Semi-Solid Preparation and Performance of Magnesium Based Thermoelectric Materials

2012 ◽  
Vol 192-193 ◽  
pp. 569-574
Author(s):  
Ren Bo Song ◽  
Yong Lin Kang ◽  
Jian Lin Sun
Keyword(s):  
Electrical Conductivity ◽  
Thermoelectric Materials ◽  
Raw Materials ◽  
Sem Analysis ◽  
Plasma Sintering ◽  
And Performance ◽  
Semi Solid ◽  
The One ◽  
Increasing Temperature ◽  
Better Than

Ternary Mg-based thermoelectric materials are prepared by Semi-Solid Processing (SSP) and Spark Plasma Sintering (SPS). DTA, XRD and SEM analysis are applied to explore the processing conditions of Mg2Si1-xSnx (x=0, 0.2, 0.4, 0.6, 0.8, 1). The results show that raw-materials should be put into the furnace at 773 K, and kept 60 min in 1123 K. Then stirring 5 min under semi-solid state and air cooled finally. At temperature of 1023 K, pressure of 30 MPa, the sample is sintered by SPS. The XRD shows that the peaks of sample are sharp and complete, and move left with increasing Sn. The thermoelectric properties of Mg2Si1-xSnx (x=0.4, 0.6) are analyzed between 373 K to 673 K. Results indicate that electrical conductivity (σ) increases continually, Seebeck coefficient (α) increases then decreases, and thermal conduction (κ) decreases and increases with increasing temperature. Except that, electrical conductivity and Seebeck of Mg2Si0.6Sn0.4 are better than Mg2Si0.4Sn0.6 made by the same method. The properties of Mg2Si0.4Sn0.6 sintered at 1023 K, is better than the one at 973 K. The maximum zT of Mg2Si0.4Sn0.6 is 0.086 at 573 K.

Study on the Preparation and Performance of Carboxymethyl Chitosan Calcium and Carboxymethyl Chitosan Zinc Composite Materials

2016 ◽  
Vol 852 ◽  
pp. 1319-1324 ◽  
Author(s):  
Jing Li ◽  
Chang Ping Wei ◽  
Feng Ming Wang ◽  
Li Dan Dong ◽  
Shuang Sun ◽  
...  
Keyword(s):  
Chloride Solution ◽  
Water Solubility ◽  
Chloroacetic Acid ◽  
Sem Analysis ◽  
Carboxymethyl Chitosan ◽  
X Ray Diffraction ◽  
Test Study ◽  
Alkaline Conditions ◽  
And Performance ◽  
Better Than

In this paper,under alkaline conditions,with chloroacetic acid to modify chitosan,obtained carboxymethyl chitosan. At pH<7 conditions,the obtained carboxymethy chitosan respectively were reacted with calcium chloride solution,zinc chloride solution,after fully reacted,obtained carboxymethyl chitosan calcium and carboxymethyl chitosan zinc .Through infrared spectrum,X-ray diffraction and scanning electron microscopy (sem) analysis means,the structure of the products were characterized.Through the cutting of mice tail hemostasia test ,study the performance of the product.The results showed that the water solubility of carboxymethyl chitosan is better than that of chitosan and with excellent performance,and the performance of carboxymethyl chitosan calcium and carboxymethyl chitosan zinc was better than that of carboxymethyl chitosan.

Thermoelectric Performance of Glass Microsphere Dispersed Bi-Sb Composites at Low Temperature

2013 ◽  
Vol 743-744 ◽  
pp. 120-125
Author(s):  
Zhen Chen ◽  
Ye Mao Han ◽  
Min Zhou ◽  
Rong Jin Huang ◽  
Yuan Zhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Thermoelectric Materials ◽  
Sem Analysis ◽  
Glass Microsphere ◽  
Thermoelectric Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Measurement Results

In the present study, the glass microsphere dispersed Bi-Sb thermoelectric materials have been fabricated through mechanical alloying followed by pressureless sintering. The phase composition and the microstructure were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. Electrical conductivity, Seebeck coefficient and thermal conductivity were measured in the temperature range of 77~300 K. The ZT values were calculated according to the measurement results. The results showed that the electrical conductivity, Seebeck coefficient and thermal conductivity decreased by adding glass microsphere into Bi-Sb thermoelectric materials. However, the optimum ZT value of 0.24 was obtained at 260 K, which was increased 10% than that of the Bi-Sb matrix. So it is confirmed that the thermoelectric performance of Bi-Sb-based materials can be improved by adding moderate glass microspheres.

