bluuebunny/crossref_metadata_2025 huggingface dataset:
The Microstructure and Characteristics of Luminescent Porous Silicon Film Prepared by the Physicochemical
Authors: Wan Xiao Jun , Jin Hui Xia
Published: September 2010

The special physicochemical environment caused by sonic-vacating provides an important outlet for the preparation of highly efficient luminescent porous silicon films. Experimental results show that sonic—chemical treatment is an effective technology for the improvement of the microstructure of porous silicon, and the luminescent efficiency and stability thereof. Luminescent porous silicon films, prepared by ultrasonic—enhanced anode electrochemical etching, display better qualities than the samples prepared by conventional methods widely used at present. This ultrasonic—chemical effect roots in sonic—vacating, i.e. the generation, formation and rapid collapse of bubbles in the etching solution. In the process of the porous silicon being etched, the escape rate and caving-in of hydrogen bubbles in the pores is increased as a result of the work of the ultrasonic waves, which is helpful to the vertical etching of the pores.
The Compound Tribological Properties of Nano-Ceramic Lubricating Additives and Ni-W-P Alloy Coating
Authors: Chen Min , Cheng W.S. , Zhao Zu Xin , Huang X.B.
Published: September 2010

The major solving ways for the material wear are surface modification and lubrication. However, the application of only one solution can not achieve desirable effect. Ni–W–P alloy coating has high hardness and high wear resistance, and is an effect way of surface modification on the 45 steel. In the friction process, the nano ceramic lubricating additives deposited on the friction surface of Ni-W-P alloy coating so as to form a protective lubricating film, therefore realizing in-situ repair on the friction surface during operation. The nano ceramic particles achieve the antiwear and friction reducing effects by the micro polishing effect, the filling and repairing effects, ball bearing effect, multiphase microcrystal effect. Experiment results confirm that Ni-W-P alloy coating and nano ceramic lubricating additive have excellent synergistic effect, and form double protection for the metal substrate, e.g., the wear resistance of Ni-W-P alloy coating (with heat treatment and the oil with nano ceramic additives) has increased hundreds times than 45 steel as the metal substrate with basic oil, zero wear is achieved，which break through the bottleneck of previous separate research of the above-mentioned the two.
Fatigue Properties of TCS Stainless Steel Weld Joints in Axial Loading
Authors: Li Wei , Li Qiang , Wang Ping
Published: September 2010

Based on the grouping method and lifting and lowering method, the weld joints of TCS stainless steel such as butt joint and corner joint were experimentally examined to clarify their fatigue properties in axial loading. The probabilistic S-N curves were established from the viewpoint of the survival probability and confidence level, and the stress concentration factors were evaluated by using finite element model. As a result, corresponding to fatigue life of N=2×106, the mean values of fatigue limit for corner joint and butt joint are evaluated to be 162.7MPa and 173.7MPa, respectively. The stress concentration factors for butt joint and corner joint are evaluated to be 1.55 and 2.22, respectively.
Inverse Dynamics of 2UPS-RPU Parallel Mechanism by Newton-Euler Formation
Authors: Wang Wen Hua , Feng Zhi You , Yang Ting Li
Published: September 2010

2UPS-RPU is a new 4-DOF parallel mechanism with serial input limb. In this paper, the inverse dynamic equation of this mechanism is formulated by Newton-Euler formation based on each limb and moving platform as the studying objects. The inverse kinematics of the mechanism is analyzed. The driving force, driving moment and the constraint moment can be obtained. Finally, a computer simulation is carried out to solve the inverse dynamics of the mechanism when the motion of moving platform is given.
Study of Combined Fuzzy Clustering Algorithm Based on F-Statistics Hierarchy Clustering
Authors: Min Min
Published: September 2010

On analyzing the common problems in fuzzy clustering algorithms, we put forward the combined fuzzy clustering one, which will automatically generate a reasonable clustering numbers and initial cluster center. This clustering algorithm has been tested by real evaluation data of teaching designs. The result proves that the combined fuzzy clustering based on F-statistic is more effective.
Design and Realization of Color Character Overlay Based on AT89S51 and MC1377
Authors: Zheng En Xing , Tang Jing
Published: September 2010

This paper describes a color character overlay using color synchrolock and coding circuit composed of color television integrated circuit AT89S51and MC1377, introduces the basic method of overlay color character on television image, discusses relevant theory from microcomputer video image and color character overlay, puts forward a new character overlay method, and gives the video image character overlay’s design method based on AT89S51.
Study on the Passive Vibration Control of Gear System
Authors: Gu Cheng Zhong , Wu Xin Yue , Zhang Ping Hao
Published: September 2010

The passive vibration control is a very effective measure to gear system. But there exist some limitations. This paper viewed the development of the passive vibration control of gear system, and researched the damping characteristics of the friction dampers and viscoelastic dampers intensively. Firstly, the limitations of the existence passive damping technology are pointed out. Secondly, the feasibility and validity of piezoelectric shunt damping is guaranteed through experimentation on the gear system vibration control. Thirdly, a new hybrid damping, piezoelectric- viscoplastic material damping, is proposed, which extracts the advantages of piezoelectric shunt damping and viscoplastic damping.
The Vehicle Dynamical Analysis of a High-Speed Train Passing through a Tunnel
Authors: Feng Zhi Peng , Zhang Ji Ye , Zhang Wei Hua
Published: September 2010

