bluuebunny/crossref_metadata_2025 huggingface dataset:
A Method for Setting the Optimal Production Status Based on Genetic Algorithm in a Discrete Assembly System
Authors: Dong Liang , Yan Zhen Guo , Zhang Jie , Du Kun Peng , Wang Yan Ping
Published: December 2011

In a discrete assembly system, setting its optimal production status is one of the key works in assembly line balancing. Based on analyzing the objectives of assembly line control, a general flow for setting the optimal production status is proposed, and a method to identify rapidly the setting objects of production status is introduced. Then an optimal configuration solution for production status and its solving method in a station of an assembly line are established based on the genetic algorithm. At last, a wing assembly line is set as an example to validate this method, and the result shows that this method can provide a solution to optimize production status parameters for each station in this assembly line, which can reduce the resource idle time and cost, and so its resource utilization rate is improved.
Numerical Simulation of Acoustic Field for the Miniature Cylindrical Transducer with a Rectangular Hole
Authors: Yu Li Li , Zhao Jin Hua , Zhao Quan Zhou , Hui Chun
Published: December 2011

In this paper the characteristics of acoustic field for miniature cylindrical focused transducer with a hole was studied in order to instruct the optimization design of the transducer for both realizing visualization and improving the treatment effect. Then the acoustic field was simulated numerically with different parameters of hole. It is found that position of focus is almost unchanged but acoustic pressure amplitude declines. In addition the performance of transverse focusing for the focal plane and levels length of acoustic pressure are lowered. Moreover, if size of transducer and rigidity of material permit, the area and ratio of width to height for the hole should be reduced appropriately to improve the focusing properties. And it is deduced that area and ratio of width to height for the cylinder can be increased to achieve the same therapeutic effect with a fixed hole size.
Conceptual Design for Degreasing Pill Machine Based on TRIZ
Authors: Liu Fang , Jiang Ping , Tan Run Hua
Published: December 2011

Conceptual design is the most meaningful period to show the creativity in the process of product design. TRIZ specially deals with innovation and conceptual design. A process model of conceptual design based on TRIZ is constructed. Dropping pill machine is improved by using the proposed process model. A new principle solution is obtained based on effect base in TRIZ. Then contradiction existed in the new principle solution is solved by using the principle of contradiction solving in TRIZ. New degreasing pill machine can output pills automatically, and has high availability.
Decouple Design of Engine Suspension System Vibration
Authors: Peng Sheng Hui , Wang Yuan , Xu Li , Dai Xi Liang
Published: December 2011

The engine is the main vibration resource of vehicle. In this paper the uncouple rate was the object function and the suspending system’s stiffness were set to the design variable, during the calculation the transfer rate and the frequency rotate the axle x were considered. With the optimization the uncouple rate was improved which can improve the engine’s vibration ability effectively.
An Improved Difference Template Matching Algorithm
Authors: Wang Yan Wei , Liang Hong , Li Jin , Pan Yan Ming , Cai Zhong Xi
Published: December 2011

Compared with the difference template matching algorithm, which is low efficiency and poor results, the improved difference template matching algorithm is proposed. Firstly, the model is subdivided into blocks that are clustered along the neighbor areas. Then, a point is set in every sub model. Furthermore, the different template matching, used in small local flied concurrently, to fix the cell center point and set the cell area circumference. Experimental results show that the proposed algorithm is effective and robust.
Study on the Monitoring Method of Overburden Failure of Shallow Wongawilli Mining Working Face
Authors: Zhang Bin , Li Wen , Li Shao Gang , Zhang Jun Ying
Published: December 2011

Through the practice and improvement of Wongawilli Mining method in Shendong Mining Area, it created Shendong Characteristic short wall mechanize room mining method. Due to the shallow coal seam, the fracture zones throughout the bedrock directly after the mining, therefore the bending sinking belt didn’t exist; the conventional "three zones" theory couldn’t explain the overburden rock deformation damage rule of this situation perfectly. In order to monitor the damage of overburden strata, based on the analysis of coal pillars stability in Wongawilli working face, the paper puts forward 3D monitoring methods of overburden strata damage as follows: underground borehole stress monitoring, roof separated strata and layer's internal monitoring, surface subsidence monitoring. The set of monitoring method can monitor the instability of coal pillars, roof caving, production of separated strata in the roof, overburden rock damage and subsidence, the study is of reference and significance.
Modeling of Surface Subsidence Based on Time Function
Authors: Han Hao Liang , Cui Bo
Published: December 2011

Base on Knothe time function, a new time function was proposed by adding parameter which is approved more accurate in predicting surface subsidence than Knothe funciton. Combing this new time function with section function of surface subsidence basin, a dynamic model is proposed to predict surface subsidence induced by underground mining and a case study based on this model was carried out. The results illustrates this model is more accurate to reflect the dynamic process of surface subsidence
The Application and Innovation of the Paper Material in Terms of Decoration Design
Authors: Yu Tian Tian , Hu Wei Ping
Published: December 2011

The paper material is a kind of green eco-friendly material, economic, practical and colorful, having various species. With the development of modern technology development of making paper, traditional paper material has different characteristics. This article aims to research the paper material and apply the environmental-friendly material to the adornment design. It can be applied and innovated not only in interior decoration wallpaper, but also in smallpox decoration and furniture material.
Force Analysis and Optimal Design of Propeller for Garbage Powder Mixer
Authors: Huang Mei Fa , Luo Wei Zhao , Qian Guang
Published: December 2011

