bluuebunny/crossref_metadata_2025 huggingface dataset:
Femtosecond Electron Pulses Production System
Authors: Rimjaem S. , Jinamoon V. , Kangrang N. , Kusoljariyakul K. , Saisut J. , Thongbai C. , Vilaithong Thiraphat , Rhodes M.W. , Wichaisirimongkol P. , Chumphongphan S.
Published: March 2009

The SURIYA project is designed to generate femtosecond (fs) electron pulses at the Fast Neutron Research Facility (FNRF), Thailand. The fs electron pulses production system consists mainly of a thermionic cathode RF-gun, a magnetic bunch compressor in form of an alpha magnet (α-magnet), a linear accelerator (linac), a beam transport line, and various electron beam diagnostic instruments. This system aims to produce a 20-25 MeV electron beam with micropulses of less than 100 fs in length. Theses pulses can be used either for direct experimentation or to produce fs pulses of intense coherent far infrared radiation (FIR) and/or x-ray. In this paper, an overview of the system and characteristics of its major components will be presented.
Efficiency of Energy Transfer in a Small Plasma Focus Device
Authors: Ngamrungroj Dusit , Mongkolnavin Rattachat , Wong Chiow San
Published: March 2009

A study of energy transfer in a small plasma focus device has been carried out during its axial phase. The snow-plough model has been used in the simulation as a basic model for the calculation of plasma dynamics. The energy transferred to the plasma is calculated by considering the work done by the electromagnetic piston during the axial phase. It was found that the plasma energy calculated by this model agrees well with the experimental data within the pressure range of 1 mbar to 4 mbar if the mass shedding effect is included in the model. According to the present computation, the energy transferred into the plasma, in the case of a plasma focus with 2.3 kJ initial energy operated with nitrogen gas within the pressure range of 1 to 4 mbar, is between 224 J to 250 J. This corresponds to energy transfer efficiency of 9.6% to 10.7%. The mass shedding factor decreases from 0.23 to 0.069 with increasing pressure. Correspondingly, the energy transfer efficiency changes slightly at a higher pressure.
"New Donors" in Czochralski Grown Silicon Annealed at T≥ 600°C under Compressive Stress
Authors: Emtsev Valentin V. , Andreev Boris A. , Oganesyan Gagik A. , Kryzhkov D.I. , Misiuk Andrzej , Londos Charalamos A. , Potsidi M.S.
Published: March 2009

Effects of compressive stress on oxygen agglomeration processes in Czochralski grown silicon heat treated at T= 450OC, used as a reference temperature, and T= 600OC to 800OC are investigated in some detail. Compressive stresses of about P= 1 GPa lead to enhanced formation of Thermal Double Donors in materials annealed over a temperature range of T= 450OC – 600OC. It has been shown that the formation of thermal donors at T= 450OC under normal conditions and compressive stress is accompanied with loss of substitutional boron. In contrast, the concentration of the shallow acceptor states of substitutional boron in silicon annealed under stress at T≥ 600OC remains constant. An enhancement effect of thermal donor formation is gradually weakened at T≥ 700OC. The oxygen diffusivity sensitive to mechanical stress is believed to be responsible for the observed effects in heat-treated silicon.
Impact of the Growth Parameters on the Structural Properties of Si0.8Ge0.2 Virtual Substrates
Authors: Bogumilowicz Y. , Hartmann J.M. , Laugier F. , Rolland G. , Billon Thierry
Published: March 2009

We have focused in this paper on the impact of the growth rate and of the grading rate on the structural properties of Si0.8Ge0.2 virtual substrates grown at 900°C in a commercial reduced pressure chemical vapour deposition reactor. Adopting a grading rate of 4% Ge / $m together with a growth rate around 140 nm min.-1 yields very high quality Si0.8Ge0.2 virtual substrates. Their macroscopic degree of strain relaxation is indeed very close to 100%, their surface root mean square roughness is around 2.3 nm and most importantly their field threading dislocation density is of the order of 6x104 cm-2 only, with almost no pile-ups.
Effects of Varying Boundary Conditions on the Buried Pipelines
Authors: Lee Ouk Sub , Kim Dong Hyeok
Published: March 2009

In this paper, the FORM (first order reliability method) has been employed to estimate the probability of failure for the buried pipeline degraded by corrosion defects. The estimated results are used to assess the reliability of buried pipeline exposed to varying external and internal boundary conditions corresponding to a required target safety level. Furthermore, the effects of distribution types of random variables affecting the strength of buried pipelines on the probability of failure and
the reliability of the buried pipeline are systematically investigated. The plant-engineers should be informed about the margin of safety level of existing pipelines corresponding to the target safety level to assess the integrity of the corroded pipeline under operation.
Fatigue Test of Al-3%Ti Using Axial Loading Testing Machine for RF MEMS Switch
Authors: Park Jun Hyub , Lee Chang Seung , Kim Yun Jae
Published: March 2009

This paper presents high cycle fatigue properties of a Al-3%Ti thin film, used in a RF
(radio-frequency) MEMS switch for a mobile phone. The thickness and width of the thin film of specimen are 1.1μm and 480.0μm, respectively. Tensile tests of five specimens are performed, from which the ultimate strength is found to be 144MPa. High cycle fatigue tests of six specimens are also performed, from which the fatigue strength coefficient and the fatigue strength exponent are found to be 336MPa and –0.1514, respectively.
A Study on Characteristics of Leak Signals of Pipeline Using Acoustic Emission Technique
Authors: Lee Min Rae , Lee Joon Hyun
Published: March 2009

