bluuebunny/crossref_metadata_2025 huggingface dataset:
Tribological Improvement of Thermal-Sprayed Ti-Based Coatings Modified by 1200 K Nitridation
Authors: Thongtem Somchai , Thongtem Titipun , Vilaithong Thiraphat , Thawornkul Thachaphan
Published: March 2009

Hardness and wear resistance of thermal-sprayed coatings of titanium containing 0, 3, 5 and 10 wt% bond coat (Ni5Al5Mo) were improved by 1200 K nitridation in 5, 10 and 15 ml.s-1 ammonia for 5 h. The improvement was due to the formation of TiN and Ti2N and governed by the ammonia flow rates and the percentage of bond coat. In addition, the coatings were analysed using a scanning electron microscope to determine the distribution of phases and cavities.
Generation of Deuteron Beam from the Plasma Focus
Authors: Wong Chiow San , Yap S.L.
Published: March 2009

The generation of deuteron beam from a 3 kJ Mather type plasma focus is studied. Two simple ion collectors made of copper plates are employed and are placed at the axis of the electrodes to detect the ion beam. The deuteron beam intensity at various deuterium gas pressures is determined together with ion beam energy using the time of flight method. For a series of discharges of the present plasma focus system operated at 15 kV discharge voltage, ion beams of energies ranging from 50 to 200 keV have been measured. The suitable deuterium filling pressure for ion beam production for electrodes lengths of 16 cm, 22 cm and 27 cm are 1 mbar, 0.7 mbar and 0.5 mbar respectively.
The Progress of Ion Beam Bioengineering in China
Authors: Yu Zeng Liang
Published: March 2009

Low-energy ion beam has widely been applied in the field of research on genetic modification since the 1980’s in China. It has been shown, in principle and practice, that ion beam, as a new mutagenic source, has many outstanding advantages: lower damage rate, higher mutation and wider mutational spectrum. Many new varieties of crops and microbes have been bred using these techniques and used in agricultural and industrial production. Meanwhile the method of transferring genes assisted by ion beam has also been developed. Scientists in China have begun to pay a big attention to study on ion beam biology. Up to now there have been seven key laboratories of ion beam bioengineering of Chinese Academy of Sciences and Chinese Provinces to be in succession created. Recent advances in research on ion beam biology have opened new areas of study in the field of life sciences, such as the role of low energy ions in the chemical origin and the interplanetary molecules forming, the health risk of low-energy particle radiation in the environment.
Plasma-Based Ion Implantation Treatments under Industrially Relevant Conditions
Authors: Ueda Mario , Wei R. , Reuther H.
Published: March 2009

Industrially relevant PIII conditions were applied to H13 and CrNiMo 316 steel as well as in CrCoMo and Ti6Al4V metal alloys. Typically, nitrogen ions were implanted at peak voltages of 10 to 15 kV, 50 to 80 (s pulse durations, and 1 to 2 kHz frequencies, for treatment times of 1 to12h. Case thicknesses of more than 20 μm were achieved in treated H13 steel which resulted in reduced friction and wear. For CrNiMo steel, a wear reduction of as high as 160 times was obtained besides a significant reduction of the coefficient of friction. Much thinner modified layer was obtained for Ti6Al4V but sufficient for an important improvement of the surface hardness.
Search for Enhanced D+D+D Reactions under D+ Beam Irradiation into TiDx Targets
Authors: Takahashi A. , Miyamaru H. , Ochiai K.
Published: March 2009

To search possible enhancement of three-body D+D+D fusion reaction in condensed matter, we have studied for 10 years about emitted charged particle spectra from titanium-deuterate (TiDx) samples under low energy D+ beam irradiation. By gas loading technique with changing temperature, we prepared TiDx samples with x = 1.4 - 1.8. A TiDx sample was mounted in a vacuum chamber with cooling and irradiated with 70 – 300 keV D+ beam. A delta-E and E type counter telescope using two Si-SSD detectors was used for charged particle spectroscopy.
Charged particles from D+D fusion reactions, e.g., 3MeV protons and 1MeV tritons were observed in every case, as usually expected. Sometimes, in addition, we observed “unknown” peaks at about 4.8MeV, which were identified to be two kinds of particles, i.e., helium and triton. We could not find any candidate reaction channels in two-body nuclear reactions of D+ beam and possible target nuclei (H, D, T, He-3, Li-6, Li-7, Be-9, C-12, N-14, N-15, Ti, etc.) including impurity reactions. We concluded that the 4.8MeV particles were from the D+D+D fusion to the out-going reaction channel of He-3 (4.75MeV) + T(4.75MeV).
The yield ratios of [3D]/[2D] were obtained as a function of D+ beam energy in the range of 50 to 300 keV, revealed the increasing trend in the lower energy range than 100 keV and were on the order of 1E-4 which was anomalously large compared with the estimated values on the order of 1E- 30 based on the conventional random nuclear process for the cascade reactions of three-body
interaction, i.e, D+D to He-4* and He-4* + D reactions.
Vacuum Arc Plasma Guns and Ion Sources
Authors: Brown Ian G.
Published: March 2009

