bluuebunny/crossref_metadata_2025 huggingface dataset:
Histopathological evaluation of renal allograft biopsies in Nepal: interpretation and significance
Authors: Aryal G , Shah DS
Published: March 2012

Background:  Renal allograft biopsy remains the gold standard for the diagnosis of graft dysfunction. Protocol renal allograft biopsies have provided insights into pathogenesis of early and late allograft injury and guided clinical management. The aim of this study was to find out the causes of early and late graft dysfunction in renal allograft biopsies taken at different time points after transplantation. Materials and Methods: Between August 2008 and February 2011, a total of 98 renal allograft biopsies from 62 kidney transplants recipients were received in the department of Pathology, KIST Medical College and Teaching Hospital. Renal allograft biopsies were interpreted according to the Schemes of Banff ’09 update. Results: The maximum numbers of recipients were in the age group of 31-40 years. Age ranges from 16 to 61 years. Out of 62 recipients, there were 47(75.8%) males and 15 (24.2%) females. The time of biopsy ranges from 0 hour to 6 years after transplantation. There were 9 (9.18%) cases of acute T cell-mediated rejection, 8 (8.16%) cases of acute antibody-mediated rejection, 6 (6.12%) cases of acute ischemic injury, 6 (6.12%) cases of borderline lesions and 4 (4.08%) cases of chronic calcineurin inhibitor toxicity. Conclusion: In the early post-transplant period (0-6 months), acute antibody-mediated rejection, acute ischemic injury and T cell-mediated rejection are the major causes for graft dysfunction. In the late post transplant period (> 6 months after transplant), transplant glomerulopathy, chronic calcineurin inhibitor toxicity, viral infections and graft senescence including donor derived disease result in poor late graft survival.DOI: http://dx.doi.org/10.3126/jpn.v2i3.6016 JPN 2012; 2(3): 172-179
Nonfunctioning adrenocortical carcinoma: a study of 12 cases
Authors: Ghanghoria S , Raje P , Jain R , Ghanghoria A
Published: March 2012

Background: Adrenal cortical carcinoma is a rare malignant tumor. Several systems were proposed for diagnosis and evaluation of adrenocortical tumors.Weiss system is most commonly used method for assessment of malignancy, but only few studies has applied this criteria, for assesement of prognosis. The aim of this study was to analyzethe histological features & immunostaining status of adrenocortical carcinoma diagnosed according to Weiss criteria and correlate the data with patient clinical finding and outcomes. Materials and Methods: In this study clinicopathological features of 12 cases were reviewed and diagnosed as adrenocortical carcinoma on the basis of Weiss criteria and immunostaining. Grading was done according to the nine histopathological criteria of Weiss and is applied for assessment of prognosis. Each tumor was labeled malignant, when it scored ≥4 point of this histological criteria, tumors with ≤3 points were considered as adenoma and not included in the series. Immunostains applied were, Vimentin, Cytokeratin, synaptophysin, chromogranin, Vinyl mandilic acid, epithelial membrane antigen and Melan A. Results: All cases studied, presented at least four of the Weiss criteria and thus diagnosed as adrenocortical carcinoma. Patients with 7 and more score of Weiss criteria is considered as high grade carcinoma. Immunostains, have role in the diagnosis of adrenal cortical tumor, but does not have any significant clinical outcome.Conclusion: Weiss criteria was found to be a good prognostic factor in adrenal cortical carcinoma. DOI: http://dx.doi.org/10.3126/jpn.v2i3.6020 JPN 2012; 2(3): 193-197
Histopathologic analysis of appendectomy specimens
Authors: Shrestha R , Ranabhat SR , Tiwari M
Published: March 2012

Background: Acute appendicitis is one of the common conditions requiring emergency surgery. A retrospective study was performed to determine various histopathological diagnoses, their demographics and the rates of perforated appendicitis, negative appendectomy and incidental appendectomy. Materials and Methods: Histopathological records of resected appendices submitted to histopathology department Chitwan medical college teaching hospital over the period of 2 yrs from May, 2009 to April 2011 were reviewed retrospectively. Results: Out of 930 specimens of appendix, appendicitis accounted for 88.8% with peak age incidence in the age group of 11 to 30 yrs in both sexes. Histopathologic diagnoses included acute appendicitis (45.6%), acute suppurative (20.8%), gangrenous (16.3%), perforated (1.7%), resolving /recurrent/non specific chronic appendicitis (2.5%), acute eosinophilic appendicitis (1.2%), periappendicitis (0.2%), and carcinoid tumour (0.1%). Other important coexisting pathologies were parasitic infestation (0.2%) and Meckel’s diverticulum (0.2%). Negative appendectomy rate was 10.8% and three times more common in females with peak occurrence in the age group of 21-30 yrs. There were 10 cases of acute appendicitis in incidental appendectomies (2.5%, 24 cases) with 7 times more common in females of age group of 31- 60 yrs. Conclusion: There is a high incidence of appendicitis in adolescents and young adults in central south region of Nepal. Negative appendectomy is also very common in females. Incidental appendectomy in elderly females may have preventive value. DOI: http://dx.doi.org/10.3126/jpn.v2i3.6025 JPN 2012; 2(3): 215-219
Paraganglioma of the Larynx
Authors: Dhakhwa R , KC Toran , Kafle S , Lakhey M
Published: March 2012