This study presents an approach to leak detection of pipeline review in terms of theoretical analysis such as acoustics and hydromechanics that should be accompanied by explanation of leakage. The acoustic emission signals during leak from circular hole of different geometries were studied both analytically and experimentally. The relationships between acoustic parameters and fluid
mechanical parameters also were derived analytically. A quadrupole aerodynamic model was applied for the analysis of leak from the circular hole. Computer simulation results demonstrate the effectiveness of the proposed approach. In addition, it was confirmed that the wavelet transform (WT) was an effective tool to determine source location. That is, arrival times of each frequency component
needed in the velocity calculation could be determined from the peak of the magnitude of wavelet transform data on the time-frequency plane.
Powder XRD and Solid-State 2H-NMR Studies on RAP-Protected Palladium Nanoparticle (RAP = Rubeanic-Acid Polymer)
Authors: Fujishima M. , Yamauchi M. , Ikeda R. , Kubo T. , Nakasuji K. , Kitagawa H.
Published: March 2009

This study reports hydrogen absorption property of newly-synthesized RAP
(rubeanic-acid polymer)-protected palladium nanoparticle (RAP-Pd). From powder X-ray diffraction measurements, the lattice constant of Pd nanoparticle was revealed to increase by 0.11 Å under 600 Torr hydrogen gas condition at room temperature, indicating that the hydrogen absorption occurs in the Pd nanoparticle. Solid-state 2H-NMR spectrum under deuterium gas showed that three different components exist in RAP-Pd, which are derived from imino group, terminal amino group in the RAP and absorbed deuterium atom inside the Pd nanoparticle. This
result gives an expectation of the hydrogen absorption in RAP itself.
Magnetic Properties of Highly-Ordered Ni, Co and Their Alloy Nanowires in AAO Templates
Authors: Pan H. , Yi J.B. , Liu B.H. , Thongmee S. , Ding J. , Feng Yuan Ping , Lin Jian Yi
Published: March 2009

We have fabricated metal/alumina hybrid materials by electrodepositon of metal
nanowires into nanopores of anodic aluminum oxide templates. Single crystalline Ni and Co nanowires have been successfully fabricated. Structural characterization (XRD and HRTEM) shows that the single crystalline Ni nanowire has a preferred orientation along (220) direction. The preferred orientation of Co nanowire is along (100). These single crystalline Ni and Co nanowires
have exhibited excellent magnetic properties. Their alloy nanowires have exhibited a large shift in hysteresis, probably due to the surface oxidation and exchange bias effect.
Topographical Functionalization of Ordered Mesoporous Silica
Authors: Lee H.J. , Shim I.K. , Park M. , Choy Jin Ho
Published: March 2009

Multi-functionalized MCM-41 has been successfully synthesized by site-selective
manipulation of pore surface. The external surface of as-synthesized MCM-41 including surfactant template was deactivated by replacing the hydroxyl group with the highly electronegative fluorine. It allows one to fabricate the nanovessel with desired functionalities for the advanced applications such
as targeted drug delivery.
Influence of Clay Addition on Ion Conductivity of Polymeric Electrolyte Composites
Authors: Kim Seok , Kang J.Y. , Lee Sung Goo , Lee Jae Rock , Park Soo Jin
Published: March 2009

In this work, the polymeric electrolyte composites (PECs) based on poly(ethylene oxide) (PEO), ethylene carbonate (EC) as a plasticizer, and lithium montmorillonite (Li-MMT) clay were fabricated, and investigated for understanding the effects of Li-MMT/EC in the polymer matrix on
the ionic conductivity. For a lithium battery application, the native sodium cations in MMT were exchanged for lithium cations. As a result, the lithium ion was intercalated into the layer of the MMT clay, and thus PEO entered the galleries of MMT clay. The ionic conductivity was enhanced with increasing MMT contents due to the immobile MMT clay serving as the anion species and the decreased crystallinity of PEO.
Low Temperature Bond Valence Sum Study of La1.7 Dy0.3 Ca0.6 Ba2 Cu4.6 Oz Oxide Superconductors
Authors: Parmar Rohini N. , Markana J.H. , Thakar C.M. , Rayaprol S. , Bhalodia J.A. , Shah N.A. , Kuberkar D.G. , Chakraborty K.R. , Krishna P.S.R. , Ramnadham M.
Published: March 2009

Bond Valence Sum (BVS) calculations were performed on neutron diffraction (ND) data measured at 12, 35, 55, 75 and 300 K on one sample (x = 0.3), of a series of La2-xDyxCa2xBa2Cu4+2xOz (La-2125) compounds. ND experiments have been carried out to study the effect of temperature on structure and to relate it with the superconducting properties. The sample, La1.7Dy0.3Ca0.6Ba2Cu4.6Oz (LD3) has been reported earlier, and exhibits superconductivity at 68 K. In this paper we discuss BVS calculations carried out on low temperature neutron diffraction data.
Effect of Fabrication Techniques on the Properties of Carbon Nanotubes Reinforced Magnesium
Authors: Goh C.S. , Wei Jun , Lee L.C. , Gupta Manoj
Published: March 2009

