bluuebunny/crossref_metadata_2025 huggingface dataset:
In-Line Monitor Introduction to Prevent Metallic Contamination in Wet Bench
Authors: Mello Domenico , Cordiano Francesco , Gerosa Andrea , Padalino Margherita , Gagliano Carmelo , Renna Giovanni , Franco Giovanni
Published: March 2009

Contamination controls are very important issues in microelectronics. Any wrong substance introduction in process chambers can cause damages to the production line. Therefore, an extensive control is important because every operation in the process flow (also the most insignificant) can become fatal for the correct functioning of a microelectronic device.
The aim of this work is to evaluate the impact of small metallic contamination in the range of 1011÷1012 at/cm2 on silicon substrates implanted with different ion species (As, B and P). An important example of failure related to metallic contamination in a wet bench is reported in this work. The problem appears in a particular class of flash memory devices processing. The electrical parametric test shows a wrong gate oxide thickness and Qbd values out of range, confirmed by early breakdown events and anomalous C-V characteristics. The cause of the failure is morphologically identified off-line by using TEM: the cross section shows a wrong gate oxide thickness and an anomalous interface between gate oxide and silicon substrate.
It appears clear that the root failure cause is related to the ion implantation (As in this case) and to the cleaning before gate oxide growth.
A short process flow was performed and analyzed step by step in order to identify the failure cause. Many different analytical techniques have been used for each step and all of these provide consistent results. In particular TXRF analysis on wafers processed immediately after cleaning do not show any contamination while Cu and Fe contaminants are observed after sample oxidation and As implant.
Metallic contaminants are captured by the substrate after it is implanted with As, and the following RCA cleaning is not able to remove them. In addition, the presence of these metallic contaminants induces roughness of the Si surface and the growth of gate oxide is not controlled (faster oxidation).
If different substrates are used, e.g. silicon implanted with B or un-implanted, this contamination level is not detected and does not lead to oxide reliability problems.
Once the mechanism of metal contaminant interaction with dopant is identified the introduction of an in-line monitoring is possible, thus allowing to prevent the device failure. The short process loop can be considered as a good method to prepare the substrate before TXRF analysis. After this study the monitor has been integrated in the production line controls
Measurement of Copper in p-Type Silicon Using Charge-Carrier Lifetime Methods
Authors: Yli-Koski Marko , Savin Hele , Saarnilehto E. , Haarahiltunen Antti , Sinkkonen Juha , Berenyi G. , Pavelka T.
Published: March 2009

We compare SPV technique with µ−PCD for the determination of recombination activity of copper precipitates in p-Si. The copper precipitates were formed in bulk silicon through illumination at room temperature. We observed that the recombination activities of copper precipitates measured with SPV are higher than the ones measured with µ−PCD technique. However, it seems that the copper detection sensitivity is about the same with SPV and µ−PCD techniques.
Ab Initio Investigations of Threshold Displacement Energies and Stability of Associated Defects in Cubic Silicon Carbide
Authors: Lucas Guillaume , Pizzagalli Laurent
Published: March 2009

Using first principles molecular dynamics simulations, we have recently determined the threshold displacement energies and the associated created defects in cubic silicon carbide. Contrary to previous studies using classical molecular dynamics, we found values close to the experimental consensus, and also created defects in good agreement with recent works on interstitials stability in silicon carbide. We have also investigated the stability of several Frenkel pairs, using transition state theory and constrained path calculations.
Recent Progress in Understanding of Lattice Defects in Czochralski-Grown Germanium: Catching-up with Silicon
Authors: Vanhellemont Jan , Hens Steven , Lauwaert J. , De Gryse Olivier , Vanmeerbeek Piet , Poelman Dirk , Śpiewak P. , Romandic Igor , Theuwis Antoon , Clauws Paul
Published: March 2009

Recent progress is presented in the understanding of grown-in defects in Czochralskigrown germanium crystals with special emphasis on intrinsic point defects, on vacancy clustering and on interstitial oxygen. Whenever useful the results are compared with those obtained for silicon.
Theoretical Investigations of the Energy Levels of Defects in Germanium
Authors: Jones R. , Carvalho A. , Coutinho J. , Torres Vitor , Öberg Sven , Briddon Patrick R.
Published: March 2009

The donor and acceptor levels of defects in Ge as well as in Si are found using a local density functional method applied to large H-terminated defective clusters. The surfaces of the clusters are modified so that their band gaps are aligned with experimental values. It is shown that the resulting energies of the first donor and acceptor levels are within about 0.2 eV of the experimental values.
Evolution of Quantum Electronic Features with the Size of Silicon Nanoparticles Embedded in a SiO2 Layer Obtained by Low Energy Ion Implantation
Authors: Grisolia Jeremie , Shalchian M. , Benassayag G. , Coffin H. , Bonafos Caroline , Dumas C. , Atarodi S.M. , Claverie A.
Published: March 2009

