bluuebunny/crossref_metadata_2025 huggingface dataset:
Polypropylene/High Density Polyethylene/Glass Fibre/Nanokaolinite Clay Composites - A Novel Material for Light Weight Manufacturing Systems
Authors: Anjana R. , Krishnan Asha , George Tresa Sunitha , George K.E.
Published: September 2013

Polypropylene (PP) and high density polyethylene (PE) and are two widely used standard plastics which can be combined to give attractive properties. In this study a selected blend of these plastics is further modified by incorporating nanokaolinite clay and e-glass fibre into the matrix, thereby converting the blend into a fibre-nanomaterial-reinforced-plastic (FNRP). In this manner the PP-PE blend can be upgraded for more critical applications requiring strength and light weight. Melt compounding technique was used to prepare FNRP and samples for testing were prepared by injection molding. Most reports suggest that kaolinite clay, though cheap and abundantly available is difficult to disperse in polymer matrix compared to costly montmorillonite clay. This difficulty is overcome by surface modification of nanokaolinite clay by an organic group and the effect is studied using mechanical properties, thermal stability, dynamic mechanical and rheological behavior. Morphological characterization is done by scanning electron microscopy. This study shows that nanoclay and e-glass fibre synergistically modify PP-PE blend. The resulting composite can be preferentially utilized for manufacturing parts of space crafts, ships, submarines etc.
The Influence of the Laser Cutting System Performance on Cutting Quality
Authors: Chang Ye , Ji Jin Jun , Yin Hong Mei
Published: September 2013

Laser cutting is widely applied in the modern industry. With the development of production, there is a higher demand for the improvement of cutting quality. Hence, investigating the influence of laser cutting parameters on the sheet quality is of important significance in the quality control of the sheet processing. So, this research mainly investigated the influence of the cutting system performance on the cutting quality. First, the experiment was conducted to investigate these system parameters such as mode of light velocity, polarity, nozzle, and airflow etc. Then, by contrasting the experimental data, the optimal system parameter was obtained.
Dynamics Analysis of ADCP Carrier and its Mooring System
Authors: Yu Zhen Jiang , Dai Yuan , Huang Peng , Zhang Xiao Peng , Chang Zong Yu
Published: September 2013

Acoustic Doppler Current Profiler (ADCP) is one effective instrument to measure the sea current and is widely utilized in oceanographic research and ocean engineering. Some structure or frame is utilized to carry or hold ADCP in mooring system. This paper studies the hydrodynamics of different kinds of ADCP carriers and the motion of mooring system with ADCP carriers. By applying Fluent software external flow field of ADCP carrier is analyzed. Meanwhile, the velocity distribution and pressure distribution are obtained. Drag coefficients of ADCP carrier are used to analyze the mechanics and profile of mooring system with ADCP. Designing the ADCP carrier and mooring system is very useful which can provide theoretic basis for current data analysis.
Research on the Embedded Nondestructive Testing System of Oil-Well Tubing
Authors: Fang Jing Xiang , Wang Tai Yong , Jing Lu Yang , Zhang Pan
Published: September 2013

A Embedded Nondestructive Testing System of Oil-well Tubing based on the method of magnetic flux leakage (MFL) is designed. The function and structure of each part of the system are analyzed. The overall structure of the system and the function of each module are analyzed. The visual data processing and analysis program of magnetic flux leakage signal based on embedded Linux Operating System is designed, and the running interface of the system is given.
Stator Current-Based Locomotive Traction Motor Bearing Fault Detection
Authors: Yang Jiang Tian , Zhao Wen Yu , Lee Jay
Published: September 2013

Rolling-element bearings are critical components in locomotive traction motors. A reliable online bearing fault-diagnostic technique is critically needed to prevent motor systems performance degradation and malfunction. Motor bearing failure induces vibration, resulting in the modulation of the stator current. Compared with conventional monitoring techniques such as vibration monitoring or temperature monitoring, stator current-based monitoring offers significant economic benefits and implementation advantages. In this paper, a novel approach to locomotive traction motor current signature analysis based on wavelet packet decomposition (WPD) of stator current is presented. The effectiveness and practicability of the proposed method is verified by locomotive running tests.
Neural Networks Based Attitude Decoupling Control for AUV with X-Shaped Fins
Authors: Sun Xiu Jun , Shi Jian , Yang Yan
Published: September 2013

Attitude control in three-dimensional space for AUV (autonomous underwater vehicle) with x-shaped fins is complicated but advantageous. Yaw, pitch and roll angles of the vehicle are all associated with deflection angle of each fin while navigating underwater. In this paper, a spatial motion mathematic model of the vehicle is built by using theorem of momentum and angular momentum, and the hydrodynamic forces acting on x-shaped fins and three-blade propeller are investigated to clarify complex principle of the vehicle motion. In addition, the nonlinear dynamics equation which indicates the coupling relationship between attitude angles of vehicle and rotation angles of x-shaped fins is derived by detailed deduction. Moreover, a decoupling controller based on artificial neural networks is developed to address the coupling issue exposed in attitude control. The neural networks based controller periodically calculates and outputs deflection angles of fins according to the attitude angles measured with magnetic compass, thus the vehicles orientation can be maintained. By on-line training, twenty four weights in this controller converged according to index function.
Design of Machine Operating Panel Based on CAN Bus for the PC-Based CNC System
Authors: Wu Kai Fa , Wang Tai Yong , Dong Jing Chuan , Liu Qing Jian , Lin Fu Xun , Liang Ruo Yu
Published: September 2013