In this study, both liquid and powder metallurgy techniques were employed to fabricate Mg nanocomposites. Comparisons were made on the physical and mechanical properties of Mg nanocomposites using these two different fabrication techniques. When similar weight fractions of carbon nanotubes (CNTs) were added to Mg using these two different techniques, the nanocomposites fabricated using powder metallurgy technique were found to be thermally more stable and has higher yield and tensile strengths than those produced using liquid metallurgy technique. The higher yield and tensile strengths were due to the presence of MgO particles which were pre-existent in the Mg powders. The MgO particles cause a hybrid reinforcement effect in the Mg-CNT nanocomposites, which surpasses the strengthening effect of the CNTs alone.
Investigation of Elemental Magnetic Moments of CoCrPt Films Using X-Ray Magnetic Circular Dichroism
Authors: Sun C.J. , Chow Gan Moog , Fecher G.H. , Lin H.J. , Hwu Y. , Wang J.P.
Published: March 2009

The elemental magnetic moments of Co and Cr in CoCrPt films were investigated using xray magnetic circular dichroism (XMCD). The spin and orbital moments of Co was calculated using the sum rules; it was found that the magnetic moment of Co in CoCrPt films was dominated by spin moment contribution. The total magnetic moment of Co was found to be lower than that of bulk Co. Further, the Cr moment was aligned anti-ferromagnetically with respect to Co, resulting in a decrease of saturation magnetization (Ms) in CoCrPt films.
Synthesis of Novel Raspberrylike Silica/Polypyrrole Hybrids Based on Single Silica Particle
Authors: Yang X.M. , Dai Ting Yang , Lu Yun
Published: March 2009

Novel raspberrylike organic-inorganic hybrids consisting of spherical silica
supporting smaller conductive polypyrrole particles were prepared through a
self-assembly polymerization process by choosing chitosan as a modifying agent of
silica surface. TEM shows the raspberrylike morphology of resulted hybrids.
Hydrogen-bonding interaction between the acetylamino of chitosan and hydrogen atom on nitrogen of polypyrrole is a determining parameter to get the raspberrylike
morphology. The raspberrylike silica-polypyrrole hybrids exhibited high conductivity of 8 s.cm-1 and its suspensions possessed good stability because of the special surface morphology. In the past few years, organic-inorganic nanocomposite particles have become the subject of rapidly growing interest for their superior properties (optical, mechanical, rheological, electrical, catalytic);1-2 In this field, silica is the most commonly used inorganic support. On the other hand, polypyrrrole(Ppy) is also commonly used organic shell.3 If Ppy nanocomposite systems can be prepared in stable colloidal form, the poor processibility of Ppy can be overcome, at lest partly, so that its applications can extended to wide areas.
However, since silica is initially hydrophilic, hydrophobic Ppy shell is very difficult
to get by direct surface polymerization. Only “raspberry” like composite was got. A
high-resolution TEM picture obtained by Gill et. al. was the first report to reveal this
unusual “raspberry” morphology where the composite particles were aggregates of the original small silica particles held together by the conducting polymer component which
Wall Slip of Suspension Flowing in Capillary at Elevated Temperature
Authors: Wang Z.Y. , Lam Yee Cheong , Chen X.
Published: March 2009

The flow of a suspension system with glass microspheres in polymer EVA
(Ethylene Vinyl Acetate) melts system was studied in a capillary rheometer. The slip velocity was determined by Mooney technique. A modified slip law describing the
slip velocity as a function of the wall shear stress and particle concentration was
proposed and employed to describe the flow behavior of the suspension system.
Phonon Mode Conversion at Planar Interfaces in Crystalline Solids. Harmonic and Anharmonic Interface Potentials
Authors: Twaróg Dariusz , Zieliński Piotr , Stagraczyński Ryszard , Łodziana Zbigniew , Gałązka Miroslaw
Published: March 2009

A generalized model of a solid-solid interface is built. The model takes into account
additional surface mass densities on both sides of the interface and an anisotropic and/or
anharmonic coupling potential. The resonances due to the potential (up to three) manifest
themselves by minima (zeros) of transmition and/or extrema in reflected and transmitted waves of
different polarization depending on physical properties of the media and of the geometry.
Critical Behaviour in Ferroelectrics as Studied by Nonlinear Dielectric Effect. Invariants of the Electric Susceptibility in a Biasing Field
Authors: Gałązka Miroslaw , Szklarz P. , Bator G. , Zieliński Piotr
Published: March 2009

The simplest equation of state compatible with the Widom and Griffiths scaling hypothesis have been built for the uniaxial ferroelectrics TGS and MAPCB. The explicit forms have been found of the scaling invariants deduced from the curves of the electric susceptibility measured in a constant biasing field. Smooth and sharp inflection points of the susceptibility curve in the vicinity of the critical temperature have been classified. The invariants and the inflection points have been used to determine critical parameters of TGS and MAPCB.
Theory of Photoinduced Phase Transitions: From Semiclassical to Quantum Aspects
Authors: Ogawa Tetsuo
Published: March 2009

We review recent progress of theoretical studies for the photoinduced phase tran- sitions (PIPTs) to clarify what the PIPTs are. There are two types of the PIPTs: (a) global change via optically excited states and (b) new material phase creation in optically excited states. First, concerning (a), photoinduced structural phase transitions via excited electronic states are discussed using a minimal one-dimensional model composed of localized electrons and lattices. We show that the global structural change by photoexcitation only at a single site is possible under the adiabatic or diabatic approximation. This dynamics of the domain bound- aries (domain walls) is called the “photoinduced domino process,” which is the photoinduced nucleation in nonequilibrium first-order phase transition. Second, concerning (b), we discuss quantum orders of electron-hole (e-h) systems, which are optically excited states of insulators consisting of many electrons and holes in two bands. In particular, the “exciton Mott transi- tion,” i.e., the “from-insulator-to-metal” transition of the e-h systems as the particle density increases is introduced. We stress that this transition depends strongly on dimensionality of the system.
Model of a Multi-Sectional Web Offset Printing Press Drive Section, Controlled by Electronic Shaft
Authors: Augustaitis Vytautas Kazimieras , Gičan V. , Iljin I. , Šešok N. , Geleževičius Vilius
Published: March 2009