In this paper, we have studied the evolution of quantum electronic features with the size of silicon nanoparticles embedded in an ultra-thin SiO2 layer. These nanoparticles were synthesized by ultralow energy (1 KeV) ion implantation and annealing. Their size was modified using the effect of annealing under slightly oxidizing ambient (N2+O2). Material characterization techniques including transmission electron microscopy (TEM) Fresnel imaging and spatially resolved electron energy loss spectroscopy (EELS) have been used to evaluate the effects of oxidation on structural characteristics of nanocrystal layer. Electrical transport characteristics have been measured on few (less than two hundred) nanoparticles by exploiting a nanoscale MOS capacitor as a probe. Top electrode of this nanoscale capacitor (100 nm x 100 nm) was patterned over the samples by electron-beam nanolithography. Room temperature I-V and I-t characteristics of these structures exhibit discrete current peaks which have been interpreted by quantized charging of the nanoparticles and electrostatic interaction between the trapped charges and the tunneling current. The effects of progressive oxidation on these current features have been studied and discussed.
Pulsed Laser Deposition of Hafnium Oxide on Silicon
Authors: Kappa Mathias , Ratzke Markus , Reif Jürgen
Published: March 2009

Hafnium oxide films were prepared by Pulsed Laser Deposition (PLD). The influence of laser wavelength (fundamental, second and third harmonic of a Nd:YAG laser), used for evaporation, and substrate temperature on the film morphology, chemical structure and interfacial quality were investigated yielding the following results: While the laser wavelength exhibits minor influence on layer structure, the substrate temperature plays a critical role regarding morphological and chemical structure of the produced hafnium oxide / silicon stacks. Atomic Force Microscopy (AFM) images show a clear transition from smooth layers consisting of small area crystallites to very rough surfaces characterized by large craters and regular, plane features when the growth temperature was increased. These facts suggest a chemical instability which is confirmed by X-ray Photoelectron Spectroscopy (XPS). Investigations of the hafnium and silicon core level spectra indicate the occurrence of silicon dioxide and hafnium silicide in the case the samples were produced at elevated temperatures.
Modification of Silicon Oxide by High Energy Electron Beam
Authors: Kolesnikova E.V. , Sitnikova Alla A. , Sokolov V.I. , Zamoryanskaya M.V.
Published: March 2009

During interaction between thin film SiO2 and electron beam with high power density, amorphous silicon dioxide modifies. Silicon nanoclusters are formed in radiated area. Result of this interaction is formation of Si/SiO2 nanocomposite. We studied modified SiO2 by TEM, microdiffraction and cathodoluminescence.
Rare Earth Ion Implantation for Silicon Based Light Emission
Authors: Skorupa Wolfgang , Sun J.M. , Prucnal S. , Rebohle L. , Gebel T. , Nazarov A. , Osiyuk I.N. , Helm M.
Published: March 2009

Using ion implantation different rare earth luminescent centers (Gd3+, Tb3+, Eu3+, Ce3+, Tm3+, Er3+) were formed in the silicon dioxide layer of a purpose-designed Metal Oxide Silicon (MOS) capacitor with advanced electrical performance, further called a MOS-light emitting device (MOSLED). Efficient electroluminescence was obtained for the wavelength range from UV to infrared with a transparent top electrode made of indium-tin oxide. Top values of the efficiency of
0.3 % corresponding to external quantum efficiencies distinctly above the percent range were reached. The electrical properties of these devices such as current-voltage and charge trapping characteristics, were also evaluated. Finally, application aspects to the field of biosensing will be shown.
Carrier Accumulation in Silicon-On-Insulator Structures Containing Ge Nanocrystals in the Burried SiO2 Layer
Authors: Tyschenko Ida E. , Frantsuzov A.A. , Naumova O.V. , Fomin B.I. , Nikolaev D.V. , Popov V.P.
Published: March 2009

Electro-physical properties of metal-oxide-silicon (MOS) structures and MOS transistors, prepared in the top silicon layer of silicon-on-insulator (SOI) structures containing Ge nanocrystals in the buried SiO2 layers, have been studied. It was obtained that carrier accumulation in MOS structures depend on the direction of built-in electrical field in MOS structures. Accumulation of the excess negative charges in the case of p-channel transistors is associated with electron trapping on Ge nanocrystals synthesized in the buried dielectric. In the case of n-channel transistor, positive charge related to the Si/SiO2 interface or to the charged oxide is accumulated. The Ge atoms diffused to the SiO2/Si interface can stimulate the formation of the excess positive charge.
Dislocation Related PL of Multi-Step Annealed Cz-Si Samples
Authors: Steinman E.A. , Tereshchenko A.N. , Vdovin V.I. , Misiuk Andrzej
Published: March 2009

The samples of Cz Si were subjected to multi-step annealing at different temperatures. After high temperature consequent steps the dislocation related spectra (DRL) were detected from the samples. The main feature of the DRL spectra was the very narrow low energy bands D1/D2, which are unusual for Cz Si. TEM analysis shown that the only candidates for DRL spectra are dislocation loops, punched out from precipitates. To explain the absence of influence of oxygen it was assumed that the distribution of interstitial oxygen is nonuniform in such samples and has some depletion regions in the vicinity of precipitates.
Defect Formation in MBE Er-Doped Si Light-Emitting Structures
Authors: Vdovin V.I. , Sobolev N.A. , Denisov D.V. , Shek Elena I.
Published: March 2009

Structural defects in Si:Er layers grown by molecular beam epitaxy have been studied by transmission electron microscopy. Two kinds of second phase precipitates are the main defects in the layers with Er concentration ≥ 2х1019 cm-3: ball-shaped precipitates (4-25 nm) of metallic Er localized at the layer-substrate interface and platelet precipitates of ErSi2 extending through the whole layer. We studied the effect of Er concentration (8х1018 - 4х1019 cm-3) and growth temperature (400 - 700°C) on the defect generation. The peculiarities of defect generation in MBE Si:Er layers implanted with B+ ions were also studied.
Atomistic Nanodevice Simulation
Authors: Lannoo Michel
Published: March 2009