Machine operating panel is an important component of controlling machine and the human-computer interaction. As CAN bus has the remote and stable transmission characteristic, the remote IO board is designed. A design of machine operating panel based on CAN bus for the PC-based CNC system is introduced, including the overall architecture design and software design method. This paper focuses on the remote IO board, as well as the practical application in the CNC system of TDNC-H8.
Study of Dynamics Characteristics for Precision Motor Spindle System
Authors: Wang Hong Jun , Han Qiu Shi , Zheng Jun
Published: September 2013

The structure of a precision high speed spindle system is described. The shaft and bearing finite element models of the spindle system are constructed by using the Timoshenko beam element and the spring-damper unit. The static mechanical properties of spindle system and modal analysis are studied with different spring element arrangement forms. The results showed that the rotary speed designed was far lower than the critical rotary speed which matched with the low-order modal natural frequency of the spindle,so resonance vibration could be effectively avoided.
Modal Analysis and Numerical Solution in Cable Drilling System
Authors: Bu Chang Gen , Li J.W. , Long B.
Published: September 2013

Cable percussive drill is an important drilling machine in the construction of large diameter pile foundation, and complicated dynamic system. However, the design of cable percussive drill is mainly relied on empirical methods or simplified formulas, the dynamic characteristics of coupling system has not been fully understood. Based on the special conditions, the two degrees of freedom dynamic system coupling with buffering mechanism and bit is analyzed, and the vibration differential equation is built. Finally, the modal frequency of system is obtained by numerical method, and the correlation between the modal frequency of system and the structure parameters is built. The result develops the design theory of cable percussive drill and provides valuable preferences for the optimal design.
Study on the Curve Reconstructing in the Process of Blade Repairing
Authors: Wang Tao , Liu Yi Liu , Tang Jie , Wang Hao , Wang Li Wen
Published: September 2013

the aero-blades are often easy to be damaged because of the severe working conditions, and the invading of out objects. Repairing is preferred to replacing with a new one due to the very high expense. The mathematical model of cross section curve is very important to the process of repairing the blade and to the analysis for the working performance of repaired blade. The method of remodeling the curve of cross section is studied including scanning the broken blade, denoising the data points, analyzing the points of cross section and dividing them into four assembles, and fitting them with adaptive mathematical equations. Lastly, the future research plans are given.
The Application of Biomimetic Materials on Industry Design Research
Authors: Li Xiao Dong
Published: September 2013

For thousands of years, people have been in nature to make use of our natural materials, among them some are harder than iron and steel, some are superior than the best optical device, what let human more amazing is that the natures reasonable application of these materials. Through the study and research of nature, humans create the biomimetic material to meet the demand of industrial design; they were widely used in the field of industrial design according to the different characteristics. Application of these new materials opened up a brand-new road for the development of industrial design.
The Curved Surface Fitting and Optimization of Scattered Points' Data Based on the Given Surface Tolerance and Fairing
Authors: Zhang Zhi Qiang , Wang Wen Jin , Zhang Jing , Zhao Jian , Sun Li Ying
Published: September 2013

The curved surface simple expression which met a given tolerance and fairing can be obtained under the conduction that the surface tolerance and fairing had been predetermined by the fitting optimization of the scattered points of the origin curved surface. The genetic factor and evaluation function are designed for the optimized expression of surface is acquired. The validity of the solution is verified by comparing the computed error between fitting optimization surface and the original surface through the numerical simulation.
Study on the 5-Axis Linked-Blade Grinder Based on Online Detection Simulation Technology
Authors: Zheng Yuan , Liu Fu Li , Xu Bing , Cheng Kan , Liu Wei
Published: September 2013

A new Online Detection Simulation Technology for 5-Axis Linked-Blade Grinder was presented, Using the modeling of virtual inspection environment, the obtaining of inspection information and the driving of the virtual machine. The experimental results show that the simulation technology provides high precision and can be used in wide fields.
Drawing Progressive Die Design for Shell Parts
Authors: Guo Guo Yi
Published: September 2013

The deep drawing progressive forming process was analyzed by introducing the drawing progressive die design of shell parts. The drawing progressive design, layout design and mold structure was described detailedly.
Influence of Cutting Conditions on the Width of Adiabatic Shear Bands: An Investigation Using Finite Element Simulation
Authors: Cui Tao , Zhao Hong Wei , Tian Ye , Liu Chuang
Published: September 2013

In this paper, a novel model combining the microstructure prediction model and a modified constitutive model of the Johnson-Cook (JC) model was developed and embedded into FEM software via the user subroutine. The chip formation and microstructure evolution in high speed cutting of Ti-6Al-4V alloy were simulated. The results indicated that dynamic recrystallization mainly happened in adiabatic shear bands (ASBs), where the grain size had a big decline. Then FEM simulations were carried out to investigate the effect of cutting velocity, uncut chip thickness, and the rake angle on the ASBs width of the serrated chips. It can be concluded that the width of ASB increases with the increasing of cutting depth and cutting velocity, and decreases with the increasing of rake angle of the tool.
Research of Surface Formation of Two Dimensional Ultrasonic Vibration Assisted Grinding of Nano-ZrO2 Ceramics
Authors: Yan Yan Yan , Wang Qi , Zhao Bo
Published: September 2013

