bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-Constrained Quadrilateral Mesh Generation for Ship Assembly
Authors: Wang Qian , Bao Jin Song , Xun Chao , Pan Yi Jun , Tang Jun Jie
Published: September 2013

The assembly of ship blocks is achieved through welding. To get a high level of closure accuracy, finite element analysis (FEA) is always needed to predict the welding deformation. However, the fast automatic mesh generation technique during the finite element method (FEM) for the ship assembly is not mature enough yet. Due to the complex ship architecture, during FEA, the model must be built up manually in most cases. This process is complicated and the errors are easy to occur. Consequently, the efficiency of FEA during the ship assembly is highly affected. Automatic mesh generation is a key factor restricting the development of FEM, since the quality and speed of the mesh generation directly influence the accuracy of calculation and the efficiency of analysis. In the field of marine engineering and aerospace engineering, the mesh elements are required to be quadrilateral. However, the technique of the quadrilateral mesh generation is still more difficult and less mature than that of the triangular mesh generation. This work proposed a hybrid mesh generation algorithm, borrowing the advantages from both the quad-morphing algorithm and the paving algorithm as well as considering the factor of multi-constraints. An example case is also given to illustrate the result of this proposed algorithm.
Smoothing of SFS Reconstructed Surface Based on Genetic Algorithm
Authors: Wang Jun , Wu Feng He , Li Xiu Liang , Wang Jia Chun
Published: September 2013

To improve the smoothness of SFS reconstructed surface, a new approach based on genetic algorithm is proposed. First, by analyzing the principle of SFS, the reason for surface error and distortion zone are found. By adding data according to the symmetric and asymmetric principle and B spline, data in the distortion zone are added and the reconstruction of SFS is realized. The evaluation criteria for smoothness of curves and surfaces are given according to the mathematical sense and concurrent level of CAGD/CAD/CAM. The surface smoothing process is turn into two curve smoothing process in two directions. The evaluation criteria is taken as the constraint condition and then the smoothing of SFS reconstructed surface based on the genetic algorithm is realized. The experimental results show that this new approach is an effective way to eliminate the bad points of SFS surface, improve the surface quality so it is a practical method for surface smoothing.
Influence of Cutting Compound on Critical Cut Depth of Glass BK7
Authors: Jia Peng
Published: September 2013

In diamond cutting of optical glasses, the magnitude of critical depth of cut for brittle-ductile transition is an important factor affecting the machinability of the work material in terms of production rate and surface quality. In this work, scratching tests with increasing depths of cut were conducted on glass BK7 to evaluate the influence of the cutting fluid properties on the critical depth of cut. Boric acid solutions of different concentrations were selected as cutting fluids in the tests. The resulting scratches were examined utilizing a white light interferometer and the values of the critical depth of cut were determined based on the observations of the micro-morphology of the scratch surfaces produced. Experimental results indicated that compared with the process without cutting fluid action, the critical depth of cut in diamond cutting of glass BK7 can be increased by using boric acid solution as the cutting fluid.
One-Axis-Oriented Crystal Growth of Lead Zirconate Titanate Thin Films on Metal Substrates Using Perovskite-Type Oxide Nanosheet Layer
Authors: Minemura Y. , Kondoh Y. , Funakubo H. , Uchida Hiroshi
Published: September 2013

One-axis-oriented Pb (Zr,Ti)O3(PZT) films were fabricated using a chemical solution deposition technique on (111)Pt/TiO2/(100)Si and Inconel625 substrates buffered by nanosheet Ca2Nb3O10(ns-CN). The (001)-oriented PZT crystals (Zr/Ti=0.40:0.60, tetragonal) were preferentially grown on (001)ns-CN/Inconel625, whereas the PZT crystals deposited on (001)ns-CN/(111)Pt/ TiO2/(100)Si exhibited preferential PZT(100) orientation. The resulting PZT film on (001)ns-CN/Inconel625 indicated remanent polarization of approximately 59 μC/cm2, which was significantly larger than that on (001)ns-CN/(111)Pt/TiO2/(100)Si.
Crystal Structures and Surface Morphologies of LaGaO3-Based Epitaxial Thin Films Grown by a Pulse Laser Deposition Method
Authors: Matsunaga Ayuko , Kitanaka Yuuki , Inoue Ryotaro , Noguchi Yuji , Miyayama Masaru , Itaka Kenji
Published: September 2013

High-quality La0.84Sr0.16Ga0.26Mg0.74O3-δ (LSGM) epitaxial thin films were successfully grown on (100)-SrTiO3 (STO) substrates at a temperature of 800 °C by a pulsed laser deposition (PLD) method with KrF excimer laser pulses at an ozone pressure of 1.3 × 103 Pa. X-ray diffraction rocking curve measurements showed that the LSGM films had a full-width at half-maximum (FWHM) value of 0.11 °for out-of-plane 002 reflection, which was smaller than that reported for LaGaO3 films grown by atomic layer deposition methods (0.18 o). The reciprocal spaces mapping of 103 refraction showed that the LSGM films had a slightly larger lattice parameter a (out-of-plane) of 0.393 nm than a// (in-plane) of 0.391 nm.
TEM Study for Self-Orientated LaNiO3 Film along [100]
Authors: Sakamoto Naonori , Ozawa Kotaro , Murakoshi Kohei , Ohno Tomoya , Kiguchi Takanori , Matsuda Takeshi , Konno Toyohiko J. , Wakiya Naoki , Suzuki Hisao
Published: September 2013

