bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Technologies about Fuzzy Environment Adaptability Design of Large Scale Wind Turbine
Authors: Ma Tie Qiang , Sun De Bin , Yao Xing Jia , Wang Shi Rong
Published: January 2015

To obtain rational environment adaptability design solution of wind turbine, a fuzzy environment adaptability design method of wind turbine based on core design platform is promoted. Firstly, the core design platform is built based on main structure of wind turbine irrelevant with environment factors. Secondly, the 1:n mapping relationship between environment factor set and environment adaptability technology set is created. Thirdly, the fuzzy relationships between environment adaptability technologies and environment factors are researched, and the relationships include dependency and contradiction. Finally, the quality function deployment (QFD) technology is used to obtain rational environment adaptability design solutions of wind turbine in the known condition of complicated environment factors. The feasibility and availability of the method above mentioned are validated by an example.
Effect of Coating on the Thermal Conductivities of Diamond/Cu Composites Prepared by Spark Plasma Sintering (SPS)
Authors: Che Q.L. , Chen X.K. , Ji Y.Q. , Li Y.W. , Wang L.X. , Cao S.Z. , Jiang Y.G. , Wang Z.
Published: January 2015

The carbide forming is proposed to improve interfacial bonding between diamond particles and copper-matrix for diamond/copper composites. The volume fraction of diamond and minor titanium are optimized. The microstructures, thermal properties, interface reaction production and its effect of minor titanium on the properties of the composites are investigated. The results show that the bonding force and thermal conductivity of the diamond/Cu-Ti alloys composites is much weaker and lower than that of the coated-diamond/Cu. the thermal conductivity of coated-60 vol. % diamond/Cu composites is 618 W/m K which is 80 % of the theoretical prediction value. The high thermal conductivity has been achieved by forming the titanium carbide at diamond/copper interface to gain a good interface.
Transmission Ratio Optimization of Two-Speed Pure Electric Vehicle
Authors: Tang Zi Qiang , Ma Dang Ping , Gong Xian Wu
Published: January 2015

In order to improve the driving range of two-speed pure electric vehicle (EV), within the constraint of EV power performance, and the optimization objective is the minimum vehicle energy consumption under the NEDC (New European Driving Cycle) drive cycle, transmission ratios of an EV were optimized by using genetic algorithm (GA) under the economy shift schedule. The driving range and the power performance before and after transmission ratio optimization were analyzed. Simulation results show that the proposed optimization algorithm is effective, and the driving range improves by 1.73% and the acceleration time increases by 0.006s after optimization, but still meets the requirements of vehicle power performances.
Evaluation of Cylindricity Geometrical Error Based on Calculational Geometry
Authors: Wang Can , Xu Ben Sheng
Published: January 2015

Cylindricity is a key index of precision of mechanical parts. For the convenience of computer programming and improving the robust of algorithm, the method of evaluation of cylindricity geometrical error base on computational geometry is presented in this paper. The transformation of coordinates in evaluation of geometrical error is discussed. Adopting the self-adapting variation, the mathematic model and criteria for evaluating of minimum zone of cylindricity are demonstrated in detail. The procedure of algorithm is given. Finally, a case study is given to validate the proposed method.
Non-Contact Measurement of Yarn Tension in Spinning Process
Authors: Chen Xiao Lan , Mei Shun Qi , Chen Xiao Bo
Published: January 2015

In this paper, the limitations of the direct contact measurement of yarn tension in domestic and foreign are analyzed by use of yarn balloon theory and digital image processing technology. A new method is established for measuring the dynamic tension of yarn ------non-contact measurement. The mathematical model is established according to the theory that yarn tension is relent to yarn balloon through the research on the dynamics of yarn balloon. In human-computer interaction, image enhancement is realized by using the gray scale linear transformation curve, image segmentation is achieved by using Canny edge detection operator and the edge of the image is extracted by using mathematical morphology and borders tracking algorithm accurately from yarn balloon which is taken by CCD immediately, finally the pattern characteristic parameters of the yarn balloon are extracted and the yarn tension is measured.
The Calibration Method of Three-Axis Magnetometer Based on Genetic Algorithm
Authors: Pang Xue Liang , Jiang Pei , Lin Chun Sheng
Published: January 2015

Because of the bias, scaling factors and non-orthogonality, it is difficult for the three-axis magnetometer to be used directly to measure the magnetic field magnitude. It is imperative that the magnetometer is properly calibrated for sensor errors. In this paper, we present a method based on Genetic Algorithm that can be used to estimate calibration model parameters. The algorithm put the parameters of the calibration model as the evolutionary population; According to the fitness, the poor individual is eliminated step by step and the optimal individual is obtained after crossing and mutation; The optimal parameter estimation corresponding to optimal individuals is achieved. It is effective for Genetic Algorithm to estimate parameters of calibration model overcoming the correlation between the parameters. The simulation and experiment show that the method based on Genetic Algorithm can converge steadily and can achieve high estimation precision.
Simulation Research of E-Business Distribution Center Operation Based on Intelligent Robot
Authors: Li Jun Tao , Zhu Jie , Geng Ying Ying , Li Bing Jian
Published: January 2015