Two dimensional ultrasonic vibration assisted grinding (TDUVG) is analyzed based on theoretical analysis of the cutting trace of a grain in the finished surface, and it gives the kinematical model of single grit during TDUVG, and the condition of the separate cutting is established, so two dimensional ultrasonic vibration are introduced into the system, which helps to form good machining way. Then TDUVG is applied in the ultra-precise machining of nanoZrO2 ceramics, and grinding experiments on surface quality of nanoZrO2 ceramics were carried out using diamond grinding both with and without ultrasonic vibration. Experimental results show that the surface quality after two dimensional ultrasonic assisted grinding is superior to that of diamond grinding. As a result, it is suitable for the ultra-precise machining of ceramics.
The Influences of Alternating Magnetic Field to the Microstructure and Mechanical Property of Diamond Agglomerations
Authors: Wang San Xing , Fu Yu Ming , Guo Jian Long , Huo Li Jun
Published: September 2013

By numerical and experimental methods, heat alternating magnetic treatment of diamond agglomerations were researched, the microstructure and mechanical properties before and after treatment were also analysed comparatively. The numerical analysis shows: the alternating magnetic field stress is bound to make solid-state microstructure change, this intensified magnetic shock can broke dendrites and tangles organization within the organization and enables organization uniform, dense. The experiments indicate: After heat alternating magnetic treatment, the HRB hardness of test pieces matrix is improved 4.34, impact toughness enhanced more than 25%, matrix organization became uniformity and density. Results revealed that alternating magnetic treatment can be an effective method for improving the performance of the diamond agglomeration.
The Research of Anti-Counterfeiting Labels Based on Reflected Light Interference Color of Glass Beads
Authors: Huang Xiao Jun , Luo Shi Yong , Zhang Xin Lin , Xu Wen Cai
Published: September 2013

Application of anti-counterfeiting technology in the label has been widespread. This paper has studied the security label based on reflected light interference color, tells the story of its structure and preparation method, and application of glass beads in the label are detailed.
Springback Behavior of Advanced High Strength Steel (AHSS) CP800
Authors: Zhang Mei , Zhang Jun , Ning Yu Xiang , Wang Tao , Wan Zi
Published: September 2013

800MPa grade Advanced High Strength Steels (AHSS), Complex Phase steel CP800, containing microalloying elements, are chosen to test the stamping properties in different test conditions and compared with traditional high strength low alloy (HSLA) steels HSLA S700MC. Tensile test, and HAT shape stamping test are taken to investigate the properties of the materials. Test results indicate that the studied 800MPa grade AHSS shows a better strength ductility balance compared with the reference HSLA steels. Under the same HAT shape springback stamping condition, HSLA steels S700MC always show the largest springback deformation among the investigated steels. While springback angles of all the AHSS studied are markedly smaller than that of steel S700MC. Among the 3 kinds of AHSS researched, CP800T always show the largest springback deformation. Domestic steel CP800 and imported CP800S show much smaller springback deformation respectively. In BHF of 100KN condition, springback deformation of 3 kinds of AHSS reaches the top value among all the BHF conditions. However, steel CP800 indicates an outstanding springback restrain trend in blank holding force (BHF) further increasing attempt. Thus, springback behavior can be restricted obviously by using a larger blank holding force (BHF) in steel CP800 stamping cases.
Experimental Study on Mechanical Characteristics of Knitted-Dapped Metal Rubber
Authors: Li Tuo , Bai Hong Bai , Lu Chun Hong
Published: September 2013

Knitted-dapped metal rubber was developed to solve problems of metal rubber with low stiffness and test samples with different sizes were manufactured. Static tests and dynamic tests were carried out to study influences of density and thickness on the static stiffness and influences of frequency, amplitude and preload on dynamic characteristics. Results show that static stiffness rises when density or thickness increases. Frequency has little influence on dynamic characteristics. Knitted-dapped metal rubber will have smaller stiffness and better characteristics of damping, if amplitude increases; if preload increases, energy consumed in the vibration will be more.
Design and Characterization of PbS/CdS Based Photovoltaic Cell
Authors: Zhao Zhong Biao , Wang Peng , Fan Li Bo , Chen Zi Fa , Shen Zi Guan
Published: September 2013

A PbS/CdS based photovoltaic cell was designed and characterized. The as-designed photovoltaic cell has a structure of Al/PbS/CdS/ITO/Glass. The CdS films were prepared by magnetron sputtering. The PbS films were synthesized by chemical bath deposition (CBD) method. The CdS and PbS films were characterized by X-ray diffraction (XRD) and photoelectrochemical (PEC) properties.
SEM Image and EDS Composition Analysis of Al2O3 Power under Low Vacuum Level Condition
Authors: Wang Zhi Gang , Jing Min , Yao Teng Teng , Liu Ke Gao
Published: September 2013

