Efficient Assessment of Physico-Chemical Properties of the Cryolite Melts for Research on the Improvement of Low-Temperature Aluminum Electrolysis

2018 ◽  
Vol 284 ◽  
pp. 839-844 ◽  
Author(s):  
V.A. Lebedev ◽  
Andrey A. Shoppert
Keyword(s):  
Low Temperature ◽  
Chemical Properties ◽  
Aluminum Electrolysis ◽  
Total Power ◽  
Potassium Cryolite ◽  
High Magnitude ◽  
Rate Of Dissolution ◽  
Physico Chemical ◽  
Hazardous Production ◽  
High Level

Modern aluminum electrolysis in cryolite-alumina melts is energy-intensive, inefficient and environmentally hazardous production. Addressing these significant shortcomings, the technology of low-temperature electrolyte is directed. The basis of low-temperature electrolysis is potassium cryolite, which results in high magnitude and rate of dissolution of alumina. Additive of sodium and lithium fluorides provide the necessary conductivity. Experimental investigation of these properties is extremely time consuming. In this work, as a parameter, which will allow to characterize effectively and rapidly the complexing ability of cryolite melts, the ratio of cationic ion power of Al3+ to the total power of the other cations of the melt is proposed. Regression analyses of the known experimental data establish the existence with a high level of reliability (R2=0.966-0.995) of a directly proportional dependence of this parameter on solubility of alumina and electrical conductivity of cryolite melts.

scholarly journals Research on Physico-Chemical Properties of Diethyl Ether/Linseed Oil Blends for the Use as Fuel in Diesel Engines

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6564
Author(s):  
Krzysztof Górski ◽  
Ruslans Smigins ◽  
Rafał Longwic
Keyword(s):  
Surface Tension ◽  
Low Temperature ◽  
Diethyl Ether ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Kinematic Viscosity ◽  
Linseed Oil ◽  
Chemical Properties ◽  
Fuel Blends ◽  
Physico Chemical

Physico-chemical properties of diethyl ether/linseed oil (DEE/LO) fuel blends were empirically tested in this article for the first time. In particular, kinematic viscosity (ν), density (ρ), lower heating value (LHV), cold filter plugging point (CFPP) and surface tension (σ) were examined. For this research diethyl ether (DEE) was blended with linseed oil (LO) in volumetric ratios of 10%, 20% and 30%. Obtained results were compared with literature data of diethyl ether/rapeseed oil (DEE/RO) fuel blends get in previous research in such a way looking on differences also between oil types. It was found that DEE impacts significantly on the reduction of plant oil viscosity, density and surface tension and improve low temperature properties of tested oils. In particular, the addition of 10% DEE to LO effectively reduces its kinematic viscosity by 53% and even by 82% for the blend containing 30% DEE. Tested ether reduces density and surface tension of LO up to 6% and 25% respectively for the blends containing 30% DEE. The measurements of the CFPP showed that DEE significantly improves the low temperature properties of LO. In the case of the blend containing 30% DEE the CFPP can be lowered up to −24 °C. For this reason DEE/LO blends seem to be valuable as a fuel for diesel engines in the coldest season of the year. Moreover, DEE/LO blends have been tested in the engine research. Based on results it can be stated that the engine operated with LO results in worse performance compared with regular diesel fuel (DF). However, it was found that these disadvantages could be reduced with DEE as a component of the fuel mixture. Addition of this ether to LO improves the quality of obtained fuel blends. For this reason, the efficiency of DEE/LO blend combustion process is similar for the engine fuelled with regular diesel fuel. In this research it was confirmed that the smoke opacity reaches the highest value for the engine fuelled with plant oils. However, addition of 20% DEE reduces this emission to the value comparable for the engine operated with diesel fuel.

scholarly journals Ichthyofaunal Diversity and Physico-Chemical Factors of Melamchi River, Sindhupalchok, Nepal

2016 ◽  
Vol 21 (1) ◽  
pp. 10-18
Author(s):  
Abha R. Mishra ◽  
Chitra Bahadur Baniya
Keyword(s):  
Fish Species ◽  
Fish Community ◽  
Diversity Index ◽  
Chemical Properties ◽  
Habitat Characteristics ◽  
Fish Diversity ◽  
Physico Chemical ◽  
Chemical Factors ◽  
High Level

The fish community and physico-chemical properties at five sites of Melamchi River were studied monthly from January 2011 to December 2013.    Melamchi River is one of tributaries larger Indrawati River basin, originates from the high snowy Jugal Mountain (5,875 m asl). Eleven fish species within two orders and five families were recorded.   Cypriniformes  was  found  to  be  the  most  dominant  order  with  ten  fish  species. Schizothorax plagiostomus  was the most common fish species followed by  Neolissochilus hexagonolepis, and  Psilorhynchus pseudecheneis.  Shannon Wiener fish diversity index and species richness recorded were highest at site 2 and lowest at site 5, whereas, evenness index was highest at site 3. The cluster analysis revealed  that  similarity  between  fish  species  decreased  as  the  distance  between  the  sites  increased.  Fish species were found distributed among four groups with respect to the significant habitat characteristics in the redundancy analysis (RDA). River water was found well-oxygenated and alkaline at all sites. However, high level for turbidity (43.25/ NTU) was observed at site 5, which exceeded compliance levels of WHO indicating the influence of intensive agriculture and deforestation along river area. To improve fish diversity and water quality of this river proper monitoring and management are an urgent need.Journal of Institute of Science and TechnologyVolume 21, Issue 1, August 2016, Page: 10-18

