scholarly journals ALTERATION OF ACTIVE SUBSTANCE CONTENT IN "HEXACHLORAN DUST" PESTICIDE FORMULATION AT EXPOSURE TO ELECTRON BEAM

2018 ◽  
Vol 3 (3) ◽  
pp. 433 ◽  
Author(s):  
T. Melnikova ◽  
A. Gordeev ◽  
L. Polyakova ◽  
A. Oudalova ◽  
G. Kozmin ◽  
...  
Keyword(s):  
Electron Beam ◽  
Active Substance ◽  
The Other ◽  
Chemical Degradation ◽  
Radiation Chemical ◽  
Organochlorinated Pesticides ◽  
Hch Isomers ◽  
Pesticide Formulation ◽  
Thermal Dechlorination ◽  
Degradation Degree

The most popular methods of organochlorinated pesticides (OCP) destruction, which are based on thermal dechlorination, are not ecologically safe. The other process – radiation-chemical degradation – has got some advantages. It does not involve high temperatures and expensive reagents. In this study, the effective OCP degradation was observed under irradiation of residuals of the active substance of ‘Hexachloran dust’ pesticide formulation, intended for utilization. Parameters for the preparation powder (dry form) exposure to electron beam are discussed. It is shown that at the exposure to electron beam at dose of 100 kGy, the degradation degree of hexachlorocyclohexane (HCH) isomers in a composition of active substance achieves 56.2–66.3%.

A very rapid in situ Kikuchi technique to determine relative crystal misorientation

1988 ◽  
Vol 46 ◽  
pp. 830-831
Author(s):  
J. I. Bennetch
Keyword(s):  
Electron Beam ◽  
Analytical Techniques ◽  
Superplastic Forming ◽  
The Other ◽  
Kikuchi Pattern ◽  
Kikuchi Line ◽  
Line Analysis

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.

Endo-D-galacturonanase immobilized by adsorption on porous polyethyleneterephthalate

1982 ◽  
Vol 47 (10) ◽  
pp. 2716-2723 ◽  
Author(s):  
Lubomíra Rexová-Benková ◽  
Jiřina Omelková ◽  
Vladimír Kubánek
Keyword(s):  
Ionic Strength ◽  
High Stability ◽  
Relative Activity ◽  
Operational Stability ◽  
The Other ◽  
Fixation Strength ◽  
Action Pattern ◽  
Salt Solutions ◽  
Buffer Solution ◽  
Degradation Degree

Endo-D-galacturonanase of Aspergillus sp. was irreversibly adsorbed on polyethyleneterephthalate in an acetate 0.1 mol l-1 buffer solution of pH 4.2. Immobilization of the enzyme resulted in lowering of its activity, the measure of which depended on the amount of the enzyme fixed on the carrier. The highest relative activity (42.4%) had the preparation containing 5.25 mg of the enzyme per 1 g of the carrier. The velocity and intensity of the sorption of the enzyme depended on the ionic strength of the medium, whilst pH, on the other hand, was of no influence. Endo-D-galacturonanase immobilized in a 0.1 mol l-1 buffer was characteristic a) of its fixation strength in salt solutions of various ionic strength and pH, in a 3 mol l-1 guanidine solution, and also in sodium pectate and pectin solutions, b) of its high stability during a long-lasting storage at 4 °C, c) of its operational stability. The immobilization led to a partial change of the action pattern onto the high-molecular substrate, manifested in lowering the decrease of viscosity to degradation degree ratio.

scholarly journals Influence of artificial aging: mechanical and physicochemical properties of dental composites under static and dynamic compression

2021 ◽  
Author(s):  
D. C. Gornig ◽  
R. Maletz ◽  
P. Ottl ◽  
M. Warkentin
Keyword(s):  
Mechanical Properties ◽  
Water Sorption ◽  
Artificial Aging ◽  
Filler Content ◽  
Dynamic Compression ◽  
The Other ◽  
Chemical Degradation ◽  
Dental Composites ◽  
Compression Tests ◽  
Acid Ph

Abstract Objective The aim of the study was to evaluate the influence of filler content, degradation media and time on the mechanical properties of different dental composites after in vitro aging. Materials and Methods Specimens (1 mm3) of three commercially available composites (GrandioSO®, Arabesk Top®, Arabesk Flow®) with respect to their filler content were stored in artificial aging media: artificial saliva, ethanol (60%), lactic acid (pH 5) and citric acid (pH 5). Parameters (Vickers microhardness, compressive strength, elastic modulus, water sorption and solubility) were determined in their initial state (control group, n = 3 for microhardness, n = 5 for the other parameters) and after 14, 30, 90 and 180 days (n = 3 for microhardness, n = 5 for the other parameters for each composite group, time point and media). Specimens were also characterized with dynamic-mechanical-thermal analysis (compression tests, F =  ± 7 N; f = 0.5 Hz, 1 Hz and 3.3 Hz; t = 0–170 °C). Results Incorporation of fillers with more than 80 w% leads to significantly better mechanical properties under static and dynamic compression tests and a better water sorption behavior, even after chemical degradation. The influence of degradation media and time is of subordinate importance for chemical degradation. Conclusion Although the investigated composites have a similar matrix, they showed different degradation behavior. Since dentine and enamel occur only in small layer thickness, a test specimen geometry with very small dimensions is recommended for direct comparison. Moreover, the use of compression tests to determine the mechanical parameters for the development of structure-compatible and functionally adapted composites makes sense as an additional standard. Clinical relevance Preferential use of highly filled composites for occlusal fillings is recommended.

