bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Stability of Fe Filaments in Deformed Cu-Fe Composites
Authors: Wang En Gang , Qu Lei , Zuo Xiao Wei , Zhang Lin , He Ji Cheng
Published: June 2010

The Cu-12.8wt%Fe alloys are prepared in a vacuum induction furnace and then drawn to Cu-Fe composite wires with the drawing ratio of 8.2. The thermal stability of Fe filaments in the deformed Cu-12.8wt% Fe composite wires under different annealed temperature is investigated. The results show that the instability of the Fe filaments in the Cu-Fe composites is controlled by the longitudinal boundary splitting, then the splitting Fe filaments subsequently evolve into the cylinders. The thermal instability of the cylindrical Fe filaments is controlled by the two instability modes of Rayleigh perturbation and two dimensional Ostwald coarsening. The model calculations of two modes indicate that the perturbation breakup of cylindrical Fe filaments firstly occurs at the ones with smaller diameter. The breakup time of cylindrical Fe filaments decreases with the increasing of the annealing temperature. The coarsening diameters of cylindrical Fe filaments increase in linear proportion with the holding time. The smaller is the diameter of cylindrical Fe filaments, the larger is the coarsening rate.
Corrosion and Wear Resistances of Ni-P-Al2O3 Composite Film Prepared by Electroless Plating
Authors: Wang Rong Guang , Sawada Hiroki , Kido Mitsuo
Published: June 2010

The electroless plating composite film Ni-P-Al2O3 was prepared on a mild steel of SS400 with stirring of the plating solution. The composite film became thinner and rougher when Al2O3 particles were blended into the plating solution. The corrosion resistance and the wear resistance of the composite film were largely enhanced in comparision to the Ni-P film.
Fabrication of Solid Oxide Fuel Cells via Thin Film Techniques
Authors: Lee Yoon Ho , Cho Goo Young , Jee Young Seok , Chang Ikwhang , Kang Sang Kyun , Lee Jong Ho , Son Ji Won , Cha Suk Won
Published: June 2010

Fabricating electrolyte with thin film is one of various methods of lowering the operation temperature for solid oxide fuel cell (SOFC). Because the major polarization of SOFCs is ohmic loss, many groups have tried to fabricate a thin film electrolyte – some proton conducting material that has the conductivity of a couple of orders higher than oxygen conducting one. We have investigated the synthesis of Membrane Electrode Assembly (MEA) including Yttria-doped Barium Zirconate(BYZ) thin film electrolyte via thin-film processes such as Pulsed Laser Deposition and Sputtering. Another approach to lower the operation temperature of SOFCs is the bi-layer structure electrolyte. The functional layer via thin film deposition could guarantee minimum power density loss and stable operation. After the study of Atomic Layer Deposition (ALD) condition to deposit Yttria Stabilized Zirconia (YSZ) on Gadonilia doped Cerate (GDC) substrate, GDC/YSZ bi-layered electrolyte button cells showed higher OCV and larger limiting current with 100nm YSZ ultra thin film. The performance improvement might be attributed to the function of electron blocking and cutting off the reducible gas.
Variation of Heat Dissipation Properties of LED Packages with Thermal Vias
Authors: Lee Hyo Soo , Shin Hyeong Won , Jung Seung Boo
Published: June 2010

Light emitting diode (LED) has been largely used in industry of consumer electronics such as cell-phones, PDAs, and computers. Since all light sources convert electric power into radiant energy and heat, LED also does the same with an increase of its power. Generally, it only converts 15~25% of electric power into visible light; the rest of the power, 75~85%, is converted into heat. This excess heat should be conducted away from the LED die to circuit boards or heat sinks since heat affects directly performance of the LED. The piled heat in LED products brings color shift and reduces light output very rapidly. Furthermore, the lifecycle of LED products shorten if the heat problem continues. In order to prevent LED products from these negative effects, effective thermal resistance paths need to be achieved so that LED products let the heat conduct from the LED to the outside such as printed circuit board. In this research, optimization studies on thermal-via is to be performed. The 1W and 3W LED assembled printed circuit board with 16 different via designs is set up to measure its temperature for 4 hours in a real time. It was obtained by this work that the optimized thermal via was very effective to dissipate the heat from the LED.
Processing, Properties and Microstructure of a 1.2%Al TRIP Steel
Authors: Liu De Lu , Zhang Jian , Li Zhong Yi
Published: June 2010

Cold rolled TRIP-600 steels has been developed on a laboratory scale. Composition of the steels is 0.12wt%C-0.30wt%Si-1.6wt%Mn-1.2wt%Al. Effects of Al concentration on phase diagram, TTT curves and T0 line of bainite formation in the steels were calculated and discussed.Cold rolled sheets of 1.7mm thick were annealed between 830 °C and 870 °C followed by austempering at 420 oC. UTS of 660~700MPa, YS 390~420MPa and total elongation 30.5~37.5% is obtained.Volume fraction of the retained austenite is 9~11% and carbon content in the retained austenite is 0.9% ~1.3wt% in the steels. The chemical composition and processing parameters of the experimental steels could be referred for trial-manufacture of TRIP 600 steels.
Characterisation of Hydrogen Release Behaviour in Cast Mg-Ni Alloys by Synchrotron XRD and XAFS
Authors: Nogita Kazuhiro , Jenke Marc , Wood David , Duguid Andrew , McDonald Stuart D.
Published: June 2010

