Shungite Carbon Nanoparticles as Modifiers of Zns:Cu Phosphor, Based on Analysis of the EPR Spectral Lines of Mn+2

2021 ◽  
Vol 1031 ◽  
pp. 201-208
Author(s):  
S.P. Rozhkov ◽  
Natalia N. Rozhkova ◽  
Maxim М. Sychov
Keyword(s):  
Integral Intensity ◽  
Subsurface Layer ◽  
Particle Surface ◽  
Chemical Properties ◽  
Spectral Lines ◽  
Nanoparticle Concentration ◽  
Epr Spectrum ◽  
Physico Chemical ◽  
Saturation Power ◽  
Shungite Carbon

Water dispersions of shungite carbon (ShC) nanoparticles were used for modifying the particle surface of ZnS:Cu, commercial electrophosphor. The EPR spectrum of ZnS:Cu powder has parameters consistent with the paramagnetic centers of Mn+2. Modifying the phodphor surface with ShC nanoparticles results in a non-monotonic change in line width, amplitude and integral intensity caused by nanoparticle concentration, which correlates with variations in the brightness of electroluminescence. Variations in the parameters of spectral lines with nanoparticle concentration and UHF saturation power are interpreted in terms of modification and creation of additional dislocations in the subsurface layer of phosphor with new physico-chemical properties.

scholarly journals Characterization of the existing soil management in relation to some selected physico-chemical properties at Bulehoraworeda, West guji zone

2018 ◽  
Vol 7 (2) ◽  
pp. 43-48 ◽  
Author(s):  
Kenea Worku ◽  
Abdissa Debela ◽  
Diriba Shanko
Keyword(s):  
Electrical Conductivity ◽  
Bulk Density ◽  
Soil Ph ◽  
Ph Value ◽  
Soil Depth ◽  
Subsurface Layer ◽  
Chemical Properties ◽  
Soil Samples ◽  
Surface Horizon ◽  
Physico Chemical

The study of soil physico-chemical properties were made on the soils of BuleHoraWoreda, WestGuji zone. The objective of the study was to characterize soil physical and chemical properties to assess the fertility status of the soils in the study areas. Soil profile pits at representative sites were described and soil samples were collected from each depth of 0-15 cm, 15 – 30 cm, and 30–60 cm depending on the root depth of the crop. Soil samples were collected from two different study areas for the determination of soil texture, bulk density, porosity, soil pH and electrical conductivity. The top layer (0-15 cm) has an average bulk density of 1.10 g/cm3, whereas the subsurface layer (15-30 and the bottom layer (30-60 cm) has an average bulk density of 1.16 g/cm3 and 1.26 g/cm3, respectively at the GuyyeKebele. The average value of bulk density 1.18 g/cm3, 1.29 g/cm3 and 1.39g/cm3 was recorded on the surface horizon (0-15 cm), subsurface horizon (15-30 cm) and the bottom horizon (30 - 60 cm) depth, respectively at BuleHora Farm. Accordingly, the highest (1.39 g/cm3) and the lowest (1.10 g/cm3) average bulk density values were recorded for BuleHoraand GuyyeKebele study Farm, respectively. The average highest porosity (58.48%) value was observed in the surface horizon (0 -15 cm) soil depth and the average lowest porosity value (52.11%) was observed in the bottom horizon (30 – 60 cm) depth at GuyyeKebele study Farm. The average porosity value of the soils in BuleHora study Farm were recorded 55.27%, 52.39% and 47.63% for the surface horizon (0 -15 cm), sub surface horizon ( 15 –30 cm) and bottom horizon (30 – 60 cm) depth , respectively. The soil textural class was changed with depth from sandy clay in surface horizon (0-15 cm) to clay in both sub surface horizon (15- 30 cm) and bottom horizon (30-60 cm) at GuyyeKebele. The pH value was observed on the soils of the GuyyeKebele study area increased from 6.08 at surface horizon (0 – 15 cm) to 6.27 at the sub surface horizon (15- 30 cm) and then slightly decreased to 6.21 at the bottom horizon (30-60 cm) of the soil depth. Lowest soil pH value (5.44) was measured in the surface horizon (0 –15 cm) and the highest pH value (6.09) was observed in bottom horizon (30-60 cm) soil depth at BuleHora farm. The electrical conductivity of the saturated soil paste extracts of the study area was low (ranging from 0.0387 to 0.1587 dS m-1) throughout the profile showing no significant accumulation of soluble salts to convert the soil to saline soil.Int. J. Agril. Res. Innov. & Tech. 7 (2): 43-48, December, 2017

scholarly journals Immersion Freezing Ability of Freshly Emitted Soot with Various Physico-Chemical Characteristics

Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1173
Author(s):  
John Falk ◽  
Kimmo Korhonen ◽  
Vilhelm B. Malmborg ◽  
Louise Gren ◽  
Axel C. Eriksson ◽  
...  
Keyword(s):  
Soot Particle ◽  
Particle Density ◽  
Particle Surface ◽  
Chemical Properties ◽  
Biomass Combustion ◽  
Soot Particles ◽  
Physico Chemical ◽  
Effective Particle ◽  
Wide Range ◽  
Immersion Freezing