For synchronization of sections of modern printing machines and equipment of such sections, driven by individual drives the system of “electronic shaft” is widely used. A development of the mathematical model of such a local drive, consisting of mechanical and electric-electronic parts as well as links between them, is provided. The model with an effective adaptive control block for increasing accuracy of the drive is provided in the form of a structural scheme. It, first of all, is usable for investigations of linear and nonlinear dynamic processes that take place in the mechanical part of the drive. Processes that take place in the electric drive are not detailed in this article. An example of the application of the model is provided.
Statistical Characteristics of a Simplex Search with the Aim Drift
Authors: Dambrauskas Algirdas , Udris Dainius
Published: March 2009

The purpose of this research is to find and analyze statistical characteristics of a simplex
search in a noisy surrounding and drifting aim conditions. The search process is described by using
multiple Markov chains. Efficient simplex search algorithms for nonstationary object optimisation
can be created on this investigation basis.
An Adaptive Superfinish Tool
Authors: Pauža V. , Bučinskas Vytautas
Published: March 2009

Final treatment of fine detail surfaces remains an important problem in modern machine
building. As a solution to such a task a super finishing processing is widely used. The proposed
system is dedicated to creating an oscillating movement of a detail or tool in super finishing wide
scale of processing details - crankshaft, cylinder shaped details. This device can create detail or tool
amplitudes equal to a detail surface or tool micro relief pitch. In difference to classical systems, the
proposed system is operating on sound frequency and enables one to perform a surface treatment
during one cycle.
Research of Possibilities of Energy Transformation Using an Autovibrating System, Excited by Small Outer Excitement
Authors: Ragaišis L. , Jonušas R. , Ragulskis K. , Jurėnas V.
Published: March 2009

There are lots of sources of disturbance in people’s surrounding environment - e.g. wind,
sea, river flow, and intensive acoustic noise. These sources can cause auto vibrations of particular
dynamic systems. Such phenomenon could be used for converting mechanical vibration energy to
electrical energy. Solving this problem is topical because it could help to create autonomic sources
of renewable energy.
Dynamic model, described by a presumptive differential motion equation, of auto vibrating system,
affected by airflow is made and inspected. Possible modes of vibrations and different states of
nonlinear auto vibrating system are analyzed using methods of Newmark and Runge-Kutta. Auto
vibration existence zones of the system are designated. Reliance on the existence of poly-solutions,
stability or chaotic solutions of vibrating system is estimated.
Consistencies of using electro dynamical principle of converting mechanical vibration energy to
electric energy are inspected.
Application of Frequency Method for Defining Threaded Joint Tightening Degree
Authors: Augustaitis Vytautas Kazimieras , Bučinskas Vytautas , Pauža V.
Published: March 2009

There is a big variety of machines and equipment – internal combustion engines, aviation
parts, building frames - joined by threaded joints, realized as bolt, nut and pin ones. For successful
and safe exploitation of such equipment, it is required to check the tightening degree of threaded
joints. There are few known methods of such control and one is presented in this paper. The
proposed method is based on contact stiffness and friction change from thread tightening degree. At
the same time, tightening changes with sufficient significance the dynamical properties of such a
system - natural and resonance frequencies, amplitude – frequency and amplitude-phase
characteristics, so, that it is possible to evaluate the tightening degree of the investigated joint.
Dynamic properties are defined by exciting transient process between bolt head and tightened by
this bolt detail using as short as possible force impact. Sensors register analogical signal of transient
process and transmit it to a special computer card. The computer card converts analogical signal to
code. Code is saved in the computer file for further processing. Processing data is saved in this file,
and we find desired dynamical characteristics. Using special experimental bench proved that
dynamic characteristics are sensitive enough to threaded joint tightening degree and the method is
applicable to practice.
Dynamic Research of a Walking Pipe Robot
Authors: Mištinas Vygantas , Spruogis Bronislovas
Published: March 2009

In this paper, a walking pipe robot for an inpipe inspection of an underground urban gas
pipeline is presented. The robot is developed for visual and Non-Destructive Testing of pipeline
networks. The robot is configured as an articulated structure – resembling a snake shape. Two
active driving vehicles are located in the front and rear parts of the system. Passive modules such as
a control module and other optional modules are inserted between the active vehicles. The design
scheme of an inpipe inspection robot with a vibratory impulse actuator is discussed. The dynamic
model of a robot with a vibratory pneumatic actuator was developed and the equations of its
movement were derived.
Accuracy, Power Consumption and Environmental Protection of Shuttle Gantry Module in Arable Farming
Authors: Bareišis Ramūnas , Kirka Aleksandras , Puronas Rolandas
Published: March 2009

