bluuebunny/crossref_metadata_2025 huggingface dataset:
Modal Analysis for APR+ Reactor Barrel
Authors: Kang Heung Seok , Lee Kang Hee , Kwon Tae Soon
Published: April 2011

Korea Atomic Energy Research Institute (KAERI) is developing an Advanced Power Reactor Plus (APR+) which has several improved safety features. For one of the safety features, four Emergency Core Barrel (ECB) ducts are attached at the outer surface of the reactor barrel to guide well ECC water from the Direct Vessel Injection (DVI) lines to the reactor core if necessary. The main purpose of this study is to identify the vibration characteristic of the APR+ barrel, having four ECB ducts, and to compare it with a conventional barrel. For the identification, FE analysis and vibration (modal) test for a 1/5 scale model have been carried out in air and in quiescent water. The collateral purpose of this study is to quantify the effects of fluid in a narrow gap between the barrel and the outer vessel, which are the so-called mass, damping and stiffness effects exerted by the fluid.
Isotope-Based Analysis of Nuclear Waste Repository Performance
Authors: Pata Joosep , Tkaczyk Alan H.
Published: April 2011

It is necessary to consider the complexities of both natural and engineered components of a nuclear waste repository since fission products and minor actinides remain harmful to the environment for tens of thousands of years. In safety and performance assessments often used in decision-making about repository designs, the effect of uncertain initial guesses on the models’ output must be understood. As the necessary safe times and hence the simulated times are often in the order of magnitude of hundreds of thousands of years, uncertain initial values become increasingly important. To minimize the danger from high-level radioactive waste and to make informed decisions over designs, sensitivity analysis of the models used should be performed. The Simplified Total System Performance Assessment (STSPA) model developed by Golder Associates Inc., Booz-Allen Hamilton, Stone and Webster and the University of Nevada Reno and used in the Yucca Mountain nuclear waste repository performance assessment is analyzed for sensitivity by varying the activities of technetium-99 and iodine-129 by several orders of magnitude. The resultant dose to a maximally-exposed individual over time periods of 100,000 and 1,000,000 years is compared to the relevant regulatory limits. Incorrect estimates can be seen to have large effects on the behavior of the model while the method used allows conclusions to be drawn about the robustness of the model.
Time-Delay Models Parameters Identification of Heat Transfer Systems Using the Hybrid Algorithm
Authors: Simeunovic Goran , Zi´tek Pavel , Chysky Jan , Miletic Marija
Published: April 2011

The paper presents the identification issues and a parameters’ identification algorithm that separates the system parameters from the time-delays for the class of single input single output (SISO) linear time delay systems (LTDS). The presence of the unknown time delay greatly complicates the parameter estimation problem, because the parameters of the model are not linear with respect to the time-delay. However, once the time delay is determined, the model becomes linear for the other coefficient parameters and hence the common least square method can be utilized directly. This problem is solved in the paper [12]. Solution presented in the previous mentioned paper is based on the nonlinear least square problem developed in the paper [3]. The hybrid method based on the Genetic algorithm and the Nelder-Mead technique is used for the minimization of variable projection functional. The both techniques use a little local information and don’t require the derivation of the cost function. According to this fact the both previous mentioned techniques have a problem with the reliability and convergence rate. The convergence rate is smaller than the optimization techniques of the first order which use more local information including the gradient of cost function. In order to achieve the better convergence rate, the Quasi-Newton optimization method is used instead of the Nelder-Mead method. The special Broyden-Fletcher-Goldfarb-Shanno (BFGS) Quasi-Newton algorithm, which involves the several initial conditions treated at the same time developed by [8], is applied here. This approach is illustrated by a particular application in the field of the heat transfer, concretely on the time-delay model of the recuperative plate heat exchanger.
Sodium-Water Reaction Elucidation With Counter-Flow Diffusion Flame Experiment and Its Numerical Simulation
Authors: Yamaguchi Akira , Takata Takashi , Ohshima Hiroyuki , Sogabe Joji , Deguchi Yoshihiro , Kikuchi Shin
Published: April 2011

Sodium-water reaction (SWR) is a design basis accident of a Sodium Fast Reactor (SFR). A breach of the heat transfer tube in a steam generator (SG) results in contact of liquid sodium with water. Typical phenomenon is that the pressurized water blows off, vaporizes and mixes with the liquid sodium. The consequence of the accident are: thermal-hydraulic and chemical impact on the heat transport equipment and structure induced by the heat of exothermic reaction and caustic reaction product. The purpose of the present paper is to delineate the mechanism and process of the SWR by a counter-flow diffusion flame experiment and a numerical simulation. Based on the numerical simulation, the most appropriate and optimum condition in which stable and continuous diffusion flame of sodium and water vapor is obtained. Key idea is to perform the experiment in a depressurized reaction vessel. According to the experiment, spatial distributions of chemical reactants and products, temperature and particles are measured in detail. The characteristics of the SWR are explained from the present study and the chemical reaction model currently used in the analytical tool of the SWR is appropriate.
Experimental Turbulence Analysis of Fuel Bundle With Spacer Grids
Authors: Dominguez-Ontiveros Elvis , Estrada-Perez Carlos , Hassan Yassin
Published: April 2011