LaNiO3 (LNO) is known as a candidate for oxide electrodes with perovskite type crystal structure which is suitable for lattice matching with conventional perovskite ferroelectrics, Pb (Zr,Ti)O3 (PZT), BaTiO3 (BTO), etc. We have been investigating thermal expansion effects of the LNO film with PZT/LNO/Si and BTO/LNO/Si structures, where ferroelectric and piezoelectric properties are enhanced by a compressive thermals stress impressed from the LNO layer to the ferrelectric films. The ferroelectric films also shows high [00 orientation owing to [100] orientation of the LNO film. In the present study, further investigation of the LNO films prepared on Si substrates by CSD method is made by transmission electron microscopy (TEM) in order to understand self-orientation along [100] perpendicular to the film plane which effectively leads orientation of PZT films prepared on the LNO film. The results obviously indicates that the 1 layer deposited LNO film has almost no orientation, whereas it shows tendency of orientation of [100] perpendicular to the film plane when the layer number increased.
Low-Temperature Fabrication of Dye-Sensitized ZnO Electrodes via Zinc Hydroxide Acetate by Utilizing Liquid Phase
Authors: Ueno Shintaro , Utsunomiya Hirokazu , Fujihara Shinobu
Published: September 2013

For fabrication of plastic dye-sensitized solar cells, we propose a dissolution and precipitation method to form nanostructured ZnO films on plastic substrates. Layered hydroxide zinc acetate (LHZA) films on plastic substrates were immersed in acetonitrile at 60 oC. They were converted into ZnO films through the dissolution of LHZA and the precipitation of ZnO in acetonitrile. The resultant films contained a large amount of zinc acetate compound impurities, which were attempted to be removed from the ZnO films by dissolving in water. We achieved the energy conversion efficiency of 2.3% for the N719/ZnO electrode on an ITO-PEN substrate.
Preparation of Barium Titanate/Strontium Titanate Accumulation Ceramics with Necking Structure of Strontium Titanate Nanocubes
Authors: Nakashima Kouichi , Iwatsuki Shogo , Fujii Ichiro , Wada Satoshi
Published: September 2013

Barium titanate (BaTiO3) / Strontium titanate (SrTiO3) accumulation ceramics with necking structure of SrTiO3 nanocubes were prepared using a solvothermal method. XRD measurements confirmed SrTiO3 and BaTiO3 with a perovskite structure. The XRD peak intensities of the BaTiO3 increased significantly as the solvothermal reaction was repeated. After heat treatment of the SrTiO3 at 900°C, the particles grew larger and formed necked contacts with each other. As the solvothermal reaction was repeated in order to coat with BaTiO3, the density increased, the porosity decreased, and the thickness of the BaTiO3 layer increased.
Preparation of Bismuth Based Perovskite Oxides and their Electric Properties
Authors: Fujii Ichiro , Shimamura Atsushi , Nakashima Kouichi , Kumada Nobuhiro , Funakubo Hiroshi , Kuroiwa Yoshihiro , Wada Satoshi
Published: September 2013

Bismuth and niobium based perovskite oxides with non-integer A and B site valences were prepared by a solid-state route. For the A1+xB5xO3 type (Bix/2K1-x/2)(TixNb1-x)O3 (x=0.1 0.9) ceramics (the examples of samples studied), the Curie temperature increased from approximately 250 to 350 °C with increasing x from 0.5 to 0.9. These results were discussed with the Abrahams relations.
Chemical Composition of Dielectric and Piezoelectric Properties for BaTiO3-Bi (Mg1/2Ti1/2)O3-BiFeO3 System Ceramics
Authors: Mitsui Ryuta , Fujii Ichiro , Nakashima Kouichi , Kumada Nobuhiro , Kuroiwa Yoshihiro , Wada Satoshi
Published: September 2013

1-x-y)BaTiO3-xBi (Mg1/2Ti1/2)O3-yBiFeO3 ceramics were prepared by a conventional solidstate synthesis, and crystal structure and electric properties were investigated. Synchrotron X-ray diffraction pattern revealed that a single perovskite phase was obtained for samples at x=0.05-0.15, y=0.46.5-73.5. Splitting of the (111) peak was observed when (x, y) = (0.050, 0.685) and (0.050, 0.735) indicating that crystal structure of samples changed from a pseudo-cubic phase to a rhombohedral phase with increasing BF. As the BF content increased, the Curie temperature increased. The largest maximum strain (Smax) over the applied maximum electric field (Emax) value (Smax / Emax) of 300 pm/V was observed for 0.365BT-0.050BMT-0.585BF at 25 °C and 1Hz with the Curie temperature of 390 °C.
Preparation of (Bi1/2K1/2)TiO3-Bi(Mg1/2Ti1/2)O3-BiFeO3 Ceramics Withnanodomain Structure and their Piezoelectric Properties
Authors: Kamei Haruumi , Fujii Ichiro , Nakashima Kouichi , Kuroiwa Yoshihiro , Minemoto Hisashi , Wada Satoshi
Published: September 2013