The surface morphology of the Al2O3powder was observed by SEM and the composition content was analyzed by EDS spectrum under different vacuum level condition. The effects of the atmosphere pressure on the SEM image quality and EDS analysis were explored systematically. The platinum sputtering treatment on the materials surface in high vacuum mode is beneficial to the observation of the images but has negtive effects on the analysis of O and Al elements. The decrease of vacuum degree in low vacuum mode can result in the drop of the image resolution and EDS spectrum accuracy. However, clear SEM image and EDS composition analysis result near to the real element kinds and contents of sample can be obtained in the low vacuum mode of 1Pa~50Pa.
Interference Analysis between Crack and General Inclusion in an Infinite Plate by Body Force Method
Authors: Ino Takuichiro , Ueno Shohei , Saimoto Akihide
Published: September 2013

A Continously Embedded Force Doublet over the Particular Region can be Regardedas the Distributing Eigen Strain. this Fact Implies that many Sorts of Inelastic Strain can Bereplaced by the Force Doublet. in the Present Paper, the Force Doublet is Used to Alter the Localconstitutive Relationship. as a Result, a Method for Analyzing the General Inclusion Problem Inwhich the Material Properties of the Inclusion are Not only Diﬀerent from those of the Matrixmaterial but also can be even a Function of Spacial Coordinate Variables is Proposed. Thetheoretical Background of the Present Analysis is Explained Followed by some Representativenumerical Results.
Boundary Conditions in a Multiscale Homogenization Procedure
Authors: Lesičar Tomislav , Tonković Zdenko , Sorić Jurica
Published: September 2013

This paper is concerned with a second-order multiscale computational homogenization scheme for heterogeneous materials at small strains. A special attention is directed to the macro-micro transition and the application of the generalized periodic boundary conditions on the representative volume element at the microlevel. For discretization at the macrolevel the C1 plane strain triangular finite element based on the strain gradient theory is derived, while the standard C0 quadrilateral finite element is used on the RVE. The implementation of a microfluctuation integral condition has been performed using several numerical integration techniques. Finally, a numerical example of a pure bending problem is given to illustrate the efficiency and accuracy of the proposed multiscale homogenization approach.
A Study on the Structural Fracture of Body Structure in Railroad Car
Authors: Yoon Sung Cheol , Kim Yeon Su , Kim Jeong Guk , Park Sung Hyuk , Lee Hee Up
Published: September 2013

An evaluation was carried out by applying a load to the underframe of the freight car to determine the structural strength of the carbody of a newly manufactured freight car for transportation. This study is aimed at evaluating the safety of the underframe of the freight car under the maximum load conditions. The freight car for use in rail freight was designed mainly with SM490A steel and ASTM A441 steel for production. The carbody for rolling stock is a principal structure supporting major underframe equipment and freight. Thus, strength evaluation of this structure is very important. Both structural analysis and loading test were performed under the loading condition. Prior to evaluating structural strength, finite element method software was used for structural analyses of stress distribution in a carbody of freight car. The strain gages were attached on the carbody based on the FEM results. A vertical load test, compressive load test, measurement of deflection amount and a natural frequency measurement test were conducted.
Partial Transient Liquid Phase Metals Layer-Surface Coating for Improved Oxidation Resistance and Low Cycle Fatigue Crack Initiation Life at 1073K in Air of TiAl Alloy
Authors: Iino Y.
Published: September 2013

The partial transient liquid phase PTLP metals layer technique for ceramic-metal bonding was applied to surface coating of TiAl alloy. Ni/Al/Ni and Ni/Ti/Ni foils (10μm) layers were coated on flat surface of oxidation specimen OS and on notch root surface of notched compact tension specimen NCT of a TiAl alloy. It is shown that the oxidation resistance is significantly improved and that the resistance to the low cycle fatigue LCF crack initiation life is improved. A procedure of application of the present technique for three dimensional surface coating is proposed.
BEM Analysis of a Piezoelectric Structural Health Monitoring System for Delamination Detection
Authors: Alaimo Andrea , Milazzo Alberto , Orlando Calogero
Published: September 2013

In the present work a piezoelectric based structural health monitoring (SHM) system is analyzed with the aim of assessing the ability of the piezoelectric patch to detect both edge and embedded delaminations proper of flange-skin composite laminated structures. The boundary element model is developed for piezoelectric solids and is implemented by taking advantage of the multidomain technique to model laminated and cracked configurations. A non-linear spring model interface is then implemented in conjunction with an iterative procedure allowing for the simulation of the finite stiffness of the bonding layers as well as of the non-penetration condition of the delamination surfaces. The dynamic behavior of the damaged structures and of the bonded piezoelectric patch is modeled by means of the dual reciprocity approach. To fully characterize the structure response the fracture mechanics behavior is studied in terms of energy release rate G and mode-mix phase angle Y. Finally, a damage index based on the electrical current output of the SHM system is introduced as an effective identification parameter of the flange-skin delamination occurrence.
Fatigue Properties of a Low-Alloy Steel with a Nano-Structured Surface Layer Obtained by Severe Mechanical Treatments
Authors: Hassani-Gangaraj Seyyed Mostafa , Moridi A. , Guagliano Mario
Published: September 2013