Propeller is one of the critical parts in garbage powder mixer and affect significantly to the performance. In order to obtain a more reasonable structure, force analysis and stress analysis is carrier out for the propeller based on the actual working condition. Optimal design for the propeller is implemented by the results of stress analysis. To verify the rationality and feasibility of this mechanism, the finite element analysis for the propeller is performed by using the ANASYS software. The simulation results show that the maximum stress of the propeller is on the joint of blade and rod. The optimized propeller is satisfied with the strength requirements.
Asset Price and the Optimal Monetary Policy: Model and Simulation
Authors: Peng Hai Cheng , Li Lu
Published: December 2011

The validity and merits of the monetary policy is reflected in the level of the attainment of its ultimate goal. We build up a decision-making model of central bank and deduce the optimal money supply reaction function of considering and ignoring asset price. In order to clarify the relationship between the optimal monetary policy and asset price volatility, we simulate the macroeconomic performance of optimal reaction function of considering and ignoring asset price in a wide range of monetary policy objective. We conclude that monetary policy should respond to volatility of asset price directly.
Research on Stiffness and Damping Characteristics of Fixed Oily Porous Materials Joint Interface
Authors: Qu Chong Nian , Wu Liang Sheng , Ma Jian Feng , Xiao Yi Chuan
Published: December 2011

In this document, using the anti-squeezed force model in the narrow parallel plate when fluid is squeezed, the equivalent stiffness and damping model is derived. It is further verified that it can increase the stiffness and damping while there are oil between the joint interfaces theoretically. Because the contact state of oily porous material can divide into liquid and solid parts, the document supposes that it is correct and effective to think the stiffness and damping of the two parts as shunt connection.
Study on Foot Pad of Tree Frog and Design of Bionic Surface
Authors: Shen Xiao , Zhuang Li Fu
Published: December 2011

Based on the observation and research of the macroscopic and microscopic foot pad of tree frog, we analyzed the influence of the surface topography of tree frog’s foot pad on its adhesion, and got the macroscopic and microscopic typical characteristics of the surface topography of tree frog’s foot pad, a bionic surface with hierarchical structure was designed, which had the advantage of increasing friction and had many important applications in life and engineering.
Some Relationship between Safety Factor of Earthquake Slope and Related Parameters
Authors: He Xiao Hei , Han Geng You , Xiao Rui Hua
Published: December 2011

Abstract:Since the Wenchuan earthquake happened, the slope stability had been paid much more attention. The safety factor is an important parameter that can be used to evaluate the stability of slope. The pseudo-static method that based on limit equilibrium and the method of numerical simulation can calculate the safety factor accurately, but the velocity that gets the result is slow. If we can establish the relationship between safety factor and some other parameters, then we can calculate the safety factor by using the relationship more quickly. This paper establishes much relationship, such as the relationship between the rock mechanics parameters and the average danymic safety factor, the relationship between the rock mechanics parameters and the ratio of average danymic safety factor to static safety factor, the relationship between the rock mechanics parameters and the average earthquake acceleration coefficient, the relationship between the average earthquake acceleration coefficient and the ratio of average danymic safety factor to static safety factor, and the relationship between the earthquake acceleration coefficient and the ratio of danymic safety factor to static safety factor on the condition of different rock mass.
Pipeline Material Reliability Analysis Regarding to Probability of Failure Using Corrosion Degradation Model
Authors: Alfon Patuan , Soedarsono Johny W. , Priadi Dedi , Sulistijono S
Published: December 2011

Reliability of equipment of the oil and gas industry is vital, whereas on pipeline transmission system, decreasing the integrity of the pipeline is generally caused by corrosion. Failure that occurs due to corrosion deterioration influenced by the environment within a certain time, and has exceeded the nominal thickness of the pipe so there is a failure. This study used the reliability analysis approach based on modeling corrosion degradation ratio that is determined by the amount of the corrosion rate externally and internally. Using the Weibull probabilistic distribution method, results that the reliability of pipeline will decrease with increasing lifetime. It was identified that internal corrosion has a major contribution to the remaining life of pipeline. From the calculation results obtained by external corrosion has the greatest reliability over 60 years, followed by internal corrosion less than 30 years and the least is by cumulative corrosion which is less than 20 years. From the value of reliability, it can be known probability of failure (POF) which is the anti reliability.
Effect of the Vehicle Aerodynamics Performance under Cross Wind Condition Caused by Stiffeners
Authors: Xiong Xiao Hui , Liang Xi Feng
Published: December 2011

New lightweight material has been applied in the vehicle manufacture of the raised speed and high speed train. In order to strength the intensity of the vehicle, some stiffeners were designed on the vehicle top. In strong cross wind, stiffeners would change the flow field distribution of the vehicle top. Phenomenon of the flow separation would occur on the part of area. In order to study the aerodynamics effected by stiffeners in cross wind, the aerodynamics performance of the 300km/h high-speed vehicle have been calculated by FLUENT when there were stiffeners on the vehicle top or not. Result obtained shows that in cross wind, the side force and the overturning moment of the vehicle with stiffeners will increase; it is greater than those of the vehicle without stiffeners. The increase values are 52.94% and 39.49%. And the lift force of the vehicle with stiffeners has some drops.
Study of Operating Parameters’ Impact on Separation Performance of Cyclone Separator
Authors: Wang Xue Ping , Zhang Ying , Xue Ju Guang , Zhang Zhen Wei
Published: December 2011