Rod bundles are widely used in industry today with applications ranging from nuclear reactors, heat exchangers, and steam generators. Accurately modeling the inherently unsteady and turbulent flow within these rods is essential in order to design for optimal efficiency while controlling vibration, noise and heat transfer. The problem complicates further when spacer-grids are used within the rods to maintain separation and structural rigidity. Computational modeling can be a useful alternative to the costly process of manufacturing and testing prototypes, but its accuracy needs to be checked with detailed experimental data. This paper describes an experimental database obtained using two-dimensional Time Resolved Particle Image Velocimetry (TR-PIV) measurements within a 5 × 5 rod bundle with spacer-grids. One of the unique characteristic of this set-up is the use of the Matched Index of Refraction technique employed in this investigation which consists of immersing plastic rods with a similar index of refraction as the one for water to achieve optical transparency across the spacer grid. This unique feature allows flow visualization and measurement within the bundle without rod obstruction. This approach also allows the use of high temporal and spatial non-intrusive dynamic measurement techniques namely TR-PIV to investigate the flow evolution below and immediately above the spacer. The data base presented includes explanation of the various cases tested such as boundary conditions, rig dimensions, measurement zones, and the test equipment in order to provide a good base for Computational Fluid Dynamics (CFD) simulations. Turbulence analysis of the obtained data is provided in order to gain insight of the physical phenomena and to compare the possible results obtained from computational simulations.
Rapid Bioassay Methods for Actinides in Urine
Authors: Dai Xiongxin , Kramer-Tremblay Sheila
Published: April 2011

Rapid bioassay methods for the determination of actinides in urine samples at ultra-trace levels are needed for both emergency and routine radiation exposure monitoring. Several rapid actinide urinalysis methods have been recently developed at the AECL Chalk River Laboratories. These methods employ hydrous titanium oxide co-precipitation followed with actinide separation using chromatographic columns; the actinide isotopes are analyzed by alpha spectrometry and inductively coupled plasma mass spectrometry. The chemical recoveries, procedural blanks, and achieved detection limits for these bioassay methods are also presented.
Droplet Measurement in a Rod Bundle Geometry for a Reflood Heat Transfer Test
Authors: Cho H. K. , Choi K. Y. , Cho S. , Song C.-H.
Published: April 2011

During the reflood phase of a postulated loss of coolant accident in a nuclear reactor, the entrainment of liquid droplets can occur at a quench front of reflooding water. It is widely recognized that the behavior of the entrained droplet crucially affects the reflood heat transfer phenomena by decreasing the superheated steam temperature and interacting with a rod bundle and spacer grids. For this reason, various experimental and numerical studies have been performed to examine droplet behavior such as the droplet size, velocity and droplet fraction inside a rod array. In this study, an experiment on the droplet behavior inside a heated rod bundle has been performed. The experiment was focused on the break-up of droplets induced by a spacer grid in a rod bundle geometry, which results in the increase of the interfacial heat transfer between droplets and superheated steam. A 6×6 rod bundle test facility in Korea Atomic Energy Research Institute was used for the experiment. Steam was supplied by an external boiler into the bottom of the test channel, and a droplet injection nozzle was equipped instead of simulating a quench front of reflooding water. The major measuring parameters of the experiment were the droplet size and velocity, and these were measured by a high-speed camera and a digital image processing technique. A series of experiments were conducted with various flow conditions of a steam injection velocity, heater temperature, droplet size and droplet flow rate. The experiments provided the data on the change of the Sauter mean diameter of droplets after collision with a spacer grid depending on flow conditions. Moreover, the data was analyzed with a droplet break-up model by a spacer grid which was implemented into a thermal hydraulic analysis code, COBRA-TF.
The Investigation of Shock Waves Forming by Disruption of Vessel With High-Enthalpy Coolant
Authors: Pribaturin N. , Lezhnin S. , Sorokin A. , Arhipov D. , Bykov M. , Posusaev D.
Published: April 2011

The physical and mathematical model of the shock wave formation and evolution in the outflow of a boiling coolant from a vessel filled with the high pressure water after depressurization was investigated. For mathematical description of the pressure waves formation processes the half-empirical relaxation model and the model of maximum superheating was used that is correspond to the description of the boiling processes as vaporization initiated by fluctuation nucleation. The amplitudes of the shock waves and the time dependencies of the pressure acting on the obstacles situated on different distances from the tube rupture were calculated. The influence of the initial coolant pressure and temperature, time of disruption and diameter on the intensity of shock wave were revealed by a series of calculations. It was found that the pressure on obstacle after the normal shock wave falling is dramatically increasing and then decreasing. Relative growth of amplitude of the reflection shock wave is increasing with a growth of initial temperature of the coolant in vessel.
Design and Analysis of Testing Platform for Study of Graphite Dust Emission Behavior During Accident Conditions
Authors: Chen Zhipeng , Yu Suyuan
Published: April 2011

Very High temperature gas-cooled reactor (VHTR), especially the pebble-bed core type reactor, is inevitable to take place the wear of graphite components and generate the graphite dust in the core. The graphite dust was taken away by helium coolant and deposited on the surface of the primary circuit, and the fission products may be absorbed on the dust. Since it is possible that the fission products are released with dust under the accident conditions such as depressurization events, they have a potential hazard of radiation exposure to the environment. In this paper, VHTR as the research object, a testing platform is to be built with the purpose of investigating the behavior of graphite dust emission during the accident conditions. Circuit loop design is used to simulate the primary system and nitrogen is used as the working substance. Experiments of graphite dust deposition and resuspension study, as well as the study of graphite dust emission behavior during the accident conditions in pebble-bed type design VHTR will be conducted on the testing platform. The experimental data will be used for the development of VHTR source term analysis modeling.
Enhanced CANDU 6: An Upgraded Reactor Product With Optimal Fuel Cycle Capability
Authors: Hopwood Jerry , Hastings Ian J. , Soulard Michael
Published: April 2011