Paraganglioma of the larynx is a rare tumor that arises from paraganglion cells. These tumors are generally considered benign and have to be differentiated from other neuroendocrine tumors. Diagnosis relies mostly on histopathologic examination followed by immunohistochemistry. Surgical excision generally confers complete cure of the tumor. We hereby present a case of laryngeal paraganglioma in a 60-yearold female, who underwent total laryngectomy following a diagnostic micro-laryngeal biopsy, which was supported by immunohistochemistry. DOI: http://dx.doi.org/10.3126/jpn.v2i3.6031 JPN 2012; 2(3): 245-247
Oxime Esters of 2,6-Diazaanthracene-9,10-dione and 4,5-Diazafluoren-9-one as Photo-induced DNA-Cleaving Agents
Authors: Chou Shang-Shing P. , Juan Jui-Chi , Tsay Shwu-Chen , Huang Kuei Pin , Hwu Jih Ru
Published: March 2012

Two series of oxime esters containing the 2,6-diazaanthracene-9,10-dione bis-(O-benzoyloxime) and 4,5-diazafluoren-9-one O-9-benzoyloxime moieties have been synthesized and tested as photo-induced DNA cleaving agents. All these compounds were found to cleave DNA upon irradiation with 312 nm UV light. The structure-activity relationship of these molecules for DNA cleavage was established. A plausible reaction mechanism is also proposed.
Vitreous Hemorrhage in a Premature Infant With Patent Hyaloid Artery and Increased Intracranial Pressure
Authors: Sharma Vinod , Biswas Susmito
Published: March 2012

Reports of intraocular bleeding in infants from nonabusive causes are rare. The authors report a case of visually significant vitreous hemorrhage in an infant with a persistent hyaloid artery who also had raised intracranial pressure secondary to an intraventricular bleed.
Single-Shot Dimension Measurements of the Mouse Eye Using SD-OCT
Authors: Jiang Minshan , Wu Pei-Chang , Fini M. Elizabeth , Tsai Chia-Ling , Itakura Tatsuo , Zhang Xiangyang , Jiao Shuliang
Published: March 2012

The authors demonstrate the feasibility and advantage of spectral-domain optical coherence tomography (SD-OCT) for single-shot ocular biometric measurement during the development of the mouse eye. A high-resolution SD-OCT system was built for single-shot imaging of the whole mouse eye in vivo. The axial resolution and imaging depth of the system are 4.5 μm (in tissue) and 5.2 mm, respectively. The system is capable of acquiring a cross-sectional OCT image consisting of 2,048 depth scans in 85 ms. The imaging capability of the SD-OCT system was validated by imaging the normal ocular growth and experimental myopia model using C57BL/6J mice. The biometric dimensions of the mouse eye can be calculated directly from one snapshot of the SD-OCT image. The biometric parameters of the mouse eye including axial length, corneal thickness, anterior chamber depth, lens thickness, vitreous chamber depth, and retinal thickness were successfully measured by the SD-OCT. In the normal ocular growth group, the axial length increased significantly from 28 to 82 days of age (
P
< .001). The lens thickness increased and the vitreous chamber depth decreased significantly during this period (
P
< .001 and
P
= .001, respectively). In the experimental myopia group, there were significant increases in vitreous chamber depth and axial length in comparison to the control eyes (
P
= .040 and
P
< .001, respectively). SD-OCT is capable of providing single-shot direct, fast, and high-resolution measurements of the dimensions of young and adult mouse eyes. As a result, SD-OCT is a potentially powerful tool that can be easily applied to research in eye development and myopia using small animal models.
Evaluation of Clear Corneal Wound Dynamics With Contrast-Enhanced Spectral-Domain Optical Coherence Tomography
Authors: Gupta Preeya K. , Ehlers Justis P. , Kim Terry
Published: March 2012

BACKGROUND AND OBJECTIVE:

To evaluate wound morphology and integrity using contrast-enhanced spectral-domain optical coherence tomography (SD-OCT).

PATIENTS AND METHODS:

Eighteen patients (18 eyes) undergoing unilateral routine cataract surgery were enrolled. SD-OCT imaging of the corneal wound was performed immediately following cataract surgery and on postoperative day 1. A topical contrast agent, prednisolone acetate 1%, was used to help evaluate wound integrity. OCT features of the corneal incision and changes in wound interface reflectivity after administration of topical prednisolone acetate 1% were analyzed. Main outcome measures were quantitative and qualitative description of wound morphology and contrast enhancement of the wound interface.

RESULTS:

Internal wound gape was found in 89% of eyes. Gape area decreased by 43% from days 0 to 1 (462 vs 273 μm
2
;
P
< .01). Contrast enhancement at the wound interface was seen in 56% of eyes on day 0 compared to 17% on day 1 following application of prednisolone acetate 1% (
P
< .05). Decreased intraocular pressure correlated with increased contrast enhancement (
P
< .05).

