bluuebunny/crossref_metadata_2025 huggingface dataset:
Accuracy Improvement of Graph-Cut Image Segmentation by Using Watershed
Authors: Rong Jing , Pan Yu Li
Published: September 2011

Traditional Graph-Cut algorithm traverses all pixels at each time of computation; consequently, it consumes a lot of time. This paper improves on Graph-Cut algorithm based on characteristics of Watershed. The basic theory is to insert watershed into Graph-Cut to conduct pre-segmentation on image. With watershed, image is divided into regions which have different sizes and pixel color similarities. Images processed by watershed algorithm are converted into weighted undirected graph; and then translate energy function on pixel into that graph on separate regions after pre-segmentation. Performance of test programs has proved that the improved Graph-Cut algorithm can increase workload of user interaction mark effectively. As long as workload considered in the interaction process, improved Graph-Cut algorithm can achieve ideal segmentation effect even on complex background.
Prediction of Concrete Strength Based on BP Neural Network
Authors: Jiang Jian Ping
Published: September 2011

Based on BP neural network, this paper had a prediction analysis on concrete strength at the 28th day. Taking the influences of application amount of cement, application amount of scoria, application amount of fly-ash, water-ash ratio into account, the prediction model of concrete strength at the 28th day based on BP neural network was obtained. It was found that, the average value of absolute value for the relative error of fitting value of concrete strength at the 28th day compared with the observed value for 43 groups of independent variables training BP neural network model was 0.64372%; And the relative error of prediction value of concrete strength at the 28th day was -2.0392%~0.964668% compared with the observed value for 5 groups of independent variables validating BP neural network model, and the average value of absolute value for the relative error was 0.95467%. The following conclusion can be drawn that, the prediction model is accurate and credible, and the BP neural network is a excellent method, and it is worthy to spread its application in the prediction analysis of concrete strength at the 28th day.
A Novel Approach for Color Tongue Image Fast Segmentation Based on Level Sets
Authors: Zhu Ming Feng , Du Jian Qiang
Published: September 2011

To make variational level set method applicable to the application of tongue segmentation, this article introduced a kind of color tongue image fast segmentation method based on level sets. The early variational level set method is improved from the following aspects: the boundary feature weight function is improved to make this method adaptable to color tongue image segmentation, and a kind of variable time step method is introduced to increase the efficiency and accuracy of segmentation. As the comparison experiment results show, our method is about 1 time faster than the early method, and its accuracy is higher than the early one.
Dimensional Stability, Mechanical Properties and Fire Resistance of MUF-Boron Treated Wood
Authors: Chai Yu Bo , Liu Jun Liang , Zhen Xing
Published: September 2011

In order to improve the dimensional stability, mechanical properties and fire resistance of the wood from Cryptomeria fortunei, the melamine-urea-formaldehyde (MUF) resin and the mixture of MUF/boric acid/borax (MBB) were prepared and used as the wood modification solution. Results show that both the MUF resin and the MBB solutions exhibit good permeability to wood. Under the same treatment conditions, the weight percent gains (WPG) of treated wood increases with the increasing concentration of modification solutions. MUF and MBB modification solutions can effectively enhance the dimensional stability, MOR, MOE and fire resistance of wood. Compared with MBB treated wood, MUF treated wood exhibits higher MOR and dimensional stability. The MBB treated wood has higher MOE and fire resistance than MUF treated wood.
Contents of the Total Flavonoids and the Total Phenols and Antioxidant Activities in the Leaf from Different Species of Phyllostachys
Authors: Hu Chong Jiu , Xu Dian Hong , Chen Hong Lei , Yuan Ke
Published: September 2011

The contents of total flavonoid(TF) and total phenolic acid(TPA) in ethanol extracts from bamboo leaves of 21 species of Phyllostachys were determined, and the scavenging effects of ethanol extracts from bamboo leaves on DPPH and ABTS were also studied. The results showed that the ethanol extracts from bamboo leaves of 20 species of Phyllostachys contained rich flavonoid and phenolic acid, total content of which were respectively 8.963 mg/g～28.0614 mg/g and 12.3767 mg/g～31.8915 mg/g. Through the studies of antioxidant activities, it indicated that ethanol extracts of different bamboo species all had potent antioxidant activities, which was positively correlated with total flavonoids and phenolic acid. This paper provided a scientific basis for the research of active constituent and the exploitation of bamboo leaves from different species.
Chemical Constituents and Bioactivity of Chloranthus Multistachys
Authors: Luo Yong Ming , Yin Xiao Yin , Xie Ming Yong
Published: September 2011

From Chloranthus multistachys, three sesquiterpene lactones, multislactone (1), codonolactone(2), lasianthuslactone A(3), and three diterpenes, 12R,15- dihydroxylabda-8(17), 13E- dien-19-oic acid(4), 12(S),15- dihydroxy labda-8(17), 13E-dien- 19-oic acid(5), 12-oxo-15- hydroxylabda-8(17), 13E-dien-19-oic acid(6) were isolated. The structures of the isolated compounds were established by means of NMR and MS analyses. Compound 1~6 were firstly isolated from this plant. Compound 1 is new natural products. Among them , compound 1 and 6 show anti- inflammatory activities.
Studies on Chemotypes of Cinnamomum Camphora
Authors: Luo Yong Ming , Li Shi Rong , Yin Xiao Yin
Published: September 2011