As the speed of train increases, flow-induced vibration of trains passing through tunnels has become a subject of discussion, to investigate this phenomenon, a simplified geometric model and a vehicle dynamics model of a high-speed train traveling through a tunnel were built. To analyze the unsteady three-dimensional flow around the train, the 3-D, transient, viscous, compressible Reynolds-averaged Navier-Stokes equations combined with the k- two-equation turbulence model were solved with the finite volume method. The motion of the train was carried out using the technique of sliding grid method. The dynamics response of the train was obtained by means of the computational multi-body dynamics calculation. Meanwhile the running safety and riding comfort of the train were analyzed. With the numerical simulation, the variation of aerodynamic forces was obtained. The research founds that, vibration of the train increases drastically during it passing through a tunnel. The running safety and riding quality of the train are reduced greatly but they are in the safe range.
A Convenient Designing Method of Feed Network at Low Frequency - The Substructure Method
Authors: Zhan Hua Wei , Guo Cai Xia , Zhang Yu , Zhou Yun
Published: September 2010

Multimode feed network is an important part of shortwave multimode multifeed antenna system. The design of feed network is a pivotal technique in the process of projecting antenna system. The substructure analyzing method of interconnect-net is based on the substructure matrix database which is formed by converting the net parameters into data. And it characterizes the non-uniform net units through the database directly. Then cascades the known database of the net units by means of ordinary net cascade method, thus performing optimization in the net. In the paper, the Substructure Analyzing Method of Interconnect-net is applied to designing multi-mode multi-feed network, a typical example of multi-mode multi-feed network optimization is given to illustrate the efficiency of the method.
Model of Heating Fuzzy Intelligent Control System of Large-Scale Coke Oven
Authors: Li Gong Fa , Kong Jian Yi , Jiang Guo Zhang , Xie Liang Xi
Published: September 2010

Coke oven production has the characteristics of nonlinear, large inertia, large disturbances, and highly-coup ling and so on. The control method of “intermittent heating control” is adopted in traditional heating control system of coke oven, and cannot satisfy the command of heating control on coke oven. The control principle of combining the “intermittent heating control” with the heating gas flow adjustment is adopted according to analysis the difficulty and strategy of heating control on coke oven. On the basis of studying deficiency of the existing control strategy, fuzzy compound control is proposed to establish heating intelligent control model of coke oven, which combines feedback control, feedforward control and fuzzy intelligent control. Carbonization index is used in the model to control coking management of coke oven. Then heating fuzzy intelligent control structure of coke oven is built. According to artificial experience and actual condition, fuzzy controller is designed. Fuzzy control can deal with fuzzy, inexact or uncertainty information and has great robust, which can realize intelligent control of heating process of coke oven. Better control result of temperature control is realized by fuzzy intelligent control model. The system has great practical value.
Nanostructured Materials for Hydrogen Storage
Authors: Sepehri Saghar , Liu Yan Yi , Cao Guo Zhong
Published: September 2010

Hydrogen generated from clean and renewable energy sources has been considered as an alternate fuel to carbon based fossil fuels for several decades. Although many advances in hydrogen production and usage have been made, storing hydrogen remains a significant challenge. Many drawbacks including energy intensive processes, low volumetric densities, and safety concerns are associated with storing hydrogen as pressured or liquefied. Solid state hydrogen storage is considered to be the most promising method as a safe and effective storage option, but there is still no material or method that satisfies the requirements for a practical approach. A feasible hydrogen storage media should address several issues including targeted storage capacities, thermodynamics and hydrogen sorption kinetics, and safety. Nanostructured materials can provide tailor-made properties for storing and releasing hydrogen to fulfill, at least, the partial requirements. This short review, not a comprehensive review of all the materials or technologies in hydrogen storage, summarizes some of the recent developments in application of nanostructures for solid state hydrogen storage; particular attention has been devoted to the most recent development of nanocomposites with tuned dehydrogenation temperatures and kinetics through the control of pore size and surface chemistry.
Oxidative Removal of Dibenzothiophene by H2O2 over Activated Carbon-Supported Phosphotungstic Acid Catalysts
Authors: Yu Guo Xian , Zhou Rui Xue , Li Ji Bing , Zhou Xiao Long , Li Cheng Lie , Chen Li Fang , Wang Jin An
Published: September 2010

Phosphotungstic acid (HPW) supported on activated carbon (AC) combined with hydrogen peroxide formed an oxidative desulfurizaiton (ODS) system to oxidize sulfur-containing compounds in diesel fuel. Dibenzothiophene (DBT) dissolved in n-octane was selected as a model feedstock for studying this new ODS system. The HPW/AC catalysts were characterized with XRD, FTIR and N2 adsorption-desorption measurements. HPW was highly dispersed on the surface of carbon support. It was found that the DBT adsorption capacity decreased from 42 mg S/g to 33.13 mg S/g as HPW loading amount increased from 0 to 15 wt.%. Oxidative removal of DBT in the model oil significantly increased with increasing HPW loadings on the support from 0 to 10 wt.%. 100 % DBT was removed by using the catalysts with HPW content higher than 10 wt. %. At 80 °C, oxidative removal of DBT reached 100 % after 40 min of reaction when O/S molar ratio ranged from 4 to 10.
Promotional Effect of Gadolinia on CuO Catalyst for Reduction of NO by Activated Carbon
Authors: Xue Yu Ye , Lu Guan Zhong , Guo Yun , Guo Yang Long , Wang Yan Qin , Zhang Zhi Gang
Published: September 2010

