bluuebunny/crossref_metadata_2025 huggingface dataset:
Ripple Line Fillet Seam Tracking with Visual Sensors in Welding Process
Authors: Bi Qi Lin , Quan Yan Ming
Published: September 2013

To overcome the problems resulting from weldment trimming and assemble errors, thermal deformation, arc blow, etc., a set of new tracking system of fillet seam for automatic corrugated plate welding was put forward based on machine vision technology. The tracking system included two cameras: the precursor was set in front of the welding torch (a corrugation cycle far away), for capturing the linear laser projected on the side plate and the base plate; the another one was installed over the melting pool for capturing the image of welding torch tip and the seam. The processed image information from the precursor camera was used to track the fillet seam three-dimensional trajectory and the seam width, according to the information the welding motion controller and the welding power made preplanning; the processed torch tip and seam image information was sent to the motion controller and the welding power so that they could make real-time motion and welding parameter adjustment. Computer simulation proved that this new tracking system could work efficiently.
Develop the Low Pressure Large Flow Overflow Valve
Authors: Zhao Xue Zeng , Wang Xi Gui , Wang Yong Mei
Published: September 2013

In the paper, for high-power marine overflow valve of low pressure big traffic problems, the design of the inside leaking mouth leaks in parallel structure ,that is suitable for the different oil and water flow, using additional flow beam, guiding type low pressure large flow overflow valve was developed and the experimental study, obtained the dynamic and static parameters of the valve. Invented the inside leaking and leaked mouth parallel connection structure, inside leaking and leaked mouth parallel connection is established the mathematical model of the overflow valve. Results show that compared with the traditional straight moving type overflow valve, the type overflow valve through a larger flow, has better dynamic and static performance and cavitation resistance.
Dynamic Characteristic Analysis of High-Speed Milling Motorized Spindle Based on ANSYS Workbench
Authors: Li Chao , Yao Ying Xue
Published: September 2013

The DGZX - 1425 high-speed milling motorized spindle which is made and designed independently by Hao Zhi electrical and mechanical company in Guangzhou China is made as the research object, the method of establishing numerical simulation model for the spindle units dynamic performances is established, and the design of the spindles structure has been verified reasonable. Modal analysis of the spindle has been completed in ANSYS Workbench to get the first six natural frequencies and mode shapes. Harmonic analysis of the spindle is also completed to obtain the dynamic stiffness at the highest speed. Modal test and vibration test of the assembled spindle are also processed, which have verified the accuracy of the finite element method. The paper has provided a theoretical basis for the motorized spindles design, structural optimization and the improvement of the dynamic performances.
Design of a Kind of Complex Part and the Application of Drawing Methods
Authors: Lin Zhuo , Song Rui Qi
Published: September 2013

A kind of measuring device for overlap values is designed and described in this paper, which can be adapted to various types of servo slide valve, especially to the large flow valve. An automatically location of the spool is realized in this equipment, as well as the auto-centering. Also, a micro-drive mechanism structure acting with high precision is fabricated. The operating process is clarified in detail. An improved reliability of the whole testing system is achieved with help of this very configuration, result from which the accuracy of overlap value measurement is enhanced.
Fatigue Life Prediction Methods Evaluation for Remanufacturing Mechanical Parts
Authors: Weng Jian Xin , Yue Wen Hui , Zhu Yong Xing , Duan Peng Hui
Published: September 2013

Aiming at the demand of remanufacturing mechanical parts fatigue life prediction, the main methods of fatigue life prediction are reviewed and summarized. The finite element and dynamics combined simulation method has been widely used at present, whose advantages are that it is suitable for most of the mechanical parts, and the forecast cycle is short, and it can be analyzed combining with the parts actual working condition, but the prediction accuracy depends on the comprehensive degree to the service condition. The experimental method is the most traditional method, and the fatigue life value obtained by the method is reliable, but the method is entirely depend on experience, and the cost of experiments is expensive, so the feasibility is bad. The fatigue life analysis method can lower the dependence on large number of experiments, but there is a great distance between the predicting fatigue life and actual fatigue life in working environment. The metal magnetic memory non-destructive testing method doesnt damage the testing objects, but the method is still in the stage of further research at present. Finally, taking the number of experiments, prediction cycle, prediction accuracy, prediction cost and the complex degree of the principle involved in the prediction process as evaluation indexes, the finite element and dynamics combined simulation method is the best fatigue life prediction method according to the score values of each method calculated by the quantitative scores based on the expert evaluation method.
Investigation of Laser Transmission Joint Strength: Based on the Surface Pitted 304 Stainless Steel and PA66
Authors: Zhao Zhen Guan , Liu Hui Xia , Huang Chuang , Chen Hao , Yan Zhang , Li Pin , Wang Xiao
Published: September 2013

