Research on Standard and Automatic Judgment of Press-fit Curve of Locomotive Wheel-set Based on AAR Standard

Science.gov (United States)

Lu, Jun; Xiao, Jun; Gao, Dong Jun; Zong, Shu Yu; Li, Zhu

2018-03-01

In the production of the Association of American Railroads (AAR) locomotive wheel-set, the press-fit curve is the most important basis for the reliability of wheel-set assembly. In the past, Most of production enterprises mainly use artificial detection methods to determine the quality of assembly. There are cases of miscarriage of justice appear. For this reason, the research on the standard is carried out. And the automatic judgment of press-fit curve is analysed and designed, so as to provide guidance for the locomotive wheel-set production based on AAR standard.

The small hydropower plant in the old river Aare in Niedergoesgen, Switzerland; Kleinwasserkraftwerk Ballyschwelle, alte Aare, Niedergoesgen. Vorprojekt

Energy Technology Data Exchange (ETDEWEB)

Eichenberger, P.

2007-07-15

This preliminary project for the Swiss Federal Office of Energy (SFOE) presents a project which proposes the construction of a new small hydro plant in Niedergoesgen/Gretzenbach, Switzerland, that is to make use of the waters of the old river Aare. The project proposes the construction of a new, 350 kW plant at the site of an existing sill across the old river that originally formed part of a water-power installation given up in 1917. The existing parts of the old installation are described and the legal situation concerning water rights and land ownership are examined. Three variants for a new installation are described. Technical figures and energy-production estimates for a new installation are discussed. Ecological aspects are examined, as are the recreational aspects of the river at this location. Cost estimates and economic viability are discussed.

Direct FEM-computation of load carrying capacity of highly loaded passive components; Direkte FEM - Berechnung der Tragfaehigkeit hochbeanspruchter passiver Komponenten

Energy Technology Data Exchange (ETDEWEB)

Staat, M; Heitzer, M [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Sicherheitsforschung und Reaktortechnik

1998-11-01

Detailed, inelastic FEM analyses yield accurate information about the stresses and deformations in passive components. The local loading conditions, however, cannot be directly compared with a limit load in terms of structural mechanics. Concentration on the load carrying capacity is an approach simplifying the analysis. Based on the plasticity theory, limit and shakedown analyses calculate the load carrying capacities directly and exactly. The paper explains the implementation of the limit and shakedown data sets in a general FEM program and the direct calculation of the load carrying capacities of passive components. The concepts used are explained with respect to common structural analysis. Examples assuming high local stresses illustrate the application of FEM-based limit and shakedown analyses. The calculated interaction diagrams present a good insight into the applicable operational loads of individual passive components. The load carrying analysis also opens up a structure mechanics-based approach to assessing the load-to-collapse of cracked components made of highly ductile fracture-resistant material. (orig./CB) [Deutsch] Genaue Kenntnis der Spannungen und Verformungen in passiven Komponenten gewinnt man mit detailierten inelastischen FEM Analysen. Die lokale Beanspruchung laesst sich aber nicht direkt mit einer Beanspruchbarkeit im strukturmechanischen Sinne vergleichen. Konzentriert man sich auf die Frage nach der Tragfaehigkeit, dann vereinfacht sich die Analyse. Im Rahmen der Plastizitaetstheorie berechnen Traglast- und Einspielanalyse die tragbaren Lasten direkt und exakt. In diesem Beitrag wird eine Implementierung der Traglast- und Einspielsaetze in ein allgemeines FEM Programm vorgestellt, mit der die Tragfaehigkeit passiver Komponenten direkt berechnet wird. Die benutzten Konzepte werden in Bezug auf die uebliche Strukturanalyse erlaeutert. Beispiele mit lokal hoher Beanspruchung verdeutlichen die Anwendung der FEM basierten Traglast- und

Piimatööstused kukkusid kahjumisse / Aare Annus ; interv. Silja Lättemäe

Index Scriptorium Estoniae

Annus, Aare

2005-01-01

Tallinna Piimatööstuse AS-i nõukogu esimees Aare Annus Eesti piimatööstuste raskest olukorrast seoses toorpiima kõrge kokkuostuhinnaga. Vt. ka: Kas saite piimahinnast kõva kasumit? Küsimusele vastavad Järvamaa talunik Arvo Kuutok ja Põlva Agro OÜ nõukogu esimees Jaak Hinrikus

Adult Attachment Ratings (AAR): an item response theory analysis.

Science.gov (United States)

Pilkonis, Paul A; Kim, Yookyung; Yu, Lan; Morse, Jennifer Q

2014-01-01

The Adult Attachment Ratings (AAR) include 3 scales for anxious, ambivalent attachment (excessive dependency, interpersonal ambivalence, and compulsive care-giving), 3 for avoidant attachment (rigid self-control, defensive separation, and emotional detachment), and 1 for secure attachment. The scales include items (ranging from 6-16 in their original form) scored by raters using a 3-point format (0 = absent, 1 = present, and 2 = strongly present) and summed to produce a total score. Item response theory (IRT) analyses were conducted with data from 414 participants recruited from psychiatric outpatient, medical, and community settings to identify the most informative items from each scale. The IRT results allowed us to shorten the scales to 5-item versions that are more precise and easier to rate because of their brevity. In general, the effective range of measurement for the scales was 0 to +2 SDs for each of the attachment constructs; that is, from average to high levels of attachment problems. Evidence for convergent and discriminant validity of the scales was investigated by comparing them with the Experiences of Close Relationships-Revised (ECR-R) scale and the Kobak Attachment Q-sort. The best consensus among self-reports on the ECR-R, informant ratings on the ECR-R, and expert judgments on the Q-sort and the AAR emerged for anxious, ambivalent attachment. Given the good psychometric characteristics of the scale for secure attachment, however, this measure alone might provide a simple alternative to more elaborate procedures for some measurement purposes. Conversion tables are provided for the 7 scales to facilitate transformation from raw scores to IRT-calibrated (theta) scores.

FEM analysis of impact of external objects to pipelines

Energy Technology Data Exchange (ETDEWEB)

Gracie, Robert; Konuk, Ibrahim [Geological Survey of Canada, Ottawa, ON (Canada)]. E-mail: ikonuk@NRCan.gc.ca; Fredj, Abdelfettah [BMT Fleet Technology Limited, Ottawa, ON (Canada)

2003-07-01

One of the most common hazards to pipelines is impact of external objects. Earth moving machinery, farm equipment or bullets can dent or fail land pipelines. External objects such as anchors, fishing gear, ice can damage offshore pipelines. This paper develops an FEM model to simulate the impact process and presents investigations using the FEM model to determine the influence of the geometry and velocity of the impacting object and also will study the influence of the pipe diameter, wall thickness, and concrete thickness along with internal pressure. The FEM model is developed by using LS-DYNA explicit FEM software utilizing shell and solid elements. The model allows damage and removal of the concrete and corrosion coating elements during impact. Parametric studies will be presented relating the dent size to pipe diameter, wall thickness and concrete thickness, internal pipe pressure, and impacting object geometry. The primary objective of this paper is to develop and present the FEM model. The model can be applied to both offshore and land pipeline problems. Some examples are used to illustrate how the model can be applied to real life problems. A future paper will present more detailed parametric studies. (author)

Advanced HVAC modeling with FemLab/Simulink/MatLab

NARCIS (Netherlands)

Schijndel, van A.W.M.

2003-01-01

The combined MatLab toolboxes FemLab and Simulink are evaluated as solvers for HVAC problems based on partial differential equations (PDEs). The FemLab software is designed to simulate systems of coupled PDEs, 1-D, 2-D or 3-D, nonlinear and time dependent. In order to show how the program works, a

User's Manual for FEM-BEM Method. 1.0

Science.gov (United States)

Butler, Theresa; Deshpande, M. D. (Technical Monitor)

2002-01-01

A user's manual for using FORTRAN code to perform electromagnetic analysis of arbitrarily shaped material cylinders using a hybrid method that combines the finite element method (FEM) and the boundary element method (BEM). In this method, the material cylinder is enclosed by a fictitious boundary and the Maxwell's equations are solved by FEM inside the boundary and by BEM outside the boundary. The electromagnetic scattering on several arbitrarily shaped material cylinders using this FORTRAN code is computed to as examples.

The timing of the maximum extent of the Rhone Glacier at Wangen a.d. Aare

Energy Technology Data Exchange (ETDEWEB)

Ivy-Ochs, S.; Schluechter, C. [Bern Univ. (Switzerland); Kubik, P.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Beer, J. [EAWAG, Duebendorf (Switzerland)

1997-09-01

Erratic blocks found in the region of Wangen a.d. Aare delineate the maximum position of the Solothurn lobe of the Rhone Glacier. {sup 10}Be and {sup 26}Al exposure ages of three of these blocks show that the glacier withdraw from its maximum position at or slightly before 20,000{+-}1800 years ago. (author) 1 fig., 5 refs.

Stress And Strain Analysis of The Hip Joint Using FEM

Czech Academy of Sciences Publication Activity Database

Vaverka, M.; Návrat, Tomáš; Vrbka, M.; Florian, Z.; Fuis, Vladimír

2006-01-01

Roč. 14, 4-5 (2006), s. 271-279 ISSN 0928-7329 R&D Projects: GA ČR GA101/05/0136 Institutional research plan: CEZ:AV0Z20760514 Keywords : hip FEM surgace replacement pathological contact pressure stress * hip FEM surgace replacement pathological contact pressure stress Subject RIV: BO - Biophysics

Numerical Modelling of the Special Light Source with Novel R-FEM Method

Directory of Open Access Journals (Sweden)

Pavel Fiala

2008-01-01

Full Text Available This paper presents information about new directions in the modelling of lighting systems, and an overview of methods for the modelling of lighting systems. The novel R-FEM method is described, which is a combination of the Radiosity method and the Finite Elements Method (FEM. The paper contains modelling results and their verification by experimental measurements and by the Matlab simulation for this R-FEM method.

FEM simulation of static loading test of the Omega beam

Science.gov (United States)

Bílý, Petr; Kohoutková, Alena; Jedlinský, Petr

2017-09-01

The paper deals with a FEM simulation of static loading test of the Omega beam. Omega beam is a precast prestressed high-performance concrete element with the shape of Greek letter omega. Omega beam was designed as a self-supporting permanent formwork member for construction of girder bridges. FEM program ATENA Science was exploited for simulation of load-bearing test of the beam. The numerical model was calibrated using the data from both static loading test and tests of material properties. Comparison of load-displacement diagrams obtained from the experiment and the model was conducted. Development of cracks and crack patterns were compared. Very good agreement of experimental data and the FEM model was reached. The calibrated model can be used for design of optimized Omega beams in the future without the need of expensive loading tests. The calibrated material model can be also exploited in other types of FEM analyses of bridges constructed with the use of Omega beams, such as limit state analysis, optimization of shear connectors, prediction of long-term deflections or prediction of crack development.

Fem1b, a proapoptotic protein, mediates proteasome inhibitor-induced apoptosis of human colon cancer cells.

Science.gov (United States)

Subauste, M Cecilia; Sansom, Owen J; Porecha, Nehal; Raich, Natacha; Du, Liqin; Maher, Joseph F

2010-02-01

In the treatment of colon cancer, the development of resistance to apoptosis is a major factor in resistance to therapy. New molecular approaches to overcome apoptosis resistance, such as selectively upregulating proapoptotic proteins, are needed in colon cancer therapy. In a mouse model with inactivation of the adenomatous polyposis coli (Apc) tumor suppressor gene, reflecting the pathogenesis of most human colon cancers, the gene encoding feminization-1 homolog b (Fem1b) is upregulated in intestinal epithelium following Apc inactivation. Fem1b is a proapoptotic protein that interacts with apoptosis-inducing proteins Fas, tumor necrosis factor receptor-1 (TNFR1), and apoptotic protease activating factor-1 (Apaf-1). Increasing Fem1b expression induces apoptosis of cancer cells, but effects on colon cancer cells have not been reported. Fem1b is a homolog of feminization-1 (FEM-1), a protein in Caenorhabditis elegans that is regulated by proteasomal degradation, but whether Fem1b is likewise regulated by proteasomal degradation is unknown. Herein, we found that Fem1b protein is expressed in primary human colon cancer specimens, and in malignant SW620, HCT-116, and DLD-1 colon cancer cells. Increasing Fem1b expression, by transfection of a Fem1b expression construct, induced apoptosis of these cells. We found that proteasome inhibitor treatment of SW620, HCT-116, and DLD-1 cells caused upregulation of Fem1b protein levels, associated with induction of apoptosis. Blockade of Fem1b upregulation with morpholino antisense oligonucleotide suppressed the proteasome inhibitor-induced apoptosis of these cells. In conclusion, the proapoptotic protein Fem1b is downregulated by the proteasome in malignant colon cancer cells and mediates proteasome inhibitor-induced apoptosis of these cells. Therefore, Fem1b could represent a novel molecular target to overcome apoptosis resistance in therapy of colon cancer.

In vitro toxicity of FemOn, FemOn-SiO2 composite, and SiO2-FemOn core-shell magnetic nanoparticles

Directory of Open Access Journals (Sweden)

Toropova YG

2017-01-01

of uncoated, FemOn-SiO2 composite flake-like, and SiO2-FemOn core-shell IONPs on cell viability, function, and morphology were tested 48 h postincubation in human umbilical vein endothelial cell culture. Cell viability and apoptosis/necrosis rate were determined using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay and annexin V-phycoerythrin kit, respectively. Cell morphology was evaluated using bright-field microscopy and forward and lateral light scattering profiles obtained with flow cytometry analysis. All tested IONP types were used at three different doses, that is, 0.7, 7.0, and 70.0 µg. Dose-dependent changes in cell morphology, viability, and apoptosis rate were shown. At higher doses, all types of IONPs caused formation of binucleated cells suggesting impaired cytokinesis. FemOn-SiO2 composite flake-like and SiO2-FemOn core-shell IONPs were characterized by similar profile of cytotoxicity, whereas bare IONPs were shown to be less toxic. The presence of either silica core or silica nanoflakes in composite IONPs can promote cytotoxic effects. Keywords: iron oxide nanoparticles, composite nanoparticles, silica coating, silica nanoflakes, cytotoxicity

Coupled FEM-DBEM method to assess crack growth in magnet system of Wendelstein 7-X

Directory of Open Access Journals (Sweden)

R. Citarella

2013-10-01

Full Text Available The fivefold symmetric modular stellarator Wendelstein 7-X (W7-X is currently under construction in Greifswald, Germany. The superconducting coils of the magnet system are bolted onto a central support ring and interconnected with five so-called lateral support elements (LSEs per half module. After welding of the LSE hollow boxes to the coil cases, cracks were found in the vicinity of the welds that could potentially limit the allowed number N of electromagnetic (EM load cycles of the machine. In response to the appearance of first cracks during assembly, the Stress Intensity Factors (SIFs were calculated and corresponding crack growth rates of theoretical semi-circular cracks of measured sizes in potentially critical position and orientation were predicted using Paris’ law, whose parameters were calibrated in fatigue tests at cryogenic temperature. In this paper the Dual Boundary Element Method (DBEM is applied in a coupled FEM-DBEM approach to analyze the propagation of multiple cracks with different shapes. For this purpose, the crack path is assessed with the Minimum Strain Energy density criterion and SIFs are calculated by the J-integral approach. The Finite Element Method (FEM is adopted to model, using the commercial codes Ansys or Abaqus;, the overall component whereas the submodel analysis, in the volume surrounding the cracked area, is performed by FEM (“FEM-FEM approach” or alternatively by DBEM (“FEM-DBEM approach”. The “FEM-FEM approach” considers a FEM submodel, that is extracted from the FEM global model; the latter provide the boundary conditions for the submodel. Such approach is affected by some restrictions in the crack propagation phase, whereas, with the “FEM-DBEM approach”, the crack propagation simulation is straightforward. In this case the submodel is created in a DBEM environment with boundary conditions provided by the global FEM analysis; then the crack is introduced and a crack propagation analysis

MODAL ANALYSIS FOR REVISION OF A FEM MODEL OF A STEEL TRUSS BEAM

Directory of Open Access Journals (Sweden)

Michal Venglar

2017-11-01

Full Text Available The paper deals with a preparation of a complex FEM model for a local damage detection. The initial verified and validated three-dimensional FEM model of a steel truss bridge in laboratory is revised step-by-step to achieve the accurate model according to the experimental model. The emphasis is on modelling of the joints with 4 rivets and modelling of correct boundary conditions, as well as mass parameters and cross-section dimensions.A modal analysis of the structure is performed in FEM software. Many experimental measurements were made to correctly revise the FEM model. The calculated natural frequencies are compared with the measured ones. In addition, mode-shapes from the calculation are validated with the measured mode-shapes. The difference between the prepared FEM model and the measured specimen is small enough after a few steps of tuning. The verified, validated and revised numerical model can be used in future for a local damage detection.

Rapid Structural Design Change Evaluation with AN Experiment Based FEM

Science.gov (United States)

Chu, C.-H.; Trethewey, M. W.

1998-04-01

The work in this paper proposes a dynamic structural design model that can be developed in a rapid fashion. The approach endeavours to produce a simplified FEM developed in conjunction with an experimental modal database. The FEM is formulated directly from the geometry and connectivity used in an experimental modal test using beam/frame elements. The model sacrifices fine detail for a rapid development time. The FEM is updated at the element level so the dynamic response replicates the experimental results closely. The physical attributes of the model are retained, making it well suited to evaluate the effect of potential design changes. The capabilities are evaluated in a series of computational and laboratory tests. First, a study is performed with a simulated cantilever beam with a variable mass and stiffness distribution. The modal characteristics serve as the updating target with random noise added to simulate experimental uncertainty. A uniformly distributed FEM is developed and updated. The results show excellent results, all natural frequencies are within 0·001% with MAC values above 0·99. Next, the method is applied to predict the dynamic changes of a hardware portal frame structure for a radical design change. Natural frequency predictions from the original FEM differ by as much as almost 18% with reasonable MAC values. The results predicted from the updated model produce excellent results when compared to the actual hardware changes, the first five modal natural frequency difference is around 5% and the corresponding mode shapes producing MAC values above 0·98.

Genotype/phenotype correlations in AARS-related neuropathy in a cohort of patients from the United Kingdom and Ireland.

Science.gov (United States)

Bansagi, Boglarka; Antoniadi, Thalia; Burton-Jones, Sarah; Murphy, Sinead M; McHugh, John; Alexander, Michael; Wells, Richard; Davies, Joanna; Hilton-Jones, David; Lochmüller, Hanns; Chinnery, Patrick; Horvath, Rita

2015-08-01

Charcot-Marie-Tooth disease (CMT) is the most common inherited neuropathy with heterogeneous clinical presentation and genetic background. The axonal form (CMT2) is characterised by decreased action potentials indicating primary axonal damage. The underlying pathology involves axonal degeneration which is supposed to be related to axonal protein dysfunction caused by various gene mutations. The overlapping clinical manifestation of CMT2 with distal hereditary motor neuropathy (dHMN) and intermediate CMT causes further diagnostic difficulties. Aminoacyl-tRNA synthetases have been implicated in the pathomechanism of CMT2. They have an essential role in protein translation by attaching amino acids to their cognate tRNAs. To date six families have been reported worldwide with dominant missense alanyl-tRNA synthetase (AARS) mutations leading to clinically heterogeneous axonal neuropathies. The pathomechanism of some variants could be explained by impaired amino acylation activity while other variants implicating an editing defect need to be further investigated. Here, we report a cohort of six additional families originating from the United Kingdom and Ireland with dominant AARS-related neuropathies. The phenotypic manifestation was distal lower limb predominant sensorimotor neuropathy but upper limb impairment with split hand deformity occasionally associated. Nerve conduction studies revealed significant demyelination accompanying the axonal lesion in motor and sensory nerves. Five families have the c.986G>A, p.(Arg329His) variant, further supporting that this is a recurrent loss of function variant. The sixth family, of Irish origin, had a novel missense variant, c.2063A>G, p.(Glu688Gly). We discuss our findings and the associated phenotypic heterogeneity in these families, which expands the clinical spectrum of AARS-related neuropathies.

RACK1 downregulates levels of the pro-apoptotic protein Fem1b in apoptosis-resistant colon cancer cells.

Science.gov (United States)

Subauste, M Cecilia; Ventura-Holman, Tereza; Du, Liqin; Subauste, Jose S; Chan, Shing-Leng; Yu, Victor C; Maher, Joseph F

2009-12-01

Evasion of apoptosis plays an important role in colon cancer progression. Following loss of the Apc tumor suppressor gene in mice, the gene encoding Fem1b is upregulated early in neoplastic intestinal epithelium. Fem1b is a pro-apoptotic protein that interacts with Fas, TNFR1 and Apaf-1, and increased expression of Fem1b induces apoptosis of cancer cells. Fem1b is a homolog of FEM-1, a protein in Caenorhabditis elegans that is negatively regulated by ubiquitination and proteasomal degradation. To study Fem1b regulation in colon cancer progression, we used apoptotis-sensitive SW480 cells, derived from a primary colon cancer, and their isogenic, apoptosis-resistant counterparts SW620 cells, derived from a subsequent metastatic lesion in the same patient. Treatment with proteasome inhibitor increased Fem1b protein levels in SW620 cells, but not in SW480 cells. In SW620 cells we found that endogenous Fem1b co-immunoprecipitates in complexes with RACK1, a protein known to mediate ubiquitination and proteasomal degradation of other pro-apoptotic proteins and to be upregulated in colon cancer. Full-length Fem1b, or the N-terminal region of Fem1b, associated with RACK1 when co-expressed in HEK293T cells, and RACK1 stimulated ubiquitination of Fem1b. RACK1 overexpression in SW620 cells led to downregulation of Fem1b protein levels. Conversely, downregulation of RACK1 led to upregulation of Fem1b protein levels, associated with induction of apoptosis, and this apoptosis was inhibited by blocking Fem1b protein upregulation. In conclusion, RACK1 downregulates levels of the pro-apoptotic protein Fem1b in metastatic, apoptosis-resistant colon cancer cells, which may promote apoptosis-resistance during progression of colon cancer.

Report on first masing and single mode locking in a prebunched beam FEM oscillator

Energy Technology Data Exchange (ETDEWEB)

Cohen, M.; Eichenbaum, A.; Kleinman, H. [Tel-Aviv Univ., Ramat-Aviv (Israel)] [and others

1995-12-31

Radiation characteristics of a table-top free electron maser (FEM) are described in this paper. The FEM employs a prebunched electron beam and is operated as an oscillator in the low-gain collective (Raman) regime. Using electron beam prebunching single mode locking at any one of the possible oscillation modes was obtained. The electron beam is prebunched by a microwave tube section before it is injected into the wiggler. By tuning the electron beam bunching frequency, the FEM oscillation frequency can be locked to any eigen frequency of the resonant waveguide cavity which is within the frequency band of net gain of the FEM. The oscillation build up process is sped up, when the FEM operates with a prebunched electron beam, and the build-up time of radiation is shortened significantly. First measurements of masing with and without prebunching and characterization of the emitted radiation are reported.

Bolt-Grout Interactions in Elastoplastic Rock Mass Using Coupled FEM-FDM Techniques

Directory of Open Access Journals (Sweden)

Debasis Deb

2010-01-01

Full Text Available Numerical procedure based on finite element method (FEM and finite difference method (FDM for the analysis of bolt-grout interactions are introduced in this paper. The finite element procedure incorporates elasto-plastic concepts with Hoek and Brown yield criterion and has been applied for rock mass. Bolt-grout interactions are evaluated based on finite difference method and are embedded in the elasto-plastic procedures of FEM. The experimental validation of the proposed FEM-FDM procedures and numerical examples of a bolted tunnel are provided to demonstrate the efficacy of the proposed method for practical applications.

Mode splitting effect in FEMs with oversized Bragg resonators

Energy Technology Data Exchange (ETDEWEB)

Peskov, N. Yu.; Sergeev, A. S. [Institute of Applied Physics Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Kaminsky, A. K.; Perelstein, E. A.; Sedykh, S. N. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kuzikov, S. V. [Institute of Applied Physics Russian Academy of Sciences, Nizhny Novgorod (Russian Federation); Nizhegorodsky State University, Nizhny Novgorod (Russian Federation)

2016-07-15

Splitting of the fundamental mode in an oversized Bragg resonator with a step of the corrugation phase, which operates over the feedback loop involving the waveguide waves of different transverse structures, was found to be the result of mutual influence of the neighboring zones of the Bragg scattering. Theoretical description of this effect was developed within the framework of the advanced (four-wave) coupled-wave approach. It is shown that mode splitting reduces the selective properties, restricts the output power, and decreases the stability of the narrow-band operating regime in the free-electron maser (FEM) oscillators based on such resonators. The results of the theoretical analysis were confirmed by 3D simulations and “cold” microwave tests. Experimental data on Bragg resonators with different parameters in a 30-GHz FEM are presented. The possibility of reducing the mode splitting by profiling the corrugation parameters is shown. The use of the mode splitting effect for the output power enhancement by passive compression of the double-frequency pulse generated in the FEM with such a resonator is discussed.

Applications of ATILA FEM software to smart materials case studies in designing devices

CERN Document Server

Uchino, Kenji

2013-01-01

ATILA Finite Element Method (FEM) software facilitates the modelling and analysis of applications using piezoelectric, magnetostrictor and shape memory materials. It allows entire designs to be constructed, refined and optimized before production begins. Through a range of instructive case studies, Applications of ATILA FEM software to smart materials provides an indispensable guide to the use of this software in the design of effective products.Part one provides an introduction to ATILA FEM software, beginning with an overview of the software code. New capabilities and loss integratio

A FEM Modeling of the Concrete Pavement Made of the Recycling Material

Directory of Open Access Journals (Sweden)

Šešlija Miloš

2016-01-01

Full Text Available Paper is a brief review of the research focused on formulation an numerical model for the concrete pavement which is made by the recycling material. For numerical modeling the finite element model (FEM and the 3D finite element model were applied. The software EverFE 2.25, was used. The results of FEM analysis is in a chapter shape showing move value change, strees and deflections for all layers a construction road model. In the next phase of the research was provided by FEM software with appropriate general purpose non-linear models, which allows the analysis of the real behavior of solid pavement under load.

FEM Modelling of Lateral-Torsional Buckling Using Shell and Solid Elements

DEFF Research Database (Denmark)

Valeš, Jan; Stan, Tudor-Cristian

2017-01-01

The paper describes two methods of FEM modelling of I-section beams loaded by bending moments. Series of random realizations with initial imperfections following the first eigenmode of lateral-torsional buckling were created. Two independent FEM software products were used for analyses of resista...... of resistance. At the end the difference and correlation between the results as well as advantages and disadvantages of both methods are discussed....

A FEM based methodology to simulate multiple crack propagation in friction stir welds

DEFF Research Database (Denmark)

Lepore, Marcello; Carlone, Pierpaolo; Berto, Filippo

2017-01-01

. The residual stress field was inferred by a thermo-mechanical FEM simulation of the process, considering temperature dependent elastic-plastic material properties, material softening and isotropic hardening. Afterwards, cracks introduced in the selected location of FEM computational domain allow stress...

Development of an artificial neural network model integrated with constitutive and FEM models

International Nuclear Information System (INIS)

Kong, L.X.; Hodgson, P.D.

2000-01-01

Although the standard error of IPANN model developed by Kong and Hodgson is lower than the constitutive model, it is found that the prediction of reaction force and torque during rolling with FEM is less accurate for IPANN model in some deformation regions. It is the summation of the product of the strain and stress in the deformation range, which contributes most to the precise prediction. An ANN model is therefore, developed in this work by integrating both the IPANN and FEM models. It is found that the integrated IPANN and FEM model is the most accurate model. (author)

Application of an enriched FEM technique in thermo-mechanical contact problems

Science.gov (United States)

Khoei, A. R.; Bahmani, B.

2018-02-01

In this paper, an enriched FEM technique is employed for thermo-mechanical contact problem based on the extended finite element method. A fully coupled thermo-mechanical contact formulation is presented in the framework of X-FEM technique that takes into account the deformable continuum mechanics and the transient heat transfer analysis. The Coulomb frictional law is applied for the mechanical contact problem and a pressure dependent thermal contact model is employed through an explicit formulation in the weak form of X-FEM method. The equilibrium equations are discretized by the Newmark time splitting method and the final set of non-linear equations are solved based on the Newton-Raphson method using a staggered algorithm. Finally, in order to illustrate the capability of the proposed computational model several numerical examples are solved and the results are compared with those reported in literature.

Uncertainty assessment of a dike with an anchored sheet pile wall using FEM

NARCIS (Netherlands)

Rippi, Aikaterini; Nuttall, Jonathan; Teixeira, Ana; Schweckendiek, T.; Lang, M.; Klijn, F.; Samuels, P.

2016-01-01

The Dutch design codes for the dikes with retaining walls rely on Finite Element Analysis (FEM) in combination with partial safety factors. However, this can lead to conservative designs. For this reason, in this study, a reliability analysis is carried out with FEM calculations aiming to

Nonlinear observer design for a nonlinear string/cable FEM model using contraction theory

DEFF Research Database (Denmark)

Turkyilmaz, Yilmaz; Jouffroy, Jerome; Egeland, Olav

model is presented in the form of partial differential equations (PDE). Galerkin's method is then applied to obtain a set of ordinary differential equations such that the cable model is approximated by a FEM model. Based on the FEM model, a nonlinear observer is designed to estimate the cable...

Investigation of Ice-PVC separation under Flexural Loading using FEM Analysis

Directory of Open Access Journals (Sweden)

H Xue

2016-08-01

Full Text Available This paper presents the FEM technique applied in the study of ice separation over a polyvinyl chloride (PVC surface. A two layer model of ice and PVC is analysed theoretically using Euler-Bernoulli beam theory and the rule of mixtures. The physical samples are prepared by freezing ice over the PVC surfaces. The samples are tested experimentally in a four-point loading setup. The experimental results contain strain data gathered through a data acquisition system using the LabView software. The data is collected at the rate of 1 kHz per load step. A model is also coded in MATLAB® and simulated using the finite element method (FEM in ANSYS® Multiphysics. The FEM model of the ice and PVC sample is built using solid elements. The mesh is tested for sensitively. A good agreement is found between the theoretical, experimental and numerical simulation results.

Prediction of the FOM FEM experimental results using multi-mode time-dependent simulations

NARCIS (Netherlands)

Caplan, M.; Bongers, W. A.; Verhoeven, A. G. A.; van der Geer, C. A. J.; Valentini, M.; Urbanus, W. H.

1998-01-01

The Free Electron Maser (FEM) constructed at the FOM Institute, Netherlands is now ready to undergo the first set of short pulse (< 20 mu s) experiments to demonstrate the capability of generating 1 MW of microwave power in the range 130-250 GHz. Predictions of the FEM performance requires a

Quantification and dating of floodplain sedimentation in a medium-sized catchment of the German uplands: a case study from the Aar Valley in the southern Rhenish Massif, Germany

Directory of Open Access Journals (Sweden)

Stolz, Christian

2013-09-01

Full Text Available The distribution, thickness and composition of the floodplain sediments in the valleys of the Aar and its tributaries (Taunus Mountains were investigated by way of extensive fieldwork at 25 locations. In the entire catchment area, 48.8 million tons of loamy f loodplain fines could be assessed. Most of these were deposited since late medieval times due to extensive historical land use and forest clearing, especially in the mining region along the middle course of the Aar. In its lower course, the enhanced sedimentation of loamy f loodplain sediments started during the Bronze Age.

FEM growth and yield data monocultures - Poplar

NARCIS (Netherlands)

Mohren, G.M.J.; Goudzwaard, L.; Jansen, J.J.; Oosterbaan, A.; Oldenburger, J.F.; Ouden, den J.

2016-01-01

The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species, with only a few plots,

Simulations of e-beam emittance effects on the performance of the fusion-FEM

NARCIS (Netherlands)

Tulupov, A. V.; Caplan, M.; Urbanus, W. H.

1996-01-01

At the FOM-Institute for Plasma Physics, The Netherlands, the construction of the Fusion Free-Electron Maser (FEM) is nearing completion. The design objective of the FEM is to generate 1 MW of microwave power during long pulses in the frequency range of 130 to 260 GHz [1,2]. Applications are in the

Internal structure of the Aar Massif: What can we learn in terms of exploration for deep geothermal energy?

Science.gov (United States)

Herwegh, Marco; Baumberger, Roland; Wehrens, Philip; Schubert, Raphael; Berger, Alfons; Maeder, Urs; Spillmann, Thomas

2014-05-01

The successful use of deep geothermal energy requires 3D flow paths, which allow an efficient heat exchange between the surrounding host rocks and the circulating fluids. Recent attempts to exploit this energy resource clearly demonstrate that the new technology is facing sever problems. Some major problems are related to the prediction of permeability, the 3D structure of the flow paths and the mechanical responses during elevated fluid pressures at depths of several kilometers. Although seemingly new in a technical perspective, nature is facing and solving similar problems since the beginning of the Alpine orogeny. Based on detailed studies in the Hasli Valley (Aar Massif) we can demonstrate that deformation and fluid flow are strongly localized along mechanical anisotropies (e.g. lithological variations, brittle and ductile faults). Some of them already evolved during Variscan and post-Variscan times. Interestingly, these inherited structures are reactivated over and over again during the Alpine orogeny. Their reactivation occurred at depths of ~13-15 km with elevated temperatures (400-475°C) and involved both ductile and brittle deformation processes. Brittle deformation in form of hydrofracking was always present due to the circulating fluids. It is this process, which was and still is responsible for seismic activity. With progressive uplift and exhumation of the Aar Massif, ductile deformation structures became replaced by brittle cataclasites and fault gouges during fault activity at shallower crustal levels. Existing hydrotest data from the Grimsel Test Site (Nagra's underground research laboratory) indicate that these brittle successors of the ductile shear zones are domains of enhanced recent fluid percolation. Note that although being exposed today, the continuation of these fault structures are still active at depth in both brittle and ductile deformation modes, a fact that can be inferred from recent uplift rates and the active seismicity. On the

Development of a 2-D Simplified P3 FEM Solver for Arbitrary Geometry Applications

Energy Technology Data Exchange (ETDEWEB)

Ryu, Eun Hyun; Joo, Han Gyu [Seoul National University, Seoul (Korea, Republic of)

2010-10-15

In the calculation of power distributions and multiplication factors in a nuclear reactor, the Finite Difference Method (FDM) and the nodal methods are primarily used. These methods are, however, limited to particular geometries and lack general application involving arbitrary geometries. The Finite Element Method (FEM) can be employed for arbitrary geometry application and there are numerous FEM codes to solve the neutron diffusion equation or the Sn transport equation. The diffusion based FEM codes have the drawback of inferior accuracy while the Sn based ones require a considerable computing time. This work here is to seek a compromise between these two by employing the simplified P3 (SP3) method for arbitrary geometry applications. Sufficient accuracy with affordable computing time and resources would be achieved with this choice of approximate transport solution when compared to full FEM based Pn or Sn solutions. For now only 2-D solver is considered

Initial experiments with the FOM-Fusion-FEM

International Nuclear Information System (INIS)

Verhoeven, A.G.A.; Bongers, W.A.; Caplan, M.; Dijk, G. van; Elzendoorn, B.S.Q.

1995-01-01

A Free Electron Maser is being built for ECRH applications on future fusion research devices such as ITER. A unique feature of the Dutch FOM-Fusion-FEM is the possibility to tune the frequency over the entire range from 130 to 260 GHz while the output power exceeds 1 MW

Simulation of HMA compaction by using FEM

NARCIS (Netherlands)

ter Huerne, H.L.; van Maarseveen, M.F.A.M.; Molenaar, A.A.A.; van de Ven, M.F.C.

2008-01-01

This paper introduces a simulation tool for the compaction process of Hot Mix Asphalt (HMA) using a roller under varying external conditions. The focus is on the use of the Finite Element Model (FEM) with code DiekA, on its necessary requirements and on the presentation of simulation results. The

Unconventional material part FEM analysis

Directory of Open Access Journals (Sweden)

Michal TROPP

2016-12-01

Full Text Available The article covers the usability of alternative materials in vehicles construction. The paper elaborates upon the setup of the process and analysis of the results of carbon composite component FEM model. The 3D model, used for the examination, is a part of axle from alternative small electric vehicle. The analysis was conducted with the help of MSC Adams and Ansys Workbench software. Color maps of von Mises stress in material and total deformations of the component are the results of calculation.

Prediction of the properties of PVD/CVD coatings with the use of FEM analysis

International Nuclear Information System (INIS)

Śliwa, Agata; Mikuła, Jarosław; Gołombek, Klaudiusz; Tański, Tomasz; Kwaśny, Waldemar; Bonek, Mirosław; Brytan, Zbigniew

2016-01-01

Highlights: • Prediction of the properties of PVD/CVD coatings with the use of (FEM) analysis. • Stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N coatings. • The experimental values of stresses were determined on X-ray diffraction patterns. • An FEM model was established for the purpose of building a computer simulation. - Abstract: The aim of this paper is to present the results of the prediction of the properties of PVD/CVD coatings with the use of finite element method (FEM) analysis. The possibility of employing the FEM in the evaluation of stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N, Ti/(Ti,Si)N/(Ti,Si)N, and Ti/DLC/DLC coatings by taking into account their deposition conditions on magnesium alloys has been discussed in the paper. The difference in internal stresses in the zone between the coating and the substrate is caused by, first of all, the difference between the mechanical and thermal properties of the substrate and the coating, and also by the structural changes that occur in these materials during the fabrication process, especially during the cooling process following PVD and CVD treatment. The experimental values of stresses were determined based on X-ray diffraction patterns that correspond to the modelled values, which in turn can be used to confirm the correctness of the accepted mathematical model for testing the problem. An FEM model was established for the purpose of building a computer simulation of the internal stresses in the coatings. The accuracy of the FEM model was verified by comparing the results of the computer simulation of the stresses with experimental results. A computer simulation of the stresses was carried out in the ANSYS environment using the FEM method. Structure observations, chemical composition measurements, and mechanical property characterisations of the investigated materials has been carried out to give a background for the discussion of the results that were

Prediction of the properties of PVD/CVD coatings with the use of FEM analysis

Energy Technology Data Exchange (ETDEWEB)

Śliwa, Agata; Mikuła, Jarosław; Gołombek, Klaudiusz; Tański, Tomasz; Kwaśny, Waldemar; Bonek, Mirosław, E-mail: miroslaw.bonek@polsl.pl; Brytan, Zbigniew

2016-12-01

Highlights: • Prediction of the properties of PVD/CVD coatings with the use of (FEM) analysis. • Stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N coatings. • The experimental values of stresses were determined on X-ray diffraction patterns. • An FEM model was established for the purpose of building a computer simulation. - Abstract: The aim of this paper is to present the results of the prediction of the properties of PVD/CVD coatings with the use of finite element method (FEM) analysis. The possibility of employing the FEM in the evaluation of stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N, Ti/(Ti,Si)N/(Ti,Si)N, and Ti/DLC/DLC coatings by taking into account their deposition conditions on magnesium alloys has been discussed in the paper. The difference in internal stresses in the zone between the coating and the substrate is caused by, first of all, the difference between the mechanical and thermal properties of the substrate and the coating, and also by the structural changes that occur in these materials during the fabrication process, especially during the cooling process following PVD and CVD treatment. The experimental values of stresses were determined based on X-ray diffraction patterns that correspond to the modelled values, which in turn can be used to confirm the correctness of the accepted mathematical model for testing the problem. An FEM model was established for the purpose of building a computer simulation of the internal stresses in the coatings. The accuracy of the FEM model was verified by comparing the results of the computer simulation of the stresses with experimental results. A computer simulation of the stresses was carried out in the ANSYS environment using the FEM method. Structure observations, chemical composition measurements, and mechanical property characterisations of the investigated materials has been carried out to give a background for the discussion of the results that were

Verification of a three-dimensional FEM model for FBGs in PANDA fibers by transversal load experiments

Science.gov (United States)

Fischer, Bennet; Hopf, Barbara; Lindner, Markus; Koch, Alexander W.; Roths, Johannes

2017-04-01

A 3D FEM model of an FBG in a PANDA fiber with an extended fiber length of 25.4 mm is presented. Simulating long fiber lengths with limited computer power is achieved by using an iterative solver and by optimizing the FEM mesh. For verification purposes, the model is adapted to a configuration with transversal loads on the fiber. The 3D FEM model results correspond with experimental data and with the results of an additional 2D FEM plain strain model. In further studies, this 3D model shall be applied to more sophisticated situations, for example to study the temperature dependence of surface-glued or embedded FBGs in PANDA fibers that are used for strain-temperature decoupling.

Higher Order, Hybrid BEM/FEM Methods Applied to Antenna Modeling

Science.gov (United States)

Fink, P. W.; Wilton, D. R.; Dobbins, J. A.

2002-01-01

In this presentation, the authors address topics relevant to higher order modeling using hybrid BEM/FEM formulations. The first of these is the limitation on convergence rates imposed by geometric modeling errors in the analysis of scattering by a dielectric sphere. The second topic is the application of an Incomplete LU Threshold (ILUT) preconditioner to solve the linear system resulting from the BEM/FEM formulation. The final tOpic is the application of the higher order BEM/FEM formulation to antenna modeling problems. The authors have previously presented work on the benefits of higher order modeling. To achieve these benefits, special attention is required in the integration of singular and near-singular terms arising in the surface integral equation. Several methods for handling these terms have been presented. It is also well known that achieving he high rates of convergence afforded by higher order bases may als'o require the employment of higher order geometry models. A number of publications have described the use of quadratic elements to model curved surfaces. The authors have shown in an EFIE formulation, applied to scattering by a PEC .sphere, that quadratic order elements may be insufficient to prevent the domination of modeling errors. In fact, on a PEC sphere with radius r = 0.58 Lambda(sub 0), a quartic order geometry representation was required to obtain a convergence benefi.t from quadratic bases when compared to the convergence rate achieved with linear bases. Initial trials indicate that, for a dielectric sphere of the same radius, - requirements on the geometry model are not as severe as for the PEC sphere. The authors will present convergence results for higher order bases as a function of the geometry model order in the hybrid BEM/FEM formulation applied to dielectric spheres. It is well known that the system matrix resulting from the hybrid BEM/FEM formulation is ill -conditioned. For many real applications, a good preconditioner is required

A new 2D FEM analysis of a disc machine with offset rotor

Energy Technology Data Exchange (ETDEWEB)

Gair, S.; Canova, A. [Napier Univ., Edinburgh (United Kingdom). Dept. of Electrical, Electronic and Computer Engineering; Eastham, J.F.; Betzer, T. [Univ. of Bath (United Kingdom). School of Electronic and Electrical Engineering

1995-12-31

The paper presents a new 2-Dimensional Finite Element Method (2D FEM) analysis of a double sided axial field, permanent magnet excited brushless DC motor. The rotor of the machine is free to move in a direction perpendicular to the axis of the shaft. Computed 2D results are compared with 3D FEM analysis and the new analysis method is shown to give close agreement.

Construction of compact FEM using solenoid-induced helical wiggler

International Nuclear Information System (INIS)

Ohigashi, N.; Tsunawaki, Y.; Fujita, M.; Imasaki, K.; Mima, K.; Nakai, S.

2003-01-01

A prototype of compact Free-Electron Maser (FEM) has been designed for the operation in a usual small laboratory which does not have electric source capacity available enough. The electron energy is 60-120 keV. As it is lower, stronger guiding magnetic field is necessary in addition to wiggler field. To fulfil this condition a solenoid-induced helical wiggler is applied from the viewpoint of saving the electric power of restricted source capacity. The wiggler, for example, with the period of 12 mm creates the field of 92 G in the guiding field of 3.2 kG. The whole system of FEM has been just constructed in a small-scale laboratory. It is so small to occupy the area of 0.7x2.9 m 2

Utilization of FEM model for steel microstructure determination

Science.gov (United States)

Kešner, A.; Chotěborský, R.; Linda, M.; Hromasová, M.

2018-02-01

Agricultural tools which are used in soil processing, they are worn by abrasive wear mechanism cases by hard minerals particles in the soil. The wear rate is influenced by mechanical characterization of tools material and wear rate is influenced also by soil mineral particle contents. Mechanical properties of steel can be affected by a technology of heat treatment that it leads to a different microstructures. Experimental work how to do it is very expensive and thanks to numerical methods like FEM we can assumed microstructure at low cost but each of numerical model is necessary to be verified. The aim of this work has shown a procedure of prediction microstructure of steel for agricultural tools. The material characterizations of 51CrV4 grade steel were used for numerical simulation like TTT diagram, heat capacity, heat conduction and other physical properties of material. A relationship between predicted microstructure by FEM and real microstructure after heat treatment shows a good correlation.

Automation of hydro power on the upper Rhine and modernization of a power station at the confluence of the Rhine and Aare rivers; Automatisierung der Wasserwirtschaft am Hochrhein und Modernisierung eines Kraftwerkes am Zusammenfluss von Aare und Rhein

Energy Technology Data Exchange (ETDEWEB)

Beltzig, C.; Schlageter, G.

1996-12-31

For the first barrage weir after the confluence of the Rhine and Aare rivers, a maximum storage level is determined and set that constitutes an operating optimum and takes the different inflow and outfall volumes as well as existing retention capacities into account. Moreover, the process control system ensures automatic operation of the three engine units of the power station including process control of the barrage weir and the external systems belonging to the Albbruck-Doggern hydroelectric power station on the Rhine (RADAG). (orig./RHM)

FEM growth and yield data monocultures - White willow

NARCIS (Netherlands)

Jansen, J.J.; Oosterbaan, A.; Goudzwaard, L.; Oldenburger, J.F.; Mohren, G.M.J.; Ouden, den J.

2016-01-01

The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species, with only a few plots,

FEM growth and yield data monocultures - other species

NARCIS (Netherlands)

Goudzwaard, L.; Jansen, J.J.; Oosterbaan, A.; Oldenburger, J.F.; Mohren, G.M.J.; Ouden, den J.

2016-01-01

The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species, with only a few plots,

The small hydropower plant in the old river Aare in Niedergoesgen, Switzerland

International Nuclear Information System (INIS)

Eichenberger, P.

2007-07-01

This preliminary project for the Swiss Federal Office of Energy (SFOE) presents a project which proposes the construction of a new small hydro plant in Niedergoesgen/Gretzenbach, Switzerland, that is to make use of the waters of the old river Aare. The project proposes the construction of a new, 350 kW plant at the site of an existing sill across the old river that originally formed part of a water-power installation given up in 1917. The existing parts of the old installation are described and the legal situation concerning water rights and land ownership are examined. Three variants for a new installation are described. Technical figures and energy-production estimates for a new installation are discussed. Ecological aspects are examined, as are the recreational aspects of the river at this location. Cost estimates and economic viability are discussed.

3D FEM Simulation of Flank Wear in Turning

Science.gov (United States)

Attanasio, Aldo; Ceretti, Elisabetta; Giardini, Claudio

2011-05-01

This work deals with tool wear simulation. Studying the influence of tool wear on tool life, tool substitution policy and influence on final part quality, surface integrity, cutting forces and power consumption it is important to reduce the global process costs. Adhesion, abrasion, erosion, diffusion, corrosion and fracture are some of the phenomena responsible of the tool wear depending on the selected cutting parameters: cutting velocity, feed rate, depth of cut, …. In some cases these wear mechanisms are described by analytical models as a function of process variables (temperature, pressure and sliding velocity along the cutting surface). These analytical models are suitable to be implemented in FEM codes and they can be utilized to simulate the tool wear. In the present paper a commercial 3D FEM software has been customized to simulate the tool wear during turning operations when cutting AISI 1045 carbon steel with uncoated tungsten carbide tip. The FEM software was improved by means of a suitable subroutine able to modify the tool geometry on the basis of the estimated tool wear as the simulation goes on. Since for the considered couple of tool-workpiece material the main phenomena generating wear are the abrasive and the diffusive ones, the tool wear model implemented into the subroutine was obtained as combination between the Usui's and the Takeyama and Murata's models. A comparison between experimental and simulated flank tool wear curves is reported demonstrating that it is possible to simulate the tool wear development.

X-ray strain tensor imaging: FEM simulation and experiments with a micro-CT.

Science.gov (United States)

Kim, Jae G; Park, So E; Lee, Soo Y

2014-01-01

In tissue elasticity imaging, measuring the strain tensor components is necessary to solve the inverse problem. However, it is impractical to measure all the tensor components in ultrasound or MRI elastography because of their anisotropic spatial resolution. The objective of this study is to compute 3D strain tensor maps from the 3D CT images of a tissue-mimicking phantom. We took 3D micro-CT images of the phantom twice with applying two different mechanical compressions to it. Applying the 3D image correlation technique to the CT images under different compression, we computed 3D displacement vectors and strain tensors at every pixel. To evaluate the accuracy of the strain tensor maps, we made a 3D FEM model of the phantom, and we computed strain tensor maps through FEM simulation. Experimentally obtained strain tensor maps showed similar patterns to the FEM-simulated ones in visual inspection. The correlation between the strain tensor maps obtained from the experiment and the FEM simulation ranges from 0.03 to 0.93. Even though the strain tensor maps suffer from high level noise, we expect the x-ray strain tensor imaging may find some biomedical applications such as malignant tissue characterization and stress analysis inside the tissues.

Numerical simulation of the solitary wave interacting with an elastic structure using MPS-FEM coupled method

Science.gov (United States)

Rao, Chengping; Zhang, Youlin; Wan, Decheng

2017-12-01

Fluid-Structure Interaction (FSI) caused by fluid impacting onto a flexible structure commonly occurs in naval architecture and ocean engineering. Research on the problem of wave-structure interaction is important to ensure the safety of offshore structures. This paper presents the Moving Particle Semi-implicit and Finite Element Coupled Method (MPS-FEM) to simulate FSI problems. The Moving Particle Semi-implicit (MPS) method is used to calculate the fluid domain, while the Finite Element Method (FEM) is used to address the structure domain. The scheme for the coupling of MPS and FEM is introduced first. Then, numerical validation and convergent study are performed to verify the accuracy of the solver for solitary wave generation and FSI problems. The interaction between the solitary wave and an elastic structure is investigated by using the MPS-FEM coupled method.

Three-dimensional FEM model of FBGs in PANDA fibers with experimentally determined model parameters

Science.gov (United States)

Lindner, Markus; Hopf, Barbara; Koch, Alexander W.; Roths, Johannes

2017-04-01

A 3D-FEM model has been developed to improve the understanding of multi-parameter sensing with Bragg gratings in attached or embedded polarization maintaining fibers. The material properties of the fiber, especially Young's modulus and Poisson's ratio of the fiber's stress applying parts, are crucial for accurate simulations, but are usually not provided by the manufacturers. A methodology is presented to determine the unknown parameters by using experimental characterizations of the fiber and iterative FEM simulations. The resulting 3D-Model is capable of describing the change in birefringence of the free fiber when exposed to longitudinal strain. In future studies the 3D-FEM model will be employed to study the interaction of PANDA fibers with the surrounding materials in which they are embedded.

The program FEM3D users manual

International Nuclear Information System (INIS)

Misfeldt, I.

1977-11-01

A short description of the program FEM3D that solves the three-dimensional, multigroup, neutron diffusion equation by the finite element method. The elements are box-formed Lagrange type elements of order 1, 2, or 3. The program gives very reliable results within reasonable calculation times, but it is not a fast program and should therefore mostly be used where high precision is needed. (author/BP)

The concepts and functions of a FEM workstation

International Nuclear Information System (INIS)

Brown, R.R.; Gloudeman, J.F.

1982-01-01

Recent advances in microprocessor-based computer hardware and associated software provide a basis for the development of a FEM workstation. The key requirements for such a workstation are reviewed and the recent hardware and software developments are discussed that make such a workstation both technically and economically feasible at this time. (orig.)

Analysis of the deep rolling process on turbine blades using the FEM/BEM-coupling

International Nuclear Information System (INIS)

Baecker, V; Klocke, F; Wegner, H; Timmer, A; Grzhibovskis, R; Rjasanow, S

2010-01-01

Highly stressed components of aircraft engines, like turbine blades, have to satisfy stringent requirements regarding durability and reliability. The induction of compressive stresses and strain hardening in their surface layer has proven as a promising method to significantly increase their fatigue resistance. The required surface layer properties can be achieved by deep rolling. The determination of optimal process parameters still requires elaborate experimental set-up and subsequent time- and cost-extensive measurements. In previous works the application of the Finite Element Method (FEM) was proposed as an effective and cost reducing alternative to predict the surface layer state for given process parameters. However, FEM requires very fine mesh in the surface layer to resolve the high stress gradients with sufficient accuracy. The hereby caused high time and memory requirements render an efficient simulation of complete turbine components as impossible. In this article a solution is offered by coupling the FEM with the Boundary Elements Method (BEM). It enables the computing of large scale models at low computational cost and high result accuracy. Different approaches of the FEM/BEM-coupling for the simulation of deep rolling are examined with regard to their stability and required computing time.

Experimental study of a high-current FEM with a broadband microwave system

Energy Technology Data Exchange (ETDEWEB)

Denisov, G.G.; Bratman, V.L.; Ginzburg, N.S. [Institute of Applied Physics, Nizhny Novgorod (Russian Federation)] [and others

1995-12-31

One of the main features of FELs and FEMs is the possibility of fast and wideband tuning of the resonant frequency of active media, which can be provided by changing the particle energy. For a frequency adjustable FEM-oscillator, a broadband microwave system, which is simply combined with an electron-optical FEM system and consists of an oversized waveguide and reflectors based on the microwave beams multiplication effect has been proposed and studied successfully in {open_quotes}cold{close_quotes} measurements. Here, the operating ability of a cavity, that includes some key elements of the broadband microwave system, was tested in the presence of an electron beam. To provide large particle oscillation velocities in a moderate undulator field and the presence of a guide magnetic field, the FEM operating regime of double resonance was chosen. In this regime the cyclotron as well as undulator resonance conditions were satisfied. The FEM-oscillator was investigated experimentally on a high-current accelerator {open_quotes}Sinus-6{close_quotes} that forms an electron beam with particle energy 500keV and pulse duration 25ns. The aperture with a diameter 2.5mm at the center of the anode allows to pass through only the central fraction of the electron beam with a current about 100A and a small spread of longitudinal velocities of the particles. Operating transverse velocity was pumped into the electron beam in the pulse plane undulator of a 2.4cm period. The cavity with a frequency near 45GHz consists of a square waveguide and two reflectors. The broadband up-stream reflector based on the multiplication effect had the power reflectivity coefficient more than 90% in the frequency band 10% for the H{sup 10} wave of the square waveguide with the maximum about 100% at a frequency 45GHz. The down-stream narrow-band Bragg reflector had the power reflection coefficient approximately 80% in the frequency band of 4% near 45GHz for the operating mode.

When the science fails and the ethics works: 'Fail-safe' ethics in the FEM-PrEP study.

Science.gov (United States)

Kingori, Patricia

2015-12-01

This paper will explore the concept of 'fail safe' ethics in the FEM PrEP trial, and the practice of research and ethics on the ground. FEM-PrEP examined the efficacy of PrEP in African women after promising outcomes in research conducted with MSM. This was a hugely optimistic time and FEM-PrEP was mobilised using rights-based ethical arguments that women should have access to PrEP. This paper will present data collected during an ethnographic study of frontline research workers involved in FEM-PrEP. During our discussions, 'fail-safe' ethics emerged as concept that encapsulated their confidence that their ethics could not fail. However, in 2011, FEM-PrEP was halted and deemed a failure. The women involved in the study were held responsible because contrary to researcher's expectations they were not taking the oral PrEP being researched. This examination of FEM-PrEP will show that ethical arguments are increasingly deployed to mobilise, maintain and in some cases stop trials in ways which, at times, are superseded or co-opted by other interests. While promoting the interests of women, rights-based approaches are argued to indirectly justify the continuation of individualised, biomedical interventions which have been problematic in other women-centred trials. In this examination of FEM-PrEP, the rights-based approach obscured: ethical concerns beyond access to PrEP; the complexities of power relationships between donor and host countries; the operations of the HIV industry in research-saturated areas and the cumulative effect of unfilled expectations in HIV research and how this has shaped ideas of research and ethics.

Femur ultrasound (FemUS)-first clinical results on hip fracture discrimination and estimation of femoral BMD

DEFF Research Database (Denmark)

Barkmann, R; Dencks, S; Laugier, P

2010-01-01

has been introduced yet. We developed a QUS scanner for measurements at the femur (Femur Ultrasound Scanner, FemUS) and tested its in vivo performance. METHODS: Using the FemUS device, we obtained femoral QUS and DXA on 32 women with recent hip fractures and 30 controls. Fracture discrimination......A quantitative ultrasound (QUS) device for measurements at the proximal femur was developed and tested in vivo (Femur Ultrasound Scanner, FemUS). Hip fracture discrimination was as good as for DXA, and a high correlation with hip BMD was achieved. Our results show promise for enhanced QUS...... and the correlation with femur bone mineral density (BMD) were assessed. RESULTS: Hip fracture discrimination using the FemUS device was at least as good as with hip DXA and calcaneal QUS. Significant correlations with total hip bone mineral density were found with a correlation coefficient R (2) up to 0...

RF Wave Simulation Using the MFEM Open Source FEM Package

Science.gov (United States)

Stillerman, J.; Shiraiwa, S.; Bonoli, P. T.; Wright, J. C.; Green, D. L.; Kolev, T.

2016-10-01

A new plasma wave simulation environment based on the finite element method is presented. MFEM, a scalable open-source FEM library, is used as the basis for this capability. MFEM allows for assembling an FEM matrix of arbitrarily high order in a parallel computing environment. A 3D frequency domain RF physics layer was implemented using a python wrapper for MFEM and a cold collisional plasma model was ported. This physics layer allows for defining the plasma RF wave simulation model without user knowledge of the FEM weak-form formulation. A graphical user interface is built on πScope, a python-based scientific workbench, such that a user can build a model definition file interactively. Benchmark cases have been ported to this new environment, with results being consistent with those obtained using COMSOL multiphysics, GENRAY, and TORIC/TORLH spectral solvers. This work is a first step in bringing to bear the sophisticated computational tool suite that MFEM provides (e.g., adaptive mesh refinement, solver suite, element types) to the linear plasma-wave interaction problem, and within more complicated integrated workflows, such as coupling with core spectral solver, or incorporating additional physics such as an RF sheath potential model or kinetic effects. USDoE Awards DE-FC02-99ER54512, DE-FC02-01ER54648.

Heat Generation Effects on U-Mo/Al through ABAQUS FEM Simulation

Energy Technology Data Exchange (ETDEWEB)

Cho, Taewon; Jeong, Gwan Yoon; Lee, Cheol Min; Sohn Dongseong [Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

2014-05-15

U-Mo/Al dispersion fuels have been considered a most promising candidate for a replacement of Highly Enriched Uranium (HEU) fuel in many research reactors. Coulson developed a FEM model which show the fuel meat realistically and compared the thermal conductivity results of two and three dimensional model. Williams also developed a FEM model which are different from the former in that it use regularly meshed unit cells. He showed a heat generation effects through FEM simulation and the effective thermal conductivity of the fuel with heat generated in the fuel particles is a little lower than that of the fuel with no heat generated. In the current work, the heat generation effects are analyzed and discussed in a wider range of volume fraction with more realistic models by using ABAQUS finite element package. The FEM model is used to determine the effective thermal conductivity of U-Mo/Al and to simulate the heat generation effects in the study. This model reflected the microscopic morphology of the fuel very well by making random distribution particles although the particle shape is considered as sphere. All simulation results show the heat generation effects although the effects are small when the volume fraction of fuels are high. When the particles are surrounded with interaction layers, the heat transfer from the particle to matrix is disturbed by interaction layers due to the low thermal conductivity of interaction layers. However this effects decreases when the sum of the volume fraction of fuels and interaction layers exceeds 40-50 vol% because a great portion of the heat must pass through fuels and interaction layers although the heat is applied on the surface. Therefore particle size and initial particle volume fractions will be the important factors for the heat generation effects when interaction layers grow during irradiations.