Based on the established occasions, and by means of eM-plant simulation software, this paper carries out operation pattern simulation research of e-business distribution center based on intelligent robot. It mainly researches the general layout design, store planning, setting up of simulation model and running results analysis of E-business distribution center, and compared with traditional electricity distribution center operation mode, in order to highlight the advantage and development prospect of the model.
A Research on the Strategy-Oriented Management Process System of Local Party and Government Leaders’ Environmental–Protection Performances
Authors: Huang Yong , Zhou Jing Kun
Published: January 2015

This paper points out that the strategy-oriented management process system of local Party and government leaders’ environmental–protection performances is composed of six parts, i.e., the design of local government strategies, de-composition of strategic targets, development of the plans for local Party and government leaders’ environmental–protection performances, environmental performances tutorship and implementation, performance evaluation and the application of the evaluation results; analyzes the dynamic circular relations between the four vital links of the strategy-oriented management process system of local Party and government leaders’ environmental–protection performances; compares the differences between the strategy-oriented performance management process sys-tem and the traditional performance management process system. The conclusion obtained in this paper is of certain directive significance to building the management process system of local Party and government leaders’ environmental performances.
Synthesis of Nano-Microsphere Titania with CTAB Assisted by Hydrothermal Method
Authors: Zhuang Yun Fei , Bian Ya Lan
Published: January 2015

Using titanium trichloride (TiCl3) as the precursor, sodium chloride (NaCl) as the mineralizer, cetyltrimethyl ammonium bromide (CTAB) as surfactant, titanium oxides (TiO2) nanomicrospheres were synthesized by hydrothermal method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize the crystal structure and morphology of the microspheres. The results indicate that the spheres were rutile with diameters of about 1μm ~5μm. The spheres were composed of radially aligned nanorods with diameters of about 40nm and lengths of 500nm. The influences of the concentration of surfactant and the concentration of mineralizer were also researched. The microsphere diameter and grain size both reduce with the increase of the concentration of CTAB. The microspheres get larger and more complete with the higher mineralizer concentration.
Ensure Laser Fluence of Laser Ablated Copper Nanowire
Authors: Hu De Zhi
Published: January 2015

This paper analyzes the micro-mechanism of interaction between femtosecond laser and one dimension material. It gets the figure of temperature change with time by calculating the Two Temperature Equation(TTE) in the process of the laser ablation. And it presents the surface characters of metal material. Additionally, the plasma is generated when the temperature of ion subsystem is far higher than the melting point of copper metal. The paper can give the laser ablation threshold by the numerical calculation. It will help the researchers ensuring the laser fluence for preparing the copper film better.
Effect of Processing Parameters on Surface Roughness in Ultrasonic Deep Rolling 6061-T6 Aluminum Alloy with Longitudinal-Torsional Vibration
Authors: Hou Ya Li , Liu Chuan Shao , Liu Si Qi
Published: January 2015

Orthogonal experiments of ultrasonic deep rolling with Longitudinal-torsional vibration (UDR-LTV) and conventional deep rolling (CDR) 6061-T6 aluminum alloy were carried out. The experimental results were analyzed by orthogonal-response surface methodology to study the effects of processing parameters on surface roughness. The results show that the values of surface roughness obtained by UDR-LTV are smaller than that of CDR with the same processing parameters. Meanwhile, feed-rate has a marked effect on surface roughness, and static pressure has a little effect on surface roughness. The quadratic regression method is used to construct the mathematic model of surface roughness based on the experimental results. The interactions between the processing parameters are analyzed using response surface method. The optimal parameters for the lowest surface roughness are given, which provide technical support for proper parameters in practical processing.
Study on the Design of Composite Transmission System for Crawler Type Full-Feeding Combine Harvester
Authors: Lou Xi Yin
Published: January 2015

Transmission system is an important part of combine harvester, and is the main indicator to measure the level of technology. This paper presents the design of a composite hydraulic mechanical transmission system for combine harvester. The system consists of engine, variable pump, quantitative hydraulic motor, planetary reducer, driving wheel, crawler etc. Author analyzes the continuous variable speed regulation characteristics of transmission; determines selection method of hydraulic components and mechanical parameters. Composite transmission system can make the engine is close to full load operation, improve combine harvester productivity and fuel economy. By optimizing the transmission system, combine harvester can reduce speed, increases the torque, realizes continuous variable speed. Practice has proved: this dynamic composite transmission system with fast response, high efficiency, and reliable, low failure rate. At the same time, combine harvester has the advantages of simple operation, forward, backward or turning without shifting, greatly reduce the labor intensity of the operator.
Synthesis of the Porous Mn2O3 Microsphere and Mn2O3@SiO2 Core-Shell Nanostructure by a Facile Method
Authors: Yang Hua Zhen , Liu Pan Xing , Tang Yue Feng
Published: January 2015

nanoporous structure is attractive since it exhibits excellent structural stability would enhance the volumetric energy density compared with the irregularly shaped nanoparticles. The porous Mn2O3 and Mn2O3@SiO2 microsphere spheres have been successfully prepared on a large scale were obtained via a general and sample supersonic atomization method combined with the modified Stöber method.
Synthesis and Characterization of Polymer-Laced Cu-ZnO Nanoparticles
Authors: Liu Xiao , Guan Zheng , Liu Hong Ling , Wu Jun Hua , Wang Xian Hong , Li Xue Mei , Chen Wen Zheng
Published: January 2015