CONCLUSION:

Wound morphology evolves during the early postoperative period. Wound gape and ingress of a topical contrast agent decrease during the first 24 hours following surgery. Contrast enhancement at the wound interface increases as the intraocular pressure decreases.
3D Model Reconstruction of the Broken Aeroengine Blade Based on the Detection Operator
Authors: Jing Li Ming , Wang Hao , Wang Li Wen
Published: March 2012

This paper made the 3D model reconstruction of the V2500 turban blade. First, collected rough points cloud data by using visual measuring equipment. Then, smoothed and filtered the point cloud data, took the rational simplification, finished pre-processing the point cloud data. Finally, the grayscale of space-image algorithm was used for fitting the edge of turban blade, and reconstructed the 3D digital model. The results proved that this method improved smoothness of the model, and reduced time and cost of modeling and machining.
Researches on Relationship between Dynamic Radius and Slip Ratio of Driving Wheel
Authors: Li Xi Qin
Published: March 2012

The dynamic radius of a driving wheel, especially for the off-road vehicles, has not been identified clear so far. This article reveals the relationships between the dynamic radius and the slip ratio of a driving wheel by theoretical analysis and experimental researches. The movement characteristics of a rigid driving wheel and an elastic pneumatic driving tire on soft roads are explained. There are many kinds of methods to measure the dynamic radius, and the magnitude of the dynamic radius is not the same according to the methods. A certain measuring method should be chosen for each kind of road conditions in order to reduce the measuring error.
Study on CMP Test Technology of 65 nm and below Node Wafers with Copper Interconnects
Authors: Wang Ru , Pan Guo Feng , Wang Juan , Yang Rui Xia , Liu Yu Ling
Published: March 2012

It is of significance to research high-removal efficiency and low-cost CMP process for the 65 nm and below node. Chemical mechanical polishing (CMP) can realize the planarization of the wafer with free defects, free contamination and below nanometer level roughness. Test project of CMP slurry is main contain of these detections such as pH value, chelating agent content, SiO2 gel particle size, ζ-potential detection and the observation by Transmission electron microscopy (TEM). End point detection method of pattern wafer CMP usually includes the non destructive optical measurement, motor current feedback measurement and polishing pad temperature test. The main problems of the measurement for pattern wafer CMP are critical dimension (CD), section, film thickness, defects and particles measurement. Some of the new type of testing technology, such as atomic force profiler (AFP), can be used to compare CMP effect, such as dishing, erosion, tungsten plugs, the height of steps and flatness of the wafer, which is significant for wafer CMP research.
Study on Control of Welding Technology of Complicate Steel
Authors: Xu Zhong Qing , Ding Yong Gang , Zeng Hang , Li Qing Jun
Published: March 2012

Based on the principle of conservation of energy，technological process that using butt weld to control the transformational relation between welding deformation and residual stress is carried out. The arrangement measures of critical closure section welds are discussed. In addition, some problems in welding about High-strength steel and Heterogeneous steel are pointed out. And the causes and solution of lamellar tearing problem are put forward through the example of Baosteel NO.2 shaft furnace.
Study on Cutting Mechanism of UD-GFRP Based on Fracture Mechanics
Authors: Zhang Xiu Li , Wei Feng Chun , Jiao You Zhou
Published: March 2012

This document explained and demonstrated the crack growth of unidirectional glass fiber-reinforced composites (UD-GFRP) using the fracture mechanics theory during the process of machining. The models of fracture mechanics were established at antidromic cutting and direct cutting. The result is obtained that mode-I crack and mode-II crack transform each other during cutting and the complex crack is come into being. The propagation of complex crack makes the material fracture. The quality of machined surface at direct cutting is better than the quality at antidromic cutting.
Study on the Telecommunication System of the Coal Mine Rescue Robot
Authors: Hu Zhen Long
Published: March 2012

Telecommunication system characters are analyzed in order to make the coal mine rescue robot to have a smooth and reliable data transmission telecommunication system. The External communication uses the optical fibre communication and Ad Hoc wireless network based on zigbee; the internal communication uses CD4052 to make a communication bus. After the experiment of data communication test both in the complex ground environment and coal mine underground, the reliability of the telecommunication system is confirmed.
The Dynamic Analysis of SFD-Sliding Bearing Flexible Rotor System Based on Optimization Design
Authors: Wang Ji Yan , Guo Rong Chun , Si Xu Fei
Published: March 2012

The paper establishes the mechanical model of SFD-sliding bearing flexible rotor system, adopting Runge-Kutta method to solve nonlinear differential equation, thus acquiring the unbalanced response curve and then gaining the first two critical speeds of the system. Meanwhile, the paper analyzes the sensitivity of the system on the first two critical speeds towards structural parameters, offering design variables to optimization analysis. Based on sensitivity analysis, genetic algorithm is employed to give an optimization analysis on critical speed, which aims to remove critical speed from working speed as much as possible. The critical speed ameliorates after the optimization which supplies theoretical basis as well as theoretical analysis towards the dynamic stability of high-speed rotor system and provides reference for the design of such rotor system.
The Parameter Model and the Non-Parameter Model of Magnetorheological Dampers in Suspension
Authors: Wang Jian Feng , Lei Zhong Xiang , Song Chuan Xue , Zheng Zhu An
Published: March 2012

The researchers have recently increased the attention in controllable fulids and its applications.Magnetorheological(MR) dampers are devices that employ rheological fluids to modify their mechanical propeties.Their mechanical simplicity,high dynamic range,lower power requirements,large force capacity,robustness and safe manner operation in case of fail have made them attractive devices to semi-active control in civil,aerospace and automotive suspension applications.The mechanical models of the magnetorheological dampers by parameter modeling and non-parameter modeling were discussed and analyzed. In especial, eight models were described in detail. It is pointed out that the different design should adapt different model in order to take advantage of its characteristic.
The Research on Bit-Product Demand
Authors: Zhu Zhu , Shu Hua Ying
Published: March 2012