The numerical simulation can be obtained by taking advantage of turbulence model of Fluent to study the gas-solid flow field of cyclone separator. The pressure of the cyclone drops increases with the enhancement of the inlet flow velocity, and the increase amplitude can become larger and larger. The separation efficiency of the cyclone enhances gradually as the increase of the flow. The increase amplitude of small and secondary particles is much lager compared with the increase amplitude of big ones. The overall separation efficiency can strengthen gradually with increasing of particles concentration as well as the each part’s efficiency. But the separation efficiency will stay in stable level when the concentration reaches a certain value with the big particles in the low concentration and small ones in a relatively high concentration.
Modification Method by Increasing and Decreasing Elements in the Emergent Design System
Authors: Kito Akira , Mizumachi Yuki , Sekiguchi Mitsuhiro , Sato Koichiro , Matsuoka Yoshiyuki
Published: December 2011

This paper describes a modification method which strengthens forms for deriving diverse design solutions in structural design. In the early process of design, diverse design ideas are generated from a global solution search under unclear design conditions. In the past study, we have proposed the emergent design system, which allows a global solution search under limited design conditions to derive diverse design solutions. The proposed system derives geometrically novel in forms, but most of them do not satisfy the evaluation standard so that they are not applicable as solutions. Therefore, if we can modify these forms to applicable solutions, the diversity of applicable solutions would increase. In this paper, we propose a modification method which satisfies the evaluation standard by increasing and decreasing elements, and show the possibility of increasing the diversity of solutions.
Differential Evolution Algorithm Used for Parameters Reconstruction of Fiber Gratings
Authors: Wen Xiao Yan , Qian Yu , Fei Nie
Published: December 2011

Differential Evolution (DE) algorithm has been used to solve the reverse problem of fiber gratings, namely, reconstructing the structure parameters of uniform and chirped fiber gratings from the target reflection spectra. The reconstructed parameters and corresponding spectra are in good agreement with the target ones. Numerical examples demonstrate the highly efficiency and accuracy of DE algorithm in solving the reverse problem of fiber Gratings.
Microstructural Characterization of Ferroelectric Bismuth Ferrite (BiFeO3) Ceramic by Electron Backscattered Diffraction
Authors: Kolte Jayant , Gulwade Devidas , Daryapurkar Aatish , Gopalan Prakash
Published: December 2011

Ferroelectric BiFeO3 (BFO) is potential candidate for future generation of FeRAM due to its large polarization. However, BFO is very sensitive to secondary phase formation during synthesis because of volatility issues related to Bismuth. Investigation of the microstructure for phase purity is the key as impurities can destroy the desired properties. We have used backscattered electron diffraction to study the microstructure of BFO ceramic. The EBSD results provide a direct evidence of the appearance of secondary phase that XRD could not be detected in XRD.
The Brass-Type Texture – How close Are we to Understand it?
Authors: Leffers Torben
Published: December 2011

This paper summarizes a recent review about the brass-type texture and its deviation from the copper-type texture by the present author and R.K. Ray – with somewhat sharpened conclusions.
Angular Precision of Automated Electron Backscatter Diffraction Measurements
Authors: Wright Stuart I. , Basinger Jay A. , Nowell Matthew M.
Published: December 2011

Electron backscatter diffraction (EBSD) has become the preferred technique for characterizing the crystallographic orientation of individual grains in polycrystalline microstructures due to its ability to rapidly measure orientations at specific points in the microstructure at resolutions of approximately 20-50nm depending on the capabilities of the scanning electron microscope (SEM) and on the material being characterized. Various authors have studied the angular resolution of the orientations measured using automated EBSD. These studies have stated values ranging from approximately 0.1° to 2° [1-6]. Various factors influence the angular resolution achievable. The two primary factors are the accuracy of the detection of the bands in the EBSD patterns and the accuracy of the pattern center (PC) calibration. The band detection is commonly done using the Hough transform. The effect of varying the Hough transform parameters in order to optimize speed has been explored in a previous work [6]. The present work builds upon the earlier work but with the focus towards achieving the best angular resolution possible regardless of speed. This work first details the methodology used to characterize the angular precision then reports on various approaches to optimizing parameters to improve precision.
Experimental Investigation of Texture Gradients in Aluminium/Copper Plates Bonded through Explosive Welding Process
Authors: Paul Henryk , Miszczyk M. , Prażmowski M.
Published: December 2011

In this study, the commercial purity Al/Cu plates were bonded through the explosive welding process. The SEM/EBSD local orientation measurements were conducted to consider the changes in the microstructure and the development of texture gradients for the applied explosive loading. A particular attention was paid to the texture changes across the interface. The detailed local orientation measurements show that the ultra-fine grained layers are formed close to the bonding zone. The layers were characterized by the copper-type rolling texture components. The interface was outlined by a characteristic sharp transition between the two materials. However, in some places, local melted zones were also encountered, mainly in the front slope of the waves.
Study on Preparation and Impact Performance of the Aluminium Foam Reinforced by ZrO2 Spheres
Authors: Wu Jian Guo , Wang Lu Cai
Published: December 2011