The polymer-laced Cu-ZnO nanoparticles were successfully synthesized by one-pot non-aqueous nanoemulsion method with the use of PEO-PPO-PEO as the surfactant, C14H29CH(OH)CH2OH as the reducing agent, octyl ether as the solvent, Zn (acac)2 and Cu (acac)2 as precursors. The Morphology and structure of nanoparticles were analyzed by transmission electron microscopy (TEM) and X-ray diffraction (XRD). UV-visible absorption spectroscopy (UV-vis) and photoluminescence spectrometry (PL) were employed to valuate the optical properties of the nanoparticles. The Cu-ZnO nanoparticles with well defined optical properties are promising for optical, catalytic and biomedical applications.
Synthesis of Fluorescent Magnetic and Plasmonic-Hybrid Multifunctional Nanopaticles
Authors: Li Xue Mei , Guan Zheng , Liu Hong Ling , Wu Jun Hua , Wang Xian Hong , Liu Xiao , Chen Wen Zheng
Published: January 2015

FeAu/ZnO nanoparticles were successfully synthesized by nanoemulsion process with the use of poly (ethylene glycol)-block-poly (propylene glycol)-block-poly (ethylene glycol) as the surfactant. The characterization of the FeAu/ZnO nanoparticles was performed using X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and UV-visible absorption spectroscopy, showing that the polymer-laced nanoparticles reveal high crystallinity, excellent dispersibility and well defined optical performance. The process of solvent dispersion-collection of FeAu/ZnO nanoparticles indicates that the nanoparticles possess good magnetic property for applications.
Preparation and Tribological Properties of Graphite-Containing Plasma Electrolytic Oxidation Coatings on Al Alloy
Authors: Li Qing Biao , Wang Qing , Liang Jun
Published: January 2015

Graphite-containing plasma electrolytic oxidation (PEO) composite coatings were prepared on Al alloy using periodically constant voltage, with addition of graphite in silicate electrolyte. The surface and cross-sectional morphologies of the coatings were examined using scanning electron microscope (SEM), the composition of the coatings was investigated by X-ray diffraction (XRD) and Raman spectra, the tribological properties of the coatings were evaluated on a tribometer. The results show that friction-reducing PEO composite coatings on Al alloy can be prepared in graphite-dispersed electrolyte using periodically constant voltage, the yielded coatings exhibit relatively lower and more stable friction coefficient.
The Preparation and Phosphate Adsorption Experiments of New Modified Bamboo Powder
Authors: He Ting , Li Xin , Gong Yun
Published: January 2015

The bamboo processing residues, as raw material, was modified by quaternary ammonium to obtain a quaternary ammonium modified bamboo powder adsorbent. The phosphate’s adsorption capacity of the powder adsorbent was investigated. In addition, the effects of dosage, pH, time, temperature, initial concentration on phosphate’s adsorption capacity. Then, the research performed the adsorption isotherm model fitting. The results showed that the adsorption rate of modified bamboo powder to phosphate increased with increase of dosing amount of modified bamboo powder, tended to be equilibrium when the removal rate reached to 97%; while the phosphate with high initial concentration could improve the adsorption capacity of modified bamboo powder. In acidic condition, the modified bamboo powder presented unsatisfied adsorption effect on phosphate, when pH= 6 the adsorption effect become well, but adsorption effect did not vary apparently with the increase of pH. With the increase of temperature (25, 35, 45°C), the maximum saturated adsorption capacity of modified bamboo powder gradually reduced. The adsorption of modified bamboo powder on phosphate was a rapid process, which could reach equilibrium status within 50 minutes. The bamboo powder before and after the modification was conducted IR element analysis, the values before modification are N=0, C=45.54 and H=6.03; while after the modification, the values are N=2.65, C=40.33 and H=6.79, it is concluded that the nitrogen content of modified bamboo powder increase obviously and the quaternary ammonium can well be grafted.
PET Fiber Surface Modified with Amine Group
Authors: Dai Guo Liang , Shi Mei Wu , Xiao Hong
Published: January 2015

PET material has excellent performance and its modification of biocompatibility had been concerned for researchers. In this paper, graft polymerization of acrylamide on PET fiber by co-irradiation was investigated, and then treated in 5% available chlorine content of NaClO solution, which make the amide groups on the PET fiber surface into amine groups, and provide the reactive groups for further functional modification. The results showed that the moisture absorption of PET fiber increases after the grafting of acrylamide, and its hygroscopicity increases with the increase of grafting yields; after the amide groups converted into the amine groups, the hygroscopicity of PET fibers decreases. The chemical structure and surface morphology of PET fiber and modified products were characterized by ATR-FTIR and SEM, which certified that acrylamide had been successfully grafted on PET fibers and the amide groups on its surface had been converted into the amine groups.
Calibration of K&C Concrete Model for UHPC in LS-DYNA
Authors: Xu Man , Wille Kay
Published: January 2015

Karagozian & Case Concrete (KCC) model in LS-DYNA is a parameter automatically generated material model for simulation of concrete. By giving the unconfined compressive strength of the concrete material, all other constitutive material parameters will be generated by the model. It is a valuable concrete model for users who have no laboratory data or conduct tentative simulations. However, the automatically generated parameters will induce error when the concrete material behavior deviates from the regular behavior. In this research, a calibration method is introduced to show a simple way for generating input material parameters of ultra-high performance concrete (UHPC). Empirical equations for triaxial compressive tests are used here for the calibration. The calibrated model is firstly checked by the simulation of uniaxial compression test with one element and the results reveal that the calibrated model shows a better agreement with the test data than the parameter automatically generated KCC model.
Preparation of Carbon Fiber Reinforced Geopolymer Composites
Authors: Liu Le Ping , Zhu He , He Yan , Cui Xue Min
Published: January 2015

