypical objects are regularly monitored for variability in optical broad-band light. If the monitoring filters are polarized, the position angles and polarization percentages can be measured and their evolution monitored over time. However, building up a statistically significant time base of polarization parameters requires the arduous task of monitoring sources for months or years to catch and follow interesting events such as flares. Fortunately, monitoring an object is easily done using remotely operated or robotic telescopes. The Remote Observatory for Variable Object Research (ROVOR is a small-aperture telescope that has monitored blazars in broad-band Johnson filters since 2009. Calibration data using a set of four plane-polarized filters suggest that it is suitable for polarimetric monitoring as well. We have successfully collected data on CTA 102 and are encouraged at the prospects of monitoring it and other similar objects. Long-term monitoring campaigns are a scientifically and educationally-effective use of underutilized smaller-aperture telescopes.

Modification of JRR-4 based on safety evaluation

Energy Technology Data Exchange (ETDEWEB)

Izumo, Hironobu; Nakajima, Teruo; Funayama, Yoshiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-10-01

Since the first criticality was achieved on January 28, 1965, JRR-4 has been operated safely until on January 12, 1996. The modification of JRR-4 was planned according to the framework of reduced enrichment on research reactor program. The modification was designed based on the several national safety guides. JRR-4 has some modifications of facilities to satisfy the guides and guides criteria. (author)

On the Measurements of Particles Smaller than 20 μM by Global Rainbow Refractometry

Science.gov (United States)

Saengkaew, S.; Bonin, D.; Gréh, G.

2007-06-01

The measurement of the thermo-chemical characteristics of particles under evaporation or cooling is a challenge. Among others techniques, Global Rainbow Refractometry (GRR) is potentially applicable to a large variety of realistic media. This paper is focused on refractive index measurements of particles smaller than 20 μm which are especially important to extract droplet temperature in spray combustion.

Rock mass modification around a nuclear waste repository in welded tuff

International Nuclear Information System (INIS)

Mack, M.G.; Brandshaug, T.; Brady, B.H.

1989-08-01

This report presents the results of numerical analyses to estimate the extent of rock mass modification resulting from the presence of a High Level Waste (HLW) repository. Changes in rock mass considered are stresses and joint deformations resulting from disposal room excavation and thermal efffects induced by the heat generated by nuclear waste. rock properties and site conditions are taken from the Site Characterization Plan Conceptual Design Report for the potential repository site at Yucca Mountain, Nevada. Analyses were conducted using boundary element and distinct element methods. Room-scale models and repository-scale models were investigated for up to 500 years after waste emplacement. Results of room-scale analyses based on the thermoelastic boundary element model indicate that a zone of modified rock develops around the disposal rooms for both vertical and horizontal waste emplacement. This zone is estimated to extend a distance of roughly two room diameters from the room surface. Results from the repository-scale model, which are based on the thermoelastic boundary element model and the distinct element model, indicate a zone with modified rock mass properties starting approximately 100 m above and below the repository, with a thickness of approximately 200 m above and 150 m below the repository. Slip-prone subhorizontal features are shown to have a substantial effect on rock mass response. The estimates of rock mass modification reflect uncertainties and simplifying assumptions in the models. 32 refs., 57 figs., 1 tab

A Novel Geometric Modification to the Newton-Secant Method to Achieve Convergence of Order 1+2 and Its Dynamics

Directory of Open Access Journals (Sweden)

Gustavo Fernández-Torres

2015-01-01

Full Text Available A geometric modification to the Newton-Secant method to obtain the root of a nonlinear equation is described and analyzed. With the same number of evaluations, the modified method converges faster than Newton’s method and the convergence order of the new method is 1+2≈2.4142. The numerical examples and the dynamical analysis show that the new method is robust and converges to the root in many cases where Newton’s method and other recently published methods fail.

A delta-rule model of numerical and non-numerical order processing.

Science.gov (United States)

Verguts, Tom; Van Opstal, Filip

2014-06-01

Numerical and non-numerical order processing share empirical characteristics (distance effect and semantic congruity), but there are also important differences (in size effect and end effect). At the same time, models and theories of numerical and non-numerical order processing developed largely separately. Currently, we combine insights from 2 earlier models to integrate them in a common framework. We argue that the same learning principle underlies numerical and non-numerical orders, but that environmental features determine the empirical differences. Implications for current theories on order processing are pointed out. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Mapping Base Modifications in DNA by Transverse-Current Sequencing

Science.gov (United States)

Alvarez, Jose R.; Skachkov, Dmitry; Massey, Steven E.; Kalitsov, Alan; Velev, Julian P.

2018-02-01

Sequencing DNA modifications and lesions, such as methylation of cytosine and oxidation of guanine, is even more important and challenging than sequencing the genome itself. The traditional methods for detecting DNA modifications are either insensitive to these modifications or require additional processing steps to identify a particular type of modification. Transverse-current sequencing in nanopores can potentially identify the canonical bases and base modifications in the same run. In this work, we demonstrate that the most common DNA epigenetic modifications and lesions can be detected with any predefined accuracy based on their tunneling current signature. Our results are based on simulations of the nanopore tunneling current through DNA molecules, calculated using nonequilibrium electron-transport methodology within an effective multiorbital model derived from first-principles calculations, followed by a base-calling algorithm accounting for neighbor current-current correlations. This methodology can be integrated with existing experimental techniques to improve base-calling fidelity.

Numerical simulation of in-situ DNAPL remediation by alcohol flooding

Energy Technology Data Exchange (ETDEWEB)

Falta, R.W.; Brame, S.E. [Earth Science Department, Clemson, SC (United States)

1995-03-01

The removal of residual saturations of dense non-aqueous phase liquids (DNAPLs) from below the water table using alcohol solutions is under investigation as a potential remediation tool. Alcohol flooding reduces the interfacial tension (IFT) an density difference between the aqueous and DNAPL phases, and increases the chemical solubility in the aqueous phase. Depending on the partitioning behavior of the alcohol/chemical system, DNAPL can be removed by either mobilization as a separate phase or through enhanced dissolution. A new three dimensional multiphase numerical simulator has been developed for modeling this process. The code is based on the general TOUGH2 Integral Finite Difference formulation for multiphase transport with modifications to account for the complex behavior of an alcohol/water/DNAPL system. The alcohol flood code uses a special equation of state module for computing phase compositions, IFT, saturations, densities, viscosities, relative permeabilities, and capillary pressures during each time step. This equation of state is based on a numerical interpolation of experimentally determined ternary phase data. The code was designed so that it can readily be applied to other three-component, two-phase problems such as surfactant and solvent floods given appropriate ternary data. Comparisons of simulation results with column experiments performed at Clemson University were used to validate the simulator.

Surface modification of polyester biomaterials for tissue engineering

International Nuclear Information System (INIS)

Jiao Yanpeng; Cui Fuzhai

2007-01-01

Surfaces play an important role in a biological system for most biological reactions occurring at surfaces and interfaces. The development of biomaterials for tissue engineering is to create perfect surfaces which can provoke specific cellular responses and direct new tissue regeneration. The improvement in biocompatibility of biomaterials for tissue engineering by directed surface modification is an important contribution to biomaterials development. Among many biomaterials used for tissue engineering, polyesters have been well documented for their excellent biodegradability, biocompatibility and nontoxicity. However, poor hydrophilicity and the lack of natural recognition sites on the surface of polyesters have greatly limited their further application in the tissue engineering field. Therefore, how to introduce functional groups or molecules to polyester surfaces, which ideally adjust cell/tissue biological functions, becomes more and more important. In this review, recent advances in polyester surface modification and their applications are reviewed. The development of new technologies or methods used to modify polyester surfaces for developing their biocompatibility is introduced. The results of polyester surface modifications by surface morphological modification, surface chemical group/charge modification, surface biomacromolecule modification and so on are reported in detail. Modified surface properties of polyesters directly related to in vitro/vivo biological performances are presented as well, such as protein adsorption, cell attachment and growth and tissue response. Lastly, the prospect of polyester surface modification is discussed, especially the current conception of biomimetic and molecular recognition. (topical review)

Surface modification and enhanced photocatalytic CO{sub 2} reduction performance of TiO{sub 2}: a review

Energy Technology Data Exchange (ETDEWEB)

Low, Jingxiang; Cheng, Bei [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070 (China); Yu, Jiaguo, E-mail: jiaguoyu@yahoo.com [State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Luoshi Road 122, Wuhan 430070 (China); Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

2017-01-15

Highlights: • Application of modified TiO{sub 2} for photocatalytic CO{sub 2} reduction is summarized. • Different surface modification strategies of TiO{sub 2} are highlighted. • Summary and future perspectives in photocatalytic CO{sub 2} reduction are presented. - Abstract: Recently, the excessive consumption of fossil fuels has caused high emissions of the greenhouse gases, CO{sub 2} into atmosphere and global energy crisis. Mimicking the natural photosynthesis by using semiconductor materials to achieve photocatalytic CO{sub 2} reduction into valuable solar fuels such as CH{sub 4}, HCO{sub 2}H, CH{sub 2}O, and CH{sub 3}OH is known as one of the best solutions for addressing the aforementioned issue. Among various proposed photocatalysts, TiO{sub 2} has been extensively studied over the past several decades for photocatalytic CO{sub 2} reduction because of its cheapness and environmental friendliness. Particularly, surface modification of TiO{sub 2} has attracted numerous interests due to its capability of enhancing the light absorption ability, facilitating the electron-hole separation, tuning the CO{sub 2} reduction selectivity and increasing the CO{sub 2} adsorption and activation ability of TiO{sub 2} for photocatalytic CO{sub 2} reduction. In this review, recent approaches of the surface modification of TiO{sub 2} for photocatalytic CO{sub 2} reduction, including impurity doping, metal deposition, alkali modification, heterojunction construction and carbon-based material loading, are presented. The photocatalytic CO{sub 2} reduction mechanism and pathways of TiO{sub 2} are discussed. The future research direction and perspective of photocatalytic CO{sub 2} reduction over surface-modified TiO{sub 2} are also presented.

Smaller hippocampal volume as a vulnerability factor for the persistence of post-traumatic stress disorder

NARCIS (Netherlands)

van Rooij, S J H; Kennis, M; Sjouwerman, R; van den Heuvel, M P; Kahn, R S; Geuze, E

2015-01-01

BACKGROUND: Smaller hippocampal volume has often been observed in patients with post-traumatic stress disorder (PTSD). However, there is no consensus whether this is a result of stress/trauma exposure, or constitutes a vulnerability factor for the development of PTSD. Second, it is unclear whether

Repair-modification of radiodamaged genes

International Nuclear Information System (INIS)

Volpe, P.; Institute of Experimental Medicine, Rome; Eremenko, T.

1995-01-01

It is proposed that through repair-modification, the modified base 5mC may have facilitated the divergent evolution of coding (hypomethylated exon) and uncoding (hypermethylated promoter and intron) sequences in eukaryotic genes. The radioinduced repair patches appearing in regions lacking 5mC are fully reconstructed by excision-repair, whereas those appearing in regions containing 5mC are incompletely reconstructed by this conventional mechanism. Such a second class of repair patches may, however, become fully reconstructed, in the S phase, by repair-modification. In fact, while DNA polymerase β - which is a key enzyme of excision-repair - is active through the whole interphase. DNA methylase - which is responsible for post-synthetic DNA modification - is essentially active in S. Uncoupling of these two enzyme systems, outside S, might explain why in unsynchronised cells repair patches of non-replicating strands are hypomethylated when compared with specific methylation of replicating strands. In other words, excision-repair would always be able to re-establish the primary ATGC language of both damaged unmethylated and methylated regions, while repair-modification would be able to re-establish the modified ATGC(5mC) language of the damaged methylated regions, only in S, but not in G 1 or G 2 . In these two phases, when DNA methylation is inversely correlated with pre-mRNA transcription (as in the case of many tissue-specific genes), such demethylation might induce a silent transcriptional unit to become active. (Author)

Numerical analysis of the spacer grids' compression strength

Energy Technology Data Exchange (ETDEWEB)

Schettino, C.F.M.; Gouvea, J.P.; Medeiros, N., E-mail: carlosschettino@inb.gov.br, E-mail: jpg@metal.eeimvr.uff.br [Universidade Federal Fluminense (UFF), Volta Redonda, RJ (Brazil). Programa de Engenharia Metalurgica

2013-07-01

Among the components of the fuel assembly, the spacer grids play an important structural role during the energy generation process, mainly for their requirement to have enough structural strength to withstand lateral impact loads, due to fuel assembly shipping/handling and due to forces outcome from postulated accidents (earthquake and LOCA). This requirement ensures a proper geometry for cooling and for guide thimble straightness in the fuel assembly. In this way, the understanding of the macroscopic mechanical behavior of this component becomes essential even to any subsequent geometrical modifications to optimize the flue assemblies' structural behavior. In the present work, three-dimensional finite element models destined to provide consistent predictions of 16X16-type spacer grids lateral strength were proposed. Firstly, buckling tests based on results available in the literature were performed to establish a methodology for spacer grid finite element-based modeling. The, by considering a spacer grid interesting geometry and some possible variations associated to its fabrication, tolerance, the proposed numerical models were submitted to compression conditions to calculate the buckling force. Also, these models were validated for comparison with experimental buckling load results. Comparison of buckling predictions combined to observations of actual and simulated deformed spacer grids geometries permitted to verify the consistency and applicability of the proposed models. Thus, these numerical results show a good agreement between the and the experimental results. (author)

Playing Linear Numerical Board Games Promotes Low-Income Children's Numerical Development

Science.gov (United States)

Siegler, Robert S.; Ramani, Geetha B.

2008-01-01

The numerical knowledge of children from low-income backgrounds trails behind that of peers from middle-income backgrounds even before the children enter school. This gap may reflect differing prior experience with informal numerical activities, such as numerical board games. Experiment 1 indicated that the numerical magnitude knowledge of…

Modification of Aortic Cannula With an Inlet Chamber to Induce Spiral Flow and Improve Outlet Flow.

Science.gov (United States)

Darlis, Nofrizalidris; Osman, Kahar; Padzillah, Muhamad Hasbullah; Dillon, Jeswant; Md Khudzari, Ahmad Zahran

2018-05-01

Physiologically, blood ejected from the left ventricle in systole exhibited spiral flow characteristics. This spiral flow has been proven to have several advantages such as lateral reduction of directed forces and thrombus formation, while it also appears to be clinically beneficial in suppressing neurological complications. In order to deliver spiral flow characteristics during cardiopulmonary bypass operation, several modifications have been made on an aortic cannula either at the internal or at the outflow tip; these modifications have proven to yield better hemodynamic performances compared to standard cannula. However, there is no modification done at the inlet part of the aortic cannula for inducing spiral flow so far. This study was carried out by attaching a spiral inducer at the inlet of an aortic cannula. Then, the hemodynamic performances of the new cannula were compared with the standard straight tip end-hole cannula. This is achieved by modeling the cannula and attaching the cannula at a patient-specific aorta model. Numerical approach was utilized to evaluate the hemodynamic performance, and a water jet impact experiment was used to demonstrate the jet force generated by the cannula. The new spiral flow aortic cannula has shown some improvements by reducing approximately 21% of impinging velocity near to the aortic wall, and more than 58% reduction on total force generated as compared to standard cannula. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Energy conserving numerical methods for the computation of complex vortical flows

Science.gov (United States)

Allaneau, Yves

One of the original goals of this thesis was to develop numerical tools to help with the design of micro air vehicles. Micro Air Vehicles (MAVs) are small flying devices of only a few inches in wing span. Some people consider that as their size becomes smaller and smaller, it would be increasingly more difficult to keep all the classical control surfaces such as the rudders, the ailerons and the usual propellers. Over the years, scientists took inspiration from nature. Birds, by flapping and deforming their wings, are capable of accurate attitude control and are able to generate propulsion. However, the biomimicry design has its own limitations and it is difficult to place a hummingbird in a wind tunnel to study precisely the motion of its wings. Our approach was to use numerical methods to tackle this challenging problem. In order to precisely evaluate the lift and drag generated by the wings, one needs to be able to capture with high fidelity the extremely complex vortical flow produced in the wake. This requires a numerical method that is stable yet not too dissipative, so that the vortices do not get diffused in an unphysical way. We solved this problem by developing a new Discontinuous Galerkin scheme that, in addition to conserving mass, momentum and total energy locally, also preserves kinetic energy globally. This property greatly improves the stability of the simulations, especially in the special case p=0 when the approximation polynomials are taken to be piecewise constant (we recover a finite volume scheme). In addition to needing an adequate numerical scheme, a high fidelity solution requires many degrees of freedom in the computations to represent the flow field. The size of the smallest eddies in the flow is given by the Kolmogoroff scale. Capturing these eddies requires a mesh counting in the order of Re³ cells, where Re is the Reynolds number of the flow. We show that under-resolving the system, to a certain extent, is acceptable. However our

DNA modification by alkylating compounds

Energy Technology Data Exchange (ETDEWEB)

Kruglyakova, E.E.

1985-09-01

Results are given for research on the physico-chemical properties of alkylating compounds - nitroso alkyl ureas (NAU) which possess a broad spectrum of biological activity, such as mutagenic, carcinogenic, and anti-tumor action that is due to the alkylation and carbamoylation of DNA as well as other cellular components. Identified chemical products of NAU interaction with DNA and its components are cited. Structural conversions of a DNA macromolecule resulting from its chemical modification are examined. NAU are used to discuss possible biological consequences of DNA modification. 148 references.

Corrosion principles and surface modification

International Nuclear Information System (INIS)

Kruger, J.

1982-01-01

This chapter examines the important strategies provided by the newer ideas of corrosion science and engineering that surface modification techniques must utilize to help prevent corrosion, especially the most damaging kind of aqueous corrosion, localized corrosion. Provides a brief introduction to the principles underlying the phenomenon of corrosion in order to use them to discuss surface modification strategies to combat corrosion. Discusses the electrochemistry of corrosion; the thermodynamics of corrosion; the kinetics of corrosion; thermodynamic strategies; and kinetic strategies (formation of more protective passive films; resistance to breakdown; ductility; repassivation)

MODIFICATION OF SURFACE KONDENSITSIONNYH AEROSOLS WELDING AND METALLURGICHESKIH PRODUCTIONS

Directory of Open Access Journals (Sweden)

A. A. Ennan

2016-04-01

Full Text Available Chemical modification of surface kondensitsionnyh aerosols (KA which formation when heat treatment metals (process of weld, foundry processes with application chlorosilanes are suggested. Adsorbtion vapor of water on modification powders KA decreases and changes in varies from modifier and conditions modification are setted.

12 CFR 725.21 - Modification of agreements.

Science.gov (United States)

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Modification of agreements. 725.21 Section 725.21 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS NATIONAL CREDIT UNION ADMINISTRATION CENTRAL LIQUIDITY FACILITY § 725.21 Modification of agreements. The...

Surface Modification of Biomaterials: A Quest for Blood Compatibility

Directory of Open Access Journals (Sweden)

Achala de Mel

2012-01-01

Full Text Available Cardiovascular implants must resist thrombosis and intimal hyperplasia to maintain patency. These implants when in contact with blood face a challenge to oppose the natural coagulation process that becomes activated. Surface protein adsorption and their relevant 3D confirmation greatly determine the degree of blood compatibility. A great deal of research efforts are attributed towards realising such a surface, which comprise of a range of methods on surface modification. Surface modification methods can be broadly categorized as physicochemical modifications and biological modifications. These modifications aim to modulate platelet responses directly through modulation of thrombogenic proteins or by inducing antithrombogenic biomolecules that can be biofunctionalised onto surfaces or through inducing an active endothelium. Nanotechnology is recognising a great role in such surface modification of cardiovascular implants through biofunctionalisation of polymers and peptides in nanocomposites and through nanofabrication of polymers which will pave the way for finding a closer blood match through haemostasis when developing cardiovascular implants with a greater degree of patency.

Generalized algorithm for control of numerical dispersion in explicit time-domain electromagnetic simulations

Directory of Open Access Journals (Sweden)

Benjamin M. Cowan

2013-04-01

Full Text Available We describe a modification to the finite-difference time-domain algorithm for electromagnetics on a Cartesian grid which eliminates numerical dispersion error in vacuum for waves propagating along a grid axis. We provide details of the algorithm, which generalizes previous work by allowing 3D operation with a wide choice of aspect ratio, and give conditions to eliminate dispersive errors along one or more of the coordinate axes. We discuss the algorithm in the context of laser-plasma acceleration simulation, showing significant reduction—up to a factor of 280, at a plasma density of 10^{23}  m^{-3}—of the dispersion error of a linear laser pulse in a plasma channel. We then compare the new algorithm with the standard electromagnetic update for laser-plasma accelerator stage simulations, demonstrating that by controlling numerical dispersion, the new algorithm allows more accurate simulation than is otherwise obtained. We also show that the algorithm can be used to overcome the critical but difficult challenge of consistent initialization of a relativistic particle beam and its fields in an accelerator simulation.

Trophic interaction modifications: an empirical and theoretical framework.