Vacuum arc plasma can be formed using particularly uncomplicated hardware, providing a means for laboratory scale formation of dense and highly-ionized metal plasma. The simplicity and versatility of the approach has led to its widespread use in recent times for both fundamental and technological applications. When embodied in a plasma gun configuration, the source can provide a valuable tool for plasma deposition of metal and metal-containing thin films, including in plasma immersion configurations. When embodied in an ion source configuration, high current beams of metal ions can be formed, and such beams have found good use for ion implantation and particle accelerator injection. Here we briefly review vacuum arc plasma guns and ion sources, outlining some of the hardware embodiments that have been developed at Berkeley and used for various materials modification applications.
Amorphisation and Recrystallisation of Nanometre Sized Zones in Silicon
Authors: Edmondson P.D. , Donnelly S.E. , Birtcher R.C.
Published: March 2009

In this paper we present a detailed study in which the formation, by heavy ion impact, and thermal recrystallisation of individual amorphous zones have been studied using in-situ transmission electron microscopy. In agreement with previous work, we observe a reduction in the total volume of amorphous material contained within the amorphous zones following thermal annealing over a wide range of temperatures. When the evolution of the individual amorphous zones is followed, those with similar starting sizes are observed to recrystallise over a range of temperatures from 70 °C to 500 °C. The temperature at which an amorphous zone fully recrystallises does not appear to be correlated with initial size. In addition, zones are occasionally observed to increase in size temporarily on some isochronal annealing steps. Furthermore, observations during a ramp anneal show that many zones recrystallise in a stepwise manner separated by periods of stability. These phenomenon are discussed in terms of the I-V pair.
Ab Initio Studies of Local Vibrations of Small Self-Interstitials Aggregates in Silicon
Authors: Carvalho A. , Jones R. , Coutinho J. , Torres Vitor , Briddon Patrick R.
Published: March 2009

We report on the energetics, electrical and optical activity of small self-interstitial (I3 and I4) clusters in Si, found from ab-initio density-functional modeling studies. I4 possesses nine local vibrational modes above the Raman edge, which account for up to three dipole-allowed vibronic transitions observed in recent experiments associated with the X-photoluminescent line. Another prominent photoluminescent line (known as the W-line) that shows a trigonal stress-induced splitting pattern, has been previously assigned to I3. Our analysis of the LVMs of a metastable form of I3 support this assignment.
A Theoretical Study of Dislocation Formation at Surfaces in Covalent Materials: Effect of Step Geometry and Reactivity
Authors: Brochard Sandrine , Godet Julien , Pizzagalli Laurent , Beauchamp Pierre , Soler José
Published: March 2009

Atomistic simulations using both semi-empirical potential and first principles calculation have been performed to study the initiation of plasticity near surface steps in silicon. A comparison of both techniques on a prototypic case shows qualitative and quantitative agreement. Then each method has been used to analyze in detail some characteristics of the surface step: the step geometry thanks to semi-empirical potential calculations, and the step reactivity with ab initio techniques.
Impact of Hydrogen Implantation on Helium Implantation Induced Defects
Authors: Gaudin G. , Cayrel Frédéric , Bongiorno Corrado , Jérisian Robert , Raineri Vito , Alquier Daniel
Published: March 2009

Silicon-based power device performances are largely affected by metal contamination occurring during device manufacturing. Among the usual gettering techniques, recent developments were done on high dose helium implantation. Even though the gettering efficiency of this technique has been demonstrated in device application, the required doses are still extremely high for an industrial application. Recently, it has been shown that the use of H/He co-implantation limits the total requested doses [1]. In this paper, co-implantation of H/He, which has been already used to reduce the dose in the smart-cut® process is explored. The goal of this work is to decrease efficiently the implanted dose maintaining an efficient metallic gettering without degrading the Si surface. The impact of H implantation on He implantation induced defects is carefully studied. The TEM observations have evidenced that hydrogen addition drastically modified the defect band structure and promotes the cavity growth.. Additionally, we demonstrate that an efficient gettering can be obtained.
The Effect of Compound Composition and Strain on Vacancies in Si/SiGe Heterostructures
Authors: Ganchenkova Mariya G. , Borodin V.A. , Nicolaysen S. , Nieminen Risto M.
Published: March 2009

In this paper we study the effect of chemical environment and elastic strains, which can arise in layered heterostructures due to the lattice parameter mismatch, on the vacancy formation energy in random Si-Ge compounds. Ab initio calculations demonstrate a number of simple trends characterizing the vacancy formation energy dependence on vacancy charge, the number of Ge atoms in its neighbourhood and on the magnitude of elastic strains. The obtained parameters of vacancy-germanium interaction indicate, in particular, a tendency for preferential vacancy accumulation in SiGe region of Si/SiGe/Si layered structures, which is confirmed here by Monte- Carlo simulation of high-temperature vacancy annealing and agrees well with recent experimental observations.
Strained Silicon on Ultrathin Silicon-Germanium Virtual Substrates
Authors: Lyutovich Klara , Kasper Erich , Oehme Michael , Werner Jens , Perova Tatiana S.
Published: March 2009

