bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure Formation Mechanism of AZ31 Magnesium Alloy Processed by Rheo-Forming
Authors: Guan Ren Guo , Zhao Zhan Yong , Lian Chao , Chao Run Ze , Liu Chun Ming
Published: March 2012

AZ31 magnesium alloy sheets with a cross section of 5mm×50mm were prepared by semisolid metallic rheo-rolling device self-designed, and microstructure formation mechanism of AZ31 magnesium alloy during rheo-rolling was investigated. The results reveal that during the preparation of semisolid slurry, melt firstly nucleates heterogeneously on the surface of sloping plate. Under the vibration and shear of sloping plate, a relatively homogenous temperature field and composition filed are formed around some grains and are favorable for the direct growths of globular grains; meantime, dendrites formed under the vibration and shear are broken up and rounded gradually and better semisolid slurry is formed. During rheo-rolling, under the action of roll interfacial friction and rolling force, laminar flow shear inside the alloy is enhanced, and grains are further broken up and elongated. When the pouring temperature is 670°C, excellent AZ31 magnesium alloy sheet with good microstructure can be obtained.
Experimentation Study of Damage Identification for Steel-Frame Structure Based on AR Model
Authors: Zhang Ning , Wei Zhuo Bin , Wu Sen
Published: March 2012

By using the AR (Auto-regressive) self-regression model, structure acceleration data are fitted. By using fitted coefficients, the characteristic vector of structure damage is constructed. Based on the Mahalanobis distance of the characteristic vectors under different states, the index of structure damage is designed. By comparing the characteristic index of healthy structures and the damaged ones, damages can be detected. By an experiment of damage identification on steel-frame structure model, the effectiveness of the method is validated.
Preparation and Spectral Analysis of Light Conversion Advanced Invisible Falsification-Resistant Ink
Authors: Liu Hai Yan , Zhu Yi Ping , Liang Duo Ping
Published: March 2012

This paper discusses the structure design, light conversion agents, vehicles, colorants and the selection of other functional additives of light conversion advanced invisible falsification- resistant ink, the preparation of the light conversion falsification-resistant ink and rare earth metal europium complex, and analyzes rare earth metal europium complex, Eu(C5H7O2)3C12H8N2, through infrared spectrometer, element analyzer and fluorescence spectrometer. The results of the above analysis identify the composition of rare earth metal europium complex, its excitation spectrum ranging from 200nm to 400nm, and its emission spectrum ranging from 580nm to 640nm. Experiments suggest when the mixture of rare earth metal europium complex and white ink with titanium dioxide in a fixed proportion is printed on any objects, it appears reddish orange light under ultraviolet irradiation, which achieves the advanced invisible anti-counterfeiting effect.
Self-Propagating High-Temperature Spraying Synthesis of Ferrites Hollow Microspheres
Authors: Xu Bao Cai , Yang Run Ze , Duan Rong Xia , Cai Xu Dong , Wang Jian Jiang , Zhang Long
Published: March 2012

The self-propagating high-temperature spraying synthesis (SHSS) route is evaluated for the synthesis of ferrite powders that are subsequently processed towards the manufacturing of high initial magnetic permeability. The powder samples are used for characterization by SEM, EDS and XRD. The results show that the obtained particles are hollow microspheres from nanometer dimension to several micrometers. The phase structure of hollow microspheres is the mixtures of ferrite and Fe2O3. Permittivity and permeability measurements are made on particles dispersed in a paraffin wax matrix. The microsphere is a ferromagnetic matter with both high magnetic loss and high dielectric loss.
Study on Impacting Performance of Bamboo-Plastic Composite
Authors: Ge Zheng Hao , Chen Wei Bo , Tian Pu Jian
Published: March 2012

In order to research impacting strength of bamboo-plastic composite from bamboo powder content, particle size, type of coupling agent, etc. The bamboo-plastic composite is made of extrusion and injection molding process. Results show: when bamboo powder content is 30%, impacting strength of the material is the highest; the bamboo-plastic composite which made of Silane and MAPE has higher impacting strength than others; when PP: HDPE = 2:3, the impacting strength of the bamboo-plastic composite is the highest. Compared with these factors, the coupling agent on impacting strength is the most obvious influence.
Study on Mass Segregation Phenomenon of Al2O3 Ceramic Slurries during Centrifugal Slip Casting
Authors: Yu Jing Yuan , Li Qiang
Published: March 2012

Mass segregation of Al2O3 slurries during centrifugal slip casing has important effect on microstructure and mechanical property of sintered Al2O3 ceramic, so the study on effect of centrifugal process parameters on mass segregation of slurries has significant meaning. Al2O3 ceramic slurries with different solid content varying from 30vol% to 50vol% were prepared. The effect of centrifugal time, centrifugal acceleration and solid content of slurries on green density uniformity of Al2O3 ceramic compacts was studied. The microstructure of centrifuged compacts was observed using scanning electron microscopy (SSX-505). The results show with the increase of centrifugal acceleration and solid content of slurries, the mass segregation of Al2O3 particles with different size increases and decreases, respectively. However, centrifugal time has no obvious effect on green density uniformity. SEM observation shows the green compacts have uniform microstructure when centrifuged at 2860g for 2h with 50vol% slurries.
Local Mean Decomposition Based Bearing Fault Detection
Authors: Li Hui
Published: March 2012

