bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Si/Al Ratio on Selective Catalytic Reduction of NOx with NH3 over Pt/Al-SBA-15
Authors: Kang Min , Park Jae Hyun , Park Eun Duck , Kim Ji Man , Kim Dae Jung , Yie Jae Eui
Published: March 2009

The selective catalytic reduction of NOx with NH3 (NH3-SCR) was investigated over Pt
catalysts supported on various supports such as alumina, ZSM-5, SBA-15, and Al-SBA-15 with
different amounts of alumina. Among them, Pt catalysts supported on Al-SBA-15 showed the higher
NOx conversion at low temperatures than those of others. These also showed high NOx conversions
over a wide reaction temperature. As the Si/Al ratio in Al-SBA-15 decreased, the NH3-SCR activity
increased. This was closely related to the amount of strongly-adsorbed NH3.
Effect of Ball-Milling Method on the Formation of ODS Fe-14Cr-2Al-1Si-0.3Ta-1Y2O3 Powders
Authors: Ahn Jung Ho , Park B. H. , Jang J.
Published: March 2009

Mechanical alloying (MA) process has been examined to synthesize ferritic stainless
steel powder dispersed with nano-sized Y2O3 particles. A pilot-scale horizontal mill was fabricated
and compared with laboratory-scale ball mills and an attrition mill. Horizontal milling resulted in a
much better distribution of particle size and dispersoids than other milling methods. Although
horizontal milling is considered as a low-energy process requiring long times, processing time could
be markedly reduced with increasing the diameter of horizontal mill with a proper control of milling
parameters.
Nickel Decoration on Multi-Walled Carbon Nanotubes Using Multi-Step Impregnation Method
Authors: Kim Shin Dong , Park Soo Jin , Lee Young Seak
Published: March 2009

In this work, nano-sized nickel particles were dispersed on multi-walled carbon nanotubes using
multi-step impregnation method, to use them as hydrogen storage media. The dispersion degree of
nickel particles on multi-walled carbon nanotubes is inversely proportional to the nickel
concentration of solution. It was observed that the low nickel concentration is efficient to decorate
nickel particles into the inner space. Multi-step impregnation method of MWNTs through several
times with low nickel concentration is more efficient to manufacture Ni-MWNTs having well
dispersed metallic nickel particles.
Oxidation of Sulfur Components in Diesel Fuel with Tert-Butyl Hydroperoxide Using Chromium Containing Catalysts
Authors: Jeong Kwang Eun , Chae Ho Jeong , Kim Ung Chul , Jeong Soon Yong , Ahn Wha Seung
Published: March 2009

Transition metal (iron, cobalt, and chromium) substituted Hexagonal Mesoporous
Aluminophosphate (HMA), and AlPO4-5 were studied for the oxidative desulfurization (ODS)
reaction of refractory sulfur compounds such as DBT (dibenzothiophene) and 4,6-DMDBT (4,6-
dimethyldibenzothiophene). Selective oxidation activity varies with the kind of transition metal
employed. The ODS activity of HMA substituted catalyst follows the order: CrHMA >> CoHMA ≥
FeHMA. Comparison between HMA and AlPO-5, CrHMA catalyst shows better performance than
Cr-AlPO4-5 catalyst when tert-butyl hydroperoxide is used as oxidizing agent.
Dynamic Response of Two-Core Sandwich Composite Structures under Impact
Authors: Jiang Da Zhi , Yang Fu Biao , Xing Su Li , Xiao Jia Yu
Published: March 2009

Traditional sandwich structure consists of two face sheets and a core. With an internal
sheet inserted into the core, a two-core sandwich structure is then formed. Two-core sandwich
structures with composite laminated face sheets and a thin internal sheet subjected to low velocity
impact are studied in this paper. Local displacement of the core under the point of impact is
investigated. Simulated results show that the local displacement of the core along the direction of
the impact has been decreased significantly by introducing the internal sheet into a traditional single
sandwich structure and by reducing the space between the internal sheet and the impacted face sheet.
Shear deformation in the cores of a two-core sandwich structure is also investigated and attention is
focused on shear strains on interfaces between face/internal sheets and the cores. Results further
show that strain levels in selected elements at the interested interfaces depend upon locations of the
selected elements and arrangements of the internal sheet.
Influence of Heat Treatment on Magnetic and Damping Properties of Fe-11 at.% Al Alloys
Authors: Mielczarek Agnieszka , Riehemann Werner , Sokolova Olga A. , Golovin Igor S.
Published: March 2009