With the building of "information highway" has been increasingly high, the bits and the Internet are ahead hand in hand; In bit-economic environment, there is no material form of atoms, only the 0 and 1 form of number sequences that are called the bit stream, which have value other than weight, have played an increasingly important role in the economic life of the people. Compared with the industrial age economics, Bit-economics has pulled out many new phenomenon, which the traditional laws of economics can’t explain the subsequent hidden new economic theories; As to bits of product demand curves out of the demand curve contrary to the phenomenon of material products, This paper using empirical analysis and the use of SPSS, MATLAB software, proves the new forms that bit-product demand curve shows to us.
Throttle Valve Parts’ Process Planning
Authors: Wang Juan Ping
Published: March 2012

Methods and steps of the process planning design were introduced by throttle valve parts. Technical requirements were determined and various parts of the stock allowance of roughcast were confirmed by process analysis of the parts, machining process route was finished completely. Theory was ready for the subsequent actual machining.
An Enhanced Resolution Three-Dimensional Transformation Method Based on Discrete Wavelet Transform
Authors: Tang Ning , Cai Jin , Li Yuan
Published: March 2012

With the development of interactive multimedia technologies, image and video compression algorithms necessitated a number of better performance and functionality. Wavelet transform based embedded image coding method is the basis of JPEG2000. Lossy image compression algorithms sacrifice perfect image reconstruction in favor of decreased storage requirements. JPEG2000 algorithm has been developed based on the discrete wavelet transform (DWT) techniques, which have shown how the results achieved in different areas in information technology can be applied to enhance the performance.
An Improved Ant Colony Optimization for Large-Scale Simple Assembly Line Balancing Problem of Type-1
Authors: Zheng Qiao Xian , Li Yuan Xiang , Li Ming , Tang Qiu Hua
Published: March 2012

An improvement ant colony optimization(ACO) is proposed to solve the simple assembly line balancing problem of type-1 (SALBP-1) which aims to minimize the number of workstations for a given cycle time of assembly line. In the algorithm, three heuristic factors and two pheromones: (1) the pheromone between task and station, (2) the pheromone among tasks, are introduced to design the selection mechanism which is used to select task for station. The task assignment mechanism is proposed to assign suitable tasks to station. Ants select task based on selection mechanism, and then assign suitable one to station according to assignment mechanism. The result of literature test problems indicates the effectiveness of the proposed algorithm.
Changing Direction Parallel Scan Path Generating Method through Matching Scan Space for Metal Laser Deposition Shaping
Authors: Bian Hong You , Yang Guang , Wang Gang , Qin Lan Yun , Wang Wei , Shang Chun
Published: March 2012

Those ultimate reasons of over-cladding and under-cladding are indicated through analyzing between the existing parallel scan mode and the characteristic of metal laser deposition shaping. A kind of scan path generating method is presented, firstly, scan path is generated base on grouping internal parallel filling scan according to the set scan space in the same layer, then, scan direction is changed base on matching different scan space in different layer. Practical application shows that the scan path can effectively enhance the flatness of shaping layer and the fabrication quality, ensure to shape successfully.
Effect of Insert Style in Milling of Titanium Alloy (TC18)
Authors: Zhang Pei Pei , Yin Zi Dong , Yan Xue
Published: March 2012

Titanium alloy (TC18) is new style alloy (α+β). It possesses better performances than common titanium alloy. However, Titanium alloy (TC18) is still classified as difficult-to-machine materials for their poor machinability, which is attributed to relatively low modulus of elasticity, strong alloying tendency or chemical reactivity with cutting materials at higher temperatures and low conductivity of heat generated by the cutting action. Due to the poor machinability of the alloys, selecting of insert style is crucial for tool life and material removal rate. In this work, milling tests, using three kinds of inserts (KC522M, YD201 and SANDVIK 4240), were carried out on this kind of titanium alloy (TC18). The results of tests show that the material removal rate of insert KC522M is the highest, but its tool life is shorter compared with insert SANDVIK 4240. The material removal rate and tool life of insert YD201 do not draw the attention because both of them are relatively low. The abrasion speed of insert SANDVIK 4240 is slow and the efficiency is high, so it is ideal for machining titanium alloy (TC18). In addition, the optimal machining parameters of insert SANDVIK 4240 for milling titanium alloy (TC18) were also given in this paper.
A Probability Assessment Method for Degradation of Bridge Power MOSFET Circuit Based on Common Turn-On State
Authors: Wang Xiang Fen , Fu Gui Cui , Gao Cheng , Yao Jin Yong
Published: March 2012

A performance degradation assessment method is proposed based on probability statistic of common turn-on state of power MOSFET circuit in this paper. Threshold shift transient characteristics of MOSFET are studied and the performance degradation behavior of a bridge power MOSFET circuit is simulated. Threshold voltage degradation of a power MOSFET circuit caused by half bridge arm is observed and the probability of a period transient common turn-on state is calculated to evaluate the degree. The result can be used to evaluate the performance degradation trend and can also provide data support for predicting the degradation degree before circuit failed.
Nonlinear Vibration Analysis of Viscoelastic Isolator
Authors: Zhou Chao , Zhong Cai Mao
Published: March 2012