Prediction of the properties of PVD/CVD coatings with the use of FEM analysis

Science.gov (United States)

Śliwa, Agata; Mikuła, Jarosław; Gołombek, Klaudiusz; Tański, Tomasz; Kwaśny, Waldemar; Bonek, Mirosław; Brytan, Zbigniew

2016-12-01

The aim of this paper is to present the results of the prediction of the properties of PVD/CVD coatings with the use of finite element method (FEM) analysis. The possibility of employing the FEM in the evaluation of stress distribution in multilayer Ti/Ti(C,N)/CrN, Ti/Ti(C,N)/(Ti,Al)N, Ti/(Ti,Si)N/(Ti,Si)N, and Ti/DLC/DLC coatings by taking into account their deposition conditions on magnesium alloys has been discussed in the paper. The difference in internal stresses in the zone between the coating and the substrate is caused by, first of all, the difference between the mechanical and thermal properties of the substrate and the coating, and also by the structural changes that occur in these materials during the fabrication process, especially during the cooling process following PVD and CVD treatment. The experimental values of stresses were determined based on X-ray diffraction patterns that correspond to the modelled values, which in turn can be used to confirm the correctness of the accepted mathematical model for testing the problem. An FEM model was established for the purpose of building a computer simulation of the internal stresses in the coatings. The accuracy of the FEM model was verified by comparing the results of the computer simulation of the stresses with experimental results. A computer simulation of the stresses was carried out in the ANSYS environment using the FEM method. Structure observations, chemical composition measurements, and mechanical property characterisations of the investigated materials has been carried out to give a background for the discussion of the results that were recorded during the modelling process.

An Integrated NDE and FEM Characterization of Composite Rotors

Science.gov (United States)

Abdul-Aziz, Ali; Baaklini, George Y.; Trudell, Jeffrey J.

2000-01-01

A structural assessment by integrating finite-element methods (FEM) and a nondestructive evaluation (NDE) of two flywheel rotor assemblies is presented. Composite rotor A is pancake like with a solid hub design, and composite rotor B is cylindrical with a hollow hub design. Detailed analyses under combined centrifugal and interference-fit loading are performed. Two- and three-dimensional stress analyses and two-dimensional fracture mechanics analyses are conducted. A comparison of the structural analysis results obtained with those extracted via NDE findings is reported. Contact effects due to press-fit conditions are evaluated. Stress results generated from the finite-element analyses were corroborated with the analytical solution. Cracks due to rotational loading up to 49 000 rpm for rotor A and 34 000 rpm for rotor B were successfully imaged with NDE and predicted with FEM and fracture mechanics analyses. A procedure that extends current structural analysis to a life prediction tool is also defined.

FEM growth and yield data Monocultures - Poplar (revised version)

NARCIS (Netherlands)

Mohren, G.M.J.; Goudzwaard, L.; Jansen, J.J.; Schmidt, P.; Oosterbaan, A.; Oldenburger, J.; Ouden, den J.

2017-01-01

The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species with only a few plots,

2-D FEM Simulation of Propagation and Radiation of Leaky Lamb Wave in a Plate-Type Ultrasonic Waveguide Sensor

Energy Technology Data Exchange (ETDEWEB)

Park, Sang-Jin; Kim, Hoe-Woong; Joo, Young-Sang; Kim, Sung-Kyun; Kim, Jong-Bum [KAERI, Daejeon (Korea, Republic of)

2016-05-15

This paper introduces the 2-D FEM simulation of the propagation and radiation of the leaky Lamb wave in and from a plate-type ultrasonic waveguide sensor conducted for the radiation beam profile analysis. The FEM simulations are performed with three different excitation frequencies and the radiation beam profiles obtained from FEM simulations are compared with those obtained from corresponding experiments. This paper deals with the 2-D FEM simulation of the propagation and radiation of the leaky Lamb wave in and from a plate-type ultrasonic waveguide sensor conducted to analyze the radiation beam profiles. The radiation beam profile results obtained from the FEM simulation show good agreement with the ones obtained from the experiment. This result will be utilized to improve the performance of the developed waveguide sensor. The quality of the visualized image is mainly affected by beam profile characteristics of the leaky wave radiated from the waveguide sensor. However, the relationships between the radiation beam profile and many parameters of the waveguide sensor are not fully revealed yet. Therefore, further parametric studies are necessary to improve the performance of the sensor and the finite element method (FEM) is one of the most effective tools for the parametric study.

Motion Sensorless Control of BLDC PM Motor with Offline FEM Info Assisted State Observer

DEFF Research Database (Denmark)

Stirban, Alin; Boldea, Ion; Andreescu, Gheorghe-Daniel

2010-01-01

This paper describes a new offline FEM assisted position and speed observer, for brushless dc (BLDC) PM motor drive sensorless control, based on the line-to-line PM flux linkage estimation. The zero-crossing of the line-to-line PM flux linkage occurs right in the middle of two commutation points...... identification. Digital simulations and experimental results are shown, demonstrating the reliability of the FEM assisted position and speed observer for BLDC PM motor sensorless control operation....

Determination of the fatigue behaviour of thin hard coatings using the impact test and a FEM simulation

Energy Technology Data Exchange (ETDEWEB)

Bouzakis, K.D. [Aristoteles Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Vidakis, N. [Aristoteles Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Leyendecker, T. [CemeCon, 52068 Aachen (Germany); Lemmer, O. [CemeCon, 52068 Aachen (Germany); Fuss, H.G. [CemeCon, 52068 Aachen (Germany); Erkens, G. [CemeCon, 52068 Aachen (Germany)

1996-12-15

The impact test, in combination with a finite element method (FEM) simulation, is used to determine stress values that characterise the fatigue behaviour of thin hard coatings, such as TiAlN, TiAlCN, CrN, MoN, etc. The successive impacts of a cemented carbide ball onto a coated probe induce high contact loads, which can vary in amplitude and cause plastic deformation in the substrate. In the present paper FEM calculations are used in order to determine the critical stress values, which lead to coating fatigue failure. The parametric FEM simulation developed considers elastic behaviour for the coating and elastic plastic behaviour for the substrate. The results of the FEM calculations are correlated to experimental data, as well as to SEM observations of the imprints and to microspectrum analyses within the contact region. Herewith, critical values for various stress components, which are responsible for distinctive fatigue failure modes of the coating-substrate compounds can be obtained. (orig.)

Comparative FEM-based Analysis of Multiphase Induction Motor

Directory of Open Access Journals (Sweden)

Leonard Livadaru

2014-09-01

Full Text Available This paper presents a comparative study of multiphase induction motor, which has alternately three-, five- and six-phase stator winding. The machine has been designed particularly for this purpose and has individual ring coils placed in each stator slot. The study consists in FEM analyses and mainly looks for the particularities of magnetic quantities such as air-gap flux density and electromagnetic torque.

On a Weak Discrete Maximum Principle for hp-FEM

Czech Academy of Sciences Publication Activity Database

Šolín, Pavel; Vejchodský, Tomáš

-, č. 209 (2007), s. 54-65 ISSN 0377-0427 R&D Projects: GA ČR(CZ) GA102/05/0629 Institutional research plan: CEZ:AV0Z20570509; CEZ:AV0Z10190503 Keywords : discrete maximum principle * hp-FEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.943, year: 2007

FEM simulation of multi step forming of thick sheet

NARCIS (Netherlands)

Wisselink, H.H.; Huetink, Han

2004-01-01

A case study has been performed on the forming of an industrial product. This product, a bracket, is made of 5mm thick sheet in multiple steps. The process exists of a bending step followed by a drawing and a flanging step. FEM simulations have been used to investigate this forming process. First,

Integrated FEM-DBEM simulation of crack propagation in AA2024-T3 FSW butt joints considering manufacturing effects

DEFF Research Database (Denmark)

Sonne, Mads Rostgaard; Carlone, P.; Citarella, R.

2015-01-01

This paper deals with a numerical and experimental investigation on the influence of residual stresses on fatigue crack growth in AA2024-T3 friction stir welded butt joints. An integrated FEM-DBEM procedure for the simulation of crack propagation is proposed and discussed. A numerical FEM model...... of the welding process of precipitation hardenable AA2024-T3 aluminum alloy is employed to infer the process induced residual stress field. The reliability of the FEM simulations with respect to the induced residual stresses is assessed comparing numerical outcomes with experimental data obtained by means...

Evaluating DEM results with FEM perspectives of load : soil interaction

NARCIS (Netherlands)

Tadesse, D.

2004-01-01

Keywords: Load - soil interaction, soil structure, soil mechanical properties, FEM (Finite Element Method), Plaxis (Finite Element Code), granular particles, shear stress, DEM (Distinct Element Method),

A Hybrid FEM-ANN Approach for Slope Instability Prediction

Science.gov (United States)

Verma, A. K.; Singh, T. N.; Chauhan, Nikhil Kumar; Sarkar, K.

2016-09-01

Assessment of slope stability is one of the most critical aspects for the life of a slope. In any slope vulnerability appraisal, Factor Of Safety (FOS) is the widely accepted index to understand, how close or far a slope from the failure. In this work, an attempt has been made to simulate a road cut slope in a landslide prone area in Rudrapryag, Uttarakhand, India which lies near Himalayan geodynamic mountain belt. A combination of Finite Element Method (FEM) and Artificial Neural Network (ANN) has been adopted to predict FOS of the slope. In ANN, a three layer, feed- forward back-propagation neural network with one input layer and one hidden layer with three neurons and one output layer has been considered and trained using datasets generated from numerical analysis of the slope and validated with new set of field slope data. Mean absolute percentage error estimated as 1.04 with coefficient of correlation between the FOS of FEM and ANN as 0.973, which indicates that the system is very vigorous and fast to predict FOS for any slope.

hp-FEM electromechanical transduction model of ionic polymer metal composites

Czech Academy of Sciences Publication Activity Database

Pugal, D.; Šolín, Pavel; Kim, K.; Aabloo, A.

2014-01-01

Roč. 260, April (2014), s. 135-148 ISSN 0377-0427 R&D Projects: GA ČR(CZ) GAP102/11/0498 Institutional support: RVO:61388998 Keywords : hp-FEM * Nernst-Planck * Poisson Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.266, year: 2014

Modification of the FEM3 model to ensure mass conservation

International Nuclear Information System (INIS)

Gresho, P.M.

1987-01-01

The problem of global mass conservation (lack thereof) in the current anelastic equations solved by FEM3 is described and its cause explained. The additional equations necessary to solve the problem are presented and methods for their incorporation into the current code are suggested. 14 refs

Space-time adaptive hp-FEM for problems with traveling sharp fronts

Czech Academy of Sciences Publication Activity Database

Šolín, Pavel; Korous, L.

2013-01-01

Roč. 95, č. 1 (2013), S709-S722 ISSN 0010-485X Institutional support: RVO:61388998 Keywords : adaptive hp-FEM * transient problems * sharp fronts Subject RIV: BA - General Mathematics Impact factor: 1.055, year: 2013

Using the accelerated Brazilian concrete prism test (ABCPT to evaluate alkali aggregate reaction (AAR

Directory of Open Access Journals (Sweden)

L. Sanchez

Full Text Available There are many test methods used in the laboratory to detect potential alkali-aggregate reactions (AAR. However, up to now, there is no consensus if they are reliable and efficient. This work presents the development of a new and accelerated concrete prism test called ABCPT (accelerate Brazilian concrete prism test as an attempt to create a reliable and fast test that can analyze and classify the potential reactivity of aggregates in the laboratory. For this research, six aggregates from different lithotypes were used. The methods CPT, ACPT and ABCPT were carried out with all the aggregates and a comparative analysis among all tests was performed. ABCPT seems to have a great potential to analyze and classify aggregates in the laboratory, although it needs further testing with other lithotypes to be confirmed as feasible.

An adaptive singular ES-FEM for mechanics problems with singular field of arbitrary order

OpenAIRE

Nguyen-Xuan, H.; Liu, G. R.; Bordas, Stéphane; Natarajan, S.; Rabczuk, T.

2013-01-01

This paper presents a singular edge-based smoothed finite element method (sES-FEM) for mechanics problems with singular stress fields of arbitrary order. The sES-FEM uses a basic mesh of three-noded linear triangular (T3) elements and a special layer of five-noded singular triangular elements (sT5) connected to the singular-point of the stress field. The sT5 element has an additional node on each of the two edges connected to the singular-point. It allows us to represent simple and efficient ...

Spacetime Discontinuous Galerkin FEM: Spectral Response

International Nuclear Information System (INIS)

Abedi, R; Omidi, O; Clarke, P L

2014-01-01

Materials in nature demonstrate certain spectral shapes in terms of their material properties. Since successful experimental demonstrations in 2000, metamaterials have provided a means to engineer materials with desired spectral shapes for their material properties. Computational tools are employed in two different aspects for metamaterial modeling: 1. Mircoscale unit cell analysis to derive and possibly optimize material's spectral response; 2. macroscale to analyze their interaction with conventional material. We compare two different approaches of Time-Domain (TD) and Frequency Domain (FD) methods for metamaterial applications. Finally, we discuss advantages of the TD method of Spacetime Discontinuous Galerkin finite element method (FEM) for spectral analysis of metamaterials

Numerical calculation of acoustic radiation from band-vibrating structures via FEM/FAQP method

Directory of Open Access Journals (Sweden)

GAO Honglin

2017-08-01

Full Text Available The Finite Element Method (FEM combined with the Frequency Averaged Quadratic Pressure method (FAQP are used to calculate the acoustic radiation of structures excited in the frequency band. The surface particle velocity of stiffened cylindrical shells under frequency band excitation is calculated using finite element software, the normal vibration velocity is converted from the surface particle velocity to calculate the average energy source (frequency averaged across intensity, frequency averaged across pressure and frequency averaged across velocity, and the FAQP method is used to calculate the average sound pressure level within the bandwidth. The average sound pressure levels are then compared with the bandwidth using finite element and boundary element software, and the results show that FEM combined with FAQP is more suitable for high frequencies and can be used to calculate the average sound pressure level in the 1/3 octave band with good stability, presenting an alternative to applying frequency-by-frequency calculation and the average frequency process. The FEM/FAQP method can be used as a prediction method for calculating acoustic radiation while taking the randomness of vibration at medium and high frequencies into consideration.

Crack growth analysis in a weld-heat-affected zone using S-version FEM

International Nuclear Information System (INIS)

Kikuchi, Masanori; Wada, Yoshitaka; Shimizu, Yuto; Li, Yulong

2012-01-01

The objective of this study is the prediction of crack propagation under thermal, residual stress fields using S-Version FEM (S-FEM). By using the S-FEM technique, only the local mesh should be re-meshed and it becomes easy to simulate crack growth. By combining with an auto-meshing technique, the local mesh is re-meshed automatically, and a curved crack path is modeled easily. Virtual crack closure integral method (VCCM) is used to evaluate energy release rate at the crack tip. For crack growth analyses, crack growth rate and growth direction are determined using criteria for mixed mode loading condition. In order to confirm the validity of this analysis, some comparisons with previously reported analyses were done, and good agreement obtained. In this study, residual stress data were provided by JAEA, Japan Atomic Energy Agency, based on their numerical simulation. Stress corrosion crack (SCC) growth analyses in a pipe are conducted in two-dimensional and three-dimensional fields. Two cases, for an axi-symmetric distribution of residual stress in the pipe wall and a non-axisymmetric one are assumed. Effects of residual stress distribution patterns on SCC cracking are evaluated and discussed.

Uncertainty assessment of a dike with an anchored sheet pile wall using FEM

Directory of Open Access Journals (Sweden)

Rippi Aikaterini

2016-01-01

Full Text Available The Dutch design codes for the dikes with retaining walls rely on Finite Element Analysis (FEM in combination with partial safety factors. However, this can lead to conservative designs. For this reason, in this study, a reliability analysis is carried out with FEM calculations aiming to demonstrate the feasibility of reliability analysis for a dike with an anchored sheet pile wall modelled in the 2D FEM, Plaxis. Sensitivity and reliability analyses were carried out and enabled by coupling the uncertainty package, OpenTURNS and Plaxis. The most relevant (ultimate limit states concern the anchor, the sheet pile wall, the soil body failure (global instability and finally the system. The case was used to investigate the applicability of the First Order Reliability Method (FORM and Directional Sampling (DS to analysing these limit states. The final goal is to estimate the probability of failure and identify the most important soil properties that affect the behaviour of each component and the system as a whole. The results of this research can be used to assess and optimize the current design procedure for dikes with retaining walls.

AN APPROACH TO EFFICIENT FEM SIMULATIONS ON GRAPHICS PROCESSING UNITS USING CUDA

Directory of Open Access Journals (Sweden)

Björn Nutti

2014-04-01

Full Text Available The paper presents a highly efficient way of simulating the dynamic behavior of deformable objects by means of the finite element method (FEM with computations performed on Graphics Processing Units (GPU. The presented implementation reduces bottlenecks related to memory accesses by grouping the necessary data per node pairs, in contrast to the classical way done per element. This strategy reduces the memory access patterns that are not suitable for the GPU memory architecture. Furthermore, the presented implementation takes advantage of the underlying sparse-block-matrix structure, and it has been demonstrated how to avoid potential bottlenecks in the algorithm. To achieve plausible deformational behavior for large local rotations, the objects are modeled by means of a simplified co-rotational FEM formulation.

An eddy current vector potential formulation for estimating hysteresis losses of superconductors with FEM

International Nuclear Information System (INIS)

Stenvall, A; Tarhasaari, T

2010-01-01

Many people these days employ only commercial finite element method (FEM) software when solving for the hysteresis losses of superconductors. Thus, the knowledge of a modeller is in the capability of using the black boxes of software efficiently. This has led to a relatively superficial examination of different formulations while the discussion stays mainly on the usage of the user interfaces of these programs. Also, if we stay only at the mercy of commercial software producers, we end up having less and less knowledge on the details of solvers. Then, it becomes more and more difficult to conceptually solve new kinds of problem. This may prevent us finding new kinds of method to solve old problems more efficiently, or finding a solution for a problem that was considered almost impossible earlier. In our earlier research, we presented the background of a co-tree gauged T-ψ FEM solver for computing the hysteresis losses of superconductors. In this paper, we examine the feasibility of FEM and eddy current vector potential formulation in the same problem.

Influence of seed layer moduli on FEM based modulus backcalculation results

CSIR Research Space (South Africa)

Matsui, K

2006-01-01

Full Text Available This paper presents recentupdates of DBALM (Dynamic Back Analysis for Layer Moduli) software whose solver is based on exi-symmetric FEM and was first developed in 1993. Examples of airfield pavement application are also presented. The results...

Fem Dewey-begreber til analyse af Facilitated Work Based Learning

DEFF Research Database (Denmark)

Thomassen, Anja Overgaard

teoretiske ramme er helt overvejende baseret på John Deweys (1859-1952) pragmatisme og herudfra er der udviklet modeller, som anvendes i analysen af de empiriske data. Det fremlægges i paperet, hvorledes disse modeller er blevet udviklet og anvendt i ph.d.-afhandlingen, og hvorledes de centrale fem begreber...

FEM-based neural-network approach to nonlinear modeling with application to longitudinal vehicle dynamics control.

Science.gov (United States)

Kalkkuhl, J; Hunt, K J; Fritz, H

1999-01-01

An finite-element methods (FEM)-based neural-network approach to Nonlinear AutoRegressive with eXogenous input (NARX) modeling is presented. The method uses multilinear interpolation functions on C0 rectangular elements. The local and global structure of the resulting model is analyzed. It is shown that the model can be interpreted both as a local model network and a single layer feedforward neural network. The main aim is to use the model for nonlinear control design. The proposed FEM NARX description is easily accessible to feedback linearizing control techniques. Its use with a two-degrees of freedom nonlinear internal model controller is discussed. The approach is applied to modeling of the nonlinear longitudinal dynamics of an experimental lorry, using measured data. The modeling results are compared with local model network and multilayer perceptron approaches. A nonlinear speed controller was designed based on the identified FEM model. The controller was implemented in a test vehicle, and several experimental results are presented.

FEM Analysis and Measurement of Residual Stress by Neutron Diffraction on the Dissimilar Overlay Weld Pipe

International Nuclear Information System (INIS)

Kim, Kang Soo; Lee, Ho Jin; Woo, Wan Chuck; Seong, Baek Seok; Byeon, Jin Gwi; Park, Kwang Soo; Jung, In Chul

2010-01-01

Much research has been done to estimate the residual stress on a dissimilar metal weld. There are many methods to estimate the weld residual stress and FEM (Finite Element Method) is generally used due to the advantage of the parametric study. And the X-ray method and a Hole Drilling technique for an experimental method are also usually used. The aim of this paper is to develop the appropriate FEM model to estimate the residual stresses of the dissimilar overlay weld pipe. For this, firstly, the specimen of the dissimilar overlay weld pipe was manufactured. The SA 508 Gr3 nozzle, the SA 182 safe end and SA376 pipe were welded by the Alloy 182. And the overlay weld by the Alloy 52M was performed. The residual stress of this specimen was measured by using the Neutron Diffraction device in the HANARO (High-flux Advanced Neutron Application ReactOr) research reactor, KAERI (Korea Atomic Energy Research Institute). Secondly, FEM Model on the dissimilar overlay weld pipe was made and analyzed by the ABAQUS Code (ABAQUS, 2004). Thermal analysis and stress analysis were performed, and the residual stress was calculated. Thirdly, the results of the FEM analysis were compared with those of the experimental methods

Efficient preconditioning of hphp-FEM matrix sequences with slowly-varying coefficients

DEFF Research Database (Denmark)

Gatto, P.; Hesthaven, J. S.; Christiansen, Rasmus Ellebæk

2017-01-01

We previously introduced a preconditioner that has proven effective for hphp-FEM discretizations of various challenging elliptic and hyperbolic problems. The construction is inspired by standard nested dissection, and relies on the assumption that the Schur complements can be approximated, to hig...

3D FEM Geometry and Material Flow Optimization of Porthole-Die Extrusion

International Nuclear Information System (INIS)

Ceretti, Elisabetta; Mazzoni, Luca; Giardini, Claudio

2007-01-01

The aim of this work is to design and to improve the geometry of a porthole-die for the production of aluminum components by means of 3D FEM simulations. In fact, the use of finite element models will allow to investigate the effects of the die geometry (webs, extrusion cavity) on the material flow and on the stresses acting on the die so to reduce the die wear and to improve the tool life. The software used to perform the simulations was a commercial FEM code, Deform 3D. The technological data introduced in the FE model have been furnished by METRA S.p.A. Company, partner in this research. The results obtained have been considered valid and helpful by the Company for building a new optimized extrusion porthole-die

Generalized multiscale finite element methods (GMsFEM)

KAUST Repository

Efendiev, Yalchin R.; Galvis, Juan; Hou, Thomasyizhao

2013-01-01

In this paper, we propose a general approach called Generalized Multiscale Finite Element Method (GMsFEM) for performing multiscale simulations for problems without scale separation over a complex input space. As in multiscale finite element methods (MsFEMs), the main idea of the proposed approach is to construct a small dimensional local solution space that can be used to generate an efficient and accurate approximation to the multiscale solution with a potentially high dimensional input parameter space. In the proposed approach, we present a general procedure to construct the offline space that is used for a systematic enrichment of the coarse solution space in the online stage. The enrichment in the online stage is performed based on a spectral decomposition of the offline space. In the online stage, for any input parameter, a multiscale space is constructed to solve the global problem on a coarse grid. The online space is constructed via a spectral decomposition of the offline space and by choosing the eigenvectors corresponding to the largest eigenvalues. The computational saving is due to the fact that the construction of the online multiscale space for any input parameter is fast and this space can be re-used for solving the forward problem with any forcing and boundary condition. Compared with the other approaches where global snapshots are used, the local approach that we present in this paper allows us to eliminate unnecessary degrees of freedom on a coarse-grid level. We present various examples in the paper and some numerical results to demonstrate the effectiveness of our method. © 2013 Elsevier Inc.

Generalized multiscale finite element methods (GMsFEM)

KAUST Repository

Efendiev, Yalchin R.

2013-10-01

In this paper, we propose a general approach called Generalized Multiscale Finite Element Method (GMsFEM) for performing multiscale simulations for problems without scale separation over a complex input space. As in multiscale finite element methods (MsFEMs), the main idea of the proposed approach is to construct a small dimensional local solution space that can be used to generate an efficient and accurate approximation to the multiscale solution with a potentially high dimensional input parameter space. In the proposed approach, we present a general procedure to construct the offline space that is used for a systematic enrichment of the coarse solution space in the online stage. The enrichment in the online stage is performed based on a spectral decomposition of the offline space. In the online stage, for any input parameter, a multiscale space is constructed to solve the global problem on a coarse grid. The online space is constructed via a spectral decomposition of the offline space and by choosing the eigenvectors corresponding to the largest eigenvalues. The computational saving is due to the fact that the construction of the online multiscale space for any input parameter is fast and this space can be re-used for solving the forward problem with any forcing and boundary condition. Compared with the other approaches where global snapshots are used, the local approach that we present in this paper allows us to eliminate unnecessary degrees of freedom on a coarse-grid level. We present various examples in the paper and some numerical results to demonstrate the effectiveness of our method. © 2013 Elsevier Inc.

Investigation of load transfer efficiency in jointed plain concrete pavements (JPCP using FEM

Directory of Open Access Journals (Sweden)

Vahid Sadeghi

2018-05-01

Full Text Available Owing to heavy traffic loads, rigid pavements encounter various types of failures at transverse joints during their lifetime. Three-dimensional finite-element method (3D-FEM was used to assess the structural response of jointed concrete pavement under moving tandem axle loads. In this study, 3D FEM was verified using an existing numerical model and field measurement of the concrete slab traversed by a moving truck. This paper also investigated the effects of multiple parameters: material properties, slab geometry, load magnitude and frictional status of the slab and base layer on load transfer efficiency (LTE of the transverse joints. Further study has been done to investigate the slab performance without the dowel bars which occurs when parts of the pavement needed to be repaired using precast slabs. The aggregate interlock between the new slab and the existing slab is simulated by frictional interface. In 3D FEM model, the load transfer efficiency has been improved by increasing the elasticity modules of the concrete slab and the base layer or increasing the slab thickness. This can decrease the joints' deflections, reduces the damages on pavement joints. Removing dowel bars adversely affected the load transfer. Keywords: Concrete pavement, Load transfer, Finite-element method, Dowel bar, Structural behavior

Experiment study and FEM simulation on erythrocytes under linear stretching of optical micromanipulation

Science.gov (United States)

Liu, Ying; Song, Huadong; Zhu, Panpan; Lu, Hao; Tang, Qi

2017-08-01

The elasticity of erythrocytes is an important criterion to evaluate the quality of blood. This paper presents a novel research on erythrocytes' elasticity with the application of optical tweezers and the finite element method (FEM) during blood storage. In this work, the erythrocytes with different in vitro times were linearly stretched by trapping force using optical tweezers and the time dependent elasticity of erythrocytes was investigated. The experimental results indicate that the membrane shear moduli of erythrocytes increased with the increasing in vitro time, namely the elasticity was decreasing. Simultaneously, an erythrocyte shell model with two parameters (membrane thickness h and membrane shear modulus H) was built to simulate the linear stretching states of erythrocytes by the FEM, and the simulations conform to the results obtained in the experiment. The evolution process was found that the erythrocytes membrane thicknesses were decreasing. The analysis assumes that the partial proteins and lipid bilayer of erythrocyte membrane were decomposed during the in vitro preservation of blood, which results in thin thickness, weak bending resistance, and losing elasticity of erythrocyte membrane. This study implies that the FEM can be employed to investigate the inward mechanical property changes of erythrocyte in different environments, which also can be a guideline for studying the erythrocyte mechanical state suffered from different diseases.

An effective FEM-based approach for discrete 3D crack growth

DEFF Research Database (Denmark)

Nielsen, Morten Eggert; Lambertsen, Søren Heide; Pedersen, Erik B.

2015-01-01

A new geometric approach for discrete crack growth modeling is proposed and implemented in a commercial FEM software. The basic idea is to model the crack growth by removing volumes of material as the crack front advances. Thereby, adaptive meshing techniques, found in commercial software, is wel...

Analysis of polyethylene terephthalate PET plastic bottle jointing system using finite element method (FEM)

Science.gov (United States)

Zaidi, N. A.; Rosli, Muhamad Farizuan; Effendi, M. S. M.; Abdullah, Mohamad Hariri

2017-09-01

For almost all injection molding applications of Polyethylene Terephthalate (PET) plastic was analyzed the strength, durability and stiffness of properties by using Finite Element Method (FEM) for jointing system of wood furniture. The FEM was utilized for analyzing the PET jointing system for Oak and Pine as wood based material of furniture. The difference pattern design of PET as wood jointing furniture gives the difference value of strength furniture itself. The results show the wood specimen with grooves and eclipse pattern design PET jointing give lower global estimated error is 28.90%, compare to the rectangular and non-grooves wood specimen of global estimated error is 63.21%.

First lasing of the Dutch Fusion-FEM: 730 kW, 200 GHz

Energy Technology Data Exchange (ETDEWEB)

Urbanus, W.H. E-mail: urbanus@rijnh.nl; Bongers, W.A.; Geer, C.A.J. van der; Manintveld, P.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Smeets, P.H.M.; Schueller, F.C.; Verhoeven, A.G.A.; Bratman, V.L.; Denisov, G.G.; Savilov, A.V.; Shmelyov, M.Yu.; Caplan, M.; Varfolomeev, A.A

1999-06-01

A high-power electrostatic free-electron maser is operated at various frequencies. An output power of 730 kW at 206 GHz is generated with a 7.2 A, 1.77 MeV electron beam, and 360 kW at 167 GHz is generated with a 7.0 A, 1.61 MeV electron beam. It is shown experimentally and by simulations that, depending on the electron beam energy, the FEM can operate in single-frequency regime. First experiments were done without electron beam energy recovery system, and the pulse length was limited to 12 {mu}s. Nevertheless, many aspects of generation of mm-wave power have been explored, such as the dependency on the electron beam energy and beam current and cavity settings such as the feedback coefficient. The achieved parameters and the FEM dynamics are in good accordance with simulations.

New progress of FEM simulation and AI application in rolling at RAL

International Nuclear Information System (INIS)

Liu Xianghua; Wang Guodong; Zhao Kun

2000-01-01

New progresses on FEM simulation and AI application in rolling have been achieved at RAL recently. The existence and uniqueness of the extreme point of total functional for rolling problem has been proved. Different rolling processes, such as H-beam rolling, ribbing strip rolling, slab sizing, have been solved by our in-house FEM software package. The simulation results have been put into production use to improve the precision of math models. The Artificial Neural Network has been used to predict rolling force, coiling temperature, microstructure and properties of the rolled products. An expert system for deviation diagnoses of strip thickness has been developed for industry use. Synergetic Artificial Intelligence has also been applied to rolling scheduling. We are making continuous efforts to develop AI applications for rolling line co-operating in China steel industry. (author)

Stress and fatigue analyses of primary circuit components of NPP using FEM

International Nuclear Information System (INIS)

Gal, P.

2015-01-01

This poster is a short illustration of the numerical assessment of the VVER-440 reactor pressure vessel (RPV) main flange. RPV main flange consists in free flange, pressure ring, flange bolts, nut and nickel gasket. Operating temperature transient modes, like heat up regime can lead to serious tension in bolts. So temperature fields have to be calculated. The fatigue assessment of the main flange bolt requires the determination of the coefficient of stress concentrators in bolt thread. Stress concentrators can be computed through FEM or given by norms (PNAEG). The most significant value of fatigue usage factor is in the first thread connection between bolt and nut. A finite element method (FEM) is used for calculation stress and temperature distribution in the reactor flange. The reassessment was performed according Czech normative document NTD-A.S.I. and VERLIFE

Structural modeling of tissue-specific mitochondrial alanyl-tRNA synthetase (AARS2 defects predicts differential effects on aminoacylation

Directory of Open Access Journals (Sweden)

Liliya eEuro

2015-02-01

Full Text Available The accuracy of mitochondrial protein synthesis is dependent on the coordinated action of nuclear-encoded mitochondrial aminoacyl-tRNA synthetases (mtARSs and the mitochondrial DNA-encoded tRNAs. The recent advances in whole-exome sequencing have revealed the importance of the mtARS proteins for mitochondrial pathophysiology since nearly every nuclear gene for mtARS (out of 19 is now recognized as a disease gene for mitochondrial disease. Typically, defects in each mtARS have been identified in one tissue-specific disease, most commonly affecting the brain, or in one syndrome. However, mutations in the AARS2 gene for mitochondrial alanyl-tRNA synthetase (mtAlaRS have been reported both in patients with infantile-onset cardiomyopathy and in patients with childhood to adulthood-onset leukoencephalopathy. We present here an investigation of the effects of the described mutations on the structure of the synthetase, in an effort to understand the tissue-specific outcomes of the different mutations.The mtAlaRS differs from the other mtARSs because in addition to the aminoacylation domain, it has a conserved editing domain for deacylating tRNAs that have been mischarged with incorrect amino acids. We show that the cardiomyopathy phenotype results from a single allele, causing an amino acid change p.R592W in the editing domain of AARS2, whereas the leukodystrophy mutations are located in other domains of the synthetase. Nevertheless, our structural analysis predicts that all mutations reduce the aminoacylation activity of the synthetase, because all mtAlaRS domains contribute to tRNA binding for aminoacylation. According to our model, the cardiomyopathy mutations severely compromise aminoacylation whereas partial activity is retained by the mutation combinations found in the leukodystrophy patients. These predictions provide a hypothesis for the molecular basis of the distinct tissue-specific phenotypic outcomes.

The Benefit of 3D Laser Scanning Technology in the Generation and Calibration of FEM Models for Health Assessment of Concrete Structures

Directory of Open Access Journals (Sweden)

Hao Yang

2014-11-01

Full Text Available Terrestrial laser scanning technology (TLS is a new technique for quickly getting three-dimensional information. In this paper we research the health assessment of concrete structures with a Finite Element Method (FEM model based on TLS. The goal focuses on the benefits of 3D TLS in the generation and calibration of FEM models, in order to build a convenient, efficient and intelligent model which can be widely used for the detection and assessment of bridges, buildings, subways and other objects. After comparing the finite element simulation with surface-based measurement data from TLS, the FEM model is determined to be acceptable with an error of less than 5%. The benefit of TLS lies mainly in the possibility of a surface-based validation of results predicted by the FEM model.

The benefit of 3D laser scanning technology in the generation and calibration of FEM models for health assessment of concrete structures.

Science.gov (United States)

Yang, Hao; Xu, Xiangyang; Neumann, Ingo

2014-11-19

Terrestrial laser scanning technology (TLS) is a new technique for quickly getting three-dimensional information. In this paper we research the health assessment of concrete structures with a Finite Element Method (FEM) model based on TLS. The goal focuses on the benefits of 3D TLS in the generation and calibration of FEM models, in order to build a convenient, efficient and intelligent model which can be widely used for the detection and assessment of bridges, buildings, subways and other objects. After comparing the finite element simulation with surface-based measurement data from TLS, the FEM model is determined to be acceptable with an error of less than 5%. The benefit of TLS lies mainly in the possibility of a surface-based validation of results predicted by the FEM model.

FEM-DEM coupling simulations of the tool wear characteristics in prestressed machining superalloy

Directory of Open Access Journals (Sweden)

Ruitao Peng

2016-01-01

Full Text Available Due to the complicated contact loading at the tool-chip interface, ceramic tool wear in prestressed machining superalloy is rare difficult to evaluate only by experimental approaches. This study aims to develop a methodology to predict the tool wear evolution by using combined FEM and DEM numerical simulations. Firstly, a finite element model for prestressed cutting is established, subsequently a discrete element model to describe the tool-chip behaviour is established based on the obtained boundary conditions by FEM simulations, finally, simulated results are experimentally validated. The predicted tool wear results show nice agreement with experiments, the simulation indicates that, within a certain range, higher cutting speed effectively results in slighter wear of Sialon ceramic tools, and deeper depth of cut leads to more serious tool wear.

CFD-FEM coupling for accurate prediction of thermal fatigue

International Nuclear Information System (INIS)

Hannink, M.H.C.; Kuczaj, A.K.; Blom, F.J.; Church, J.M.; Komen, E.M.J.

2009-01-01

Thermal fatigue is a safety related issue in primary pipework systems of nuclear power plants. Life extension of current reactors and the design of a next generation of new reactors lead to growing importance of research in this direction. The thermal fatigue degradation mechanism is induced by temperature fluctuations in a fluid, which arise from mixing of hot and cold flows. Accompanied physical phenomena include thermal stratification, thermal striping, and turbulence [1]. Current plant instrumentation systems allow monitoring of possible causes as stratification and temperature gradients at fatigue susceptible locations [1]. However, high-cycle temperature fluctuations associated with turbulent mixing cannot be adequately detected by common thermocouple instrumentations. For a proper evaluation of thermal fatigue, therefore, numerical simulations are necessary that couple instantaneous fluid and solid interactions. In this work, a strategy for the numerical prediction of thermal fatigue is presented. The approach couples Computational Fluid Dynamics (CFD) and the Finite Element Method (FEM). For the development of the computational approach, a classical test case for the investigation of thermal fatigue problems is studied, i.e. mixing in a T-junction. Due to turbulent mixing of hot and cold fluids in two perpendicularly connected pipes, temperature fluctuations arise in the mixing zone downstream in the flow. Subsequently, these temperature fluctuations are also induced in the pipes. The stresses that arise due to the fluctuations may eventually lead to thermal fatigue. In the first step of the applied procedure, the temperature fluctuations in both fluid and structure are calculated using the CFD method. Subsequently, the temperature fluctuations in the structure are imposed as thermal loads in a FEM model of the pipes. A mechanical analysis is then performed to determine the thermal stresses, which are used to predict the fatigue lifetime of the structure

Efficiency improvement and torque ripple minimization of Switched Reluctance Motor using FEM and Seeker Optimization Algorithm

International Nuclear Information System (INIS)

Navardi, Mohammad Javad; Babaghorbani, Behnaz; Ketabi, Abbas

2014-01-01

Highlights: • This paper proposes a new method to optimize a Switched Reluctance Motor (SRM). • A combination of SOA and GA with Finite Element Method (FEM) analysis is employed to solve the SRM design optimization. • The results show that optimized SRM obtains higher average torque and higher efficiency. - Abstract: In this paper, performance optimization of Switched Reluctance Motor (SRM) was determined using Seeker Optimization Algorithm (SOA). The most efficient aim of the algorithm was found for maximum torque value at a minimum mass of the entire construction, following changing the geometric parameters. The optimization process was carried out using a combination of Seeker Optimization Algorithm and Finite Element Method (FEM). Fitness value was calculated by FEM analysis using COMSOL3.4, and the SOA was realized by MATLAB. The proposed method has been applied for a case study and it has been also compared with Genetic Algorithm (GA). The results show that the optimized motor using SOA had higher torque value and efficiency with lower mass and torque ripple, exhibiting the validity of this methodology for SRM design

Electrical performance analysis of HTS synchronous motor based on 3D FEM

International Nuclear Information System (INIS)

Baik, S.K.; Kwon, Y.K.; Kim, H.M.; Lee, J.D.; Kim, Y.C.; Park, G.S.

2010-01-01

A 1-MW class superconducting motor with High-Temperature Superconducting (HTS) field coil is analyzed and tested. This machine is a prototype to make sure applicability aimed at generator and industrial motor applications such as blowers, pumps and compressors installed in large plants. This machine has the HTS field coil made of Bi-2223 HTS wire and the conventional copper armature (stator) coils cooled by water. The 1-MW class HTS motor is analyzed by 3D electromagnetic Finite Element Method (FEM) to get magnetic field distribution, self and mutual inductance, and so forth. Especially excitation voltage (Back EMF) is estimated by using the mutual inductance between armature and field coils and compared with experimental result. Open and short circuit tests were conducted in generator mode while a 1.1-MW rated induction machine was rotating the HTS machine. Electrical parameters such as mutual inductance and synchronous inductance are deduced from these tests and also compared with the analysis results from FEM.

Effect of Cervical Lessions on the Tooth FEM Study

OpenAIRE

Gabriela Bereşescu; Ligia Brezeanu; Claudia Şoaita

2010-01-01

The approach used until recently concerning the phenomena of dental abfraction points to the conclusion that the cervical area of the tooth, were this type of lesion usually occur, concentrates the stress resulted from the action of the forces applied on various areas on the crown. Moreover, any lesion in the cervical area facilitates the possibility of its advance into the tooth, ultimately fracturing it. Our paper presents a FEM (finite element method) study on the results of a mechanical a...

Stress and displacement analysis of a modern design lathe body by the fi nite element method (FEM

Directory of Open Access Journals (Sweden)

R. Staniek

2012-01-01

Full Text Available The Finite element method (FEM was used in this study for the analysis of the strain and stress of a turning machine body. The fi nal design decisions were made on the basis of stress and displacement fi eld analysis of various design versions related to the structure of the considered machine tool. The results presented in this paper will be helpful for practical static and dynamic strength evaluation as well as for the appropriate design of machine tools using the FEM.

A study on directional resistivity logging-while-drilling based on self-adaptive hp-FEM

Science.gov (United States)

Liu, Dejun; Li, Hui; Zhang, Yingying; Zhu, Gengxue; Ai, Qinghui

2014-12-01

Numerical simulation of resistivity logging-while-drilling (LWD) tool response provides guidance for designing novel logging instruments and interpreting real-time logging data. In this paper, based on self-adaptive hp-finite element method (hp-FEM) algorithm, we analyze LWD tool response against model parameters and briefly illustrate geosteering capabilities of directional resistivity LWD. Numerical simulation results indicate that the change of source spacing is of obvious influence on the investigation depth and detecting precision of resistivity LWD tool; the change of frequency can improve the resolution of low-resistivity formation and high-resistivity formation. The simulation results also indicate that the self-adaptive hp-FEM algorithm has good convergence speed and calculation accuracy to guide the geologic steering drilling and it is suitable to simulate the response of resistivity LWD tools.

Fluxball magnetic field analysis using a hybrid analytical/FEM/BEM with equivalent currents

International Nuclear Information System (INIS)

Fernandes, João F.P.; Camilo, Fernando M.; Machado, V. Maló

2016-01-01

In this paper, a fluxball electric machine is analyzed concerning the magnetic flux, force and torque. A novel method is proposed based in a special hybrid FEM/BEM (Finite Element Method/Boundary Element Method) with equivalent currents by using an analytical treatment for the source field determination. The method can be applied to evaluate the magnetic field in axisymmetric problems, in the presence of several magnetic materials. Same results obtained by a commercial Finite Element Analysis tool are presented for validation purposes with the proposed method. - Highlights: • The Fluxball machine magnetic field is analyzed by a new FEM/BEM/Analytical method. • The method is adequate for axisymmetric non homogeneous magnetic field problems. • The source magnetic field is evaluated considering a non-magnetic equivalent problem. • Material magnetization vectors are accounted by using equivalent currents. • A strong reduction of the finite element domain is achieved.

Welding distortion analysis of multipass joint combination with different sequences using 3D FEM and experiment

International Nuclear Information System (INIS)

Manurung, Yupiter H.P.; Lidam, Robert Ngendang; Rahim, M. Ridzwan; Zakaria, M. Yusof; Redza, M. Ridhwan; Sulaiman, M. Shahar; Tham, Ghalib; Abas, Sunhaji K.

2013-01-01

This paper presents an investigation of the welding sequence effect on induced angular distortion using FEM and experiments. The specimen of a combined joint geometry was modeled and simulated using Multipass Welding Advisor (MWA) in SYSWELD 2010 based on the thermal-elastic-plastic approach with low manganese carbon steel S3355J2G3 as specimen material and Goldak's double ellipsoid as heat source model. To validate the simulation results, a series of experiments was conducted with two different welding sequences using automated welding process, low carbon steel as parent metal, digital GMAW power source with premixed shielding gas and both-sided clamping technique. Based on the results, it was established that the thermo-elastic-plastic 3D FEM analysis shows good agreement with experimental results and the welding sequence “from outside to inside” induced less angular distortion compared to “from inside to outside”. -- Highlights: • 3D FEM was used to analyze the welding distortion on two different sequences. • Simulation results were validated with experiments using automated welding system. • Simulation results and experiments showed acceptable accuracy. • Welding sequence “outside–inside” showed less distortion than “inside–outside”

Financial security for women -- Fem Consult congress.

Science.gov (United States)

1996-01-01

The nongovernmental organization "Fem Consult," which seeks to strengthen the socioeconomic position of women by applying a gender perspective to programs and projects in developing countries, celebrated its 10th anniversary in 1996 by holding a conference in the Netherlands on financial security for women in the developing world. During the conference, the President of the WWF (Working Women's Forum) described her agency's 17 years of experience in lending to impoverished rural and urban women in India. By extending microcredit assistance through a network of cooperatives, the WWF has been the catalyst for lasting improvements in the economic and social status of impoverished women. Representatives of the Grameen Bank, Women's World Banking, the Ecumenical Development Cooperative Society, and other organizations also addressed the conference.

Effect of Cervical Lessions on the Tooth FEM Study

Directory of Open Access Journals (Sweden)

Gabriela Bereşescu

2010-12-01

Full Text Available The approach used until recently concerning the phenomena of dental abfraction points to the conclusion that the cervical area of the tooth, were this type of lesion usually occur, concentrates the stress resulted from the action of the forces applied on various areas on the crown. Moreover, any lesion in the cervical area facilitates the possibility of its advance into the tooth, ultimately fracturing it. Our paper presents a FEM (finite element method study on the results of a mechanical analysis of the phenomena involving the tooth damaged by cervical lesions.

Application of FEM flow analysis to environmental engineering. FEM ryutai kaiseki no kankyo gijutsu eno tekiyo

Energy Technology Data Exchange (ETDEWEB)

Higuchi, M; Ando, K; Shimada, S; Umetani, H [Toyota Motor Corp., Aichi (Japan)

1990-04-25

In order to apply FEM (finite element method) flow analysis to environmental engineering, the two-dimensional analysis system was developed, and applied to the design of plant ventilation and improvement of an enviromental control equipment. Furthermore, the three-dimensional analysis system was developed to extend its application. Since in a large scale model, no enhancement of a processing capacity was expected even by a supercomputer because of longer I/O times between internal and external memories caused by a small internal memory space, the parallel processing system with multiple external memories was introduced to analyze such models. To achieve more efficient processing, multiple series of renumbering codes were also prepared to optimize the processing order of solvers, elements and nodes. As examples, the improvement of a thermal oxidizer and the ventilation design for a forging plant, and as an example of a three-dimensional large scale model, the flow analysis around a plant were presented. 8 refs., 17 figs., 1 tab.

Arbitrary-Level Hanging Nodes and Automatic Adaptivity in the hp-FEM

Czech Academy of Sciences Publication Activity Database

Šolín, Pavel; Červený, Jakub; Doležel, Ivo

2008-01-01

Roč. 77, č. 1 (2008), s. 117-132 ISSN 0378-4754 R&D Projects: GA ČR(CZ) GA102/07/0496; GA ČR GA102/05/0629; GA AV ČR IAA100760702 Institutional research plan: CEZ:AV0Z20570509 Keywords : constrained approximation * hanging nodes * hp-FEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.930, year: 2008

Mixed FEM for Second Order Elliptic Problems on Polygonal Meshes with BEM-Based Spaces

KAUST Repository

Efendiev, Yalchin; Galvis, Juan; Lazarov, Raytcho; Weiß er, Steffen

2014-01-01

We present a Boundary Element Method (BEM)-based FEM for mixed formulations of second order elliptic problems in two dimensions. The challenge, we would like to address, is a proper construction of H(div)-conforming vector valued trial functions

A highly detailed FEM volume conductor model based on the ICBM152 average head template for EEG source imaging and TCS targeting.

Science.gov (United States)

Haufe, Stefan; Huang, Yu; Parra, Lucas C

2015-08-01

In electroencephalographic (EEG) source imaging as well as in transcranial current stimulation (TCS), it is common to model the head using either three-shell boundary element (BEM) or more accurate finite element (FEM) volume conductor models. Since building FEMs is computationally demanding and labor intensive, they are often extensively reused as templates even for subjects with mismatching anatomies. BEMs can in principle be used to efficiently build individual volume conductor models; however, the limiting factor for such individualization are the high acquisition costs of structural magnetic resonance images. Here, we build a highly detailed (0.5mm(3) resolution, 6 tissue type segmentation, 231 electrodes) FEM based on the ICBM152 template, a nonlinear average of 152 adult human heads, which we call ICBM-NY. We show that, through more realistic electrical modeling, our model is similarly accurate as individual BEMs. Moreover, through using an unbiased population average, our model is also more accurate than FEMs built from mismatching individual anatomies. Our model is made available in Matlab format.

Genetic and molecular analyses of UV radiation-induced mutations in the fem-3 gene of Caenorhabditis elegans

Energy Technology Data Exchange (ETDEWEB)

Hartman, P S; De Wilde, D; Dwarakanath, V N [Texas Christian Univ., Fort Worth, TX (United States). Dept. of Biology

1995-06-01

The utility of a new target gene (fem-3) is described for investigating the molecular nature of mutagenesis in the nematode Caenorhabditis elegans. As a principal attribute, this system allows for the selection, maintenance and molecular analysis of any type of mutation that disrupts the gene, including deletions. In this study, 86 mutant strains were isolated, of which 79 proved to have mutations in fem-3. Twenty of these originally tested as homozygous inviable. Homozygous inviability was expected, as Stewart and coworkers had previously observed that, unlike in other organisms, most UV radiation-induced mutations in C. elegans are chromosomal rearrangements of deficiencies (Mutat. Res 249, 37-54, 1991). However, additional data, including Southern blot analyses on 49 of the strains, indicated that most of the UV radiation-induced fem-3 mutations were not deficiencies, as originally inferred from their homozygous inviability. Instead, the lethals were most likely ``coincident mutations`` in linked, essential genes that were concomitantly induced. As such, they were lost owing to genetic recombination during stock maintenance. As in mammalian cells, yeast and bacteria, the frequency of coincident mutations was much higher than would be predicted by chance. (Author).

Discrete conservation of nonnegativity for elliptic problems solved by the hp-FEM

Czech Academy of Sciences Publication Activity Database

Šolín, P.; Vejchodský, Tomáš; Araiza, R.

2007-01-01

Roč. 76, 1-3 (2007), s. 205-210 ISSN 0378-4754 R&D Projects: GA ČR GP201/04/P021 Institutional research plan: CEZ:AV0Z10190503 Keywords : discrete nonnegativity conservation * discrete Green's function * elliptic problems * hp-FEM * higher-order finite element methods * Poisson equation * numerical experimetns Subject RIV: BA - General Mathematics Impact factor: 0.738, year: 2007

On Scientific Data and Image Compression Based on Adaptive Higher-Order FEM

Czech Academy of Sciences Publication Activity Database

Šolín, Pavel; Andrš, David

2009-01-01

Roč. 1, č. 1 (2009), s. 56-68 ISSN 2070-0733 R&D Projects: GA ČR(CZ) GA102/07/0496; GA AV ČR IAA100760702 Institutional research plan: CEZ:AV0Z20570509 Keywords : data compress ion * image compress ion * adaptive hp-FEM Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering http://www.global-sci.org/aamm

Diagnostic Accuracy of APRI, AAR, FIB-4, FI, and King Scores for Diagnosis of Esophageal Varices in Liver Cirrhosis: A Retrospective Study.

Science.gov (United States)

Deng, Han; Qi, Xingshun; Peng, Ying; Li, Jing; Li, Hongyu; Zhang, Yongguo; Liu, Xu; Sun, Xiaolin; Guo, Xiaozhong

2015-12-20

BACKGROUND Aspartate aminotransferase-to-platelet ratio index (APRI), aspartate aminotransferase-to-alanine aminotransferase ratio (AAR), FIB-4, fibrosis index (FI), and King scores might be alternatives to the use of upper gastrointestinal endoscopy for the diagnosis of esophageal varices (EVs) in liver cirrhosis. This study aimed to evaluate their diagnostic accuracy in predicting the presence and severity of EVs in liver cirrhosis. MATERIAL AND METHODS All patients who were consecutively admitted to our hospital and underwent upper gastrointestinal endoscopy between January 2012 and June 2014 were eligible for this retrospective study. Areas under curve (AUCs) were calculated. Subgroup analyses were performed according to the history of upper gastrointestinal bleeding (UGIB) and splenectomy. RESULTS A total of 650 patients with liver cirrhosis were included, and 81.4% of them had moderate-severe EVs. In the overall analysis, the AUCs of these non-invasive scores for predicting moderate-severe EVs and presence of any EVs were 0.506-0.6 and 0.539-0.612, respectively. In the subgroup analysis of patients without UGIB, their AUCs for predicting moderate-severe varices and presence of any EVs were 0.601-0.664 and 0.596-0.662, respectively. In the subgroup analysis of patients without UGIB or splenectomy, their AUCs for predicting moderate-severe varices and presence of any EVs were 0.627-0.69 and 0.607-0.692, respectively. CONCLUSIONS APRI, AAR, FIB-4, FI, and King scores had modest diagnostic accuracy of EVs in liver cirrhosis. They might not be able to replace the utility of upper gastrointestinal endoscopy for the diagnosis of EVs in liver cirrhosis.

ALOAD - a code to determine the concentrated forces equivalent with a distributed pressure field for a FEM analysis

Directory of Open Access Journals (Sweden)

Nicolae APOSTOLESCU

2010-12-01

Full Text Available The main objective of this paper is to describe a code for calculating an equivalent systemof concentrate loads for a FEM analysis. The tables from the Aerodynamic Department containpressure field for a whole bearing surface, and integrated quantities both for the whole surface andfor fixed and mobile part. Usually in a FEM analysis the external loads as concentrated loadsequivalent to the distributed pressure field are introduced. These concentrated forces can also be usedin static tests. Commercial codes provide solutions for this problem, but what we intend to develop isa code adapted to the user’s specific needs.

FEM-model of the Naesliden Mine: requirements and limitations at the outset of the project. [Sweden

Energy Technology Data Exchange (ETDEWEB)

Krauland, N.

1980-05-15

The design of any instrument depends entirely on the application planned for the instrument. This applies also to the FEM-representation of the Naesliden Mine. With reference to the aims of the project the requirements on the model are outlined with regard to - simulation of the mining process - modelling with special reference to the aims of the project - comparison of FEM-results with in situ observations to determine the validity of the model. The proposed model is two-dimensional and incorporates joint elements to simulate the weak alteration zone between orebody and sidewall rock. The remainder of the model exhibits linear elastic behaviour. This model is evaluated with respect to the given requirements. The limitations of the chosen model are outlined.

Numerical analysis of melting/solidification phenomena using a moving boundary problem analysis method X-FEM

International Nuclear Information System (INIS)

Uchibori, Akihiro; Ohshima, Hiroyuki

2008-01-01

A numerical analysis method for melting/solidification phenomena has been developed to evaluate a feasibility of several candidate techniques in the nuclear fuel cycle. Our method is based on the eXtended Finite Element Method (X-FEM) which has been used for moving boundary problems. Key technique of the X-FEM is to incorporate signed distance function into finite element interpolation to represent a discontinuous gradient of the temperature at a moving solid-liquid interface. Construction of the finite element equation, the technique of quadrature and the method to solve the equation are reported here. The numerical solutions of the one-dimensional Stefan problem, solidification in a two-dimensional square corner and melting of pure gallium are compared to the exact solutions or to the experimental data. Through these analyses, validity of the newly developed numerical analysis method has been demonstrated. (author)

Three-dimensional Reconstruction and Homogenization of Heterogeneous Materials Using Statistical Correlation Functions and FEM

Energy Technology Data Exchange (ETDEWEB)

Baniassadi, Majid; Mortazavi, Behzad; Hamedani, Amani; Garmestani, Hamid; Ahzi, Said; Fathi-Torbaghan, Madjid; Ruch, David; Khaleel, Mohammad A.

2012-01-31

In this study, a previously developed reconstruction methodology is extended to three-dimensional reconstruction of a three-phase microstructure, based on two-point correlation functions and two-point cluster functions. The reconstruction process has been implemented based on hybrid stochastic methodology for simulating the virtual microstructure. While different phases of the heterogeneous medium are represented by different cells, growth of these cells is controlled by optimizing parameters such as rotation, shrinkage, translation, distribution and growth rates of the cells. Based on the reconstructed microstructure, finite element method (FEM) was used to compute the effective elastic modulus and effective thermal conductivity. A statistical approach, based on two-point correlation functions, was also used to directly estimate the effective properties of the developed microstructures. Good agreement between the predicted results from FEM analysis and statistical methods was found confirming the efficiency of the statistical methods for prediction of thermo-mechanical properties of three-phase composites.

FEM × DEM: a new efficient multi-scale approach for geotechnical problems with strain localization

Directory of Open Access Journals (Sweden)

Nguyen Trung Kien

2017-01-01

Full Text Available The paper presents a multi-scale modeling of Boundary Value Problem (BVP approach involving cohesive-frictional granular materials in the FEM × DEM multi-scale framework. On the DEM side, a 3D model is defined based on the interactions of spherical particles. This DEM model is built through a numerical homogenization process applied to a Volume Element (VE. It is then paired with a Finite Element code. Using this numerical tool that combines two scales within the same framework, we conducted simulations of biaxial and pressuremeter tests on a cohesive-frictional granular medium. In these cases, it is known that strain localization does occur at the macroscopic level, but since FEMs suffer from severe mesh dependency as soon as shear band starts to develop, the second gradient regularization technique has been used. As a consequence, the objectivity of the computation with respect to mesh dependency is restored.

Optimization of force-cooled power transmission cables by means of 3D FEM simulations; Optimierung zwangsgekuehlter Energiekabel durch dreidimensionale FEM-Simulationen

Energy Technology Data Exchange (ETDEWEB)

Zhang, Dongping

2009-10-26

Lateral forced cooling can significantly increase the temporary overload capacity of a cable system, but the design of such systems requires a time-dependent 3D analysis of the nonlinear thermal behavior as the cooling water along the cable is heated up, resulting in position-dependent and time-dependent heat uptake. For this, a new calculation method was developed on the basis of an available 3D FEM software. The new method enables 3D simulation of force-cooled cables in consideration of the potential partial dryout of soil and of thermal stabilizations. The new method was first applied to a 110 kV wind power transmission cable for different configurations and grid conditions. It was found that with lateral forced cooling, the 110 kV will have a temporal 50 percent overload capacity. Further, the thermal characteristics and limiting capacity of a force-cooled 380 kV cable system were investigated. According to the results so far, laterally cooled cable systems open up new operating options, with advantages in terms of availability, economic efficiency, and flexibility. (orig.) [German] Eine laterale Zwangskuehlung kann die temporaere Ueberlastbarkeit einer Kabelanlage signifikant erhoehen. Der Entwurf solcher zwangsgekuehlter Kabelanlagen erfordert jedoch eine zeitabhaengige, dreidimensionale Analyse des nichtlinearen thermischen Verhaltens, da sich das Kuehlwasser entlang der Trasse erwaermt und sich so eine orts- und zeitabhaengige Waermeaufnahme ergibt. Zu diesem Zweck wurde auf der Basis eines vorhandenen zweidimensionalen FEM-Programms ein neues Berechnungsverfahren entwickelt, das die dreidimensionale Simulation zwangsgekuehlter Kabelanlagen unter Beruecksichtigung einer moeglicherweise auftretenden partiellen Bodenaustrocknung und von thermischen Stabilisierungen erlaubt. Mit Hilfe dieses Berechnungsverfahrens wurde zuerst eine 110-kV-Kabelanlage zur Windenergieuebertragung bei unterschiedlichen Anordnungen und unterschiedlichen Netzsituationen untersucht

Protection Performance Simulation of Coal Tar-Coated Pipes Buried in a Domestic Nuclear Power Plant Using Cathodic Protection and FEM Method

Energy Technology Data Exchange (ETDEWEB)

Chang, H. Y.; Lim, B. T.; Kim, K. S.; Kim, J. W.; Park, H. B. [KEPCO Engineering and Construction Company, Gimcheon (Korea, Republic of); Kim, Y. S.; Kim, K. T. [Andong National University, Andong (Korea, Republic of)

2017-06-15

Coal tar-coated pipes buried in a domestic nuclear power plant have operated under the cathodic protection. This work conducted the simulation of the coating performance of these pipes using a FEM method. The pipes, being ductile cast iron have been suffered under considerably high cathodic protection condition beyond the appropriate condition. However, cathodic potential measured at the site revealed non-protected status. Converting from 3D CAD data of the power plant to appropriate type for a FEM simulation was conducted and cathodic potential under the applied voltage and current was calculated using primary and secondary current distribution and physical conditions. FEM simulation for coal tar-coated pipe without defects revealed over-protection condition if the pipes were well-coated. However, the simulation for coal tar-coated pipes with many defects predict that the coated pipes may be severely degraded. Therefore, for high risk pipes, direct examination and repair or renewal of pipes are strongly recommended.

A modified moment-fitted integration scheme for X-FEM applications with history-dependent material data

Science.gov (United States)

Zhang, Ziyu; Jiang, Wen; Dolbow, John E.; Spencer, Benjamin W.

2018-01-01

We present a strategy for the numerical integration of partial elements with the eXtended finite element method (X-FEM). The new strategy is specifically designed for problems with propagating cracks through a bulk material that exhibits inelasticity. Following a standard approach with the X-FEM, as the crack propagates new partial elements are created. We examine quadrature rules that have sufficient accuracy to calculate stiffness matrices regardless of the orientation of the crack with respect to the element. This permits the number of integration points within elements to remain constant as a crack propagates, and for state data to be easily transferred between successive discretizations. In order to maintain weights that are strictly positive, we propose an approach that blends moment-fitted weights with volume-fraction based weights. To demonstrate the efficacy of this simple approach, we present results from numerical tests and examples with both elastic and plastic material response.