Atomic Energy of Canada Limited (AECL) has two CANDU® reactor products matched to markets: the Enhanced CANDU 6™ (EC6™)[1,] a modern 700 MWe class HWR design, and the Advanced CANDU Reactor™ (ACR-1000™), a 1200 MWe class Gen III+ design. Both reactor types are designed to meet both market-, and customer-driven needs. Some of the new features incorporated into the EC6 reactor include increased power output, optimized maintenance outages, more automated testing and an Advanced Control Room. Lessons learned through feedback obtained from the operating plants have been incorporated into the design, and equipment obsolescence has been addressed. This paper presents basic EC6 design improvements; AECL works with its customers to assess their individual design requirements. Excellent neutron economy, on-power refueling, a simple fuel bundle, and the fundamental CANDU fuel channel design provide the EC6 reactor with unsurpassed flexibility in accommodating a wide range of advanced fuels and fuel cycles in addition to the standard natural uranium. These advanced fuels provide the promise of extending resources, reducing waste and enhancing proliferation resistance.
Progress of the Study on Corrosion Behavior of Graphite in HTGRs
Authors: Wang Peng , Yu Xinli , Yu Suyuan
Published: April 2011

The graphite has been widely used as moderator and structure materials in high-temperature gas-cooled reactors (HTGRs). However the graphite can be corroded by such oxidizing impurities as O2, H2O and CO2 in the coolant, resulting in the degradation of its thermal and mechanical properties. In addition, in water ingress and air ingress accidents, the corrosion of graphite materials is more serious. In this paper, the recent researches, which include the experimental study and computational simulations, on the graphite oxidation behavior during normal operation, water ingress and air ingress accidents were reviewed. Some significant problems concerned in the graphite oxidation for further studying were also put forward.
Quantitative Characterization of Long-Period Fluctuations in a Turbulent Bubbly Flow by Using a Four-Tip Optical Fiber Probe
Authors: Saito Takayuki , Imaizumi Ryota
Published: April 2011

Quantitatively characterizing the large-scale structure of buoyancy flows inevitably induced by bubble swarms is essential to deeply understand turbulent bubbly flows. In the present investigation, we discuss how to extract the long-period fluctuations of gas- and liquid-phase hydrodynamics of the flows in a large-diameter pipe, which correspond to the large-scale structure of the turbulent bubbly flows. For this specific purpose, using a newly developed method (combination use of a four-tip optical fiber probe (F-TOP) and a newly developed data processing algorism), we extracted and characterized long-period fluctuations of the turbulent bubbly flows in a large-diameter pipe apparatus of 380 mm in diameter and 2000 mm in height. First, we discuss a method to extract such fluctuations formed in the bubbly flow based on the time-series point-wise void fractions measured by the F-TOP. The fluctuations of the void fractions in time and space are modeled from a point-wise void fraction based on consideration of the relationship between time-average and space-average void fraction. We have found out a simple relationship between them. The space-average void fraction at the larger region shall reflect some larger organized structure of the bubbly flow. As a result, the time-average point-wise void fraction at a given point in appropriately integral time range shall indirectly represent corresponding organized structure. We demonstrate the effectiveness of the proposed method. Analyzing the time-series point-wise void fractions measured via the F-TOP by applying the above method, we have succeeded in extracting the long-period fluctuations. The extracted long-period fluctuations well agree with those obtained from visualization (i.e. large-scale structure of the bubble swarms). Second, the large-scale liquid-phase motion is characterized based on the results obtained by LDA measurements. We discuss the liquid-phase large-scale motion and the coupling between the large-scale motion and the long-period fluctuations of void fraction.
Single Phase and Two-Phase Flow Pressure Drop in Pebble Beds
Authors: Bai Bofeng , Liu Maolong , Lv Xiaofei , Su Wang , Yan Xiao , Xiao Zejun
Published: April 2011

An experimental study was conducted on the pressure drop of single phase and air-water two-phase flow in the bed of rectangular cross sections filled with uniform spheres densely. In the present flow-regime model, the bed was subdivided into a near-wall region and a central region. And a new empirical correlation for the prediction of single-phase flow pressure drops was proposed based on the model. The correlation can be used to predict the single phase pressure drop for both great tube-to-particle diameter ratio packed beds and small tube-to-particle diameter ratio packed beds and for the pebble beds packing with spherical particles and non spherical particles. A new empirical correlation for the prediction of two-phase flow pressure drops was proposed based on the gas phase relative permeability as a function of the gas phase saturation and the void fraction. The correlation fit well also for both experimental data points of spherical particles and non spherical particles.
Research on Digital Nuclear Power Measurement Equipment
Authors: Li Duo , Xiong Huasheng , Zhang Liangju
Published: April 2011

A research on digital nuclear power measurement equipment is discussed in this paper. In the research, some mainstream microprocessor technologies are compared and an embedded PC microprocessor system based on PC/104 bus is selected as the equipment development platform, which makes the equipment have all advantages of compact structure, high reliability, convenient adjustment and short development cycle. A concept design on the nuclear power measurement equipment is covered in this paper, and a prototype of the equipment with all expected functions is developed.
Technology computer-aided design simulation study for a strained InGaAs channel n-type metal-oxide-semiconductor field-effect transistor with a high-k dielectric oxide layer and a metal gate electrode
Authors: Chang Shu-Tong , Lee Chang-Chun , Sun P.-H.
Published: April 2011