The aluminium foam can be reinforced by compositing high hardness ZrO2 ceramic spheres. On the condition of preparing the precursor composed of the salt particals and ceramic spheres, the sample of composite aluminium foam is parpared by the press casting infiltration process.By the Hopkinson Bar hopkinson bar experiment, the result shows the composite sample holded the better impact performance than the aluminium foam .All of these should establish a basement to promote the deeper study and developmenter of composite foamed material.
Preparation of Activated Carbons for Electrochemical Capacitors by Microwave Heating
Authors: Xing Bao Lin , Chen Lun Jian , Zhang Chuan Xiang , Guo Hui
Published: December 2011

Activated carbons (ACs) were prepared from lignite by microwave heating with KOH as activation agent, the effects of the weight ratio of KOH to coal and microwave heating time on the pore structure of ACs were investigated by N2 adsorption. The electrochemical characteristics of electrochemical capacitors (ECs) with ACs as electrodes in 3mol/L KOH electrolyte were evaluated by galvanostatic charge/discharge cycling, cyclic voltammetry and electrochemical impedance spectroscopy. The results show that the BET specific surface area and total pore volume of ACs (denoted as AC-R3) can reach 2097m2/g and 1.19cm3/g respectively when the weight ratio of KOH to coal is 3:1 and the microwave heating time is 10 min. The ECs with AC-R3 as electrodes presents a high specific capacitance of 335F/g at a low current density of 50mA/g and still remains 288F/g even at a high current density of 5A/g, it has excellent cycling stability and low leakage current, and the residual specific capacitance is as high as 93.6% after 1000 cycles under the current density of 2.5A/g. The results have demonstrated that the microwave heating with KOH activation is an efficient approach to prepare ACs with high performance for ECs. Keywords: Activated Carbons; Microwave Heating; Electrochemical Capacitors; Electrochemical Characteristics
Surface Finishing for Al2O3 Ceramics
Authors: Wang Hong
Published: December 2011

A process for electroless copper plating on Al2O3 ceramic products was provided. The bath is composed of components A (containing potassium tartrate 35 ~ 45 g/L, sodium hydroxide 7 ~ 9 g/L and sodium carbonate 3 ~ 4 g/L) and B (containing copper sulfate 7 ~ 14 g/L, nickel chloride 1 ~ 2 g/L and formaldehyde 15 ~ 20 g/L) with a volume ratio of 3:1. The bath composition and technological conditions of surface pretreatment were given, including degreasing, roughening, sensitizing, activating, and reducing. The formulation and process parameters for electroplating copper followed by coloring in five different colors, which are widely demanded in the market, were introduced. The coatings obtained by the presented processes on Al2O3 ceramic products are smooth and bright, producing an elegant appearance and greatly extending their service lives. All these technologies have been successfully applied to practical electroplating production, showing a wide development future.
Flux Jet Technique for Purification of Molten Aluminum
Authors: Zeng Jian Min , Liang Han Qing , Hao Cheng Gang
Published: December 2011

In this paper a new technology for purification of molten aluminum, namely flux jet technology has been presented. The basic principle of this method is that the molten flux is forced to inject into the molten aluminum and create strong vortex and is uniformly mixed with the molten aluminum under the pressure differential. The flux and the molten aluminum will mix fully to contact each other. In this way, the inclusions in the aluminum will transfer into the flux because of the absorption of the flux to the inclusions. As the result, the molten aluminum will be purified. The experiments were carried out for A357 aluminum foundry alloy with the flux (40% NaCl, 30% KCl, 10% NaF and 20% Na3AlF6). The results show that after 3 cycles, the inclusion contents dramatically decreases from 1.61% to 0.333%, a decline rate of 79.4%; and hydrogen concentration decreased from 0.32ml/100gAl to 0.09ml/100gAl, with hydrogen removal rate being 72%.
Fabrication and Properties of APS- and RTS-Sprayed TiB2/Mo2FeB2 Multiphase Ceramic Coating on Q235 Steel
Authors: Guo Xin Ling , Wang Wei , Li Shao Jie
Published: December 2011

A kind of TiB2/Mo2FeB2 composite powders for reactive thermal spraying (RTS) and atmospheric plasma spraying (APS) were prepared using Mo powder, Fe-B alloy powder, Fe powder and TiB2 powder. The TiB2/Mo2FeB2 composite ceramic coatings were synthesized and deposited by APS and RTS on Q235 steel. Microstructure and phases were investigated by X-ray diffraction (XRD) and scanning electrical microscopy (SEM). The thermal shock resistance, wear resistance and corrosion resistance were characterized with the relevant lab testing equipment. The result indicates that the coatings are composed of the major phases Mo2FeB2, TiB2 and α-Fe, a little of Fe2O3, FeO, and B2O3.The thermal shock times of RTS-sprayed coatings is 44, the corrosion resistance is 6.07 times than those of the substrate, respectively, while those of APS-sprayed coatings are 55 and 15.5, respectively. The mass loss of Q235 steel is 138.6g/m2, while the mass loss of the coatings with 30% TiB2 which were prepared by RTS is 28.0952g/m2, the mass loss of the coatings with 30% which were prepared by APS is 15.4028g/m2, when the testing load was 400N. Therefore, the coatings with 30%TiB2 prepared by APS possess better wear resistance than the Q235 steel substrate.
Numerical Simulation of Eccentric Extrusion Form Bending Pipe Parts
Authors: Song Ji Shun , Li Yun Tao , Du De Heng , Ma Xu , Yin Kang
Published: December 2011