Gas chromatography coupled with mass spectrometry (GC-MS) was applied to analyze the essential oil extracted from the leaves of 50 individual plants of Cinnamomum camphora, which were collected from the same mountain in Jiangxi province of China. 32 peaks in total were identified in these samples, which were then categorized into five chemotypes (bornel type, BN; camphor type, CP; isoneolidol type, ID; cineole type, CE; linalool type, LN) according to the primary component in the essential oil. In the meanwhile, total DNA was extracted from each sample for random amplified polymorphic DNA (RAPD) analysis, As a result, a total of 97 amplification products derived from 10 RAPD primers were obtained. These RAPD data were then analyzed using SPSS 10.0 software with 1 and 0 matrix, Jaccard’s coefficient and between-group linkage methods. Our results revealed that the estimated Jaccard’s differences between chemotypes varied in the range of 0-25, and that the pattern obtained from RAPD was totally accordant with the identification of GC-MS and the biosynthesis pathways of terpene. Thus, we propose that both GC-MS and RAPD are reliable and useful to identify the chemotypes of Cinnamomum camphora, and that quality control and large-scale cultivation of Cinnamomum camphora are possible.
Thermodynamic Study on SiHCl3 Hydrogen Reduction System in Siemens Process
Authors: Yu Xiao Hua , He En , Hou Yan Qing , Xie Gang
Published: September 2011

The complex chemical reactions in the Si-Cl-H system with relation to modified Siemens process have been studied in this paper based on the thermodynamic data of related substance. The influence of the temperature, pressure and initial feed ratio (nSi / nSiHCl3) on the silicon yield have been studied. Furthermore, the diagram of Kinetic constant k as a function of temperature for the rate controlled reaction has also been fitted in the SiHCl3 hydrogen system. Finally 1425K, 1.5atm and the initial feed ratio of 15 is the best conditions. Under these conditions, the silicon yield is 34.815%.
Ultrasonic-Assisted Dialysis Coupled with CE-ICP-OES for Determination of Calcium Species in the Dialysate of Human Blood
Authors: Deng Bi Yang , Xu Xiang Shu , Wang Ying Zi , Zhu Ping Chuan
Published: September 2011

The analytical method for calcium species in human blood was studied using ultrasonic-assisted dialysis coupled with capillary electrophoreisi (CE) inductively coupled plasma optical emission spectrometry (ICP-OES). The optimal ultrasonic dialysis conditions were 72 W power, 60 min extraction time and 70 μL volume of blood sample. Ultrasonic-assisted dialysis improves significantly the dialysis efficiecy by comparing with balance dialysis. The optimized conditions of separation and detection (a 120 cm length×100 μm i.d. fused-silica capillary, 20 kV separation voltage, 30 mmol/L Tris-HCl with pH7.4 buffer solution) for calcium species were achieved by CE-ICP-OES. The forms of calcium in the dialysate of human blood have five different species. The concentration of free Ca2+ in the dialysate was 0.7 mg/L. The hyphenated technique is simple and convenience, which is fit for the separation and analysis of metal-containing biological samples.
Treatment Effect of Multilayer Vermifiltration on Living Wastewater
Authors: Li Yin Sheng , Wang Xiu Hong , Dai Yi Qi , Qiu Jiang Ping , Robin Paul , Cluzeau Daniel , Morand Philippe
Published: September 2011

Former studies and application of vermifiltration process to organic wastewater treatment has given an affirmative effect for the pollutant removal in wastewater. It could be used for the disperse wastewater treatment, especially for rural living sewage. We developed a new multilayer vermifiltration system in this study, expecting to enhance this ability for the disposal of rural living sewage. The result showed that all the COD, BOD5 and SS values in outflow after vermifiltration could meet GB18918-2002. The removal rates of COD，BOD5 and SS were above 75%, 85% and 90% respectively. The N and P could be partly removed. These preliminary results give a positive prospective for the application of multilayer vermifiltration in rural sewage treatment in the future.
Immunomodulating Effects of the Peptides Derived from Whey Protein
Authors: Fan Wen Ya , Gong Hun Yu , Qu Yin Hong , Miao Yu Ping , Liu Zhi Dong
Published: September 2011

Immunomodulating properties of the peptides derived from whey protein isolates (WPI) were evaluated by measuring their effects on the proliferation of mice spleen lymphocytes and the phagocytosis of mice peritoneal macrophages in vitro. The results showed that the peptides derived-from WPI significantly increased the mice lymphocytes proliferation and the mice peritoneal macrophages phagocytosis at a concentration of 200 mgmL-1. Therefore, the results demonstrate that WPI contain some immunomodulating peptides, which can be released by hydrolyzed.
Fluorescence Property of Rhodamine B Encapsulated in the Channels of MOF-5 Crystal
Authors: Wang Hai Jun , Zhu Guang Shan
Published: September 2011

Metal-organic framework composites RhB/MOF-5 have been successfully prepared by diffusion of solvent method for the first time. The investigations of LM, XRD, FT-IR, UV-Vis, and photoluminescence confirm the existence of RhB in the pores of MOF-5. The composites which show strong fluorescence and obvious red-shift compared with RhB in CHCl3 could be candidates for applications in optics, especially in laser systems.
Study of Peptides QSAR Based on Multidimensional Attributes (E) Using Multiple Linear Regression
Authors: Yin Jia Jian
Published: September 2011