The influence of heat treatment on the amplitude dependence of internal friction in Fe -
11 at. % Al alloys with carbon contents in the range 0.005 - 0.2 at. % has been studied using an
inverted torsion pendulum in the temperature range 300 – 950 K and a vibrating reed apparatus at
room temperature. The specimens were annealed at 1273 K in vacuum and cooled down with
different cooling rates in order to obtain different degrees of order. It was found that ordering is
hardly avoidable in Fe - Al alloys with Al contents > 11 at. %. Ordered alloys are characterised by
lower damping capacity due to higher coercivity caused by additional pinning of magnetic domain
walls by antiphase boundaries. X-ray diffraction investigations indicate that water-cooling
suppresses ordering in Fe - 11 at. % Al alloys while cooling in air or in furnace provokes D03–type
ordering. Slowly cooled specimens are characterised by higher damping capacity due to lower
coercivity than water cooled or plastically deformed specimens. The amplitude dependent
magneto-mechanical damping was determined as the difference between amplitude dependent
damping without and with saturating magnetic field (~ 20 kA/m). Magneto-mechanical damping
was found to be proportional to the strain where the amplitude dependent damping is maximum
and reciprocal to the coercivity and saturation polarisation. Cold rolling increases the coercivity
and therefore decreases the magneto-mechanical damping. An increase of the grain size in the
investigated samples by heat treatment leads to a qualitatively expected decrease of coercivity and
therefore to an increase of magneto-mechanical damping.
Mechanical and Fatigue Properties of Cu-Al-Mn Shape Memory Alloys with Influence of Mechanical Cycling on Amplitude Dependence of Internal Friction at Room Temperature
Authors: Mielczarek Agnieszka , Riehemann Werner , Vogelgesang Sönke , Tonn Babette
Published: March 2009

The mechanical and fatigue properties of Cu - Al - Mn shape memory alloys with
different phase fractions at room temperature were investigated. The specimens with different
chemical compositions (Al: 8.9 - 12.5 wt. % and Mn: 3.3 - 9.3 wt. %) were tensile loaded with 10-3
s-1 tensile strain rate. Austenitic specimens have the highest tensile strength and fracture strain.
Yield strength, tensile strength and elongation of martensitic alloys were lower compared with
austenitic alloys. Fracture strain of martensitic alloys depend only little on the chemical
composition. Specimens of martensitic, austenitic and three different multiple phase specimens
were tested in the high cycle fatigue range at room temperature. The Woehler curves for multiple
specimens depend on the phase fraction at testing temperatures. Different elements as Co, Ni, Fe
and Si were alloyed to CuAl11.6Mn5. All decreased the ductility of the specimens, and their fatigue
properties.
Maxima could be detected in the strain amplitude dependence of damping for multiple phase
specimen. These maximum are shifted to lower damping and to higher strains with increasing
number of mechanical cycles, compared to the as cast condition for not cycled specimen. The strain
amplitude dependence of damping in martensitic and austenitic Cu – Al – Mn shape memory alloys
does not change much during mechanical cycling.
Effect of Heat Treatment on Acoustic Properties of Chromium Polycrystals at Low Temperatures
Authors: Pal-Val P.P. , Pal-Val L.N. , Golovina S.B. , Golovin Igor S.
Published: March 2009

Acoustic properties of polycrystalline Cr samples of 99.99 % purity are investigated at
frequencies of longitudinal vibrations f ~ 75 kHz and of bending vibrations at 0.6 < f < 1.5 kHz
when thermocycling within the temperature interval 5 − 330 K. Special attention is paid to the
acoustic anomalies in the vicinity of the magnetic phase transitions: the Néel point and the spin-flip
transition. In the as-received samples, a significant hysteresis of the acoustic properties has been
found for the first time. The effect of heat treatments on internal friction and elastic properties of
chromium polycrystals is also investigated. The data obtained are compared with the effect of small
preliminary deformation and а long-time ageing at room temperature on the ultrasound anomalies in
Cr single crystal. The observed behavior of the acoustic properties may be caused by changes in the
antiferromagnetic domain structure in Cr polycrystals under the action of thermoelastic stresses
arising from quenching, preliminary plastic deformation or thermocycling.
Analysis of Internal Friction Peaks in High Purity Molybdenum by a Viscoelastic Procedure Independent of the Relaxation Strength
Authors: Matteo C.L. , Lambri O.A. , Zelada-Lambri G.I. , Sorichetti P.A. , García Jose Angel
Published: March 2009

In this work we present a novel procedure, involving linear viscoelastic analysis, to
discriminate the two possible contributions of the observed damping peak which appears around
840 K – 1050 K in mechanically deformed high purity single-crystalline molybdenum. An
interesting feature of the procedure is that, for low damping samples, it can efficiently resolve
experimental peaks that result from the superposition of different processes independently of the
ratio between their relaxation strengths. This allows us to confirm that two different relaxation
processes appear in molybdenum in the temperature range about 0.3 Tm, one around 840 K, and the
other one near 1050 K. These can be related to diffusion and to a coupled mechanism involving
creation and diffusion of vacancies, respectively.
On the Physicochemical Mechanism of the Influence of Preliminary Mechanical Activation on Self-Propagating High-Temperature Synthesis
Authors: Khina Boris B. , Formanek Boleslaw
Published: March 2009

The analysis of physicochemical mechanism of the influence of mechanical activation
(MA) of a charge mixture on the subsequent self-propagating high-temperature synthesis (SHS) of
intermetallic compounds is performed. Numerical estimates have revealed an insignificant role of
the energy stored in solid reactants due to cold work during MA. The characteristic time of
relaxation of non-equilibrium vacancies, which were generated in metals by MA, during heating in
the SHS wave is estimated, and their insignificant influence on the reaction kinetics at high
temperatures is demonstrated. It is shown that a strong effect of preliminary MA on SHS can be
attributed only to deformation-enhanced solid-state diffusion during MA, which can lead to the
formation of a supersaturated solid solution and thus affect the conditions for nucleation of a
product phase (intermetallic compound) upon heating.
Diffusional Growth Kinetics of Boride Layers on Iron-Chromium Alloys
Authors: Dybkov Vasil I. , Goncharuk L.V. , Khoruzha V.G. , Meleshevich K.A. , Samelyuk A.V. , Sidorko V.R.
Published: March 2009