The immersion freezing ability of soot particles has in previous studies been reported in the range of low/insignificant to very high. The aims of this study were to: (i) perform detailed physico-chemical characterisation of freshly produced soot particles with very different properties, (ii) investigate the immersion freezing ability of the same particles, and (iii) investigate the potential links between physico-chemical particle properties and ice-activity. A miniCAST soot generator was used to produce eight different soot samples representing a wide range of physico-chemical properties. A continuous flow diffusion chamber was used to study each sample online in immersion mode over the temperature (T) range from −41 to −32 °C, at a supersaturation of about 10% with respect to liquid water. All samples exhibited low to no heterogeneous immersion freezing. The most active sample reached ice-activated fractions (AF) of 10−3 and 10−4 at temperatures of 1.7 and 1.9 K , respectively, above the homogeneous freezing temperature. The samples were characterized online with respect to a wide range of physico-chemical properties including effective particle density, optical properties, particle surface oxidation and soot maturity. We did observe indications of increasing immersion freezing ice-activity with increasing effective particle density and increasing particulate PAH fraction. Hence, those properties, or other properties co-varying with those, could potentially enhance the immersion freezing ice-activity of the studied soot particle types. However, we found no significant correlation between the physico-chemical properties and the observed ice-nucleating ability when the particle ensemble was extended to include previously published results including more ice-active biomass combustion soot particles. We conclude that it does not appear possible in general and in any straightforward way to link observed soot particle physico-chemical properties to the ice-nucleating ability using the online instrumentation included in this study. Furthermore, our observations support that freshly produced soot particles with a wide range of physico-chemical properties have low to insignificant immersion freezing ice-nucleating ability.

Decoration of specific sites on freeze-fractured membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 140-141
Author(s):  
H. Gross ◽  
H. Moor
Keyword(s):  
Pure Water ◽  
Freeze Fracture ◽  
Chemical Properties ◽  
Surface Forces ◽  
Sulfate Pentahydrate ◽  
Copper Sulfate Pentahydrate ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
Small Container ◽  
Binding Forces

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

Physico-chemical properties of the rare-earth metals, scandium, and yttrium

1963 ◽  
Vol 79 (2) ◽  
pp. 263-293 ◽  
Author(s):  
E.M. Savitskii ◽  
V.F. Terekhova ◽  
O.P. Naumkin
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Chemical Properties ◽  
Physico Chemical ◽  
The Rare Earth

Physico chemical properties and gas adsorption separation characteristics of Itaya zeolite and its modified products.

1990 ◽  
Vol 39 (442) ◽  
pp. 996-1000 ◽  
Author(s):  
Ayao TAKASAKA ◽  
Hideyuki NEMOTO ◽  
Hirohiko KONO ◽  
Yoshihiro MATSUDA
Keyword(s):  
Gas Adsorption ◽  
Chemical Properties ◽  
Physico Chemical

Development of Ketchup from Sudanese Red karkade (Hibiscus sabdariffa L.) byproduct

Food Biology ◽  
1970 ◽  
pp. 19-23
Author(s):  
Nawal Abdel-Gayoum Abdel-Rahman
Keyword(s):  
Sensory Quality ◽  
Chemical Properties ◽  
Storage Period ◽  
Gum Arabic ◽  
Raw Material ◽  
Soluble Solids ◽  
Hibiscus Sabdariffa ◽  
Overall Acceptability ◽  
Physico Chemical ◽  
Tomato Ketchup

The aim of this study is to use of karkede (Hibiscus sabdariffa L.) byproduct as raw material to make ketchup instead of tomato. Ketchup is making of various pulps, but the best type made from tomatoes. Roselle having adequate amounts of macro and micro elements, and it is rich in source of anthocyanine. The ketchup made from pulped of waste of soaked karkede, and homogenized with starch, salt, sugar, ginger (Zingiber officinale), kusbara (Coriandrum sativum) and gum Arabic. Then processed and filled in glass bottles and stored at two different temperatures, ambient and refrigeration. The total solids, total soluble solids, pH, ash, total titratable acidity and vitamin C of ketchup were determined. As well as, total sugars, reducing sugars, colour density, and sodium chloride percentage were evaluated. The sensory quality of developed product was determined immediately and after processing, which included colour, taste, odour, consistency and overall acceptability. The suitability during storage included microbial growth, physico-chemical properties and sensory quality. The karkede ketchup was found free of contaminants throughout storage period at both storage temperatures. Physico-chemical properties were found to be significantly differences at p?0.05 level during storage. There were no differences between karkade ketchup and market tomato ketchup concerning odour, taste, odour, consistency and overall acceptability. These results are encouraging for use of roselle cycle as a raw material to make acceptable karkade ketchup.

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