Research on nonlinear dynamic response of passive vibration isolator, which was excited by foundation vibration and isolated by viscoelastic material was done. Nonlinear stiffness was expressed by the cubic polynomial function of deformation and nonlinear damping was characterized by viscoelastic fractional derivative operator. Then the fractional derivative nonlinear dynamic equation of passive vibration isolator was established. The dynamic response characteristics were analyzed by harmonic balance method and the frequency response equation and amplitude-frequency curve were obtained, and furthermore, the influence of nonlinearity on system was analyzed. Finally, the stability and the stable interval of the periodic solution were argued by the Floquet theory. The result s indicates that the proposed equation can precisely describe the dynamic characteristics of viscoelastic vibration isolator. The ignorance of nonlinearity of stiffness and damping will result in obvious error. The proposed method provides theoretic reference for design of viscoelastic isolator and the evaluation of its effect.
Computer Simulation Analysis for Material Mechanics
Authors: Wang Zhong Ya , Li Xiao Jing , Yu Dong Man
Published: March 2012

With the development of modern high technology, the request of exploring material of the request has been a high demand for researchers. Along with the understanding of microscopic structure and macro structure for material property, people have can theoretically predicted with special structure and function of the material system, thus designed more to meet the requirements of new material. In the rapid development of the computer technology today, the computer simulation has become an efficiency tool for solving practical problems in materials science. This paper has detailed described the basic principle of computer simulation and then provide an example to show the research work flow of computer simulation. This example can calculate the shear and bending moment of beam under simple load condition. The research contribute to apply the simulation method in material science.
Research on Application of Nano-TiO2 in Automotive Coating
Authors: Cao Peng Jun , Wu Hai Dong , Dong Ji Ling
Published: March 2012

In this article, the mechanism of the effects of nano-TiO2 on the properties of automotive topcoat is discussed. Based on the original thought that nano-TiO2 may improve the aging property, a research is carried out into the effects of nano-TiO2 on the properties of automotive topcoat, and the formulation design of nano-TiO2 coating is optimized. The coating properties such as glossiness, adhesion, resisting impact strength, hardness, water fastness and resistance to aging are measured by experiments. The results show that with 1.0~2.0 percent of nano-TiO2 content, the aging resistance of the coating increases by approximaSubscript texttely 20 percent with higher glossiness, while adhesion, impact strength, hardness and water fastness are not meaningfully improved.
The Dynamic Response Analysis for Frame Structure in Consideration of Soil Structure Interaction under Explosive Load
Authors: Kuang Zhi Ping , Yang Qiu Hua , Xie Lei , Xu Hao
Published: March 2012

The article selects proper finite element type, material props, element wreck props etc; builds structure-foundation interaction frame construction model and analyzes its response under typical blast loads; Contrast the difference of response between structure-foundation interaction frame construction model and common frame construction model, the results can provide reference with design theory under blast for future.
Active Transient Vibration Control Using a Novel Repetitive Algorithm
Authors: Zhou Ya Li , Yin Yi Xin , Zhang Qi Zhi , Gan Woon Seng
Published: March 2012

In this paper, active control of periodic transient vibration based on repetitive control (RC) algorithm is studied. According to the stability condition of an active vibration control (AVC) system, a novel non-causal stable inversion approach combined with an optimal criterion is used to design the RC controller for an AVC system with a non-minimum phase secondary path. Computer simulations have been carried out to validate the effectiveness of the proposed algorithm. The plant model used in the computer simulations is obtained from a practical AVC system in our laboratory. Simulation results show that the proposed scheme can significantly reduce periodic transient vibration and the convergence rate is acceptable for a non-minimum phase plant.
Thermal Analysis and Cooling Optimization of the Built-In Micro Projector
Authors: Wei Wei , Yang Ping , He Qian Hong , Chen Quay Le
Published: March 2012

With the rapid development of the micro projector, the problems of its power consumption and heat dissipation have been increasingly serious. The thermal design can improve its reliability and cut costs at the design stage. This article selects DLP built-in micro projector provided by TI Company to analyze, uses thermal analysis software Flotherm to get the temperature distribution and temperature curves of the measuring points in the steady state, then compares the simulation results of the cooling optimization with the numerical analysis, which reduces the temperatures of thermal sources and shells. The conclusion supplies new theoretical basis on the development of mobile phones integrated with the projection function.
Vibration Suppression of Flexible Parallel Manipulator Based on Sliding Mode Control with Reaching Law
Authors: Hu Jun Feng , Cui Xiang Fu , Li Pei
Published: March 2012

A discrete sliding mode control based on reaching law is investigated to suppress vibration of high-speed flexible manipulator. The finite element method and experimental modal test is applied to obtain the dynamic model of the system. Due to the influence from uncertain external disturbances and measurement noise, and uncertain parameters, sliding mode control has invariance of the sliding mode. The discrete sliding mode control approach with reaching law is applied to design the vibration controller which enables the system to be zero state as the system states are away from the equilibrium one due to external disturbances. The discrete Kalman filtering technique is employed to construct state estimator because the state variables cannot be directly measured. The first three natural frequencies and damping ratio are obtained by using experimental modal testing. The experimental control system is constructed and experimental validation is carried out using dSPACE real-time simulation system and MATLAB/Simulink. The experimental results showed that the proposed controller can effectively suppress the vibration response of the flexible manipulator.
An Improved Edge Antialiasing Method for 3D Graphics Pipeline
Authors: Zhou Fang Fei , Sun Yong
Published: March 2012

In this paper, we proposed an improved antialiasing method for graphics hardware. We first give a detail introduction for the edge antialiasing methods which are popular now. Then, an improved edge antialiasing method is proposed. The basic idea of this method is that we employ five scanlines to scan all the sampling occurently. Thus, every three samples will be formed into a final sample and be stored into a unused storage space. Actually, this method is feasible to be implemented by hardware since it is low-cost. Experimental results show that our method can achieve good appearance.
Dynamic Analysis of Planetary Mechanism for the Cutting Part of Coal Shearer
Authors: Wu Wei Dong , Li Hua Liang , Xue Hong Rui
Published: March 2012