Lead-free (Bi0.5K0.5)TiO3)-Bi (Mg0.5Ti0.5)O3-BiFeO3 (BT-BMT-BF) ceramics were prepared by a conventional solidstate synthesis. Synchrotron x-ray diffraction studies indicated two compositional phase boundaries. An increased strain of 0.070% was obtained at 50 kV/cm, 1 Hz, 25 °C for one of the phase boundary compositions of 0.45BKT-0.1BMT-0.45BF with the temperature of the dielectric maximum of 331 °C.
Origin of Semiconducting Behavior of CaO Added BaTiO3-(Bi1/2Na1/2)TiO3 Ceramics
Authors: Akutsu Hitomi , Zubair Mohammad A. , Hoshina Takuya , Takeda Hiroaki , Tsurumi Takaaki
Published: September 2013

An effect of addition of CaO on electrical resistivity in BaTiO3-(Bi1/2Na1/2)TiO3(BT-BNT) solid solution ceramics was investigated. Three kinds of CaO adding processes were applied. Extra CaO additive against stoichiometric composition is effective to give semiconductive property into the BT-BNT ceramics. However, the ceramics with CaO-inclusive composition such as Ba0.9(Bi0.5Na0.15Ca0.35)0.1TiO3had a high resistivity. From chemical composition analysis and structure analysis, it was concluded that Ca2+dominantly substituted for Na+in theAsite of perovskite-typeABO3structure and then that residual Bi3+acts a donor.
Alternative Approaches Using Animal Model for Implant Biomaterials: Advantages and Disadvantages
Authors: Cavalu Simona , Simon Viorica , Ratiu Cristian , Oswald Ioan George , Silviu Vlad , Ponta Oana
Published: September 2013

This study presents some aspects regarding the evaluation of bone-implant interactions using two animal models (rabbit and rat). The proposed implants are new alumina/zirconia bioceramics designed for hard tissue replacement (oral implantology or arthroplasty). The animal selection was made based on the number and size or design of implants to be tested as these factors influence directly the species of animal chosen for this study. The correct placement and stability of the implants were evaluated by radiographic images. SEM micrographs were recorded on the bone/implant area along with the elemental composition of the sheared implant surfaces at different time intervals after the surgery. Calcium/phosphate ratio was considered as an indicative of the surface implant coverage for a successful osseointegration. Histological examination of the bone and bone marrow in direct contact with the implants was performed to detect any immunological or inflammatory responses. Each of the animal species (rat or rabbit) demonstrated unique advantages and disadvantages as a model for demonstrating the response of bone tissue to an implant material. The size and design of the implants also influenced the bone turnover as demonstrated histologically.
Specific Biomaterials Used within the Department of Anatomy
Authors: Petru Bordei , Constantin Dina , Ionut Bulbuc , Dan Iliescu
Published: September 2013

As one of our main topics of interest within the Department of Anatomy, the usage of biomaterials involved two directions: preparation of anatomical casts by injection and corrosion and preservation of anatomical samples through plastination. For injection we used several substances, such as polyvinyl chloride, with the solvent cyclohexanone, a polyester oil used in furnishing and glass fiber industry and mostly TECHNOVIT 7143, of German production. Another preservation method that includes the usage of biopolymers is plastination, a perfect method for the preservation of perishable biological specimens, especially for soft, putrifiable ones with high water content. The method we applied is the silicone plastination (S10) that addresses to macroscopical samples, such as internal organs (hearts, kidneys) or slices of nervous tissue (brain slices) greater than 10 mm, samples resulted from the dissection process in the Anatomy Department.
Control of Crystallinity of Hydroxyapatite Sheet
Authors: Kusunoki Masanobu , Matsuda Taiyo , Fujita Naoki , Sakoishi Yasuhiro , Iguchi Ryou , Hontsu Shigeki , Nishikawa Hiroaki , Hayami Takashi
Published: September 2013

A technique to control the crystallinity of hydroxyapatite (HA) was investigated for applications such as dentistry, regenerative medicine, cell culture scaffolding, and bio-sensors. An amorphous HA film was first produced by pulsed laser deposition. After deposition, it was separated from a substrate as a free-standing sheet. Annealing was then performed to control the crystallinity of the sheet. It was found that conventional annealing in an electric oven was not suitable for HA sheets, because it led to curling and cracking. Since such problems were assumed to be caused by thermal stress, annealing was next carried out with the HA sheet enclosed in HA powder in the center of a metal capsule. This method allowed annealing to be successfully carried out without causing any curling or cracking. Uniform pieces with dimensions of 10 mm × 10 mm cut from a large HA sheet were annealed at temperatures of 200 to 800 ºC and then examined using X-ray diffraction. It was found that the intensity of the diffraction peaks associated with crystalline HA changed with annealing temperature, and that the strongest peaks were observed for the sample annealed at 500 ºC. These results indicate that the crystallinity of the HA sheet can be controlled using the proposed method.
Biopolymer Blends as Potential Biomaterials and Cosmetic Materials
Authors: Sionkowska Alina , Lewandowska Katarzyna , Planecka A. , Szarszewska P. , Krasinska K. , Kaczmarek B. , Kozlowska J.
Published: September 2013

Blends of two polymer, namely chitosan with silk fibroin or partially hydrolysed polyacrylamide (HPAM) were prepared. The surface properties of chitosan/silk fibroin and chitosan/HPAM blended films were investigated using the technique of Atomic Force Microscopy (AFM) and by means of contact angle measurements allowing the calculation of surface free energy. Measurements of the contact angle for diiodomethane (D), and glycerol (G) on the surface of chitosan films and chitosan/silk fibroin films were made and surface free energy was calculated. It was found that chitosan/silk fibroin blend surface is enriched in high surface energy component i.e. silk fibroin. The surface roughness of chitosan, silk fibroin, HPAM, chitosan/silk fibroin and chitosan/HPAM blended films differs with the composition of the blend. Film-forming polymeric blends can be potentially used as biomaterials and cosmetic materials.
Design and Development of Experiment Platform for AC Speed Control System Based on DSP
Authors: Li Zhi Yong , Ji Hua
Published: September 2013