The stress and stress intensity factors computation by BEM and FEM combination for nozzle junction under pressure and thermal loads

International Nuclear Information System (INIS)

Du, Q.; Cen, Z.; Zhu, H.

1989-01-01

This paper reports linear elastic fracture analysis based upon the stress intensity factor evaluation successfully applied to safety assessments of cracked structures. The nozzle junction are usually subjected to high pressure and thermal loads simultaneously. In validity of linear elastic fracture analysis, K can be decomposed into K P (caused by mechanic loads) and K τ (caused by thermal loads). Under thermal transient loading, explicit analysis (say by the FEM or BEM) of K tracing an entire history respectively for a range of crack depth may be much more time consuming. The techniques of weight function provide efficient means for transforming the problem into the stress computation of the uncracked structure and generation of influence function (for the given structure and size of crack). In this paper, a combination of BE-FEM has been used for the analysis of the cracked nozzle structure by techniques of weight function. The influence functions are obtained by coupled BE-FEM and the uncracked structure stress are computed by finite element methods

Modular hp-FEM system HERMES and its application to Maxwell´s equations

Czech Academy of Sciences Publication Activity Database

Vejchodský, Tomáš; Šolín, P.; Zítka, M.

2007-01-01

Roč. 76, č. 2 (2007), s. 223-228 ISSN 0378-4754. [MODELLING 2005. Plzeň, 04.06.2005-08.06.2005] R&D Projects: GA ČR GP201/04/P021 Institutional research plan: CEZ:AV0Z10190503 Keywords : hp-FEM * time-harmonic Maxwell´s equations * hierarchic higher-order edge elements Subject RIV: BA - General Mathematics Impact factor: 0.738, year: 2007

Tolko poetom hotel bõt : Rastrogannost; Dozhdlivõi den; Jaanov ogon; Setumaa I-II; Tolko poetom. Haralskije zhizneopissanija : Aire Valgus; Aare Valgus; Peeter Petrov; Vaike Metsleht; Valdur Laiapea; Hillar Aruda, ekonomist; Pärja Lumendi; Valjo Z

Index Scriptorium Estoniae

Traat, Mats, 1936-

1996-01-01

Orig.: Heldimus; Sajupäev; Jaanituli; Setumaa I-II; Ainult poeet. Harala elulood: Aire Valgus; Aare Valgus; Peeter Petrov; Vaike Metsleht; Valdur Laiapea; Hillar Aruda, ökonomist; Pärja Lumendi; Valjo Zeiger; Pavlo Moskalenko; Johannes Iva; Viljar Laanemägi; Olga Kaljusaar; Aimi Vaimets; Einard Kalm (1923-1984); Sonetid vaikimisest I; Kui

Finite-element-method (FEM model generation of time-resolved 3D echocardiographic geometry data for mitral-valve volumetry

Directory of Open Access Journals (Sweden)

Kikinis Ron

2006-03-01

Full Text Available Abstract Introduction Mitral Valve (MV 3D structural data can be easily obtained using standard transesophageal echocardiography (TEE devices but quantitative pre- and intraoperative volume analysis of the MV is presently not feasible in the cardiac operation room (OR. Finite element method (FEM modelling is necessary to carry out precise and individual volume analysis and in the future will form the basis for simulation of cardiac interventions. Method With the present retrospective pilot study we describe a method to transfer MV geometric data to 3D Slicer 2 software, an open-source medical visualization and analysis software package. A newly developed software program (ROIExtract allowed selection of a region-of-interest (ROI from the TEE data and data transformation for use in 3D Slicer. FEM models for quantitative volumetric studies were generated. Results ROI selection permitted the visualization and calculations required to create a sequence of volume rendered models of the MV allowing time-based visualization of regional deformation. Quantitation of tissue volume, especially important in myxomatous degeneration can be carried out. Rendered volumes are shown in 3D as well as in time-resolved 4D animations. Conclusion The visualization of the segmented MV may significantly enhance clinical interpretation. This method provides an infrastructure for the study of image guided assessment of clinical findings and surgical planning. For complete pre- and intraoperative 3D MV FEM analysis, three input elements are necessary: 1. time-gated, reality-based structural information, 2. continuous MV pressure and 3. instantaneous tissue elastance. The present process makes the first of these elements available. Volume defect analysis is essential to fully understand functional and geometrical dysfunction of but not limited to the valve. 3D Slicer was used for semi-automatic valve border detection and volume-rendering of clinical 3D echocardiographic

Calculation of marine propeller static strength based on coupled BEM/FEM

Directory of Open Access Journals (Sweden)

YE Liyu

2017-10-01

Full Text Available [Objectives] The reliability of propeller stress has a great influence on the safe navigation of a ship. To predict propeller stress quickly and accurately,[Methods] a new numerical prediction model is developed by coupling the Boundary Element Method(BEMwith the Finite Element Method (FEM. The low order BEM is used to calculate the hydrodynamic load on the blades, and the Prandtl-Schlichting plate friction resistance formula is used to calculate the viscous load. Next, the calculated hydrodynamic load and viscous correction load are transmitted to the calculation of the Finite Element as surface loads. Considering the particularity of propeller geometry, a continuous contact detection algorithm is developed; an automatic method for generating the finite element mesh is developed for the propeller blade; a code based on the FEM is compiled for predicting blade stress and deformation; the DTRC 4119 propeller model is applied to validate the reliability of the method; and mesh independence is confirmed by comparing the calculated results with different sizes and types of mesh.[Results] The results show that the calculated blade stress and displacement distribution are reliable. This method avoids the process of artificial modeling and finite element mesh generation, and has the advantages of simple program implementation and high calculation efficiency.[Conclusions] The code can be embedded into the code of theoretical and optimized propeller designs, thereby helping to ensure the strength of designed propellers and improve the efficiency of propeller design.

Precision structural engineering of self-rolled-up 3D nanomembranes guided by transient quasi-static FEM modeling.

Science.gov (United States)

Huang, Wen; Koric, Seid; Yu, Xin; Hsia, K Jimmy; Li, Xiuling

2014-11-12

Micro- and nanoscale tubular structures can be formed by strain-induced self-rolled-up nanomembranes. Precision engineering of the shape and dimension determines the performance of devices based on this platform for electronic, optical, and biological applications. A transient quasi-static finite element method (FEM) with moving boundary conditions is proposed as a general approach to design diverse types of three-dimensional (3D) rolled-up geometries. This method captures the dynamic release process of membranes through etching driven by mismatch strain and accurately predicts the final dimensions of rolled-up structures. Guided by the FEM modeling, experimental demonstration using silicon nitride membranes was achieved with unprecedented precision including controlling fractional turns of a rolled-up membrane, anisotropic rolling to form helical structures, and local stress control for 3D hierarchical architectures.

FEM validation of a double porosity elastic model for consolidation of structurally complex clayey soils

Science.gov (United States)

Callari, C.; Federico, F.

2000-04-01

Laboratory consolidation of structured clayey soils is analysed in this paper. The research is carried out by two different methods. The first one treats the soil as an isotropic homogeneous equivalent Double Porosity (DP) medium. The second method rests on the extensive application of the Finite Element Method (FEM) to combinations of different soils, composing 2D or fully 3D ordered structured media that schematically discretize the complex material. Two reference problems, representing typical situations of 1D laboratory consolidation of structured soils, are considered. For each problem, solution is obtained through integration of the equations governing the consolidation of the DP medium as well as via FEM applied to the ordered schemes composed of different materials. The presence of conventional experimental devices to ensure the drainage of the sample is taken into account through appropriate boundary conditions. Comparison of FEM results with theoretical results clearly points out the ability of the DP model to represent consolidation processes of structurally complex soils. Limits of applicability of the DP model may arise when the rate of fluid exchange between the two porous systems is represented through oversimplified relations. Results of computations, obtained having assigned reasonable values to the meso-structural and to the experimental apparatus parameters, point out that a partially efficient drainage apparatus strongly influences the distribution along the sample and the time evolution of the interstitial water pressure acting in both systems of pores. Data of consolidation tests in a Rowe's cell on samples of artificially fissured clays reported in the literature are compared with the analytical and numerical results showing a significant agreement.

Mechatronic FEM model of an electromagnetic-force-compensated load cell

International Nuclear Information System (INIS)

Weis, Hanna; Hilbrunner, Falko; Fröhlich, Thomas; Jäger, Gerd

2012-01-01

In this paper, a mechatronic model for an electromagnetic-force-compensated (EMC) load cell is presented. Designed in ANSYS Mechanical APDL®, the model consists of two modules: the mechanical behaviour of the load cell is represented by a FEM model. The electronic and the electromagnetic parts, consisting of a position indicator, controller and electromagnetic actuator, are implemented into the model as a set of differential equations via ANSYS Parametric Design Language (APDL). Optimization of the mechanical, electromagnetic and controller components can be performed using this model, as well as experiments to determine the sensitivity of the complete system to changes of environmental properties, e.g., the stiffness of the support. (paper)

Simulation of ultrasonic and EMAT arrays using FEM and FDTD.

Science.gov (United States)

Xie, Yuedong; Yin, Wuliang; Liu, Zenghua; Peyton, Anthony

2016-03-01

This paper presents a method which combines electromagnetic simulation and ultrasonic simulation to build EMAT array models. For a specific sensor configuration, Lorentz forces are calculated using the finite element method (FEM), which then can feed through to ultrasonic simulations. The propagation of ultrasound waves is numerically simulated using finite-difference time-domain (FDTD) method to describe their propagation within homogenous medium and their scattering phenomenon by cracks. Radiation pattern obtained with Hilbert transform on time domain waveforms is proposed to characterise the sensor in terms of its beam directivity and field distribution along the steering angle. Copyright © 2015 Elsevier B.V. All rights reserved.

Discrete maximum principle for Poisson equation with mixed boundary conditions solved by hp-FEM

Czech Academy of Sciences Publication Activity Database

Vejchodský, Tomáš; Šolín, P.

2009-01-01

Roč. 1, č. 2 (2009), s. 201-214 ISSN 2070-0733 R&D Projects: GA AV ČR IAA100760702; GA ČR(CZ) GA102/07/0496; GA ČR GA102/05/0629 Institutional research plan: CEZ:AV0Z10190503 Keywords : discrete maximum principle * hp-FEM * Poisson equation * mixed boundary conditions Subject RIV: BA - General Mathematics

Considerations on FEM modeling in analyzing buckling and plastic collapse of a detection control; Boto panel no zakutsu sosei hokai kaiseki ni okeru FEM model ka ni kansuru kosatsu

Energy Technology Data Exchange (ETDEWEB)

Yao, T; Fujikubo, M; Yanagihara, D; Irisawa, M [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

1997-10-01

Buckling and plastic collapse of upper decks and bottom outer plates of a hull results directly in longitudinal bending collapse of the hull. Therefore, discussions were given on analysis for pressure destruction strength of a detection control panel which assumes an upper deck and a bottom outer plate. Pressure destruction behavior of the panting panel is a complex phenomenon accompanying non-linearity and geometrical non-linearity of the materials. Its whole phenomenon may be analyzed by using the finite element method (FEM) as a principle, but the analysis is not efficient. Therefore, considerations were given in relation to modeling when using the FEM. The considerations were given on a panel attached with flat steel panting members with respect to the modeling scope which considers the buckling mode according to the aspect ratio of the panel partitioned by the deflection control members. If the local buckling mode of the panel is an even number wave mode in the longitudinal direction, a triple span model is required. A modeling scope for a case of being subjected to water pressure and in-plane compression was considered on a panel attached with angle-type steel members having non-symmetric cross section. In this case, a triple bay model is more preferable to reproduce the behavior under water pressure loading. 1 ref., 6 figs.

Effects of long-range transported pollutants on vegetation in boreal coniferous forests: Results from an five year investigation in the Solholmfjell area, Gjerstad, Aust-Agder; Effekter av langtransporterte luftforurensninger i boreal barskog: resultater av fem aars undersoekelser i Solhomfjell-omraadet, Gjerstad, Aust-Agder

Energy Technology Data Exchange (ETDEWEB)

Oekland, R H

1996-01-01

The conference paper relates to a project on investigating the effects of long-range transported pollutants in Norway. The paper gives a brief description of the more important results obtained in the project. The aim of the project was to investigate the pollution load in vegetation, soils and trees in Norwegian forest areas of the coniferous type. The project included the collection of samples from 200 test areas in a period of five years. 11 refs.

Determination of the fatigue properties of multilayer PVD coatings on various substrates, based on the impact test and its FEM simulation

Energy Technology Data Exchange (ETDEWEB)

Bouzakis, K.D.; Vidakis, N. [Aristotle Univ., Thessaloniki (Greece). Dept. of Mech. Eng.; Leyendecker, T.; Erkens, G.; Wenke, R.

1997-10-31

The coating impact test, in combination with its finite elements method (FEM) simulation, is used to quantitatively characterize the fatigue behaviour of thin hard physical vapour deposited (PVD) coatings as well as of multilayer ones. Successive impacts of a cemented carbide ball onto a plane coated specimen induce severe contact loads and strain superficially the layered compound. The fatigue failure mode of each specimen is classified by means of scanning electron microscope (SEM) observations, microspectral analyses and profilometry. FEM simulating models of the impact test are used to determine the critical stress components, which introduce coating fatigue failure. The FEM computational results are correlated to the experimental ones and used to interpret them quantitatively. Herewith, critical values for stress components, responsible for distinctive fatigue failure modes of the coating substrate compounds are obtained and the fatigue limits of the examined multilayer coatings are inserted in general applicable Smith diagrams. Furthermore, the derived critical stresses are verified by investigating the same multilayer coatings on different substrates. (orig.) 14 refs.

Stress Induced in Periodontal Ligament under Orthodontic Loading (Part II): A Comparison of Linear Versus Non-Linear Fem Study.

Science.gov (United States)

Hemanth, M; Deoli, Shilpi; Raghuveer, H P; Rani, M S; Hegde, Chatura; Vedavathi, B

2015-09-01

Simulation of periodontal ligament (PDL) using non-linear finite element method (FEM) analysis gives better insight into understanding of the biology of tooth movement. The stresses in the PDL were evaluated for intrusion and lingual root torque using non-linear properties. A three-dimensional (3D) FEM model of the maxillary incisors was generated using Solidworks modeling software. Stresses in the PDL were evaluated for intrusive and lingual root torque movements by 3D FEM using ANSYS software. These stresses were compared with linear and non-linear analyses. For intrusive and lingual root torque movements, distribution of stress over the PDL was within the range of optimal stress value as proposed by Lee, but was exceeding the force system given by Proffit as optimum forces for orthodontic tooth movement with linear properties. When same force load was applied in non-linear analysis, stresses were more compared to linear analysis and were beyond the optimal stress range as proposed by Lee for both intrusive and lingual root torque. To get the same stress as linear analysis, iterations were done using non-linear properties and the force level was reduced. This shows that the force level required for non-linear analysis is lesser than that of linear analysis.

1963 Vajont rock slide: a comparison between 3D DEM and 3D FEM

Science.gov (United States)

Crosta, Giovanni; Utili, Stefano; Castellanza, Riccardo; Agliardi, Federico; Bistacchi, Andrea; Weng Boon, Chia

2013-04-01

Data on the exact location of the failure surface of the landslide have been used as the starting point for the modelling of the landslide. 3 dimensional numerical analyses were run employing both the discrete element method (DEM) and a Finite Element Method (FEM) code. In this work the focus is on the prediction of the movement of the landlside during its initial phase of detachment from Mount Toc. The results obtained by the two methods are compared and conjectures on the observed discrepancies of the predictions between the two methods are formulated. In the DEM simulations the internal interaction of the sliding blocks and the expansion of the debris is obtained as a result of the kinematic interaction among the rock blocks resulting from the jointing of the rock mass involved in the slide. In the FEM analyses, the c-phi reduction technique was employed along the predefine failure surface until the onset of the landslide occurred. In particular, two major blocks of the landslide were identified and the stress, strain and displacement fields at the interface between the two blocks were analysed in detail.

SU-E-T-644: QuAArC: A 3D VMAT QA System Based On Radiochromic Film and Monte Carlo Simulation of Log Files

Energy Technology Data Exchange (ETDEWEB)

Barbeiro, A.R.; Ureba, A.; Baeza, J.A.; Jimenez-Ortega, E.; Plaza, A. Leal [Universidad de Sevilla, Departamento de Fisiologia Medica y Biofisica, Seville (Spain); Linares, R. [Hospital Infanta Luisa, Servicio de Radiofisica, Seville (Spain); Mateos, J.C.; Velazquez, S. [Hospital Universitario Virgen del Rocio, Servicio de Radiofisica, Seville (Spain)

2015-06-15

Purpose: VMAT involves two main sources of uncertainty: one related to the dose calculation accuracy, and the other linked to the continuous delivery of a discrete calculation. The purpose of this work is to present QuAArC, an alternative VMAT QA system to control and potentially reduce these uncertainties. Methods: An automated MC simulation of log files, recorded during VMAT treatment plans delivery, was implemented in order to simulate the actual treatment parameters. The linac head models and the phase-space data of each Control Point (CP) were simulated using the EGSnrc/BEAMnrc MC code, and the corresponding dose calculation was carried out by means of BEAMDOSE, a DOSXYZnrc code modification. A cylindrical phantom was specifically designed to host films rolled up at different radial distances from the isocenter, for a 3D and continuous dosimetric verification. It also allows axial and/or coronal films and point measurements with several types of ion chambers at different locations. Specific software was developed in MATLAB in order to process and evaluate the dosimetric measurements, which incorporates the analysis of dose distributions, profiles, dose difference maps, and 2D/3D gamma index. It is also possible to obtain the experimental DVH reconstructed on the patient CT, by an optimization method to find the individual contribution corresponding to each CP on the film, taking into account the total measured dose, and the corresponding CP dose calculated by MC. Results: The QuAArC system showed high reproducibility of measurements, and consistency with the results obtained with the commercial system implemented in the verification of the evaluated treatment plans. Conclusion: A VMAT QA system based on MC simulation and high resolution dosimetry with film has been developed for treatment verification. It shows to be useful for the study of the real VMAT capabilities, and also for linac commissioning and evaluation of other verification devices.

Analysis of the effect of the fluid-structure interface on elastic wave velocity in cornea-like structures by OCE and FEM

International Nuclear Information System (INIS)

Han, Zhaolong; Li, Jiasong; Singh, Manmohan; Wu, Chen; Liu, Chih-hao; Raghunathan, Raksha; Larin, Kirill V; Vantipalli, Srilatha; Aglyamov, Salavat R; Twa, Michael D

2016-01-01

Air-pulse optical coherence elastography (OCE) is a promising technique for quantifying biomechanical properties of the cornea. This technique typically involves imaging and analysis of the propagation of the air-pulse induced elastic waves to reconstruct corneal biomechanical properties using an analytical model. However, the effect of the fluid-structure interface (FSI) at the corneal posterior surface on the elastic wave velocity is not accounted for in many models. In this study, we examined the effect of the FSI with OCE experiments on contact lenses with and without fluid in the posterior gap. Finite element models (FEM), also with and without the FSI, were constructed to simulate the elastic wave propagation based on the OCE measurements. The FEM and OCE results were in good agreement demonstrating the feasibility of the method. To further investigate the effect of the FSI, OCE experiments and subsequent FEM simulations were conducted on in situ rabbit corneas before and after rose bengal/green light corneal collagen cross-linking (RGX). Both the OCE experiments and the FE simulations demonstrated that the FSI significantly reduced the group velocity of the elastic wave, and thus, should be considered when determining corneal biomechanical properties from an appropriate mechanical model. By matching the FEM-calculated velocity to the OCE-measured velocity, the corneal elasticity was quantified. The Young’s modulus of the rabbit cornea before RGX was E  =  65  ±  10 kPa at a controlled intraocular pressure (IOP) of 15 mmHg. After RGX, the Young’s modulus increased to E  =  102  ±  7 kPa at the same IOP. (letter)

Modelling Sawing of Metal Tubes Through FEM Simulation

International Nuclear Information System (INIS)

Bort, C. M. Giorgio; Bosetti, P.; Bruschi, S.

2011-01-01

The paper presents the development of a numerical model of the sawing process of AISI 304 thin tubes, which is cut through a circular blade with alternating roughing and finishing teeth. The numerical simulation environment is the three-dimensional FEM software Deform v.10.1. The teeth actual trajectories were determined by a blade kinematics analysis developed in Matlab. Due to the manufacturing rolling steps and subsequent welding stage, the tube material is characterized by a gradient of properties along its thickness. Consequently, a simplified cutting test was set up and carried out in order to identify the values of relevant material parameters to be used in the numerical model. The dedicated test was the Orthogonal Tube Cutting test (OTC), which was performed on an instrumented lathe. The proposed numerical model was validated by comparing numerical results and experimental data obtained from sawing tests carried out on an industrial machine. The following outputs were compared: the cutting force, the chip thickness, and the chip contact area.

Modelling Sawing of Metal Tubes Through FEM Simulation

Science.gov (United States)

Bort, C. M. Giorgio; Bosetti, P.; Bruschi, S.

2011-05-01

The paper presents the development of a numerical model of the sawing process of AISI 304 thin tubes, which is cut through a circular blade with alternating roughing and finishing teeth. The numerical simulation environment is the three-dimensional FEM software Deform™ v.10.1. The teeth actual trajectories were determined by a blade kinematics analysis developed in Matlab™. Due to the manufacturing rolling steps and subsequent welding stage, the tube material is characterized by a gradient of properties along its thickness. Consequently, a simplified cutting test was set up and carried out in order to identify the values of relevant material parameters to be used in the numerical model. The dedicated test was the Orthogonal Tube Cutting test (OTC), which was performed on an instrumented lathe. The proposed numerical model was validated by comparing numerical results and experimental data obtained from sawing tests carried out on an industrial machine. The following outputs were compared: the cutting force, the chip thickness, and the chip contact area.

NDE (Nondestructive examination) by ultrasonic, photo-elastic, strain measuring and FEM (Finite Element Method)

International Nuclear Information System (INIS)

Gu Fangyu; Zeng Xiao

1990-01-01

It is considered impossible to inspect flaw by using ordinary mechanical measuring methods. In this paper, it is found that the stree and strain distortions of pressure vessel with 2D linear shape crack in the deep location appear the 'cat effect' on the surface of stracture, and that the location and size of the crack can be determined with strain measuring and FEM according to 'cat effect' of strain distortion

'Men don't need to know everything': a field trial of a discreet, female-initiated, contraceptive barrier method (FemCap™) among Haitian-American women.

Science.gov (United States)

Gollub, Erica L; Cyrus, Elena; Dévieux, Jessy G; Jean-Gilles, Michèle; Neptune, Sandra; Pelletier, Valerie; Michel, Hulda; Sévère, Marie; Pierre, Laurinus

2015-01-01

Worldwide, women report the need for safe, non-hormonal, woman-initiated methods of family planning. Cervical barriers provide such technology but are under-researched and under-promoted. In the USA, there are few studies of cervical barriers among women at high unmet need for contraception. A feasibility study of the FemCap™ was conducted among US women of Haitian origin. Participants were heterosexual and seeking to avoid pregnancy. At first visit, participants completed baseline assessments, underwent group counselling and were fitted with FemCap™. Women were asked to insert or use the cap at home. The second visit (2-3 weeks) included an interviewer-administered questionnaire and a focus-group discussion. Participants (n  =  20) were Haitian-born (70%), married (55%) and parous (85%). Their mean age was 32.6 years. Seventy percent reported recent unprotected sex. All women inserted the device at home and 9 women used it during intercourse, including 5 without prior partner negotiation. Of 20 women, 11 liked FemCap™ very much or somewhat; 7 considered it 'OK'; 2 disliked it. Best-liked attributes were comfort, discreet wear and reusability. Difficulties with removal abated over time. Qualitative data revealed a high value placed on lack of systemic side effects. Use of FemCap™ was feasible and acceptable, supporting expansion of research, particularly among relevant populations with unmet need.

Environmental equipment for usages of FEM software. ADVENTURE system user's guide

International Nuclear Information System (INIS)

Yamasaki, Ichirou; Yoshimura, Shinobu

2003-05-01

The community softwares, databases, and other various tools have been installed in the ITBL environment by the Office of ITBL Promotion as a common utility property for each research field. Among those softwares, Finite Element Method (FEM) code, Adventure (which was originally developed by Prof. Yoshimura, the University of Tokyo), is provided as one of structure analysis programs for ITBL users. The code is well known to possess a high performance ability for parallel processing, especially for massively parallel environments. In this report, a chain of processes for usages of the system as well as the installation method to PC cluster are described. (author)

Investigation of the fittest shear transfer model used to FEM analysis of RC structures

International Nuclear Information System (INIS)

Endo, Tatumi; Aoyagi, Masao; Endo, Takao

1988-01-01

In order to rationalize the design method of reinforced concrete (RC) structures in the nuclear power plant, the structural analysis, which is able to simulate the seismic behavior of RC structures, should be established. In this report, the investigation of shear transfer model at shear plane to be applied to FEM analysis is performed. Main conclusions obtained within the limit of the study are as follows. 1. Development of the shear transfer model at shear plane. 1) Two shear transfer models are developed to be used to the 2-dimensional nonlinear FEM analysis. 2) In one model suggested, reinforcements are modeled by plate elements and the nonlinearity of concrete surrounding reinforcement but the properties of bond-slip relation between concrete and reinforcements is also considered. 3) In another model, reinforcements are modeled by equivalent concrete properties, in which axial regidity and dowel effects of reinforcements are considered. 2. Verification of the suggested model. 1) It is confirmed that the computational results using the above-mentioned model could simulate the experimental ones fairly well. 2) Considering the application to the analysis of RC structures in the design, the model, in which reinforcement are modeled by equivalent concrete properties, is useful in view point of accuracy and simplicity. (author)

FEM simulation of TBC failure in a model system

Energy Technology Data Exchange (ETDEWEB)

Seiler, P; Baeker, M; Roesier, J [Institut fuer Werkstoffe (IfW), Technische Universitaet Braunschweig (Germany); Beck, T; Schweda, M, E-mail: p.seiler@tu-bs.d [Institut fuer Energieforschung/ Werkstoffstruktur und -Eigenschaften (IEF 2), Forschungszentrum Juelich (Germany)

2010-07-01

In order to study the behavior of the complex failure mechanisms in thermal barrier coatings on turbine blades, a simplified model system is used to reduce the number of system parameters. The artificial system consists of a bond-coat material (fast creeping Fecralloy or slow creeping MA956) as the substrate with a Y{sub 2}O{sub 3} partially stabilized plasma sprayed zircon oxide TBC on top and a TGO between the two layers. A 2-dimensional FEM simulation was developed to calculate the growth stress inside the simplified coating system. The simulation permits the study of failure mechanisms by identifying compression and tension areas which are established by the growth of the oxide layer. This provides an insight into the possible crack paths in the coating and it allows to draw conclusions for optimizing real thermal barrier coating systems.

Effect of the drift gap between the undulator sections on the operation of the Fusion-FEM

NARCIS (Netherlands)

van der Geer, C. A. J.; Militsyn, B. L.; Bongers, W. A.; Bratman, V. L.; Denisov, G. G.; Manintveld, P.; Savilov, A. V.; Varfolomeev, A. A.; Verhoeven, A. G. A.; Urbanus, W. H.

2000-01-01

The 'Fusion-FEM' is a free electron MASER based on an electrostatic accelerator. An electron beam of 12 A, 1.35-2 MeV is injected into a step-tapered undulator to generate 1 MW of radiation in the range 130-250 GHz. The undulator is built from two sections with different field strength

Discrete Maximum Principle for a 1D Problem with Piecewise-Constant Coefficients Solved by hp-FEM

Czech Academy of Sciences Publication Activity Database

Vejchodský, Tomáš; Šolín, Pavel

2007-01-01

Roč. 15, č. 3 (2007), s. 233-243 ISSN 1570-2820 R&D Projects: GA ČR GP201/04/P021; GA ČR GA102/05/0629 Institutional research plan: CEZ:AV0Z10190503; CEZ:AV0Z20570509 Keywords : discrete maximum principle * hp-FEM * Poisson equation Subject RIV: BA - General Mathematics

A Novel Technique for Rotor Bar Failure Detection in Single-Cage Induction Motor Using FEM and MATLAB/SIMULINK

Directory of Open Access Journals (Sweden)

Seyed Abbas Taher

2011-01-01

Full Text Available In this article, a new fault detection technique is proposed for squirrel cage induction motor (SCIM based on detection of rotor bar failure. This type of fault detection is commonly carried out, while motor continues to work at a steady-state regime. Recently, several methods have been presented for rotor bar failure detection based on evaluation of the start-up transient current. The proposed method here is capable of fault detection immediately after bar breakage, where a three-phase SCIM is modelled in finite element method (FEM using Maxwell2D software. Broken rotor bars are then modelled by the corresponding outer rotor impedance obtained by GA, thereby presenting an analogue model extracted from FEM to be simulated in a flexible environment such as MATLAB/SIMULINK. To improve the failure recognition, the stator current signal was analysed using discrete wavelet transform (DWT.

FEM-based linear inverse modeling using a 3D source array to image magma chambers with free geometry. Application to InSAR data from Rabaul Caldera (PNG).

Science.gov (United States)

Ronchin, Erika; Masterlark, Timothy; Dawson, John; Saunders, Steve; Martí Molist, Joan

2015-04-01

In this study, we present a method to fully integrate a family of finite element models (FEMs) into the regularized linear inversion of InSAR data collected at Rabaul caldera (PNG) between February 2007 and December 2010. During this period the caldera experienced a long-term steady subsidence that characterized surface movement both inside the caldera and outside, on its western side. The inversion is based on an array of FEM sources in the sense that the Green's function matrix is a library of forward numerical displacement solutions generated by the sources of an array common to all FEMs. Each entry of the library is the LOS surface displacement generated by injecting a unity mass of fluid, of known density and bulk modulus, into a different source cavity of the array for each FEM. By using FEMs, we are taking advantage of their capability of including topography and heterogeneous distribution of elastic material properties. All FEMs of the family share the same mesh in which only one source is activated at the time by removing the corresponding elements and applying the unity fluid flux. The domain therefore only needs to be discretized once. This precludes remeshing for each activated source, thus reducing computational requirements, often a downside of FEM-based inversions. Without imposing an a-priori source, the method allows us to identify, from a least-squares standpoint, a complex distribution of fluid flux (or change in pressure) with a 3D free geometry within the source array, as dictated by the data. The results of applying the proposed inversion to Rabaul InSAR data show a shallow magmatic system under the caldera made of two interconnected lobes located at the two opposite sides of the caldera. These lobes could be consistent with feeding reservoirs of the ongoing Tavuvur volcano eruption of andesitic products, on the eastern side, and of the past Vulcan volcano eruptions of more evolved materials, on the western side. The interconnection and

Identification of Methicillin-Resistant Staphylococcus aureus (MRSA) Using Simultaneous Detection of mecA, nuc, and femB by Loop-Mediated Isothermal Amplification (LAMP).

Science.gov (United States)

Chen, Changguo; Zhao, Qiangyuan; Guo, Jianwei; Li, Yanjun; Chen, Qiuyuan

2017-08-01

The aim of this study was to develop a rapid detection assay to identify methicillin-resistant Staphylococcus aureus by simultaneous testing for the mecA, nuc, and femB genes using the loop-mediated isothermal amplification (LAMP) method. LAMP primers were designed using online bio-software ( http://primerexplorer.jp/e/ ), and amplification reactions were performed in an isothermal temperature bath. The products were then examined using 2% agarose gel electrophoresis. MecA, nuc, and femB were confirmed by triplex TaqMan real-time PCR. For better naked-eye inspection of the reaction result, hydroxy naphthol blue (HNB) was added to the amplification system. Within 60 min, LAMP successfully amplified the genes of interest under isothermal conditions at 63 °C. The results of 2% gel electrophoresis indicated that when the Mg 2+ concentration in the reaction system was 6 μmol, the amplification of the mecA gene was relatively good, while the amplification of the nuc and femB genes was better at an Mg 2+ concentration of 8 μmol. Obvious color differences were observed by adding 1 μL (3.75 mM) of HNB into 25 μL reaction system. The LAMP assay was applied to 128 isolates cases of methicillin-resistant Staphylococcus aureus, which were separated from the daily specimens and identified by Vitek microbial identification instruments. The results were identical for both LAMP and PCR. LAMP offers an alternative detection assay for mecA, nuc, and femB and is faster than other methods.

A Validation of FEM3MP with Joint Urban 2003 Data

Energy Technology Data Exchange (ETDEWEB)

Chan, S T; Leach, M J

2006-08-29

Under the sponsorship of the U.S. DOE and DHS, we have recently developed a computational fluid dynamics (CFD) model for simulating airflow and dispersion of chemical/biological agents released in urban areas. Our model, FEM3MP, is based on solving the three-dimensional, time-dependent Navier-Stokes equations with appropriate physics submodels on massively parallel computer platforms. It employs finite-element discretization for effective treatment of complex geometries and a semi-implicit projection scheme for efficient time-integration. A simplified CFD approach, using both explicitly resolved and virtual buildings, was implemented to further improve the model's efficiency. Predictions from our model are continuously being verified against measured data from wind tunnel and field studies. Herein our model is further evaluated using observed data from IOPs (intensive operation periods) 3 and 9 of the Joint Urban 2003 field study conducted in Oklahoma City, Oklahoma, in July 2003. Our model predictions of wind and concentration fields in the near and intermediate regions, as well as profiles of wind speed, wind direction, friction velocity, and turbulent kinetic energy (TKE) in the urban wake region, are generally consistent with and compared reasonably well with field observations. In addition, our model was able to predict the observed split plume of IOP 3 and the end vortices along Park Avenue in IOP 9. The dispersion results and TKE profiles at the crane station indicate the effects of convective mixing are relatively important for the daytime release of IOP 3 but the stable effects are relatively unimportant for the nighttime release of IOP 9. Results of this study also suggest that the simplified CFD approach implemented in FEM3MP can be a cost-effective tool for simulating urban dispersion problems.

3D-FEM Analysis on Geogrid Reinforced Flexible Pavement Roads

Science.gov (United States)

Calvarano, Lidia Sarah; Palamara, Rocco; Leonardi, Giovanni; Moraci, Nicola

2017-12-01

Nowadays, the need to increase pavement service life, guarantee high performance, reduce service and maintenance costs has been turned a greater attention on the use of reinforcements. This paper presents findings of a numerical investigation on geogrid reinforced flexible pavement roads, under wheel traffic loads, using a three-dimensional Finite Element Method (FEM). The results obtained show the effectiveness of glass fibre grids as reinforcement which, with appropriate design and correct installation, by improving interface shear resistance, can be used to expand the performance of flexible pavements in different ways: by increasing the road service life providing a relevant contribution against superficial rutting or by decreasing the construction costs due to the reduction in the reinforced HMA layer thickness and thus of mineral aggregate required for its construction.

Elasto-viscoplastic FEM simulations of the aluminium flow in the bearing area for extrusion of thin-walled sections

NARCIS (Netherlands)

Lof, J.

2001-01-01

The use of the finite element method (FEM) is getting increasingly important in the understanding of processes that occur during aluminium extrusion. The bearing area is one of the most difficult areas to model in a numerical simulation. To investigate the phenomena that occur in the bearing,

Charge-conserving FEM-PIC schemes on general grids

International Nuclear Information System (INIS)

Campos Pinto, M.; Jund, S.; Salmon, S.; Sonnendruecker, E.

2014-01-01

Particle-In-Cell (PIC) solvers are a major tool for the understanding of the complex behavior of a plasma or a particle beam in many situations. An important issue for electromagnetic PIC solvers, where the fields are computed using Maxwell's equations, is the problem of discrete charge conservation. In this article, we aim at proposing a general mathematical formulation for charge-conserving finite-element Maxwell solvers coupled with particle schemes. In particular, we identify the finite-element continuity equations that must be satisfied by the discrete current sources for several classes of time-domain Vlasov-Maxwell simulations to preserve the Gauss law at each time step, and propose a generic algorithm for computing such consistent sources. Since our results cover a wide range of schemes (namely curl-conforming finite element methods of arbitrary degree, general meshes in two or three dimensions, several classes of time discretization schemes, particles with arbitrary shape factors and piecewise polynomial trajectories of arbitrary degree), we believe that they provide a useful roadmap in the design of high-order charge-conserving FEM-PIC numerical schemes. (authors)

Adaptive stochastic Galerkin FEM with hierarchical tensor representations

KAUST Repository

Eigel, Martin

2016-01-08

PDE with stochastic data usually lead to very high-dimensional algebraic problems which easily become unfeasible for numerical computations because of the dense coupling structure of the discretised stochastic operator. Recently, an adaptive stochastic Galerkin FEM based on a residual a posteriori error estimator was presented and the convergence of the adaptive algorithm was shown. While this approach leads to a drastic reduction of the complexity of the problem due to the iterative discovery of the sparsity of the solution, the problem size and structure is still rather limited. To allow for larger and more general problems, we exploit the tensor structure of the parametric problem by representing operator and solution iterates in the tensor train (TT) format. The (successive) compression carried out with these representations can be seen as a generalisation of some other model reduction techniques, e.g. the reduced basis method. We show that this approach facilitates the efficient computation of different error indicators related to the computational mesh, the active polynomial chaos index set, and the TT rank. In particular, the curse of dimension is avoided.

Integrity evaluation for stud female threads on pressure vessel according to ASME code using FEM

International Nuclear Information System (INIS)

Kim, Moon Young; Chung, Nam Yong

2003-01-01

The extension of design life among power plants is increasingly becoming a world-wide trend. Kori no.1 unit in Korea is operating two cycle. It has two man-ways for tube inspection in a steam generator which is one of the important components in a nuclear power plant. Especially, stud bolts for man-way cover have damaged by disassembly and assembly several times and degradation for bolt materials for long term operation. It should be evaluated and compared by ASME code criteria for integrity evaluation. Integrity evaluation criteria which has been made by the manufacturer is not applied on the stud bolts of nuclear pressure vessels directly because it is controlled by the yield stress of ASME code. It can apply evaluation criteria through FEM analysis to damaged female threads and to evaluated safety for helical-coil method which is used according to code case-N-496-1. From analysis results, we found that it is the same results between stress intensity which got from FEM analysis on damaged female threads over 10% by manufacture integrity criteria and 2/3 yield strength criteria on ASME code. It was also confirmed that the helical-coil repair method would be safe

Structural design of DEMO Divertor Cassette Body: provisional FEM analysis and introductive application of RCC-MRx design rules

Energy Technology Data Exchange (ETDEWEB)

Frosi, Paolo, E-mail: paolo.frosi@enea.it [Unità Tecnica Fusione-ENEA C.R. Frascati, Via E. Fermi 45, 00044 Frascati (Italy); Mazzone, Giuseppe [Unità Tecnica Fusione-ENEA C.R. Frascati, Via E. Fermi 45, 00044 Frascati (Italy); You, Jeong-Ha [Max Planck Institute of Plasma Physics, Boltzmann Str. 2, 85748 Garching (Germany)

2016-11-01

This paper deals with the early steps in developing a structural fem model of DEMO Divertor. The study is focused on the thermal and structural analysis of the Cassette Body: a new geometry has been developed for this component: it is foreseen that the plasma facing component (PFC) will be directly placed on the cassette but for the Dome no choice has been adopted yet. For now the model contains only a suitable schematization of the Cassette Body and its objective is to analyze the effect produced by the main loads (electromagnetic loads, coolant pressure, thermal neutron and convective loads) on itself: an available estimate of loads is that one derived from ITER: for a proper translation some assumptions have been made and they are described in the paper. Now it is not a primary purpose to obtain some definitive statements about stresses, displacements, temperatures and so on; the authors want to construct a set of FEM models that will help all the decisions of DEMO Divertor design in its future development. This set is conceived as a tool that shall be improved to account for all the main enhancements that will be found in geometry, in material properties data and in load evaluations. Moreover, the main design variables (loads, material properties, some geometric items, mesh element size) are defined as parameters. This work considers also an introductive approach for future structural verification of the Divertor Cassette Body: so a concern of the Design and Construction Rules for Mechanical Components of Nuclear Installation (RCC-MRx) has been implemented. The FEM code used is Ansys rel. 15.

Accurate Calculation of Magnetic Fields in the End Regions of Superconducting Accelerator Magnets using the BEM-FEM Coupling Method

CERN Document Server

Kurz, S

1999-01-01

In this paper a new technique for the accurate calculation of magnetic fields in the end regions of superconducting accelerator magnets is presented. This method couples Boundary Elements (BEM) which discretize the surface of the iron yoke and Finite Elements (FEM) for the modelling of the nonlinear interior of the yoke. The BEM-FEM method is therefore specially suited for the calculation of 3-dimensional effects in the magnets, as the coils and the air regions do not have to be represented in the finite-element mesh and discretization errors only influence the calculation of the magnetization (reduced field) of the yoke. The method has been recently implemented into the CERN-ROXIE program package for the design and optimization of the LHC magnets. The field shape and multipole errors in the two-in-one LHC dipoles with its coil ends sticking out of the common iron yoke is presented.

Nodal DG-FEM solution of high-order Boussinesq-type equations

DEFF Research Database (Denmark)

Engsig-Karup, Allan Peter; Hesthaven, Jan S.; Bingham, Harry B.

2006-01-01

We present a discontinuous Galerkin finite element method (DG-FEM) solution to a set of high-order Boussinesq-type equations for modelling highly nonlinear and dispersive water waves in one and two horizontal dimensions. The continuous equations are discretized using nodal polynomial basis...... functions of arbitrary order in space on each element of an unstructured computational domain. A fourth order explicit Runge-Kutta scheme is used to advance the solution in time. Methods for introducing artificial damping to control mild nonlinear instabilities are also discussed. The accuracy...... and convergence of the model with both h (grid size) and p (order) refinement are verified for the linearized equations, and calculations are provided for two nonlinear test cases in one horizontal dimension: harmonic generation over a submerged bar; and reflection of a steep solitary wave from a vertical wall...

FEM Techniques for High Stress Detection in Accelerated Fatigue Simulation

Science.gov (United States)

Veltri, M.

2016-09-01

This work presents the theory and a numerical validation study in support to a novel method for a priori identification of fatigue critical regions, with the aim to accelerate durability design in large FEM problems. The investigation is placed in the context of modern full-body structural durability analysis, where a computationally intensive dynamic solution could be required to identify areas with potential for fatigue damage initiation. The early detection of fatigue critical areas can drive a simplification of the problem size, leading to sensible improvement in solution time and model handling while allowing processing of the critical areas in higher detail. The proposed technique is applied to a real life industrial case in a comparative assessment with established practices. Synthetic damage prediction quantification and visualization techniques allow for a quick and efficient comparison between methods, outlining potential application benefits and boundaries.

The Influence of Pressure Distribution on the Maximum Values of Stress in FEM Analysis of Plain Bearings

Directory of Open Access Journals (Sweden)

Vasile Cojocaru

2016-12-01

Full Text Available Several methods can be used in the FEM studies to apply the loads on a plain bearing. The paper presents a comparative analysis of maximum stress obtained for three loading scenarios: resultant force applied on the shaft – bearing assembly, variable pressure with sinusoidal distribution applied on the bearing surface, variable pressure with parabolic distribution applied on the bearing surface.

Structural model of standard ultrasonic transducer array developed for FEM analysis of mechanical crosstalk.

Science.gov (United States)

Celmer, M; Opieliński, K J; Dopierała, M

2018-02-01

One of the reasons of distortions in ultrasonic imaging are crosstalk effects. They can be divided into groups according to the way of their formation. One of them is constituted by mechanical crosstalk, which is propagated by a construction of a multi-element array of piezoelectric transducers. When an individual transducer is excited, mechanical vibrations are transferred to adjacent construction components, thereby stimulating neighboring transducers to an undesired operation. In order to explore ways of the propagation of such vibrations, the authors developed the FEM model of the array of piezoelectric transducers designed for calculations in COMSOL Multiphysics software. Simulations of activating individual transducers and calculated electrical voltages appearing on transducers unstimulated intentionally, were performed in the time domain in order to assess the propagation velocity of different vibration modes through the construction elements. On this basis, conclusions were drawn in terms of the participation of various construction parts of the array of piezoelectric transducers in the process of creating the mechanical crosstalk. The elaborated FEM model allowed also to examine the ways aimed at reducing the transmission of mechanical crosstalk vibrations through the components of the array. Studies showed that correct cuts in the fasteners and the front layer improve the reduction of the mechanical crosstalk effect. The model can become a helpful tool in the process of design and modifications of manufactured ultrasonic arrays particularly in terms of mechanical crosstalk reduction. Copyright © 2017 Elsevier B.V. All rights reserved.

Fracture Capabilities in Grizzly with the extended Finite Element Method (X-FEM)

Energy Technology Data Exchange (ETDEWEB)

Dolbow, John [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Ziyu [Idaho National Lab. (INL), Idaho Falls, ID (United States); Spencer, Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jiang, Wen [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-09-01

Efforts are underway to develop fracture mechanics capabilities in the Grizzly code to enable it to be used to perform deterministic fracture assessments of degraded reactor pressure vessels (RPVs). A capability was previously developed to calculate three-dimensional interaction- integrals to extract mixed-mode stress-intensity factors. This capability requires the use of a finite element mesh that conforms to the crack geometry. The eXtended Finite Element Method (X-FEM) provides a means to represent a crack geometry without explicitly fitting the finite element mesh to it. This is effected by enhancing the element kinematics to represent jump discontinuities at arbitrary locations inside of the element, as well as the incorporation of asymptotic near-tip fields to better capture crack singularities. In this work, use of only the discontinuous enrichment functions was examined to see how accurate stress intensity factors could still be calculated. This report documents the following work to enhance Grizzly’s engineering fracture capabilities by introducing arbitrary jump discontinuities for prescribed crack geometries; X-FEM Mesh Cutting in 3D: to enhance the kinematics of elements that are intersected by arbitrary crack geometries, a mesh cutting algorithm was implemented in Grizzly. The algorithm introduces new virtual nodes and creates partial elements, and then creates a new mesh connectivity; Interaction Integral Modifications: the existing code for evaluating the interaction integral in Grizzly was based on the assumption of a mesh that was fitted to the crack geometry. Modifications were made to allow for the possibility of a crack front that passes arbitrarily through the mesh; and Benchmarking for 3D Fracture: the new capabilities were benchmarked against mixed-mode three-dimensional fracture problems with known analytical solutions.

FEM modeling of the reinforcement mechanism of Hydroxyapatite in PLLA scaffolds produced by supercritical drying, for Tissue Engineering applications.

Science.gov (United States)

Baldino, L; Naddeo, F; Cardea, S; Naddeo, A; Reverchon, E

2015-11-01

Scaffolds have been produced by supercritical CO2 drying of Poly-L-Lactid Acid (PLLA) gels loaded with micrometric fructose particles used as porogens. These structures show a microporous architecture generated by the voids left in the solid material by porogen leaching, while they maintain the nanostructure of the gel, consisting of a network of nanofilaments. These scaffolds have also been loaded with Hydroxyapatite (HA) nanoparticles, from 10 to 50% w/w with respect to the polymer, to improve the mechanical properties of the PLLA structure. Based on miscroscopic and mechanical considerations, we propose a parametric Finite Element Method (FEM) model of PLLA-HA composites that describes the microporous structure as a close-packing of equal spheres and the nanoscale structure as a space frame of isotropic curved fibers. The effect of HA on the mechanical properties of the scaffolds has been modeled on the basis of SEM images and by taking into consideration the formation of concentric cylinders of HA nanoparticles around PLLA nanofibers. Modeling analysis confirms that mechanical properties of these scaffolds depend on nanofibrous network connections and that bending is the major factor causing deformation of the network. The FEM model also takes into account the formation of HA multi-layer coating on some areas in the nanofiber network and its increase in thickness with HA percentage. The Young modulus tends to a plateau for HA percentages larger than 30% w/w and when the coverage of the nanofibers produced by HA nanoparticles reaches a loaded surface index of 0.14 in the FEM model. Copyright © 2015 Elsevier Ltd. All rights reserved.

Analytical Calculation And FEM Analysis Main Girder Double Girder Bridge Crane

Directory of Open Access Journals (Sweden)

Muamer Delić

2017-02-01

Full Text Available The cranes are now not replaceable mode of transport of materials and finished products both in production halls and in the open space. This paper made the whole analytical calculation of double girder bridge cranes to be used in laboratories exclusively for testing, determined by the maximum bending stress and deflection of the main girder. After calculating the dimensions, we created a model cranes in software CATIA V5. The same model was subjected to FEM analysis of the same name software. At the end of the paper comparison has been done. The objective of the calculation and analysis of the model was to develop a model crane and to serve for the next tests. Dimensions of the crane are given according to the laboratory where it will be located.

Environmental equipment for usages of FEM software. ADVENTURE system user's guide

Energy Technology Data Exchange (ETDEWEB)

Yamasaki, Ichirou [Japan Atomic Energy Research Inst., Center for Promotion of Computional Science and Engineering, Kizu, Kyoto (Japan); Yoshimura, Shinobu [Tokyo Univ., Tokyo (Japan)

2003-05-01

The community softwares, databases, and other various tools have been installed in the ITBL environment by the Office of ITBL Promotion as a common utility property for each research field. Among those softwares, Finite Element Method (FEM) code, Adventure (which was originally developed by Prof. Yoshimura, the University of Tokyo), is provided as one of structure analysis programs for ITBL users. The code is well known to possess a high performance ability for parallel processing, especially for massively parallel environments. In this report, a chain of processes for usages of the system as well as the installation method to PC cluster are described. (author)

Identification of the numerical model of FEM in reference to measurements in situ

Science.gov (United States)

Jukowski, Michał; Bec, Jarosław; Błazik-Borowa, Ewa

2018-01-01

The paper deals with the verification of various numerical models in relation to the pilot-phase measurements of a rail bridge subjected to dynamic loading. Three types of FEM models were elaborated for this purpose. Static, modal and dynamic analyses were performed. The study consisted of measuring the acceleration values of the structural components of the object at the moment of the train passing. Based on this, FFT analysis was performed, the main natural frequencies of the bridge were determined, the structural damping ratio and the dynamic amplification factor (DAF) were calculated and compared with the standard values. Calculations were made using Autodesk Simulation Multiphysics (Algor).

Converter-level FEM simulation for lifetime prediction of an LED driver with improved thermal modelling

DEFF Research Database (Denmark)

Niu, H.; Wang, H.; Ye, X.

2017-01-01

application. A converter-level finite element simulation (FEM) simulation is carried out to obtain the ambient temperature of electrolytic capacitors and power MOSFETs used in the LED driver, which takes into account the impact of the driver enclosure and the thermal coupling among different components....... Therefore, the proposed method bridges the link between the global ambient temperature profile outside of the enclosure and the local ambient temperature profiles of the components of interest inside the driver. A quantitative comparison of the estimated annual lifetime consumptions of MOSFETs...

Quantitative assessment of alkali-reactive aggregate mineral content through XRD using polished sections as a supplementary tool to RILEM AAR-1 (petrographic method)

International Nuclear Information System (INIS)

Castro, Nélia; Sorensen, Bjørn E.; Broekmans, Maarten A.T.M.

2012-01-01

The mineral content of 5 aggregate samples from 4 different countries, including reactive and non-reactive aggregate types, was assessed quantitatively by X-ray diffraction (XRD) using polished sections. Additionally, electron probe microanalyzer (EPMA) mapping and cathodoluminescence (CL) were used to characterize the opal-CT identified in one of the aggregate samples. Critical review of results from polished sections against traditionally powdered specimen has demonstrated that for fine-grained rocks without preferred orientation the assessment of mineral content by XRD using polished sections may represent an advantage over traditional powder specimens. Comparison of data on mineral content and silica speciation with expansion data from PARTNER project confirmed that the presence of opal-CT plays an important role in the reactivity of one of the studied aggregates. Used as a complementary tool to RILEM AAR-1, the methodology suggested in this paper has the potential to improve the strength of the petrographic method.

The application of NISA II FEM package in seismic qualification of small class IE electric motors

International Nuclear Information System (INIS)

Fancev, T.; Saban, I.; Grgic, D.

1995-01-01

According to the IEEE standards 323/1974 and 344/1975, seismic qualification of class IE equipment is appropriate combination of test and analysis methods. Complex equipment and assemblies are usually tested through seismic testing. The analysis is recommended for simple equipment that can be easily modeled to correctly predict its response. This article deals with the application of NISA II FEM package in 3D FE modeling and mode shape calculations of small power low voltage electric motors. (author)

FEM analysis of an single stator dual PM rotors axial synchronous machine

Science.gov (United States)

Tutelea, L. N.; Deaconu, S. I.; Popa, G. N.

2017-01-01

The actual e - continuously variable transmission (e-CVT) solution for the parallel Hybrid Electric Vehicle (HEV) requires two electric machines, two inverters, and a planetary gear. A distinct electric generator and a propulsion electric motor, both with full power converters, are typical for a series HEV. In an effort to simplify the planetary-geared e-CVT for the parallel HEV or the series HEV we hereby propose to replace the basically two electric machines and their two power converters by a single, axial-air-gap, electric machine central stator, fed from a single PWM converter with dual frequency voltage output and two independent PM rotors. The proposed topologies, the magneto-motive force analysis and quasi 3D-FEM analysis are the core of the paper.

Mixed FEM for Second Order Elliptic Problems on Polygonal Meshes with BEM-Based Spaces

KAUST Repository

Efendiev, Yalchin

2014-01-01

We present a Boundary Element Method (BEM)-based FEM for mixed formulations of second order elliptic problems in two dimensions. The challenge, we would like to address, is a proper construction of H(div)-conforming vector valued trial functions on arbitrary polygonal partitions of the domain. The proposed construction generates trial functions on polygonal elements which inherit some of the properties of the unknown solution. In the numerical realization, the relevant local problems are treated by means of boundary integral formulations. We test the accuracy of the method on two model problems. © 2014 Springer-Verlag.

FEM simulation of the die compaction of pharmaceutical products: influence of visco-elastic phenomena and comparison with experiments.

Science.gov (United States)

Diarra, Harona; Mazel, Vincent; Busignies, Virginie; Tchoreloff, Pierre

2013-09-10

This work studies the influence of visco-elastic behavior in the finite element method (FEM) modeling of die compaction of pharmaceutical products and how such a visco-elastic behavior may improve the agreement between experimental and simulated compression curves. The modeling of the process was conducted on a pharmaceutical excipient, microcrystalline cellulose (MCC), by using Drucker-Prager cap model coupled with creep behavior in Abaqus(®) software. The experimental data were obtained on a compaction simulator (STYLCAM 200R). The elastic deformation of the press was determined by performing experimental tests on a calibration disk and was introduced in the simulation. Numerical optimization was performed to characterize creep parameters. The use of creep behavior in the simulations clearly improved the agreement between the numerical and experimental compression curves (stresses, thickness), mainly during the unloading part of the compaction cycle. For the first time, it was possible to reproduce numerically the fact that the minimum tablet thickness is not obtained at the maximum compression stress. This study proves that creep behavior must be taken into account when modeling the compaction of pharmaceutical products using FEM methods. Copyright © 2013 Elsevier B.V. All rights reserved.

Interactive tool that empowers structural understanding and enables FEM analysis in a parametric design environment

DEFF Research Database (Denmark)

Christensen, Jesper Thøger; Parigi, Dario; Kirkegaard, Poul Henning

2014-01-01

This paper introduces an interactive tool developed to integrate structural analysis in the architectural design environment from the early conceptual design stage. The tool improves exchange of data between the design environment of Rhino Grasshopper and the FEM analysis of Autodesk Robot...... Structural Analysis. Further the tool provides intuitive setup and visual aids in order to facilitate the process. Enabling students and professionals to quickly analyze and evaluate multiple design variations. The tool has been developed inside the Performance Aided Design course at the Master...... of Architecture and Design at Aalborg University...

Pregnancy and contraceptive use among women participating in the FEM-PrEP trial.

Science.gov (United States)

Callahan, Rebecca; Nanda, Kavita; Kapiga, Saidi; Malahleha, Mookho; Mandala, Justin; Ogada, Teresa; Van Damme, Lut; Taylor, Douglas

2015-02-01

Pregnancy among study participants remains a challenge for trials of new HIV prevention agents despite promotion and provision of contraception. We evaluated contraceptive use, pregnancy incidence, and study drug adherence by contraceptive method among women enrolled in the FEM-PrEP trial of once-daily oral tenofovir disoproxil fumarate and emtricitabine (TDF-FTC) for HIV prevention. We required women to be using effective non-barrier contraception at enrollment. At each monthly follow-up visit, women were counseled on contraceptive use and tested for pregnancy. TDF-FTC adherence was determined by measuring plasma drug concentrations at 4-week intervals. We used Cox proportional hazards models to assess factors associated with incident pregnancy and multivariate logistic regression to examine the relationship between contraceptive method used at enrollment and TDF-FTC adherence. More than half of women were not using effective contraception before enrollment. Ninety-eight percent of these women adopted either injectable (55%) or oral (43%) contraceptives. The overall pregnancy rate was 9.6 per 100 woman-years. Among injectable users and new users of combined oral contraceptives (COCs), the rates were 1.6 and 35.1, respectively. New users of injectables had significantly greater odds of adhering to TDF-FTC than new COC users [odds ratio (95% confidence interval): 4.4 (1.7 to 11.6), P = 0.002], existing COC users [3.1 (1.3 to 7.3), P = 0.01], and existing injectable users [2.4 (1.1 to 5.6), P = 0.04]. Women using COCs during FEM-PrEP, particularly new adopters, were more likely to become pregnant and less likely to adhere to study product than injectable users. HIV prevention trials should consider requiring long-acting methods, including injectables, for study participation.

The sexual risk context among the FEM-PrEP study population in Bondo, Kenya and Pretoria, South Africa.

Directory of Open Access Journals (Sweden)

Jennifer Headley

Full Text Available Incidence rates in the FEM-PrEP and VOICE trials demonstrate that women from diverse sub-Saharan African communities continue to be at substantial HIV risk.To describe and compare the sexual risk context of the study population from two FEM-PrEP trial sites-Bondo, Kenya, and Pretoria, South Africa.At baseline we collected information about demographics, sexual behaviors, and partnership beliefs through quantitative questionnaires with all participants (Bondo, n = 720; Pretoria, n = 750. To explore the sexual risk context, we also conducted qualitative, semi-structured interviews with HIV-negative participants randomly selected at several time points (Bondo, n = 111; Pretoria, n = 69.Demographics, sexual behavior, and partnership beliefs varied significantly between the sites. Bondo participants were generally older, had fewer years of schooling, and were more likely to be employed and married compared to Pretoria participants. Bondo participants were more likely to report multiple partners and not knowing whether their partner had HIV than Pretoria participants. A significantly higher percentage of Bondo participants reported engaging in sex without a condom with their primary and other partners compared to Pretoria participants. We found a borderline association between participants who reported not using condoms in the 4 weeks prior to baseline and lower risk of HIV infection, and no association between having more than one sexual partner at baseline and HIV infection.Despite significantly different demographics, sexual behaviors, and partnership beliefs, many women in the FEM-PrEP trial were at risk of acquiring HIV as demonstrated by the sites' high HIV incidence. Though gender dynamics differed between the populations, they appear to play a critical role in women's sexual practices. The findings highlight different ways women from diverse contexts may be at-risk for HIV and the importance of providing HIV prevention options

In-situ observation of dislocation and analysis of residual stresses by FEM/DDM modeling in water cavitation peening of pure titanium

International Nuclear Information System (INIS)

Ju, D Y; Han, B

2015-01-01

In this paper, in order to approach this problem, specimens of pure titanium were treated with WCP, and the subsequent changes in microstructure, residual stress, and surface morphologies were investigated as a function of WCP duration. The influence of water cavitation peening (WCP) treatment on the microstructure of pure titanium was investigated. A novel combined finite element and dislocation density method (FEM/DDM), proposed for predicting macro and micro residual stresses induced on the material subsurface treated with water cavitation peening, is also presented. A bilinear elastic-plastic finite element method was conducted to predict macro-residual stresses and a dislocation density method was conducted to predict micro-residual stresses. These approaches made possible the prediction of the magnitude and depth of residual stress fields in pure titanium. The effect of applied impact pressures on the residual stresses was also presented. The results of the FEM/DDM modeling were in good agreement with those of the experimental measurements. (paper)

Mass conservation for instantaneous sources in FEM3 simulations of material dispersion

International Nuclear Information System (INIS)

Rodean, H.C.

