bluuebunny/crossref_metadata_2025 huggingface dataset:
An Analytical Singular Element for Kirchhoff Plate Bending With V-Shaped Notches
Authors: Yao Weian , Wang Shan
Published: March 2012

An analytical singular element with arbitrary high-order precision is constructed using the analytical symplectic eigenfunctions of an annular sector thin plate with both straight sides free. These values can be used to describe the local stress singularities near an arbitrary V-notch or a crack tip. Numerical examples of Kirchhoff’s plate bending problem with V-shaped notches are given by applying the Local-Global method. This method combines the present analytical singular element and the conventional finite element method. The numerical results show that the present method is an effective numerical technique for analysis of Kirchhoff plate bending problems with boundary stress singularities.
Constitutive-Law Modeling of Microfilaments From Their Discrete-Structure Simulations—A Method Based on an Inverse Approach Applied to a Static Rod Model
Authors: Hinkle Adam R. , Goyal Sachin , Palanthandalam-Madapusi Harish J.
Published: March 2012

Twisting and bending deformations are crucial to the biological functions of several microfilaments such as DNA molecules. Although continuum-rod models have emerged as efficient tools to describe the nonlinear dynamics of these deformations, a major roadblock in the continuum–mechanics-based description of microfilaments is the accurate modeling of the constitutive law, which follows from their atomistic-level structure and interactions. In this paper, we present a method for estimating the constitutive law using a static rod model and deformed configuration data generated from discrete-structure simulations. Furthermore, we illustrate the method on a filament with an artificial discrete-structure. We simulate its deformation in response to a prescribed loading using a multibody dynamics (MBD) solver. Using position data generated from the MBD solver, we first estimate the curvature of the filament, and subsequently use it to estimate the effective relationship between the restoring moment and curvature.
Some Results on the Random Wear Coefficient of the Archard Model
Authors: Antonio Dorini Fabio , Sampaio Rubens
Published: March 2012

The most used model for predicting wear is the linear wear law proposed by Archard. A common generalization of Archard’s wear law is based on the assumption that the wear rate at any point on the contact surface is proportional to the local contact pressure and the relative sliding velocity. This work focuses on a stochastic modeling of the wear process to take into account the experimental uncertainties in the identification process of the contact-state dependent wear coefficient. The description of the dispersion of the wear coefficient is described by a probability density function, which is performed using the maximum entropy principle using only the information available. Closed-form results for the probability density function of the wear depth for several situations that commonly occur in practice are provided.
Comment on “Productivity Is a Poor Predictor of Plant Species Richness”
Authors: Pan Xubin , Liu Fengqiao , Zhang Mi
Published: March 2012

Adler
et al
. (Reports, 23 September 2011, p. 1750) analyzed the standardized sampling data from 48 herbaceous-dominated plant communities and concluded that “Productivity is a poor predictor of plant species richness” at fine-scale. However, their method was biased toward site-number–dominated plant communities. They also failed to provide enough data for regional analysis and detailed information for within-site analysis.
Photoacoustic Tomography: In Vivo Imaging from Organelles to Organs
Authors: Wang Lihong V. , Hu Song
Published: March 2012

Lights, Sound, Images

Optical microscopy can readily image thin samples such as cells, but thicker samples, such as tissue, are more difficult to image directly, because of the multiple scattering of light.
Wang and Hu
(p.
1458
) review methods for imaging biological samples on length scales ranging from organelles to whole organs that rely on the photoacoustic effect—the excitation of ultrasonic pressure waves when light is absorbed by molecules in solution. The incident light can be focused and scanned across a sample in a microscopy mode to create ultrasound images, or the entire region of interest can be illuminated and the ultrasound waves analyzed with a computer algorithm in a tomography mode. Imaging studies can reveal changes in oxygen metabolism and gene expression and in image biomarkers and vasculature.
Long-Range–Projecting GABAergic Neurons Modulate Inhibition in Hippocampus and Entorhinal Cortex
Authors: Melzer Sarah , Michael Magdalena , Caputi Antonio , Eliava Marina , Fuchs Elke C. , Whittington Miles A. , Monyer Hannah
Published: March 2012

Inhibiting the Inhibitors

Excitatory neurons in the hippocampus and entorhinal cortex are under control of local γ-aminobutyric acid–releasing (GABAergic) interneurons that are the major source of inhibition in the adult brain. In contrast to the wealth of knowledge regarding connectivity in the hippocampus, much less is known about the cross-talk between the hippocampus and other brain regions.

Melzer
et al.

(p.
1506
) investigated long-range GABAergic projections from the hippocampal formation to the medial entorhinal cortex and vice versa. These GABAergic neurons bidirectionally couple the hippocampus and medial entorhinal cortex and preferentially target local inhibitory neurons, forming disinhibitory loops that could help synchronize neuronal activity.
Experimental Realization of a Magnetic Cloak
Authors: Gömöry Fedor , Solovyov Mykola , Šouc Ján , Navau Carles , Prat-Camps Jordi , Sanchez Alvaro
Published: March 2012

Hidden from Magnetic View

An electromagnetic cloak is a device within which electromagnetic fields cannot penetrate, but, more importantly, the device itself does not disturb the electromagnetic fields surrounding it. An article placed in the cloak therefore vanishes from view, creating no shadow or reflection. Such devices have been demonstrated, but only for a particular band of frequencies. Confirming theoretical work that predicts such cloaking should be possible down to zero frequency,

Gömöry
et al.