Recent development in mechanical technologies and processes have shown that by performing traditional mechanical treatments with unusual and severe parameters it is possible to obtain metal surfaces characterized by grain size with dimension in the order of 50-100 nm. This confers peculiar and superior properties to the surface layer of material. Since the surface is the usual point of fatigue crack initiation it is expected that the parts treated this way show a better fatigue behavior with respect to the coarse grain materials, even if treated with conventional mechanical treatments. This work explores any opportunities to obtain nano-structured surface layers by means of two popular mechanical treatments, shot peening and deep rolling. To this end particularly severe processing parameters are applied on a low alloy steel fatigue test specimens. The treated surface is characterized by means of optical Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) analysis of residual stress and roughness measurements. In the end a series of fatigue tests on smooth specimens severely treated, conventionally treated and not treated were executed. The results show the potential benefits of severe mechanical treatments and were interpreted in the light of peculiar effects of these novel treatments on the characteristics of the treated surfaces.
Nodular Cast Iron – Fatigue Crack Measurement and Simulation
Authors: Čanžar Predrag , Tonković Zdenko
Published: September 2013

Study presented in this paper is concerned with fatigue crack initiation detection, crack propagation observation and measurement as well as with numerical simulation of damage accumulation and propagation in the nodular cast iron grade EN-GJS-400-18-LT. Material properties of nodular cast iron are well elaborated in previous authors' papers. Crack initiation and its propagation observation as well as crack length measurement is performed on standardized specimens using ARAMIS 4M optical system. Based on the experimental results, a new three-dimensional constitutive model is proposed to simulate the low-cycle fatigue behaviour of considered material. An efficient algorithm for modelling cyclic plasticity is used for performing numerical simulation of crack initiation and growth on standardized specimens made from nodular cast iron. The computational procedure accuracy is verified by comparing the computed results with the real experimental data.
A Numerical Model to Study the Hydrogen Embrittlement Effect on Low-Alloy Steels
Authors: Vergani Laura , Gobbi Giorgia , Colombo Chiara
Published: September 2013

Pipeline working environment is characterised by corrosive conditions, able to develop hydrogen formation. The presence of atomic hydrogen localized in correspondence of crack tip, where the plastic strain reaches the maximum value, is responsible for life reduction. For this reason, it is important to estimate and predict the mechanical properties decay, in terms of toughness and crack propagation, when steel is in contact with hydrogen. Aim of this study is to develop FE models of two carbon, low-alloyed steels used in pipelines applications: X65 and F22. A complex model including three simulations steps is presented. It considers the combined effect of plastic strain and hydrogen concentration on the material toughness. The results of the model are validated by a comparison with experimental tests carried out on the two low-alloyed steel.
Effect of Stress Wave Dispersion on Hopkinson Pressure Bar Loaded Fracture Test
Authors: Guo Chun Huan , Shen Xin Hui , Jiang Feng Chun , Zou Guang Ping
Published: September 2013

Some fundamental issues, such as stress wave dispersion effect, loss of contact, pulse shaping effect are still needed to thoroughly understand in Hopkinson pressure bar loaded fracture experimental techniques. In order to avoid the influence of stress wave dispersion on the analysis of dynamic experimental results, a computational procedure has been developed based on the combined analytical solution of Pochhammer-Chree with Fourier spectroscopy analysis. The validity of this proposed computational procedure was confirmed via the comparison with the experimental stress pulses obtained from pulse-shaped tests. The experimental results can be easily interpreted and the testing accuracy can be improved using this computational procedure.
Numerical Observation of Damage and Cracking Behavior in Three-Point Bending Asphalt Mixture Beam
Authors: Yang Xin Hua , Zeng Guo Wei , Qian Qin
Published: September 2013

This paper presents a damage constitutive model to characterize the softening behavior of asphalt mastic in the fracture process. The three-point bending asphalt mixture beams with different crack locations and aggregate distributions are modeled with the parameterization modeling method. It is found that there is good agreement between the predicted and experimental results. The effects of crack location and coarse aggregate distribution on the crack path are numerically evaluated, and damage distributions near the crack tip are analyzed. Some conclusions are given.
Long-Term Monitoring of FRP-Concrete Composite Bridge Deck for Cable-Stayed Bridges Using Optical Fiber Sensors
Authors: Kim Sung Tae , Park Sung Yong , Cho Keun Hee , Cho Jeong Rae
Published: September 2013

The Korea Institute of Construction Technology has developed a precast FRP-concrete composite deck to be applied to cable-stayed bridges. This deck is a precast structural system in which concrete is disposed at the upper part and a hollow FRP tube is disposed at the bottom to play the role of tensile reinforcement and form. This paper presents the prototype of the so-developed FRP-concrete composite deck fabricated for trial construction. Electrical resistance sensors and optical fiber sensors were installed on the prototype to evaluate its structural stability and serviceability during the 17 months of operation through a series of field loading tests. From the field loading test results, the FRP-concrete composite deck was verified to secure sufficient structural stability and serviceability along the 17 months of operation even after the repeated passage of the heavy construction trucks. Besides, it appeared also that, for long-term monitoring, the optical fiber sensor provided more reliable measurement than the electrical resistance sensor glued to the structure.
Cyclic Creep and Recovery Behaviour of Glass Fibre Reinforced Epoxy Composite
Authors: Lovrenić-Jugović Martina , Tonković Zdenko , Slokar Ljerka
Published: September 2013

