bluuebunny/crossref_metadata_2025 huggingface dataset:
High expression of Wls is associated with lymph node metastasis and advanced TNM stage in gastric carcinomas
Authors: Zhang Wei , Tao Hong , Chen Xiao , Sugimura Haruhiko , Wang Jiandong , Zhou Ping
Published: January 2017

The roles of Wnt protein in carcinogenesis have been well documented in human cancers. Wls is a key modulator for the secretion of Wnt protein. We previously found that Wls was aberrantly expressed in colorectal carcinomas. Studies have revealed that dysregulation of Wnt signal transduction plays an important role in gastric carcinoma. We hypothesized that Wls may play a role in the development and progression of gastric carcinoma. In this study, three gastric cancer cell lines MGC‐803, SGC‐7901, and AGS, and a set of gastric carcinoma tissue specimens were subjected to immunohistochemistry. The relationship between the expression of Wls and clinicopathological parameters was analyzed. Wls was negatively detected in MGC‐803, positively detected in SGC‐7901 and AGS cell lines. Wls was weakly expressed in 9.7% (15/154), moderately in 33.1% (51/154), and strongly in 57.1% (88/154) of tested gastric carcinoma specimens. High expression of Wls was positively associated with well and moderately differentiated tumors (P = 0.035, rs = 0.170), lymph node metastasis (P = 0.001, rs = 0.276), and advanced TNM stage (P = 0.006, rs = 0.219). Our data suggest that Wls protein is related to tumor metastasis and advanced TNM stage, and may be used as a new marker for prognosis of gastric carcinoma.
Dynamic changes in mitochondrial DNA, distribution and activity within cat oocytes during folliculogenesis
Authors: Songsasen N , Henson LH , Tipkantha W , Thongkittidilok C , Henson JH , Chatdarong K , Comizzoli P
Published: January 2017

Contents

Mitochondria play fundamental roles during oocyte development. The accumulation and spatial redistribution of these energy‐producing organelles have been linked to the developmental competence of mammalian oocytes. Here, we assessed the copy number, distribution and activity of mitochondria within cat oocytes during folliculogenesis. In Experiment 1, oocytes were recovered from primordial (n = 152), primary (112), secondary (95), early (131), small (118), antral (86) and advanced antral (5) stages follicles, and mitochondria DNA extracted and quantified using qPCR. In Experiment 2, oocytes from pre‐antral (n = 44), early antral (n = 66), small antral (n = 59), antral (n = 41) and advanced antral (n = 21) follicles were isolated and stained with CMXRos MitoTracker dye to assess mitochondrial distribution pattern and activity levels. Oocyte's mitochondria DNA (mtDNA) copy numbers gradually increased as folliculogenesis progressed, with a significant shift at the small antral stage (0.5 to <1 mm in diameter). The location of mitochondria gradually shifted from a homogeneous distribution throughout the cytoplasm in pre‐antral oocytes to a pericortical concentration in the advanced antral stage. Quantification of CMXRos fluorescent intensity revealed a progressive increase in mitochondrial activity in oocytes from the pre‐antral to the large antral follicles. Taken together, these findings demonstrated that cat oocytes undergo dynamic changes in mitochondrial copy number, distribution and activity during folliculogenesis. These significant modifications to this crucial cytoplasmic organelle are likely associated with the acquisition of developmental competency by cat oocytes.
The influence of compost and zeolite co‐addition on the nutrients status and plant growth in intensively cultivated Mediterranean soils
Authors: Litaor M. I. , Katz L. , Shenker M.
Published: January 2017

The main objective of the study was to test the benefits of compost and zeolite co‐addition on the fertility of organic‐rich Mediterranean soils. Previous pot study in greenhouse found that zeolites mixed with compost significantly improved potassium availability as well as exchangeable potassium capacity in the soils. To further test this finding, a field experiment was conducted using potato – Solanum tuberosum L., desiree cultivar in peat soils of the Hula Valley, Israel. Adhering to the protocol of the greenhouse experiments, the treatments included 5% compost addition with no zeolites, 2% zeolite addition without compost, co‐addition of 5% compost mixed with 2% zeolites and control. We found that compost addition increased significantly the potatoes yield and the number of large tubers; however, the zeolite addition had no impact on yield. Co‐addition of compost and zeolites did not improve total crop yield or number of large tubers compared with compost addition only. The results are consistent with nutrients availability (N, P, K) across the treatments. In a commercialized field using the experiment conditions, the 2% zeolite addition would amount to 18 ton of zeolites per hectare. Hence, we conclude that soil amendment with the tested zeolite might be beneficial to improve soil retention for cationic nutrients (e.g. K+) under high leaching systems such as plant culture in pots, but in the field with high loads of compost, its effect is minor.
Factor Analysis Aspects of the Enterprise’s Operating Leverage
Authors: Chiladze Izolda
Published: January 2017