The Gd2O3 (gadolinia) modified CuO/AC catalysts for NO reduction by activated carbon were prepared and characterized by XRD, TPD-MS, EPR, XPS techniques. The results show that adding a small amount of Gd2O3 in the CuO catalyst can improve effectively its catalytic performance for NO reduction by activated carbon, and the appropriate molar ratio of Gd2O3/CuO is 0.03:1. The promotional effect of Gd2O3 stems from the cooperative effects between CuO and Gd2O3. The presence of Gd2O3 in the catalyst can alter the chemical state and environment of the CuO active sites and improve the catalytic activation of carbon by CuO to form more carbon reactive sites, resulting in the quicker transfer and release of oxygen decomposed from NO. The carboxylic groups on the surface of activated carbon play an important role in the catalytic reduction of NO by carbon at temperature below 300 °C.
Strength Evaluation of Joint Formed by Powder Injection Molding
Authors: Li Tao , Zhang Su Xia , Li Qing Fa , Pook Siew Fei , Ong Zi Yan Amanda
Published: September 2010

Powder injection molding technology is currently applied to the joining processes to produce multi-functional components. In this paper, the strength of the joint of green and sintered samples produced by powder injection molding was evaluated using four-point bending test. The microstructures of the green samples showed that a very good joint was formed by the re-melting of the first injection molded half part followed by a high pressure compacting in the second injection molding. The strength of joined green samples was almost equal to the reference green samples without joining. The microstructures and flexure strength of sintered joined samples, which was more than 90% of base materials, showed that the good joining was maintained after sintering. This high strength sintered joint was an integrative result of powder injection molding and sintering diffusion. The crack observed at the sample surface accounted for the slight drop of the strength.
An Easy-to-Manufacture 2 Degree-of-Freedom Remote Center of Compliance for Micro-Transfer Printing
Authors: Ahmed Numair , Saeidpourazar Reza , Ferreira Placid M.
Published: September 2010

This paper presents the design and development of a remote center of compliance (RCC) for a stamp holder for the micro-transfer printing process. One important aspect of the design of an automated printer to implementing the micro-transfer printing process is the generation of conformal contact between the stamp and the donor and acceptor substrates. Orientation errors during set up make this very hard to achieve with the introduction of some compliance. To introduce such compliance without the loss of overlay registration accuracy, a 2 degree of freedom (2-dof) remote centre of compliance is designed into the stamp holder so that its instantaneous rotation center at the face of the stamp. This design is implemented using flexure hinges in a configuration that makes the resulting system compact, in-expensive and easy to manufacture.
Electrical Conductivity and Micro Hardness of Synthetic and Natural Graphite Epoxy Composite
Authors: Suherman Hendra , Sahari Jaafar , Sulong Abu Bakar
Published: September 2010

This study investigates the electrical conductivity and micro hardness of synthetic and natural graphite epoxy composite. Graphite used on this study is synthetic graphite (SG) and natural graphite (NG) with particle size 44m and 30m, respectively. Different graphite concentrations (50 ~ 80 wt.%) were added into the epoxy resin. The dispersion of graphite in epoxy resin was conducted by high speed mixer through mechanical shearing mechanism, its graphite epoxy suspension was poured into the mold and compression molding was conducted for fabrication of graphite epoxy composites. Electrical conductivity was measured by the four point probe. Microscopic analyses conducted on fracture surface use scanning electron microscopic. Results reveal that non conductive epoxy polymer becomes conductor as addition of graphite. Electrical conductivity of NG higher than SG at the same weight percentage (Wt. %) of conducting filler loading. The highest loading concentration, it exhibited values 12.6 S/cm and 7 S/cm at (80 Wt. %). Hardness property of epoxy composites of both type of graphite increase continuously and reached peak at 60 wt% for NG and 70 wt % for SG, while more addition decreased it.
Fiber-Complected and Reeled Microstructure of Insect Cuticle and Biomimetic Fabrication
Authors: Chen Bin , Yuan Quan , Luo Ji
Published: September 2010

A scanning electron microscope (SEM) was used for the observation of the microstructures of a chafer cuticle. It showed that the cuticle is a kind of biocomposite consisting of complected chitin-fiber plies and sclerous protein matrix. The observation also showed that there are many holes in the cuticle and the complected fibers continuously reel these holes forming a kind of fiber-complected and reeled microstructure. Based on the SEM observation, a kind of biomimetic composite laminate with complected and reeled structure was fabricated with a special mould and process. The ultimate strength of the obtained biomimetic composite laminate was experimentally investigated and compared with that of the conventional drilling-hole composite laminate. It showed that the ultimate strength of the biomimetic composite laminate is markedly larger than that of the drilling-hole composite laminate.
Fiber-Intersected Microstructure of Cockle Shell and Biomimetic Fabrication
Authors: Chen Bin , Yuan Quan , Luo Ji
Published: September 2010