The theoretical and the experimental researches of guidance, energy consumption and environment protection of the shuttle gantry module are submitted. Influence of a micro-relief, chassis speed differences and correction intensity for accuracy of guidance has been determined. The characteristics of the chassis have more influences for accuracy of guidance than a rough ground. It is not effective to supply more than 60 % of oil flow for the chassis with a lower speed, because it has a negative influence on the accuracy of guidance and on the consumption of power. When distance between the optical sensors is 50 mm, the maximum declination of guidance from mean trajectory is 33 mm. The useful factors and perspectives for energy saving and environment protection are established. The energy demand for chassis and operating working parts do not match in time. 3.5 - 4.5 kW installed power is enough to operate the module. The resistance of the chassis moving through constant technological tracks and that of the implemented carriage moving though beam are low. The energy consumption that is of no avail to soil deformation decreases to minimum. The resistance power of implements passes to the gear. Soil in the plant vegetation zone is not influenced by chassis. Inter-row could be reduced. Thus, there emerges a possibility to satisfy energy demand by alternative energy sources, to reduce pollution, and the deleterious influence on soil features. Direct human participation in technological processes is not required. The dependence on meteorological conditions is reduced. In order to calculate energy consumption, the operation efficiency of implements and chassis was established. Common efficiency of the module is calculated as a reverse value of common working time input. 40 m length beam will allow working at 0.42 ha/h efficiency. Positioning energy is just 0.6 kWh/ha, common one – 8.6 kWh/ha.
Problem of the Service Life of Self-Lubricated Friction Couples
Authors: Giemza Bolesław , Król Artur , Kałdoński Tadeusz
Published: March 2009

In the article one investigation’s results regarding the influence of work parameters of the
porous bearings on the process of oil ageing is presented. Firstly stand tests were performed for the
porous bearings sintered of iron powder Höganas (Sweden) and impregnated by protection oils,
often used by porous bearings manufactures. Stand tests were performed until the seizure of the
bearing was achieved – loss of self-lubricating capability. Then oil was extracted from all bearings
and the degree of oil ageing was observed by two methods: investigation of IR spectrums and total
acid number. After that all results were compared with those achieved for fresh oils.
Determining Major Factors Causing the Wear of Wheelset Tyres
Authors: Vaičiūnas Gediminas , Lingaitis Leonas Povilas , Mikaliūnas Šarūnas
Published: March 2009

Graphical representation of laws governing the abrasion of locomotive wheelsets shows different distribution of values obtained for oiled and not oiled wheelset tyres. When wheelset tyres are oiled, the much higher deviation of abrasion values can be observed. This allows us to assume that oiling is more important for reducing the wear of not heavily loaded wheelset tyres.
Scale Effects in Cavitation Erosion of Materials
Authors: Szkodo Marek
Published: March 2009

This work presents a mathematical model describing the cavitation erosion of materials. The model of cavitation erosion is based on Weibull’s distribution. The model describes the influence of material properties and also dimensions of the eroded area and volume of the eroded material on cavitation erosion curves i.e. cumulative volume loss and volume loss rate as a function of time of cavitation loading. In addition, there is a possibility to define cavitation resistance of materials, upon the base of the adduced model.
One-Dimensional Nonlinear and Nonlocal Oscillations of Plasma in Solid Body
Authors: Miškinis Paulius
Published: March 2009

A simple one-dimensional model describing nonlinear and nonlocal oscillations of
electron plasma is considered. Due to regard of the nonlocality of the field potential, it allows one to
smooth down the peaks of nonlinear waves, to steep up the wave front, and to modify the velocity
amplitude and phase of the traveling wave.
The Application of Composite Materials in Pulsed Inductor Design
Authors: Novickij J. , Višniakov N.
Published: March 2009

The multilayer construction of metal-matrix Cu-Nb microcomposite wire wound
Zylon-epoxy composite reinforced inductor is analyzed. Inductor geometry was verified
analytically to find the maximal available value of a magnetic field. For comparison, the soft copper
wire wound inductor was made by the same geometry and technology and both inductors were
investigated at room and liquid nitrogen temperatures. Experimental results were compared with
calculated data. The acceptable agreement of calculated and measured data for soft copper wire
wound inductor and the significant decrease of amplitude and distortions of sinus shape pulse due to
weak heat dissipation of metal-matrix Cu-Nb wire wound inductor took place.
Investigation of Possibilities for Ceramic Coating of Biological Polyethylene Implants
Authors: Mariūnas Mečislovas , Šešok A. , Lisauskas V.
Published: March 2009

The paper analyses chemical and magnetronic coating methods. The investigation is
made into the types of such implant-oriented materials that are best featured for their bonding
properties. It has been established that the most durable and solid coatings are the ones that are
made by way of magnetronic method. The coatings are less subject to wear-out process when cobalt
plays the function of the bonding material once inserted between polyethylene and ceramics and
subsequently coated with the layer of ceramic material.
Development of High-Speed Steels for Cast Metal-Cutting Tools
Authors: Chaus Alexander S. , Chovanec J. , Legerská M.
Published: March 2009

As-cast high-speed steels heat-treated have completely much lower impact toughness
than that of the steels of a similar chemical composition but undergone hot working – rolling or
forging. That is attributed to the influence of eutectic carbides, which especially being coarse,
provide easily brittle intergrain fracture sites under low stress intensity factor levels. This is
especially real for cast cutting tools. In order to exhibit good all-round performance the impact
toughness enhancement of as-cast high-speed steels is obligatorily needed. In this connection it is
expedient to turn from high-speed steels of conventional ledeburitic origin to high-speed steels of
hypereutectoid and ferritic-carbidic ones with considerably lower carbide heterogeneity resulting in
enhanced impact toughness. In the present work special features of the structure, phase composition
and properties of such high-speed steels designed for cast tool are studied. In order to substitute
tungsten by chromium in as-cast high-speed steel a special alloying system has also been
developed.
Operation Reliability of Bent Elbows of Steam Pipelines
Authors: Rudzinskas Vitalijus , Valiulis Algirdas Vaclovas , Chernashejus O.
Published: March 2009