The transmission load on planetary gear to the cutting part of coal mining machine is bigger, and the force is uneven stress while the gear driving. In order to solve this problem, and puts forward the coal mining machine cutting part planetary transmission gear contact dynamic meshing analysis method. This paper build entity modeling of coal minning machine cutting part transmission gear by established 2d model by CAXA and import PRO/E, and by using ABAQUS/Explicit as the simulation platform, assembly and analysis with dynamic meshing contact, get in gear stress of gear tooth distribution, and provide the basis to the gear shape design.
Investigation into the Noise Characteristics Based on Rotating Instabilities Mechanism in a Multi-Stage Axial Compressor
Authors: Sha Yun Dong , Cui Xian Zhi , Zhao Feng Tong , Luan Xiao Chi
Published: March 2012

Rotating instability can be observed in the tip flow region of axial compressor stage while stable operation. In order to investigate the noise characteristics in a multi-stage axial compressor, the noise inner compressor casing is measured simultaneously with the vibration of the rotor blades on a high pressure compressor component rig testing. An azimuthal mode analysis and theoretical formulation of the rotating source mechanism are applied to the unsteady pressure at the casing wall immediately upstream of the inlet plane of the rotor. It is shown that RIs might be described by a group of superimposed modes. This is the reason why RIs can be identiﬁed as an amplitude increase in a frequency band. The mode orders of RI are consecutively numbered riseing with frequency. The frequency in the source frame (ωN) closed to the frequency in the rotating frame (ωN) can be got well recovered. The results presented in this paper can be a reference for further understanding of the characteristics of unsteady flow field and the effects of the high intensity sound waves on the rotor blades.
Analysis of the Residual Stress in Multi-Layer Materials
Authors: Shi Kun , Yuan Yuan , Wei Feng Tao
Published: March 2012

The residual stresses due to the mismatch between metallic bond coat and ceramic top coat lead to a collapse of all thermal barrier system. For measuring residual strain in elastic multilayer materials, the incremental hole-drilling strain-gauge method was studied. The main stresses, which is interrelated with the residual strain, is resolved on planes that are normal to a deep hole. In order to link the surface strain to the residual stress, calibration coefficients were obtained by the finite element method. The result shows that the coefficients depend on the substrate and the type of coating, the strain gauge used and the size of the step drilled.
Structural Design and Model Establishment of Reducer Device
Authors: Guo Hui , Gao Zhi Hua , Li Xiao Jing , Qu Pei Xin
Published: March 2012

The reducer device is a complicated mechanical system composed by several important components, which should establish model before manufacture and carry out dynamic simulation of movement mechanism. It could assemble component model into mechanical system by using the assembly module of Solidworks. Compared with three-dimensional assembly modeling processes that was created by the traditional CAD. This study has calculated and listed the key parameters of mechanical design and established a full model of assembly. The resulting model contribute to technical analysis for future manufacture.
Ambiguity-Function-Based Methods for Near-Field Source Localization
Authors: Sun Xin , Jiang Hong , Wang Bo
Published: March 2012

In this paper, the AD-MUSIC method for far-field source localization is introduced to near-field, a two-dimensional MUSIC method based on ambiguity function distribution is proposed. Further, a novel AD-ROOT-MUSIC method is proposed for near-field source localization which constructes two matrices based on ambiguity function. They both have high accuracy and resolution for the bearing and range estimation of non-stationary signals in the near field, even when the signal-to-noise ratio (SNR) is low. The effectivity of the methods are validated by simulations.
Narrowband Notch Filters with Composite Nanostructure Layers on a GaN-Based Light Emitting Diode
Authors: Cao Bing , Zhang Gui Ju , Wang Chin Hua , Wang Jian Feng , Xu Ke
Published: March 2012

In this paper, novel active narrowband notch filters with triple-layer composite nanostructures on a GaN-based LED are obtained by mainly adjusting the grating period and duty cycle. The three layers consist of two dielectric thin layers and one metallic / dielectric grating layer. The grating layer composes of subwavelength period and thickness rectangular stripes, which lies between a transition layer and a protecting layer. Line-width and attenuation peak properties of the resonance filters are calculated and investigated by using a full vector implementation of Rigorous Coupled Wave Analysis (RCWA) algorithm. It is shown that the grating period can significantly change the filter peak wavelength, and the grating duty cycle heavily changes the filter line-width. The filter attenuation peak has a red shift with 23.3nm as the grating period increases 18nm. The FWHM (Full Width at Half Maximum) of the filter reduces from 1.9nm to 0.28nm as the duty cycle changes from 0.55 to 0.3, which compressed more than six times. Moreover, thickness of each composite nanostructure layer can also affect the narrowband width and peak wavelength of the filter. The results provide guidance in designing, optimizing and fabricating such an active narrowband filter with highly integrated photonic devices.
ITO Nanofibers Prepared from Electrospun ITH/PVA Precursors
Authors: Pan Yi Jun , He Ting Ting , Wei Qu Fu , Chuang Wei Sheng , Ni Hao Hsin , Chen Yu Zan
Published: March 2012