A scanning electronic microscope (SEM) was used for observing the microstructures of a Cockle shell. It showed that the shell is a kind of natural bioceramic composite consisting of aragonite sheets and organic collagen matrix. The aragonite sheets are further composed of aragonite fibers. The aragonite fibers are of long and thin shape and compose various reinforced microstructures, which include a kind of fiber-intersected reinforced one. The fiber-intersected reinforced microstructure was employed as the design example for the structure of man-made fiber-reinforced composite, a kind of fiber-reinforced composite with the fiber-intersected reinforced structure was biomimetically fabricated. The fracture toughness of the biomimetical composite was tested and compared with that of the conventional composite with fiber-parallel structure. It indicated that the fracture toughness of the biomimetical composite is markedly larger than that of the fiber-parallel composite.
Effect of Mixture of Plasticizer on the Thermoplastics Formability of Polyvinyl Alcohol (PVA)
Authors: Liu Bin , Qiu Die , Zhao Chun Zhen
Published: September 2010

In this paper, PVA was modified by mixture of plasticizer with glycerol and caprolactam. DSC and FTIR were used to test the thermoplastics formability of modified PVA. The results showed that the melt temperature of modified PVA with plasticizer was decreased significantly. With the same content of mixture of plasticizer (20%), the melt temperature of modified PVA is 207°C when the mass ratio of glycerol and caprolactam is 3:2. Under the same content of plasticizer, plasticized effect of mixture of plasticizer was enhanced more than the plasticizer of glycerine or caprolactam alone, so the melt temperature of modified PVA with mixture of plasticizer was lowest relatively.
Thin Film of Palladium on Alumina Ceramic Membrane Tube: Effect of Combine Sol-Gel Process with Electroless Plating on Deposits Morphology
Authors: Ratna Sari , Yaakob Zahira , Manal Ismail , Wan Daud Wan Ramli
Published: September 2010

In this work, the potential of utilizing the porous alumina ceramic membrane coated with palladium as a hydrogen permselective membrane has been studied. The ceramic membrane is characterized by high permeability but at low hydrogen selectivity. In order to increase the pure hydrogen selectivity and to obtain high hydrogen yield on the ceramic membrane, palladium was coated on the alumina membrane surface. Such an arrangement would also enable the ceramic membrane to be operated at higher temperature. The preparation of the palladium coated ceramic membrane was carried out using combine sol-gel process and the electroless plating technique. The effect of combine sol-gel process with electroless plating towards deposits morphology, hydrogen permeability, and hydrogen permselectivity were analysed. The thickness and morphology of the α- Alumina and Pd composite membranes were analysed using a scanning electron microscopy (SEM) and atomic force microscopy (AFM).
Influence of Crystal Structure, Morphology and Sodium Ion on the Photocatalytic Reactivity of Spray Deposited Titanium Dioxide Film
Authors: Cai R. , Tan W.K. , Ng Fern Lan , Sun Chang Q.
Published: September 2010

In this paper, three types of titanium dioxide structures (anatase, heated amorphous and amorphous) from peroxo titanium complex were deposited on glass and wafer substrates by spraying technique. Influences of crystal structure, morphology and sodium ion on UV induced hydrophilicity were studied. X-ray diffraction revealed that crystalline anatase coatings are extremely hydrophilic (<10°) under UV irradiation (indoor) while the amorphous coatings are still hydrophobic on both glass and wafer substrate with contact angles as high as 70º. When amorphous coating was heated at 450°C, its structure was converted into crystalline anatase, and hence its UV induced hydrophilicity behavior on wafer substrate became similar to that of anatase. However, this UV induced hydrophilicity was inhibited on heated glass (450°C), suggesting that sodium ions in the glass might be responsible for the differences between silicon wafer and glass. With increasing coating thickness, such inhibition effect was reduced, but the hydrophilicity still could not reach the level of anatase. After 6 months of outdoor exposure, water contact angle for amorphous, heated amorphous and anatase were 61°, 26.6° and 12.1°, respectively. Also, X-ray diffraction suggested that amorphous is not converted into anatase after long period of UV exposure, although coating morphologies are changed based on Scanning Electron Microscopic observation. It is concluded that the crystal structure, coating morphology and sodium ion concentration have key impact on the photocatalytic properties on glass substrate.
A Portable Device for Fabricating Biomaterial Microfiber Bundles
Authors: Liu A. , An J. , Chua Chee Kai , Leong Kah Fai
Published: September 2010

Engineered tendon and ligament scaffolds are ideally a bunch of biocompatible and biodegradable microfibers that are three-dimensionally aligned with no fusion between individual fibers. In this paper, a simple yet effective device that is able to fabricate this nearly native structure is presented, including design and operation method. Briefly, the device is die-free and requires only simple components such as a plate with an orifice, an aluminum holder, a ring heater and a rotating mandrel. The fabrication is done by a single step with microfiber (10 µm diameter) bundles being directly obtained at a very low take-up speed. The as-spun microfiber bundles appear silvery and shiny, apparently similar to a native tendon. This device and the method associated opens up a new way to diversify the structure of biomaterials.
Study on Reduction of Residual Stress Induced during Rapid Tooling Process: Influence of Heating Conditions on Residual Stress
Authors: Furumoto Tatsuaki , Ueda Takashi , Abdul Aziz Mohd Sanusi , Hosokawa Akira , Tanaka Ryutaro
Published: September 2010