The stress distributions in the InGaAs channel regions of strained InGaAs metal-oxide-semiconductor (MOS) field-effect transistors with high-k dielectric layer, metal gate, and InGaAs alloy souce/drain (S/D) stressors were studied with three-dimensional process simulations. It was shown that the geometric effects, such as channel width and length, could impact the achievable transistor performance gains. In this work, high-performance III-V MOS devices were achieved by stressors, such as S/D stressors, with the InGaAs alloy material. The resulting mobility improvement was analyzed by the Monte Carlo simulations. Tensile stress along the transport direction was found to dominate mobility gain while narrower devices (<1 μm), and a decrease of tensile stress along the channel direction contributed to a decrease in mobility gain owing to the decreasing width. This work helps the future III-V-based MOS device design and demonstrates that strain engineering is important for future nanoscale device technology.
PI3Kβ Plays a Critical Role in Neutrophil Activation by Immune Complexes
Authors: Kulkarni Suhasini , Sitaru Cassian , Jakus Zoltan , Anderson Karen E. , Damoulakis George , Davidson Keith , Hirose Misa , Juss Jatinder , Oxley David , Chessa Tamara A. M. , Ramadani Faruk , Guillou Herve , Segonds-Pichon Anne , Fritsch Anja , Jarvis Gavin E. , Okkenhaug Klaus , Ludwig Ralf , Zillikens Detlef , Mocsai Attila , Vanhaesebroeck Bart , Stephens Len R. , Hawkins Phillip T.
Published: April 2011

The β isoform of phosphoinositide 3-kinase may be an effective therapeutic target in inflammatory diseases.
A secure protocol for protecting the identity of providers when disclosing data for disease surveillance
Authors: El Emam Khaled , Hu Jun , Mercer Jay , Peyton Liam , Kantarcioglu Murat , Malin Bradley , Buckeridge David , Samet Saeed , Earle Craig
Published: April 2011

Background Providers have been reluctant to disclose patient data for public-health purposes. Even if patient privacy is ensured, the desire to protect provider confidentiality has been an important driver of this reluctance.

Methods Six requirements for a surveillance protocol were defined that satisfy the confidentiality needs of providers and ensure utility to public health. The authors developed a secure multi-party computation protocol using the Paillier cryptosystem to allow the disclosure of stratified case counts and denominators to meet these requirements. The authors evaluated the protocol in a simulated environment on its computation performance and ability to detect disease outbreak clusters.

Results Theoretical and empirical assessments demonstrate that all requirements are met by the protocol. A system implementing the protocol scales linearly in terms of computation time as the number of providers is increased. The absolute time to perform the computations was 12.5 s for data from 3000 practices. This is acceptable performance, given that the reporting would normally be done at 24 h intervals. The accuracy of detection disease outbreak cluster was unchanged compared with a non-secure distributed surveillance protocol, with an F-score higher than 0.92 for outbreaks involving 500 or more cases.

Conclusion The protocol and associated software provide a practical method for providers to disclose patient data for sentinel, syndromic or other indicator-based surveillance while protecting patient privacy and the identity of individual providers.
I.: THE FISHES OF GEORGIAN BAY.
Authors: Bensley B.A., Ph.D., F.R. B. A.
Published: April 2011

not available
Weighted residual approach to constant strain rate test
Authors: Stolle Dieter , Stolle Jonathan
Published: April 2011

This note presents a virtual displacement approach to analyze the constant rate of strain consolidation test. It yields simplified “exact” equations within the weighted residual context for interpreting test data. Equations corresponding to larger time factors are similar to those presented in the literature, although the transient effects are clearer than in previous formulations. An advantage of the framework is that assumptions concerning the uniformity of properties through a sample can be relaxed. The derivation shows that E must be constant for the coefficient of consolidation to be independent of position. Depending on the sequencing of sublayers, it is shown that basal pore pressure can be higher or lower for layered media compared with uniform material when allowing E to vary, even though cvis kept constant.
COORDINATION OF AGRI-FOOD CHAIN WITH REVENUE-SHARING CONTRACT UNDER STOCHASTIC OUTPUT AND STOCHASTIC DEMAND
Authors: ZHAO XIA , WU FANGWEI
Published: April 2011

Due to the effects of uncertain factors such as seasonal weather and plant/animal diseases, the output of agricultural production is uncertain given certain agricultural inputs. This paper addresses the issue of coordinating agri-food chain with perishable goods by revenue-sharing (RS) contract when both output and demand are random. Following a RS contract, a supplier decides on agricultural input (e) and deliveries all goods with a price (ω) lower than unit production cost to the retailer while a retailer decides on the retail price (p) and return 1–Φ share (percentage) of its revenue to the supplier. For such a contract, the necessary condition of coordinating the chain is that the expected revenue function is concave. Under the channel coordination, the relationship between RS contract parameters ω and Φ as well as the range of Φ are given. For both output and demand random factor with uniform distribution, the concavity of the expected revenue function is presented. A numerical example illustrates the correctness of our analysis. The results of numerical example show that RS contract is able to coordinate the agri-food chain when the expected revenue function is concave. The results also show that the optimal decisions of p and e are closely related to the demand price elasticity and the range of Φ is widened when the expected output increases.
THE STUDY OF COLLECTIVE FLOW AND BARYON STOPPING OF RELATIVISTIC HEAVY-ION COLLISIONS IN THE AGS, SPS, RHIC AND LHC ENERGY REGIONS
Authors: FENG SHENGQIN , ZHONG YANG
Published: April 2011