In this paper,the laser transmission joint strength is studied with semiconductor laser based on the surface pitting of 304 stainless steel and PA66.Unevenly distributed pits are formed on the surface of 304 stainless steel with 10% ferric chloride solution for two hours, which have certain morphology, depth and size. Different laser power, welding speed and welding pressure are used in laser transmission joining 304 stainless steel and PA66,which 304 stainless steel contains pitting corrosion before and after. The tensile strength test of joined samples shows that: the joint strength of pitted 304 stainless steel and PA66 with laser transmission joining is improved at least 135%; the riveted structure formed at the joining interface improve the joint strength.
Systematic Odometry Error Modeling and Correction in Wheeled Robots
Authors: Yu Zhong Da , Pei Yan Bo , Shao Dong Xiang
Published: September 2013

Odometry is a relative position measuring method widely used in robot position estimation. However, the error accumulates in an unbounded fashion. In this paper, a new model based on castors is proposed. The final pose accuracy is only affected by the position of castors according to the new model. Experiment is also conducted to demonstrate the feasibility and high accuracy of the new method.
The Prediction of Material Removal and Surface Roughness of Workpiece during Abrasive Flow Machining
Authors: Zheng Guang Zhen , Zhang Ke Hua , Ding Jin Fu , Fang Zeng Hao , He Li Bin
Published: September 2013

In order to study the finishing mechanism of abrasive flow machining (AFM), the model of material removal and solving method of surface roughness during material deformation have developed based on axial force and radial force. However, the axial force and radial force have been respectively measured by two pressure transducers fixed in the fixture. Both the material removal weight and surface roughness of workpiece have been calculated and measured during AFM experiments. The conclusions arrived by the analysis about the results of theoretical calculation are in agreement with the experimental AFM in some extent.
Energy-Efficient Routing Protocol of Wireless Sensor Network for Industrial Application
Authors: Ma Zhi Yan , Yang Guang You , Zhou Jing Jing , Gan Xiong
Published: September 2013

An energy-efficient wireless sensor routing protocol (Energy-efficient clustering hierarchy routing protocol, EECH) for industrial field is proposed based on LEACH protocol according to the energy inefficiency of existing routing protocols and the characteristics of industrial field applications. The EECH protocol takes full advantages of the node clustering and time slot distribution in LEACH and implements the functions such as clustering, multi hop time slot distribution, node sleeping and data gathering. The cluster heads can be evenly distributed in the area with the geography location information of the wireless nodes, so that the optimal data gathering path can be established. Meanwhile, the EECH protocol can reduce the conflict in data receiving/transmitting and the energy consumption of the nodes, and extend the network lifetime through the multi hop time slot distribution and node sleep mechanism. The simulation results have shown that the death time of the first node in EECH protocol is extended double time than that of LEACH protocol. When most of the nodes dies, the amount of received data of the base station node is more than twice as much as the LEACH protocol, which has verified the energy efficiency characteristic of the EECH protocol.
Research on Key Technology of the Simulation Visualization System of the Virtual Wind Farm
Authors: Wan Xiao Jing , Sun Wen Lei , Yu Qing
Published: September 2013

From the start of the key technology of 3D model creating, motion simulation, visualization and interaction of roaming, and elaborates the development method of visual simulation system of virtual wind farm. this article achieved that the system not only can realize real-time roaming interaction between participants and 3D simulation system, and can simulate the interaction between the wind turbine and wind field, but also will be the application of VR technology in the dynamic analysis, processing and analysis result, enhance product development from degree and gain a higher level of details.
Mathematical Model and Characteristic Analysis of Electric Loading System
Authors: Zhang Xiang , Wang Guang Lin , Pan Xu Dong , Xie Hai Bing
Published: September 2013

In this paper, a mathematical model of the loading system is established. The characteristics of the loading channel and disturbance channel are analyzed through this mathematical model. Analysis results show that the loading channel is unstable and disturbance torque leading the input command. It directly impact on the output torque, serious affect the systems loading precision. Characteristics of the loading system are analyzed, and the results show that stiffnesss effect on the loading system is twofold, should be considered at the same time. Reduce the system's moment of inertia is good for the characteristics of the loading system.
Research of Missile Radome NC Grinding Based on Iso-Scallop Method
Authors: Li Li Jun , Sun Wei , Bai Wei Tao
Published: September 2013

Based on the iso-scallop 5-axis NC machining theory, analyses the convexity and concavity of the missile radome, then research on the processing strategy while using cylindrical grinding wheel and wheeled grinding wheel. At last, discrete the bus of the gyro-rotor and find out the most reasonable grinding parameters according to the radius of curvature of the whole processing bus. So the grinding precision can be increased and controlled.
A Coupled Thermal Structural Finite Element Analysis of a Single Pulse Micro-EDM Process
Authors: Guo Cheng , Wang Yu Kui , Wang Zhen Long , Xie Bao Cheng
Published: September 2013