Numerical Simulation of Temperature Field and Thermal Shock Resistance Property of Permeable Brick

2008 ◽  
Vol 368-372 ◽  
pp. 1152-1154
Author(s):  
Hua Zhi Gu ◽  
Hou Zhi Wang ◽  
Mei Jie Zhang ◽  
Ao Huang ◽  
Wen Jie Zhang
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Gas Flow ◽  
Raw Materials ◽  
Large Change ◽  
Water Cooling ◽  
Working Face ◽  
Shock Resistance ◽  
The One ◽  
Better Than

The temperature distribution of the permeable brick was modeled using CFX software. The influence of magnesia and corundum on thermal shock resistance of non-cement bonded alumina-based permeable brick was investigated. The results indicated that, in the gas blow process, the high temperature regions near the working face of the brick gradually expanded with the increase of the gas flow rate. Therefore the inner part of the brick had the complex and large change of thermal stress. Further experiments demonstrated that thermal shock resistance of alumina-magnesia based castable refractory was better than that of alumina-chrome based castable refractory. With the increase of magnesia amount, the alumina-magnesia based castable refractory had more cycles of heating and water-cooling. When different kinds of corundum were added in the raw materials, the sample with tabular corundum showed the best thermal shock resistance, the one with white fused corundum performed worse and the one with fused dense corundum performed worst.

High Temperature Thermoelectric Properties of Oxide Ca2Co2O5

2009 ◽  
Vol 79-82 ◽  
pp. 2143-2146 ◽  
Author(s):  
Guo Jing Li ◽  
Shu Jin Zhao ◽  
Ao Mei ◽  
Jin Le Lan ◽  
Yuan Hua Lin
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Seebeck Coefficient ◽  
Thermoelectric Properties ◽  
The Body ◽  
Ceramic Powders ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Maximum Power Factor ◽  
Better Than

Ca2Co2O5 ceramic powders were synthesized by the coprecipitation method and consolidated by spark plasma sintering (SPS) technique.The observation by the SEM indicated that the ceramics body showed fine and layer microstructure.The density of the body increased with an increase of the fritting temperature.XRD patterns showed that the ceramics sample exhibits inpure phase with increasing the sintering temperayure to 850°C and that the grain was preferentially oriented.The electrical conductivity was reduce and the Seebeck coefficient slightly increased with an increase of the sintering temperature.As a result,the thermoelectric properties of the sample prepared by SPS at 800 °C for 5 min was better than the sample prepared by SPS at 750 °C for 5 min at high temperature.The sample treated by the SPS process under the condition of 800 °C,40 MPa and 5 min showed the maximum power factor (PF) of 3.85×10-4W∙m-1∙K-2 at 923 K.

scholarly journals Evolution of Folate Content During Wort Production

2020 ◽  
Vol 49 (4) ◽  
pp. 433-440
Author(s):  
D. Koren ◽  
B. Hegyesné Vecseri ◽  
G. Kun-Farkas
Keyword(s):  
Raw Materials ◽  
Pilot Scale ◽  
Limited Information ◽  
Scientific Publications ◽  
Barley Malt ◽  
Extract Content ◽  
Negative Effect ◽  
Brewing Process ◽  
The One ◽  
Increasing Temperature