The aim of the research is to selection general coefficient of operating leverage of enterprise and to great factor model of this.The subject of the research is operating risk of enterprise. Accordingly had study coefficients operating leverage, the fixed and variable costs, the conception of marginal profit and break-even points.Had mace comparative analysis of well-known coefficients of enterprise operating leverage in the article. Here are discussed relationship between coefficients of Operating Leverage, Marginal Profit, Break-even point, the production Margin of Safety and structure of costs.Generally accepted methods of analysis are used in the paper, such as analysis and synthesis, induction and deduction, quantitative and qualitative analysis methods, traditional analysis methods.Results of research had proofed that fixed costs and operating profit ratio can be recognition with General Coefficient of Operating Leverage of enterprise. Had great four-factors model of this indicator too, whose practical use will help the management of enterprises to explore positive and negative factors through the traditional analytical methods and to the adequate decisions will making.
La disputa por la tierra en Colombia sobre los resguardos: conceptos, ángulos analíticos y puntos de vista
Authors: Mora Vera Germán Andrés
Published: January 2017

Por más de cuatrocientos años ha existido un con-flicto entre los Gobiernos y los indígenas en Colombia por las tierras de los resguardos y que aún hoy en día sigue vigente. Este artículo intentará demostrar, por medio de un estudio comparativo realizado dentro de lo que se denomina los ángulos superior e inferior, las diferencias y similitudes entre los intereses y las creencias que estos dos actores tienen sobre estas tierras. Las discusiones académicas que se mencionan en este estudio revelan que no solo hay una falta de consenso entre los autores que estudian este tema, sino que, a su vez, demuestran que hay una brecha entre los principios establecidos en la ley y el contexto real que sigue prolongando este conflicto.
Gobernabilidad en Honduras y Paraguay: reforma pública y cooperación internacional en rupturas presidenciales
Authors: Gomis Balestreri Miguel
Published: January 2017

Desde la tercera ola democratizadora en América Latina, las rupturas presidenciales en la región se han presentado en contextos socialmente opuestos. Los mecanismos constitucionales son diversos, pero han ofrecido reducidas opciones de revocación de mandatos presidenciales. Las rupturas de Paraguay y Honduras llevaron a un intenso clima de polarización de la opinión pública interna y externa. Aunque se conocen los debates sobre la legalidad y las causas de dichas rupturas, quedan condicionantes por analizar. En este artículo se investiga la relación entre la cooperación internacional y las reformas de gestión pública en contextos de ruptura presidencial en Honduras y Paraguay.
Factores determinantes de la salud y la enfermedad: mujeres en condición de desplazamiento en Medellín,, Colombia 2015
Authors: Posada-Zapata Isabel Cristina , Mendoza-Ríos Abraham , Restrepo-Correa Carolina , Cano-Bedoya Sara María , Orozco-Giraldo Isabel Cristina
Published: January 2017

condiciones de vida estructurales y la situación de salud o enfermedad de poblaciones específicas. Esta relación tiende a complejizarse cuando se viven situaciones de conflicto, las cuales agudizan la vulnerabilidad. El objetivo fue describir las vivencias de mujeres en condición de desplazamiento y sus efectos en los procesos de salud-enfermedad. Con un enfoque cualitativo, se tomaron aspectos de la teoría fundamentada de Strauss y Corbin. Participaron 49 mujeres en situación de desplazamiento. Para el análisis se utilizó la codificación, la categorización y la interpretación, y finalmente se llevó a cabo la teorización. Se consideró la descripción conceptual de percepción, significado, la salud-enfermedad, la salud pública, el género y el desplazamiento. Como hallazgo principal se encontró que el desplazamiento y las representaciones socioculturales marcan considerablemente la significación y la forma de asumir los procesos de salud-enfermedad de las mujeres.
Índice de internación ajustado por riesgo en hospitales públicos de Costa Rica
Authors: Morera-Salas Melvin
Published: January 2017

La estancia prolongada constituye un importante problema de gestión hospitalaria. El objetivo de este estudio es estimar un índice que identifique los hospitales con una gestión inadecuada de las estancias. El índice de adecuación de estancias se calcula dividiendo las estancias observadas entre las estancias esperadas en cada hospital. Estas últimas se estiman con un modelo de regresión que considera las características sociodemográficas y clínicas de los pacientes. Se utiliza la base de egresos hospitalarios del seguro público de salud de Costa Rica del 2014. El 43 % de los hospitales tiene una inadecuada gestión de las estancias, dado que registran mayores días de hospitalización que los esperados, de acuerdo a lo que le correspondía por la casuística. Se concluye que la información clínico-administrativa del sistema público de Costa Rica permite estimar un índice de adecuación de estancias, para identificar los hospitales con una gestión inadecuada de las estancias.
¿Qué es primero: desigualdades o inequidades? A propósito del caso de la mortalidad por VIH/ sida en Cali, Colombia (1986-2012)
Authors: Arrivillaga-Quintero Marcela , Pérez-Flórez Mauricio , Borrero-Ramírez Yadira Eugenia , Cecilia-Zea María , Holguín-Ruiz Jorge , Ross Michael W.
Published: January 2017

