bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Alloying Elements on the Corrosion Wear Behaviors of Low Chromium Cast Iron
Authors: Huang Ru Qing , Ma Ri Lai , Lu Zhen Lin , Zhang Yan
Published: August 2011

The effect of alloying elements on the corrosion wear behaviors of low chromium cast iron in slurry with different ions was studied by self-made three-body corrosion wear tester. The results show that the corrosion wear resistance of low chromium cast iron was decreased with the increase of concentration of Cu2+ ion or SO42- ion in slurry. The corrosion wear mechanism of low chromium cast iron was dominated by micro-cutting of abrasive, accompanying by corrosion action. The addition of alloying elements did not improve the corrosion wear properties of low chromium cast iron obviously, because the amount of carbide and its hardness was decreased when the alloying elements were added into low chromium cast iron as well as the amount of silicon element was increased.
A Study on Mechanical and Tribological Properties of Hot Pressed Al2O3/ZrO2/h-BN/TiO2 Composites
Authors: Lee Hyun Hwi , Kim Seung Ho , Joshi Bhupendra , Lee Soo Wohn
Published: August 2011

Oxide ceramics such as alumina and zirconia are industrially utilized as cutting tools, a variety of bearings, biomaterials, and thermal and corrosion-resistant coatings due to their high hardness, chemical inertness, high melting point, and ability to retain mechanical strength at elevated temperatures. In this research, the effect of other ceramic additives (TiO2) and h-BN within alumina(α-Al2O3) and yttria-stabilized tetragonal (Y-TZP) composite was studied with respect to the mechanical and tribological properties. The lowest coefficient of frction of 0.45 was observed for the ZTA ceramic composite with hBN-TiO2. The highest hardness, fracture toughness and flexural strength were obtained as 15.7GPa, 5.2MPam-1/2, 712MPa, respectively.
Studies on Corrosion Behavior of S-165 and HP Supermartensitic Stainless Steels in Cl- Environment
Authors: Wang Duo , Zou De Ning , Tang Chang Bin , Wu Kun , Liu Huan
Published: August 2011

Supermartensitic stainless steel grades are widely used in oil and gas industries to substitute duplex and super duplex stainless steels these years. In this paper the corrosion behavior of supermartensitic stainless steels with different chemical compositions, S-165 and HP, was investigated in Cl-environment. All the samples were treated by quenching at 1000 °C followed by tempering at 630 °C for 2h. After heat treatment, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) were determined on both kinds of samples. Polarization curves shows that the metastable pitting nucleuses were formed in passive area and the Cr content is the most important factor leading to the differences of pitting potential. The potentiodynamic polarization curves were conducted at various NaCl contents (5000, 15000 and 35000 ppm) and emphasized the need to account for the Cl-sensitivity of samples under corrosion environment. The results show that, the pitting potential decrease with the increase of chloride contents. The behavior of passive film was analyzed by electrochemical impedance spectroscopy.
Synthesis of Ti(C,N)/Al2O3 by Mechanically Induced Self-Propagating Reactive Synthesis
Authors: Zhu Jian Feng , Ye Lan , Tong Hai , Wang Fen
Published: August 2011

Ti(C,N)/Al2O3in situ solid solution composites have been synthesized by mechanically induced self-propagating reactive synthesis (MSR) from the mixture of Ti, Al, C and TiO2in nitrogen milling atmosphere. The phase transformation and powder morphology characteristics were studied by using XRD and SEM. Full dense and pure Ti(C,N)/Al2O3composites were fabricated at 1450 °C for 1 h under 10 MPa. The phase composition, microstructure and some mechanical properties of the composites were investigated. The results show that the synthesized Ti(C,N)/Al2O3composites posses a density of 4.66 g/cm3and a good combination of mechanical properties of hardness of 25.54 GPa and the flexural strength of 404 MPa. The reaction process mechanism was also discussed.
Preparation and Characterization of Sulfonated Imide-Grafted Poly(ethersulfone)s
Authors: Seo Dong Wan , Lim Young Don , Lee Soon Ho , Islam Md. Monirul , Jin Hyun Mi , Jang Ho Hyoun , Kim Whan Gi
Published: August 2011

Poly(ethersulfone)s carrying pendant sulfonated imide side group. The first step in the preparation involved nitration of poly(ethersulfone) (ultrason®-S6010), with ammonium nitrate and trifluoroacetic anhydride resulting in the nitrated poly(ethersulfone) (NO2-PES). In the second step, the nitro groups on polymer were reacted with tin(II)chloride and sodium iodide as reducing agents for creating the amino poly(ethersulfone) (NH2-PES). The imide-poly(ethersulfone)s (IPES) were obtained by reaction of phthalic anhydride and the amino-poly(ethersulfone) with triethyl amine. The sulfonated imide-poly(ethersulfone)s (SIPES) were prepared by chlorosulfonic acid. The different degrees of sulfonated imide units of poly(ethersulfone) were successfully synthesized by an optimized condition. The Sulfonated imide-poly(ethersulfone)s (SIPES) were studied by FT-IR,1H-NMR spectroscopy and thermo gravimetric analysis(TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water. The ion exchange capacity (IEC) and proton conductivity of SIPES membranes were evaluated with increase of degree of sulfonation. The water uptake of synthesized SIPES membranes exhibit 30 ~ 65 % compared with 28 % of Nafion 211®. The SIPES membranes exhibit proton conductivities (25 °C) of 1.21 ~ 2.62´10-3S/cm compared with 3.37´10-3S/cm of Nafion 211®.
Influencing of Ca-Based Sorbent on the Sulfur Retention
Authors: Zhang Zhao Hui , Lu Si Yuan , Ju Jian Tao , Yang Kui , Yan Dong Na
Published: August 2011