(p.
1466
) designed a cloak for a dc magnetic field. With a composite design of ferromagnetic and superconducting material, together with a relatively simple structure, the device could potentially find immediate application.
Searching for a Better Thermal Battery
Authors: Gur Ilan , Sawyer Karma , Prasher Ravi
Published: March 2012

Improved materials for storing heat could save energy in applications such as heating and cooling and could enhance generation from solar thermal plants.
America's Community Colleges
Authors: Miner Judy C.
Published: March 2012

In the 2009 American graduation initiative, President Obama enthusiastically highlighted the importance of community colleges—publicly funded 2-year institutions—for meeting the projected growth in jobs requiring a college degree. Increasing the number of college graduates earning science- and math-related degrees depends on these institutions increasing workforce preparation through science, technology, engineering, and mathematics (STEM) education. Community colleges are accessible, affordable, diverse, and flexible, and thus well positioned to meet this need. However, the current demand for courses far exceeds capacity,
*
thereby calling for more government, business, and local resources to support these institutions.
Objectifying Our Past
A History of the World in 100 Objects
From the Handaxe to the Credit Card

by Neil MacGregor

Viking (Penguin), New York, 2011. 733 pp. $45. ISBN 9780670022700. Allen Lane (Penguin), London, 2010. £30. ISBN 9781846144134. Penguin, London, 2012. Paper, £12.99. ISBN 9780241951774.
Authors: Riddihough Guy
Published: March 2012

In this kaleidoscopic history of humankind (originally presented on BBC radio), MacGregor views people's lives through the prisms of 100 artifacts.
Seeking Cures for North Korea's Environmental Ills
Authors: Stone Richard
Published: March 2012

At a landmark seminar in Pyongyang, capital of North Korea, participants took stock of the country's ecological issues and shared ideas on how to restore its ecosystems and improve food security.
Gut Microbes Keep Rare Immune Cells in Line
Authors: Leslie Mitch
Published: March 2012

A new study reported online in
Science
this week has found that the typical intestinal bacteria in mice rein in a rare type of immune cell, curtailing asthma and colitis in the rodents.
Field Biologists Cry Foul Over Ban
Authors: Bagla Pallava
Published: March 2012

In the past 2 years, southern India's Karnataka State has canceled 40 out of 42 research permits in four tiger reserves, shutting down studies on topics as diverse as Asian elephant migrations and long-term ecological plots.
It's a Bird, It's a Plane, It's a … Spy?
Authors: Mackenzie Dana
Published: March 2012

A new 19-gram crewless aircraft called the Nano Hummingbird with a wingspan of 17 centimeters can hover in place and fly in any direction (including backward) as fast as 18 kilometers per hour.
FAMILY INVOLVEMENT IN CHINESE AND GERMAN SMALL BUSINESSES
Authors: SCHMITT ANTJE , FRESE MICHAEL
Published: March 2012

The goal of this study was to examine cultural differences in the value of family involvement in German and Chinese small businesses due to their differences in collectivism/individualism. Our analyses, based on a sample of 562 Chinese and German owners, showed that family involvement — measured as the number of family members that work in the business — is higher in China than in Germany. Compared to German business owners, Chinese owners received most of their start-up capital from family members. Moreover, we were interested in whether family involvement is related to the business owner's ability to make use of start-up capital to turn it into business outcomes. Building on existing literature and based on the match hypothesis we hypothesized that the effects of family involvement on business outcomes depend on the cultural values underlying a business. Our analyses revealed that family involvement negatively affected relationships of start-up capital with business outcomes both in China and in Germany. Our study contributes by showing that a negative effect of family involvement on the ability to make use of start-up capital is not only evident in individualistic cultures such as Germany but does also apply to collectivistic Chinese businesses. Practically, owners in both cultures are suggested to develop strategies in order to prevent and overcome negative effects of family involvement on business outcomes. Our results suggest fruitful avenues for future research.
SOCIAL CAPITAL IMPEDIMENTS IN THE UNITED ARAB EMIRATES: A CASE OF EMIRATI FEMALE ENTREPRENEURS
Authors: EROGUL MURAT SAKIR
Published: March 2012

It is possible that when looked at from the outside, the Gulf Arab countries give an impression that they are not very supportive to female entrepreneurs. This perception may be pertinent to a certain degree; however, Emirati female entrepreneurs (EFE) in the United Arab Emirates demonstrate that enhancing co-operation and support is possible through increasing interaction and networking with men. Analysis is undertaken of the observations and actions of conveniently selected 17 EFEs. The scoping of the respondents reveal that EFEs who engage with indirect male ties require a 'male contact facilitator' from their family or relatives to do so. These men are facilitated by the entrepreneur to adopt the role of a 'male network partner (MNP) and provide support in overcoming challenges and achieving business objectives. The paper sets new standards of support for Emirati women in business ventures as it attempts to describe Emirati female entrepreneurship in a different language and proposes that co-operation, interaction and networking with men help EFEs access and use key resources, alleviate or remove key challenges and achieve business objectives.
GREEN'S FUNCTION AND LARGE TIME BEHAVIOR OF THE NAVIER–STOKES–MAXWELL SYSTEM
Authors: DUAN RENJUN
Published: March 2012

In this paper, we are concerned with the system of the compressible Navier–Stokes equations coupled with the Maxwell equations through the Lorentz force in three space dimensions. The asymptotic stability of the steady state with the strictly positive constant density and the vanishing velocity and electromagnetic field is established under small initial perturbations in regular Sobolev space. For that, the dissipative structure of this hyperbolic-parabolic system is studied to include the effect of the electromagnetic field into the viscous fluid and turns out to be more complicated than that in the simpler compressible Navier–Stokes system. Moreover, the detailed analysis of the Green's function to the linearized system is made with applications to derive the rate of the solution converging to the steady state.
Heteroarray of cobalt(II)tetrasulfophthalocyanine and cobalt(II) tetrakis(N-methyl-4-pyridyl)porphyrin: synthesis, isolation and electronic properties
Authors: Tasso Thiago T. , Moreira Wania C.
Published: March 2012