Este estudio tuvo como objetivo analizar la mortalidad por VIH/sida en Cali, Colombia, en el periodo 1986-2012, y a partir de ahí, comprender, desde el punto de vista conceptual, los determinantes sociales relacionados. Se llevó a cabo un estudio observacional, longitudinal, retrospectivo, con un total de 14 192 casos. Se encontró una tendencia creciente de la tasa de mortalidad, en especial a partir del año 1996; en el 2011 se presentó la mayor tasa de todo el periodo. La medición de la desigualdad reveló que se han producido más muertes en estratos medios y bajos, en comparación con el estrato alto. Este estudio aporta evidencia sobre las desigualdades persistentes en la mortalidad por VIH/sida como expresión de inequidades de tipo estructural en la ciudad de Cali. En la perspectiva de Breilh, son procesos críticos de determinación económica y social que pudieron afectar la mortalidad, especialmente de los grupos con más vulnerados socialmente. 
Nonlinear Dynamic Behavior of a Heavy Articulated Vehicle With Magnetorheological Dampers
Authors: Fakhraei Javad , Khanlo Heshmatallah Mohammad , Dehghani Reza
Published: January 2017

The chaotic vibration analysis of a heavy articulated vehicle (HAV) under consecutive speed control humps (SCHs) excitation is studied. The vehicle is modeled as a nonlinear half-truck oscillatory system with three axles. The suspension system between the truck bodies and axles is equipped with passive viscous damper and magnetorheological (MR) damper. The consecutive SCHs-speed coupling excitation function is presented by a half-sine wave with constant amplitude and variable frequency. The nonlinear dynamic behavior of the system is investigated by special respective techniques. Also, the ride comfort is assessed by the RMS value of truck bodies' accelerations. The results reveal that the quasi-periodic motion is observed at lower speeds when the truck moves on SCHs without load; while in the presence of the load, the dynamic characteristics of the system confirm the chaotic vibration possibility in a widespread range at higher speeds. Further studies indicate that the chaotic behaviors can directly affect on driving comfort and lead to the ride comfort becoming lower. The obtained results can be helpful in designing the oscillatory system for the heavy vehicles to preserve the comfort of drivers and the protection of load.
Efficient Design Module Capture and Representation for Product Family Reuse
Authors: Lundin Michael , Lejon Erik , Dagman Andreas , Näsström Mats , Jeppsson Peter
Published: January 2017

New business models and more integrated product development processes require designers to make use of knowledge more efficiently. Capture and reuse are means of coping, but support, techniques, and mechanisms have yet to be sufficiently addressed. This paper consequently explores how computer-aided technologies (CAx) and a computer-aided design (CAD) model-oriented approach can be used to improve the efficiency of design module capture and representation for product family reuse. The first contribution of this paper is the investigation performed at a Swedish manufacturing company and a set of identified challenges related to design capture and representation for reuse in product family development. The second contribution is a demonstrated and evaluated set of systems and tools, which exemplifies how these challenges can be approached. Efficient design capture is achieved by a combination of automated and simplified design capture, derived from the design implementation (CAD model definition) to the extent possible. Different design representations can then be accessed by the designer using the CAD-internal tool interface. A web application is an example of more general-purpose representation to tailor design content, all of which is managed by a product lifecycle management (PLM) system. Design capture is based on a modular view block definition, stored in formal information models, management by a PLM system, for consistent and reliable design content. It was, however, introduced to support the rich and expressive forms of capture and representation required to facilitate understanding, use, and reuse of varied and increasingly complex designs. A key element in being able to describe a complex design and its implementation has been capture and representation of a set of design states. The solution has been demonstrated to effectively be able to capture and represent significant portions of a step-by-step design training material and the implementation of complex design module through a set of design decisions taken. The validity and relevance of the proposed solution is strengthened by the level of acceptance and perceived value from experienced users, together with the fact that the company is implementing parts of it today.
Integrated Blast Resistance Model of Nuclear Power Plant Auxiliary Facilities
Authors: Brandys Irad , Ornai David , Ronen Yigal
Published: January 2017

Standards, guidelines, manuals, and researches refer mainly to the required protection of a nuclear power plant (NPP) containment structure (where the reactor's vessel is located) against different internal and external extreme events. However, there is no consideration regarding the man-made extreme event of external explosion resulting from air bomb or cruise missile. A novel integrated blast resistance model (IBRM) of NPP's reinforced concrete (RC) auxiliary facilities due to an external above ground explosion based on two components is suggested. The first is structural dynamic response analysis to the positive phase of an external explosion based on the single degree-of-freedom (SDOF) method combined with spalling and breaching empirical correlations. The second is in-structure shock analysis, resulting from direct-induced ground shock and air-induced ground shock. As a case study, the resistance of Westinghouse commercial NPP AP1000 control room, including a representative equipment, to an external above ground blast loading of Scud B-100 missile at various standoff distances ranging from 250 m (far range) till contact, was analyzed. The structure's damage level is based on its front wall supports' angle of rotation and the ductility ratio (dynamic versus elastic midspan displacement ratio). Due to the lack of specific structural damage demands and equipment's dynamic capacities, common protective structures standards and manuals are used while requiring that no spalling or breaching shall occur in the control room while it remains in the elastic regime. The engineering systems and equipments' spectral motions should be less than their capacity. The integrated blast resistance model (IBRM) of the structure and its equipment may be used in wider researches concerning other NPP's auxiliary facilities and systems based upon their specifications.
An Experimental Study of Chilton–Colburn Analogy Between Turbulent Flow and Convective Heat Transfer of Supercritical Kerosene
Authors: Zhang Yongjiang , Zhong Fengquan , Xing Yunfei , Zhang Xinyu
Published: January 2017