Alloys of the hypo-eutectic Mg-Mg2Ni system can be modified by trace elemental additions which change the microstructure and the functional properties. The modified microstructure results in improvements to the hydrogen storage properties. In alloys of optimal composition, it has been shown that the reversible storage of 6.5-7wt% H2 is possible at a rate of reaction that is realistic for industrial applications. This paper discusses the mechanism of hydrogen release in air at atmospheric pressure with in-situ crystallographic phase transformation analysis obtained by synchrotron radiation X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS).
Hydrogen Exchange Effect in MgH2-LiBH4 System
Authors: Zeng Liang , Miyaoka Hiroki , Ichikawa Takayuki , Kojima Yoshitsugu
Published: June 2010

MgH2-LiBH4 system is one of the promising hydrogen storage materials. In the system, it was found that there was a mutual interaction between the two hydrides, but its mechanism has not been clarified yet. In this work, we found an “H-D” exchange between MgD2 and LiBH4 during heating. IR absorption spectroscopy revealed that the peak of “B-D” vibration appeared at 275 °C below the melting and hydrogen desorption of the system, indicating that this exchange proceeded even in solid phases. The hydrogen desorption properties of the composite of catalyst-doped MgH2 and LiBH4 under inert gas were investigated by mass spectroscopy. The results showed that the hydrogen desorption temperature of the first step was over 300 °C, in spite of catalyst-doped MgH2 can release hydrogen at 200 °C. The above results might suggest the hydrogen desorption from catalyst-doped MgH2 is somehow suppressed by the exchange effect between MgH2 and LiBH4.
Catalysing Effect of Intermetallic Compounds on Hydrogen Desorption Kinetics in Cast Magnesium Alloys
Authors: Cho Young Hee , Dahle Arne K.
Published: June 2010

Magnesium based hydrogen storage materials were prepared by a conventional melting and casting technique. Characterisation of microstructure and hydrogen sorption properties of the alloys was carried out. Additions of Al, Cu and Ni lead to the formation of eutectic mixtures, Mg-Mg17Al12, Mg-Mg2Cu and Mg-Mg2Ni, respectively, with an inter-lamellar spacing of a few hundred nanometers. 3d and 4d transition metals were also added to Mg based alloys and were found to form intermetallic compounds that were homogeneously dispersed in the alloys. The dehydrogenation rate of the Mg alloys was quantitatively analysed in order to determine the rate-limiting step for the hydrogen desorption kinetics. The catalysing role of each intermetallic compound for the hydrogen desorption kinetics is further discussed.
In-Situ TEM Observation for Dehydrogenation Mechanism in MgH2 with Catalyst
Authors: Morita Eri , Ono Akifumi , Isobe Shigehito , Wang Yong Ming , Hashimoto Naoyuki , Ohnuki Somei
Published: June 2010

We carried out in-situ observation on the catalytic effect of Nb2O5 in MgH2 by using a high voltage transmission electron microscope (HVEM). We synthesized two kinds of samples, which were prepared by ball milling and by hand mixing. In milled sample, Nb2O5 was not confirmed from high resolution images, however, NbO was identified. As the temperature increased, the decomposition of MgH2 proceeded, while Mg formed and grew. It suggested that NbO had the catalytic effect to promote the dehydrogenation of MgH2. In mixed sample, which was prepared to clearly observe the boundary between the catalyst and Mg phase, it was revealed that the dehydrogenation started from the boundary of MgH2 and Nb2O5. This result suggested that the dehydrogenation could proceed with hydrogen diffusion from MgH2 through Mg phase to the boundary.
High Water Diffusivity in Low Hydration Plasma-Polymerised Proton Exchange Membranes
Authors: Peterson Vanessa K. , Corr Cormac , Kearley Gordon J. , Boswell Roderick , Izaola Zunbeltz
Published: June 2010

This paper compares proton diffusion through plasma-polymerised proton-exchange membranes (PEMs) produced using traditional wet-chemical methods (Nafion®) and those produced using plasma-polymerisation. Using quasielastic neutron scattering and a simple model of proton motion we find the measured diffusion-rate of protons in the plasma-polymerised material and Nafion® is the same (within 1 standard error) even though the plasma-polymerised membrane has 80 % less water than the Nafion®. We attribute this result to the highly cross-linked structure of the plasma-polymerised membrane.
Effects of Chemical Composition on the Impact Properties of A533B Steels
Authors: Kim Byung Jun , Kasada Ryuta , Kimura Akihiko
Published: June 2010

In order to estimate the long life integrity of vessel steels with considering various material compositions and irradiation conditions, it is necessary to understand physical mechanisms of the degradation of mechanical properties. In this research, chemical composition effects were investigated for Reactor Pressure Vessel Steels (RPVS) to apply small specimen test technique to surveillance test method. All specimens used in this study were machined from the A533B plate material, which are standard, low Mn, high Cu, high P, and high Cu and high P steels. Tensile strength is increased by phosphorous and copper additions. Charpy tests were carried out at temperature from 73 K to 473 K. The ductile to brittle transition temperature (DBTT) is shifted to higher temperatures with phosphorus additions accompanied by the reduction of the upper shelf energy (USE). The fracture mode of P-added A533B steels at temperatures in the lower shelf energy (LSE) region is intergranular cracking. Test results were discussed in view of the differences on elements of Cu, Mn and P.
Neutron Irradiation Hardening of Fe-Based Binary Alloys
Authors: Yabuuchi Kiyohiro , Saito Masashi , Kasada Ryuta , Kimura Akihiko
Published: June 2010