Science.gov (United States)

Terry, J Christopher D; Morris, Rebecca J; Bonsall, Michael B

2017-10-01

Consumer-resource interactions are often influenced by other species in the community. At present these 'trophic interaction modifications' are rarely included in ecological models despite demonstrations that they can drive system dynamics. Here, we advocate and extend an approach that has the potential to unite and represent this key group of non-trophic interactions by emphasising the change to trophic interactions induced by modifying species. We highlight the opportunities this approach brings in comparison to frameworks that coerce trophic interaction modifications into pairwise relationships. To establish common frames of reference and explore the value of the approach, we set out a range of metrics for the 'strength' of an interaction modification which incorporate increasing levels of contextual information about the system. Through demonstrations in three-species model systems, we establish that these metrics capture complimentary aspects of interaction modifications. We show how the approach can be used in a range of empirical contexts; we identify as specific gaps in current understanding experiments with multiple levels of modifier species and the distributions of modifications in networks. The trophic interaction modification approach we propose can motivate and unite empirical and theoretical studies of system dynamics, providing a route to confront ecological complexity. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Drug delivery from hydrophobic-modified mesoporous silicas: Control via modification level and site-selective modification

International Nuclear Information System (INIS)

Tang Qunli; Chen Yuxi; Chen Jianghua; Li Jin; Xu Yao; Wu Dong; Sun Yuhan

2010-01-01

Dimethylsilyl (DMS) modified mesoporous silicas were successfully prepared via co-condensation and post-grafting modification methods. The post-grafting modification was carried out by the reaction of the as-synthesized MCM-41 material (before CTAB removal) with diethoxydimethylsinale (DEDMS). N 2 adsorption-desorption and 29 Si MAS NMR characterization demonstrated that different amount of DMS groups were successfully incorporated into the co-condensation modified samples, and the functional DMS groups were placed selectively on the pore openings and external pore surfaces in the post-grafting modified samples. Subsequently, the controlled drug delivery properties from the resulting DMS-modified mesoporous silicas were investigated in detail. The drug adsorption experiments showed that the adsorption capacities were mainly depended on the content of silanol group (CSG) in the corresponding carriers. The in vitro tests exhibited that the incorporation of DMS groups greatly retarded the ibuprofen release rate. Moreover, the ibuprofen release profiles could be well modulated by varying DMS modification levels and site-selective distribution of functional groups in mesoporous carriers. - The distribution of DMS groups on the pore surfaces of the mesostructures strongly affects the drug release rate. The P-M41-1 and the P-M41-2 possess the close DMS modification levels as the C-M41-10, but the ibuprofen release rates from the P-M41-1 and P-M41-2 are much slower than that from the C-M41-10.

Medium Modifications of Hadrons in Photon Induced Reactions

International Nuclear Information System (INIS)

Schadmand, S.

2004-01-01

Indications for in-medium modifications of hadron properties are reported from photoabsorption and meson production experiments. Strong medium modifications are observed in inclusive photoabsorption experiments and theoretical models investigate the in-medium dynamics of baryon resonances and their coupling to mesons. Recent experiments study the in-medium behavior of scalar and vector mesons where theoretical models expect in-medium modifications of the meson spectral functions that might be connected to partial restoration of chiral symmetry

Protein covalent modification by biologically active quinones

Directory of Open Access Journals (Sweden)

MIROSLAV J. GASIC

2004-11-01

Full Text Available The avarone/avarol quinone/hydroquinone couple shows considerable antitumor activity. In this work, covalent modification of b-lactoglobulin by avarone and its derivatives as well as by the synthetic steroidal quinone 2,5(10-estradiene-1,4,17-trione and its derivatives were studied. The techniques for studying chemical modification of b-lactoglobulin by quinones were: UV/Vis spectrophotometry, SDS PAGE and isoelectrofocusing. SDS PAGE results suggest that polymerization of the protein occurs. It could be seen that the protein of 18 kD gives the bands of 20 kD, 36 kD, 40 kD, 45 kD, 64 kD and 128 kD depending on modification agent. The shift of the pI of the protein (5.4 upon modification toward lower values (from pI 5.0 to 5.3 indicated that lysine amino groups are the principal site of the reaction of b-lactoglobulin with the quinones.

Physics, mathematics and numerics of particle adsorption on fluid interfaces

Science.gov (United States)

Schmuck, Markus; Pavliotis, Grigorios A.; Kalliadasis, Serafim

2012-11-01

We study two arbitrary immiscible fuids where one phase contains small particles of the size of the interface and smaller. We primarily focus on charge-free particles with wetting characteristics described by the contact angle formed at the interface between the two phases and the particles. Based on the experimental observation that particles are adsorbed on the interface to reduce the interfacial energy and hence the surface tension as well, we formulate a free-energy functional that accounts for these physical effects. Using elements from calculus of variations and formal gradient flow theory, we derive partial differential equations describing the location of the interface and the density of the particles in the fluid phases. Via numerical experiments we analyse the time evolution of the surface tension, the particle concentration, and the free energy over time and reflect basic experimentally observed phenomena.

Trends and patterns in contemporary management in smaller companies: The Danish perspective

DEFF Research Database (Denmark)

Ulhøi, John Parm; Madsen, Henning

2001-01-01

This paper reports empirical findings from a recent survey of Danish managers with a special focus on managers from smaller companies. The survey has been initiated in Denmark and it is called the 'Danish Management Barometer'. The project is a joint research program between the Aarhus School...... of Business and the Danish Association of Managers and Executives. It is based on a structured, pre-tested questionnaire send out to 1500 pre-notified managers in Denmark aiming at establishing a data base to further monitor and identify interesting changes and patterns within a broad range of managerial...

Post-Translational Modifications of H2A Histone Variants and Their Role in Cancer

Directory of Open Access Journals (Sweden)

David Corujo

2018-02-01

Full Text Available Histone variants are chromatin components that replace replication-coupled histones in a fraction of nucleosomes and confer particular characteristics to chromatin. H2A variants represent the most numerous and diverse group among histone protein families. In the nucleosomal structure, H2A-H2B dimers can be removed and exchanged more easily than the stable H3-H4 core. The unstructured N-terminal histone tails of all histones, but also the C-terminal tails of H2A histones protrude out of the compact structure of the nucleosome core. These accessible tails are the preferential target sites for a large number of post-translational modifications (PTMs. While some PTMs are shared between replication-coupled H2A and H2A variants, many modifications are limited to a specific histone variant. The present review focuses on the H2A variants H2A.Z, H2A.X, and macroH2A, and summarizes their functions in chromatin and how these are linked to cancer development and progression. H2A.Z primarily acts as an oncogene and macroH2A and H2A.X as tumour suppressors. We further focus on the regulation by PTMs, which helps to understand a degree of context dependency.

Numerical simulation of transient moisture transfer into an electronic enclosure

Energy Technology Data Exchange (ETDEWEB)

Nasirabadi, P. Shojaee; Jabbari, M.; Hattel, J. H. [Process Modelling Group, Department of Mechanical Engineering, Technical University of Denmark, Nils Koppels Allé, 2800 Kgs. Lyngby (Denmark)

2016-06-08

Electronic systems are sometimes exposed to harsh environmental conditions of temperature and humidity. Moisture transfer into electronic enclosures and condensation can cause several problems such as corrosion and alteration in thermal stresses. It is therefore essential to study the local climate inside the enclosures to be able to protect the electronic systems. In this work, moisture transfer into a typical electronic enclosure is numerically studied using CFD. In order to reduce the CPU-time and make a way for subsequent factorial design analysis, a simplifying modification is applied in which the real 3D geometry is approximated by a 2D axial symmetry one. The results for 2D and 3D models were compared in order to calibrate the 2D representation. Furthermore, simulation results were compared with experimental data and good agreement was found.

Numerical simulation of transient moisture transfer into an electronic enclosure

International Nuclear Information System (INIS)

Nasirabadi, P. Shojaee; Jabbari, M.; Hattel, J. H.

2016-01-01

Electronic systems are sometimes exposed to harsh environmental conditions of temperature and humidity. Moisture transfer into electronic enclosures and condensation can cause several problems such as corrosion and alteration in thermal stresses. It is therefore essential to study the local climate inside the enclosures to be able to protect the electronic systems. In this work, moisture transfer into a typical electronic enclosure is numerically studied using CFD. In order to reduce the CPU-time and make a way for subsequent factorial design analysis, a simplifying modification is applied in which the real 3D geometry is approximated by a 2D axial symmetry one. The results for 2D and 3D models were compared in order to calibrate the 2D representation. Furthermore, simulation results were compared with experimental data and good agreement was found.

How to Build an AppleSeed: A Parallel Macintosh Cluster for Numerically Intensive Computing

Science.gov (United States)

Decyk, V. K.; Dauger, D. E.

We have constructed a parallel cluster consisting of a mixture of Apple Macintosh G3 and G4 computers running the Mac OS, and have achieved very good performance on numerically intensive, parallel plasma particle-incell simulations. A subset of the MPI message-passing library was implemented in Fortran77 and C. This library enabled us to port code, without modification, from other parallel processors to the Macintosh cluster. Unlike Unix-based clusters, no special expertise in operating systems is required to build and run the cluster. This enables us to move parallel computing from the realm of experts to the main stream of computing.

The ethics of molecular memory modification.

Science.gov (United States)

Hui, Katrina; Fisher, Carl E

2015-07-01

Novel molecular interventions have recently shown the potential to erase, enhance and alter specific long-term memories. Unique features of this form of memory modification call for a close examination of its possible applications. While there have been discussions of the ethics of memory modification in the literature, molecular memory modification (MMM) can provide special insights. Previously raised ethical concerns regarding memory enhancement, such as safety issues, the 'duty to remember', selfhood and personal identity, require re-evaluation in light of MMM. As a technology that exploits the brain's updating processes, MMM helps correct the common misconception that memory is a static entity by demonstrating how memory is plastic and subject to revision even in the absence of external manipulation. Furthermore, while putatively safer than other speculative technologies because of its high specificity, MMM raises notable safety issues, including potential insidious effects on the agent's emotions and personal identity. Nonetheless, MMM possesses characteristics of a more permissible form of modification, not only because it is theoretically safer, but because its unique mechanism of action requires a heightened level of cooperation from the agent. Discussions of memory modification must consider the specific mechanisms of action, which can alter the weight and relevance of various ethical concerns. MMM also highlights the need for conceptual accuracy regarding the term 'enhancement'; this umbrella term will have to be differentiated as new technologies are applied to a widening array of purposes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Safety improvement plant modifications at Forsmark 3, 1986-1995

Energy Technology Data Exchange (ETDEWEB)

Kjellander, M. [Kaernkraftsaekerhet och utbildning, Nykoeping (Sweden)

1998-10-01

All important plant modifications implemented in safety-related equipment or software at Forsmark 3 are compiled in this report. The report covers the period from the start of commercial operation in 1985 up to and including 1995. The plant modifications, which were carried out by different suppliers during the guarantee period, are not included in the report since they have not been administered by the Forsmark organisation. The report contains references to relevant modification notices and to files and file divider numbers. These data refer to the Safety Department central archives. The report is based on Forsmark 3 Technical Specifications (STF) which means that Chapter 3 is divided into the same sections as in the STF. Modifications, which cannot be directly attributed to any specific STF chapter, and major modifications are described separately

Detection of smaller J{sub c} region and damage in YBCO coated conductors by using permanent magnet method

Energy Technology Data Exchange (ETDEWEB)

Hattori, K., E-mail: tey88221@st.yamagata-u.ac.jp [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510 (Japan); Saito, A. [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510 (Japan); Takano, Y.; Suzuki, T. [Tohoku Seiki Industries, Ltd., 3-1246, Tachiyagawa, Yamagata 990-2251 (Japan); Yamada, H.; Takayama, T.; Kamitani, A.; Ohshima, S. [Graduate School of Science and Engineering, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510 (Japan)

2011-11-15

We developed a non-destructive method for measuring the critical current density (J{sub c}) in YBCO-coated conductors by using a permanent magnet (Sm{sub 2}Co{sub 17}). J{sub c} could be determined from the repulsive force (F{sub r}) generated between a permanent magnet and a coated conductor where shielding current flows. We also examined the influence of damage to the film on the J{sub c} distribution. The measured F{sub r} when the permanent magnet approached the cut part was smaller than that of the undamaged area. We developed a non-destructive method for measuring the critical current density (J{sub c}) in YBCO-coated conductors by using a permanent magnet (Sm{sub 2}Co{sub 17}). J{sub c} could be determined from the repulsive force (F{sub r}) generated between a permanent magnet and a coated conductor where shielding current flows. We tried to detect a smaller J{sub c} region in the coated conductor by using the system. The J{sub c} distribution could be determined without influence from the thick copper film on YBCO thin film. We also examined the influence of damage to the film on the J{sub c} distribution. The surface of the coated conductors was cut by using a knife. The measured F{sub r} when the permanent magnet approached the cut part was smaller than that of the undamaged area. This J{sub c} measurement technique will be useful for detecting smaller J{sub c} regions and defects in coated conductors.

Chemical modification of b-lactoglobulin by quinones

Directory of Open Access Journals (Sweden)

DUSAN SLADIC

2003-05-01

Full Text Available The avarone/avarol quinone/hydroquinone couple, as well as their derivatives show considerable antitumor activity. In this work, covalent modifications of b-lactoglobulin, isolated from cow milk, by avarone, its model compound 2-tert-butyl-1,4-benzoquinone, and several of their alkylthio derivatives were studied. The techniques applied for assaying the modifications were: UV/VIS spectrophotometry, SDS PAGE and isoelectrofocusing. The results of the SDS PAGE suggest that polymerisation of the protein occurs. The shift of the pI of the protein upon modification toward lower values indicates that lysine amino groups are the principal site of the reaction of b-lactoglobulin with the quinones.

OCCASIONAL ADNOMINAL IDIOM MODIFICATION - A COGNITIVE LINGUISTIC APPROACH

Directory of Open Access Journals (Sweden)

Andreas Langlotz

2006-06-01

Full Text Available occasional Adnominal Idiom Modification - A Cognitive Linguistic Approach From a cognitive-linguistic perspective, this paper explores alternative types of adnoniinal modification in occasional variants of English verbal idioms. Being discussed against data extracted from the British National Corpiis (BNC, the model claims that in idioni-production idiomatic constructions are activated as complex linguistic schemas to code a context-specific target-conceptualisation. Adnominal pre- and postmodifications are one specific form of creative alteration to adapt the idiom for this purpose. Semantically, idiom-interna1 NPextension is not a uniforni process. It is necessary to distinguish two systematic types of adnominal modification: external and internal modification (Ernst 1981. While external NPmodification has adverbial function, ¡.e. it modifies the idiom as a unit, internal modification directly applies to the head-noun and thus depends on the degree of motivation and analysability of a given idiom. Following the cognitive-linguistic framework, these dimensions of idiom-transparency result from the language user's ability to remotivate the bipartite semantic structure by conceptual metaphors and metonymies.

Numerical study of the aerodynamics of sound sources in a bass-reflex port

Directory of Open Access Journals (Sweden)

V.M. Garcia-Alcaide

2017-01-01

Full Text Available The aim of this paper is to study the aerodynamics phenomena of a bass-reflex port that causes noise in the audible frequency range. After discarding structural and mechanical vibration issues, the hypothesis considered is that vortex shedding is the source of the noise. Experimental and numerical evidences of the vortex, an analysis of its noise and the similarities between real and simulated performance are presented. The numerically simulated cases with the original geometry are excited at different frequencies and with modifications of the port geometry. Likewise, the internal performance of an enclosure with a closed port was simulated. The simulations have been performed with axisymmetrical geometries using the open-source OpenFOAM® toolbox. Moreover, experimental measurements were carried out. First, acoustic signal experiments were done to analyse the response of the bass-reflex ports. Secondly, a structure vibration measurement was conducted in order to exclude the cabinet structure vibration as a source of the noise in question. A good agreement was found between numerical and experimental results, especially in the frequency band of the detected noise, i.e. the 1000–1500 Hz range. Despite no remarkable improvement being made with the geometry changes explored, the presented CFD approach has proved a useful and cost-effective tool to address this kind of phenomenon.

42 CFR 412.72 - Modification of base-year costs.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Modification of base-year costs. 412.72 Section 412... Modification of base-year costs. (a) Bases for modification of base-year costs. Base-year costs as determined... before November 16, 1983 has until November 15, 1983 to request its intermediary to reestimate its base...

Numerical and experimental studies of droplet-gas flow

Energy Technology Data Exchange (ETDEWEB)

Joesang, Aage Ingebret

2002-07-01

This thesis considers droplet-gas flow by the use of numerical methods and experimental verification. A commercial vane separator was studied both numerical and by experiment. In addition some efforts are put into the numerical analysis of cyclones. The experimental part contains detailed measurements of the flow field between a pair of vanes in a vane separator and droplet size measurements. LDA (Laser Doppler Anemometry) was used to measure the velocity in two dimensions and corresponding turbulence quantities. The results from the LDA measurements are considered to be of high quality and are compared to numerical results obtained from a CFD (Computational Fluid Dynamics) analysis. The simulation showed good agreement between the numerical and experimental results. Combinations of different turbulence models; the standard k-epsilon model and the Reynold Stress Mode, different schemes; first order and higher order scheme and different near wall treatment of the turbulence; the Law of the wall and the Two-Layer Zonal model were used in the simulations. The Reynold Stress Model together with a higher order scheme performed rather poorly. The recirculation in parts of the separator was overpredicted in this case. For the other cases the overall predictions are satisfactory. PDA (Phase Doppler Anemometry) measurements were used to study the changes in the droplet size distribution through the vane separator. The PDA measurements show that smaller droplets are found at the outlet than present at the inlet. In the literature there exists different mechanisms for explaining the re-entrainment and generation of new droplets. The re-entrainments mechanisms are divided into four groups where droplet-droplet interaction, droplet break-up, splashing of impinging droplet and re-entrainment from the film are defined as the groups of re-entrainment mechanisms. Models for these groups are found in the literature and these models are tested for re-entrainment using the operational

Deaggregation, Modification, and Developing Applications for Detonation Nanodiamond

Science.gov (United States)

Mochalin, Vadym

2017-06-01

Nanodiamond powder (ND) is one of the most promising materials for advanced composites and biomedical applications. It is also a commercial precursor for carbon nanoonions - material for high power micrometer size supercapacitors and potentially, Li-ion batteries. ND is produced by detonation of explosives with negative oxygen balance in a closed chamber, where extremely high pressures and temperatures develop during detonation. ND consists of diamond particles of 5 nm diameter, combining fully accessible large surface and rich and tailorable surface chemistry. ND has unique properties including optical, electrical, thermal, and mechanical, and is biocompatible and non-toxic. Due to numerous surface functional groups, ND has catalytic and electrochemical activity. Several techniques have been proposed for ND deaggregation based on milling with costly ceramic microbeads, leaving difficult to remove contaminations in the resulting ND suspension. We have recently discovered a novel, green technique for ND deaggregation using sonication in aqueous sodium chloride slurry. Upon completion of the process sodium chloride can be easily washed out with water leaving behind no contaminants and yielding stable single-digit ND colloids. Modification and development of applications for ND in composites, drug delivery, biomedical imaging, etc., will be also discussed.

A Kantian argument against comparatively advantageous genetic modification.

Science.gov (United States)

Jensen, David

2011-08-01

The genetic modification of children is becoming a more likely possibility given our rapid progress in medical technologies. I argue, from a broadly Kantian point of view, that at least one kind of such modification-modification by a parent for the sake of a child's comparative advantage-is not rationally justified. To argue this, I first characterize a necessary condition on reasons and rational justification: what is a reason for an agent to do an action in one set of circumstances must be a reason for any in those circumstances to do the action. I then show that comparatively advantageous genetic modification violates this principle since a child's "getting ahead" through genetic modification cannot be rationally justified unless other children also could receive the modification, thus rendering the advantage useless. Finally, I consider the major objection to this it seems to disallow all cases of a parent's helping a child get ahead, something that parents normally engage in with their children. I argue that typical practices of developing a comparative advantage in a child, as well as practices of societal competition in general, do not conflict because they involve circumstances that mitigate the universal character of reasons. Many ordinary cases of competitive advantage that we think of as unjust, in fact, can be explained by my argument.

Tribological effects of polymer surface modification through plastic

Indian Academy of Sciences (India)

Tribological effects of polymer surface modification through plastic deformation. K O Low K J Wong ... In this regard, a surface modification technique through plastic deformation has been implemented. ... Bulletin of Materials Science | News.

Modifications of small intestine lysosomal enzymes after irradiation at different times of the day

Energy Technology Data Exchange (ETDEWEB)

Becciolini, A; Giache, V; Lanini, A; Cremonini, D; Drighi, E [Florence Univ. (Italy). Ist. di Radiologia

1982-01-01

The modification of lysosomal enzyme activities in animals irradiated with the same sublethal dose at 4 different times of the day is reported. The results confirmed the absence of circadian fluctuations in all the lysosomal enzymes and in protein content. A difference in behaviour between acid ..beta..-galactosidase and ..beta..-glucuronidase on the one hand and between acid phosphatase and cathepsin D on the other was evident in irradiated animals. The results showed that acid ..beta..-galactosidase and ..beta..-glucuronidase increase from the early intervals after irradiation and reach the highest activity between 36 and 48 h. At these intervals autolysis phenomena, heavy cellular alterations and numerous phlogosis cells are present in the epithelium. Only ..beta..-glucuronidase and acid ..beta..-galactosidase indicate the level of radiation injury.

Enzymatic modification of starch

DEFF Research Database (Denmark)

Jensen, Susanne Langgård

In the food industry approaches for using bioengineering are investigated as alternatives to conventional chemical and physical starch modification techniques in development of starches with specific properties. Enzyme-assisted post-harvest modification is an interesting approach to this, since...... it is considered a clean and energy saving technology. This thesis aimed to investigate the effect of using reaction conditions, simulating an industrial process, for enzymatic treatment of starch with branching enzyme (BE) from Rhodothermus obamensis. Thus treatements were conducted at 70°C using very high...... substrate concentration (30-40% dry matter (DM)) and high enzyme activity (750-2250 BE units (BEU)/g sample). Starches from various botanical sources, representing a broad range of properties, were used as substrates. The effects of the used conditions on the BE-reaction were evaluated by characterization...

Nuclear Plant Modification in a Risk-Informed Environment

International Nuclear Information System (INIS)

Gallucci, Raymond H.V.

2002-01-01

This paper examines a specific nuclear power plant modification performed in a risk-informed regulatory environment. It quantifies both the permanent and temporary effects of the modification, and performs a cost-benefit evaluation. (authors)

Economic potential of smaller-sized nuclear plants in today's economy

International Nuclear Information System (INIS)

Behrens, C.E.