A three-dimensional coupled thermal structural model for micro electrical discharge is presented in this paper. Temperature field and thermal stress field of a single spark discharge process are analysed using this model by indirect coupling method. Temperature field is firstly solved which acts as the foundation of solving thermal stress field. To make the simulation results more reliable, these important elements are also taken into account, such as temperature-dependent properties of material, the phenomenon of plasma channel radius expanding, the percentage of discharge energy transferred to the workpiece and Gaussian distribution of heat flux. The results can explain the formation of cracks around the discharge crater. The thickness of the white layer and residual stresses can be predicated using this model.
A Quality Tracing and Management Model of Complex Products Based on SPC and Two-Dimensional Code
Authors: Yang Xiao Long , Qin Wei , Zhang Jie , Li Hua , Xu Zeng Guang , Xiao Hai Peng
Published: September 2013

t is a big challenge faced by the enterprises that how to trace and manage the quality information of complex products effectively in the overall life circle. In this paper, two-dimensional code is regarded as a carrier of quality information,and statistical process control (SPC) is used to evaluate the production process and control the on-line quality.Quality tracing and management model is established which consists of three parts:the identification of parts by two-dimensional code,the real-time acquisition of process information and the quality management.The proposed model is validated and successfully implemented in a typical complex products manufacturer for quality tracing and management.
Preparation and Characterization of Spherical Fine Nickel Particles by Ultrasonic Spray Pyrolysis
Authors: Kodera Takayuki , Oomura Takuya , Wu Qiong , Minami Ryouma , Ogihara Takashi
Published: September 2013

Spherical fine Ni particles were prepared by ultrasonic spray pyrolysis, and the effects of starting materials, carrier gas, and pyrolysis temperature on the crystal phase of the fine particles were investigated. When the mist of starting solution was pyrolyzed at 850 °C in a N2 atmosphere, the crystal phase of fine particles obtained from Ni (CH3COO)2·4H2O was in good agreement with that of Ni. Furthermore, the other phases were not observed. The average particle size of the spherical Ni fine particles was 0.45 μm.
Synthesis of Carbons Added LiFePO4 Powders by Two-Fluid Nozzle Spray Pyrolysis and Measurement the Charge-Discharge Properties
Authors: Nakamura Takahiro , Kodera Takayuki , Minami Ryoma , Ogihara Takashi
Published: September 2013

LiFePO4/C powders were synthesized by ultrasonic spray pyrolysis using carbon powder instead of organic substances as the carbon source. LiFePO4 (LFP) powders containing different types of carbon powders were prepared and used as cathode active materials in lithium ion batteries. The charge-discharge properties of lithium ion batteries with LFP, LFP/AB, and LFP/CNT powders as the cathode material were worse than those of the battery with LFP/sucrose powder as the cathode active material.
Synthesis of Titania Nanotubes with Different Diameters for Dye-Sensitized Solar Cells
Authors: Tang Jie , Nakamura Takahiro , Ogihara Takashi , Xiong Jie
Published: September 2013

TiO2 nanotubes with different diameters were synthesized by anodic oxidation in fluoride-contained organic solution. It was found out that the diameters of nanotubes became larger with the rise of used times of Ti plate. The TiO2 nanotubes were applied to dye-sensitized solar cells (DSCs). It turned out that the generation efficiencies of DSCs versus the increase of diameter of nanotubes presented a curve with maximal value. The highest generation efficiency was 3.60%.
Temperature Dependence of Resistivity of MoSi2-Si Composite Thin Films
Authors: Kanai Ryo , Hikita Shinya , Sato Yuuki , Yoshikado Shinzo
Published: September 2013

The temperature dependence of resistivity for thin films of a composite of molybdenum disilicide (MoSi2) and silicon (Si) fabricated by radio frequency magnetron sputtering using a target made of a powder mixture of MoSi2 and Si with molar ratio of Si to Mo of 1:X (2.02X2.55) was analyzed. The temperature dependence could be explained by the multiplicative model consisting of a conduction model similar to the Grüneisen-Bloch model, a modified Anderson localization model for 2.02X2.21 and the modified Anderson localization model for 2.39X2.55 over a wide temperature range.
Preparation of BaZrO3 Nanocrystals at Low Temperature
Authors: Nakashima Kouichi , Fujii Ichiro , Wada Satoshi
Published: September 2013

Barium zirconate (BaZrO3) was prepared by the composite-hydroxide-mediated (CHM) approach at low temperature. The CHM method is based on chemical reactions of materials in the eutectic hydroxide melt. In this method, the eutectic point at an sodium hydroxide (NaOH) : potassium hydroxide (KOH) molar ratio of 51.5 : 48.5 is about 165°C. In the present work, the low-temperature preparation and morphology of BaZrO3 nanocrystals were investigated. Zirconium tetra-n-butoxide ((CH3CH2CH2CH2O)4Zr) and/or zirconium dioxide (ZrO2) were used as a zirconium source. X-ray diffraction measurements confirmed that the BaZrO3 had a perovskite structure. Barium hydroxide (Ba (OH)2) was used as a barium source. BaZrO3 nanoparticles were obtained when (CH3CH2CH2CH2O)4Zr was used as a raw material. On the other hand, BaZrO3 nanocubes were formed when ZrO2 was used as a raw material. Scanning electron microscopy and transmission electron microscopy observations indicated that BaZrO3 nanocrystals were formed.
Improvement of the Stability of X-Ray Emission by Thermal Excitation of a Pyroelectric Single Crystal
Authors: Naruse Fumihiko , Honda Hiroyuki , Nakanishi Yoshikazu , Fukao Shinji , Sato Yuuki , Ito Yoshiaki , Yoshikado Shinzo
Published: September 2013