The carbon fiber reinforced geopolymer composites were synthesized with metakaolin, water glass and short carbon fibers. The surface treatment short carbon fibers are homogeneously distributed in the geopolymer matrix. The composites exhibit excellent mechanical properties and electrical conductivity. The flexural strength of the Cf /geopolymer composites reached 27 MPa with carbon fiber content of 2.78 %, and its electrical conductivity are increased from 10-5 to 10-1 S.m-1. However, when the carbon fiber content exceeded 4.15 %, the conductivity of the composites kept a constant.
Study on the Thermo Physical Properties of Deeply Undercooled Silver Melts
Authors: Li Li Xin , Zhao Jun Liang , Cao Guo Hua , Guan Xue Mao
Published: January 2015

Using the flux processing technique, the undercooling of pure silver melts could reach to 205K. Combining the Differential Scanning Calorimeter (DSC) technique, the specific heat of pure silver melts was measured, which showed a linear dependence on temperature in the range of the obtained undercooling from 0 K to 205K. The related thermodynamic properties of silver, such as the entropy change, the enthalpy change and the Gibbs free energy difference between the undercooled melt and the solid phase, were derived from the measured specific heat. The results showed that the model of Singh-Holz can reveal the reality of the non-equilibrium solidification more accurately than other models.
Synthesis of Lanthanum Oxide Using Hydrogen Peroxide as Auxiliary Reagent by Spray Pyrolysis Method
Authors: Wang Zhen Feng , Wu Wen Yuan , Bian Xue , Xue Shou Feng
Published: January 2015

With lanthanum chloride solution as raw material, and use the hydrogen peroxide of clean and pollution-freeobtained from oxidation reaction as auxiliary reagent, and with the carrier gas together form spray pyrolysis to obtain lanthanum oxide. On the one hand, in the hydrogen peroxide system, the temperature of direct pyrolysis reaction of lanthanum chloride solution decreased obviously, The reaction temperature is decreased from 1280°C to 1000°C or less. That reduce the energy consumption and simplify the requirements of pyrolysis equipment technology. The production process does not use NH3.H2O and NaOH to precipitate. It does not produce the traditional process of NH4+, Na+ to pollute water. It can greatly reduce the damage to the environment, and can product with high yield, high purity of the rare earth oxide. This method not only applies to the pyrolysis of the rare earth chloride solution, also applies to metal chloride solution, such as FeCl3, AlCl3, NiCl2. It was shown that the reaction temperature has been effectively reduced, VLaCl3: VH2O2 with 1: 1.5 can get high purity of La2O3.
Boric Acid Corrosion in the Primary System of PWRs
Authors: Li Tian , Peng Zhi Zhen , Fan Yan Cheng , Tang Xi Ming , Kong Chen Guang , Yin Qin
Published: January 2015

Borated water leakage could lead to boric acid corrosion of nuclear equipment, and it’s a danger to the pressurized water reactor nuclear power plants (PWRs). In this study, the principle of boric acid corrosion was studied first. Through the experiences of borated water leakages and boric acid corrosion at home and abroad, the main leakage sources in PWRs were summarized. Combining the technique features of visual inspection, the detecting principles were proposed. In the end, a protection strategy of boric acid corrosion was established including the control of borated water leakage, the detection of equipment, the treatment of leakages and the improvement of the equipment material.
Synthesis of 5-(4-nitrophenyl)-2-aminopyrazine
Authors: Zhu Wu Fu , Wu Chun Jiang , Xu Shan , Wang Min , Wang Wen Hui , Chen Le , Xia Hui , Zheng Peng Wu
Published: January 2015

5-(4-nitrophenyl)-2-aminopyrazine (13) was synthesized from 2-aminopyrazine (9) through two steps including monobrominated reaction, Suzuki-Miyaura coupling and the structures were confirmed by 1H NMR and MS spectrum. The synthetic method of 13 was optimized and can be used to synthesize 5-(4-nitrophenyl)-2-aminopyrazine derivatives.
Effect of Hydrazine Dihydrochloride on Cure Characteristics of NR
Authors: Wang Yong Zhou , Zhang Bei Long , Huang Mao Fang
Published: January 2015

The effect of constant viscosity natural rubber (CVNR) prepared with hydrazine dihydrochloride was studied, The results showed that the relation of dependence of tC10 and tC90 on temperature followed the rule below: CVNR > NR a;the sensitivity of tC10 increment to tC90 increment due to increasing of cure temperature followed the rule below: NR>CVNR; The relation of MH0 were as follows: NR>CVNR.
The Effect of Organic Matter and Organic Acid on the Chromium Release in Sediment
Authors: Liu Hui , Dai Jiu Lan
Published: January 2015

Effect of organic matter and organic acid on the heavy metals, especially, chromium (Cr) release in the sediment was researched. Glucose and soluble organic starch was used as organic matter, as well, citric acid and ethylene diamine tetraacetic acid (EDTA) were simulated as organic acid. The results showed that best adsorption time of glucose on Cr was 5h, the optimal dosage was 0.1g g-1; best adsorption time of organic soluble starch was 4h, and the optimum adding amount of 0.08g/g; best adsorption time of citric acid was 5h, the best concentration 0.005mol g-1; optimal adsorption time of organic acid EDTA was 3h, the optimum adding amount of 0.12g g-1. Glucose, soluble starch and citric acid significantly effected on the release of Cr in the sediment, however, influence of EDTA on the release of Cr was not so evident.
A New Sintered Hard Metal Composite
Authors: Santos Alessandra A.A. , Gomes U.U. , Furukava M.
Published: January 2015