Poly (Vinyl Alcohol)(PVA)/In-Sn hydroxide (ITH) nanofibers were prepared via electrospinning, then followed by calcining at 400 , 475 , and 550 to obtain indium tin oxide (ITO) nanofibers. The influencing factors of solution properties, viscosity and electrical conductivity on the formation and morphology of electrospun fibers was investigated. The microstructure of PVA/ITH and ITO nanocomposites were characterized by scanning electron microscopy (SEM). And the crystalline structure of ITO nanocomposites was analyzed by X-ray diffractometry (XRD). The results showed that the average diameter and variation coefficient of obtained PVA/ITH nanofibers decreased after the adding of ITH. The ITO nanofibers became thinner and more uneven with the increasing of calcined temperature. XRD patterns proved that ITO nanoparticles existed after calcined and showed the structure was strongly depended on the calcined temperature. The bixbyite and the corundum type could be fabricated according the calcined temperature.
Obtaining of Nanomaterials in Combustion Processes
Authors: Mansurov Zulkhair A.
Published: March 2012

An experimental study has been conducted in premixed and counterflow diffusion flames in order to obtain the nanocarbon materials. In this paper the synthesis of fullerenes, carbon nanotubes and superhydrophobic soot surface in the regime of hydrocarbon flames were studied. The original results in the field of synthesis of fullerenes, carbon nanotubes and syperhydrophobic soot in hydrocarbon flames were carried out for the last years at the Institute of Combustion Problems.
The Dispersion Characteristic of 2D Air-Hole-Type Square Photonic Crystal Calculated by Plane Wave Expansion Method
Authors: Zhou Li Bin , Xu Qin Fang , Liang Lei
Published: March 2012

To study the dispersion characteristic of photonic crystal, the eigen-equations matrix of the light transmitting in is gotten in plane-wave expansion method, then the dispersion curves are calculated for two dimensional air-hole-type square photonic crystal respectively. And the influence on the band structures caused by oblique incidence also is studied by change incidence angle. The results of calculations demonstrate that: For two dimensional square structure photonic crystals, the shape of the band structures of TE mode is very similar to that of TM mode, but their positions of band gaps are different, especially the first band gap of TE mode in the square structure in <11> direction is completely staggered with that of the TM mode. Moreover, we get the conclusion that the width of band gap enlarges with the increasing radius of the hole in square photonic crystal in <10> direction.
Synthesis and Photophysical Properties of Crosslinkable Multi-Branched Ethynyl Fluorene-Labeled Molecules
Authors: Hu Xiao Dan , Wang Shao Hong , Hou Zhao Xia
Published: March 2012

The simple way to synthesize crosslinkable multi-branched ethynyl fluorene-labeled molecules has been reported in this work. A three-armed molecule, OxDBFP is prepared by cyclotrimerization and phase transfer catalysis methods. 3-(6-Bromo-2-oxahexyl)-3-methyloxetane tethered to 9-position of fluorene is crosslinked when exposed to UV light. This kind of compounds can be proper candidates for full-color displays or solid-state lighting by low-cost solution prosessing.
Effect of Pd Nanoparticle on the Thermal Degradation Kinetics of Nylon 6/Pd Nanocomposite Prepared by a Dry Process
Authors: Lee Jae Young , Hong Sung Wan , Han Kyeong Sik , Lee Taeck Hong , Lee Hong Ki
Published: March 2012

Palladium (Pd) nanoparticles were incorporated into a nylon 6 film via a dry process which consisted of simultaneous vaporization, penetration and reduction processes of palladium (II) bis (acetylacetonate, Pd (acac)2) at 180°C for various exposure time. The even dispersion of the generated Pd nanoparticles were observed by transmission electron microscope (TEM) and the Pd loading weight of about 15~43 wt% was measured by thermogravimetric analysis (TGA). In order to study the catalytic effect of Pd nanoparticles on the thermal degradation kinetics of nylon 6, TGA data at various heating rates were introduced to Flynn & Wall equation. The thermal degradation activation energy for neat nylon 6 was ca. 162~178 kJ/mol over the thermal degradation fraction of 0.05~0.40 while that of the nylon 6/Pd (26.5 wt%) nanocomposite was ca. 110~169 kJ/mol over the same fraction range. It meant the Pd nanoparticles were acted as a catalyst on the depolymerization of amide group in nylon 6. It was also found that the activation energy decreased slightly with the increasing Pd loading weight.
Microstructure and Properties of a Bismuth-Brass
Authors: Han He Bing , Huang Xin Min , Wu Yu Cheng , Qin Yong Qiang , Cao Jun Li
Published: March 2012

The Cu-40wt%Zn-1.0wt%Bi-1.0wt%Mn bismuth-brass was prepared by casting and annealing. The microstructure was investigated by scanning electron microscopy (SEM), the phase composition was analyzed by X-ray diffraction (XRD), and the properties of mechanics and cutting were tested, too. The results show that the bismuth-rich phase is mainly distributed in the grain boundary as the shape of granules, which lead to the mechanics property and cutting property of bismuth-brass can basically reach the requirements of replace the traditional cutting-free brasses.
Control of Jet Flows and their Effects on the Alignment of Electrospun Nanofibers
Authors: Yin Gui Bo
Published: March 2012