We investigated mechanical properties of neutron irradiated Fe based binary alloys in order to extract roles of each alloying element in reactor pressure vessel (RPV) steels on irradiation hardening and annealing recovery behavior. Materials used were Pure-Fe, Fe-1Cr, Fe-1Mn, Fe-1Ni, Fe-1Cu and Fe-1Mo in at.%. Neutron irradiations were carried out at various irradiation doses from 0.3 to 8.5 × 1019 n/cm2 ( > 1.0 MeV) at 290 °C. Irradiation hardening of Fe-1Cu showed a tendency of saturation at a low dose. Irradiation hardening of Pure-Fe and the other binary alloys increased with increasing in irradiation dose. Especially, Fe-1Mn irradiated over 4.3 × 1019 n/cm2 showed significant irradiation hardening which is comparable to Fe-1Cu. However, the post-irradiation annealing recovery behavior of the irradiation hardening in Fe-Mn showed one-stage recovery at around 450 °C, which was completely different from the two-stages recovery behavior of Fe-1Cu.
Grain Size Dependence of the Flow Stress of TWIP Steel
Authors: Dini Ghasem , Ueji Rintaro , Najafizadeh Abbas
Published: June 2010

The effect of grain size on the flow stress in TWinning Induced Plasticity (TWIP) steel was investigated via the X-ray diffraction (XRD) measurements of dislocation density. The results indicated that the hardening behavior of fine grained samples (mean grain sizes in the range of 2.1-3.8μm) can be described as typical dislocation interactions. However in coarse grained samples (mean grain sizes in the range of 4.7-38.5μm) where extensive mechanical twinning occurs, another strengthening mechanism is required. Consequently, the effect of grain size on the flow stress parameters of the proposed equation was considered and it was found that in the fine grained samples, the Holloman analysis can describe the hardening behavior. However, in coarse grained samples, a second hardening term due to the strengthening effect of mechanical twin boundaries needs to be added to the Holloman equation.
Aluminide Coating Formation on Hot Press Forming Steels
Authors: Fan Dong Wei , Kim Han Soo , Park Rho Bum , De Cooman Bruno C.
Published: June 2010

In the present work, the formation of an aluminide coating prior to Hot Press Forming (HPF) was investigated. It was found that the formation of Fe3Al phases could suppress coating degradation during the HPF process. This new method was studied as a way to simultaneously improve the coating ductility and achieve a good hot corrosion resistance. In this new method, the conventional type1 aluminized coating was transformed into an aluminide coating. This aluminide coating protects the steel from high temperature oxidation and enables its plastic deformation at high temperature. The effect of this new solution on the mechanical properties of HPF steel is reviewed in detail.
Mechanical Properties and Marine Corrosion Resistance of P-Bearing ULCB Steels
Authors: Cui Wen Fang , Liu Chun Ming , Zhang Si Xun
Published: June 2010

The research aims to evaluate the microstructure, mechanical properties and marine corrosion resistance of P-bearing ULCB steels. P produced stronger solution strengthening effect, but had less effect on the low temperature impact toughness of ULCB steel. With increasing P content to 0.09(mass)%, the immersion corrosion rate of ULCB steel in 3.5% NaCl obviously decreased in comparison with those steels without or with lower P content. This is attributed to that the complex effect of Cu and P promoted the formation of dense amorphous oxyhydroxide in the inner scale, which inhibited further corrosion from NaCl solution. Mo in ULCB steel played an important role in avoiding pitting corrosion in Cl- environment.
The Effect of Alloying Elements on Microstructure and Strength Property of Dual Two-Phase Intermetallic Alloys Based on Ni3Al-Ni3V Pseudo-Binary Alloy System
Authors: Kawahara K. , Moronaga T. , Kaneno Yasuyuki , Kakitsuji A. , Takasugi Takayuki
Published: June 2010

The microstructures and hardness property of dual two-phase intermetallic alloys that arecomposed of various kind of volume fractions of geometrically closed packed (GCP) Ni3Al(L12) and Ni3V(D022) phases were studied. The hardness of dual two-phase intermetallic alloys basically was explained by mixture rule in hardness between primary Ni3Al precipitates and eutectoid region.Nb and Ti addition raised the hardness of dual two-phase intermetallic alloys by solid solute hardening in the constituent phases.The additional hardening arising from interfacial area between primary Ni3Al precipitates and eutectoid region was also found. As temperature increases, theadditional hardening decreased for the base and Nb added alloys but decreased little for the Ti added alloys.
Property Responses in Nb-Si-Hf-Ti-Al-W-B-Cr Alloys for High-Temperature Applications
Authors: Yang Xiu Xia , Sha Jiang Bo , Zhang Hu
Published: June 2010

