Physical Aspects of the Liquid Zones Thermomigration Method for Formation of Electronic Technics Materials with the Required Substructure

2016 ◽  
Vol 843 ◽  
pp. 145-150
Author(s):  
A.V. Blagin ◽  
N.A. Nefedova ◽  
B.M. Seredin
Keyword(s):  
Process Temperature ◽  
Semiconductor Materials ◽  
Diffusion Method ◽  
Liquid Inclusion ◽  
Crystal Perfection ◽  
Doping Impurity ◽  
Distribution Uniformity ◽  
Increasing Process ◽  
Temperature Time ◽  
Process Speed

The paper analyzes the features of a liquid zones thermomigration process in a crystal for the formation of semiconductor materials with the required substructure, carried out in comparison with a diffusion method. The primary factors defining and accompanying the thermomigration process of liquid inclusion in a crystal are considered. The geometrical, concentration, temperature-time and other conditions at which the choice of the thermomigration effect as a local doping method is preferable are revealed and described. It is shown, that the thermomigration method possesses considerable advantages, in particular, the possibilities of decreasing doping process temperature, increasing process speed, increasing the distribution uniformity of the doping impurity and improves the crystal perfection of the doped layers. The quantitative estimations related to the revealed conditions, are illustrated with an aluminium-silicon example.

Fuel properties of biochar from torrefaction of ground coffee residue: effect of process temperature, time, and sweeping gas

2020 ◽  
Vol 10 (3) ◽  
pp. 743-753 ◽  
Author(s):  
Jiaranai Pathomrotsakun ◽  
Kamonwat Nakason ◽  
Wasawat Kraithong ◽  
Pongtanawat Khemthong ◽  
Bunyarit Panyapinyopol ◽  
...  
Keyword(s):  
Fuel Properties ◽  
Process Temperature ◽  
Sweeping Gas ◽  
Temperature Time ◽  
Ground Coffee

Obtaining of High Purity Amorphous Silicon Dioxide from Rice Husk

2016 ◽  
Vol 10 (4) ◽  
pp. 499-505 ◽  
Author(s):  
Tatiana Gridneva ◽  
◽  
Alexander Kravchenko ◽  
Vadim Barsky ◽  
Natalia Gurevina ◽  
...  
Keyword(s):  
Silicon Dioxide ◽  
Amorphous Silicon ◽  
Rice Husk ◽  
High Purity ◽  
Process Temperature ◽  
Solid Residue ◽  
Technological Factors ◽  
Amorphous Silicon Dioxide ◽  
Maximum Extraction ◽  
Temperature Time

Using maximum extraction of carbon-containing components the content of amorphous silicon dioxide was increased in the rice husk solid residue. In accordance with the hypothesis about the mechanism of extracting carbon-containing components from rice husk by liquid extractants, proper extractants were selected. The effect of main technological factors including process temperature, time and concentration of the extractants was determined.

Disappearance Voltage Determinations Using a Convergent Beam

1971 ◽  
Vol 29 ◽  
pp. 184-185
Author(s):  
W. L. Bell
Keyword(s):  
Second Order ◽  
Objective Method ◽  
Uniform Thickness ◽  
Rocking Curve ◽  
Crystal Perfection ◽  
Kikuchi Line ◽  
Central Maximum ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Beam Technique

Disappearance voltages for second order reflections can be determined experimentally in a variety of ways. The more subjective methods, such as Kikuchi line disappearance and bend contour imaging, involve comparing a series of diffraction patterns or micrographs taken at intervals throughout the disappearance range and selecting that voltage which gives the strongest disappearance effect. The estimated accuracies of these methods are both to within 10 kV, or about 2-4%, of the true disappearance voltage, which is quite sufficient for using these voltages in further calculations. However, it is the necessity of determining this information by comparisons of exposed plates rather than while operating the microscope that detracts from the immediate usefulness of these methods if there is reason to perform experiments at an unknown disappearance voltage.The convergent beam technique for determining the disappearance voltage has been found to be a highly objective method when it is applicable, i.e. when reasonable crystal perfection exists and an area of uniform thickness can be found. The criterion for determining this voltage is that the central maximum disappear from the rocking curve for the second order spot.

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

Relative Intensities in ED Patterns From Thin Gold Films

1972 ◽  
Vol 30 ◽  
pp. 636-637
Author(s):  
R. H. Morriss ◽  
J. D. C. Peng ◽  
C. D. Melvin
Keyword(s):  
Theoretical Calculations ◽  
Diffraction Theory ◽  
Gold Films ◽  
Reasonable Accuracy ◽  
Experimental Conditions ◽  
Crystal Perfection ◽  
Heavy Atoms ◽  
Fine Focus ◽  
Convergent Beam ◽  
Beam Diffraction

Although dynamical diffraction theory was modified for electrons by Bethe in 1928, relatively few calculations have been carried out because of computational difficulties. Even fewer attempts have been made to correlate experimental data with theoretical calculations. The experimental conditions are indeed stringent - not only is a knowledge of crystal perfection, morphology, and orientation necessary, but other factors such as specimen contamination are important and must be carefully controlled. The experimental method of fine-focus convergent-beam electron diffraction has been successfully applied by Goodman and Lehmpfuhl to single crystals of MgO containing light atoms and more recently by Lynch to single crystalline (111) gold films which contain heavy atoms. In both experiments intensity distributions were calculated using the multislice method of n-beam diffraction theory. In order to obtain reasonable accuracy Lynch found it necessary to include 139 beams in the calculations for gold with all but 43 corresponding to beams out of the [111] zone.