Porphyrin and phthalocyanine macrocycles with ionic substituents can form mixed assemblies with interesting electronic properties for potential application on the development of new devices. This paper reports the synthesis, isolation and purification of heteroaggregate formed by cobalt(II) 4,4′,4″,4‴-tetrasulfophthalocyanine (CoTsPc) and cobalt(II) tetrakis(N-methyl-4-pyridyl)porphyrin (CoTMPyP), followed by its spectroscopic characterization. Spectroscopic titration, performed with a CoTsPc water/acetone solution, allowed the use of Job's method for determination of the heteroaggregates stoichiometry. The Job's plot revealed the formation of only one predominant heterocomplex in solution, containing two CoTsPc molecules in terminal positions and a central CoTMPyP one. For the first time, a method for isolation and purification of a mixed ionic array has been reported in the literature. The triad's electronic spectrum is quite different from the sum of the macrocycles isolated spectra, due to the overlap of their electronic densities and a charge transfer process between CoTsPc and CoTMPyP.
LOW COST PROCESSING OPTIONS FOR CA-α-SIALONS
Authors: JONES MARK IAN , LAWRIE KATARINA , KUGLER KURT
Published: March 2012

The aim of this work is to investigate the potential for lower cost production of Ca -α- SiAlON materials. In order to reduce the costs typically associated with the production of these materials, we have investigated Reaction Bonding (RB) as an alternative processing route, as well as alternative raw materials for the source of calcium by recycling waste mussel shells from the New Zealand aquaculture industry. Full transformation to Ca -α- SiAlON was achieved at 1400°C in the reaction bonded materials, whereas the conventional silicon nitride based materials required temperatures of 1800°C to achieve full transformation. The relative density of the sintered samples was low but, as a production route for SiALON powders or for materials for low tech applications, the reaction bonding / mussel shell combination offers significant cost benefits.
DISBOND DETECTION TECHNIQUE FOR LINER/PROPELLANT INTERFACE USING ULTRASONIC RESONANCE AND LAMB WAVES
Authors: KIM DONG-RYUN , KIM JAE-HOON
Published: March 2012

Adhesive interface tests using ultrasonic waves are far superior to other nondestructive tests for detecting the disbond interface. However, a multilayered structure consisting of a steel case, rubber insulation, liner, and propellant poses many difficulties for analyzing ultrasonic waves because of the superposition of the reflected waves and the large differences in the acoustic impedances of the various materials. Therefore, ultrasonic tests for detecting the disbond interface of multilayered structures have been applied in very limited areas between the steel case and rubber insulation using an automatic system. The existing ultrasonic test cannot detect the disbond interface between the rubber and propellant of a multilayered structure because most of the ultrasonic waves are absorbed in the rubber material, which has low acoustic impedance. This problem could be overcome by amplifying the ultrasonic waves using the ultrasonic resonance method. The Lamb waves were used to evaluate the instability of the ultrasonic waves caused by the contact condition on the surface of the multilayered structure. In this paper, a new technique to detect the disbond interface between the liner and propellant using the property of ultrasonic resonance and Lamb waves is discussed in detail.
PHOTOINDUCED ELECTRON ACCUMULATION OF TITANIUM DIOXIDE NANOPARTICLES MODIFIED ELECTRODES
Authors: MIYOSHI HIROKAZU , SAKAMOTO KENSHO , KURASHINA MASARU , KANEZAKI EIJI
Published: March 2012

Titanium dioxide ( TiO 2) nanoparticles (Nps) were prepared by the hydrolysis of titanium tetraisopropoxide ( TTIP ) in 2-propanol with different water contents (0.5 vol% to 7.2 vol%) at 45 °C. The diameter of the Nps was estimated to be 1.5±0.5 nm ( L - TiO 2) and 3.0±0.6 nm ( S - TiO 2) from the onset wavelength in the absorption spectra and by transmission electron microscopy (TEM). A modified Pt electrode with a three-layered sandwich structure was prepared; the outermost and innermost layers were composed of S - TiO 2 and L - TiO 2, respectively, and the middle layer contained 1, 1'-dimethyl-4,4'-bipyridyl ( MV 2+)/Nafion®. Irradiation by a 500 W superhigh-pressure mercury lamp produced electrons in the conduction band of TiO 2. An anodic current was observed after turning off the light. The mechanism by which anodic current is generated after turning off the radiation involves the reduction of MV 2+ to MV +. by photogenerated electrons on the Nps and the diffusion of MV +. in the middle layer. After turning off the irradiation, MV +. transferred an electron to the Pt electrode via holes in the innermost layer or the conduction band of S - TiO 2 coincidentally localized on the Pt electrode, resulting in the generation of the anodic current. The generation of MV +. was confirmed by the absorption spectra of MV +.. As a sacrificial reagent, 2-propanol (0.1 M) was used.
A STUDY ON PERFORMANCE EVALUATION OF THERMOELECTRIC COOLING SYSTEM USING PIEZOELECTRIC BENDING ACTUATOR
Authors: Yoon Hee-Sung , Yang Ho-Dong , Oh Yool-Kwon
Published: March 2012