X-ray emission using pyroelectric crystals is intermittent, and has low intensity and stability. One of the factors for low stability is related to creeping discharge, due to the accumulation of surface electric charges that change in response to the temperature. The time dependence of the net amount of electric charge was investigated by changing the cycle period of the crystal temperature. The stability of the X-ray emission is demonstrated to be strongly dependent on the temperature cycle period.
Domain Contribution to Elastic Nonlinearity in Pb(Zr, Ti)O3-Based Piezoelectric Ceramics
Authors: Hagiwara Manabu , Hoshina Takuya , Takeda Hiroaki , Tsurumi Takaaki
Published: September 2013

In order to clarify the origin of the elastic nonlinearity in piezoelectric ceramics, the effect of Mn substitution into Pb (Zr,Ti)O3-based ceramics on the nonlinear elastic stiffness was investigated by analyzing the transient response after burst excitation. The real part of 3rd-order elastic stiffness drastically decreased with increasing Mn content. It was also found that the appearance of the elastic nonlinearity enhanced the mechanical loss. From the results, the irreversible domain wall motion overcoming the potential barrier due to defect complexes was considered as a possible origin of the elastic nonlinearity.
Domain Dynamics under Unipolar Electric Fields for BaTiO3 Single Crystals
Authors: Ishikawa Shotaro , Kitanaka Yuuki , Noguchi Yuji , Miyayama Masaru , Moriyoshi Chikako , Kuroiwa Yoshihiro
Published: September 2013

Domain structures and dynamics of BaTiO3 single crystals under in-situ electric fields along <110>c were investigated by using synchrotron radiation single-crystal X-ray diffractions. Diffraction patterns clearly show the presence of a 90 ° domain structure in the crystals poled along <110>c. The diffraction analysis provides direct evidence of a reversible change in the volume fractions of two kinds of the 90 o domains under unipolar in-situ electric fields. This reversible change in the domain structures under unipolar fields is suggested to originate from the interaction between spontaneous polarization and defect dipoles composed of acceptor and oxygen vacancy.
Mössbauer Spectra of 57Fe-Enriched BiFeO3 Thin Films Fabricated on SiO2/Si Substrates by Chemical Solution Deposition Process
Authors: Tanaka Kiyotaka , Tsukamoto Yoshinori , Okamura Soichiro , Yoshida Yutaka
Published: September 2013

sup>57Fe-enriched BiFeO3 (BFO) thin films were fabricated on SiO2/Si substrates from a stoichiometric precursor solution by chemical solution deposition process. The Bi/Fe molar ratio of the thin films decreased from 0.95 to 0.80 with increase in the sintering temperature. A perovskite phase and flat surface were obtained in the BFO thin films sintered at 500 and 600 °C. However, the 57Fe Mössbauer spectra showed a mixture phase due to amorphous and/or Bi2Fe4O9 phases in the BFO thin films. The valence state of Fe ions of the BFO thin films was confirmed to be only Fe3+ by the Mössbauer spectra.
The Performance Analysis of Double Beam Bridge Crane Based on Computer Simulation Technology
Authors: Yu Qing , Mao Xu Dong
Published: September 2013

Due to lifting large loads and lifting smooth, it is widely used for double beam bridge crane in machinery industry. The numerical analysis of stress and strain field for 200t×28m double beam bridge crane is done under maximum load conditions by using ABAQUS finite element platform in this paper, the distribution and largest area under load of bridge is obtained. At the same time three natural frequencies and mode shapes of double beam bridge crane is analyzed, which the results provide a theoretical basis and reference for double beam bridge crane designer.
Design of Key Parts of a Pneumatic Conveying System Used in a New Small Trenchless Drilling Robot
Authors: Li Xiao Ping , Liu Hai Lan , Rui Yan Nian
Published: September 2013

Through research on Pneumatic Conveying technology and the principle of Laval Jet, we completed the design of key parts of a mud dust conveying system used a new small trenchless drilling robot in municipal road construction.
Experiment Study on Micro-Seam in Electrochemical Machining
Authors: Li Zhi Yong , Dong Pei Yu , Wang Yi Gang
Published: September 2013

In this study, we firstly developed a numerical electrochemical micro-machining (EMM) setup. Furthermore, the effects of five vital process parameters, applied voltage, electrolyte type, electrode shape and diameter, electrode feed rate on micro-seams machining accuracy and process stability were evaluated. The experimental results show that: Wire electrodes machining accuracy is higher than that of sheet electrode. With the wire electrodes diameter decreased from 0.2mm to 0.06mm, micro-seam width is reduced by 36.55%. With the wire electrode feed rate increased from 0.2mm/min to 0.6mmm/min, micro-seam width is reduced by 44.2%. Sheet electrodes machining stability is better than that of wire electrode. The number of machining stability of sheet electrode is 25% higher than that of wire electrode in the condition of 8V applied voltage.
Experimental Studies on Cutting Temperature of Nickel-Based Supper Alloy Inconel 718
Authors: Xiao Mao Hua , He Ning , Li Liang , Fu Xiu Qing
Published: September 2013

