scholarly journals Coupling experimental data and a prototype model to probe the physical and chemical processes of 2,4-dinitroimidazole solid-phase thermal decomposition

1998 ◽  
Author(s):  
R. Behrens ◽  
L. Minier ◽  
S. Bulusu
Keyword(s):  
Experimental Data ◽  
Thermal Decomposition ◽  
Solid Phase ◽  
Chemical Processes ◽  
Prototype Model ◽  
Physical And Chemical

scholarly journals Biological decolourization of textile industry wastewater by a developed bacterial consortium

2019 ◽  
Vol 80 (10) ◽  
pp. 1910-1918
Author(s):  
Hewayalage Gimhani Madhushika ◽  
Thilini U. Ariyadasa ◽  
Sanja H. P. Gunawardena
Keyword(s):  
Textile Industry ◽  
Solid Phase ◽  
Bacterial Consortium ◽  
Chemical Processes ◽  
Biological Processes ◽  
Bacterial Strains ◽  
Morganella Morganii ◽  
Treatment Processes ◽  
Physical And Chemical ◽  
Industry Effluent

Abstract Most currently employed textile effluent decolourization methods use physical and chemical processes where dyes do not get degraded instead concentrated or transferred into a solid phase. Therefore, further treatment processes are required to destroy dyes from the environment. In contrast, biological decolourization may result in degradation of the dye structure due to microbial activities and hence biological processes can be considered environmentally friendly. In the present study, bacterial strains with dye decolourization potential were isolated from the natural environment and their ability to decolourize four different reactive textile dyes was studied individually and in a bacterial consortium. The developed bacterial consortium composed with Proteus mirabilis, Morganella morganii and Enterobacter cloacae indicated more than 90% color removals for all four dyes and optimum decolourization of the dye mixture was observed at 40 °C and pH 7. The developed bacterial consortium decolourized 60% of dyes in textile industry effluent at 35 °C and pH 7 showing their ability to endure in highly complex and toxic environments and application in textile industry wastewaters.

The Theoretical Evaluation of Localised Corrosion in Radioactive Waste Canisters.

1986 ◽  
Vol 84 ◽  
Author(s):  
S.M. Sharland
Keyword(s):  
Experimental Data ◽  
Radioactive Waste ◽  
Growth Rates ◽  
Crevice Corrosion ◽  
Chemical Processes ◽  
Uniform Corrosion ◽  
Theoretical Evaluation ◽  
Input Parameters ◽  
Physical And Chemical

AbstractUnder repository conditions, it is likely that radioactive waste canisters will be subjected to both uniform and localised corrosion. Localised corrosion can take many forms depending on the precise physical and chemical environment of the metal at the time of attack, but generally the rates of penetration are much greater than those associated with uniform corrosion. The most likely forms under aerated repository conditions are pitting and crevice corrosion. To ensure adequate radionuclide containment an allowance for these rates must be included in the final canister dimensions. It is considered the best way to predict long term penetration rates is to develop mathematical models, which include all the physical and chemical processes necessary to describe the system and use experimentally determined input parameters relating to these processes. These models must then draw on further experimental data for validation over short timescales. In this paper, we discuss several techniques of modelling long term pit propagation in waste canisters. The complexity of the problem has lead to a number of physical and chemical approximations in the modelling. We investigate the applicability and ranges of validity of several of the more common approximations, both in our own models and in the literature, and compare the predictions with experimental pit growth rates. An investigatation of the sensitivity of the models to the various empirical input parameters indicates which need to be determined most accurately.

scholarly journals The Heuristic Model Based on LPR in the Context of Material Conversion

2017 ◽  
Vol 62 (3) ◽  
pp. 1603-1607
Author(s):  
D. Wilk-Kołodziejczyk ◽  
S. Kluska-Nawarecka ◽  
E. Nawarecki ◽  
B. Śnieżyński ◽  
K. Jaśkowiec ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mechanical Properties ◽  
Chemical Processes ◽  
Analytical Models ◽  
Process Conditions ◽  
Heuristic Model ◽  
High Complexity ◽  
Model Based ◽  
The Cost ◽  
Physical And Chemical