Extensive work has been performed on WC-Co hard metals for mining tools, tool inserts and other components. Cobalt is widely used as the binder metal because it’s good wetting behavior and solubility. However, the cost is high. Fe-Cr-Ni alloys show similar characteristics to Cobalt regard to melting temperature and crystal structure. Additionally, Fe-Cr-Ni alloys are a less expensive and nontoxic alternative. The present work analyze sintering characteristics of the WC / Fe-Cr-Ni alloys composite and development of new sintered hard metal composite for mining tools. The composite WC-316L was processed via Powder Metallurgy and sintering was performed at different temperatures: 1200oC, 1300oC and 1400oC rate and 20oC and isotherm 1hour in vacuum atmosphere. The composite sintered WC-316L was characterized by XRD, SEM and Vickers micro hardness test. The samples processed at temperatures of 1200oC and 1300oC showed considerable porosity, heterogeneity microstructure, low density relative and low Micro hardness, 300 HV and 700 HV, respectively. The samples sintered at temperature 1400oC showed higher homogeneity microstructure compared to the samples sintered at temperatures of 12000C and 13000C, higher density relative, 86%, and micro hardness value compatible with the composite WC-Co, 1890 HV.These analyzes infer that stainless steel can be used instead of cobalt.
Synthesis and Characterization of Silver Nanoparticles
Authors: de Freitas Rosa Paula , Rodrigues Cirqueira Samirys Sara , Lopes Aguiar Mônica , Bernardo André
Published: January 2015

Nanoparticles have large surface area, which gives them more pronounced effects. Silver nanoparticles, for example, have pronounced biocidal effects, since they can inactivate certain enzymes and alter the DNA synthesis of some microorganisms. In this context, the study of the synthesis and characterization of nanoparticles becomes potentially important. The aim of this work was to synthesize nanoparticles and to characterize them in order to contribute to the development of synthesis and characterization of nanomaterials. Several methods are used for the synthesis of silver nanoparticles; however, in this study we used the Turchevich method which makes use of a reduction reaction using sodium citrate as the reducing agent, and silver nitrate as starting material. After being synthesized, nanoparticles were analyzed with the technique of transmission electron microscopy (TEM). Also, a curve of the size distribution of the particles formed was obtained. This distribution was obtained through a nanoparticle filtration equipment connected to a particle counter-SMPS (Scanning Mobility Particle Sizer).
Nanocrystalline Diamond Films Prepared with Different Diamond Seeding Processes of 4 Nm and 0.25 Μm Diamond Powders
Authors: Santos Marta , Campos R.A. , Azevedo A.F. , Baldan M.R. , Ferreira N.G.
Published: January 2015

The growth of diamond films in metastable condition occurs in two steps: nucleation and growth of crystals. Studies have shown that the nucleation process is the most critical step and essential to optimize the properties of the diamond, but its understanding is still very limited. Furthermore, the nucleation process is directly related to the pretreatment applied to the surface of the substrate: cleaning the surface and seeding. When the substrate is silicon, it is cleaned with acetone and scratching with diamond particles dispersed in a suitable solvent followed by ultrasonic agitation (nucleation rate = 109 part/cm2). However, research has demonstrated that the use of diamond nanoparticles (ND) prepared with the use of a powerful ultrasound (750W) provides nucleation density much higher (1012 part/cm2) compared to that processed with larger size particles. This work demonstrates that diamond films prepared with ND different solutions exhibit differences in relation to diamond films prepared using diamond particle dispersed in an organic solvent. Morphological analysis and the quality of the films were evaluated by Scanning Electron Microscopy, Optical Perfilometry and Raman Scattering Spectroscopy.
An Investigation of the Different Flow Regimes in a Rotating Drum through Experimental and Simulation
Authors: Santos D.A. , Petri Jr. Irineu , Duarte C.R. , Barrozo Marcos A.S.
Published: January 2015

This paper aims to investigate the particle dynamic behavior in a rotating drum operating in a rolling regime under different rotating velocity, based on experimental results and simulations. Simple superphosphate fertilizer (SSP) was used as particulate matter in the current study. The Eulerian–Eulerian multiphase model along with the kinetic theory of granular flow was used in the simulations. In order to evaluate the simulation results, velocity distributions of the particulate phase were compared with experimental data. The experimental particle velocity distribution was obtained by using a high speed video camera. The numerical simulation results showed significant insights towards understanding of the particle dynamic in a rotating drum. The simulated results of particle velocity were in good agreement with the experimental data.
CFD Applied to the Analysis of Hydrodynamics in a Hydrocyclone
Authors: Bicalho Isabele Cristina , Mognon José Lucas , Shimoyama Juliana , Ataíde Carlos Henrique , Duarte Claudio Roberto
Published: January 2015