Ca-based sorbents has good performance on retening SO2 during coal combustion. In this paper, the effect of Ca/S molar ratio, coal size, combustion temperature and pretreatment time of the materials on sulfur-retention efficiency has been investigated by the method of orthogonal experiment. The work shown that the sulfur-retention is promoted greatly as Ca/S molar ratio of Ca-based agent increased. Simultaneously, the optimum experiment reveals that CaO as sulfur-fixing agent, Ca/S molar ratio 2.0, combustion temperature of 900°C, coal particle size of smaller than 180 mesh and pretreatment for 30min could attain the best results.
Comparative Study on the Effects of Different Molecular Weight Polyethylene Powders in Soil
Authors: He Jing , Luo Xue Gang , Ying Tao , Wu Ji Liang
Published: August 2011

In order to resolve the soil polluted problem which were brought by polyethylene, the study focus on the effects of different molecular weight polyethylene powders to soil, and discuss the molecular weight change of polyethylene. This study made use of four kinds of molecular weight polyethylene powders as materials, added them into the soil of potted soybean to test efficient N content, efficient P content, efficient K content in every development period of soybean, and test the molecular weight of four kinds of polyethylene after the whole development periods of soybean. The Important findings in this study were that there are no significant differences among the efficient N content, efficient P content, efficient K of control group and every experimental group, the molecular weight of polyethylene are nearly no change. it means that the different molecular weight polyethylene powders have no effect to soil.
Study on Microstructure and Impact Strength of Nano-SiO2 Toughened Epoxy Resin Composites
Authors: Gao Nai Kui , Dong Pu , Yu Xin , Fang Xin , Gao Chao , Jin Hai Yun
Published: August 2011

In this paper, composites with different contents of epoxy resin/nano-SiO2were fabricated, the influence of compounding process on nano-SiO2dispersion was studied, the microstructure and the relationship between impact strength and nano-SiO2content were investigated. The results showed that the distribution of nano-SiO2particles in the composites could be improved efficiently using high-speed shearing dispersion method. To composites with or without the coupling agent treatment, the impact strength grew with increasing nano-SiO2content, and increase to a maximum value when nano-SiO2content was 3wt.%. The maximum value was 75.4%, and 45.5% higher than that of monolithic epoxy resin respectively. With the nano-SiO2 content increased continually, the impact strength of composite materials decreased. The coupling agent treatment of nano-SiO2administered to improve the impact strength of the composites.
Pulsed Electric Current Sintering of the Al2O3 - 15wt% ZrO2 Nanocomposites with 3wt% of Different Solid Lubricants
Authors: Cura M. Erkin , Kim Seung Ho , Cho Sung Hun , Suhonen Tomi , Muukkonen Tatu , Vaajoki Antti , Söderberg Outi , Kanerva Ulla , Lee Soo Wohn , Hannula Simo Pekka
Published: August 2011

High temperature low friction materials are sought for use in engines in order to reduce energy consumption of the machines. Due to the high service temperatures solid lubricating materials are necessary. This study is designed to find the optimal processing conditions for preparing these materials by pulsed electric current sintering. In this study, the Al2O3- 15wt% ZrO2(AZ) nanocomposite was modified with 3 wt% of self-lubricating component (CaF2, BaF2, MoS2, WS2, h-BN, or graphite). After the preparation of the alumina-zirconia powder mixture solid lubricant powder was added. Powders were then mixed in ethanol for 24 h, dried in a rotary evaporator, and in oven at 80°C for 24 h. The particle size distribution of the powders was established with the laser method. Powders were compacted by using pulsed electric current sintering technique at 1300 °C with 50 MPa for 5 min in vacuum. The structure of the materials was studied with XRD and SEM. Density of the compacts was measured with the Archimedes method and their hardness was evaluated by applying HV1 hardness with the instrumented indentation techniques. Their mechanical behavior was further studied with the instrumented scratch testing.
The Effects of Aging Treatment on the Strength and Conductivity of Cu-Ag-Zr-Co Alloy
Authors: Park Kyung Hun , Cho Hoon , Hyun Soong Keun
Published: August 2011

The development trend for diagnostics is reducing the diameter of coaxial signal cables that comprise the probe cable. The thinner super-fine coaxial cable which is offering superior electronic and mechanical properties, such as 75 %IACS(International Annealed Copper Standard, electrical conductivity) and 700 ~ 800 MPa in tensile strength has to be developed. Cu-Ag based system is one of the most promising systems for high strength and high conductivity Cu alloys. In order to find the optimum conditions to obtain Cu-Ag-Zr-Co alloy with high strength and high electrical conductivity, the aging characteristics including work hardening of micro-Vickers hardness, tensile strength and electrical conductivity of this alloy were systematically measured at room temperature. Also the influence of aging treatment was investigated by transmission electron microscopy(TEM) and scanning electron microscopy(SEM) in this study. The aging treatment for precipitation was divided into two steps and carried out at various time and at different temperature and the multi-step aging treatment coupled with cold rolling was proposed for realizing Cu-Ag-Zr-Co alloys with high strength and high electrical conductivity. The electrical conductivity was improved from 31 %IACS to 91 %IACS remarkably and the tensile strength was increased from 230Mpa to 690Mpa greatly by an optimization of alloy composition and manufacturing process including aging.
Laboratory Evaluation of Ultraviolet Radiation for Asphalt Pavement Performance in Desert Regions
Authors: Li Li , Tong Shen Jia
Published: August 2011