This paper introduces a novel experiment platform for AC speed control system based on TMS320LF2407A. The system composition and the design method of hardware and software function modules are set forth. In this experimental platform, Users can carry out the experiments of many kinds of motor control strategy for induction motor, synchronous motor and the other motors. This experimental platform is transparent to hardware and is open to software system, and achieved good results in the practical teaching and research.
Research of the PLC Module Based on the Embedded NC System
Authors: Cui Yu Long , Wang Tai Yong , Dong Jing Chuan , Ding Yan Yu , Liu Zhe
Published: September 2013

PLC module is an important part of embedded NC system, and mainly accomplishes the auxiliary functions of CNC machine tools. This paper completes the work of research and development of the PLC programming software for PC side of the host computer, and the software is developed in VC++6.0 environment based on windows XP system, to realize the editing functions and the mutual conversion between the ladder and instruction language. Focus on the realization of the mutual conversion between ladder with instruction table, use the logical structure of tree when the ladder converts to the instruction table, and use the data structure of stack to complete the conversion. Instruction table is transformed to Ladder by the operation of the stack to complete the conversion.
Study of Trigonometric Function Improved Acceleration-Deceleration Algorithm and Velocity Look-Ahead Control
Authors: Li Bo , Liu Qing Jian , Liu Lu , Dong Jing Chuan , Wang Tai Yong
Published: September 2013

The final process of workpiece is composed of a series of connected trajectories, and the expectation speed of the different trajectories may be different, so it requires the changes of acceleration and deceleration speed. This paper introduces the improved acceleration-deceleration algorithm of trigonometric function, and presents an optimization algorithm according to the changing trend of velocity to the method of forward-looking processing speed.
Dynamic Analysis of Flexible Space Manipulators with Harmonic Reducer
Authors: Zhao Jie Liang , Gu Yong Xia , Yan Shao Ze , Wu Jia Ning
Published: September 2013

Space manipulator is an important tool for spacecraft to complete a variety of tasks in space. The trajectory precision of the manipulator determines whether the mechanism performs normally. Nowadays the harmonic drive is widely used as the reducer in the space manipulator, which may influence the dynamical properties of the flexible space manipulator. This paper establishes the dynamical models of space manipulator considering the harmonic hysteresis phenomenon derived from the harmonic reducer. A numerical simulation is proposed to analyze the nonlinear dynamic characteristics of flexible space manipulator with harmonic drive. The results of angular velocities reveal that non-linear and high-frequency disturbance detected in the output dynamical property is caused by flexibility of the space manipulator. Moreover, the observed hysteresis phenomenon in the dynamic behavior is not only determined by the flexibility of manipulator but the transmission feature embedded the harmonic drive.
Analysis and Research of Reliability Technology of CNC Machine Tools
Authors: Liu Zhe , Dong Jing Chuan , Wang Tai Yong , Li Bo , Cui Yu Long
Published: September 2013

From the middle of the 20th century, CNC(Computer numerical control) machine tool has brought a revolutionary change to the mechanical manufacturing industry. CNC machine tool is a kind of highly mechatronics product. It has the Characteristic of high precision and high productivity. Therefore it develops quite fast and improves various kind of the quality of the products. It speeds up the development of machinery industry. In order to meet the requirements of the processing accuracy and speed of modern society, the structure and components of the machine have also become complicated. In order to protect the safety of operators and reduce time of machine repaired as well as improve efficiency, the requirements of the reliability of CNC machine tool should be greatly improved. This study will briefly introduce the concept of reliability and put forward some measures to improve the reliability.
Finite Element Analysis on Key Components of Horizontal Refuse Compactor
Authors: Chen He Nan , Wang Shou Cheng , Wang Yuan
Published: September 2013

This subject is proposed via authentic market investigation, based on the sharp increase of household garbage in urban cities and urgent demand for environmental amelioration in recent years. Taking horizontal refuse compactor as an example, this paper optimizes the configuration of key components of refuse compactors, by employing Finite Element Analysis (FEA) method, aiming to select the most appropriate components to equip compactors, whose operation efficiency can be markedly enhanced. The statics analysis for each key component is individually conducted by applying ABAQUS, the FEA simulation software, to test the reliability of this new structure.
Study on Technological Innovation Model of High-Tech Manufacturing Enterprise
Authors: Zhang Ming Lin , Zhou Rong Hua
Published: September 2013

High-tech enterprises are established on the basis of high technology, technological innovation is the premise of survival and development of high-tech enterprises. In this paper, it summarizes the academic situation of technological innovation mode. At present, the research on the definition and characteristics of high-tech enterprises, technological innovation and technological innovation mode are mature, but in some other aspects the research is insufficient. For example, research on the relationship between high-tech enterprises and different innovation mode. Also, scholars focus on qualitative analysis, and seldom do quantitative empirical research.
Simulation Model of Cultural Industry Agglomeration Based on SD-System Dynamics Theory
Authors: He Yong Jun , Fu Li Ping
Published: September 2013