The number of potentially dangerous equipment that has completed its established
operational time, but is still being used, is permanently increasing. Therefore there is a problem of
its further operations. A decision to continue to operate power-generating plants, when the initial
resource of the equipment’s working time is ended, and its further operation without considerable
expenditures on repair and the diagnostic of a metal state is possible only with the help of long-term
research of metal in power-generating plants. Only a complex of research techniques can estimate
the real state of a construction. In the article problems connected with the definition of operation
reliability of steam pipeline elbows are investigated. Different areas of an elbow were researched.
Results of a microstructure analysis, and mechanical characteristics (time history) research of an
elbow metal are presented. Also results of calculation of an elbow on low - cyclic thermal fatigue
are presented.
New Trends in Biomechatronic Engineering Education
Authors: Mândru Dan , Măties Vistrian , Roş Victor , Tătar Mihai Olimpiu
Published: March 2009

In the first part, the paper presents objectives of education in the biosystem engineering
field, generally, and in the field of biomechatronics, especially. A hybrid system of Engineering and
Biosystem is developed. Based on this, interrelations between components of engineering and
biological systems are developed. In the second part, our experience during the past three years in
introducing students to Biomechatronic engineering is described. The paper presents the specific
team – work project elements and some examples of typical projects.
A Robust Controller for Electrohydraulic Drives
Authors: Gosiewski Zdzisław , Henzel Maciej
Published: March 2009

Highly maneuverable aircraft has redundant electrohydraulic actuators that generate the
forces to drive the aircraft control surfaces. Two problems are important in these actuators. First,
during reconfiguration of the actuator channels the hydraulic system works in the full range of its
parameters. It leads to strongly nonlinear models of the redundant servo. Second, the frequency
bandwidth of elements, which are located in the feedback loop of the servo, should be as wide as
possible. Therefore, it is necessary to choose proper control method for actuator, where the
controller of control system adjusts the set point signal. The advanced control methods can ensure
the new quality of the systems.
The new, advanced methods can cope with such problem in practical applications. There are
available: adaptive methods, predictive methods, etc. and first of all, the robust control methods.
These methods are robust on external disturbance. The causes of disturbances are very different: the
inaccuracy in the mathematical and simulation model, the change of the operation point, the
weather and temperature conditions, etc. We have designed such models in the Matlab/Simulink
environment and we divided the full actuator into small subsystems.
Analysis of the Deformation Behaviour of Cu Processed by High Pressure Torsion
Authors: Sitdikov Vil D. , Chembarisova Roza G. , Alexandrov Igor V.
Published: March 2009

In the investigation the 3D version of the Estrin-Tóth dislocation model was used to analyze deformation behaviour of pure Cu, subjected to high pressure torsion (HPT) under pressures equal to 0.8, 2, 5, 8 GPa. As a result of the computer simulation, the nature and reasons for strain hardening are analyzed, the dislocation density evolution versus degree of SPD and graincell size versus degree of SPD curves were plotted. It is shown that the model adequately reflects the acting deformation mechanisms and structural changes during HPT at different applied pressures. It has been stated that an increase of the applied pressure at HPT leads to an increase in the activity of dislocation sources and sinks in the grain-cell walls. Misorientations between boundaries are estimated. It is revealed that an increase of the applied pressure contributes to a growth of the misorientation angles between neighbouring grain-cells.
Features of Cyclic Extrusion Compression: Method, Structure & Materials Properties
Authors: Richert Maria W.
Published: March 2009

The Cyclic Extrusion Compression (CEC) is one of the methods of severe plastic deformation (SPD), used for producing nanomaterials. The CEC method allows materials to be deformed to arbitrarily large strains without changing the initial shape of sample. Large hydrostatic compressive stresses are exerted during deformation avoiding sample cracking. Using the CEC method Cu and aluminum alloys nanomaterials were produced. It has been found that, after exerting true strain of about ϕ = 14, only some part of the sample changes into a nanomaterial, while the remainder volume still shows the ultrafine microstructure. The nanometric microstructure is created generally inside the areas of intersecting microbands. Large misorientation has been found between the microbands and the surrounding material, facilitating the formation of nanograin boundaries. The hardness of samples increases with the increase of deformation, however only to a boundary level of about 100 MPa. The stabilization of hardening, above a deformation of about ϕ = 4, suggests the activation of softening processes. Independently to the stabilization of properties, the refinement of nanograins is continued, indicating the development of anomalies in the hardening – grain size relationship.
Microstructural Evolution during Mechanical Alloying and Hot Pressing of a Powder Blend of Aluminium and 316 Stainless Steel
Authors: Samanta A. , Chattopadhyay P.P. , Łojkowski Witold , Gierlotka Stanislaw , Fecht Hans Jorg , Manna I.
Published: March 2009