The method to measure the cutting speed when high speed milling nickel alloy Inconel 718 based on semi-artificial thermocouple. The cutting parameters, tool wear and so on the cutting temperature were analyzed. The tests showed that the temperature was gradually increased with the increase of cutting speed. The cutting speed must be more than 600m/min, when the ceramic tools would perform better cutting performance in the high-speed milling nickel-based superalloy. In order to achieve more efficient machining, milling speed can be increased to more than 1000m/min. The impact amount of Radial depth of cut and feed per tooth were relatively small.
Review on the Research of Dynamic Characteristics for Spacecraft Solar Arrays
Authors: Pan Ze Hao , Wu Jia Ning , Yan Shao Ze , Zhao Jie Liang
Published: September 2013

In this paper, a review of developments in the dynamic characteristics of traditional and inflatable solar array is presented. Three major aspects that affect the dynamic behavior of solar array are reviewed: component flexibility, joint clearance and thermally induced vibration. Important results and methods of exploring the dynamic characteristics of inflatable solar array are discussed. Future research areas in dynamic characteristics of solar array are identified as damping mechanism of inflatable structure, the relationship between pressurization level and damping ratio, application of more advanced contact model, dynamic characteristics of solar array made of new materials and consideration of deformation in multiple dimensions.
Study on Green Materials and its Management Model Used in Construction
Authors: Miao Yu Jun , Sheng Qiu Sheng
Published: September 2013

Article building enterprises as the research object, the first analyzed the connotation and characteristics of green management, from the enterprise management pattern, the construction process of environmental impact of Building industry has not been formed, green management concept of green design, such problems as the raw material capital investment in enterprises, the existing problems, using green management theory, this paper puts forward the idea of sustainable development of green management concept, the implementation of the green design and construction, increase the capital input material solutions. Green management model and discusses the Building industry green management of construction technology, in order to ensure long-term effective implementation of enterprise management.
Influence of Hydrogen Contents of Ti-6Al-4V Alloy on Friction and Wear Mechanism between Titanium Alloy and Cemented Carbide
Authors: Wei Wei Hua , Xu Jiu Hua , Fu Yu Can
Published: September 2013

Ti-6Al-4V alloy was hydrogenated at 800°C by thermohydrogen treatment technology. Sliding friction and wear tests were carried out in a special device assembled on CA6140 turning lathe to investigate the friction and wear mechanism between hydrogenated titanium alloys and WC-Co cemented carbide. The morphological analyses of the worn surface were made by scanning electron microscope (SEM) and the diffusion and chemical reaction behavior of elements were analyzed by X-ray energy dispersive spectrometer (EDS). It was found that the main wear mechanisms of the unhydrogenated alloys were abrasion and adhesion and surface fatigue, while the main wear mechanisms of the hydrogenated alloys were abrasion and adhesion. The main wear mechanisms of the cemented carbide were all serious adhesion and spalling, and the specific wear forms were closed related to hydrogen contents. There are all not the chemical reaction wear and element diffusion wear in the friction region of whether the unhydrogenated alloys or the hydrogenated alloys or cemented carbide.
Double Phase Differences Correction Method for Frequency and Phase in Spectrum Analysis
Authors: Luo Jiu Fei , Xie Zhi Jiang , Chen Ping
Published: September 2013

This paper advances a new method, double phase differences correction method, which aims at correcting the errors of frequency, phase and amplitude of the harmonic signal. The employment of this method involves that two phase differences of two highest spectral lines in the main lob are used to get the correcting value of frequency and then phase and amplitude can be rectified by corresponding formula. It solves the problem that the traditional formula of translation of window center is only for rectangle window. This new formula can correct for the different window by the principle of translation of window center. Simulation shows that the maximum error of frequency of the signal with white noise is less than 1% of frequency resolution. The maximum error of phase is around 1.5º, and the maximum error of amplitude is within 0.01. The average errors in frequency, phase and amplitude are approximately 0.002Hz, 1º and 0.005, respectively.
Modelling factors that affect the presence of larval mosquitoes (Diptera: Culicidae) in stormwater drainage systems to improve the efficacy of control programmes
Authors: Jackson Michael J. , Gow Jennifer L. , Evelyn Michelle J. , McMahon T.J. Scott , Campbell Harlan , Sheppard Jennifer , Howay Tim J. , Fladmark Disa , Thielman Aynsley
Published: September 2013

Stormwater catch basins form part of artificial drainage systems in urban areas and can provide larval habitat for mosquito vector species of West Nile virus (WNv), such asCulex pipiensLinnaeus (Diptera: Culicidae). We evaluated the impact of management techniques and targeted applications of larvicide on larval populations of this potential WNv mosquito vector species in catch basins from the Lower Mainland of Vancouver and on Vancouver Island of British Columbia, Canada. A mixed effects logistic regression model described the relationship between larval presence and larvicide treatment while controlling for other parameters. Parameter estimates showed that larvicide treatment reduced the odds of larvae presence by a factor of ∼7.23. The model also revealed relationships between larval presence and water temperature and adjacent land use but larvicide treatment consistently reduced the presence of larvae regardless of these other factors. This knowledge can now be used to prioritise and target control efforts to most efficiently reduce WNv mosquito vector populations, and most effectively reduce the risk of WNv transmission to humans. A similar research strategy could be applied to emerging threats from other potential mosquito vectors of disease around the world, to help lower the incidence of mosquito-borne disease.
South Africa’s service-delivery crisis: From contextual understanding to diaconal response
Authors: Swart Ignatius
Published: September 2013