Multi-component Nb-(11,15)Si-5Hf-30Ti-4Al-4W-2B-(8,16)Cr alloys have been proposed, attempting to obtain the Nb-Si based alloys with a comprehensive property. The results show that three phases of NbSS, Nb5Si3 and Laves Cr2Nb exist in the alloys with a Cr content of 16 at%. With increasing Si and Cr contents the fracture toughness KQ decreases, while the oxidation resistance at 1250°C and strength at 1250°C and 1350°C exhibit an increasing tendency. The 15Si-16Cr alloy shows the highest strength and oxidation resistance, and the lowest toughness; they are 385MPa at 1350°C, 215mg/cm2 at 1250°C for 100 h, and 5.45 MPa•m1/2 at room temperature, respectively. The 11Si-8Cr alloy with an NbSS/Nb5Si3 microstructure only has the highest toughness of 11.87 MPa•m1/2, its strength and oxidation resistance are the lowest.
Creep Behavior for Alloy 617 in Air at 950°C
Authors: Kim Woo Gon , Yin Song Nan , Lee Gyeong Geon , Kim Yong Wan
Published: June 2010

Creep behavior for Alloy 617, which is considered as one of the major structural materials of a very high temperature reactor, was investigated in air at 950oC. Creep experimental data was obtained by a series of creep tests with different stress levels at 950oC. Alloy 617 revealed little primary creep strains and unclear secondary creep stages. A tertiary creep stage was initiated from a low strain level and was dominant in full creep curves. The creep constants of A, n, m, and C in Norton’s power law and Monkman-Grant relationships were determined. In microstructure observations of crept specimens, it was found that a Cr2O3 oxidation layer was formed on the surface, and just beneath the Cr2O3 layer, an internal Al-oxide sub layer was formed with rod shapes. Also, below the internal sub layer, a thick carbide-depleted zone was developed due to reaction of the chromia and carbide precipitates. The thickness of the outer Cr-oxide layer increased with increasing creep rupture times. The increasing tendency showed a smooth slope like a parabolic curve.
Oxidation of TiAl Alloys Coated by Fluorine Resin in SO2 Containing Atmosphere
Authors: Gil Aleksander , Żurek Zbigniew , Stawiarski Adam
Published: June 2010

There are several ways to improve the oxidation resistance of TiAl alloys. One of them is alloying with elements such as Nb, Ta, W, Si, Ag, Zr or Hf. However, bulk alloying influences the mechanical properties. Surface treatment of TiAl alloys by the small amounts of halogens leads to the formation of the protective alumina scale (“halogen effect”). The halogens can be applied by ion techniques (ion implantation, plasma immersion implantation) but also by spraying or dipping with halogen-containing inorganic and organic compounds. Deposition of the fluorine-containing resin on the surface of TiAl alloys is the easiest way to achieve the best results. SO2 impurity in air significantly influences oxidation behavior of TiAl alloys. In this work the results of the oxidation of a Ti-48Al-2Cr alloy coated with a fluorine-containing resin in the synthetic air and air containing 1% SO2 were presented. The oxidation runs were carried out in the temperature range 800-1000°C.
Effect of Nb Content on Hot Flow Stress, Dynamic Recrystallization and Strain Accumulation Behaviors in Low Carbon Bainitic Steel
Authors: Miao Cheng Liang , Zhang Guo Dong , Shang Cheng Jia
Published: June 2010

Compressive deformation behaviors of low carbon steels with different Nb contents were investigated in the temperature range 900oC to 1100oC and strain rates from 0.05s-1 to 2s-1 by single pass deformation. Multi-pass compressive deformation processes were also carried out to examine strain accumulation under different Nb contents. In single pass deformations, dynamic recrystallization (DRX) can be observed in the case of low strain rate and high temperature, and the higher Nb steel exhibits higher deformation activation energy (Qdef) and critical strain value (εc) for the onset of DRX. However during multi-pass compression process (interval time of 3-4s), the higher Nb steel has larger strain accumulation between passes, so it is easier for high Nb steel that DRX happens during hot strip rolling process, which starts at relative high rolling temperature.
The Skin Effect in an Mg-RE High Pressure Die Cast Alloy
Authors: Yang K. , Nagasekhar A.V. , Cáceres Carlos H. , Easton Mark
Published: June 2010

Cross-sectional microhardness maps of cast-to-shape flat tensile specimens have been obtained for a binary Mg-3.44 mass% La alloy. Higher microhardness numbers were generally found near the casting surface, at the corners and along the segregation band. The higher hardness values were ascribed to the finer solidification microstructure near the surface and to localized positive macro segregation. The majority of lower hardness numbers was found at the core region. Lower hardness values were ascribed to the coarser grain size prevalent at the core and to dispersed microporosity. The non uniformity of the harder surface layer in both depth and hardness appeared related to local homogeneities in the grain size distribution caused by the scattered presence of large externally solidified grains.
Deformation Behavior of Magnesium Single Crystal in c-Axis Compression and a-Axis Tension
Authors: Ando Shinji , Tsushida Masayuki , Kitahara Hiromoto
Published: June 2010

In general, deformation behavior of magnesium in compression is different from tensile. To investigate deformation behavior of magnesium single crystals by non-basal slips and twins, c-axis compression and a-axis tension tests were performed in the range of 77K-573K. The crystals were yielded by second order pyramidal slip, and the yield stress shows anomalous temperature dependence (increased with increasing temperature) between 203K and 293K. Yield stress of c-axis compression was bigger than that of a-axis tensile. In compression, fracture surface were (11 4) under 293K and were {30 4} above 373K, and fracture strain was smaller than the case of tension test. {10 1}-{10 2} double twin were activated at higher temperature and the crystal, therefore, fractured along the twin interface.
Thermal Analysis of a Bi-Metallic Chill Vent for High Pressure Die Casting
Authors: Imran Mohammad , Dhaliwal Rajpreet , Masood Syed H.
Published: June 2010