Although the construction, maintenance and operation of hydrocyclones is simple in nature, it is known that the hydrodynamic behavior inside hydrocyclones is quite complex. Among the features which confer this complexity stands out: high vorticity preservation, vortex breakdown, flow inversion, and the possibility of formation of air core due to the generation of a low pressure area in the central axis of the separator. In this sense this work aimed to study the hydrodynamics of a hydrocyclone using as tool the Computational Fluid Dynamics (CFD). The simulated results were obtained considering two different models for turbulence: Reynolds stress model and Large Eddy simulation methodology. Can be highlighted as main simulated variables the flow ratio and the pressure drop of the hydrocyclone, which were compared with experimental values. In order to evaluate the influence of air core on the simulated variables, were done numerical simulations of the hydrocyclone operating in the presence of air core, using for this, the volume of fluid (VOF) model.
Obtaining Ceramic Filter from Rice Husk and Kaolinitic Clay
Authors: Souza R.P.A. , Motta F.V. , Carvalho R.G. , Acchar W. , Harima E. , Maribondo R. , Paskocimas C.A.
Published: January 2015

In this study, different compositions based on rice husk carbon and kaolinitic clay aimed at obtaining ceramic filter were studied. Three compositions of 40, 60 and 80% rice husk of the total mass were prepared. The specimens were uniaxially compressed in rectangular shape at pressure of 28 MPa and were sintered at temperatures of 1100oC, 1150oC and 1200oC for 1 h. The sintered samples were characterized according to standard technique for linear shrinkage, water absorption, apparent porosity and flexural strength. Scanning Electron Microscopy (SEM) was also performed to check the average pore size, and X-Ray Diffraction (XRD) to verify existing crystalline phases, chemical analysis and mercury porosimetry. The X-ray diffraction results showed mostly alpha quartz peaks and mullite after sintering. Mercury porosimetry showed porosity of 44.33% and average pore size of approximately 8.33 μm for sample with 60% rice husk sintered at 1200°C.
Physical Properties of Cuttings, Drilling Fluid and Organic Phase Recovered in the Drying Operation in Oil and Gas Well Drilling
Authors: Pereira Marina Seixas , de Andrade Martins Ronaldo , Martins André Leibsohn , de Souza Barrozo Marcos Antônio , Ataíde Carlos Henrique
Published: January 2015

Oil companies have increasingly invested in alternative technologies for cuttings treatment. The research for new operations or equipments leads to investigate the properties and characteristics of drilled cuttings and drilling fluids. This work presents the physical characterization of cuttings, drilling fluid and organic phase recoved after cuttings drying. It was carried out analysis of rheology for the drilling fluid and particle size and shape for the cuttings. Considering the microwave drying technology, which has been investigated for cuttings treatment, it was also determined the dielectric properties for the drilling fluid. The quality of the organic phase recovered in the microwave cuttings drying was also analysed.
Dry Aggregate Particle Size Distribution Optimization for Soderberg Anode Paste Production Applied to Aluminum Industry
Authors: Vry Beatriz Furquim , Pomarico Walter , Ferraço Fabio , Fernandes Rodrigo Sampaio , Maestrelli Sylma Carvalho
Published: January 2015

For a Soderberg Technology, paste production process consists of four basic steps: raw material handling; dry aggregate preparation; mixing; and briquettes loading at electrolytic cells for aluminum production. Dry aggregate is prepared from calcined petroleum coke, where the grains are crushed and separated between 3 different fractions of pre-determined sizing and a dust component. Petroleum pitch blended with the finest particles from dry aggregate forms the binder used for wetting, lubricating and filling open pores of larger coke grains, resulting into a higher anode paste quality with adequate mechanical properties, higher density, oxidation resistance and lower electrical resistivity. Raw materials recent trends showed significant quality degradation and cost raise, pushing up industry to look forward for untraditional suppliers, in addition to process optimization. This paper describes enablers chosen to improve paste properties, through dry aggregate particle size distribution using two of the most traditional particle packing models: Andreasen and Alfred. The formulations developed in this work were compared to the formulation originally used by an industry through measures flowability and apparent baked density. The results have shown that both the equations of Alfred and Andreasen, for distribution coefficient 0.30 and 0.52 respectively, can be applied to the Aluminum Industry, resulting into products significantly different from the point of view of quality.
Analysis of the Collection Efficiency of Fiber Filters on the Filtration of Nano-Sized Particles from Aerosol
Authors: Nunes Deivid Marques , Damasceno João Jorge Ribeiro , de Oliveira Arouca Fábio
Published: January 2015

Several studies on removal of nanosized particles are being developed with the aim of minimizing the adverse effects nanoaerosols can cause to the environment and human health due to poor air quality. Moreover, scientific and technological studies have developed in the application of nanosized particles. In academy and industry there are many mechanisms to remove nanoparticles from aerosols, such as fiber filters. Thus, this study aims to analyze the performance of fibrous filters, such as polyester filters (porosity is 0.82 and thickness is 2.2 mm and fiber mean diameter of 26 μm. A nanoparticle generator constitutes an atomizer that was used to generate nanoaerosols of monodisperses polystyrene latex) in a size distribution from 20 nm to 200 nm. The performance of the fibrous media was evaluated through the analysis of removal efficiency of nanoaerossols, using a particle counter TSI model 3007 before and after the filtering device. The experimental system consists of a compressor, which generates air current; high efficiency filters, in order to generate ultra-pure air; an atomizer and a container of polystyrene solution to generate aerosol; diffusion dryer to remove silica humidity from the gas stream; a filtration device; and, a counter to particles. The results obtained showed that the efficiency of a filter decreases with increasing filtration rate and diameter in the range in work. The diffusion mechanism is dominant in the separation process.
Behaviour of Fluids in Porous Materials
Authors: Martínez M.A. , Velasco Francisco , Abenojar Juana
Published: January 2015