1984-01-01

In this study, the cost of producing power was modelled for a utility with specified financial and production parameters. Two reference cases were considered: in one, it was assumed that the utility would build 400-megawatt nuclear units as necessary to meet its growth in load; in the second, that it would meet its load growth by building 1200-MW units. The smaller plants were assumed to cost 12 percent more per kilowatt than the larger units. The object was to see if the lower financing costs of the 400-megawatt units were enough to overcome the larger plants' economies of scale. In addition to the reference cases, the sensitivity of the cost measurement to changes in various parameters was modelled. The parameters tested included interest rates, fuel mix, cost differential between the 400-megawatt and 1200-megawatt plants, and the rate of growth in load. The results of these cases indicate strongly that small nuclear power plants could have a market

Identifying modifications in RNA by MALDI mass spectrometry

DEFF Research Database (Denmark)

Douthwaite, Stephen; Kirpekar, Finn

2007-01-01

as RNA modifications added in cell-free in vitro systems. MALDI-MS is particularly useful in cases in which other techniques such as those involving primer extension or chromatographic analyses are not practicable. To date, MALDI-MS has been used to localize rRNA modifications that are involved......Posttranscriptional modifications on the base or sugar of ribonucleosides generally result in mass increases that can be measured by mass spectrometry. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a direct and accurate means of determining the masses of RNAs. Mass...... spectra produced by MALDI are relatively straightforward to interpret, because they are dominated by singly charged ions, making it possible to analyze complex mixtures of RNA oligonucleotides ranging from trinucleotides up to 20-mers. Analysis of modifications within much longer RNAs, such as ribosomal...

Methane hydrate induced permeability modification for multiphase flow in unsaturated porous media

Science.gov (United States)

Seol, Yongkoo; Kneafsey, Timothy J.

2011-08-01

An experimental study was performed using X-ray computed tomography (CT) scanning to capture three-dimensional (3-D) methane hydrate distributions and potential discrete flow pathways in a sand pack sample. A numerical study was also performed to develop and analyze empirical relations that describe the impacts of hydrate accumulation habits within pore space (e.g., pore filling or grain cementing) on multiphase fluid migration. In the experimental study, water was injected into a hydrate-bearing sand sample that was monitored using an X-ray CT scanner. The CT images were converted into numerical grid elements, providing intrinsic sample data including porosity and phase saturations. The impacts of hydrate accumulation were examined by adapting empirical relations into the flow simulations as additional relations governing the evolution of absolute permeability of hydrate bearing sediment with hydrate deposition. The impacts of pore space hydrate accumulation habits on fluid migration were examined by comparing numerical predictions with experimentally measured water saturation distributions and breakthrough curves. A model case with 3-D heterogeneous initial conditions (hydrate saturation, porosity, and water saturation) and pore body-preferred hydrate accumulations best captured water migration behavior through the hydrate-bearing sample observed in the experiment. In the best matching model, absolute permeability in the hydrate bearing sample does not decrease significantly with increasing hydrate saturation until hydrate saturation reaches about 40%, after which it drops rapidly, and complete blockage of flow through the sample can occur as hydrate accumulations approach 70%. The result highlights the importance of permeability modification due to hydrate accumulation habits when predicting multiphase flow through high-saturation, reservoir quality hydrate-bearing sediments.

Albumin modification and fragmentation in renal disease.

Science.gov (United States)

Donadio, Carlo; Tognotti, Danika; Donadio, Elena

2012-02-18

Albumin is the most important antioxidant substance in plasma and performs many physiological functions. Furthermore, albumin is the major carrier of endogenous molecules and exogenous ligands. This paper reviews the importance of post-translational modifications of albumin and fragments thereof in patients with renal disease. First, current views and controversies on renal handling of proteins, mainly albumin, will be discussed. Post-translational modifications, namely the fragmentation of albumin found with proteomic techniques in nephrotic patients, diabetics, and ESRD patients will be presented and discussed. It is reasonable to hypothesize that proteolytic fragmentation of serum albumin is due to a higher susceptibility to proteases, induced by oxidative stress. The clinical relevance of the fragmentation of albumin has not yet been established. These modifications could affect some physiological functions of albumin and have a patho-physiological role in uremic syndrome. Proteomic analysis of serum allows the identification of over-expressed proteins and can detect post-translational modifications of serum proteins, hitherto hidden, using standard laboratory techniques. Copyright © 2011 Elsevier B.V. All rights reserved.

Covalent Surface Modifications of Carbon Nanotubes.

Energy Technology Data Exchange (ETDEWEB)

Pavia Sanders, Adriana [Sandia National Lab. (SNL-CA), Livermore, CA (United States); O' Bryan, Greg [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

2017-07-01

A report meant to document the chemistries investigated by the author for covalent surface modification of CNTs. Oxidation, cycloaddition, and radical reactions were explored to determine their success at covalently altering the CNT surface. Characterization through infrared spectroscopy, Raman spectroscopy, and thermo gravimetric analysis was performed in order to determine the success of the chemistries employed. This report is not exhaustive and was performed for CNT surface modification exploration as it pertains to the "Next Gen" project.

Modifications of Steepest Descent Method and Conjugate Gradient Method Against Noise for Ill-posed Linear Systems

Directory of Open Access Journals (Sweden)

Chein-Shan Liu

2012-04-01

Full Text Available It is well known that the numerical algorithms of the steepest descent method (SDM, and the conjugate gradient method (CGM are effective for solving well-posed linear systems. However, they are vulnerable to noisy disturbance for solving ill-posed linear systems. We propose the modifications of SDM and CGM, namely the modified steepest descent method (MSDM, and the modified conjugate gradient method (MCGM. The starting point is an invariant manifold defined in terms of a minimum functional and a fictitious time-like variable; however, in the final stage we can derive a purely iterative algorithm including an acceleration parameter. Through the Hopf bifurcation, this parameter indeed plays a major role to switch the situation of slow convergence to a new situation that the functional is stepwisely decreased very fast. Several numerical examples are examined and compared with exact solutions, revealing that the new algorithms of MSDM and MCGM have good computational efficiency and accuracy, even for the highly ill-conditioned linear equations system with a large noise being imposed on the given data.

Modifications of the laser beam coherence inertial confinement fusion plasmas; Modifications des proprietes de coherence des faisceaux laser dans les plasmas de fusion par confinement inertiel

Energy Technology Data Exchange (ETDEWEB)

Grech, M

2007-06-15

Inertial confinement fusion by laser requires smoothed laser beam with well-controlled coherence properties. Such beams are made of many randomly distributed intensity maxima: the so-called speckles. As the laser beam propagates through plasma its temporal and spatial coherence can be reduced. This phenomenon is called plasma induced smoothing. For high laser intensities, instabilities developing independently inside the speckles are responsible for the coherence loss. At lower intensities, only collective effects, involving many speckles, can lead to induced smoothing. This thesis is a theoretical, numerical and experimental study of these mechanisms. Accounting for the partially incoherent behavior of the laser beams requires the use of statistical description of the laser-plasma interaction. A model is developed for the multiple scattering of the laser light on the self-induced density perturbations that is responsible for a spreading of the temporal and spatial spectra of the transmitted light. It also serves as a strong seed for the instability of forward stimulated Brillouin scattering that induces both, angular spreading and red-shift of the transmitted light. A statistical model is developed for this instability. A criterion is obtained that gives a laser power (below the critical power for filamentation) above which the instability growth is important. Numerical simulations with the interaction code PARAX and an experiment performed on the ALISE laser facility confirm the importance of these forward scattering mechanisms in the modification of the laser coherence properties. (author)

Numerical investigation of the late-time Kerr tails

Energy Technology Data Exchange (ETDEWEB)

Racz, Istvan; Toth, Gabor Zs, E-mail: iracz@rmki.kfki.hu, E-mail: tgzs@rmki.kfki.hu [RMKI, H-1121 Budapest, Konkoly Thege Miklos ut 29-33 (Hungary)

2011-10-07

The late-time behavior of a scalar field on fixed Kerr background is examined in a numerical framework incorporating the techniques of conformal compactification and hyperbolic initial value formulation. The applied code is 1+(1+2) as it is based on the use of the spectral method in the angular directions while in the time-radial section fourth order finite differencing, along with the method of lines, is applied. The evolution of various types of stationary and non-stationary pure multipole initial states are investigated. The asymptotic decay rates are determined not only in the domain of outer communication but along the event horizon and at future null infinity as well. The decay rates are found to be different for stationary and non-stationary initial data, and they also depend on the fall off properties of the initial data toward future null infinity. The energy and angular momentum transfers are found to show significantly different behavior in the initial phase of the time evolution. The quasinormal ringing phase and the tail phase are also investigated. In the tail phase, the decay exponents for the energy and angular momentum losses at I{sup +} are found to be smaller than at the horizon which is in accordance with the behavior of the field itself and it means that at late times the energy and angular momentum falling into the black hole become negligible in comparison with the energy and angular momentum radiated toward I{sup +}. The energy and angular momentum balances are used as additional verifications of the reliability of our numerical method.

Numerical investigation of the late-time Kerr tails

International Nuclear Information System (INIS)

Racz, Istvan; Toth, Gabor Zs

2011-01-01

The late-time behavior of a scalar field on fixed Kerr background is examined in a numerical framework incorporating the techniques of conformal compactification and hyperbolic initial value formulation. The applied code is 1+(1+2) as it is based on the use of the spectral method in the angular directions while in the time-radial section fourth order finite differencing, along with the method of lines, is applied. The evolution of various types of stationary and non-stationary pure multipole initial states are investigated. The asymptotic decay rates are determined not only in the domain of outer communication but along the event horizon and at future null infinity as well. The decay rates are found to be different for stationary and non-stationary initial data, and they also depend on the fall off properties of the initial data toward future null infinity. The energy and angular momentum transfers are found to show significantly different behavior in the initial phase of the time evolution. The quasinormal ringing phase and the tail phase are also investigated. In the tail phase, the decay exponents for the energy and angular momentum losses at I + are found to be smaller than at the horizon which is in accordance with the behavior of the field itself and it means that at late times the energy and angular momentum falling into the black hole become negligible in comparison with the energy and angular momentum radiated toward I + . The energy and angular momentum balances are used as additional verifications of the reliability of our numerical method.

Engineerig of structural modifications for operating nuclear plants

International Nuclear Information System (INIS)

Duffy, T.J.; Gazda, P.A.

1983-01-01

The engineering of structural modifications for operating nuclear plants offers many challenges in the areas of scheduling of work, field adjustments, and engineering staff planning. The scheduling of structural modification work for operating nuclear plants is normally closely tied to planned or unplanned outages of the plant. Coordination between the structural engineering effort, the operating plant staff, and the contractor who will be performing the modifications is essential to ensure that all work can be completed within the allotted time. Due to the inaccessibility of areas in operating plants or the short time available to perform the structural engineering in the case of an unscheduled outage, field verification of a design is not always possible prior to initiating the construction of the modification. This requires the structural engineer to work closely with the contractor to promptly resolve problems due to unanticipated interferences or material procurement that may arise during the course of construction. The engineering staff planning for structural modifications at an operating nuclear plant must be flexible enough to permit rapid response to the common 'fire drills', but controlled enough to assure technically correct designs and minimize the expenditure of man-hours and resulting engineering cost. (orig.)

Collision-dominated dust sheaths and voids - observations in micro-gravity experiments and numerical investigation of the force balance relations

International Nuclear Information System (INIS)

Tsytovich, V N; Morfill, G; Konopka, U; Thomas, H

2003-01-01

critical ionization rate and that in the presence of the floating potential walls the central void should be surrounded by two dust sheaths. The necessary condition for this dust structure to be formed is found to be that between the sheaths and the walls there are formed two other wall-void regions. The size of the central void and the distributions of the structure parameters in the two sheaths and in the three voids are computed. The qualitative features of the structure obtained in the numerical computations correspond to those observed. The distributions of the structure parameters in the case of the two dust sheaths are quite different from that for the case of a single central sheath. The possible structures between the electrodes for the case of the presence of dust particles of two different sizes are analysed numerically. It is shown that dust particles with different sizes cannot coexist in equilibrium at the same position and that the regions with different size dust particles must be separated in space. This conclusion is in agreement with most observations performed so far. It is illustrated numerically that for the case where the central void is present the dust particles of larger size form a separate dust sheath which should be located at larger distances from the centre than that for the smaller dust particles. This result also coincides qualitatively with the observations. Computations for the distributions of the parameters in the larger size dust sheath were performed both in the case where the central part is occupied by a dust sheath with smaller size dust particles and for the case where in the central part there exists a dust void surrounded by dust sheaths with smaller size dust particles. The size of the dust void between the sheaths with different size dust particles is calculated and shown to be small as compared to the sheath thickness. In the sheath with larger size dust particles the distribution of dust and plasma parameters differs

Modification of cadmium pigments for colouring of polyolefins

International Nuclear Information System (INIS)

Kalinskaya, T.V.; Livshits, I.M.

1976-01-01

Modification conditions are studied of cadmium pigments, obtained by different methods, aliphatic acids(C 5 , C 8 and C 17 ). It is found, that cadmium pigments can adsorb acids with the number of atoms of carbon not less than 8. Stearic acid adsorption on lemon cadmium pigment taken as an example has shown the efficiency of pigment modification influence on its dispersancy in non-polar medium. Modification of yellow cadmium pigments of stearic acid makes possible to obtain pigment output forms ensuring a good particle distribution during polyolefine colouring

Smaller self-inflating bags produce greater guideline consistent ventilation in simulated cardiopulmonary resuscitation.

Science.gov (United States)

Nehme, Ziad; Boyle, Malcolm J

2009-02-20

Suboptimal bag ventilation in cardiopulmonary resuscitation (CPR) has demonstrated detrimental physiological outcomes for cardiac arrest patients. In light of recent guideline changes for resuscitation, there is a need to identify the efficacy of bag ventilation by prehospital care providers. The objective of this study was to evaluate bag ventilation in relation to operator ability to achieve guideline consistent ventilation rate, tidal volume and minute volume when using two different capacity self-inflating bags in an undergraduate paramedic cohort. An experimental study using a mechanical lung model and a simulated adult cardiac arrest to assess the ventilation ability of third year Monash University undergraduate paramedic students. Participants were instructed to ventilate using 1600 ml and 1000 ml bags for a length of two minutes at the correct rate and tidal volume for a patient undergoing CPR with an advanced airway. Ventilation rate and tidal volume were recorded using an analogue scale with mean values calculated. Ethics approval was granted. Suboptimal ventilation with the use of conventional 1600 ml bag was common, with 77% and 97% of participants unable to achieve guideline consistent ventilation rates and tidal volumes respectively. Reduced levels of suboptimal ventilation arouse from the use of the smaller bag with a 27% reduction in suboptimal tidal volumes (p = 0.015) and 23% reduction in suboptimal minute volumes (p = 0.045). Smaller self-inflating bags reduce the incidence of suboptimal tidal volumes and minute volumes and produce greater guideline consistent results for cardiac arrest patients.

Numerical analysis

CERN Document Server

Scott, L Ridgway

2011-01-01

Computational science is fundamentally changing how technological questions are addressed. The design of aircraft, automobiles, and even racing sailboats is now done by computational simulation. The mathematical foundation of this new approach is numerical analysis, which studies algorithms for computing expressions defined with real numbers. Emphasizing the theory behind the computation, this book provides a rigorous and self-contained introduction to numerical analysis and presents the advanced mathematics that underpin industrial software, including complete details that are missing from most textbooks. Using an inquiry-based learning approach, Numerical Analysis is written in a narrative style, provides historical background, and includes many of the proofs and technical details in exercises. Students will be able to go beyond an elementary understanding of numerical simulation and develop deep insights into the foundations of the subject. They will no longer have to accept the mathematical gaps that ex...

A nerve stimulation method to selectively recruit smaller motor-units in rat skeletal muscle.

Science.gov (United States)

van Bolhuis, A I; Holsheimer, J; Savelberg, H H

2001-05-30

Electrical stimulation of peripheral nerve results in a motor-unit recruitment order opposite to that attained by natural neural control, i.e. from large, fast-fatiguing to progressively smaller, fatigue-resistant motor-units. Yet animal studies involving physiological exercise protocols of low intensity and long duration require minimal fatigue. The present study sought to apply a nerve stimulation method to selectively recruit smaller motor-units in rat skeletal muscle. Two pulse generators were used, independently supplying short supramaximal cathodal stimulating pulses (0.5 ms) and long subthreshold cathodal inactivating pulses (1.5 s) to the sciatic nerve. Propagation of action potentials was selectively blocked in nerve fibres of different diameter by adjusting the strength of the inactivating current. A tensile-testing machine was used to gauge isometric muscle force of the plantaris and both heads of the gastrocnemius muscle. The order of motor-unit recruitment was estimated from twitch characteristics, i.e. peak force and relaxation time. The results showed prolonged relaxation at lower twitch peak forces as the intensity of the inactivating current increased, indicating a reduction of the number of large motor-units to force production. It is shown that the nerve stimulation method described is effective in mimicking physiological muscle control.

tRNA modification profiles of the fast-proliferating cancer cells

Energy Technology Data Exchange (ETDEWEB)

Dong, Chao; Niu, Leilei; Song, Wei [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China); Xiong, Xin; Zhang, Xianhua [Departmentof Pharmacy, Peking University Third Hospital, Peking University, Beijing 100191 (China); Zhang, Zhenxi; Yang, Yi; Yi, Fan [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China); Zhan, Jun; Zhang, Hongquan [Department of Anatomy, Histology and Embryology, Laboratory of Molecular Cell Biology and Tumor Biology, Peking University, Beijing 100191 (China); Yang, Zhenjun; Zhang, Li-He [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China); Zhai, Suodi [Departmentof Pharmacy, Peking University Third Hospital, Peking University, Beijing 100191 (China); Li, Hua, E-mail: huali88@sina.com [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China); Ye, Min, E-mail: yemin@bjmu.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China); Du, Quan, E-mail: quan.du@pku.edu.cn [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Department of Obstetrics and Gynecology, Peking University Third Hospital, Peking University, Beijing 100191 (China)

2016-08-05

Despite the recent progress in RNA modification study, a comprehensive modification profile is still lacking for mammalian cells. Using a quantitative HPLC/MS/MS assay, we present here a study where RNA modifications are examined in term of the major RNA species. With paired slow- and fast-proliferating cell lines, distinct RNA modification profiles are first revealed for diverse RNA species. Compared to mRNAs, increased ribose and nucleobase modifications are shown for the highly-structured tRNAs and rRNAs, lending support to their contribution to the formation of high-order structures. This study also reveals a dynamic tRNA modification profile in the fast-proliferating cells. In addition to cultured cells, this unique tRNA profile has been further confirmed with endometrial cancers and their adjacent normal tissues. Taken together, the results indicate that tRNA is a actively regulated RNA species in the fast-proliferating cancer cells, and suggest that they may play a more active role in biological process than expected. -- Highlights: •RNA modifications were first examined in term of the major RNA species. •A dynamic tRNA modifications was characterized for the fast-proliferating cells. •The unique tRNA profile was confirmed with endometrial cancers and their adjacent normal tissues. •tRNA was predicted as an actively regulated RNA species in the fast-proliferating cancer cells.

tRNA modification profiles of the fast-proliferating cancer cells

International Nuclear Information System (INIS)

Dong, Chao; Niu, Leilei; Song, Wei; Xiong, Xin; Zhang, Xianhua; Zhang, Zhenxi; Yang, Yi; Yi, Fan; Zhan, Jun; Zhang, Hongquan; Yang, Zhenjun; Zhang, Li-He; Zhai, Suodi; Li, Hua; Ye, Min; Du, Quan

2016-01-01

Despite the recent progress in RNA modification study, a comprehensive modification profile is still lacking for mammalian cells. Using a quantitative HPLC/MS/MS assay, we present here a study where RNA modifications are examined in term of the major RNA species. With paired slow- and fast-proliferating cell lines, distinct RNA modification profiles are first revealed for diverse RNA species. Compared to mRNAs, increased ribose and nucleobase modifications are shown for the highly-structured tRNAs and rRNAs, lending support to their contribution to the formation of high-order structures. This study also reveals a dynamic tRNA modification profile in the fast-proliferating cells. In addition to cultured cells, this unique tRNA profile has been further confirmed with endometrial cancers and their adjacent normal tissues. Taken together, the results indicate that tRNA is a actively regulated RNA species in the fast-proliferating cancer cells, and suggest that they may play a more active role in biological process than expected. -- Highlights: •RNA modifications were first examined in term of the major RNA species. •A dynamic tRNA modifications was characterized for the fast-proliferating cells. •The unique tRNA profile was confirmed with endometrial cancers and their adjacent normal tissues. •tRNA was predicted as an actively regulated RNA species in the fast-proliferating cancer cells.

Numerical and Theoretical Investigations Concerning the Continuous-Surface-Curvature Effect in Compressor Blades

Directory of Open Access Journals (Sweden)

Yin Song

2014-12-01

Full Text Available Though the importance of curvature continuity on compressor blade performances has been realized, there are two major questions that need to be solved, i.e., the respective effects of curvature continuity at the leading-edge blend point and the main surface, and the contradiction between the traditional theory and experimental observations in the effect of those novel leading-edge shapes with smaller curvature discontinuity and sharper nose. In this paper, an optimization method to design continuous-curvature blade profiles which deviate little from datum blades is proposed, and numerical and theoretical analysis is carried out to investigate the continuous-curvature effect on blade performances. The results show that the curvature continuity at the leading-edge blend point helps to eliminate the separation bubble, thus improving the blade performance. The main-surface curvature continuity is also beneficial, although its effects are much smaller than those of the blend-point curvature continuity. Furthermore, it is observed that there exist two factors controlling the leading-edge spike, i.e., the curvature discontinuity at the blend point which dominates at small incidences, and the nose curvature which dominates at large incidences. To the authors’ knowledge, such mechanisms have not been reported before, and they can help to solve the sharp-leading-edge paradox.

Body modification and substance use in adolescents: is there a link?