The experience of countries and regions with developed cultural industries has shown that environment of gathering development could boost the cultural industries with distinctive character and good brand, which supports the development of the whole regional cultural industries. Gathering development could strongly bring the cultural industry stronger. This paper, on the current research situation of cultural industry agglomeration studying, introduces system dynamics theory into the research of cultural industry gathering, builds its model on system dynamics theory.
Study on the Standardization of a Manufacturing Inform System Software Interface
Authors: Wang Xing
Published: September 2013

Methods for the standardization of a manufacturing information system (MIS) software interface are put forward in this paper, the interface is described and test methods are raised, and CAD system application interface standardization is instantiated for explanation.
Research on the Concept of Controlled Speed Based on Cutting Band Saw
Authors: Xue Ying Chun
Published: September 2013

Speed control is the core problem of cutting machine design, the past has been the experience of adjusting the cutting speed, the lack of theoretical basis, randomness. In view of this, according to the basic requirements of cutting efficiency maximization, deduces the removal rate and feed speed, time equation, solving the cutting efficiency problem exists in the design of machine, and established when the removal rate is constant, relation curves of shear rate and time. Use of the method of cutting machine design, can improve the accuracy and scientific design, has higher application value.
Research on the Impact of Vent Pressure on the Yarn Splicing Based on ANSYS
Authors: Chang De Gong , Li Deng Chen , Li Song Mei , Zhou Guang Zhen , Zhao Hai Xia
Published: September 2013

Pneumatic splice makes use of high-speed compressed air as the driving force to complete the yarn splicing, noticing that the change of the vent pressure has a significant effect on yarn splicing. This paper studies the impact of vent pressure on the quality of yarn splicing when twisting and untwisting. Modeling, analysis and simulation of the air splice is done with the integration of Pro/E and ANSYS software, to study the flow filed and obtain the influence on the speed and pressure of the inside the splicing chamber when changing the speed and pressure while keeping the diameter of splicing chamber diameter, the vent hole diameter and the relative angle are unchanged. The results of the analysis of the air splice will lay a solid foundation for the further optimized structure design.
Study of Blowholes Formation and its Prevention in Nodular Iron Castings
Authors: Sun Shao Dong , He Shi Jian , Zhang Meng Qun , Ma Xiang
Published: September 2013

The content of magnesium in various parts of a nodular iron casting is measured by using spectrum analyzer. The results show that the skin of castings has an enrichment of magnesium, and the inner has a gradient distribution of magnesium, not an average distribution. Discussions on the results indicate that bubbles in the liquid metal would not move upward under the action of buoyancy, but migrate toward all directions and the bubble stranded below the surface of the liquid metal form blowholes, because these bubbles can not migrate with the obstruction of oxide films and dendrites. The results of production practices show that increasing carbon equivalent in the liquid metal is helpful to avoid blowhole defects.
Report on 2012 field activities and collection of ground thermal and active layer data in the Mackenzie Corridor completed under Northwest Territories Science Licence #15053
Authors: Ednie M , Chartrand J , Smith S L , Duchesne C , Riseborough D W
Published: September 2013

This report presents a summary of field activities conducted in 2011 in the Mackenzie Corridor under N.W.T. Science Licence #14918. Air temperature, ground thermal and active layer data acquired from permafrost monitoring sites visited in 2011 throughout the
corridor are provided in graphical and tabular format. This report will be distributed to community organizations and stakeholders in the study region to provide an update on field activities. The ground thermal and active layer data presented provide essential baseline information that can be
utilized by stakeholders and others for various purposes such as land management activities, regulatory processes and design of northern infrastructure.
An assessment of the moderating role of employees’ cultural orientations amongst foreign manufacturing multinational companies in Kenya
Authors: Dimba Beatrice A. , Rugimbana Robert
Published: September 2013

Orientation: This article investigates the question, of whether culture really matters in implementing international strategic human resource management (SHRM) practices.Research purpose: Specifically, this study sought to investigate the extent to which employee cultural orientations moderate the link between SHRM practices and firm performance in large foreign manufacturing multinational companies in Kenya. Motivation for the study: Large foreign multinational companies have generally applied SHRM practices without adaptation when trying to improve employee performance even though resource based perspectives argue for the consideration of employees’ cultural orientations. Research design, approach and method: SHRM practices were conceptualised as independent variables measured through distinct practices. Organisational performance as a dependent variable was measured using constructs of image, interpersonal relations, and product quality. Cultural dimensions adopted for this study were power distance, uncertainty avoidance, individualism or collectivism, and masculinity or femininity. The above conceptual framework was tested by the use of both quantitative and qualitative techniques with data from fifty (50) large foreign multinational companies operating in Kenya. Main findings: Findings indicated that the relationship between SHRM practices and firm performance depend to a greater extent on employee cultural orientations when power distance is considered. Power distance (PD) refers to the extent of people accepting that power in institutions and organisations when distributed unequally. The greater the PD, the greater the acceptance of this inequality. Practical/managerial implications: The study supported the notion that the relationship between SHRM practices and firm performance is moderated by power distance through motivation but not by the other three bipolar dimensions namely, Uncertainty Avoidance, Masculinity or Femininity and Individualism or Collectivism. Contribution/value-add: This is the first large-scale empirical article that has focused on the moderating role of employees’ cultural orientations in large foreign manufacturing companies operating in Kenya.
Evaluation of a shelf-stable direct-fed microbial for control of Escherichia coli O157 in commercial feedlot cattle
Authors: Stanford K. , Gibb D. , McAllister T. A.
Published: September 2013