This paper deals with the reduction of residual stress induced during the selective laser melting with a mixture of ferrous based metal powder. To evaluate the residual stresses induced during layered manufacturing processes, a strain gauge is attached on the bottom face of the base plate. The residual stress within the consolidated structure is calculated from the amount of strain change measured by the strain gauge when the consolidated structure is cut with an end mill. The influences of base plate thickness and consolidated structure height on the residual stresses are investigated. In addition, the effect of pre-heating and post heating by a laser beam irradiation are evaluated. The results showed that the deformation of the base plate increased with the increase of the consolidated layer and the decrease of base plate thickness, and the deformation was flattened when the consolidated structure was completely removed with the end mill. The deformation was related to the induced residual stresses. The residual stress distribution within the consolidated structure in the z direction was extremely large at the top layer of the structure and the boundary between the base plate and consolidated structure. The residual stress at the first layer of the structure decreased when the base plate was heated before consolidating the deposited powder. The residual stresses decreased when each of the consolidated layers was repeatedly heated by the laser beam irradiation.
Fracture Indentation on AISI 1018 Borided Steels
Authors: Campos-Silva Ivan , Ortíz-Domínguez M. , Hernández-Sánchez E. , Bravo-Bárcenas D. , Bravo-Bárcenas O. , Doñu-Ruíz Marco Antonio , Martínez-Trinidad J. , Jiménez-Bernal J.A. , Domínguez-Galicia Y.
Published: September 2010

Fracture indentation was applied to estimate the fracture toughness of AISI 1018 borided steels. The Fe2B hard layers were formed using the powder-pack boriding process for two temperatures with 4 and 8 h of exposure times. The fracture toughness of the iron boride layer of the AISI 1018 borided steels was estimated using a Vickers microindentation induced-fracture testing at distances of 15 and 30 m from the surface, applying four loads (0.49, 0.98, 1.96 and 2.9 N). The microcracks generated at the corners of the Vickers microindentation were considered as experimental parameters, which are introduced in a Palmqvist crack model to determine their corresponding fracture toughness KC. As a result, the experimental parameters, such as exposure time and boriding temperature are compared with the resulting fracture toughness of the borided phase.
New Theoretical Approach of the Fracture Ductility of Steels and its Relation with the Microscopy Structural Characterization
Authors: Yermishkin Viacheslav A. , Tamayo Meza Pedro A. , Muñoz Aguirre N. , Mendez Arait M. , Vilchis Leonardo D.
Published: September 2010

It is well known that the formation of a highly hardening state of the standard steels is related with the improvement of its mechanical characteristics, which means an increment in the ductility of the fracture. Commonly, the ductility of the fracture is measured by means of mechanical methods involving large size and geometrical special shape of the sample. Satisfy these requirements in the initial steps of the development of a new material, or during the treatment for improving the hardness, is a dif ficult task. The present work shows the theoretical determination of the ductility of the fracture when the researchers have a small piece of the sample. Also, from the analysis of microscopy images, by the first time, it is demonstrated that an ultra-hardening state of the steel corresponds to a nano-fragmented dislocational structure in accordance to the theory.
Designing of Virtual Reality Environments for Mobile Robots Programming
Authors: Duguleana Mihai , Barbuceanu Florin Grigore
Published: September 2010

In this paper are presented some of the main issues in designing and developing of mobile robots in virtual environments that can be used for completing various tasks. Due to high complexity of robotic systems, real experiments are demanding unsatisfying timeframes and high financial resources. Other problems scientists encounter in real tests are the difficulty of concurrent use, space restrictions or hardware malfunctions. Several related studies are treating these issues by proposing the usage of virtual reality (VR) as a solution for reducing costs and decreasing development time. We are focusing our study on designing and developing of a virtual mobile robot and integrating it within various virtual environments. Furthermore, we describe the technologies that can be used to accomplish our goals, listing their good and weak points, we integrate our work in an immersive VR environment like Cave Automatic Virtual Environment (CAVE) and we present the study results.
Extended Mobility Carried Out with a Double Hexapod Robot
Authors: Margaritescu Mihai , Ivan Ana Maria Eulampia , Vaduva Vlad , Brisan Cornel
Published: September 2010

The double hexapod robot consists in two staged hexapod platforms – Stewart Gough platforms - combining in a certain measure the advantages of the robots with parallel kinematics and of the serial robots: high accuracy, high stiffness, fast response and small dimensions, having an extended operating space. Different modelling and construction aspects were described in few previous articles. Some examples of trajectories generated with this positioning system are now presented to illustrate its mobility, as well as the workspaces for one and two hexapods in order to make possible a visual comparison between the two volumes.
Development of a Tactile Sensor Array
Authors: Marian Nicolae , Drimus Alin , Bilberg Arne
Published: September 2010