Two boride layers were found to form at the interface of iiron-chromiium alllloys (10 and 25% Cr) or an industrial 13% Cr steel and boron at 850-950 oC and reaction times in the range 1-12 h. In the case of a Fe-10% Cr alloy and the steel, the layers are based on the FeB and Fe2B compounds. With a Fe-25% Cr alloy, the constituent phases are FeB and CrB for the outer layer and Fe2B and Cr2B for the inner layer. Both layers are characterized by a pronounced texture. Diffusional growth kinetics of boride layers are close to parabolic and can alternatively be described by a system of two non-linear differential equations, producing a good fit to the experimental data. The temperature dependence of the layer growth-rate constants obeys a relation of the Arrhenius type.
Manifestations of Short-Range and Long-Range Parts of Interatomic Potentials In Rearrangement Processes of Multicomponent Condensed Systems
Authors: Zakharov Anatoly Yu.
Published: March 2009

Helmholtz free energy functional for generalized lattice model is reduced to Ginzburg- Landau-like form. Connections between interatomic potentials characteristics and parameters of Ginzburg-Landau-like functional are established. Equations for equilibrium distributions of species in multicomponent systems are derived. Equations of rearrangement kinetics of multicomponent systems are obtained. Description of the rearrangement processes via non-classical partial differential equations is proposed.
Modelling of Elastic Modulus and Molecular Structure Interrelationship of an Oriented Crystalline Polymer
Authors: Gafurov Ulmas
Published: March 2009

A modeling method is suggested on the basis of measurable structural and deformation
parameters to estimate the interrelation between the interconnecting chains over amorphous
segments conformation structure distribution and the elastic modulus in tension experimental
value for a loaded oriented linear amorphous- crystalline polymer. Macromolecule chain pulling
out value of polymer crystallite was defined using the Frenkel-Kontorowa’s dislocation model .
Simulation of the Columnar-to-Equiaxed Transition in Alloy Solidification - The Effect of Nucleation Undercooling, Density of Nuclei in Bulk Liquid and Alloy Solidification Range on the Transition
Authors: Dai H.J. , Dong H.B. , Atkinson H.V. , Lee Peter D.
Published: March 2009

A coupled cellular automaton-finite difference (CA-FD) model is used to simulate the
detailed dendritic structure evolution of the columnar-to-equiaxed transition (CET) for Al-Cu alloys
during solidification. The effects of material properties (nucleation undercooling, density of nuclei in
bulk liquid and alloy solidification range) on the CET are investigated. Simulated results reveal that:
(1) equiaxed grains form at an earlier stage with a smaller critical nucleation undercooling; (2) CET is
promoted if the density of nuclei in bulk liquid is increased; (3) extending the alloy solidification
range promotes the CET. Finally, CET maps corresponding to different alloy concentrations are
constructed, illustrating the relationship between processing conditions and the resulting grain
structures for alloys with different solidification ranges.
Simulation of Surface-Enhanced Ordering in Smectic Films
Authors: Abukhdeir Nasser Mohieddin , Rey Alejandro D.
Published: March 2009

A Landau-de Gennes type model for the direct isotropic/smectic A phase transition is
used to study surface-enhanced smectic ordering in the stable smectic temperature regime. A
unified surface-free energy functional is proposed which can be utilized for homeotropic and planar
surface anchoring. The time-dependent complex Landau-Ginzburg evolution equations and
boundary conditions are derived for thin-film geometry. Simulation results are presented for the
two types of anchoring and compared to observations from experiments and previous simulations.
Simple visualization software for smectic layering was developed and is also presented that is
compatible with discretized numerical solutions of the model.
Dynamical Interaction between Thermally Activated Glide of Screw Dislocation and Self-Interstitial Clusters in Bcc Fe
Authors: Liu X.Y. , Biner S.B.
Published: March 2009

Constant strain rate molecular dynamics simulations under the modified boundary
conditions were performed to elucidate the interaction processes between the kink motion of screw
dislocation and the glissile self-interstitial atom cluster loops in bcc Fe by using an EAM potential
for Fe fitted to ab initio forces. The junction formation and the helical dislocation mechanisms
were identified as two possible interaction processes. In the junction mechanism, the initial Burgers
vector 1/2<111> of the cluster loop was transformed into <100>. In the helical dislocation
mechanism first the absorption, followed by the formation of the helical dislocation and the
emission of the cluster loop through Hirsch mechanism was observed. Substantial hardening was
seen as result of the interactions. The stress-strain plots obtained for different loop sizes,
temperature and strain rates were used to estimate the strengthening factors.
The Effects of Solute Segregation on the Evolution and Strength of Dislocation Junctions
Authors: Chen Qian , Liu X.Y. , Biner S.B.
Published: March 2009

In this study, the role of solute segregation on the strength and the evolution behavior of
dislocation junctions is studied by utilizing kinetic Monte Carlo and 3D dislocation dynamics
simulations. The different solute concentrations and the character of the junctions are all included
in the simulations in an effort to make a parametric investigation. The results indicate that solute
segregation can lead to both strengthening and weakening behavior depending upon the evolution
of the dislocation junctions.
Diffusion Mechanisms near Tilt Grain Boundaries in Ni3Al Intermetallide
Authors: Starostenkov Mikhail D. , Sinyaev Dmitry V. , Rakitin Roman Y. , Poletaev Gennady M.
Published: March 2009