In this paper, characteristics of turbulent flow and convective heat transfer of supercritical China RP-3 kerosene in a horizontal straight circular tube are studied experimentally, and the validity of Chilton–Colburn analogy is examined. Using a three-stage heating system, experiments are conducted at a fuel temperature range of 650–800 K, a pressure range of 3–4 MPa, and a Reynolds number range of 1 × 105–3.5 × 105. The Nusselt number and skin friction coefficient are calculated through control volume analysis proposed in this paper. Heat transfer enhancement and deterioration were observed in the experiments as well as the similar change of skin friction coefficient. The present results show that Chilton–Colburn analogy is also valid for turbulent flow and heat transfer of supercritical kerosene in horizontal straight circular tubes.
Comparative Assessment of the Finite Difference, Finite Element, and Finite Volume Methods for a Benchmark One-Dimensional Steady-State Heat Conduction Problem
Authors: Mazumder Sandip
Published: January 2017

The finite difference (FD), finite element (FE), and finite volume (FV) methods are critically assessed by comparing the solutions produced by the three methods for a simple one-dimensional steady-state heat conduction problem with heat generation. Three issues are assessed: (1) accuracy of temperature, (2) accuracy of heat flux, and (3) satisfaction of global energy conservation. It is found that if the order of accuracy of the numerical discretization schemes is the same (central difference for FD and FV, linear basis functions for FE), the accuracy of the temperature produced by the three methods is similar, except close to the boundaries where the FV method outshines the other two methods. Consequently, the FV method is found to predict more accurate heat fluxes at the boundaries compared to the other two methods and is found to be the only method that guarantees both local and global conservation of energy irrespective of mesh size. The FD and FE methods both violate energy conservation, and the degree to which energy conservation is violated is found to be mesh size dependent. Furthermore, it is shown that in the case of prescribed heat flux (Neumann) and Newton cooling (Robin) boundary conditions, the accuracy of the FD method depends in large part on how the boundary condition is implemented. If the boundary condition and the governing equation are both satisfied at the boundary, the predicted temperatures are more accurate than in the case where only the boundary condition is satisfied.
Energy Straggling Function by Fα-Calculus
Authors: Ashrafi Saleh , Golmankhaneh Ali Khalili
Published: January 2017

In this manuscript, we have used the recently developed Fα-calculus to calculate the energy straggling function through the fractal distributed structures. We have shown that such a fractal structure of space causes the fractal pattern of the energy loss. Also, we have offered Fα-differential Fokker–Planck equation for thick fractal absorbers.
Load Controlled Cyclic Loading of Transversely Isotropic Cylindrical Vessels Based on the Anisotropic Kinematic Hardening Models
Authors: Ejtemajou M. , Mahbadi H. , Eslami M. R.
Published: January 2017

This study evaluates the plastic responses of thick cylinders made of transversely isotropic materials under mechanical cyclic loads, using the kinematic hardening theory of plasticity. The Hill yield criterion is adapted to the kinematic hardening theory of plasticity. The constitutive equations of plastic strains are obtained using the adapted yield criterion. The flow rule based on the kinematic hardening theory of plasticity associated with the Hill yield criterion is represented to evaluate the cyclic behavior of transversely isotropic cylindrical vessels. A numerical method is proposed to calculate the stresses and plastic strains in this structure due to the cycling of pressure at its inside surface. The numerical solution is validated simplifying the results with those of isotropic materials. Using the proposed method, the effect of anisotropy on ratcheting and shakedown response of the vessel is evaluated. It has been shown that the ratcheting or shakedown response of the vessel and the rate of ratcheting are highly affected by the anisotropy ratio. The numerical results of this paper show that the yield strength ratio, which is affected by initial work hardening of the metal, may control the ratcheting behavior of the cylindrical vessels.
Combustion Characteristics of a Two-Dimensional Twin Cavity Trapped Vortex Combustor
Authors: Ezhil Kumar P. K. , Mishra D. P.
Published: January 2017