Flexible grasping robots are needed for enabling automated, profitable and competitive production of small batch sizes including complex handling processes of often fragile objects. This development will create new conditions for value-adding activities in the production of the future world. The paper describes the related research work we have developed for sensor design, exploration and control for a robot gripping system, in order to analyze normal forces applied on the tactile pixels for gripping force control and generate tactile images for gripping positioning and object recognition. Section 1 gives an introduction of principles and technologies in tactile sensing for robot grippers. Section 2 presents the sensor cell (taxel) and array design and characterization. Section 3 introduces object recognition and shape analysis ideas showing a few preliminary examples, where geometrical features of small objects are identified. Slip detection in order to define optimum grasp pressure is addressed in section 4. The paper will conclude by addressing future ideas about how to judge or forecast a good grasp quality from sensory information.
Aspects Concerning Voice Cognitive Control Systems for Mobile Robots
Authors: Topoleanu Tudor Sabin , Mogan Gheorghe Leonte
Published: September 2010

In this paper we present a general structure of a cognitive control system that allows a mobile robot to behave semi-autonomously while receiving tasks through vocal commands. Furthermore, the paper contains an analysis of human robot interfaces, voice interface systems and cognitive systems. The main purpose is to identify the optimum structure of a mobile robot control platform and determine the outlines within which this solution will be developed. The mobile robot using such a solution will operate in the services and leisure domain, and therefore the specifications for the cognitive system will be tailored to the needs of such applications.
Retest Reliability of Force-Time Variables of Neck Muscles Under Isometric Conditions
Authors: Almosnino Sivan , Pelland Lucie , Stevenson Joan M.
Published: September 2010

Context:

Proper conditioning of the neck muscles may play a role in reducing the risk of neck injury and, possibly, concussions in contact sports. However, the ability to reliably measure the force-time–based variables that might be relevant for this purpose has not been addressed.

Objective:

To assess the between-days reliability of discrete force-time–based variables of neck muscles during maximal voluntary isometric contractions in 5 directions.

Design:

Cohort study.

Setting:

University research center.

Patients or Other Participants:

Twenty-six highly physically active men (age  =  21.6 ± 2.1 years, height  =  1.85 ± 0.09 m, mass  =  81.6 ± 9.9 kg, head circumference  =  0.58 ± 0.01 m, neck circumference  =  0.39 ± 0.02 m).

Intervention(s):

We used a custom-built testing apparatus to measure maximal voluntary isometric contractions of the neck muscles in 5 directions (extension, flexion, protraction, left lateral bending, and right lateral bending) on 2 separate occasions separated by 7 to 8 days.

Main Outcome Measure(s):

Variables measured were peak force (PF), rate of force development (RFD), and time to 50% of PF (T50PF). Reliability indices calculated for each variable comprised the difference in scores between the testing sessions, with corresponding 95% confidence intervals, the coefficient of variation of the typical error of measurement (CVTE), and intraclass correlation coefficients (ICC [3,3]).

Results:

No evidence of systematic bias was detected for the dependent measures across any movement direction; retest differences in measurements were between 1.8% and 2.7%, with corresponding 95% confidence interval ranges of less than 10% and overlapping zero. The CVTE was lowest for PF (range, 2.4%–6.3%) across all testing directions, followed by RFD (range, 4.8%–9.0%) and T50PF (range, 7.1%–9.3%). The ICC score range for all dependent measures was 0.90 to 0.99.

Conclusions:

Discrete variables representative of the force-generating capacity of neck muscles under isometric conditions can be measured with an acceptable degree of reliability. This finding has possible applications for investigating the role of neck muscle strength-training programs in reducing the risk of injuries in sport settings.
Ultrasound and Joint Mobilizations for Achieving Normal Wrist Range of Motion After Injury or Surgery: A Case Series
Authors: Draper David O.
Published: September 2010

Context:

Regaining full, active range of motion (AROM) after trauma to the wrist is difficult.

Objective:

To report the cases of 6 patients who lacked full range of motion (ROM) in the wrist due to trauma. The treatment regimen was thermal 3-MHz ultrasound and joint mobilizations.

Design:

Case series.

Setting:

University therapeutic modalities laboratory.

Patients or Other Participants:

Six patients (2 women, 4 men) from the university population lacked a mean AROM of 21.7° of flexion and 26.8° of extension approximately 2.1 years after trauma or surgery.

Main Outcome Measure(s):

I assessed changes in flexion and extension AROM before and after each treatment. Treatment consisted of 6 minutes of 3-MHz continuous ultrasound at an average intensity of 1.4 W/cm2 on the dorsal and volar aspects of the wrist, immediately followed by approximately 10 minutes of joint mobilizations. After posttreatment ROM was recorded, ice was applied to the area for about 20 minutes. Once the patient achieved full AROM or did not improve on 2 consecutive visits, he or she was discharged from the study.

Results:

By the sixth treatment, 5 participants achieved normal flexion AROM, and 3 exceeded the norm. All 6 achieved normal extension AROM, and 4 exceeded the norm. All returned to normal activities and normal use of their hands. One month later, they had, on average, maintained 93% of their final measurements.