The paper examines the phase evolution in blends consisting of different proportions of stainless steel (SS316) and Al (0, 25, 65 and 85 wt. %) powders during high-energy ball milling by x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) and high-resolution transmission electron microscopy. An attempt has also been made to study the mechanical property of the bulk samples obtained by hot pressing the ball milled powder blend at suitable a temperature and pressure. The results of microstructural changes and mechanical property and the ability of consolidation of the amorphous/nanocrystalline powders by high-pressure techniques to develop engineering components has been discussed and highlighted.
Pulse Plasma Sintering of Nano-Crystalline Cu Powder
Authors: Michalski Andrzej , Rosiński Marcin , Siemiaszko D. , Jaroszewicz Jakub , Kurzydlowski Krzysztof Jan
Published: March 2009

Nanocrystalline copper powders, produced by the reduction of the CuO with hydrogen, were consolidated using the pulse plasma sintering (PPS) method. The sintering process was carried out at temperatures between 500 and 900 oC under a load of 60 MPa for 5 min. The average crystallite size of the sintered component obtained at 500 oC was about 80nm and at 900 oC 1880 nm. The components produced at 500 oC had a relative density of 90 %, and those sintered at 900 oC 92 %; their hardness was 215 and 140 HV0.1, respectively.
SiC – Zn Nanocomposites Obtained Using the High – Pressure Infiltration Technique
Authors: Swiderska-Sroda Anna , Kalisz Grzegorz , Grzanka Ewa , Gierlotka Stanislaw , Stelmakh Svetlana , Herlin-Boime Nathalie , Palosz Bogdan F.
Published: March 2009

Two-nanophase SiC-Zn composites were synthesized under pressure up to 8 GPa at up to
1000oC using an high-pressure infiltration method. The advantage of this technique is that in a
single, continuous process the ceramic nanopowder is compressed to form the matrix with
nanopores; the nanopores are filled with a liquid secondary phase, (here Zn), which crystallizes as
nano-scale grains. The key limitation is that the pores in the infiltrated preform have to stay open
during the entire process. For this reason only powders of very hard ceramic materials can be used
as a matrix. Two types of SiC nanopowders with average crystallite size of 10 nm and 60 nm and
average particle size of 30 nm and 100 nm, respectively were used. The measurements of porosity
of the green compacts prepared from these powders, pressed at 2.5 GPa and 8 GPa at room
temperature, indicated that open porosity was maintained. The nanocomposites obtained show a
“nano-nano” type microstructure with a uniform mixture of SiC and Zn phases. The volume
fraction of Zn is 20 % independent of the process conditions and initial powder morphology. The
process parameters and powder granularity influenced the crystal size of the secondary phase. The
average grain size of Zn varied from 20 to 85 nm and was smaller in the composites obtained with
the finer matrix, under higher pressure and at lower temperature. The microhardness HV02 of SiCZn
nanocomposites varied from 6 to 22 GPa and increased with an increase of pressure and
temperature of the infiltration process, and was significantly larger for the finer grained composites.
Metallic Nano-Materials and Nanostructures: Development of Technology Roadmap
Authors: Daniszewska Agnieszka , Łojkowski Witold , Fecht Hans Jorg , Kurzydlowski Krzysztof Jan , Narkiewicz Urszula , Salishchev Gennady A. , Zehetbauer Michael , Kulczyk Mariusz , Chmielecka Małgorzata , Kuzmenko Dmytro
Published: March 2009

Current and prospective trends in application of metallic nanomaterials have been studied. The
study has been conducted within the Nanoroad SME European project – as the first step for a
roadmap for industrial application of nanomaterials. The web page of the project is
http://www.nanoroad.net/. The present report presents an analysis of patents, papers, national and
European projects in the field of nano-metals, and also an analysis of the present state of research
and expected trends in this domain. Based on the performed analysis a data base of nanomaterials
has been developed as well as roadmaps with expected time to applications. It can be found under
http://bourgogne.arist.tm.fr/nanoroadsme/home/. The roadmap is mainly addressed to SMEs to help
them to decide about applications or production of nanomaterials.
Combination of ECAP and Hydrostatic Extrusion for UFG Microstructure Generation in Nickel
Authors: Kulczyk Mariusz , Pachla Wacław , Swiderska-Sroda Anna , Krasilnikov Nikolay A. , Diduszko Ryszard , Mazur Andrzej , Łojkowski Witold , Kurzydlowski Krzysztof Jan
Published: March 2009

An ultra-fine grained microstructure was obtained in high purity nickel by a combination of (a) equal-channel angular pressing (ECAP) and (b) hydrostatic extrusion (HE) with a cumulative true strain of ~11.2. The resulting microstructure was examined by light and TEM microscopy. Mechanical properties have been measured by tensile and hardness tests. It was found that HE of ECAP-ed samples leads to a significant grain size refinement (from 330 to 160nm) and to an increase in microstructural homogeneity. SPD nickel, made by a combination of the ECAP and hydrostatic extrusion methods, has high strength and ductility (i.e.: YS=1120MPa and εf = 11%). The microstructure transformation was accompanied by a strength increase of 78% compared to ECAP alone. The results obtained fit well with the Hall-Petch relationship. A combination of ECAP and HE has achieved much better properties than either single process and show it to be a promising procedure for manufacturing bulk UFG nickel.
The New SPD Processing Trends to Fabricate Bulk Nanostructured Materials
Authors: Valiev Ruslan
Published: March 2009