The pore structure and the presence of open and close porosity has always made difficult the study of the interaction between fluids and porous materials, being complicated the analysis of liquids wettability and permeability, capillarity or speed of wetting, among others. This work tries to deal with these problems in a simple way, from a theoretical point of view, applying hydrostatic laws and the effect of capillarity to address the effect of open porosity. Moreover, surface roughness of these materials is the consequence of surface finishing (e.g. polishing) and porosity. This work also faces this aspect of wettability of surfaces, important to understand sealing conditions or lubricant retention in powder metallurgical components. From a practical point of view, the speed of fluids through metallic filters is compared to that through metallic meshes.
Production of Ti-10V-2Fe-3Al for Aerospace Application from Ti-Al Pre-Alloyed Powder
Authors: Araujo Eliane Silveira Romagnolli , Costa Jamilson Oliveira , de Lima Raphael Oliveira Pires , Rodrigues Henriques Vinicius André
Published: January 2015

Titanium is found in its raw form in nature mainly in rutile, ilmenite, and anatase which appears in abundant quantities in the earth crust. However, its extraction through the conventional process is still very expensive. Powder metallurgy has been used as an alternative technique for production of titanium alloys parts due to its low cost compared with conventional melting techniques. The process involves the use of powders under high pressure and temperature. Using this technique, Ti-10V-2Fe-3Al samples were produced from Ti-Al pre-alloyed powder with additions of different contents of aluminum in order to study the influence of aluminum particles on the formation of residual porosity. After cold uniaxial and isostatic pressing and sintering at 1100°C and 1400oC, samples were characterized by SEM (Scanning Electron Microscopy), XRD (X-ray Diffraction), EDS (Energy Dispersive Spectrometry) and density analyses. Sintered samples presented homogeneous microstructure and increased densification due to increased content of Ti-Al pre-alloyed powder.
Obtainment of a NiCrNbC Alloy by Mechanical Alloying
Authors: da Silva Alisson K. , Cintho Osvaldo Mitsuyuki , Capocchi José D.T.
Published: January 2015

The present work investigate the possibility of obtainment by mechanical alloying of Ni superalloys based on the Ni-Cr-Nb-C system strengthened by γ”(Ni3Nb), since γ”(Ni3Nb) as γ’ (Ni3Al) are typical coherent phase strengthening mechanisms in nickel superalloys. In order to evaluate this possibility, a composition with 71,65wt%Ni, 7,90wt%Cr, 20,00wt%Nb and 0,45wt%C was processed in a SPEX mill by 8 hours, consolidated and sintered at different temperatures (1200oC, 1250oC and 1300oC). The powder processed by MA and the sintered products were characterized by x-ray diffraction, SEM and EDS.
Plasma Sintering-Carburizing of 410 LHC Steel in Carbon Containing Atmosphere
Authors: Brunatto Silvio Francisco , Meier Alisson , Henke Sérgio , Binder Cristiano , Klein Aloísio Nelmo
Published: January 2015

First results of a possible alternative route for plasma assisted processing of 410 LHC steel powder compacts are shown in present work. Carburizing treatment was performed simultaneously with the sintering of samples. The main motivation of this study was verifying the possibility to eliminate the manufacturing step of the carburizing thermochemical treatment, which is normally applied in the production of sintered steel parts subjected for extreme wear conditions. Treatment was carried out in pulsed DC abnormal glow discharge, using gas mixture (atmosphere) of 99%(80% Ar + 20% H2) + 1.0% CH4, at 1100 °C, during 60 min, and 9 Torr, for two different conditions, termed: a) Sintering-Carburizing at high flow (for 480 sccm); and b) Sintering-Carburizing at low flow (for 120 sccm). Characterization of the treated samples was performed by Optical Microscopy, SEM, XRD, and microhardness measurements. The presence of CH4 in the plasma atmosphere proved to be viable to carburize the sample surface while the sintering stage was carried out. Despite of this, further studies are required to optimize both the carburizing + sintering effects, aiming to produce non-brittle structures and parts, opening a new R&D field to the plasma sintering of metallic materials.
Study of Cooling Rate Influence on SAF 2205 Duplex Stainless Steel Solution Annealed
Authors: Cronemberger Maria Eurenice Rocha , Mariano Neide A. , Coelho Mariny F.C. , Pereira Juliete N. , Ramos Érika C.T. , de Mendonça Renato , Nakamatsu Sandra , Maestrelli Sylma Carvalho
Published: January 2015

In this work was investigated the microstructural evolution process of the duplex stainless steel SAF 2205 as-cast after solution annealing treatment. The aim was to detect the effects on the material microstructure by the cooling rate variation. The studied material were submitted to solution anneal at 1100 °C for 240 min, followed by cooling in water, air and furnace. The results evaluation was based on micrographic analysis, energy dispersive spectrometry measurements (EDS), X-ray diffraction and hardness tests. The ferrite volume fraction obtained in the microstructure increased with the cooling rate, because it causes diffusion inhibition of the steel constituent elements, promoting retention of the ferrite. The volume fraction of austenite phase increased with a lower cooling rate. The cooling rate is an important factor in defining the steel microstructure, particularly about intermetallic phases precipitation, which occurred by the slow cooling rate. Additionally, it was observed the precipitation of sigma phase.
Sintering Studies and Microstructural Evolution of Fe-MoS2 Mixtures
Authors: Furlan Kaline Pagnan , de Assunção Julia Zimmermann , Paz Gustavo , Binder Cristiano , Klein Aloisio Nelmo
Published: January 2015