This article proceeded from the assumption that the theme of service delivery in present-day South Africa could well be qualified by the notion of ‘crisis’, to the extent that this qualification, from a theological perspective and on the basis of comparative social analysis, well recalls the statements in such critical and profound theological documents as The Kairos Document and Evangelical Witness in South Africa on the ‘crisis’ in the latter years of apartheid. The further recognition that the theme of service delivery constitutes an essentially new focus for practical-theological scholarship in South Africa led the author, who has a pertinent interest in the field of Christian diaconia, to thereupon go the full circle of practical-theological interpretation in developing such a focus. This was done by, firstly, attempting to develop a deeper contextual understanding of the problem of service delivery in the country on the basis of the prevailing debate on service delivery in South Africa, after which the ideas from conceptualisations of two different modes of diaconal practice within contexts of endemic poverty in the practical-theological literature were explored. The discussion concluded with a more pertinent consideration of the extent to which these two conceptualisations could be taken as providing direction in conceptualising a transformational diaconal response to the current service-delivery problem.
Effect of Acidic Environment on the Surface Microhardness of BiodentineTM
Authors: Poplai Gaurav , Jadhav Sameer K
Published: September 2013

Aim

To compare the effects of various levels of acidic pH on surface microhardness of Biodentine.TM

Materials and methods

Biodentine was mixed and packed into stainless steel molds (diameter = 5 mm and height = 1.5 mm). Four groups of 10 specimens each were formed and exposed to pH: 7.4, 6.4, 5.4 and 4.4 respectively for 4 days. Vickers microhardness was measured for each of the specimens and was measured 4 days after the exposure.

Results

Data was subjected to one-way ANOVA using Tukey's post hoc test. Group I (control pH = 7.4) showed greatest surface microhardness of 67.5 ± 4.1 HV. The least microhardness of 46.3 ± 5.0 HV was observed for group IV where the specimens were soaked at pH 4.4. A p-value less than 0.05 was considered to be statistically significant.

Conclusion

Under the limitations of the present study, surface hardness of Biodentine was impaired in the presence of acidic environment.

How to cite this article

Poplai G, Jadhav SK, Hegde V. Effect of Acidic Environment on the Surface Microhardness of Biodentine„§ƒ| World J Dent 2013;4(2):100-102.
To Evaluate the Effect of Presence and Absence of Smear Layer with Different Instruments and Obturation Methods on Microleakage of Root Canal-Filled Teeth: An in vitro Study
Authors: Shetty Dinesh , Uppin Veerendra , Shetty Priyadarshini
Published: September 2013

Aim

To evaluate the effects of presence and absence of smear layer with different instruments and obturation methods on microleakage of root canal-filled teeth.

Materials and methods

A total of 100 extracted human maxillary central incisors with closed apices and single roots were taken for the study. The teeth were divided into six groups A to F consisting of 15 teeth each. Control group consisted of 10 teeth with five positive and five negative teeth each.

Groups A, B, C and D were instrumented with rotary files and groups E and F were instumented with conventional stainless steel files.

Groups A, B, C and D were flushed with 3 ml of EDTA to remove the smear layer prior to obturation. All teeth were flushed with 5% NaOCl, then obturated with AH-26 sealer with lateral condensation technique on groups C, D, E, F and injectable thermoplasticized gutta-percha obturation technique on groups A and B.

Using electrochemical technique the current flow in the circuit was observed for 45 days. The magnitude of the current for each tooth was directly proportional to the extent of leakage. At the intervals of 10, 20, 30 and 45 days the groups A-F were compared to identify statistically significant differences using students t-test.

Results

Significantly less microleakage occurred when the smear layer was removed and when the canals were obturated with thermoplasticized gutta-percha. Canals instrumented with engine driven NiTi files exhibited less leakage than hand instrumented canals.

Conclusion

Rotary instrumentation of the root canals provides a superior preparation in comparison to hand instrumentation. Removal of smear layer increases the resistance of microleakage. Thermoplasticized gutta-percha obturation appears to provide a superior seal as compared to lateral condensation.

How to cite this article

Shetty P, Uppin V, Shetty D. To Evaluate the Effect of Presence and Absence of Smear Layer with Different Instruments and Obturation Methods on Microleakage of Root Canal-Filled Teeth: An in vitro Study. World J Dent 2013;4(2):103-107.
Fabrication of Overdenture against a Nonmodified Natural Dentition and Removable Partial Denture using Meyer's Technique: A Preventive Approach
Authors: Mishra Niraj , Singh Kamleshwar , Agrawal Kaushal K , Bhalla Gaurav
Published: September 2013

A clinical report of a patient having partially edentulous maxillary arch and dentulous mandibular arch has been presented. Patient came to the Department of Prosthodontics with the chief complaints of loosening of the prosthesis. The patient was rehabilitated with a maxillary complete overdenture and mandibular removable partial denture using the functionally generated path technique to achieve harmonious occlusion between the complete denture and the natural dentition.