Trapped vortex combustor (TVC) is a relatively new concept, having potential application in gas turbine engines. In this work, an attempt has been made to characterize the 2D twin cavity TVC experimentally in terms of its visible flame length, pollutant emission level, and exit temperature profile. Besides this, numerical results are also discussed to explain certain intricacies in flow and flame characteristics. Experimental results reveal that visible flame length value is sensitive to mainstream Reynolds number (Rems), primary (cavity) air velocity (Vp), and cavity equivalence ratio (Φc). For a particular Rems and Φc, an increase in Vp results in longer flame length; whereas, flame length gets shortened at higher mainstream Reynolds number cases. Numerical studies indicate that shortening of flame length at higher Rems cases is caused due to quenching of flame at the shear layer by the incoming flow. An attempt has been made to correlate flame length data with the operating parameters and Damkohler number (Da); Da takes care of flame quenching effects. Moreover, it is also brought out that the emission profile at the combustor exit is dependent on primary air velocity, mainstream Reynolds number, and cavity equivalence ratio. Emission studies indicate that higher primary air velocity cases make the carbon monoxide (CO) and unburned hydrocarbon (UHC) emission levels to lower values. Reduction in emission level is caused mainly due to the flame merging effects. Besides this, the influence of cavity flame merging on the exit temperature profile uniformity is also brought out. This study reveals that merging of cavity flames is essential for the optimized operation of a 2D trapped vortex combustor.
Hydropower Plant Load Frequency Control Via Second-Order Sliding Mode
Authors: Ding Xibei , Sinha Alok
Published: January 2017

Super-twisting algorithm, a second-order sliding mode control method, is studied for hydropower plant frequency control. Two versions of this algorithm are introduced in this paper. Simulation results from both of these second-order methods and regular sliding mode control are compared on the basis of system responses and control efforts. It is shown that the second-order sliding mode controller is able to reduce chattering effects associated with the regular sliding mode control and preserve the robustness of the regular sliding mode control as well.
Quasi Two-Dimensional Flow-Adaptive Algorithm for Pneumatic Probe Measurements
Authors: Bartsch Christian , Hölle Magnus , Jeschke Peter , Metzler Timo
Published: January 2017

The subject of this paper is a flow-adaptive measurement grid algorithm developed for one-dimensional (1D) and two-dimensional (2D) flow field surveys with pneumatic probes in turbomachinery flows. The algorithm automatically determines the distribution and the amount of measurement points needed for an approximation of the pressure distribution within a predefined accuracy. The algorithm is based on transient traverses, conducted back and forth in the circumferential direction. A correction of the dynamic response is applied by deconvolving the transient measurement data using the information embedded in both transient measurements. In consequence, the performance of the algorithm is largely independent of the transient traversing speed and the geometry of the pressure measuring system. Insertion and removal strategies are incorporated in order to reduce measurement points and increase robustness toward differing flow field conditions. The performance of the algorithm is demonstrated for 2D flow field surveys with a pneumatic five-hole probe in an annular cascade wind tunnel. The measurement grid points are automatically adjusted so that a consistent resolution of the flow features is achieved within the measurement domain. Furthermore, the application of the algorithm shows a significant reduction in the number of measurement points. Compared to the measurement duration based on uniform grids, the duration is reduced by at least 7%, while maintaining a high accuracy of the measurement. The purpose of this paper is to demonstrate the performance of measurement grids adapted to local flow field conditions. Consequently, valuable measurement time can be saved without a loss in quality of the data obtained.
On the Inclusion of Time Derivatives of State Variables for Parametric Model Order Reduction for a Beam on a Nonlinear Foundation
Authors: Segala David B. , Naseradinmousavi Peiman
Published: January 2017

The computational burden of parameter exploration of nonlinear dynamical systems can become a costly exercise. A computationally efficient lower dimensional representation of a higher dimensional dynamical system is achieved by developing a reduced order model (ROM). Proper orthogonal decomposition (POD) is usually the preferred method in projection-based nonlinear model reduction. POD seeks to find a set of projection modes that maximize the variance between the full-scale state variables and its reduced representation through a constrained optimization problem. Here, we investigate the benefits of an ROM, both qualitatively and quantitatively, by the inclusion of time derivatives of the state variables. In one formulation, time derivatives are introduced as a constraint in the optimization formulation—smooth orthogonal decomposition (SOD). In another formulation, time derivatives are concatenated with the state variables to increase the size of the state space in the optimization formulation—extended state proper orthogonal decomposition (ESPOD). The three methods (POD, SOD, and ESPOD) are compared using a periodically, periodically forced with measurement noise, and a randomly forced beam on a nonlinear foundation. For both the periodically and randomly forced cases, SOD yields a robust subspace for model reduction that is insensitive to changes in forcing amplitudes and input energy. In addition, SOD offers continual improvement as the size of the dimension of the subspace increases. In the periodically forced case where the ROM is developed with noisy data, ESPOD outperforms both SOD and POD and captures the dynamics of the desired system using a lower dimensional model.
Response of Cylindrical Composite Structures Subjected to Underwater Impulsive Loading: Experimentations and Computations
Authors: Qu Tao , Avachat Siddharth , Zhou Min
Published: January 2017