A novel method of bearing fault diagnosis based on local mean decomposition (LMD) is proposed. LMD method is self-adaptive to non-stationary and non-linear signal. LMD can adaptively decompose the vibration signal into a series of product functions (PFs), which is the product of an envelope signal and a frequency modulated signal. Then the envelope spectrum is applied to the selected product function that stands for the bearing faults. Therefore, the character of the bearing fault can be recognized according to the envelope spectrum of product function. The experimental results show that local mean decomposition based envelope spectrum can effectively detect and diagnose bearing inner and outer race fault under strong background noise condition.
Research on the Determination of Calcium Content in Calcium Tablet by Microscale Chemistry Experiment
Authors: Zhuo Yu Guo , Liu Jun
Published: March 2012

Calcium content is an important index to evaluate calcium tablet quality. Calcium content in calcium tablet was determined by micro titration and conventional titration seperately and parallel determination results of microscale chemical laboratory and constants experiment were compared. The results of micro titration were accurate and reliable. Microscale laboratory has such characteristics as obvious phenomena, saving reagents, fast analysis. So the cost was reduced and the innovative ability of students was improved by full compliance with the concept of green chemistry. Microscale laboratory is worth promoting
Cellular Competitive Decision Algorithm for Minimum Ratio Spanning Tree
Authors: Xiong Xiao Hua , Ning Ai Bing
Published: March 2012

Minimum ratio spanning tree(MRST) is the problem of finding a minimum spanning tree when the objective function is the ratio of two linear cost functions(such as the ratio of cost to weight). MRST problem is NP-hard when the denominator is unrestricted in sign. Cellular Competitive decision algorithm(CCDA) is a newly proposed meta-heuristic algorithm for solving combinatorial optimization problems. In this paper, a cellular competitive decision algorithm for MRST is presented. To verify the efficiency of the algorithm, it is been coded in Delphi 7, by which series of instances are tested and results result in good performance.
The Casting Process Design and Simulation of the Rear Wearing Plate of 65ZGB Slurry Pump
Authors: Liu Jin Zhi , Han Yan Jun , Qiao Feng Li
Published: March 2012

Four kinds of casting process were designed for the rear wearing plate of 65ZGB slurry pump in this paper. The casting process design principle, process parameters, points of attention, and the simulation parameters for the kind of high chromium cast iron casting were introduced. Huazhu CAE was used to optimize the casting process and the best casting process was selected. Practical production also showed that the casting process can reduce shrinkage defects of the casting.
The Influence of Decomposition and Slagging of Limestone to Temperature in Convertor
Authors: Li Yong Qing , Li Hong , Guo Luo Fang , Feng Jia , Song Wen Chen
Published: March 2012

The influences of converter temperature on decomposition and slagging of limestone were discussed by industrial tests and numerical calculation. The results showed that heat transfers quickly in the internal of limestone because heat energy is sufficient and surface of limestone is constantly updated in convertor, which makes the temperature of the centre of spherical limestone particle higher than the decomposition temperature, but the decomposition reaction has not arrived at the centre. Consequently, it is deduced that heat transfer is not the restrictive step of limestone decomposition in convertor steelmaking process.
Ti Microalloying Effect on Corrosion Resistance and Thermal Stability of Cu45Zr48Al7 Bulk Metallic Glass
Authors: Yang Xiao Hong , Nie Xi Peng , Jiang Jian Zhong
Published: March 2012

Bulk metallic glasses (BMGs) of Cu45Zr48-xAl7Tix with x= 0, 1.5, and 3 at.% were prepared by copper mould casting. The corrosion resistance of the BMGs with different Ti contents was examined by potentiodynamic polarization tests and weight loss measurements in 1 N NaOH, 1 N H2SO4, 1 N H2SO4 + 0.01 N NaCl and 0.5 N NaCl solutions, respectively. The newly-developed BMGs’ corrosion resistance in Cl-- or both H+ and Cl--ions containing solutions can be greatly enhanced. The influence of Ti addition on glass forming ability (GFA) and thermal stability was investigated by x-ray diffraction and differential scanning calorimetry in detail. The alloy containing 1.5 at.% Ti exhibits the largest GFA, the critical size comes up to 10 mm in diameter.
The Influence of Different Ph Values and High Concentrations of Na2SO4 and NaCl on the Photocatalytic Oxidation (PCO) of Methylene Blue (MB) by Aqueous Suspension of Nano-Sized TiO2
Authors: Jiang Yu Ping
Published: March 2012

To study the PCO of high-salinity organic wastewater, nano-sized TiO2 was used for PCO of MB in solutions with different pH values and high concentrations of Na2SO4 or NaCl. The rates of PCO were monitored by total organic carbon (TOC) measurement. The results showed that the degradation rates increased with increasing pH and decreased as the concentration of Na2SO4 or NaCl increased. The difference of degradation rates in Na2SO4 or NaCl aqueous solutions increased as the ion concentration increased. In the orthogonal experiments, the rates decreased remarkably under certain ratios of the ions concentration. The mechanisms were explored in some detail.
Precise Study and Application of Long Distance Lead Forecast Technology in Tunnel
Authors: Pan Wei Dong , Luo Yong Lei , Gu Ren Guo , Hu Zheng Bo , Mao Fan Cheng
Published: March 2012