High pressure die casting (HPDC) is widely used for manufacturing aluminum parts in automotive industry. In high pressure die casting mold, chill vents are used to allow residual air and gases to exhaust out from the mold cavity. The objective of this paper is to design and develop a bi- metallic chill vent for high pressure die casting using copper alloy material having high thermal conductivity, coated with steel layer on the surface. Transient thermal analysis was carried out using ANSYS software, and temperature distribution was compared with bimetallic and tool steel chill vents. The results show a faster extraction of heat in bi-metallic chill vent than that with steel. This paper also presents the effect of varying internal diameter of cooling channel in chill vent cooling.
Effect of Aging Treatment on Microstructure and Mechanical Properties of a Two-Phase Titanium Alloy
Authors: Song Miao , Lei Jia Feng , Ma Ying Jie , Liu Yu Yin
Published: June 2010

In present work, microstructure of Ti-6Al-2Mo-1.5Cr-2Sn-2Zr-1V-0.15Si-0.4Fe alloy as a function of aging temperature was investigated using optical microscopy, scanning electron microscopy (SEM), x-ray diffraction (XRD) and transmission electron microscopy (TEM).Three types of precipitates were found in this alloy, they were α2 phase (Ti3Al), silicides, and Sn rich phase. Ti3Al were observed in all aged specimens covering a range 500-740°C. A method of quantitative analysis toward α2 based on high resolution images and Flourier transformation is used. The results showed that the ordering in α phase was highly related to the property of fracture toughness. Silicides were first found at 580°C ageing and later determined in the formulate (Ti5+xZr3-x)Si3 in the specimens aged at 740°C, and they were found to influent the fracture toughness significantly. The Sn rich phase was emerged with large area during the 780°C aging. And its direct correlation to property was not found. The density of acicular α phase was found almost invariable by calculating through the modification XRD quantitative analysis during the elevated aging temperature.
Electron Microscopy Study of Deformation Microstructure in Metastable β Titanium Alloy
Authors: Xing Hui , Sun Jian
Published: June 2010

The deformation microstructure of a metastable beta-Ti alloy with chemical composition of Ti-23Nb-0.7Ta-2Zr-1.2O at.% after cold swaging has been studied by electron backscattering diffraction and high-resolution transmission electron microscope. The results showed that the deformation structure of the cold-swaged alloy appears to be similar to the swirled structure that commonly found in bcc metals heavily deformed either by wire-drawing or by rotary swaging process, and <110> fiber texture is a typical texture component of bcc metals. HRTEM results further showed <111> dislocations in the deformed alloy. Additionally, {112}<111> mechanical twinning and stress-induced omega transition were further revealed.
Control Algorithms in Mechatronic Systems with Parallel Processes
Authors: Gubarev Aleksandr , Yakhno Oleg , Ganpantsurova Oksana
Published: June 2010

The interconnection of process of functioning and control algorithm in mechatronic systems with hydraulic and pneumatic drives is considered in this paper. It is proposed to use operation speed difference of mechanical devices and PLC for organization of a pseudo-parallel control algorithm. General structure of the algorithm is developed, check for test examples of a system is executed, typical patterns of algorithm for different types of operating hydraulic and pneumatic devices are provided.
Selection of Method for Underwater Robot Control
Authors: Szymak Piotr
Published: June 2010

Automatic control of motion of underwater robots, particularly along desired trajectory, requires application of proper controllers taking into account dynamics of the underwater robot and features of the marine environment.
In the paper the mathematical model of an underwater vehicle [2] and the architecture of designed control system [4] have been presented. Moreover, selected results of numerical analysis in the form of comparison of different course controllers have been provided.
Synthesis of Planetary Gears by Means of Artificial Intelligence Approach ‒ Graph-Theoretical Modeling
Authors: Drewniak Józef , Zawiślak Stanisław
Published: June 2010

Graph-based modeling of planetary gears was applied in the presented research work for their synthesis. The tailored Hsu and contour graphs were used. Graphs encode the structure (layout) of a planetary gear and upon them - the systems of equations can be generated. These systems enable determination of rotational velocities of planetary gear elements. The method is algorithmic and simple. It allows for an easy comparison of different design solutions and selection of the most appropriate one. The list of the possible modes of operation for an exemplary planetary gear is also provided in the paper.
Verification of Vibration Power Generator Model for Prediction of Harvested Power
Authors: Hadas Zdenek , Singule Vladislav , Ondrusek Cestmir
Published: June 2010

This paper deals with modeling of a vibrational power generator and verification of a complex generator model for prediction of harvested power. The power generator is an electromagnetic device, which uses ambient energy of mechanical vibrations for generating useful electrical energy. This energy harvesting device constitutes a complex mechatronic system consisting of a resonance mechanism, electromechanical converter, power management (electronics and energy storage) and a powered device. When this system is placed in environment with sufficient mechanical vibration, the generator harvests energy and it can be used as autonomous source of electrical energy for powering of wireless sensors in remote applications. The verified simulation model of this device can provide a prediction of possible harvested power without any physical position of this device in a vibratory environment (only acceleration measurement is used as input).
Discrete Action Dependant Heuristic Dynamic Programming in Control of a Wheeled Mobile Robot
Authors: Hendzel Zenon , Szuster Marcin
Published: June 2010