During the last decade severe plastic deformation (SPD) has become a widely known method of materials processing used for fabrication of ultrafine-grained materials with attractive properties. Nowadays SPD processing is rapidly developing and is on the verge of a transition from lab-scale research to commercial production. This paper focuses on several new trends in the development of SPD techniques for effective grain refinement, including those for commercial alloys and presents new SPD processing routes to produce bulk nanocrystalline materials.
Mechanical Properties and Deformation Behaviour of Ultra-Fine Grained Nickel
Authors: Krasilnikov Nikolay A. , Łojkowski Witold , Pakiela Zbigniew , Kurzydlowski Krzysztof Jan
Published: March 2009

The mechanical properties and deformation behaviour of ultra-fine grained (UFG) Ni subjected to severe plastic deformation (SPD) were investigated. The UFG Ni characterized possessed an homogeneous structure with a grain size of 120 nm and high angle nonequilibrium grain boundaries. This nickel possessed an ultimate tensile stress of 1270 MPa. Investigation of the deformation relief on the polished surface of the UFG Ni sample by HRSEM revealed grain boundaries (GBs) steps already at small degrees of tension that testifying to the involvement of grain boundaries in the deformation process at room temperature. After significant tensile strain the deformation relief revealed a network of crossed shear bands oriented at an angle in the range 35°- 45° to the axis of tensile deformation. Shear bands propagated along GBs parallel to the plane of maximal shear stress. The formation of shear bands occurred due to a strong shift and rotation of grain groups. This led to a deformation mechanism involving collective relative displacement of grain groups, with extensive grain boundary sliding at room temperature. Over a length of a few micrometers the material can be regarded as uniform and therefore the local strain distribution becomes more uniform than in coarse-grained materials. It is plausible that this mode of deformation may contribute to the enhanced ductility. The deformation behaviour of Ni having different grain sizes and various grain boundary states are also considered. The Opportunity to achieve a combination high strength and good ductility by control of the microstructure of in metals and alloys opens perspectives industrial applications, particularly, for mirco-systems and for items of complex geometry to be produced by superplastic forming.
An Acoustic Study of Irreversible Structural Relaxation in a Bulk Metallic Glass
Authors: Kobelev N.P. , Kolyvanov E.L. , Khonik V.A.
Published: March 2009

Irreversible structural relaxation of bulk amorphous Zr52.5Ti5Cu17.9Ni14.6Al10 was studied by means of logarithmic decrement and shear modulus measurements using an inverse torsion pendulum in the frequency range from 5 Hz to 40 Hz. Irreversible contributions to the decrement and shear modulus and their frequency, temperature, and time dependences were investigated. The activation energy spectrum of irreversible structural relaxation has been reconstructed. It has been shown that irreversible structural relaxation can be regenerated by a special heat treatment. The results obtained are discussed within the framework of a phenomenological model, which implies existence of two-well relaxation centers in the glass structure.
Comparing Irreversible and Reversible Structural Relaxation in Bulk and Ribbon Metallic Glasses Zr52.5Ti5Cu17.9Ni14.6Al10 and Pd40Cu30Ni10P20 by Mechanical Spectroscopy
Authors: Eggers M. , Khonik V.A. , Neuhäuser Hartmut
Published: March 2009

By means of the vibrating reed technique, measurements of internal friction have been performed in the temperature range of 120 K < T < Tg (= glass temperature) on two amorphous alloys, each produced as ribbon and bulk material. The different contents of free volume result in an only slight shift of the onset of irreversible structural relaxation to lower temperatures (i.e., lower activation energies) for the ribbons, while considerably different amounts of structural relaxation occur. After correcting for the thermoelastic effect, the reversible structural relaxation, i.e., an approximately exponential increase of damping with rising temperature, is well described by KWW kinetics (β ≈ 0.3). For the Zr-based alloy only, a clear relaxation peak occurs in the range from 270 K to 320 K (for the first flexural vibration mode between 100 Hz and 400 Hz) induced by hydrogenation. In addition, the effect of plastic deformation on the damping behavior by cold rolling of the bulk materials has been examined.
Relaxations and Thermomechanical Stability of a Crosslinked Photopolymer
Authors: Ayadi Z. , Etienne S. , Nivoit M. , Fiorani J.M. , Cunat Ch.
Published: March 2009

Thermal and thermomechanical stability of a crosslinked diacryl photopolymer is
examined by means of various experimental techniques. Aging is observed and it is explained by
the polymerization which is not completely achieved or/and by liquid glass transition
manifestations related to the thermomechanical history of the material.
Magnetoplastic Effect: From Spin Dynamics to Dislocation Mobility
Authors: Morgunov R.B. , Baskakov A. , Blokhin I. , Dunin-Barkovskii L. , Shmurak S. , Tanimoto Y.
Published: March 2009

Microscopic elementary events responsible for magnetoplastic effect are studied in detail by means of photoluminescence, electron spin resonance and SQUID magnetometry in NaCl:Eu single crystals. The Eu2+ clusters being dislocation obstacles were used as a spin and luminescent labels allowed detecting simultaneous spin and atomic structure transitions in exchange-coupled few-atomic Eu2+ clusters under static magnetic field B = 5 T. Rearrangement of atomic structure of these clusters changes the lattice distortions around them and effectiveness of clusters interaction with moving dislocations during plastic flow. From the comparison of spectroscopic data and numerical calculations of aggregation pathways of small clusters it was concluded that magnetosensitive clusters contain two Eu2+ ions with parallel spins (dimers). Two different ways of creating of magnetosensitive dimers in the crystal lattice are found: (1) slow diffusion limited aggregation in freshly quenched crystals, and (2) fast aggregation stimulated by dislocations dynamical distortions of lattice provided by the plastic deformation of aged crystals.