Sb-V-Ox catalysts—Role of chemical composition of MCM-41 supports in physicochemical properties

2009 ◽  
Vol 142 (3-4) ◽  
pp. 175-180 ◽  
Author(s):  
H. Golinska ◽  
P. Decyk ◽  
M. Ziolek ◽  
J. Kujawa ◽  
E. Filipek
2002 ◽  
Vol 45 (spe) ◽  
pp. 83-86 ◽  
Author(s):  
Malcolm Frier

Imaging of sentinel nodes is a valuable technique in the management of some types of cancer. Several different radiopharmaceuticals have been successfully employed in the technique, but there have been few systematic studies to examine the relationship between physicochemical properties of the radiopharmaceuticals used and in-vivo performance. The present study describes the preparation and characterisation of radiocolloids of similar chemical composition but differing in particle size distribution in an attempt to identify the role of variations in the single parameter of size.


2018 ◽  
Vol 48 (1) ◽  
pp. 223-251
Author(s):  
Marta Skolniak ◽  
Anna Turlej

Abstract The article presents the role of lubricating oils for aviation applications, along with their classification, and discusses the key physicochemical properties. It characterises engine, transmission gear, hydraulic and instrumentation oils and their impact on a device operational reliability. It also points out the requirements for these products in relation to the operating conditions and the chemical composition of a product.


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Manzoor Ahmad Gatoo ◽  
Sufia Naseem ◽  
Mir Yasir Arfat ◽  
Ayaz Mahmood Dar ◽  
Khusro Qasim ◽  
...  

Nanotechnology has emerged as one of the leading fields of the science having tremendous application in diverse disciplines. As nanomaterials are increasingly becoming part of everyday consumer products, it is imperative to assess their impact on living organisms and on the environment. Physicochemical characteristics of nanoparticles and engineered nanomaterials including size, shape, chemical composition, physiochemical stability, crystal structure, surface area, surface energy, and surface roughness generally influence the toxic manifestations of these nanomaterials. This compels the research fraternity to evaluate the role of these properties in determining associated toxicity issues. Reckoning with this fact, in this paper, issues pertaining to the physicochemical properties of nanomaterials as it relates to the toxicity of the nanomaterials are discussed.


The authors' methodic for assessing the role of chemical and physic-chemical factors during the structure formation of gypsum stone is presented in the article. The methodic is also makes it possible to reveal the synergistic effect and to determine the ranges of variation of controls factors that ensure maximum values of such effect. The effect of a micro-sized modifier based on zinc hydro-silicates on the structure formation of building gypsum is analyzed and corresponding dependencies are found. It is shown that effects of influence of modifier on the properties of gypsum compositions are determined by chemical properties of modifier. Among the mentioned properties are sorption characteristics (which depend on the amount of silicic acid and its state) and physicochemical properties - the ability to act as a substrate during crystal formation. The proposed method can also be extended to other binding substances and materials. This article contributes to the understanding of the processes that occur during the structure formation of composites, which will make it possible to control the structure formation in the future, obtaining materials with a given set of properties.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 374
Author(s):  
Teresa Szczęsna ◽  
Ewa Waś ◽  
Piotr Semkiw ◽  
Piotr Skubida ◽  
Katarzyna Jaśkiewicz ◽  
...  

The aim of this study was to determine the influence of storage temperature and time on physicochemical parameters of starch syrups recommended for the winter feeding of bee colonies. The studies included commercially available three starch syrups and an inverted saccharose syrup that were stored at different temperatures: ca. 20 °C, 10–14 °C, and ca. 4 °C. Physicochemical parameters of fresh syrups (immediately after purchase) and syrups after 3, 6, 9, 12, 15, 18, 21, and 24 months of storage at the abovementioned temperatures were measured. It was observed that the rate of unfavorable changes in chemical composition of starch syrups and the inverted saccharose syrup, mainly the changes in the 5-hydroxymethylfurfural (HMF) content, depended on the type of a syrup and storage conditions (temperature, time). Properties of tested starch syrups intended for winter feeding of bees stored at ca. 20 °C maintained unchanged for up to 6 months, whereas the same syrups stored at lower temperatures (10–14 °C) maintained unchanged physicochemical parameters for about 12 months. In higher temperatures, the HMF content increased. To date, the influence of this compound on bees has not been thoroughly investigated.


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