There now a large variety of methods exists for the elaboration of nanoobjects and nanodevices. At the same time the reduction in size together with the improvement of
theoretical techniques and computational power should allow efficient quantitative simulation of these objects. Such predictive simulation is highly needed since it can serve as a useful guide to build new nanostructures with the desired properties. The aim of this talk is than to give an overview of what has already been achieved in this rapidly evolving field, what can be done at present and what is expected for the future. The focus will be mostly on semiconductor nanostructures and especially silicon.
Interfacing Biology with Electronic Devices
Authors: Offenhäusser Andreas , Ingebrandt Sven , Mayer Dirk
Published: March 2009

Due to a number of advances in molecular biology, cell and tissue culture in combination with more sensitive methods to transduce biological signals, it has become increasingly feasible to detect unknown toxicity or pharmacological effects by using biological systems which are electrically coupled to micro- or nanoelectrodes or field-effect transistors (FETs). The coupling of biomolecules with electronic devices is demonstrated. In order to identify the contributions of the various cell signals we have investigated the coupling of cardiac myocytes with FETs. On the other side such systems can also be used to study the very basics of distributed information processing by interfacing cultured neuronal networks with microelectronic devices.
Thin SiGe Relaxed Buffer for Strain Adjustment
Authors: Kasper Erich , Lyutovich Klara
Published: March 2009

Strain adjustment is obtained by virtual substrates which are composed of a silicon substrate and a strain relaxed buffer. The basics of strain relaxation are explained and applied to the covalent bonded Si/Ge system which shows a large regime of metastability. A solution to ultrathin strain relaxed buffers is given by the injection of point defects which nucleate to dislocation loops in the interface. Principle and injection mechanism are shown.
Ge Nanoclusters in GeO2: Synthesis and Optical Properties
Authors: Volodin Vladimir A. , Gorokhov E.B. , Marin D.V. , Cherkov A.G. , Gutakovskii Anton K. , Efremov M.D.
Published: March 2009

Ge nanocrystals (NCs) in GeO2 films obtained with the use of two methods were studied. The first method is a film deposition from supersaturated GeO vapor with subsequent dissociation of metastable GeO on heterophase system Ge:GeO2. The second method is growth of anomalous thick native germanium oxide layers with chemical composition GeOx(H2O) during catalytically enhanced Ge oxidation. The obtained films were studied with the use of photoluminescence (PL), Raman scattering spectroscopy, high-resolution electron microscopy (HREM). Strong PL signals were detected in GeO2 films with Ge-NCs at room temperature. “Blue-shift” of PL maximum was observed with reducing of Ge excess in anomalous thick native germanium oxide films. Also a correlation between reducing of the NC sizes (estimated from position of Raman peaks) and PL “blue-shift” was observed. The Ge NCs presence was confirmed by HREM data. The optical gap in Ge-NCs was calculated with taking into account quantum size effects and compared with the position of the experimental PL peaks. It can be concluded that a Ge-NC in GeO2 matrix is a quantum dot of type I.
A Nondestructive Life Evaluation Using Creep-Fatigue Damage by SDA
Authors: Kim Bum Joon , Lim Byeong Soo , Song Sung Jin
Published: March 2009

Generally, as the hold time of static load increases, the degradation of material becomes more rapid and the creep-fatigue life decreases. Under the creep-fatigue interaction, the cause of life decrease was mainly the initiation and growth of microvoid with increasing hold time. In this study, using the newly developed alloy of P92, the artificial creep-fatigue degradation tests and its ultrasonic
inspection were carried out to evaluate creep-fatigue life. From the relations between the creep-fatigue life and the nondestructive degradation assessment by backscattered ultrasound inspection, the new nondestructive life evaluation parameter, SDA (Slope of Decaying Amplitude) was proposed. Also, to verify the nondestructive life evaluation ability, the life evaluation results by SDA were compared with those of the destructive life evaluation obtained through the fraction of
cavity area. From the test result of backscattering Rayleigh surface wave, the linear relationship between SDA and experimental life could be obtained. The good agreement between the experimental life and the predicted life by SDA was also obtained. Finally, it can be stated that the new life evaluation/degradation parameter, SDA (Slope of Decaying Amplitude) could be utilized for the evaluation of the material degradation under creep-fatigue interaction.
Dynamic Analysis of Contacting Spur Gear Pair for Fast System Simulation
Authors: Suzuki Daisuke , Horiuchi Shigeru , Choi Jin Hwan , Ryu Han Sik
Published: March 2009

The prime source of vibration and noise in a gear system is originated from transmission error between the meshing gears. In this paper, the dynamic modeling method and response of a spur gear pair for the efficient system simulation are investigated by using a detailed contact analysis at each time step. Input values such as time-varying mesh stiffness and static transmission error excitation are not required in this investigation because mesh forces are obtained by contact analysis directly. The efficient contact search kinematics and algorithms in the context of the compliant contact model are developed to detect the interactions between teeth surfaces. In this investigation the compliant force model based on the Herzian law is employed using Coulomb friction force model, and dynamic transmission error (DTE) and mesh frequency values of contacting gear system are also illustrated.
Numerical Analysis of Compound ECT Signals due to Various Tube Defects near Support Plate in Steam Generator
Authors: Shin Young Kil , Lee Yun Tai , Song Myung Ho
Published: March 2009