Electrospinning offers a versatile way to produce micrometer or nanometer fibers; however, electrospun fibers are typically collected in a random orientation limiting their applications. In the present study, we used the high speed rotational roller fixed with parallel sticks and an auxiliary electrode at the splitting zone of jet flows to control the fiber orientation. Because of the electrostatic forces acting on the charged fibers spanning the gap between two sticks and tangential force of the rolling collector stretching fibers, together with the electrostatic force imposed by the auxiliary electrodes, the higher aligned fibers could be produced. The simultaneous application of a rotating drum and an auxiliary electrode in the spinning zone may provide a viable method of controlling the alignment of electrospun fibers.
Solvothemal Synthesis and Characterization of α-MnS Micronsized Architectures
Authors: Wu Rong , Tao Le Tian , Jian Ji Kang
Published: March 2012

Mixed solvent of ethylenediamine (EDA) and ethylene glycol (EG) using MnCl4H2O, and (NH2)2CS as precursors was used to synthesize α-MnS micronsized architectures. Optimal α-MnS crystals were successfully grown from a mixed solvent of EDA:EG with a volume ratio of 1:1, reaction temperature of 140-180 °C and maintained for 6h. X-ray diffraction (XRD), scanning electron microscopy (SEM) was employed to characterize the structure and morphology of the product. The results show that the morphologies of α-MnS are found to be temperature dependent.
Finite Element and Experimental Investigation of Human Femur Cortical Bone Microdamage during Radial Fretting
Authors: Liu Juan , Shen Huo Ming , Yang Yi Ren , Cai Zhen Bing
Published: March 2012

Accumulation of microdamage can result in increased bone fragility and osteoporotic fracture in human bone.Microcracks in bone have been implicated in the development of stress fractures.The goal of this study was to investigate the human femur cortical bone microdamage during radial fretting and its stress and strain distribution. Modeling and analysis were taken for Haversian system using FEM soft. Analytical results indicated that stress concentration which occurred in the haversian canal and around circumferential lamellas and through the circumferential lamellas and the interstitial tissues could lead to microcrack initiation of multi-areas. In addition, microcrack could occur as a result of a rather large plastic area which crossed interstitial bone and connected adjacent osteon under high load condition. In the meantime, radial fretting behaviors of the fresh human axial femur compact bone were investigated under a flat-on-ball configuration in high accuracy hydraulic servo fretting experimental machine. The kinetics behaviors of the compact bone were revealed by the F-D curves. The surface damage was analyzed combined with the examinations by laser confocal scanning microscopy (LCSM) and scanning electron microscopy (SEM) . The morphologies showed that the microcracks were the primary damage form.The results showed that three typical types of cracks-radial microcrackannular microcrack and linking microcrack were observed. The test results and the FEM analysis results were of good consistency, and brought forth that most of microcracks run between the surrounding interstitial bone and the cement line.
Corrosion Behavior of Zr-Based Bulk Metallic Glasses by Addition of Ni
Authors: Yuan Chuan Jie , Zeng Xie Rong , Qian Hai Xia , Xie Sheng Hui
Published: March 2012

Fully amorphous Zr48Cu43-xAl7Ag2Nix(x=0, 2, 4, 6, 8 at. %) alloy system synthesized by Cu mould casting method were utilized to study corrosion behavior due to the poor corrosion resistance of Zr-Cu-Al-Ag alloy system by addition of Ni. High temperature DSC revealed that the Zr-based alloy system still maintained good glass-forming ability and thermal stability with the addition of Ni element. The result obtained from both the immersion test and the potentiodynamic polarization test showed that the addition of Ni element significantly improved the corrosion resistance compared to the Ni-free Zr-based alloy system. SEM graph showed a phenomenon of corrosive pit where there existed corrosion deposits as well as cellular textures and microcracks. In summary, proper addition of Ni could modify the corrosion resistance of the Zr-based alloy system.
Crystallinity and Characterization of Rf-Magetron Sputtered ZnO-Doped (Zr0.8Sn0.2)TiO4 Thin Films on ITO/Glass Substrate
Authors: Hsu Cheng Hsing , Yang Pai Chuan , Chen Wen Shiush , Lin Jenn Sen
Published: March 2012

Microstructure, optical and electrical properties of ZnO-doped (Zr0.8Sn0.2)TiO4 thin films prepared by rf magnetron sputtering on ITO/Glass substrates at different argon-oxygen (Ar/O2) mixture have been investigated. The surface structural and morphological characteristics analyzed by X-ray diffraction (XRD) and atomic force microscope (AFM) were found to be sensitive to the Ar/O2 ratio. Optical transmittance spectroscopy further revealed high transparency (over 70%) in the visible region of the spectrum. At an Ar/O2 ratio of 100/0 and a substrate temperature of 400°C, the ZnO-doped (Zr0.8Sn0.2)TiO2 films possess a dielectric constant of 44 at 10 MHz, a dissipation factor of 0.03 at 10 MHz, a leakage current density of 3.73×10-9 A/cm2.
Synthesis of PLA-PEG Block Polymer Catalyzed by Solid Super Acid
Authors: Liu Wen Ming , Gong Ming , Yang Hui , Xia Lu
Published: March 2012

The PLA-PEG block polymer was prepared by opening ring polymerization catalyzed by solid super acid SO42-/ZrO2-CeO2. The acidic property was measured by IR spectra, Hammett Indicator and NH3-TPD techniques. The copolymer was measured by FTIR spectra. The results show the solid super acid SO42-/ZrO2-CeO2 had the strongest acid strength and maximal acid content roasted at 650. Under reaction conditions which were the amount of catalyst 1.0% vs lactide, and polymerization at 170 for 9 h, the intrinsic viscosity reached 1.562 dl. g-1.