There is very strong ultraviolet radiation in western desert of China. In order to study the behavior of ultraviolet aging for bitumen, three type of bitumen were aged in the laboratory. The ultraviolet aging and thermal aging under the condition of artificial intensive ultraviolet radiation environment test and the rolling thin-film oven test (RTFOT) were comparative investigated. The results showed that the impact of ultraviolet aging manifests longer time than that of thermal aging for bitumen.
Fuel Gases from Gasification Process of Glass Fiber/Epoxy Composite Waste
Authors: Saetiaw Kaew , Atong Duangduen , Sricharoenchaikul Viboon , Aht-Ong Duangdao
Published: August 2011

Currently solid wastes generated from manufacturing process of thermosetting composite have caused environmental problems because they are non biodegradable product and cannot be recycled or remolded due to chemically crosslinked. Thus, the aim of this research is to convert glass fiber reinforced epoxy composite waste to fuel gases by gasification process. The composite waste was first grounded and its thermal decomposition behavior was then investigated using isothermal thermogravimetric analysis (TGA) from an ambient to 900°C at heating rate of 10°C/min under nitrogen atmosphere. The results showed that major decomposition temperatures of the epoxy matrix were ranging from 300 to 450°C. The composite sample was then mixed with two different catalysts, olivine (LiFePO4) or 10%NiAl2O3in order to study the effect of catalyst on gas conversion efficiency before it was gasified in a fixed bed reactor at final temperature of 500, 600, 700, and 800°C under nitrogen mixed with air at total flow rate of 200 mL/min. Gasification process indicated that solid residues were mainly brittle black containing residual glass fiber. The significant increasing of carbon monoxide and carbon dioxide conversion was achieved from sample mixed with olivine catalyst at gasification temperature of 700°C, when compared with result without catalyst at baseline conversion of 500°C as. Therefore, it can be expected that gasification process is a promising method to deal with epoxy composite for producing renewable energy.
The Influence of Polyethylene Film on the Concentration of CO2 in the Soil
Authors: Wu Ji Liang , Luo Xue Gang , Lin Xiao Yan , He Jing
Published: August 2011

After entering the soil, the degradation products of polyethylene film have a series of influences on ecological environment of the soil. The influences of the molecular weight and the cumulative amount of degraded polyethylene, soil type and soil depth burying polyethylene on the concentration of CO2 in the soil were investigated through the orthogonal test L9(34) . Collection and testing of CO2 were conducted by gas collector underground and the infrared detector of the Automatic Monitoring System of Soil. The change of CO2 in the soil at a growth cycle of maize was detected continuously by online monitor. The experimental data was analyzed using DPS data processing system. The results show that the impact of soil depth burying polyethylene on CO2 concentration increase with the increase of burying time, and the molecular weight of polyethylene has a decreasing impact on CO2 concentration with the increase of burying time. In the former period of the maize growth, the CO2 concentration is higher in the clay than in the sand and loam. But in the later growth stage the CO2 concentration in the loam are more abundant than other two soils.
Preparation of Adsorbent from Blue Coke Powder and its Application in Coking Wastewater
Authors: Tian Yu Hong , Lan Xin Zhe , Zhang Qiu Li , Xue Juan Qin , Song Yong Hui , Li Lin Bo
Published: August 2011

The low-cost blue coke industrial by-product, blue coke powder was used as raw material for the production of porous carbons adsorbent by steam activating at temperature of 800°C under the atmosphere of N2 for 60 minutes. The specific surface area and pore properties of the adsorbent were characterized by using N2 adsorption-desorption isotherms. Furthermore, the adsorption effects of the adsorbent for ammonia nitrogen in coking wastewater were investigated in terms of particle size, dosage of absorbent and adsorption time. The results show that the specific surface area is 620.94m2/g, the total pore volume is 0.4442cm3/g and the average mesopore size is 4.5808nm, the adsorbent possesses predominant mesoporous structures. In aeration, the removal rate of ammonia nitrogen can reach to 39.5% under the conditions of the ammonia nitrogen concentration of 625mg/L, the dosage of adsorbent 10g/L at the adsorption time of 60 minutes.
Defects Study by Activation Energy Profile for Lowering Leakage Current in P-N Junction
Authors: Srithanachai Itsara , Ueamanapong Surada , Rujanapich Poopol , Atiwongsangthong Narin , Niemcharoen Surasak , Poyai Amporn , Titiroongruang Wisut
Published: August 2011