Molecular beam epitaxy is employed for the growth of strained-Si layers on top of virtual substrates with highly-relaxed ultrathin SiGe buffers in a continuous procedure. An initial growth stage at a temperature-ramp down to below 200°C causes misfit-dislocation generation by nucleation from point defects and provides an early relaxation in the SiGe buffers. In situ monitoring is used for the growth control. Layer thicknesses and composition are proved by ex situ spectroscopic ellipsometry. %Raman investigations on the layer stacks reveal high degrees of relaxation (70-100%) in sub-100nm SiGe buffer layers containing from 12 to 42 % Ge. Stress in strained Si layers estimated by means of Raman-spectra shift is adjustable from 0.92 to 6.84 GPa by the Ge-content in virtual substrates. Surface morphology of strained Si and of relaxed SiGe buffers is smooth and crosshatch-free. Device test structures show substantial increase of carrier mobilities in nMOSFETs fabricated on these strained-Si layers.
DLTS Study on Deep Levels Formed in Plasma Hydrogenated and Subsequently Annealed Silicon
Authors: Huang Yue Long , Simoen Eddy , Claeys Cor , Job Reinhart , Ma Yue , Düngen Wolfgang , Fahrner Wolfgang R. , Versluys J. , Clauws Paul
Published: March 2009

P-n junctions are created in p-type Czochralski silicon after a low temperature (270°C) hydrogen plasma exposure. This is attributed to the formation of hydrogen-related shallow donors. A deep level (E1) with an activation energy of about EC-0.12 eV is observed by DLTS measurement and assigned to a metastable state of the hydrogen-related shallow donors. At an annealing temperature of 340°C, the E1 centres disappear and oxygen thermal donors appear. The concentrations of the oxygen thermal donors are found typically to be 2-3 decades lower than that required for over-compensating the initial p-type doping and for contributing the excess free carriers.
Atomic Environment of Positrons Annihilating in HT Cz-Si Crystal
Authors: Arutyunov N.Yu. , Emtsev Valentin V.
Published: March 2009

A probing of the atomic environment of positron in Cz-Si single crystal heat-treated at T=600C and T=450C has been performed by one-dimensional angular correlation of annihilation radiation (ACAR). It has been established that positrons get trapped by the oxygen-related complexes. The penetration of positrons into the core region of surrounding atoms results in emission of the elementally specific high-momentum annihilation radiation. The processes of expelling of positron from ion cores and its penetration into the core region are regulated by the potential barrier (to be considered as the Coulomb’s one as a first approximation). The characteristic electron-positron ion radius and the probabilities of correlated events of the highmomentum annihilation are due to the chemical nature of the ion cores of atoms involved in the composition of the oxygen-related complexes. The interpretation of the results is based on the notion of the positron localization in the field of negative effective charge resulted from comparatively high electron affinity of the oxygen impurity atom. The presence of a free volume (perhaps, a vacancy) as well as the carbon atom in the microstructure of the oxygen-related positron-sensitive thermal defects is briefly discussed.
Some Recent Advances on the n-Type Doping of Diamond
Authors: Chevallier Jacques , Kociniewski T. , Saguy Cecile , Kalish R. , Cytermann C. , Barbé M. , Ballutaud D. , Jomard François , Deneuville A. , Baron C. , Butler James E. , Koizumi Satoshi
Published: March 2009

The n-type doping of diamond with phosphorus suffers from defects reducing the electron mobilities and inducing some degree of compensation. In addition, the relatively high ionization energy (0.6 eV) of phosphorus severely limits the electrical activity of the dopants. Here, we present two recent advances of the n-type doping of diamond. One is based on the significant reduction of the compensation ratio of highly compensated phosphorus-doped diamond by thermal annealings. The second one presents the possibility of converting p-type boron-doped diamond into n-type by deuterium diffusion and formation of deuterium-related shallow donors with ionization energy of 0.33 eV.
Helium Implantation Damage in SiC
Authors: Leclerc Stephanie , Beaufort Marie France , Audurier Valerie , Déclemy Alain , Barbot Jean François
Published: March 2009

Single crystals SiC were implanted with 50 keV helium ions at room temperature and fluences in the range 1x1016 -1x1017 cm-2. The helium implantation induced swelling was studied through the measurement of the step height. The damage was studied by using X-ray diffraction measurements and the transmission electron microscopy observations. Degradation of mechanical properties is found after helium implantation.
Morphological Transformation of Oxide Particles and Thresholds for Effective Gettering in Silicon
Authors: Falster Robert J. , Voronkov Vladimir V. , Resnick V.Y. , Mil'vidskii M.G.
Published: March 2009

This paper presents a qualitative description and quantitative model of the technologically important problem of the transition from ineffective to effective internal gettering (IG) states in CZ silicon wafers as the precipitation of oxygen proceeds at high temperatures. Of central importance to the problem is a morphological transformation of growing oxide preciptitates from an initial strain free to a strained platelet state. The transition to effective IG occurs when approximately 107 cm-3 precipitate sites are transformed into the strained state. The transformation rates as a function of oxygen concentration and precipitate site density, deduced from etching and TEM, are presented. A model for the morphological transformation to the strained state is developed and with it a model for the annealing criteria for the threshold for effective gettering.
Ultrasonic NDE System Modeling and Reliability – An Overview
Authors: Schmerr Lester W.
Published: March 2009

Over the past two and a half decades there has been considerable progress made in the modeling of ultrasonic nondestructive evaluation (NDE) inspections. These models have also been combined with models of the noise and variability present in an inspection to estimate probability of detection (POD) versus flaw size curves. An overview will be given of the past and present accomplishments made in ultrasonic NDE modeling, POD modeling, and the relationship of those advances to reliability modeling that incorporates explicitly the results of inspections. A brief look into the future of this modeling technology will also be given.
Study on Large Scale Analysis for Infra-Structure
Authors: Park Young Jae , Chang Yoon Suk , Choi Jae Boong , Kim Young Jin
Published: March 2009