Science.gov (United States)

Brooks, Traci L; Woods, Elizabeth R; Knight, John R; Shrier, Lydia A

2003-01-01

To describe the characteristics of body modification among adolescents and to determine whether adolescents who engage in body modification are more likely to screen positive for alcohol and other drug problems than those who do not. Adolescents aged 14 to 18 years presenting to an urban adolescent clinic for routine health care completed a questionnaire about body modification and a substance use assessment battery that included the 17-item Problem Oriented Screening Instrument for Teenagers Alcohol/Drug Use and Abuse Scale (POSIT-ADS). Body modification was defined as piercings (other than one pair of bilateral earlobe piercings in females), tattoos, scarification, and branding. Problem substance use was defined as a POSIT-ADS score > or =1. Data were analyzed using logistic regression to determine whether the presence of body modification was an independent predictor of problem substance use. The 210 participants had a mean (+/- SD) age of 16.0 (+/- 1.4) years and 63% were female. One hundred adolescents (48%) reported at least one body modification; girls were more likely than boys to have body modification (59% vs. 28%, p branding; 21 (10%) had more than one type of body modification. These were in a variety of locations, most commonly the ear and the nose (piercings) or the extremities (tattoos). One-third of the sample (33%) screened positive for problem substance use on the POSIT-ADS questionnaire. Controlling for age, adolescents with body modification had 3.1 times greater odds of problem substance use than those without body modification (95% CI 1.7, 5.8). Body modification was associated with self-reported problem alcohol and other drug use among middle adolescents presenting for primary care. More research is needed to determine the clinical and sociocultural significance of body modification and its relationship to substance use in this population. Copyright Society for Adolescent Medicine, 2003

Participation of smaller size renewable generation in the electricity market trade in UK: Analyses and approaches

DEFF Research Database (Denmark)

Romanovsky, G.; Xydis, G.; Mutale, J.

2011-01-01

a number of specific historical, technical and economic reasons that significantly influenced the ability of the smaller size RES/DG to participate in the electricity market and in provision of balancing services in accordance with the UK National Grid requirements. This paper discusses some perspectives...

Numerical evaluation of methods for computing tomographic projections

International Nuclear Information System (INIS)

Zhuang, W.; Gopal, S.S.; Hebert, T.J.

1994-01-01

Methods for computing forward/back projections of 2-D images can be viewed as numerical integration techniques. The accuracy of any ray-driven projection method can be improved by increasing the number of ray-paths that are traced per projection bin. The accuracy of pixel-driven projection methods can be increased by dividing each pixel into a number of smaller sub-pixels and projecting each sub-pixel. The authors compared four competing methods of computing forward/back projections: bilinear interpolation, ray-tracing, pixel-driven projection based upon sub-pixels, and pixel-driven projection based upon circular, rather than square, pixels. This latter method is equivalent to a fast, bi-nonlinear interpolation. These methods and the choice of the number of ray-paths per projection bin or the number of sub-pixels per pixel present a trade-off between computational speed and accuracy. To solve the problem of assessing backprojection accuracy, the analytical inverse Fourier transform of the ramp filtered forward projection of the Shepp and Logan head phantom is derived

Numerical approach for quantification of self wastage phenomena in sodium-cooled fast reactor

International Nuclear Information System (INIS)

Jang, Sung Hyun; Takata, Takashi; Yamaguchi, Akira; Uchbori, Akihiro; Kurihara, Akikazu; Ohshima, Hiroyuki

2015-01-01

Sodium-cooled fast breeder reactors use liquid sodium as a moderator and coolant to transfer heat from the reactor core. The main hazard associated with sodium is its rapid reaction with water. Sodium-water reaction (SWR) takes place when water or vapor leak into the sodium side through a crack on a heat-transfer tube in a steam generator. If the SWR continues for some time, the SWR will damage the surface of the defective area, causing it to enlarge. This self-enlargement of the crack is called 'self-wastage phenomena'. A stepwise numerical evaluation model of the self-wastage phenomena was devised using a computational code of multicomponent multiphase flow involving a sodium-water chemical reaction: sodium-water reaction analysis physics of interdisciplinary multiphase flow (SERAPHIM). The temperature of gas mixture and the concentration of NaOH at the surface of the tube wall are obtained by a numerical calculation using SERAPHIM. Averaged thermophysical properties are used to assess the local wastage depth at the tube surface. By reflecting the wastage depth to the computational grid, the self-wastage phenomena are evaluated. A two-dimensional benchmark analysis of an SWAT (Sodium-Water reAction Test rig) experiment is carried out to evaluate the feasibility of the numerical model. Numerical results show that the geometry and scale of enlarged cracks show good agreement with the experimental result. Enlarged cracks appear to taper inward to a significantly smaller opening on the inside of the tube wall. The enlarged outer diameter of the crack is 4.72 mm, which shows good agreement with the experimental data (4.96 mm)

Numerical approach for quantification of self wastage phenomena in sodium-cooled fast reactor

Energy Technology Data Exchange (ETDEWEB)

Jang, Sung Hyun; Takata, Takashi [Graduate School of Engineering, Osaka University, Osaka (Japan); Yamaguchi, Akira [Graduate School of Engineering, The University of Tokyo, Ibaraki (Japan); Uchbori, Akihiro; Kurihara, Akikazu; Ohshima, Hiroyuki [Japan Atomic Energy Agency, Ibaraki (Japan)

2015-10-15

Sodium-cooled fast breeder reactors use liquid sodium as a moderator and coolant to transfer heat from the reactor core. The main hazard associated with sodium is its rapid reaction with water. Sodium-water reaction (SWR) takes place when water or vapor leak into the sodium side through a crack on a heat-transfer tube in a steam generator. If the SWR continues for some time, the SWR will damage the surface of the defective area, causing it to enlarge. This self-enlargement of the crack is called 'self-wastage phenomena'. A stepwise numerical evaluation model of the self-wastage phenomena was devised using a computational code of multicomponent multiphase flow involving a sodium-water chemical reaction: sodium-water reaction analysis physics of interdisciplinary multiphase flow (SERAPHIM). The temperature of gas mixture and the concentration of NaOH at the surface of the tube wall are obtained by a numerical calculation using SERAPHIM. Averaged thermophysical properties are used to assess the local wastage depth at the tube surface. By reflecting the wastage depth to the computational grid, the self-wastage phenomena are evaluated. A two-dimensional benchmark analysis of an SWAT (Sodium-Water reAction Test rig) experiment is carried out to evaluate the feasibility of the numerical model. Numerical results show that the geometry and scale of enlarged cracks show good agreement with the experimental result. Enlarged cracks appear to taper inward to a significantly smaller opening on the inside of the tube wall. The enlarged outer diameter of the crack is 4.72 mm, which shows good agreement with the experimental data (4.96 mm)

Nanofibrillated Cellulose Surface Modification: A Review

Directory of Open Access Journals (Sweden)

Julien Bras

2013-05-01

Full Text Available Interest in nanofibrillated cellulose (NFC has increased notably over recent decades. This bio-based nanomaterial has been used essentially in bionanocomposites or in paper thanks to its high mechanical reinforcement ability or barrier property respectively. Its nano-scale dimensions and its capacity to form a strong entangled nanoporous network have encouraged the emergence of new high-value applications. It is worth noting that chemical surface modification of this material can be a key factor to achieve a better compatibility with matrices. In order to increase the compatibility in different matrices or to add new functions, surface chemical modification of NFC appears to be the prior choice to conserve its intrinsic nanofibre properties. In this review, the authors have proposed for the first time an overview of all chemical grafting strategies used to date on nanofibrillated cellulose with focus on surface modification such as physical adsorption, molecular grafting or polymer grafting.

Quality planning for major plant design modifications

International Nuclear Information System (INIS)

Dulee, R.J.

1988-01-01

This paper reviews the approach and activities undertaken by Public Service Electric and Gas Company's (PSE and G's) nuclear quality assurance (QA) department to support major plant design modifications conducted during refueling outages at Salem Generating Station. It includes the planning and implementation of quality plans developed to provide both QA and quality control (QC) coverage of modification performed by contracted service organizations

Modification of the perturbative QCD towards confinement

International Nuclear Information System (INIS)

Arodz, H.

1981-01-01

Modification of the low momentum behaviour of the perturbative SU(2) gauge theory is proposed. The modification is closely related (although not equivalent) to a nonstandard choice of boundary condition for the Euclidean 2-point gluonic Green function. In the resulting theory already single graphs lead to the confining potential between heavy, static quarks, V(r) = ar 2 for r → infinity. (author)

Numerical and experimental investigations on the time dependent behavior of a salt dome with a high-level waste repository

International Nuclear Information System (INIS)

Prij, J.; Vons, L.H.

1984-01-01

Results are presented of in-situ measurements, performed in a 300 m deep dry-drilled borehole, in the ASSE-mine. Convergence measurements at ambient as well as elevated temperatures and pressure measurements at elevated temperatures are discussed. Creep equations derived from these experiments are used for the numerical analysis of the time dependent behavior of a salt dome with a HLW repository. The analyses show that the total stresses in the salt remain compressive with deviatoric components smaller than 3 MPa. 9 references, 6 figures, 1 table

Mechanisms of behavior modification in clinical behavioral medicine in China.

Science.gov (United States)

Yang, Zhiyin; Su, Zhonghua; Ji, Feng; Zhu, Min; Bai, Bo

2014-08-01

Behavior modification, as the core of clinical behavioral medicine, is often used in clinical settings. We seek to summarize behavior modification techniques that are commonly used in clinical practice of behavioral medicine in China and discuss possible biobehavioral mechanisms. We reviewed common behavior modification techniques in clinical settings in China, and we reviewed studies that explored possible biobehavioral mechanisms. Commonly used clinical approaches of behavior modification in China include behavior therapy, cognitive therapy, cognitive-behavioral therapy, health education, behavior management, behavioral relaxation training, stress management intervention, desensitization therapy, biofeedback therapy, and music therapy. These techniques have been applied in the clinical treatment of a variety of diseases, such as chronic diseases, psychosomatic diseases, and psychological disorders. The biobehavioral mechanisms of these techniques involve the autonomic nervous system, neuroendocrine system, neurobiochemistry, and neuroplasticity. Behavior modification techniques are commonly used in the treatment of a variety of somatic and psychological disorders in China. Multiple biobehavioral mechanisms are involved in successful behavior modification.

Pnp gene modification for improved xylose utilization in Zymomonas

Science.gov (United States)

Caimi, Perry G G; Qi, Min; Tao, Luan; Viitanen, Paul V; Yang, Jianjun

2014-12-16

The endogenous pnp gene encoding polynucleotide phosphorylase in the Zymomonas genome was identified as a target for modification to provide improved xylose utilizing cells for ethanol production. The cells are in addition genetically modified to have increased expression of ribose-5-phosphate isomerase (RPI) activity, as compared to cells without this genetic modification, and are not limited in xylose isomerase activity in the absence of the pnp modification.

Comparison of several innovative bridge cable surface modifications

DEFF Research Database (Denmark)

Kleissl, Kenneth; Georgakis, Christos T.

Over the last two decades, several bridge cable manufacturers have introduced surface modifications on the high-density polyethylene (HDPE) sheathing that is installed for the protection of inner cable strands or wires. The modifications are based on research undertaken predominantly in Europe...

Surface modification of silica particles with gold nanoparticles as an augmentation of gold nanoparticle mediated laser perforation

Science.gov (United States)

Kalies, Stefan; Gentemann, Lara; Schomaker, Markus; Heinemann, Dag; Ripken, Tammo; Meyer, Heiko

2014-01-01

Gold nanoparticle mediated (GNOME) laser transfection/perforation fulfills the demands of a reliable transfection technique. It provides efficient delivery and has a negligible impact on cell viability. Furthermore, it reaches high-throughput applicability. However, currently only large gold particles (> 80 nm) allow successful GNOME laser perforation, probably due to insufficient sedimentation of smaller gold nanoparticles. The objective of this study is to determine whether this aspect can be addressed by a modification of silica particles with gold nanoparticles. Throughout the analysis, we show that after the attachment of gold nanoparticles to silica particles, comparable or better efficiencies to GNOME laser perforation are reached. In combination with 1 µm silica particles, we report laser perforation with gold nanoparticles with sizes down to 4 nm. Therefore, our investigations have great importance for the future research in and the fields of laser transfection combined with plasmonics. PMID:25136494

[New approaches in pharmacology: numerical modelling and simulation].

Science.gov (United States)

Boissel, Jean-Pierre; Cucherat, Michel; Nony, Patrice; Dronne, Marie-Aimée; Kassaï, Behrouz; Chabaud, Sylvie

2005-01-01

The complexity of pathophysiological mechanisms is beyond the capabilities of traditional approaches. Many of the decision-making problems in public health, such as initiating mass screening, are complex. Progress in genomics and proteomics, and the resulting extraordinary increase in knowledge with regard to interactions between gene expression, the environment and behaviour, the customisation of risk factors and the need to combine therapies that individually have minimal though well documented efficacy, has led doctors to raise new questions: how to optimise choice and the application of therapeutic strategies at the individual rather than the group level, while taking into account all the available evidence? This is essentially a problem of complexity with dimensions similar to the previous ones: multiple parameters with nonlinear relationships between them, varying time scales that cannot be ignored etc. Numerical modelling and simulation (in silico investigations) have the potential to meet these challenges. Such approaches are considered in drug innovation and development. They require a multidisciplinary approach, and this will involve modification of the way research in pharmacology is conducted.

Experimental and numerical investigation of sprays in two stroke diesel Engines

DEFF Research Database (Denmark)

Dam, Bjarke Skovgård

2007-01-01

. The latter is the subject of this dissertation. The theory and experimental findings on diesel sprays are investigated, including e.g. spray parameters and droplet break up. It is found that no complete theory is yet present and large challenges lie ahead. Generally, there is fairly good consensus on which......The control of the injected spray is important when optimizing performance and reducing emissions from diesel engines. The research community has conducted extensive research especially on smaller four stroke engines, but so far only little has been done on sprays in large two stroke engines...... have different scales and other designs than those used in the literature, so extending results from the literature will require experiments on this particular type of setup. Numerical investigations of diesel sprays are performed using the Eulerian/Lagrangian engine CFD code Kiva. In agreement...

Modification of bauxite residue generated in the Bayer process by thermal treatment

International Nuclear Information System (INIS)

Garcia, M.C.S.; Pileggi, R.G.; John, V.M.; Gouvea, D.

2011-01-01

Red mud is the waste generated by the aluminum industry, and as other industrial waste presents complex characteristics with numerous difficulties in handling, as well as being a hazardous material due to its low granulometry, alkalinity and high amount generated. It is a waste with potential high polluter, aggravated by the generally adopted vulnerable disposal form, being this, the disposition of the residue in ponds designed for this purpose. The study and development of sustainable alternatives for the use of sludge, treated as raw materials from other processes, are important tendency and necessary trends in the global context of environmental preservation. This work deals with the thermal treatment as a method of modification of the characteristics of the residue, suggesting the reduction of alkalinity together with the lower leaching of alkaline ions. This approach can be a more reliable and environmentally safe disposal alternatives

Radiation modification of glass fiber - reinforced plastics

International Nuclear Information System (INIS)

Allayarov, S.R.; Smirnov, Yu.N.; Lesnichaya, V.A.; Ol'khov, Yu.A.; Belov, G.P.; Dixon, D.A.; Kispert, L.D.

2007-01-01

Modification of glass fiber - reinforced plastics (GFRPs) by gamma-irradiation has been researched to receipt of polymeric composite materials. They were produced by the film - technology method and the cheapest thermoplastics (polythene, polyamide were used as polymeric matrixes for their manufacture. GFRPs were irradiated with Co 60 gamma-rays from a Gammatok-100 source in air and in vacuum. The strength properties of GFRPs and initial polymeric matrixes were investigated before and after radiolysis. Molecular - topological structure of the polymeric matrixes were tested by the method of thermomechanical spectroscopy. The strength properties of GFRPs depend on a parity of speeds of structural (physical) and chemical modification of the polymeric matrixes. These two processes proceed simultaneously. The structural modification includes physical transformation of polymers at preservation of their chemical structure. Covalent bonds between various macromolecules or between macromolecules and surface of fiberglasses are formed at the chemical modification of polymeric matrixes induced by radiation. Action of ionizing radiation on the used polymeric matrix results to its structurization (polythene) or to destruction (polyamide). Increasing of durability of GFRPs containing polythene is caused by formation of the optimum molecular topological structure of the polymeric matrix. (authors)

O-GlcNAc modification: why so intimately associated with phosphorylation?

Directory of Open Access Journals (Sweden)

Ande Sudharsana R

2011-01-01

Full Text Available Abstract Post-translational modification of proteins at serine and threonine side chains by β-N-acetylglucosamine (O-GlcNAc mediated by the enzyme β-N-acetylglucosamine transferase has been emerging as a fundamental regulatory mechanism encompassing a wide range of proteins involved in cell division, metabolism, transcription and cell signaling. Furthermore, an extensive interplay between O-GlcNAc modification and serine/threonine phosphorylation in a variety of proteins has been reported to exist. However, our understanding of the regulatory mechanisms involved in O-GlcNAc modification and its interplay with serine/threonine phosphorylation in proteins is still elusive. Recent success in the mapping of O-GlcNAc modification sites in proteins as a result of technological advancement in mass spectrometry have revealed two important clues which may be inherently connected to the regulation of O-GlcNAc modification and its interplay with phosphorylation in proteins. First, almost all O-GlcNAc modified proteins are known phospho proteins. Second, the prevalence of tyrosine phosphorylation among O-GlcNAc modified proteins is exceptionally higher (~68% than its normal occurrence (~2% alone. We hypothesize that phosphorylation may be a requisite for O-GlcNAc modification and tyrosine phosphorylation plays a role in the interplay between O-GlcNAc modification and serine/threonine phosphorylation in proteins. In other words, the interplay between O-GlcNAc modification and phosphorylation is not limited to serine/threonine phosphorylation but also includes tyrosine phosphorylation. Our hypothesis provides an opportunity to understand the underlying mechanism involved in O-GlcNAc modification and its interplay with serine/threonine phosphorylation in proteins. Furthermore, implication of our hypothesis extends to tyrosine kinase signaling.

Femtosecond laser modification of an array of vertically aligned carbon nanotubes intercalated with Fe phase nanoparticles.

Science.gov (United States)

Labunov, Vladimir; Prudnikava, Alena; Bushuk, Serguei; Filatov, Serguei; Shulitski, Boris; Tay, Beng Kang; Shaman, Yury; Basaev, Alexander

2013-09-03

Femtosecond lasers (FSL) are playing an increasingly important role in materials research, characterization, and modification. Due to an extremely short pulse width, interactions of FSL irradiation with solid surfaces attract special interest, and a number of unusual phenomena resulted in the formation of new materials are expected. Here, we report on a new nanostructure observed after the interaction of FSL irradiation with arrays of vertically aligned carbon nanotubes (CNTs) intercalated with iron phase catalyst nanoparticles. It was revealed that the FSL laser ablation transforms the topmost layer of CNT array into iron phase nanospheres (40 to 680 nm in diameter) located at the tip of the CNT bundles of conical shape. Besides, the smaller nanospheres (10 to 30 nm in diameter) are found to be beaded at the sides of these bundles. Some of the larger nanospheres are encapsulated into carbon shells, which sometime are found to contain CNTs. The mechanism of creation of such nanostructures is proposed.

Shape Modification and Size Classification of Microcrystalline Graphite Powder as Anode Material for Lithium-Ion Batteries

Science.gov (United States)

Wang, Cong; Gai, Guosheng; Yang, Yufen

2018-03-01

Natural microcrystalline graphite (MCG) composed of many crystallites is a promising new anode material for lithium-ion batteries (LiBs) and has received considerable attention from researchers. MCG with narrow particle size distribution and high sphericity exhibits excellent electrochemical performance. A nonaddition process to prepare natural MCG as a high-performance LiB anode material is described. First, raw MCG was broken into smaller particles using a pulverization system. Then, the particles were modified into near-spherical shape using a particle shape modification system. Finally, the particle size distribution was narrowed using a centrifugal rotor classification system. The products with uniform hemispherical shape and narrow size distribution had mean particle size of approximately 9 μm, 10 μm, 15 μm, and 20 μm. Additionally, the innovative pilot experimental process increased the product yield of the raw material. Finally, the electrochemical performance of the prepared MCG was tested, revealing high reversible capacity and good cyclability.

14 CFR 151.99 - Modifications of programming standards.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Modifications of programming standards. 151... (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.99 Modifications of programming standards. The Director, Airports, Service, or the Regional Director concerned may, on individual...

Treating Retentive Encopresis: Dietary Modification and Behavioral Techniques.

Science.gov (United States)

Nabors, Laura; Morgan, Sam B.

1995-01-01

A home-based contingency management program, consisting of diet modification, laxatives, correction for soiling accidents, stimulus control training, and positive reinforcement, was implemented for treatment of a 4-year-old encopretic male. The findings provide evidence supporting the effectiveness of dietary modification combined with behavior…

Modifications to the NRAD reactor (1977 to present)

International Nuclear Information System (INIS)

Weeks, A.A.; Pruett, D.P.; Heidel, C.C.

1986-01-01

The NRAD facility utilizes a 250-kW TRIGA reactor and is completely dedicated to neutron radiography and the development of radiography techniques. Criticality was first achieved at the NRAD reactor in October 1977. Since that time, a number of modifications have been implemented to improve operational efficiency and radiography production. The modifications to the NRAD reactor are categorized as either 'operational improvements', which have increased operational efficiency and reliability, or as 'production improvements', which have reduced the number of unscheduled shutdowns due to instrument malfunctions or mechanical failures. A brief synopsis of the significant reactor modifications in both categories is presented

POSTRANSLATIONAL MODIFICATIONS OF P53: UPSTREAM SIGNALING PATHWAYS.

Energy Technology Data Exchange (ETDEWEB)

ANDERSON,C.W.APPELLA,E.

2003-10-23

The p53 tumor suppressor is a tetrameric transcription factor that is posttranslational modified at >20 different sites by phosphorylation, acetylation, or sumoylation in response to various cellular stress conditions. Specific posttranslational modifications, or groups of modifications, that result from the activation of different stress-induced signaling pathways are thought to modulate p53 activity to regulate cell fate by inducing cell cycle arrest, apoptosis, or cellular senescence. Here we review recent progress in characterizing the upstream signaling pathways whose activation in response to various genotoxic and non-genotoxic stresses result in p53 posttranslational modifications.