A new amino acids descriptor E, which (E1~E5) has been introduced in bioactive peptides Quantitative Structure-Activity Relationship (QSAR) Study. It has been proved that correlate good with hydrophobicity, size, preference for amino acids to occur in -helices, composition and the net charge, respectively. They were then applied to construct characterization and QSAR analysis on 48 bitter tasting dipeptides and 30 bradykinin potentiating (BP) pentapeptides using multiple linear regression (MLR). The leave-one-out cross validation values (Q2(CV)) were 0.888 and 0.797, the multiple correlation coefficients (R2) were 0.940 and 0.891, respectively for bitter tasting dipeptides and BP pentapeptides. The results showed that, in comparison with the conventional descriptors, the descriptor (E) is a useful structure characterization method for peptide QSAR analysis. The importance of each property at each position in peptides is estimated by the regression coefficient value of the MLR model. The establishment of such methods will be a very meaningful work to peptide bioactive investigation in peptide drug design.
Development of an Indirect Competitive Enzyme-Linked Immunosorbent Assay for Detection of Enrofloxacin Residue in Chicken
Authors: Jiang Jin Qing , Zhang Hai Tang , An Zhi Xing , Zhang Xiao Jian , Chen Jun Jie , Huang Hua Guo , Wang Zi Liang
Published: September 2011

A rapid indirect competitive ELISA (icELISA) format has been developed for the determination of enrofloxacin (ENR) residues in chicken. For this purpose, carbodiimide active ester method was employed to synthesize the artificial antigen of ENR-BSA, and anti- serum produced from the immunized rabbits was tested by indirect ELISA and icELISA. By the square matrix titration, the icELISA method was developed for the quantitative detection of ENR, based on the pAb. The Linear range was from 0.006 to 31.5 ng/mL, with LOD and IC50 value of 0.003 ng/mL and 0.45 ng/mL, respectively. Except for a high cross-reactivity (105.2%) to Ciprofloxacin, negligible cross-reactivity to the other compounds was observed. The recoveries of ENR were in the range of 98.3-127.5%, 85.7-112.5% and 97.4-103.8% for chicken muscle, liver and kidney, respectively. After optimization, 0.03 mol/L of HCl was used in the assay buffer and this ELISA system can tolerate acetonitrile not higher than 10%. The correlation coefficients (R2) of the ELISA and LC-MS data were 0.9472 in muscle, 0.9843 in liver, and 0.9382 in kidney. Therefore, this assay has the potential to be incorporated into a quantitative monitoring program for the rapid screening of ENR residue in food.
Numerical Simulation and Performance Optimization of the Gain Characteristic of EY-CDWA Optical Waveguide Amplifier
Authors: Yin Xiang Bao , Li Xiao Ping , Li She
Published: September 2011

The gain model of the Yb-Er codoped optical waveguide amplifier as well as the gain equation has been established based on the analysis of energy level structure of Yb-Er codoped system and the related transition utilizing the rate and transmission equations, and then simulation of the gain characteristic has been carried out. Some most important parameters influencing the gain of the optical waveguide amplifier are discussed and the correlative conditions are optimized. Through numerical simulation, the parameter optimization scheme has been proposed, with which the pump wave length, power and the gain of the amplifier are optimized synchronously, and the maximum gain under the optimum length is obtained. Experimental results show good accordance with the numerical simulation.
A Novel Amperometric Immunosensor for Detection of Alpha-Fetoprotein Based on Magnetic and Electroactive Nanoprobes
Authors: Meng Ling Hua , Cao Yu Ting , Hu Fu Tao , Li Tian Hua , Gan Ning
Published: September 2011

A novel three-dimensional, magnetic and electroactive nanoprobes were constructed for the first time. Using hemin (TPP) as electron mediator, mutli-walled carbon nanotubes with carboxyl groups (MCNTs) as supporter, a novel (MCNTs-TPP-Fe3O4)magnetic nanocomposites were first prepared. Then using alpha-fetoprotein (AFP) as model system, gold nanoparticles (Au NPs) as immobilizing matrix, the AFP/anti-AFP/Au NPs/ MCNTs-TPP-Fe3O4nanoprobes were prepared and then dropped on the surface of screen-printed working electrode (SPCE) to construct a new amperometric immunosensors for detecting biomakers. The microstructure of different nanoparticles were observed by transmission electron microscopy (TEM) andX-ray fluorescence spectrometery (XRFS). Under optimal experimental conditions, the logarithm of response signal was proportional to the logarithm of AFP concentration from 0.1 to 200 ng/mL, with a correlation coefficient of 0.998. The detection limit was 0.04 ng/mL at a signal-to-noise ratio of 3. The proposed method offered a platform for fast, sensitive and simultaneous determination for serum samples.
Simulation and Analysis of a Masticatory Robot Based on Biological Structure
Authors: Cong Ming , Liu Tong Zhan , Chang Zhan Bo , Xu Wei Liang
Published: September 2011

To meet the demand of the food texture analysis, dental training, speech therapy and temporomandibular joint (TMJ) research, a device is required to enable the reproduction of human chewing behaviour accurately. Based on the biological structure of masticatory system, this paper presented a robotic model for human chewing system in Solidworks, and analyzed the kinematics character for the masticatory robot via ADAMS. Results have showed that the robotic model is proper to reproduce the human chewing behaviour.
Anti-Control Research on Permanent Magnet Synchronous Motor System
Authors: Liu Yu Liang , Liu Juan Yi , Liu Guo Ping
Published: September 2011