During the last two decades, the interests of large scale seamless analysis have been increased with respect to lifetime extension and management of infra-structure. And then, a seamless analysis of complex geometry is one of greatly interesting topic. However, there are still gaps between the industrial applications and fundamental academic studies owing to time consuming the modeling and analyzing process. To resolve these problems, the integrity evaluation procedure from knowledge-based information system (KIS) to ADVENTRUE has been proposed for the application of auto mesh generation and large scale analysis. The virtual plant which is used for the master of KIS, provides the 3D information of entities for mesh generation. And then, the ADVENTURE makes a domain decomposed mesh and analyzes it using hierarchical domain decomposition method.
Considering the good applicability in both efficiency and exactness point of views, it is anticipated that the proposed study on large scale analysis can be used as a promising integrity evaluation method of infra-structures.
Simplified Static Analysis for Shock Behavior Evaluation of Thin Glass Plates
Authors: Moon Seong In , Kim Chang Hoi , Koo Ja Choon , Choi Jae Boong , Kim Young Jin , Kim Yun Jae
Published: March 2009

Recently, mechanical shock failures of a flat display unit such as TFT-LCD device have been an important concern of designers. In order to achieve the mechanical shock requirement, it is necessary to perform the detailed FE analyses which could be very expensive either by the lengthy computation or by the complicated geometry modeling. The objective of this study is to propose a simplified analysis methodology to simulate impact behavior of thin glass plates. The static problem
equivalent to the impact one is found from the concept of solid mechanics to estimate the maximum deflection and stress under impact loading. To show the plausibility of the proposed approach, it is applied to the idealized problem which is a two dimensional beam subjected to impact loading. Based on explicit FE analyses using the LS-DYNA FE program, it was shown that the impact problem can
be solved by the equivalent static analysis which is much easier to solve in practice. Therefore, the proposed approach provides significant advantages in design optimization of a TFT-LCD device against shock failure, and enables the designer to avoid ad hoc modeling of the transient dynamics so that product design cycle could be shortened.
The Effect of Various Surface Coatings on Tribological Characteristics of Rotary Compressor Vane in Carbon Dioxide Environment
Authors: Oh Se Doo , Lee Young Ze
Published: March 2009

The tribology of lubricated sliding vanes in the rotary compressor was investigated to replace the HFC refrigerants by the carbon dioxide. The carbon dioxide is a natural refrigerant and very favorable to environment. Because new compressors with the carbon dioxide are going to be operated under the high pressure, the tribology of sliding surfaces in the compressor becomes very important. To develop new compressors, especially rotary type, the friction and wear characteristics
of sliding surfaces between a vane and a roller in the rotary compressor were evaluated in this paper. Several hard coatings, such as TiN, CrN, WC/C and two types of nitridings, were applied on vane surfaces in order to improve the tribological characteristics, and their performances were evaluated experimentally. The vane-on-disk type sliding tests were carried out under the various sliding speeds,
normal loads, and carbon dioxide pressures with an exclusive high pressure wear tester. From the tests wear volume of vane surfaces applied various coatings were compared. During the tests coefficients of friction and surface temperatures were monitored. Test results showed that WC/C coatings showed good tribological properties. TiN and CrN coated vanes showed good wear resistance properties but produced high friction.
Analysis of Three-Dimensional Cracks with Independent Crack Mesh
Authors: Kim Tae Soon , Park Jai Hak , Park June Soo , Kim Jong Sung , Jin Tae Eun
Published: March 2009

In order to simulate the growth of arbitrarily shaped three-dimensional cracks, the finite element alternating method is extended. As the required solution for a crack in an infinite body, the symmetric Galerkin boundary element method formulated by Li and Mear is used. In the study, a crack is modeled as distribution of displacement discontinuities, and the governing equation is formulated as singularity-reduced integral equations. With the proposed method several example problems, such as a penny-shaped crack, an elliptical crack in an infinite solid and a semi-elliptical
surface crack in an elbow are solved. And their growth under fatigue loading is also considered and the accuracy and efficiency of the method are demonstrated.
A Method of J Testing Based on Crack Opening Displacement for Circumferential Through-Wall Cracked Pipes under Combined Tension and Bending
Authors: Huh Nam Su , Stumpfrock Ludwig , Roos Eberhard , Kim Yun Jae , Kim Young Jin
Published: March 2009

Application of the leak-before-break concept to nuclear piping requires accurate fracture mechanics assessment on pipes with postulated circumferential through-wall crack subject to combined tension and bending. One important element is determination of relevant J-resistance curve for pipes under combined loading. This paper provides experimental J estimation method for the circumferential through-wall cracked pipe under combined tension and bending, based on the load-crack opening displacement (COD) record to estimate J-resistance curve. To give confidence in the proposed method, the J results from detailed elastic-plastic finite element (FE) analysis are also compared with estimated J based not only on proposed method but also on conventional method using load-load line displacement, which shows that estimated J based on the proposed method provides reliable J estimates regardless of analysis condition, on the other hand, the conventional method using the load-load line displacement record gives erroneous results for shallow cracks.
Application of Ultrasonic Phased Array Techniques for Inspection of Stud Bolts in Nuclear Power Plants
Authors: Choi Sang Woo , Lee Joon Hyun
Published: March 2009