Effects of surface modification on the critical behaviour in multiple-surface-layer ferroelectric thin films

International Nuclear Information System (INIS)

Lu, Z X

2013-01-01

Using the usual mean-field theory approximation, the critical behaviour (i.e. the Curie temperature T c and the critical surface transverse field Ω sc ) in a multiple-surface-layer ferroelectric thin film is studied on the basis of the spin- 1/2 transverse Ising model. The dependence of the Curie temperature T c on the surface transverse field Ω s and the surface layer number N s are discussed in detail. Meanwhile the dependence of the critical surface transverse field Ω sc on the surface layer number N s is also examined. The numerical results indicate that the critical behaviour of ferroelectric thin films is obviously affected by modifications of the surface transverse field Ω s and surface layer number N s .

Numerical Optimization in Microfluidics

DEFF Research Database (Denmark)

Jensen, Kristian Ejlebjærg

2017-01-01

Numerical modelling can illuminate the working mechanism and limitations of microfluidic devices. Such insights are useful in their own right, but one can take advantage of numerical modelling in a systematic way using numerical optimization. In this chapter we will discuss when and how numerical...... optimization is best used....

The Role of Protein Modifications of T-Bet in Cytokine Production and Differentiation of T Helper Cells

Directory of Open Access Journals (Sweden)

Sera Oh

2014-01-01

Full Text Available T-Bet (T-box protein expressed in T cells, also called as TBX21 was originally cloned as a key transcription factor involved in the commitment of T helper (Th cells to the Th1 lineage. T-Bet directly activates IFN-γ gene transcription and enhances development of Th1 cells. T-Bet simultaneously modulates IL-2 and Th2 cytokines in an IFN-γ-independent manner, resulting in an attenuation of Th2 cell development. Numerous studies have demonstrated that T-bet plays multiple roles in many subtypes of immune cells, including B cell, dendritic cells, natural killer (NK cells, NK T cells, and innate lymphoid cells. Therefore, T-bet is crucial for the development and coordination of both innate and adaptive immune responses. To fulfill these multiple roles, T-bet undergoes several posttranslational protein modifications, such as phosphorylation at tyrosine, serine, and threonine residues, and ubiquitination at lysine residues, which affect lineage commitment during Th cell differentiation. This review presents a current overview of the progress made in understanding the roles of various types of T-bet protein modifications in the regulation of cytokine production during Th cell differentiation.

Hindi Numerals.

Science.gov (United States)

Bright, William

In most languages encountered by linguists, the numerals, considered as a paradigmatic set, constitute a morpho-syntactic problem of only moderate complexity. The Indo-Aryan language family of North India, however, presents a curious contrast. The relatively regular numeral system of Sanskrit, as it has developed historically into the modern…

Functional Modification of Thioether Groups in Peptides, Polypeptides, and Proteins.

Science.gov (United States)

Deming, Timothy J

2017-03-15

Recent developments in the modification of methionine and other thioether-containing residues in peptides, polypeptides, and proteins are reviewed. Properties and potential applications of the resulting functionalized products are also discussed. While much of this work is focused on natural Met residues, modifications at other side-chain residues have also emerged as new thioether-containing amino acids have been incorporated into peptidic materials. Functional modification of thioether-containing amino acids has many advantages and is a complementary methodology to the widely utilized methods for modification at cysteine residues.

Methods of numerical relativity

International Nuclear Information System (INIS)

Piran, T.

1983-01-01

Numerical Relativity is an alternative to analytical methods for obtaining solutions for Einstein equations. Numerical methods are particularly useful for studying generation of gravitational radiation by potential strong sources. The author reviews the analytical background, the numerical analysis aspects and techniques and some of the difficulties involved in numerical relativity. (Auth.)

Kicking velocity and effect on match performance when using a smaller, lighter ball in women's football

DEFF Research Database (Denmark)

Andersen, Thomas B.; Krustrup, Peter; Bendiksen, Mads

2016-01-01

The present study evaluated the effect of a smaller, lighter ball on kicking speed and technical-tactical and physical match performance in high-level adult female footballers. In the laboratory test setting, the peak ball velocity was 6% higher with the new ball (NB) than the standard ball (SB...

Biofouling Control in Spiral-Wound Membrane Systems: Impact of Feed Spacer Modification and Biocides

KAUST Repository

Siddiqui, Amber

2016-12-01

High-quality drinking water can be produced with membrane-based filtration processes like reverse osmosis and nanofiltration. One of the major problems in these membrane systems is biofouling that reduces the membrane performance, increasing operational costs. Current biofouling control strategies such as pre-treatment, membrane modification, and chemical cleaning are not sufficient in all cases. Feed spacers are thin (0.8 mm), complex geometry meshes that separate membranes in a module. The main objective of this research was to evaluate whether feed spacer modification is a suitable strategy to control biofouling. Membrane fouling simulator studies with six feed spacers showed differences in biofouled spacer performance, concluding that (i) spacer geometry influences biofouling impact and (ii) biofouling studies are essential for evaluation of spacer biofouling impact. Computed tomography (CT) was found as a suitable technique to obtain three-dimensional (3D) measurements of spacers, enabling more representative mathematical modeling of hydraulic behavior of spacers in membrane systems. A strategy for developing, characterizing, and testing of spacers by numerical modeling, 3D printing of spacers and experimental membrane fouling simulator studies was developed. The combination of modeling and experimental testing of 3D printed spacers is a promising strategy to develop advanced spacers aiming to reduce the impact of biofilm formation on membrane performance and to improve the cleanability of spiral-wound membrane systems.

X-ray studies on piroxicam modifications

International Nuclear Information System (INIS)

Reck, G.; Bannier, G.; Hoehne, E.

1988-01-01

The anti-inflammatory drug piroxicam, 4-hydroxy-2-methyl-N-(2-pyridyl)2H-1,2-benzothiazine-3-car-boxamide-1,1-dioxide, crystallizes in three different forms, two anhydrates and one monohydrate. Crystal structure analyses of the monohydrate and one of the anhydrate were carried out by Bordner et al. and Kojic-Prodic et al., respectively. The results of the analysis of the third piroxicam modification and of an independently performed structure determination of the monohydrate are reported. Molecular structures and hydrogen bonding of all modifications are discussed. (author)

"What time is my next meal?" delay-discounting individuals choose smaller portions under conditions of uncertainty.

Science.gov (United States)

Zimmerman, Annie R; Ferriday, Danielle; Davies, Sarah R; Martin, Ashley A; Rogers, Peter J; Mason, Alice; Brunstrom, Jeffrey M

2017-09-01

'Dietary' delay discounting is typically framed as a trade-off between immediate rewards and long-term health concerns. Our contention is that prospective thinking also occurs over shorter periods, and is engaged to select portion sizes based on the interval between meals (inter-meal interval; IMI). We sought to assess the extent to which the length of an IMI influences portion-size selection. We predicted that delay discounters would show 'IMI insensitivity' (relative lack of concern about hunger or fullness between meals). In particular, we were interested in participants' sensitivity to an uncertain IMI. We hypothesized that when meal times were uncertain, delay discounters would be less responsive and select smaller portion sizes. Participants (N = 90) selected portion sizes for lunch. In different trials, they were told to expect dinner at 5pm, 9pm, and either 5pm or 9pm (uncertain IMI). Individual differences in future-orientation were measured using a monetary delay-discounting task. Participants chose larger portions when the IMI was longer (p relationship between BMI and smaller portion selection in uncertainty (p < 0.05). This is the first study to report an association between delay discounting and IMI insensitivity. We reason that delay discounters selected smaller portions because they were less sensitive to the uncertain IMI, and overlooked concerns about potential future hunger. These findings are important because they illustrate that differences in discounting are expressed in short-term portion-size decisions and suggest that IMI insensitivity increases when meal timings are uncertain. Further research is needed to confirm whether these findings generalise to other populations. Copyright © 2017. Published by Elsevier Ltd.

Smaller self-inflating bags produce greater guideline consistent ventilation in simulated cardiopulmonary resuscitation

Directory of Open Access Journals (Sweden)

Boyle Malcolm J

2009-02-01

Full Text Available Abstract Background Suboptimal bag ventilation in cardiopulmonary resuscitation (CPR has demonstrated detrimental physiological outcomes for cardiac arrest patients. In light of recent guideline changes for resuscitation, there is a need to identify the efficacy of bag ventilation by prehospital care providers. The objective of this study was to evaluate bag ventilation in relation to operator ability to achieve guideline consistent ventilation rate, tidal volume and minute volume when using two different capacity self-inflating bags in an undergraduate paramedic cohort. Methods An experimental study using a mechanical lung model and a simulated adult cardiac arrest to assess the ventilation ability of third year Monash University undergraduate paramedic students. Participants were instructed to ventilate using 1600 ml and 1000 ml bags for a length of two minutes at the correct rate and tidal volume for a patient undergoing CPR with an advanced airway. Ventilation rate and tidal volume were recorded using an analogue scale with mean values calculated. Ethics approval was granted. Results Suboptimal ventilation with the use of conventional 1600 ml bag was common, with 77% and 97% of participants unable to achieve guideline consistent ventilation rates and tidal volumes respectively. Reduced levels of suboptimal ventilation arouse from the use of the smaller bag with a 27% reduction in suboptimal tidal volumes (p = 0.015 and 23% reduction in suboptimal minute volumes (p = 0.045. Conclusion Smaller self-inflating bags reduce the incidence of suboptimal tidal volumes and minute volumes and produce greater guideline consistent results for cardiac arrest patients.

Stress wave propagation in thin long-fiber carbon/epoxy composite panel. Numerical and experimental solutions

Directory of Open Access Journals (Sweden)

Kroupa T.

2007-10-01

Full Text Available The article deals with experimental and numerical analysis of stress wave propagation in a thin long fiber carbon/epoxy composite material. Experiments were performed on in-plane loaded square composite panels with dimensions 501mm x 501mm x 2:2 mm. The panels have several fiber orientations (0°, 30°, 60° and 90° measured from the loaded edge. They were loaded by in-plane impact of steel sphere. The impact area was on the edge, exactly 150mm from top left corners corner of the panels. The loading force was approximated by atime dependent function. Its shape was obtained from three dimensional contact analysis, which was performed on smaller area of panel. The function was used in further plane stress analysis of the whole panels. The comparison of the numerical and experimental results was executed. An attempt at determination of velocity of propagation of Rayleigh waves on the loaded edge was performed and the results are discussed in the paper. Further directions of the research are proposed.

Application of Atmospheric Dielectric Barrier Discharge Plasma for Polyethylene Powder Modification

International Nuclear Information System (INIS)

Pichal, J.; Aubrecht, L.; Pichal, J.; Hladik, J.; Spatenka, P.; Spatenka, P.

2006-01-01

Paper refers about a novel plasma reactor exploiting the dielectric barrier discharge (DBD) burning in air at atmospheric pressure by ambient temperature and its usability tests. Test modifications were performed with the high density polyethylene powder Borealis CB 9155-01. Modification effect was evaluated by means of dynamic capillarity rising measurements. Tests proved significant powder capillarity changes. The existence of powder surface changes was also confirmed by ESCA tests. Modification aging effect was remarkably small, hence modification effect is very time stable. In comparison with other in literature described apparatus used for this purpose the plasma reactor is of a simple construction and needs no vacuum equipment. Its operation costs are low. Described plasma modification method seems to be an appropriate method for plasma modification of polyethylene powder on the industrial scale

The effect of halloysite modification combined with in situ matrix modifications on the structure and properties of polypropylene/halloysite nanocomposites

Directory of Open Access Journals (Sweden)

V. Khunova

2013-05-01

Full Text Available The effect of various modifications/intercalations of halloysite and the combination of these modifications with in situ PP matrix modification was investigated with respect to the structure and properties of the polypropylene/halloysite nanocomposites. Hexadecyl-tri-methyl-ammonium-bromide (HEDA, 3-aminopropyltrimethoxysilane and urea were used as the intercalators/modifiers. The best intercalation was found for urea, although an unexpected insignificant impact on the mechanical properties also resulted as a consequence of the urea polarity and the significant decrease in PP crystallinity. However, the simultaneous application of 4,4!-diphenylmethylene dimaleinimide (DBMI brought about an increase in the mechanical behavior by increasing the halloysite/PP affinity as a result of in situ matrix modification. This effect was further supported by coupling between the PP and halloysite (HNT in the system containing urea-intercalated HNT. This can be explained by the occurrence of a urea-supported reaction between the imide ring of DBMI and the OH groups of the HNT, which resulted in the best mechanical behaviors achieved in this study.

Smaller Anterior Cruciate Ligament Diameter Is a Predictor of Subjects Prone to Ligament Injuries: An Ultrasound Study

Directory of Open Access Journals (Sweden)

Parag Suresh Mahajan

2015-01-01

Full Text Available Purpose. To test if diameter of normal anterior cruciate ligament (ACL can be measured by ultrasound (US, to see if there is a relationship between smaller ACL diameter and ACL injury, and to assess agreement between radiologists in measuring ACL diameter in cases and matched controls. Materials and Methods. In this ethics committee-approved study, maximum diameter of ACL near tibial insertion site was measured by static and dynamic US study in 25 normal contralateral knees of subjects who suffered noncontact ACL injury and in 25 matched control subjects. Results. ACL was visualized as a thick linear hypoechoic band inserted approximately 11 mm caudal to the tibial plateau and the intercondylar eminence. Maximum diameter of contralateral ACL near tibial insertion site among injured subjects was significantly smaller than in noninjured subjects (0.62 ± 0.07 cm versus 0.81 ± 0.06 cm; P<0.0001. In the regression analysis, the diameter of ACL near tibial insertion site was found significantly proportional to body weight and not significantly associated to height, gender, and age. Conclusion. Diameter of normal ACL near tibial insertion site can be measured by US and the maximum diameter is significantly smaller among subjects with noncontact ACL injury. US is a promising modality that can be used as an excellent screening test to detect subjects especially aspiring athletes prone to ACL injury. Very strong agreement was observed between radiologists in measuring ACL diameter.

Analysis of selected problems of biomass combustion process in batch boilers - experimental and numerical approach

Science.gov (United States)

Szubel, Mateusz

2016-03-01

It is possible to list numerous groups of heating units that are used in households, such as boilers, stoves and units used as supporting heat sources, namely fireplaces. In each case, however, the same operational problems may be evoked [1]. To understand the causes of energy losses in a boiler system, a proper definition of significant elements of the unit's heat balance is necessary. In the group of energy losses, the flue gas loss and the incomplete combustion loss are the most significant factors. The problem with the loss resulting from incomplete combustion, which is related to the presence of combustible substances in the exhaust, is especially significant in case of biomass boilers [2, 3]. The paper presents results of the research and the optimisation of the biomass combustion process in the 180 kW batch boiler. The studies described have been focused on the reduction of the pollutants emission, which was primarily realised by the modifications of the air feeding system. Results of the experiments and the CFD simulations have been compared and discussed. Both in case of the model as well as the experiment, positive influence of the modifications on the emission have been observed.

Investigation of eddy currents in the components of the dynamic ergodic divertor of TEXTOR using analytical and numerical approaches

International Nuclear Information System (INIS)

Giesen, B.; Neubauer, O.; Bondarchuk, E.; Doinikov, N.; Kitaev, B.; Obidenko, T.; Panin, A.

2003-01-01

Analytical and numerical approaches for the calculation of eddy currents in mechanical structures of the TEXTOR tokamak in view of operating the dynamic ergodic divertor (DED) coil system fed with the alternating current up to 15 kA at frequencies up to 10 kHz are described. The design of the in-vessel components located close to the DED coils requires detailed investigation of eddy current effects to avoid unacceptable heating and forces. Different approaches depending on skin-layer depths compared with the body dimensions are analyzed. The applied algorithms are based on analytical and simplified numerical methods. Precision and application range of these algorithms have been checked by a numerical code. The simplified technique is rather effective for first step engineering estimation and gives a good understanding for the problem. In a certain parameter range, it results in even precise values and can be used for design optimization of the structures without huge efforts in numerical modeling. After modification of the component's shape prototypes have been manufactured and successfully tested in a full-scale model under the real DED field. The design recommendations resulting from the eddy current studies contributed significantly to the optimized lay out of the DED in-vessel components

Simultaneous compared with sequential blood pressure measurement results in smaller inter-arm blood pressure differences.

Science.gov (United States)

van der Hoeven, Niels V; Lodestijn, Sophie; Nanninga, Stephanie; van Montfrans, Gert A; van den Born, Bert-Jan H

2013-11-01

There are currently few recommendations on how to assess inter-arm blood pressure (BP) differences. The authors compared simultaneous with sequential measurement on mean BP, inter-arm BP differences, and within-visit reproducibility in 240 patients stratified according to age (simultaneous and three sequential BP measurements were taken in each patient. Starting measurement type and starting arm for sequential measurements were randomized. Mean BP and inter-arm BP differences of the first pair and reproducibility of inter-arm BP differences of the first and second pair were compared between both methods. Mean systolic BP was 1.3±7.5 mm Hg lower during sequential compared with simultaneous measurement (Psequential measurement was on average higher than the second, suggesting an order effect. Absolute systolic inter-arm BP differences were smaller on simultaneous (6.2±6.7/3.3±3.5 mm Hg) compared with sequential BP measurement (7.8±7.3/4.6±5.6 mm Hg, PSimultaneous measurement of BP at both arms reduces order effects and results in smaller inter-arm BP differences, thereby potentially reducing unnecessary referral and diagnostic procedures. ©2013 Wiley Periodicals, Inc.

Numerical analysis of the bearing capacity of complex rock mechanical underground systems with filigree structures in the presence of imponderables. A contribution to the systematization of the investigative process with application/demonstration using the example of the salt cavern ASSE II/south flank

International Nuclear Information System (INIS)

Dyogtyev, Oleksandr

2017-01-01

The thesis dealing with the numerical analysis of the bearing capacity of complex rock mechanical underground systems with filigree structures in the presence of imponderables covers the following issues: status of science and technology, concept for the performance of numerical studies on the bearing capacity of large-volume underground systems, application example salt cavern ASSE II - application of the developed concept/development of numerical tools for the overall system/application of the global model to the given questions/realization of the modification potential.

Numerical Modelling of Rayleigh Wave Propagation in Course of Rapid Impulse Compaction

Science.gov (United States)

Herbut, Aneta; Rybak, Jarosław

2017-10-01

As the soil improvement technologies are the area of a rapid development, they require designing and implementing novel methods of control and calibration in order to ensure the safety of geotechnical works. At Wroclaw University of Science and Technology (Poland), these new methods are continually developed with the aim to provide the appropriate tools for the preliminary design of work process, as well as for the further ongoing on-site control of geotechnical works (steel sheet piling, pile driving or soil improvement technologies). The studies include preliminary numerical simulations and field tests concerning measurements and continuous histogram recording of shocks and vibrations and its ground-born dynamic impact on engineering structures. The impact of vibrations on reinforced concrete and masonry structures in the close proximity of the construction site may be destroying in both architectural and structural meaning. Those limits are juxtaposed in codes of practice, but always need an individual judgment. The results and observations make it possible to delineate specific modifications to the parameters of technology applied (e.g. hammer drop height). On the basis of numerous case studies of practical applications, already summarized and published, we were able to formulate the guidelines for work on the aforementioned sites. This work presents specific aspects of the active design (calibration of building site numerical model) by means of technology calibration, using the investigation of the impact of vibrations that occur during the Impulse Compaction on adjacent structures. A case study entails the impact of construction works on Rayleigh wave propagation in the zone of 100 m (radius) around the Compactor.

Numerical simulations of natural or mixed convection in vertical channels: comparisons of level-set numerical schemes for the modeling of immiscible incompressible fluid flows

International Nuclear Information System (INIS)

Li, R.

2012-01-01

The aim of this research dissertation is at studying natural and mixed convections of fluid flows, and to develop and validate numerical schemes for interface tracking in order to treat incompressible and immiscible fluid flows, later. In a first step, an original numerical method, based on Finite Volume discretizations, is developed for modeling low Mach number flows with large temperature gaps. Three physical applications on air flowing through vertical heated parallel plates were investigated. We showed that the optimum spacing corresponding to the peak heat flux transferred from an array of isothermal parallel plates cooled by mixed convection is smaller than those for natural or forced convections when the pressure drop at the outlet keeps constant. We also proved that mixed convection flows resulting from an imposed flow rate may exhibit unexpected physical solutions; alternative model based on prescribed total pressure at inlet and fixed pressure at outlet sections gives more realistic results. For channels heated by heat flux on one wall only, surface radiation tends to suppress the onset of re-circulations at the outlet and to unify the walls temperature. In a second step, the mathematical model coupling the incompressible Navier-Stokes equations and the Level-Set method for interface tracking is derived. Improvements in fluid volume conservation by using high order discretization (ENO-WENO) schemes for the transport equation and variants of the signed distance equation are discussed. (author)

Eco-friendly surface modification on polyester fabrics by esterase treatment

Energy Technology Data Exchange (ETDEWEB)

Wu, Jindan; Cai, Guoqiang; Liu, Jinqiang; Ge, Huayun; Wang, Jiping, E-mail: jipingwanghz@gmail.com

2014-03-01

Graphical abstract: - Highlights: • We used a simple and easy way to measure the enzyme activity. • We studied the mechanism by characterizing the chemical changes in the surface of fabric. • We studied the advantages in surface wettability, fiber integrity and mechanical performance of cutinase treated fabrics. • Cutinase pretreated fibers exhibited much improved fabric wicking and better fiber integrity comparing to alkali treated ones. • Cutinase pretreatment technology promotes energy conservation and emission reduction. - Abstract: Currently, traditional alkali deweighting technology is widely used to improve the hydrophilicity of polyester fabrics. However, the wastewater and heavy chemicals in the effluent cause enormous damage to the environment. Esterase treatment, which is feasible in mild conditions with high selectivity, can provide a clean and efficient way for polyester modification. Under the optimum conditions, the polyester fabric hydrolysis process of esterase had a linear kinetics. X-ray photoelectron spectrometry (XPS) results showed that hydroxyl and carboxyl groups were produced only on the surface of modified fiber without changing the chemical composition of the bulk. These fibers exhibited much improved fabric wicking, as well as greatly improved oily stain removal performance. Compared to the harsh alkali hydrolysis, the enzyme treatment led to smaller weight loss and better fiber integrity. The esterase treatment technology is promising to produce higher-quality polyester textiles with an environmental friendly approach.