Effect of a low temperature step during fermentation on the physico-chemical properties of fat-free yogurt

2014 ◽  
Vol 36 (1) ◽  
pp. 14-20 ◽  
Author(s):  
R. Trejo ◽  
M. Corzo-Martínez ◽  
S. Wilkinson ◽  
K. Higginbotham ◽  
F.M. Harte
Keyword(s):  
Low Temperature ◽  
Chemical Properties ◽  
Temperature Step ◽  
Physico Chemical

scholarly journals Positional Effect of π-extension in Triple Helicenes

2021 ◽  
Author(s):  
Alex van der Ham ◽  
Thomas Hansen ◽  
Hermen S. Overkleeft ◽  
Trevor A. Hamlin ◽  
Dmitri V. Filippov ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rational Design ◽  
Marked Effect ◽  
Chemical Properties ◽  
Spectroscopic Properties ◽  
Positional Effect ◽  
Physico Chemical ◽  
Optical Applications ◽  
High Level ◽  
Vt Nmr

The targeted application of multiple helicenes in photo-optical applications requires their rational design. Toward this goal, we report on the synthesis of pyrene-based triple helicene 1 and investigate the positional effect of extension of the π-conjugated system on the photo-chemical and chiro-optical properties of triple helicenes. The conformational and aggregatory behavior of 1 were studied both experimentally using VT NMR spectroscopy and computationally using high-level DFT computations. Although π-extension was observed to have a marked effect on the spectroscopic properties of triple helicenes, comparison with other known π-extended helicenes reveals that the position at which π-extension is introduced is only of nominal importance. Our results thus suggest that the presence of a particular helicene motif is dominant in dictating the physico-chemical properties of triple helicenes.

Ceria added Sb-V2O5/TiO2 catalysts for low temperature NH3 SCR: Physico-chemical properties and catalytic activity

2013 ◽  
Vol 142-143 ◽  
pp. 705-717 ◽  
Author(s):  
Kyung Ju Lee ◽  
Pullur Anil Kumar ◽  
Muhammad Salman Maqbool ◽  
Komateedi Narayana Rao ◽  
Kwang Ho Song ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Low Temperature ◽  
Chemical Properties ◽  
Nh3 Scr ◽  
Physico Chemical

Some physico-chemical properties of porcine milk

1975 ◽  
Vol 42 (1) ◽  
pp. 43-56 ◽  
Author(s):  
M. C. T. Hoynes ◽  
P. F. Fox
Keyword(s):  
Bovine Milk ◽  
Chemical Properties ◽  
Complete Removal ◽  
Heat Stability ◽  
Rennet Coagulation ◽  
Physico Chemical ◽  
Water Of Hydration ◽  
High Level ◽  
Ph Curve ◽  
Porcine Milk

SummaryThe principal results of an investigation of the major physico-chemical properties of porcine milk were:Heat stability: all individual porcine milks examined had poor heat stability and some coagulated in 2 min at 95°C; the Q10°C was high and variable and was 40 for some samples. Dialysis of porcine milk against bulk bovine milk did not influence its heat stability; removal of colloidal calcium phosphate (CCP) from porcine milk increased its heat stability 4-fold, but it was still very unstable. Unlike bovine milk, porcine milk did not exhibit a maximum-minimum in the heat stability-pH curve, but rather resembled bovine casein micelles suspended in milk dialysate. Addition of isolated bovine β-lactoglobulin to porcine milk did not influence its heat stability-pH curve.Rennet coagulation: under similar conditions, porcine milk coagulated about 4 times faster than bovine milk and the resultant curd was about twice as soft. Dialysis of porcine milk against a large excess of bulk bovine milk did not influence its rennet coagulability nor did removal of 50% of its CCP, but complete removal of the CCP rendered porcine milk non-coagulable by rennin. Porcine milk was readily coagulated by rennin down to 5°C; its second-stage coagulation was independent of temperature – a characteristic due mainly to its high level of CCP.Alcohol stability: porcine milk was coagulated by 66–68% (v/v) ethanol, as compared with 74% (v/v) for bovine milk.Calcium stability: porcine milk was stable to at least 300 mM-CaCl2 at both 2 and 37°C.Solvation: porcine milk contained significantly less water of hydration than bovine milk, 1·7g H2O/g casein compared with 2·0g H2O/g casein.

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