Eccentric extrusion method is used in this paper，through this method achieved bending aluminum-alloy tube extrusion forming process. Used finite element method，achieved three-dimensional numerical simulation of bending aluminum-alloy tube in eccentric extrusion by DEFORM-3D finite element commercial software，analyzed velocity field distribution，material flow，squeezing pressure，stress and strain field distribution of the process；Introduce the mechanism of one step direct extrusion forming tube bending process，it will be of great guiding significance the actual die design.
Hot Deformation Behavior and Processing Maps of Cr-Ni-Mn-N Austenitic Stainless Steel
Authors: Bao Er , Wang Ming Jia , Wang Zi Xi , He Huan
Published: December 2011

The hot deformation behavior of a Cr-Ni-Mn-N series stainless steel was studied at temperatures from 850°C to 1175°C with the strain rate ranging from 0.01 s−1 to 10 s−1 using a Gleeble-3500 simulator. The constitutive equation and processing maps were compiled based on a hot compression test to strain of 0.9. The deformation microstructures were observed systematically by optical microscopy. Results show that the efficiency of power dissipation gradually increases with rising temperature and decreasing strain rate. The maps at strains of 0.5 and 0.9 show two distinct domains with one having the peak efficiency of about 28–35% at 1150°C–1175°C and 1–10 s−1 and the other having the peak efficiency of about 33–45% at 1050°C–1150°C and 0.01–0.5 s−1, while complete recrystallization is evident.
Numerical Simulation Analysis on Shrinkage and Porosity of ZL101A Alloy Mechanism Box
Authors: Zhou Yan Jun , Song Ke Xing , Zhang Yan Min , Guo Xiu Hua
Published: December 2011

The Shrinkage and porosity of ZL101A alloy mechanism box prepared by sand gravity casting process was investigated. The solidification process was simulation analysis by using InteCAST software and the original casting process was optimized based on the above simulated results. The results showed that the shrinkage and porosity defects’ position of ZL101A alloy mechanism box were accurately predicted by the analysis procedure which was from liquid distribution to shrinkage formation and then to Niyama shrinkage porosity. The shrinkage and porosity of the ZL101A alloy mechanism box prepared by optimized process were clearly reduced and the distribution of them was reasonable. Keywords: InteCAST software;ZL101A; Mechanism box; Shrinkage and porosity; Numerical simulation
The St Venant Zone Extent of the Self-Balancing Longitudinal Elastic Stress
Authors: Mazur Igor , Bel’skii Sergey M.
Published: December 2011

In the gaps between cells within continuous groups of rolling mills, as a result of local temperature and mechanical factors, longitudinal elastic stress may arise in the strip; this stress is the sum of uniform and self-balancing components. These components affect metal flow in the deformation source. According to the St Venant principle, the influence of the self-balancing component declines with increasing distance from the point of action. The longitudinal and transversal distribution of the self-balancing elastic stress in the strip was analyzed as well as the maximum distance between the deformation source and the point of elastic stress in the strip at which the self-balancing component still affects the plastic deformation of the metal, i.e., the extent of the influence zone of the self-balancing component. The results of this analysis will be useful for a design of new flatness control methods and devices.
Quantitative Separation of NMR Signal Amplitude of Water in Wood on the Basis of T2
Authors: Ma Da Yan , Wang Xi Ming , Zhang Ming Hui , Li Xue Qi
Published: December 2011

As a kind of crude and green material, wood is essential to human life. Meanwhile, the amount of water played a vital role to almost all engineering properties of wood. Moisture affects dimensional stability, physical and mechanical properties, and susceptibility toward biological degradation. Consequently, it provides a theoretical basis for the reasonable drying model to explore the water assignment and content in timber. we present here the application of a nuclear magnetic resonance technique, which is used to quantitatively analyse water distribution in wood on the basis of T2. In this paper, we will analyse the water distribution in hardwood on the basis of T2. Refer to the scanning electron micrographs of the hardwood, we can speculate the relaxation time of the water in different cell lumens respectively. Moreover, it is even more important to calculate the organic proportion in wood by the corresponding amplitude of signal derived from the water in different cell lumens. This, compared with a scanning electron micrograph, has allowed us to produce a assumable distribution of water in wood, even the corresponding organic proportion in wood, which allows us to speculate physical and mechanical properties of wood. A mobile NMR probe has been used as a non-destructive and non-invasive tool for water content analysis on wood samples. In this paper, we will adopt NMR methods to explain. This, has opened up a way for the accurate determination of the moisture content of wood, even can be applied to the areas of food and so on. Keywords: Nuclear magnetic resonance; Water distribution in wood; T2; Scanning electron micrograph; Water content
The Heat Treatment Parameters and Microconstituent Content Prediction of ADI Based on Fuzzy Subtractive Clustering Method
Authors: Guo Xu Hong , Liu Chang , Zhang Quan
Published: December 2011