The dynamic response of both thick-walled and thin-walled cylindrical composite structures subjected to underwater impulsive loads is analyzed. In the case of thick-walled structures, a novel experimental setup, the underwater shock loading simulator (USLS), is used to generate the impulsive loads. Deflection and core compression are characterized using high-speed digital imaging. The experiments are supported by fully dynamic numerical calculations which account for fluid–structure interactions (FSIs) and damage and failure mechanisms in the materials. The analysis focuses on the effect of varying structural attributes and material properties on load-carrying capacity, deformation mechanisms, and damage. Results show that cylindrical sandwich structures have superior blast-resistance than cylindrical monolithic structures of equal mass with only relatively minor increases in wall thickness. In the case of thin-walled structures, a unique computational framework based on a coupled Eulerian–Lagrangian (CEL) approach is developed to study the structural collapse and damage evolution under large impulsive loads which induces an implosion event. Simulations are carried out for a range of hydrostatic pressure and impulsive load intensity, with different loading configurations. Ply level stress analysis provides an insight on the stress–structural deformation–damage evolution relationship during the severe explosion-induced implosion event. The experiments, computations, and structure–performance relations developed in the current study offer approaches for improving the blast-mitigation capabilities of cylindrical composite sections in critical parts of marine structures, such as the keel, hull, and pipes.
An Approximate Solution of Muijderman's Model for Performance Calculation of Spiral Grooved Gas Seal
Authors: Xu Wanjun , Yang Jiangang
Published: January 2017

This paper presents an approximate solution of Muijderman's model for compressible spiral grooved gas film. The approximate solution is derived from Muijderman's equations by Adomian decomposition method. The obtained approximate solution expresses the gas film pressure as a function of the gas film radius. The traditional Runge–Kutta method is avoided. The accuracy of the approximate solution is acceptable, and it brings convenience for performance calculation of spiral grooved gas seal. A complete Adomian decomposition procedure of Muijderman's equations is presented. The approximate solution is validated with published results.
Modeling Tangential Contact of Rough Surfaces With Elastic- and Plastic-Deformed Asperities
Authors: Wang Dong , Xu Chao , Wan Qiang
Published: January 2017

A new tangential contact model between a rough surface and a smooth rigid flat is proposed in this paper. The model considers the contribution of both elastically deformed asperities and plastically deformed asperities to the total tangential load of rough surface. The method combining the Mindlin partial slip solution with the Hertz solution is used to model the contact formulation of elastically deformed asperities, and for the plastically deformed asperities, the solution combining the fully plastic theory of normal contact with the bilinear relation between the tangential load and deformation developed by Fujimoto is implemented. The total tangential contact load is obtained by Greenwood and Williamson statistical analysis procedure. The proposed model is first compared to the model considering only elastically deformed asperities, and the effect of mean separation and plasticity index on the relationship between the tangential load and deformation is also investigated. It is shown that the present model can be used to describe the stick–slip behavior of the rough surface, and it is a more realistic-based model for the tangential rough contact. A comparison with published experimental results is also made. The proposed model agrees very well with the experimental results when the normal load is small, and shows an error when the normal load is large.
Progression of Severe Accidents, Containment Performance, and Estimates of Releases of Radionuclides-Level-2 Probabilistic Safety Assessment IPHWR
Authors: Guptan Rajee , Vijaya A. K. , Hari Vibha , Nama Rajeev
Published: January 2017

Probabilistic safety assessment (PSA) of nuclear power plants is performed to yield insights into the safety, design, and performance of the plants and their potential environmental effects. This includes the identification of dominant risk contributors, determination of the vulnerabilities of plant and containment systems, and comparison of options for risk reduction. Three levels of PSA are recognized. Level-1 addresses the identification of plant failures leading to core damage and their frequencies of occurrence. Level-2 addresses the assessment of containment response leading together with level-1 results to the determination of containment release frequencies. A level-2 PSA analyses the challenges to the containment, the possible containment responses and their estimated probabilities, and an assessment of the consequent releases to the environment. Level-3 is the assessment of off-site consequences leading, together with the results of level-2 analysis, for estimation of public risks. A comprehensive level-2 PSA study of a 220 MWe Indian Pressurized Heavy Water Reactor (IPHWR) is performed to assess the challenges to the containment, the possible containment responses and their estimated probabilities, and consequent releases to the environment. The dominating sequences consist of small-break loss of coolant accident (SBLOCA) and station black out (SBO) followed by containment isolation failure. The results of this are used as an input for developing the severe accident management guidelines (SAMG) measures. All the SAMG measures incorporated in this study have been found as beneficial and resulted in reduced large early release frequency (LERF).
Periodic Motions With Overshooting Phases of a Two-Mass Stick–Slip Oscillator
Authors: Pascal Madeleine
Published: January 2017

We investigate the dynamics of a two degrees-of-freedom oscillator excited by dry friction. The system consists of two masses connected by linear springs and in contact with a belt moving at a constant velocity. The contact forces between the masses and the belt are given by Coulomb's laws. Several periodic orbits including slip and stick phases are obtained. In particular, the existence of periodic orbits involving a part where one of the masses moves at a higher speed than the belt is proved.
Simplified Multistage Computational Approach to Assess the Fatigue Behavior of a Niti Transcatheter Aortic Valve During In Vitro Tests: A Proof-of-Concept Study
Authors: Petrini Lorenza , Dordoni Elena , Allegretti Dario , Pott Desiree , Kütting Maximilian , Migliavacca Francesco , Pennati Giancarlo
Published: January 2017