There are numerous scientific publications about the folate content of several types of beers available in commercial trade, but there is limited information about the effect of raw materials and technological steps of brewing on folate content. In this study the aim was to investigate different raw materials and the evolution of folate content during laboratory and pilot scale brewing. For the determination of folate content of different malts, three types of barley malts (Pilsner, Caramel, and Coloring), wheat malt, rye malt, and oat malt were analysed. For the study of the evolution of folate content during the brewing process, worts were produced on laboratory and pilot scale. Among malts, Pilsner type barley malt had the highest folate content (44.7 μg/100 g d.m.). During brewing the protein rest seemed to dissolve the majority of the folate content, and with the increasing temperature of the β- and α-amylase rests there was a further dissolution. Filtration and sparging did not have negative effect on folate concentration related to the extract content of the wort. Hop boiling had no negative effect on folate content, folate seemed to be stable during the one-hour boiling. Natural folate of barley malt seemed to be stable through the technological steps of brewing, offering the possibility to produce a foodstuff with high natural folate content.

Fabrication and evaluation of CA-doped SrTiO3 thermoelectric materials by molten salt method

2021 ◽  
pp. 2140040
Author(s):  
Kei-Ichiro Murai ◽  
Takuya Nishiura ◽  
Ryutaro Nagata ◽  
Toshihiro Moriga
Keyword(s):  
Electrical Conductivity ◽  
Relative Density ◽  
Molten Salt ◽  
Electric Conductivity ◽  
Thermoelectric Materials ◽  
Simple Synthesis ◽  
Molten Salt Method ◽  
Mixed Salt ◽  
Mild Conditions ◽  
Increasing Temperature

In this study, we focused on the molten salt method and attempted a simple synthesis of SrTi[Formula: see text]Co[Formula: see text]O3. It was clarified that SrTi[Formula: see text]Co[Formula: see text]O3 can be obtained under relatively mild conditions by using the molten salt. In all samples, the electrical conductivity increased with increasing temperature. Compared with the sample without the molten salt, the electric conductivity of the samples with the molten salt was greatly improved. The sample using the KCl-NaCl mixed salt showed the highest electrical conductivity of 83 S/cm at 973 K. The relative densities of all the samples using the molten salt were above 85%. It is considered that the improvement in the electrical conductivity is partly due to the increase in the relative density.

Microstructure and Electrical Properties of CeO2-Doped WO3 Ceramics Prepared by Nanopowders

2007 ◽  
Vol 280-283 ◽  
pp. 381-384
Author(s):  
Xin Sheng Yang ◽  
Yu Wang ◽  
Liang Dong
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
High Dielectric Constant ◽  
Raw Materials ◽  
Nonlinear Coefficient ◽  
Metallic Behavior ◽  
High Dielectric ◽  
Increasing Temperature ◽  
Semiconducting Behavior

CeO2-doped WO3 ceramics were fabricated by using nanometer WO3 and CeO2 powders as raw materials. The microstructure and electrical properties were studied. The ceramics have relatively low breakdown voltage and high dielectric constant. The nonlinear coefficient does not decrease with the increase of the ambient temperature. The electrical conductivity decreases with increasing temperature, indicating that the ceramics have metallic behavior instead of semiconducting behavior.

scholarly journals Investigation of Electromagnetic Pulse Compaction on Conducting Graphene/PEKK Composite Powder

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 636
Author(s):  
Quanbin Wang ◽  
Deli Jia ◽  
Xiaohan Pei ◽  
Xuelian Wu ◽  
Fan Xu ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electromagnetic Pulse ◽  
Composite Powder ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Discharge Voltage ◽  
Discharge Capacitance ◽  
Graphene Composite ◽  
Plasma Sintering ◽  
Spark Plasma

Polymer-composite materials have the characteristics of light weight, high load, corrosion resistance, heat resistance, and high oil resistance. In particular, graphene composite has better electrical conductivity and mechanical performance. However, the raw materials of graphene composite are processed into semi-finished products, directly affecting their performance and service life. The electromagnetic pulse compaction was initially studied to get the product Graphene/PEKK composite powder. Simultaneously, spark plasma sintering was used to get the bars to determine the electrical conductivity of Graphene/PEKK composite. On the basis of this result, conducting Graphene/PEKK composite powder can be processed by electromagnetic pulse compaction. Finite element numerical analysis was used to obtain process parameters during the electromagnetic pulse compaction. The results show that discharge voltage and discharge capacitance influence on the magnetic force, which is a main moulding factor affecting stress, strain and density distribution on the specimen during electromagnetic pulse compaction in a few microseconds.