We study the features of baryon stopping and collective flow in relativistic heavy-ion collisions at energies reached at the CERN Large Hadron Collider (LHC), BNL Relativistic Heavy Ion Collider (RHIC), CERN Super Proton Synchrotron (SPS) and BNL Alternating Gradient Synchrotron (AGS) with the model of Non-Uniform Flow Model (NUFM) in this paper. The dependencies of the features of baryon stopping and collective flow on the collision energies are investigated.
A NOTE ON THIRD RANK KILLING–YANO TENSORS AND DIRAC-TYPE OPERATORS
Authors: POPA FLORIAN CATALIN
Published: April 2011

We show that third rank Killing–Yano tensors are useful objects in the study of Dirac-type operators and their existence for a given background guarantees the absence of gravitational anomalies.
COLLECTIVE TREATMENT OF HIGH ENERGY THRESHOLDS IN SUSY GUT's
Authors: KATSIKATSOU A.
Published: April 2011

Supersymmetric GUT's are the most natural extension of the Standard Model unifying electroweak and strong forces. Despite their indubitable virtues, among these the gauge coupling unification and the quantization of the electric charge, one of their shortcomings is the large number of parameters used to describe the high energy thresholds, which are hard to handle. We present a new method according to which the effects of the high energy thresholds, in any GUT model, can be described by fewer parameters that are randomly produced from the original set of the parameters of the model. In this way, regions favored by the experimental data are easier to locate, avoiding a detailed and time-consuming exploration of the parameter space, which is multidimensional even in the most economic unifying schemes. To check the efficiency of this method, we directly apply it to a SUSY SO(10) GUT model in which the doublet–triplet splitting is realized through the Dimopoulos–Wilczek mechanism. We show that the demand of gauge coupling unification, in conjunction with precision data, locates regions of the parameter space in which values of the strong coupling α strong are within the experimental limits, along with a suppressed nucleon decay, mediated by a higgsino driven dimension five operators, yielding lifetimes that are comfortably above the current experimental bounds. These regions open up for values of the SUSY breaking parameters m0, M1/2 < 1 TeV being therefore accessible to LHC.
NONLINEAR FREE VIBRATION OF SIMPLY SUPPORTED BEAMS CONSIDERING THE EFFECTS OF SHEAR DEFORMATION AND ROTARY INERTIA, A HOMOTOPY PERTURBATION APPROACH
Authors: MOJAHEDI MAHDI , MOEENFARD HAMID , AHMADIAN MOHAMMAD TAGHI
Published: April 2011

The objective of this paper is to apply He's homotopy perturbation method (HPM) to analyze nonlinear free vibration of simply supported Timoshenko beams considering the effects of rotary inertia and shear deformation. First, the equation governing the nonlinear free vibration of a Timoshinko beam is nondimensionalized. Galerkin's projection method is utilized to reduce the governing nonlinear partial differential equation to a nonlinear ordinary differential equation. HPM is then used to find analytic expressions for nonlinear natural frequencies of the pre-stretched beam. A parametric study has also been applied in order to investigate the effects of design parameters such as applied axial load and slenderness ratio. Comparison between presented results and numerical results which are in full agreement shows that HPM can significantly improve the accuracy of previously reported results in the literature.
SIMULATION OF KdV-BURGERS EQUATION WITH LATTICE BGK MODEL
Authors: CHEN LINJIE , MA CHANGFENG
Published: April 2011

The lattice BGK method is a recently developed numerical scheme for simulating a variety of physical systems in recent years. In this paper, a four-speed lattice BGK model is given for simulating KdV-Burgers equation ut+uux-αuxx+βuxxx = 0. Simulating results are compared with the analytical solution of the KdV-Burgers equation and they are in excellent agreement with each other.
THERMALLY ACTIVATED FLUX CREEP AND CURRENT CONDUCTION IN YBCO + BZO COMPOSITES
Authors: MOHANTA A. , DASH S. , BEHERA D.
Published: April 2011

BaZrO 3 submicron powder obtained from chemical route was added to YBCO for preparation of YBCO + xBZO (x = 0, 1, 2.5, 5, 10 rm wt%) composites samples. The X-ray peak profile analyses and the scanning electron microscopy have indicated that the mean powder size for BZO ranges from 500 to 800 nm. In fact, the presence of BZO brings about a significant modification in the microstructure of the composites. The resistive transition in presence of magnetic field (0–8 T) was investigated. With application of magnetic field, Tc0 decreases significantly, suggesting that grain boundaries (Josephson junctions) are affected more than the grains (Abrikosov junctions). Activation energy is found dependent not only on the particle size, but also on penetration depth and decreases with increasing doping concentration of BZO submicron size particles in contrast to what has been recently observed by M. Safonchik et al. with grain sizes of 40 nm BZO. It has also been observed by H. Shakeripour, M. Akhavan [Supercond. Sci. Technol.14, 234 (2001)] and Gamchi et al. [Phys. Rev. B50, 12950 (1994)] that the activation energy depends not only on the temperature and magnetic field, but also on the doping concentration.
SUBTRACTIVE COMPOSITE SIMPSON METHOD FOR LOW COST INERTIAL NAVIGATION SYSTEMS
Authors: NIA AMIR MOOSAVIE , MIRZAJANI R. , ESFALANI M.
Published: April 2011