1987-11-01

This report presents the results of a systematic study in which it is shown that the numerical integration errors in determining material mass content are negligible; the material phase-change model by itself is not a cause of material mass variation; and a linear relation between fractional mass change and fractional density change at the source center for given mesh and source geometries exists over a range of values from 10 -5 to 10 -1 . This suggests that the omission of the ∂ rho/∂t term from the mass conservation equation is the cause of the observed non-conservation of mass by FEM3. It is shown that these mass variations can be minimized by minimizing the initial density gradients in the source region. 5 refs., 18 figs., 4 tabs

Inverse-FEM Characterization of a Brain Tissue Phantom to Simulate Compression and Indentation Caracterización de tejido cerebral artificial utilizando Inverse-FEM para simular indentación y comprensión

Directory of Open Access Journals (Sweden)

Elizabeth Mesa-Múnera

2012-12-01

Full Text Available The realistic simulation of tool-tissue interactions is necessary for the development of surgical simulators and one of the key element for it realism is accurate bio-mechanical tissue models. In this paper, we determined the mechanical properties of soft tissue by minimizing the difference between experimental measurements and the analytical or simulated solution of the deformation. Then, we selected the best model parameters that fit the experimental data to simulate a bonded compression and a needle indentation with a flat-tip. We show that the inverse FEM allows accurate material property estimation. We also validated our results using multiple tool-tissue interactions over the same specimen.Una simulación realista de la interacción tejido-herramienta es necesaria para desarrollar simuldores quirúrgicos, y la presición en modelos biomecánicos de tejidos es determinante para cumplir tal fin. Los trabajos previos han caracterizado las propiedades de tejidos blandos; sin embargo, ha faltado una validación apropiada de los resultados. En este trabajo se determinaron las propiedades mecánicas de un tejido blando minimizando la diferencia entre las mediciones experimentales y la solución analítica o simulada del problema. Luego, fueron seleccionados los parámetros que mejor se ajustaron a los datos experimentales para simular una compresión con fricción y la indentación de una aguja con punta plana. Se concluye que el inverse-FEM permite la precisa estimación de las propiedades del material. Además, estos resultados fueron validados con varias interacciones tejido-herramienta sobre el mismo espécimen.

Comparison of multimesh hp-FEM to interpolation and projection methods for spatial coupling of thermal and neutron diffusion calculations

International Nuclear Information System (INIS)

Dubcova, Lenka; Solin, Pavel; Hansen, Glen; Park, HyeongKae

2011-01-01

Multiphysics solution challenges are legion within the field of nuclear reactor design and analysis. One major issue concerns the coupling between heat and neutron flow (neutronics) within the reactor assembly. These phenomena are usually very tightly interdependent, as large amounts of heat are quickly produced with an increase in fission events within the fuel, which raises the temperature that affects the neutron cross section of the fuel. Furthermore, there typically is a large diversity of time and spatial scales between mathematical models of heat and neutronics. Indeed, the different spatial resolution requirements often lead to the use of very different meshes for the two phenomena. As the equations are coupled, one must take care in exchanging solution data between them, or significant error can be introduced into the coupled problem. We propose a novel approach to the discretization of the coupled problem on different meshes based on an adaptive multimesh higher-order finite element method (hp-FEM), and compare it to popular interpolation and projection methods. We show that the multimesh hp-FEM method is significantly more accurate than the interpolation and projection approaches considered in this study.

Structural optimization of wind turbine rotor blades by multilevel sectional/multibody/3D-FEM analysis

DEFF Research Database (Denmark)

Bottasso, C. L.; Campagnolo, F.; Croce, A.

2014-01-01

model fully-populated cross sectional stiffness matrices. Next, a "fine"-level 3D FEM model is used for the refinement of the coarse-level solution. Improved results obtained at the level of the 3D model are utilized at the following coarse-level iteration through a heuristic modification of the design...... constraints. In addition, a buckling analysis is performed at the fine description level, which in turn affects the nonstructural blade mass. The updated constraint bounds and mass make their effects felt at the next coarse-level constrained design optimization, thereby closing the loop between the coarse...

Induction Machine with Improved Operating Performances for Electric Trucks. A FEM-Based Analysis

Directory of Open Access Journals (Sweden)

MUNTEANU, A.

2010-05-01

Full Text Available The paper presents a study concerning the performance developed by induction motors destined for motorization of heavy electric vehicles such as trucks. Taking into consideration the imposed restrictions, one presents, in a comparative manner, the main geometrical parameters which come of the classical design algorithms. A special attention is dedicated to the winding design, since it has to ensure two synchronous speeds corresponding to 16 and 8 poles, respectively. Moreover, the influence of the rotor slots shape for the improvement of the start-up is analyzed. Finally, a FEM-based study (approach based on finite element method is performed to put in view specific torque and slip values such as rated, start-up and pull-out ones.

Theoretical and FEM analysis of suspension and propulsion system with HTS hybrid electromagnets in an EMS Maglev model

Energy Technology Data Exchange (ETDEWEB)

Chung, Y.D., E-mail: ydchung@suwon.ac.kr [Department of Electrical Engineering, Suwon University, Bongdang Eup, Hwaseong Si 445-743 (Korea, Republic of); Lee, C.Y. [Korea Railroad Research Institute, Woram Dong, Uiwang Si 437-757 (Korea, Republic of); Jang, J.Y. [Department of Electrical Engineering, Ansan College of Technology, Choji-Dong, Ansan Si 425-792 (Korea, Republic of); Yoon, Y.S. [Department of Electrical and Electronic Engineering, Yonsei University, Sinchon-dong, Seoul 120-749 (Korea, Republic of); Ko, T.K. [Department of Electrical Engineering, Ansan College of Technology, Choji-Dong, Ansan Si 425-792 (Korea, Republic of)

2011-11-15

We examine levitation and propulsion forces of the proto-type maglev vehicle system based on 3D FEM. The levitation force increases over 15% due to AC current of the guideway. The levitation force by HTS electromagnet (EM) and AC current is larger over 30% than that of only HTS EM. We have been constructed a proto-type electromagnetic suspension (EMS) based maglev vehicle system. The maglev concept utilizes magnetic forces for noncontact suspension, guidance and propulsion. The suspension system with high temperature superconducting (HTS) hybrid electromagnet (EM) is composed of HTS coils and normal coils, which consume little power to keep large suspension gap. The magnetic forces realize to guide the vehicle, propel the vehicle along the guide-way and assist in braking action. The proto-type EMS-based Maglev model is designed to keep the suspension gap of 20 mm. This paper presents the theoretical analysis of the maglev vehicle based on the EMS model to obtain the designing parameters for levitation and propulsion forces. The magnetic field distributions of the electromagnetic forces with hybrid EM and propulsion stator coils are analyzed based on three dimension (3D) finite element method (FEM) analysis. From the simulation results, appropriately design parameters of the suspension, guidance and propulsion were obtained.

Theoretical and FEM analysis of suspension and propulsion system with HTS hybrid electromagnets in an EMS Maglev model

International Nuclear Information System (INIS)

Chung, Y.D.; Lee, C.Y.; Jang, J.Y.; Yoon, Y.S.; Ko, T.K.

2011-01-01

We examine levitation and propulsion forces of the proto-type maglev vehicle system based on 3D FEM. The levitation force increases over 15% due to AC current of the guideway. The levitation force by HTS electromagnet (EM) and AC current is larger over 30% than that of only HTS EM. We have been constructed a proto-type electromagnetic suspension (EMS) based maglev vehicle system. The maglev concept utilizes magnetic forces for noncontact suspension, guidance and propulsion. The suspension system with high temperature superconducting (HTS) hybrid electromagnet (EM) is composed of HTS coils and normal coils, which consume little power to keep large suspension gap. The magnetic forces realize to guide the vehicle, propel the vehicle along the guide-way and assist in braking action. The proto-type EMS-based Maglev model is designed to keep the suspension gap of 20 mm. This paper presents the theoretical analysis of the maglev vehicle based on the EMS model to obtain the designing parameters for levitation and propulsion forces. The magnetic field distributions of the electromagnetic forces with hybrid EM and propulsion stator coils are analyzed based on three dimension (3D) finite element method (FEM) analysis. From the simulation results, appropriately design parameters of the suspension, guidance and propulsion were obtained.

Temperature control at DBS electrodes using a heat sink: experimentally validated FEM model of DBS lead architecture

Science.gov (United States)

Elwassif, Maged M.; Datta, Abhishek; Rahman, Asif; Bikson, Marom

2012-08-01

There is a growing interest in the use of deep brain stimulation (DBS) for the treatment of medically refractory movement disorders and other neurological and psychiatric conditions. The extent of temperature increases around DBS electrodes during normal operation (joule heating and increased metabolic activity) or coupling with an external source (e.g. magnetic resonance imaging) remains poorly understood and methods to mitigate temperature increases are being actively investigated. We developed a heat transfer finite element method (FEM) simulation of DBS incorporating the realistic architecture of Medtronic 3389 leads. The temperature changes were analyzed considering different electrode configurations, stimulation protocols and tissue properties. The heat-transfer model results were then validated using micro-thermocouple measurements during DBS lead stimulation in a saline bath. FEM results indicate that lead design (materials and geometry) may have a central role in controlling temperature rise by conducting heat. We show how modifying lead design can effectively control temperature increases. The robustness of this heat-sink approach over complimentary heat-mitigation technologies follows from several features: (1) it is insensitive to the mechanisms of heating (e.g. nature of magnetic coupling); (2) it does not interfere with device efficacy; and (3) can be practically implemented in a broad range of implanted devices without modifying the normal device operations or the implant procedure.

Application de X-FEM et des level-sets à l'homogénéisation de matériaux aléatoires caractérisés par imagerie numérique

OpenAIRE

Ionescu , Irina; Moës , Nicolas; Cartraud , Patrice; Béringhier , Marianne

2007-01-01

International audience; The advances of material characterization by means of imaging techniques require powerful computational methods for numerical analyses. This paper focuses on the advantages of coupling the X-FEM and level sets to solve microstructures with complex geometry. The level set information is obtained from a digital image and then used within a X-FEM computation, where the mesh does not need to conform to the material interface. An example of homogeniza-tion is presented.; La...

Simple rules for design of exhaust mufflers and a comparison with four-pole and FEM calculations

DEFF Research Database (Denmark)

Jensen, Morten Skaarup; Ødegaard, John

1999-01-01

For good muffler design it is advisable to use an advanced computational method such as four-pole theory or FEM or BEM. To get a starting points for these methods and to suggest adjustments to the geometry and materials it is useful to have some simple rules of thumb. This paper presents a number...... of such "rules", and illustrates their reliability and limitations by comparing with results using some of the advanced computational methods. At the same time, this investigation also gives a comparison between four-pole theory and BEM....

A continuum based fem model for friction stir welding-model development

Energy Technology Data Exchange (ETDEWEB)

Buffa, G. [Ohio State University, Department of Industrial, Welding and Systems Engineering, 1971 Neil Avenue, 210 Baker Systems, Columbus, OH 43210 (United States) and Dipartimento di Tecnologia Meccanica, Produzione e Ingegneria Gestionale, Universita di Palermo, Viale delle Scienze, 90128 Palermo (Italy)]. E-mail: g.buffa@dtpm.unipa.it; Hua, J. [Ohio State University, Department of Industrial, Welding and Systems Engineering, 1971 Neil Avenue, 210 Baker Systems, Columbus, OH 43210 (United States)]. E-mail: hua.14@osu.edu; Shivpuri, R. [Ohio State University, Department of Industrial, Welding and Systems Engineering, 1971 Neil Avenue, 210 Baker Systems, Columbus, OH 43210 (United States)]. E-mail: shivpuri.1@osu.edu; Fratini, L. [Dipartimento di Tecnologia Meccanica, Produzione e Ingegneria Gestionale, Universita di Palermo, Viale delle Scienze, 90128 Palermo (Italy)]. E-mail: abaqus@dtpm.unipa.it

2006-03-15

Although friction stir welding (FSW) has been successfully used to join materials that are difficult-to-weld or unweldeable by fusion welding methods, it is still in its early development stage and, therefore, a scientific knowledge based predictive model is of significant help for thorough understanding of FSW process. In this paper, a continuum based FEM model for friction stir welding process is proposed, that is 3D Lagrangian implicit, coupled, rigid-viscoplastic. This model is calibrated by comparing with experimental results of force and temperature distribution, then is used to investigate the distribution of temperature and strain in heat affect zone and the weld nugget. The model correctly predicts the non-symmetric nature of FSW process, and the relationships between the tool forces and the variation in the process parameters. It is found that the effective strain distribution is non-symmetric about the weld line while the temperature profile is almost symmetric in the weld zone.

A continuum based fem model for friction stir welding-model development

International Nuclear Information System (INIS)

Buffa, G.; Hua, J.; Shivpuri, R.; Fratini, L.

2006-01-01

Although friction stir welding (FSW) has been successfully used to join materials that are difficult-to-weld or unweldeable by fusion welding methods, it is still in its early development stage and, therefore, a scientific knowledge based predictive model is of significant help for thorough understanding of FSW process. In this paper, a continuum based FEM model for friction stir welding process is proposed, that is 3D Lagrangian implicit, coupled, rigid-viscoplastic. This model is calibrated by comparing with experimental results of force and temperature distribution, then is used to investigate the distribution of temperature and strain in heat affect zone and the weld nugget. The model correctly predicts the non-symmetric nature of FSW process, and the relationships between the tool forces and the variation in the process parameters. It is found that the effective strain distribution is non-symmetric about the weld line while the temperature profile is almost symmetric in the weld zone

Simulation, calibration and validation protocols for the model 3D-CMCC-CNR-FEM: a case study in the Bonis’ watershed (Calabria, Italy

Directory of Open Access Journals (Sweden)

Collalti A

2017-08-01

Full Text Available Simulation, calibration and validation protocols for the model 3D-CMCC-CNR-FEM: a case study in the Bonis’ watershed (Calabria, Italy. At present, the climate changes issue is perhaps the greatest threat that is affecting people and the environment. Forest ecosystems have a key role in the mitigation of climate change. In this context, the prediction of the evolution and growth dynamics of the forests including carbon and water fluxes, and in relation to forest management has become a primary objective. The present study aims at defining a protocol for data collection and the workflow for using the 3D-CMCC-CNR-FEM model in a small mountain watershed in the Calabria region. Within this work we synergistically integrate data coming from different methods (e.g., LiDAR, eddy covariance and sample area to predict forest dynamics (growth, carbon and water fluxes. Carbon and water fluxes will be simulated considering also the effects of forest management.

Application of FEM analytical method for hydrogen migration behaviour in Zirconium alloys

Energy Technology Data Exchange (ETDEWEB)

Arioka, K; Ohta, H [Takasago Research and Development Center, Mitsubishi Heavy Industries Ltd, Hyogo-ken (Japan)

1997-02-01

It is well recognized that the hydriding behaviours of Zirconium alloys are very significant problems as a safety issues. Also, it is well known that the diffusion of hydrogen in Zirconium alloys are affected not only by concentration but also temperature gradient. But in actual component, especially heat transfer tube such as fuel rod, we can not avoid the temperature gradient in some degree. So, it is very useful to develop the computer code which can analyze the hydrogen diffusion and precipitation behaviours under temperature gradient as a function of the structure of fuel rod. For this objective, we have developed the computer code for hydrogen migration behaviour using FEM analytical methods. So, following items are presented and discussed. Analytical method and conditions; correlation between the computed and test results; application to designing studies. (author). 8 refs, 4 figs, 2 tabs.

The Incidence, Classification, and Management of Acute Adverse Reactions to the Low-Osmolar Iodinated Contrast Media Isovue and Ultravist in Contrast-Enhanced Computed Tomography Scanning.

Science.gov (United States)

Zhang, Bin; Dong, Yuhao; Liang, Long; Lian, Zhouyang; Liu, Jing; Luo, Xiaoning; Chen, Wenbo; Li, Xinyu; Liang, Changhong; Zhang, Shuixing

2016-03-01

Some epidemiologic surveillance studies have recorded adverse drug reactions to radiocontrast agents. We aimed to investigate the incidence and management of acute adverse reactions (AARs) to Ultravist-370 and Isovue-370 in patients who underwent contrast-enhanced computed tomography (CT) scanning.Data from 137,473 patients were analyzed. They had undergone enhanced CT scanning with intravenous injection of Ultravist-370 or Isovue-370 during the period of January 1, 2006 to December 31, 2012 in our hospital. We investigated and classified AARs according to the American College of Radiology and the Chinese Society of Radiology (CSR) guidelines for iodinated contrast media. We analyzed risk factors for AARs and compared the AARs induced by Ultravist-370 and Isovue-370.Four hundred and twenty-eight (0.31%) patients experienced AARs, which included 330 (0.24%) patients with mild AARs, 82 (0.06%) patients with moderate AARs, and 16 (0.01%) patients with severe AARs (including 3 cases of cardiac arrest and one case of death). The incidence of AARs was higher with Ultravist-370 than with Isovue-370 (0.38% vs 0.24%, P management, the symptoms and signs of 96.5% of the AARs resolved within 24 hours without sequelae.Ultravist-370 and Isovue-370 are safe for patients undergoing enhanced CT scanning. The incidence of AARs is higher with Ultravist-370 than with Isovue-370, but this difference is limited only to the mild AARs. The incidence of AARs could be affected by multiple factors.

DVD. Aare Ermel tutvustab / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2007-01-01

Eluloofilm "Lermontov" : režissöör Nikolai Burljajev : NSV Liit 1986 ja teleseriaal "Petshorin: meie aja kangelane" ("Petshorin: geroi nashego vremeni") : režissöör Aleksandr Kott : nimiosas Igor Petrenko : Venemaa 2006

Application of multi-thread computing and domain decomposition to the 3-D neutronics Fem code Cronos

International Nuclear Information System (INIS)

Ragusa, J.C.

2003-01-01

The purpose of this paper is to present the parallelization of the flux solver and the isotopic depletion module of the code, either using Message Passing Interface (MPI) or OpenMP. Thread parallelism using OpenMP was used to parallelize the mixed dual FEM (finite element method) flux solver MINOS. Investigations regarding the opportunity of mixing parallelism paradigms will be discussed. The isotopic depletion module was parallelized using domain decomposition and MPI. An attempt at using OpenMP was unsuccessful and will be explained. This paper is organized as follows: the first section recalls the different types of parallelism. The mixed dual flux solver and its parallelization are then presented. In the third section, we describe the isotopic depletion solver and its parallelization; and finally conclude with some future perspectives. Parallel applications are mandatory for fine mesh 3-dimensional transport and simplified transport multigroup calculations. The MINOS solver of the FEM neutronics code CRONOS2 was parallelized using the directive based standard OpenMP. An efficiency of 80% (resp. 60%) was achieved with 2 (resp. 4) threads. Parallelization of the isotopic depletion solver was obtained using domain decomposition principles and MPI. Efficiencies greater than 90% were reached. These parallel implementations were tested on a shared memory symmetric multiprocessor (SMP) cluster machine. The OpenMP implementation in the solver MINOS is only the first step towards fully using the SMPs cluster potential with a mixed mode parallelism. Mixed mode parallelism can be achieved by combining message passing interface between clusters with OpenMP implicit parallelism within a cluster

Application of multi-thread computing and domain decomposition to the 3-D neutronics Fem code Cronos

Energy Technology Data Exchange (ETDEWEB)

Ragusa, J.C. [CEA Saclay, Direction de l' Energie Nucleaire, Service d' Etudes des Reacteurs et de Modelisations Avancees (DEN/SERMA), 91 - Gif sur Yvette (France)

2003-07-01

The purpose of this paper is to present the parallelization of the flux solver and the isotopic depletion module of the code, either using Message Passing Interface (MPI) or OpenMP. Thread parallelism using OpenMP was used to parallelize the mixed dual FEM (finite element method) flux solver MINOS. Investigations regarding the opportunity of mixing parallelism paradigms will be discussed. The isotopic depletion module was parallelized using domain decomposition and MPI. An attempt at using OpenMP was unsuccessful and will be explained. This paper is organized as follows: the first section recalls the different types of parallelism. The mixed dual flux solver and its parallelization are then presented. In the third section, we describe the isotopic depletion solver and its parallelization; and finally conclude with some future perspectives. Parallel applications are mandatory for fine mesh 3-dimensional transport and simplified transport multigroup calculations. The MINOS solver of the FEM neutronics code CRONOS2 was parallelized using the directive based standard OpenMP. An efficiency of 80% (resp. 60%) was achieved with 2 (resp. 4) threads. Parallelization of the isotopic depletion solver was obtained using domain decomposition principles and MPI. Efficiencies greater than 90% were reached. These parallel implementations were tested on a shared memory symmetric multiprocessor (SMP) cluster machine. The OpenMP implementation in the solver MINOS is only the first step towards fully using the SMPs cluster potential with a mixed mode parallelism. Mixed mode parallelism can be achieved by combining message passing interface between clusters with OpenMP implicit parallelism within a cluster.

FEM investigation and thermo-mechanic tests of the new solid tungsten divertor tile for ASDEX Upgrade

International Nuclear Information System (INIS)

Jaksic, Nikola; Greuner, Henri; Herrmann, Albrecht

2013-01-01

Highlights: • New solid tungsten divertor for fusion experiment ASDEX Upgrade. • Design validation in the high heat flux (HHF) test facility GLADIS (Garching Large Divertor Sample Test Facility). • FEA simulation. -- Abstract: A new solid tungsten divertor for the fusion experiment ASDEX Upgrade is under construction at present. A new divertor tile design has been developed to improve the thermal performance of the current divertor made of tungsten coated fine grain graphite. Compared to thin tungsten coatings, divertor tiles made of massive tungsten allow to extend the operational range and to study the plasma material interaction of tungsten in more detail. The improved design for the solid tungsten divertor was tested on different full scale prototypes with a hydrogen ion beam. The influence of a possible material degradation due to thermal cracking or recrystallization can be studied. Furthermore, intensive Finite Element Method (FEM) numerical analysis with the respective test parameters has been performed. The elastic–plastic calculation was applied to analyze thermal stress and the observed elastic and plastic deformation during the heat loading. Additionally, the knowledge gained by the tests and especially by the numerical analysis has been used to optimize the shape of the divertor tiles and the accompanying divertor support structure. This paper discusses the main results of the high heat flux tests and their numerical simulations. In addition, results from some special structural mechanic analysis by means of FEM tools are presented. Finally, first results from the numerical lifecycle analysis of the current tungsten tiles will be reported

Numerical Analysis of Diaphragm Wall Model Executed in Poznań Clay Formation Applying Selected Fem Codes

Directory of Open Access Journals (Sweden)

Superczyńska M.

2016-09-01

Full Text Available The paper presents results of numerical calculations of a diaphragm wall model executed in Poznań clay formation. Two selected FEM codes were applied, Plaxis and Abaqus. Geological description of Poznań clay formation in Poland as well as geotechnical conditions on construction site in Warsaw city area were presented. The constitutive models of clay implemented both in Plaxis and Abaqus were discussed. The parameters of the Poznań clay constitutive models were assumed based on authors’ experimental tests. The results of numerical analysis were compared taking into account the measured values of horizontal displacements.

GABA in Paraventricular Nucleus Regulates Adipose Afferent Reflex in Rats.

Directory of Open Access Journals (Sweden)

Lei Ding

Full Text Available Chemical stimulation of white adipose tissue (WAT induces adipose afferent reflex (AAR, and thereby causes a general sympathetic activation. Paraventricular nucleus (PVN is important in control of sympathetic outflow. This study was designed to investigate the role of γ-aminobutyric acid (GABA in PVN in regulating the AAR.Experiments were carried out in anesthetized rats. Renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP were continuously recorded. AAR was evaluated by the RSNA and MAP responses to electrical stimulation of the right epididymal WAT (eWAT afferent nerve. Electrical stimulation of eWAT afferent nerve increase RSNA. Bilateral microinjection of the GABAA receptor agonist isoguvacine or the GABAB receptor agonist baclofen attenuated the AAR. The effect of isoguvacine on the AAR was greater than that of baclofen. The GABAA receptor antagonist gabazine enhanced the AAR, while the GABAB receptor antagonist CGP-35348 had no significant effect on the AAR. Bilateral PVN microinjection of vigabatrin, a selective GABA-transaminase inhibitor, to increase endogenous GABA levels in the PVN abolished the AAR. The inhibitory effect of vigabatrin on the AAR was attenuated by the pretreatment with gabazine or CGP-35348. Pretreatment with combined gabazine and CGP-35348 abolished the effects of vigabatrin.Activation of GABAA or GABAB receptors in the PVN inhibits the AAR. Blockade of GABAA receptors in the PVN enhances the AAR. Endogenous GABA in the PVN plays an important role in regulating the AAR.

Reliability techniques and Coupled BEM/FEM for interaction pile-soil

Directory of Open Access Journals (Sweden)

Ahmed SAHLI

2017-06-01

Full Text Available This paper deals with the development of a computational code for the modelling and verification of safety in relation to limit states of piles found in foundations of current structures. To this end, it makes use of reliability techniques for the probabilistic analysis of piles modelled with the finite element method (FEM coupled to the boundary element method (BEM. The soil is modelled with the BEM employing Mindlin's fundamental solutions, suitable for the consideration of a three-dimensional infinite half-space. The piles are modelled as bar elements with the MEF, each of which is represented in the BEM as a loading line. The finite element of the employed bar has four nodes and fourteen nodal parameters, three of which are displacements for each node plus two rotations for the top node. The slipping of the piles in relation to the mass is carried out using adhesion models to define the evolution of the shaft tensions during the transfer of load to the soil. The reliability analysis is based on three methods: first order second moment (FOSM, first order reliability method and Monte Carlo method.

Performance Analysis of FEM Algorithmson GPU and Many-Core Architectures

KAUST Repository

Khurram, Rooh

2015-04-27

The roadmaps of the leading supercomputer manufacturers are based on hybrid systems, which consist of a mix of conventional processors and accelerators. This trend is mainly due to the fact that the power consumption cost of the future cpu-only Exascale systems will be unsustainable, thus accelerators such as graphic processing units (GPUs) and many-integrated-core (MIC) will likely be the integral part of the TOP500 (http://www.top500.org/) supercomputers, beyond 2020. The emerging supercomputer architecture will bring new challenges for the code developers. Continuum mechanics codes will particularly be affected, because the traditional synchronous implicit solvers will probably not scale on hybrid Exascale machines. In the previous study[1], we reported on the performance of a conjugate gradient based mesh motion algorithm[2]on Sandy Bridge, Xeon Phi, and K20c. In the present study we report on the comparative study of finite element codes, using PETSC and AmgX solvers on CPU and GPUs, respectively [3,4]. We believe this study will be a good starting point for FEM code developers, who are contemplating a CPU to accelerator transition.

Characterization of the Mechanical Stress-Strain Performance of Aerospace Alloy Materials Using Frequency-Domain Photoacoustic Ultrasound and Photothermal Methods: An FEM Approach

Science.gov (United States)

Huan, Huiting; Mandelis, Andreas; Liu, Lixian

2018-04-01

Determining and keeping track of a material's mechanical performance is very important for safety in the aerospace industry. The mechanical strength of alloy materials is precisely quantified in terms of its stress-strain relation. It has been proven that frequency-domain photothermoacoustic (FD-PTA) techniques are effective methods for characterizing the stress-strain relation of metallic alloys. PTA methodologies include photothermal (PT) diffusion and laser thermoelastic photoacoustic ultrasound (PAUS) generation which must be separately discussed because the relevant frequency ranges and signal detection principles are widely different. In this paper, a detailed theoretical analysis of the connection between thermoelastic parameters and stress/strain tensor is presented with respect to FD-PTA nondestructive testing. Based on the theoretical model, a finite element method (FEM) was further implemented to simulate the PT and PAUS signals at very different frequency ranges as an important analysis tool of experimental data. The change in the stress-strain relation has an impact on both thermal and elastic properties, verified by FEM and results/signals from both PT and PAUS experiments.

First lasing of the Dutch fusion-FEM in the long-pulse configuration

Energy Technology Data Exchange (ETDEWEB)

Militsyn, B.L. E-mail: militsyn@rijnh.nl; Bongers, W.A.; Bratman, V.L.; Caplan, M.; Denisov, G.G.; Geer, C.A.J. van der; Manintveld, P.; Oomens, A.A.M.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Riet, M.; Savilov, A.V.; Smeets, P.H.M.; Tito, C.J.; Turk, G.H.B.; Varfolomeev, A.A.; Urbanus, W.H

2002-05-01

The Dutch Fusion-FEM is the prototype of a high-power, long-pulse, rapid-tunable free-electron maser. The target is to generate mm-wave power in a frequency range of 130-260 GHz, e.g. for tokamak heating and diagnostics experiments in fusion devices. For these applications a high system efficiency is needed. The electron beam is first DC-accelerated to the FEL interaction region. The unused electron beam energy is recovered by a DC-decelerator and a three-stage depressed collector. In short-pulse regime, without energy recovery system, 730 kW, 200 GHz of net output power was generated. Single-frequency operation and tunability have been demonstrated. In the present set-up, with the energy recovery system being operational, initial experiments showed a net output power of 110 kW on average and 140 kW peak power at a pulse length of 40 {mu}s. During the full-pulse length, a stable-frequency operation around 170 GHz has been observed.

Development of seismic analysis model for HTGR core on commercial FEM code

International Nuclear Information System (INIS)

Tsuji, Nobumasa; Ohashi, Kazutaka

2015-01-01

The aftermath of the Great East Japan Earthquake prods to revise the design basis earthquake intensity severely. In aseismic design of block-type HTGR, the securement of structural integrity of core blocks and other structures which are made of graphite become more important. For the aseismic design of block-type HTGR, it is necessary to predict the motion of core blocks which are collided with adjacent blocks. Some seismic analysis codes have been developed in 1970s, but these codes are special purpose-built codes and have poor collaboration with other structural analysis code. We develop the vertical 2 dimensional analytical model on multi-purpose commercial FEM code, which take into account the multiple impacts and friction between block interfaces and rocking motion on contact with dowel pins of the HTGR core by using contact elements. This model is verified by comparison with the experimental results of 12 column vertical slice vibration test. (author)

First lasing of the Dutch fusion-FEM in the long-pulse configuration

CERN Document Server

Militsyn, B L; Bratman, V L; Caplan, M; Denisov, G G; Geer, C A J; Manintveld, P; Oomens, A A M; Plomp, J; Pluygers, J; Poelman, A J; Riet, M; Savilov, A V; Smeets, P H M; Tito, C J; Turk, G H B; Varfolomeev, A A; Urbanus, W H

2002-01-01

The Dutch Fusion-FEM is the prototype of a high-power, long-pulse, rapid-tunable free-electron maser. The target is to generate mm-wave power in a frequency range of 130-260 GHz, e.g. for tokamak heating and diagnostics experiments in fusion devices. For these applications a high system efficiency is needed. The electron beam is first DC-accelerated to the FEL interaction region. The unused electron beam energy is recovered by a DC-decelerator and a three-stage depressed collector. In short-pulse regime, without energy recovery system, 730 kW, 200 GHz of net output power was generated. Single-frequency operation and tunability have been demonstrated. In the present set-up, with the energy recovery system being operational, initial experiments showed a net output power of 110 kW on average and 140 kW peak power at a pulse length of 40 mu s. During the full-pulse length, a stable-frequency operation around 170 GHz has been observed.

Structural FEM analysis of the strut-to-fuselage joint of a two-seat composite aircraft

International Nuclear Information System (INIS)

Vargas-Rojas, Erik; Camarena-Arellano, Diego; Hernández-Moreno, Hilario

2014-01-01

An analysis of a strut-to-fuselage joint is realized in order to evaluate the zones with a high probability of failure by means of a safety factor. The whole section is analyzed using the Finite Element Method (FEM) so as to estimate static resistance behavior, therefore it is necessary a numerical mock-up of the section, the mechanical properties of the Carbon-Epoxy (C-Ep) material, and to evaluate the applied loads. Results of the analysis show that the zones with higher probability of failure are found around the wing strut and the fuselage joint, with a safety factor lower than expected in comparison with the average safety factor used on aircrafts built mostly with metals

Cone Beam X-Ray Luminescence Tomography Imaging Based on KA-FEM Method for Small Animals.

Science.gov (United States)

Chen, Dongmei; Meng, Fanzhen; Zhao, Fengjun; Xu, Cao

2016-01-01

Cone beam X-ray luminescence tomography can realize fast X-ray luminescence tomography imaging with relatively low scanning time compared with narrow beam X-ray luminescence tomography. However, cone beam X-ray luminescence tomography suffers from an ill-posed reconstruction problem. First, the feasibility of experiments with different penetration and multispectra in small animal has been tested using nanophosphor material. Then, the hybrid reconstruction algorithm with KA-FEM method has been applied in cone beam X-ray luminescence tomography for small animals to overcome the ill-posed reconstruction problem, whose advantage and property have been demonstrated in fluorescence tomography imaging. The in vivo mouse experiment proved the feasibility of the proposed method.

The adenosine A2A receptor — Myocardial protectant and coronary target in endotoxemia

Science.gov (United States)

Reichelt, Melissa E.; Ashton, Kevin J.; Tan, Xing Lin; Mustafa, S. Jamal; Ledent, Catherine; Delbridge, Lea M.D.; Hofmann, Polly A.; Headrick, John P.; Morrison, R. Ray

2013-01-01

Background Cardiac injury and dysfunction are contributors to disease progression and mortality in sepsis. This study evaluated the cardiovascular role of intrinsic A2A adenosine receptor (A2AAR) activity during lipopolysaccharide (LPS)-induced inflammation. Methods We assessed the impact of 24 h of LPS challenge (20 mg/kg, IP) on cardiac injury, coronary function and inflammatory mediator levels in Wild-Type (WT) mice and mice lacking functional A2AARs (A2AAR KO). Results Cardiac injury was evident in LPS-treated WTs, with ∼7-fold elevation in serum cardiac troponin I (cTnI), and significant ventricular and coronary dysfunction. Absence of A2AARs increased LPS-provoked cTnI release at 24 h by 3-fold without additional demise of contraction function. Importantly, A2AAR deletion per se emulated detrimental effects of LPS on coronary function, and LPS was without effect in coronary vessels lacking A2AARs. Effects of A2AAR KO were independent of major shifts in circulating C-reactive protein (CRP) and haptoglobin. Cytokine responses were largely insensitive to A2AAR deletion; substantial LPS-induced elevations (up to 100-fold) in IFN-γ and IL-10 were unaltered in A2AAR KO mice, as were levels of IL-4 and TNF-α. However, late elevations in IL-2 and IL-5 were differentially modulated by A2AAR KO (IL-2 reduced, IL-5 increased). Data demonstrate that in the context of LPS-triggered cardiac and coronary injury, A2AAR activity protects myocardial viability without modifying contractile dysfunction, and selectively modulates cytokine (IL-2, IL-5) release. A2AARs also appear to be targeted by LPS in the coronary vasculature. Conclusions These experimental data suggest that preservation of A2AAR functionality might provide therapeutic benefit in human sepsis. PMID:22192288

Force Limiting Vibration Tests Evaluated from both Ground Acoustic Tests and FEM Simulations of a Flight Like Vehicle System Assembly

Science.gov (United States)

Smith, Andrew; LaVerde, Bruce; Waldon, James; Hunt, Ron

2014-01-01

Marshall Space Flight Center has conducted a series of ground acoustic tests with the dual goals of informing analytical judgment, and validating analytical methods when estimating vibroacoustic responses of launch vehicle subsystems. The process of repeatedly correlating finite element-simulated responses with test-measured responses has assisted in the development of best practices for modeling and post-processing. In recent work, force transducers were integrated to measure interface forces at the base of avionics box equipment. Other force data was indirectly measured using strain gauges. The combination of these direct and indirect force measurements has been used to support and illustrate the advantages of implementing the Force Limiting approach for equipment qualification tests. The comparison of force response from integrated system level tests to measurements at the same locations during component level vibration tests provides an excellent illustration. A second comparison of the measured response cases from the system level acoustic tests to finite element simulations has also produced some principles for assessing the suitability of Finite Element Models (FEMs) for making vibroacoustics estimates. The results indicate that when FEM models are employed to guide force limiting choices, they should include sufficient detail to represent the apparent mass of the system in the frequency range of interest.

FEM simulation of friction testing method based on combined forward rod-backward can extrusion

DEFF Research Database (Denmark)

Nakamura, T; Bay, Niels; Zhang, Z. L

1997-01-01

A new friction testing method by combined forward rod-backward can extrusion is proposed in order to evaluate frictional characteristics of lubricants in forging processes. By this method the friction coefficient mu and the friction factor m can be estimated along the container wall and the conical...... curves are obtained by rigid-plastic FEM simulations in a combined forward rod-backward can extrusion process for a reduction in area R-b = 25, 50 and 70 percent in the backward can extrusion. It is confirmed that the friction factor m(p) on the punch nose in the backward cart extrusion has almost...... in a mechanical press with aluminium alloy A6061 as the workpiece material and different kinds of lubricants. They confirm the analysis resulting in reasonable values for the friction coefficient and the friction factor....

FEM Analysis of Beam-coupling Impedance and RF Contacts Criticality on the LHC UA9 Piezo Goniometer

CERN Document Server

Danisi, A; Passarelli, A; Masi, A; Losito, R; Salvant, B

2014-01-01

The UA9 piezo-goniometer has been designed to guarantee micro-radians-accuracy angular positioning of a silicon crystal for a crystal collimation experiment in the LHC, and to minimize the impact on the LHC beam coupling impedance. This paper presents a Finite Element Method (FEM) study of the device, in both parking and operational positions, to evaluate its impact on the LHC impedance budget. In addition, the shielding contribution of the RF gaskets has been carefully evaluated, with the objective to assess the consequences for operation in case of their failure. A final word is drawn on the overall device impedance criticality.

Toroidal HTS transformer with cold magnetic core - analysis with FEM software

International Nuclear Information System (INIS)

Grzesik, B; Stepien, M; Jez, R

2010-01-01

The aim of this paper is to present a thorough characterization of the toroidal HTS transformer by means of FEM analysis. The analysis was a 2D/3D harmonic electromagnetic and thermal analysis. The toroidal transformer operated in LN2 by being immersed together with the magnetic core in it, for which its power losses were acceptable. Two extreme variants of windings were analysed. The first one called parallel and the second called perpendicular. Three variants of the magnetic core were considered. In the first one the core was put outside of the windings, in the second the core was inside of the windings and in the third variant the core was outside as well as inside of the windings. The windings were made of HTS tape BiSCCO-2223/Ag while the magnetic core was made of the nanocrystalline material Finemet. The two windings, with a 1:1 turn-to-turn ratio, were uniformly distributed along the whole torus circumference. The output power, efficiency and power density are in the results of the analysis. The temperature distribution was also calculated. In summary, the performance of the transformer is better than those currently known.

Elastic-plastic FEM-analysis of a nozzle corner crack and discussion of the results by some fracture mechanics concepts

International Nuclear Information System (INIS)

Aurich, D.; Brocks, W.; Noack, D.; Veith, H.

1981-01-01

From a three-dimensional elastic-plastic stress-distortion analysis according to the finite element method (FEM) for a straight inner edge crack at room temperature in a nozzle of the intermediate vessel ZB 2 made of 22 NiMoCr 37 steel, the results obtained for stresses and strains in the ligament before the crack front, the crack opening profile, and the propagation of the plastic zone as a function of internal pressure until through-plastifying of the ligament are shown and explained. (orig.) [de

Optimization of a Centrifugal Boiler Circulating Pump's Casing Based on CFD and FEM Analyses

Directory of Open Access Journals (Sweden)

Zhigang Zuo

2014-04-01

Full Text Available It is important to evaluate the economic efficiency of boiler circulating pumps in manufacturing process from the manufacturers' point of view. The possibility of optimizing the pump casing with respect to structural pressure integrity and hydraulic performance was discussed. CFD analyses of pump models with different pump casing sizes were firstly carried out for the hydraulic performance evaluation. The effects of the working temperature and the sealing ring on the hydraulic efficiency were discussed. A model with casing diameter of 0.875D40 was selected for further analyses. FEM analyses were then carried out on different combinations of casing sizes, casing wall thickness, and materials, to evaluate its safety related to pressure integrity, with respect to both static and fatigue strength analyses. Two models with forging and cast materials were selected as final results.

FEM simulation study on relationship of interfacial morphology and residual stress in TBCs

Energy Technology Data Exchange (ETDEWEB)

Liqiang Chen; Shengkai Gong; Huibin Xu [School of Materials Science and Engineering, Beihang Univ., Beijing, BJ (China)

2005-07-01

It is generally believed that the failure of TBCs is attributed to the spallation occurred in the ceramic coat. The spallation is closed linked with sinuate morphology factors, including its amplitude and period, at the TGO/bond coat interface. In this work, dependence of the residual stress distribution on the sinuate morphology in the TBCs has been studied by means of finite element method (FEM) simulation for isothermally annealed specimens. The simulation results indicated that the maximum value of residual stress existed inside the TGO layer. It was also found that the maximum residual stress occurred at different points, near the TGO/bond coat interface at the peak of the sinuate interface, while near the TGO/ceramic coat interface at the valley, respectively. And the maximum residual stress increased with increasing the ratio of the amplitude to period in the sine morphology, which has been proved by the thermal cycle experimental results. (orig.)

FEM Analysis of Brushless DC Servomotor with Fractional Number of Slots per Pole

Directory of Open Access Journals (Sweden)

BALUTA, G.

2014-02-01

Full Text Available The authors present in this paper the analysis with Finite Element Method (FEM of the magnetic circuit for a Brushless DC servomotor with fractional number of slots/pole (9 slots and 10 poles. For this purpose, FEMM 4.2 software package was used for the analysis. To obtain the waveforms of Back-ElectroMotive Forces (BEMFs, electromagnetic and cogging torque for servomotor a program in LUA scripting language (integrated into interactive shell of FEMM4.2 has been created. A comparation with a structure with integer number of slots/pole (18 slots and 6 poles was also realized. The analysis results prove that the structure chosen is an optimal solution: sinusoidal waveforms of BEMFs, improved electromagnetic torque and reduced cogging torque. Therefore, the operating characteristics of the servomotor with 9/10 slots/poles manufactured by Sistem Euroteh Company and included in an integrated electrical drives system are presented in this paper.

Body Composition Assessment in Axial CT Images Using FEM-Based Automatic Segmentation of Skeletal Muscle.

Science.gov (United States)

Popuri, Karteek; Cobzas, Dana; Esfandiari, Nina; Baracos, Vickie; Jägersand, Martin

2016-02-01

The proportions of muscle and fat tissues in the human body, referred to as body composition is a vital measurement for cancer patients. Body composition has been recently linked to patient survival and the onset/recurrence of several types of cancers in numerous cancer research studies. This paper introduces a fully automatic framework for the segmentation of muscle and fat tissues from CT images to estimate body composition. We developed a novel finite element method (FEM) deformable model that incorporates a priori shape information via a statistical deformation model (SDM) within the template-based segmentation framework. The proposed method was validated on 1000 abdominal and 530 thoracic CT images and we obtained very good segmentation results with Jaccard scores in excess of 90% for both the muscle and fat regions.

The fusion-FEM: 0,75 MW of mm-wave power

Energy Technology Data Exchange (ETDEWEB)

Smeets, P.H.M.; Bongers, W.A.; Brons, S.; Geer, C.A.J. van der; Lingier, K.L.; Manintveld, P.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Sterk, A.B.; Verhoeven, A.G.A.; Urbanus, W.H. [FOM Inst. voor Plasmafysica ' Rijnhuizen' , Nieuwegein (Netherlands); Bratman, V.L.; Denisov, G.G.; Savilov, A.V. [Inst. of Applied Physics, Nizhny Novgorod (Russian Federation); Caplan, M. [Lawrence Livermore National Lab., CA (United States); Varfolomeev, A.A. [Russian Research Center ' Kurchatov Inst.' , Moscow (Russian Federation)

1998-07-01

The free-electron maser for fusion applications (Fusion-FEM) is the prototype for a high power, rapid tunable mm-wave source. The basic parameters such as frequency range (130 - 260 GHz) and output power (1 MW) are dedicated to Electron Cyclotron Resonance applications on future plasma fusion research devices, such as ITER. In October 1996 the electron beam was successfully accelerated and transported through the undulator and the mm-wave cavity. Loss currents are below 0.05 %. In October 1997 first lasing was achieved. The mm-wave output power has been measured at various frequencies and for various electron beam currents and energies. The highest output power reached so far is 730 kW at 205 GHz, for an electron beam of 7.2 A and 1.77 MeV. Both output power and start-up time correspond well with simulation results. The output beam has a Gaussian mode content of more than 99.8 % for all operating frequencies. So far, the pulse length was limited to 12{mu}s, because the electron beam recovery system was not yet installed. This system, an electron decelerator and a 3-stage depressed collector, is presently under construction. It serves to recover the charge and energy of the spend electron beam. In this paper we will address some aspects of the design of the collector. (author)

The fusion-FEM: 0,75 MW of mm-wave power

International Nuclear Information System (INIS)

Smeets, P.H.M.; Bongers, W.A.; Brons, S.; Geer, C.A.J. van der; Lingier, K.L.; Manintveld, P.; Plomp, J.; Pluygers, J.; Poelman, A.J.; Sterk, A.B.; Verhoeven, A.G.A.; Urbanus, W.H.; Bratman, V.L.; Denisov, G.G.; Savilov, A.V.; Caplan, M.; Varfolomeev, A.A.

1998-01-01

The free-electron maser for fusion applications (Fusion-FEM) is the prototype for a high power, rapid tunable mm-wave source. The basic parameters such as frequency range (130 - 260 GHz) and output power (1 MW) are dedicated to Electron Cyclotron Resonance applications on future plasma fusion research devices, such as ITER. In October 1996 the electron beam was successfully accelerated and transported through the undulator and the mm-wave cavity. Loss currents are below 0.05 %. In October 1997 first lasing was achieved. The mm-wave output power has been measured at various frequencies and for various electron beam currents and energies. The highest output power reached so far is 730 kW at 205 GHz, for an electron beam of 7.2 A and 1.77 MeV. Both output power and start-up time correspond well with simulation results. The output beam has a Gaussian mode content of more than 99.8 % for all operating frequencies. So far, the pulse length was limited to 12μs, because the electron beam recovery system was not yet installed. This system, an electron decelerator and a 3-stage depressed collector, is presently under construction. It serves to recover the charge and energy of the spend electron beam. In this paper we will address some aspects of the design of the collector. (author)

Aspartic acid racemisation in purified elastin from arteries as basis for age estimation.

Science.gov (United States)

Dobberstein, R C; Tung, S-M; Ritz-Timme, S

2010-07-01

Aspartic acid racemisation (AAR) results in an age-dependent accumulation of D: -aspartic acid in durable human proteins and can be used as a basis for age estimation. Routinely, age estimation based on AAR is performed by analysis of dentine. However, in forensic practise, teeth are not always available. Non-dental tissues for age estimation may be suitable for age estimation based on AAR if they contain durable proteins that can be purified and analysed. Elastin is such a durable protein. To clarify if purified elastin from arteries is a suitable sample for biochemical age estimation, AAR was determined in purified elastin from arteries from individuals of known age (n = 68 individuals, including n = 15 putrefied corpses), considering the influence of different stages of atherosclerosis and putrefaction on the AAR values. AAR was found to increase with age. The relationship between AAR and age was good enough to serve as basis for age estimation, but worse than known from dentinal proteins. Intravital and post-mortem degradation of elastin may have a moderate effect on the AAR values. Age estimation based on AAR in purified elastin from arteries may be a valuable additional tool in the identification of unidentified cadavers, especially in cases where other methods cannot be applied (e.g., no available teeth and body parts).

Assessment of nasal obstruction with rhinomanometry and subjective scales and outcomes of surgical and medical treatment.

Science.gov (United States)

Lara-Sánchez, Hugo; Álvarez Nuño, Candelas; Gil-Carcedo Sañudo, Elisa; Mayo Iscar, Agustín; Vallejo Valdezate, Luis Ángel

Prospective study of patients with nasal obstruction (NO) in order to measure therapeutic success by anterior active rhinomanometry (AAR), Nasal Obstruction Symptom Evaluation (NOSE) scale and Visual Analogue Scale (VAS) and to establish the correlation between these tests. Patients with NO, on whom we performed an AAR, NOSE and VAS scales at baseline and after medical treatment (topical nasal steroid) or surgery (septoplasty, turbinoplasty or septoplasty and turbinoplasty). The nasal flow obtained by the AAR and the score of both subjective scales (NOSE and VAS) were compared and analyzed. A total of 102 patients were included in the study. Surgical treatment resulted in statistically significant differences with the AAR and the subjective scales. While in patients with medical treatment there was an increase in the AAR nasal flow but without statistical significance (P=.1363). The correlation between the AAR, the NOSE and VAS scales was measured finding a strong correlation between the NOSE and VAS scales only (r=.83327). The patients with NO treated surgically have better results when these are evaluated by AAR or with subjective scales. There is no significant correlation between AAR, NOSE and VAS scales, this is considered to be because the AAR and subjective scales are complementary and measure different aspects of NO. The AAR and subjective scales are useful tools to be used together for the follow up of patients with NO. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Otorrinolaringología y Cirugía de Cabeza y Cuello. All rights reserved.

CVD diamond Brewster window: feasibility study by FEM analyses

Directory of Open Access Journals (Sweden)

Vaccaro A.

2012-09-01

Full Text Available Chemical vapor deposition (CVD diamond windows are a crucial component in heating and current drive (H&CD applications. In order to minimize the amount of reflected power from the diamond disc, its thickness must match the desired beam wavelength, thus proper targeting of the plasma requires movable beam reflectors. This is the case, for instance, of the ITER electron cyclotron H&CD system. However, looking at DEMO, the higher heat loads and neutron fluxes could make the use of movable parts close to the plasma difficult. The issue might be solved by using gyrotrons able to tune the beam frequency to the desired resonance, but this concept requires transmission windows that work in a given frequency range, such as the Brewster window. It consists of a CVD diamond disc brazed to two copper cuffs at the Brewster angle. The brazing process is carried out at about 800°C and then the temperature is decreased down to room temperature. Diamond and copper have very different thermal expansion coefficients, therefore high stresses build up during the cool down phase that might lead to failure of the disc. Considering also the complex geometry of the window with the skewed position of the disc, analyses are required in the first place to check its feasibility. The cool down phase was simulated by FEM structural analyses for several geometric and constraint configurations of the window. A study of indirect cooling of the window by water was also performed considering a HE11 mode beam. The results are here reported.

Calibration of amino acid racemization (AAR) kinetics in United States mid-Atlantic Coastal Plain Quaternary mollusks using 87Sr/ 86Sr analyses: Evaluation of kinetic models and estimation of regional Late Pleistocene temperature history

Science.gov (United States)

Wehmiller, J.F.; Harris, W.B.; Boutin, B.S.; Farrell, K.M.

2012-01-01

The use of amino acid racemization (AAR) for estimating ages of Quaternary fossils usually requires a combination of kinetic and effective temperature modeling or independent age calibration of analyzed samples. Because of limited availability of calibration samples, age estimates are often based on model extrapolations from single calibration points over wide ranges of D/L values. Here we present paired AAR and 87Sr/ 86Sr results for Pleistocene mollusks from the North Carolina Coastal Plain, USA. 87Sr/ 86Sr age estimates, derived from the lookup table of McArthur et al. [McArthur, J.M., Howarth, R.J., Bailey, T.R., 2001. Strontium isotopic stratigraphy: LOWESS version 3: best fit to the marine Sr-isotopic curve for 0-509 Ma and accompanying Look-up table for deriving numerical age. Journal of Geology 109, 155-169], provide independent age calibration over the full range of amino acid D/L values, thereby allowing comparisons of alternative kinetic models for seven amino acids. The often-used parabolic kinetic model is found to be insufficient to explain the pattern of racemization, although the kinetic pathways for valine racemization and isoleucine epimerization can be closely approximated with this function. Logarithmic and power law regressions more accurately represent the racemization pathways for all amino acids. The reliability of a non-linear model for leucine racemization, developed and refined over the past 20 years, is confirmed by the 87Sr/ 86Sr age results. This age model indicates that the subsurface record (up to 80m thick) of the North Carolina Coastal Plain spans the entire Quaternary, back to ???2.5Ma. The calibrated kinetics derived from this age model yield an estimate of the effective temperature for the study region of 11??2??C., from which we estimate full glacial (Last Glacial Maximum - LGM) temperatures for the region on the order of 7-10??C cooler than present. These temperatures compare favorably with independent paleoclimate information

FEM modeling on the compaction of Fe and Al composite powders

Directory of Open Access Journals (Sweden)

Han P.

2015-01-01

Full Text Available The compaction process of Fe and Al composite powders subjected to single action die compaction was numerically modeled by FEM method. The relationship between the overall relative density and compaction pressure of the compacts with various Al contents was firstly identified, and the influences of Al content on the local relative density, stress, and their distributions were studied. Then the compaction pressure effects on the above properties with fixed Al content were discussed. Furthermore, detailed flow behaviors of the composite powders during compaction and the relationship between the compaction pressure and the ejection force/spring back of the compact were analyzed. The results show that: (1 With each compaction pressure, higher relative density can be realized with the increase of Al content and the relative density distribution tends to be uniform; (2 When the Al content is fixed, higher compaction pressure can lead to composite compact with higher relative density, and the equivalent Von Mises stress in the central part of the compact increases gradually; (3 Convective flow occurs at the top and bottom parts of the compact close to the die wall, each indicates a different flow behavior; (4 The larger the compaction pressure for each case, the higher the residual elasticity, and the larger the ejection force needed.

FEM correlation and shock analysis of a VNC MEMS mirror segment

Science.gov (United States)

Aguayo, Eduardo J.; Lyon, Richard; Helmbrecht, Michael; Khomusi, Sausan

2014-08-01

Microelectromechanical systems (MEMS) are becoming more prevalent in today's advanced space technologies. The Visible Nulling Coronagraph (VNC) instrument, being developed at the NASA Goddard Space Flight Center, uses a MEMS Mirror to correct wavefront errors. This MEMS Mirror, the Multiple Mirror Array (MMA), is a key component that will enable the VNC instrument to detect Jupiter and ultimately Earth size exoplanets. Like other MEMS devices, the MMA faces several challenges associated with spaceflight. Therefore, Finite Element Analysis (FEA) is being used to predict the behavior of a single MMA segment under different spaceflight-related environments. Finite Element Analysis results are used to guide the MMA design and ensure its survival during launch and mission operations. A Finite Element Model (FEM) has been developed of the MMA using COMSOL. This model has been correlated to static loading on test specimens. The correlation was performed in several steps—simple beam models were correlated initially, followed by increasingly complex and higher fidelity models of the MMA mirror segment. Subsequently, the model has been used to predict the dynamic behavior and stresses of the MMA segment in a representative spaceflight mechanical shock environment. The results of the correlation and the stresses associated with a shock event are presented herein.

Interdependence, Reflexivity, Fidelity, Impedance Matching, and the Evolution of Genetic Coding

Science.gov (United States)

Carter, Charles W; Wills, Peter R

2018-01-01

Abstract Genetic coding is generally thought to have required ribozymes whose functions were taken over by polypeptide aminoacyl-tRNA synthetases (aaRS). Two discoveries about aaRS and their interactions with tRNA substrates now furnish a unifying rationale for the opposite conclusion: that the key processes of the Central Dogma of molecular biology emerged simultaneously and naturally from simple origins in a peptide•RNA partnership, eliminating the epistemological utility of a prior RNA world. First, the two aaRS classes likely arose from opposite strands of the same ancestral gene, implying a simple genetic alphabet. The resulting inversion symmetries in aaRS structural biology would have stabilized the initial and subsequent differentiation of coding specificities, rapidly promoting diversity in the proteome. Second, amino acid physical chemistry maps onto tRNA identity elements, establishing reflexive, nanoenvironmental sensing in protein aaRS. Bootstrapping of increasingly detailed coding is thus intrinsic to polypeptide aaRS, but impossible in an RNA world. These notions underline the following concepts that contradict gradual replacement of ribozymal aaRS by polypeptide aaRS: 1) aaRS enzymes must be interdependent; 2) reflexivity intrinsic to polypeptide aaRS production dynamics promotes bootstrapping; 3) takeover of RNA-catalyzed aminoacylation by enzymes will necessarily degrade specificity; and 4) the Central Dogma’s emergence is most probable when replication and translation error rates remain comparable. These characteristics are necessary and sufficient for the essentially de novo emergence of a coupled gene–replicase–translatase system of genetic coding that would have continuously preserved the functional meaning of genetically encoded protein genes whose phylogenetic relationships match those observed today. PMID:29077934

An Experimental Simulation to Validate FEM to Predict Transverse Young’s Modulus of FRP Composites

Directory of Open Access Journals (Sweden)

V. S. Sai

2013-01-01

Full Text Available Finite element method finds application in the analysis of FRP composites due to its versatility in getting the solution for complex cases which are not possible by exact classical analytical approaches. The finite element result is questionable unless it is obtained from converged mesh and properly validated. In the present work specimens are prepared with metallic materials so that the arrangement of fibers is close to hexagonal packing in a matrix as similar arrangement in case of FRP is complex due to the size of fibers. Transverse Young’s moduli of these specimens are determined experimentally. Equivalent FE models are designed and corresponding transverse Young’s moduli are compared with the experimental results. It is observed that the FE values are in good agreement with the experimental results, thus validating FEM for predicting transverse modulus of FRP composites.

FEM BASED PARAMETRIC DESIGN STUDY OF TIRE PROFILE USING DEDICATED CAD MODEL AND TRANSLATION CODE

Directory of Open Access Journals (Sweden)

Nikola Korunović

2014-12-01

Full Text Available In this paper a finite element method (FEM based parametric design study of the tire profile shape and belt width is presented. One of the main obstacles that similar studies have faced is how to change the finite element mesh after a modification of the tire geometry is performed. In order to overcome this problem, a new approach is proposed. It implies automatic update of the finite elements mesh, which follows the change of geometric design parameters on a dedicated CAD model. The mesh update is facilitated by an originally developed mapping and translation code. In this way, the performance of a large number of geometrically different tire design variations may be analyzed in a very short time. Although a pilot one, the presented study has also led to the improvement of the existing tire design.

Thermal modal analysis of novel non-pneumatic mechanical elastic wheel based on FEM and EMA

Science.gov (United States)

Zhao, Youqun; Zhu, Mingmin; Lin, Fen; Xiao, Zhen; Li, Haiqing; Deng, Yaoji

2018-01-01

A combination of Finite Element Method (FEM) and Experiment Modal Analysis (EMA) have been employed here to characterize the structural dynamic response of mechanical elastic wheel (ME-Wheel) operating under a specific thermal environment. The influence of high thermal condition on the structural dynamic response of ME-Wheel is investigated. The obtained results indicate that the EMA results are in accordance with those obtained using the proposed Finite Element (FE) model, indicting the high reliability of this FE model applied in analyzing the modal of ME-Wheel working under practical thermal environment. It demonstrates that the structural dynamic response of ME-Wheel operating under a specific thermal condition can be predicted and evaluated using the proposed analysis method, which is beneficial for the dynamic optimization design of the wheel structure to avoid tire temperature related vibration failure and improve safety of tire.

Study of structure of HTS coated conductor with ferromagnetic substrate having low AC transport current loss using FEM

International Nuclear Information System (INIS)

Miyagi, D.; Amadutsumi, Y.; Takahashi, N.; Tsukamoto, O.

2007-01-01

AC transport current losses of coated conductors with ferromagnetic substrates are higher than the loss calculated by the Norris equation. In order to reduce the AC transport current loss we propose in this paper a structure of the coated conductor that has wider substrate than the SC (Superconducting) layer. The current distribution and AC loss of the proposed model are analyzed by means of FEM. The AC transport current loss is reduced due to the change of current density distribution near the edge of SC layer, consequent to the high value of magnetic permeability of the ferromagnetic substrate, that is wider than the SC layer

Krylov solvers preconditioned with the low-order red-black algorithm for the PN hybrid FEM for the instant code

Energy Technology Data Exchange (ETDEWEB)

Wang, Yaqi; Rabiti, Cristian; Palmiotti, Giuseppe, E-mail: yaqi.wang@inl.gov, E-mail: cristian.rabiti@inl.gov, E-mail: giuseppe.palmiotti@inl.gov [Idaho National Laboratory, Idaho Falls, ID (United States)

2011-07-01

This paper proposes a new set of Krylov solvers, CG and GMRes, as an alternative of the Red-Black (RB) algorithm on on solving the steady-state one-speed neutron transport equation discretized with PN in angle and hybrid FEM (Finite Element Method) in space. A pre conditioner with the low-order RB iteration is designed to improve their convergence. These Krylov solvers can reduce the cost of pre-assembling the response matrices greatly. Numerical results with the INSTANT code are presented in order to show that they can be a good supplement on solving the PN-HFEM system. (author)

Krylov solvers preconditioned with the low-order red-black algorithm for the PN hybrid FEM for the instant code

International Nuclear Information System (INIS)

Wang, Yaqi; Rabiti, Cristian; Palmiotti, Giuseppe

2011-01-01

This paper proposes a new set of Krylov solvers, CG and GMRes, as an alternative of the Red-Black (RB) algorithm on on solving the steady-state one-speed neutron transport equation discretized with PN in angle and hybrid FEM (Finite Element Method) in space. A pre conditioner with the low-order RB iteration is designed to improve their convergence. These Krylov solvers can reduce the cost of pre-assembling the response matrices greatly. Numerical results with the INSTANT code are presented in order to show that they can be a good supplement on solving the PN-HFEM system. (author)

From LIDAR Scanning to 3d FEM Analysis for Complex Surface and Underground Excavations

Science.gov (United States)

Chun, K.; Kemeny, J.