In this paper, eddy current signals from various anomalous defects in the steam generator tube are numerically predicted and their signal slope characteristics are investigated. The signal variations due to increased frequencies are also observed. Based on the accumulated knowledge, the analysis of compound signal is attempted which includes the effect of support plate. Both differential and absolute bobbin probe signals are analyzed. For the signal prediction, axisymmetric finite element
modeling is used and this leads us to the utilization of slope angle analysis of the signal. Results show that differential signals are useful for locating the position of defect under the support plate, while absolute signals are easy to presume and interpret even though the effect of support plate is mixed. Combined use of these two types of signals will help us accomplish a more reliable inspection.
Development of a Neural Network-Based Real-Time Fatigue Monitoring System for the Heavy Load Carrying Facility
Authors: Kim Jong Choon , Jung Sung Wook , Choi Jae Boong , Chang Yoon Suk , Kim Young Jin , Hwang In-Ju
Published: March 2009

The heavy load carrying facility, such as ladle crane, is operating under severe working environment. It usually carries melted iron to the furnace, and thus, the accident due to crane failure may cause detrimental damage to the entire steel making factory. While the ladle crane is designed for 20 years of safe operation in a steel making company, several critical cracks due to fatigue loading
have been reported during the maintenance process. In order to prevent fatal failure due to crack growth, ladle crane has been periodically inspected and maintained. However, the inspection and maintenance including repair and replacement cause the whole manufacturing line to stop, it is critical to set the appropriate inspection interval and replacement criteria. For this reason, the importance of
plant maintenance (PM) has been highly raised to provide efficient plant operation. Recently, a number of engineering methodologies, such as fitness for service guidelines (FFS) and plant lifecycle management (PLM) system, have been applied to improve the plant operation efficiency. Also, a network-based business operation system, which is called ERP (Enterprise Resource Planning), has been introduced in the field of plant maintenance. However, there hasn’t been any attempt to connect engineering methodologies to the ERP PM(Plant Maintenance) system. In this paper, an engineering methodology which provides life time evaluation under fatigue loading has been implemented to the web-based ERP PM system along with real-time fatigue monitoring system. In order to monitor the real time loading, a web-based fatigue monitoring system for ladle
crane has been developed and installed inside the ladle crane. For the estimation of fatigue life, 3-dimensional finite element (FE) analyses were conducted for actual transients. Finally, the fatigue life time estimation program is developed by integrating FE analysis results and real-time monitoring data. For the direct calculation of remained fatigue life, an artificial neural network (ANN) algorithm
has been applied. The proposed system is expected to play a great role in determining appropriate inspection and maintenance schedule which has become critical issue for the efficient plant maintenance.
Risk Assessments of Columns Using RBI Program in Petrochemical Plant
Authors: Lee Sang Min , Chang Yoon Suk , Choi Jae Boong , Kim Young Jin , Han Sang In , Choi Song Chun , Kim Ji Yoon
Published: March 2009

Risk-based inspection (RBI) guideline based on API 581 provides a methodology for calculating the risks of equipment in refinery or petrochemical plant. However, there is a major limitation of its application to the petrochemical plant directly since only a representative material is considered in calculating the risk, especially in part of the consequence of failure, even though the equipment is composed of numerous materials. The objectives of this paper are to develop an enhanced RBI program to resolve shortcoming inclusive of the above issue and to evaluate the risks of
equipment in petrochemical plant using the program. In this respect, the mole fractions of materials were used to fully incorporate the characteristics of different materials. The proposed RBI program consists of qualitative, semi-quantitative and quantitative risk evaluation modules in which toxic materials as well as representative materials were selected automatically for comparison with those in
the current guideline. The RBI program has been applied to evaluate the risks of equipment in Naphtha Cracking Center (NCC) which is a typical facility of petrochemical plant. Thereby, promising evaluation results were obtained and applicability of the proposed RBI program was proven.
Structural Stress Based Fatigue Life Evaluation for Heat Exchanger Motor Operated Valve
Authors: Chang Yoon Suk , Kim H.K. , Choi Jae Boong , Kim Young Jin
Published: March 2009

In ASME Sec. III ‘design by analysis’ approach, stresses are generally calculated by finite element method and compared to corresponding stress limits after categorizing those components. However, in order to obtain optimum results, time consuming and expensive manipulations are required owing to its mesh size dependency and complicate stress categorization. In this paper, a new approach based on structural stress is proposed to resolve the issues and applied to a heat exchanger motor operated valve. At first, the technical bases and specific features of structural stress approach are briefly discussed. Secondly a series of finite element analyses are carried out to show the limitations of current ASME approaches and to get basic data for the proposed approach. Finally, a structural stress concentration factor of motor operated valve is determined after comparison of local stresses and structural stresses, and utilized for fatigue life evaluation. Since the results show a promising applicability, it seems that the structural stress based approach can be utilized for fatigue life evaluation of components with complex geometries.
Quantification of Crack-Tip Constraint Effect on Master Curve Reference Temperature Based on Two-Parameter Approach
Authors: Huh Nam Su , Stumpfrock Ludwig , Schuler Xaver , Roos Eberhard
Published: March 2009