The paper is devoted to the research of diffusion mechanism in Ni3Al intermetallide over
grain boundaries of tilt <111> and <100> by the method of molecular dynamics. It was found that
grain boundary diffusion represented the combination of three main mechanisms: migration of
atoms along the nuclei of grain boundary dislocations, cyclic mechanism near the nuclei and the
formation of the chain of displaced atoms from one nucleus of dislocation to the nucleus of the
other one. Diffusion mobility of Ni atoms was essentially bigger than the mobility of Al atoms.
Grain boundary slipping and intergrain slipping were also observed during the deformation of the
bicrystal.
A Titanium-Decorated Fullerene Cluster – A Molecular Dynamics Simulation
Authors: Piątek A. , Nowak Roman , Gburski Z.
Published: March 2009

A small titanium-decorated fullerene cluster (C60[TiH2]6)7 was studied by MD
simulation over a wide range of energy, from the solid state to the vaporization of the nanosystem.
The low energy, solid state structure of the cluster was obtained as a deformed pentagonal
bipyramid. Several physical characteristics: the radial distribution function, the mean square
displacement, the translational velocity autocorrelation function, translational diffusion coefficient,
Lindemann index, etc., were calculated for a wide range of energy in the system.
Nanomaterials in Dental Applications
Authors: Lewandowska Małgorzata , Siejka-Kulczyk Joanna , Andrzejczuk Mariusz , Kurzydlowski Krzysztof Jan
Published: March 2009

Currently, nanopowders and nanocomposites reinforced with nanofillers are one of the
most rapidly developing groups of materials possessing excellent prospects for a wide range of
industrial and medical applications. This paper presents several examples of the nanomaterials
developed in the Faculty of Materials Science and Engineering of Warsaw University of
Technology which can have dental applications.
Ceramic-polymer composites are the most popular materials for dental fillings. The influence of
the nanofiller additions on the relevant properties of ceramic-polymer dental composites are
discussed in the paper.
The other group of nanomaterials applicable as dental materials are based on nanostructured yttrium
stabilized zirconium oxide ceramic. This ceramic is widely used for the fabrication of crowns,
bridges, inlays and other dental elements for which high strength, durability and esthetical
appearance is required. The effect of the nano-grain size of the ceramic powder on the sintering
parameters, microstructure and properties of the zirconia is discussed.
Computer Simulation of the Dynamics of Homocysteine Molecules Surrounding a Carbon Nanotube
Authors: Raczynski P. , Dawid A. , Dendzik Z. , Gburski Z.
Published: March 2009

Excessive amounts of homocysteine in the human body have been considered recently as
a factor which increases the risk of developing diseases of the cardiovascular system. The
nanosystem composed of homocysteine molecules covering a single walled carbon nanotube have
been studied by MD technique. The translational and rotational velocity correlation functions have
been calculated for several temperatures, including the physiological temperature of 309 K. The
qualitative interpretation of translational and reorientational dynamics of homocysteine molecules
in this specific environment is presented.
Influence of Hydrostatic Extrusion Parameters on the Microstructure and Mechanical Properties of 6082 Aluminium Alloy
Authors: Widlicki Pawel , Wiecinski Piotr , Garbacz Halina , Kurzydlowski Krzysztof Jan
Published: March 2009

The aim of the work was to optimise the Hydrostatic Extrusion, HE, parameters in terms
of their influence on the microstructure and certain mechanical properties of 6082 aluminium alloy.
The investigations focused on the fabrication of a nano- or ultrafine-grained microstructure of the
alloy. The effects of a multi-pass process were compared with those of a one-pass process
producing the same cumulated true strain of 3.75. Both the multi-pass and the one-pass
deformation resulted in profound grain refinement of the alloy. The microstructure contained grains
with an average size of 195 nm and 239 nm, respectively. The grain refinement brought about a
significant improvement in the microhardness and tensile strength of the alloy. It should be noted
that the multi-pass HE produced slightly greater improvement than the single pass process.
Optical Properties of Nanocrystalline YAG:Ce
Authors: Paul Heiko , Kessler Dominik , Herr Ulrich
Published: March 2009

Due to its high quantum efficiency (QE) for luminescence, conventional coarse-grained
YAG:Ce (Y3Al5O12:Ce) finds widespread use in light conversion and scintillator applications.
Nanocrystalline YAG:Ce may possess modified optical properties which are advantageous for
technological applications, but this will depend on highly efficient energy conversion. In this work,
the effect of the particle size and Ce concentration on the quantum efficiency and the optical
lifetime of the YAG:Ce emission will be characterized and discussed. Nanocrystalline YAG:Ce
with an average particle size of 20 to 50 nm was synthesized by the chemical vapour reaction
(CVR) method and subsequently analyzed using various techniques. When comparing the
nanocrystalline samples to a coarse-grained reference sample, the particle size and doping
concentration was found to have a significant influence on quantum efficiency. It was established
that the nanocrystalline samples investigated exhibit a lower QE at ambient temperature than the
coarse-grained reference. The results of the optical lifetime measurements are discussed in relation
to this reduction in QE.
Preparation of Semi-Solid Slurry of Hypereutectic Al-Si Alloy by Ultrasonic Vibration
Authors: Zhao Jun Wen , Wu Shu Sen , An Ping , Mao You Wu
Published: March 2009