Diode leakage current consists of diffusion (Id) and generation current (Ig), which is strongly sensitive to the residual defect density. These defects can be studied by activation energy (Ea). Therefore, this paper presents a method for calculating activation energy of silicon p-n junctions from volume generation current. It combines temperature-dependent current–voltage (I –V) and capacitance–voltage (C-V) measurements of diodes. The Igcan be found from the volume leakage current by subtraction of the volume diffusion current, which is calculated while the depletion width is zero. The activation energy (Ea) is derived from slope of an Arrhenius plot of Ig. To derive the correct slope the temperature dependence of the depletion width, which is obtained from the corrected volume capacitance has been applied. The Ea profile below junction has been shown. The lower Ea value has been found near the junction, which may relate to the junction implantation.
Sol-Gel Derived La0.56Sr0.4Co0.2Fe0.8O3-δ Cathodes for IT-SOFC Applications
Authors: Mongkolkachit Charusporn , Wanakitti Suda
Published: August 2011

The La0.56Sr0.4Co0.2Fe0.8O3-δ(LSCF) perovskite cathode, substituted by Sr and Fe at the A and B sites, respectively, is a good candidate for intermediate temperature solid oxide fuel cell (IT-SOFC) applications. The powders were prepared by sol-gel method using various metal nitrates as starting materials. The adipic acid was used as a chelating agent and ethylene glycol as a dispersant. The gel precursor was heated at 700 °C for 4 h to obtain LSCF cathode powders. X-ray diffraction pattern showed the single phase of the perovskite structure. The microstructure of LSCF materials was observed by scanning electron microscopy which was loosely aggregated and could be ground easily into fine powders. The average particle size of the powders was found to be around 80-200 nm. TGA/DTA techniques exhibited the weight loss after high temperature process. It was found that no weight loss after 550 °C suggests the completion of combustion process.
A Study on Adhesive Properties of a Damascene Electroplated Cu Composite Sheet
Authors: Moon Hyung Kwon , Jung Seung Boo , Shin Je Sik
Published: August 2011

In this paper, it was aimed to develop a new interconnect material having high electrical conductivity and strength simultaneously. The Cu composite sheet, possessing mesh type Ag conduction paths on the surface of a high strength Cu alloy sheet, was manufactured by damascene electroplating. The peel strength of Cu composite sheet prepared by damascene electroplating increased by above 50 times compared to Cu composite sheet by conventional electroplating. Al wire wedge bonding was able to be successfully conducted without extra metal thin film coating.
Effect of Ball Milling of Composite Additives on the Microstructure and Electrical Properties of ZnO Varistors
Authors: Zhu Jian Feng , Qi Guo Quan , Yang Hai Bo , Wang Fen
Published: August 2011

ZnO varistors were synthesized with ZnO powders and intensity milled composite additives as raw materials. The effect of milling time of the composite additives on the grain boundary phase distribution as well as the electrical properties was investigated in detail. The results show that ball milling composite additives have a significant effect on the ZnO varistors. The samples derived from ball milled composite additives possess the smaller size and more uniform distribution of the second phases, which improved the electrical properties obviously. The optimal ZnO varistor samples were obtained by ball milling 15 h for the composite additives, which possess average ZnO crystalline grain size of about 4 µm, the gradient voltage V1mA of 454 V/mm, the leakage current IL of 0.12 µA, and the nonlinear coefficient α of 55.
Structural Properties and Microstructures of SrTiO3/SrTi1-xNbxO3 Superlattices Grown by Ion Beam Deposition
Authors: Panomsuwan Gasidit , Saito Nagahiro , Takai Osamu
Published: August 2011

Superlattice structure of SrTiO3and Nb-doped SrTiO3have been epitaxially grown on atomically flat surface of LaAlO3substrates by ion beam deposition method. Epitaxial superlattices were grown at 800 °C in the presence of partial oxygen pressure under optimizing growth conditions. The Nb-doped SrTiO3layers were varied from 2 to 15 unit cell thickness approximately, while SrTiO3layers are maintained at 15 unit cell thickness with 10 periods. The superlattices with various Nb-doped SrTiO3layer thicknesses were investigated using X-ray diffractometer (XRD) and atomic force microscope (AFM), in order to clearly understand structural properties and surface structure, which are significant for fabrication of the high quality superlattice structure.
Development of Multiple Water Quality Measurement Devices
Authors: Kwak Pill Jae , Kim Seog Ku , Yun Sang Leen , Kang Sung Won , Lee Hyun Dong , Yang Keun Ho , Oh Hee Jae , Kim Young Sung
Published: August 2011

The water quality measurement device that we developed measures pH, water temperature, conductivity, dissolved oxygen, turbidity and nitrate. And it measures all parameters simultaneously. The water resistant and screw packing technology also applied for improved mechanical reliability during water quality monitoring. A comparison between the performances of major company products (YSI, Hydrolab etc.) and this device don't provide a stark contrast. This device was verified through the KOREA’s Environmental Examination Methods. This device is offered reliable and cost-effective water quality monitoring solutions. Upgrades will be available and will include the technologies that are self-cleaning optical sensors with integrated wipers remove biofouling and maintain high data accuracy and optimal power management and built-in battery compartment extends in situ monitoring periods.
Study on the Reaction of Acetylated Konjac Glucomannan and EVA during Processing
Authors: Li Xian Hong , Lin Xiao Yan , Luo Xue Gang , Li Ji Wei
Published: August 2011