The master curve has evolved into a mature technology for characterizing the fracture toughness transition of ferritic steels. However, it is well known that the master curve reference temperature (To) values estimated from small laboratory specimen may be biased low due to loss of crack-tip constraint. To quantify such variations of To resulting from differences of crack-tip constraint of testing specimen, two-parameter fracture mechanics approaches are employed in the present study. In this context, fracture toughness test and 3-dimensional finite element (FE) analysis for several standard and nonstandard test specimens are performed to quantify relationship between variations of To and constraint parameters and to find best constraint parameter representing effect of crack-tip constraint on To values evidently. Based on testing and present FE results, To and constraint parameter loci are constructed and engineering To correlation models considering crack-tip constraint are suggested
Structure-Property Relations in xCuO-(1-x)As2O3-0.7B2O3 (0.01≤x≤0.05) Glasses by Magnetic Susceptibility Measurements, IR and EPR Spectroscopy
Authors: Das B.B. , Gopinath A.
Published: March 2009

Studies on xCuO-(1-x)As2O3-0.7B2O3(0.01≤x≤0.05) (G1-G5: x = 0.01, 0.02, 0.03, 0.04, 0.05) glasses were done using varieties of structure sensitive techniques. The powder X-ray diffraction (XRD) studies show the formation of glasses in the composition. The IR spectral results show the presence of Cu-O bond, planar [BO3/2] and [BO3 -n](n=1, 2, 3) units and tetrahedral
{BO4/2]- units. The magnetic susceptibility results show Curie-Weiss behaviour in the range 4.2-400 K. The calculated values of the exchange integral from the Weiss constant obtained form the linear fit of the Curie-Weiss law are found to be in the range 5.22-29.50 meV. From the trend of the gmatrices of gơ>g⊥>ge (ge =2.0023) obtained from electron paramagnetic resonance (EPR) lineshapes
simulation we conclude that the paramagnetic site in these glasses is Cu2+(3d9) which is in a tetragonally elongated octahedron [O1/2-CuO4/2-O1/2] exhibiting Jahn-Teller distortion having D4h symmetry with orbital singlet 3dx2-y2 (2B1g) as the ground state.
Preparation and Characterization of Polyimide-Silica Nanocomposites by Sol-Gel Process
Authors: Cheng Yao Yi , Chuang Kun Chang
Published: March 2009

Polyimide (PI)-based nanocomposites were prepared by the in-situ generation of
organic silica nano-particles through a sol-gel process, combined with spin coating and multi-step curing process. In this study, silica nano-particles were introduced into the PI matrix to promote its thermal properties. Nanometer-scale composites were successfully obtained from poly(amic acid) (PAA) mixture loaded with silica. 3,3’,4,4’- Biphenyl tetracarboxylic dianhydride (BPDA) and p-phenylenediamine (p-PDA) were employed to synthesize the PAA precursor. The hybrid thin film was prepared from aminoalkoxysilane-capped PAA and tetraethoxysilane (TEOS). In this work, we investigated the effect of coupling agent, 3-aminopropyltriethoxysilane (APrTEOS). The TGA results
indicate that the thermal stability of the nanocomposites can be enhanced as silica content increases. Without the incorporation of APrTEOS, less improvement can be achieved.
Finite Deformation Behavior of Biological Soft Material on Cartilage Anisotropy under Loading Conditions
Authors: Punantapong Boonyong , Thongtem Somchai , Fagan M.J. , Soorapanth C.
Published: March 2009

Cartilage and bone are specialized connective tissues composed of roughly the same material: cell embedded in an extracellular matrix, permeated by the network of fibers. Then the properties of cartilage are anisotropic and inhomogeneous structure. At the same time, the structure of cartilage is rather porous allowing fluid to move in and out of the tissue. Thus the properties of cartilage were changed with the fluid content. The objective of this study is to demonstrate that the
biomechanical properties of the pericellular matrix vary with depth from the coated cartilage surface, and observed regions of cartilage failure. This objective is achieved by solving problems with the finite element method. The conceptual model was subjected to the boundary conditions of confined compression on porous of cartilage anisotropy. The experimental results were demonstrated that neither the Young’s modulus nor the Poisson’s ratios exhibit the same values
when measured along the loading directions. The results were supported an essential functional property of the tissue which the glenoid surface may be susceptible to cartilage degeneration.
The Influence of the Interactions between the Organic and Inorganic Species on the Structural Stabilities of Hybrids (CnH2n+1NH3)2 MCl4
Authors: Guo L.L. , Chen L.M. , Liu H.X. , Ouyang Shi Xi
Published: March 2009

This paper focuses on the influence of interactions between different species in hybrids (CnH2n+1NH3)2MCl4 (M = Mn, Cu; n =2,4,6,8,10) on the structural stabilities. DSC-TG curves were used to find out the onset and the end decomposition temperatures. The results show that the hybrids of M =Cu start to decompose at about 210 centigrade degrees, average 25 centigrade
degrees lower than that of M=Mn. The end temperatures of M=Cu are also lower. This suggests that in this case the thermal stabilities of the hybrids would be governed by the interactions between the organic and inorganic species and are little affected by weak Van de Waals interactions between the
organic and organic species.
Characterization of TiOxNy Films Grown by PECVD Method: Structural and Optical Properties
Authors: Jung C.K. , Bae I.S. , Song Y.H. , Cho S.J. , Boo Jin Hyo
Published: March 2009