It is important to accurately previse the circumstances of the tunnel face in advance to realize a safe construction, because of the polytrope and indefinability to mountain ridge tunnel surrounding rock. However, it is also painful evaluating the detecting zone precisely because of the influence of complex geological conditions and uncertain interpreting outcome. With the study and application on long distance lead forecast in Sheng Ren Moutain tunnel of Mei Zhou-Da Pu highway using TSP48, this paper introduces the principle of parameters electing in data managing and detecting to achieve precisely explaining about the detecting zone. The interpretation is not only more close to practice, but also can provide a piece of reliable data to the construction, which can effectively promote the construction safe.
Double-Equilateral-Triangle Array and Precision Analysis
Authors: Zhang Bing Wen , Zheng Jian , Xiong Chao
Published: March 2012

The location and direction precision is passive acoustic technology of important technical index. Put forward a double-equilateral-triangle array of six elements. According to passive acoustic theory for the location algorithm. Azimuth and elevation Angle is deduced, and the distance of the error formula, through the simulation test, the time delay estimation error analysis of the influence of the location precision. Simulation results show that: double-equilateral-triangle array eliminates the sound velocity and the formation parameters diagonal coordinates estimation precision effect, which have practical significance.
Reliability Index Assignment and Application of Small-Caliber Ammunition
Authors: Wang Jian , Rong Guang , Huang De Wu
Published: March 2012

Reliability index assignment is an important process in reliability design. On account of some engineering designers with less experience and irrationality for reliability index assignment, according to the characteristics of small-caliber artillery ammunition, the efficient principle and methods are introduced for adaption of the reliability index assignment in this paper. Taking the modification process in developing an aero demolition and incendiary bomb as an example, to analyze and improve tactical and technical indexes such as reliability and blasting power, the reliability index assignment and calculation were carried out by experts grading method for the reference to application
Scheme Design and Experimental Verification of Gas Sub-Line Measurement
Authors: Zeng Qing Heng , Gao Zheng Xian , Nie Li Ping , Yu Ying
Published: March 2012

It is well known that the gas flow rate will not be indicated normally in any metering instrument when the really gas pipe rate is less than Flow Meter’s starting flow. This type of leakage indicator is the main factor that affects the measurement shortage of the settlement of the gas transaction, which could affected the production management and economic benefits of the gas company. In this paper, based on the PLC controller technology, the sub-line measurement scheme with double switching mode is designed and accomplished, which is suitable for industrial gas users through rationally designing of controller characteristics and properly adopting the improved split-range control logic. Through testing in site, the sub-line measurement scheme can obviously decrease the measurement shortage of gas pipe network caused by measuring leakage
Steady-State Circular Motion Performance Experiments Research about an All Terrain Vehicle
Authors: Yan Chun Li , Cao Yan Qiong
Published: March 2012

An all terrain vehicle is a kind of special vehicle that travels on all-road. It should have better handling characteristics. In order to evaluate handling performance of an ATV, steady-state circular motion performance experiments about the ATV are done and steady state response characteristic is analyzed. The results show that the ATV studied has under-steering characteristics which is a good turning state and the results correspond with test report about Santana Xi5 on the road test at Journal of Motor Fan in Japan.
Simulation Research on Networked Control System Based on NS-2
Authors: Zhang Xiao Hui , Li Mu , Li Na
Published: March 2012

A key issue in NCS is network transmission. In the research of network control, in some special fields, the system performance could be evaluated based on the real-time character of data transmission in the LAN, but the result gotten in this kind of method isn’t representative. In this paper, a simulation model is firstly established via the NS-2 software under research of network transmission, and then the interval segmentation time-delay and the constant time-delay compensation methods of network control are investigated under this environment. Simulation result validates the effectiveness of the model.
The Full Wave Numerical Solution for Fast Wave Current Drive in Tokamak
Authors: Liu Yan , Gong Xue Yu , Yang Lei , Peng Xiao Wei , Liu Wen Yan
Published: March 2012

This paper uses the full wave method to study the fast wave current drive (FWCD) problem for Ion cyclotron resonance frequency (ICRF). It exists in such plasma bodies as circumferential Tokamak. The research has considered finite Larmor radius effect (FLR) and flattened dispersion. It found the physical model for full wave calculation-full wave method. Through the numerical solution of full wave method, the distribution of electric field strength can be obtained, which is stimulated and produced when fast wave stays in plasma body.
The Study on Mobile Robot Path Planning Based on Frog Leaping Algorithm
Authors: Zhang Zheng Ran , Yin Ji Ying
Published: March 2012

We have proposed a method of robot path planning in a partially unknown environment in this paper. We regard the problem of robot path planning as an optimization problem and solve it with the SFL algorithm. The position of globally best frog in each iterative is selected, and reached by the robot in sequence. The obstacles are detected by the robot sensors are applied to update the information of the environment. The optimal path is generated until the robot reaches its target. The simulation results validate the feasibility of the proposed method.
Analysis of the Effect of Rain Attenuation to the Optical Communication
Authors: Xia Ming , He Feng , Jiang Wei Hong
Published: March 2012