Ductile cast iron was quenched at different austempering temperatures with different isothermal time, so there were austempered ductile iron (ADI) materials with nine different mechanical properties. Their metallographic structures were qualitatively and quantitatively analyzed with scanning electron microscope and X-ray diffraction method. Curves of the relationships between heat treatment parameters, content of retained austenite and carbon content in retained austenite were studied respectively. Models that showed their relationships were built in the base of fuzzy subtractive clustering method to research the rules of isothermal temperatures and time affecting the microconstituent of ADI. The results show that the metallographical matrix structures of ADI become ausferrite, and its mechanical properties are strengthened notably. From the curves and fuzzy models, we knew that the effect of austempering temperature on the component content of ADI was predominant, and austempering time was inferior. Thus, as the temperature increased, the content of retained austenite, carbon content in retained austenite increased markedly. Keywords: ADI, heat treatment parameters, retained austenite, carbon content of retained austenite, fuzzy subtractive clustering model
Effects of External Loads on the Reliability of A131 Welded Pipe with Circumferential Crack
Authors: He Bo Lin , Yu Ying Xia , Huo Li Xing , Zhang Yu Feng
Published: December 2011

In this paper, the reliability of welded pressure pipe with circumferential surface crack was calculated by using three dimensional stochastic finite element method for A131 pipe steel. This method has overcome the shortcomings of conservative results in safety assessment with deterministic fracture mechanics method. The calculation of reliability was based on three dimensional elastic-plastic stochastic finite element programs which were developed by ourselves. The calculation results indicate that the external load has great effect on the reliability of the welded pipe. When the mean value of bending moment changes from 10000N.m to 20000N.m, the failure probability of the welded pipe will change from 3.3750×10-9 to 1.6794×10-1. When the mean value of moment is changed from10000N.m to 20000N.m, the failure probability of the welded pipe increases dramatically for the same circumferential crack opening angle, inner pressure and the crack depth. The method has put forward a new way for safety assessment of welded pipe with circumferential surface crack.
Coarsening of Particles in Coarse Grain Heat-Affected Zone for Ti Microalloyed Steels
Authors: Zhang Ying Qiao , Zhang Han Qian , Li Zhi Yong
Published: December 2011

The coarsening behavior of Ti (CxN1-x) particles in CGHAZ for Ti-microalloyed steel has been studied after different welding thermal cycles corresponding to heat inputs 30, 60, 100kJ/cm using Gleeble-3800 thermo/mechanical simulator and transmission electron microscopy. Cuboid TiN and a lot of ellipsoidal or elongated particles VC, M3C and M23C6 are observed in the base metal. After welding thermal cycle with peak temperature of 1350°C, irregular particles existed in base metal have also been dissolved even at the lowest heat input of 30kJ/cm. TiN Particles coarsening are observed in CGHAZ with the increase of heat inputs that is just related to dissolution and reprecipitation of particles and irrelevant to isothermal growth of particles. Keywords: microalloyed steel; coarse grain heat-affected zone; TiN particles
Finite Element Analysis of Transient Welding Stress and Strain during Ti-6Al-4V Thin Plate Welding with Impact Rotation
Authors: Zhang Yong , Yang Jian Guo , Liu Xue Song , Fang Hong Yuan
Published: December 2011

The internal thermal transient stress and strain is difficult to be real time measured by experimental methods during welding, but the stress and strain is vital to understand the mechanism of the control on the wave-like deformation. Large nonlinear finite element software of MSC.Mrac is used to illustrate decrease of the wave-like deformation of the Ti-6Al-4V thin plate weldment by a new technique called welding with impacting rotation. Some simulation results such as temperature field, thermal transient stress evolution, elastic strain, plastic strain and distortion of thin plate are shown. By the help of the finite element analysis, the mechanism of control on the wave-like deformation was put forward, i.e. the residual stress was decreased by the certain amount plastic extensive deformation generated by the impacting revolution. Keywords: finite element analysis (FEA), Ti-6Al-4V, thin plate weldment, wave-like deformation, residual stress
Predication of Wettability of Sn Droplet on Copper Plate by MEAM Method
Authors: Yang Jian Guo , Cheng Hong Tao , Fang Hong Yuan
Published: December 2011

In this paper, Modified Embedded Atom Method (MEAM) method, one of the molecular dynamic (MD) methods, was utilized to investigate the wettability of Sn droplet on the copper plate to simulate the wetting and spreading phenomena of the solder process. And the experiment of spreading and wetting process of Sn droplet on the copper plate was performed by sessile-drop as well to get the contact angles. The results show that the MEAM method is fit to simulate the soldering process. Keywords: Wettability; Soldering; MEAM; Sessile-drop; Molecular dynamic
The Synthesis of CNTs over Hydroxyapatite by CVD and the Preparation of CNTs/HA in Situ Composite
Authors: Li Hai Peng , Wang Li Hui , Liang Chun Yong , Wang Hong Shui
Published: December 2011

Carbon nanotubes (CNTs) over hydroxyapatite (HA) as catalyst carrier were synthesized successfully using transition metal by chemical vapor deposition (CVD). The influences of catalyst types on the synthesis of CNTs were investigated when using Fe, Co and Ni as transition metal catalyst respectively. The results showed that CNTs synthesized by Fe catalyst normally possess more ideal morphology and higher crystallinity than those by the other two. But the yield rates of CNTs synthesized by CVD were in the order of Ni>Fe>Co. On the basis of this, HA matrix composites reinforced by CNTs in-situ were prepared and their mechanical properties were studied preliminarily. This study supplies valuable information for controlling the property of CNTs/HA composite by the selection of catalyst.
Overactive bladder syndrome in the ageing population
Authors: Finney Steven Mark , Eardley Ian
Published: December 2011