Numerical simulation of seismic performance of the underground structure buried in the dense saturated sand

International Nuclear Information System (INIS)

Kawai, Tadashi

2006-01-01

The applicability of the advanced earthquake resistant performance verification method on reinforced concrete underground structures developed by CRIEPI was investigated for the structures which buried in the dry sand. For the advancement of the method in practical use, the applicability to the structures buried in the saturated ground is expected to be verified. In this study the applicability of the effective stress based soil modeling method in numerical analysis, which was proposed through the modification of the formerly developed model by CRIEPI, was verified through the non-linear dynamic numerical simulations of the large centrifuge tests conducted by using a model comprised of fully saturated sand and a aluminium duct type structure specially prepared for the measurement of the load acting on the structure surface with the soil-structure interaction. The magnitudes of the simulated loads and the resultant deformations of the structure were almost same as those of experiments. As a result it is confirmed that the performance verification method is useful for the structures buried in the saturated ground with using the proposed effective stress based ground modeling method. (author)

One-dimensional map-based neuron model: A logistic modification

International Nuclear Information System (INIS)

Mesbah, Samineh; Moghtadaei, Motahareh; Hashemi Golpayegani, Mohammad Reza; Towhidkhah, Farzad

2014-01-01

A one-dimensional map is proposed for modeling some of the neuronal activities, including different spiking and bursting behaviors. The model is obtained by applying some modifications on the well-known Logistic map and is named the Modified and Confined Logistic (MCL) model. Map-based neuron models are known as phenomenological models and recently, they are widely applied in modeling tasks due to their computational efficacy. Most of discrete map-based models involve two variables representing the slow-fast prototype. There are also some one-dimensional maps, which can replicate some of the neuronal activities. However, the existence of four bifurcation parameters in the MCL model gives rise to reproduction of spiking behavior with control over the frequency of the spikes, and imitation of chaotic and regular bursting responses concurrently. It is also shown that the proposed model has the potential to reproduce more realistic bursting activity by adding a second variable. Moreover the MCL model is able to replicate considerable number of experimentally observed neuronal responses introduced in Izhikevich (2004) [23]. Some analytical and numerical analyses of the MCL model dynamics are presented to explain the emersion of complex dynamics from this one-dimensional map

Strong coupling results in the AdS{sub 5}/CFT{sub 4} correspondence from the numerical solution of the quantum spectral curve

Energy Technology Data Exchange (ETDEWEB)

Hegedűs, Árpád; Konczer, József [MTA Lendület Holographic QFT Group, Wigner Research Centre,H-1525 Budapest 114, P.O.B. 49 (Hungary)

2016-08-09

In this paper, we solved numerically the Quantum Spectral Curve (QSC) equations corresponding to some twist-2 single trace operators with even spin from the sl(2) sector of AdS{sub 5}/CFT{sub 4} correspondence. We describe all technical details of the numerical method which are necessary to implement it in C++ language. In the S=2,4,6,8 cases, our numerical results confirm the analytical results, known in the literature for the first 4 coefficients of the strong coupling expansion for the anomalous dimensions of twist-2 operators. In the case of the Konishi operator, due to the high precision of the numerical data we could give numerical predictions to the values of two further coefficients, as well. The strong coupling behaviour of the coefficients c{sub a,n} in the power series representation of the P {sub a}-functions is also investigated. Based on our numerical data, in the regime, where the index of the coefficients is much smaller than λ{sup 1/4}, we conjecture that the coefficients have polynomial index dependence at strong coupling. This allows one to propose a strong coupling series representation for the P-functions being valid far enough from the real short cut. In the paper the qualitative strong coupling behaviour of the P-functions at the branch points is also discussed.

Finger-Based Numerical Skills Link Fine Motor Skills to Numerical Development in Preschoolers.

Science.gov (United States)

Suggate, Sebastian; Stoeger, Heidrun; Fischer, Ursula

2017-12-01

Previous studies investigating the association between fine-motor skills (FMS) and mathematical skills have lacked specificity. In this study, we test whether an FMS link to numerical skills is due to the involvement of finger representations in early mathematics. We gave 81 pre-schoolers (mean age of 4 years, 9 months) a set of FMS measures and numerical tasks with and without a specific finger focus. Additionally, we used receptive vocabulary and chronological age as control measures. FMS linked more closely to finger-based than to nonfinger-based numerical skills even after accounting for the control variables. Moreover, the relationship between FMS and numerical skill was entirely mediated by finger-based numerical skills. We concluded that FMS are closely related to early numerical skill development through finger-based numerical counting that aids the acquisition of mathematical mental representations.

Reproductive cloning combined with genetic modification.

Science.gov (United States)

Strong, C

2005-11-01

Although there is widespread opposition to reproductive cloning, some have argued that its use by infertile couples to have genetically related children would be ethically justifiable. Others have suggested that lesbian or gay couples might wish to use cloning to have genetically related children. Most of the main objections to human reproductive cloning are based on the child's lack of unique nuclear DNA. In the future, it may be possible safely to create children using cloning combined with genetic modifications, so that they have unique nuclear DNA. The genetic modifications could be aimed at giving such children genetic characteristics of both members of the couple concerned. Thus, cloning combined with genetic modification could be appealing to infertile, lesbian, or gay couples who seek genetically related children who have genetic characteristics of both members. In such scenarios, the various objections to human reproductive cloning that are based on the lack of genetic uniqueness would no longer be applicable. The author argues that it would be ethically justifiable for such couples to create children in this manner, assuming these techniques could be used safely.

Identification of histone modifications in biomedical text for supporting epigenomic research.

Science.gov (United States)

Kolárik, Corinna; Klinger, Roman; Hofmann-Apitius, Martin

2009-01-30

Posttranslational modifications of histones influence the structure of chromatine and in such a way take part in the regulation of gene expression. Certain histone modification patterns, distributed over the genome, are connected to cell as well as tissue differentiation and to the adaption of organisms to their environment. Abnormal changes instead influence the development of disease states like cancer. The regulation mechanisms for modifying histones and its functionalities are the subject of epigenomics investigation and are still not completely understood. Text provides a rich resource of knowledge on epigenomics and modifications of histones in particular. It contains information about experimental studies, the conditions used, and results. To our knowledge, no approach has been published so far for identifying histone modifications in text. We have developed an approach for identifying histone modifications in biomedical literature with Conditional Random Fields (CRF) and for resolving the recognized histone modification term variants by term standardization. For the term identification F1 measures of 0.84 by 10-fold cross-validation on the training corpus and 0.81 on an independent test corpus have been obtained. The standardization enabled the correct transformation of 96% of the terms from training and 98% from test the corpus. Due to the lack of terminologies exhaustively covering specific histone modification types, we developed a histone modification term hierarchy for use in a semantic text retrieval system. The developed approach highly improves the retrieval of articles describing histone modifications. Since text contains context information about performed studies and experiments, the identification of histone modifications is the basis for supporting literature-based knowledge discovery and hypothesis generation to accelerate epigenomic research.

More, smaller bacteria in response to ocean's warming?

KAUST Repository

Moran, Xose Anxelu G.

2015-06-10

Heterotrophic bacteria play a major role in organic matter cycling in the ocean. Although the high abundances and relatively fast growth rates of coastal surface bacterioplankton make them suitable sentinels of global change, past analyses have largely overlooked this functional group. Here, time series analysis of a decade of monthly observations in temperate Atlantic coastal waters revealed strong seasonal patterns in the abundance, size and biomass of the ubiquitous flow-cytometric groups of low (LNA) and high nucleic acid (HNA) content bacteria. Over this relatively short period, we also found that bacterioplankton cells were significantly smaller, a trend that is consistent with the hypothesized temperature-driven decrease in body size. Although decadal cell shrinking was observed for both groups, it was only LNA cells that were strongly coherent, with ecological theories linking temperature, abundance and individual size on both the seasonal and interannual scale. We explain this finding because, relative to their HNA counterparts, marine LNA bacteria are less diverse, dominated by members of the SAR11 clade. Temperature manipulation experiments in 2012 confirmed a direct effect of warming on bacterial size. Concurrent with rising temperatures in spring, significant decadal trends of increasing standing stocks (3% per year) accompanied by decreasing mean cell size (-1% per year) suggest a major shift in community structure, with a larger contribution of LNA bacteria to total biomass. The increasing prevalence of these typically oligotrophic taxa may severely impact marine foodwebs and carbon fluxes by an overall decrease in the efficiency of the biological pump. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Numerical investigation on the gas entrainment rate on ventilated supercavity body

Directory of Open Access Journals (Sweden)

WuGang Yang

2016-12-01

Full Text Available The supercavitation technique provides a means of significantly increasing the velocity of an underwater vehicle. This technique involves essentially the creation of stable supercavity shape. The method of artificial ventilation is most effective for generating and dominating the supercavity. This paper focuses on the numerical simulation of flow field around three-dimensional body. The method is based on the multiphase computational fluid dynamics model combined with the turbulence model and the full cavity model. The fundamental similarity parameters of ventilated supercavity flows that include cavitation number, Froude number Fr, entrainment rate CQ, and drag coefficient Cx are all investigated numerically in the case of steady flow and gravity field. We discuss the following simulations results in three parts: (1 the variations of the cavitation number and the supercavity’s relative diameter with entrainment rate; (2 the drag coefficient versus the cavitation number; and (3 deformation of supercavity axis caused by gravitational effect for three different fixed three Froude numbers. In the full paper, we give the comparison results of the drag reduction ratio among numerical simulation and experiment conducted in hydrodynamic tunnel and towing tank, respectively. We summarize our discussion of gravitational effect on the axis deformation of supercavity as follows: in the case of smaller Froude number, the inclination of the cavity axis increases monotonously with increasing horizontal length and reaches its maximal value at the end of supercavity; this deformation can be almost completely negligible when the Froude number Fr is larger than 7.0. The comparisons with the experimental data in the hydrodynamic tunnel and the towing tank indicate that the present method is effective for predicting the flows around ventilated supercavity; that the numerical results is in good agreement with the experimental ones and that the maximal value of the

An approach to nuclear plant design and modification support for Russian-designed plants in Eastern Europe

International Nuclear Information System (INIS)

Ioannidi, J.; Akins, M.J.

2002-01-01

The Western nuclear countries have embarked on numerous programs to improve the safety of the Russian-designed nuclear power plants. In Russian-designed plants in Eastern Europe, plant management is being asked for the first time to decide which safety projects to implement and is finding itself lacking in nuclear safety analytical tools and practices, funds, and experience with project management and project engineering skills and tools. Some of the major areas where assistance is needed are: 1) Defining plant weaknesses toward nuclear safety. 2) Evaluating and grading the importance to safety of proposed modification. 3) Project Planning and Scheduling using computer based scheduling software. 4) Project Finance Development and Management using well defined cash flow management techniques. 5) Contract Management and Change Control. 6) Interface Management. Each of these areas requires a significant amount of discussion to understand the issues and problems associated with them. However, this paper is limited to the Project Management areas. This paper encourages the use of a design engineering firm experienced in safety practices and associated management and technical skills to serve as the Owner's Engineer/Project Management Consultant for the program period for a Russian-designed plants located outside Russia. This approach would allow for the availability and transfer of knowledge of safety practices to plant personnel and owners engineers at nuclear plants outside Russia, improving their nuclear safety culture. The plant personnel would control plant modernizations and upgrades based upon a proven and well-defined process for detailed project definition, configuration change control, and project management. This offers the opportunity to enhance the long-term safety culture by developing plant personnel knowledgeable of the safety practices, plant design basis, developing a modification control process enabling them to control the design basis through future

Ion bombardment modification of surfaces

International Nuclear Information System (INIS)

Auciello, O.

1984-01-01

An historical overview of the main advances in the understanding of bombardment-induced surface topography is presented. The implantation and sputtering mechanisms which are relevant to ion bombardment modification of surfaces and consequent structural, electronic and compositional changes are described. Descriptions of plasma and ion-beam sputtering-induced film formation, primary ion-beam deposition, dual beam techniques, cluster of molecule ion-beam deposition, and modification of thin film properties by ion bombardment during deposition are presented. A detailed account is given of the analytical and computational modelling of topography from the viewpoint of first erosion theory. Finally, an account of the possible application and/or importance of textured surfaces in technologies and/or experimental techniques not considered in previous chapters is presented. refs.; figs.; tabs

Microscale surface modifications for heat transfer enhancement.

Science.gov (United States)

Bostanci, Huseyin; Singh, Virendra; Kizito, John P; Rini, Daniel P; Seal, Sudipta; Chow, Louis C

2013-10-09

In this experimental study, two surface modification techniques were investigated for their effect on heat transfer enhancement. One of the methods employed the particle (grit) blasting to create microscale indentations, while the other used plasma spray coating to create microscale protrusions on Al 6061 (aluminum alloy 6061) samples. The test surfaces were characterized using scanning electron microscopy (SEM) and confocal scanning laser microscopy. Because of the surface modifications, the actual surface area was increased up to 2.8× compared to the projected base area, and the arithmetic mean roughness value (Ra) was determined to vary from 0.3 μm for the reference smooth surface to 19.5 μm for the modified surfaces. Selected samples with modified surfaces along with the reference smooth surface were then evaluated for their heat transfer performance in spray cooling tests. The cooling system had vapor-atomizing nozzles and used anhydrous ammonia as the coolant in order to achieve heat fluxes up to 500 W/cm(2) representing a thermal management setting for high power systems. Experimental results showed that the microscale surface modifications enhanced heat transfer coefficients up to 76% at 500 W/cm(2) compared to the smooth surface and demonstrated the benefits of these practical surface modification techniques to enhance two-phase heat transfer process.

Modification of Material Surface Using Plasma-Enhanced Ion Beams

National Research Council Canada - National Science Library

Bystritskii, V

1998-01-01

...) Technology for Materials Surface Modification. Following second year programmatic plan, formulated in the conclusion of the 1-st year report we focused our effort on study of aluminum alloys modification (Al2024, 6061, 7075...

Safety in the Utilization and Modification of Research Reactors. Specific Safety Guide

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-15

This Safety Guide is a revision of Safety Series No. 35-G2 on safety in the utilization and modification of research reactors. It provides recommendations on meeting the requirements for the categorization, safety assessment and approval of research reactor experiments and modification projects. Specific safety considerations in different phases of utilization and modification projects are covered, including the pre-implementation, implementation and post-implementation phases. Guidance is also provided on the operational safety of experiments, including in the handling, dismantling, post-irradiation examination and disposal of experimental devices. Examples of the application of the safety categorization process for experiments and modification projects and of the content of the safety analysis report for an experiment are also provided. Contents: 1. Introduction; 2. Management system for the utilization and modification of a research reactor; 3. Categorization, safety assessment and approval of an experiment or modification; 4. Safety considerations for the design of an experiment or modification; 5. Pre-implementation phase of a modification or utilization project; 6. Implementation phase of a modification or utilization project; 7. Post-implementation phase of a utilization or modification project; 8. Operational safety of experiments at a research reactor; 9. Safety considerations in the handling, dismantling, post-irradiation examination and disposal of experimental devices; 10. Safety aspects of out-of-reactor-core installations; Annex I: Example of a checklist for the categorization of an experiment or modification at a research reactor; Annex II: Example of the content of the safety analysis report for an experiment at a research reactor; Annex III: Examples of reasons for a modification at a research reactor.

Safety in the Utilization and Modification of Research Reactors. Specific Safety Guide

International Nuclear Information System (INIS)

2012-01-01

This Safety Guide is a revision of Safety Series No. 35-G2 on safety in the utilization and modification of research reactors. It provides recommendations on meeting the requirements for the categorization, safety assessment and approval of research reactor experiments and modification projects. Specific safety considerations in different phases of utilization and modification projects are covered, including the pre-implementation, implementation and post-implementation phases. Guidance is also provided on the operational safety of experiments, including in the handling, dismantling, post-irradiation examination and disposal of experimental devices. Examples of the application of the safety categorization process for experiments and modification projects and of the content of the safety analysis report for an experiment are also provided. Contents: 1. Introduction; 2. Management system for the utilization and modification of a research reactor; 3. Categorization, safety assessment and approval of an experiment or modification; 4. Safety considerations for the design of an experiment or modification; 5. Pre-implementation phase of a modification or utilization project; 6. Implementation phase of a modification or utilization project; 7. Post-implementation phase of a utilization or modification project; 8. Operational safety of experiments at a research reactor; 9. Safety considerations in the handling, dismantling, post-irradiation examination and disposal of experimental devices; 10. Safety aspects of out-of-reactor-core installations; Annex I: Example of a checklist for the categorization of an experiment or modification at a research reactor; Annex II: Example of the content of the safety analysis report for an experiment at a research reactor; Annex III: Examples of reasons for a modification at a research reactor.

Industrial assessment of nonbackfittable PWR design modifications. Final report

International Nuclear Information System (INIS)

Matzie, R.A.; Daleas, R.S.; Miller, D.D.

1980-11-01

As part of the US Department of Energy's Advanced Reactor Design Study, various nonbackfittable PWR design modifications were evaluated to determine their potential for improved uranium utilization and commercial viability. Combustion Engineering, Inc. contributed to this effort through participation in the Battelle Pacific Northwest Laboratory industrial assessment of such design modifications. Seven modifications, including the use of higher primary system temperatures and pressures, rapid-frequent refueling, end-of-cycle stretchout, core periphery modifications, radial blankets, low power density cores, and small PWR assemblies, were evaluated with respect to uranium utilization, economics, technical and operational complexity, and several other subjective considerations. Rapid-frequent refueling was judged to have the highest potential although it would probably not be economical for the majority of reactors with the design assumptions used in this assessment

Numerical Simulation of Hydro-mechanical Deep Drawing — A Study on the Effect of Process Parameters on Drawability and Thickness Variation

Science.gov (United States)

Singh, Swadesh Kumar; Kumar, D. Ravi

2005-08-01

Hydro-mechanical deep drawing is a process for producing cup shaped parts with the assistance of a pressurized fluid. In the present work, numerical simulation of the conventional and counter pressure deep drawing processes has been done with the help of a finite element method based software. Simulation results were analyzed to study the improvement in drawability by using hydro-mechanical processes. The thickness variations in the drawn cups were analyzed and also the effect of counter pressure and oil gap on the thickness distribution was studied. Numerical simulations were also used for the die design, which combines both drawing and ironing processes in a single operation. This modification in the die provides high drawability, facilitates smooth material flow, gives more uniform thickness distribution and corrects the shape distortion.

Asymptotic preserving and all-regime Lagrange-Projection like numerical schemes: application to two-phase flows in low mach regime

International Nuclear Information System (INIS)

Girardin, Mathieu

2014-01-01

Two-phase flows in Pressurized Water Reactors belong to a wide range of Mach number flows. Computing accurate approximate solutions of those flows may be challenging from a numerical point of view as classical finite volume methods are too diffusive in the low Mach regime. In this thesis, we are interested in designing and studying some robust numerical schemes that are stable for large time steps and accurate even on coarse meshes for a wide range of flow regimes. An important feature is the strategy to construct those schemes. We use a mixed implicit-explicit strategy based on an operator splitting to solve fast and slow phenomena separately. Then, we introduce a modification of a Suliciu type relaxation scheme to improve the accuracy of the numerical scheme in some regime of interest. Two approaches have been used to assess the ability of our numerical schemes to deal with a wide range of flow regimes. The first approach, based on the asymptotic preserving property, has been used for the gas dynamics equations with stiff source terms. The second approach, based on the all-regime property, has been used for the gas dynamics equations and the homogeneous two-phase flows models HRM and HEM in the low Mach regime. We obtained some robustness and stability properties for our numerical schemes. In particular, some discrete entropy inequalities are shown. Numerical evidences, in 1D and in 2D on unstructured meshes, assess the gain in term of accuracy and CPU time of those asymptotic preserving and all-regime numerical schemes in comparison with classical finite volume methods. (author) [fr

How genetic modification of roots affects rhizosphere processes and plant performance

NARCIS (Netherlands)

Kabouw, P.; Van Dam, N.M.; Van der Putten, W.H.; Biere, A.

2012-01-01

Genetic modification of plants has become common practice. However, root-specific genetic modifications have only recently been advocated. Here, a review is presented regarding how root-specific modifications can have both plant internal and rhizosphere-mediated effects on aboveground plant

ZT-40M system design, modification, and installation

International Nuclear Information System (INIS)

Hammer, C.F.

1981-01-01

ZT-40 is a reversed field pinch experiment which had been operated as originally designed, with a ceramic discharge tube until November 1980. At that time, the experiment was shut down for major modifications. This paper will describe these modifications in general and discuss in detail the design of the energy system

21 CFR 640.74 - Modification of Source Plasma.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Modification of Source Plasma. 640.74 Section 640...) BIOLOGICS ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.74 Modification of Source Plasma. (a) Upon approval by the Director, Center for Biologics Evaluation and Research, Food and...

Representation of Numerical and Non-Numerical Order in Children

Science.gov (United States)

Berteletti, Ilaria; Lucangeli, Daniela; Zorzi, Marco

2012-01-01

The representation of numerical and non-numerical ordered sequences was investigated in children from preschool to grade 3. The child's conception of how sequence items map onto a spatial scale was tested using the Number-to-Position task (Siegler & Opfer, 2003) and new variants of the task designed to probe the representation of the alphabet…

Cosmic-ray-modified stellar winds. III. A numerical iterative approach

International Nuclear Information System (INIS)

Ko, C.M.; Jokipii, J.R.; Webb, G.M.

1988-01-01

A numerical iterative method is used to determine the modification of a stellar wind flow with a termination shock by the galactic cosmic rays. A two-fluid model consisting of cosmic rays and thermal stellar wind gas is used in which the cosmic rays are coupled to the background flow via scattering with magnetohydrodynamic waves or irregularities. A polytropic model is used to describe the thermal stellar wind gas, and the cosmic-rays are modeled as a hot, low-density gas with negligible mass flux. The positive galactic cosmic-ray pressure gradient serves to brake the outflowing stellar wind gas, and the cosmic rays modify the location of the critical point of the wind, the location of the shock, the wind fluid velocity profile, and the thermal gas entropy constants on both sides of the shock. The transfer of energy to the cosmic rays results in an outward radial flux of cosmic-ray energy. 21 references

30 CFR 18.81 - Field modification of approved (permissible) equipment; application for approval of modification...

Science.gov (United States)

2010-07-01

... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES... having jurisdiction at the mine where such equipment is to be operated stating the modifications which...