2017-12-01

Light detection and ranging (LIDAR) has been a prevalent remote-sensing technology applied in the geological fields due to its high precision and ease to use. One of the major applications is to use the detailed geometrical information of underground structures as a basis for the generation of three-dimensional numerical model that can be used in FEM analysis. To date, however, straightforward techniques in reconstructing numerical model from the scanned data of underground structures have not been well established or tested. In this paper, we propose a comprehensive approach integrating from LIDAR scanning to finite element numerical analysis, specifically converting LIDAR 3D point clouds of object containing complex surface geometry into finite element model. This methodology has been applied to the Kartchner Caverns in Arizona for the stability analysis. Numerical simulations were performed using the finite element code ABAQUS. The results indicate that the highlights of our technologies obtained from LIDAR is effective and provide reference for other similar engineering project in practice.

Evaluation of Package Stress during Temperature Cycling using Metal Deformation Measurement and FEM Simulation

International Nuclear Information System (INIS)

Hoeglauer, J.; Bohm, C.; Otremba, R.; Maerz, J.; Nelle, P.; Stecher, M.; Alpern, P.

2006-01-01

Plastic encapsulated devices that are exposed to Temperature Cycling (TC) tests undergo an excessive mechanical stress due to different Coefficients of Thermal Expansion (CTE) of the various materials used in the system. Especially in the corners of the die, passivation cracks and shifted metal lines can be observed, which demonstrates an increasing mechanical stress from chip center to the corners of the die. This effect has been known for a long time. This paper presents a simple measurement technique to quantify the mechanical shear stress at the chip-Mold Compound (MC) interface by measuring the deformation of a periodical metal structure. Based on this deformation measurement, we evaluated the stress distribution within the package, and the influence of different parameters such as number of cycles and chip size. Furthermore, these experimental results were compared with FEM simulation, and showed good agreement but could not account in all cases for the total amount of observed shift

Numerical survey of pressure wave propagation around and inside an underground cavity with high order FEM

Science.gov (United States)

Esterhazy, Sofi; Schneider, Felix; Schöberl, Joachim; Perugia, Ilaria; Bokelmann, Götz

2016-04-01

The research on purely numerical methods for modeling seismic waves has been more and more intensified over last decades. This development is mainly driven by the fact that on the one hand for subsurface models of interest in exploration and global seismology exact analytic solutions do not exist, but, on the other hand, retrieving full seismic waveforms is important to get insides into spectral characteristics and for the interpretation of seismic phases and amplitudes. Furthermore, the computational potential has dramatically increased in the recent past such that it became worthwhile to perform computations for large-scale problems as those arising in the field of computational seismology. Algorithms based on the Finite Element Method (FEM) are becoming increasingly popular for the propagation of acoustic and elastic waves in geophysical models as they provide more geometrical flexibility in terms of complexity as well as heterogeneity of the materials. In particular, we want to demonstrate the benefit of high-order FEMs as they also provide a better control on the accuracy. Our computations are done with the parallel Finite Element Library NGSOLVE ontop of the automatic 2D/3D mesh generator NETGEN (http://sourceforge.net/projects/ngsolve/). Further we are interested in the generation of synthetic seismograms including direct, refracted and converted waves in correlation to the presence of an underground cavity and the detailed simulation of the comprehensive wave field inside and around such a cavity that would have been created by a nuclear explosion. The motivation of this application comes from the need to find evidence of a nuclear test as they are forbidden by the Comprehensive Nuclear-Test Ban Treaty (CTBT). With this approach it is possible for us to investigate the wave field over a large bandwidth of wave numbers. This again will help to provide a better understanding on the characteristic signatures of an underground cavity, improve the protocols for

A Simple FEM Formulation Applied to Nonlinear Problems of Impact with Thermomechanical Coupling

Directory of Open Access Journals (Sweden)

João Paulo de Barros Cavalcante

Full Text Available Abstract The thermal effects of problems involving deformable structures are essential to describe the behavior of materials in feasible terms. Verifying the transformation of mechanical energy into heat it is possible to predict the modifications of mechanical properties of materials due to its temperature changes. The current paper presents the numerical development of a finite element method suitable for nonlinear structures coupled with thermomechanical behavior; including impact problems. A simple and effective alternative formulation is presented, called FEM positional, to deal with the dynamic nonlinear systems. The developed numerical is based on the minimum potential energy written in terms of nodal positions instead of displacements. The effects of geometrical, material and thermal nonlinearities are considered. The thermodynamically consistent formulation is based on the laws of thermodynamics and the Helmholtz free-energy, used to describe the thermoelastic and the thermoplastic behaviors. The coupled thermomechanical model can result in secondary effects that cause redistributions of internal efforts, depending on the history of deformation and material properties. The numerical results of the proposed formulation are compared with examples found in the literature.

Geophysical Investigation of Upper Mantle Anomalies of the Australian-Antarctic Ridge

Science.gov (United States)

Park, S. H.; Choi, H.; Kim, S. S.; Lin, J.

2017-12-01

Australian-Antarctic Ridge (AAR) is situated between the Pacific-Antarctic Ridge (PAR) and Southeast Indian Ridge (SEIR), extending eastward from the Australian-Antarctic Discordance (AAD). Much of the AAR has been remained uncharted until 2011 because of its remoteness and harsh weather conditions. Since 2011, four multidisciplinary expeditions initiated by the Korea Polar Research Institute (KOPRI) have surveyed the little-explored eastern ends of the AAR and investigated the tectonics, geochemistry, and hydrothermal activity of this intermediate spreading system. Recent isotope studies using the new basalt samples from the AAR have led to the new hypothesis of the Southern Ocean mantle domain (SOM), which may have originated from the super-plume activity associated with the Gondwana break-up. In this study, we characterize the geophysics of the Southern Ocean mantle using the newly acquired shipboard bathymetry and available geophysical datasets. First, we computed residual mantle Bouguer gravity anomalies (RMBA), gravity-derived crustal thickness, and residual topography along the AAR in order to obtain a geological proxy for regional variations in magma supply. The results of these analyses revealed that the southern flank of the AAR is associated with shallower seafloor, more negative RMBA, thicker crust, and/or less dense mantle in comparison to the conjugate northern flank. Furthermore, this north-south asymmetry becomes more prominent toward the central ridge segments of the AAR. Interestingly, the along-axis depths of the entire AAR are significantly shallower than the neighboring ridge systems and the global ridges of intermediate spreading rates. Such shallow depths are also correlated with regional negative geoid anomalies. Furthermore, recent mantle tomography models consistently showed that the upper mantle (< 250 km) below the AAR has low S-wave velocities, suggesting that it may be hotter than the nearby ridges. Such regional-scale anomalies of the

Material Selection for an Ultra High Strength Steel Component Based on the Failure Criteria of CrachFEM

International Nuclear Information System (INIS)

Kessler, L.; Beier, Th.; Werner, H.; Horstkott, D.; Dell, H.; Gese, H.

2005-01-01

An increasing use of combining more than one process step is noticed for coupling crash simulations with the results of forming operations -- mostly by inheriting the forming history like plastic strain and material hardening. Introducing a continuous failure model allows a further benefit of these coupling processes; it sometimes can even be the most attractive result of such a work. In this paper the algorithm CrachFEM for fracture prediction has been used to generate more benefit of the successive forming and crash simulations -- especially for ultra high strength steels. The choice and selection of the material grade in combination with the component design can therefore be done far before the prototyping might show an unsuccessful crash result; and in an industrial applicable manner

Temporal and spatial characteristics of the area at risk investigated using computed tomography and T1-weighted magnetic resonance imaging

DEFF Research Database (Denmark)

van der Pals, Jesper; Hammer-Hansen, Sophia; Nielles-Vallespin, Sonia

2015-01-01

AIMS: Cardiovascular magnetic resonance (CMR) imaging can measure the myocardial area at risk (AAR), but the technique has received criticism for inadequate validation. CMR commonly depicts an AAR that is wider than the infarct, which in turn would require a lateral perfusion gradient within...... and fluorescent microparticle pathology were used to investigate the AAR in a canine model (n = 10) of ischaemia and reperfusion. AAR size by CMR correlated well with CT (R(2) = 0.80), microsphere blood flow (R(2) = 0.80), and pathology (R(2) = 0.74) with good limits of agreement [-0.79 ± 4.02% of the left.......05 ± 0.02 mL/g/min, lateral vs. core, P = 0.001). The transmural extent of MI was lower in the lateral portion of the AAR than the core (28.2 ± 10.2 vs. 17.4 ± 8.4% of the wall, P = 0.001). CONCLUSION: T1-weighted CMR accurately quantifies size of the AAR with excellent agreement compared with three...

Free-flying dynamics and control of an astronaut assistant robot based on fuzzy sliding mode algorithm

Science.gov (United States)

Gao, Qing; Liu, Jinguo; Tian, Tongtong; Li, Yangmin

2017-09-01

Space robots can perform some tasks in harsh environment as assistants of astronauts or substitutions of astronauts. Taking the limited working time and the arduous task of the astronauts in the space station into account, an astronaut assistant robot (AAR-2) applied in the space station is proposed and designed in this paper. The AAR-2 is achieved with some improvements on the basis of AAR-1 which was designed before. It can exploit its position and attitude sensors and control system to free flight or hover in the space cabin. And it also has a definite environmental awareness and artificial intelligence to complete some specified tasks under the control of astronauts or autonomously. In this paper, it mainly analyzes and controls the 6-DOF motion of the AAR-2. Firstly, the system configuration of AAR-2 is specifically described, and the movement principles are analyzed. Secondly, according to the physical model of the AAR-2, the Newton - Euler equation is applied in the preparation of space dynamics model of 6-DOF motion. Then, according to the mathematical model's characteristics which are nonlinear and strong coupling, a dual closed loop position and attitude controller based on fuzzy sliding mode control is proposed and designed. Finally, simulation experiments are appropriate to provide for AAR-2 control system by using Matlab/Simulink. From the simulation results it can be observed that the designed fuzzy sliding mode controller can control the 6-DOF motion of AAR-2 quickly and precisely.

Optimization Design and Performance Analysis of a PM Brushless Rotor Claw Pole Motor with FEM

Directory of Open Access Journals (Sweden)

Zhenyang Zhang

2016-07-01

Full Text Available A new type of permanent magnet (PM brushless claw pole motor (CPM with soft magnetic composite (SMC core is designed and analyzed in this paper. The PMs are mounted on the claw pole surface, and the three-phase stator windings are fed by variable-frequency three-phase AC currents. The advantages of the proposed CPM are that the slip rings on the rotor are cast off and it can achieve the efficiency improvement and higher power density. The effects of the claw-pole structure parameters, the air-gap length, and the PM thinner parameter of the proposed CPM on the output torque are investigated by using three-dimensional time-stepping finite element method (3D TS-FEM. The optimal rotor structure of the proposed CPM is obtained by using the response surface methodology (RSM and the particle swarm optimization (PSO method and the comparison of full-load performances of the proposed CPM with different material cores (SMC and silicon steel is analyzed.

Experimental study and FEM simulation of the simple shear test of cylindrical rods

Science.gov (United States)

Wirti, Pedro H. B.; Costa, André L. M.; Misiolek, Wojciech Z.; Valberg, Henry S.

2018-05-01

In the presented work an experimental simple shear device for cutting cylindrical rods was used to obtain force-displacement data for a low-carbon steel. In addition, and FEM 3D-simulation was applied to obtain internal shear stress and strain maps for this material. The experimental longitudinal grid patterns and force-displacement curve were compared with numerical simulation results. Many aspects of the elastic and plastic deformations were described. It was found that bending reduces the shear yield stress of the rod material. Shearing starts on top and bottom die-workpiece contact lines evolving in an arc-shaped area. Due to this geometry, stress concentrates on the surface of the rod until the level of damage reaches the critical value and the fracture starts here. The volume of material in the plastic zone subjected to shearing stress has a very complex shape and is function of a dimensionless geometrical parameter. Expressions to calculate the true shear stress τ and strain γ from the experimental force-displacement data were proposed. The equations' constants are determined by fitting the experimental curve with the stress τ and strain γ simulation point tracked data.

The FEM simulation of continuous rotary extrusion (CRE) of aluminum alloy AA3003

Science.gov (United States)

Rajendran, Nijenthan; Valberg, Henry; Misiolek, Wojciech Z.

2017-10-01

Continuous Rotary Extrusion (CRE) process is also known in literature under Conform TM name and it is mainly used for the continuous extrusion of Aluminum and Copper alloys. CRE use a feedstock in the form of rod, powders and chips, which are fed into the groove of the rotating wheel. As the wheel rotates the feedstock moves along with it due to friction with the wheel. Once the feedstock reaches the abutment the material deforms plastically and it is extruded through the die. CRE has lot to offer when compared to other more conventional extrusion processes such as low energy input, no limit in billet length as it is a continuous process as well as improved material physical properties due to plastic deformation under constant parameters. In this work a FEM model has been developed using Deform TM 3D, to study the metal flow and state variables of AA3003 CRE extrusion. The effect of extrusion wheel velocity has been investigated. The results show that increase in wheel velocity will heat up the feedstock metal due to high shear deformation and higher friction, which significantly changes metal flow conditions at the die exit.

FEM simulation of a friction testing method based on combined forward conical can-backward straight can extrusion

DEFF Research Database (Denmark)

Nakamura, T; Bay, Niels

1998-01-01

A new friction testing method based on combined forward conical can-backward straight can extrusion is proposed in order to evaluate friction characteristics in severe metal forming operations. By this method the friction coefficient along the conical punch surface is determined knowing...... the friction coefficient along the die wall. The latter is determined by a combined forward and backward can extrusion of straight cans. Calibration curves determining the relationship between punch travel, can heights, and friction coefficient for the two rests are calculated based on a rigid-plastic FEM...... analysis. Experimental friction tests are carried out in a mechanical press with aluminium alloy A6061 as the workpiece material and different kinds of lubricants. They confirm that the theoretical analysis results irt reasonable values for the friction coefficient....

Design and fabrication of liner-arroy ultrasonic transducer using KLM and FEM simulation for non-destructive testing

International Nuclear Information System (INIS)

Park, Chan Yuk; Sung, Jin Ho; Jeong, Jong Seob

2015-01-01

In this paper, a linear-array transducer capable of overcoming the faults of a single element and phased array transducers with convex shape for non-destructive ultrasonic testing was designed and fabricated. A 5.5 MHz linear-array transducer was designed using the PiezoCAD program based on the KLM analysis and the PZFlex program based on the FEM analysis. A 2-2 composite structure was employed to achieve broad-band characteristics. A 128 element linear-array transducer was fabricated and its performance was compared with the simulation results. The center frequency of the fabricated transducer was 5.5 Mhzand the -6 dB frequency bandwidth was 70 %. Thus, we expect that the designed transducer can provide an effective inner image of the test material during non-destructive ultrasonic testing.

Design and fabrication of liner-arroy ultrasonic transducer using KLM and FEM simulation for non-destructive testing

Energy Technology Data Exchange (ETDEWEB)

Park, Chan Yuk; Sung, Jin Ho; Jeong, Jong Seob [Dept. of Medical Biotechnology, Dongguk University Biomedi Campus, Goyang (Korea, Republic of)

2015-04-15

In this paper, a linear-array transducer capable of overcoming the faults of a single element and phased array transducers with convex shape for non-destructive ultrasonic testing was designed and fabricated. A 5.5 MHz linear-array transducer was designed using the PiezoCAD program based on the KLM analysis and the PZFlex program based on the FEM analysis. A 2-2 composite structure was employed to achieve broad-band characteristics. A 128 element linear-array transducer was fabricated and its performance was compared with the simulation results. The center frequency of the fabricated transducer was 5.5 Mhzand the -6 dB frequency bandwidth was 70 %. Thus, we expect that the designed transducer can provide an effective inner image of the test material during non-destructive ultrasonic testing.

Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

CERN Document Server

Tecimer, M; Efimov, S; Gover, A; Sokolowski, J

2001-01-01

A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 pi mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic i...

RILEM recommendations for the prevention of damage by alkali-aggregate reactions in new concrete structures state-of-the-art report of the RILEM technical committee 219-ACS

CERN Document Server

Sims, Ian

2016-01-01

This book contains the full set of RILEM Recommendations which have been produced to enable engineers, specifiers and testing houses to design and produce concrete which will not suffer damage arising from alkali reactions in the concrete. There are five recommended test methods for aggregates (designated AAR-1 to AAR-5), and an overall recommendation which describes how these should be used to enable a comprehensive aggregate assessment (AAR-0). Additionally, there are two Recommended International Specifications for concrete (AAR-7.1 & 7.2) and a Preliminary International Specification for dams and other hydro structures (AAR-7.3), which describe how the aggregate assessment can be combined with other measures in the design of the concrete to produce a concrete with a minimised risk of developing damage from alkali-aggregate reactions.

Inhibition of A2A Adenosine Receptor Signaling in Cancer Cells Proliferation by the Novel Antagonist TP455

Directory of Open Access Journals (Sweden)

Stefania Gessi

2017-12-01

Full Text Available Several evidences indicate that the ubiquitous nucleoside adenosine, acting through A1, A2A, A2B, and A3 receptor (AR subtypes, plays crucial roles in tumor development. Adenosine has contrasting effects on cell proliferation depending on the engagement of different receptor subtypes in various tumors. The involvement of A2AARs in human A375 melanoma, as well as in human A549 lung and rat MRMT1 breast carcinoma proliferation has been evaluated in view of the availability of a novel A2AAR antagonist, with high affinity and selectivity, named as 2-(2-furanyl-N5-(2-methoxybenzyl[1,3]thiazolo[5,4-d]pyrimidine-5,7-diammine (TP455. Specifically, the signaling pathways triggered in the cancer cells of different origin and the antagonist effect of TP455 were investigated. The A2AAR protein expression was evaluated through receptor binding assays. Furthermore, the effect of A2AAR activation on cell proliferation at 24, 48 and 72 hours was studied. The selective A2AAR agonist 2-p-(2-carboxyethylphenethylamino-5′-N-ethylcarboxamidoadenosine hydrochloride (CGS21680, concentration-dependently induced cell proliferation in A375, A549, and MRMT1 cancer cells and the effect was potently antagonized by the A2AAR antagonist TP455, as well as by the reference A2AAR blocker 4-(2-[7-amino-2-(2-furyl[1,2,4]triazolo[2,3-a][1,3,5]triazin-5-ylamino]ethylphenol (ZM241385. As for the signaling pathway recruited in this response we demonstrated that, by using the specific inhibitors of signal transduction pathways, the effect of A2AAR stimulation was induced through phospholipase C (PLC and protein kinase C-delta (PKC-δ. In addition, we evaluated, through the AlphaScreen SureFire phospho(p protein assay, the kinases enrolled by A2AAR to stimulate cell proliferation and we found the involvement of protein kinase B (AKT, extracellular regulated kinases (ERK1/2, and c-Jun N-terminal kinases (JNKs. Indeed, we demonstrated that the CGS21680 stimulatory effect on kinases was

Study on seismic stability of seawall in man-made island. Pt. 4. Deformation analysis of seawall during earthquake by DEM-FEM coupled analysis method (SEAWALL-2D)

International Nuclear Information System (INIS)

Kanatani, Mamoru; Tochigi, Hitoshi; Kawai, Tadashi

1999-01-01

In the development of the man-made island siting technology of nuclear power plants, assessing the stability of the seawall against large ocean waves and earthquakes is indispensable. Concerning with the seismic stability of the seawall, prediction of the deformation like sliding and settlement of the seawall during earthquake including the armour units in front of the caisson becomes important factor. For this purpose, the authors have developed the two-dimensional DEM-FEM coupled analysis method (SEAWALL-2D) to predict the deformation of the seawall covered with the armour units during earthquake. In this method, movements of the armour units are calculated in DEM analysis part and deformation of the caisson, rubble moundsand seabed and back fill are calculated in FEM analysis part taking the nonlinearity of the soil materials based on the effective stress into account. Numerical simulations of dynamic centrifuge model tests of the seawall are conducted to verify the applicability of this method. Results of the simulation analyses have successfully reproduced the movements of the armour units and the residual deformation of the caisson, sand seabed and back fill compared with the test results. (author)

25-Hydroxyvitamin D, IL-31, and IL-33 in Children with Allergic Disease of the Airways

Directory of Open Access Journals (Sweden)

Anna Bonanno

2014-01-01

Full Text Available Low vitamin D is involved in allergic asthma and rhinitis. IL-31 and IL-33 correlate with Th2-associated cytokines in allergic disease. We investigated whether low vitamin D is linked with circulating IL-31 and IL-33 in children with allergic disease of the airways. 25-Hydroxyvitamin D [25(OH Vit D], IL-31, and IL-33 plasma levels were measured in 28 controls (HC, 11 allergic rhinitis (AR patients, and 35 allergic asthma with rhinitis (AAR patients. We found significant lower levels of 25(OH Vit D in AR and in AAR than in HC. IL-31 and IL-33 plasma levels significantly increased in AAR than HC. IL-31 and IL-33 positively correlated in AR and AAR. 25(OH Vit D deficient AAR had higher levels of blood eosinophils, exacerbations, disease duration, and total IgE than patients with insufficient or sufficient 25(OH Vit D. In AAR 25(OH Vit D levels inversely correlated with total allergen sIgE score and total atopy index. IL-31 and IL-33 did not correlate with 25(OH Vit D in AR and AAR. In conclusion, low levels of 25(OH Vit D might represent a risk factor for the development of concomitant asthma and rhinitis in children with allergic disease of the airways independently of IL-31/IL-33 Th2 activity.

Study on vibration characteristics of the shaft system for a dredging pump based on FEM

International Nuclear Information System (INIS)

Zhai, L M; Liu, X; He, L Y; Wang, Z W; Qin, L; Liu, C Y; He, Y

2012-01-01

The dynamic characteristics of the shaft system for a dredging pump were studied with the Finite Element Method (FEM) by SAMCEF ROTOR. At first, the influence of the fluid-solid coupling interaction of mud water and impeller, water sealing and pump shaft on the lateral critical speeds were analyzed. The results indicated that the mud water must be taken into consideration, while the water sealing need not to. Then the effects of radial and thrust rolling bearings on the lateral critical speeds were discussed, which shows that the radial bearing close to the impeller has greatest impact on the 1st order critical speed. At last, the upper and lower limits of the critical speeds of lateral, axial and torsional vibration were calculated. The rated speed of the dredging pump was far less than the predicted critical speed, which can ensure the safe operation of the unit. Each vibration mode is also shown in this paper. This dynamic analysis method offers some reference value on the research of vibration and stability of the shaft system in dredging pump.

FEM and Von Mises Analysis on Prosthetic Crowns Structural Elements: Evaluation of Different Applied Materials.

Science.gov (United States)

Bramanti, Ennio; Cervino, Gabriele; Lauritano, Floriana; Fiorillo, Luca; D'Amico, Cesare; Sambataro, Sergio; Denaro, Deborah; Famà, Fausto; Ierardo, Gaetano; Polimeni, Antonella; Cicciù, Marco

2017-01-01

The aim of this paper is to underline the mechanical properties of dental single crown prosthodontics materials in order to differentiate the possibility of using each material for typical clinical condition and masticatory load. Objective of the investigation is to highlight the stress distribution over different common dental crowns by using computer-aided design software and a three-dimensional virtual model. By using engineering systems of analyses like FEM and Von Mises investigations it has been highlighted the strength over simulated lower first premolar crowns made by chrome cobalt alloy, golden alloy, dental resin, and zirconia. The prosthodontics crown models have been created and put on simulated chewing stresses. The three-dimensional models were subjected to axial and oblique forces and both guaranteed expected results over simulated masticatory cycle. Dental resin presented the low value of fracture while high values have been recorded for the metal alloy and zirconia. Clinicians should choose the better prosthetic solution for the teeth they want to restore and replace. Both prosthetic dental crowns offer long-term success if applied following the manufacture guide limitations and suggestions.

Plastic deformation behavior and bonding strength of an EBW joint between 9Cr-ODS and JLF-1 estimated by symmetric four-point bend tests combined with FEM analysis

International Nuclear Information System (INIS)

Fu, Haiying; Nagasaka, Takuya; Muroga, Takeo; Guan, Wenhai; Nogami, Shuhei; Serizawa, Hisashi; Geng, Shaofei; Yabuuchi, Kiyohiro; Kimura, Akihiko

2016-01-01

The joint between 9Cr-ODS and JLF-1 made by electron beam welding (EBW) fractured at the JLF-1 base metal (BM) during uniaxial tensile tests. Thus, the bonding strength of the joint was not determined and was estimated as more than the ultimate tensile strength of the BM in this case. Symmetric four-point bend tests which concentrate the stress inside the inner span including the weld metal (WM) were carried out at room temperature (RT) and 550 °C to investigate how the bonding strength is more than the ultimate tensile strength of the BM. The normal stress at the center of the weld bead can be calculated with elastic theory up to only 0.25% in strain, though the joint showed more than 10% in strain due to plastic deformation. Thus, finite element method (FEM) was utilized to simulate the plastic deformation behavior of the joint during bend tests. According to the fitting of the FEM output, such as load and displacement of the upper jig contacting the specimens, to the experimental results, the bonding strength of the joint at RT and 550 °C were estimated as 854 MPa and 505 MPa, respectively.

Plastic deformation behavior and bonding strength of an EBW joint between 9Cr-ODS and JLF-1 estimated by symmetric four-point bend tests combined with FEM analysis

Energy Technology Data Exchange (ETDEWEB)

Fu, Haiying [SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); Nagasaka, Takuya; Muroga, Takeo [SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292 (Japan); Guan, Wenhai; Nogami, Shuhei [Tohoku University, 6-6-01-2 Aramaki-aza-Aoba, Aoba-ku, Sendai 980-8578 (Japan); Serizawa, Hisashi [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki 567-0047 (Japan); Geng, Shaofei [SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi-cho, Toki 509-5292 (Japan); Yabuuchi, Kiyohiro; Kimura, Akihiko [Institute of Advanced Energy, Kyoto University, Uji 611-0011 (Japan)

2016-01-15

The joint between 9Cr-ODS and JLF-1 made by electron beam welding (EBW) fractured at the JLF-1 base metal (BM) during uniaxial tensile tests. Thus, the bonding strength of the joint was not determined and was estimated as more than the ultimate tensile strength of the BM in this case. Symmetric four-point bend tests which concentrate the stress inside the inner span including the weld metal (WM) were carried out at room temperature (RT) and 550 °C to investigate how the bonding strength is more than the ultimate tensile strength of the BM. The normal stress at the center of the weld bead can be calculated with elastic theory up to only 0.25% in strain, though the joint showed more than 10% in strain due to plastic deformation. Thus, finite element method (FEM) was utilized to simulate the plastic deformation behavior of the joint during bend tests. According to the fitting of the FEM output, such as load and displacement of the upper jig contacting the specimens, to the experimental results, the bonding strength of the joint at RT and 550 °C were estimated as 854 MPa and 505 MPa, respectively.

Thermomechanical behaviour of two heterogeneous tungsten materials via 2D and 3D image-based FEM

International Nuclear Information System (INIS)

Zivelonghi, Alessandro

2011-01-01

An advanced numerical procedure based on imaging of the material microstructure (Image- Based Finite Element Method or Image-Based FEM) was extended and applied to model the thermomechanical behaviour of novel materials for fusion applications. Two tungsten based heterogeneous materials with different random morphologies have been chosen as challenging case studies: (1) a two-phase mixed ductile-brittle W/CuCr1Zr composite and (2) vacuum plasma-sprayed tungsten (VPS-W 75 vol.%), a porous coating system with complex dual-scale microstructure. Both materials are designed for the future fusion reactor DEMO: W/CuCr1Zr as main constituent of a layered functionally graded joint between plasma-facing armor and heat sink whereas VPS-W for covering the first wall of the reactor vessel in direct contact with the plasma. The primary focus of this work was to investigate the mesoscopic material behaviour and the linkage to the macroscopic response in modeling failure and heat-transfer. Particular care was taken in validating and integrating simulation findings with experimental inputs. The solution of the local thermomechanical behaviour directly on the real material microstructure enabled meaningful insights into the complex failure mechanism of both materials. For W/CuCr1Zr full macroscopic stress-strain curves including the softening and failure part could be simulated and compared with experimental ones at different temperatures, finding an overall good agreement. The comparison of simulated and experimental macroscopic behaviour of plastic deformation and rupture also showed the possibility to indirectly estimate micro- and mesoscale material parameters. Both heat conduction and elastic behaviour of VPS-W have been extensively investigated. New capabilities of the Image-Based FEM could be shown: decomposition of the heat transfer reduction as due to the individual morphological phases and back-fitting of the reduced stiffness at interlamellar boundaries. The

Residual stress measurement of EB-welded plates with contour method. Part 2: FEM analysis of contour profiles

International Nuclear Information System (INIS)

Romppanen, A.-J.; Immonen, E.

2013-12-01

The residual stresses formed as a result of Electronic Beam welding (EB-welding) in copper are investigated by Posiva. In the present study, residual stresses of EB-welded copper plates were studied with contour method. In the method eleven copper plates (X436 - X440 and X453 - X458) were cut in half with wire electric discharge machining (EDM) after which the deformation due to stress relaxation was measured with coordinate measurement system. The measured data was then used as boundary displacement data for the FEM analyses, in which the corresponding residual stresses were calculated. Before giving the corresponding displacement boundary conditions to the FE models, the deformation data was processed and smoothed appropriately. The residual stress levels of the copper plates were found to be around 40 - 55 MPa at maximum. This corresponds to other reported residual stress measurements and current state of knowledge with this material in Posiva. (orig.)

Ring rotational speed trend analysis by FEM approach in a Ring Rolling process

Science.gov (United States)

Allegri, G.; Giorleo, L.; Ceretti, E.

2018-05-01

Ring Rolling is an advanced local incremental forming technology to fabricate directly precise seamless ring-shape parts with various dimensions and materials. In this process two different deformations occur in order to reduce the width and the height of a preform hollow ring; as results a diameter expansion is obtained. In order to guarantee a uniform deformation, the preform is forced toward the Driver Roll whose aim is to transmit the rotation to the ring. The ring rotational speed selection is fundamental because the higher is the speed the higher will be the axial symmetry of the deformation process. However, it is important to underline that the rotational speed will affect not only the final ring geometry but also the loads and energy needed to produce it. Despite this importance in industrial environment, usually, a constant value for the Driver Roll angular velocity is set so to result in a decreasing trend law for the ring rotational speed. The main risk due to this approach is not fulfilling the axial symmetric constrain (due to the diameter expansion) and to generate a high localized ring section deformation. In order to improve the knowledge about this topic in the present paper three different ring rotational speed trends (constant, linearly increasing and linearly decreasing) were investigated by FEM approach. Results were compared in terms of geometrical and dimensional analysis, loads and energies required.

Preclinical evaluation of a 68Ga-labeled biotin analogue for applications in islet transplantation

International Nuclear Information System (INIS)

Eriksson, Olof; Carlsson, Fredrik; Blom, Elisabeth; Sundin, Anders; Långström, Bengt; Korsgren, Olle; Velikyan, Irina

2012-01-01

Introduction: Islet transplantation is a promising treatment for type 1 diabetes mellitus, but the fate of the cells after intraportal infusion is unclear. It is therefore imperative to develop novel techniques for noninvasive imaging and quantification of events following islet transplantation. Methods: Small islet-like microbeads, avidin-covered agarose resins (AARs), were used as a model system for islet transplantation. Capability for specific [ 68 Ga]Ga-DOTA-(PEG) 2 -biotin uptake and retention for either AARs or human islets conjugated with avidin by means of a heparin scaffold was studied in vitro. Biodistribution of the novel positron emission tomography (PET) tracer [ 68 Ga]Ga-DOTA-(PEG) 2 -biotin was evaluated in mice treated by intraportal transplantation of AARs by μPET/computed tomography and ex vivo organ distribution and compared with control mice. Results: AARs had high capability to bind [ 68 Ga]Ga-DOTA-(PEG) 2 -biotin, close to 50% of administrated tracer/μl in vitro (>0.25 MBq/μl). Avidin-tagged human islets could bind on average 2.2% of administered tracer/μl. Specificity (>90%) and retention (>90% after 1 h) were high for both AARs and avidin-tagged islets. Hepatic tracer uptake and retention were increased in mice transplanted with AARs [standardized uptake value (SUV)=2.6] compared to the untreated group (SUV=1.4). In vivo uptake of tracer to AARs was blocked by preadministration of unlabeled biotin. Conclusions: Avidin-tagged islet-like objects can be tracked in hepatic volume after intraportal transplantation by using [ 68 Ga]Ga-DOTA-(PEG) 2 -biotin and PET.

Imaging the complex geometry of a magma reservoir using FEM-based linear inverse modeling of InSAR data: application to Rabaul Caldera, Papua New Guinea

Science.gov (United States)

Ronchin, Erika; Masterlark, Timothy; Dawson, John; Saunders, Steve; Martì Molist, Joan

2017-06-01

We test an innovative inversion scheme using Green's functions from an array of pressure sources embedded in finite-element method (FEM) models to image, without assuming an a-priori geometry, the composite and complex shape of a volcano deformation source. We invert interferometric synthetic aperture radar (InSAR) data to estimate the pressurization and shape of the magma reservoir of Rabaul caldera, Papua New Guinea. The results image the extended shallow magmatic system responsible for a broad and long-term subsidence of the caldera between 2007 February and 2010 December. Elastic FEM solutions are integrated into the regularized linear inversion of InSAR data of volcano surface displacements in order to obtain a 3-D image of the source of deformation. The Green's function matrix is constructed from a library of forward line-of-sight displacement solutions for a grid of cubic elementary deformation sources. Each source is sequentially generated by removing the corresponding cubic elements from a common meshed domain and simulating the injection of a fluid mass flux into the cavity, which results in a pressurization and volumetric change of the fluid-filled cavity. The use of a single mesh for the generation of all FEM models avoids the computationally expensive process of non-linear inversion and remeshing a variable geometry domain. Without assuming an a-priori source geometry other than the configuration of the 3-D grid that generates the library of Green's functions, the geodetic data dictate the geometry of the magma reservoir as a 3-D distribution of pressure (or flux of magma) within the source array. The inversion of InSAR data of Rabaul caldera shows a distribution of interconnected sources forming an amorphous, shallow magmatic system elongated under two opposite sides of the caldera. The marginal areas at the sides of the imaged magmatic system are the possible feeding reservoirs of the ongoing Tavurvur volcano eruption of andesitic products on the

Numerical Analyses of Subsoil-structure Interaction in Original Non-commercial Software based on FEM

Science.gov (United States)

Cajka, R.; Vaskova, J.; Vasek, J.

2018-04-01

For decades attention has been paid to interaction of foundation structures and subsoil and development of interaction models. Given that analytical solutions of subsoil-structure interaction could be deduced only for some simple shapes of load, analytical solutions are increasingly being replaced by numerical solutions (eg. FEM – Finite element method). Numerical analyses provides greater possibilities for taking into account the real factors involved in the subsoil-structure interaction and was also used in this article. This makes it possible to design the foundation structures more efficiently and still reliably and securely. Currently there are several software that, can deal with the interaction of foundations and subsoil. It has been demonstrated that non-commercial software called MKPINTER (created by Cajka) provides appropriately results close to actual measured values. In MKPINTER software stress-strain analysis of elastic half-space by means of Gauss numerical integration and Jacobean of transformation is done. Input data for numerical analysis were observed by experimental loading test of concrete slab. The loading was performed using unique experimental equipment which was constructed in the area Faculty of Civil Engineering, VŠB-TU Ostrava. The purpose of this paper is to compare resulting deformation of the slab with values observed during experimental loading test.

Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media

Energy Technology Data Exchange (ETDEWEB)

Gao, Kai, E-mail: kaigao87@gmail.com [Department of Geology and Geophysics, Texas A& M University, College Station, TX 77843 (United States); Fu, Shubin, E-mail: shubinfu89@gmail.com [Department of Mathematics, Texas A& M University, College Station, TX 77843 (United States); Gibson, Richard L., E-mail: gibson@tamu.edu [Department of Geology and Geophysics, Texas A& M University, College Station, TX 77843 (United States); Chung, Eric T., E-mail: tschung@math.cuhk.edu.hk [Department of Mathematics, The Chinese University of Hong Kong, Shatin, NT (Hong Kong); Efendiev, Yalchin, E-mail: efendiev@math.tamu.edu [Department of Mathematics, Texas A& M University, College Station, TX 77843 (United States); Numerical Porous Media SRI Center (NumPor), King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

2015-08-15

It is important to develop fast yet accurate numerical methods for seismic wave propagation to characterize complex geological structures and oil and gas reservoirs. However, the computational cost of conventional numerical modeling methods, such as finite-difference method and finite-element method, becomes prohibitively expensive when applied to very large models. We propose a Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media, where we construct basis functions from multiple local problems for both the boundaries and interior of a coarse node support or coarse element. The application of multiscale basis functions can capture the fine scale medium property variations, and allows us to greatly reduce the degrees of freedom that are required to implement the modeling compared with conventional finite-element method for wave equation, while restricting the error to low values. We formulate the continuous Galerkin and discontinuous Galerkin formulation of the multiscale method, both of which have pros and cons. Applications of the multiscale method to three heterogeneous models show that our multiscale method can effectively model the elastic wave propagation in anisotropic media with a significant reduction in the degrees of freedom in the modeling system.

FEM and Von Mises Analysis on Prosthetic Crowns Structural Elements: Evaluation of Different Applied Materials

Directory of Open Access Journals (Sweden)

Ennio Bramanti

2017-01-01

Full Text Available The aim of this paper is to underline the mechanical properties of dental single crown prosthodontics materials in order to differentiate the possibility of using each material for typical clinical condition and masticatory load. Objective of the investigation is to highlight the stress distribution over different common dental crowns by using computer-aided design software and a three-dimensional virtual model. By using engineering systems of analyses like FEM and Von Mises investigations it has been highlighted the strength over simulated lower first premolar crowns made by chrome cobalt alloy, golden alloy, dental resin, and zirconia. The prosthodontics crown models have been created and put on simulated chewing stresses. The three-dimensional models were subjected to axial and oblique forces and both guaranteed expected results over simulated masticatory cycle. Dental resin presented the low value of fracture while high values have been recorded for the metal alloy and zirconia. Clinicians should choose the better prosthetic solution for the teeth they want to restore and replace. Both prosthetic dental crowns offer long-term success if applied following the manufacture guide limitations and suggestions.

Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media

International Nuclear Information System (INIS)

Gao, Kai; Fu, Shubin; Gibson, Richard L.; Chung, Eric T.; Efendiev, Yalchin

2015-01-01

It is important to develop fast yet accurate numerical methods for seismic wave propagation to characterize complex geological structures and oil and gas reservoirs. However, the computational cost of conventional numerical modeling methods, such as finite-difference method and finite-element method, becomes prohibitively expensive when applied to very large models. We propose a Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media, where we construct basis functions from multiple local problems for both the boundaries and interior of a coarse node support or coarse element. The application of multiscale basis functions can capture the fine scale medium property variations, and allows us to greatly reduce the degrees of freedom that are required to implement the modeling compared with conventional finite-element method for wave equation, while restricting the error to low values. We formulate the continuous Galerkin and discontinuous Galerkin formulation of the multiscale method, both of which have pros and cons. Applications of the multiscale method to three heterogeneous models show that our multiscale method can effectively model the elastic wave propagation in anisotropic media with a significant reduction in the degrees of freedom in the modeling system

Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media

KAUST Repository

Gao, Kai

2015-04-14

It is important to develop fast yet accurate numerical methods for seismic wave propagation to characterize complex geological structures and oil and gas reservoirs. However, the computational cost of conventional numerical modeling methods, such as finite-difference method and finite-element method, becomes prohibitively expensive when applied to very large models. We propose a Generalized Multiscale Generalized Multiscale Finite-Element Method (GMsFEM) for elastic wave propagation in heterogeneous, anisotropic media, where we construct basis functions from multiple local problems for both boundaries and the interior of a coarse node support or coarse element. The application of multiscale basis functions can capture the fine scale medium property variations, and allows us to greatly reduce the degrees of freedom that are required to implement the modeling compared with conventional finite-element method for wave equation, while restricting the error to low values. We formulate the continuous Galerkin and discontinuous Galerkin formulation of the multiscale method, both of which have pros and cons. Applications of the multiscale method to three heterogeneous models show that our multiscale method can effectively model the elastic wave propagation in anisotropic media with a significant reduction in the degrees of freedom in the modeling system.

3-D FEM Modeling of fiber/matrix interface debonding in UD composites including surface effects

International Nuclear Information System (INIS)

Pupurs, A; Varna, J

2012-01-01

Fiber/matrix interface debond growth is one of the main mechanisms of damage evolution in unidirectional (UD) polymer composites. Because for polymer composites the fiber strain to failure is smaller than for the matrix multiple fiber breaks occur at random positions when high mechanical stress is applied to the composite. The energy released due to each fiber break is usually larger than necessary for the creation of a fiber break therefore a partial debonding of fiber/matrix interface is typically observed. Thus the stiffness reduction of UD composite is contributed both from the fiber breaks and from the interface debonds. The aim of this paper is to analyze the debond growth in carbon fiber/epoxy and glass fiber/epoxy UD composites using fracture mechanics principles by calculation of energy release rate G II . A 3-D FEM model is developed for calculation of energy release rate for fiber/matrix interface debonds at different locations in the composite including the composite surface region where the stress state differs from the one in the bulk composite. In the model individual partially debonded fiber is surrounded by matrix region and embedded in a homogenized composite.

A Study of the Influence of Gas Channel Parameters on HT-PEM Fuel Cell Performance Using FEM Analysis

Directory of Open Access Journals (Sweden)

Ionescu Viorel

2016-01-01

Full Text Available Proton Exchange Membrane Fuel Cells (PEMFC are highly efficient power generators, achieving up to 50–60% conversion efficiency, even in sizes of a few kilowatts. Comsol Multiphysics, a commercial solver based on the Finite Element Method (FEM was used for developing a three dimensional model of a high temperature PEMFC that can deal with both anode and cathode flow field for examining the micro flow channel with electrochemical reaction. Cathode gas flow velocity influence on the cell performance was investigated at first. Polarization curves for three different channel widths (0.8, 1.6 and 2.4 mm and three different channel depths (1, 2 and 3 mm were computed at a cathode inlet flow velocity of 0.06 m/s. Oxygen molar concentration at cathode catalyst layer-GDL channel interface and local current density variation along the cell length were also studied for specific gas channel geometries.

Chapter K: Progress in the Evaluation of Alkali-Aggregate Reaction in Concrete Construction in the Pacific Northwest, United States and Canada

Science.gov (United States)

Shrimer, Fred H.

2005-01-01

The supply of aggregates suitable for use in construction and maintenance of infrastructure in western North America is a continuing concern to the engineering and resources-management community. Steady population growth throughout the region has fueled demand for high-quality aggregates, in the face of rapid depletion of existing aggregate resources and slow and difficult permitting of new sources of traditional aggregate types. In addition to these challenges, the requirement for aggregates to meet various engineering standards continues to increase. In addition to their physical-mechanical properties, other performance characteristics of construction aggregates specifically depend on their mineralogy and texture. These properties can result in deleterious chemical reactions when aggregate is used in concrete mixes. When this chemical reaction-termed 'alkali-aggregate reaction' (AAR)-occurs, it can pose a major problem for concrete structures, reducing their service life and requiring expensive repair or even replacement of the concrete. AAR is thus to be avoided in order to promote the longevity of concrete structures and to ensure that public moneys invested in infrastructure are well spent. Because the AAR phenomenon is directly related to the mineral composition, texture, and petrogenesis of the rock particles that make up aggregates, an understanding of the relation between the geology and the performance of aggregates in concrete is important. In the Pacific Northwest, some aggregates have a moderate to high AAR potential, but many others have no or only a low AAR potential. Overall, AAR is not as widespread or serious a problem in the Pacific Northwest as in other regions of North America. The identification of reactive aggregates in the Pacific Northwest and the accurate prediction of their behavior in concrete continue to present challenges for the assessment and management of geologic resources to the owners and operators of pits and quarries and to the

Förändring av förpackning som utökning av marknadsmixen : En studie av fem snabbrörliga konsumentvaror inom livsmedelsbranschen

OpenAIRE

Sandström, Carolina; Eriksson, Sofie

2011-01-01

Denna uppsats behandlar förändring av förpackning som en möjlig utökning av produktkategorin i Kotler & Kellers utvidgade marknadsmix. I marknadsmixen behandlas förpackningen som statisk under en varas livstid och studiens syfte var att se om förpackningsförändringar istället bör ske vid flertalet tillfällen. Genom existerande litteratur identifierades tre centrala begrepp som ansågs betydelsefulla för studien; förpackning, förändring av förpackning och differentiering. Fem olika företag ...

Influence of M=Al, Ga and Si on microstructure and HDDR-processing of Sm2(Fe,M)17 and magnetic properties of their nitrides and carbides

International Nuclear Information System (INIS)

Kubis, M.; Gutfleisch, O.; Gebel, B.; Mueller, K.-H.; Schultz, L.

1999-01-01

Microstructural investigations by means of scanning electron microscopy and X-ray diffraction showed that the formation of high amounts of α-Fe in as-cast Sm 2 (Fe,M) 17 alloys can be suppressed by using the substitutions M=Al or Si together with excess Sm. Ga, on the other hand, does not induce this beneficial effect. The hydrogen absorption and desorption behaviour was investigated by temperature-pressure-analysis and hydrogen differential thermal analysis. Decreasing amounts of hydrogen were absorbed in Sm 2 (Fe,M) 17 for increasing contents of all substitutions M=Ga, Al and Si due to their stabilising effect on the 2:17 phase with regard to its disproportionation. Compared with the homogenised alloys, the as-cast materials show a weaker interstitial hydrogen absorption and a stronger disproportionation reaction at lower temperatures due to the higher content of Sm-rich phases in the as-cast alloys. A second cycle of the hydrogenation-disproportionation-desorption-recombination (HDDR) process leads to a faster disproportionation reaction at lower temperatures due to the grain refinement during the first cycle. Magnetic properties of as-cast and homogenised materials were investigated after HDDR treatment and nitrogenation or carburisation of pre-milled powders. Nitrogenated and carburised samples showed coercivities up to 3.0 T and 2.3 T, respectively. There were only slight differences of the magnetic properties of materials prepared from homogenised and from as-cast samples. (orig.)

Prediction of flow- induced dynamic stress in an axial pump impeller using FEM

International Nuclear Information System (INIS)

Gao, J Y; Hou, Y S; Xi, S Z; Cai, Z H; Yao, P P; Shi, H L

2013-01-01

Axial pumps play an important role in water supply and flood control projects. Along with growing requirements for high reliability and large capacity, the dynamic stress of axial pumps has become a key problem. Unsteady flow is a significant reason which results structural dynamic stress of a pump. This paper reports on a flow-induced dynamic stress simulation in an axial pump impeller at three flow conditions by using FEM code. The pressure pulsation obtained from flow simulation using CFD code was set as the force boundary condition. The results show that the maximum stress of impeller appeared at joint between blade and root flange near trailing edge or joint between blade and root flange near leading edge. The dynamic stress of the two zones was investigated under three flow conditions (0.8Q d , 1.0Q d , 1.1Q d ) in time domain and frequency domain. The frequencies of stress at zones of maximum stress are 22.9Hz and 37.5Hz as the fundamental frequency and its harmonics. The fundamental frequencies are nearly equal to vane passing frequency (22.9 Hz) and 3 times blade passing frequency (37.5Hz). The first dominant frequency at zones of maximum stress is equal to the vane passing frequency due to rotor-stator interaction between the vane and the blade. This study would be helpful for axial pumps in reducing stress, improving structure design and fatigue life

A two-step FEM-SEM approach for wave propagation analysis in cable structures

Science.gov (United States)

Zhang, Songhan; Shen, Ruili; Wang, Tao; De Roeck, Guido; Lombaert, Geert

2018-02-01

Vibration-based methods are among the most widely studied in structural health monitoring (SHM). It is well known, however, that the low-order modes, characterizing the global dynamic behaviour of structures, are relatively insensitive to local damage. Such local damage may be easier to detect by methods based on wave propagation which involve local high frequency behaviour. The present work considers the numerical analysis of wave propagation in cables. A two-step approach is proposed which allows taking into account the cable sag and the distribution of the axial forces in the wave propagation analysis. In the first step, the static deformation and internal forces are obtained by the finite element method (FEM), taking into account geometric nonlinear effects. In the second step, the results from the static analysis are used to define the initial state of the dynamic analysis which is performed by means of the spectral element method (SEM). The use of the SEM in the second step of the analysis allows for a significant reduction in computational costs as compared to a FE analysis. This methodology is first verified by means of a full FE analysis for a single stretched cable. Next, simulations are made to study the effects of damage in a single stretched cable and a cable-supported truss. The results of the simulations show how damage significantly affects the high frequency response, confirming the potential of wave propagation based methods for SHM.

FEM-DBEM approach to analyse crack scenarios in a baffle cooling pipe undergoing heat flux from the plasma

Directory of Open Access Journals (Sweden)

R. Citarella

2017-02-01

Full Text Available Wendelstein 7-X is the world’s largest nuclear fusion experiment of stellarator type, in which a hydrogen plasma is confined by a magnet field generated with external superconducting coils, allowing the plasma to be heated up to the fusion temperature. The water-cooled Plasma Facing Components (PFC protect the Plasma Vessel (PV against radiative and convective heat from the plasma. After the assembly process of heat shields and baffles, several cracks were found in the braze and cooling pipes. Due to heat load cycles occurring during each Operational Phase (OP, thermal stresses are generated in the heat sinks, braze root and cooling pipes, capable to drive fatigue crack-growth and, possibly, a water leak through the pipe thickness. The aim of this study is to assess the most dangerous initial crack configurations in one of the most critical baffles by using numerical models based on a FEM-DBEM approach.

FEM numerical analysis of excimer laser induced modification in alternating multi-layers of amorphous and nano-crystalline silicon films

International Nuclear Information System (INIS)

Conde, J.C.; Martín, E.; Stefanov, S.; Alpuim, P.; Chiussi, S.

2012-01-01

Highlights: ► nc-Si:H is a material with growing importance for a large-area of nano-electronic, photovoltaic or biomedical devices. ► UV-ELA technique causes a rapid heating that provokes the H 2 desorption from the Si surface and bulk material. ► Next, diffusion of P doped nc-Si films and eventually, for high energy densities would be possible to reach the melting point. ► These multilayer structures consisting of thin alternating a-Si:H(10 nm) and n-doped nc-Si:H(60 nm) films deposited on SiO 2 . ► To optimize parameters involved in this processing, FEM numerical analysis of multilayer structures have been performed. ► The numerical results are compared with exhaustive characterization of the experimental results. - Abstract: UV excimer laser annealing (UV-ELA) is an alternative annealing process that, during the last few years, has gained enormous importance for the CMOS nano-electronic technologies, with the ability to provide films and alloys with electrical and optical properties to fit the desired device performance. The UV-ELA of amorphous (a-) and/or doped nano-crystalline (nc-) silicon films is based on the rapid (nanoseconds) formation of temperature profiles caused by laser radiation that is absorbed in the material and lead to crystallisation, diffusion in solid or even in liquid phase. To achieve the desired temperature profiles and to optimize the parameters involved in the processing of hydrogenated nanocrystalline silicon (nc-Si:H) films with the UV-ELA, a numerical analysis by finite element method (FEM) of a multilayer structure has been performed. The multilayer structures, consisting of thin alternating a-Si:H(10 nm) and n-doped nc-Si:H(60 nm) layers, deposited on a glass substrate, has also been experimentally analyzed. Temperature profiles caused by 193 nm radiation with 25 ns pulse length and energy densities ranging from 50 mJ/cm 2 to 400 mJ/cm 2 have been calculated. Numerical results allowed us to estimate the dehydrogenation

Filmimaailm / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2010-01-01

Lühisõnumeid filmimaailmast: Režissöör Terry Gilliami unistus ekraniseerida klassikateos "Don Quijote" nurjus. Ansambel Queenist hakatakse filmi tegema. "Kadunud paradiis" on tulekul. Lähiminevikus lahkunuid: Alain Corneau (7. aug. 1943 - 29. aug. 2010) ja Claude Chabrol (24. juuni 1930 - 12. sept. 2010)

Filmimaailm / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2010-01-01

Oliver Stone töödest. Charlie Chaplin virtuaalmaailmas. Lähiminevikus lahkunud: inglise-kanada filmiajaloolane ja -kriitik Robin Wood (23. II 1931 - 18. XII 2009), vene filmihelilooja Isaak Švarts (13. V 1923 - 27. XII 2009), prantsuse filmi- ja teatrilavastaja Eric Rohmer (4. IV 1920 - 11. I 2010)

Joonisfilmid / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2005-01-01

Eesti Joonisfilm ja Nukufilm üllitasid firma V&K Holding kaudu kaks videokassetti "Armastuskolmnurgad" ja "Rebasenaine läheb taevasse" eesti noorte animaatorite Kaspar Jancise, Ülo Pikkovi ja Priit Tenderi loominguga

Eros / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2006-01-01

Kolmest iseseisvast armastusloost koosnev episoodfilm "Eros" : režissöörid Wong Kar-Wai ("Käsi"), Steven Soderbergh ("Tasakaal" / "Equilibrium"), Michelangelo Antonioni ("Asjade ohtlik käik") : Hongkong - Hiina - USA - Prantsuse - Itaalia 2004

Filmimaailm / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2011-01-01

Lühisõnumeid filmimaailmast: Scorsesel valmib dokumentaalfilm George Harrisonist. Meirellesel uus mängufilm "360". Lähiminevikus lahkunuid: Gualtiero Jacopetti (4.09.1919 - 17. 08.2011), Raoul Ruiz (25.07.1941 - 19.08.2011), Ia Savvina (2.03.1938-27.08.2011)

Filmimaailm / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2009-01-01

Lühisõnumeid filmimaailmast: 21.- 30. augustini peetavast 20. rahvusvahelisest filmifestivalist "Espoo Cine"; Martin Scorsese hakkab tegema eluloofilmi Frank Sinatrast; Lahkus itaalia filmikriitik, dramaturg ja stsenarist Tullio Kezich (17. IX 1928 - 17. VIII 2009)

Filmimaailm / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2008-01-01

Lühisõnumid: Prantsuse kinodesse on jõudnud retrofilmid - "Couche, ühe inimese lugu" (koomik Michel Coluche'ist, rezh. Antoine de Gaunes; ), "Tapainstinkt" ja "Ühiskonna vaenlane nr 1" (mõlemad gangster Jacques Mesrine'ist, rezh. Jean-Francois Richet). Jean-Jacques Annaud' "Kashmir". Roomas triumfeeris "Resolution 819" (rezh. Giacomo Battiato). Humberto Solas (4. XII 1941 - 17. IX 2008)

Filmimaailm / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2009-01-01

Ameeriklase Rob Marshalli Fellini klassikafilmi "8 1/2" kaasajastatud versioon "Üheksa" ("Nine"). Nimekiri filmidest, millest võiks uusversioone luua. Lahkus vene filminäitleja Vjatšeslav Tihhonov

Filmimaailm / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2009-01-01

Woody Alleni uusimatest filmiprojektidest. Ingmar Bergmanni kodusaare Fårö tulevikust kunstiinimeste puhke- ja loomekoduna. Lahkunud on Mikheil Kalatozišvili (19. 05. 1959 - 12. 10. 2009) ja Rosanna Schiaffino (25. 11. 1939 - 17. 10. 2009)

Filmimaailm / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2010-01-01

Lühisõnumid filmimaailmast: Prantsusmaal käivitub keskkooliõpilastele mõeldud üleriigiline filmiõpe. James Nguyeni õudusfilm "Linnuepideemia: šokk ja terror" osutus keskpäraseks soperdiseks. Clint Eastwood ja mitmed tuntud filmiinimesed tähisatvad tänavu 80ndat sünnipäeva. Lahkus operaator William Lubtchansky

Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

Science.gov (United States)

Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.

2001-12-01

A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.

Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

Energy Technology Data Exchange (ETDEWEB)

Tecimer, M. E-mail: tecimer@post.tau.ac.il; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J

2001-12-21

A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 {pi} mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design.

Design and beam transport simulations of a multistage collector for the Israeli EA-FEM

International Nuclear Information System (INIS)

Tecimer, M.; Canter, M.; Efimov, S.; Gover, A.; Sokolowski, J.

2001-01-01

A four stage asymmetric type depressed collector has been designed for the Israeli mm-wave FEM that is driven by a 1.4 MeV, 1.5 A electron beam. After leaving the interaction section the spent beam has an energy spread of 120 keV and 75 π mm mrad normalized beam emittance. Simulations of the beam transport system from the undulator exit through the decelerator tube into the collector have been carried out using EGUN and GPT codes. The latter has also been employed to study trajectories of the primary and scattered particles within the collector, optimizing the asymmetrical collector geometry and the electrode potentials at the presence of a deflecting magnetic field. The estimated overall system and collector efficiencies reach 50% and 70%, respectively, with a beam recovery of 99.6%. The design is aimed to attain millisecond long pulse operation and subsequently 1 kW average power. Simulation results are implemented in a mechanical design that leads to a simple, cost efficient assembly eliminating ceramic insulator rings between collector stages and the associated brazing in the manufacturing process. Instead, each copper plate is supported by insulating posts and freely displaceable within the vacuum chamber. We report on the simulation results of the beam transport and recovery systems and on the mechanical aspects of the multistage collector design

Analysis of submerged implant towards mastication load using 3D finite element method (FEM

Directory of Open Access Journals (Sweden)

Widia Hafsyah Sumarlina Ritonga

2016-11-01

Full Text Available Introduction: The surgical procedure for implantation of a surgical implant comprising a stage for the implant design nonsubmerged and two stages for submerged. Submerged implant design often used in Faculty of Dentistry Universitas Padjadjaran because it is safer in achieving osseointegration. This study was conducted to evaluate the failure of dental implant based on location and the value of internal tensiones as well as supporting tissues when given mastication load by using the 3D Finite Element Method (FEM. Methods: This study used a photograph of the mandibular CBCT patient and CT Scan Micro one implant submerged. Radiograph image was then converted into a digital model of the 3D computerized finite element, inputted the material properties, pedestal, then simulated the occlusion load  as much as 87N and 29N of frictional Results: The maximum tension location on the implant was located on the  exact side of the contact area between the implant and alveolar crest. The maximum tension value was 193.31MPa on the implant body. The value was below the limit value of the ability of the titanium alloy to withstand fracture (860 MPa. Conclusion: The location of the maximum tension on the body of the implant was located on the exact contact area between the implant-abutment and alveolar crest. Under the mastication load, this implant design found no failure.

Psychophysiological Assessment in Pilots Performing Challenging Simulated and Real Flight Maneuvers.

Science.gov (United States)

Johannes, Bernd; Rothe, Stefanie; Gens, André; Westphal, Soeren; Birkenfeld, Katja; Mulder, Edwin; Rittweger, Jörn; Ledderhos, Carla

2017-09-01

The objective assessment of psychophysiological arousal during challenging flight maneuvers is of great interest to aerospace medicine, but remains a challenging task. In the study presented here, a vector-methodological approach was used which integrates different psychophysiological variables, yielding an integral arousal index called the Psychophysiological Arousal Value (PAV). The arousal levels of 15 male pilots were assessed during predetermined, well-defined flight maneuvers performed under simulated and real flight conditions. The physiological data, as expected, revealed inter- and intra-individual differences for the various measurement conditions. As indicated by the PAV, air-to-air refueling (AAR) turned out to be the most challenging task. In general, arousal levels were comparable between simulator and real flight conditions. However, a distinct difference was observed when the pilots were divided by instructors into two groups based on their proficiency in AAR with AWACS (AAR-Novices vs. AAR-Professionals). AAR-Novices had on average more than 2000 flight hours on other aircrafts. They showed higher arousal reactions to AAR in real flight (contact: PAV score 8.4 ± 0.37) than under simulator conditions (7.1 ± 0.30), whereas AAR-Professionals did not (8.5 ± 0.46 vs. 8.8 ± 0.80). The psychophysiological arousal value assessment was tested in field measurements, yielding quantifiable arousal differences between proficiency groups of pilots during simulated and real flight conditions. The method used in this study allows an evaluation of the psychophysiological cost during a certain flying performance and thus is possibly a valuable tool for objectively evaluating the actual skill status of pilots.Johannes B, Rothe S, Gens A, Westphal S, Birkenfeld K, Mulder E, Rittweger J, Ledderhos C. Psychophysiological assessment in pilots performing challenging simulated and real flight maneuvers. Aerosp Med Hum Perform. 2017; 88(9):834-840.