Titanium oxynitride (TiOxNy) films were prepared by RF PECVD on Si(100) and glass substrates using nitrogen and argon mixture gas. Titanium iso-propoxide (Ti[OCH(CH3) 2] 4, 97%) was used as precursor with different nitrogen flow rate to control oxygen and nitrogen contents in the films. Changes of chemical states of constituent elements in the deposited films were examined
by X-ray photoelectron spectroscopy (XPS) analysis. With increasing nitrogen flow rate the total amount of nitrogen was increased while that of oxygen was decreased. The film growth orientation and N-H peak intensity characteristics were also analyzed by X-ray diffraction (XRD), atomic force microscopy (AFM), and infrared spectroscopy (FT-IR). Through refractive index as well as contact
angle analysis, we can suggest that relationship to surface energy and optical property. Moreover, transmission electron microscopy (TEM) was also used to investigate the morphology of TiOxNy thin film and the phase of the TiOxNy thin film different nitrogen flow rate.
Hybrid MOS/CNTs Materials for Gas Sensing
Authors: Liou W.J. , Lin Hong Ming , Yang T.Y. , Lin K.N.
Published: March 2009

Most of the gases detecting metal oxide semiconductors are operated at temperatures above 250oC. It is not energy efficient for MOS gas sensors to operate at such high temperature. To solve this problem, research and investigations are trying to obtain new MOS sensing materials that can operate at ambient temperature. In this study, gas sensing materials consisting of MOS and carbon nanotubes (CNTs) are developed for detecting gases at lower temperature. The hybrid system, MWCNTs/TiO2, demonstrates the possibility of detecting the gases at ambient temperature with high energy efficiency.
Synthesis and Characterization of Hybrid Aluminum Composites Reinforced with Ni Particulates and Interconnected Fe Mesh
Authors: Wong W.L.Eugene , Gupta Manoj , Lim C.Y.H.
Published: March 2009

In this study, pure aluminum reinforced with interconnected galvanized iron mesh and Ni particulates was synthesized using an innovative disintegrated melt deposition technique followed by hot extrusion. Microstructural characterization of composite samples showed uniform distribution of Ni and Al-Ni based intermetallic particulates in the matrix material, good interfacial integrity of aluminum matrix with iron mesh and Ni particulates and the presence of minimal porosity. Results of
thermal mechanical analysis indicate a decrease in the average coefficient of thermal expansion of the aluminum matrix with the use of hybrid reinforcements. Mechanical characterization also revealed that the coupled use of galvanized iron mesh and Ni particulates lead to an improvement in the hardness, dynamic modulus, 0.2% yield strength and UTS but ductility was adversely affected. An attempt is made to correlate the use of hybrid reinforcements with the improved properties exhibited
by the synthesized composites.
Naphthalene Containing Polyimide Nanocomposites Hybrid with Organo-Modified Montmorillonite
Authors: Chen B.K. , Tsay S.Y. , Chen C.P.
Published: March 2009

To improve the thermal and mechanical properties of polyimides, a nanocomposite of naphthalene containing polyimide (PI) was hybridized with Montmorillonite (MMT). The PI was synthesized from a diamine, 2,7-bis (4-aminophenoxy) naphthalene and polymerized with a 3,3’,4,4’-benzophenone tetracarboxylic dianhydride via thermal imidization. PI-MMT nanocomposites were then prepared from a DMAc solution of poly(amic acid) precursor and a DMAc dispersion of MMT which were organo-modified with various amount of n-dodecylamine. Characterization results demonstrated that the introduction of a small amount of MMT (up to 5%) led to enhanced thermal stability and mechanical properties of PI. The 5% weight loss temperature in N2 was increased by 46oC in comparison to pristine PI with an organoclay content of 5%. The CTE and dielectric constant were decreased. However, at organoclay contents higher than 5% these properties were reduced because the organoclay was poorly dispersed and resulted in aggregate formation.
The Band Structure Analysis of the Hybrid Compound (C4H9NH3)2Gel4
Authors: Dai Y.D. , Hu M.J. , Guo L.L. , Cao M.H. , Liu H.X.
Published: March 2009

The organic-inorganic hybrid compounds have attracted much attention for their
interesting structures and various properties. In present work, we concentrated on the band structures of the hybrid compound (C4H9NH3)2GeI4 and tried to find out the relations between the geometry structure and the properties. The hybrid’s primitive cell was large and including too many atoms, so it was difficult to have a direct and clear analysis on the band structure. The hybrids’ DOS
and PDOS were analyzed instead, as it was another effective way to analyze the band structure of the hybrid especially when the band structure was complicated. The model of (C4H9NH3)2GeI4 was set up, and the program based on the first principle had been employed to calculate its band structure. The difference of iodine’s PDOS caused by structure was also discussed.
Analytical and Numerical Analyses of Delamination Buckling in Layer Beams
Authors: Parlapalli Madusudhanan R. , Shu Dong Wei , Chai G.B.
Published: March 2009