Atmosphere laser communication, as a very good wireless communication method, has been studied by so many people theoretically and experimentally since the invention of laser. In the atmosphere laser communication system the effect of different weather conditions to the transmission was different, there was no theoretical formula of the effect of rainfall to laser communication and only the empirical formula could be achieved by plenty of observations. Since the parameters of empirical formula from different literatures were different, in this article rainfall attenuation was simulated according to the empirical formula under different parameters and the results differed. It was proved that the conditions to the empirical formula could not be incarnated in the formula itself, large numbers of tests were needed to make sure that the parameters were confirmed. In this article rain attenuation under normal weather conditions was presented with some familiar parameters.
Two Methods to SVPWM Harmonic Analysis and the Essential Relation
Authors: Zhu Yuan , Wu Zhi Hong , Chen Guo Qiang
Published: March 2012

Aiming at the problem of the harmonic of the space vector pulse width modulation (SVPWM), the analysis methods to SVPWM are studied. After introducing the principle of SVPWM, the paper discusses the harmonic distortion factor (HDF) that is an important assessing index of the harmonics. The two analysis methods- ripple current method and error triangle method – are discussed, and the relation between them is revealed. Finally, the micro HDF of the random zero distribution PWM (RZDPWM) is computed based on the two methods and analyzed.
A Test Study of Wet Dual Clutch Transmission during Vehicle Launch
Authors: Sun Wei , Hua Yu Long , Liu Guo Qiang
Published: March 2012

This paper focuses on the model and analysis of wet dual clutch transmission (DCT) during vehicle launch. Two evaluation indexes, slipping friction work and degree of jerk, is presented, and a single clutch control strategy is established and has been validated after applied for an experimental vehicle equipped with a wet dual clutch transmission.
Monitoring Aero-Engine Fuel Flow Based on Neural Net
Authors: Ji Zhao Hui , Jiang Shen
Published: March 2012

Engine fuel flow is one of the most important parameters of aero-engine performance, which can accurately reflect the actual condition of aero-engine. It'is possible to monitor the aero-engine fuel flow (FF) by reading the data of QAR (Quick Access Recorder). However, it's difficult to monitor the actual condition of aero-engine through the traditional method because of the vast amount of QAR data and the complexity of the engine itself. Feed forward process neural network is adopted to monitor the QAR-based aero-engine fuel flow . The results of the simulation are acceptable and show that the Neural Net model is an effective method to monitor aero-engine conditions.
Electrophoretic Deposition of Bioactive Glass Coatings on Ti12Mo5Ta Alloy
Authors: Fauré Joël , Drevet Richard , Potiron Sylvain , Gordin Doina Margareta , Oudadesse Hassane , Gloriant Thierry , Benhayoune Hicham
Published: March 2012

Titanium alloys used in orthopedic surgery are usually coated with hydroxyapatite to improve their biocompatibility and osseointegration. Bioactive glasses (BGs) are an interesting alternative to hydroxyapatite for the production of prosthetic coatings due to their osteoproductive property (Class A bioactivity) and to their resorbability. However the classical techniques used to obtain prosthetic coatings are not suitable in the case of BGs. In this study bioactive glass coatings are obtained by electrophoretic deposition on a Ti12Mo5Ta alloy. These coatings were obtained from ethanol suspensions of two different bioglass powders: a Sol-Gel derived 58S and a Melting-Quenching derived 46S. Scanning electron microscopy observations were used to characterize the coatings (morphology and thickness) and the coating/substrate interfaces. The chemical composition of the coatings was studied by X-ray microanalysis and X-ray maps were performed to characterize the spatial distributions of all elements composing the coatings.
AC Electrophoresis, a New Technique for Deposition of Ceramic Nanoparticles; Introduction, Application and Mechanism
Authors: Riahifar Reza , Raissi Babak , Marzbanrad Ehsan , Zamani Cyrus
Published: March 2012

Deposition of ceramic nanoparticles (dispersed in non-aqueous suspension) on in-plane electrodes and under the influence of AC electric fields in the frequency range of 0.01 Hz - 10 kHz is investigated. Analysis of the particle response to the applied field is a difficult task due to the mutual effect of electric and hydrodynamic forces which are present in the system. In this work, however, we show the possibility of dividing the frequency range into four domains with four distinct governing mechanisms. Possible mechanisms are suggested and dominant forces are determined for each domain. In situ optical microscopy observations are used for visualization of nanoparticles´ movement dispersed in liquid medium. These observations show that applying AC electrophoresis at frequencies below 10 kHz is an effective way for manipulating ceramic nanoparticles and device fabrication.
Parameter Study on Laser Surface Finishing with 2D Scan Head
Authors: Ukar Eneko , Tabernero I. , Liebana F. , Saitua I. , Villaseca R. , Sobrado J.
Published: March 2012

In recent years laser polishing is becoming an alternative for automated surface finishing of dies and molds. This process involves melting and subsequent solidification of the material. Depending on the initial topography, the energy density necessary to reduce surface asperities can cause excessive heat damage, and thus, limit the applicability of the process. The work presented here focuses on the use of a high quality laser beam, with a spot diameter below 50 microns driven by a 2D scanner for processing of materials typically used in dies and mold manufacturing. So, the highly focused beam ensures minimal thermal damage, and the scan head allows high productivity rates. A new processing strategy based on two stages surface processing was developed to process topographies with strong directionality.
Tensile Ductility of Electron Beam Welded Titanium Alloys
Authors: Pasang Timotius , Sabol J.C. , Misiolek Wojciech Z. , Mitchell Ryan , Short Andrew B. , Littlefair G.
Published: March 2012