Chaos behavior has many advantages in motor systems such as improving mixing efficiency and it involves with one kind of problem called chaos anti-control. This paper focused on chaos anti-control problem in permanent magnet synchronous motor (PMSM) systems through chaos synchronization. By synchronizing PMSM system with a typical chaotic system, the chaos anti-control problem was studied, where a controller was derived to make the error dynamical system converge at origin point O(0, 0, 0). The theory foundation in point is Lyapunov stability theorem, and the study conclusion was verified by numerical simulations.
Optimization Algorithm for Task Allocation with Multi-Objectives in Collaborative Manufacturing Project
Authors: Wu Xian Jie , Cao Jin Zhu
Published: September 2011

In the collaborative manufacturing project, task allocation among cooperative enterprises directly impacts the competition ability of enterprises and the overall economic benefits of the project. Aiming at this problem, a new algorithm is proposed to get the optimal combination of shortest project time, lowest cost and minimum number of selected cooperative enterprises. The algorithm is evaluated with an example and the result shows that the optimization solution can be applied in the actual collaborative projects with good effect.
Structural Feature-Based Model Templates Design for Ultra-Precision Positioning System
Authors: Jia Wen Chuan , Luo Xin , Yuan Fang , Zhou Lei , Jiang Wei
Published: September 2011

Ultra-precision mechanism lies in the core of ultra-precision electromechanical equipment, and is characterized by direct electromagnetic driving, air bearing supporting and ultra-precise vibration-isolation, putting a great challenge on design methodology and tools. This paper presents a model template design method which can provide effective computer aided design and engineering tools for new system design by encapsulating the design methods and design experience of ultra-precision mechanism into series of design templates. The model template contains toolkits both for forward structural design applied to new systems, and for the analysis and optimization of existing systems, as well as mathematical model and visualization tool in physical domain. The model templates are encapsulated and assembled according to the dynamical parameters and specific design parameters. Using planar electromagnetic drive structure in ultra-precision positioning system as an example, this paper discusses the design scheme of structure’s model template in detail, and introduces fast calculation method for magnetic field and visualization program, as well as forward design method for electromagnetic coil structure. Fast scheme design and analysis for ultra-precision mechanism can be achieved by using design templates.
Characterisation of High Calcium Wood Ash for Use as a Constituent in Wood Ash-Silica Fume Ternary Blended Cement
Authors: Ban Cheah Chee , Mahyuddin Ramli
Published: September 2011

The potential stabilization of high calcium wood waste ash (HCWWA) derived from the wood biomass energy production for use as cementitious material using another industrial by-product, silica fume, was investigated. Throughout the study, both HCWWA and DSF were characterized in term of their respective chemical composition and mineralogical phases. Besides, physical characteristics of HCWWA and DSF in terms of particle grading and specific surface area were established in order to evaluate their suitability as for use as constituent material in blended cement. Additionally, compressive strength properties of high strength mortar produced using HCWWA and DSF blended cement were investigated. Results indicated that the use of HCWWA as a partial cement replacement did not have significant adverse effect on the workability of fresh mortar. The enhancement of the compressive of mortar was observed for mortar mixes containing DSF and HCWWA levels of cement replacement up to 16%.
Roll Vibration Analysis of Planar Aerostatic Bearings through a Distributed Spring Model
Authors: Jiang Wei , Jia Wen Chuan , Liu Shan Shan , Hu Yuan Tai , Hu Hong Ping
Published: September 2011

The aerostatic bearings used in guide ways in ultra precision motion stages can provide both normal stiffness and roll stiffness, which are critical to the dynamic characteristics and control of systems. The normal stiffness has been widely investigated so far, but the roll one has seldom been studied. A new method for analyzing the roll stiffness is proposed, in which the aerostatic bearing is modeled as a set of distributed springs. The stiffness distribution is obtained by using the derivate of the pressure distribution with respect to the air gap. All the distributed springs are then integrated by using the presented transformation and it leads to an equivalent spatial spring which contains both the normal stiffness and the roll stiffness. A planar aerostatic bearing is taken as an example to illustrate the procedure of the calculation. The proposed method can be used to predict the vibration characteristics of various kinds of aerostatic bearings under working conditions.
A Study on Measurement Uncertainty of a Vortex Flow Meter in Discrete Liquid Phase
Authors: Jia Yun Fei , Kong De Ren
Published: September 2011

The measurement uncertainty of vortex flowmeter was examined when the gas flow measured was injected with liquid. This test was performed in a multiphase flow calibration facility. A vortex flowmeter of 50 mm in diameter was installed in a 100 mm test section. The gas volume flow rate was held in 141m3/h and the liquid was injected into the gas flow. The liquid volume fractions used at the gas volume flow rate were 0.0106%, 0.0213%,0.0355%,0.0496%,0.0638%,0.0780% and 0.0922%. The small amount of liquid in the gas as discrete droplet is called discrete liquid phase. Analysis on the vortex shedding frequency obtained from a frequency spectra showed that the strouhal values changed from 0.305 to 0.385 with the discrete liquid phase increasing and the total uncertainty of vortex flowmeter was from 0.869% to 2.196%. The experimental result can supply experimental basis for the measurement error correction of vortex flowmeter worked in gas flow with discrete liquid phase.
Visual Servo Control for Wheeled Robot Trajectory Tracking
Authors: Xu Guang Yan , Jia Xiao Yan , Shi Hong , Cui Jian Guo
Published: September 2011