This paper presents a new method to decrease the error of real time numerical integration in an Inertial Navigation System (INS), which is widely used in aircrafts, spacecrafts, and field robotics. The well-known Runge–Kutta method is often used for real time numerical integration in INS algorithms. Here a combination of the composite Simpson's 1/3 and 3/8 rules is developed to effectively reduce the total integration error, named Subtractive Composite Simpson Method (SCSM). Also we propose a new method that efficiently reduces the error of the integrator block using the combination of a fourth-order Runge–Kutta (RK4) and SCSM. Simulation results show one order of magnitude decrease in position error after double integration of acceleration value. Extra accuracy gain using this new method makes it possible to choose low cost inertial sensors to realize a low cost INS.
A NEW DYNAMIC FUNCTIONAL UNIT ALLOCATION STRATEGY IN HIGH-LEVEL SYNTHESIS TO ACHIEVE POWER–AREA TRADE-OFFS
Authors: WU FENG , XU NING
Published: April 2011

The increasing power consumption levels of integrated circuits (ICs) have become a major concern of the semiconductor industry. Excessive power dissipation causes overheating, which can lead to soft errors or permanent damage. It also limits battery life in portable equipment. High power consumption can be reduced by properly increasing area. However, arbitrarily large area, namely high number of functional units (FU) in high-level view, dramatically increases IC cost. This paper describes a new dynamic-power aware High Level Synthesis data path approach that considers dynamic FU allocation while attempting to minimize area, power, or make a trade-off between them. The experimental results have shown that when the area is nearly the same, our approach delivers a 5.99% reduction in power consumption. And when the power consumption is nearly the same, a 11.81% reduction in total FU area occurs. And we can obtain different optimal power–area trade-off values by adjusting power and area ratios.
BIFURCATION ANALYSIS OF A NFDE ARISING FROM MULTIPLE-DELAY FEEDBACK CONTROL
Authors: NIU BEN , WEI JUNJIE
Published: April 2011

We study the stability and Hopf bifurcation of a neutral functional differential equation (NFDE) which is transformed from an amplitude equation with multiple-delay feedback control. By analyzing the distribution of the eigenvalues, the stability and existence of Hopf bifurcation are obtained. Furthermore, the direction and stability of the Hopf bifurcation are determined by using the center manifold and normal form theories for NFDEs. Finally, we carry out some numerical simulations to illustrate the results.
ASYMPTOTICALLY OPTIMAL KINODYNAMIC MOTION PLANNING FOR A CLASS OF MODULAR SELF-RECONFIGURABLE ROBOTS
Authors: REIF JOHN , SLEE SAM
Published: April 2011

Self-reconfigurable robots are composed of many individual modules that can autonomously move to transform the shape and structure of the robot. The task of self-reconfiguration, transforming a set of modules from one arrangement to another specified arrangement, is a key problem for these robots and has been heavily studied. However, consideration of this problem has typically been limited to kinematics and so in this work we introduce analysis of dynamics for the problem. We characterize optimal reconfiguration movements in terms of basic laws of physics relating force, mass, acceleration, distance traveled, and movement time. A key property resulting from this is that through the simultaneous application of constant-bounded forces by a system of modules, certain modules in the system can achieve velocities exceeding any constant bounds. This delays some modules in order to accelerate others.

To exhibit the significance of simultaneously considering both kinematic and dynamics bounds, we consider the following "x-axis to y-axis" reconfiguration problem. Given a horizontal row of n modules, reconfigure that collection into a vertical column of n modules. The goal is to determine the sequence of movements of the modules that minimizes the movement time needed to achieve the desired reconfiguration of the modules. In this work we prove tight [Formula: see text] upper and lower bounds on the movement time for the above reconfiguration problem. Prior work on reconfiguration problems which focused only on kinematic constraints kept a constant velocity bound on individual modules and so required time linear in n to complete problems of this type.
SOME CONSEQUENCES OF SMALL INTERSECTION NUMBERS IN THE DEHN QUANDLE AND BEYOND
Authors: ZABLOW JOEL
Published: April 2011

We extend the notion of geometric intersection numbers 0 and 1, for circles in the Dehn quandle, to general quandles, assuming existence of elements having certain algebraic properties in the latter. These properties enable the construction of many useful 2 and 3 cycles in Dehn quandle homology. Particularly, we construct a special 2-cycle homology representative and an operation which promotes it to higher dimensional cycles of the same type, in the Dehn quandle, and show how to do so in any quandles admitting such elements. For such quandles, this gives some non-triviality results in the quandle homology. We look at a secondary rack formed by tuples of elements of the Dehn quandle and using the ideas above, obtain some basic non-triviality results in its homology as well. We also give some initial possibilities for its application in representing monodromy of singularities of elliptic fibrations.
OPTIMALLY IMMERSED PLANAR CURVES UNDER MÖBIUS ENERGY
Authors: DUNNING RYAN P.
Published: April 2011

This paper investigates the existence of optimally immersed planar self-intersecting curves. Because any self-intersecting curve will have infinite knot energy, parameter-dependent renormalizations of the Möbius energy remove the singular behavior of the curve. The direct method of the calculus of variations allows for the selection of optimal immersions in various restricted classes of curves. Careful energy estimates allow subconvergence of these optimal curves as restrictions are relaxed.
HAUSDORFF DIMENSION OF CERTAIN RANDOM SELF-AFFINE FRACTALS
Authors: LUZIA NUNO
Published: April 2011