In presented paper we propose a discrete tracking control algorithm for a two-wheeled mobile robot. The control algorithm consists of discrete Adaptive Critic Design (ACD) in Action Dependant Heuristic Dynamic Programming (ADHDP) configuration, PD controller and
a supervisory term, derived from the Lyapunov stability theorem and based on the variable structure systems theory. Adaptive Critic Designs are a group of algorithms that use two independent structures for estimation of optimal value function from Bellman equation and estimation of optimal control law. ADHDP algorithm consists of Actor (ASE - Associate Search Element) that estimates the optimal control law and Critic (ACE - Adaptive Critic Element) that evaluates quality of control by estimation of the optimal value function from Bellman equation. Both structures are realized in a form of Neural Networks (NN). ADHDP algorithm does not require a plant model (the wheeled mobile robot (WMR) model) for ACE or ASE neural network weights update procedure (in contrast with other ACD configurations e.g. Heuristic Dynamic Programming or Dual Heuristic Programming that use the plant model). In presented control algorithm Actor-Critic structure is supported by PD controller and the supervisory term, that guarantee stable implementation of tracking in an initial adaptive critic neural networks learning phase, and robustness in a face of disturbances. Verification of proposed control algorithm was realized on the two-wheeled mobile robot Pioneer-2DX.
Advanced Materials Research and Technologies Development: Lithuanian Experience
Authors: Valiulis Algirdas Vaclovas , Škamat Jelena
Published: June 2010

Lithuania, as a small country, cannot afford creating new knowledge in all the fields of science. It is reasonable to firstly focus on those fields in which Lithuania already has scientific and industrial potential and that clearly declare the biggest demand for innovations as well as capability to invest into innovations. Research institutions here usually focus on fundamental research but both the revenues and the human resources of research institutions are rather poor. Dispersion of the Lithuanian potential of science and studies and the absence of critical mass represent the main reasons why R&D lacks effectiveness. The paper presents the main research fields and high-tech research institutions in Lithuania.
Generation of Optimal Process Plan Alternatives for Manufacturing Mechanical Components
Authors: Deja Mariusz , Siemiatkowski Mieczyslaw
Published: June 2010

The focus of this paper is on computer-aided process planning (CAPP) for parts manufacture in systems of definite processing capabilities, involving multi-axis machining centers. A methodical approach is developed to optimally solve for process planning problems, which consists in the identification of process alternatives and sequencing working steps. The approach involves the use of the branch and bound (B&B) concept from the field of artificial intelligence (AI). A conceptual scheme for generation of alternative process plans in the form of a network is developed, based on part design data modeling in terms of machining features. A relevant algorithm is proposed for creating such a network and searching for the optimal process plan solution from the viewpoint of its operational performance, under formulated process constraints. The use of the approach is studied numerically with regard to a real life case study and diverse machine tools with relevant tooling are considered. Generated process alternatives for complex machining with given systems are studied using models programmed in the Matlab environment.
Diagnostic Models of the States of Developing Fault for Working Parts of the Excavator
Authors: Kowalczyk Marcin , Czmochowski Jerzy , Derlukiewicz Damian
Published: June 2010

The approach of designing a power transmission model (diagnoser) of the multi-bucket wheel excavator used in brown coal mining, presented in the study, helps prepare an effective method for identifying the states of developing fault. In order to develop such model/diagnoser it was necessary to measure the loads required for determination of the distribution function of the mining moment. Probabilistic methods were applied for establishing the state of initiating activities to protect against fault.
New Roll Pass Design to the Bar Rolling Process Using Longitudinal Slitting Passes
Authors: Mróz Sebastian
Published: June 2010

: groove-rolling, energy-force parameters, numerical modeling, FEM
Abstract. The paper presents the developed new roll pass design and a new method of rolling in slitting passes of bar with longitudinal band, which reduce energy consumption and increase durability of slitting passes compared to the methods used previously. The results of theoretical analysis were verified based on the measurements of rolling power taken during bar rolling according to the multi-strand rolling technology. Forge2007 software was employed in the numerical analysis of the process of rolling with band slitting.
Analysis of the Fatigue Fractures in the Eccentric Press Shaft
Authors: Rusiński Eugeniusz , Harnatkiewicz P. , Przybyłek G. , Moczko Przemysław
Published: June 2010

The paper presents selected aspects of stress analysis of eccentric press. This approach is based on the assumption that fractures can be present in the analyzed constructions. Calculations define the current state of the component with respect to fracture mechanics. Reported research work was performed using analytical, numerical and experimental methods in order to evaluate durability of the considered structural element.
Structural Modifications of Excavator’s Bucket Wheel by the Use of Numerical Methods
Authors: Rusiński Eugeniusz , Moczko Przemysław , Kaczyński Paweł
Published: June 2010

In this paper the character of loads exerted on bucket wheel was evaluated. The places of maximal stresses were determined by using finite element analysis. After this operation, a new wheel hub design was initiated. The first phase was related to development of new conceptions of the hub. The proposed conceptions were rated with respect to mass and total length of welds. This procedure led to selection of the most suitable design, which was optimized in order to minimize stress. The work at this stage consisted of continuous modification of the geometrical form, meshing of finite element model and structural analysis thereby providing information about stresses and deformations. The workmanship of the structural component and welded joints were defined according to DIN 22261 2:2006 standard.
Mechatronics Engineering Programs at German Universities of Applied Sciences
Authors: Loose Harald
Published: June 2010

