Acute Inhalation Toxicity of Some Halogenated and Non-halogenated Hydrocarbons

1982 ◽  
Vol 1 (3) ◽  
pp. 239-247 ◽  
Author(s):  
D.G. Clark ◽  
D.J. Tinston

1 The relative potency of effect of a wide range of halogenated and unsubstituted hydrocarbons on the central nervous system (CNS) and the heart of experimental animals have been determined. 2 The chemicals used caused either stimulation or depression of the rat CNS after 10 minutes' inhalation of concentrations ranging from 0.24% to > 80% (v/v), and cardiac sensitization in dogs after 5 minutes' inhalation of 0.12% to approximately 80% (v/v). 3 The toxicity could not be correlated with chemical structure, molecular weight, the presence or absence of various halogen atoms or the degree of saturation, but it was inversely related to the saturated vapour pressure. When the results were expressed on a thermodynamic scale the chemicals had similar potencies at relative saturations of 0.004 to 0.04 4 It is suggested that the effects of these chemicals on the CNS and the heart are probably structurally non-specific, and the chemicals may be regarded as physical toxicants whose effects are predictable from their physico-chemical properties.

2020 ◽  
Vol 10 (3) ◽  
pp. 5355-5360

The study of ion- solvent interaction is of much importance to investigate the nature of different solutions. Measurement of electrical conductivity and evaluation of physico-chemical properties, such as molar conductance, limiting molar conductance, ion-pair association, Walden product etc. shade light on different intermolecular interactions present in electrolyte solutions. Solvation properties can be varied by mixing two or more solvents. An extensive literature survey on conductometric studies has been carried out on different electrolytes dissolved in a wide range of mixed solvent systems. The reported results show that strong solute-solute, solute-solvent and solvent-solvent interactions are responsible for the physico- chemical behavior of a solution in mixed solvents.


2019 ◽  
Vol 6 (2) ◽  
pp. 181823 ◽  
Author(s):  
Guangyu Shi ◽  
Yizhu Qian ◽  
Fengzhi Tan ◽  
Weijie Cai ◽  
Yuan Li ◽  
...  

Oil/water separation is a field of high significance as it might efficiently resolve the contamination of industrial oily wastewater and other oil/water pollution. In this paper, an environmentally-friendly hydrophobic aerogel with high porosity and low density was successfully synthesized with renewable pomelo peels (PPs) as precursors. Typically, a series of sponge aerogels (HPSA-0, HPSA-1 and HPSA-2) were facilely prepared via high-speed dispersion, freeze-drying and silanization with methyltrimethoxysilane. Indeed, the physical properties of aerogel such as density and pore diameter could be tailored by different additives (filter paper fibre and polyvinyl alcohol). Hence, their physico-chemical properties including internal morphology and chemical structure were characterized in detail by Fourier transform infrared, Brunauer–Emmett–Teller, X-ray diffraction, scanning electron microscope, Thermal gravimetric analyzer (TG) etc. Moreover, the adsorption capacity was further determined and the results revealed that the PP-based aerogels presented excellent adsorption performance for a wide range of oil products and/or organic solvents (crude oil 49.8 g g −1 , soya bean oil 62.3 g g −1 , chloroform 71.3 g g −1 etc.). The corresponding cyclic tests showed the absorption capacity decreased slightly from 94.66% to 93.82% after 10 consecutive cycles, indicating a high recyclability.


2000 ◽  
Vol 84 (S1) ◽  
pp. 19-25 ◽  
Author(s):  
Klaas D. Kussendrager ◽  
A. C. M. van Hooijdonk

Lactoperoxidase (LP) is one of the most prominent enzymes in bovine milk and catalyses the inactivation of a wide range of micro-organisms in the lactoperoxidase system (LP-s). LP-systems are also identified as natural antimicrobial systems in human secretions such as saliva, tear-fluid and milk and are found to be harmless to mammalian cells. The detailed molecular structure of LP is identified and the major products generated by the LP-s and their antimicrobial action have been elucidated for the greater part. In this paper several aspects of bovine LP and LP-s are discussed, including physico-chemical properties, occurrence in milk and colostrum and mechanisms of action. Since the introduction of industrial processes for the isolation of LP from milk and whey the interest in this enzyme has increased considerably and attention will be paid to potential and actual applications of LP-systems as biopreservatives in food and other products.


2016 ◽  
Vol 1 (1) ◽  
pp. 28-37
Author(s):  
Mohd Nasarudin Harith ◽  
Ruhana Hassan

A study was carried out to evaluate the diversity and similarity of cyanobacterial populations in selected Sarawak aquatic ecosystem using β-indices. Eight stations including aquaculture ponds, cage cultures, waterfall and artificial lake located in Serian, Bau and Batang Ai areas were selected. A total of 43 species belonging to 30 genera of cyanobacteria were recorded. The most distributed pattern among all sampling stations belongs to the genera Chroococcus, Lyngbya, Nostoc and Oscillatoria. The highest β diversity values were found among non-contiguous stations. Besides, no identical or totally different cyanobacteria diversity values were obtained among those non-contiguous stations. The highest β diversity value (0.84) was found among stations with contrasting environmental characteristics. The wide range of β-diversity and similarity suggested that different locations and types of aquatic ecosystems may have variations in physico-chemical properties of the water and eventually lead to the different composition of cyanobacteria.


2015 ◽  
Vol 229 (1-2) ◽  
Author(s):  
Neus G. Bastús ◽  
Edgar Gonzalez ◽  
Joan Esteve ◽  
Jordi Piella ◽  
Javier Patarroyo ◽  
...  