In this paper, we discussed the trajectory tracking control problem of the kinematic model of wheel mobile robot. Designed an asymptotic stability tracking controller, using visual servo method based on inverse system and sliding mode variable structure control, and proposed a method to measure motion state of a target mobile robot. Simulation results show this method is feasible.
Application of Micro-PIV on the Microscale Flow and a Modified System Based on Ordinary 2-D PIV
Authors: Yang Bin , Wang Yuan , He Wen Bo
Published: September 2011

This paper briefly presents the working principle of micro-PIV (Particle Imaging Velocimetry) and its development and application on the microscale flow. Compared with ordinary PIV, micro-PIV has much higher spatial resolution. In addition, the adoption of fluorescent tracer and filter lens could enable flow field near wall surface to be measured. In view of the ordinary 2-D PIVs have been widespread among the scientific research institution related on fluid flow, the way that an ordinary 2-D PIV was modified to enable measurement of microscale flow was discussed in the paper. The extra elements of microscope objective lens, relay mirror, filter lens and telescopic focusing barrel are necessary. Some experiment results of the flow in microscale channels have been introduced to verify the availability of the modified PIV system. It could be found from the experimental results that the modified PIV system could be feasible and reliable for measuring micro-scale flows.
A Simultaneous Phase Shift Interferometry Used to Pulse Laser Pump-Probe Approach
Authors: Song Hai Ying , He Xue Peng , Liu Shi Bing , Chen Tao
Published: September 2011

A simultaneous phase shift interferometry was proposed to determine the time delay accurately in the pulse laser pump-probe detecting. The relevant optical system formed by four light interference channels was designed and optimized based on Jones theory. The light intensity distribution of interference pattern associated with the phase lag from these four light interference channels was derived by Jones matrix. The possible errors that exist in the applications were calculated. The theoretical results show that the minimum resolution of the time delay can be achieved to attosecond level for 800nm laser wavelength.
Safety Accident Analysis and Risk Control in Subsea Tunneling
Authors: Zhang Cheng Ping , Li Li Min , Song Hao Ran , Zhang Ding Li
Published: September 2011

There are more safety risks in subsea tunneling due to the particularity and complexity of its surroundings, so how to control the safety risks effectively has become an urgent problem. Based on the analysis of safety accident cases induced by the subsea tunneling, accident types and corresponding harms are pointed out. By analyzing the engineering characteristics and technical difficulties of the subsea tunnel systematically, the characteristics and occurring mechanism of the safety risk are revealed, and the fact that water inrush is the main safety risk in subsea tunneling is pointed out definitely. Furthermore, the contents of the safety risk control as well as relevant technical system are provided mainly based on water inrush risk, which can be referenced to make control schemes against the safety risk in subsea tunneling.
Ultrasound Wireless System for Sensor Data Transmission of Ultra-Thickness Plank
Authors: Feng Yong Jian , Wang Shao Jie
Published: September 2011

In this paper, Ultrasound Wireless System is introduced for wireless communication between the sides of ultra-thickness plank without breach of the structure. This system could be applied in the plank of the difference material of metal or non-metal and in environment in which high seal condition is required in uttermost, for instance ultra-pressure, radiation and virulent test. In this wireless system, the ultrasonic telemetry using single pulse for driving and receiving PZT has been designed and built to demonstrate the ability of the ultrasonic telemetry. This paper describes the designed transmitting circuit and receiving circuit and the results of a pilot set up. The driving characteristics and frequency response of PZT was analyzed and tested. It is very important that the transmitting circuit and receiving circuit were designed according to the frequency characteristics of the PZT and coupling, that is, the width of pulse and frequency of signal for the driving PZT must be properly chosen. It has been shown that communication of sensor signals can be made at two sides of steel enclosed container using PZT as ultrasonic transmitters and receivers.
Influence of Magnetorheological Fluid Volume onto Obtained Critical Pressures on Rotary Shaft Seals
Authors: Potoczny Marcin , Zachara Bolesław
Published: September 2011

Structure and basal application of magnetorheological fluids as well as their application in rotary shaft seals, have been presented in this study. As the application of magnetorheological fluid in seals is relatively purely known, the conducted studies were aimed at defining their operational parameters. The most essential was manner of the MR fluid delivery into oil gap, mostly the applied fluid volume. Not sufficient volume of the MR fluid often results in non-uniform oil gap filling what in turn decreases the seal efficiency. Results of studies on MR fluid-based seal burst pressure, conducted on specially designed testing stand, have been presented. The results comprise three oil gap sizes of d=0,15mm, d=0,3mm and d=0,5mm, for tests conducted with various volume of MR fluid applied on single sealing stage. Comparative values of the seal burst pressures obtained for three oil gap sizes of multi-stage seal, with the same apparent volume of MR fluid (the same fluid and oil gap volume ratio), were also presented.
Influence of Shaft Misalignment on Water Lubricated Turbine Sliding Bearings with Various Bush Modules of Elasticity
Authors: Litwin Wojciech , Olszewski Artur , Wodtke Michał
Published: September 2011