Mechatronics engineering study programs were established at German universities approximately 15 years ago. Today at about 50 universities of applied sciences mechatronics education is offered in undergraduate and graduate courses as full programs, majors or minors. In 2005 the MECHATRONIK e.V. – the mechatronics association in Germany - published a recommendation for undergraduate and graduate education in mechatronics, which defines minimum requirements to mechatronics study programs. In this paper the mechatronics study programs of a number of German universities are analyzed and compared.
Surficial geology, File Lake, Manitoba
Authors: Henderson P J , McMartin I
Published: June 2010

The geoscientific data presented on this map were collected during field work as part of the Canada-Manitoba Mineral Development Agreement (1984-1989), the EXTECH Snow Lake Project (1990-1991) and the Shield Margin NATMAP Project (1991-1996). The map compilation
is based on field work, air photo interpretation (1:60 000 scale aerial photographs) and available drift composition and was completed as part the TGI-3 Flin Flon Project in 2008-2009.
A whole‐basin study of sediment accumulation using stable lead isotopes and flyash particles in an acidified lake, Sweden
Authors: Bindler Richard , Renberg Ingemar , Brännvall Maja-Lena , Emteryd Ove , El-Daoushy Farid
Published: June 2010

Using analyses of lead concentrations, lead isotopes (206Pb/207Pb), and spheroidal carbonaceous flyash particles (SCP), we studied sediment accumulation patterns in the acidified lake Haärsvatten in southwest Sweden. After determining the natural background 206Pb/207Pb ratio (1.5) in deeper sediments in long sediment cores from three basins in the lake, we applied an isotope mixing model to quantify pollution Pb accumulation in 46 gravity cores. The mean pollution Pb inventory in the cores was 2.6 g m−2 (range, 0.3–11 g m−2). Although some variation in Pb concentrations can be explained by loss on ignition (LOI) and water depth (together, R2adj = 0.33), there is no relationship between pollution Pb inventories and these variables. Contrary to the traditional model of sediment focusing, where higher accumulations of pollutants are expected in deeper waters, the highest inventories for pollution Pb and SCP are generally found at shallow sites (<4 m water depth) and not in the three deep basins of the lake (10, 12, and 24 m deep). Furthermore, the model for sediment focusing, which may be appropriate for describing the physical building of sediments in a lake basin, may be inappropriate for describing the specific processes controlling the distribution of pollutants in a lake basin of this type.
Quantifying the flux of hydrothermal fluids into Mono Lake by use of helium isotopes
Authors: Clark Jordan F. , Hudson G. Bryant
Published: June 2010

In Mono Lake, concentrations of 3He and 4He are greater than atmospheric equilibrium values, indicating a subsurface helium source. This assertion is supported by vertical concentration profiles that show maximum d3He values (168%) occurring within the pycnocline. The slope of the regression between 3He and 4 He concentrations is near 2.8 Ra (Ra is the atmospheric helium isotope ratio), indicating that the subsurface source has a component of mantle helium. Hydrothermal springs and gas vents from Paoha Island have similar ratios, which suggests that discharge from this thermal system is the most important source. A 3He mass balance indicated that below the deep pycnocline at 17 m, ~25 cc STP of 3He accumulates each year (~90% from the influx of hydrothermal water and ~10% from the in situ decay of tritium). Although it is not retained because of gas transfer across the air‐water interface, ~70 cc STP of 3He is injected each year into the upper 17 m. When 3He is used as a tracer, the influx of hydrothermal water below the deep pycnocline was estimated to be 0.045 ± 0.025 m3 s−1. Because the hydrothermal water is fresher than Mono Lake, this influx causes the salinity of the monimolimnion to decrease by ~0.1 salinity units per year and may play a small but important role in the salinity budget of this layer, which is presently denser than and isolated from the surface water.
A high‐resolution pore water sampler for sandy sediments
Authors: Berg Peter , McGlathery Karen J.
Published: June 2010

In this paper, we present a new technique for collecting pore‐water samples in coarse‐to fine‐grained sandy sediments. We have used the technique both for in situ sampling and for pore‐water extraction from sediment cores brought back to the laboratory, in both cases with a depth resolution as fine as 1 cm. The key device is a long, thin (~2 mm) stainless steel tube with a specially designed tip that functions as a filter. Pore‐water samples are collected by inserting the tube into the sediment at the desired depth and applying a light suction from a syringe connected to the tube. The sample is injected immediately into a vial through a syringe filter and stored for later analysis. The technique has some clear advantages over other methods that are used commonly in sandy sediments. In comparison with lysimeters or sippers, it gives pore‐water samples with a much higher depth resolution, which often is needed to accurately estimate fluxes across the sediment‐water interface or transformation rates of solutes within the sediments. In comparison with dialysis cells or peepers, the new technique gives measurements that truly represent the time of collection. This can be crucial when non‐steady‐state systems are studied. Furthermore, disturbance of the sediment is minimal because of the small dimension of the tube. This is especially important in vegetated sediments, in which the deployment of larger conventional samplers is likely to cause significant disturbance. Finally, sample extraction is less laborious than other techniques, requiring only one site visit and typically <1 min of sampling time per sample. In laboratory tests using a dye tracer, we showed that pore water was drawn evenly toward the tube tip from all directions in the surrounding sediment. On the basis of these results, we provide guidelines for choosing the appropriate sampling depth intervals as a function of the sample size. Data from representative pore‐water profiles are presented for PO432 from vegetated coarse‐grained carbonate sediments in the Bahamas and NH4+1 from fine‐grained unvegetated sands in a temperate coastal lagoon in Virginia.
Remote sensing of biotic effects: Zebra mussels (Dreissena polymorpha) influence on water clarity in Saginaw Bay, Lake Huron
Authors: Budd Judith W. , Drummer Thomas D. , Nalepa Thomas F. , Fahnenstiel Gary L.
Published: June 2010