Overactive bladder syndrome (OAB) is a common problem in the older age group that can seriously effect quality of life. It raises challenges in the assessment and treatment of the patient with attention needed to be given to the presence of co-existent disease, cognition, patient motivation and the potential negative effects of pharmacological treatment. Though with the correct approach a substantial amount patients should derive some benefit.
Encapsulation of Polyunsaturated Fatty Acid Esters with Solid Lipid Particles
Authors: Holser Ronald
Published: December 2011

Encapsulation of structurally sensitive compounds within a solid lipid matrix provides a barrier to prooxidant compounds and effectively limits the extent of oxidative degradation. This offers a simple approach to preserve the bioactivity of labile structures. The technology was developed for cosmetic and pharmaceutical products but may be applied to additives used in food and feed formulations. The encapsulation of docosahexaenoic acid (DHA) and α-linolenic acid (ALA) was examined as model compounds of current interest in functional foods and feeds. Solid lipid particles were prepared from triglycerides containing saturated and unsaturated fatty acids and evaluated by differential scanning calorimetry. The thermal characteristics of the lipids used to form the particle were related to molecular structure and could be adjusted by selection of the appropriate component fatty acids. Encapsulation by solid lipid particles provides a method to inhibit oxidation and improve shelf life of products formulated with DHA and ALA.
Construction of non separable dyadic compactly supported orthonormal wavelet bases for $L^2 (\mathbb R^2)$ of arbitrarily high regularity
Authors: Ayache Antoine
Published: December 2011

By means of simple computations we construct new classes of non separable QMFs. Some of these QMFs will lead to non separable dyadic compactly supported orthonormal wavelet bases for

L^2 (\mathbb R^2)

of arbitrarily high regularity.
Local limit theorems on some non unimodular groups
Authors: Le Page Emile , Peigné Marc
Published: December 2011

Let

G_d

be the semi-direct product of

\mathbb R^{*+}

and

\mathbb R^d

,

d≥1

and let us consider the product group

G_{d,N} = G_d \times \mathbb R^N

,

N≥1

. For a large class of probability measures

\mu

on

G_{d,N}

, one proves that there exists

\rho (\mu) \in ]0,1]

such that the sequence of finite measures

\Big\lbrace\frac {n^{(N+3)/2}}{\rho (\mu)^n} \mu^{*n}\Big\rbrace_{n≥1}

converges weakly to a non-degenerate measure.

Soit

G_d

le produit semi-direct de

\mathbb R^{*+}

et de

\mathbb R^d

et

G_{d,N}

le
groupe produit

G_d \times \mathbb R^N

,

N≥0

. Pour une large classe de mesures de
probabilité sur

G_{d,N}

nous montrons qu'il existe

\rho (\mu) \in ]0,1]

tel que la
suite de mesures finies

\Big\lbrace\frac {n^{(N+3)/2}}{\rho (\mu)^n} \mu^{*n}\Big\rbrace_{n≥1}

converge vaguement vers une mesure non nulle.
Harmonic analysis in value at risk calculations
Authors: Albanese Claudio , Seco Luis
Published: December 2011

Value at Risk is a measure of risk exposure of a portfolio and is defined as the maximum possible loss in a certain time frame, typically 1-20 days, and within a certain confidence, typically 95%. Full valuation of a portfolio under a large number of scenarios is a lengthy process. To speed it up, one can make use of the total delta vector and the total gamma matrix of a portfolio and compute a Gaussian integral over a region bounded by a quadric. We use methods from harmonic analysis to find approximate analytic formulas for the Value at Risk as a function of time and of the confidence level. In this framework, the calculation is reduced to the problem of evaluating linear algebra invariants such as traces of products of matrices, which arise from a Feynmann expansion. The use of Fourier transforms is crucial to re-sum the expansions and to obtain formulas that smoothly interpolate between low and large confidence levels, as well as between short and long time horizons.
An X-ray transform estimate in $\mathbb R^n$
Authors: Laba Izabella , Tao Terence
Published: December 2011

We prove an x-ray estimate in general dimension which is a stronger version of Wolff's Kakeya estimate [12]. This generalizes the estimate in [13] which dealt with the

n=3

case.
Endpoint multiplier theorems of Marcinkiewicz type
Authors: Tao Terence , Wright James
Published: December 2011

We establish sharp

(H^1, L^{1,q})

and local (

L

log

^r L, L^{1,q}

) mapping properties for rough one-dimensional multipliers. In particular we show that the multipliers in the Marcinkiewicz multiplier theorem map

H^1

to

L^{1,\infty}

and

L

log

^{1/2}L

to

L^{1,\infty}

, and that these estimates are sharp.
Moduli of certain Fano 4-folds
Authors: Bailey, Jr. Walter L.
Published: December 2011

In this brief note we give a proof that a certain family of Fano 4-folds described below is complex locally complete and effectively parametrized in the sense of Kodaira-Spencer [Ko-Sp].
The infinite Brownian loop on a symmetric space
Authors: Anker Jean-Philippe , Bougerol Philippe , Jeulin Thierry
Published: December 2011