The reactor vessel body and closure head are fastened with the stud bolt that is one of crucial parts for safety of the reactor vessels in nuclear power plants. It is reported that the stud bolt is often experienced by fatigue cracks initiated at threads. Stud bolts are inspected by the ultrasonic technique during the overhaul periodically for the prevention of failure which leads to radioactive
leakage from the nuclear reactor. The conventional ultrasonic inspection for stud bolts was mainly conducted by reflected echo method based on shadow effect. However, in this technique, there were numerous spurious signals reflected from every oblique surfaces of the thread. In this study, ultrasonic phased array technique was applied to investigate detectability of flaws in stud bolts and
characteristics of ultrasonic images corresponding to different scanning methods, that is, sector and linear scan. For this purpose, simplified stud bolt specimens with artificial defects of various depths were prepared.
Biological Hybrid Materials for Drug Delivery System
Authors: Choy Jin Ho
Published: March 2009

We have attempted to realize new biomolecular-inorganic nanohybrids with two different functions, one from inorganic moiety and the other from biological one. Recently we were quite successful in demonstrating that a two-dimensional inorganic compound like layered double hydroxide (LDH) can be used as gene or drug delivery carriers. Such inorganic vectors are completely new and different from conventionally developed ones such as viral-based, naked, and cationic liposomes, those which are limited in certain cases of applications due to their toxicity, immunogenecity, poor integration, and etc. But the mentioned problems can be overcome by synthesizing inorganic vectors properly with non-toxic metal ions having biological compatibility. Since LDHs with positive layer charge have an anion exchange capacity, functional biomolecules with a negative charge can be intercalated into hydroxide layers of LDH by a simple ion-exchange reaction to form a bio-LDH nanohybrid. We also found that the hydroxide layers of LDHs could protect the intercalated molecules very efficiently. If necessary, inorganic materials, as reservoir and delivery carrier, can be intentionally removed by dissolving it in an acidic which offer a way of recovering the encapsulated biomolecules. The possible roles of inorganic lattice as the gene and drug delivery carrier will be shown by demonstrating the cellular uptake experiments of FITC, fluorophore, with laser scanning confocal fluorescence microscopy. A
Pulsed Laser Deposition and Fabrication of CoO/ZnO and CoO/TiO2 Nano-Hybrid Thin Film
Authors: Van L.H. , Hong M.H. , Ding J.
Published: March 2009

Nano-hybrid CoO/ZnO and CoO/TiO2 thin films are interesting magnetic
semiconductors, which may be the potential candidates in spintronic devices. We
report a study of the morphology and properties of highly crystalline and textured
CoO/ZnO and CoO/TiO2 nanohybrid thin films grown on Al2O3 (006) substrates by pulse laser deposition (PLD). The structural and magnetic properties of the deposited films were analyzed by AFM, SEM, XRD and AGM. Highly crystalline CoO/ZnO and CoO/TiO2 films were formed on single crystal Al2O3 substrates at 1x10-4 Torr oxygen partial pressure. It has been found that with a fine tune of the deposition conditions and heat treatment, the films can have highly crystalline ZnO zincite hexagonal and TiO2 rutile structure. The XRD rocking curves showed that the thin films grown are highly textured with FWHM of 0.251o for ZnO zincite and 0.065o for TiO2 rutile respectively. Both zincite and rutile exhibited properties of ferromagnetics above room temperature. The AGM results show that the saturation magnetization (Ms) is strongly dependent on substrate temperature.
Dielectric, Magnetic and Magnetoelectric Properties of a Laminated Composite with 1-3 Connection
Authors: Or S.W. , Cai N.
Published: March 2009

A two-phase laminated composite was prepared by stacking one layer of thicknesspolarized 1−3 piezoelectric composite (PECP) plate between two layers of length-magnetized 1−3 magnetostrictive composite (MSCP) plates in the thickness direction. The PECP plate consisted of 0.68 volume-fraction PZT bars embedded in Spurr epoxy matrix, while the MSCP plates comprised
0.51 volume-fraction Terfenol-D particles embedded and magnetically aligned in Spurr epoxy matrix. The dielectric, magnetic and magnetoelectric properties of the laminate were measured as a function of both frequency and magnetic bias field. A giant magnetoelectric voltage coefficient ( αE) of 15.4 V/cm·Oe was observed at the resonance frequency of ~59 kHz under a relatively low bias field of
0.75 kOe. This resonance αE was ~30 times larger than its non-resonance values, showing promising application of the proposed laminate in magnetoelectric conversion devices.
Thermal Stabilities and Mechanical Interfacial Properties of Polyethresulfone-Modified Epoxy Resin
Authors: Park Soo Jin , Li K. , Hong S.K.
Published: March 2009

The thermal stabilities and mechanical interfacial properties of a diglycidyl ether of
bisphenol-A (DGEBA) epoxy resin modified with different contents of polyethersulfone (PES) have been investigated. As a result, the curing reaction rate of DGEBA/PES blends was decreased with increasing the PES content. The blends exhibited slight decrease of thermal stabilities compared to the neat DGEBA. The mechanical interfacial properties, characterized by KIC, were significantly
increased as the PES content increased.
Mechanochemical Synthesis of Fe-Based Nanocomposites and Their Application in the Catalytic Formation of Carbon Nanostructures
Authors: Liu B.H. , Ding J. , Dong Z.L. , Zhong Zeng Yong , Lin Jian Yi , White T.
Published: March 2009