AbstractThe design of new protocols for the colloidal synthesis of complex nanocrystals (NCs) with advanced functionalities, comprising both hybrid and hollow structures, and the study of their fundamental properties is of paramount importance for the development of a new generation of nanostructured materials. The possibility of tailoring the dimensional regime of NCs, along with its composition and structure, represents a landmark achievement in the control of their unique physico-chemical properties. These properties, alongside with the ability to cheaply produce high quality NCs in fairly large amounts by wet-chemistry techniques, leads to their potential applicability from materials science to nanomedicine. Within this context, this review is focused on describing a successful framework for designing synthetic strategies for the production of advanced complex NCs, integrating the development of new synthetic methods with its structural characterization, monitoring of their properties, and study of its reactivity. As a result, it is expected to provide new routes to produce robust and easy-to-process NCs in a wide range of sizes, shapes and configurations that can be explored to achieve the combination of all degrees of control, aiming to produce a complete and diverse library of material combinations that will expand its applicability in a wide diversity of fields.


2020 ◽  
Vol 10 (2) ◽  
pp. 5332-5337

The study of ion- solvent interaction is of much importance to investigate the nature of different solutions. Measurement of electrical conductivity and evaluation of physico-chemical properties, such as molar conductance, limiting molar conductance, ion-pair association, Walden product etc. shade light on different intermolecular interactions present in electrolyte solutions. Solvation properties can be varied by mixing two or more solvents. An extensive literature survey on conductometric studies has been carried out on different electrolytes dissolved in a wide range of mixed solvent systems. The reported results show that strong solute-solute, solute-solvent and solvent-solvent interactions are responsible for the physico- chemical behavior of a solution in mixed solvents.


2021 ◽  
Vol 9 (2) ◽  
pp. 8
Author(s):  
Anca-Luiza Stănilă

The studied territory located in the central-western part of Olt County, belongs to the Caracal Plain and extremely little in the Leu-Rotunda Field in the SW part, both as divisions of the Romanati Plain.Locality presents a predominant relief of plain low altitude that is characterized by alluvio-proluvial plains moderately fragmented with local terraces, covered with loess-like deposit but relief of saucer.The soil cover of the territory under study is the direct reflection of all environmental factors, each having a role in the pedogenetic processes. Climate, as a pedogenetic factor, acted by its components, namely: temperature, precipitation, evapotranspiration, global radiation.Forest steppe vegetation was the supply of organic matter and biomass, because the hydrological regime is deficient, but especially the lithological substrate (loess-like complex) to steer solification to types characteristic of the cernisols class.Under the influence of environmental factors and pedogenetic processes within the locality Dobrosloveni it formed a wide range of soils, namely: protisols, cernisols, luvisols and hydrisols.


2020 ◽  
pp. 294-298
Author(s):  
Z. Bubnik ◽  
P. Kadlec ◽  
E. Sarka ◽  
V. Pour ◽  
A. Hinkova ◽  
...  

This paper represents a summary of most important research activities in sucrose crystallization, in which the Department of Carbohydrates and Cereals, part of the University of Chemistry and Technology (UCT) Prague, has been involved over the last 25 years. A wide range of these projects has been carried out in cooperation with other research institutes, universities and industrial partners. These activities can be divided into four main research areas that are interconnected and support each other. – Physical and chemical properties of sucrose and sugar solutions; – Growth kinetics of sugar crystals in pure and technical sugar solutions; – Simulation and mathematical modeling of new processes and technologies; – Experimental work for industry and cooperation with industrial partners.


2020 ◽  
Vol 8 (2) ◽  
pp. 1
Author(s):  
Anca-Luiza Stănilă

The territory studied is situated in the South-Eastern part of Olt County, it is part of the great unit of the Romanian Plain, that is, from the subunit of Boianu Plain (Calmatui Plain), being located on the left bank of Olt River. Locality presents a predominant relief of plain low altitude that is characterized by alluvio-proluvial plains moderately fragmented with local terraces, covered with loess-like deposit but relief of saucer.The soil cover of the territory under study is the direct reflection of all environmental factors, each having a role in the pedogenetic processes. Thus, the climate conditions have ensured the solification direction, taking into account the temperature regime and the specific precipitation of the Boianu Plain.Steppe vegetation was the supply of organic matter and biomass, because the hydrological regime is deficient, but especially the lithological substrate (loess) to steer solification to types characteristic of the cernisols class.Under the influence of environmental factors and pedogenetic processes within the locality Daneasa it formed a wide range of soils, namely: protisols, cernisols, luvisols, hydrisols and salsodisols.


2021 ◽  
Vol 928 (1) ◽  
pp. 012003
Author(s):  
G V Larina ◽  
E V Kaigorodov ◽  
E B Daibova ◽  
O A Yalbacheva ◽  
L G Vidyaykina

Abstract The results of the study of acid-base indicators of peat in the Altai mountainous region are presented. The natural factors that in the aggregate determine the peculiarities of the physico-chemical properties of mountain peat of different agro-climatic zones of the Altai Mountains have been revealed. The variation in the acid values, total absorbed bases, adsorption capacity and the degree of saturation of raised-bog, transitional, fen peat, the number of exchangeable ions Ca2+ and Mg2+ has been estimated. The interrelation among these indicators has been presented. For the first time, regression equations of the relationship between exchangeable acidity pHKC1 and the degree of peat base saturation V, between total absorbed bases S and the degree of peat base saturation V have been obtained using nonlinear regression analysis. The adequacy and stability of the developed models have been verified. The calculated mean errors of approximation of regression models characterise the high accuracy of the forecast and are indicative of a good selection of models for the initial data.


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