This paper presents the results of an experimental and numerical investigation of the tensile behaviour of glass fibre reinforced epoxy composite for incremental and cyclic creep-recovery load conditions. The proposed constitutive model incorporates linear viscoelasticity coupled with damage and viscoplasticity for prediction of the creep-recovery responses. The material parameters are determined by fitting the experimental results. Scanning electron microscopy (SEM) of composite fracture surfaces is performed to explain the failure mechanisms. A computational algorithm for the integration of the proposed constitutive model at the material point level is derived and implemented into the finite element code ABAQUS. The model predictions are found to be in good agreement with the experimental data.
Assessment of Crack Growth from a Cold Worked Hole by Coupled FEM-DBEM Approach
Authors: Citarella Roberto G. , Cricrì G. , Lepore M. , Perrella M.
Published: September 2013

The main objective of the present work is the study of the effect of residual stresses, induced by a cold working split sleeve process, on the fatigue life of a holed specimen. The crack propagation is simulated by a two-parameters crack growth model, based on the usage of two threshold material parameters (ΔKth and Kmax,th) and on the allowance for residual stresses, introduced on the crack faces by material plastic deformations. The coupled usage of Finite Element Method (FEM) and Dual Boundary Element Method (DBEM) is proposed to simulate the crack propagation, in order to take advantage of the main capabilities of the two methods. The procedure is validated by comparison with experimental results (crack growth rates and crack path) available from literature, in order to assess its capability to predict the crack growth retardation phenomena.
Fracture Toughness of Advanced TRIP-Aided Martensitic Steels
Authors: Sugimoto Koh Ichi , Kobayashi Junya , Ina Daiki
Published: September 2013

The effects of microalloying on the fracture toughness of 0.2%C1.5%Si1.5%Mn 0.05%Nb (mass%) transformation-induced plasticity-aided steel with a lath-martensite structure matrix were investigated. When 0.002% B or 1.0% Cr was added to the base steel, the steel achieved a fracture toughness that was as high as that of 18%Ni maraging steel. Based on our results, the high fracture toughness was essentially caused by (i) a matrix with a softened lath-martensite structure, low carbide content and low carbon concentration; (ii) the effective plastic relaxation of localized stress concentration by the strain-induced transformation of metastable retained austenite of about 3 vol% in the martensite-austenite constituent or phase.
Preparation and application of various nanoparticles in biology and medicine
Authors: Gasparyan Vardan
Published: September 2013

The present paper considers prospects for application of various nanoparticles in biology and medicine. Here are presented data on preparation of gold and silver nanoparticles, and effects of shape of these nanoparticles on their optical properties. Application of these nanoparticles in diagnostics, for drug delivery and therapy, and preparation of magnetic nanoparticles from iron and cobalt salts are also discussed. Application of these nanoparticles as magnetic resonance imaging (MRI) contrast agents and as vehicles for drug delivery, and preparation of quantum dots and their application as prospective nanoparticles for multiplex analysis and for visualization of cellular processes will be tackled. Finally, prospects for new types of nanocomposites (metallic nano-shells) will be not overlooked.
Monitoring of Technical Variation in Quantitative High-Throughput Datasets
Authors: Lauss Martin , Visne Ilhami , Kriegner Albert , Ringnér Markus , Jönsson Göran , Höglund Mattias
Published: September 2013

High-dimensional datasets can be confounded by variation from technical sources, such as batches. Undetected batch effects can have severe consequences for the validity of a study's conclusion(s). We evaluate high-throughput RNAseq and miRNAseq as well as DNA methylation and gene expression microarray datasets, mainly from the Cancer Genome Atlas (TCGA) project, in respect to technical and biological annotations. We observe technical bias in these datasets and discuss corrective interventions. We then suggest a general procedure to control study design, detect technical bias using linear regression of principal components, correct for batch effects, and re-evaluate principal components. This procedure is implemented in the R package swamp, and as graphical user interface software. In conclusion, high-throughput platforms that generate continuous measurements are sensitive to various forms of technical bias. For such data, monitoring of technical variation is an important analysis step.
The Relationship Between Faculty Performance Assessment and Results on the In-Training Examination for Residents in an Emergency Medicine Training Program
Authors: Ryan James G. , Barlas David , Pollack Simcha
Published: September 2013

Background

Medical knowledge (MK) in residents is commonly assessed by the in-training examination (ITE) and faculty evaluations of resident performance.

Objective

We assessed the reliability of clinical evaluations of residents by faculty and the relationship between faculty assessments of resident performance and ITE scores.

Methods

We conducted a cross-sectional, observational study at an academic emergency department with a postgraduate year (PGY)-1 to PGY-3 emergency medicine residency program, comparing summative, quarterly, faculty evaluation data for MK and overall clinical competency (OC) with annual ITE scores, accounting for PGY level. We also assessed the reliability of faculty evaluations using a random effects, intraclass correlation analysis.