Hydropower industry increasingly frequently uses water lubricated bearings in turbines. This stems from the lack of negative impact of such solution on the environment. The paper presents an analysis of the influence of shaft misalignment in a turbine with water lubricated main shaft bearing on its hydrodynamic capacity. The theoretical analysis was based on the results of calculations for experimentally verified elastohydrodynamic lubrication (EHL) model. The obtained results showed impact of the stiffness of bush material and the degree of misalignment on bearing's hydrodynamic capacity.
Relieving the Measuring System of the Trailer for Tyre/Road Rolling Resistance Measurements from the Inertia Force
Authors: Woźniak Ryszard , Taryma Stanislaw , Ronowski Grzegorz
Published: September 2011

In the article the principle of measuring of tyre/road rolling resistance tyres in road conditions applied in a special measuring trailer is presented. This trailer was built in Faculty of Mechanical Engineering at Gdansk University of Technology. The construction of two special devices used in this trailer was discussed. These devices eliminate the influence of some chosen confounding measurements factors such as: the inertia force acting on the measuring arm with the wheel and the tested tyre and vibrations of the measuring arm. The operation of these devices was proven in practice. The conclusions arising from the use of these systems are described.
Construction Analysis of Mini-Generator of Electric Energy Using Working Medium Flow as the Working Environment
Authors: Kaczyński Roman , Wilczewska Izabela , Hoscilo Boguslaw
Published: September 2011

Monitoring systems for water distribution and sewerage networks constitutes an indispensable condition for smooth operational management of existing communal infrastructure. The question of an effective use of resources and means to supervise, regulate and control water supply networks requires special care already in the planning stage and also during the implementation process of maintenance equipment. To meet the above demand telemetry and data system to monitor the performance of water mains has been developed making use of GSM/GPRS data transfer technology. One of the fundamental problems of building the system is how to supply energy to the distributed control and measurement devices. A possible solution to these problems could be, as proposed in this paper, a wireless energy supply system using the measuring medium, i.e. the flowing water for energy transport. To this end, a construction of a mini-hydrodynamic generator, i.e. a device transforming the kinetic energy of water into electrical energy using carbon polymers reinforced with carbon fibers has been made, in which the flow of the operational medium is the working environment.
Constitutive Laws for the Deformation Estimation of Extrusion Die in the Creep-Fatigue Regime
Authors: Reggiani Barbara , Donati Lorenzo , Tomesani Luca
Published: September 2011

Tools are exposed to severe working conditions during the hot extrusion process. In particular, dies and mandrels can be subjected to an excessive amount of deformation as a result of the developed high cyclic loads and temperatures. In this scenario, a physical experiment reproducing the thermo-mechanical conditions of a mandrel in a porthole die was performed with the Gleeble machine on the AISI H11 tool steel with the aim to investigate the mechanisms that influence the die deformation. The design of experiment consisted of 4 levels of temperature, 3 levels of stress and 3 types of load, i.e. pure creep, pure fatigue and creep-fatigue. In all the testing conditions, a comparable pattern of the mandrel displacement-time curve was found reproducing the 3 stages of softening typical of the strain evolution in a standard creep test but with a marked primary phase. Thus, with the aim to identify an easy-applicable equation to estimate the die deformation, the time hardening creep law was chosen. Coefficients of the time-hardening law were optimized, for each testing condition, on the basis of experimental data starting from values for similar alloys taken from the literature. Results in terms of mandrel displacement were then compared to experimental data for the creep-fatigue condition at different stress and temperature levels. The values found were validated against additional experimental data performed with different specimen geometries. A good average agreement was found between experimental and numerical results. The developed procedure was then applied to an industrial die.
Effect of Strain Rate on Metal Flow Pattern in T-Section Extrusion Process
Authors: Homayoun Pouria , Ketabchi Mostafa
Published: September 2011

Extrusion is a deformation process used in metal sections fabrication. Metal flow pattern during extrusion process is of great importance. How circular initial section of billet changes to final section provides more details of extrusion process, and plays an important role in optimizing the extrusion energy. Extrusion in flat-faced die, without intermediate section, needs much more energy than is required for die having intermediate section. The aim of this study was to investigate the effect of strain rate on metal flow pattern in T-section extrusion process. Four different ram speeds were applied to realize how the shape and position of intermediate section would be affected. Flat-faced die with “T” final section was designed and manufactured. Straight layout of metal was of top concern in die design. Commercial purity aluminum, Al 99.5, was extruded in flat-faced die in hot condition. Graphite was used as lubricant in deformation process. After partial extrusion of billets, the residual part of billets pounced out of container and then mounted for metallographic tests. This part of billets consisted of dead-metal zone and deformation zone. Then, step-by-step decreasing of specimen height followed by macro-etching of metal surface paved the way for determining the metal flow pattern. An egg-shaped intermediate section appeared between initial round section and final “T” section. The size and position of the intermediate section changed by varying the strain rate of extrusion process; It was also revealed that as the strain rate of extrusion process is increased, the dead-metal zones become narrower and the dead-metal zone semi angle increases.
Advanced Technologies Used in the Manufacture of Products from Aluminium Alloys Powder in Extrusion Process
Authors: Płonka Bartłomiej , Senderski Juliusz
Published: September 2011

The subject of the research was an alloy AlZnMg and AlCuMg with addition of Zr and Ag manufactured of powders by hot plastic consolidation in process of direct extrusion. Paper also presents results of research of structure evolution and mechanical properties for different tempers of precipitation strengthening and further plastic deformation, including hydrostatic extrusion. Obtained results Rm above 700MPa (for AlZnMg alloy) and above 500MPa (for AlCuMg alloy) shows significant possibilities of manufacturing from Al alloys powders products with ultrafine grain and nanometric structure which properties exceeding alloys manufactured with standard methods.
Ferroelectric Properties of Bismuth Titanate Ceramics by Eu3+/V5+ Substitution
Authors: Mei X.A. , Chen M. , Liu R. F. , Sun Y.H. , Liu J.
Published: September 2011