The Research of EVA to PLA/E-AA-GMA Blend Materials Toughening

2012 ◽  
Vol 535-537 ◽  
pp. 1210-1213
Author(s):  
Wei Yuan ◽  
Jian Ping Liu ◽  
Xia Song ◽  
Hong Mei Yan
Keyword(s):  
Maleic Anhydride ◽  
Impact Strength ◽  
Polylactic Acid ◽  
Sem Analysis ◽  
Elongation Rate ◽  
Breaking Elongation ◽  
The One ◽  
Toughening Modification ◽  
Better Than

The toughening modification of PLA(polylactic acid) and PLA/ethylene-maleic anhydride-methylacrylic acid glycerid shrink commonly terpolymer (E-AA-GMA) with different proportions of EVA was studied in the paper.We tested the breaking elongation rate and impact strength of the modified materials. The results showed that EVA had toughening role for PLA , and the toughening present a trend of improving slowly along with EVA increased. The EVA's toughening effect was more apparent when PLA with the compatibilizer (E-AA-GMA).The results of SEM analysis showed that the compatibility of blend material with the compatibilizer was better than the one without.

scholarly journals The Effect of Crystal Mismatch on the Thermoelectric Performance Enhancement of Nano Cu2Se

2021 ◽  
Vol 7 ◽  
Author(s):  
Yunus Demirci ◽  
Aminu Yusuf ◽  
Bejan Hamawandi ◽  
Muhammet S. Toprak ◽  
Sedat Ballikaya
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Seebeck Coefficient ◽  
Transport Properties ◽  
Performance Enhancement ◽  
Sem Analysis ◽  
Total Thermal Conductivity ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Two Phases

In the past decades, Cu2−xSe compounds have attracted great attention due to the inclusion of non-toxic and abundant elements, besides having a promising thermoelectric (TE) performance. In this work, we investigated the effect of a crystal mismatch of a nanoinclusion phase on the TE properties of Cu2−xSe. Nano-Cu2Se was synthesized using microwave assisted thermolysis, while the p-type skutterudite, Fe3.25Co0.75Sb12 (FeCoSb), compound was synthesized using a chemical alloying route. Nano-Cu2Se, and (nano-Cu2Se)1−x(nano-FeCoSb)x composites, where x = 0.05 and 0.1, were prepared via mechanical alloying followed by Spark Plasma Sintering process. Structural properties were evaluated by PXRD and SEM analysis, while the high temperature transport properties were examined via electrical conductivity, Seebeck coefficient, and thermal conductivity measurements in the temperature range of 300–800 K. Powder X-ray diffraction (PXRD) confirmed a single phase of nano Cu2Se, while the samples with FeCoSb inclusion consist of two phases as Cu2Se and CoSb3. SEM micrographs of all samples show that Cu2Se has randomly oriented grains with different sizes. Cu2Se samples with a FeCoSb inclusion show a rather different structure. In these samples, a rod-shaped FeCoSb phase, with a size varying between 20 and 100 nm, showed an inhomogeneous distribution in the structure and stacked between the Cu2Se layers. Transport data indicate that crystal mismatch between Cu2Se and FeCoSb has a strong effect on the TE transport properties. Electrical conductivity decreases but Seebeck coefficient enhances with nano FeCoSb inclusion. Total thermal conductivity was suppressed by 30% and ZT value enhanced by 15% with 5% nano FeCoSb inclusion at 750 K, likely due to a decrease in the electronic contribution of the thermal conductivity. Structural and transport data show that small amount of nanoinclusion of FeCoSb has a beneficial effect on the TE performance of nano Cu2Se at temperatures below 800 K.

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