The preparation of semi-solid slurry of hypereutectic Al-Si alloy by Ultrasonic Vibration
(USV) has been studied. The A390 alloy melt was poured into a preheated metal cup, and
subsequently the ultrasonic vibrator was dipped into the melt and USV was imposed. The solidified
microstructure of the slurry has been analyzed, and the mechanical properties of the alloy have been
tested by making samples through diecasting of the slurry. The results show that the primary Si
particles of A390 alloy became finer, rounder and uniformly distributed in microstructure of A390
alloy slurry if imposed with USV, and average diameter of primary Si particles was about 20μm. With
USV, the ultimate tensile strength and the hardness of rheo-casted samples increased by over 25% and
near 50% respectively besides the elongation rose by above 100%. After heat treatment, the
mechanical properties were further improved. In addition, the mechanism of preparation of semi-solid
slurry of hypereutectic Al-Si alloy by USV is discussed.
Multi-Fingered Haptic Interface Robot and its Application Systems
Authors: Kawasaki Haruhiko
Published: March 2009

Haptic interfaces that represent force and tactile feeling have been utilized in the areas of
telemanipulation, interaction with microscale and nanoscale phenomena, and medical training and
evaluation, to mention only some applications. A multi-fingered haptic interface has greater
potential for these kinds of applications than does a singlepoint haptic interface. We developed a
five-fingered haptic interface robot named HIRO II, which consists of a hand with 15 dof and an
arm with 6 dof. The following research issues are presented: the design method of mechanism, an
interface control that takes the redundancy of the mechanism into consideration, physical simulation
including frictional force and moment, a haptic rendering with a deformable object, the system
architecture and two application systems--a future science encyclopedia and a VR breast palpation
system.
Modeling of Magnetoelastic Materials for Force and Torque Sensors
Authors: Szewczyk Roman , Salach Jacek , Bieńkowski Adam
Published: March 2009

The paper presents a new idea of extension of the Jiles-Atherton-Sablik model for
modeling of the influence of mechanical stresses on magnetic hysteresis loops of amorphous alloys.
In the extended model changes of parameter k are considered during the magnetization and the
influence of stresses on eight parameters of the Jiles-Atherton-Sablik model is taken into account.
Verification of the model was carried out on the base of experimental results obtained for
Fe40Ni38Mo4B18 amorphous alloy subjected to both stress from external compressive force as well
as shearing stresses from torque. In the experiment uniform stress distribution was achieved in both
cases due to special mechanical system of backings. Evolutionary strategies were used in
conjunction with gradient optimization for calculation of the model parameters. Results of
simulation are in good agreement with experimental findings. As a result the extended Jiles-
Atherton-Sablik model enables modeling of the magnetoelastic characteristics of amorphous
materials for mechatronic inductive components such as compressive stress and torque sensors.
Calculation Spectral Characteristics of Magnetic Field of the Linear Induction Motor at the Braking Modes
Authors: Karaliunas Bronius , Matkevicius Edvardas
Published: March 2009

The paper considers some problems of calculating spectral characteristics of magnetic
field of the linear induction motor (LIM), operating at the electrical braking modes. In automatic
drives with LIM the electric braking modes are usually applied: dynamic, recuperation, single –
phase, capacitor type, braking by means of opposite connection, by pulsating current and inverter
type (frequency) braking. During the process of braking in the moving part of the LIM and in some
cases in an inductor there are initiated complicated interrelated electromagnetic and
electromechanical non – stationary processes.
The braking processes have been analysed in the motionless right – sided Descartes system of
coordinates x, y, z. There have been presented the expressions of volumetric density of braking
current which have been regarded the non – periodic functions of coordinate x. Besides that in
cases of single – phase and capacitor braking these expressions are also regarded as the non –
periodic functions of time. Therefore when compiling the mathematical model there have been
applied Laplace and Fourier integral transformations. After having applied Fourier transformation
there have been received the expressions of the spectra amplitudes of primary magnetic field at the
dynamic braking under the condition that the number of excited zones in the inductor is even,
uneven and fractional. The continuous spectra of amplitudes have been calculated by the software
Mathcad 2001 Profesional.
Optimum Rapidity Ensuring and Power Resource Saving Two-Coordinate Positioning System
Authors: Blažiūnas Giedrius , Geleževičius Vilius
Published: March 2009

The article represents two-coordinate positioning system, which ensures optimum
rapidity of positioning process in two-dimensional space and minimizes equipment wear and power
loss. Proposed control principal guarantees harmonized control of two drives, where the bigger
displacement performing drive acts under maximum velocity and acceleration conditions, and
smaller displacement performing drive is positioned is such way when target position is reached in
the same time, which is needed for bigger displacement drive to fulfil task. The article presents
structure of two-coordinate positioning system, control algorithms and research results describing
control quality of process.
The Operation of the Linear Induction Motor by Changing the Position of the Inductors between each other
Authors: Radzevicius Lionginas , Matkevicius Edvardas
Published: March 2009