The ferroelectricity of Bi3.25Eu0.75Ti3O12(BET), and Bi3.25Eu0.75Ti2.97V0.03O12(BETV) ceramics prepared at 1100°C by a conventional ceramic technique was investigated. These ceramics possess random-oriented polycrystalline structure. The remanent polarization (Pr) and coercive field (Ec) of the BET ceramics are 16 µC/cm2and 62kV/cm, respectively. Furthermore, V substitution improves the Prvalue of the BET ceramics up to 25 μC/cm2which is larger than that of the BET ceramics. Therefore, co-sustitution of Eu and V in Bi4Ti3O12 (BIT) ceramic is effective for the improvement of its ferroelectricity.
Comparison of Fracture Strength and Fracture Modes of Zirconia Dental Ceramics Manufactured by Four Different CAD/CAM Systems
Authors: Wang Dan , Xu Yuan Zhi , Lu Cheng Lin , Yang Qi Xiang , Zhang Dong Sheng , Shao Long Quan , Wang Rao Rao
Published: September 2011

Four sorts of zirconia dental ceramic systems including Cercon smart, Lava, Porcera, and CEREC 3 were studied to analyze fracture mechanism of different CAD/CAM zirconia ceramic. In each system, 12 sectioned specimens were prepared, 6 specimens were taken as controlled group, 6 as experimental group. Quasi-statistic loading before and after cyclic loading was applied at the veneer surface of the specimen. Deformation and crack initiation were monitored with camera in order to carry out digital image correlation (DIC) analysis. The results showed that median cracks were observed under the yielding zone. Specimens fractured along the core/veneer interface with the crack growth. No cone crack was confirmed and fracture only existed in veneer layer. After cyclic loading there were no significant differences for the four ceramic systems in terms of the critical load, while significant differences existed in terms of the fracture load. Both critical load and fracture load were lowered after cyclic loading. After cycling loading, the 4 tested zirconia CAD/CAM ceramic possess high fracture strength to meet the requirement for oral functions. The fracture modes of the four zirconia ceramic systems indicate that the strength of the veneer should be enhanced.
Charactering and Sintering of BaZrO3 Doped with TiO2
Authors: Zhang Cheng , Zhang Na , Jiang Dan Yu , Fan Ling Cong
Published: September 2011

The high sintering temperatures required for solid-state derived powders is a significant obstacle inhibiting more widespread use of single pure phase BaZrO3with high density. The aim of this research was to reduce the sintering temperature whilst maintaining pure single phase BaZrO3. By using of sintering aid, such as TiO2additive, the pure perovskite BaZrO3powder have been fabricated with the solid state chemistry at 1250°C. Low levels of TiO2(3%) produced the pure BaZrO3particles with the smallest size, and the corresponding sintered ceramic has the density of 95% theoretical using sintering temperature as low as 1550°C. The microstructure of the particular ceramic with full density confirmed that the particle grain in ceramic block have shaped with the less pore and connected thickly.
Fatigue Damage Modes of Bilayered Zirconia and Alumina Dental Composites
Authors: Zhu Lin Jia , Liu Yi Hong , Feng Hai Lan , Chen Hui Juan , Zhang Qing Hui , Qiu Yan , Bao Yi Wang
Published: September 2011

Bi-layer all-ceramic dental crowns comprise an inner core made of alumina or zirconia and an outer porcelain shell. The veneer safe from damage is mainly depended on the properties of core materials due to the poor strength and toughness of porcelain. The fracture modes and crack transformation of zirconia/porcelain and alumina/porcelain bi-layer composites reveal the potential feasibilities of improving the fatigue life of all-ceramic restorations. The failure modes of bi-layer composites were confirmed under cyclic spherical fatigue loading by dynamic microcosmic observation. Crack modes and evolvement of bi-layered composites were explored inflecting with fatigue load, cycles, frequency and water environment. Microcosmic morphology of the samples was observed by high depth of field stereomicroscope to determine degree and modes of fatigue damage. The appearance of cone cracks of porcelain surface was almost consistent in both of zirconia and alumina bi-layer composites. However, the pattern and process of the damage are different under cycle fatigue load. Furthermore, process of fatigue damage of bi-layer composites were observed to failure rapidly under water environment in both of zirconia and alumina bi-layer composites.
Influence of Light Source and Cathodoluminescence on the Color Parameters of Ruby Red
Authors: Li Xiang , Guo Ying
Published: September 2011

According to different light sources and cathodoluminescence (CL) intensity, the performance of color parameters (lightness L*, chromaticity a* and b*, chroma C*, hue angle ho) and chromophore contents (Cr3+, åFe) are studied to analyze the impact of all these elements on ruby red color. Ruby red under the standard light source D65 (a*=5.65 ~ 26.97, b*= -5.43~3.98) is similar with the color under natural sun-light. Purplish red ho Î (354.14°, 0.7°) with medium-low lightness (L*= 32 ~ 40) under D65 displays the best visual appearance, showing a relatively high value. Comparing with D65, standard light source A reveals ruby a deep red hue (a*= 10.61 ~ 37.39, b*= -6.59 ~ 7.50). Because of the strongest spectrum power distribution in the orange range and fluorescence of light source U30, the hue of orangish tone is mixed in ruby red (a*= 6.92 ~ 31.23, b*= 0.31 ~ 9.34). It is illustrated that åFe can inhibit the intensity of CL which is compared in different voltages. Low lightness purplish red is easy to be influenced by CL and always shows strong luminescence correspondingly. It is concluded that ruby purplish red has strong luminescence of CL which is usually supported by a few of åFe and medium-low lightness under D65, which has an excellent visual perception.
The Contribution of Co2+ to Blue Color of Synthetic Spinel
Authors: Ma Ye , Guo Ying
Published: September 2011