The transesterification in acetylated konjac glucomannan/ethylene vinyl acetate (AKGM/EVA) melting blend system with the presence of dibutyltin oxide (DBTO) catalyst was investigated by means of a torque rheometer during compounding. The characteristics of the products were evaluated by DSC and FT-IR. The glass transition temperature at about 179.4 °C was found in the DSC curve of AKGM-EVA, the equilibrium torque of AKGM/EVA with 0.25 wt% DBTO was lower than that without DBTO. The results showed that the transesterification took place in the AKGM/EVA blend system.
Field Application of Particle Filtration with EPP (Expanded Polypropylene) Engineered Media of Road Runoff
Authors: Kang Sung Won , Kim Seog Ku , Yun Sang Leen , Ban Hyo Jin , Lee Won Tae , Kwak Pill Jae
Published: August 2011

Metal elements or other constituents transported in urban and transportation land use rainfall runoff are often adsorbed on or incorporated with entrained particles that are ubiquitous in such runoff. EPP(Expanded Polypropylene) engineered media with a large surface area was developed to treat road runoff. Field application of particle filtration reactor(PFR), which combined the EPP engineered media with filtration called EcoTank system, provided control of water quality. Under the operating conditions with 0.55 hours hydraulic retention time(HRT) and a capable of treating a maximum road runoff 9.5 m3/h, the mean residual Cd, Cr, Cu, Pb and Zn were 0.24, 2.8, 13.4, 11 and 112.3 ㎍/L and corresponding percentage mean removal values were 91, 93, 85, 91 and 80%, respectively. Results suggest that a properly designed PFR can provide effective in situ control for particles and could be combined with or function separately from source control.
Multistage Soil Filter System for Rainwater Collection and Use
Authors: Lee Sang Ho , Mun Jung Soo , Kim Young Min , Nam Sookh Yun , Kim Ree Ho
Published: August 2011

Rainwater collection and use is usually considered for runoff from building roofs. Runoff from impervious layers such as roads and pavements, however, has hardly been used as water supply due to its high pollutant concentration. If runoff from roads will be treated and used properly, though, it can be a good water resource and will contribute minimally to a non-point source. In this study, a multistage soil filter system (MSFS) composed of a gravel layer, a functional-media layer with zeolite, a sand layer, and a lawn layer, was developed to treat the runoff from roads and green areas. To evaluate the performance of MSFS, its removal rate of total suspended solids (TSS) was investigated based on the rainfall intensity and the thickness of each layer. The experiment results were compared with the predicted values using the MinitabTM program. The TSS removal rates ranged from 82 to 96%, with various combinations of experiment conditions. The predicted removal rates well fitted with the removal rates obtained from the experiment. An equation was formulated for predicting the TSS removal rate based on the rainfall intensity and the thickness of each layer. The optimum design factors for MSFS considering its TSS removal rate could be derived based on such equation. Based on the study results, it is expected that MSFS can contribute to securing water resources and to controlling non-point sources.
Synthesis and Thermoelectric Properties of Co4-XFeXSb12-YSnY Skutterudites
Authors: Park Kwan Ho , Kim Il Ho
Published: August 2011

Co4-xFexSb12-ySny skutterudites were synthesized by mechanical alloying and hot pressing, and thermoelectric properties were examined. The carrier concentration increased by doping and thereby the electrical conductivity increased compared with intrinsic CoSb3. Every specimen had a positive Seebeck coefficient. Fe doping caused a decrease in the Seebeck coefficient but it could be enhanced by Fe/Sn double doping possibly due to charge compensation. The thermal conductivity was desirably very low and this originated from ionized impurity-phonon scattering. Thermoelectric properties were improved remarkably by Fe/Sn doping, and a maximum figure of merit, ZT = 0.5 was obtained at 723 K in the Co3FeSb11.2Sn0.8 specimen.
The Adsorption of Cd(II) Ions on Sodium Hydroxide-Treated Bamboo Powder
Authors: Luo An Kai , Luo Xue Gang , Lin Xiao Yan
Published: August 2011

The adsorption of Cd(II) ions from aqueous solution by sodium hydroxide-treated bamboo powder（STB） was studied in a batch adsorption system. Characteristics of STB were investigated by scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS). Factors influencing adsorption such as pH of the solution, adsorbent dosage, cadmium concentration and temperature have been studied. The adsorption process was relatively fast and equilibrium was achieved after 120 min, and the maximum adsorption of Cd(II) ions occurred at around pH 6.5. The equilibrium data were fitted using Langmuir, Temkin and Freundlich isotherm models to calculate isotherm constants. And the adsorption isotherm fitted well Langmuir isotherm, and the maximum adsorption capacity was 8.987 mg/g.
Application of a Visual Measurement Technique to the Assessment of Electrodynamic Stamping
Authors: Bednarczyk Józef , Sioma Andrzej
Published: August 2011

This paper discusses a visual method of measuring the geometric parameters of elements produced by electrodynamic stamping. This paper presents also electrodynamic method which is an unconventional machining technology, which complements the capabilities of traditional technologies, in particular as regards the formation of metal elements with low-profile dies of complex shape. The article discusses issues related to resolution of the vision system, resolution of laser beam analysis, and resolution relating to the measurement of the height profile on the surface of the product. Based on the model constructed in such a way, measurements are presented in order to assess the dimensional parameters. Based on tests and analyses of the three-dimensional model, a range of inspection tasks using 3D vision systems is indicated.
Modified Clipped-LQR Method for Semi-Active Vibration Reduction Systems with Hysteresis
Authors: Sibielak Marek , Rączka Waldemar , Konieczny Jarosław
Published: August 2011