Butt welded joins were produced between commercially pure (CP) titanium and various titanium alloys using an electron beam welding technique. The materials used were CP Ti, Ti-6Al-4V (Ti64) and Ti-5Al-5V-5Mo-3Cr (Ti5553). Grain boundary structures, mechanical properties, compositional profiles across the welds and fracture modes are presented. CP Ti has always been known for its excellent weldability, Ti64 has good weldability and, preliminary results indicated that Ti5553 alloy is also weldable.
Comparison between FEM and Experimental Results in the Upsetting of Nano-Structured Materials
Authors: Luis-Pérez C.J. , Puertas Ignacio , Salcedo Daniel , León Javier , Pérez Ivan
Published: March 2012

Over recent years, some severe plastic deformation processes have been developed with the aim of obtaining a material with sub-micrometric or even nanometric grain size, such as: ECAE (Equal channel angular extrusion) and HPT (High pressure torsion) among many others. The main aim of this present study is to analyse the upsetting of the 5083 Al-Mg-Mn alloy, which had been previously deformed by ECAE. Different processing temperatures will be used and the final properties of the resulting material will be determined.
Kerf Profile Modelling in Abrasive Waterjet Milling
Authors: Alberdi A. , Rivero A. , Carrascal A. , Lamikiz Aitzol
Published: March 2012

The Abrasive Water Jet milling process is demonstrated to be an efficient technology for milling low machinability materials. Although its capability is demonstrated, the industrial application of this technology requires a depth control, for which a work focused in process modelling is needed. This research work introduces a model to predict the kerf shape in AWJ slot milling in Aluminium 7075-T651 in terms of four important process parameters: pressure, abrasive mass flow rate, stand-off distance and traverse feed rate. A hybrid evolutionary approach was employed for modelling the profile through two parameters: the maximum cutting depth and the full width at half maximum. Both the maximum depth and the width were also modelled as a function of aforementioned process parameters based on Analysis of Variance and regression techniques. Combination of two models resulted in an adequate strategy to predict the kerf shape for different machining conditions.
Characterization of Al65.0Cu32.9Co2.1 Alloy Containing Nanofibres
Authors: Krawczyk Jacek , Bogdanowicz Włodzimierz , Dercz Grzegorz , Gurdziel Wojciech
Published: March 2012

Microstructure of terminal area of Al65Cu32.9Co2.1ingots (numbers indicate at.%), obtained via directional solidification was studied. Scanning Electron Microscopy, Transmission Electron Microscopy and X-ray powder diffraction were applied. Point microanalysis by Scanning Electron Microscope was used for examination of chemical compositions of alloy phases. It was found that tetragonal θ phase of Al2Cu stoichiometric formula was the dominate phase (matrix). Additionally the alloy contained orthogonal set of nanofibres of Al7Cu2Co T phase with the average diameter of 50-500 nm and oval areas of hexagonal Al3(Cu,Co)2H-phase, surrounded by monoclinic AlCu η1phase rim. Inside some areas of H-phase cores of decagonal quasicrystalline D phase were observed.
Microstructural Changes Induced during Hydrogen Charging Process in Stainless Steels with and without Nitrided Layers
Authors: Gołębiowski Bartosz , Świątnicki Wiesław
Published: March 2012

The purpose of this study is to analyze the effect of glow discharge nitriding on hydrogen degradation of two types of steels: two-phase austenitic-ferritic and single-phase austenitic. The nitriding process resulted in formation of surface layers composed of expanded austenite (S phase), and in the case of two-phase steel of expanded austenite and expanded ferrite. Microstructural changes occurring under the influence of hydrogen on steels without and with nitrided layers were investigated with the use of scanning (SEM) and transmission (TEM) electron microscopy techniques. It was shown that the density of cracks formed during cathodic hydrogen charging is higher on the surface of the non-nitrided steels compared to the nitrided steels after identical hydrogen charging process. Moreover in non nitrided steel hydrogenation leads to considerable increase of dislocation density, which results from the high concentration of hydrogen absorbed to the steel during its cathodic charging. This leads in turn to high stress concentration and local embrittlement giving rise to cracks formation. Conversely nitriding reduces the absorption of hydrogen and prevents structural changes resulting in hydrogen embrittlement. The conducted studies show that glow discharge nitriding can be used to increase resistance to hydrogen embrittlement of austenitic and austenitic ferritic stainless steels.
Study of Silicon Nanoparticles Formation in Silicon Nitride
Authors: Ratajczak Jacek , Hejduk Krzysztof , Lipiński Marek , Piotrowski Tadeusz , Płuska Mariusz , Łaszcz Adam , Czerwiński Andrzej
Published: March 2012