The most important scientific theoretical research works of the linear induction motor
(LIM) are made having in mind double – sided symmetric model with the uniform secondary
element. Its operation is investigated by already well-known methods used for the rotor
asynchronous machines and as a rule with the opposite value of the magnetic poles of the inductors
(NS). Authors give the results of the research only of LIM (the scientific aspect of the problem is
not well studied yet, it is little known about the ways of the speed and development regulation of
the LIM force, by changing the location of the magnetic poles of the inductors (the inductors
position between each other) from opposite (NS) to the same (NN) magnetic poles value which is
the change of the phase of the inductor current from α = 0 till α = π. By theoretical methods were
studied only the LIM features and possibilities their natural speed and the way of the force
regulation, which could be used in the mechatronics systems.
Mechatronics Approach for Desk-Top CNC Milling Machine Design
Authors: Gürbüz Riza
Published: March 2009

The marriage of computer, electronic technology and traditional machining disciplines
has given birth to revolutionary new disciplines, Mechatronics. Therefore Mechatronics requires
mechanical, electronic and computer knowledge together. The main aim of this article is to present
the mechatronics approach for desk-top CNC milling machine design. Construction of computer
controlled (CNC) Machine differs greatly from that of conventional machine tools. This difference
arises from the requirement of higher performance levels. Machine Structure, guide ways, feed
drives, spindle and spindle bearings, measuring systems, machine control unit, software and
operator interface, gauging and tool monitoring should be considered as mechatronics approach.
Servo motors, motor drivers and motor control unit were used in this CNC milling machine to make
it flexible and easy programming. Ball screws were used to X-Y –Z axes to eliminate backlash of
the slides. Non-contact home and Limit switches were used to prevent possible damages against
over travels. Necessary torque and power have been calculated to select the motors by taking care
of the load, ball screws, motor inertia and required cutting tools and etc. and developed CNC
milling machine has been tested several times for reliable machining of machine parts.
Transition Test Patterns Generation for BIST Implemented in ASIC and FPGA
Authors: Abraitis Vidas , Tamoševičius Žydrūnas
Published: March 2009

Transition delay testing of sequential circuits in a clocked environment is analyzed.
There are presented two test pattern generator methods for built in self testing of the circuit
implemented as Application Specific Integrated Circuit (ASIC) and Field Programmable Gate
Array (FPGA) of Virtex family. Cellular automaton and Linear Feedback Shift Register (LFSR)
structures are used for test sequence generation. The circuits are tested as the black boxes under
Transition fault model. Experimental results of the test pattern generation methods are presented
and analyzed. Results compared with exhaustive test of transition faults for ASICs and
programmable integrated circuits with given configuration.
Vibration Control of Oscillating System Based on Governing Visco-Elastic Characteristics of Absorber by Means of External Electric Signal
Authors: Bilyk V.A. , Korobko E.V. , Reizina G.N. , Bashtovaya E.A. , Kaberdina E.B. , Kuzmin V.A.
Published: March 2009

Electro-rheological fluids (ERF) allow us to create «smart» devices. One of the basic
directions of application of such materials is damping in oscillating systems. This work describes
simulation model and offers the results of experimental research by rheological properties and
damping characteristic of ERF. Control signal is defined by electric field intensity, which is
changed within the bounds of 0…0.5 kV/mm. Amplitude of oscillation – up to 5 mm, oscillation
frequency is modified within the bounds of 0.5…5 Hz. The logarithmic damping decrement and
natural oscillation frequency of oscillating system, shear stress and viscosity of ERF are
determined.
Design of Dynamic Nonlinear Control Techniques for Flexible-Link Manipulators
Authors: Gavriloiu V. , Yurkevich V. , Khorasani K.
Published: March 2009

In this paper, we develop robust dynamical controllers for addressing the problems of
tracking and regulation of flexible-link manipulators. The design of dynamical controllers is based
on construction of a two-time scale dynamical motion of the closed-loop system. The main control
objective is to achieve stability of the closed-loop system while ensuring boundedness of all the
control signals as well as sufficiently small tip-position tracking requirement. In order to achieve a
minimum phase behaviour for utilizing output feedback control strategy, a new redefined output is
proposed. Instead of using the joint angles as outputs in the rigid-link case, a new output is chosen
for the flexible-link case which will provide and guarantee stability of the closed-loop flexible
system. Simulations results are provided for flexible-link manipulators using the proposed control
strategies. A comparative analysis is also included to demonstrate and illustrate the advantages and
disadvantages of the considered control methodologies.
Structure and Properties Enhancement in High-Speed Steels upon Primary Solidification of a Melt
Authors: Chaus Alexander S.
Published: March 2009

In order to exhibit good all-round performance the impact toughness enhancement of cast
high-speed steels (HSS) is obligatorily needed. In general, different methods are used commercially
to achieve cast structure refinement and, as a consequence, their properties are improved.
Introduction into the melt of inoculants particles or surface-active additions is among most
beneficial. However, the effect of modifying additions in cast HSS has been studied insufficiently.
For this reason the theoretical evaluation and experimental confirmation of the modifying and
refining effects of 23 chemical elements in HSS have been carried out. The relationships between
the structural parameters and mechanical properties in the M2 and T30 HSS have been established.
The Differential Passive Magnetic Bearing for High-Speed Flexible Rotor
Authors: Gosiewski Zdzisław , Falkowski Krzysztof
Published: March 2009

Lab stand of a differential passive magnetic bearing is presented in the paper. The
passive bearing will be used in high-speed flexible rotor. The one neodymium magnet MP
41x15x10 – N38 and two neodymium magnets MP 40x22x10 – N38 were used to design the
passive magnetic bearing. The mathematical model of differential bearing, laboratory model and
distribution of magnetic flux density are presented and analyzed.
Examination of Selective Transfer Phenomenon
Authors: Kotnarowski Andrzej
Published: March 2009