This study investigated the performance of thermoelectric cooling system using the piezoelectric bending actuator. The temperatures in the cooling region of thermoelectric cooling system were measured with and without operation of piezoelectric bending actuator at the frequencies of 90 Hz and 120 Hz. The cooling coefficients were calculated by the temperature measurement results, and the thermo-flow phenomenon in the cooling region was visualized under the same condition. The coefficient of performance of the thermoelectric cooling system was improved by the piezoelectric bending actuator when the results of temperature measurement and thermo-flow visualization were compared, because that the vibration from the piezoelectric bending actuator generated compulsive convection and the cold air in the cooling region was actively circulated by the compulsive convection.
A-SITE DEFICIENCY AND STRUCTURAL AND ELECTRICAL CHARACTERISTICS OF (Sr1-xREx)1-yTiO3 PEROVSKITES (RE=La, Nd and Sm)
Authors: MORIGA TOSHIHIRO , YABUI SHINTARO , HIGASHI YUTA , MURAI KEI-ICHIRO , WANG ZHEN-WEI , MORI MASASHI
Published: March 2012

The A-site deficient ( Sr 1- x RE x )1- y TiO 3 perovskites ( RE = La , Nd and Sm , 0≤ x ≤0.5, y =0, 0.05 and 0.10) were studied using samples prepared by solid-state reaction method. The substitution of Sr by the smaller RE seemed to result in the increased x region of TiO 2 appearance as an impurity phase against the larger y compositions. A slope of the tied line of the lattice parameters a as a function of x was steepened with an increase of y . Electrical conductivity measurements of ( Sr 0.9 RE 0.1)1- y TiO 3 revealed that the samples without cationic deficiency in the A-site were semiconducting whereas the A-site deficient samples showed basically metallic behavior. The absolute value of observed conductivities for all the measured samples were also reduced in the order of the size of RE .
STUDY OF MULTIELEMENTAL ADSORPTION ON ACTIVATED CARBON
Authors: THUY LE THI XUAN , YASUZAWA MIKITO , YABUTANI TOMOKI
Published: March 2012

In this study, multielemental adsorption on activated carbon (AC) was investigated. The treatment parameters (pH, AC concentration, metal concentration and contact time) in the adsorption process of multiple metals such as Bi , Cd , Co , Ga , Mn , Mo , Ni , In , Pb , Pd , Sn , Rh , Ru and W were experimented. Three types of characteristic behaviors of analyte elements were observed when the pH was varied. The adsorption rate of Bi , Co , Ga , Ni , In , Pb , Sn , Ru and W were over 80% within 30 min.
THE EVALUATION OF SURFACE MORPHOLOGY USING FLEXURE GUIDED NANO-POSITIONING SYSTEM AND ULTRA-PRECISION LATHE
Authors: Kwak Nam-Su , Kim Jae-Yeol
Published: March 2012

In this study, piezoelectric actuator, Flexure guide, Power transmission element and control method and considered for Nano-positioning system apparatus. The main objectives of this thesis were to develop the 3-axis Ultra-precision stages which enable the 3-axis control by the manipulation of the piezoelectric actuator and to enhance the precision of the Ultra-Precision CNC lathe which is responsible for the ductile mode machining of the hardened-brittle material where the machining is based on the single crystal diamond. Ultra-precision CNC lathe is used for machining and motion error of the machine are compensated by using 3-axis Ultra-precision stage. Through the simulation and experiments on ultra-precision positioning, stability and priority on Nano-positioning system with 3-axis ultra-precision stage and control algorithm are secured by using NI Labview. And after applying the system, is to analyze the surface morphology of the mold steel (SKD61)
DIELECTRIC BEHAVIOUR, COMPLEX IMPEDANCE SPECTROSCOPY AND MAGNETOELECTRIC EFFECT IN LSMO-BT COMPOSITES
Authors: VEER S. S. , KULKARNI S. V. , CHAKANE S. D. , JOSHI P. B.
Published: March 2012

The paper deals with Dielectric Behaviour, Complex Impedance Spectroscopy and Magnetoelectric effect in La 0.7 Sr 0.3 MnO 3(LSMO) and BaTiO 3 (BT) Composites. The LSMO and BT are synthesized by hydroxide co-precipitation route. The nanocomposites are prepared by two series x LSMO + (1-x) BT + 2 wt % Bi 2 O 3, for x = 0.05, 0.1, 0.15 and 0.2 ……series 1. x LSMO + (1-x) BT + 3 wt % Bi 2 O 3, for x = 0.05, 0.1, 0.15 and 0.2 ……series 2. and sintered at Ts=1000°C and 1080°C. The composites are termed as LSMO - BT . The paper reports the crystal structure, micro-structural analysis, dielectric constant, complex impedance spectroscopy and magnetoelectric properties of LSMO - BT composites. It has been observed that the ε r passes through a broad maximum at T ~ 124° C, which is nearly the ferroelectric transition temperature of BT . Both ε r and ε rmax increases as x increases from 0.05 to 0.2. The ε r ' and ε r '' decreases sharply for all the compositions at low frequencies. This feature is typical of the presence of interfacial polarization. The variation of 4πMs is almost linear with x , the 4πMs increases with x as well as sintering aid. The 4πMs of respective compositions reduce as the sintering temperature is increased. The value of α increases for increase in sintering temperature as well as increase in wt % of the sintering aid. The magnitude of α is in the range as reported earlier for composites based on BT .
DEVELOPMENT OF MANILA HEMP FIBER EPOXY COMPOSITE WITH HIGH TENSILE PROPERTIES THROUGH HANDPICKING FIBER FRAGMENTS
Authors: LIU KE , TAKAGI HITOSHI , YANG ZHIMAO
Published: March 2012