We present results of the study on the silicon nanoparticles formation in multilayer silicon nitride structures. These structures consist of pairs of stoichiometric silicon nitride dielectric layers (SiNx) and silicon rich nitride layers (SRN). Silicon nanocrystals precipitate from the SRN layer during annealing at high temperatures (1000 °C or 1100 °C). High resolution transmission electron microscopy has been applied for investigation of the nanocrystals formation. Surface photovoltage spectroscopy technique was used for the spectral characterization of prepared structures
Review ofEuthera(Diptera: Tachinidae) in North America with the description of a new species
Authors: O'Hara James E.
Published: March 2012

EutheraLoew is a small but cosmopolitan genus of Tachinidae with distinctive smoky black cross bands on the wings. There are three described species in North America,Euthera bicolorCoquillett,Euthera setifaciesBrooks, andEuthera tentatrixLoew. A new species from California and New Mexico is described asEuthera woodisp. nov.in honour of dipterist D. Monty Wood. A key and digital images are provided for the identification of the four species, and the three previously described species are diagnosed.Oebalus mexicana(Sailer) andNezara viridula(L.) (Heteroptera: Pentatomidae) are new host records forE. bicolorandE. tentatrix, respectively.
Spatial-temporal variations in surface ozone in Northern China as observed during 2009–2010 and possible implications for future air quality control strategies
Authors: Tang G. , Wang Y. , Li X. , Ji D. , Hsu S. , Gao X.
Published: March 2012

Abstract. The Project of Atmospheric Combined Pollution Monitoring over Beijing and its Surrounding Areas, was an intensive field campaign conducted over Northern China between June 2009 and August 2011 to provide a comprehensive record of ozone (O3) and nitrogen oxides (NOx) and contribute to an in-depth understanding of air pollution in Northern China and its driving forces. In this campaign, 25 stations in an air-quality monitoring network provided regional-scale spatial coverage. In this study, we analyzed the data on O3 and NOx levels obtained at 22 sites (out of 25 sites due to data availability) over Northern China between 1 September 2009 and 31 August 2010. Our goal was to investigate the O3 spatial-temporal variations and control strategy in this area. Significant diurnal and seasonal variations were noted, with the highest concentrations typically found at around 03:00 p.m. (local time) and in June. The lowest concentrations were generally found during early morning hours (around 06:00 a.m.) and in December. Compared with July and August, June has increased photochemical production due to decreased cloud cover coupled with reduced O3 loss due to less dry deposition, inducing an O3 peak appearing in June. The averaged O3 concentrations were lower in the plains area compared with the mountainous area due to the titration effects of high NOx emissions in urban areas. When the characteristics of O3 pollution in different regions were distinguished by factor analysis, we found high levels of O3 that exceeded China's National Standard throughout the plains, especially over Beijing and the surrounding areas. An integrated analysis with emissions data, meteorological data, and topography over Northern China found that the meteorological conditions were the main factors that dominated the spatial variations of O3, with the presence of abundant emissions of precursors in this area. The smog production algorithm and space-based HCHO/NO2 column ratio were used to show the O3-NOx-VOCs sensitivity and examine the control strategy of O3 over Northern China. The results show that summer O3 production in the plains and northern mountainous areas was sensitive to VOCs and NOx, respectively. The presented results are intended to provide guidance for redefining government strategies to control the photochemical formation of air pollutants over Northern China and are relevant for developing urban agglomerations worldwide.
Numerical modelling of climate change impacts on freshwater lenses on the North Sea Island of Borkum
Authors: Sulzbacher H. , Wiederhold H. , Siemon B. , Grinat M. , Igel J. , Burschil T. , Günther T. , Hinsby K.
Published: March 2012

Abstract. A numerical variable-density groundwater model is set up for the North Sea Island of Borkum to estimate climate change impacts on coastal aquifers and especially the situation of barrier islands in the Wadden Sea. The database includes information from boreholes, a seismic survey, a helicopter-borne electromagnetic survey (HEM), monitoring of the freshwater-saltwater boundary by vertical electrode chains in two boreholes, measurements of groundwater table, pumping and slug tests, as well as water samples. Based on a statistical analysis of borehole columns, seismic sections and HEM, a hydrogeological model is set up. The groundwater model is developed using the finite-element programme FEFLOW. The variable-density groundwater model is calibrated on the basis of hydraulic, hydrological and geophysical data, in particular spatial HEM and local monitoring data. Verification runs with the calibrated model show good agreement between measured and computed hydraulic heads. A good agreement is also obtained between measured and computed density or total dissolved solids data for both the entire freshwater lens on a large scale and in the area of the well fields on a small scale. For simulating future changes in this coastal groundwater system until the end of the current century we use the climate scenario A2, specified by the Intergovernmental Panel on Climate Change and in particular the data for the German North Sea coast. Simulation runs show proceeding salinization with time beneath the well fields of the two waterworks Waterdelle and Ostland. The modelling study shows that spreading of well fields is an appropriate protection measure against excessive salinization of the water supply until the end of the current century.
Large sensitivity of a Greenland ice sheet model to atmospheric forcing fields
Authors: Quiquet A. , Punge H. J. , Ritz C. , Fettweis X. , Kageyama M. , Krinner G. , Salas y Mélia D. , Sjolte J.
Published: March 2012