Through to 110 pieces purity transparent and color uniform, 3 x 5 x 7mm blue synthetic spinel made with the flame fusion method on chemical compositions and color parameter measurement the Co2+ content and color changes, clear the influence on Co2+ relationship of blue synthetic spinels’ color appearance. Through LA-ICP-MS to analysis the cause of colorant content, proof that with Co2+, the increase of the content of synthetic spinel will shift blue to purple tone, and C* shows a parabola form with the drop of L*, 700 ppm ~ 900 ppm place in peak. DL* Î (3.55 ~ 76.94) with Co2+ Î (4.59 ppm ~ 1849 ppm) change the largest amount, DC* Î (-9.99 ~ 29.32) next, DH* Î (-20.34 ~ 4.67) compared with before two changes smallest. Co2+ content in 100ppm below, blue color of synthetic spinel with Co2+ content increased changes greatly; 500 ~ 1500 ppm, visually achieve optimal color (C* higher); above 1500ppm, because of the Co2+ overmuch make the color burn cause the overall decline of transparency, the change of L* tends to be gentle, C* decrease obviously. Use Color i5 in standard color measurement instrument lighting source D65, measured the lightness L*, specimen Color a* and b*, chroma C* and tonal angle ho, based on the uniform color space CIE 1976 L*a*b*, in lightness minimum L 9-10 specimen (processing data for standard to 9th), with the help of DE2000 benchmark for calculating formulas, the Color, the color difference train E* by partial correlation analysis card clearly degrees of off color changes L* has certain influence on rDL*×DE*= 0.996, while rDC*×DE*= -0.427, rDH*×DE*= -0.339. Conclusion, the bule color of synthetic spinel because of its Co2+ content changes main influencing L* to contribute to its color appearance.
An Experimental Study of the Nano-Scratch Behavior of Cement Composite Material
Authors: Xu Jing , Yao Wu
Published: September 2011

This paper presents a preliminary exploration in tribological property and dynamic elastic/plastic behavior of cement composite material at micro- and nano- scale. Pastes were prepared by pure cement clinker with water-to-cement ratio of 0.3 and 0.4. For comparison, a polymer-based clinker composite was also introduced. Nano-scratch test was carried out to study the scratch process. Different constituents were identified by penetration depth value. Based on this identification, the coefficient of friction and elastic deformation status were analyzed. Substrate effect was found when refers to the coefficient of friction of hard clinker particles embedded in soft matrix. An H/E ratio dependent elastic/plastic behavior was also revealed for cement composite. The results confirm the nano-scratch test as a promising method for cement composite investigation; however, some important attributes of this type of material, including the complexity of multi-phase structure and the viscous effect, need to be taken into account in experimental analysis and practical application.
Microstructure of Interface between Zirconia and Veneer Porcelain
Authors: Deng Bin , Liu Hong Chen , Yi Yuan Fu , Shao Long Quan , Hou Kang Lin , Lu Rong Jian , Tian Jie Mo , Wen Ning
Published: September 2011

To study whether the veneering technique will have an impact on zirconia grain and the bonding type and relationship on interface between zirconia and veneer porcelain. Materials and methods: After sintered, zirconia was annealed for 15 minute to finish the phase transition from m to t.4 types of veneer porcelains were sintered and observed with SEM (scanning electron microscopy) and TEM (transmission electron microscopy). Results: With etching time extending, it appeared that many materials loosed and corrosional pit deepened, enlarged in the veneer porcelain, which made crystallize structure move into veneering surface. Composition of interface mainly was amorphous glass matrix and zirconia. Energy spectrum analysis showed that there was no remnant glass composition in the zirconia side departing from interface. SEM showed that crystal in veneering side did not participate interface bonding. Conclusion: The interface between 4 types of veneer porcelains and zirconia bonded well. Veneering sintering technique didn’t change lattice structure of zirconia, which still was tetragonal structure. The specific bonding property of interface still remained to be analyzed further to determine.
Evaluation on Structure and Tribological Properties of Carbon Nitride Films Deposited on YG8 Carbide Alloy Substrates
Authors: Liu Jun , Chen Zhi Gang , Bi Kai , Wang Yue Min
Published: September 2011

CNx films were deposited on YG8 carbide alloy (WC+8%Co) substrates by DC or RF magnetron sputtering. The composition, bonding state, adhesion, and tribological behavior of CNx films were researched. X-ray Photoelectron spectroscopy results showed that C-N, C=N and C≡N bond existed in CNx films. RF magnetron sputtering is in favor of the bonding of C and N, the adhesion and the wear resistance of CNx films. DC magnetron sputtering is in favor of lubricating ability of CNx films. Substrate bias has some effect on the bonding of C and N, the adhesion of the films, decrease of adhesive wear and the friction coefficient of films.