Smart materials are being applied more and more widely in semi-active vibration reduction systems. Actuators built with their use are characterized by nonlinearities and hysteretic effects. Their omission in mathematical descriptions may lead to deterioration of the vibration reduction systems. For that reason, it is important to take into account these negative phenomena associated with the actuators at the controller synthesis stage. One method for determining the control laws in semi-active vibration reduction systems that is frequently discussed in academic literature is “Clipped-LQR”. The present paper proposes modification of that method to allow inclusion in the controller synthesis of the hysteretic properties and other nonlinearities of an actuator. The method developed was verified by determining the controller for the semi-active suspension of a machine operator’s seat. A magnetorheological damper was used as an actuator. The dynamic properties of the foam covering of the operator’s seat were included in model. Simulation tests were performed on the vibration reduction system and function of vibration transmissibility was determined. The semi-active vibration reduction system tested was compared to a passive system. The considerations presented herein relate to the semi-active suspension of a machine operator’s seat, and the method presented may be applied to other controlled systems with many degrees of freedom.
Self-Excited Travelling Waves as a Model of Cable Galloping
Authors: Snamina Jacek
Published: August 2011

In the paper the galloping phenomenon is modelled by self-excited waves travelling along the cable. The critical conditions of air flow and corresponding changes in the lift coefficient are presented. The motion of the cable was described in relation to equilibrium configuration. Since the wavelengths are small with reference to considered distances and additionally the tension and curvature of equilibrium line of the cable are slowly varying functions of the arc co-ordinate, the problems concerning the travelling waves can be solved using the Wentzel-Kramers-Brillouin (WKB) method. Using this method the equations describing wave numbers and amplitudes of waves were derived. The results of the calculations of amplitudes are presented in the form of plots.
Model Testing of Flow Phenomena in the Squeeze Chamber of a Cold-Chamber Diecasting Machine
Authors: Stojek Jerzy , Dańko Rafał
Published: August 2011

A review of the studies carried out on this subject so far was made, and the available mathematical models applicable at Phase I of the diecasing process were presented. Own model testing of the examined process phase was described. The tests were conducted on a laboratory station designed and constructed to serve this purpose. Basing on the obtained results, the fundamental Garber's model was modified and extended further to include the coefficient of liquid metal viscosity.
Phenomena Occurring during the Electro-Dynamic Forming of Non-Ferrous Pipe Elements
Authors: Kot Andrzej
Published: August 2011

The paper presents description of physical phenomena arising during the process of electrodynamic forming by means of axisymetric inductors generating pulse magnetic field. Presented material shows the way for determination of pressures acting on non-ferrous pipe elements with an assumption of magnetic flux variation character in system. The paper describes also stages of energy conversion from electric energy of capacitors discharge into mechanical energy of pressure forming semi-finished product. The knowledge about presented phenomena allow to predict final shape of formed product during free forming by electrodynamic method.
Testing of Throttle Valve Prototype Controlled by Piezoelectric Stack
Authors: Pluta Janusz , Sibielak Marek
Published: August 2011

This paper aims to present the results of the testing a single-stage electrically actuated throttle valve, in which a piezoelectric stack was used for adjustment of the flow section area of the throttle aperture. The valve prototype was built based on a proprietary design, using the components of a standard manufactured overflow valve. The complete valve was designed on the basis of the results of simulation tests performed on a mathematical model. The constitutive equations presented herein, describing all critical phenomena and influences present in the component, were applied for the modelling of the piezoelectric stack. Laboratory tests were carried out to establish the valve’s characteristics, describing its usefulness for control of flow intensity. LabView software was used for measuring the data gathered. The test results, after conversion, were developed using the Matlab/Simuling software package. This paper presents the most notable results of the tests of a normally open valve equipped with a high-voltage piezoelectric stack. Based on the results obtained, the functional correlation between the volumetric flow rate, pressure drop in the throttling aperture and control signal input to the piezoelectric stack were determined. Due to the comprehensive approach involved, the material presented herein may be prove useful to designers of valves and hydraulic units using piezoelectric stacks for controlling their operating units.
Automated Determination and On-Line Correction of Emissivity Coefficient in Controlled Cooling of Drop Forgings
Authors: Skubisz Piotr , Micek Piotr , Sińczak Jan , Tumidajewicz Marek
Published: August 2011

The paper presents the methodology of determination of emissivity coefficient of steel in the direct cooling temperature range, which allow self-definition of this parameter in automated temperature control system used for direct cooling of drop-forged parts. Based on the actual temperature of the surface of the workpiece, the system automatically adjusts the velocity of fan-forced air to produce desired cooling rate and course of cooling curves. To enable automatic correction of cooling rate, the system must rely on exact remote temperature measurements. This is conditioned by correct definition of emissivity in pyrometer gauge system. Traditionally, pyrometers use presets of a constant value, selected as to get optimum consistency for the temperature range concerned. As the emissivity is time-dependent, the idea of the approach presented in the paper is to use time dependent characteristics, to attain the minimum discrepancy between actual and measured values during the whole cooling cycle.
On the Use of Potential Denaturing Agents for Ethanol in Direct Ethanol Fuel Cells
Authors: Bayer Domnik , Jung Florina , Kintzel Birgit , Joos Martin , Cremers Carsten , Martin Dierk , Bernard Jörg , Tübke Jens
Published: August 2011