Results

We analyzed data for 59 emergency medicine residents during a 6-year period. Faculty evaluations of MK and OC were highly reliable (κ  =  0.99) and remained reliable after stratification by year of training (mean κ  =  0.68–0.84). Assessments of resident performance (MK and OC) and the ITE increased with PGY level. The MK and OC results had high correlations with PGY level, and ITE scores correlated moderately with PGY. The OC and MK results had a moderate correlation with ITE score. When residents were grouped by PGY level, there was no significant correlation between MK as assessed by the faculty and the ITE score.

Conclusions

Resident clinical performance and ITE scores both increase with resident PGY level, but ITE scores do not predict resident clinical performance compared with peers at their PGY level.
Hoarseness of Voice: Presentation of Neglected Denture Esophagus
Authors: Kumar Sunil , Singh Devendra Bahadur
Published: September 2013

Aspiration or ingestion of a foreign body is well-known in the pediatric as well as in the adult population. The majority of esophageal foreign bodies pass through the gastrointestinal tract without causing complications. However, large sharp foreign bodies like dentures and meat bones can get deeply embedded in the wall leading to life-threatening complications. We report a case of a neglected denture in a 55-year-old patient who presented with an unusual complaint as hoarseness of voice and was removed with the help of rigid esophagoscope.

How to cite this article

Kumar S, Singh DB. Hoarseness of Voice: Presentation of Neglected Denture Esophagus. Int J Prosthodont Restor Dent 2013;3(1):30-32.
Management of a Complicated Crown-Root Fracture using Single-Visit Endodontic Treatment and Fiber Post as an Intracanal Anchorage
Authors: Bansode Pradnya Vilas , Pathak Seema Dhananjay , Deore Rahul Bhikanrao
Published: September 2013

This case report describes the management of complicated crown-root fracture of a maxillary central incisor. Initially, the fractured fragment was stabilized by splinting it with composite and wire splint to adjacent teeth. During next appointment single-visit endodontic treatment was performed, the fractured crown portion was reattached using fiber post and composite resin. Success was achieved by normality in function, esthetics, health of tooth and surrounding periodontal structures. This reattachment technique presents several advantages, such as better and long-lasting esthetics, improved function and a positive psychological response, faster and less complicated procedure. The main objective of the presented technique restoration is to provide highly conservative approach that combines esthetics and function. Advantages, disadvantages and prognosis of this treatment approach are discussed.

How to cite this article

Bansode PV, Pathak SD, Deore RB. Management of a Complicated Crown-Root Fracture using Single-Visit Endodontic Treatment and Fiber Post as an Intracanal Anchorage. Int J Prosthodont Restor Dent 2013; 3(1):33-36.
Overview of the first HyMeX Special Observation Period over Italy: observations and model results
Authors: Ferretti R. , Pichelli E. , Gentile S. , Maiello I. , Cimini D. , Davolio S. , Miglietta M. M. , Panegrossi G. , Baldini L. , Pasi F. , Marzano F. S. , Zinzi A. , Mariani S. , Casaioli M. , Bartolini G. , Loglisci N. , Montani A. , Marsigli C. , Manzato A. , Pucillo A. , Ferrario M. E. , Colaiuda V. , Rotunno R.
Published: September 2013

Abstract. During the first Hymex campaign (5 September–6 November 2012) referred to as Special Observation Period (SOP-1), dedicated to heavy precipitation events and flash floods in Western Mediterranean, three Italian hydro-meteorological monitoring sites were activated: Liguria-Tuscany, North-Eastern Italy and Central Italy. The extraordinary deployment of advanced instrumentation, including instrumented aircrafts, and the use of several different operational weather forecast models has allowed an unprecedented monitoring and analysis of high impact weather events around the Italian hydro-meteorological sites. This activity has seen the strict collaboration between the Italian scientific and operational communities. In this paper, an overview of the Italian organization during the SOP-1 is provided, and selected Intensive Observation Periods (IOPs) are described. A significant event for each Italian target area is chosen for this analysis: IOP2 (12–13 September 2012) in North-Eastern Italy, IOP13 (15–16 October 2012) in Central Italy and IOP19 (3–5 November 2012) in Liguria and Tuscany. For each IOP the meteorological characteristics, together with special observations and weather forecasts, are analyzed with the aim of highlighting strengths and weaknesses of the forecast modeling systems. Moreover, using one of the three events, the usefulness of different operational chains is highlighted.
Scatter of mass changes estimates at basin scale for Greenland and Antarctica
Authors: Barletta V. R. , Sørensen L. S. , Forsberg R.
Published: September 2013