Stanford, K, Gibb, D. and McAllister, T. A. 2013. Evaluation of a shelf-stable direct-fed microbial for control of Escherichia coli O157 in commercial feedlot cattle. Can. J. Anim. Sci. 93: 535–542. A direct-fed microbial (DFM) registered for use in cattle in Canada containing Lactobacillus acidophilus strain BT-1386 and a Saccharomyces cerevisiae yeast autolysate was evaluated for control of E. coli O157. Weaned calves entered the feedlot in October and November and in January were sorted into Control (12 pens with a total of 2170 calves) and DFM treatment groups (10 pens with a total of 2040 calves). Although targeted dosage of L. acidophilus was 9 log10 colony forming units (CFU) head−1 d−1, analyses after storage at ambient temperature showed an average dose of 8.6 Log10 CFU head−1 d−1 and demonstrated stability of DFM over the range of temperatures encountered (−32.6 to 32.9°C) during storage. Calves entering the feedlot had low prevalence (0.8%) of E. coli O157 in feces, which increased to 11.2% in January. A 47°C range in ambient temperature for that month may have stressed cattle and led to increased shedding of E. coli O157 compared with seasonal norms. Comparing hide swabs collected at initiation of DFM feeding with those at shipping for slaughter, prevalence of E. coli O157 declined (P<0.05) in cattle fed DFM, although prevalence of E. coli O157 in hide swabs from Control and DFM-treated cattle did not differ at any time. As well, numbers of E. coli O157 and prevalence of the organism in fecal pats did not differ among treatments. Colonization of calves with E. coli O157 prior to DFM feeding likely reduced efficacy of DFM in the present study. Additional information regarding timing of feeding DFM relative to interactions among organisms within the gastrointestinal tract of cattle are required to ensure consistent efficacy of DFM for pre-harvest control of E. coli O157.
Pasmo disease and lodging in flax as affected by pyraclostrobin fungicide, N fertility and year
Authors: Vera C. L. , Irvine R. B. , Duguid S. D. , Rashid K. Y. , Clarke F. R. , Slaski J. J.
Published: September 2013

Vera, C. L., Irvine, R. B., Duguid, S. D., Rashid, K. Y., Clarke, F. R. and Slaski, J. J. 2014. Pasmo disease and lodging in flax as affected by pyraclostrobin fungicide, N fertility and year. Can. J. Plant Sci. 94: 119–126. Severe infection of the fungal disease known as pasmo, caused by Septoria linicola (Speg.) Garassini, reduces seed yield of flax (Linum usitatissimum L.) in western Canada. Pasmo may also indirectly affect seed yield by predisposing flax plants, under favorable weather and soil fertility conditions, to lodge. With the objective of studying the possible association of this disease with the occurrence of lodging and their effect on seed yield, a study was conducted at Melfort, Saskatchewan, Canada, during 4 consecutive years (2009, 2010, 2011 and 2012), with two fungicide regimes (application and no application) and five rates of nitrogen (N) fertilization (0, 33, 66, 100 and 133% of recommended). The application of pyraclostrobin fungicide reduced disease severity and increased seed yield of flax in the 3 yr (2010, 2011 and 2012) that pasmo infection was detected, and prevented or reduced the occurrence of lodging in the 2 yr (2010 and 2012) with favorable weather conditions for the occurrence of lodging. Increasing rates of N resulted in increased seed yield in 2009 and 2012, regardless of whether fungicide was used or not. Increasing rates of N also increased the severity of pasmo disease in 2010, 2011 and 2012, and of lodging severity in 2010 and 2012. The increase in disease severity due to N occurred in the absence of fungicide in 2011 and when fungicide was applied in 2012, while in 2010 just the effect of N on the two fungicide treatments combined was significant. Only low levels of disease severity (near 20%) were observed when fungicide was applied in 2011, while extreme disease severity (near 100%) occurred in 2012 at all levels of N when fungicide was not applied. The increase in lodging, as N rates increased, was observed only in the absence of fungicide, in both years. The occurrence of lodging took place late in the development of flax.
A Large Keratocystic Odontogenic Tumor
Authors: Jolly Saurabh , Lata Jeevan
Published: September 2013

Keratocystic odontogenic tumor (KCOT) is described as a benign uni- or multicystic, intraosseous tumor arising from the dental lamina or its remnants. Various treatment modalities available are decompression, marsupialization, enucleation, curettage, resection with and without continuity defect, and disarticulation. Among all of these treatment modalities for large keratocystic odontogenic tumor, marsupialization followed by enucleation is preferred owing to its conservative nature as it decreases the size of the cystic cavity gradually thus, it can save the adjacent anatomic structures. Here, we describe a case of large KCOT which was treated using conservative approach.

How to cite this article

Jolly S, Lata J. A Large Keratocystic Odontogenic Tumor. World J Dent 2013;4(2):138-143.
Successful Cerclage at Advanced Cervical Dilatation in the Second Trimester
Authors: Deb Purnima , Aftab Nighat , Rangwala Tasneem
Published: September 2013

The aim of our study is to verify whether some maternal features are related to pregnancy outcome of emergency cerclage when membranes are protruding through the dilated cervix. We present a retrospective review of 20 cases of emergency cervical cerclage performed over a 3 years period at Al Wasl hospital, a tertiary level centers in Dubai. Analysis shows presence of membrane prolapse with infection causing rupture of membranes, to be the strongest predictor of poor outcome. Analysis also reveals a significant association between initial white blood cell count and perinatal outcome. This information is helpful in decision making and counseling patients regarding the likely outcome.

