scholarly journals Electrical properties and microstructure fractal analysis of magnesium-modified aluminium-silicate ceramics

2011 ◽  
Vol 43 (2) ◽  
pp. 193-204 ◽  
Author(s):  
J. Purenovic ◽  
V.V. Mitic ◽  
Lj. Kocic ◽  
V.B. Pavlovic ◽  
V. Paunovic ◽  
...  
Keyword(s):  
Fractal Analysis ◽  
Sintering Temperature ◽  
Electrical Characterization ◽  
Porous Ceramics ◽  
Before And After ◽  
High Degree ◽  
Highly Porous ◽  
Aluminium Silicate

The addition of Mg2(NO)3 and some active additives, composed of Al salts, to the mixtures of kaolinite and bentonite can provide clay compositions which, after sintering at high temperatures, produce very porous ceramics with microcrystalline and amorphous regions and highly developed metalized surfaces (mainly with magnesium surplus). Characterization of sintered samples was done before and after treatment in ?synthetic water?, i.e. in aqueous solution of arsenic-salt. Microstructure investigations have revealed non-uniform and highly porous structure with broad distribution of grain size, specifically shaped grains and high degree of agglomeration. Electrical characterization was estimated by determining dielectric constant and electrical resistivity in function of active additives amount and sintering temperature. Fractal analysis has included determination of grain contour fractal dimension.

scholarly journals Microstructure characterization of porous microalloyed aluminium-silicate ceramics

2011 ◽  
Vol 47 (2) ◽  
pp. 157-169 ◽  
Author(s):  
Jelena Purenovic ◽  
V.V. Mitic ◽  
V. Paunovic ◽  
M. Purenovic
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Energy Dispersive Spectrometer ◽  
Bentonite Clay ◽  
Porous Ceramics ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
High Degree ◽  
Aluminium Silicate

Kaolinite and bentonite clay powders mixed with active additives, based on Mg(NO3)2 and Al(NO3)2, sintered at high temperatures produce very porous ceramics with microcrystalline and amorphous regions and highly developed metalized surfaces (mainly with magnesium surplus). Microstructure investigations have revealed non-uniform and highly porous structure with broad distribution of grain size, specifically shaped grains and high degree of agglomeration. The ceramics samples were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction analysis (XRD) and IR spectroscopy analysis, prior and after treatment in ?synthetic water?, i.e. in aqueous solution of arsenic-salt. Grain size distribution for untreated and treated samples was done with software SemAfore 4. It has shown great variety in size distribution of grains from clay powders to sintered samples.

Characterization of Nigerian Clay as Porous Ceramic Material

2013 ◽  
Vol 845 ◽  
pp. 256-260 ◽  
Author(s):  
M. Abubakar ◽  
A.B. Aliyu ◽  
Norhayati Ahmad
Keyword(s):  
Thermal Properties ◽  
Bulk Density ◽  
Sintering Temperature ◽  
Starch Content ◽  
Porous Ceramic ◽  
Porous Ceramics ◽  
Cassava Starch ◽  
Compaction Method ◽  
Percentage Porosity

Porous ceramics were produced by compaction method of Nigerian clay and cassava starch. The samples were prepared by adding an amount from 5 to 30%wt of cassava starch into the clay and sintered at temperature of 900-1300°C. The influence of cassava starch content on the bulk density and apparent porosity was studied. The result of XRD and DTA/TGA shows that the optimum sintering temperature was found to be 1300°C. The percentage porosity increased from 12.87 to 43.95% while bulk density decreased from 2.16 to 1.46g/cm3 with the increase of cassava starch from 5 to 30%wt. The effect of sintering temperature and cassava starch content improved the microstructure in terms of porosity and the thermal properties of porous clay for various applications which requires a specific porosity.

Morphological and electrical characterization of conductive polylactic acid based nanocomposite before and after FDM 3D printing

2018 ◽  
Vol 136 (6) ◽  
pp. 47040 ◽  
Author(s):  
Razieh Hashemi Sanatgar ◽  
Aurélie Cayla ◽  
Christine Campagne ◽  
Vincent Nierstrasz
Keyword(s):  
3D Printing ◽  
Polylactic Acid ◽  
Electrical Characterization ◽  
Before And After

Preparation of Porous ZrO2-Al2O3 Composite Ceramic with High Strength and Good Corrosion-Resistance

2011 ◽  
Vol 197-198 ◽  
pp. 1545-1548 ◽  
Author(s):  
Qi Bing Chang ◽  
Xing Qin Liu ◽  
Xia Wang ◽  
Yong Qing Wang ◽  
Jian Er Zhou
Keyword(s):  
Corrosion Resistance ◽  
Bending Strength ◽  
Sintering Temperature ◽  
High Strength ◽  
Composite Ceramic ◽  
Ceramic Membranes ◽  
Porous Ceramics ◽  
Sintering Aid ◽  
Filtration Membrane ◽  
Before And After

In order to develop porous ceramics with high strength and corrosion resistance as the support for the preparation of asymmetric ceramic membranes, porous ZrO2-Al2O3 composite is designed and fabricated by adding Zr(OH)4.as sintering aid. The content of Zr(OH)4, the sintering temperature and the bending strength before and after corrosion of the composite are discussed. The results shows that 10wt% ZrO2-10wt% Zr(OH)4 -80wt%Al2O3 composite bar fabricated by cold press with the porosity of 32% can be fabricated in 1550°C for 4 h. The bending strength of the composite is 111.2MPa. After corrosion, the quality lose and the bending strength lose is no more than 1%. The tubular composite is suit for the preparation of micro-filtration membrane.