The paper describes investigation of possibilities of generation of selective transfer
phenomenon in sliding friction couples that consist of copper cooperating with steel in glycerol,
which serves as model liquid that promotes this phenomenon. Several types of copper employed for
production of electric traction wires were used for samples cooperating with samples made of carbon
steel. Tribological tests carried out at stepwise increasing load demonstrated that in this type of
couples (copper-steel instead copper alloy-steel) the selective transfer phenomenon can occur with
intensity depending on slight differences in content of additives and impurities present in copper.
Effect of Nanofillers on Wear Resistance of Polymer Coatings
Authors: Kotnarowska Danuta
Published: March 2009

The paper presents results of investigation of the influence of copper nanoparticles (of
mean diameter 66 nm and mass share – 3.5%) on erosive wear of acrylic coatings. It was
demonstrated that addition of copper nanoparticles increased the erosive wear resistance of
modified coatings in the range from 25% for impact angle of α = 30° to 65% for α = 75° on the
average.
Assessment of Dynamical Properties of Die Hammer MPM 10000 B Considering Deformations of Working Material
Authors: Majewski Ludwik , Trąbka Arkadiusz
Published: March 2009

This paper presents an assessment of dynamic properties of a die hammer. The object of
research is the steam-air die hammer MPM 10000 B that is considered taking into account the
deformations of the working material. Based upon the technical specifications, two calculation
models of the hammer were developed assuring the proper selection of the parameters. Next, the
numerical simulations were performed, which results were presented in a graphical form as time
histories of displacements and accelerations of particular elements of the hammer. It was
demonstrated that the analyzed design of a die hammer has sufficiently low level of vibration
amplitudes as well as their accelerations.
Control of Operational Motions of a Mobile Crane under a Threat of Loss of Stability
Authors: Kłosiński Jacek , Janusz Jarosław
Published: March 2009

A mathematical model of the control system of a mobile crane is presented in the paper.
The system controls the slewing motion of the chassis as well as it is applied in the model of the
emergency subsystem which changes the jib reach. The latter one is initiated at the moment when
the threat of loss of stability occurs. Some results of numerical analysis are presented in this paper.
The results are related to different strategies of control of the slewing motion as well as to different
types of controllers applied in the main loop of control and emergency subsystem. The results of
experimental studies are reported as well. The experiments were performed using custom-built
testing setup, which represents a kinematic model of a crane.
Prevention of Condensation Defects on Contact Patterns by Improving Rinse Process
Authors: Oh Jung Min , Han Jeong Nam , Lee Kun Tack , Hong Chang Ki , Han Woo Sung , Moon Joo Tae , Park Jin Goo
Published: March 2009

The present work reports a method to prevent the condensation defects on contact hole patterns by improving the rinsing process after a dry etching. In general, residual gases on the surface after the dry etching can be easily removed by using a DI water rinse. However, the residual gas can not be completely removed in high aspect ratio contact holes, resulting in the condensation defect. In this work, in order to completely remove the residual gas inside the contact holes, several rinse processes were employed such as a megasonic rinse, a sequential rinse and a hot temperature rinse. These proposed rinse methods were effective in eliminating the residual dry etching gases in the high aspect ratio contact holes and thus were able to remove condensation defects on contact holes.
Surface Preparation and Passivation of III-V Substrates for Future Ultra-High Speed, Low Power Logic Applications
Authors: Rachmady Willy , Blackwell James , Dewey Gilbert , Hudait Mantu , Radosavljevic Marko , Turkot Jr. Robert , Chau Robert
Published: March 2009

III-V compound semiconductors have been recognized among the potential options for continuing transistor power-performance scaling owing to their ultra high charge carrier mobility. In order to realize their potential in high performance and lower-power digital logic applications, there must be strong gate control and a high Ion-Ioff ratio, achieved by integrating a stable, ultra thin high-K dielectric between the semiconductor and the gate [1, 2]. Unlike Si, which has long benefited from its very stable native oxide, III-V materials suffer from their poor native oxides that cause charge traps and Fermi level pinning at the semiconductor-oxide interface. Attempts to deposit high-K directly on III-V often produce MIS structures with fast surface state and CV instability [3].
Three-Step Room Temperature Wet Cleaning Process for Silicon Substrate
Authors: Hasebe Rui , Teramoto Akinobu , Suwa Tomoyuki , Kuroda Rihito , Sugawa Shigetoshi , Ohmi Tadahiro
Published: March 2009

With a progress of device dimension miniaturization, an ultraclean wafer surface is continuously increasing its importance crucial for high quality processing in Silicon Technologies [1]-[8]. Cleaning of silicon wafer surface has been accomplished by RCA wet cleaning in the past [9], where there exists high temperature processes consisting of H2SO4/H2O2/H2O, NH4OH/H2O2/H2O and HCl/H2O2/H2O treatments. Thus, RCA cleaning requires a large number of processing steps, resulting in the consumption of a huge volume of liquid chemicals and UPW, and simultaneously consuming a large volume of clean air exhaust to suppress chemical vapor from getting into the clean room. Moreover, RCA cleaning is used at high temperature and contain alkali solutions, which increase the roughness of the silicon wafer surface [10].
Poly-Silicon Etch with Diluted Ammonia: Application to Replacement Gate Integration Scheme
Authors: Sebaai Farid , Del Agua Borniquel Jose Ignacio , Vos Rita , Absil Philippe , Chiarella Thomas , Vrancken Christa , Boelen Pieter , Baiya Evans
Published: March 2009