Cluster in the Auroral Acceleration Region

Science.gov (United States)

Pickett, Jolene S.; Fazakerley, Andrew N.; Marklund, Gorun; Dandouras, Iannis; Christopher, Ivar W.; Kistler, Lynn; Lucek, Elizabeth; Masson, Arnaud; Taylor, Matthew G.; Mutel, Robert L.;

Variations in the Spatial Distribution of Gall Bladder Cancer: A Call ...

African Journals Online (AJOL)

adjusted incidence rates (AAR) of certain cancers in specific geographical regions within ... which is second to the highest (Chile) in the world and AAR of carcinoma gall bladder .... Conflict of Interest: None declared. 4. Asmarian NS, Ruzitalab ...

Numerical Modeling of the Thomson Ring in Stationary Levitation Using FEM-Electrical Network and Newton-Raphson

Directory of Open Access Journals (Sweden)

Guzmán Juan

2015-07-01

Full Text Available There are a lot of applications of the Thomson ring: levitation of superconductor materials, power interrupters (used as actuator and elimination of electric arcs. Therefore, it is important the numerical modeling of Thomson ring. The aim of this work is to model the stationary levitation of the Thomson ring. This Thomson ring consists of a copper coil with ferromagnetic core and an aluminum ring threaded in the core. The coil is fed by a cosine voltage to ensure that the aluminum ring is in a stationary levitated position. In this situation, the state of the electromagnetic field is stable and can be used the phasor equations of the electromagnetic field. These equations are discretized using the Galerkin method in the Lagrange base space (finite element method, FEM. These equations are solved using the COMSOL software. A methodology is also described (which uses the Newton-Raphson method that obtains the separation between coil and aluminum ring. The numerical solutions of this separation are compared with experimental data. The conclusion is that the magnetic coupling of the aluminum ring on the coil can be neglected if the source voltage is high.

A new meshless approach to map electromagnetic loads for FEM analysis on DEMO TF coil system

International Nuclear Information System (INIS)

Biancolini, Marco Evangelos; Brutti, Carlo; Giorgetti, Francesco; Muzzi, Luigi; Turtù, Simonetta; Anemona, Alessandro

2015-01-01

Graphical abstract: - Highlights: • Generation and mapping of magnetic load on DEMO using radial basis function. • Good agreement between RBF interpolation and EM TOSCA computations. • Resultant forces are stable with respect to the target mesh used. • Stress results are robust and accurate even if a coarse cloud is used for RBF interpolation. - Abstract: Demonstration fusion reactors (DEMO) are being envisaged to be able to produce commercial electrical power. The design of the DEMO magnets and of the constituting conductors is a crucial issue in the overall engineering design of such a large fusion machine. In the frame of the EU roadmap of the so-called fast track approach, mechanical studies of preliminary DEMO toroidal field (TF) coil system conceptual designs are being enforced. The magnetic field load acting on the DEMO TF coil conductor has to be evaluated as input in the FEM model mesh, in order to evaluate the stresses on the mechanical structure. To gain flexibility, a novel approach based on the meshless method of radial basis functions (RBF) has been implemented. The present paper describes this original and flexible approach for the generation and mapping of magnetic load on DEMO TF coil system.

Extracellular Synthesis and Characterization of Gold Nanoparticles Using Mycobacterium sp. BRS2A-AR2 Isolated from the Aerial Roots of the Ghanaian Mangrove Plant, Rhizophora racemosa.

Science.gov (United States)

Camas, Mustafa; Sazak Camas, Anil; Kyeremeh, Kwaku

2018-06-01

Through the use of genomes that have undergone millions of years of evolution, marine Actinobacteria are known to have adapted to rapidly changing environmental pressures. The result is a huge chemical and biological diversity among marine Actinobacteria . It is gradually becoming a known fact that, marine Actinobacteria have the capability to produce nanoparticles which have reasonable sizes and structures with possible applications in biotechnology and pharmacology. Mycobacterium sp. BRS2A-AR2 was isolated from the aerial roots of the mangrove plant Rhizophora racemosa . The Mycobacterium was demonstrated for the first time ever to produce AuNPs with sizes that range between 5 and 55 nm. The highest level absorbance of the biosynthesized AuNPs was typical for actinobacterial strains (2.881 at 545 nm). The polydispersity index was measured as 0.207 in DLS and the zeta potential was negatively charged (- 28.3 mV). Significant vibration stretches were seen at 3314, 2358, 1635 and 667 cm -1 in FT-IR spectra. This demonstrated the possible use of small aliphatic compounds containing -COOH, -OH, -Cl and -NH 2 functional groups in the stabilization of the AuNPs. The effect of the biosynthesized AuNPs on HUVEC and HeLA cell lines was measured at 48 h. IC 50 values were determined at 3500 µg/ml concentration for HUVEC and HeLA cell lines at 45.25 and 53.41% respectively.

Evaluation of the effects of an arm artifact reduction filter in computed tomography

International Nuclear Information System (INIS)

Nozaki, Fumie; Ohno, Hajime; Hirako, Tetsuya

2002-01-01

While performing CT during arterial portography (CTAP) or CT arteriography (CTA), we have instructed patients to in order to reduce streak artifacts. However the repetitive raising and lowering their arms has made it difficult to keep a clean zone and as well as to maintain the position of a target organ. An arm artifact reduction (AAR) filter developed by GE Yokokawa Medical System has been reported to be useful for reducing streak artifacts in CTAP and CTA. The purpose of this study was to estimate the effectiveness of the AAR filter in terms of artifact reduction ratio, CT value, standard deviation and spatial resolution. The use of an AAR filter reduced streak artifacts on images by 15-22% compared with those on images obtained by without the use of the filter and limited deterioration of spatial resolution to within 1%. Moreover, CT value in examination using AAR filter showed no significant change compared with that in non-filter's examination. It is concluded that the use of an AAR filter reduces the burden for the patient and increase the accuracy and flexibility of CT examination while minimizing the reduction in the image quality in CTAP and CTA. (author)

Amino acid repeats avert mRNA folding through conservative substitutions and synonymous codons, regardless of codon bias

Directory of Open Access Journals (Sweden)

Sailen Barik

2017-12-01

Full Text Available A significant number of proteins in all living species contains amino acid repeats (AARs of various lengths and compositions, many of which play important roles in protein structure and function. Here, I have surveyed select homopolymeric single [(An] and double [(ABn] AARs in the human proteome. A close examination of their codon pattern and analysis of RNA structure propensity led to the following set of empirical rules: (1 One class of amino acid repeats (Class I uses a mixture of synonymous codons, some of which approximate the codon bias ratio in the overall human proteome; (2 The second class (Class II disregards the codon bias ratio, and appears to have originated by simple repetition of the same codon (or just a few codons; and finally, (3 In all AARs (including Class I, Class II, and the in-betweens, the codons are chosen in a manner that precludes the formation of RNA secondary structure. It appears that the AAR genes have evolved by orchestrating a balance between codon usage and mRNA secondary structure. The insights gained here should provide a better understanding of AAR evolution and may assist in designing synthetic genes.

Amino acid repeats avert mRNA folding through conservative substitutions and synonymous codons, regardless of codon bias.

Science.gov (United States)

Barik, Sailen

2017-12-01

A significant number of proteins in all living species contains amino acid repeats (AARs) of various lengths and compositions, many of which play important roles in protein structure and function. Here, I have surveyed select homopolymeric single [(A)n] and double [(AB)n] AARs in the human proteome. A close examination of their codon pattern and analysis of RNA structure propensity led to the following set of empirical rules: (1) One class of amino acid repeats (Class I) uses a mixture of synonymous codons, some of which approximate the codon bias ratio in the overall human proteome; (2) The second class (Class II) disregards the codon bias ratio, and appears to have originated by simple repetition of the same codon (or just a few codons); and finally, (3) In all AARs (including Class I, Class II, and the in-betweens), the codons are chosen in a manner that precludes the formation of RNA secondary structure. It appears that the AAR genes have evolved by orchestrating a balance between codon usage and mRNA secondary structure. The insights gained here should provide a better understanding of AAR evolution and may assist in designing synthetic genes.

Structure-Activity Relationships of Truncated C2- or C8-Substituted Adenosine Derivatives as Dual Acting A2A and A3 Adenosine Receptor Ligands

Science.gov (United States)

Hou, Xiyan; Majik, Mahesh S.; Kim, Kyunglim; Pyee, Yuna; Lee, Yoonji; Alexander, Varughese; Chung, Hwa-Jin; Lee, Hyuk Woo; Chandra, Girish; Lee, Jin Hee; Park, Seul-gi; Choi, Won Jun; Kim, Hea Ok; Phan, Khai; Gao, Zhan-Guo; Jacobson, Kenneth A.; Choi, Sun; Lee, Sang Kook; Jeong, Lak Shin

2011-01-01

Truncated N6-substituted-4′-oxo- and 4′-thioadenosine derivatives with C2 or C8 substitution were studied as dual acting A2A and A3 adenosine receptor (AR) ligands. The lithiation-mediated stannyl transfer and palladium-catalyzed cross coupling reactions were utilized for functionalization of the C2 position of 6-chloropurine nucleosides. An unsubstituted 6-amino group and a hydrophobic C2 substituent were required for high affinity at the hA2AAR, but hydrophobic C8 substitution abolished binding at the hA2AAR. However, most of synthesized compounds displayed medium to high binding affinity at the hA3AR, regardless of C2 or C8 substitution, and low efficacy in a functional cAMP assay. Several compounds tended to be full hA2AAR agonists. C2 substitution probed geometrically through hA2AAR-docking, was important for binding in order of hexynyl > hexenyl > hexanyl. Compound 4g was the most potent ligand acting dually as hA2AAR agonist and hA3AR antagonist, which might be useful for treatment of asthma or other inflammatory diseases. PMID:22142423

Myocardial area at risk after ST-elevation myocardial infarction measured with the late gadolinium enhancement after scar remodeling and T2-weighted cardiac magnetic resonance imaging

DEFF Research Database (Denmark)

Lønborg, Jacob; Engstrøm, Thomas; Mathiasen, Anders B

2011-01-01

To evaluate the myocardial area at risk (AAR) measured by the endocardial surface area (ESA) method on late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) when applied after scar remodeling (3 months after index infarction) compared to T2-weighted CMR imaging. One hundred...... and sixty nine patients with ST-elevation myocardial infarction, treated with primary percutaneous coronary intervention, underwent one CMR within 1 week after index treatment to determine the AAR with T2-weighted imaging and a second scan 3 months after to measure AAR with the ESA method...

Myocardial area at risk after ST-elevation myocardial infarction measured with the late gadolinium enhancement after scar remodeling and T2-weighted cardiac magnetic resonance imaging

DEFF Research Database (Denmark)

Lønborg, Jacob; Engstrøm, Thomas; Mathiasen, Anders B

2012-01-01

To evaluate the myocardial area at risk (AAR) measured by the endocardial surface area (ESA) method on late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) when applied after scar remodeling (3 months after index infarction) compared to T2-weighted CMR imaging. One hundred...... and sixty nine patients with ST-elevation myocardial infarction, treated with primary percutaneous coronary intervention, underwent one CMR within 1 week after index treatment to determine the AAR with T2-weighted imaging and a second scan 3 months after to measure AAR with the ESA method...

Estimates of peak electric fields induced by Transcranial magnetic stimulation in pregnant women as patients using an FEM full-body model.

Science.gov (United States)

Yanamadala, J; Noetscher, G M; Makarov, S N; Pascual-Leone, A

2017-07-01

Transcranial magnetic stimulation (TMS) for treatment of depression during pregnancy is an appealing alternative to fetus-threatening drugs. However, no studies to date have been performed that evaluate the safety of TMS for a pregnant mother patient and her fetus. A full-body FEM model of a pregnant woman with about 100 tissue parts has been developed specifically for the present study. This model allows accurate computations of induced electric field in every tissue given different locations of a shape-eight coil, a biphasic pulse, common TMS pulse durations, and using different values of the TMS intensity measured in SMT (Standard Motor Threshold) units. Our simulation results estimate the maximum peak values of the electric field in the fetal area for every fetal tissue separately and for the TMS intensity of one SMT unit.

DVD. Aare Ermel tutvustab : "Rome : The Complete First Season" / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2006-01-01

6 DVD-na on saadaval 12-osaline ajalooline kostüümidraama - seriaal Rooma impeeriumi ajast "Rooma" ("Rome"), mille tootsid aastail 2005-2006 Ameerika tootja Home Box Office (HBO) ja inglaste BBC. Levitab Home Box Office, Inc

78 FR 75573 - Agency Information Collection Activities: Submission for OMB Review; Comment Request

Science.gov (United States)

2013-12-12

..., facsimile number (202) 646-3347, or email address [email protected] (HSEEP) After Action Report (AAR) Improvement Plan (IP). Type of Information Collection: Revision of a... Exercise and Evaluation Program (HSEEP) After Action Report (AAR) Improvement Plan (IP). Abstract: The...

GPCR Interaction: 30 [GRIPDB[Archive

Lifescience Database Archive (English)

Full Text Available ernalize upon exposure to the agonist. Oxymetazoline (alpha1aAR selective agonist) induces the cointernali...zation of the alpha1aAR and alpha1bAR, whereas the alpha1bAR does not cointernalize

FEM design and simulation of a short, 10 MV, S-band Linac with Monte Carlo dose simulations

International Nuclear Information System (INIS)

Baillie, Devin; Aubin, J. St.; Steciw, S.; Fallone, B. G.

2015-01-01

Purpose: Current commercial 10 MV Linac waveguides are 1.5 m. The authors’ current 6 MV linear accelerator–magnetic resonance imager (Linac–MR) system fits in typical radiotherapy vaults. To allow 10 MV treatments with the Linac–MR and still fit within typical vaults, the authors design a 10 MV Linac with an accelerator waveguide of the same length (27.5 cm) as current 6 MV Linacs. Methods: The first design stage is to design a cavity such that a specific experimental measurement for breakdown is applicable to the cavity. This is accomplished through the use of finite element method (FEM) simulations to match published shunt impedance, Q factor, and ratio of peak to mean-axial electric field strength from an electric breakdown study. A full waveguide is then designed and tuned in FEM simulations based on this cavity design. Electron trajectories are computed through the resulting radio frequency fields, and the waveguide geometry is modified by shifting the first coupling cavity in order to optimize the electron beam properties until the energy spread and mean energy closely match values published for an emulated 10 MV Linac. Finally, Monte Carlo dose simulations are used to compare the resulting photon beam depth dose profile and penumbra with that produced by the emulated 10 MV Linac. Results: The shunt impedance, Q factor, and ratio of peak to mean-axial electric field strength are all matched to within 0.1%. A first coupling cavity shift of 1.45 mm produces an energy spectrum width of 0.347 MeV, very close to the published value for the emulated 10 MV of 0.315 MeV, and a mean energy of 10.53 MeV, nearly identical to the published 10.5 MeV for the emulated 10 MV Linac. The depth dose profile produced by their new Linac is within 1% of that produced by the emulated 10 MV spectrum for all depths greater than 1.5 cm. The penumbra produced is 11% narrower, as measured from 80% to 20% of the central axis dose. Conclusions: The authors have successfully

Multilevel Monte Carlo methods using ensemble level mixed MsFEM for two-phase flow and transport simulations

KAUST Repository

Efendiev, Yalchin R.

2013-08-21

In this paper, we propose multilevel Monte Carlo (MLMC) methods that use ensemble level mixed multiscale methods in the simulations of multiphase flow and transport. The contribution of this paper is twofold: (1) a design of ensemble level mixed multiscale finite element methods and (2) a novel use of mixed multiscale finite element methods within multilevel Monte Carlo techniques to speed up the computations. The main idea of ensemble level multiscale methods is to construct local multiscale basis functions that can be used for any member of the ensemble. In this paper, we consider two ensemble level mixed multiscale finite element methods: (1) the no-local-solve-online ensemble level method (NLSO); and (2) the local-solve-online ensemble level method (LSO). The first approach was proposed in Aarnes and Efendiev (SIAM J. Sci. Comput. 30(5):2319-2339, 2008) while the second approach is new. Both mixed multiscale methods use a number of snapshots of the permeability media in generating multiscale basis functions. As a result, in the off-line stage, we construct multiple basis functions for each coarse region where basis functions correspond to different realizations. In the no-local-solve-online ensemble level method, one uses the whole set of precomputed basis functions to approximate the solution for an arbitrary realization. In the local-solve-online ensemble level method, one uses the precomputed functions to construct a multiscale basis for a particular realization. With this basis, the solution corresponding to this particular realization is approximated in LSO mixed multiscale finite element method (MsFEM). In both approaches, the accuracy of the method is related to the number of snapshots computed based on different realizations that one uses to precompute a multiscale basis. In this paper, ensemble level multiscale methods are used in multilevel Monte Carlo methods (Giles 2008a, Oper.Res. 56(3):607-617, b). In multilevel Monte Carlo methods, more accurate

Uljas ja uudishimulik 20-aastane / Madli Pesti

Index Scriptorium Estoniae

Pesti, Madli, 1980-

2007-01-01

VAT Teatri lavastustest - Amélie Nothombi romaani järgi "Vaenlase kosmeetika" (lav. Peeter Raudsepp), Kristof Magnussoni "Meeste varjupaik" (lav. Christian Römer), Hans Christian Anderseni järgi "Merineitsi" (lav. Aare Toikka) ja Urmas Vadi "Elvis oli kapis" (lav. Aare Toikka)

Acute antibody-mediated rejection of skin grafts without involvement of granulocytes or complement

International Nuclear Information System (INIS)

Bogman, M.J.; Cornelissen, I.M.; Koene, R.A.

1984-01-01

In immunosuppressed mice that carry rat skin xeno-grafts, acute antibody-mediated graft rejection (AAR) can be induced by intravenous administration of mouse anti-rat globulin. Dependent on the amount of antibody injected and on the complement status of the recipient, an Arthus-like or a Shwartzman-like pattern of vasculitis occurs. The role of polymorphonuclear granulocytes (PMNs) in either type of vasculitis was tested by inducing AAR in recipients depleted of PMNs by total body irradiation. Despite the absence of PMNs in the graft vessels, AAR occurred both in the Arthus-like and in the Shwartzman-like type. Moreover, AAR could be elicited in PMN-depleted recipients that were complement-depleted by cobra venom factor treatment or were congenitally C5-deficient. We conclude that neither the PMN nor complement is an essential mediator the PMN nor complement is an essential mediator in this form of antibody-mediated vasculitis

FEM for modelling 193 nm excimer laser treatment of SiO{sub 2}/Si/Si{sub (1-x)}Ge{sub x} heterostructures on SOI substrates

Energy Technology Data Exchange (ETDEWEB)

Conde, J.C.; Chiussi, S.; Gontad, F.; Gonzalez, P. [Dpto. Fisica Aplicada, E.T.S.I.I. University of Vigo, Campus Universitario, Rua Maxwell s/n, 36310 Vigo (Spain); Martin, E. [Dpto. de Mecanica, Maquinas, Motores Termicos y Fluidos, E.T.S.I.I. University of Vigo, Campus Universitario, Rua Maxwell s/n, 36310 Vigo (Spain)

2011-03-15

Research on epitaxial crystalline silicon (c-Si) and silicon-germanium (Si{sub 1-x}Ge{sub x}) alloys growth and annealing for microelectronic purposes, such as Micro- or Nano-Electro-Mechanical Systems (MEMS or NEMS) and Silicon-On-Nothing (SON) devices is continuously in progress. Laser assisted annealing techniques using commercial ArF Excimer Laser sources are based on ultra-rapid heating and cooling cycles induced by the 193 nm pulses of 20 ns, which are absorbed in the near surface region of the heterostructures. During and after the absorption of these laser pulses, complex physical processes appear that strongly depend on sample structure and applied laser pulse energy densities. The control of the experimental parameters is therefore a key task for obtaining high quality alloys. The Finite ElementsMethod (FEM) is a powerful tool for the optimization of such treatments, because it provides the spatial and temporal temperature fields that are produced by the laser pulses. In this work, we have used a FEM commercial software, to predict the temperatures gradients induced by ArF excimer laser over a wide energy densities range, 0.1<{phi}<0.4 J/cm{sup 2}, on different SiO{sub 2}/Si/Si{sub (1-x)}Ge{sub (x)} thin films deposited on SOI substrate. These numerical results allow us to predict the threshold energies needed to reach the melting point (MP) of the Si and SiGe alloy without oxidation of the thin films system. Therefore, it is possible to optimize the conditions to achieve high quality epitaxy films. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

A FEM simulation study of the solid state hydrostatic extrusion of PMMA

Science.gov (United States)

Costa, André L. M.; Riffel, Douglas B.; Misiolek, Wojciech Z.; Valberg, Henry S.

2018-05-01

Solid state hydrostatic extrusion (SSHE) of polymers below glass transition temperature is used to obtain highly oriented structures. Experimental studies on the SSHE of polymethyl-methacrylate (PMMA) have been made since early eighties but there is no information on internal temperature, stress and strain distribution. In this work we have made 3D FEM simulations of SSHE of PMMA by using the commercial DEFORM package with experimental flow curves and thermal properties from literature. The initial temperature of tooling and workpiece was 90°C, ram speeds were 1.0 and 10.0 mm/min with extrusion ratio R = 3.0. For a comparative analysis, SSHE simulation of the AA7108 aluminum alloy at 400°C was also performed. These ranges of parameters were chosen in order to encompass the parameters found in previously mentioned experiments. The best correlation with experimental hydrostatic pressure was verified for a shear friction coefficient at the material-conical die interface m = 0.50. Force-displacement curve for PMMA presented a constitutive and thermal softening in contrast to a constant force curve for aluminum. The internal temperature in the deformation zone increased in a characteristic "owl's face" profile in contrast to quasi-constant profile of aluminum alloy. In both PMMA and aluminum the stress is hydrostatic inside the container, but the stress profiles are significantly different inside the deformation zone. As expected, the strain and strain-rate profiles are practically the same for the two materials, but the temperature profile has promoted slightly differences in material flow. The velocity gradient from center to surface is higher in PMMA than aluminum. It's supposed that during hydrostatic extrusion solid PMMA has a characteristic thermally-inducted mechanical behavior.

A FEM-BEM interactive coupling for modeling the piezoelectric health monitoring systems

Directory of Open Access Journals (Sweden)

Abid A. Shah

Full Text Available In this research, finite element and boundary element methods are coupled together to model the interaction of a piezoelectric ceramic working as an actuator with an elastic material. Piezoelectric-elastic material's interaction occurs in smart structures. This work is aimed at determining the actuation effects being transferred from the actuators to the host and the resulting overall structural response. To obtain the amount of these actuations, the system of the host structure and an actuator has been modeled by using coupled finite element boundary element method in frequency domain. The host structure, which is assumed as an isotropic elastic solid region is modeled as a half space. The piezoelectric ceramic region is modeled by the 3-D finite element method, while the elastic half space with boundary element method. Finite element model of piezoelectric ceramic and boundary element model of the elastic half space are coupled together at their interface such that the vibrations of the piezo-actuator induce vibrations in the elastic half space. A couple of examples are given to show the induced displacement field around the piezo-actuator on the surface of the elastic medium. The results show that high jump in magnitude of horizontal displacements at the corners of the actuator attached to the structure occurs, which is an indication of high stress concentration, of the shear stress type at the corners. This stress concentration sometimes causes complete debonding of the actuator from the base structure. By using the suggested BEM-FEM coupled model for actuators with different dimensions or material properties much useful information concerning the amount of actuation and load transfer can be obtained. The presented work is a step towards modeling of structural health monitoring systems.

GPCR Interaction: 35 [GRIPDB[Archive

Lifescience Database Archive (English)

Full Text Available and alpha2aAR form robust hetero dimer in HEK-293 cells. An interaction between beta1AR and alpha2aAR is reg...ulated by glycosylation. The interaction may play a key role in cross-talk and mu

Azacitidine for Front-Line Therapy of Patients with AML: Reproducible Efficacy Established by Direct Comparison of International Phase 3 Trial Data with Registry Data from the Austrian Azacitidine Registry of the AGMT Study Group

Directory of Open Access Journals (Sweden)

Lisa Pleyer

2017-02-01

Full Text Available We recently published a clinically-meaningful improvement in median overall survival (OS for patients with acute myeloid leukaemia (AML, >30% bone marrow (BM blasts and white blood cell (WBC count ≤15 G/L, treated with front-line azacitidine versus conventional care regimens within a phase 3 clinical trial (AZA-AML-001; NCT01074047; registered: February 2010. As results obtained in clinical trials are facing increased pressure to be confirmed by real-world data, we aimed to test whether data obtained in the AZA-AML-001 trial accurately represent observations made in routine clinical practice by analysing additional AML patients treated with azacitidine front-line within the Austrian Azacitidine Registry (AAR; NCT01595295; registered: May 2012 and directly comparing patient-level data of both cohorts. We assessed the efficacy of front-line azacitidine in a total of 407 patients with newly-diagnosed AML. Firstly, we compared data from AML patients with WBC ≤ 15 G/L and >30% BM blasts included within the AZA-AML-001 trial treated with azacitidine (“AML-001” cohort; n = 214 with AAR patients meeting the same inclusion criteria (“AAR (001-like” cohort; n = 95. The current analysis thus represents a new sub-analysis of the AML-001 trial, which is directly compared with a new sub-analysis of the AAR. Baseline characteristics, azacitidine application, response rates and OS were comparable between all patient cohorts within the trial or registry setting. Median OS was 9.9 versus 10.8 months (p = 0.616 for “AML-001” versus “AAR (001-like” cohorts, respectively. Secondly, we pooled data from both cohorts (n = 309 and assessed the outcome. Median OS of the pooled cohorts was 10.3 (95% confidence interval: 8.7, 12.6 months, and the one-year survival rate was 45.8%. Thirdly, we compared data from AAR patients meeting AZA-AML-001 trial inclusion criteria (n = 95 versus all AAR patients with World Health Organization (WHO-defined AML (“AAR

The research on optimal design using FEM (finite elements method) analysis for ultraprecision six-axis nano-stage

Science.gov (United States)

Kwak, Nam-su; Kim, Jae-Yeol

2012-04-01

The world, coming into the 21st century, is preparing a new revolution called a knowledge-based society after the industrial society. The interest of the world is concentrated on information technology, Nano-technology and biotechnology. In particular, the Nano-technology of which study was originally started from an alternative for overcoming semiconductor micro-technology. It can be applied to most industry subject such as electronics, information and communication, machinery, chemistry, bioengineering, energy, etc. They are emerging into the technology that can change civilization of human beings. Specially, ultra precision machining is quickly applied to Nano-technology in the field of machinery. Lately, with rapid development of electronics industry and optic industry, there are needs for super precision finishing of various core parts required in such related apparatuses. This paper handles stability of a super precision micro cutting machine that is a core unit of such a super precision finisher, and analyzes the results depending on the hinge type and material change, using FEM analysis. By reviewing the stability, it is possible to achieve the effect of basic data collection for unit control and to reduce trials and errors in unit design and manufacturing.

FEM numerical analysis of excimer laser induced modification in alternating multi-layers of amorphous and nano-crystalline silicon films

Energy Technology Data Exchange (ETDEWEB)

Conde, J.C., E-mail: jconde@uvigo.es [Dpto. Fisica Aplicada, Universidade de Vigo, Rua Maxwell s/n, Campus Universitario Lagoas Marcosende, Vigo (Spain); Martin, E. [Dpto. Mecanica, Maquinas, Motores Termicos y Fluidos, Universidade de Vigo, Rua Maxwell s/n, Campus Universitario Lagoas Marcosende, Vigo (Spain); Stefanov, S. [Dpto. Fisica Aplicada, Universidade de Vigo, Rua Maxwell s/n, Campus Universitario Lagoas Marcosende, Vigo (Spain); Alpuim, P. [Departamento de Fisica, Universidade do Minho, 4800-058 Guimaraes (Portugal); Chiussi, S. [Dpto. Fisica Aplicada, Universidade de Vigo, Rua Maxwell s/n, Campus Universitario Lagoas Marcosende, Vigo (Spain)

2012-09-15

Highlights: Black-Right-Pointing-Pointer nc-Si:H is a material with growing importance for a large-area of nano-electronic, photovoltaic or biomedical devices. Black-Right-Pointing-Pointer UV-ELA technique causes a rapid heating that provokes the H{sub 2} desorption from the Si surface and bulk material. Black-Right-Pointing-Pointer Next, diffusion of P doped nc-Si films and eventually, for high energy densities would be possible to reach the melting point. Black-Right-Pointing-Pointer These multilayer structures consisting of thin alternating a-Si:H(10 nm) and n-doped nc-Si:H(60 nm) films deposited on SiO{sub 2}. Black-Right-Pointing-Pointer To optimize parameters involved in this processing, FEM numerical analysis of multilayer structures have been performed. Black-Right-Pointing-Pointer The numerical results are compared with exhaustive characterization of the experimental results. - Abstract: UV excimer laser annealing (UV-ELA) is an alternative annealing process that, during the last few years, has gained enormous importance for the CMOS nano-electronic technologies, with the ability to provide films and alloys with electrical and optical properties to fit the desired device performance. The UV-ELA of amorphous (a-) and/or doped nano-crystalline (nc-) silicon films is based on the rapid (nanoseconds) formation of temperature profiles caused by laser radiation that is absorbed in the material and lead to crystallisation, diffusion in solid or even in liquid phase. To achieve the desired temperature profiles and to optimize the parameters involved in the processing of hydrogenated nanocrystalline silicon (nc-Si:H) films with the UV-ELA, a numerical analysis by finite element method (FEM) of a multilayer structure has been performed. The multilayer structures, consisting of thin alternating a-Si:H(10 nm) and n-doped nc-Si:H(60 nm) layers, deposited on a glass substrate, has also been experimentally analyzed. Temperature profiles caused by 193 nm radiation with 25

49 CFR 1135.1 - Quarterly adjustment.

Science.gov (United States)

2010-10-01

... subsequent amendments thereto. In addition, the AAR shall calculate the productivity-adjusted RCAF as..., the Association of American Railroads (AAR) shall calculate and file with the Board by the fifth day... all-inclusive index of railroad costs and calculate and file the RCAF unadjusted for changes in...

Using Rapid Improvement Events for Disaster After-Action Reviews: Experience in a Hospital Information Technology Outage and Response.

Science.gov (United States)

Little, Charles M; McStay, Christopher; Oeth, Justin; Koehler, April; Bookman, Kelly

2018-02-01

The use of after-action reviews (AARs) following major emergency events, such as a disaster, is common and mandated for hospitals and similar organizations. There is a recurrent challenge of identified problems not being resolved and repeated in subsequent events. A process improvement technique called a rapid improvement event (RIE) was used to conduct an AAR following a complete information technology (IT) outage at a large urban hospital. Using RIE methodology to conduct the AAR allowed for the rapid development and implementation of major process improvements to prepare for future IT downtime events. Thus, process improvement methodology, particularly the RIE, is suited for conducting AARs following disasters and holds promise for improving outcomes in emergency management. Little CM , McStay C , Oeth J , Koehler A , Bookman K . Using rapid improvement events for disaster after-action reviews: experience in a hospital information technology outage and response. Prehosp Disaster Med. 2018;33(1):98-100.

Aneurisma da Artéria Renal: cirurgia renal ex-vivo - a propósito de um caso clínico Renal Artery Aneurysm: ex-vivo repair - a case report

Directory of Open Access Journals (Sweden)

Clara Nogueira

2012-09-01

Full Text Available Os aneurismas da artéria renal (AAR são raros, frequentemente assintomáticos, de etiologia variada, frequentemente secundários a aterosclerose e anomalias congénitas. Os AAR com diâmetro superior a 2 cm têm indicação cirúrgica. A escolha da técnica cirúrgica depende da localização anatómica e complexidade do AAR, bem como do tempo previsível de isquemia renal. Os autores descrevem um caso de auto-transplante renal, para tratamento de dois AAR complexos.Renal artery aneurysms (RAA are rare, frequently asymptomatic, with variable etiology, frequently due to atherosclerosis and congenital anomalies. Surgical treatment is indicated for RAA with a diameter greater to 2 cm. Surgical technique will depend on RAA anatomic localization and complexity, as well as, predicted renal isquemic time. The authors report an auto-transplant for treatment of two complex RAA.

Clinical value of spleen acoustic radiation force impulse, aspartate aminotransferase-to-platelet ratio index, and aspartate aminotransferase/alanine aminotransferase ratio in predicting esophageal varices in patients with liver cirrhosis

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ZHANG Dakun

2018-03-01

Full Text Available ObjectiveTo investigate the spleen stiffness of patients with chronic hepatitis and liver cirrhosis by spleen acoustic radiation force impulse (ARFI, aspartate aminotransferase-to-platelet ratio index (APRI, and aspartate aminotransferase/alanine aminotransferase ratio (AAR, as well as the clinical value of these three noninvasive techniques in predicting esophageal varices (EV in patients with liver cirrhosis. MethodsA total of 247 patients with chronic hepatitis and liver cirrhosis were enrolled, and ARFI was used to measure real-time spleen stiffness. APRI and AAR were calculated. Gastroscopy was performed within one week before and after measurement to clarify the degree of EV. With the results of gastroscopy as the gold standard, the receiver operating characteristic (ROC curve was used to compare the clinical value of spleen ARFI value, APRI, and AAR in the diagnosis of EV in patients with liver cirrhosis. The t-test was used for comparison of continuous data between two groups. ResultsThere were significant differences between the EV group (n=169 and the non-EV group (n=78 in spleen ARFI stiffness (3.64±0.53 m/s vs 2.97±0.65 m/s, t=-7.93, P＜0.001, APRI (0.87±091 vs 0.52±0.80, t=-2.90, P=0.004, and AAR (1.54±0.67 vs 1.29±0.55, t=-2.93, P=0.004. Spleen ARFI, APRI, and AAR had an area under the ROC curve of 0.80, 0.72, and 0.63, respectively, in predicting EV in patients with liver cirrhosis, there was a significant difference between spleen ARFI stiffness and AAR (P=0.005, while there was no significant difference between spleen ARFI stiffness and APRI (P=0.10. ConclusionARFI is a real-time ultrasound elastography technique, and compared with APRI and AAR, spleen stiffness measured by ARFI can predict EV in patients with chronic hepatitis and liver cirrhosis more accurately and noninvasively and thus holds promise for clinical application.

DVD. Aare Ermel soovitab "Meie isade lipud", "Kirjad Iwo Jimalt" / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2007-01-01

Clint Eastwoodi kaks filmi on Teises Maailmasõjas USA-Jaapani Iwo Jima saarel peetud lahingu teemal. USA poolt vaadatuna - "Meie isade lipud" ("Flags of Our Fathers"), Jaapani poolt - "Kirjad Iwo Jimalt" ("Letters From Iwo Jima") : Ameerika Ühendriigid 2006

Finite Element Method (FEM) Modeling of Freeze-drying: Monitoring Pharmaceutical Product Robustness During Lyophilization.

Science.gov (United States)

Chen, Xiaodong; Sadineni, Vikram; Maity, Mita; Quan, Yong; Enterline, Matthew; Mantri, Rao V

2015-12-01

Lyophilization is an approach commonly undertaken to formulate drugs that are unstable to be commercialized as ready to use (RTU) solutions. One of the important aspects of commercializing a lyophilized product is to transfer the process parameters that are developed in lab scale lyophilizer to commercial scale without a loss in product quality. This process is often accomplished by costly engineering runs or through an iterative process at the commercial scale. Here, we are highlighting a combination of computational and experimental approach to predict commercial process parameters for the primary drying phase of lyophilization. Heat and mass transfer coefficients are determined experimentally either by manometric temperature measurement (MTM) or sublimation tests and used as inputs for the finite element model (FEM)-based software called PASSAGE, which computes various primary drying parameters such as primary drying time and product temperature. The heat and mass transfer coefficients will vary at different lyophilization scales; hence, we present an approach to use appropriate factors while scaling-up from lab scale to commercial scale. As a result, one can predict commercial scale primary drying time based on these parameters. Additionally, the model-based approach presented in this study provides a process to monitor pharmaceutical product robustness and accidental process deviations during Lyophilization to support commercial supply chain continuity. The approach presented here provides a robust lyophilization scale-up strategy; and because of the simple and minimalistic approach, it will also be less capital intensive path with minimal use of expensive drug substance/active material.

A boundary integral method for numerical computation of radar cross section of 3D targets using hybrid BEM/FEM with edge elements

Science.gov (United States)

Dodig, H.

2017-11-01

This contribution presents the boundary integral formulation for numerical computation of time-harmonic radar cross section for 3D targets. Method relies on hybrid edge element BEM/FEM to compute near field edge element coefficients that are associated with near electric and magnetic fields at the boundary of the computational domain. Special boundary integral formulation is presented that computes radar cross section directly from these edge element coefficients. Consequently, there is no need for near-to-far field transformation (NTFFT) which is common step in RCS computations. By the end of the paper it is demonstrated that the formulation yields accurate results for canonical models such as spheres, cubes, cones and pyramids. Method has demonstrated accuracy even in the case of dielectrically coated PEC sphere at interior resonance frequency which is common problem for computational electromagnetic codes.

Machoideal och/eller meningslös underhållning? : Om fem mäns berättelser kring krigsfilmen Saving Private Ryan med fokus på maskulinitet och publiken som meningsskapare.

OpenAIRE

Olsson, Eva

2005-01-01

Uppsatsen undersöker fem mäns berättelser kring krigsfilmen Saving Private Ryan, med fokus på maskulinitet. Föreställningarna och bilderna kring maskulinitet som kan urskiljas i intervjupersonernas berättelser, knyts till R.W. Connells teoretiska ramverk kring hegemonisk maskulinitet och de hierarkiska relationerna mellan olika maskuliniteter. Vidare resoneras det kring hur berättelserna exemplifierar en syn på mediepublik som aktiva meningsskapare, då intervjupersonerna tar fasta på olika as...

The effect of load and thickness variation on stress analysis of monocoque frame of electric city car using FEM

Science.gov (United States)

Makhrojan, Agus; Suprihadi, Agus; Budi, Sigit Setijo; Jamari, J.; Ismail, Rifky

2017-01-01

The electric car is transportation which growing and constantly put through improvisation vehicle design. One of the structural components of the electric car which holds a major role is a frame. The purpose of this study is to get monocoque frame design which lightweight and powerful for a city car with two passengers that was able to improve the efficiency of the battery voltage source. Monocoque frame should be able to accept the normal loads such as the weight of batteries, passenger, and body. The most important thing, monocoque frame should also be able to protect the driver and passengers in the event of a collision. Mild steel was chosen for the design because it is easy to obtain and reasonable price as well as easy to shaped for two-seater electric car. FEM (finite element method) was used to determine stress determination and rigidity of the monocoque frame when receiving a static load. The results show that the monocoque frame was still able to withstand the required loads with minimal deflection.

Optimization on cooperative feed strategy for radial–axial ring rolling process of Inco718 alloy by RSM and FEM

Directory of Open Access Journals (Sweden)

Zhu Xinglin

2016-06-01

Full Text Available During radial–axial ring rolling process, cooperative strategy of the radial–axial feed is critical for dimensional accuracy and thermo mechanical parameters distribution of the formed ring. In order to improve the comprehensive quality of the ring parts, response surface method (RSM is employed for the first time to optimize the cooperative feed strategy for radial–axial ring rolling process by combining it with an improved and verified 3D coupled thermo-mechanical finite element model. The feed trajectory is put forward to describe cooperative relationship of the radial–axial feed and three variables are designed based on the feed trajectory. In order to achieve multi-objective optimization, four responses including thermo mechanical parameters distribution and rolling force are proposed. Based on the FEM results, RSM is used to establish a response model to depict the function relationship between the objective response and design variables. Through this approximate model, effects of different variables on ring rolling process are analyzed connectedly and optimal feed strategy is obtained by resorting to the optimal chart specific to a constraint condition.

Design of process parameters for the incremental tube forming (ITF) by FEM to control product properties

Science.gov (United States)

Nazari, Esmaeil; Löbbe, Christian; Gallus, Stefan; Izadyar, S. Ahmad; Tekkaya, A. Erman

2018-05-01

The incremental tube forming (ITF) is a process combination of the kinematic tube bending and spinning to shape high strength and tailored tubes with variable diameters and thicknesses. In contrast to conventional bending methods, the compressive stress superposition by the spinning process facilitates low bending stresses, so that geometrical errors are avoided and the shape accuracy is improved. The study reveals the interaction of plastic strains of the rolling and bending process through an explicit FEM investigation. For this purpose, the three-dimensional machine set-up is discretized and modeled in terms of the fully disclosed spinning process during the gradual deflection of the tube end for bending. The analysis shows that, depending on the forming tool shape, the stress superposition is accompanied by high plastic strains. Furthermore, this phenomenon is explained by the three dimensional normal and shear strains during the incremental spinning. Analyzing the strains history also shows a nonlinearity between the strains by bending and spinning. It is also shown that process parameters like rotational velocity of the spinning rolls have a huge influence on the deformation pattern. Finally, the method is used for the manufacturing of an example product, which reveals the high process flexibility. In one clamp a component with a graded wall thickness and outside diameter along the longitudinal axis is produced.

Study of Corona Discharge on 160 KeV, 10 mA Electron Accelerator Facility Using FEM

International Nuclear Information System (INIS)

Ghazali, Abu Bakar Mhd; Sobri, Rokiah Mohd

2008-01-01

This paper describes a method to verify the overall design of our electron accelerator. It is free from corona or spark discharge phenomenon. This locally designed electron accelerator facility is located at Nuclear Malaysia Complex, Bangi, Selangor. In this study, we describe the geometry of the pressure vessel filled with SF 6 gas at 2 atm to enclose the high voltage area of the accelerating tube. The Poisson's equation is used to calculate the contours of the electric field that is created between the cathode of -160 kV maximum and the wall of the vessel. The nearest sharp edge between the cathode and the pressure wall is 163 mm apart. The calculation is based on finite element method (FEM) for electrostatic charges in order to obtain an electric field contour in two-dimensional plane. We found that the surface charge density of the cathode is 1.1x10 -5 C/m 2 for the corona glowing seen at -90 kV. Moreover, the highest electric field near to (about 5 mm from) the sharp edge is about 2.7 MV/m, which is less than the dielectric strength of SF 6 gas, i.e. 6 MV/m and therefore, it proved that our design of the pressure vessel is save from corona or spark discharges

Study of Corona Discharge on 160 KeV, 10 mA Electron Accelerator Facility Using FEM

Science.gov (United States)

Ghazali, Abu Bakar Mhd; Sobri, Rokiah Mohd

2008-05-01

This paper describes a method to verify the overall design of our electron accelerator. It is free from corona or spark discharge phenomenon. This locally designed electron accelerator facility is located at Nuclear Malaysia Complex, Bangi, Selangor. In this study, we describe the geometry of the pressure vessel filled with SF6 gas at 2 atm to enclose the high voltage area of the accelerating tube. The Poisson's equation is used to calculate the contours of the electric field that is created between the cathode of -160 kV maximum and the wall of the vessel. The nearest sharp edge between the cathode and the pressure wall is 163 mm apart. The calculation is based on finite element method (FEM) for electrostatic charges in order to obtain an electric field contour in two-dimensional plane. We found that the surface charge density of the cathode is 1.1×10-5 C/m2 for the corona glowing seen at -90 kV. Moreover, the highest electric field near to (about 5 mm from) the sharp edge is about 2.7 MV/m, which is less than the dielectric strength of SF6 gas, i.e. 6 MV/m and therefore, it proved that our design of the pressure vessel is save from corona or spark discharges.

3D FEM Analysis of a Pile-Supported Riverine Platform under Environmental Loads Incorporating Soil-Pile Interaction

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Denise-Penelope N. Kontoni

2018-01-01

Full Text Available An existing riverine platform in Egypt, together with its pile group foundation, is analyzed under environmental loads using 3D FEM structural analysis software incorporating soil-pile interaction. The interaction between the transfer plate and the piles supporting the platform is investigated. Two connection conditions were studied assuming fixed or hinged connection between the piles and the reinforced concrete platform for the purpose of comparison of the structural behavior. The analysis showed that the fixed or hinged connection condition between the piles and the platform altered the values and distribution of displacements, normal force, bending moments, and shear forces along the length of each pile. The distribution of piles in the pile group affects the stress distribution on both the soil and platform. The piles were found to suffer from displacement failure rather than force failure. Moreover, the resulting bending stresses on the reinforced concrete plate in the case of a fixed connection between the piles and the platform were almost doubled and much higher than the allowable reinforced concrete stress and even exceeded the ultimate design strength and thus the environmental loads acting on a pile-supported riverine offshore platform may cause collapse if they are not properly considered in the structural analysis and design.

FEM Modeling of the Relationship between the High-Temperature Hardness and High-Temperature, Quasi-Static Compression Experiment.

Science.gov (United States)

Zhang, Tao; Jiang, Feng; Yan, Lan; Xu, Xipeng

2017-12-26

The high-temperature hardness test has a wide range of applications, but lacks test standards. The purpose of this study is to develop a finite element method (FEM) model of the relationship between the high-temperature hardness and high-temperature, quasi-static compression experiment, which is a mature test technology with test standards. A high-temperature, quasi-static compression test and a high-temperature hardness test were carried out. The relationship between the high-temperature, quasi-static compression test results and the high-temperature hardness test results was built by the development of a high-temperature indentation finite element (FE) simulation. The simulated and experimental results of high-temperature hardness have been compared, verifying the accuracy of the high-temperature indentation FE simulation.The simulated results show that the high temperature hardness basically does not change with the change of load when the pile-up of material during indentation is ignored. The simulated and experimental results show that the decrease in hardness and thermal softening are consistent. The strain and stress of indentation were analyzed from the simulated contour. It was found that the strain increases with the increase of the test temperature, and the stress decreases with the increase of the test temperature.

Structural control on the Tohoku earthquake rupture process investigated by 3D FEM, tsunami and geodetic data.

Science.gov (United States)

Romano, F; Trasatti, E; Lorito, S; Piromallo, C; Piatanesi, A; Ito, Y; Zhao, D; Hirata, K; Lanucara, P; Cocco, M

2014-07-09

The 2011 Tohoku earthquake (Mw = 9.1) highlighted previously unobserved features for megathrust events, such as the large slip in a relatively limited area and the shallow rupture propagation. We use a Finite Element Model (FEM), taking into account the 3D geometrical and structural complexities up to the trench zone, and perform a joint inversion of tsunami and geodetic data to retrieve the earthquake slip distribution. We obtain a close spatial correlation between the main deep slip patch and the local seismic velocity anomalies, and large shallow slip extending also to the North coherently with a seismically observed low-frequency radiation. These observations suggest that the friction controlled the rupture, initially confining the deeper rupture and then driving its propagation up to the trench, where it spreads laterally. These findings are relevant to earthquake and tsunami hazard assessment because they may help to detect regions likely prone to rupture along the megathrust, and to constrain the probability of high slip near the trench. Our estimate of ~40 m slip value around the JFAST (Japan Trench Fast Drilling Project) drilling zone contributes to constrain the dynamic shear stress and friction coefficient of the fault obtained by temperature measurements to ~0.68 MPa and ~0.10, respectively.

FEM Modeling of the Relationship between the High-Temperature Hardness and High-Temperature, Quasi-Static Compression Experiment

Directory of Open Access Journals (Sweden)

Tao Zhang

2017-12-01

Full Text Available The high-temperature hardness test has a wide range of applications, but lacks test standards. The purpose of this study is to develop a finite element method (FEM model of the relationship between the high-temperature hardness and high-temperature, quasi-static compression experiment, which is a mature test technology with test standards. A high-temperature, quasi-static compression test and a high-temperature hardness test were carried out. The relationship between the high-temperature, quasi-static compression test results and the high-temperature hardness test results was built by the development of a high-temperature indentation finite element (FE simulation. The simulated and experimental results of high-temperature hardness have been compared, verifying the accuracy of the high-temperature indentation FE simulation.The simulated results show that the high temperature hardness basically does not change with the change of load when the pile-up of material during indentation is ignored. The simulated and experimental results show that the decrease in hardness and thermal softening are consistent. The strain and stress of indentation were analyzed from the simulated contour. It was found that the strain increases with the increase of the test temperature, and the stress decreases with the increase of the test temperature.

An analysis of root cause identification and continuous quality improvement in public health H1N1 after-action reports.

Science.gov (United States)

Singleton, Christa-Marie; Debastiani, Summer; Rose, Dale; Kahn, Emily B

2014-01-01

To identify the extent to which the Homeland Security Exercise and Evaluation Program's (HSEEP) After Action Report/Improvement Plan (AAR/IP) template was followed by public health entities and facilitated the identification of detailed corrective actions and continuous improvement. Data were drawn from the US H1N1 Public Health Emergency Response (PHER) federal grant awardees (n = 62). After action report/improvement plan text was examined to identify the presence of AAR/IP HSEEP elements and characterized as "minimally complete," "partially complete," or "complete." Corrective actions (CA) and recommendations within the IP focusing on performance deficits were coded as specific, measurable, and time-bound, and whether they were associated with a problem that met root cause criteria and whether the CA/recommendation was intended to address or fix the root cause. A total of 2619 CA/recommendations were identified. More than half (n = 1480, 57%) addressed root causes. Corrective actions/recommendations associated with complete AARs more frequently addressed root cause (58% vs 51%, χ = 9.1, P < 0.003) and were more specific (34% vs 23%, χ = 32.3, P < 0.0001), measurable (30% vs 18%, χ = 37.9, P < 0.0001), and time-bound (38% vs 15%, χ = 115.5, P < 0.0001) than partially complete AARs. The same pattern was not observed with completeness of IPs. Corrective actions and recommendations were similarly specific and measurable. Recommendations significantly addressed root cause more than CAs. Our analysis indicates a possible lack of awardee distinction between CA and recommendations in AARs. As HSEEP adapts to align with the 2011 National Preparedness Goal and National Preparedness System, future HSEEP documents should emphasize the importance of root cause analysis as a required element within AAR documents and templates in the exercise and real incident environment, as well as the need for specific and measurable CAs.

Parimaid õpetajaid näeb taas terve Eesti / Sirje Pärismaa

Index Scriptorium Estoniae

Pärismaa, Sirje, 1958-

2014-01-01

Üleriigilise üldhariduse tunnustussüsteemi „Eestimaa õpib ja tänab“ tänuüritusest, kus pälvisid auhinna aasta klassijuhataja Aare Veedla, Luua Metsanduskooli õpetaja Aino Mölder, Hugo Treffneri Gümnaasiumi õpetaja Aare Ristikivi, aasta lasteaiaõpetaja Julia Faizullova ning aasta teo tiitli pälvis Konguta kool

Uso de la distribución normal para cuantificar la calidad del riego en sistemas de aspersión estacionario

Directory of Open Access Journals (Sweden)

José Nicolás Ortiz Romero

2017-12-01

Full Text Available En el campo experimental de riego del Decanato de Agronomía de la UCLA se llevó a cabo un estudio cuyo objetivo fue cuantificar el reparto del agua y los parámetros de calidad del riego en un sistema de aspersión estacionario durante dos ciclos del cultivo de caraota usando la distribución normal. Se determinó el área adecuadamente regada (AAR en 13 eventos de riego, y esta se relacionó con los parámetros eficiencia de aplicación (Efa, pérdidas por percolación, eficiencia de almacenamiento (Efal y el déficit. Los resultados mostraron que la Efal y la percolación aumentaron con el incremento del AAR; mientras, la Efa y el déficit disminuyeron con el aumento del AAR. Los parámetros de calidad del riego en función del AAR se ajustaron apropiadamente a una regresión lineal, donde los coeficientes y el modelo resultaron significativos (p

Evolutionary Limitation and Opportunities for Developing tRNA Synthetase Inhibitors with 5-Binding-Mode Classification

Directory of Open Access Journals (Sweden)

Pengfei Fang

2015-12-01

Full Text Available Aminoacyl-tRNA synthetases (aaRSs are enzymes that catalyze the transfer of amino acids to their cognate tRNAs as building blocks for translation. Each of the aaRS families plays a pivotal role in protein biosynthesis and is indispensable for cell growth and survival. In addition, aaRSs in higher species have evolved important non-translational functions. These translational and non-translational functions of aaRS are attractive for developing antibacterial, antifungal, and antiparasitic agents and for treating other human diseases. The interplay between amino acids, tRNA, ATP, EF-Tu and non-canonical binding partners, had shaped each family with distinct pattern of key sites for regulation, with characters varying among species across the path of evolution. These sporadic variations in the aaRSs offer great opportunity to target these essential enzymes for therapy. Up to this day, growing numbers of aaRS inhibitors have been discovered and developed. Here, we summarize the latest developments and structural studies of aaRS inhibitors, and classify them with distinct binding modes into five categories.

Aminoacyl-tRNA synthetases database Y2K.

Science.gov (United States)

Szymanski, M; Barciszewski, J

2000-01-01

The aminoacyl-tRNA synthetases (AARS) are a diverse group of enzymes that ensure the fidelity of transfer of genetic information from DNA into protein. They catalyse the attachment of amino acids to transfer RNAs and thereby establish the rules of the genetic code by virtue of matching the nucleotide triplet of the anticodon with its cognate amino acid. Currently, 818 AARS primary structures have been reported from archaebacteria, eubacteria, mitochondria, chloro-plasts and eukaryotic cells. The database is a compilation of the amino acid sequences of all AARSs, known to date, which are available as separate entries or alignments of related proteins via the WWW at http://rose.man.poznan.pl/aars/index.html

75 FR 59108 - Positive Train Control Systems

Science.gov (United States)

2010-09-27

..., place the two agencies in conflict. According to AAR, ``[i]f under the PHMSA analysis of two routes one... requirement conflicts with RSIA08. AAR states that: [i]f FRA decides that TIH should be routed on a line... an inevitable impact on some routing decisions. One of the 27 factors called out for analysis under...

76 FR 52918 - Positive Train Control Systems

Science.gov (United States)

2011-08-24

... Railroads (AAR) filed suit in the U.S. Court of Appeals for the District of Columbia Circuit challenging the..., 2010, the AAR filed a petition for review of the rule with the U.S. Court of Appeals for the District... rational bases. IV. Regulatory Impact and Notices A. Executive Orders 12866 and 13563 and DOT Regulatory...

Interesting coin finds of 2006 / Mauri Kiudsoo

Index Scriptorium Estoniae

Kiudsoo, Mauri, 1973-

2007-01-01

2006. aasta huvitavamatest mündileidudest. Lisaks arheoloogilistelt kaevamistelt saadud vermingutele omandati 2006. aastal kolm mündiaaret : Alansi aare Harjumaalt, ligi poolsada araabia hõbemünti sisaldav aare Tartust ning tänu politsei kaasabile jõudsid Eestisse tagasi Ubina hõbeaadre kaevamistelt varastatud hõbemündid. Eestist leitud rooma müntidest

Chemically reacting fluid flow induced by an exponentially accelerated infinite vertical plate in a magnetic field and variable temperature via LTT and FEM

Directory of Open Access Journals (Sweden)

Srinivasa Raju R.

2016-01-01

Full Text Available In this research paper, we found both numerical and analytical solutions for the effect of chemical reaction on unsteady, incompressible, viscous fluid flow past an exponentially accelerated vertical plate with heat absorption and variable temperature in a magnetic field. The flow problem is governed by a system of coupled non-linear partial differential equations with suitable boundary conditions. We have solved the governing equations by an efficient, accurate, powerful finite element method (FEM as well as Laplace transform technique (LTT. The evaluation of the numerical results are performed and graphical results for the velocity, temperature and concentration profiles within the boundary layer are discussed. Also, the expressions for the skin-friction, Nusselt number and the Sherwood number coefficients have been derived and discussed through graphs and tabular forms for different values of the governing parameters.

Madame Bovary / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2001-01-01

Austraalias oma filmikarjääri alustanud näitlejanna Frances O'Connor (1969), kes mängib nimiosa Inglismaa-USA seriaalis Gustave Flaubert'i romaani "Madame Bovary" ainetel. Ka : Nädal nr. 52, lk. 17

Tavaline roomlane / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2007-01-01

Iiri päritolu näitleja Ray Richardson, kes kehastab ajaloolises teleseriaalis "Rooma" (tootjad Ameerika HBO, inglaste BBC ja itaallaste RAI) Gaius Julius Caesari sõdurit Titus Pullot. Sama : Teleleht nr. 1, lk. 14 : ill

Fosforiidisõda / Juhan Aare

Index Scriptorium Estoniae

Aare, Juhan, 1948-

1999-01-01

Järg Jan/5;6;7;8;9;11;12;13;14;15;16;18;19;20;21;22;23;25;26;27;28;29;30/Feb/1;2;3;4;5;6;8;9;10;11;12;13;15;16;17;18;19;20;22;23;25;26;27/Mar/1;2;3;4;5;6;8;9;10;11;12;13;15;16;17;18;20;22;23;24;25;26;27;29;30;31/Apr/1;2;35;6;7;8;9;10;12;13;14;15;16;17;19;20;21;22;23;24;26;27;28;29;30/May/3;4;5;6;7;8;10;11;12;13;14;15;17;18;19;20;21;22;24;25;26;27;28;29;31

Current Practice and Theoretical Foundations of the After Action Review

Science.gov (United States)

2011-06-01

Stephen L. Goldberg , Chief U.S. Army Research Institute for the Behavioral and Social Sciences 2511 Jefferson Davis Highway, Arlington, Virginia...were many occasions where 37 the facilitators’ knowledge of the battle tempo , dynamics, and resources added to the SA of team members. Such...attending AARs. There appear to be frequent variations in organizational status among participants in traditional industry AARs. In military

Puhu ristist maailma teedele / Helmut Piirimäe

Index Scriptorium Estoniae

Piirimäe, Helmut, 1930-

2009-01-01

Tutvustus: Varje dag...-sextio år av lycka. Till minnet av Aare R. Mörner (1926-2008). Utgivare: Magnus och Henrik Mörner. Printed in Hungary, 2008. /Tõlge/: Iga päev...- kuuskümmend aastat õnne. Aare-R. Mörneri (1926-2008) mälestuseks. Väljaandjad: Magnus ja Henrik Mörner. Trükitud Ungaris, 2008. 199 lk.

The growing pipeline of natural aminoacyl-tRNA synthetase inhibitors for malaria treatment.

Science.gov (United States)

Saint-Léger, Adélaïde; Sinadinos, Christopher; Ribas de Pouplana, Lluís

2016-04-02

Malaria remains a major global health problem. Parasite resistance to existing drugs makes development of new antimalarials an urgency. The protein synthesis machinery is an excellent target for the development of new anti-infectives, and aminoacyl-tRNA synthetases (aaRS) have been validated as antimalarial drug targets. However, avoiding the emergence of drug resistance and improving selectivity to target aaRS in apicomplexan parasites, such as Plasmodium falciparum, remain crucial challenges. Here we discuss such issues using examples of known inhibitors of P. falciparum aaRS, namely halofuginone, cladosporin and borrelidin (inhibitors of ProRS, LysRS and ThrRS, respectively). Encouraging recent results provide useful guidelines to facilitate the development of novel drug candidates which are more potent and selective against these essential enzymes.

Slope stability and rockfall assessment of volcanic tuffs using RPAS with 2-D FEM slope modelling

Science.gov (United States)

Török, Ákos; Barsi, Árpád; Bögöly, Gyula; Lovas, Tamás; Somogyi, Árpád; Görög, Péter

2018-02-01

Steep, hardly accessible cliffs of rhyolite tuff in NE Hungary are prone to rockfalls, endangering visitors of a castle. Remote sensing techniques were employed to obtain data on terrain morphology and to provide slope geometry for assessing the stability of these rock walls. A RPAS (Remotely Piloted Aircraft System) was used to collect images which were processed by Pix4D mapper (structure from motion technology) to generate a point cloud and mesh. The georeferencing was made by Global Navigation Satellite System (GNSS) with the use of seven ground control points. The obtained digital surface model (DSM) was processed (vegetation removal) and the derived digital terrain model (DTM) allowed cross sections to be drawn and a joint system to be detected. Joint and discontinuity system was also verified by field measurements. On-site tests as well as laboratory tests provided additional engineering geological data for slope modelling. Stability of cliffs was assessed by 2-D FEM (finite element method). Global analyses of cross sections show that weak intercalating tuff layers may serve as potential slip surfaces. However, at present the greatest hazard is related to planar failure along ENE-WSW joints and to wedge failure. The paper demonstrates that RPAS is a rapid and useful tool for generating a reliable terrain model of hardly accessible cliff faces. It also emphasizes the efficiency of RPAS in rockfall hazard assessment in comparison with other remote sensing techniques such as terrestrial laser scanning (TLS).