Study of a-Si:H / c-Si Heterojunctions for PV Applications

1996 ◽  
Vol 420 ◽  
Author(s):  
F. Zignani ◽  
R. Galloni ◽  
R. Rizzoli ◽  
M. Ruth ◽  
C. Summonte ◽  
...  
Keyword(s):  
Gas Phase ◽  
Open Circuit Voltage ◽  
Accurate Determination ◽  
Electrical Characterization ◽  
Silicon Layer ◽  
Open Circuit ◽  
Hydrogen Dilution ◽  
Intrinsic Efficiency

Abstracta-Si:H / c-Si heterojunction diodes were produced by PECVD with varying amorphous silicon layer thickness and hydrogen dilution of the gas phase. An accurate determination of the growth rate also in the initial stages of the deposition was made possible by an original chemical method based on the dissolution of the films followed by spectroscopical analysis of the obtained solution.The electrical characterization of the diodes confirms the generation - recombination - multitunneling nature of the transport. Although H2 dilution is important, however, beyond a certain level it is detrimental for the junction quality, probably due to the transition to a microcrystalline phase deposition. Solar cells were also produced, the best results being an open circuit voltage of 610 mV and an intrinsic efficiency of 14.2%.

scholarly journals Intergranular area microalloyed aluminium-silicate ceramics fractal analysis

2013 ◽  
Vol 45 (1) ◽  
pp. 117-126 ◽  
Author(s):  
J. Purenovic ◽  
V.V. Mitic ◽  
Lj. Kocic ◽  
V. Pavlovic ◽  
M. Randjelovic ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Electrical Properties ◽  
Fractal Analysis ◽  
Fractal Nature ◽  
Place Making ◽  
Richardson Method ◽  
Micro Morphology ◽  
Solid System ◽  
Aluminium Silicate

Porous aluminium-silicate ceramics, modified by alloying with magnesium and microalloying with alluminium belongs to a group of advanced multifunctional ceramics materials. This multiphase solid-solid system has predominantly amorphous microstructure and micro morphology. Intergranular and interphase areas are very complex, because they represent areas, where numbered processes and interactions take place, making new boundaries and regions with fractal nature. Fractal analysis of intergranular microstructure has included determination of ceramic grain fractal dimension by using Richardson method. Considering the fractal nature of intergranular contacts, it is possible to establish correlation between material electrical properties and fractal analysis, as a tool for future correlation with microstructure characterization.

scholarly journals Pembuatan dan Karakterisasi Bioplastik Berbahan Dasar Biomassa dengan Plasticizer Gliserol

Jurnal MIPA ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 23
Author(s):  
Engellita Maneking ◽  
Hanny Frans Sangian ◽  
Seni Herlina Juita Tongkukut
Keyword(s):  
Acetic Acid ◽  
Xrd Analysis ◽  
Cassava Starch ◽  
Glycerol Water ◽  
The Second Variation ◽  
High Degree ◽  
Tga And Dsc ◽  
Degree Of Degradation