scholarly journals Transient fields produced by a cylindrical electron beam flowing through a plasma

2012 ◽  
Vol 30 (3) ◽  
pp. 497-507
Author(s):  
Marie-Christine Firpo
Keyword(s):  
Magnetic Field ◽  
Electron Beam ◽  
Laplace Transform ◽  
Control Parameter ◽  
Bessel Functions ◽  
Skin Depth ◽  
The Other ◽  
Beam Radius ◽  
Equilibrium Situation ◽  
Detailed Computation

AbstractThe out-of-equilibrium situation in which an initially sharp-edged cylindrical electron beam, that could, e.g., model electrons flowing within a wire, is injected into a plasma is considered. A detailed computation of the subsequently produced magnetic field is presented. The control parameter of the problem is shown to be the ratio of the beam radius to the electron skin depth. Two alternative ways to address analytically the problem are considered: one uses the usual Laplace transform approach, the other one involves Riemann's method in which causality conditions manifest through some integrals of triple products of Bessel functions.

scholarly journals Density gradient effects on beam plasma linear instabilities for fast ignition scenario

2006 ◽  
Vol 24 (2) ◽  
pp. 269-273 ◽  
Author(s):  
ANTOINE BRET ◽  
CLAUDE DEUTSCH
Keyword(s):  
Electron Beam ◽  
Relativistic Electron ◽  
Density Gradient ◽  
Relativistic Electron Beam ◽  
Fast Ignition ◽  
The Other ◽  
Inertial Fusion ◽  
Linear Phase ◽  
Unstable System ◽  
Gradient Effects

In the fast ignition scenario for inertial fusion, a relativistic electron beam is supposed to travel from the side of the fusion pellet to its core. One one hand, a relativistic electron beam passing through a plasma is a highly unstable system. On the other hand, the pellet core is denser than its side by four orders of magnitude so that the beam makes its way through a important density gradient. We here investigate the effect of this gradient on the instabilities. It is found that they should develop so early that gradient effects are negligible in the linear phase.

The radiation-chemical degradation of polytetrafluoroethylene to low-molecular and functionalized perfluorinated compounds

1985 ◽  
Vol 29 (1-2) ◽  
pp. 234
Author(s):  
Klaus Lunkwitz ◽  
Armin Ferse ◽  
Hans-Jürgen Brink ◽  
Dietmar Handte ◽  
Udo Gross
Keyword(s):  
Perfluorinated Compounds ◽  
Chemical Degradation ◽  
Radiation Chemical

Radiation-chemical degradation of the paper insulation of power transformers

2005 ◽  
Vol 39 (3) ◽  
pp. 196-197
Author(s):  
V. N. Bondareva ◽  
V. B. Komarov ◽  
A. F. Seliverstov ◽  
B. G. Ershov ◽  
M. Yu. L’vov ◽  
...  
Keyword(s):  
Chemical Degradation ◽  
Power Transformers ◽  
Radiation Chemical ◽  
Paper Insulation

Studies of Australian Soft Corals. XII. Further Cembranolide Diterpenes from Lobophytum crassospiculatum and a Correction of a Previous Stereochemical Assignment

1979 ◽  
Vol 32 (6) ◽  
pp. 1273 ◽  
Author(s):  
A Ahond ◽  
BF Bowden ◽  
JC Coll ◽  
J Fourneron ◽  
SJ Mitchell
Keyword(s):  
Spectroscopic Data ◽  
The Other ◽  
Chemical Degradation ◽  
Soft Corals ◽  
Stereochemical Assignment ◽  
Derivatives Of

Three new cembranolide diterpenes from Lobophytum crassospiculatum are reported. The structure of one of these was deduced from spectroscopic data and chemical degradation, then confirmed as (E,E,E)-6,10,14-trimethyl-3-methylene-trans-3a,4,7,8,11,12,15,15a- octahydrocyclotetradeca[b]furan-2(3H)-one (3), by synthesis from the previously reported (2). The other two diterpenes,(4) and (5), are shown to be the epimeric 15-acetoxyl derivatives of (2).

scholarly journals ANALYZING THE EFFECT OF MICRO RUBBER, MICRO SIO2, AND NANO SIO2 IN MICROCRACKS IN SELF-CONSOLIDATING CONCRETE (SEM OBSERVATION)

2021 ◽  
Vol 30 (1) ◽  
Author(s):  
Ehsan Adili ◽  
Moein Riginejad
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Secondary Electron ◽  
Point Of View ◽  
The Other ◽  
Self Consolidating Concrete ◽  
Nano Sio2 ◽  
Rubber Waste ◽  
Scanning Electron

The present study is an attempt to analyze the effect of micro rubber waste in self- consolidating concrete (SCC) and to compare the concrete containing SCC with conventional additives such as micro SiO2 and nano SiO2. The use of rubber waste can be substantially important from the environmental point of view. Hence, concrete specimens containing 1, 3 and 5% micro rubber waste were made. Moreover, specimens containing 1, 3 and 5% nano SiO2 and 4, 8 and 12% micro SiO2 were prepared to compare their behaviour and microstructure with each other and with the witness specimens. The effect of the other parameters such as the specimen age and the w/c ratio on the microstructure of concrete containing rubber waste was also studied. Thereafter, the specimens were imaged using a scanning electron microscope (SEM) to observe and compare the microcracks in the concrete and secondary electron beam (SE) was used to obtain their images. The results of the microstructural consideration of different specimens showed that 1% of micro rubber waste can improve the behaviour of self-consolidating concrete, but the concrete microstructure strength and quality decline with an increase in its amount.

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