The alpha(2a)-adrenergic receptor plays a protective role in mouse behavioral models of depression and anxiety.

Science.gov (United States)

Schramm, N L; McDonald, M P; Limbird, L E

2001-07-01

The noradrenergic system is involved in the regulation of many physiological and psychological processes, including the modulation of mood. The alpha(2)-adrenergic receptors (alpha(2)-ARs) modulate norepinephrine release, as well as the release of serotonin and other neurotransmitters, and are therefore potential targets for antidepressant and anxiolytic drug development. The current studies were undertaken to examine the role of the alpha(2A) subtype of alpha(2)-AR in mouse behavioral models of depression and anxiety. We have observed that the genetic knock-out of the alpha(2A)-AR makes mice less active in a modified version of Porsolt's forced swim test and insensitive to the antidepressant effects of the tricyclic drug imipramine in this paradigm. Furthermore, alpha(2A)-AR knock-out mice appear more anxious than wild-type C57 Bl/6 mice in the rearing and light-dark models of anxiety after injection stress. These findings suggest that the alpha(2A)-AR may play a protective role in some forms of depression and anxiety and that the antidepressant effects of imipramine may be mediated by the alpha(2A)-AR.

A randomized controlled trial with a Canadian electronic pill dispenser used to measure and improve medication adherence in patients with schizophrenia.

Science.gov (United States)

Stip, Emmanuel; Vincent, Philippe D; Sablier, Juliette; Guevremont, Catherine; Zhornitsky, Simon; Tranulis, Constantin

2013-01-01

Medication adherence is extremely important in preventing relapse and lowering symptoms in schizophrenic patients. However, estimates show that nearly half of these patients have poor adherence. The Brief Adherence Rating Scale (BARS) seems to be the most reliable tool assessing adherence in schizophrenia and shows that the antipsychotic adherence ratio (AAR) is about 49.5% in schizophrenia. The aim of the study was to test if an electronic pill dispenser named DoPill(®) improved AAR of schizophrenic patients. Furthermore, we compared AAR obtained by the DoPill(®) and the BARS, in order to verify whether the DoPill(®) provides reliable assessment of medication adherence. The DoPill(®) is a smart pill dispenser that beeps and flashes at the appropriate time of the day. Each of its 28 compartments is covered by a plastic lamina that, when taken off, sends a signal to the pharmacist. Patients were randomized to the DoPill(®) or treatment as usual groups for 6 weeks. The BARS was used as a reference measure. Forty-six percent of patients were deemed to be non-adherent with antipsychotic medication. The mean AAR was 67% after 6 weeks. DoPill(®) recorded better AAR than some of those found in the literature and were lower than the BARS estimate we found. These results suggest that DoPill(®) is a valid tool that provides more reliable and objective data for the clinician about their patient's adherence, than existing assessment tools like the BARS. Furthermore, the device may help patients successfully manage their medication regimen.

A FEM-based method to determine the complex material properties of piezoelectric disks.

Science.gov (United States)

Pérez, N; Carbonari, R C; Andrade, M A B; Buiochi, F; Adamowski, J C

2014-08-01

Numerical simulations allow modeling piezoelectric devices and ultrasonic transducers. However, the accuracy in the results is limited by the precise knowledge of the elastic, dielectric and piezoelectric properties of the piezoelectric material. To introduce the energy losses, these properties can be represented by complex numbers, where the real part of the model essentially determines the resonance frequencies and the imaginary part determines the amplitude of each resonant mode. In this work, a method based on the Finite Element Method (FEM) is modified to obtain the imaginary material properties of piezoelectric disks. The material properties are determined from the electrical impedance curve of the disk, which is measured by an impedance analyzer. The method consists in obtaining the material properties that minimize the error between experimental and numerical impedance curves over a wide range of frequencies. The proposed methodology starts with a sensitivity analysis of each parameter, determining the influence of each parameter over a set of resonant modes. Sensitivity results are used to implement a preliminary algorithm approaching the solution in order to avoid the search to be trapped into a local minimum. The method is applied to determine the material properties of a Pz27 disk sample from Ferroperm. The obtained properties are used to calculate the electrical impedance curve of the disk with a Finite Element algorithm, which is compared with the experimental electrical impedance curve. Additionally, the results were validated by comparing the numerical displacement profile with the displacements measured by a laser Doppler vibrometer. The comparison between the numerical and experimental results shows excellent agreement for both electrical impedance curve and for the displacement profile over the disk surface. The agreement between numerical and experimental displacement profiles shows that, although only the electrical impedance curve is

New erection program of the hydroelectric power plant Beznau. Das Neubauprojekt des hydraulischen Kraftwerkes Beznau

Energy Technology Data Exchange (ETDEWEB)

Bretscher, B; Hauenstein, W [NOK Nordostschweizerische Kraftwerke AG, Baden (Switzerland)

1992-02-21

The projected hydroelectric power plant at Beznau on the Aare river will produce about 43% more electric power than the present hydroelectric power plant. The water level and the buildings in the Aare will remain unchanged, so that the enviromental impact will be relativley slight. The project is in accordance with the building permit so that no adaptations on modifications will be required. (orig.).

Analysis of Feedback in after Action Reviews

Science.gov (United States)

1987-06-01

CONNTSM Page INTRODUCTIUN . . . . . . . . . . . . . . . . . . . A Perspective on Feedback. . ....... • • ..... • 1 Overviev of %,•urrent Research...part of their training program . The AAR is in marked contrast to the critique method of feedback which is often used in military training. The AAR...feedback is task-inherent feedback. Task-inherent feedback refers to human-machine interacting systems, e.g., computers , where in a visual tracking task

Development of a three-dimensional groundwater flow model for Western Melton Valley: Application of P-FEM on a DOE waste site

International Nuclear Information System (INIS)

West, O.R.; Toran, L.E.

1994-04-01

Modeling the movement of hazardous waste in groundwater was identified by the US Department of Energy (DOE) as one of the grand challenges in scientific computation. In recognition of this need, DOE has provided support for a group of scientists from several national laboratories and universities to conduct research and development in groundwater flow and contaminant transport modeling. This group is part of a larger consortium of researchers, collectively referred to as the Partnership in Computational Science (PICS), that has been charged with the task of applying high-performance computational tools and techniques to grand challenge areas identified by DOE. One of the goals of the PICS Groundwater Group is to develop a new three-dimensional groundwater flow and transport code that is optimized for massively parallel computers. An existing groundwater flow code, 3DFEMWATER, was parallelized in order to serve as a benchmark for these new models. The application of P-FEM, the parallelized version of 3DFEMWATER, to a real field site is the subject of this report

Development of a three-dimensional groundwater flow model for Western Melton Valley: Application of P-FEM on a DOE waste site

Energy Technology Data Exchange (ETDEWEB)

West, O.R.; Toran, L.E.

1994-04-01

Modeling the movement of hazardous waste in groundwater was identified by the US Department of Energy (DOE) as one of the grand challenges in scientific computation. In recognition of this need, DOE has provided support for a group of scientists from several national laboratories and universities to conduct research and development in groundwater flow and contaminant transport modeling. This group is part of a larger consortium of researchers, collectively referred to as the Partnership in Computational Science (PICS), that has been charged with the task of applying high-performance computational tools and techniques to grand challenge areas identified by DOE. One of the goals of the PICS Groundwater Group is to develop a new three-dimensional groundwater flow and transport code that is optimized for massively parallel computers. An existing groundwater flow code, 3DFEMWATER, was parallelized in order to serve as a benchmark for these new models. The application of P-FEM, the parallelized version of 3DFEMWATER, to a real field site is the subject of this report.

Electric potential structures of auroral acceleration region border from multi-spacecraft Cluster data

Science.gov (United States)

Sadeghi, S.; Emami, M. R.

2018-04-01

This paper studies an auroral event using data from three spacecraft of the Cluster mission, one inside and two at the poleward edge of the bottom of the Auroral Acceleration Region (AAR). The study reveals the three-dimensional profile of the region's poleward boundary, showing spatial segmentation of the electric potential structures and their decay in time. It also depicts localized magnetic field variations and field-aligned currents that appear to have remained stable for at least 80 s. Such observations became possible due to the fortuitous motion of the three spacecraft nearly parallel to each other and tangential to the AAR edge, so that the differences and variations can be seen when the spacecraft enter and exit the segmentations, hence revealing their position with respect to the AAR.

Slope stability and rockfall assessment of volcanic tuffs using RPAS with 2-D FEM slope modelling

Directory of Open Access Journals (Sweden)

Á. Török

2018-02-01

Full Text Available Steep, hardly accessible cliffs of rhyolite tuff in NE Hungary are prone to rockfalls, endangering visitors of a castle. Remote sensing techniques were employed to obtain data on terrain morphology and to provide slope geometry for assessing the stability of these rock walls. A RPAS (Remotely Piloted Aircraft System was used to collect images which were processed by Pix4D mapper (structure from motion technology to generate a point cloud and mesh. The georeferencing was made by Global Navigation Satellite System (GNSS with the use of seven ground control points. The obtained digital surface model (DSM was processed (vegetation removal and the derived digital terrain model (DTM allowed cross sections to be drawn and a joint system to be detected. Joint and discontinuity system was also verified by field measurements. On-site tests as well as laboratory tests provided additional engineering geological data for slope modelling. Stability of cliffs was assessed by 2-D FEM (finite element method. Global analyses of cross sections show that weak intercalating tuff layers may serve as potential slip surfaces. However, at present the greatest hazard is related to planar failure along ENE–WSW joints and to wedge failure. The paper demonstrates that RPAS is a rapid and useful tool for generating a reliable terrain model of hardly accessible cliff faces. It also emphasizes the efficiency of RPAS in rockfall hazard assessment in comparison with other remote sensing techniques such as terrestrial laser scanning (TLS.

A randomized-controlled trial with a Canadian electronic pill dispenser used to measure and improve medication adherence in patients with schizophrenia

Directory of Open Access Journals (Sweden)

Emmanuel eStip

2013-08-01

Full Text Available Objective: Medication adherence is extremely important in preventing relapse and lowering symptoms in schizophrenic patients. However, estimates show that nearly half of these patients have poor adherence. The Brief Adherence Rating Scale (BARS seems to be the most reliable tool assessing adherence in schizophrenia and shows that the antipsychotic adherence ratio (AAR is about 49.5 % in schizophrenia. The aim of the study was to test if an electronic pill dispenser named DoPill® improved AAR of schizophrenic patients. Furthermore, we compared AAR obtained by the DoPill® and the BARS, in order to verify whether the DoPill® provides reliable assessment of medication adherence. Methods: The DoPill® is a smart pill dispenser that beeps and flashes at the appropriate time of the day. Each of its 28 compartments is covered by a plastic lamina that, when taken off, sends a signal to the pharmacist. Patients were randomized to the DoPill® or Treatment As Usual group (TAU for six weeks. The BARS was used as a reference measure. Results: Forty-six percent of patients were deemed to be non-adherent with antipsychotic medication. The mean AAR was 67 % after six weeks. DoPill® recorded better AAR than some of those found in the literature and were lower than the BARS estimate we found. Conclusion: These results suggest that DoPill® is a valid tool that provides more reliable and objective data for the clinician about their patient’s adherence, than existing assessment tools like the BARS. Furthermore, the device may help patients successfully manage their medication regimen.

Area at risk can be assessed by iodine-123-meta-iodobenzylguanidine single-photon emission computed tomography after myocardial infarction: a prospective study.

Science.gov (United States)

Hedon, Christophe; Huet, Fabien; Ben Bouallegue, Fayçal; Vernhet, Hélène; Macia, Jean-Christophe; Cung, Thien-Tri; Leclercq, Florence; Cade, Stéphane; Cransac, Frédéric; Lattuca, Benoit; Vandenberghe, D'Arcy; Bourdon, Aurélie; Benkiran, Meriem; Vauchot, Fabien; Gervasoni, Richard; D'estanque, Emmanuel; Mariano-Goulart, Denis; Roubille, François

2018-02-01

Myocardial salvage is an important surrogate endpoint to estimate the impact of treatments in patients with ST-segment elevation myocardial infarction (STEMI). The aim of this study was to evaluate the correlation between cardiac sympathetic denervation area assessed by single-photon emission computed tomography (SPECT) using iodine-123-meta-iodobenzylguanidine (I-MIBG) and myocardial area at risk (AAR) assessed by cardiac magnetic resonance (CMR) (gold standard). A total of 35 postprimary reperfusion STEMI patients were enrolled prospectively to undergo SPECT using I-MIBG (evaluates cardiac sympathetic denervation) and thallium-201 (evaluates myocardial necrosis), and to undergo CMR imaging using T2-weighted spin-echo turbo inversion recovery for AAR and postgadolinium T1-weighted phase sensitive inversion recovery for scar assessment. I-MIBG imaging showed a wider denervated area (51.1±16.0% of left ventricular area) in comparison with the necrosis area on thallium-201 imaging (16.1±14.4% of left ventricular area, Parea (P=0.23) and was adequately correlated (R=0.56, P=0.0002). Myocardial salvage evaluated by SPECT imaging (mismatch denervated but viable myocardium) was significantly higher than by CMR (P=0.02). In patients with STEMI, I-MIBG SPECT, assessing cardiac sympathetic denervation may precisely evaluate the AAR, providing an alternative to CMR for AAR assessment.

The effect of alkali-aggregate reaction on concrete bridge structures

Directory of Open Access Journals (Sweden)

Grković Slobodan

2016-01-01

Full Text Available This paper shows contemporary issues related to unfavorable effects of concrete alkali-aggregate reaction (AAR on concrete bridge structures (CBS. Although AAR unfavorable effects on CBS were identified in 1930s, it was much later that AAR was acknowledged as one of the most pronounced deterioration processes in concrete that results in damages to concrete structures. There are two basic forms of AAR: alkali-silica reaction (ASR and alkali-carbonate reaction (ACR. Compared to ACR, ASR is more prominent, especially in certain geographic parts of the world. Damages to concrete caused by the ASR have negative effect primarily on usability and durability of CBS, what is followed by the decrease in load bearing capacity of structural components and reliability of the whole structure, shortening of service life (SL and costly repairs. For CBS, simultaneous occurrence of ASR and other degradation processes in concrete, such as those caused by the presence of moisture, water, temperature variations and use of deicing salt during winter, are especially damaging. Based on review of the most relevant literature, this paper is focused on mechanisms and mechanisms factors of the ASR, related contemporary research and reliability design guidelines for CBS that are based on prevention of the initiation and development of ASR.

Quantification of myocardial area at risk in the absence of collateral flow: the validation of angiographic scores by myocardial perfusion single-photon emission computed tomography.

Science.gov (United States)

Rodríguez-Palomares, José F; Alonso, Albert; Martí, Gerard; Aguadé-Bruix, Santiago; González-Alujas, M T; Romero-Farina, Guillermo; Candell-Riera, Jaume; García del Blanco, Bruno; Evangelista, Artur; García-Dorado, David

2013-02-01

Our study aimed to compare the area at risk (AAR) determined by single-photon emission computed tomography (SPECT) with the Bypass Angioplasty Revascularization Investigation (BARI) and modified Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) angiographic scores in the setting of patients undergoing coronary angioplasty for either unstable angina or an STEMI. Radionuclide myocardial perfusion imaging prior to reperfusion has classically been the most widely practised technique for assessing the AAR and has been successfully used to compare the efficacy of various reperfusion strategies in patients with an ST-segment elevation myocardial infarction (STEMI). The BARI and modified APPROACH scores are angiographic methods widely used to provide a rapid estimation of the AAR; however, they have not been directly validated with myocardial perfusion single-photon emission computed tomography (SPECT). Fifty-five patients with no previous myocardial infarction who underwent coronary angioplasty for single-vessel disease (unstable angina: n = 25 or an STEMI: n = 30) with no evidence of collaterals (Rentrop Collateral Score collateral flow, BARI and APPROACH scores constitute valid methods for AAR estimation in current clinical practice, with more accurate results when used for the LAD territory; both are useful not only in STEMI patients but also in patients with unstable angina.

Urban Combat Advanced Training Technology (Technologie avancee d’entrainement au combat urbain)

Science.gov (United States)

2015-07-01

For example, skills and drills (techniques) in an urban environment can be best trained or evaluated in a live environment, because other simulations...evidence as an AAR, and have the required skills to conduct an effective AAR. Some key 0 /C tasks are listed below. The precise tasks will be dependent...improvised “ Helpers ”, breaching material. Demo-Buildings and Showcases Detail of cut-away buildings, set-piece demonstrations and prepared rooms. STO

Loengud seaduseelnõude koostajaile / Margit Kikas

Index Scriptorium Estoniae

Kikas, Margit

2004-01-01

Eesti Juristide Liidu poolt koostöös Riigikantselei ja Justiitsministeeriumiga korraldatud loengusarjast: Õigusloome ja normitehnika: areng ja probleemid. Sõnavõtjad loengutel: Raul Narits, Katre Kont-Kontson, Lauri Mälksoo, Raigo Sõlg, Jüri Heinla, Anno Aedmaa, Aare Kasemets, Juhani Lemmik, Ülo Siivelt, Külli Koit, Aare Reenumägi, Mall Gramberg, Toomas Sepp, Julia Laffranque, Kristel Aguraiuja, Aime Vettik, Hille Saluäär, Hiie Tamm, Kristina Nõgols, Eve Randvere

The growing pipeline of natural aminoacyl-tRNA synthetase inhibitors for malaria treatment

OpenAIRE

Saint-L?ger, Ad?la?de; Sinadinos, Christopher; Ribas de Pouplana, Llu?s

2016-01-01

Malaria remains a major global health problem. Parasite resistance to existing drugs makes development of new antimalarials an urgency. The protein synthesis machinery is an excellent target for the development of new anti-infectives, and aminoacyl-tRNA synthetases (aaRS) have been validated as antimalarial drug targets. However, avoiding the emergence of drug resistance and improving selectivity to target aaRS in apicomplexan parasites, such as Plasmodium falciparum, remain crucial challenge...

FEM Analysis of Sezawa Mode SAW Sensor for VOC Based on CMOS Compatible AlN/SiO2/Si Multilayer Structure

Directory of Open Access Journals (Sweden)

Muhammad Zubair Aslam

2018-05-01

Full Text Available A Finite Element Method (FEM simulation study is conducted, aiming to scrutinize the sensitivity of Sezawa wave mode in a multilayer AlN/SiO2/Si Surface Acoustic Wave (SAW sensor to low concentrations of Volatile Organic Compounds (VOCs, that is, trichloromethane, trichloroethylene, carbon tetrachloride and tetrachloroethene. A Complimentary Metal-Oxide Semiconductor (CMOS compatible AlN/SiO2/Si based multilayer SAW resonator structure is taken into account for this purpose. In this study, first, the influence of AlN and SiO2 layers’ thicknesses over phase velocities and electromechanical coupling coefficients (k2 of two SAW modes (i.e., Rayleigh and Sezawa is analyzed and the optimal thicknesses of AlN and SiO2 layers are opted for best propagation characteristics. Next, the study is further extended to analyze the mass loading effect on resonance frequencies of SAW modes by coating a thin Polyisobutylene (PIB polymer film over the AlN surface. Finally, the sensitivity of the two SAW modes is examined for VOCs. This study concluded that the sensitivity of Sezawa wave mode for 1 ppm of selected volatile organic gases is twice that of the Rayleigh wave mode.

Modelling the tearing crack growth in a ductile ferritic steel using X-FEM elements

International Nuclear Information System (INIS)

Simatos, A.; Prabel, B.; Marie, S.; Nedelec, M.; Combescure, A.

2012-01-01

Extended Finite Element Method (X-FEM) is used to model a cracked structure without meshing explicitly the crack. Indeed, the crack is represented by a discontinuity of the displacement field through additional degrees of freedom using Heaviside type function or derived from the Irwin's singular fields. Initially, the stress integration in the XFEM framework supposed to divide the cut elements into sub-triangles that are conform to the crack. This was motivated in order to integrate the behaviour accurately on both sides of the crack in particular at proximity of the crack tip where singular enrichments are present. This strategy induces field projections from the usual Gauss point configuration to a variable new one that depends on the crack position in the element. For ductile fracture modelization, this approach is not applicable, because in presence of large scale yield, the projection of internal variable fields is not conservative, in particular at proximity of the crack tip. In order to circumvent this problem, a new integration strategy was proposed by B. Prabel. It consists in using 64 Gauss points that are placed without regards to the crack position. This simple integration scheme permits to take implicitly into account the crack position and the fields in the element in an accurate and consistent way. This strategy was used in problem calculation for which the plastic radius remained small. It allowed introducing the over integrated elements in the probable propagation zone, just before plastification. In the case of ductile tearing, the plasticity is not confined near the crack tip and an improvement of the proposed strategy is made. This is then used to model large ductile crack growth in a ductile ferritic steel. To validate the predictions, the modelization is compared to a second F.E. calculation using the node release technique for the crack propagation. It is then shown that the two predictions are strictly equivalents. (authors)

Analysis on the geometrical shape of T-honeycomb structure by finite element method (FEM)

Science.gov (United States)

Zain, Fitri; Rosli, Muhamad Farizuan; Effendi, M. S. M.; Abdullah, Mohamad Hariri

2017-09-01

Geometric in design is much related with our life. Each of the geometrical structure interacts with each other. The overall shape of an object contains other shape inside, and there shapes create a relationship between each other in space. Besides that, how geometry relates to the function of the object have to be considerate. In this project, the main purpose was to design the geometrical shape of modular furniture with the shrinking of Polyethylene Terephthalate (PET) jointing system that has good strength when applied load on it. But, the goal of this paper is focusing on the analysis of Static Cases by FEM of the hexagonal structure to obtain the strength when load apply on it. The review from the existing product has many information and very helpful to finish this paper. This project focuses on hexagonal shape that distributed to become a shelf inspired by honeycomb structure. It is very natural look and simple in shape and its modular structure more easily to separate and combine. The method discusses on chapter methodology are the method used to analysis the strength when the load applied to the structure. The software used to analysis the structure is Finite Element Method from CATIA V5R21 software. Bending test is done on the jointing part between the edges of the hexagonal shape by using Universal Tensile Machine (UTM). The data obtained have been calculate by bending test formulae and sketch the graph between flexural strains versus flexural stress. The material selection of the furniture is focused on wood. There are three different types of wood such as balsa, pine and oak, while the properties of jointing also be mentioned in this thesis. Hence, the design structural for honeycomb shape already have in the market but this design has main objective which has a good strength that can withstand maximum load and offers more potentials in the form of furniture.

Evaluating the effects of consolidation on intrusion and retraction using temporary anchorage devices—a FEM study

Directory of Open Access Journals (Sweden)

Monica Namburi

2017-01-01

Full Text Available Abstract Background Extraction of premolars and retracting the anterior teeth using mini-implants and anterior retraction hooks became advent now a day. In such treatments, consolidation of arches is not done in regular practice. So, the present study is concentrated on effects of consolidation in two implant and three implant combinations of retraction and intrusion. Methods A three-dimensional FEM model of maxillary teeth and periodontal ligament housed in the alveolar bone with the first premolars extracted is generated with appropriate number of elements and nodes. The models were broadly divided into two groups according to the no. of implants. Mini-implants were placed bilaterally between the second premolar and molar at varying heights (7, 10, 13 mm in group I, and along with bilateral implants, an additional mid-implant is placed between the central incisors as group II. Brackets with 0.022 slot were placed on the teeth, 19 × 25 SS wire is placed in the brackets, an anterior retraction hook was placed at 9 mm height, and analysis was done to evaluate the stresses and displacement patterns in consolidation and non-consolidation models. Results The results showed that consolidation of the anterior teeth during intrusion and retraction shows various advantages such as less stresses on the bone, PDL, implant, teeth, and no labial flaring of the anterior teeth and three implant system, i.e., two bilateral implant at 10 mm and a mid-implant at 12 mm between the centrals has shown to be better than other models as bodily movement is observed. Conclusion Consolidation is better than non consolidation during enmasse retraction and intrusion.

Attenuation of alpha2A-adrenergic receptor expression in neonatal rat brain by RNA interference or antisense oligonucleotide reduced anxiety in adulthood.

Science.gov (United States)

Shishkina, G T; Kalinina, T S; Dygalo, N N

2004-01-01

Brain alpha2-adrenergic receptors (alpha2-ARs) have been implicated in the regulation of anxiety, which is associated with stress. Environmental treatments during neonatal development could modulate the level of brain alpha2-AR expression and alter anxiety in adults, suggesting possible involvement of these receptors in early-life programming of anxiety state. The present study was undertaken to determine whether the reduction of the expression of A subtype of these receptors most abundant in the neonatal brain affects anxiety-related behavior in adulthood. We attenuated the expression of alpha2A-ARs during neonatal life by two different sequence specific approaches, antisense technology and RNA interference. Treatment of rats with the antisense oligodeoxynucleotide or short interfering RNA (siRNA) against alpha2A-ARs on the days 2-4 of their life, produced a marked acute decrease in the levels of both alpha2A-AR mRNA and [3H]RX821002 binding sites in the brainstem into which drugs were injected. The decrease of alpha2A-AR expression in the neonatal brainstem influenced the development of this receptor system in the brain regions as evidenced by the increased number of [3H]RX821002 binding sites in the hypothalamus of adult animals with both neonatal alpha2A-AR knockdown treatments; also in the frontal cortex of antisense-treated, and in the hippocampus of siRNA-treated adult rats. These adult animals also demonstrated a decreased anxiety in the elevated plus-maze as evidenced by an increased number of the open arm entries, greater proportion of time spent in the open arms, and more than a two-fold increase in the number of exploratory head dips. The results provide the first evidence that the reduction in the brain expression of a gene encoding for alpha2A-AR during neonatal life led to the long-term neurochemical and behavioral alterations. The data suggests that alterations in the expression of the receptor-specific gene during critical periods of brain

FEM Analyses for T-H-M-M Coupling Processes in Dual-Porosity Rock Mass under Stress Corrosion and Pressure Solution

Directory of Open Access Journals (Sweden)

Yu-Jun Zhang

2012-01-01

Full Text Available The models of stress corrosion and pressure solution established by Yasuhara et al. were introduced into the 2D FEM code of thermo-hydro-mechanical-migratory coupling analysis for dual-porosity medium developed by the authors. Aiming at a hypothetical model for geological disposal of nuclear waste in an unsaturated rock mass from which there is a nuclide leak, two computation conditions were designed. Then the corresponding two-dimensional numerical simulation for the coupled thermo-hydro-mechanical-migratory processes were carried out, and the states of temperatures, rates and magnitudes of aperture closure, pore and fracture pressures, flow velocities, nuclide concentrations and stresses in the rock mass were investigated. The results show: the aperture closure rates caused by stress corrosion are almost six orders higher than those caused by pressure solution, and the two kinds of closure rates climb up and then decline, furthermore tend towards stability; when the effects of stress corrosion and pressure solution are considered, the negative fracture pressures in near field rise very highly; the fracture aperture and porosity are decreases in the case 1, so the relative permeability coefficients reduce, therefore the nuclide concentrations in pore and fracture in this case are higher than those in case 2.

A randomized controlled trial with a Canadian electronic pill dispenser used to measure and improve medication adherence in patients with schizophrenia

OpenAIRE

Stip, Emmanuel; Vincent, Philippe D.; Sablier, Juliette; Guevremont, Catherine; Zhornitsky, Simon; Tranulis, Constantin

2013-01-01

Objective: Medication adherence is extremely important in preventing relapse and lowering symptoms in schizophrenic patients. However, estimates show that nearly half of these patients have poor adherence. The Brief Adherence Rating Scale (BARS) seems to be the most reliable tool assessing adherence in schizophrenia and shows that the antipsychotic adherence ratio (AAR) is about 49.5% in schizophrenia. The aim of the study was to test if an electronic pill dispenser named DoPill® improved AAR...

Thermo-Mechanical Characterization of Friction Stir Spot Welded AA7050 Sheets by Means of Experimental and FEM Analyses.

Science.gov (United States)

D'Urso, Gianluca; Giardini, Claudio

2016-08-11

The present study was carried out to evaluate how the friction stir spot welding (FSSW) process parameters affect the temperature distribution in the welding region, the welding forces and the mechanical properties of the joints. The experimental study was performed by means of a CNC machine tool obtaining FSSW lap joints on AA7050 aluminum alloy plates. Three thermocouples were inserted into the samples to measure the temperatures at different distance from the joint axis during the whole FSSW process. Experiments was repeated varying the process parameters, namely rotational speed, axial feed rate and plunging depth. Axial welding forces were measured during the tests using a piezoelectric load cell, while the mechanical properties of the joints were evaluated by executing shear tests on the specimens. The correlation found between process parameters and joints properties, allowed to identify the best technological window. The data collected during the experiments were used to validate a simulation model of the FSSW process, too. The model was set up using a 2D approach for the simulation of a 3D problem, in order to guarantee a very simple and practical solution for achieving results in a very short time. A specific external routine for the calculation of the thermal energy due to friction acting between pin and sheet was developed. An index for the prediction of the joint mechanical properties using the FEM simulations was finally presented and validated.

Thermo-Mechanical Characterization of Friction Stir Spot Welded AA7050 Sheets by Means of Experimental and FEM Analyses

Directory of Open Access Journals (Sweden)

Gianluca D’Urso

2016-08-01

Full Text Available The present study was carried out to evaluate how the friction stir spot welding (FSSW process parameters affect the temperature distribution in the welding region, the welding forces and the mechanical properties of the joints. The experimental study was performed by means of a CNC machine tool obtaining FSSW lap joints on AA7050 aluminum alloy plates. Three thermocouples were inserted into the samples to measure the temperatures at different distance from the joint axis during the whole FSSW process. Experiments was repeated varying the process parameters, namely rotational speed, axial feed rate and plunging depth. Axial welding forces were measured during the tests using a piezoelectric load cell, while the mechanical properties of the joints were evaluated by executing shear tests on the specimens. The correlation found between process parameters and joints properties, allowed to identify the best technological window. The data collected during the experiments were used to validate a simulation model of the FSSW process, too. The model was set up using a 2D approach for the simulation of a 3D problem, in order to guarantee a very simple and practical solution for achieving results in a very short time. A specific external routine for the calculation of the thermal energy due to friction acting between pin and sheet was developed. An index for the prediction of the joint mechanical properties using the FEM simulations was finally presented and validated.

α(2A)-adrenergic receptors filter parabrachial inputs to the bed nucleus of the stria terminalis.

Science.gov (United States)

Flavin, Stephanie A; Matthews, Robert T; Wang, Qin; Muly, E Chris; Winder, Danny G

2014-07-09

α2-adrenergic receptors (AR) within the bed nucleus of the stria terminalis (BNST) reduce stress-reward interactions in rodent models. In addition to their roles as autoreceptors, BNST α(2A)-ARs suppress glutamatergic transmission. One prominent glutamatergic input to the BNST originates from the parabrachial nucleus (PBN) and consists of asymmetric axosomatic synapses containing calcitonin gene-related peptide (CGRP) and vGluT2. Here we provide immunoelectron microscopic data showing that many asymmetric axosomatic synapses in the BNST contain α(2A)-ARs. Further, we examined optically evoked glutamate release ex vivo in BNST from mice with virally delivered channelrhodopsin2 (ChR2) expression in PBN. In BNST from these animals, ChR2 partially colocalized with CGRP, and activation generated EPSCs in dorsal anterolateral BNST neurons that elicited two cell-type-specific outcomes: (1) feedforward inhibition or (2) an EPSP that elicited firing. We found that the α(2A)-AR agonist guanfacine selectively inhibited this PBN input to the BNST, preferentially reducing the excitatory response in ex vivo mouse brain slices. To begin to assess the overall impact of α(2A)-AR control of this PBN input on BNST excitatory transmission, we used a Thy1-COP4 mouse line with little postsynaptic ChR2 expression nor colocalization of ChR2 with CGRP in the BNST. In slices from these mice, we found that guanfacine enhanced, rather than suppressed, optogenetically initiated excitatory drive in BNST. Thus, our study reveals distinct actions of PBN afferents within the BNST and suggests that α(2A)-AR agonists may filter excitatory transmission in the BNST by inhibiting a component of the PBN input while enhancing the actions of other inputs. Copyright © 2014 the authors 0270-6474/14/349319-13$15.00/0.

Automatic localization of IASLC-defined mediastinal lymph node stations on CT images using fuzzy models

Science.gov (United States)

Matsumoto, Monica M. S.; Beig, Niha G.; Udupa, Jayaram K.; Archer, Steven; Torigian, Drew A.

2014-03-01

Lung cancer is associated with the highest cancer mortality rates among men and women in the United States. The accurate and precise identification of the lymph node stations on computed tomography (CT) images is important for staging disease and potentially for prognosticating outcome in patients with lung cancer, as well as for pretreatment planning and response assessment purposes. To facilitate a standard means of referring to lymph nodes, the International Association for the Study of Lung Cancer (IASLC) has recently proposed a definition of the different lymph node stations and zones in the thorax. However, nodal station identification is typically performed manually by visual assessment in clinical radiology. This approach leaves room for error due to the subjective and potentially ambiguous nature of visual interpretation, and is labor intensive. We present a method of automatically recognizing the mediastinal IASLC-defined lymph node stations by modifying a hierarchical fuzzy modeling approach previously developed for body-wide automatic anatomy recognition (AAR) in medical imagery. Our AAR-lymph node (AAR-LN) system follows the AAR methodology and consists of two steps. In the first step, the various lymph node stations are manually delineated on a set of CT images following the IASLC definitions. These delineations are then used to build a fuzzy hierarchical model of the nodal stations which are considered as 3D objects. In the second step, the stations are automatically located on any given CT image of the thorax by using the hierarchical fuzzy model and object recognition algorithms. Based on 23 data sets used for model building, 22 independent data sets for testing, and 10 lymph node stations, a mean localization accuracy of within 1-6 voxels has been achieved by the AAR-LN system.

The Finite Elements Method (FEM versus traditional Methods (TM, in the estimation of settlement and modulus of soil reaction for foundation slabs design on soils with natural or man-made cavities

Directory of Open Access Journals (Sweden)

Escolano-Sánchez, F.

2015-03-01

Full Text Available Direct foundations with continuous elements, such as slabs, provide more advantages than direct foundations with isolated elements, such as footings, and deep foundations, such as piles, in the case of soil with natural or man-made cavities. The slabs are usually designed by two-dimensional models which show their shape on the plant, on a lineal elastic support, represented by a modulus of soil reaction. Regarding the settlement estimation, the following article compares the Finite Elements Method (FEM versus the classical Method (CM to select the modulus of soil reaction used to design foundations slabs in sensitive soils and sites with possible cavities or collapses. This analysis includes one of these cavities in the design to evaluate the risk of fail.Las cimentaciones directas con elementos continuos «losas», tienen ventajas sobre las cimentaciones directas con elementos aislados «zapatas» y sobre las cimentaciones profundas «pilotes», frente a la presencia de terrenos problemáticos. Las losas se diseñan de forma habitual con modelos bidimensionales que representan su forma en planta, apoyada en un medio elástico y lineal, representado por un módulo de balasto. En el presente artículo se realiza un análisis comparativo, para la estimación de asientos, entre el Método de Elementos Finitos (FEM y el Método Clásico (MC, para la elección de los módulos de balasto que se utilizan en el diseño de losas de cimentación en terrenos con blandones y cavidades naturales o antrópicas. Este análisis considera el peligro de la presencia de una de estas cavidades dentro de su diseño, de esta forma, el riesgo de fallo puede ser valorado por ambos métodos.

Pariisis jagati Cesare / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2006-01-01

Sel aastal sai prantsuse rahvuslike filmiauhindade Cesaride jagamisel kõige enam (8) auhindu J. Audiard'i mängufilm "Mu süda jättis vahele löögi" ("De battre mon coeur s'est arrete"). Näitlejapreemiad said Michel Bouquet, Nathalie Baye

Werner Herzog Tallinnas / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2002-01-01

Detsembris toimuvat Pimedate Ööde Filmifestivali laiendatakse ka suvele, et sobivates paikades näidata väärtfilme. Alates 6. juunist näidatakse Katariina kirikus kuuel õhtul algusega kell 22 Werner Herzogi (1942) filme. Režissöörist ja näidatavatest filmidest

Retrofilm kultusõudukast / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2004-01-01

Mängufilm "Vampiiri vari" ("The Shadow of the Vampire") : režissöör E. Elias Merhige : Ameerika Ühendriigid - Suurbritannia 2000. Inspireerituna samast F.W. Murnau õudusfilmist "Nosferatu, õuduste sümfoonia" (1922), oli ka Werner Herzog loonud 1978.a. filmi "Nosferatu - öö fantoom"

Pattulangemine ja lunastus / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2005-01-01

PÖFFi filme - "Taevane lahing" ("Batalla en el cielo" : režissöör Carlos Reygadas : Mehhiko - Prantsusmaa - Saksamaa - Belgia 2005, "Valede kammitsas" ("Separate Lies") : Nigel Balchini rom. "A Way Through the Wood" järgi režissöör Julian Fellowes : Suurbritannia 2005

Tõeline Crocodile Dundee / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2006-01-01

4. sept. hukkus veealuse dokfilmi võtetel Austraalia loodusuurija, loomakaitsja, telekanali Animal Planet sarja "Krokodillikütt" ("Crocodile Hunter") populaarne autor ja esineja Steve Irwin (1962-2006)

Almodovari esimesed katsetused / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2006-01-01

Pedro Almodovarile tehti ettepanek restaureerida oma esimesi eksperimentaalseid katsetusi "Kaks hoora / Armastuslugu, mis lõpeb pulmadega" (1974), "Seks tuleb, seks läheb" (1977), Soodoma lõpp (1979)

Vabaduse tuuled Ungarist / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2006-01-01

Sõpruse kinos algab homme filmiprogramm "Vabaduse tuuled" Ungari 1956.a. ülestõusule pühendatud mängufilmide programm (6 ungari filmi aastaist 1965-2004) : Ungari Instituudi, kino "Sõprus" ja PÖFFi koostööprojekt

Veebruarikuus 2000 lahkunuid / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2000-01-01

Surid : Autant-Lara, Claude prantsuse režissöör (5.08.1903-5.02.2000), Vadim, Roger ukraina päritolu prantsuse režissöör (26.01.1928-11.02.2000), Kedrova, Lila vene päritolu prantsuse näitlejanna (1918-16.02.2000), Martelli, Otello itaalia filmioperaator (19.05.1903-20.02.2000)

Feodaalne verepulm teleekraanil / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2011-01-01

Alates 8. septembrist Fox Life'i eestikeelsel kanalil jooksma hakkavast George R. R. Martini raamatul põhinevast USA telekanali HBO telesarjast "Troonide mäng" (sarja loojad David Benioff ja Dan Weiss)

Automatic anatomy recognition on CT images with pathology

Science.gov (United States)

Huang, Lidong; Udupa, Jayaram K.; Tong, Yubing; Odhner, Dewey; Torigian, Drew A.

2016-03-01

Body-wide anatomy recognition on CT images with pathology becomes crucial for quantifying body-wide disease burden. This, however, is a challenging problem because various diseases result in various abnormalities of objects such as shape and intensity patterns. We previously developed an automatic anatomy recognition (AAR) system [1] whose applicability was demonstrated on near normal diagnostic CT images in different body regions on 35 organs. The aim of this paper is to investigate strategies for adapting the previous AAR system to diagnostic CT images of patients with various pathologies as a first step toward automated body-wide disease quantification. The AAR approach consists of three main steps - model building, object recognition, and object delineation. In this paper, within the broader AAR framework, we describe a new strategy for object recognition to handle abnormal images. In the model building stage an optimal threshold interval is learned from near-normal training images for each object. This threshold is optimally tuned to the pathological manifestation of the object in the test image. Recognition is performed following a hierarchical representation of the objects. Experimental results for the abdominal body region based on 50 near-normal images used for model building and 20 abnormal images used for object recognition show that object localization accuracy within 2 voxels for liver and spleen and 3 voxels for kidney can be achieved with the new strategy.

Effects of Silodosin and Tamsulosin on the Seminal Vesicle Contractile Response.

Science.gov (United States)

Hayashi, Tokumasa; Takeya, Mitsue; Nakamura, Kei-ichiro; Matsuoka, Kei

2016-01-01

To understand the mechanisms underlying ejaculation dysfunction caused by α1A-adrenocetor (AR) antagonists, the effects of α1A-AR antagonists on the contractile responses of the seminal vesicle were investigated. Isolated seminal vesicles from guinea pigs were cannulated and pressurized, and the changes in the intraluminal pressure were recorded. Periodic applications of electrical stimulation (ES) caused biphasic increase in the intraluminal pressure, that is, initial and subsequent contractions. The effects of silodosin and tamsulosin, α1A-AR antagonists, on the contractile responses were examined. The ES-induced biphasic contractions were blocked by tetrodotoxin (TTX). Silodosin and tamsulosin suppressed the initial contractions in a dose-dependent manner, while also exerting various inhibitory effects on the subsequent contractions. Increases in the intraluminal pressure facilitated spontaneous phasic contractions. The spontaneous contractions were not affected by TTX or α1A-AR antagonists, but were abolished by nifedipine. The initial contractions triggered by neuronal excitations were suppressed by silodosin and tamsulosin, suggesting that the ejaculation dysfunction may be attributed to the α1A-AR antagonist-mediated suppression of nerve-evoked contractions in the seminal vesicle. The subsequent contractions may be induced by mechanical stimulation associated with the initial, nerve-evoked contractions. Alternatively, other transmitters may be involved to various degrees in the neuromuscular transmission of the seminal vesicle. © 2014 Wiley Publishing Asia Pty Ltd.

Backbone Brackets and Arginine Tweezers delineate Class I and Class II aminoacyl tRNA synthetases

Science.gov (United States)

Haupt, V. Joachim; Schroeder, Michael; Labudde, Dirk

2018-01-01

The origin of the machinery that realizes protein biosynthesis in all organisms is still unclear. One key component of this machinery are aminoacyl tRNA synthetases (aaRS), which ligate tRNAs to amino acids while consuming ATP. Sequence analyses revealed that these enzymes can be divided into two complementary classes. Both classes differ significantly on a sequence and structural level, feature different reaction mechanisms, and occur in diverse oligomerization states. The one unifying aspect of both classes is their function of binding ATP. We identified Backbone Brackets and Arginine Tweezers as most compact ATP binding motifs characteristic for each Class. Geometric analysis shows a structural rearrangement of the Backbone Brackets upon ATP binding, indicating a general mechanism of all Class I structures. Regarding the origin of aaRS, the Rodin-Ohno hypothesis states that the peculiar nature of the two aaRS classes is the result of their primordial forms, called Protozymes, being encoded on opposite strands of the same gene. Backbone Brackets and Arginine Tweezers were traced back to the proposed Protozymes and their more efficient successors, the Urzymes. Both structural motifs can be observed as pairs of residues in contemporary structures and it seems that the time of their addition, indicated by their placement in the ancient aaRS, coincides with the evolutionary trace of Proto- and Urzymes. PMID:29659563

Validation of Contrast Enhanced Cine Steady-State Free Precession and T2-Weigthed CMR for Assessment of Ischemic Myocardial Area- At-Risk

DEFF Research Database (Denmark)

Søvsø Szocska Hansen, Esben; Pedersen, Steen Fjord; Pedersen, Steen Bønløkke

2017-01-01

-CINE) has recently been used to quantify AAR and validated against myocardial perfusion SPECT. In this study we sought to determine how well T2-STIR and CE-CINE depicts AAR in an experimental porcine model of myocardial ischemia-reperfusion injury using histopathology as the reference for infarct size......Measuring myocardial salvage is important to evaluate the possible cardioprotective effects of adjunctive cardioprotective intervention in patients with myocardial infarction undergoing primary percutaneous intervention. Contrast-enhanced steady-state free precession magnetic resonance imaging (CE...

A Flexible Method for Producing F.E.M. Analysis of Bone Using Open-Source Software

Science.gov (United States)

Boppana, Abhishektha; Sefcik, Ryan; Meyers, Jerry G.; Lewandowski, Beth E.

2016-01-01

This project, performed in support of the NASA GRC Space Academy summer program, sought to develop an open-source workflow methodology that segmented medical image data, created a 3D model from the segmented data, and prepared the model for finite-element analysis. In an initial step, a technological survey evaluated the performance of various existing open-source software that claim to perform these tasks. However, the survey concluded that no single software exhibited the wide array of functionality required for the potential NASA application in the area of bone, muscle and bio fluidic studies. As a result, development of a series of Python scripts provided the bridging mechanism to address the shortcomings of the available open source tools. The implementation of the VTK library provided the most quick and effective means of segmenting regions of interest from the medical images; it allowed for the export of a 3D model by using the marching cubes algorithm to build a surface mesh. To facilitate the development of the model domain from this extracted information required a surface mesh to be processed in the open-source software packages Blender and Gmsh. The Preview program of the FEBio suite proved to be sufficient for volume filling the model with an unstructured mesh and preparing boundaries specifications for finite element analysis. To fully allow FEM modeling, an in house developed Python script allowed assignment of material properties on an element by element basis by performing a weighted interpolation of voxel intensity of the parent medical image correlated to published information of image intensity to material properties, such as ash density. A graphical user interface combined the Python scripts and other software into a user friendly interface. The work using Python scripts provides a potential alternative to expensive commercial software and inadequate, limited open-source freeware programs for the creation of 3D computational models. More work

Opportunities Missed: A Cross-Sectional Survey of the Provision of Smoking Cessation Care to Pregnant Women by Australian General Practitioners and Obstetricians.

Science.gov (United States)

Zeev, Yael Bar; Bonevski, Billie; Twyman, Laura; Watt, Kerrianne; Atkins, Lou; Palazzi, Kerrin; Oldmeadow, Christopher; Gould, Gillian S

2017-05-01

Similar to other high-income countries, smoking rates in pregnancy can be high in specific vulnerable groups in Australia. Several clinical guidelines exist, including the 5A's (Ask, Advice, Assess, Assist, and Arrange), ABCD (Ask, Brief advice, Cessation, and Discuss), and AAR (Ask, Advice, and Refer). There is lack of data on provision of smoking cessation care (SCC) of Australian General Practitioners (GPs) and Obstetricians. A cross-sectional survey explored the provision of SCC, barriers and enablers using the Theoretical Domains Framework, and the associations between them. Two samples were invited: (1) GPs and Obstetricians from a college database (n = 5571); (2) GPs from a special interest group for Indigenous health (n = 500). Dimension reduction for the Theoretical Domains Framework was achieved with factor analysis. Logistic regression was carried out for performing all the 5A's and the AAR. Performing all of the 5A's, ABCD, and AAR "often and always" was reported by 19.9%, 15.6%, and 49.2% respectively. "Internal influences" (such as confidence in counselling) were associated with higher performance of the 5A's (Adjusted OR 2.69 (95% CI 1.5, 4.8), p workplace routine) were associated with higher performance of AAR (Adjusted OR 1.7 (95% CI 1, 2.8), p = .035). Performance in providing SCC to pregnant women is low among Australian GPs and Obstetricians. Training clinicians should focus on improving internal influences such as confidence and optimism. The AAR may be easier to implement, and interventions at the service level should focus on ensuring easy, effective, and acceptable referral mechanisms are in place. Improving provision of the 5A's approach should focus on the individual level, including better training for GPs and Obstetricians, designed to improve specific "internal" barriers such as confidence in counselling and optimism. The AAR may be easier to implement in view of the higher overall performance of this approach. Interventions on a more

Study of a Steel’s Energy Absorption System for Heavy Quadricycles and Nonlinear Explicit Dynamic Analysis of its Behavior under Impact by FEM

Directory of Open Access Journals (Sweden)

José Ángel López Campos

2015-10-01

Full Text Available Current knowledge of the behavior of heavy quadricycles under impact is still very poor. One of the most significant causes is the lack of energy absorption in the vehicle frame or its steel chassis structure. For this reason, special steels (with yield stresses equal to or greater than 350 MPa are commonly used in the automotive industry due to their great strain hardening properties along the plastic zone, which allows good energy absorption under impact. This paper presents a proposal for a steel quadricycle energy absorption system which meets the percentages of energy absorption for conventional vehicles systems. This proposal is validated by explicit dynamics simulation, which will define the whole problem mathematically and verify behavior under impact at speeds of 40 km/h and 56 km/h using the finite element method (FEM. One of the main consequences of this study is that this FEM–based methodology can tackle high nonlinear problems like this one with success, avoiding the need to carry out experimental tests, with consequent economical savings since experimental tests are very expensive. Finally, the conclusions from this innovative research work are given.

Study of a Steel’s Energy Absorption System for Heavy Quadricycles and Nonlinear Explicit Dynamic Analysis of its Behavior under Impact by FEM

Science.gov (United States)

López Campos, José Ángel; Segade Robleda, Abraham; Vilán Vilán, José Antonio; García Nieto, Paulino José; Blanco Cordero, Javier

2015-01-01

Current knowledge of the behavior of heavy quadricycles under impact is still very poor. One of the most significant causes is the lack of energy absorption in the vehicle frame or its steel chassis structure. For this reason, special steels (with yield stresses equal to or greater than 350 MPa) are commonly used in the automotive industry due to their great strain hardening properties along the plastic zone, which allows good energy absorption under impact. This paper presents a proposal for a steel quadricycle energy absorption system which meets the percentages of energy absorption for conventional vehicles systems. This proposal is validated by explicit dynamics simulation, which will define the whole problem mathematically and verify behavior under impact at speeds of 40 km/h and 56 km/h using the finite element method (FEM). One of the main consequences of this study is that this FEM–based methodology can tackle high nonlinear problems like this one with success, avoiding the need to carry out experimental tests, with consequent economical savings since experimental tests are very expensive. Finally, the conclusions from this innovative research work are given. PMID:28793607

Molecular epidemiology of Staphylococcus spp. contamination in the ward environment: study on mecA and femA genes in methicillin-resistant strains.

Science.gov (United States)

Ashimoto, A; Hamada, T; Adachi, A; Tanigawa, T; Tanaka, Y

1995-01-01

Staphylococcus spp. were isolated from the ward environment and antibiotic susceptibility tests were performed. Twenty-nine strains out of 274 isolates were S. aureus, and 41.4% of the S. aureus strains were methicillin resistant (MRSA). All 12 strains of MRSA were also resistant to oxacillin, ceftizoxime, ampicillin and clindamycin. Among the coagulase-negative staphylococci (CNS), methicillin-resistant (MR) strains of S. epidermidis, S. capitis, S. warneri, S. haemolyticus, S. hominis, S. auricularis, S. saprophyticus and S. cohnii were isolated. Eight of the 10 S. Haemolyticus strains were methicillin resistant. The femA gene was detected in S. aureus (MSSA and MRSA), but not in CNS by polymerase chain reaction (PCR) analysis and Southern blot analysis. The mecA gene was found in all the MRSA and MR-S. epidermidis strains tested, and one of the two MR-S. hominis strains, but not in MSSA, MS-S. epidermidis, MS-S. hominis, or MS-S. haemolyticus. DNA from one strain of MR-S. hominis and 2 strains of MR-S. haemolyticus was not amplified by PCR using the mecA gene primer, or hybridized by Southern blotting. The ambiguity that mecA was detected in some MR-CNS strains, but not in others is discussed.

Insulin-increased L-arginine transport requires A(2A adenosine receptors activation in human umbilical vein endothelium.

Directory of Open Access Journals (Sweden)

Enrique Guzmán-Gutiérrez

Full Text Available Adenosine causes vasodilation of human placenta vasculature by increasing the transport of arginine via cationic amino acid transporters 1 (hCAT-1. This process involves the activation of A(2A adenosine receptors (A(2AAR in human umbilical vein endothelial cells (HUVECs. Insulin increases hCAT-1 activity and expression in HUVECs, and A(2AAR stimulation increases insulin sensitivity in subjects with insulin resistance. However, whether A(2AAR plays a role in insulin-mediated increase in L-arginine transport in HUVECs is unknown. To determine this, we first assayed the kinetics of saturable L-arginine transport (1 minute, 37°C in the absence or presence of nitrobenzylthioinosine (NBTI, 10 µmol/L, adenosine transport inhibitor and/or adenosine receptors agonist/antagonists. We also determined hCAT-1 protein and mRNA expression levels (Western blots and quantitative PCR, and SLC7A1 (for hCAT-1 reporter promoter activity. Insulin and NBTI increased the extracellular adenosine concentration, the maximal velocity for L-arginine transport without altering the apparent K(m for L-arginine transport, hCAT-1 protein and mRNA expression levels, and SLC7A1 transcriptional activity. An A2AAR antagonist ZM-241385 blocked these effects. ZM241385 inhibited SLC7A1 reporter transcriptional activity to the same extent in cells transfected with pGL3-hCAT-1(-1606 or pGL3-hCAT-1(-650 constructs in the presence of NBTI + insulin. However, SLC7A1 reporter activity was increased by NBTI only in cells transfected with pGL3-hCAT-1(-1606, and the ZM-241385 sensitive fraction of the NBTI response was similar in the absence or in the presence of insulin. Thus, insulin modulation of hCAT-1 expression and activity requires functional A(2AAR in HUVECs, a mechanism that may be applicable to diseases associated with fetal insulin resistance, such as gestational diabetes.

Effects of α2A Adrenoceptors on Norepinephrine Secretion from the Locus Coeruleus during Chronic Stress-Induced Depression

Directory of Open Access Journals (Sweden)

Hong-ping Huang

2017-05-01

Full Text Available Chronic stressors can often lead to the development of psychological disorders, such as depression and anxiety. The locus coeruleus (LC is a stress sensitive brain region located in the pons, with noradrenergic neurons that project to the hypothalamus, especially the paraventricular nucleus (PVN of the hypothalamus. The purpose of this paper is to better understand how alpha 2A-adrenoceptors (α2A-ARs and LC-hypothalamus noradrenergic system participate in the pathophysiological mechanism of depression. In vivo norepinephrine (NE release in the PVN triggered by electrical stimulation in the LC was detected with carbon fiber electrodes in depression model of rats induced by chronic unpredictable mild stress (CUMS. Also, the extracellular level of NE in the PVN was measured by microdialysis in vivo without any stimulation in the LC. The alpha 2-adrenoceptor (α2-AR antagonist yohimbine and α2A-ARs antagonist BRL-44408 maleate were systemically administered to rats to determine the effects of α2A-ARs on NE release in the PVN. The peak value of elicited NE release signals in the PVN induced by electrical stimulation in the LC in the CUMS rats were lower than that in the control rats. The extracellular levels of NE in the PVN of the CUMS rats were significantly less than that of the control rats. Intraperitoneal injection of yohimbine or BRL-44408 maleate significantly potentiated NE release in the PVN of the CUMS rats. The CUMS significantly increased protein expression levels of α2A-AR in the hypothalamus, and BRL-44408 maleate significantly reversed the increase of α2A-AR protein expression levels in the CUMS rats. Our results suggest that the CUMS could significantly facilitate the effect of α2-adrenoceptor-mediated presynaptic inhibition and decrease the release of NE in the PVN from LC. Blockade of the inhibitory action of excessive α2A-adrenergic receptors in the CUMS rats could increase the level of NE in the PVN, which is effective in

Aare Anderson : Elva-taoline väikelinn on parimaid kohti elamiseks / Aare Anderson ; interv. Mare Nõmmik

Index Scriptorium Estoniae

Anderson, Aare, 1966-

2006-01-01

Elva endine linnapea ja aselinnapea, rahandusministeeriumi töötaja vastab küsimustele, mis on seotud tema ametikohaga, Elvaga, võimalusega siduda end tulevikus poliitikaga. Isamaa ja Res Publica Liidu loosungist "Õnn ei ole rahas"

Automated Aerial Refueling Hitches a Ride on AFF

Science.gov (United States)

Hansen, Jennifer L.; Murray, James E.; Bever, Glenn; Campos, Norma V.; Schkolnik, Gerard

2007-01-01

The recent introduction of uninhabited aerial vehicles [UAVs (basically, remotely piloted or autonomous aircraft)] has spawned new developments in autonomous operation and posed new challenges. Automated aerial refueling (AAR) is a capability that will enable UAVs to travel greater distances and loiter longer over targets. NASA Dryden Flight Research Center, in cooperation with the Defense Advanced Research Projects Agency (DARPA), the Naval Air Systems Command (NAVAIR), the Naval Air Force Pacific Fleet, and the Air Force Research Laboratory, rapidly conceived and accomplished an AAR flight research project focused on collecting a unique, high-quality database on the dynamics of the hose and drogue of an aerial refueling system. This flight-derived database would be used to validate mathematical models of the dynamics in support of design and analysis of AAR systems for future UAVs. The project involved the use of two Dryden F/A-18 airplanes and an S-3 hose-drogue refueling store on loan from the Navy. In this year-long project, which was started on October 1, 2002, 583 research maneuvers were completed during 23 flights.

Finite element flow analysis; Proceedings of the Fourth International Symposium on Finite Element Methods in Flow Problems, Chuo University, Tokyo, Japan, July 26-29, 1982

Science.gov (United States)

Kawai, T.

Among the topics discussed are the application of FEM to nonlinear free surface flow, Navier-Stokes shallow water wave equations, incompressible viscous flows and weather prediction, the mathematical analysis and characteristics of FEM, penalty function FEM, convective, viscous, and high Reynolds number FEM analyses, the solution of time-dependent, three-dimensional and incompressible Navier-Stokes equations, turbulent boundary layer flow, FEM modeling of environmental problems over complex terrain, and FEM's application to thermal convection problems and to the flow of polymeric materials in injection molding processes. Also covered are FEMs for compressible flows, including boundary layer flows and transonic flows, hybrid element approaches for wave hydrodynamic loadings, FEM acoustic field analyses, and FEM treatment of free surface flow, shallow water flow, seepage flow, and sediment transport. Boundary element methods and FEM computational technique topics are also discussed. For individual items see A84-25834 to A84-25896

Anomalous rostral lumbosacral root emergence from the thecal sac

International Nuclear Information System (INIS)

Peyster, R.G.; Parghi, A.; Siegal, T.; Hershey, B.L.; Yablon, J.; Jaffe, S.

1989-01-01

Anomalous rostral lumbosacral root emergence (AARE) has important clinical implications and has received little attention. The authors have studied the occurrence of this anomaly and presentation of cases in which it was paramount in causing radiculopathy. AARE was noted with the following occurrence rates in 500 cases: L3, 0%; L4, 1%; L5, 9%, and S1, 16%. In ARRE, the roots lie laterally between the superior facet and the annulus and are subject to compression by minimal disk bulging or facet hypertrophy. One must track the individual nerve roots on lumbar CT and MR imaging to detect this subtle condition

Script Identification from Printed Indian Document Images and Performance Evaluation Using Different Classifiers

Directory of Open Access Journals (Sweden)

Sk Md Obaidullah

2014-01-01

multiscript country like India. In this paper the real life problem of printed script identification from official Indian document images is considered and performances of different well-known classifiers are evaluated. Two important evaluating parameters, namely, AAR (average accuracy rate and MBT (model building time, are computed for this performance analysis. Experiment was carried out on 459 printed document images with 5-fold cross-validation. Simple Logistic model shows highest AAR of 98.9% among all. BayesNet and Random Forest model have average accuracy rate of 96.7% and 98.2% correspondingly with lowest MBT of 0.09 s.

Accelerator assisted repositories, technical issue identification and economic assessment

Energy Technology Data Exchange (ETDEWEB)

Myers, T.; Favale, A.; Berwald, D. [Northrop Grumman Corp., Bethpage, NY (United States)

1995-12-31

An investigation (technical and economic) is presented to quantify the impact of accelerator assisted repository (AAR) system on the US national nuclear repository strategy. An overview of US spent fuel policy is presented which provides a means to comparatively assess competing spent fuel disposition technologies under investigation. The advantages of an AAR system are highlighted and discussed. A companion economic analysis is presented. The results indicate that although a US geologic waste repository will continue to be required, waste partitioning and accelerator transmutation of selected actinides, and long-lived fission products, can result in substantial benefits. (author) 18 refs.