Manila hemp fibers are separated to several sequent fragments from single fiber. The tensile strength of each fiber fragments and their epoxy composite are measured, followed by scanning electronic microscopic (SEM) analysis. The results show that the tensile strength of fiber fragments is almost constant along fiber. For composite, the tensile strength first increases and then decreases at the position near to root. The Young's modulus presents increasing with location from root to top for fiber and composite. Microstructure analysis indicates that the difference of tensile properties between fiber fragments derive from the difference of fiber diameter.
SYNTHESIS AND CHARACTERIZATION OF Co3O4 POWDERS FOR HUMIDITY SENSING
Authors: SHELKE P. N. , KHOLLAM Y. B. , PABREKAR P. N. , MORE P. S. , DATIR A. M. , CHAKANE S. D. , MOHITE K. C. , KOINKAR PANKAJ
Published: March 2012

In last few decades, great deal of research efforts were directed towards the development of miniaturized gas-sensing devices, particularly for toxic gas detection and for pollution monitoring. Though various techniques are available for gas detection, solid state metal oxides offer wide spectrum of materials with their high sensitivities for the detection of different gaseous species. In this paper, we report the humidity sensing behavior of cobalt oxide ( Co 3 O 4) pellets. The Co 3 O 4 powder was prepared from the precipitation of CoSO 4 using NaOH solution. This as-prepared powder was heated at 600 °C for 2hr. The as-prepared powder was characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The humidity sensing behavior of Co 3 O 4 pellets (wt. ~ 0.5 gm, diameter ~ 10 mm) was noted by using home-built static gas sensing system. The characterization studies showed the high material purity and single phase Co 3 O 4 with cubic spinel symmetry in the as-prepared particles of resultant powders. The humidity sensing characteristics of Co 3 O 4 pellets were found to be good. The recovery time (~ 20 sec) was found to be small as compared to its response time (~ 60 sec).
LOAD CELL DESIGN USING FIBER BRAGG GRATING SENSORS
Authors: Park Dong Jin , Kang Min Kyu , Lee Jong Hyun , Lee Seok Soon , Jung Hyo Seok
Published: March 2012

A load cell is the representative converter that changes load to the quantity of electricity. The load cell is used to a large mechanical structure and offshore structures to measure the force. Currently, the load cell using electrical strain gauges are commonly used. Basic measuring principle of electrical strain gauge is the electrical method. A load cell with electrical strain gauges is not available in the electromagnetic and corrosion environment. A Fiber Bragg Grating (FBG) sensor is not affected by the EMI (Electro Magnetic Interference)/EMC (Electro Magnetic Compatibility) and is strong in corrosion under the sea water. In this paper, we use the FBG sensors to make a load cell under the sea water condition and the electromagnetic environment and show FBG sensors' availability.
EFFECT OF MICROSTRUCTURE ON FATIGUE PROPERTIES OF Al ALLOYS
Authors: HIGASHI AKIHIRO , KARIYA KOHJI , KAWAGOISHI NORIO , CHEN QIANG , GOTO MASAHIRO
Published: March 2012

Effects of a texture and atmospheric moisture on fatigue properties of an extruded bar and a drawn one of age-hardened Al alloy were investigated under rotating bending in relative humidity of 25% and 85%. The extruded alloy had a marked texture of (111) plane, but the drawn one did not have a specified orientation. Fatigue strength was largely decreased by high humidity in both alloys. The decrease in fatigue strength was larger in the extruded alloy than in the drawn one. Macroscopic growth mode of a crack of the extruded alloy was a shear mode inclined 35° to the specimen axis in high humidity, though those were a tensile mode in low humidity and in both humidity in the drawn alloy. The fracture surface yielded by the shear mode crack was occupied by many slip planes and voids and was (100) plane, though the fracture surface formed by the growth of a tensile mode crack was mainly covered with striations. The shear mode crack was related to the marked texture of the extruded Al alloy and promoted by high humidity.
FATIGUE PROPERTIES OF SUS304 STAINLESS STEEL AFTER ULTRASONIC NANOCRYSTAL SURFACE MODIFICATION (UNSM)
Authors: Zhang K.Y. , Pyoun Y.S. , Cao X.J. , Wu B. , Murakami R.
Published: March 2012

The changing of materials surface properties method always was taken into improving the fatigue strength. In this paper, an ultrasonic nanocrystal surface modification(UNSM) technique was used on the SUS 304 stainless steel to form a nanostructured surface layer with different static load(70N, 90N, 110N, 130N) and the vibration strike number was about 20,000times/mm2. The untreated and different condition specimens fatigue strength was all tested by a dual-spindle rotating bending fatigue test machine. SPring-8(a large synchrotron radiation facility) was used to test the surface nanocrystallization components. The X-ray diffraction (XRD), the scanning electron microscopy (SEM), optical microscope and a micro-Vickers hardness tester (MVK-E3, Akashi) were separately used to get the surface residual stresses, fracture surface after fatigue testing, metallographic structure and the microhardness of the nanostructured surface layer. The result showed that martensite transformation took place on the surface of specimens, the surface residual stresses had only a small increase and some cracks occurred between the martensite layer and the austenite layer, but the fatigue strength of 90N improved 81%.
IMPROVEMENT OF FATIGUE LIFE OF A HOLED SPECIMEN OF ALUMINUM-ALLOY 2024-T3 BY INDENTATION AND HOLE EXPANSION
Authors: SHAFIUL FERDOUS MD. , MAKABE CHOBIN , MIYAZAKI TATSUJIRO , HATTORI NOBUSUKE
Published: March 2012