Therapeutic efficacy of some extracts of hot pepper fruits (Capsicum annuum) and Sumac seeds (Rhus coriaria) on the growth of some isolated dermatophytes species

2018 ◽  
Vol 1 (3) ◽  
pp. 52-62
Author(s):  
Sara Omran ◽  
Abdulghani Alsamarai ◽  
Firas Razzzaq
Keyword(s):  
Antifungal Activity ◽  
Fungal Infection ◽  
Aqueous Extract ◽  
Plant Extracts ◽  
Therapeutic Efficacy ◽  
Diffusion Method ◽  
Quantitative Detection ◽  
Hot Pepper ◽  
Alcoholic Extract ◽  
Dermatology Clinic

Background: Fungal infections are one of the common skin diseases with difficulty in their treatment approach. The present efficient drugs for fungal infection are limited. Aim: To determine the therapeutic efficacy of plant extracts as alternative antifungal agents. Materials and methods: 100 clinical samples [68 from female and 32 from male] were collected during the period from March to July 2017 from subjects attending Dermatology Clinic in Salah Uldean General Hospital. Fungal infection was diagnosed with using KOH wet preparation. Fungal species identified by using conventional approach. The active ingredients existing in the plant extracts were detected and analyzed through qualitative and quantitative detection technique of chemical compounds using a high performance liquid chromatographic device (HPLC). Agar diffusion method was used to determine antifungal activity of plant extracts. Results: Direct microscopic examination showed that there were (75%) positive samples, while culture shows (67%) positive samples. The isolated dermatophytes belong to Epidermophyoton, Microsporum, and Trichophyton genus. The predominant dermatophytes were T. rubrum (25%) species. The highest frequency of infection was in the age group of 11-20 years. The sensitivity of the tested fungi to the aqueous and alcoholic plant extracts varies. Alcoholic extract of the hot pepper plant was more effective as antifungal than the aqueous extract of the same plant. However, aqueous hot pepper extracts was more effective against T. mentagrophyte than that of alcoholic extract. Additionally, alcoholic Sumac extract shows higher efficacy that aqueous extract. Conclusion: Hot pepper and Sumac extracts show antifungal activity against Microsporum canis, Trichophyton rubrum and T. mentagrophyte.

ANTIMICROBIAL SUSCEPTIBILITY IN CULTURE POSITIVE ENTERIC FEVER

2019 ◽  
Vol 3 (7) ◽  
Author(s):  
Dr. Manish Kulshrestha ◽  
Dr. Anjali Kulshrestha
Keyword(s):  
Bone Marrow ◽  
Blood Culture ◽  
Nalidixic Acid ◽  
Antimicrobial Susceptibility ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Multidrug Resistant ◽  
Bone Marrow Culture ◽  
Diffusion Method ◽  
Culture Positive

INTRODUCTION: Enteric fever includes typhoid and paratyphoid fever. Peak incidence is seen in children 5–15 years of age; but in regions where the disease is highly endemic, as in India, children younger than 5 years of age may have the highest infection rates. There are about 22 million new typhoid cases occur each year. Young children in poor, resource limited areas, who make up the majority of the new cases and there is a mortality figures of 215,000 deaths annually. A sharp decline in the rates of complications and mortality due to typhoid fever is observed as a result of introduction of effective antibiotic therapy since 1950s. MDR-ST became endemic in many areas of Asia, including India soon after multidrug-resistant strains of Salmonella enterica serotype typhi (MDR-ST) that were resistant to all the three first-line drugs then in use, namely chloramphenicol, amoxycillin and co-trimoxazole emerged in early 1990s. MATERIAL AND METHODS: Only blood culture or bone marrow culture positive cases were included. The patients with culture isolated enteric fever were included in the study. Antimicrobial susceptibility testing was carried out by disk diffusion method using antibiotic discs. The analysis of the antimicrobial susceptibility was carried out as per CLSI interpretative guidelines. RESULTS: A total of 82 culture positive cases were included in the present study. 80 culture isolates were from blood culture and 2 from the bone marrow culture. Salmonella entericasubspecies enterica serovartyphi (S typhi) was isolated from 67 (81.70%) patients while Salmonella enterica subspecies entericaserovarparatyphi (S paratyphi A) was isolated from 13 (15.85%) cases and 2 (2.44%) were Salmonella enterica subspecies entericaserovarschottmuelleri (S paratyphi B). Of the 82 cases 65(79.3%) isolates were resistant to ciprofloxacin, 17 (20.7%) were resistant to nalidixic acid, one (1.2%) case each was resistant to Cefotaxime and ceftriaxone, 2 (2.4%) were resistant to chloramphenicol, 10 (12.2%) were resistant and to cotrimoxazole 3 (3.7%) were resistant. CONCLUSION: In a culture positive cases 65(79.3%) isolates were resistant to ciprofloxacin and 17 (20.7%) were resistant to nalidixic acid. Multidrug resistant isolates were 65(79.3%).

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