Conclusions:

A combination of thermal ultrasound and joint mobilizations was effective in restoring AROM to wrists lacking ROM after injury or surgery.
Autopsy in older medical patients: concordance in ante- and post-mortem findings and changing trends
Authors: Swaro A , Adhiyaman V
Published: September 2010

Despite modern diagnostics, the discordance between ante- and postmortem diagnoses is still around 25%, reiterating the need for high post-mortem rates. In our study, 3.5% had class I errors that, had they been detected during life, would or might have affected short-term outcome. Another 14% had major errors, conditions recorded as primary cause of death that were clinically missed or unrecorded but would not have affected the outcome. There has been an unexplained decline in hospital post mortems and more than a third of UK autopsies are now performed under the instruction of the relevant Coroner’s office. The UK Coroners’ system is currently under judicial and administrative review to improve the speed of and reduce the need for post-mortem analysis.
Improved measurement of carbonaceous aerosol: evaluation of the sampling artifacts and inter-comparison of the thermal-optical analysis methods
Authors: Cheng Y. , He K. B. , Duan F. K. , Zheng M. , Ma Y. L. , Tan J. H. , Du Z. Y.
Published: September 2010

Abstract. The sampling artifacts (both positive and negative) and the influence of thermal-optical methods (both charring correction method and the peak inert mode temperature) on the split of organic carbon (OC) and elemental carbon (EC) were evaluated in Beijing. The positive sampling artifact constituted 10% and 23% of OC concentration determined by the bare quartz filter during winter and summer, respectively. For summer samples, the adsorbed gaseous organics were found to continuously evolve off the filter during the whole inert mode when analyzed by the IMPROVE-A temperature protocol. This may be due to the oxidation of the adsorbed organics during sampling (reaction artifact) which would increase their thermal stability. The backup quartz approach was evaluated by a denuder-based method for assessing the positive artifact. The quartz-quartz (QBQ) in series method was demonstrated to be reliable, since all of the OC collected by QBQ was from originally gaseous organics. Negative artifact that could be adsorbed by quartz filter was negligible. When the activated carbon impregnated glass fiber (CIG) filter was used as the denuded backup filter, the denuder efficiency for removing gaseous organics that could be adsorbed by the CIG filter was only about 30%. EC values were found to differ by a factor of about two depending on the charring correction method. Influence of the peak inert mode temperature was evaluated based on the summer samples. The EC value was found to continuously decrease with the peak inert mode temperature. Premature evolution of light absorbing carbon began when the peak inert mode temperature was increased from 580 to 650 °C; when further increased to 800 °C, the OC and EC split frequently occurred in the He mode, and the last OC peak was characterized by the overlapping of two separate peaks. The discrepancy between EC values defined by different temperature protocols was larger for Beijing carbonaceous aerosol compared with North America and Europe, perhaps due to the higher concentration of brown carbon in Beijing aerosol.
Temporal and spatial variations of soil carbon dioxide, methane, and nitrous oxide fluxes in a Southeast Asian tropical rainforest
Authors: Itoh M. , Kosugi Y. , Takanashi S. , Hayashi Y. , Kanemitsu S. , Osaka K. , Tani M. , Nik A. R.
Published: September 2010

Abstract. To clarify the factors controlling temporal and spatial variations of soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) fluxes, we investigated these gas fluxes and environmental factors in a tropical rainforest in Peninsular Malaysia. Temporal variation of CO2 flux in a 2-ha plot was positively related to soil water condition and rainfall history. Spatially, CO2 flux was negatively related to soil water condition. When CO2 flux hotspots were included, no other environmental factors such as soil C or N concentrations showed any significant correlation. Although the larger area sampled in the present study complicates explanations of spatial variation of CO2 flux, our results support a previously reported bipolar relationship between the temporal and spatial patterns of CO2 flux and soil water condition observed at the study site in a smaller study plot. Flux of CH4 was usually negative with little variation, resulting in the soil at our study site functioning as a CH4 sink. Both temporal and spatial variations of CH4 flux were positively related to the soil water condition. Soil N concentration was also related to the spatial distribution of CH4 flux. Some hotspots were observed, probably due to CH4 production by termites, and these hotspots obscured the relationship between both temporal and spatial variations of CH4 flux and environmental factors. Temporal variation of N2O flux and soil N2O concentration was large and significantly related to the soil water condition, or in a strict sense, to rainfall history. Thus, the rainfall pattern controlled wet season N2O production in soil and its soil surface flux. Spatially, large N2O emissions were detected in wet periods at wetter and anaerobic locations, and were thus determined by soil physical properties. Our results showed that, even in Southeast Asian rainforests where distinct dry and wet seasons do not exist, variation in the soil water condition related to rainfall history controlled the temporal variations of soil CO2 flux, CH4 uptake, and N2O emission. The soil water condition associated with soil hydraulic properties was also the important controlling factor of the spatial distributions of these gas fluxes.
Do crustal deformations observed by GPS in Tierra del Fuego (Argentina) reflect glacial-isostatic adjustment?
Authors: Mendoza L. , Richter A. , Hormaechea J. L. , Perdomo R. , Del Cogliano D. , Dietrich R. , Fritsche M.
Published: September 2010