Mechanochemical process was employed to prepare Fe/MgO and Fe/NaCl
nanocomposites. The carbon nanostructures (nanotubes and carbon-encapsulated Fe nanoparticles) were successfully synthesized using two nanocomposites as the catalyst. Our wok revealed that the
morphology of Fe nanoparticles in the Fe/MgO nanocomposites depended on the distribution and particle size of iron oxides in the precursors. The size of Fe nanoparticles greatly affected their catalytic properties and the morphologies of carbon nanotubes. The successful carbon encapsulation of Fe nanoparticles was achieved by using the mechanochemically derived Fe/NaCl catalyst.
Sensitivity of Zn1-xCdx Te to Tera-Hertz Signals Enhanced by Structural Orderings
Authors: Han S.W. , Kang S.H.
Published: March 2009

A better efficiency of sensing tera-hertz signals (T-rays) depends on a better
crystalline structure which is obtained by replacing a small amount of Cd on Zn sites of ZnTe crystals. Zn1-xCdxTe (ZCT) crystals were fabricated with an advanced vertical Bridgeman method and the structural properties of the ZCT crystals were studied with high resolution x-ray diffraction (HRXRD) and x-ray absorption fine structure (XAFS) measurements. The Rietveld refinement to the HRXRD data showed that the ZCT crystals at x ~ 0.05 were slightly less disordered than the ZnTe crystals. These results were confirmed by the XAFS data analysis. The better structural orderings can be directly related to the sensing and emitting efficiencies of T-ray by the ZCT crystals.
Effect of the Presence of Continuous/ Discontinuous/ Hybrid Reinforcement on the Damping Characteristics of Pure Aluminium Matrix
Authors: Narasimalu S. , Gupta Manoj
Published: March 2009

Al is well known to serve as a metallic matrix in a composite due to its
enhanced ductility and toughness. In the present study, pure Al (AA1050) is
reinforced with two different reinforcements viz., an interconnected, axisymmetrical,
galvanized iron wire perform and SiC particulates and were tested in a free-free type
suspended beam arrangement, coupled with circle-fit approach to determine damping
characteristics. The results show the effect of individual and combined presence of
two different reinforcements in terms of damping loss factor. Addition of ~ 2 vol. %
of interconnected reinforcement increases the overall damping capacity of the
aluminium matrix by ~ 15 % which is equivalent to the presence of ~ 4.8 vol. % of
SiCp. But combined presence of ~2 vol. % of interconnected wire reinforcement along with ~0.5 vol. % of SiCp increases the damping capacity to 24 % which forms a new breed of hybrid composites. This increase in damping can be rationalized in terms of the induced plastic zone and reinforcement’s aspect ratio.
An Influence of the Local Environment on Local Magnetic Moments and Hyperfine Fields in Fe3-xMnxAl
Authors: Go Anna , Pugaczowa-Michalska Maria , Dobrzyński Ludwik
Published: March 2009

Ferromagnetic, intermetallic compound Fe3Al exhibits DO3-type crystal structure. There are two non-equivalent types of iron with different chemical neighbourhood – (A,C) and B sublattices. As a consequence of the different nearest environments of the iron atoms at these sites the different electronic and magnetic properties connected with these positions are observed. The aim of our research is to investigate the influence of the local surrounding of the iron on its magnetic moment and hyperfine field in compound Fe3-xMnxAl where iron is substituted by manganese.
Mechatronic System of the Injection of Ethanol in an Intake Manifold of a Diesel Engine
Authors: Pukalskas S. , Chernashejus O. , Garbincius G.
Published: March 2009

This research was carried out with an Audi-80 turbo diesel engine that has a
supplementary ethanol feed to air intake. The obtained results allowed for a mathematical
expression to get a description of the optimal ethanol supply, which ensures the maximum heat
efficiency coefficient for different engine working conditions.
Experimental Research of a Mechatronical System
Authors: Strishka V. , Vekteris Vladas
Published: March 2009

Systems “spindle – bearings” will inevitably have some errors and discrepancies in the
dimensions and form of elements. These inaccuracies cause spindle’s run out. The run out is a
complex periodic process which may include three types of frequency components: with
frequencies exceeding the spindle’s rotary frequency, with frequency equal to the spindle’s rotary
frequency and with frequencies lower that the spindle’s rotary frequency. Each individual frequency
component may be caused by eccentricity or out-of-roundness of the inner race, out-of-roundness of
the outer race, spread of ball diameters, and inaccuracy of their form.
Self-adjustable pad-type bearings are sensitive to technological, service and construction
perturbations. This is characteristic of vortex trajectories of the spindles. Character of these
trajectories depends on the thickness of lubricant film over the pad supports and on the geometrical
precision of the spindle journal and pads (segments). Geometrical precision under a high unbalance
of the grinding wheel is crucial for functional quality, size and form of the orbit. Geometrical
precision of trajectories and its state are subject to change depending on a number of parameters
especially on the rigidity of the lubricant film and dynamic system.
Investigation of Electrostatic Cantilever-Type Micromechanical Actuator
Authors: Dauksevicius Rolanas , Ostaševičius Vytautas , Tamulevičius Sigitas , Bubulis Algimantas , Gaidys Rimvydas
Published: March 2009