A method of improving the fatigue life and crack growth behavior of a center holed specimen was investigated. Local plastic deformation was applied around the hole by indentation to achieve the purpose. A series of fatigue tests was conducted on aluminum-alloy 2024-T3. Push-pull tests were performed under a stress ratio of R= -1 and a frequency of 10Hz. The observations of the crack initiation and growth were performed with a microscope, and hardness around the hole was measured by Vickers hardness testing machine. In the present study, the longest fatigue life was observed in the case of an indentation specimen with the highest load. The indentation was performed on both sides of the hole edges. The crack growth rate was decreased by indentation or expansion of the material around the hole. From the experimental results, it is found that the fatigue life and crack growth behavior of a holed or notched specimen can be improved by a simple technical method that is related to the local plastic working.
THE EFFECT OF GEOMETRY ON FATIGUE LIFE FOR BELLOWS
Authors: KIM JINBONG
Published: March 2012

A bellows is a component installed in the automobile exhaust system to reduce or prevent the impact from engine. Generally, the specifications on the bellows are determined in the system design process of exhaust system and the component design is carried out to meet the specifications such as stiffness. Consideration of fatigue is generally an important aspect of design on metallic bellows expansion joints. These components are subject to displacement loading which frequently results in cyclic strains. This study has been investigated to analyze the effect of geometry on fatigue life for automotive bellows. 8 node shell element and non-linear method is employed for the analysis. The optimized shapes of the bellows are expected to give good guidelines to the practical designs.
MECHANICAL PROPERTIES OF A SINGLE CANCELLOUS BONE TRABECULAE TAKEN FROM BOVINE FEMUR
Authors: ENOKI SHINICHI , SATO MITSUHIRO , TANAKA KAZUTO , KATAYAMA TSUTAO
Published: March 2012

The increase of patients with osteoporosis is becoming a social problem, thus it is an urgent issue to find its prevention and treatment methods. Since cancellous bone is metabolically more active than cortical bone, cancellous bone is often used for diagnosis of osteoporosis and has received much attention within the study of bone. Bone is a hierarchically structured material and its mechanical properties vary at different structural levels, therefore it is important to break down the mechanical testing of bone according to the various levels within bone material. Mechanical properties of cancellous bone is said to be depended on quantities and orientation of trabecular bone. It is supposed that mechanical properties of trabecular bone are constant without depending on any structural arrangement and parts. However, such assumption has not been established in studies of trabecular bone. Furthermore test results have a large margin of error caused by insufficient shape assessment. In this study, three point bending tests of single cancellous bone trabeculae extracted from bovine femur were conducted to evaluate the effects of directions to the femur major axis direction on the mechanical properties. X-ray μCT was used to obtain shape of trabecular bone specimens. Furthermore compression tests of cancellous bone specimens, which were extracted in 10mm cubic geometry, were conducted for evaluation of directional properties.There were small difference in the elastic modulus of the trabecular bones which were extracted in parallel and in perpendicular to the major axis of femur. Considering from the results that the cancellous bone specimens, which were extracted in 10mm cubic geometry, have different elastic properties depending on the tested directions; the bone structure has larger influence than bone material property on the mechanical properties of cancellous bone.
IR SPECTROSCOPIC ANALYSIS OF THERMAL BEHAVIOR OF ADSORBED WATER ON Y-TYPE ZEOLITE
Authors: KATOH MASAHIRO , KOIDE RYUHEI , YAMADA KENZO , YOSHIDA TAKANORI , HORIKAWA TOSHIHIDE
Published: March 2012

In this study, we measured the IR spectra of water adsorbed at a differential temperature under constant pressure. Our purpose is to present a simple estimation method for the recycled temperature condition of water adsorbents. For a NaY zeolite, the IR integrated intensity of the bending vibration band of adsorbed water was increased with a decrease of temperature. The IR spectra were measured from 230°C to 30°C for several ion-exchanged Y-type zeolites. On the other hand, the adsorption isotherms of water on these zeolites were measured at 30°C. The result of this work is that the best correlation between the IR integrated intensity and the amount of adsorbed water was found for some of the zeolites. We concluded that the obtained correlation equation could easily estimate the amount of water desorbed between arbitrary temperatures.
A STUDY OF RICOCHET PHENOMENON FOR INCLINED IMPACT OF PROJECTILE
Authors: JO JONG-HYUN , LEE YOUNG-SHIN
Published: March 2012

In this study, the numerical simulation using AUTODYN-3D program was investigated for trajectory prediction for inclined impacts of projectiles. The penetration and perforation of polycarbonate( PC ) plate by 7.62 mm projectile was investigated numerically. The characteristic structure of the projectile's trajectory in the PC plates was studied. Two combined failure criteria were used in the target plate, and the target plate was modeled with the properties of polycarbonate for simulating the ricochet phenomenon. The numerical analyses were used to study the effect of the angle of inclination on the trajectory and kinetic energy of the projectile. The dynamic deformation behaviors tests of PC were compared with numerical simulation results which can be used for predictive purpose. Ricochet phenomenon for angles of inclination of 0° ≤ θ ≤ 20° in the analysis. The projectile perforated the plate for θ > 30°, thus defined a failure envelope for numerical configuration. The numerical analyses was used to study the effect under the projectile impact velocity on the depth of penetration(DOP).
THE PERFORMANCE ANALYSIS OF ULTRA HIGH SPEED PM TYPE SYNCHRONOUS MOTOR-GENERATOR FOR MICRO TURBINE
Authors: HONG DO-KWAN , WOO BYUNG-CHUL , JEONG YEON-HO , KOO DAE-HYUN , CHO YUN-HYUN
Published: March 2012