How to cite this article

Deb P, Aftab N, Rangwala T. Successful Cerclage at Advanced Cervical Dilatation in the Second Trimester. Int J Infertility Fetal Med 2013;4(2):56-58.
A Case of Fetal Cardiac Rhabdomyoma
Authors: Ganesh Chitra , Sridhar Anjana
Published: September 2013

Rhabdomyoma is one of the commonest cardiac tumor detected in prenatal ultrasound. Though its benign and self-limiting, it has a strong association with tuberous sclerosis, and hence needs thorough evaluation not only of the fetus but of the parents for signs of tuberous sclerosis. When isolated, fetus with rhabdomyoma needs to be only followed up for any cardiac complications associated with the mass and delivered.

How to cite this article

Ganesh C, Sridhar A. A Case of Fetal Cardiac Rhabdomyoma. Int J Infertility Fetal Med 2013;4(2):66-69.
Clinical and Radiographic Evaluation of Regenerative Potential of GTR Membrane (Biomesh®) along with Alloplastic Bone Graft (Biograft®) in the Treatment of Periodontal Intrabony Defects
Authors: Mopur James Manohar , Devi T Rama , Ali Syed Muhammad , Srinivasa TS , Gopinath V , Salam AR Tariq
Published: September 2013

Background and objectives

The primary goal of periodontal therapy is to restore the tooth supporting tissues lost due to periodontal disease. The aim of the present study was to compare the efficacy of combination of GTR membrane and alloplastc bone graft with open flap debridement (OFD) in treatment of periodontal intrabony defects.

Methods

Twenty paired intrabony defects were surgically treated using split mouth design. The defects were randomly assigned to treatment with OFD, GTR membrane + bone graft (test) or OFD alone (control). The clinical efficacy of two treatment modalities was evaluated at 6 months postoperatively by clinical, radiographical parameters. The measurements included probing pocket depth (PD), clinical attachment level (CAL), gingival recession (GR), bone fill (BF), bone density (BD).

Results

The mean reduction in PD at 0 to 6 months was 3.20 ± 0.82 mm and CAL gain of 3.10 ± 1.51 mm occurred in the GTR membrane + bone graft (test) group; corresponding values for OFD (control) were 2.10 ± 0.63 mm and 1.90 ± 0.57 mm. Similar pattern of improvement was observed when radiographically postoperative evaluation was made. All improvement in different parameters was statistically significant (p < 0.01).

Conclusion

Treatment with a combination of collagen membrane and bone graft led to a significantly more favorable clinical outcome in intrabony defects as compared to open flap debridement alone.

How to cite this article

Mopur JM, Devi TR, Ali SM, Srinivasa TS, Gopinath V, Salam ART. Clinical and Radiographic Evaluation of Regenerative Potential of GTR Membrane (Biomesh®) along with Alloplastic Bone Graft (Biograft®) in the Treatment of Periodontal Intrabony Defects. J Contemp Dent Pract 2013;14(3):434-439.
Shaping Potential of Manual NiTi K-File and Rotary ProTaper and Analyzing the Final Outcome of Shaped Canals using CT
Authors: Dhingra Anil , Kakar Surbhi
Published: September 2013

Aim

To assess and compare the shaping potential of manual NiTi K-files and Rotary ProTaper instruments in narrow canals using CT.

Objective

To assess the shaping potential of manual NiTi K-files and Rotary ProTaper and analyzing the final outcome of shaped canals using CT and determining different variables, like

• Working time

• Change in volume

• Change in cross-sectional area.

Materials and methods

From a pool of fifty freshly extracted permanent maxillary molars (1st and 2nd), 30 were selected with curvatures (20 to 40°) (Schneider 1971). Tissue fragments and calcified debries were removed from the teeth by scaling. The teeth were then stored in normal saline until used.

All the mesiobuccal canals were scanned by CT to obtain preinstrumented images. Teeth were scaled and stored in normal saline. This study was divided in two groups with 15 samples each.

Group I (ProTaper Rotary)

Canals were instrumented with Protaper Rotary instruments using crown down technique according to manufacturer's instructions.

Group II (NiTi K-file)

Were instrumented by NiTi K-files using step back technique with a quarter turn/pull motion.

Evaluations of working time

Comparative evaluations of working time was done for both the experimental groups.

CT analysis and measurements

The samples were analyzed and evaluated for:

• Postinstrumentation change in volume.

• Postinstrumentation change in cross-sections area.

Result

From the observations and statistical analysis carried out in this study, it was found that:

There was a statistically significant difference between all the parameters judged for the present study that is:

1. Instrumentation with ProTaper Rotary system took significantly less time than instrumentation with manual NiTi K-file.

2. Change in the canal volume following instrumentation with ProTaper Rotary was significantly greater than that produced by manual NITi K-file.

3. a. Change in cross-section area at 2 and 3 mm from the apex was significantly greater with manual NiTi K-file as compared to ProTaper Rotary.

b. Change in cross sections at 4.5, 6 and 7.5 mm from the apex with ProTaper Rotary was significantly greater than that produced by manual NITi K-file.

Conclusion

This clearly establishes that there is a drastic difference in the shaping ability of manual and Rotary NiTi instruments used with step back and crown down technique respectively with the rotary instrumentation being faster and producing greater changes in the canal anatomy.