Acidic or alkaline direct ethanol fuel cells (DEFCs) can be a sustainable alternative for power generation if they are fuelled with bio-ethanol. However, in order to keep the fuel cheap, ethanol has to be exempted from tax on spirits by denaturing. In this investigation the potential denaturing agents fusel oil, tert-butyl ethyl ether, and Bitrex were tested with regard to their compatibility with fuel cells. Experiments were carried out both in sulphuric acid and potassium hydroxide solution. Beside, basic electrochemical tests, differential electrochemical mass spectrometry (DEMS) and fuel cell tests were conducted. It was found that fusel oil is not suitable as denaturing agent for DEFC. However, tert-butyl ethyl ether does not seem to hinder the ethanol conversion as much. Finally, a mixture of tert-butyl ethyl ether and Bitrex can be proposed as promising candidate as denaturing agent for use in acidic and alkaline DEFC.
Inhibition Effect of Miconazole Nitrate on the Corrosion of Mild Steel in Hydrochloric Acid Medium
Authors: Bhat J. Ishwara , Alva Vijaya D. P.
Published: August 2011

The corrosion inhibition of mild steel by miconazole nitrate, an antifungal drug has been investigated using potentiodynamic polarization, electrochemical impedance spectroscopy technique, and weight loss methods. The experimental results suggested miconazole nitrate is a good corrosion inhibitor for mild steel in 1 M hydrochloric acid medium. The inhibition efficiency increased with increase in inhibitor concentration. The thermodynamic parameters were determined and discussed. The inhibition was assumed to occur via adsorption of the inhibitor molecule on the surface of mild steel following Langmuir adsorption isotherm.
A Morphological Approach to the Diagnosis of Protozoal Infections of the Central Nervous System
Authors: Chimelli Leila
Published: August 2011

Protozoal infections, though endemic to certain regions, can be seen all around the world, because of the increase in travel and migration. In addition, immunosuppression associated with various conditions, particularly with HIV infection, favors the occurrence of more severe manifestations and failure to respond to treatments. The CNS may be the only affected system; when not, it is often the most severely affected. Despite information obtained from clinical, laboratory, and imaging procedures that help to narrow the differential diagnosis of intracranial infections, there are cases that need confirmation with biopsy or autopsy. Predominant presentations are meningoencephalitis (trypanosomiasis), encephalopathy (cerebral malaria), or as single or multiple pseudotumoral enhancing lesions (toxoplasmosis, reactivated Chagas' disease). The immune reconstitution disease, resulting from enhancement of pathogen-specific immune responses after HAART, has altered the typical presentation of toxoplasmosis and microsporidiosis. In this paper, a morphological approach for the diagnosis of protozoal infections affecting the CNS (amoebiasis, cerebral malaria, toxoplasmosis, trypanosomiasis, and microsporidiosis) is presented.
The Role of Salt in the Pathogenesis of Fructose-Induced Hypertension
Authors: Soleimani Manoocher , Alborzi Pooneh
Published: August 2011

Metabolic syndrome, as manifested by visceral obesity, hypertension, insulin resistance, and dyslipidemia, is reaching epidemic proportions in the Western World, specifically the United States. Epidemiologic studies suggest that the increased prevalence of metabolic syndrome directly correlates with an increase in the consumption of fructose, mainly in the form of high-fructose corn syrup. This inexpensive alternative to traditional sugar has been increasingly utilized by the food industry as a sweetener since the 1960s. While augmented caloric intake and sedentary lifestyles play important roles in the increasing prevalence of obesity, the pathogenesis of hypertension in metabolic syndrome remains controversial. One intriguing observation points to the role of salt in fructose-induced hypertension. Recent studies in rodents demonstrate that increased dietary fructose intake stimulates salt absorption in the small intestine and kidney tubules, resulting in a state of salt overload, thus setting in motion a cascade of events that will lead to hypertension. These studies point to a novel interaction between the fructose-absorbing transporter, Glut5, and the salt transporters, NHE3 and PAT1, in the intestine and kidney proximal tubule. This paper will focus on synergistic roles of fructose and salt in the pathogenesis of hypertension resulting from salt overload.
Immunogenicity of Simulated PCECV Postexposure Booster Doses 1, 3, and 5 Years after 2-Dose and 3-Dose Primary Rabies Vaccination in Schoolchildren
Authors: Kamoltham Thavatchai , Thinyounyong Wiravan , Khawplod Pakamatz , Phraisuwan Phran , Phongchamnaphai Phana , Anders Gerlind , Malerczyk Claudius
Published: August 2011

Objectives. To assess the immunogenicity of intradermal (ID) booster doses of Purified Chick Embryo Cell rabies vaccine (PCECV, Rabipur) administered to Thai schoolchildren one, three and five years after a primary ID pre-exposure (PrEP) vaccination series.Methods. In this follow-up study of a randomized, open-label, phase II clinical trial, two simulated post-exposure booster doses of PCECV were administered on days 0 and 3 intradermally to 703 healthy schoolchildren, one, three or five years after primary vaccination with either two or three ID doses of 0.1 mL PCECV. Blood was drawn immediately before and 7, 14 and 365 days after the first booster dose to determine rabies virus neutralizing antibody (RVNA) concentrations.Results. An anamnestic response of approximately 30-fold increase in RVNA concentrations was demonstrated within 14 days after booster. All children (100%) developed adequate RVNA concentrations above 0.5 IU/mL. No vaccine related serious adverse events were seen in any of the vaccinees.Conclusion. ID rabies PrEP with PCECV is safe and immunogenic in schoolchildren and the anamnestic response to a two booster dose vaccination series was found to be adequate one, three, and five years after a two- or three-dose primary PrEP vaccination series.
Surface Potential of Polycrystalline Hematite in Aqueous Medium
Authors: Preočanin Tajana , Stipić Filip , Selmani Atiđa , Kallay Nikola
Published: August 2011