The infinite Brownian loop

\{B_t^0,t\ge 0\}

on a Riemannian manifold

\mathbb{M}

is the limit in distribution of the Brownian bridge of length

T

around a fixed origin

0

, when

T\to+\infty

. It has no spectral gap. When

\mathbb{M}

has nonnegative Ricci curvature,

B^0

is the Brownian motion itself. When

\mathbb{M}=G/K

is a noncompact symmetric space,

B^0

is the relativized

\Phi_0

-process of the Brownian motion, where

\Phi_0

denotes the basic spherical function of Harish-Chandra, i.e. the

K

-invariant ground state of the Laplacian. In this case, we consider the polar decomposition

B_t^0=(K_t,X_t)

, where

K_t\in K/M

and

X_t\in\bar{\mathfrak a}_+

, the positive Weyl chamber. Then, as

t\to+\infty

,

K_t

converges and

d(0,X_t)/t\to 0

almost surely. Moreover the processes

\{X_{tT}/\sqrt{T},t\ge 0\}

converge in distribution, as

T\to+\infty

, to the intrinsic Brownian motion of the Weyl chamber. This implies in particular that

d(0,X_{tT})/\sqrt{T}

converges to a Bessel process of dimension

D=\mathrm{rank} \mathbb{M}+2j

, where

j

denotes the number of positive indivisible roots. An ingredient of the proof is a new estimate on

\Phi_0

.
A Parabolic Quasilinear Problem for Linear Growth Functionals
Authors: Andreu Fuensanta , Caselles Vicent , Mazón José M.
Published: December 2011

We prove existence and uniqueness of solutions for the Dirichlet problem for quasilinear parabolic equations in divergent form for which the energy functional has linear growth. A typical example of energy functional we consider is the one given by the nonparametric area integrand

f(x, \xi) = \sqrt{1 + \Vert \xi \Vert^2}

, which corresponds with the time-dependent minimal surface equation. We also study the asymptotic behaviour of the solutions.
High Frequency limit of the Helmholtz Equations
Authors: Benamou Jean-David , Castella François , Katsaounis Theodoros , Perthame Benoît
Published: December 2011

We derive the high frequency limit of the Helmholtz equations in terms of quadratic observables. We prove that it can be written as a stationary Liouville equation with source terms. Our method is based on the Wigner Transform, which is a classical tool for evolution dispersive equations. We extend its use to the stationary case after an appropriate scaling of the Helmholtz equation. Several specific difficulties arise here; first, the identification of the source term (which does not share the quadratic aspect) in the limit, then, the lack of

L^{2}

bounds which can be handled with homogeneous Morrey-Campanato estimates, and finally the problem of uniqueness which, at several stage of the proof, is related to outgoing conditions at infinity.
Reflexivity of the isometry group of some classical spaces
Authors: Cabello Sánchez Félix , Molnár Lajos
Published: December 2011

We investigate the reflexivity of the isometry group and the automorphism group of some important metric linear spaces and algebras. The paper consists of the following sections: 1) Preliminaries. 2) Sequence spaces. 3) Spaces of measurable functions. 4) Hardy spaces. 5) Banach algebras of holomorphic functions. 6) Fréchet algebras of holomorphic functions. 7) Spaces of continuous functions.
Pointwise multipliers of Besov spaces of smoothness zero and spaces of continuous functions
Authors: Koch Herbert , Sickel Winfried
Published: December 2011

We characterize the set of pointwise multipliers of the Besov spaces

B^0_{\infty,1}

and

B^0_{\infty,\infty}

. These characterizations are used to obtain regularity results for elliptic partial differential equations. In addition several counterexamples are provided and the relation of various spaces of continuous functions to these multiplier classes are studied.
Some questions on quasinilpotent groups and related classes
Authors: Iranzo María Jesús , Medina Juan , Pérez-Monasor Francisco
Published: December 2011

In this paper we will prove that if

G

is a finite group,

X

a subnormal subgroup of

X F^*(G)

such that

X F^*(G)

is quasinilpotent and

Y

is a quasinilpotent subgroup of

N_G(X)

, then

Y F^*(N_G(X))

is quasinilpotent if and only if

Y F^*(G)

is quasinilpotent. Also we will obtain that

F^*{G}

controls its own fusion in

G

if and only if

G=F^*{G}

.
Complex geometrical optics solutions for Lipschitz conductivities
Authors: Päivärinta Lassi , Panchenko Alexander , Uhlmann Gunther
Published: December 2011

We prove the existence of complex geometrical optics solutions for Lipschitz conductivities. Moreover we show that, in dimensions

n\ge 3

that one can uniquely recover a

W^{3/2, \infty}

conductivity from its associated Dirichlet-to-Neumann map or voltage to current map.
Harmonic Analysis of the space BV
Authors: Cohen Albert , Dahmen Wolfgang , Daubechies Ingrid , DeVore Ronald A.
Published: December 2011

We establish new results on the space BV of functions with bounded variation. While it is well known that this space admits no unconditional basis, we show that it is "almost" characterized by wavelet expansions in the following sense: if a function

f

is in BV, its coefficient sequence in a BV normalized wavelet basis satisfies a class of weak-

\ell^1

type estimates. These weak estimates can be employed to prove many interesting results. We use them to identify the interpolation spaces between BV and Sobolev or Besov spaces, and to derive new Gagliardo-Nirenberg-type inequalities.