In this work we are interested in the self-affine fractals studied by Gatzouras and Lalley [5] and by the author [11] who generalize the famous general Sierpinski carpets studied by Bedford [1] and McMullen [13]. We give a formula for the Hausdorff dimension of sets which are randomly generated using a finite number of self-affine transformations each generating a fractal set as mentioned before. The choice of the transformation is random according to a Bernoulli measure. The formula is given in terms of the variational principle for the dimension.
NEW CHARACTERIZATIONS OF GENERALIZED DEDEKIND PRIME RINGS
Authors: AKALAN EVRIM , SARAC BÜLENT
Published: April 2011

In this paper, we give new characterizations of generalized Dedekind prime rings in the class of prime Noetherian rings satisfying a polynomial identity. We provide examples to illustrate our results.
ON A SPECIAL CLASS OF EXACT SEQUENCES
Authors: LÜ JIA-FENG , CHEN MIAO-SEN
Published: April 2011

The notion of good exact sequence is introduced, which is a special class of exact sequences including split exact sequences as special examples. Several criteria characterizing good exact sequences are given. In particular, we prove that the exact sequence ξ: 0 → K → M → N → 0 is good if and only if the Horseshoe Lemma is true in the "minimal version" with respect to ξ. We also give a lot of nontrivial examples of good exact sequences via "Koszul" objects. Moreover, some applications of good exact sequences are also provided in the end.
CLOSED AND PRIME IDEALS IN PARTIAL SKEW GROUP RINGS OF ABELIAN GROUPS
Authors: ÁVILA JESÚS , FERRERO MIGUEL
Published: April 2011

In this paper we study partial actions of abelian groups on a ring R having an enveloping action. Among other results we prove that if α is such a partial action and (T, β) its globalization, then there exists a one-to-one correspondence between closed (respectively, R-disjoint prime) ideals of R ⋆α G and closed (respectively, T-disjoint prime) ideals of T ⋆β G. We also prove that there exists a one-to-one correspondence between closed (respectively, R-disjoint prime) ideals of R ⋆α G and closed (respectively, [Formula: see text]-disjoint prime) ideals of [Formula: see text], where [Formula: see text] is the left α-quotient ring of R. Finally, we use these results to study strongly prime ideals and nonsingular prime ideals of R ⋆α G.
ON THE REPRESENTATIONS OF WEAK CROSSED PRODUCTS
Authors: SHEN BING-LIANG , XIONG BAO-LIN
Published: April 2011

Let H be a finite-dimensional weak Hopf algebra in the sense of [G. Böhm and K. Szlachányi, A coassociative C*-quantum group with nonintegral dimensions, Lett. Math. Phys.35 (1996) 437–456] which is semisimple as well as its dual H*, A be a finite-dimensional algebra measured by H and A#σH be a weak crossed product. Then we first prove that the representation dimension of A#σH equals to that of A. Moreover, we will show that over an algebraically closed field k, the representation type between A and its weak crossed product algebra A#σH is coincident, which extends the result given by Liu [On the structure of tame graded basic Hopf algebras, J. Algebra 299 (2006) 841–853]. Finally, we show that A#σH is a CM-finite n-Gorenstein algebra if and only if so is A and the global Gorenstein projective dimension of A#σH is equal to that of A.
ZERO-DIVISOR GRAPHS OF ÖRE EXTENSION RINGS
Authors: AFKHAMI M. , KHASHYARMANESH K. , KHORSANDI M. R.
Published: April 2011

Let R be an associative ring with two-sided multiplicative identity. In this paper, in the case that R is a commutative α-compatible ring, we compare the diameter (and girth) of the zero-divisor graphs Γ(R) and Γ(R[x;α, δ]). Moreover, we study the zero-divisors of the Öre extension ring R[x;α, δ], whenever R is reversible and (α, δ)-compatible.
A GENERALIZATION OF PRÜFER'S ASCENT RESULT TO NORMAL PAIRS OF COMPLEMENTED RINGS
Authors: DOBBS DAVID E. , SHAPIRO JAY
Published: April 2011

Let R ⊆ T be a (unital) extension of (commutative) rings, such that the total quotient ring of R is a von Neumann regular ring and T is torsion-free as an R-module. Let T ⊆ B be a ring extension such that B is a reduced ring that is torsion-free as a T-module. Let R* (respectively, A) be the integral closure of R in T (respectively, in B). Then (R*, T) is a normal pair (i.e. S is integrally closed in T for each ring S such that R* ⊆ S ⊆ T) if and only if (A, AT) is a normal pair. This generalizes results of Prüfer and Heinzer on Prüfer domains to normal pairs of complemented rings.
SKEW POWER SERIES RINGS OF DERIVATION TYPE
Authors: BERGEN JEFFREY , GRZESZCZUK PIOTR
Published: April 2011

In this paper, we contrast the structure of a noncommutative algebra R with that of the skew power series ring R[[y;d]]. Several of our main results examine when the rings R, Rd, and R[[y;d]] are prime or semiprime under the assumption that d is a locally nilpotent derivation.
ON THETA PAIRS FOR A MAXIMAL SUBALGEBRA
Authors: SALEMKAR ALI REZA , CHEHRAZI SARA , NIRI SOMAIEH ALIZADEH
Published: April 2011