Nowadays, transcatheter aortic valve (TAV) replacement is an alternative to surgical therapy in selected high risk patients for the treatment of aortic stenosis. However, left ventricular contraction determines a severe cyclic loading for the implanted stent-frame, undermining its long-term durability. Technical standards indicate in vitro tests as a suitable approach for the assessment of TAV fatigue behavior: generally, they do not specify test methods but require to test TAV in the worst loading conditions. The most critical conditions could be different according to the specific valve design, hence the compartment where deploying the valve has to be properly identified. A fast and reliable computational methodology could significantly help to face this issue. In this paper, a numerical approach to analyze Nickel-Titanium TAV stent-frame behavior during in vitro durability tests is proposed. A simplified multistage strategy was adopted where, in each stage, only two of the three involved components are considered. As a proof-of-concept, the method was applied to a TAV prototype. Despite its simplifications, the developed computational framework gave useful insights into the stent-frame failures behavior during a fatigue test. Numerical results agree with experimental findings. In particular, the most dangerous condition was identified among a number of experimental tests, where different compartments and pressure gradients were investigated. The specific failure location was also correctly recognized. In conclusion, the presented methodology provides a tool to support the choice of proper testing conditions for the in vitro assessment of TAV fatigue behavior.
Efficient Closed-Form Solution of the Kinematics of a Tunnel Digging Machine
Authors: Boscariol Paolo , Gasparetto Alessandro , Scalera Lorenzo , Vidoni Renato
Published: January 2017

In this work, the kinematics of a large size tunnel digging machine is investigated. The closed-loop mechanism is made by 13 links and 13 class 1 couplings, seven of which are actuated. This kind of machines are commonly used to perform ground drilling for the placement of reinforcement elements during the construction of tunnels. The direct kinematic solution is obtained using three methods: the first two are based on the numerical solution of the closure equation written using the Denavit–Hartenberg convention, while the third is based on the definition and solution in closed form of an equivalent spherical mechanism. The procedures have been tested and implemented with reference to a real commercial tunnel digging machine. The use of the proposed method for the closed-form solution of direct kinematics allows to obtain a major reduction of the computation time in comparison with the standard numerical solution of the closure equation.
Deceiving proteins! A case of lymphoma and high creatinine
Authors: Metraiah El Hakem Abdelkarim , Regan Helen , Louw Johanna , Kidder Dana
Published: January 2017

Estimation of kidney function by measuring serum creatinine is one the commonest laboratory tests conducted in clinical practice. Enzymatic methods are often used to measure serum creatinine. Clinicians should be aware of the limitations of these methods, such as test interference with paraproteins.We present a case of falsely elevated serum creatinine in a patient referred for renal biopsy. The combination of fluctuating creatinine and normal blood urea level was unusual. Serum protein electrophoresis revealed the presence of an IgM paraprotein. Further investigations confirmed an underlying diagnosis of lymphoplasmacytoid lymphoma. This case highlights how IgM paraprotein can interfere with creatinine estimation by enzymatic assay and the utility of alternative methods of estimating serum creatinine.
Comprehensive atomic wavelengths, energy levels, and hyperfine structure for singly ionized iron-group elements
Authors: Nave Gillian , Sansonetti Craig J. , Townley-Smith Keeley , Pickering Juliet C. , Thorne Anne P. , Liggins Florence , Clear Christian
Published: January 2017

We summarize recent work at the National Institute of Standards and Technology and Imperial College London on wavelengths, hyperfine structure, energy levels, and analysis of singly ionized iron-group elements of astrophysical interest.
Semileptonic and leptonicBdecays, circa 2016
Authors: Ricciardi Giulia
Published: January 2017

We summarize the status of semileptonic and leptonic B decays, including [Formula: see text] and [Formula: see text] exclusive and inclusive determinations, decays to excited states of the charm meson spectrum and decays into [Formula: see text] leptons.
A Method for Unifying the Representations of Domain Knowledge and Planning Algorithm in Hierarchical Task Network
Authors: Cheng Kai , Chen Gang , Zhang Rui , Wu Liu , Wang Zhiteng , Kang Ruizhi
Published: January 2017

Domain knowledge of hierarchical task network (HTN) usually involves logical expressions with predicates. One needs to master two different languages which are used to describe domain knowledge and implement planner. This has presented enormous challenges for most programmers who are not familiar with logical expressions. To solve the problem a method of state variable representation from the programmer’s point of view is introduced. This method has powerful expressivity and can unify the representations of domain knowledge and planning algorithm. In Pyhop a HTN planner written in Python, methods and operators are all as ordinary Python functions rather than using a special-purpose language. Pyhop uses a Python object that contains variable bindings and does not include a horn-clause inference engine for evaluating preconditions of operators and methods. By taking a simple travel-planning problem, it shows that the method is easy to understand and integrate planning into ordinary programming.
Cascadable and Tunable Analog Building Blocks Using EX-CCCII
Authors: Maheshwari Sudhanshu , Agrawal Deepak
Published: January 2017