Abstract. The prediction of future climate and ice sheet evolution requires coupling of ice sheet and climate models. Before proceeding to a coupled setup, we propose to analyze the impact of model simulated climate on an ice sheet. Here, we undertake this exercise for a set of regional and global climate models. Modelled near surface air temperature and precipitation are provided as upper boundary condition to the GRISLI (GRenoble Ice Shelf and Land Ice model) hybrid ice sheet model (ISM) in its Greenland configuration. After 20 kyr of simulation, the resulting ice sheets highlight the differences between the climate models. While modelled ice sheet sizes are generally comparable to the observed ones, there are considerable deviations among the ice sheets on regional scales. These can be explained by difficulties in modelling local temperature and precipitation near the coast. This is especially true in the case of global models. But the deviations of each climate model are also due to the differences in the atmospheric general circulation. In the context of coupling ice sheet and climate models, we conclude that appropriate downscaling methods will be needed and systematic corrections of the climatic variables at the interface may be required in some cases to obtain realistic results for the Greenland ice sheet (GIS).
Evaluation of a Culturally Adapted Training in Indigenous Mental Health and Wellbeing for the Alcohol and Other Drug Workforce
Authors: Hinton Rachael , Nagel Tricia
Published: March 2012

Indigenous Australians have high rates of mental illness comorbid with substance misuse. The complex needs of this client group create challenges for the alcohol and other drug (AOD) workforce. This paper describes the outcomes of an Indigenous-specific “Yarning about Mental Health” training for the AOD workforce to strengthen knowledge and skills in mental health approaches and in their engagement with Indigenous clients. The training provides culturally adapted strategies and tools for understanding mental health, promoting wellbeing, and delivering brief interventions in the substance misuse setting. A nonexperimental evaluation which incorporated pre-post questionnaires was conducted with workshop participants attending one of four trainings. The training was perceived to be highly appropriate and helpful in participants’ work with Indigenous AOD clients. There was significant improvement in confidence and knowledge related to Indigenous mental health and wellbeing and qualitative data supported these positive outcomes. This study supports the need to blend Indigenous concepts of health and wellbeing with non-Indigenous ways of understanding and treating illness in order to develop services which are appropriate to Indigenous peoples. It also suggests research is required to understand whether self-reported increases in knowledge and confidence can translate into behavioural changes in participants' teaching and practice of culturally competent care and to improved client outcomes.
Recent Progress in Silicon Photonics: A Review
Authors: Fang Zhou , Zhao Ce Zhou
Published: March 2012

With the increasing bandwidth requirement in computing and signal processing, the inherent limitations in metallic interconnection are seriously threatening the future of traditional IC industry. Silicon photonics can provide a low-cost approach to overcome the bottleneck of the high data rate transmission by replacing the original electronic integrated circuits with photonic integrated circuits. Although the commercial promise has not been realized, this perspective gives huge impetus to the development of silicon photonics these years. This paper provides an overview of the progress and the state of the art of each component in silicon photonics, including waveguides, filters, modulators, detectors, and lasers, mainly in the last five years.
Education in Global Health: Experience in Health-Promoting Schools Provides Trainees with Defined Core Competencies
Authors: Moodley Shreya , Kasangaki Arabat , Macnab Andrew J.
Published: March 2012

Introduction. Medical education has defined essential “universal” core competencies. The value of global health education gained through participation in a health-promoting school project was assessed using Canada’s CanMEDS roles and competencies.Methods. The project involved health care trainees in delivery of “Brighter Smiles,” a global health education program addressing children’s oral health in Canada and Uganda based on the WHO health-promoting (HP) school model. Multidisciplinary teams first visit a Canadian First Nations community for an introduction to HP schooling, team building, and experience working in different cultural environments and then have 4–6 weeks of global health project delivery in rural HP schools in Uganda in partnership with local College of Health Sciences trainees/faculty. Learning opportunities afforded were evaluated by conventional questionnaire and pilot categorization against the 7 CanMEDS roles (divided into 126 core competencies).Results. All collaborator and health Advocate competencies and 16/17 of the communicator roles were addressed. Overall, project experience included 88 (70%) of the 126 competencies.Conclusions. This pilot suggests CanMEDS criteria can be used to effectively evaluate trainee participation in HP school program delivery, allowing the comprehensive educational opportunities to acquire global health knowledge and skills reported by conventional evaluation to be formally categorized against defined educational roles and competencies.
A new subspecies of Bulbophyllum (Orchidaceae, Bulbophyllinae) from The Society Islands
Authors: Margońska Hanna B.
Published: March 2012

A new subspecies of the Bulbophyllum tahitense (Orchidaceae), from The Society Islands (French Polynesia) is proposed. A new subspecies is described and illustrated. Keys to taxa of Society Islands genus Bulbophyllum, is added.
Measurement of Autophagic Activity in Mammalian Cells
Authors: Menzies Fiona M. , Moreau Kevin , Puri Claudia , Renna Maurizio , Rubinsztein David C.
Published: March 2012