Theoretical investigations into the influence of the position of a breaking line on the tensile failure of flat, round, bevel-edged tablets using finite element methodology (FEM) and its practical relevance for industrial tablet strength testing.

Science.gov (United States)

Podczeck, Fridrun; Newton, J Michael; Fromme, Paul

2014-12-30

Flat, round tablets may have a breaking ("score") line. Pharmacopoeial tablet breaking load tests are diametral in their design, and industrially used breaking load testers often have automatic tablet feeding systems, which position the tablets between the loading platens of the machine with the breaking lines in random orientation to the applied load. The aim of this work was to ascertain the influence of the position of the breaking line in a diametral compression test using finite element methodology (FEM) and to compare the theoretical results with practical findings using commercially produced bevel-edged, scored tablets. Breaking line test positions at an angle of 0°, 22.5°, 45°, 67.5° and 90° relative to the loading plane were studied. FEM results obtained for fully elastic and elasto-plastic tablets were fairly similar, but they highlighted large differences in stress distributions depending on the position of the breaking line. The stress values at failure were predicted to be similar for tablets tested at an angle of 45° or above, whereas at lower test angles the predicted breaking loads were up to three times larger. The stress distributions suggested that not all breaking line angles would result in clean tensile failure. Practical results, however, did not confirm the differences in the predicted breaking loads, but they confirmed differences in the way tablets broke. The results suggest that it is not advisable to convert breaking loads obtained on scored tablets into tablet tensile strength values, and comparisons between different tablets or batches should carefully consider the orientation of the breaking line with respect to the loading plane, as the failure mechanisms appear to vary. Copyright © 2014 Elsevier B.V. All rights reserved.

Study on the influence of finite element formulation and equation of motion solution scheme on FEM analysis results based on the asymmetrically loaded plate problem

Directory of Open Access Journals (Sweden)

Marcin Krzeszowiec

2015-03-01

Full Text Available Computer simulations of physical phenomena are at the moment common both in science and industry. The possibility of finding approximate solutions for complicated systems of differential equations, mathematically describing issues in the fields of mechanics, physics or chemistry, allows for shorten design and research time, often significantly reducing the need for expensive experimental studies or costly production of prototypes. However, the mentioned prevalence of these methods, particularly the Finite Element Method, resulted in analysis outcomes to be often in advance regarded as accurate ones. The purpose of the article is to showcase, on a simple stress analysis problem, how parameters such as the density of the finite element mesh, finite element formulation or integration scheme significantly influence on the simulation results and how easy it is to end up with the results that do not hold any physical sense, despite the fact that all the basic assumptions of correct analysis (suitable boundary conditions, total system energy stored etc. have been met. The results of this study can serve as a warning against premature conclusion drawing from calculations carried out by means of FEM simulation.[b]Keywords[/b]: computational mechanics, finite element method, shell elements, numerical integration

Meshless Local Petrov-Galerkin Method for Solving Contact, Impact and Penetration Problems

Science.gov (United States)

2006-11-30

as the residual forces to the FEM domain, denoted as pFEM ≡ −pSGBEMu on SI in Fig. 2(c), re-solve the FEM problem and obtain the traction pSGBEMc on...crack surfaces SSGBEMc . 4. Repeat steps 2 and 3 until the residual load pFEM is small enough. 5. By adding the SGBEM solution to the FEM one, the...the given traction on St , we have pFEM = p and pSGBEM = 0 and get pOrg = pFEM + pSGBEM = p on St (21) ii) for the given displacement on Su, the SGBEM

FEM modeling and histological analyses on thermal damage induced in facial skin resurfacing procedure with different CO2 laser pulse duration

Science.gov (United States)

Rossi, Francesca; Zingoni, Tiziano; Di Cicco, Emiliano; Manetti, Leonardo; Pini, Roberto; Fortuna, Damiano

2011-07-01

Laser light is nowadays routinely used in the aesthetic treatments of facial skin, such as in laser rejuvenation, scar removal etc. The induced thermal damage may be varied by setting different laser parameters, in order to obtain a particular aesthetic result. In this work, it is proposed a theoretical study on the induced thermal damage in the deep tissue, by considering different laser pulse duration. The study is based on the Finite Element Method (FEM): a bidimensional model of the facial skin is depicted in axial symmetry, considering the different skin structures and their different optical and thermal parameters; the conversion of laser light into thermal energy is modeled by the bio-heat equation. The light source is a CO2 laser, with different pulse durations. The model enabled to study the thermal damage induced into the skin, by calculating the Arrhenius integral. The post-processing results enabled to study in space and time the temperature dynamics induced in the facial skin, to study the eventual cumulative effects of subsequent laser pulses and to optimize the procedure for applications in dermatological surgery. The calculated data where then validated in an experimental measurement session, performed in a sheep animal model. Histological analyses were performed on the treated tissues, evidencing the spatial distribution and the entity of the thermal damage in the collageneous tissue. Modeling and experimental results were in good agreement, and they were used to design a new optimized laser based skin resurfacing procedure.

Saaremaa Fond turgutab õppureid / Aare Laine

Index Scriptorium Estoniae

Laine, Aare, 1951-

2012-01-01

Saaremaa Fond andis kõrgkoolides häid õpitulemusi näidanud ja pere kõrvalt õppivatele tudengitele üle aastastipendiumid. Õppiva pere stipendium: Viljandi kultuuriakadeemias rahvuslikku käsitööd õppiv Alliki Oidekivi, Tallinna ülikoolis 2. kursusel kutsepedagoogikat õppiv Ahti Paju ning Tallinna ülikoolis magistriõppes haridustehnoloogiat õppiv Irena Sink. Peeter Palu nimeline stipendium: Eesti mereakadeemia tüürimehe eriala 2. kursuse tudengile Ott Kuusele. Tallinna Sadama nimelise stipendium: mereakadeemias tüürimehe eriala õppiv Dmitri Mišin

Poeetilisest mõõtmest / Aare Pilv

Index Scriptorium Estoniae

Pilv, Aare, 1976-

2016-01-01

Luule tõlkimisest, selgitades mõistet "poeetiline mõõde". Artikli teises pooles käsitletakse ka sama keeleruumi klassikaliste luuletuste tõlkimist tänapäeva keelde, kasutades Aleksandr Puškini luuletuse "A. P. Kernile" näidet

Digitaalallkirja seadus saab sisu / Aare Reivart

Index Scriptorium Estoniae

Reivart, Aare, 1968-

2000-01-01

Sideoperaatorid ja pangad hakkavad välja töötama ühtset avalikku võtme infrastruktuuri (PKI), mis võimaldab telefoni ja interneti vahendusel kasutada mitmesuguseid teenuseid kiiresti ja turvaliselt

Poola teadlane uurib kraatrit / Aare Laine

Index Scriptorium Estoniae

Laine, Aare, 1951-

2004-01-01

Poznani ülikooli geoloogiainstituudi direktor Wojciech Stankowaki koos tudengitega võtab pinnaseproove edasiseks uurimiseks. Kahe riigi koostöö toimub mõlema riigi teaduste akadeemia ühisprogrammi "Eesti ja Poola meteoriidikraatrite võrdlev uurimine" alusel

Kõik algas tinapanekuga saunas / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2007-01-01

Eldar Rjazanov ja tema aastavahetuse menufilmid. "Saatuse iroonia ehk Hüva leili!" (1975) järjefilm "Saatuse iroonia: lugu läheb edasi" ("Ironija sudbõ. Prodolzhenije") : režissöör Timur Bekmambetov : Venemaa 2007

Avariide kiuste Monte Carlosse / Aare Arula

Index Scriptorium Estoniae

Arula, Aare

2007-01-01

Vt. ka Tehnika dlja Vsehh nr. 3, lk. 26-27. 26. jaanuaril 1937 Tallinnast Monte Carlo tähesõidule startinud Karl Siitanit ja tema meeskonda ootasid ees seiklused, mis oleksid neile peaaegu elu maksnud

Silmatagusest teatrist / Sirle Põdersoo, Aare Pilv

Index Scriptorium Estoniae

Põdersoo, Sirle

2003-01-01

J. Tombergi ja Andreas W "Aurora temporalis" H. Toompere jun lavastuses Tartu Sadamateatris, Lendava Hollandlase ja Tartu Teatrilabori projekt ning "Maja Jaama uulitsas" M. Heinsaare juttude põhjal Tartu Teatrilaboris, projektijuht J. Jaanus, lavastus ja tants T. Mölder, H. Reitsnik, K. Essenson, E. Ülevain, M. Plakso, A. Vamper

Lugu, milles puuduvad kangelased / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2001-01-01

W.M. Thackeray (1811-1863) romaani "Edevuse laat" ekraniseeringutest. Lähemalt Suurbritannias 1998. aastal valminud 6-osalisest teleseriaalist ja selle kesksetest osatäitjatest. Ka : Teleleht nr. 6, lk. 36-38

Ise kaklevad, ise lepivad / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2001-01-01

Mängufilm "Kes kardab Virginia Woolfi?" ("Who's Afraid Of Virginia Woolf?") : stsenarist Ernest Lehman Edward Albee näidendi järgi : režissöör Mike Nichols : Ameerika Ühendriigid 1966. Ka : Teleleht nr. 11, lk.4

Huvitavaid kohtulahendeid kindlustusasjades / Aare-Matti Inglist

Index Scriptorium Estoniae

Inglist, Aare-Matti

2007-01-01

Kindlustushüvitise määramisest tules hävinud elumaja ja koduse vara näitel (Riigikohtu lahendid 3-2-1-155-05 ja 3-21-1-155-06) ning lepinguvälise kahju hüvitamisest liiklusõnnetusjuhtumi näitel (Riigikohtu lahend 3-2-1-81-04)

A Study on the Coupled FEM-Analysis for Reactor Vessel Lower Head of APR1400 under the Severe Accident Scenario

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyonam; Namgung, Ihn [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2014-10-15

For the stabilization of the RPV the in-vessel retention strategy with external reactor vessel cooling (IVR-ERVC) is adopted in APR1400. Under this severe accident condition, a good understanding of the mechanical behavior of the reactor vessel lower head (RVLH) is necessary both for verification of structural integrity and for improving the design applying appropriate accident mitigation strategies. The purpose of this study is to develop the analysis method of the RVLH with thermo-mechanical analysis using FEM tool (ANSYS v.15) in case of core-melting severe accident condition, and then analyze the RVLH of APR1400 including creep behavior. The plastic strain can be the major cause of lower head failure on the reactor vessel, and the creep cannot be not negligible factor of the failure under the severe accident condition. In the study, we applied constant convection coefficient at assumed temperature on the outside wall of RPV and substitute creep data of SA-508. In addition, it was found that the steel ablation at the interface between corium and vessel steel is not only a thermal phenomenon in the METCOR experiments. Corrosion processes and the formation of eutectics lead to the erosion of the vessel steel at temperatures that are significantly lower than the melting temperature of steel. It called thermo-chemical attack of the corium (corrosion). Reduced wall thickness because of the thermo-chemical effect by corium increase the equivalent plastic strain, and decrease the minimum time to reach 20% creep strain.

Adaptive Aggregation Routing to Reduce Delay for Multi-Layer Wireless Sensor Networks.

Science.gov (United States)

Li, Xujing; Liu, Anfeng; Xie, Mande; Xiong, Neal N; Zeng, Zhiwen; Cai, Zhiping

2018-04-16

The quality of service (QoS) regarding delay, lifetime and reliability is the key to the application of wireless sensor networks (WSNs). Data aggregation is a method to effectively reduce the data transmission volume and improve the lifetime of a network. In the previous study, a common strategy required that data wait in the queue. When the length of the queue is greater than or equal to the predetermined aggregation threshold ( N t ) or the waiting time is equal to the aggregation timer ( T t ), data are forwarded at the expense of an increase in the delay. The primary contributions of the proposed Adaptive Aggregation Routing (AAR) scheme are the following: (a) the senders select the forwarding node dynamically according to the length of the data queue, which effectively reduces the delay. In the AAR scheme, the senders send data to the nodes with a long data queue. The advantages are that first, the nodes with a long data queue need a small amount of data to perform aggregation; therefore, the transmitted data can be fully utilized to make these nodes aggregate. Second, this scheme balances the aggregating and data sending load; thus, the lifetime increases. (b) An improved AAR scheme is proposed to improve the QoS. The aggregation deadline ( T t ) and the aggregation threshold ( N t ) are dynamically changed in the network. In WSNs, nodes far from the sink have residual energy because these nodes transmit less data than the other nodes. In the improved AAR scheme, the nodes far from the sink have a small value of T t and N t to reduce delay, and the nodes near the sink are set to a large value of T t and N t to reduce energy consumption. Thus, the end to end delay is reduced, a longer lifetime is achieved, and the residual energy is fully used. Simulation results demonstrate that compared with the previous scheme, the performance of the AAR scheme is improved. This scheme reduces the delay by 14.91%, improves the lifetime by 30.91%, and increases energy

Adaptive Aggregation Routing to Reduce Delay for Multi-Layer Wireless Sensor Networks

Directory of Open Access Journals (Sweden)

Xujing Li

2018-04-01

Full Text Available The quality of service (QoS regarding delay, lifetime and reliability is the key to the application of wireless sensor networks (WSNs. Data aggregation is a method to effectively reduce the data transmission volume and improve the lifetime of a network. In the previous study, a common strategy required that data wait in the queue. When the length of the queue is greater than or equal to the predetermined aggregation threshold ( N t or the waiting time is equal to the aggregation timer ( T t , data are forwarded at the expense of an increase in the delay. The primary contributions of the proposed Adaptive Aggregation Routing (AAR scheme are the following: (a the senders select the forwarding node dynamically according to the length of the data queue, which effectively reduces the delay. In the AAR scheme, the senders send data to the nodes with a long data queue. The advantages are that first, the nodes with a long data queue need a small amount of data to perform aggregation; therefore, the transmitted data can be fully utilized to make these nodes aggregate. Second, this scheme balances the aggregating and data sending load; thus, the lifetime increases. (b An improved AAR scheme is proposed to improve the QoS. The aggregation deadline ( T t and the aggregation threshold ( N t are dynamically changed in the network. In WSNs, nodes far from the sink have residual energy because these nodes transmit less data than the other nodes. In the improved AAR scheme, the nodes far from the sink have a small value of T t and N t to reduce delay, and the nodes near the sink are set to a large value of T t and N t to reduce energy consumption. Thus, the end to end delay is reduced, a longer lifetime is achieved, and the residual energy is fully used. Simulation results demonstrate that compared with the previous scheme, the performance of the AAR scheme is improved. This scheme reduces the delay by 14.91%, improves the lifetime by 30.91%, and increases

GPS navigation algorithms for Autonomous Airborne Refueling of Unmanned Air Vehicles

Science.gov (United States)

Khanafseh, Samer Mahmoud

Unmanned Air Vehicles (UAVs) have recently generated great interest because of their potential to perform hazardous missions without risking loss of life. If autonomous airborne refueling is possible for UAVs, mission range and endurance will be greatly enhanced. However, concerns about UAV-tanker proximity, dynamic mobility and safety demand that the relative navigation system meets stringent requirements on accuracy, integrity, and continuity. In response, this research focuses on developing high-performance GPS-based navigation architectures for Autonomous Airborne Refueling (AAR) of UAVs. The AAR mission is unique because of the potentially severe sky blockage introduced by the tanker. To address this issue, a high-fidelity dynamic sky blockage model was developed and experimentally validated. In addition, robust carrier phase differential GPS navigation algorithms were derived, including a new method for high-integrity reacquisition of carrier cycle ambiguities for recently-blocked satellites. In order to evaluate navigation performance, world-wide global availability and sensitivity covariance analyses were conducted. The new navigation algorithms were shown to be sufficient for turn-free scenarios, but improvement in performance was necessary to meet the difficult requirements for a general refueling mission with banked turns. Therefore, several innovative methods were pursued to enhance navigation performance. First, a new theoretical approach was developed to quantify the position-domain integrity risk in cycle ambiguity resolution problems. A mechanism to implement this method with partially-fixed cycle ambiguity vectors was derived, and it was used to define tight upper bounds on AAR navigation integrity risk. A second method, where a new algorithm for optimal fusion of measurements from multiple antennas was developed, was used to improve satellite coverage in poor visibility environments such as in AAR. Finally, methods for using data-link extracted

Salivary alpha amylase in on-call from home fire and emergency service personnel

Directory of Open Access Journals (Sweden)

Sarah J Hall

2017-10-01

Full Text Available The effect of working on-call from home on the sympatho-adrenal medullary system activity is currently unknown. This study had two aims, Aim 1: examine salivary alpha amylase awakening response (AAR and diurnal salivary alpha amylase (sAA profile in fire and emergency service workers who operate on-call from home following a night on-call with a call (NIGHT-CALL, a night on-call without a call (NO-CALL and an off-call night (OFF-CALL, and Aim 2: explore whether there was an anticipatory effect of working on-call from home (ON compared to when there was an off-call (OFF on the diurnal sAA profile. Participants wore activity monitors, completed sleep and work diaries and collected seven saliva samples a day for one week. AAR area under the curve with respect to ground (AUCG, AAR area under the curve with respect to increase (AUCI, AAR reactivity, diurnal sAA slope, diurnal sAA AUCG and mean 12-h sAA concentrations were calculated. Separate generalised estimating equation models were constructed for each variable of interest for each aim. For Aim 1, there were no differences between NIGHT-CALL or NO-CALL and OFF-CALL for any response variable. For Aim 2, there was no difference between any response variable of interest when ON the following night compared to when OFF the following night (n = 14. These findings suggest that there is no effect of working on-call from home on sAA, but should be interpreted with caution, as overnight data were not collected. Future research, using overnight heart rate monitoring, could help confirm these findings.

Alpha1a-Adrenoceptor Genetic Variant Triggers Vascular Smooth Muscle Cell Hyperproliferation and Agonist Induced Hypertrophy via EGFR Transactivation Pathway.

Directory of Open Access Journals (Sweden)

Irina Gradinaru

Full Text Available α1a Adrenergic receptors (α1aARs are the predominant AR subtype in human vascular smooth muscle cells (SMCs. α1aARs in resistance vessels are crucial in the control of blood pressure, yet the impact of naturally occurring human α1aAR genetic variants in cardiovascular disorders remains poorly understood. To this end, we present novel findings demonstrating that 3D cultures of vascular SMCs expressing human α1aAR-247R (247R genetic variant demonstrate significantly increased SMC contractility compared with cells expressing the α1aAR-WT (WT receptor. Stable expression of 247R genetic variant also triggers MMP/EGFR-transactivation dependent serum- and agonist-independent (constitutive hyperproliferation and agonist-dependent hypertrophy of SMCs. Agonist stimulation reduces contractility Using pathway-specific inhibitors we determined that the observed hyperproliferation of 247R-expressing cells is triggered via β-arrestin1/Src/MMP-2/EGFR/ERK-dependent mechanism. MMP-2-specific siRNA inhibited 247R-triggered hyperproliferation indicating MMP-2 involvement in 247R-triggered hyperproliferation in SMCs. β-arrestin1-specific shRNA also inhibited 247R-triggered hyperproliferation but did not affect hypertrophy in 247R-expressing SMCs, indicating that agonist-dependent hypertrophy is independent of β-arrestin1. Our data reveal that in different cardiovascular cells the same human receptor genetic variant can activate alternative modulators of the same signaling pathway. Thus, our findings in SMCs demonstrate that depending on the type of cells expressing the same receptor (or receptor variant, different target-specific inhibitors could be used to modulate aberrant hyperproliferative or hypertrophic pathways in order to restore normal phenotype.

Alanyl-tRNA synthetase mutation in a family with dominant distal hereditary motor neuropathy

Science.gov (United States)

Zhao, Z.; Hashiguchi, A.; Sakiyama, Y.; Okamoto, Y.; Tokunaga, S.; Zhu, L.; Shen, H.; Takashima, H.

2012-01-01

Objective: To identify a new genetic cause of distal hereditary motor neuropathy (dHMN), which is also known as a variant of Charcot-Marie-Tooth disease (CMT), in a Chinese family. Methods: We investigated a Chinese family with dHMN clinically, electrophysiologically, and genetically. We screened for the mutations of 28 CMT or related pathogenic genes using an originally designed microarray resequencing DNA chip. Results: Investigation of the family history revealed an autosomal dominant transmission pattern. The clinical features of the family included mild weakness and wasting of the distal muscles of the lower limb and foot deformity, without clinical sensory involvement. Electrophysiologic studies revealed motor neuropathy. MRI of the lower limbs showed accentuated fatty infiltration of the gastrocnemius and vastus lateralis muscles. All 4 affected family members had a heterozygous missense mutation c.2677G>A (p.D893N) of alanyl-tRNA synthetase (AARS), which was not found in the 4 unaffected members and control subjects. Conclusion: An AARS mutation caused dHMN in a Chinese family. AARS mutations result in not only a CMT phenotype but also a dHMN phenotype. PMID:22573628

The Discontinuous Galerkin Finite Element Method for Solving the MEG and the Combined MEG/EEG Forward Problem

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Maria Carla Piastra

2018-02-01

Full Text Available In Electro- (EEG and Magnetoencephalography (MEG, one important requirement of source reconstruction is the forward model. The continuous Galerkin finite element method (CG-FEM has become one of the dominant approaches for solving the forward problem over the last decades. Recently, a discontinuous Galerkin FEM (DG-FEM EEG forward approach has been proposed as an alternative to CG-FEM (Engwer et al., 2017. It was shown that DG-FEM preserves the property of conservation of charge and that it can, in certain situations such as the so-called skull leakages, be superior to the standard CG-FEM approach. In this paper, we developed, implemented, and evaluated two DG-FEM approaches for the MEG forward problem, namely a conservative and a non-conservative one. The subtraction approach was used as source model. The validation and evaluation work was done in statistical investigations in multi-layer homogeneous sphere models, where an analytic solution exists, and in a six-compartment realistically shaped head volume conductor model. In agreement with the theory, the conservative DG-FEM approach was found to be superior to the non-conservative DG-FEM implementation. This approach also showed convergence with increasing resolution of the hexahedral meshes. While in the EEG case, in presence of skull leakages, DG-FEM outperformed CG-FEM, in MEG, DG-FEM achieved similar numerical errors as the CG-FEM approach, i.e., skull leakages do not play a role for the MEG modality. In particular, for the finest mesh resolution of 1 mm sources with a distance of 1.59 mm from the brain-CSF surface, DG-FEM yielded mean topographical errors (relative difference measure, RDM% of 1.5% and mean magnitude errors (MAG% of 0.1% for the magnetic field. However, if the goal is a combined source analysis of EEG and MEG data, then it is highly desirable to employ the same forward model for both EEG and MEG data. Based on these results, we conclude that the newly presented

The Discontinuous Galerkin Finite Element Method for Solving the MEG and the Combined MEG/EEG Forward Problem.

Science.gov (United States)

Piastra, Maria Carla; Nüßing, Andreas; Vorwerk, Johannes; Bornfleth, Harald; Oostenveld, Robert; Engwer, Christian; Wolters, Carsten H

2018-01-01

In Electro- (EEG) and Magnetoencephalography (MEG), one important requirement of source reconstruction is the forward model. The continuous Galerkin finite element method (CG-FEM) has become one of the dominant approaches for solving the forward problem over the last decades. Recently, a discontinuous Galerkin FEM (DG-FEM) EEG forward approach has been proposed as an alternative to CG-FEM (Engwer et al., 2017). It was shown that DG-FEM preserves the property of conservation of charge and that it can, in certain situations such as the so-called skull leakages , be superior to the standard CG-FEM approach. In this paper, we developed, implemented, and evaluated two DG-FEM approaches for the MEG forward problem, namely a conservative and a non-conservative one. The subtraction approach was used as source model. The validation and evaluation work was done in statistical investigations in multi-layer homogeneous sphere models, where an analytic solution exists, and in a six-compartment realistically shaped head volume conductor model. In agreement with the theory, the conservative DG-FEM approach was found to be superior to the non-conservative DG-FEM implementation. This approach also showed convergence with increasing resolution of the hexahedral meshes. While in the EEG case, in presence of skull leakages, DG-FEM outperformed CG-FEM, in MEG, DG-FEM achieved similar numerical errors as the CG-FEM approach, i.e., skull leakages do not play a role for the MEG modality. In particular, for the finest mesh resolution of 1 mm sources with a distance of 1.59 mm from the brain-CSF surface, DG-FEM yielded mean topographical errors (relative difference measure, RDM%) of 1.5% and mean magnitude errors (MAG%) of 0.1% for the magnetic field. However, if the goal is a combined source analysis of EEG and MEG data, then it is highly desirable to employ the same forward model for both EEG and MEG data. Based on these results, we conclude that the newly presented conservative DG-FEM

Integrated Battlefield Effects Research for the National Training Center. Appendix E. Requirements Design Specification and Demonstration Report for the Exercise Coordination and Control (ECC) Demonstration System

Science.gov (United States)

1984-12-31

mode 3. Edit AAR mode 4. Run AR mode Each of the modes shall be mutually eclusive. In the real-time mode, the station tactical display shall reflect...periods of the exercise segment. The edit AAR mode shall provide the operator with the capability of creating/ editing a command file for use during an...II .,II IH 0 - hUi I -24 .6d, -I" @ 0 M% A A a a dJ a) 6 I I - -- a’ 1.* % 46- 8 ’ 0 "S 8 -- -- "- - I .-36 aISa "S-a:z:-a I I b 0 Il -- I -- I1 -I

Soft tissue deformation estimation by spatio-temporal Kalman filter finite element method.

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Yarahmadian, Mehran; Zhong, Yongmin; Gu, Chengfan; Shin, Jaehyun

2018-01-01

Soft tissue modeling plays an important role in the development of surgical training simulators as well as in robot-assisted minimally invasive surgeries. It has been known that while the traditional Finite Element Method (FEM) promises the accurate modeling of soft tissue deformation, it still suffers from a slow computational process. This paper presents a Kalman filter finite element method to model soft tissue deformation in real time without sacrificing the traditional FEM accuracy. The proposed method employs the FEM equilibrium equation and formulates it as a filtering process to estimate soft tissue behavior using real-time measurement data. The model is temporally discretized using the Newmark method and further formulated as the system state equation. Simulation results demonstrate that the computational time of KF-FEM is approximately 10 times shorter than the traditional FEM and it is still as accurate as the traditional FEM. The normalized root-mean-square error of the proposed KF-FEM in reference to the traditional FEM is computed as 0.0116. It is concluded that the proposed method significantly improves the computational performance of the traditional FEM without sacrificing FEM accuracy. The proposed method also filters noises involved in system state and measurement data.

An inexpensive underwater mine countermeasures simulator with real-time 3D after action review

Directory of Open Access Journals (Sweden)

Robert Stone

2016-10-01

Full Text Available This paper presents the results of a concept capability demonstration pilot study, the aim of which was to investigate how inexpensive gaming software and hardware technologies could be exploited in the development and evaluation of a simulator prototype for training Royal Navy mine clearance divers, specifically focusing on the detection and accurate reporting of the location and condition of underwater ordnance. The simulator was constructed using the Blender open source 3D modelling toolkit and game engine, and featured not only an interactive 3D editor for underwater scenario generation by instructors, but also a real-time, 3D After Action Review (AAR system for formative assessment and feedback. The simulated scenarios and AAR architecture were based on early human factors observations and briefings conducted at the UK's Defence Diving School (DDS, an organisation that provides basic military diving training for all Royal Navy and Army (Royal Engineers divers. An experimental pilot study was undertaken to determine whether or not basic navigational and mine detection components of diver performance could be improved as a result of exposing participants to the AAR system, delivered between simulated diving scenarios. The results suggest that the provision of AAR was accompanied by significant performance improvements in the positive identification of simulated underwater ordnance (in contrast to non-ordnance objects and on participants' description of their location, their immediate in-water or seabed context and their structural condition. Only marginal improvements were found with participants' navigational performance in terms of their deviation accuracies from a pre-programmed expert search path. Overall, this project contributes to the growing corpus of evidence supporting the development of simulators that demonstrate the value of exploiting open source gaming software and the significance of adopting established games design

Alkane biosynthesis genes in cyanobacteria and their transcriptional organization

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Stephan eKlähn

2014-07-01

Full Text Available In cyanobacteria, alkanes are synthesized from a fatty acyl-ACP by two enzymes, acyl-acyl carrier protein reductase (AAR and aldehyde deformylating oxygenase (ADO. Despite the great interest in the exploitation for biofuel production, nothing is known about the transcriptional organization of their genes or the physiological function of alkane synthesis. The comparison of 115 microarray datasets indicates the relatively constitutive expression of aar and ado genes. The analysis of 181 available genomes showed that in 90% of the genomes both genes are present, likely indicating their physiological relevance. In 61% of them they cluster together with genes encoding acetyl-CoA carboxyl transferase and a short chain dehydrogenase, strengthening the link to fatty acid metabolism and in 76% of the genomes they are located in tandem, suggesting constraints on the gene arrangement. However, contrary to the expectations for an operon, we found in Synechocystis sp. PCC 6803 specific promoters for the two genes, sll0208 (ado and sll0209 (aar, that give rise to monocistronic transcripts. Moreover, the upstream located ado gene is driven by a proximal as well as a second, distal, promoter, from which a third transcript, the ~160 nt sRNA SyR9 is transcribed. Thus, the transcriptional organization of the alkane biosynthesis genes in Synechocystis sp. PCC 6803 is of substantial complexity. We verified all three promoters to function independently from each other and show a similar promoter arrangement also in the more distant Nodularia spumigena, Trichodesmium erythraeum, Anabaena sp. PCC 7120, Prochlorococcus MIT9313 and MED4. The presence of separate regulatory elements and the dominance of monocistronic mRNAs suggest the possible autonomous regulation of ado and aar. The complex transcriptional organization of the alkane synthesis gene cluster has possible metabolic implications and should be considered when manipulating the expression of these genes in

Application of finite element method in mechanical design of automotive parts

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Gu, Suohai

2017-09-01

As an effective numerical analysis method, finite element method (FEM) has been widely used in mechanical design and other fields. In this paper, the development of FEM is introduced firstly, then the specific steps of FEM applications are illustrated and the difficulties of FEM are summarized in detail. Finally, applications of FEM in automobile components such as automobile wheel, steel plate spring, body frame, shaft parts and so on are summarized, compared with related research experiments.

An approach regarding aging management program for concrete containment structure at the Gentilly-2 Nuclear Power Plant

Energy Technology Data Exchange (ETDEWEB)

Chenier, J-O.; Komljenovic, D., E-mail: Chenier.jean-olivier@hydro.qc.ca [Nuclear Power Plant Gentilly-2, Becancour, Quebec (Canada); Gocevski, V. [Hydro-Quebec Equipment, Structural Dept., Quebec (Canada); Picard, S.; Chretien, G. [Nuclear Power Plant Gentilly-2, Becancour, Quebec (Canada)

2012-07-01

The current paper presents the approach used by the Gentilly-2 Nuclear Power Plant, Hydro-Quebec, in elaborating a specific Aging Management Program (AMP) for its concrete containment structure. It is developed as a part of preparation activities for the plant refurbishment project. The specificity of the AMP consists in addressing Alkali-Aggregate Reaction (AAR) degradation mechanism which is not well known in the nuclear power industry. HQ developed a numerical model based on finite elements for assessing the concrete containment structure behaviour under the impact of AAR and other relevant degradation mechanisms. Such predictions enable a better targeting of corrective and mitigating actions during the second cycle of the G-2 operation while required. (author)

Noormees paneb Kanepi kooli tantsima / Milvi Hirvlaane

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Hirvlaane, Milvi

2006-01-01

Tantsupedagoog Aare Laine tegevusest Kanepi gümnaasiumis, kus ta on lapsed esimesest kuni viimase klassini tantsima pannud. Tema viimaseid tantsuhitte "Chicken Power" teenis Koolitantsu finaalis eripreemia

Plasma Levels of Dimethylarginines in Preterm Very Low Birth Weight Neonates: Its Relation with Perinatal Factors and Short-Term Outcome

Directory of Open Access Journals (Sweden)

Rob M. Moonen

2014-12-01

Full Text Available Endogenously produced inhibitors of nitric oxide (NO synthase, in particular asymmetric dimethylarginine (ADMA, are currently considered of importance in various disease states characterized by reduced NO availability. We investigated the association between plasma levels of ADMA, symmetric dimethylarginine (SDMA, l-arginine, and citrulline and perinatal factors and outcome in 130 preterm (gestational age ≤30 weeks very low birth weight (VLBW, <1500 g infants. Plasma samples were collected 6–12 h after birth. We did not find significant correlations between ADMA, SDMA, l-arginine, and citrulline levels and gestational age or birth weight. However, the arginine:ADMA ratio (AAR, a better indicator of NO availability than either arginine or ADMA separately was positively correlated with gestational age. ADMA and arginine levels were not significantly different between males and females but males showed a negative correlation between ADMA levels and gestational age. Perinatal factors such as preeclampsia, chrorioamnionitis, prolonged rupture of membranes, or form of delivery did not significantly alter dimethylarginine levels or AAR. In contrast, the AAR was significantly reduced in the infants with respiratory distress, mechanical ventilation, and systemic hypotension Therefore, our data suggest that altered NO availability may play a role in the respiratory and cardiovascular adaptation in preterm VLBW infants.

Age estimation based on aspartic acid racemization in human sclera.

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Klumb, Karolin; Matzenauer, Christian; Reckert, Alexandra; Lehmann, Klaus; Ritz-Timme, Stefanie

2016-01-01

Age estimation based on racemization of aspartic acid residues (AAR) in permanent proteins has been established in forensic medicine for years. While dentine is the tissue of choice for this molecular method of age estimation, teeth are not always available which leads to the need to identify other suitable tissues. We examined the suitability of total tissue samples of human sclera for the estimation of age at death. Sixty-five samples of scleral tissue were analyzed. The samples were hydrolyzed and after derivatization, the extent of aspartic acid racemization was determined by gas chromatography. The degree of AAR increased with age. In samples from younger individuals, the correlation of age and D-aspartic acid content was closer than in samples from older individuals. The age-dependent racemization in total tissue samples proves that permanent or at least long-living proteins are present in scleral tissue. The correlation of AAR in human sclera and age at death is close enough to serve as basis for age estimation. However, the precision of age estimation by this method is lower than that of age estimation based on the analysis of dentine which is due to molecular inhomogeneities of total tissue samples of sclera. Nevertheless, the approach may serve as a valuable alternative or addition in exceptional cases.

The effects of micro-implant assisted rapid palatal expansion (MARPE) on the nasomaxillary complex--a finite element method (FEM) analysis.

Science.gov (United States)

MacGinnis, Matt; Chu, Howard; Youssef, George; Wu, Kimberley W; Machado, Andre Wilson; Moon, Won

2014-08-29

Orthodontic palatal expansion appliances have been widely used with satisfactory and, most often, predictable clinical results. Recently, clinicians have successfully utilized micro-implants with palatal expander designs to work as anchors to the palate to achieve more efficient skeletal expansion and to decrease undesired dental effects. The purpose of the study was to use finite element method (FEM) to determine the stress distribution and displacement within the craniofacial complex when simulated conventional and micro-implant-assisted rapid palatal expansion (MARPE) expansion forces are applied to the maxilla. The simulated stress distribution produced within the palate and maxillary buttresses in addition to the displacement and rotation of the maxilla could then be analyzed to determine if micro-implants aid in skeletal expansion. A three-dimensional (3D) mesh model of the cranium with associated maxillary sutures was developed using computed tomography (CT) images and Mimics modeling software. To compare transverse expansion stresses in rapid palatal expansion (RPE) and MARPE, expansion forces were distributed to differing points on the maxilla and evaluated with ANSYS simulation software. The stresses distributed from forces applied to the maxillary teeth are distributed mainly along the trajectories of the three maxillary buttresses. In comparison, the MARPE showed tension and compression directed to the palate, while showing less rotation, and tipping of the maxillary complex. In addition, the conventional hyrax displayed a rotation of the maxilla around the teeth as opposed to the midpalatal suture of the MARPE. This data suggests that the MARPE causes the maxilla to bend laterally, while preventing unwanted rotation of the complex. In conclusion, the MARPE may be beneficial for hyperdivergent patients, or those that have already experienced closure of the midpalatal suture, who require palatal expansion and would worsen from buccal tipping of the teeth

Julia on elus / Ivika Sillar

Index Scriptorium Estoniae

Sillar, Ivika, 1934-

2011-01-01

VAT-teatri "Nisa" (Marjorie Shostaki raamatu põhjal), dramatiseerija, lavastaja ja esitaja Katariina Unt, kaaslavastaja Aare Toikka, muusikaline kujundaja ja esitaja Tanel Ruben. Esietendus 15. aprillil Rahvusraamatukogu teatrisaalis

Fem landskabsstrategiske principper

DEFF Research Database (Denmark)

Bach, Rune Christian; Juel Clemmensen, Thomas

2005-01-01

to their return as investment, and less in respect to their physical surroundings. Consequently the space “between” the building enclaves becomes increasingly relevant in the architectural planning in terms of creating cohesion in the built environment. (Smets) This change of perspective from the built...... influence on the physical environment in the new urban-rural landscape? Global market economy and the withdrawal of public authority create a situation where urban development is increasingly influenced by fluctuations on the real estate market and where buildings are considered more in respect...

49 CFR 179.7 - Quality assurance program.

Science.gov (United States)

2010-10-01

... means to detect any nonconformity in the manufacturing, repair, inspection, testing, and qualification... nonconformities. (8) Provisions indicating that the requirements of the AAR Specifications for Tank Cars (IBR, see...

Saaremaa politseijuht pensionile / Andres Sepp

Index Scriptorium Estoniae

Sepp, Andres, 1976-

2005-01-01

Kuressaare politseijaoskonna ülemkomissar Ants Ley esitas politseiametile lahkumisavalduse. Väidetavalt on nimetatud ühe võimaliku politseijuhikandidaadina Lääne prefektuuri teenistusosakonna komissari Aare Alliku nime. Lisa: Ants Ley

Application of 3D X-ray CT data sets to finite element analysis

International Nuclear Information System (INIS)

Bossart, P.L.; Martz, H.E.; Brand, H.R.; Hollerbach, K.

1995-01-01

Finite Element Modeling (FEM) is becoming more important as industry drives toward concurrent engineering. A fundamental hindrance to fully exploiting the power of FEM is the human effort required to acquire complex part geometry, particularly as-built geometry, as a FEM mesh. Many Quantitative Non Destructive Evaluation (QNDE) techniques that produce three-dimensional (3D) data sets provide a substantial reduction in the effort required to apply FEM to as-built parts. This paper describes progress at LLNL on the application of 3D X-ray computed tomography (CT) data sets to more rapidly produce high-quality FEM meshes of complex, as-built geometries. Issues related to the volume segmentation of the 3D CT data as well as the use of this segmented data to tailor generic hexahedral FEM meshes to part specific geometries are discussed. The application of these techniques to FEM analysis in the medical field is reported here

Routine blood tests to predict liver fibrosis in chronic hepatitis C.

Science.gov (United States)

Hsieh, Yung-Yu; Tung, Shui-Yi; Lee, Kamfai; Wu, Cheng-Shyong; Wei, Kuo-Liang; Shen, Chien-Heng; Chang, Te-Sheng; Lin, Yi-Hsiung

2012-02-28

To verify the usefulness of FibroQ for predicting fibrosis in patients with chronic hepatitis C, compared with other noninvasive tests. This retrospective cohort study included 237 consecutive patients with chronic hepatitis C who had undergone percutaneous liver biopsy before treatment. FibroQ, aspartate aminotransferase (AST)/alanine aminotransferase ratio (AAR), AST to platelet ratio index, cirrhosis discriminant score, age-platelet index (API), Pohl score, FIB-4 index, and Lok's model were calculated and compared. FibroQ, FIB-4, AAR, API and Lok's model results increased significantly as fibrosis advanced (analysis of variance test: P fibrosis score in chronic hepatitis C compared with other noninvasive tests. FibroQ is a simple and useful test for predicting significant fibrosis in patients with chronic hepatitis C.

A 9,000-year-old caribou hunting structure beneath Lake Huron.

Science.gov (United States)

O'Shea, John M; Lemke, Ashley K; Sonnenburg, Elizabeth P; Reynolds, Robert G; Abbott, Brian D

2014-05-13

Some of the most pivotal questions in human history necessitate the investigation of archaeological sites that are now under water. Nine thousand years ago, the Alpena-Amberley Ridge (AAR) beneath modern Lake Huron was a dry land corridor that connected northeast Michigan to southern Ontario. The newly discovered Drop 45 Drive Lane is the most complex hunting structure found to date beneath the Great Lakes. The site and its associated artifacts provide unprecedented insight into the social and seasonal organization of prehistoric caribou hunting. When combined with environmental and simulation studies, it is suggested that distinctly different seasonal strategies were used by early hunters on the AAR, with autumn hunting being carried out by small groups, and spring hunts being conducted by larger groups of cooperating hunters.

Oral cancer statistics in India on the basis of first report of 29 population-based cancer registries

Science.gov (United States)

Sharma, Swati; Satyanarayana, L; Asthana, Smitha; Shivalingesh, KK; Goutham, Bala Subramanya; Ramachandra, Sujatha

2018-01-01

Objectives: To summarize and provide an overview of age-specific oral cancer incidence reported in 29 population-based cancer registry in India. Materials and Methods: Secondary data on age-adjusted rates (AARs) of incidence of oral cancer and other associated sites for all ages (0–75 years) were collected from the report of the National Cancer Registry Programme 2012–2014 in 29 population-based control registries. Results: Among both males and females, mouth cancer had maximum Age adjusted incidence rates (64.8) in the central zone, while oropharynx cancer had minimum AAR (0) in all regions. Conclusion: Oral cancer incidence increases with age with typical pattern of cancer of associated sites of oral cavity seen in the northeast region. PMID:29731552

Armastusest kahel ajajärgul / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2000-01-01

Mängufilm "Prantsuse leitnandi naine" ("The French Lieutenant's Woman") : stsenarist Harold Pinter John Fowles'i romaani järgi : režissöör Karel Reisz : Suurbritannia 1981. Ka : Nädal nr. 35, lk. 14

Pictures of fear and horror / Aare Pilv

Index Scriptorium Estoniae

Pilv, Aare, 1976-

2009-01-01

Autor lapsena unes hirmu põhjustanud piltidest. Ants Laikmaa pastellmaalist "Marie Underi portree (1904), selle sarnasusest Edvard Munchi kujutatud naistega ("Angstgefühl", 1896). Jüri Arraku illustratsioonist "Vanapagan" lasteraamatule "Suur Tõll" (1982). Otsa vaatavatest portreedest (Leonardo da Vinci "Mona Lisa")

Avastamata aare - Soomaa / Merle Adams, Rait Parts

Index Scriptorium Estoniae

Adams, Merle

2009-01-01

Euroopa Komisjoni algatatud rahvusvahelisest projektist EDEN "European Tourist Destinations of Exellence" ning selle raames toimunud Euroopa kontekstis loodusturismi sihtkohtade konkursi "European Destinations of Exellence" Eesti 2009. aasta sihtkoha tiitli võitnud Soomaa rahvuspargist

Sõjas nagu sõjas ikka / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2006-01-01

10-osaline sõjaseriaal "Relvavennad" ("Band of Brothers") ajalooprofessor Stephen Ambrose'i raamatu järgi : produtsendid Tom Hanks, Steven Spielberg : režissöörid Tom Hanks, David Frenkel jt. : Ameerika Ühendriigid - Suurbritannia 2001. Lühidalt ka teistest ilmasõda kajastavatest seriaalidest

Karl Kello - elukutse olla saarlane / Aare Laine

Index Scriptorium Estoniae

Laine, Aare, 1951-

2004-01-01

Kuressaare Kuursaalis näidati kadripäeval nelja Ruta Celma ja Karl Kello kultuuriloolist dokumentaalfilmi : "Narr Jumala kojas" (2000), "Phaetonit otsides" (1999), "Eestlased Lätis" (2004) ja Kalevipoja temaatikat arendav "Küll siis Kalev..." (2004). Filmide operaator on Arvo Vilu. Artikli autor kõneleb Karl Kellost, tema Karja kiriku ja Kaali järve problemaatika arendustest peale filmide ka kirjasõnas

Veemajandus saab jõudsalt areneda / Aare Lepaste

Index Scriptorium Estoniae

Lepaste, Aare, 1970-

2004-01-01

8. detsembril kirjutasid seitsme vee-ettevõtte esindajad, KIK-i juhataja ja keskkonnaminister alla Eesti suurimale keskkonnaprojektile. Projekti eesmärk on viia omavalitsuste veemajanduse infrastruktuur vastavusse EL-i direktiividega.

Kivisildnik versus Under : lausuvad subjektid / Aare Pilv

Index Scriptorium Estoniae

Pilv, Aare, 1976-

2016-01-01

Sven Kivisildniku tekstidest, eriti "Märg Viktor" ja seal leiduvast intertekstuaalsusest. Artikli aluseks on 18.-19. apr. 1997 Otepääl TÜ ja TPÜ kirjandustudengite ja -magistrantide konverentsil 'Vaade sillalt' peetud ettekanne

Halvad, halvemad ja äravalitud / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2003-01-01

Ameerika Filmiinstituudi küsitluse järgi on maailma kõigi aegade kõige meeldejäävamaks kurjuse kehastuseks kinolinal Hannibal Lecter mängufilmides "Voonakeste vaikimine", "Hannibal" ja "Punane draakon" Anthony Hopkinsi kehastuses. Kõige sümpaatsemaks positiivseks tegelaseks valiti Atticus Finch draamas "Tappa laulurästast" Gregory Pecki kehastuses

Perekonnaportree interjööris / Aare Ermel

Index Scriptorium Estoniae

Ermel, Aare, 1957-2013

2005-01-01

Lühiseriaal Mannide kirjanikedünastia saatusest 1930-1940-ndail aastail "Mannide perekond" ("Die Manns") : stsenaristid Heinrich Breloer ja Horst Königstein : režissöör Heinrich Breloer : Saksamaa 2001

Double trouble: combined action of meiotic drive and Wolbachia feminization in Eurema butterflies.

Science.gov (United States)

Kern, Peter; Cook, James M; Kageyama, Daisuke; Riegler, Markus

2015-05-01

Arthropod sex ratios can be manipulated by a diverse range of selfish genetic elements, including maternally inherited Wolbachia bacteria. Feminization by Wolbachia is rare but has been described for Eurema mandarina butterflies. In this species, some phenotypic and functional females, thought to be ZZ genetic males, are infected with a feminizing Wolbachia strain, wFem. Meanwhile, heterogametic WZ females are not infected with wFem. Here, we establish a quantitative PCR assay allowing reliable sexing in three Eurema species. Against expectation, all E. mandarina females, including wFem females, had only one Z chromosome that was paternally inherited. Observation of somatic interphase nuclei confirmed that W chromatin was absent in wFem females, but present in females without wFem. We conclude that the sex bias in wFem lines is due to meiotic drive (MD) that excludes the maternal Z and thus prevents formation of ZZ males. Furthermore, wFem lines may have lost the W chromosome or harbour a dysfunctional version, yet rely on wFem for female development; removal of wFem results in all-male offspring. This is the first study that demonstrates an interaction between MD and Wolbachia feminization, and it highlights endosymbionts as potentially confounding factors in MD of sex chromosomes. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

India rentslimiljonär tegi ilma ka Oscarite peol / Tiit Tuumalu

Index Scriptorium Estoniae

Tuumalu, Tiit, 1971-

2009-01-01

2008.a. filmiloomingu kaheksa Oscarit sai Danny Boyle'i mängufilm "Rentslimiljonär" ("Slumdog Millionaire"), produtsent Christian Colson. Lisatud Aare Tilga ja Timo Dieneri kommentaarid ning peamiste Oscarite nimekiri

"Миллионер из трущоб" покорил США / Тийт Туумалу

Index Scriptorium Estoniae

Туумалу, Тийт

2009-01-01

2008.a. filmiloomingu kaheksa Oscarit sai Danny Boyle'i mängufilm "Rentslimiljonär" ("Slumdog Millionaire"), produtsent Christian Colson. Lisatud Aare Tilga ja Timo Dieneri kommentaarid ning peamiste Oscarite nimekiri

ORF Sequence: NC_003282 [GENIUS II[Archive

Lifescience Database Archive (English)

Full Text Available inization of XX and XO animals FEM-3 (46.2 kD) (fem-3) [Caenorhabditis elegans] MEVDPGSDDVEADRETRAQKLKLKRNVK... NC_003282 gi|17540880 >gi|17540880|ref|NP_501587.1| sex determination protein, FEM

Finite elements as an integrated part of Computer-Aided-Engineering (CAE)

International Nuclear Information System (INIS)

Groth, P.; Kammerer, R.

1986-01-01

The prerequisites for software will be demonstrated using a standard interface for embedding FEM in a CAE system. The realization of a powerful system concept with workstations and personal computers tied to host computers will be presented together with colour graphic terminals for result display. As a standard interface the usage of IGES for the transfer of geometrical data from the CAD system to the FEM preprocessor will be discussed along with the possibilities of usage for new designs and variations for 2D and 3D tasks. In the sectors of pre- and postprocessors a proposal for standardizing the interfaces Pre/FEM, FEM/Post as well as FEM/FEM will be presented (working title FEDIS). The entire problematics will be illustrated by practical examples from mechanical industry and plant design. (orig.)

Kohtumine küünlasäras. Dave Benton annab 12 jõulukontserti

Index Scriptorium Estoniae

2005-01-01

Tõnu Raadiku ja Aare Jaama kontserdist "Lumevarjude vahel" 11. dets. Pärnu Raekoja saalis. Uue albumi "Generations" üllitanud Dave Bentoni ja gospelkooride kontsertidest Eesti kirikutes (9. dets. Pärnu Eliisabeti kirikus)

Kehanarratiivid / Gregory Slick ; tõlk. Mari Laaniste

Index Scriptorium Estoniae

Slick, Gregory

2003-01-01

Reio Aare, Toomas Kalve, Margot Kase, Herkki-Erich Merila fotonäitus "The Fragments of Silence: Meditative moments in contemporary Estonian photography" 10.-26. IV New Yorgi galeriis Annex. Kuraator Rael Artel

Eestlased vigu parandamas ehk väikevormidest suurvormini, disainist reekviemini / Märt Kubo

Index Scriptorium Estoniae

Kubo, Märt, 1944-

2007-01-01

Eesti Kultuurfilmis valminud Juhan Aare (produtsent, autor) dokumentaalfilm NSVL rahvasaadikute kongressil 1989-1991 tegutsenud Eesti saadikute tegevusest ja iseseisvuse eest võitlemisest "Eestlased Kremlis" (režissöör Toomas Lepp)

Thoracic lymph node station recognition on CT images based on automatic anatomy recognition with an optimal parent strategy

Science.gov (United States)

Xu, Guoping; Udupa, Jayaram K.; Tong, Yubing; Cao, Hanqiang; Odhner, Dewey; Torigian, Drew A.; Wu, Xingyu

2018-03-01

Currently, there are many papers that have been published on the detection and segmentation of lymph nodes from medical images. However, it is still a challenging problem owing to low contrast with surrounding soft tissues and the variations of lymph node size and shape on computed tomography (CT) images. This is particularly very difficult on low-dose CT of PET/CT acquisitions. In this study, we utilize our previous automatic anatomy recognition (AAR) framework to recognize the thoracic-lymph node stations defined by the International Association for the Study of Lung Cancer (IASLC) lymph node map. The lymph node stations themselves are viewed as anatomic objects and are localized by using a one-shot method in the AAR framework. Two strategies have been taken in this paper for integration into AAR framework. The first is to combine some lymph node stations into composite lymph node stations according to their geometrical nearness. The other is to find the optimal parent (organ or union of organs) as an anchor for each lymph node station based on the recognition error and thereby find an overall optimal hierarchy to arrange anchor organs and lymph node stations. Based on 28 contrast-enhanced thoracic CT image data sets for model building, 12 independent data sets for testing, our results show that thoracic lymph node stations can be localized within 2-3 voxels compared to the ground truth.

The Effect of Numerical 2D and 3D Fem Element Modelling on Strain and Stress Distributions at Laser Weld Notches in Steel Sandwich Type Panels

Directory of Open Access Journals (Sweden)

Niklas Karol

2018-03-01

Full Text Available Like other means of transport, merchant ships face the problem of increasing requirements concerning the environment protection, which, among other issues, implies the reduction of fuel consumption by the ship. Here, the conventional approach which consists in making use of higher strength steels to decrease the mass of the ship hull can be complemented by the use of new steel structures of sandwich panel type. However, the lack of knowledge and experience concerning, among other issues, fatigue strength assessment of thin-walled sandwich structures makes their use limited. Untypical welds imply the need for individual approach to the fatigue analysis. The article presents the effect of numerical FEM modelling with the aid of two-dimensional (2D and three-dimensional (3D elements on the results of strain and stress distributions in the areas of toe and root notches of the analysed laser weld. The presented results of computer simulation reveal that modelling of strain and stress states in 2D (instead of full 3D affects only the results in close vicinity of the notch, and the observed differences rapidly disappear at a distance of 0.05 mm from the bottom of the notch. The obtained results confirm the possibility of use of numerically effective 2D strain and stress state models for analysing the fatigue strength of laser weld according to local approach.

Development of Test-Analysis Models (TAM) for correlation of dynamic test and analysis results

Science.gov (United States)

Angelucci, Filippo; Javeed, Mehzad; Mcgowan, Paul

1992-01-01

The primary objective of structural analysis of aerospace applications is to obtain a verified finite element model (FEM). The verified FEM can be used for loads analysis, evaluate structural modifications, or design control systems. Verification of the FEM is generally obtained as the result of correlating test and FEM models. A test analysis model (TAM) is very useful in the correlation process. A TAM is essentially a FEM reduced to the size of the test model, which attempts to preserve the dynamic characteristics of the original FEM in the analysis range of interest. Numerous methods for generating TAMs have been developed in the literature. The major emphasis of this paper is a description of the procedures necessary for creation of the TAM and the correlation of the reduced models with the FEM or the test results. Herein, three methods are discussed, namely Guyan, Improved Reduced System (IRS), and Hybrid. Also included are the procedures for performing these analyses using MSC/NASTRAN. Finally, application of the TAM process is demonstrated with an experimental test configuration of a ten bay cantilevered truss structure.

2007. aasta raamatute tipp-10 / Kadri Kõusaar

Index Scriptorium Estoniae

Kõusaar, Kadri, 1980-

2007-01-01

Ilukirjandusest: Dovlatov, Sergei. Leivatöö. Võõramaa naine; Pilv, Aare. Näoline; Tsvetajeva, Marina. Elu tules : pihtimused; Kaplinski, Jaan. Seesama jõgi; García Márquez, Gabriel. Elada, et sellest jutustada

Study of the quantitative assessment method for high-cycle thermal fatigue of a T-pipe under turbulent fluid mixing based on the coupled CFD-FEM method and the rainflow counting method

Energy Technology Data Exchange (ETDEWEB)

Zhang, Y.; Lu, T., E-mail: likesurge@sina.com

2016-12-01

Highlights: • Two characteristic parameters of the temperature fluctuations are used for qualitative analysis. • A quantitative assessment method for high-cycle thermal fatigue of a T-pipe is proposed. • The time-dependent curves for the temperature and thermal stress are not always “in-phase”. • Large magnitude of thermal stresses may not mean large number of fatigue cycles. • The normalized fatigue damage rate and normalized RMS temperature are positively related. - Abstract: With the development of nuclear power and nuclear power safety, high-cycle thermal fatigue of the pipe structures induced by the flow and heat transfer of the fluid in pipes have aroused more and more attentions. Turbulent mixing of hot and cold flows in a T-pipe is a well-recognized source of thermal fatigue in piping system, and thermal fatigue is a significant long-term degradation mechanism. It is not an easy work to evaluate thermal fatigue of a T-pipe under turbulent flow mixing because of the thermal loads acting at fluid–structure interface of the pipe are so complex and changeful. In this paper, a one-way Computational Fluid Dynamics-Finite Element Method (CFD-FEM method) coupling based on the ANSYS Workbench 15.0 software has been developed to calculate transient thermal stresses with the temperature fields of turbulent flow mixing, and thermal fatigue assessment has been carried out with this obtained fluctuating thermal stresses by programming in the software platform of Matlab based on the rainflow counting method. In the thermal analysis, the normalized mean temperatures and the normalized root mean square (RMS) temperatures are obtained and compared with the experiment of the test case from the Vattenfall benchmark facility to verify the accuracy of the CFD calculation and to determine the position which thermal fatigue is most likely to occur in the T-junction. Besides, more insights have been obtained in the coupled CFD-FEM analysis and the thermal fatigue

Interesting coin finds of 2005 / Mauri Kiudsoo

Index Scriptorium Estoniae

Kiudsoo, Mauri, 1973-

2006-01-01

2005. aasta arheoloogilistel kaevamistel avastatud müntidest väärivad eraldi märkimist nn. traatkopikad. Kõige rohkem traatkopikaid leiti Vastseliina piiskopilinnuselt. Üks traatkopikatest koosnenud aare leiti Koruste külast

Lugedes Pilve ja Pazi / Mathura

Index Scriptorium Estoniae

Mathura, pseud., 1973-

2007-01-01

Võrdlevalt Aare Pilve luulekogust "Näoline" (kirj. Tuum, 2007) ja Octavio Pazi luulekogust "Alati on olevik" (hispaania k. tlk. Ain Kaalep, Jaan Kaplinski, Asta Põldmäe ja Jüri Talvet, kirj. Perioodika, 1984)

Influence of mesostasis in volcanic rocks on the alkali-aggregate reaction

KAUST Repository

Tiecher, Francieli

2012-11-01

Mesostasis material present in the interstices of volcanic rocks is the main cause of the alkali-aggregate reaction (AAR) in concretes made with these rock aggregates. Mesostasis often is referred to as volcanic glass, because it has amorphous features when analyzed by optical microscopy. However, this study demonstrates that mesostasis in the interstitials of volcanic rocks most often consists of micro to cryptocrystalline mineral phases of quartz, feldspars, and clays. Mesostasis has been identified as having different characteristics, and, thus, this new characterization calls for a re-evaluation of their influence on the reactivity of the volcanic rocks. The main purpose of this study is to correlate the characteristics of mesostasis with the AAR in mortar bars containing basalts and rhyolites. © 2012 Elsevier Ltd. All rights reserved.

Influence of mesostasis in volcanic rocks on the alkali-aggregate reaction

KAUST Repository

Tiecher, Francieli; Dal Molin, Denise Carpena Coitinho; Gomes, Má rcia Elisa Boscato; Hasparyk, Nicole Pagan; Monteiro, Paulo José Meleragno

2012-01-01

Mesostasis material present in the interstices of volcanic rocks is the main cause of the alkali-aggregate reaction (AAR) in concretes made with these rock aggregates. Mesostasis often is referred to as volcanic glass, because it has amorphous features when analyzed by optical microscopy. However, this study demonstrates that mesostasis in the interstitials of volcanic rocks most often consists of micro to cryptocrystalline mineral phases of quartz, feldspars, and clays. Mesostasis has been identified as having different characteristics, and, thus, this new characterization calls for a re-evaluation of their influence on the reactivity of the volcanic rocks. The main purpose of this study is to correlate the characteristics of mesostasis with the AAR in mortar bars containing basalts and rhyolites. © 2012 Elsevier Ltd. All rights reserved.

Hidden State Conditional Random Field for Abnormal Activity Recognition in Smart Homes

Directory of Open Access Journals (Sweden)

Yu Tong

2015-03-01

Full Text Available As the number of elderly people has increased worldwide, there has been a surge of research into assistive technologies to provide them with better care by recognizing their normal and abnormal activities. However, existing abnormal activity recognition (AAR algorithms rarely consider sub-activity relations when recognizing abnormal activities. This paper presents an application of the Hidden State Conditional Random Field (HCRF method to detect and assess abnormal activities that often occur in elderly persons’ homes. Based on HCRF, this paper designs two AAR algorithms, and validates them by comparing them with a feature vector distance based algorithm in two experiments. The results demonstrate that the proposed algorithms favorably outperform the competitor, especially when abnormal activities have same sensor type and sensor number as normal activities.

[Application of Finite Element Method in Thoracolumbar Spine Traumatology].

Science.gov (United States)

Zhang, Min; Qiu, Yong-gui; Shao, Yu; Gu, Xiao-feng; Zeng, Ming-wei

2015-04-01

The finite element method (FEM) is a mathematical technique using modern computer technology for stress analysis, and has been gradually used in simulating human body structures in the biomechanical field, especially more widely used in the research of thoracolumbar spine traumatology. This paper reviews the establishment of the thoracolumbar spine FEM, the verification of the FEM, and the thoracolumbar spine FEM research status in different fields, and discusses its prospects and values in forensic thoracolumbar traumatology.