In this study, Advanced Very High Resolution Radiometer (AVHRR) remote sensing reflectance (Rrs ), imagery from 1987–1993 is used to study changes in water clarity before and after zebra mussels (Dreissena polymorpha) were discovered in Saginaw Bay, Lake Huron. Spatial and temporal trends in the data indicate distinct and persistent increases in water clarity in the inner bay after the first large recruitment of zebra mussels in the fall of 1991. The pre‐Dreissena imagery show that turbidity in the inner bay was influenced by the Saginaw River discharge in spring, biological production (plankton) in summer, and wind‐driven resuspension in fall, with highest turbidity in spring and fall. Spatial patterns in the post‐Dreissena images were more similar regardless of season, with low reflectances in the shallow regions of the inner bay where zebra mussel densities were highest. A regression model based on point data from 24 sampling stations over the 7‐yr period indicates that reflectances varied significantly by site and zebra mussel densities, as well as seasonally. Trends in observed and predicted values of reflectances followed similar patterns at each station—highest values were found during 1991 and lowest during 1992 at all stations, with slightly higher Rrs in 1993 compared to 1992. Whereas AVHRR Rrs highlight the value of historical imagery for reconstructing seasonal and interannual turbidity patterns in near‐shore waters, a new generation of operational ocean color satellites, such as SeaWiFS (Sea‐viewing Wide Field‐of‐view Sensor) and the newly launched MODIS (moderate resolution imaging spectroradiometer), now provide for routine monitoring of important biological and physical processes from space.
Asymmetric mixing transport: A horizontal transport mechanism for sinking plankton and sediment in tidal flows
Authors: Pringle James M. , Franks Peter J. S.
Published: June 2010

A mechanism is described for the net horizontal transport of sinking plankton or sediment by oscillatory tidal flows. The mean motion of the plankton or particles is driven by the modulation of vertical mixing between flood and ebb. Cold water forced over warm water on the flood tide creates enhanced vertical mixing and resuspension of sinking particles higher into the water column. On ebb, the converse occurs, and sinking particles are lower in the water column. Since friction retards the tidal flow near the bottom, this leads to a net horizontal transport toward the less dense water. Because less dense water tends to be shallower, this will tend to move sinking plankton and sediment toward the crest of banks, toward the coast, and up embayments, even in the absence of any mean currents. A one‐dimensional Eulerian model of this horizontal transport is developed and is compared to particle motion in a fully nonlinear two‐dimensional model with an advanced turbulence closure scheme. The Eulerian model can, in most circumstances, predict the net horizontal motion of the particles as a function of their sinking speed and observable oceanographic properties. The mean horizontal speed of sinking particles is greatest when the sinking speed of the particles is about one‐seventieth of the tidal velocities, or equivalently, about one‐third of the mean turbulent velocity scale u*. This horizontal transport of plankton and particles requires no behavior more complicated than simple sinking to achieve net horizontal speeds of several kilometers per day for realistic planktonic sinking speeds. It is possible that such a mechanism is a factor in larval recruitment and retention in coastal regions, for example, scallop larvae on Georges Bank.
In situ exposure to ultraviolet radiation alters the depth distribution of Daphnia
Authors: Leech Dina M. , Williamson Craig E.
Published: June 2010

Damaging solar radiation was one of the first factors proposed to explain zooplankton diel vertical migrations (DVM), yet other factors such as temperature, food, and especially predation have typically been more widely studied and identified as the primary factors inducing DVM. This is true in spite of the fact that recent experiments have shown that ambient levels of solar ultraviolet radiation (UVR) are potentially lethal to zooplankton and negative phototactic behavior has been demonstrated in the laboratory. Here we present the first evidence from in situ experiments demonstrating that UVR wavelengths influence the vertical swimming behavior of zooplankton under full spectrum solar radiation. Cylindrical acrylic columns that transmitted or blocked UVR were used to examine the behavioral responses of Daphnia pulicaria to UVR. Experiments were conducted in the epilimnion of a high‐UV system at midday and in late afternoon. In both experiments, a large proportion of individuals migrated downward in the presence of UVR, whereas those in the UVR‐shielded treatments tended to remain closer to the surface.
Identification of a natural desferrioxamine siderophore produced by a marine bacterium
Authors: Martinez J. S. , Haygood M. G. , Butler Alison
Published: June 2010

Desferrioxamine B (DFOB, a terrestrial bacterial siderophore) has been used in experiments on waters from iron‐replete areas of the oceans to manipulate the levels of iron available to the biota. Addition of DFOB complexes the available iron (III) and has been suggested to render this complexed iron unavailable to marine microorganisms. We have identified a marine bacterium belonging to the genus Vibrio that produces the siderophore desferrioxamine G. Desferrioxamine G, another known terrestrial siderophore, is very similar in structure to DFOB, differing only by the substitution of a terminal methyl group by a propionic acid moiety. These results could affect the interpretation of DFOB iron‐removal experiments and further suggest that addition of DFOB might not impose iron stress uniformly across the biological community.