Macroautophagy (referred to herein as autophagy) is a process in which cells engulf portions of cytoplasm in double‐membrane vesicles called autophagosomes. These autophagosomes can also capture protein oligomers associated with neurodegenerative diseases, infectious agents (like bacteria), and even organelles (like mitochondria). Autophagosomes are transported along microtubules towards the microtubule organizing center of cells, where the lysosomes are clustered. After fusion and content exchange with lysosomes, the autophagosome cargo is degraded by lysosomal hydrolases. This unit describes some of the core autophagy assays that are in common use, including LC3 immunoblotting, light microscopy analyses of different stages of autophagy, electron microscopy, and an assay of autophagy substrate accumulation. Autophagy assays should generally not be performed alone, but should be accompanied by complementary assays to enable robust interpretations. Curr. Protoc. Cell Biol. 54:15.16.1‐15.16.25. © 2012 by John Wiley & Sons, Inc.
Analysis of Nonsense‐Mediated mRNA Decay in Saccharomyces cerevisiae
Authors: Kebaara Bessie W. , Baker Kristian E. , Patefield Krista D. , Atkin Audrey L.
Published: March 2012

Nonsense‐mediated mRNA decay is a highly conserved pathway that degrades mRNAs with premature termination codons. These mRNAs include mRNAs transcribed from nonsense or frameshift alleles as well as wild‐type mRNA with signals that direct ribosomes to terminate prematurely. This unit describes techniques to monitor steady‐state mRNA levels, decay rates, and structural features of mRNAs targeted by this pathway, as well as in vivo analysis of nonsense suppression and allosuppression in the yeast Saccharomyces cerevisiae. Protocols for the structural features of mRNA include analysis of cap status, 5′ and 3′ untranslated region (UTR) lengths, and poly(A) tail length. Curr. Protoc. Cell Biol. 54:27.3.1‐27.3.39. © 2012 by John Wiley & Sons, Inc.
Laser Spectrometric Techniques in Analytical Atomic Spectrometry
Authors: Axner Ove , Galbács Gábor
Published: March 2012

The main purpose of this article is to describe the theory, instrumentation, and analytical performance of laser analytical atomic spectrometry, focusing on absorption, fluorescence, and ionization techniques. The structure of the article is such that it first provides an outline of the theory of light‐matter interactions that prevail for each type of technique as well as of the most common modulation techniques, primarily, wavelength modulation (WM). This is followed by a section that covers the most important types of instrumentation used. The article finally provides a detailed discussion on the specific instrumentation, mode of operation, use, performance, and applications (both analytical and diagnostic) of each technique.

In terms of laser atomic absorption, the focus of the discussion is on the use of approaches to enhance the detection capability by either reducing the amount of noise (as is done by the wavelength modulation absorption spectrometry (WMAS) technique) or by providing an extended interaction length (giving rise to cavity‐enhanced absorption spectrometry (CEAS) techniques in general, and cavity ring‐down spectrometry (CRDS) in particular). Laser atomic fluorescence techniques (often referred to aslaser‐excited atomic fluorescence spectrometry(LEAFS)) as well as laser ionization techniques (termed eitherlaser‐enhanced ionization(LEI) orresonance ionization spectrometry(RIS)) are also covered in some detail. It is shown that several of these techniques are capable of detecting a variety of elements in liquid samples down to low picogram per milliliter (pg mL−1) or parts‐per‐trillion (ppt) concentrations and in low femtogram amounts. Also other properties of the techniques, e.g. selectivity and linear dynamic range (LDR), are in general superior to those of conventional (nonlaser‐based techniques).
Amylase: Phadebas test, saliva
Authors: Mullen Carrie
Published: March 2012

Phadebas is a presumptive test used in forensic science examinations for the detection of areas of possible saliva staining. The test is designed to react with amylase, a digestive enzyme present in saliva. Some caution is required when a positive test result is obtained, however, as saliva is not the only substance to contain amylase. Phadebas, therefore, cannot confirm that saliva is present upon the surface of interest, it simply suggests that there is amylase activity present. When interpreting a positive casework result some consideration must therefore be given to what substances other than saliva could be present and reacting with the Phadebas and also to the positioning of the staining; whether it fits with the transfer method described in the allegation and whether there might also be other innocent mechanisms which could explain the presence of the presumed saliva staining.
Stabel Isotope Analysis: Bone and Teeth
Authors: Meier‐Augenstein Wolfram , Kemp Helen F
Published: March 2012

In most of the different body deposition scenarios but for cremation, bone and teeth are typically the human remains that remain intact the longest after death has occurred. In the absence of any distinguishing features or other evidence that could help with positive victim identification, stable isotope profiles or signatures can provide useful information about a person's diet and geographic life trajectory, which can bring focus to an investigation involving unidentified victims of serious crime or mass disasters. No matter what the case circumstance, victim identification is of paramount importance to provide closure for next of kin and to help dealing with legal processes ensuing from the death of a person. In cases of serious crime, identification of the victim is a major stepping stone toward identifying the perpetrator/s.
Stable Isotope Analysis: Drugs
Authors: Carter James F. , Meier‐Augenstein Wolfram
Published: March 2012

The stable isotopic composition of materials, often referred to as the “isotopic profile” or “isotopic signature”, provides a means to associate or discriminate samples with different geographical or synthetic orginis. Studies have measured the range and variation in the isotopic composition of seized controlled drugs and examined the effects of synthesis and chemical modification in order to assist the interpreting of data from samples of unknown origin. The technique has been applied to a range of natural, modified‐natural and synthetic controlled substances for law enforcement and forensic intelligence purposes.