EG and G electron linac modifications

International Nuclear Information System (INIS)

Norris, N.J.; Detch, J.L.; Kocimski, S.M.; Sawyer, C.R.; Hudson, C.L.

1986-01-01

The electron linear accelerator at EG and G/EM, Santa Barbara Operations, installed in 1963, has been subsequently modified to produce short, intense beam pulses used in the test, calibration and development of many types of fast radiation detectors and systems. The first practical use of the single RF pulse operation, now used in many accelerators, was demonstrated on this accelerator in the late 60s. A major three-year modification, to replace obsolete equipment and bring all the subsystems up to the current state of the art, has increased the beam intensity, stability and reliability. These modifications are discussed

Experimental and numerical investigation of centrifugal pumps with asymmetric inflow conditions

Science.gov (United States)

Mittag, Sten; Gabi, Martin

2015-11-01

Most of the times pumps operate off best point states. Reasons are changes of operating conditions, modifications, pollution and wearout or erosion. As consequences non-rotational symmetric flows, transient operational conditions, increased risk of cavitation, decrease of efficiency and unpredictable wearout can appear. Especially construction components of centrifugal pumps, in particular intake elbows, contribute to this matter. Intake elbows causes additional losses and secondary flows, hence non-rotational velocity distributions as intake profile to the centrifugal pump. As a result the impeller vanes experience permanent changes of the intake flow angle and with it transient flow conditions in the blade channels. This paper presents the first results of a project, experimentally and numerically investigating the consequences of non-rotational inflow to leading edge flow conditions of a centrifugal pump. Therefore two pumpintake- elbow systems are compared, by only altering the intake elbow geometry: a common single bended 90° elbow and a numerically optimized elbow (improved regarding rotational symmetric inflow conditions and friction coefficient). The experiments are carried out, using time resolved stereoscopic PIV on a full acrylic pump with refractions index matched (RIM) working fluid. This allows transient investigations of the flow field simultaneously for all blade leading edges. Additional CFD results are validated and used to further support the investigation i.e. for comparing an analog pump system with ideal inflow conditions.

Evaluation of proposed panel closure modifications at WIPP

Energy Technology Data Exchange (ETDEWEB)

Allen, Lawrence E.; Silva, Matthew K.; Channell, James K.; Abel, John F.; Morgan, Dudley R.

2001-12-31

A key component in the design of the WIPP repository is the installation of concrete structures as panel seals in the intake and exhaust drifts after a panel has been filled with waste containers. As noted in the EPA final rule, the panel seal closure system is intended to block brine flow between the waste panels at the WIPP. On April 17, 2001, the DOE proposed seven modifications to the EPA concerning the design of the panel closure system. EPA approval of these modifications is necessary since the details of the panel design are specified in EPA’s final rule as a condition for WIPP certification. However, the EPA has not determined whether a rulemaking would be required for these proposed design modifications. On September 4, 2001, the DOE withdrew the request, noting that it would be resubmitted on a future date. The Environmental Evaluation Group (EEG) contracted with two engineers, Dr. John Abel and Dr. Rusty Morgan, to evaluate the proposed modifications. The EEG has accepted the conclusions and recommendations from these two experts: 1) replacement of Salado Mass Concrete with a generic salt-based concrete; 2) replacement of the explosion wall with a construction wall; 3) replacement of freshwater grouting with salt-based grouting; 4) option to allow surface or underground mixing; and 5) option to allow up to one year for completion of closure. The proposed modification to allow local carbonate river rock as aggregate is acceptable pending demonstration that no problems will exist in the resulting concrete. The proposed modification to give the contractor discretion in removal of steel forms is not supported. Instead, several recommendations are made to specifically reduce the number of forms left, thereby reducing potential migration pathways.

Modification of Particle Distributions by MHD Instabilities II

International Nuclear Information System (INIS)

White, Roscoe B.

2011-01-01

The modification of particle distributions by low amplitude magnetohydrodynamic modes is an important topic for magnetically confined plasmas. Low amplitude modes are known to be capable of producing significant modification of injected neutral beam profiles, and the same can be expected in burning plasmas for the alpha particle distributions. Flattening of a distribution in an island due to phase mixing and portions of phase space becoming stochastic lead to modification of the particle distribution, a process extremely rapid in the time scale of an experiment but still very long compared to the time scale of guiding center simulations. Large amplitude modes can cause profile avalanche and particle loss. Thus it is very valuable to be able to predict the temporal evolution of a particle distribution produced by a given spectrum of magnetohydrodynamic modes. In this paper we further develop and investigate the use of a new method of determining domains of phase space in which good KAM surfaces do not exist and use this method to examine a well documented case of profile modification by instabilities.

Evaluating the scope for energy-efficiency improvements in the public sector: Benchmarking NHSScotland's smaller health buildings

International Nuclear Information System (INIS)

Murray, Joe; Pahl, O.; Burek, S.

2008-01-01

The National Health Service in Scotland (NHSScotland) has, in recent years, done much to reduce energy consumption in its major healthcare buildings (hospitals). On average, a reduction of 2% per year has been achieved since 2000, based on hospital buildings. However, there had been little or no attention paid to smaller premises such as health centres, clinics, dentists, etc. Such smaller healthcare buildings in Scotland constitute 29% of the total treated floor area of all NHSScotland buildings and, therefore, may contribute a similar percentage of carbon and other emissions to the environment. By concentrating on a sample of local health centres in Scotland, this paper outlines the creation of an energy benchmark target, which is part of a wider research project to investigate the environmental impacts of small healthcare buildings in Scotland and the scope for improvements. It was found that energy consumption varied widely between different centres but this variation could not be linked to building style, floor area or volume. Overall, it was found that a benchmark of 0.2 GJ/m 3 would be challenging, but realistic

Multi-Chromatic Ultrashort Pulse Filamentation and Bulk Modification in Dielectrics

Science.gov (United States)

2016-05-05

AFRL-AFOSR-VA-TR-2016-0194 Multi- Chromatic Ultrashort Pulse Filamentation and Bulk Modification in Dielectrics Jeremy Gulley KENNESAW STATE...Jan 2016 4. TITLE AND SUBTITLE Multi- chromatic Ultrashort Pulse Filamentation and Bulk Modification in Dielectrics 5a. CONTRACT NUMBER 5b. GRANT...in, and modification of, dielectric solids by multi- chromatic ultrashort laser pulses. It was a theoretical effort to develop models of multi

Global study of nuclear modifications on parton distribution functions

Directory of Open Access Journals (Sweden)

Rong Wang

2017-07-01

Full Text Available A global analysis of nuclear medium modifications of parton distributions is presented using deeply inelastic scattering data of various nuclear targets. Two obtained data sets are provided for quark and gluon nuclear modification factors, referred as nIMParton16. One is from the global fit only to the experimental data of isospin-scalar nuclei (Set A, and the other is from the fit to all the measured nuclear data (Set B. The scale-dependence is described by DGLAP equations with nonlinear corrections in this work. The Fermi motion and off-shell effect, nucleon swelling, and parton–parton recombination are taken into account together for modeling the complicated x-dependence of nuclear modification. The nuclear gluon shadowing in this paper is dynamically generated by the QCD evolution of parton splitting and recombination processes with zero gluon density at the input scale. Sophisticated nuclear dependence of nuclear medium effects is studied with only two free parameters. With the obtained free parameters from the global analysis, the nuclear modifications of parton distribution functions of unmeasured nuclei can be predicted in our model. Nuclear modification of deuteron is also predicted and shown with recent measurement at JLab.

Detection of Genetic Modification 'ac2' in Potato Foodstuffs

Directory of Open Access Journals (Sweden)

Petr Kralik

2009-01-01

Full Text Available The genetic modification 'ac2' is based on the insertion and expression of ac2 gene, originally found in seeds of amaranth (Amaranthus caudatus, into the genome of potatoes (Solanum tuberosum. The purpose of the present study is to develop a PCR method for the detection of the mentioned genetically modified potatoes in various foodstuffs. The method was used to test twenty different potato-based products; none of them was positive for the genetic modification 'ac2'. The European Union legislation requires labelling of products made of or containing more than 0.9 % of genetically modified organisms. The genetic modification 'ac2' is not allowed on the European Union market. For that reason it is suitable to have detection methods, not only for the approved genetic modifications, but also for the 'unknown' ones, which could still occur in foodstuffs.

Effects of content and surface hydrophobic modification of BaTiO3 on the cooling properties of ASA (acrylonitrile-styrene-acrylate copolymer)

Science.gov (United States)

Xiang, Bo; Zhang, Jun

2018-01-01

For the field of cool material, barium titanate (BaTiO3, BT) is still a new member that needs to be further studied. Herein, the effects of both content and surface hydrophobic modification of BT on the cooling properties of acrylonitrile-styrene-acrylate copolymer (ASA) were detailedly investigated, aiming to fabricate composited cool material. Butyl acrylate (BA) was employed to convert the surface of BT from hydrophilic to hydrophobic. The addition of unmodified BT could significantly improve the solar reflectance of ASA, especially when the addition amount is 3 vol%, the near infrared (NIR) reflectance increased from 22.02 to 72.60%. However, serious agglomeration occurred when the addition amount increased to 5 vol% and therefore led to a relatively smaller increase in solar reflectance and an obvious decline in impact strength. After surface hydrophobic modification, the modified BT (M-BT) presented better dispersibility in ASA matrix, which contributed to the improvement of both solar reflectance and impact strength. In addition, the temperature test provided a more sufficient and intuitive way to evaluate the cooling effect of the composited cool materials, and a significant decrease (over 10 °C) could be achieved in the temperature test when M-BT particles were introduced.

Lost in Translation: Defects in Transfer RNA Modifications and Neurological Disorders

Directory of Open Access Journals (Sweden)

Andrea Bednářová

2017-05-01

Full Text Available Transfer RNAs (tRNAs are key molecules participating in protein synthesis. To augment their functionality they undergo extensive post-transcriptional modifications and, as such, are subject to regulation at multiple levels including transcription, transcript processing, localization and ribonucleoside base modification. Post-transcriptional enzyme-catalyzed modification of tRNA occurs at a number of base and sugar positions and influences specific anticodon–codon interactions and regulates translation, its efficiency and fidelity. This phenomenon of nucleoside modification is most remarkable and results in a rich structural diversity of tRNA of which over 100 modified nucleosides have been characterized. Most often these hypermodified nucleosides are found in the wobble position of tRNAs, where they play a direct role in codon recognition as well as in maintaining translational efficiency and fidelity, etc. Several recent studies have pointed to a link between defects in tRNA modifications and human diseases including neurological disorders. Therefore, defects in tRNA modifications in humans need intensive characterization at the enzymatic and mechanistic level in order to pave the way to understand how lack of such modifications are associated with neurological disorders with the ultimate goal of gaining insights into therapeutic interventions.

Recent Advances in Attention Bias Modification for Substance Addictions

Directory of Open Access Journals (Sweden)

Melvyn Weibin Zhang

2018-04-01

Full Text Available Research on attentional bias modification has increased since 2014. A recent meta-analysis demonstrates evidence for bias modification for substance disorders, including alcohol and tobacco use disorders. Several pharmacological trials have shown that pharmacological agents can attenuate and modify such attentional bias. The pharmacological trials that have appeared to date have produced mixed results, which has clinical implications. Developments in Internet and mobile technologies have transformed how attention bias modification is currently being achieved. There remains great potential for further research that examines the efficacy of technology-aided attention bias interventions.

Proposed Modification of the Progressive Retirement Programme

CERN Document Server

2003-01-01

After discussion at TREF on 29 October 2003, the Management proposes in this document a modification affecting one of the general principles of the Progressive Retirement Programme (PRP), decided by the Council in December 1996 and introduced in April 1997. This modification would authorise the Director-General, in exceptional cases, as indicated in section 3 below, and, with the staff member's consent, to cancel his or her participation in the PRP and to reinstate the staff member in his or her original contractual situation. No modifications to the Staff Rules and Regulations are required. The proposal set out in section 3 of the present document is submitted by the Management, after consultation of the Governing Board of the Pension Fund, for recommendation by the Finance Committee to the Council and for approval by the Council, to enter into force as of 1 January 2004.

Multiple Smaller Missions as a Direct Pathway to Mars Sample Return

Science.gov (United States)

Niles, P. B.; Draper, D. S.; Evans, C. A.; Gibson, E. K.; Graham, L. D.; Jones, J. H.; Lederer, S. M.; Ming, D.; Seaman, C. H.; Archer, P. D.;

An atlas of the smaller maps in orientable and nonorientable surfaces

CERN Document Server

Jackson, David

2000-01-01

Maps are beguilingly simple structures with deep and ubiquitous properties. They arise in an essential way in many areas of mathematics and mathematical physics, but require considerable time and computational effort to generate. Few collected drawings are available for reference, and little has been written, in book form, about their enumerative aspects. An Atlas of the Smaller Maps in Orientable and Nonorientable Surfaces is the first book to provide complete collections of maps along with their vertex and face partitions, number of rootings, and an index number for cross referencing. It provides an explanation of axiomatization and encoding, and serves as an introduction to maps as a combinatorial structure. The Atlas lists the maps first by genus and number of edges, and gives the embeddings of all graphs with at most five edges in orientable surfaces, thus presenting the genus distribution for each graph. Exemplifying the use of the Atlas, the authors explore two substantial conjectures with origins in ...

Exploring oxidative modifications of tyrosine

DEFF Research Database (Denmark)

Houée-Lévin, C; Bobrowski, K; Horakova, L

2015-01-01

residues are oxidised in vivo with impact on cellular homeostasis and redox signalling pathways. A notable example is tyrosine, which can undergo a number of oxidative post-translational modifications to form 3-hydroxy-tyrosine, tyrosine crosslinks, 3-nitrotyrosine and halogenated tyrosine, with different...... effects on cellular functions. Tyrosine oxidation has been studied extensively in vitro, and this has generated detailed information about the molecular mechanisms that may occur in vivo. An important aspect of studying tyrosine oxidation both in vitro and in biological systems is the ability to monitor...... residues modified and the nature of the modification. These approaches have helped understanding of the consequences of tyrosine oxidation in biological systems, especially its effects on cell signalling and cell dysfunction, linking to roles in disease. There is mounting evidence that tyrosine oxidation...

Numerical simulation of ventilation air movement in partitioned offices

Energy Technology Data Exchange (ETDEWEB)

Plett, E.G.; Soultogiannis, A.A.; Jouini, D.B. (Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa, Ontario (Canada))

1993-01-01

Good air quality can only be assured throughout an office complex if each workspace receives an adequate supply of ventilation air. The likelihood of achieving this situation would be increased if the building engineer had a means of easily predicting the air movement in each office configuration. A simple computer-based solution to this need is proposed. To this end, the development and validation testing of a numerical solution technique to simulate the ventilation air movement in a room or office is described. The predictions of the two-dimensional, isothermal, inviscid formulation are seen to be in good agreement with experimentally measured airflows in configurations of interest. The computer code is then used to illustrate the airflow in offices served by a single row of supply air diffusers, when partitions are used to divide the space into smaller workspaces. It is observed that the partitions distort the airflow patterns to the extent that it would be difficult to provide desirable ventilation airflows to all the workspaces formed by the partitions. (au) (26 refs.)

Numerical simulations and linear stability analysis of a boundary layer developed on wavy surfaces

Science.gov (United States)

Siconolfi, Lorenzo; Camarri, Simone; Fransson, Jens H. M.

2015-11-01

The development of passive methods leading to a laminar to turbulent transition delay in a boundary layer (BL) is a topic of great interest both for applications and academic research. In literature it has been shown that a proper and stable spanwise velocity modulation can reduce the growth rate of Tollmien-Schlichting (TS) waves and delay transition. In this study, we investigate numerically the possibility of obtaining a stabilizing effect of the TS waves through the use of a spanwise sinusoidal modulation of a flat plate. This type of control has been already successfully investigated experimentally. An extensive set of direct numerical simulations is carried out to study the evolution of a BL flow developed on wavy surfaces with different geometric characteristics, and the results will be presented here. Moreover, since this configuration is characterized by a slowly-varying flow field in streamwise direction, a local stability analysis is applied to define the neutral stability curves for the BL flow controlled by this type of wall modifications. These results give the possibility of investigating this control strategy and understanding the effect of the free parameters on the stabilization mechanism.

Numerical study of plasma generation process and internal antenna heat loadings in J-PARC RF negative ion source

Energy Technology Data Exchange (ETDEWEB)

Shibata, T., E-mail: shibat@post.j-parc.jp; Ueno, A.; Oguri, H.; Ohkoshi, K.; Ikegami, K.; Takagi, A.; Asano, H.; Naito, F. [J-PARC Center, Tokai-mura, Naka-gun, Ibaraki-ken 319-1195 (Japan); Nishida, K.; Mochizuki, S.; Hatayama, A. [Keio University, Hiyoshi, Kohoku-ku, Yokohama-shi, Kanagawa-ken 223-8522 (Japan); Mattei, S.; Lettry, J. [European Organization for Nuclear Research (CERN), 1211 Geneva 23 (Switzerland)

2016-02-15

A numerical model of plasma transport and electromagnetic field in the J-PARC (Japan Proton Accelerator Research Complex) radio frequency ion source has been developed to understand the relation between antenna coil heat loadings and plasma production/transport processes. From the calculation, the local plasma density increase is observed in the region close to the antenna coil. Electrons are magnetized by the magnetic field line with absolute magnetic flux density 30–120 Gauss which leads to high local ionization rate. The results suggest that modification of magnetic configuration can be made to reduce plasma heat flux onto the antenna.

Functional Modification of Thioether Groups in Peptides, Polypeptides, and Proteins

OpenAIRE

Deming, TJ

2017-01-01

Recent developments in the modification of methionine and other thioether-containing residues in peptides, polypeptides, and proteins are reviewed. Properties and potential applications of the resulting functionalized products are also discussed. While much of this work is focused on natural Met residues, modifications at other side-chain residues have also emerged as new thioether-containing amino acids have been incorporated into peptidic materials. Functional modification of thioether-cont...

Numerical study of the effect of earth tides on recurring short-term slow slip events

Science.gov (United States)

Matsuzawa, T.; Tanaka, Y.; Shibazaki, B.

2017-12-01

Short-term slow slip events (SSEs) in the Nankai region are affected by earth tides (e.g., Nakata et al., 2008; Ide and Tanaka, 2014; Yabe et al., 2015). The effect of tidal stress on the SSEs is also examined numerically (e.g., Hawthorne and Rubin, 2013). In our previous study (Matsuzawa et al., 2017, JpGU-AGU), we numerically simulated SSEs in the Shikoku region, and reported that tidal stress makes the variance of recurrence intervals of SSEs smaller in relatively isolated SSE regions. However, the reason of such stable recurrence was not clear. In this study, we examine the tidal effect on short-term SSEs based on a flat plate and a realistic plate model (e.g., Matsuzawa et al., 2013, GRL). We adopt a rate- and state-dependent friction law (RS-law) with cutoff velocities as in our previous studies (Matsuzawa et al., 2013). We assume that (a-b) value in the RS-law is negative within the short-term SSE region, and positive outside the region. In a flat plate model, the short-term SSE region is a circular patch with the radius of 6 km. In a realistic plate model, the short-term SSE region is based on the actual distribution of low-frequency tremor. Low effective normal stress is assumed at the depth of SSEs. Calculating stress change by earth tides as in Yabe et al., (2015), we examine the stress perturbation by two different earth tides with the period of semidiurnal (M2) and fortnight (Mf) tide in this study. In the result of a flat plate case, amplitude of SSEs becomes smaller just after the slip at whole simulated area. Recurring SSEs become clear again within one year in the case with tides (M2 or Mf), while the recurrence becomes clear after seven years in the case without tides. Interestingly, the effect of the Mf tide is similar to the case with the M2 tide, even though the amplitude of the Mf tide (0.01 kPa) is two-order smaller than that of the M2 tide. In the realistic plate model of Shikoku, clear recurrence of short-term SSEs is found earlier than the

FEMWATER: a finite-element model of water flow through saturated-unsaturated porous media

International Nuclear Information System (INIS)

Yeh, G.T.; Ward, D.S.

1980-10-01

Upon examining the Water Movement Through Saturated-Unsaturated Porous Media: A Finite-Element Galerkin Model, it was felt that the model should be modified and expanded. The modification is made in calculating the flow field in a manner consistent with the finite element approach, in evaluating the moisture-content increasing rate within the region of interest, and in numerically computing the nonlinear terms. With these modifications, the flow field is continuous everywhere in the flow regime, including element boundaries and nodal points, and the mass loss through boundaries is much reduced. Expansion is made to include four additional numerical schemes which would be more appropriate for many situations. Also, to save computer storage, all arrays pertaining to the boundary condition information are compressed to smaller dimension, and to ease the treatment of different problems, all arrays are variably dimensioned in all subroutines. This report is intended to document these efforts. In addition, in the derivation of finite-element equations, matrix component representation is used, which is believed more readable than the matrix representation in its entirety. Two identical sample problems are simulated to show the difference between the original and revised models

On P values and effect modification.

Science.gov (United States)

Mayer, Martin

2017-12-01

A crucial element of evidence-based healthcare is the sound understanding and use of statistics. As part of instilling sound statistical knowledge and practice, it seems useful to highlight instances of unsound statistical reasoning or practice, not merely in captious or vitriolic spirit, but rather, to use such error as a springboard for edification by giving tangibility to the concepts at hand and highlighting the importance of avoiding such error. This article aims to provide an instructive overview of two key statistical concepts: effect modification and P values. A recent article published in the Journal of the American College of Cardiology on side effects related to statin therapy offers a notable example of errors in understanding effect modification and P values, and although not so critical as to entirely invalidate the article, the errors still demand considerable scrutiny and correction. In doing so, this article serves as an instructive overview of the statistical concepts of effect modification and P values. Judicious handling of statistics is imperative to avoid muddying their utility. This article contributes to the body of literature aiming to improve the use of statistics, which in turn will help facilitate evidence appraisal, synthesis, translation, and application.