Abstract. Vertical site velocities determined by geodetic GPS observations in the Lago Fagnano area, Tierra del Fuego main island, are interpreted with respect to their potential relation with the glacial-isostatic crustal response to ice mass changes. The spatial pattern of the uplift rates, in combination with the horizontal crustal deformation pattern, point towards a fault-tectonic rather than glacial-isostatic origin of the determined vertical crustal deformations. This implies rather small GIA effects pointing towards relatively small Holocene ice-mass changes in Tierra del Fuego. However, these findings are considered to be preliminary. They should be confirmed by additional observations covering an extended area with GPS sites.
Predicting Peptide Retention Times for Proteomics
Authors: Krokhin Oleg V. , Spicer Vic
Published: September 2010

The vast majority of modern bottom‐up proteomic protocols include chromatographic reversed‐phase (RP) fractionation of peptides prior to mass‐spectrometric analysis. Retention time information can be easily extracted from LC‐MS data and it can be used to improve protein identification/characterization procedures. The key to the success of this procedure is the correct retention time prediction based on compositional and structural properties of the separated species. Our Sequence Specific Retention Calculator (SSRCalc) is a Web‐based peptide retention prediction that covers the separation selectivity of the most popular RP‐HPLC conditions applied in proteomics. Procedures for the application of SSRCalc to proteomic analyses are described in this unit. Curr. Protoc. Bioinform. 31:13.14.1‐13.14.15. © 2010 by John Wiley & Sons, Inc.
Oxygen and Water Plasma‐Immersion Ion Implantation of Copper into Titanium for Antibacterial Surfaces of Medical Implants
Authors: Polak Martin , Ohl Andreas , Quaas Marion , Lukowski Gerold , Lüthen Frank , Weltmann Klaus‐Dieter , Schröder Karsten
Published: September 2010

Plasma‐immersion ion implantation (PIII) is used for the insertion of copper into titanium and its alloys to impart antimicrobial properties. Physicochemical changes inside the subsurface of titanium are investigated after PIII with either oxygen or water vapor. O2‐Cu‐PIII produces copper oxides inside the surface of the titanium oxide; H2O‐Cu‐PIII produces metallic copper inside the created titanium oxide compound. The length of the PIII pulses can exert control over the ion flux and the substrate temperature. H2O‐Cu‐PIII produces rutile structures with copper inside the lattice. The antimicrobial activity is tested with bacteria and the cytocompatibility with osteoblasts is investigated.
High‐Pressure Torsion for Giant Magnetoresistance and Better Magnetic Properties
Authors: Nishihata Shingo , Suehiro Kenichiro , Arita Makoto , Masuda Masataka , Horita Zenji
Published: September 2010

High‐pressure torsion (HPT) was conducted on Cu alloys containing ferromagnetic Co and Fe particles. Electron probe microanalysis, X‐ray diffraction analysis, and transmission electron microscopy confirmed that the particles were significantly refined through fragmentation and some fractions were dissolved into the Cu matrix with straining by HPT. Saturation magnetization decreases with straining and coercive force increases with straining but they level off after intense straining. Magnetoresistance with an isotropic feature corresponding to giant magnetoresistance (GMR) appears at room temperature by processing with HPT. It is demonstrated that HPT is a potential process for controlling magnetic properties such as saturation magnetization and coercive force and also for creating GMR in the alloys prepared by conventional ingot metallurgy.
The Effect of Stress Relaxation on the Microstructure and Hardness Evolution of Pure Amorphous‐Carbon and C/Ti Multilayer Films
Authors: Hong Chunfu , Tu Jiangping , Gu Changdong , Zheng Xiaohua , Liu Dongguang , Li Ruiling , Mao Scott X
Published: September 2010

Pure amorphous‐carbon (a‐C) and C/Ti multilayer films are prepared by pulsed‐laser deposition. For each fluence (7 or 10 J cm−2), a‐C films are deposited with two durations (35 and 120 min) to vary the thickness. The thin films have an sp3 bond ratio and hardness dependant on the fluence. The as‐deposited, thick a‐C films delaminate and provide a more‐nanosized graphitic microstructure, and a lower sp3 bond ratio and hardness compared to thin a‐C films, correlating with stress relaxation of the films. The C/Ti multilayer films can be deposited at large thicknesses due to the low internal stress, while the sp3 bond ratio and the hardness increase with decreasing thickness of the Ti bilayer.
Spark Plasma Sintering, Microstructures, and Mechanical Properties of Macroporous Titanium Foams
Authors: Zhang Faming , Otterstein Eileen , Burkel Eberhard
Published: September 2010

Macroporous pure titanium (Ti) foams with porosity of 30–70% and pore size of 125–800 µm were fabricated by using spark plasma sintering (SPS) and NaCl dissolution methods. A mixture of Ti and sodium chloride (NaCl) powders were spark plasma sintered in a temperature range from 550 to 800 °C and the NaCl phase was then dissolved in water. High purity Ti foams were obtained at the SPS temperature of 700 °C for holding time of 8 min under pressure of 50 MPa. The resulting Ti foams consist of pure α‐Ti phase with interconnected macropores in square cross sections. The plateau stress and Young's modulus agree with the Gibson–Ashby models, and coarsely follow of linear decline with the increase of the pore sizes, and exponential decay with the increase of the porosity. The macroporous Ti foams with plateau stress 27.2–94.2 MPa and Young's modulus 6.2–36.1 GPa may have a potential to be used as bone implants.