How to cite this article

Singh K, Mishra N, Agrawal KK, Bhalla G. Fabrication of Overdenture against a Nonmodified Natural Dentition and Removable Partial Denture using Meyer's Technique: A Preventive Approach. World J Dent 2013;4(2): 131-133.
A Clinical Study to Correlate Maxillary Anterior Natural Teeth with that of the Commercially Available Acrylic and Porcelain Shade Guides
Authors: Khurana Punit RS , Thomas P Vivek , Rao Soudhamini V , Balamuragan R , Singh Mohan Preet
Published: September 2013

The success of the dental treatment as perceived by our patients is often preferentially evaluated on the appearance of the restoration. Usually visual determination is unreliable and inconsistent, complicated by the inability of the shade guide to cover the entire dental color range and also there is lack of logical order of arrangement of the tabs. Hence a clinical study is planned to perform visual shade selection in standardized conditions to correlate the shades of maxillary anterior natural teeth in adult subjects of Davengere district origin to one acrylic and three porcelain shade guides commercially available in India.

How to cite this article

Khurana PRS, Thomas PV, Rao SV, Balamuragan R, Singh MP. A Clinical Study to Correlate Maxillary Anterior Natural Teeth with that of the Commercially Available Acrylic and Porcelain Shade Guides. J Contemp Dent Pract 2013;14(3):427-433.
Keratocystic Odontogenic Tumor
Authors: Galinde Jyotsna , Sidana Sunil , Ramaswami Radhika , Srivalli N
Published: September 2013

In 2005, the World Health Organization renamed the lesion, previously known as an odontogenic keratocyst, as the keratocystic odontogenic tumor (KOT or KCOT). The term odontogenic keratocyst (OKC) was first used by Philipson in 1963 and its clinical and histologic features were confirmed by Browne in 1970 and 1971. In this case report, a young patient with a histology report as an orthokeratinized variety of KCOT and it was a primary lesion with amcystic lining that was thick may be due to chronic irritation because of which it could be removed in toto. Resection was not advocated as it causes morbidity, peripheral ostectomy could not be performed as the buccal and lingual cortical plates were already thinned out with areas of perforation. Thus, enucleation with Carnoy's solution was considered ideal for this case. Also, this patient has been on regular follow-up for around 8 months showed good healing with no signs of recurrence.

How to cite this article

Ramaswami R, Galinde J, Srivalli N, Sidana S. Keratocystic Odontogenic Tumor. J Contemp Dent 2013;3(2):87-91.
Estimation of regional differences in wind erosion sensitivity in Hungary
Authors: Mezõsi G. , Blanka V. , Bata T. , Kovács F. , Meyer B.
Published: September 2013

Abstract. In Hungary, wind erosion is one of the most serious natural hazards. Spatial and temporal variation in the factors that determine the location and intensity of wind erosion damage are not well known, nor are the regional and local sensitivities to erosion. Because of methodological challenges, no multi-factor, regional wind erosion sensitivity map is available for Hungary. The aim of this study was to develop a method to estimate the regional differences in wind erosion sensitivity and exposure in Hungary. Wind erosion sensitivity was modelled using the key factors of soil sensitivity, vegetation cover and wind erodibility as proxies. These factors were first estimated separately by factor sensitivity maps and later combined by fuzzy logic into a regional-scale wind erosion sensitivity map. Large areas were evaluated by using publicly available datasets of remotely sensed vegetation information, soil maps and meteorological data on wind speed. The resulting estimates were verified by field studies and examining the economic losses from wind erosion as compensated by the state insurance company. The spatial resolution of the resulting sensitivity map is suitable for regional applications, as identifying sensitive areas is the foundation for diverse land development control measures and implementing management activities.
The impact of initial spread calibration on the RELO ensemble and its application to Lagrangian dynamics
Authors: Wei M. , Jacobs G. , Rowley C. , Barron C. N. , Hogan P. , Spence P. , Smedstad O. M. , Martin P. , Muscarella P. , Coelho E.
Published: September 2013