Electrostatic microswitch and its fabrication technology have been developed for the first time in Lithuania, at Kaunas University of Technology (KTU). The microdevices were produced by using a nickel surface micromachining process. The microswitch consists of a cantilevered nickel structure suspended over the bottom electrodes. The width of the structure is 30 μm, thickness - 2 μm and length ranges from 67 to 150 μm. Implementation of microswitches as a substitute for the present solid-state switching devices poses many problems. In particular higher actuation voltages, lower switching speed and a reduced lifetime are considered to be among the most significant ones. With the aim of improving these parameters a finite element model is currently developed that takes into account not only microscale-specific electrostatic actuation and air damping effects but also includes the bouncing phenomena. Experimental studies of electrical and dynamic characteristics were also carried out with the purpose of model validation and correction. The paper presents initial results of theoretical modal and air damping analysis as well it shows the first attempts to measure vibration modes of the cantilever structure of the microswitch using Laser Doppler vibrometer.
Analysis of a Microelectrostatic Motor
Authors: Ostaševičius Vytautas , Bagdonas Vytautas , Tamulevičius Sigitas , Grigaliūnas V.
Published: March 2009

An electrostatic motor is a very complex dynamical system whose performance critically
depends on the shape of the rotor and stator, number of poles, clearances between axis and rotor,
friction, rotor vibrations, and levitation, etc. There are many possible micromotor constructions
depending on the required accuracy, the speed of rotation and power of the motor. This work shows
the technology required to build a micromotor using UV lithography. Studies of vibration
characteristics using ANSYS and MATLAB modeling software and an experimental analysis to
optimize the dynamical properties of the system and to improve its manufacturing process are also
shown.
Universal Coupling for Shaft of Actuators in Mechatronic Systems
Authors: Spruogis Bronislovas , Turla Vytautas , Jakštas Arūnas
Published: March 2009

The design of shaft coupling ensuring serviceability of an actuator under varying conditions is presented in this paper. The driving half coupling is an eccentric balanced over the axis of rotation. The torque of the coupling is determined by the parameters of the flexible ring and eccentricity. When the parameters of coupling are properly selected, the transfer coefficient of vibration can be reduced markedly.
Dynamic Processes of Rotating System with Coupling
Authors: Barzdaitis Vytautas , Bogdevicius Marijonas , Didžiokas Rimantas
Published: March 2009

The article concerns dynamics and vibration of a high power rotating system with
toothed wheel coupling that inserts elastic plate packets. Theoretical modeling and simulation of the
rotating system with toothed wheel coupling have been provided by a finite element method.
Complex model involved a rotating system, hydrodynamic bearings and coupling. The dynamics of
semi-couplings and plates have been simulated. Experimental measurement of vibration has been
measured with stationary machine condition monitoring and a diagnostic system.
Dynamic Processes of Gas in Plastic Pipes
Authors: Bogdevicius Marijonas
Published: March 2009

In the article gas movement in elastic pipelines is considered. The following things are
taken into account in the present model: distribution of sound waves in gas, elastic and viscous
properties of elastic pipelines, and friction of gas on the pipeline wall. The elastic properties of
pipeline’s material are simulated by the rheological model of Kelvin - Foight. The received system
of the equations of gas movements and deformations of the pipeline is solved by a method of the
characteristics. Nonlinear algebraic equations are solved by Newton method. Movement of gas (air)
in pipelines made from polyvinilchloride (PVC) is considered.
Creating a Mathematical Model from the Realization of the Measuring of a Transient Process of a Mechanical System
Authors: Slivinskas Vytautas , Slivinskas Kastytis , Bučinskas Vytautas
Published: March 2009

In the paper the method of creating the dynamical model of the mechanical system is
considered. The transient process measured after the hammer blow is used as input data. Prony
method with its improvements is used for the estimation of unknown parameters of the model.
Using the FFT and IFFT procedures the sample data is decomposed into two parts: a high frequency
component and a low frequency component. Each part is investigated separately. While the high
frequency component was modeled by using a simple six poles model, the low frequency
component was modeled by a single multiple pole. The correctness of the model was checked by
RMSE criteria. The RMSE of the low frequency component model versus the multiplicity of the
pole was investigated. The results show good agreement with experimental data. The full final
model was used to get the amplitude-frequency response of the system.
Method Reduction of Vibrations of a Cylindrical Shell with a Longitudinal Plate Rib
Authors: Čiučelis A. , Gužas Danielius , Maskeliūnas R.
Published: March 2009

With the purpose of clarifying the impact of a model of a longitudinal plate rib on the
excitation of vibrations of a cylindrical shell and sound radiation, research of this model was
performed. The article shows that the longitudinal plate enforced inside the cylinder may be an
efficient mean for the reduction of vibrations and sound radiated from the cylindrical shell at
separate shell resonance frequencies.
Microprocessor Control System of an Electric Arc Welding Unit
Authors: Dambrauskas Algirdas , Karaliunas Bronius , Shulskis D.
Published: March 2009

The main flaws of electric arc welds and factors determining the quality of the welded
seams are considered in this paper. In practice, welding tools and their control systems are affected
by some external factors causing deviation of the weld’s quality from the specified values.
Currently used control systems of welding tools do not always satisfy the requirements for quality
of welded joints. Major principles of developing the adaptive control system of the welding tool are
considered here and the developed functional and block diagrams of microprocessor system are
presented. General equations describing the welding process are also provided and the obtained
transfer function of a closed system is described.
Path Planning in the Case of PKM with Hybrid Topology
Authors: Brisan Cornel , Hiller Manfred
Published: March 2009