How to cite this article

Kakar S, Dhingra A, Sharma H. Shaping Potential of Manual NiTi K-File and Rotary ProTaper and Analyzing the Final Outcome of Shaped Canals using CT. J Contemp Dent Pract 2013;14(3):451-455.
Fluoride Release from Glass Ionomer Cements: Effect of Temperature, Time Interval and Storage Condition
Authors: Kotian Ravindra , Madhyastha Prashanthi , Pai Vivekananda , Khader AMA
Published: September 2013

Objectives

Fluoride plays a pivotal role in oral health promotion and is the corner stone in the prevention of dental caries. The purpose of this study was to evaluate the effects of temperature, time interval and storage conditions on fluoride release by three commercial glass ionomer cements (GIC).

Materials and Methods

Three commercial glass ionomers: GC Gold Label Universal Restorative (conventional), GC Gold Label Light-Cured Universal Restorative and GC Fuji VII (GC Corporation, Tokyo, Japan) were used to investigate fluoride release. The 6 × 2 mm disk-shaped specimens prepared from each material were immersed in distilled water or artificial saliva at temperatures 4°C, 37°C or 55°C. The amount of fluoride release from these specimens was studied for the period of 1, 7, 14 and 28 days with the help of fluoride selective ion electrode.

Results

The amount of fluoride release was significantly (p < 0.001) high in distilled water when compared to artificial saliva in all the three types of GIC studied. The highest level of fluoride release was observed on the first day of the study, followed by days 7 and 14, with least release on days 28. It was also observed that at 55°C, the amount of fluoride release was significantly (p < 0.001) high in all three GIC. However, there was no significant difference among the three GIC studied.

Conclusion

The amount of fluoride release depends on temperature, time interval and storage condition. The result from the study concludes that GIC in the oral cavity serve as fluoride reservoir and contribute a low fluoride release in oral fluids.

Clinical significance

The clinical use of GIC that release fluoride is relevant mainly in patients at risk of or with caries activity, thereby preventing initiation of secondary caries and failure of restorations. It may also be important in developing regimes for improving the delivery of tropical fluoride products. This study would be helpful to make some considerations about clinical indication and longevity of restorative materials studied.

How to cite this article

Madhyastha P, Kotian R, Pai V, Khader AMA. Fluoride Release from Glass Ionomer Cements: Effect of Temperature, Time Interval and Storage Condition. J Contemp Dent 2013;3(2):68-73.
Socket Preservation at Molar Site using Platelet Rich Fibrin and Bioceramics for Implant Site Development
Authors: Pathak Tushar Sakal , Gupta Himani Swatantrakumar , Chowdhary Kamedh Yashwant , Kini Vineet Vaman , Mistry Abhishek
Published: September 2013

Background

The extraction socket preservation technique conserves the alveolar architecture and prevents hard and soft tissue collapse that minimizes the necessity for future augmentation procedures. Also, considerable interest has recently emerged over the potential benefits of using platelet rich fibrin (PRF), a highly concentrated form of platelets power packed with growth factors encased in a leukocyte rich matrix that enhances osteogenic differentiation and bone repair. This article describes the currently improved technique utilizing alloplasts with autologous PRF to be implemented for preserving a future implant site.

Materials and Methods

Following the atraumatic extraction of the periodontally compromised tooth, the socket bony walls were debrided and decorticated to facilitate regional acceleratory phenomenon. Venous blood was drawn from the antecubital fossa of the patient and was centrifuged according to Choukroun's method to yield autologous PRF that was minced into uniformly sized bits. Except for 2 to 3 mm of the coronal aspect of the socket, the rest was filled with particles of a slowly resorbing bone substitute material mixed homogeneously with minced PRF. A collagen membrane was used to seal the coronal end of the socket and was stabilized using 3-0 black braided silk sutures.

Results

Clinically and radiographically satisfactory and successful regeneration of the deficient ridge's hard and soft tissues was demonstrated after 6 months post therapy.

Conclusion

Socket preservation surgery utilizing bioceramics and PRF is an effective procedure for posterior socket preservation coupled with rapid healing and aids in providing sound bone quality for successful implant placement.

How to cite this article

Gupta HS, Chowdhary KY, Pathak TS, Kini VV, Pereira R, Mistry A. Socket Preservation at Molar Site using Platelet Rich Fibrin and Bioceramics for Implant Site Development. J Contemp Dent 2013;3(2):102-107.
Focal Cemento-osseous Dysplasia
Authors: Kumar Shwetha , Kadam Rahul
Published: September 2013

Focal cemento-osseous dysplasia (FCOD) is a benign fibroosseous condition that can be seen in dentulous and edentulous patients. It is an asymptomatic lesion and needs no treatment; however, follow-up is essential due to the possibility that it can progress to a condition called florid cemento-osseous dysplasia. Clinically, the lesion resembles periapical pathosis of odontogenic origin. FCOD is an asymptomatic lesion and occurs in the periapical area of teeth with vital pulps or in regions of extractions. The lesion is detected only on radiographic examination varying from completely radiolucent to densely radiopaque. The histopathologic appearance consists of trabeculae of bone and cementum like material present within a vascular fibrous stroma. Presented here is a case of FCOD in the mandible that occurred in the periapical region of a vital tooth.

How to cite this article

Kadam R, Patel S, Pathak J, Swain N, Kumar S. Focal Cemento-osseous Dysplasia. J Contemp Dent 2013;3(2):112-115.