In the present paper, new nondimensionalized parameters, namely, nondimensionalized axial and bending stiffnesses have been introduced to study analytically the buckling behavior of two-layer beams with separated delaminations. Numerical analysis has been carried out by using ANSYS software to validate the developed analytical model. Delaminations are modeled with gap
elements in ANSYS. A detailed parametric study has been carried out and it is found that the buckling behavior strongly depends on these new nondimensionalized parameters. Another nondimensionalized parameter, effective-slenderness ratio is also introduced and it is found to be a controlling parameter of delamination buckling mode configurations.
Neutron Scattering for Materials Science
Authors: Szytuła A.
Published: March 2009

The work is a review paper concerning application of neutron diffraction methods for
condensed matter investigations and for characterizing modern materials, namely for crystal and
magnetic structures determination, small-angle scattering, investigations of chemical reactions and
some practical applications. It addresses briefly a few of more prominent techniques that are
important for materials scientists. In the first part of the work information on the methods and ways
of interpretation of obtained results is given. Then the results for some chosen compounds are
presented.
Structural Investigation of the Photoinduced Spin Transition in the [Fe(PM-BiA)2(NCS)2] Compound
Authors: Ichiyanagi Kouhei , Hebert Johan , Toupet Loic , Cailleau Hérve , Collet Eric , Guionneau Philippe , Létard Jean-François
Published: March 2009

We investigated the thermo- and photo-induced phase transitions between low spin (LS) and high spin (HS) states of the molecular crystal of [Fe(PM-BiA)2(NCS)2] in the orthorhombic form, by using X-ray diffraction. The structure of the photoinduced HS state, generated from the LS state at low temperature, is compared to the structures of the HS and LS phases at thermal equilibrium and to the thermally trapped HS state. The preliminary results presented here show that the structural reorganization is similar in the different HS states.
Neutron Scattering in 3,3-Dimethyl-2-Butanol and 2,3-Dimethyl-2-Butanol
Authors: Juszyńska Ewa , Massalska-Arodź M. , Mayer J. , Natkaniec Ireneusz , Krawczyk J. , Tracz P.
Published: March 2009

Influence of the OH group position in the molecule on solid state polymorphism was found. Dynamics in solid phases of two dimethyl butanols were studied by inelastic incoherent neutron scattering. In glass of plastic crystal the boson peak was detected.
Hydromechatronical Testing System
Authors: Jurevichius Mindaugas , Vekteris Vladas
Published: March 2009

This hydromechatronical testing system is used for workload simulation while testing
technological machines to determine their dynamic characteristics. The authors have described
structure and principles of operation of the created equipment and equations of balances of the
hydrostatic bearings of the slider. Also, boring bar and equations of motion of the boring bar have
been formed in the article. Analytical and graphical dependences of motion of the slider and boring
bar have been determined after entering digital data into the computer.
Investigation of the Relationship of Muscle Mechanical Characteristics with Biosignal Energy
Authors: Mariūnas Mečislovas , Kojelyte Kristina
Published: March 2009

Based on biosignal energy equality to the work performed by a muscle, in the estimation of energy dissipation within a biolotronic system, analytical expressions have been derived that have helped to calculate major mechanical characteristics of the muscle including elongation of the muscle, speed and acceleration of such elongation. The paper presents the analysis of relevant digital methods alongside with the formulae for the calculation of major mechanical characteristics when the relationship of a muscle biosignal that is presented in a graphical way. As shown, fatigue of the muscle is characterized by one of extreme points of the phase shift function. The values of the first and the second derivatives of the elongation function may be used for the evaluation of functional capacity of the muscle.
Dynamics of a Mechatronic System with Flexible Vertical Rotor
Authors: Barzdaitis Vytautas , Žemaitis Vytautas , Jonušas R. , Augustaitis Vytautas Kazimieras , Bučinskas Vytautas
Published: March 2009

The paper is dedicated to research on flexible rotor systems with anisotropic rotor
material properties. In addition, the anisotropy of rotor supports alters the rotor system resonance
frequencies and the machine has to pass till it attains the operating angular speed. This phenomenon
of rotor vibration is observed in vertical rotors. The aim of this work is to compare experimental
vibration measurements and results of theoretical modeling. In the paper theoretical model, created
from physical one of really existing rotor system is described. Collected experimental data of rotor
vibrations in bearings are compared with results of theoretically derived equations. The results of
theoretical modeling and research enables for estimation of a more precise technical condition of
the rotor system both after the overhaul and during the maintenance and thus to avoid unexpected
breakdowns, especially concerning the fatigue development in ball bearing elements.
Influence of Shock-Absorber Parameters on Vehicle Vibrations during Braking
Authors: Pečeliūnas Robertas , Prentkovskis Olegas
Published: March 2009

The main goals of the work are to define consistent patterns of impacts exercised by vibration of the vehicle in emergency braking on the vehicle’s movement mode and on the braking distance and to analyze the formation of oscillation. Besides, it is aimed to extend expert’s opportunities for modeling vehicle movement for investigation of accidents’ circumstances related to vehicle braking with the aid of the developed models. A mathematical model of impact exercised by bumper’s characteristics on the vehicle’s braking process has been designed, enabling the determination of coefficients of longitudinal relative forces of the vehicle’s front and rear axles, which depend on the road’s pavement and its condition. The obtained research results extend the vehicle vibration theory in transitional movement modes, which are used in the design and improvement of vehicle suspensions, as well as in traffic accident’s investigation and improvement of methodology of their expertise calculations.
Influence of Rigidity of Acoustic Shield Walls on Sound Insulation
Authors: Gužas Danielius , Klimas R. , Tričys V.
Published: March 2009