The surface potential of polycrystalline hematite in aqueous sodium perchlorate environment as a function of pH was examined. Surface potential of hematite was obtained from measured electrode potential of a nonporous polycrystalline hematite electrode. Acidic solution was titrated with base, and the backward titration with acid was performed. Substantial hysteresis was obtained which enabled location of the point of zero potential and equilibrium values of surface potentials. The theoretical interpretation of the equilibrium data was performed by applying the surface complexation model and the thermodynamic equilibrium constants for the first and the second step of surface protonation was obtained aslogK1∘=11.3;logK2∘=2.8.
Pattern of the Antimalarials Prescription during Pregnancy in Bangui, Central African Republic
Authors: Manirakiza Alexandre , Soula Georges , Laganier Remi , Klement Elise , Djallé Djibrine , Methode Moyen , Madji Nestor , Heredeïbona Luc Salva , Le Faou Alain , Delmont Jean
Published: August 2011

Introduction. The aim of this study was to identify the antimalarials prescribed during the pregnancy and to document their timing. Method. From June to September 2009, a survey was conducted on 565 women who gave birth in the Castors maternity in Bangui. The antenatal clinics cards were checked in order to record the types of antimalarials prescribed during pregnancy according to gestational age. Results. A proportion of 28.8% ANC cards contained at least one antimalarial prescription. The commonest categories of antimalarials prescribed were: quinine (56.7%), artemisinin-based combinations (26.8%) and artemisinin monotherapy (14.4%). Among the prescriptions that occurred in the first trimester of pregnancy, artemisinin-based combinations and artemisinin monotherapies represented the proportions of (10.9%) and (13.3%). respectively. Conclusion. This study showed a relatively high rate (>80%) of the recommended antimalarials prescription regarding categories of indicated antimalarials from national guidelines. But, there is a concern about the prescription of the artemisinin derivatives in the first trimester of pregnancy, and the prescription of artemisinin monotherapy. Thus, the reinforcement of awareness activities of health care providers on the national malaria treatment during pregnancy is suggested.
Metronomic Cyclophosphamide and Methotrexate Chemotherapy Combined with 1E10 Anti-Idiotype Vaccine in Metastatic Breast Cancer
Authors: Soriano Jorge L. , Batista Noyde , Santiesteban Eduardo , Lima Mayté , González Joaquín , García Robin , Zarza Yohanka , López María V. , Rodríguez Myriam , Loys Jorge L. , Montejo Narciso , Aguirre Frank , Macías Amparo , Vázquez Ana M.
Published: August 2011

The use of low doses of cytotoxic agents continuously for prolonged periods is an alternative for the treatment of patients with metastatic breast cancer who have developed resistance to conventional chemotherapy. The combination of metronomic chemotherapy with therapeutic vaccines might increase the efficacy of the treatment. Twenty one patients with metastatic breast cancer in progression and a Karnosky index ≥60%, were treated with metronomic chemotherapy (50 mg of cyclophospamide orally daily and 2.5 mg of methotrexate orally bi-daily), in combination with five bi-weekly subcutaneous injections of 1 mg of aluminum hydroxide-precipitated 1E10 anti-idiotype MAb (1E10-Alum), followed by reimmunizations every 28 days. Five patients achieved objective response, eight showed stable disease and eight had disease progression. Median time to progression was 9,8 months, while median overall survival time was 12,93 months. The median duration of the response (CR+PR+SD) was 18,43 months (12,20–24,10 months), being higher than 12 months in 76,9% of the patients. Overall toxicity was generally mild. Metronomic chemotherapy combined with 1E10-Alum vaccine immunotherapy might be a useful therapeutic option for the treatment of metastatic breast cancer due to its potential impact on survival and patient quality of live, low toxicity and advantages of the administration.
Thyroid Peroxidase Antibody and Screening for Postpartum Thyroid Dysfunction
Authors: Adlan Mohamed A. , Premawardhana Lakdasa D.
Published: August 2011

Postpartum thyroid dysfunction (PPTD) is a common disorder which causes considerable morbidity in affected women. The availability of effective treatment for hypothyroid PPTD, the occurrence of the disease in subsequent pregnancies and the need to identify subjects who develop long term hypothyroidism, has prompted discussion about screening for this disorder. There is currently no consensus about screening as investigations hitherto have been variable in their design, definitions and assay frequency and methodology. There is also a lack of consensus about a suitable screening tool although thyroid peroxidase antibody (TPOAb) is a leading contender. We present data about the use of TPOAb in early pregnancy and its value as a screening tool. Although its positive predictive value is moderate, its sensitivity and specificity when used in early pregnancy are comparable or better compared to other times during pregnancy and the postpartum period. Recent studies have also confirmed this strategy to be cost effective and to compare favourably with other screening strategies. We also explore the advantages of universal screening.