Given a maximal subalgebra M of a finite-dimensional Lie algebra L, a θ-pair for M is a pair (A, B) of subalgebras such that A ≰ M, B is an ideal of L contained in A ∩ M, and A/B includes properly no nonzero ideal of L/B. This is analogous to the concept of θ-pairs associated to maximal subgroups of a finite group, which has been studied by a number of authors. A θ-pair (A, B) for M is said to be maximal if M has no θ-pair (C, D) such that A < C. In this paper, we obtain some properties of maximal θ-pairs and use them to give some characterizations of solvable, supersolvable and nilpotent Lie algebras.
SYMMETRY FOR COMODULE CATEGORIES
Authors: CRIVEI SEPTIMIU , IOVANOV MIODRAG CRISTIAN
Published: April 2011

For coalgebras C over a field, we study when the categories [Formula: see text] of left C-comodules and [Formula: see text] of right C-comodules are symmetric categories, in the sense that there is a duality between the categories of finitely presented unitary left R-modules and finitely presented unitary left L-modules, where R and L are the functor rings associated to the finitely accessible categories [Formula: see text] and [Formula: see text].
ON PROJECTIVELY RELATED WARPED PRODUCT FINSLER MANIFOLDS
Authors: REZAII M. M. , ALIPOUR-FAKHRI Y.
Published: April 2011

Let 𝔽1 = (M1,F1) and 𝔽2 = (M2,F2) be two Finsler manifolds and let M = M1 × M2 and S is a spray in M. Also 𝔽 = (M1 × f M2, F) is a warped product Finsler manifolds, such that the function f : M1 → ℝ+ is not constant. In this paper, we define a non-linear connection on warped product 𝔽, and finally, we have presented some necessary and sufficient conditions under which the spray manifold (M1 × M2, S) is projectively equivalent to the warped product Finsler manifolds (M1 × f M2, F).
Influence of Synthesis Process on Mechanical and Electrical Characteristics of Mesoporous Pure Silica-Zeolite
Authors: Seo T. , Yoshino T. , Ohnuki N. , Seino Y. , Cho Y. , Hata N. , Kikkawa T.
Published: April 2011

The dielectric constant, elastic modulus and reliability of the pure silica-zeolite composite film which was formed by self-assembly of porous silica having hydrothermally crystallized zeolite nanoparticles. Fourier-transform-infrared spectroscopy indicated that Si-OH and O-H bonds decreased by zeolite formation, resulting in the decrease of the dielectric constant. Silylation hardening by 1,3,5,7-tetramethylcyclotetrasiloxane (TMCTS) vapor treatment could decrease the dielectric constant due to the decrease of Si-OH and O-H bonds. The elastic modulus of 7.03 GPa and the dielectric constant of 1.94 were achieved for the meso-porous silica-zeolite film by silylation hardening. Furthermore, mean-time-to-failure (MTF) lifetime of time-dependent dielectric breakdown (TDDB) is longer than ten years at 125°C under the electric field of 3.4 MV/cm.
X-Linked Lymphoproliferative Syndrome and Common Variable Immunodeficiency May Not Be Differentiated bySH2D1AandXIAP/BIRC4Genes Sequence Analysis
Authors: Gulez Nesrin , Aksu Guzide , Berdeli Afig , Karaca Neslihan , Tanrıverdi Sema , Kutukculer Necil , Azarsiz Elif
Published: April 2011

The X-linked lymphoproliferative syndrome (XLP) is a rare, inherited immunodeficiency characterized by recurrent episodes of hemophagocytic lymphohistiocytosis, hypogammaglobulinemia, and/or lymphomas. Recently, X-linked inhibitor of apoptosis (XIAP/BIRC4) gene defects, in families with XLP but withoutSH2D1Agene defects, has been defined. The distinction from primary immunodeficiencies with a defined genetic cause is mandatory. A six-year-old male patient was admitted with the complaints of persistent general lymphadenopathy, for two years had fever, bilateral cervical multiple microlymphadenopathy, hepatic/splenic enlargement with laboratory findings as decreased serum immunoglobulins, negative EBV VCA IgM (viral capsid antigen) and anti-EBV EA (antibody to early D antigen), positive EBV VCA IgG (viral capsid antigen) and EBV EBNA (antibody to nuclear antigen).SH2D1Agene analysis was negative.XIAP/BIRC4sequencing revealed two novel single nucleotide variants (exon 7, 1978G > A, and 1996T > A) in the 3′UTR of the gene in both patient and mother which were not disease causing. XIAP protein expression was found to be normal. The clinical and laboratory resemblance, no gene mutations, and normal XIAP protein expression led us to think that there may be another responsible gene for XLP. The patient will to be followed up as CVID until he presents new diagnostic signs or until the identification of a new gene.
A Security Scheme for Dependable Key Insertion in Mobile Embedded Devices
Authors: Klimm Alexander , Glas Benjamin , Wachs Matthias , Vogel Sebastian , Müller-Glaser Klaus D. , Becker Jürgen
Published: April 2011

Public Key Cryptography enables entity authentication protocols based on a platform's knowledge of other platforms' public key. This is particularly advantageous for embedded systems, such as FPGA platforms, with limited or none read-protected memory resources. For access control systems, an access token is authenticated by the mobile system. Only the public key of authorized tokens needs to be stored inside the mobile platform. At some point during the platform's lifetime, these might need to be updated in the field due to loss or damage of tokens. This paper proposes a holistic approach for an automotive access control system based on Public Key Cryptography. Next to a FPGA-based hardware architecture, we focus on a secure scheme for key flashing of public keys to highly mobile systems. The main goal of the proposed scheme is the minimization of online dependencies to Trusted Third Parties, Certification Authorities, or the like, to enable key flashing in remote locations with only minor technical infrastructure. Introducing trusted mediator devices, new tokens can be authorized and later their public key can be flashed into a mobile system on demand.