This paper deals with loss analysis, structural, thermal-fluid and rotordynamics (critical speed and unbalance) which need in developing the motor-generator. This machine has designed of a generator of 800 W, 400 krpm and a starter of 400 W, 200 krpm. The generated losses of motor-generator are derived by magnetic analysis. Thermal-fluid analysis is performed using loss analysis result. The critical speed is extracted by Campbell diagram. Unbalance vibration response analysis enable to predict the expected vibration amplitude by unbalance. The motor-generator is well-developed using the applied several techniques of analysis.
MICROSTRUCTURE EVOLUTION AND DEFORMATION FEATURE OF AZ31 MAGNESIUM ALLOY DURING SEVERE PLASTIC DEFORMATION
Authors: HOU LI-FENG , WEI YING-HUI , SHU XUE-FENG
Published: March 2012

A nanostructured surface layer was produced on commercially AZ31 magnesium alloy using surface mechanical attrition treatment (SMAT). The microstructure evolution and deformation feature along the depth of the treated surface layer were characterized by transmission electron microscope (TEM) investigations. The grain refinement process, accompanied by an increase in the surface layer, involves: the onset of twins; the formation of microbands associated with the dislocation slipping; the subdivision of microbands into low angle grains and then highly disoriented polygonal submicronic grains, and further breakdown into randomly oriented nanograins with progression of dynamic recrystallization.
BORON DOPED nc-Si:H WINDOW LAYER PREPARED BY HW-CVD FOR SOLAR CELL APPLICATIONS
Authors: PRAMOD M. R , KAMBLE M. M. , WAMAN V. S. , GORE S. P. , FUNDE A. M. , SATHE V. G. , PATIL K. R. , GOSAVI S. W. , JADKAR S. R.
Published: March 2012

In this work, we report on synthesis of boron doped hydrogenated nanocrystalline silicon ( p - nc - Si : H ) films by HW-CVD method. Films were prepared at low substrate temperature (165 °C) and low process pressure (20 mTorr) by varying diborane gas phase ratio [defined as R B 2 H 6 = ( F B 2 H 6/ F SiH 4)×100%]. The material properties of these films are studied using micro-Raman spectroscopy, low angle X-ray diffraction, X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy, dark conductivity measurements etc. The correlation between R B 2 H 6 and resulting material properties such as crystalline volume fraction, crystallite size, band gap and hydrogen content has been established. We have obtained high band gap (~ 2.48 eV) p - nc - Si : H films having dark conductivity (~ 0.6 S/cm) with low hydrogen content (~ 1.8 at. %) at high deposition rate (~19.2 Å/s). The employment of these films in a - Si : H based p - i - n solar cell as a p -type window layer could have low absorption losses thereby enhancing the current density which in turn would enhance the conversion efficiency of solar cell.
THE CONCEPTS AND PROPERTIES OF NANO-SKIN MATERIALS AND COMPONENTS CREATED BY ULTRASONIC NANOCRYSTAL SURFACE MODIFICATION
Authors: PYUN YOUNG SIK , KAYUMOV RAVIL
Published: March 2012

Material surface and immediate subsurface layers can be called "skin". A novel Ultrasonic Nanocrystal Surface Modification (UNSM) technology produces uniformed micro dimples on the top surface and nanometer grain in the subsurface; increases surface hardness and induces compressive residual stress, therefore mechanical characteristics related to fatigue, wear, friction, etc. can be improved. The concepts and properties of nanoskin materials and components are proposed with their potential application.
A DEVELOPMENT OF MULTI PURPOSE TESTING MACHINE FOR FRICTION, WEAR AND ROLLING CONTACT FATIGUE
Authors: CHOI GAB-SU , PYUN YOUNG-SIK , KIM JUN-HYOUNG , KIM HAK-DOO , TOMINAGA YASUTOSHI , DARISUREN SHIRMENDAGWA
Published: March 2012

In this paper, the newly developed tribometer was introduced. Ball-on-disk, pin-on-disk, small-sized journal and thrust bearings tests on friction and wear were carried out using a newly developed tribometer which is built up according to the ASTM G99. Those friction and wear test results were compared with the friction results which were approved by Korean (KOLAS) and CSM Instruments. The comparison revealed that friction characteristics and trends of three different tribometers were similar to each other. The objective of this paper is to demonstrate the capability of the newly developed tribometer. As a result, the newly developed tribometer is capable of performing friction tests using pin-on-disk, disk-on-disk, journal and thrust bearings configurations.
THE OPTICAL AND ELECTRICAL PROPERTIES OF ZnO/Ag/ZnO FILMS ON FLEXIBLE SUBSTRATE
Authors: Yu Xiaojing , Zhang Dongyan , Wang Pangpang , Murakami Ri-ichi , Ding Bingjun , Song Xiaoping
Published: March 2012

The deposition of ZnO / Ag / ZnO film on polyethylene terephthalate (PET) substrate was fabricated by DC magnetron sputtering method. The thicknesses of ZnO layers were 30 nm and Ag films' thicknesses were changed from 1 nm to 6 nm by controlled the sputtering time. This kind of film can be used as transparent conductive oxide (TCO) materials. The electrical and optical properties of composite layers were determined by Ag films. The optimum sputtering time of Ag thin films was found to be 20 s for the high optical transmittance with good electrical conductivity. The ZnO / Ag (20 s )/ ZnO layer, which has high optical transmittance of 73% at 550 nm, shows sheet resistance as low as 6.7 ohm/sq. These multilayer transparent films had low electrical resistance as the widely used transparent conductive oxide electrodes. SEM, XRD, the UV-Vis-NIR and Hall Effect measurement system were used to characterize properties of fabricated films. The reasons for the change of transmittance and resistance will also be interpreted.
STRAIN MEASUREMENT AT CANTILEVER BEAM WITH FIBER BRAGG GRATING SENSORS AND COLLIMATORS AND ITS CORRECTION METHOD
Authors: Tak Seung Min , Kang Min Kyu , Park Dong Jin , Lee Seok Soon
Published: March 2012