The development of dry self-lubricating materials is directly linked to the rising requirements of performance. Iron and steel are the most used metals around the world and molybdenum disulfide (MoS2) one of the most used solid lubricant. Therefore it is expected that one might try to develop self-lubricating steels containing MoS2, however MoS2 reacts with steel matrices during sintering. This work has focused on the study of these reactions; temperatures at which this occurs; the influence of particle sizes and MoS2 content and also MoS2 influence during processing and in the parts properties. The results showed that the reaction occurs at lower temperatures than the predicted and the products are iron-molybdenum and iron sulfides. The sintering studies revealed that MoS2 enhances sintering and the particle size and MoS2 content directly influenced the morphology and chemical composition of the resulting phases.
Microstructure and Electrochemical Characteristics of LaPrMgAlMnCoNi Hydrogen Storage Alloys for Nickel-Metal Hydride Batteries
Authors: Zarpelon Lia Maria Carlotti , Faria Jr Rubens Nunes
Published: January 2015

The effect of the substitution of La with Pr on the microstructure and some electrochemical properties of La0.7-xPrxMg0.3Al0.3Mn0.4Co0.5Ni3.8 (x=0.0, 0.1, 0.3, 0.5, and 0.7) ingot alloys as powder electrode was studied in this paper. XDR and SEM (+EDX) analyses revealed that the as-cast alloys consist mainly of similar LaNi5 and (La,Pr)Mg2Ni9 phases. With the increase in Pr content, both the relative abundance of the phases and microstructure changed. The electrochemical studies showed that the maximum discharge capacity decreased with the increase in Pr content. For the alloy without Pr, the self-discharge studies revealed a major stability of the hydride until the first 984 hours (41 days) of the charge/discharge cycles. The high-rate dischargeability of this alloy electrode showed the best result HRD=88% at a discharge current density of Id=250 mA/g.
Effect of Heat Treatment on Microstructure and Mechanical Properties of Ti-13Nb-13Zr Alloy Produced by Powder Metallurgy
Authors: Duvaizem José Hélio , Mendes N.M.F. , Casini J.C.S. , Bressiani A.H. , Takiishi H.
Published: January 2015

Ti-13Nb-13Zr alloy produced via powder metallurgy was submitted to heat treatment under various conditions and the effects on microstructure and elastic modulus were investigated. Heat treatment was performed using temperatures above and below α/β transus combined with different cooling rates – furnace cooling and water quenching. Microstructure and phases were analyzed employing scanning electron microscopy and X-ray diffraction. Elastic Modulus was determined using a dynamic mechanical analyzer (DMA). The results indicated that α phase precipitation and elastic modulus values increased after heat treatment performed using temperature below α/β transus. However, when it was performed above α/β transus and using higher cooling rate, a decrease in elastic modulus was observed despite higher α phase precipitation, indicating that the microstructural modifications observed via SEM, due to the presence of martensitic α phase, influenced on elastic modulus values.
Syntesis of Niobium Nitride Using Cryogenic Milling
Authors: de Moraes Tamura Helena , Vurobi Selauco , Maeda Milene Yumi , Capocchi José Deodoro Trani , Cintho Osvaldo Mitsuyuki
Published: January 2015

In the present paper a preliminary study was performed on the influence of mechanical milling on the synthesis of niobium nitrade. The niobium metal powder sample, passing # 635 mesh sieve, was processed by mechanical milling in SPEX mill for 8 hours using a ball-to-powder ratio of 7:1 and a nitrogen atmosphere. The powder was annealed at different temperatures, 900 °C, 1000 °C, 1100 °C and 1200 °C for 1 hour in a hydrogen and argon atmosphere to study their crystallization, which then were formed into blanks for analysis of the compressibility curves. These samples were also subjected to X-ray diffraction and the data were compared between the annealing temperatures. The compressibility curves of niobium samples with and without grinding were also evaluated, showing high compacting capacity. These samples were subjected to X-ray diffraction and X-ray fluorescence. As the formation of nitrides (Nb2N) was observed in SPEX type mill, the interest in studying the synthesis of nitrides came up, using mechanical milling in Attritor type mill. Same previous results of Attritor processing indicate a Nb2N and NbN synthesis after annealing treatments.
Spark Plasma Sintering and Hot Compression Analysis of Pure Mg and AZ91 Alloy
Authors: de Oliveira Botelho Pedro Augusto , Straffelini Giovanni , Menapace Cinzia
Published: January 2015

In this paper, we study the behavior of Pure Mg and AZ91 Mg alloy processed by Spark Plasma Sintering (SPS) under hot compression. On Pure Mg, SPS it was performed at 400OC. For AZ91 the powder was first homogenized for 50 minutes at 420OC and sintered at 470OC. The produced samples were able to produce a solid cylinder capable of being further processed with extrusion process and called preform. The same samples were submitted to a hot compression test at 330 and 380OC where they supported without breaking a strain of 0.5. We report a difference on the behavior of both materials after the yield point. For pure Mg, the work hardening was bigger than the so-called dynamic softening, and then the curve starts to rise after the yield point. On the AZ91 the effect is the opposite.