Abstract. During the last decade, the GRACE mission has provided valuable data for determining the mass changes of the Greenland and Antarctic ice sheets. Yet, discrepancies still exist in the published mass balance results, and comprehensive analyses on the sources of errors and discrepancies are lacking. Here, we present monthly mass changes together with trends derived from GRACE data at basin scale for both the Greenland and Antarctic ice sheets, and we assess the variability and errors for each of the possible sources of discrepancies, and we do this in an unprecedented systematic way, taking into account mass inference methods, data sets and background models. We find a very good agreement between the monthly mass change results derived from two independent methods, which represents a cross validation. For the monthly solutions, we find that most of the scatter is caused by the use of the two different data sets rather than the two different methods applied. Besides the well-known GIA trend uncertainty, we find that the geocenter motion and the recent de-aliasing corrections significantly impact the trends, with contributions of +13.2 Gt yr−1 and −20 Gt yr−1, respectively, for Antarctica, which is more affected by these than Greenland. We show differences between the use of release RL04 and the new RL05 and confirm a lower noise content in the new release. The overall scatter of the solutions well exceeds the uncertainties propagated from the data errors and the leakage (as done in the past); hence we calculate new sound total errors for the monthly solutions and the trends. We find that the scatter in the monthly solutions caused by applying different estimates of geocenter motion time series (degree-1 corrections) is significant – contributing with up to 40% of the total error. For the whole GRACE period (2003–2011) our trend estimate for Greenland is −234 ± 20 Gt yr−1 and −83 ± 36 Gt yr−1 for Antarctica (−111 ± 15 Gt yr−1 in the western part). We also find a clear (with respect to our errors) increase of mass loss in the last four years.
Evidence of meltwater retention within the Greenland ice sheet
Authors: Rennermalm A. K. , Smith L. C. , Chu V. W. , Box J. E. , Forster R. R. , Van den Broeke M. R. , Van As D. , Moustafa S. E.
Published: September 2013

Abstract. Greenland ice sheet mass losses have increased in recent decades with more than half of these attributed to surface meltwater runoff. However, the magnitudes of englacial storage, firn retention, internal refreezing and other hydrologic processes that delay or reduce true water export to the global ocean remain less understood, partly due to a scarcity of in situ measurements. Here, ice sheet surface meltwater runoff and proglacial river discharge between 2008 and 2010 near Kangerlussuaq, southwestern Greenland were used to establish sub- and englacial meltwater storage for a small ice sheet watershed (36–64 km2). This watershed lacks significant potential meltwater storage in firn, surface lakes on the ice sheet and in the proglacial area, and receives limited proglacial precipitation. Thus, ice sheet surface runoff not accounted for by river discharge can reasonably be attributed to retention in sub- and englacial storage. Evidence for meltwater storage within the ice sheet includes (1) characteristic dampened daily river discharge amplitudes relative to ice sheet runoff; (2) three cold-season river discharge anomalies at times with limited ice sheet surface melt, demonstrating that meltwater may be retained up to 1–6 months; (3) annual ice sheet watershed runoff is not balanced by river discharge, and while near water budget closure is possible as much as 54% of melting season ice sheet runoff may not escape to downstream rivers; (4) even the large meltwater retention estimate (54%) is equivalent to less than 1% of the ice sheet volume, which suggests that storage in en- and subglacial cavities and till is plausible. While this study is the first to provide evidence for meltwater retention and delayed release within the Greenland ice sheet, more information is needed to establish how widespread this is along the Greenland ice sheet perimeter.
Workplace violence: A call for action
Authors: Pekar Bunnany Chhun , Gillespie Gordon Lee
Published: September 2013

Workplace violence (WPV) is a serious threat to the nursing workforce. WPV results in decrease morale, job dissatisfaction, and increase nurse turnover and intentions to leave the profession. WPV has been associated with decrease in the quality of care rendered and could negatively affect patient safety. Given the direct and indirect financial consequences of WPV, it is critical that nursing leaders take actions to reduce WPV by establishing violence prevention programs. Nursing leaders should also reach out to the public, their professional health organization, and the scientific community to provide education and craft regulation to reduce this threat on the nursing workforce and change the perception that violence is part of the job.
De l’intérêt de la notion de littératie en francophonie : un état des lieux en sciences de l’éducation1
Authors: Hébert Manon , Lépine Martin
Published: September 2013

La notion de littératie a le mérite de bousculer des frontières trop communément admises entre les différentes composantes de l’enseignement et de l’apprentissage d’une langue maternelle (lecture, écriture et oral), mais il s’agit d’une notion multidimensionnelle dont les contours restent flous. Et même si le développement des habiletés associées à cette notion apparaît comme un des enjeux majeurs de la scolarisation, pour l’instant, le mot littératie demeure absent des curriculums scolaires des principaux pays de la francophonie. Pour faire un état des lieux de l’usage de cette notion en francophonie, nous avons recensé et analysé en fonction de leurs dimensions sociocognitive, épistémologique et didactique le contenu des principales définitions proposées par les chercheurs francophones de 1985 à 2011 inclusivement. À titre de résultats, nous faisons ressortir dix valeurs ajoutées que l’on semble attribuer actuellement à la notion de littératie en francophonie et qui permettraient de mieux comprendre en quoi les compétences en littératie se distinguent du savoir lire-écrire de base. La littératie touche d’une part un ensemble d’attitudes, de connaissances, d’habiletés et de compétences qui sont, d’autre part, à mesurer ou à situer dans une dynamique espace/temps et dans une visée émancipatrice du développement de la personne. Ainsi, l’utilisation de la notion de littératie permet de pointer plusieurs objectifs personnels, professionnels et socioculturels dont l’interdépendance apparaît déterminante pour l’appropriation de l’écrit et, par conséquent, pour l’orientation des recherches en sciences de l’éducation et en didactique du français.