Available shields are of a certain thickness that has an influence on sound diffraction.
Judging by the research results, the influence of shield thickness is insignificant if the thickness is
less than the length of a sound wave. A thick shield plate or a wide shield has two edges, and this
increases noise reduction at the expense of double diffraction. Solution of flat monochromatic wave
diffraction has been analyzed. The compact formula of sound insulation at uniform field in front of
the shield has been obtained.
The Use of Rigidity Properties in Cylindrical Shells for Noise Reduction
Authors: Butkus R. , Deikus J. , Gužas Danielius , Šarlauskas A.
Published: March 2009

The present paper deals with methods aimed at developing calculation models of sound
insulation of various cylindrical shells, making it possible to estimate the shell-radiated noise levels.
The proposed methodology is based on the mathematical analysis of the cylindrical shell as an
element that is subordinated to the equation of dynamic theory of elasticity of thin-walled
constructions of variable rigidity. The work provides the corresponding controls of dynamic theory
of elasticity in partial derivatives with variable coefficients. Theoretical research and calculations
carried out show that sound insulation under analysis at low frequencies is quite high. A slight
reduction of sound insulation at high frequencies conditioned by wave processes is also considered.
Research of Tight Band Coiling Dynamics
Authors: Kepalas Vytautas , Ramonas Česlovas , Marcinkevičius Stanislovas , Masteika Romualdas Konstantinas
Published: March 2009

Purpose of the work is to analyze tight band coiling machine dynamics for processing
wire, thread, texture, paper, leatherette or other elastic bands with a steady-state tension force. Band
coiling block diagram and mathematical models for cases with one and two regulators has been
made for research of elastic band coiling processing using software MATLAB-SIMULINK.
Transient response curves of linear speeds in the band feed section and in a coiling machine, of
band tension force and of relative elongation are presented. The digital model was used for
obtaining parameters of controllers when parameters of feedback and regulators have been
changing.
Calculation of Dynamic Parameters of Floating Up of the Rotor in Gas Vibrobearings
Authors: Kanapėnas Rimantas
Published: March 2009

Floating up of the rotor in gas vibrobearings with squeezed gas vibrofilms is investigated.
Individual cases of efficiency of gas vibrobearings in relation to a rotor load have been studied. A
dynamic model of a self-alignment gas vibrobearing is described; dynamic parameters of floating up
of the rotor are presented in relation to the parameters of vibration of vibrosupporting surfaces.
Framework for Teleoperation and Maintenance of an Industrial Robot
Authors: Sallinen Mikko , Pieskä Sakari , Annala Matti , Sumi Yasushi , Mäkelä Jari
Published: March 2009

In this paper, we present a framework for teleoperation and the maintenance of industrial
robots. The idea of the framework is to provide a rapid change of products to be manufactured and
safely monitor and carry out the maintenance remotely. Also, the goal of the work is to provide an
easy-to-use HMI for user of the robot. Remote connection relies on the Internet that is nowadays
easily available, cheap and includes a lot of existing components to be used. As an illustration of
this framework we present a web-based user interface that enables the user to operate remotely to
robot workcell with an industrial robot.
Friction Force and Stresses Analysis for Contact of Assembled Details
Authors: Dreija Z. , Liniņš O. , Sudnieks Fr. , Mozga N.
Published: March 2009

The present work deals with the computation of surface stresses and deformation in the presence
of friction. The evaluation of the elastic-plastic contact is analyzed revealing three distinct stages that range
from fully elastic through elastic-plastic to fully plastic contact interface.
Several factors of sliding friction model are discussed: surface roughness, mechanical properties and contact
load and areas that have strong effect on the friction force.
The critical interference that marks the transition from elastic to elastic- plastic and plastic deformation is
found out and its connection with plasticity index.
A finite element program for determination contact analysis of the assembled details and due to details of
deformation that arose a normal and tangencial stress is used.
Tribochemistry of Selected Ceramic Materials
Authors: Kajdas C.K.
Published: March 2009

Ceramics, especially nitrides, oxides and carbides, offer advantages over conventional tribological mating elements. Such solids usually are very stable chemically. However, under friction conditions they become quite reactive. It is even possible to say that the friction and wear behavior of ceramics might be more sensitive to the environment than friction and wear behavior of metals. Considering the present trend towards the incorporation of these ceramics in tribological applications, the importance of a more comprehensive understanding of the ceramic surface physics and chemistry cannot be overestimated. The primary aim of this paper is to present some physicochemical factors that may influence the wear process of ceramics and account for some specific tribological findings related to lubrication of these materials from the view-point of a better understanding of their tribochemistry. Model of ceramic reaction with water, implying the effect of triboelectron emission process, leads to the generation of acidic and basic active sites. The model is mostly focused on silicon nitride tribochemistry. It accounts well for the formation of specific silicon compounds from silicon nitride lubricated with water and alcohols. The model is based on the emission process of low-energy electrons during friction with generation of positively charged sites (Si+) and free radicals (N●). Interaction of the emitted low-energy electrons with water or alcohol molecules (HOH, ROH) produces negative HO‾ or RO‾ ions, respectively and hydrogen radicals (H●). The described model provides a better understanding of silicon nitride tribochemistry than previous ones. The same is due to other ceramics.