Abstract. A number of real-time ocean model forecasts were carried out successfully at Naval Research Laboratory (NRL) to provide modeling support and numerical guidance to the CARTHE GLAD at-sea experiment during summer 2012. Two RELO ensembles and three single models using NCOM and HYCOM with different resolutions were carried out. A calibrated ensemble system with enhanced spread and reliability was developed to better support this experiment. The calibrated ensemble is found to outperform the un-calibrated ensemble in forecasting accuracy, skill, and reliability for all the variables and observation spaces evaluated. The metrics used in this paper include RMS error, anomaly correlation, PECA, Brier score, spread reliability, and Talagrand rank histogram. It is also found that even the un-calibrated ensemble outperforms the single forecast from the model with the same resolution. The advantages of the ensembles are further extended to the Lagrangian framework. In contrast to a single model forecast, the RELO ensemble provides not only the most likely Lagrangian trajectory for a particle in the ocean, but also an uncertainty estimate that directly reflects the complicated ocean dynamics, which is valuable for decision makers. The examples show that the calibrated ensemble with more reliability can capture trajectories in different, even opposite, directions, which would be missed by the un-calibrated ensemble. The ensembles are applied to compute the repelling and attracting Lagrangian coherent structures (LCSs), and the uncertainties of the LCSs, which are hard to obtain from a single model forecast, are estimated. It is found that the spatial scales of the LCSs depend on the model resolution. The model with the highest resolution produces the finest, small-scale, LCS structures, while the model with lowest resolution generates only large-scale LCSs. The repelling and attracting LCSs are found to intersect at many locations and create complex mesoscale eddies. The fluid particles and drifters in the middle of these tangles are subject to attraction and repulsion simultaneously from these two kinds of LCSs. As a result, the movements of particles near the Deepwater Horizon (DWH) location are severely limited. This is also confirmed by the Lagrangian trajectories predicted by the ensembles.
Positive surgical margins at radical prostatectomy: Population-based averages within PSA and Gleason strata
Authors: Izard Jason P. , Salazar Marco A. , Chatterjee Suman , Lin Daniel W. , Wright Jonathan L.
Published: September 2013

Background: Positive surgical margins (PSM) are an important determinant of biochemical recurrence after radical prostatectomy (RP). We use a population-based cancer registry to evaluate PSM by stage, Gleason and prostate-specific antigen (PSA).Methods: We identified men undergoing RP from the Surveillance, Epidemiology and End Results (SEER) database between 2004 and 2007. Differences between those with and without PSM were compared with chi-squared tests. The proportion of cases with PSM were stratified by PSA and Gleason sum for both pT2 and pT3a tumours. Factors associated with PSM were analyzed using chi-square and multivariate logistic regression analysis. A composite variable was used in a second multivariate analysis to display the odds ratio (OR) for a PSM for each discrete combination of PSA, Gleason score and pT stage.Results: In total, 28 461 RP patients were identified and a PSM was present in 19.5%. PSM were 42% in pT3a and 16% in pT2 cases. Higher PSAs (<4.0, 4-9.9, >10) were associated with higher proportions of PSM (12%, 20% and 28%, p < 0.001). Similarly, higher Gleason scores (≤6, 3+4, 4+3, ≥8) were associated with higher PSM (12%, 22%, 27% and 33%, p < 0.001). For pT2 tumours, the proportion of PSM ranged from 8% (Gleason ≤6, PSA <4.0) to 28% (Gleason 8-10, PSA ≥10). For pT3a tumours, the PSM was higher in each Gleason/PSA strata compared to those with pT2 tumours, reaching 63% for those with pT3a, Gleason 8-10, PSA >10 disease. On multivariate analysis, stage was the largest predictor for PSM (OR 3.05, 95% confidence interval 2.81-3.30), although Gleason score and PSA remained statistically significant.Conclusion: In this population-based study of PSM after RP, the proportion of PSM vary significantly within different PSA and Gleason strata for organ-confined and extracapsular disease. These data can be used as a reference for urologist self-assessment.
A severe complication of mid urethral tapes solved by laparoscopic tape removal and ureterocutaneostomy
Authors: Schätz Tobias , Hruby Stephan , Colleselli Daniela , Janetschek Günter , Lusuardi Lukas
Published: September 2013

Mid-urethral tapes are largely used to manage stress urinary incontinence(SUI). In certain cases, however, this procedure results in bothersome complications that lead to complete resection. We present the case of an 85-year-old woman who presented with ongoing suprapubic pain, hematuria, vaginal bleeding and recurrent urinary tract infections. The patient had undergone a tension-free vaginal tape (TVT) procedure in 1999 and a transobturator tape (TOT) placement in 2003 for SUI. Investigations revealed a urethral stone, erosion of both TOT and TVT and an urethra-vaginal fistula. Under local anesthesia the urethral stone was removed endoscopically and the TOT removed via a vaginal approach. Due to her comorbidity, she underwent a laparoscopic intraperitoneal removal of the TVT and a definitive ureterocutaneostomy to relieve her pain, inflammation and incontinence. This is the first ever presented case of erosion of mid-urethral tapes and incontinence treated with a laparoscopic resection of the tape and ureterocutaneostomy as definitive urinary diversion.
Classification, diagnosis and treatment of ACTH-independent macronodular adrenal hyperplasia
Authors: Su Heng-Chuan , Huang Xin , Dai Jun , Zhou Wen-long , Huang Bao-xing , Cao Wan-li , Sun Fu-Kang
Published: September 2013

ACTH-independent macronodular adrenal hyperplasia (AIMAH) is a distinctive subtype of Cushing’s syndrome (CS), with different clinical manifestations according to the level of serum cortisol. Based on clinical manifestations and serum cortisol, we divide AIMAH into three types, subclinical AIMAH, clinical AIMAH and high-risk AIMAH, with varied treatment methods being adapted to different subtypes. At the same time, we describe 3 patients who represent these subtypes of this disease, and review some cases of AIMAH which have been previously reported in the English literature. To our knowledge, this is the first article discussing classification, diagnosis and treatment of this disease and should be useful for future therapy of AIMAH.