Parallel robots have often been used during the last decade because of their advantages,
such as: good dynamic behavior, easiness of inverse kinematics, and higher accuracy etc. Despite
those advantages, parallel robots are criticized in relation to their small work space, and not really
modular topology and complex mechanical architecture. Industrial experience has realized that the
major disadvantage of parallel robots is the small dimension of work space. Strong economical
reasons and all technical advantages of parallel robots recommend these robots to do tasks that are
proper to machine tools.
Wall Press Walking In-Pipe Robot
Authors: Matuliauskas A. , Spruogis Bronislovas , Pikūnas A.
Published: March 2009

This paper reviews a new wall press walking in-pipe robot. The provided design method is based on pneumatic actuators. This mobile robot can move in pipe of 300 mm diameter. In the first part of this paper, we explain the locomotion principle of the robot, and then we present the design method of the wall press walking in-pipe robot parts.
Robotic Grippers with Accuracy Centering Fingers
Authors: Marcinkevičius Andrejus Henrikas
Published: March 2009

A new design scheme of a robotic gripper for rotational family parts is presented and
analyzed in the paper. The third or first class lever type of coupled fingers located from contrary
sides of common longitudinal axis of symmetry of the gripper are used so that no less than two
fingers from each side of the symmetry axis create an artificial centering prism. Distance of a
centerline of the prisms, so the centerline of the part being handled, from the basic surface of the
gripper is kept constant at changing diameter of the parts. Fingers are driven by a motion of sliders
assembled inside of carriageways inclined to some angle to the symmetry axis of a gripper hand. It
is shown that by keeping some rates of dimensions of mechanism elements straight lined finger
surfaces will be kept tangent to the cylindrical surface of handled parts. Mathematical equations
defining these rates are derived.
Autonomous Robot in an Adverse Environment: Intelligent Control by Voice
Authors: Navakauskas Dalius , Paulikas Šarūnas
Published: March 2009

In this paper we investigate the voice control of an autonomous robot in the presence of impulsive noise. We propose an original structure of the intelligent voice control system, present experimental investigation of separate modules and outline the performance of the system by the simulation example. Our approach differs from others in twofold: the noise detection is carried out by specialized artificial neural network; and the restoration of the missing speech signal is performed by using an intelligent multirate-processing scheme. The simplicity of neural network’s employment and unnecessary a priori knowledge of noise characteristics are the main merits of this approach. The employment of nonlinear re-sampling improved the precision of speech signal restoration and consequently increased the overall recognition performance.
Calculation of the Parameters of a Linear Electric Drive
Authors: Karaliunas Bronius , Matkevicius Edvardas
Published: March 2009

The paper considers some problems of calculating major parameters and characteristics
of a mechatronic system with a linear induction motor (LIM). It has been shown that LIM operating
in the presence of traveling magnetic fields are widely used alongside other actuators. These motors
allow for modular design because inductors may be made as independent modules. Then, by
choosing the required number of inductors and their arrangement in a mechatronic system, a desired
trajectory of transverse motion may be obtained.
A theoretical model for LIM calculation, taking into account major assumptions about onedimensional
magnetic field, is offered. Complex amplitude is expressed as the exponential function
of a longitudinal coordinate of current volumetric density of the inductor. The above inductances as
the parameters of dynamic equations may be used in further investigation of dynamics of
mechatronic systems. However, in order to create optimal control systems for mechatronic systems
with linear actuators, the major parameters and characteristics of a linear motor should be known.
Therefore, the present investigation is aimed at developing methods for calculating the parameters
of mechatronic systems with linear electric drives.
Analytical Research of Hydrodynamic Bearings in Mechatronical Systems
Authors: Cereska A. , Vekteris Vladas
Published: March 2009

The problem of quality diagnostics of systems with hydrodynamic bearings is analyzed in
the paper. In analyzing the problem, the analytical research of the change of friction coefficient,
pressure, rotor rotation axis eccentricity in dependence on the wear magnitude between the rotor
and the bearing are performed. The method of the analytical research is presented. Results of the
analytical research and experimental measurements are depicted in graphs.
Physicochemical Self - Lubricating Mechanism of Porous Sliding Bearings
Authors: Kałdoński Tadeusz , Kałdoński Tomasz J.
Published: March 2009

In this paper are physicochemical bases of self–lubricating mechanism of porous sliding
bearings is presented. Up to now information about this, which took into consideration mainly
aspects, e.g. mechanical, thermal, hydromechanical etc, and knowledge of chemical elements
concerned with the course of chemical reactions into diphase system fluid – solid (porous) was
completed.
Continuous Method for Assessment of Wear under Conditions of Technically Dry Friction
Authors: Pakowski Czesław , Kałdoński Tomasz J. , Kałdoński Tadeusz
Published: March 2009

In the article a continuous method for measurement of wear under conditions of
technically dry friction of tribological kinematic pairs of the type pin–on–disk of T–11 tester, as an
example is presented. Also taken up was a test of an evolved simple method for evaluation of
correction on the participation of thermal expansion in size change of a frictional kinematic pair.
The analysis of obtained results showed the existence of correlation between total experimental
wear and analytical value of total wear (decrease of linear dimension of pin).