With the continuous down scaling features sizes, the need of speed increase and power consumption reduction start to be more and more critical. The classical integration scheme of poly silicon gate on CMOS devices does not meet the requirements of the 45 nm technology node and beyond. On this matter, new materials and different integration flows are being investigated in order to improve the device performance. High-k materials associated with metals are actively investigated as new gate materials in which different integration approaches like metal gate first or metal gate last are proposed [1].
Advances on 45nm SiGe-Compatible NiPt Salicide Process
Authors: Chen Yi Wei , Ho Nien Ting , Lai Jerander , Tsai T.C. , Huang C.C. , Tzou S.F. , Chu James M.M.
Published: March 2009

NiPt self-aligned silicide (salicide) has become a major candidate for the 45nm node due to its better thermal stability and the surface morphology of NiSi on Si substrate [1,2]. SiGe has been proposed for PMOS strain engineering [3]. The relevant SiGe oxidation behavior [4], reaction with platinum [5] and thermal stress behavior [6] are important factors in developing a process for 45nm NiPt salicide over SiGe stressor. These concerns require the review of the current process for NiPt to verify its compatibility and extendibility.
Material Loss Impact on Device Performance for 32nm CMOS and Beyond
Authors: Kirkpatrick Brian K. , Chambers James J. , Prins Steven L. , Riley Deborah J. , Xiong Wei Ze , Wang Xin
Published: March 2009

As semiconductor technology moves past the 32nm CMOS node, material loss becomes an ever more important topic. Besides impacting the size of physical features, material loss impacts electrical results, process control, and defectivity. The challenge this poses is further exacerbated by the introduction of new materials. The largest single influx of new materials has come over the last decade with the introduction of high-k/metal gate (HK/MG) materials. This paper focuses on the front-end-of-line (FEOL), summarizing key materials loss issues by process loop.
Evaluation of Plasma Strip Induced Substrate Damage
Authors: Han Ke Ping , Luo S. , Escorcia O. , Waldfried Carlo , Berry Ivan L.
Published: March 2009

High dose, ultra shallow junction implant resist strip requires minimal substrate loss and dopant loss. Silicon recess (silicon loss) under the source/drain (S/D) extensions increases the S/D extension resistance and decreases drive currents by changing the junction profile. ITRS surface preparation technology roadmap [1] targets silicon loss to be 0.4Å per cleaning step for 45nm and 0.3Å for 32nm generation. Fluorine-containing chemistries which are often used to enhance implanted resist strip and residue removal result in unacceptable substrate loss. A non-fluorine plasma strip was developed in earlier work and is qualified for 45nm logic production [2]. The objective of this work is to study the substrate damage that is induced by the resist strip plasma process. Silicon surface oxidation and silicon loss of different plasma strip chemistries were evaluated with various metrologies such as optical ellipsometry, electrical oxide measurement, XPS, TEM and mass measurement. The impact of different strip chemistries on dopant retention and distribution is also discussed.
Novel Methods for Wet Stripping High Dose Implanted Photoresist Using Sulfur Trioxide
Authors: Bergman Eric J. , Leonhard J. Dusty
Published: March 2009

Ion implantation is one of many critical processes in the fabrication of semiconductor devices. While device geometries have been shrinking, the implant dose has typically been increasing. Historically, photoresist removal has been achieved through a combination of plasma “ashing” and a subsequent wet clean, often using a mixture of sulfuric acid and hydrogen peroxide at elevated temperature. The “piranha” or SPM strip is often followed by an ammonia based clean such as APM to remove particles and sulfate residues from the device. However, device constraints are presently having difficulty accommodating the film loss, surface roughening, high molecular temperatures and hot electron injection which may accompany a plasma ash. [1] The APM clean is also having to undergo modification in order to minimize oxide loss which would adversely affect device performance.
Direct Observation of Single Bubble Cavitation Damage for MHz Cleaning
Authors: Tomita Hiroshi , Inukai Minako , Umezawa Kaori , Ji Li Nan
Published: March 2009

It is well known that the physical force cleaning such as megasonic (MS) and ultrasonic (US) cleaning are used in FEOL (front-end-of-line) and BEOL (back-end-of-line). Recently, with scaling down below 43 nm, the influence of pattern damage by physical force methods such as MS and US irradiation has been reported. Hence, for the 2x and 3x nm node devices, it will be very difficult to apply MS cleaning for particle removal process without understanding the cavitation force. Cavitation is a complex phenomena based on bubble formation and explosion in the liquid. To control “MS cleaning” and “cavitation” induced pattern damage, many studies using “Sonoluminescence” have been reported. This method is able to demonstrate the existence of high energy fields such as cavitation throughout the megasonic field. The damage clustering distribution was investigated for the damage size and damage length in batch MS conditions using gate structure patterned [1]. In this method, it is difficult to discuss the cavitation force, quantitatively. And this method can not obtain the quantitative physical force on the wafer surface, directly. To understand “cavitation force” induced pattern damage, the observation of “cavitation force” is highlighted with “imaging films” such as blanket aluminum film and resist film, directly.