Treatment plan modification using voxel-based weighting factors/dose prescription

International Nuclear Information System (INIS)

Wu Chuan; Olivera, Gustavo H; Jeraj, Robert; Keller, Harry; Mackie, Thomas R

2003-01-01

Under various clinical situations, it is desirable to modify the original treatment plan to better suit the clinical goals. In this work, a method to help physicians modify treatment plans based on their clinical preferences is proposed. The method uses a weighted quadratic dose objective function. The commonly used organ-/ROI-based weighting factors are expanded to a set of voxel-based weighting factors in order to obtain greater flexibility in treatment plan modification. Two different but equivalent modification schemes based on Rustem's quadratic programming algorithms -modification of a weighting matrix and modification of prescribed doses - are presented. Case studies demonstrated the effectiveness of the two methods with regard to their capability to fine-tune treatment plans

Numerical modelling to assess maintenance strategy management options for a small tidal inlet

Science.gov (United States)

Shaeri, Saeed; Tomlinson, Rodger; Etemad-Shahidi, Amir; Strauss, Darrell

2017-03-01

Small tidal inlets are found to be more sensitive to anthropogenic alteration than their larger counterparts. Such alterations, although typically supported by technical design reports, sometimes require amendments or modification. One of the most suitable tools to conduct the necessary studies in this regard is numerical modelling, since the behaviour of the inlet system in response to proposed remedial actions, can easily be identified. In this paper, various alternative proposals are investigated to determine the most practical and viable option to mitigate the need for ongoing maintenance at a typical small, jettied tidal inlet. The main tool to investigate the alternatives is the hydro-sedimentological modelling of the inlet system, which was performed using the Delft3D software package. The proposed alternative entrance modifications were based upon structural alterations of the inlet system (such as a jetty extension or submerged weir) and non-structural scenarios (such as a change of the time of the dredging campaign or the deposition location of the dredged material). It was concluded that whilst a detailed study is inevitable in order to achieve a comprehensive design plan, based upon the results of this study the construction of a submerged weir at the entrance channel can satisfy the needs of most of the stakeholders, with justifiable costs over a longer period.

Stability studies of plasma modification effects of polylactide and polycaprolactone surface layers

Energy Technology Data Exchange (ETDEWEB)

Moraczewski, Krzysztof, E-mail: kmm@ukw.edu.pl [Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz (Poland); Stepczyńska, Magdalena [Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz (Poland); Malinowski, Rafał [Institute for Engineering of Polymer Materials and Dyes, Marii Skłodowskiej-Curie 55, 87‐100 Toruń (Poland); Rytlewski, Piotr; Jagodziński, Bartłomiej; Żenkiewicz, Marian [Kazimierz Wielki University, Chodkiewicza 30, 85-064 Bydgoszcz (Poland)

2016-07-30

Highlights: • Plasma modification affects surface roughness, wettability and surface energy. • Polylactide and polycaprolactone aging causes decay of the modification effects. • Changes in the surface characteristic and wettability deterioration were observed. • The decay occurs due to migration of low molecular weight molecules to the surface. • Plasma modification effect lasts longer in the case of polycaprolactone. - Abstract: The article presents results of research on the stability of oxygen plasma modification effects of polylactide and polycaprolactone surface layers. The modified samples were aged for three, six or nine weeks. The studies were carried out using scanning electron microscopy, goniometry and Fourier transform infrared spectroscopy. Studies have shown that the plasma modification has significant impact on the geometric structure and chemical composition of the surface, wettability and surface energy of tested polymers. The modification effects are not permanent. It has been observed that over time the effects of plasma modification fade. Studies have shown that modifying effect lasts longer in the case of polycaprolactone.

Polymersomes, smaller than you think: ferrocene as a TEM probe to determine core structure

International Nuclear Information System (INIS)

Johnston, A. H.; Dalton, P. D.; Newman, T. A.

2010-01-01

By incorporating ferrocene into the hydrophobic membrane of PEG-b-PCL polymersome nanoparticles it is possible to selectively visualize their core using Transmission Electron Microscopy (TEM). Two different sizes of ferrocene-loaded polymersomes with mean hydrodynamic diameters of approximately 40 and 90 nm were prepared. Image analysis of TEM pictures of these polymersomes found that the mean diameter of the core was 4-5 times smaller than the mean hydrodynamic diameter. The values obtained also allow the surface diameter and internal volume of the core to be calculated.

Chromatin proteins and modifications as drug targets

DEFF Research Database (Denmark)

Helin, Kristian; Dhanak, Dashyant

2013-01-01

A plethora of groundbreaking studies have demonstrated the importance of chromatin-associated proteins and post-translational modifications of histones, proteins and DNA (so-called epigenetic modifications) for transcriptional control and normal development. Disruption of epigenetic control...... is a frequent event in disease, and the first epigenetic-based therapies for cancer treatment have been approved. A generation of new classes of potent and specific inhibitors for several chromatin-associated proteins have shown promise in preclinical trials. Although the biology of epigenetic regulation...

Materials surface modification by plasma bombardment under simultaneous erosion and redeposition conditions

International Nuclear Information System (INIS)

Hirooka, Y.; Goebel, D.M.; Conn, R.W.

1986-07-01

The first in-depth investigation of surface modification of materials by continuous, high-flux argon plasma bombardment under simultaneous erosion and redeposition conditions have been carried out for copper and 304 stainless steel using the PISCES facility. The plasma bombardment conditions are: incident ion flux range from 10 17 to 10 19 ions sec -1 cm -2 , total ion fluence is controlled between 10 19 and 10 22 ions cm -2 , electron temperature range from 5 to 15 eV, and plasma density range from 10 11 to 10 13 cm -3 . The incident ion energy is 100 eV. The sample temperature is between 300 and 700K. Under redeposition dominated conditions, the material erosion rate due to the plasma bombardment is significantly smaller (by a factor up to 10) than that can be expected from the classical ion beam sputtering yield data. It is found that surface morphologies of redeposited materials strongly depend on the plasma bombardment condition. The effect of impurities on surface morphology is elucidated in detail. First-order modelings are implemented to interpret the reduced erosion rate and the surface evolution. Also, fusion related surface properties of redeposited materials such as hydrogen reemission and plasma driven permeation have been characterized

The conceptual design for the modification of HL-2A tokamak

International Nuclear Information System (INIS)

Dequan Liu

2006-01-01

The medium-sized tokamak HL-2A, based on the former ASDEX's main components has approached its rating operational parameters with I p = 450 kA and B T =2.8 T so far. The HL-2A was originally designed to operate under an axisymmetrical double-null configuration by two triplets of shaping coils located in the vacuum vessel. Because the shaping coils were set very close to the plasma column, the nulls are normally fixed and the plasma has a nearly circular cross-section. It is difficult to increase the parameters further and obtain a preferable plasma shape with certain values of triangularity and elongation. Due to the defects on upper shaping coils' electrical insulation, the HL-2A is presently just operated with lower single null divertor configuration. Additionally, the experiment has to occasionally terminate due to incidental damages of the weak parts. With the experimental progress on HL-2A, the plasma stored energy and auxiliary heating power is being increased, a more efficient, compact and tight divertor is needed. Based on present status of HL-2A tokamak and for satisfying the requirements of the experiment, the modification of HL-2A tokamak device will be carried out. The modification design of HL-2A intents to obtain optimized plasma parameters, e.g., aspect ratio, I p , b, plasma volume, certain plasma shaping with preferable elongation and triangularity, a stable vacuum vessel easy to be maintained and an advanced divertor. The primary consideration of the modification is to take all of the shaping coils out of the vessel to enlarge the plasma volume. The elongated and triangular cross section with double null of plasma is to be obtained by composite distribution of eight sets of poloidal coils. Because all poloidal coils will be located between the TF coil and the vessel, the vacuum vessel will be remade with a smaller size to make rooms for the poloidal coil system. With an optimized operation mode, the volt-second of the plasma may be increased a

Chemical mechanisms of histone lysine and arginine modifications

OpenAIRE

Smith, Brian C.; Denu, John M.

2008-01-01

Histone lysine and arginine residues are subject to a wide array of post-translational modifications including methylation, citrullination, acetylation, ubiquitination, and sumoylation. The combinatorial action of these modifications regulates critical DNA processes including replication, repair, and transcription. In addition, enzymes that modify histone lysine and arginine residues have been correlated with a variety of human diseases including arthritis, cancer, heart disease, diabetes, an...

Sexually selected nest-building--Pomatoschistus minutus males build smaller nest-openings in the presence of sneaker males.

Science.gov (United States)

Svensson, O; Kvarnemo, C

2003-09-01

Both natural selection and sexual selection may act on nest-building. We tested experimentally how different regimes of egg-predation and male-male competition influence nest-building before mating, using the marine fish sand goby, Pomatoschistus minutus. Males with sneaker males present built the smallest nest-openings, smaller than males held alone or with Pomatoschistus microps males (which may predate eggs and compete over nest-sites but not compete over fertilizations). Males with visual access to other nest-building males tended also to build smaller openings than males held alone or with P. microps. Males with egg-predators present built nests with openings not differing significantly from any other treatment. Our results indicate that the small nest-openings found in the sneaker male treatment are sexually selected through protection against sneaking or by female choice. Across treatments, time span before a male started to build his nest also explained variation in nest-opening width; males starting late built larger nest-openings.

Modification to the lower hybrid system

International Nuclear Information System (INIS)

Gormezano, C.

1989-01-01

The main modifications which have to be done to the Lower Hybrid system are related in the change of the plasma shape in front of the grill mouth. In effect, the theoretical coupling efficiency of the LHCD grill depends only upon the density at the grill mouth and upon the launched wave index. In order to minimize the number of modifications to the launcher it is proposed to modify the length of the vacuum waveguides connecting the multijunctions to the vacuum windows. To obtain the new poloidal contour, it is proposed to recover the L1 multijunctions and to remachine their mouth. (U.K.)

Modeling polyvinyl chloride Plasma Modification by Neural Networks

Science.gov (United States)

Wang, Changquan

2018-03-01

Neural networks model were constructed to analyze the connection between dielectric barrier discharge parameters and surface properties of material. The experiment data were generated from polyvinyl chloride plasma modification by using uniform design. Discharge voltage, discharge gas gap and treatment time were as neural network input layer parameters. The measured values of contact angle were as the output layer parameters. A nonlinear mathematical model of the surface modification for polyvinyl chloride was developed based upon the neural networks. The optimum model parameters were obtained by the simulation evaluation and error analysis. The results of the optimal model show that the predicted value is very close to the actual test value. The prediction model obtained here are useful for discharge plasma surface modification analysis.

Parametric characterization of a mesomechanic kinematic caused by ondulation in fabric reinforced composites: analytical and numerical investigations

Directory of Open Access Journals (Sweden)

Marco Romano

2017-01-01

Full Text Available A parametric characterization of a mesomechanic kinematic caused by ondulation in fabric reinforced composites is investigated by analytical and numerical investigations. Due to the definition of plain representative sequences of balanced plain-weave fabric reinforced single layers based on sines the variable geometric parameters are the amplitude and the length of the ondulation. The mesomechanic kinematic can be observed in both the analytic model and the FE-analyses. The analytic model yields hyperbolic correlations due to the strongly simplifying presumptions that neglect elasticity. In contrast the FE-analyses yield linear correlations in much smaller amounts due to the consideration of elastic parts, yet distinctly.

[Tattoos and piercings: motives for body modification in women suffering from borderline symptomatology].

Science.gov (United States)

Höhner, Gesche; Teismann, Tobias; Willutzki, Ulrike

2014-02-01

Do women suffering from borderline symptomatology differ from women without these symptoms regarding their motives for body modifications?A sample of 289 women with body modifications were questioned about their tattoos, piercings and motives for body modifications as well as about symptoms of borderline personality disorder. Women with borderline symptomatology were compared to women without borderline symptomatology concerning the extent of and motives for body modification.The 2 groups showed no differences in regard to amount and extent of body modifications. The "borderline"-group considered individuality, coping and management of negative life-events to be more crucial reasons for body modification than the non-borderline females.The degree of a person's body modification is not a feasible indicator for psychopathological strain. Though, for people with borderline tendency body modification may serve as a coping strategy similar to self-injury. © Georg Thieme Verlag KG Stuttgart · New York.

Modification of First-line Antiretroviral Therapy in Treatment-naive, HIV Positive Patients

Directory of Open Access Journals (Sweden)

Smita Shenoy

2017-10-01

Full Text Available Introduction: Modification of initial Antiretroviral Therapy (ART program is an important issue in HIV infected patients as the number of ART regimens available is limited. Hence, there is a need to understand the factors that affect modification and therefore, the durability of the initial antiretroviral regimen. Aim: To study the type of modification of first line ART in treatment-naive HIV positive patients and factors influencing it. Materials and Methods: A retrospective observational study was carried out in the HIV clinic of a tertiary care hospital, using data obtained from the case records of the subjects who were initiated on ART between January 2012 to December 2014. Data on patient baseline characteristics, proportion of patients who required modification, type and time of modification was collected. The determinants of time to modification were analysed using Chi-square test. Binomial logistic regression was utilized to assess independent risk factors for change in regimen. Results: Out of 200 case records analysed, 54 patients had to undergo a modification in their initial regimen. The mean age of patients was 44.68 ± 11.31 years. Majority of the patients were males. The most common reason for modification was Adverse Drug Reactions (ADRs (79.63% followed by treatment failure (9.25%. In 85.18% cases, modification involved substitution. Occurrence of ADRs and non-tenofovir based first-line regimens were associated with higher likelihood of substitution in regimen (p<0.05. The median time (IQR to modification was 173 (152.25, 293.50 days. Conclusion: ADRs and the use of non-tenofovir based regimens resulted in significantly higher rates of modification of antiretroviral therapy. There should be monitoring of patients on ART to detect ADRs at the earliest and to obtain increased use of single tablet containing tenofovir based regimen to improve durability of first line regimens.

Identification and Interrogation of Combinatorial Histone Modifications

Directory of Open Access Journals (Sweden)

Kelly R Karch

2013-12-01

Full Text Available Histone proteins are dynamically modified to mediate a variety of cellular processes including gene transcription, DNA damage repair, and apoptosis. Regulation of these processes occurs through the recruitment of non-histone proteins to chromatin by specific combinations of histone post-translational modifications (PTMs. Mass spectrometry has emerged as an essential tool to discover and quantify histone PTMs both within and between samples in an unbiased manner. Developments in mass spectrometry that allow for characterization of large histone peptides or intact protein has made it possible to determine which modifications occur simultaneously on a single histone polypeptide. A variety of techniques from biochemistry, biophysics, and chemical biology have been employed to determine the biological relevance of discovered combinatorial codes. This review first describes advancements in the field of mass spectrometry that have facilitated histone PTM analysis and then covers notable approaches to probe the biological relevance of these modifications in their nucleosomal context.

Characteristic measurements of JRR-2 after modification

International Nuclear Information System (INIS)

1977-03-01

JRR-2 was shut down in December 1973, to improve it in heavy water leakage from the metal packing between core tank and support ring, corrosion of the lower shielding plug, and fault in the control-rod mechanism. Modification was on a standing seal to stop heavy water leakage at the support ring, replacement of the reactor top shield, replacement of the control-rod mechanism, improvement of the helium system, improvement of the irradiated air system to reduce radioactive argon gas release from the stack. Works were completed in September 1975. Functional tests and characteristic measurements then followed, to show good results of the modification. Described are; modification, critical experiments, calibration of the control rods, reactor thermal power, measurements of the neutron flux distribution, core heavy water flow distribution, heavy water decomposition rate, helium leak rate and tritium concentration in the thermal shielding light water, radioactive argon gas release from the stack, and effect of the reactor top shield. (auth.)

48 CFR 252.236-7000 - Modification proposals-price breakdown.

Science.gov (United States)

2010-10-01

...-price breakdown. 252.236-7000 Section 252.236-7000 Federal Acquisition Regulations System DEFENSE... CLAUSES Text of Provisions And Clauses 252.236-7000 Modification proposals—price breakdown. As prescribed in 236.570(a), use the following clause: Modification Proposals—Price Breakdown (DEC 1991) (a) The...

Investigation of surface halide modification of nitrile butadiene rubber

Science.gov (United States)

Sukhareva, K. V.; Mikhailov, I. A.; Andriasyan, Yu O.; Mastalygina, E. E.; Popov, A. A.

2017-12-01

The investigation is devoted to the novel technology of surface halide modification of rubber samples based on nitrile butadiene rubber (NBR). 1,1,2-trifluoro-1,2,2-trichlorethane was used as halide modifier. The developed technology is characterized by production stages reduction to one by means of treating the rubber compound with a halide modifier. The surface halide modification of compounds based on nitrile butadiene rubber (NBR) was determined to result in increase of resistance to thermal oxidation and aggressive media. The conducted research revealed the influence of modification time on chemical resistance and physical-mechanical properties of rubbers under investigation.

Muonic X-ray intensities in phosphorus- and selenium modifications

International Nuclear Information System (INIS)

Kaeser, K.; Robert-Tissot, B.; Schaller, L.A.; Schellenberg, L.; Schneuwly, H.

1979-01-01

Muonic X-ray intensity measurements have been performed at SIN on allotropic modifications of phosphorus (white, red and black) and of selenium (red and black). Structure effects have been found in the intensity ratios of the K-series between amorphous and crystalline modifications of the same element. The effect in the higher series (Se) is less pronounced. On the other hand, the two crystalline phosphorus modifications (red and black) show the same intensity behavior. The root-mean-square radii 2 >sup(1/2) of phosphorus and (natural) selenium were found to be 3.187(3) fm and 4.138(1) fm respectively. (Auth.)

TEXTILE SURFACE MODIFICATION BY PYHSICAL VAPOR DEPOSITION – (REVIEW

Directory of Open Access Journals (Sweden)

YUCE Ismail

2017-05-01

Full Text Available Textile products are used in various branches of the industry from automotive to space products. Textiles produced for industrial use are generally referred to as technical textiles. Technical textiles are nowadays applied to several areas including transportation, medicine, agriculture, protection, sports, packaging, civil engineering and industry. There are rapid developments in the types of materials used in technical textiles. Therefore, modification and functionalization of textile surfaces is becoming more crucial. The improvements of the properties such as anti-bacterial properties, fire resistivity, UV radiation resistance, electrical conductivity, self cleaning, and super hydrophobic, is getting more concern with respect to developments in textile engineering. The properties of textile surfaces are closely related to the fiber structure, the differences in the polymer composition, the fiber mixture ratio, and the physical and chemical processes applied. Textile surface modifications can be examined in four groups under the name mechanical, chemical, burning and plasma. Surface modifications are made to improve the functionality of textile products. Textile surface modifications affect the properties of the products such as softness, adhesion and wettability. The purpose of this work is to reveal varieties of vapor deposition modifications to improve functionality. For this purpose, the pyhsical vapor deposition methods, their affects on textile products and their end-uses will be reviewed.

Role of Oxidative Stress in Epigenetic Modification in Endometriosis.

Science.gov (United States)

Ito, Fuminori; Yamada, Yuki; Shigemitsu, Aiko; Akinishi, Mika; Kaniwa, Hiroko; Miyake, Ryuta; Yamanaka, Shoichiro; Kobayashi, Hiroshi

2017-11-01

Aberrant DNA methylation and histone modification are associated with an increased risk of reproductive disorders such as endometriosis. However, a cause-effect relationship between epigenetic mechanisms and endometriosis development has not been fully determined. This review provides current information based on oxidative stress in epigenetic modification in endometriosis. This article reviews the English-language literature on epigenetics, DNA methylation, histone modification, and oxidative stress associated with endometriosis in an effort to identify epigenetic modification that causes a predisposition to endometriosis. Oxidative stress, secondary to the influx of hemoglobin, heme, and iron during retrograde menstruation, is involved in the expression of CpG demethylases, ten-eleven translocation, and jumonji (JMJ). Ten-eleven translocation and JMJ recognize a wide range of endogenous DNA methyltransferases (DNMTs). The increased expression levels of DNMTs may be involved in the subsequent downregulation of the decidualization-related genes. This review supports the hypothesis that there are at least 2 distinct phases of epigenetic modification in endometriosis: the initial wave of iron-induced oxidative stress would be followed by the second big wave of epigenetic modulation of endometriosis susceptibility genes. We summarize the recent advances in our understanding of the underlying epigenetic mechanisms focusing on oxidative stress in endometriosis.

Postulated weather modification effects of large energy releases

Energy Technology Data Exchange (ETDEWEB)

Ramsdell, J.V.; Scott, B.C.; Orgill, M.M.; Renne, D.S.; Hubbard, J.E.; McGinnis, K.A.

1977-02-01

Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing each impact. The primary and secondary atmospheric modifications may affect recreation, transportation, and aesthetics as well as agriculture and forestry. Economic values can be placed on some of the effects. However, the willingness of people to pay to gain benefits and avoid damages in many cases can only be determined through extensive surveys. The economic consequences of a given energy release would be highly site specific.

Postulated weather modification effects of large energy releases

International Nuclear Information System (INIS)

Ramsdell, J.V.; Scott, B.C.; Orgill, M.M.; Renne, D.S.; Hubbard, J.E.; McGinnis, K.A.

1977-02-01

Postulated impacts of large energy releases were examined in the light of existing technical information. The magnitudes of direct atmospheric modifications were estimated, and the ecological and economic implications of the modifications were explored. Energy releases from energy centers (10 to 40 power plants at a single site) and individual power plant clusters (1 to 4 power plants) were considered. In the atmosphere the energy will exist initially as increased temperature (sensible heat), moisture (latent heat), and air motion (kinetic energy). Addition of energy could result in increased cloudiness and fog, and changed precipitation patterns. A framework for economic analysis of the impacts of the postulated atmospheric modifications was established on the basis of costs and benefits. Willingness-to-pay was selected as the appropriate measure for valuing each impact. The primary and secondary atmospheric modifications may affect recreation, transportation, and aesthetics as well as agriculture and forestry. Economic values can be placed on some of the effects. However, the willingness of people to pay to gain benefits and avoid damages in many cases can only be determined through extensive surveys. The economic consequences of a given energy release would be highly site specific