A new cascadable voltage-input, current-output first-order all-pass filter and its applications in second-order filter and oscillator are presented. The proposed circuit employs a single active element namely extra-X current-controlled current conveyor (EX-CCCII) and only a single grounded capacitor. The circuit exhibits high input and high output impedances, so that the filter can be cascaded without additional buffers. The pole frequency is electronically tunable and the circuit requires no component matching constraints. Effects of nonidealities and parasitics are also discussed. As applications, a second-order transadmittance (TA)-mode all-pass filter and a quadrature oscillator are also realized using the proposed voltage-input, current-output first-order all-pass filter. These examples validate easy cascading feature of the proposed circuit. The validity of the proposed circuit is verified through PSPICE simulations using 0.25[Formula: see text][Formula: see text]m parameters with a supply voltage of [Formula: see text][Formula: see text]V.
A MATHEMATICAL MODEL OF PANCREATIC CANCER WITH TWO KINDS OF TREATMENTS
Authors: HE DAN-HUA , XU JIAN-XIN
Published: January 2017

In this paper, we investigate a mathematical model of pancreatic cancer, which extends the existing pancreatic cancer models with regulatory T cells (Tregs) and Treg inhibitory therapy. The model consists of tumor-immune interaction and immune suppression from Tregs. In the absence of treatments, we first characterize the system dynamics by locating equilibrium points and determining stability properties. Next, cytokine induced killer (CIK) immunotherapy is incorporated. Numerical simulations of prognostic results illustrate that the median overall survival associated with treatment can be prolonged approximately from 7 to 13 months, which is consistent with the clinical data. Furthermore, we consider cyclophosphamide (CTX) therapy as well as the combined therapy with CIK and CTX. Intensive simulation results suggest that both CTX therapy and the combined CIK/CTX therapy can reduce the number of Tregs and increase the overall survival (OS), but Tregs and tumor cells will gradually rise to equilibrium state as long as therapies are ceased.
Stabilization of Internal Dynamics of Underactuated Systems by Periodic Servo-Constraints
Authors: Bencsik László , Kovács László L. , Zelei Ambrus
Published: January 2017

The model-based motion control of underactuated, multiple degree-of-freedom, complex multibody systems is in focus. Underactuated mechanical systems possess less number of independent control inputs than degrees-of-freedom. The main difficulty in their control is caused by the dynamics of the uncontrolled part of the system. The complexity of multibody systems makes the dynamical and control formulation difficult. The direct application of traditional control techniques available in the literature can lead to unstable dynamic behavior in many cases. In order to avoid instability, these general methods are usually adapted for specific problems in an intuitive way. Here, we present a direct, more algorithmic approach, and propose the use of periodic servo-constraints to overcome stability problems and enhance the dynamic behavior. An exact, stability analysis-based method is also proposed for tuning the control parameters. A stability analysis procedure is developed which is directly applicable for investigating the dynamics of mechanical systems described by dependent coordinates and mathematically formulated as a set of algebraic differential equations.
Thresholded spectral algorithms for sparse approximations
Authors: Guo Zheng-Chu , Xiang Dao-Hong , Guo Xin , Zhou Ding-Xuan
Published: January 2017

Spectral algorithms form a general framework that unifies many regularization schemes in learning theory. In this paper, we propose and analyze a class of thresholded spectral algorithms that are designed based on empirical features. Soft thresholding is adopted to achieve sparse approximations. Our analysis shows that without sparsity assumption of the regression function, the output functions of thresholded spectral algorithms are represented by empirical features with satisfactory sparsity, and the convergence rates are comparable to those of the classical spectral algorithms in the literature.
Quasineutral limit for a model of three-dimensional Euler–Poisson system with boundary
Authors: Liu Chundi , Wang Boyi
Published: January 2017

Quasineutral limit for a model of three-dimensional Euler–Poisson system in half space with a boundary layer is studied. Based on the matched asymptotic expansion method of singular perturbation problem and the elaborate energy method, we prove that the quasineutral regime is the incompressible Euler equation.
Optimal harvesting of a prey–predator model with variable carrying capacity
Authors: Ganguli Chaity , Kar T. K. , Mondal P. K.
Published: January 2017

This work deals with a prey–predator model in an environment where the carrying capacities are assumed to be variable with time and one species feeds upon the other. Independent harvesting efforts are applied in either species and asymmetrical intraguild predation occurs. A common resource is consumed by two competing species and at the same time predator also consumes the prey. At first we discuss the model under constant carrying capacity and make the conclusion that no limit cycle exists in this case. Then we discuss the model without intraspecific competition. Our main concern is to cover the above mentioned two cases together, i.e. the model with variable carrying capacity and intraspecific competition. We determine the steady states and examine the dynamical behavior. We also analyze the local and global stability of the interior equilibrium by Routh–Hurwitz criterion and a suitable Lyapunov function respectively. A Hopf bifurcation occurs with respect to a parameter which is the ratio of predator’s and prey’s intrinsic growth rate. The possibility of bionomic equilibrium has been considered. The optimal harvest policy is formulated and solved with Pontryagin’s maximum principle. Some numerical simulations are given to explain most of the analytical results.