Penelitian ini bertujuan untuk membuat dan mengkarakterisasi bioplastik yang memanfaatkan biomassa singkong. Pembuatan bioplastik dilakukan dengan dua variasi campuran yaitu pati singkong sebagai bahan dasar, gliserol + air sebagai plasticizer, asam asetat (cuka) sebagai katalis dan variasi kedua dengan kombinasi yang sama dengan penambahan alkohol sebagai pembanding. Karakterisasi bioplastik meliputi pengamatan permukaan menggunakan SEM; kristalinitas menggunakan XRD; penentuan gugus fungsi menggunakan FTIR; serta menganalisis sifat termal menggunakan TGA dan DSC. Hasil karakterisasi menunjukkan bahwa bioplastik dengan kombinasi pati singkong+ gliserol + air + asam asetat (cuka) + alkohol mempunyai tingkat degradasi yang tinggi. Hal ini sesuai dengan analisis XRD dimana kombinasi ini memiliki nilai kristalinitas rendah. Hasil spektra IR menunjukkan adanya gugus C-H Alkana, C=O ester, dan C-H Alkena. Sementara hasil SEM memperlihatkan permukaan yang rata dan hasil analisis TGA/DSC yang memperlihatkan pengurangan massa sebesar 2,3234 mgThis study aims to create and characterize bioplastics that utilize cassava biomass. The making of bioplastics is carried out for two variations of mixture, namely cassava starch as the material-based, glycerol + water as plasticizer, acetic acid (vinegar) as a catalyst and the second variation with the same combination with the addition of alcohol as a comparison. Characterization of bioplastics includes surface observations using SEM; crystallinity using XRD; determination of functional groups using FTIR; and analyzing of thermal properties using TGA and DSC. The characterization results show that bioplastics with a combination of cassava starch + glycerol + water + acetic acid (vinegar) + alcohol have a high degree of degradation. This is in accordance with the XRD analysis where this combination has a low crystallinity value. IR spectra showed that the presence of C-H Alkana groups, C = O esters, and C-H alkenes. While the SEM results showed a flat surface and the results of the TGA / DSC analysis which showed a mass reduction of 2.3234 mg.This study aims to create and characterize bioplastics that utilize cassava biomass. The making of bioplastics is carried out for two variations of mixture, namely cassava starch as the material-based, glycerol + water as plasticizer, acetic acid (vinegar) as a catalyst and the second variation with the same combination with the addition of alcohol as a comparison. Characterization of bioplastics includes surface observations using SEM; crystallinity using XRD; determination of functional groups using FTIR; and analyzing of thermal properties using TGA and DSC. The characterization results show that bioplastics with a combination of cassava starch + glycerol + water + acetic acid (vinegar) + alcohol have a high degree of degradation. This is in accordance with the XRD analysis where this combination has a low crystallinity value. IR spectra showed that the presence of C-H Alkana groups, C = O esters, and C-H alkenes. While the SEM results showed a flat surface and the results of the TGA / DSC analysis which showed a mass reduction of 2.3234 mg.

scholarly journals Characterization of Irradiated Boron, Carbon-Enriched and Gallium Si-on-Si Wafer Low Gain Avalanche Detectors

Instruments ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Lucía Castillo García ◽  
Evangelos Leonidas Gkougkousis ◽  
Chiara Grieco ◽  
Sebastian Grinstein
Keyword(s):  
Performance Studies ◽  
Hadron Collider ◽  
Electrical Characterization ◽  
Full Characterization ◽  
Silicon Sensors ◽  
Pile Up ◽  
Before And After ◽  
And Performance ◽  
Si Wafer

Low Gain Avalanche Detectors (LGADs) are n-on-p silicon sensors with an extra doped p-layer below the n-p junction which provides signal amplification. The moderate gain of these sensors, together with the relatively thin active region, provides excellent timing performance for Minimum Ionizing Particles (MIPs). To mitigate the effect of pile-up during the High-Luminosity Large Hadron Collider (HL-LHC) era, both ATLAS and CMS experiments will install new detectors, the High-Granularity Timing Detector (HGTD) and the End-Cap Timing Layer (ETL), that rely on the LGAD technology. A full characterization of LGAD sensors fabricated by Centro Nacional de Microelectrónica (CNM), before and after neutron irradiation up to 1015 neq/cm2, is presented. Sensors produced in 100 mm Si-on-Si wafers and doped with boron and gallium, and also enriched with carbon, are studied. The results include their electrical characterization (I-V, C-V), bias voltage stability and performance studies with the Transient Current Technique (TCT) and a Sr-90 radioactive source setup.

scholarly journals Preparation and characterization of protective self-cleaning TiO2/kaolin composite coating

2018 ◽  
Vol 68 (331) ◽  
pp. 163
Author(s):  
V. Jovanov ◽  
V. Zečević ◽  
T. Vulić ◽  
J. Ranogajec ◽  
E. Fidanchevska
Keyword(s):  
Photocatalytic Activity ◽  
Composite Coating ◽  
Building Materials ◽  
Support Surface ◽  
Tio2 Content ◽  
Cleaning Efficiency ◽  
Before And After ◽  
Self Cleaning ◽  
Highly Porous

The application of self-cleaning coatings presents one of the most effective ways to protect the surfaces of the building materials. The effect of TiO2/kaolin based coatings applied to three types of substrates: non-porous, porous and highly porous, was investigated. Mechanical activation was applied for the impregnation of the active TiO2 component (in content of 3 and 10 wt. %) into the kaolin support. Surface properties (roughness, hydrophilicity and micro-hardness) and functional properties (photocatalytic activity and self-cleaning efficiency) were studied in order to define the optimal formulation of the applied coatings. The effect of the photocatalytic behavior of the coated substrates in terms of self-cleaning ability was assessed by the photodegradation of Rhodamine B, performed before and after durability tests. The results obtained in this paper showed that photocatalytic activity of the TiO2/kaolin composite coating generally depends on the procedure of TiO2 impregnation into the kaolin clay and the loaded TiO2 content.

Sign in / Sign up

Export Citation Format

Share Document