Recently, Fiber Bragg Grating(FBG) sensors are being used in various fields. However, it has difficulty to measure at the place where it is not possible to connect fibers each other physically. In this study, using FBG a collimator, we have measured strains with a single optical fiber with many FBG sensors where FBG sensors on one optical fiber line is installed on the beam and the other optical fiber line is connected with an optical interrogator installed at stationary side. The optical fiber lines between an optical fiber line with FBG sensors on the beam and the other optical fiber line on the stationary part are connected by the collimator which makes the use of light's unique characteristic - light travels through space. The experiment showed that the wave length of the light were changed to be linear as strains increased, and the accurate strains were measured by applying the collimator collection factor, which was proposed in this paper.
A STUDY OF OPTIMUM DESIGN AND ANALYSIS WITH D.O.E FOR AUTOMOTIVE SEAT FRAME
Authors: JUNG H. J. , CHO Y.H. , LEE D. S. , OH J.C. , KWON Y. D.
Published: March 2012

In modern times, development trend of automobiles is the tendency to prefer the high fuel efficiency of automobile. Also, the structure of seat that takes 4% of automobile's weight is the target to be secured the stability enough and attain the lightweight, To meet this, the characteristics of load to be applied to seat structure must be analyzed from the initial time, and it must be considered and designed material, thickness, distance to be assembled with recliner and condition of section through the calculation of numerical value. This study performed to reduce stress and moments to be occurred to seat frame through keep the optimum condition with D.O.E for cushion frame of seat due to passenger inertia weight at the rear Collision of automobile, This study looked for optimum values with Minitab and analyzed the cushion frame of seat with LS-DYNA, FEA tool, according to those Factor.
EXPERIMENTAL VERIFICATION OF COUPLED STIFFNESS MATRIX IN MULTILAYER COMPOSITE STRUCTURE WITH COMPLEX CURVATURE
Authors: Jang Jun Hwan , Kim Jae Hoon
Published: March 2012

The paper presents an experimental verification for calculating coupled stiffness matrix in complex curvature composite structure. The results of the analytical procedure using Variational Asymptotic Beam Sectional Analysis also indicate that the calculation of 2-D, beam, cross-sectional properties can then be incorporated into and 1-D beam analysis expressed coupled stiffness matrix. This paper presents the 2-D cross-sectional analysis of active anisotropic beams. Comparison between the analytical and experimental results shows that the proposed analytical procedure can provide an accurate and efficient prediction of the both deflection and flexural stiffness of multilayer composite slender structure. Verified comparison results can be used to efficiently design accurate complex slender structure properties for preliminary design and optimization.
EFFECTS OF POROSITY ON ULTRASONIC CHARACTERISTIC PARAMETERS AND MECHANICAL PROPERTIES OF GLASS FIBER REINFORCED COMPOSITES
Authors: Ma Wen , Liu Fushun
Published: March 2012

Voids are inevitable in the fabrication of fiber reinforced composites and have a detrimental impact on mechanical properties of composites. Different void contents were acquired by applying different vacuum bag pressures. Ultrasonic inspection and ablation density method were adopted to measure the ultrasonic characteristic parameters and average porosity, the characterization of voids' distribution, shape and size were carried out through metallographic analysis. Effects of void content on the tensile, flexural and interlaminar shear properties and the ultrasonic characteristic parameters were discussed. The results showed that, as vacuum bag pressure went from -50kPa to -98kPa, the voids content decreased from 4.36 to 0.34, the ultrasonic attenuation coefficient decreased, but the mechanical strengths all increased.
NON-DESTRUCTIVE EVALUATION FOR HORIZONTAL CRACKS IN EXISTING RC SLABS BY ANALYSIS-AIDED IMPACT ELASTIC-WAVE METHODS
Authors: Lee Heung-Soo , Kamada Toshiro , Uchida Shinya , Iwasaki Toshiki
Published: March 2012

In this study, impact elastic-wave method was performed at the bottom surface of RC slab cut from an existing highway bridges to survey the horizontal cracks. Before measurements by impact elastic-wave method, impact response analysis was applied to determine optimal steel ball diameter, distance between impact point and receiving point of elastic-wave. Efficiency of analysis-aided impact elastic-wave method was confirmed by drilling and observing the interior of the RC slab by stick scanner. Evaluation results by this method agreed well with results of visual inspection. Thus, validity of the analysis-aided impact elastic-wave method on detection of horizontal cracks in RC slabs of highway bridges was demonstrated.
MICROSTRUCTURAL OBSERVATION AND SIMULATION OF POLYMER CEMENT WATERPROOFING MEMBRANE
Authors: TSUKAGOSHI MASAYUKI , TANAKA KYOJI
Published: March 2012

A polymer-modified cement waterproofing membrane is formed by simultaneous cement hydration and polymer film formation, these rates are affected by the moisture content of the polymer emulsion used. The moisture content gradually decreases due to cement hydration and evaporation from the surface. This study focused on the changes caused in the waterproof layer by differences in the moisture environment. Four test pieces with different cement, polymer, and moisture contents were prepared and cured at 20 °C and relative humidities of 25, 60, and 98 %. The basic physical properties of the test pieces were studied in tensile tests; the structures were observed using an EPMA. Furthermore a simulation was carried out using a model that considers cement hydration, polymer film formation, and moisture evaporation rate. The simulation results well reproduced the experimental results.