AbstractHigh complexity of the physical and chemical processes occurring in liquid metal is the reason why it is so difficult, impossible even sometimes, to make analytical models of these phenomena. In this situation, the use of heuristic models based on the experimental data and experience of technicians is fully justified since, in an approximate manner at least, they allow predicting the mechanical properties of the metal manufactured under given process conditions. The study presents a methodology applicable in the design of a heuristic model based on the formalism of the logic of plausible reasoning (LPR). The problem under consideration consists in finding a technological variant of the process that will give the desired product parameters while minimizing the cost of production. The conducted tests have shown the effectiveness of the proposed approach.

scholarly journals Study of the well near-bottomhole zone permeability during treatment by process fluids

2020 ◽  
Vol 242 ◽  
pp. 169
Author(s):  
Evgenii ROGOV
Keyword(s):  
Solid Phase ◽  
Chemical Processes ◽  
Negative Consequences ◽  
Drilling Mud ◽  
Reservoir Properties ◽  
Clay Particles ◽  
Increase Productivity ◽  
Process Fluid ◽  
Cementing Material ◽  
Physical And Chemical

In the process of drilling-in productive horizons, several irreversible physical and chemical processes take place in the near-wellbore zone of the formation: stress state of the rocks changes, penetration of the filtrate and solid phase, as well as drilling mud into the reservoir, and swelling of clay particles of intergranular cementing material are observed. As a result, permeability of productive horizon is significantly reduced and, consequently, potential inflow of oil or gas from formation is excluded. An equally serious problem exists during well servicing and workover, when the use of irrational fluids of well killing causes negative consequences associated with deterioration of reservoir properties of formations in the wells being repaired. Article presents the results of the experiments on permeability of clayed porous samples after exposure to various compositions of liquids. In order to increase permeability of near-borehole zone of the formation and increase productivity of wells completed by drilling, and after well servicing and workover, a composition of the process fluid containing a 15 % aqueous solution of oxyethylene diphosphonic acid (OEDA) with addition of a surfactant is proposed.

Nucleophilicity and its parametrization

1989 ◽  
Vol 54 (1) ◽  
pp. 117-135
Author(s):  
Oldřich Pytela ◽  
Vítězslav Zima
Keyword(s):  
Regression Analysis ◽  
Linear Correlation ◽  
Correlation Equation ◽  
Chemical Processes ◽  
General Tendency ◽  
Orbital Interaction ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
Two Parameter ◽  
Better Than

The method of conjugate deviations based on the regression analysis has been suggested for construction of a new nucleophilicity scale. This method has been applied to a set of 28 nucleophiles participating in 47 physical and chemical processes described in literature. The two-parameter nucleophilicity scale obtained represents-in the parameter denoted as ND-the general tendency to form a bond to an electrophile predominantly on the basis of the orbital interaction and-in the parameter denoted as PD-the ability to interact with a centre similar to the proton (basicity). The linear correlation equation involving the ND, PD parameters and the charge appears to be distinctly better than the most significant relations used. The correlation dependences have the physico-chemical meaning. From the position of individual nucleophiles in the space of the ND and PD parameters, some general conclusions have been derived about the factors governing the reactivity of nucleophiles.

The Tree

2018 ◽  
Author(s):  
Andrew Steane
Keyword(s):  
Carbon Capture ◽  
Chemical Processes ◽  
Physical And Chemical

The life of an ordinary tree is described, in terms of the main physical and chemical processes: carbon capture by photosynthesis; entropy and energy; moisture. The information expressed in the tree comes partly from the DNA and partly from the sunlight. The tree does not push upwards from the ground, but solidifies the air.

scholarly journals Control of Physical and Chemical Processes with Nonlocal Metal–Dielectric Environments

ACS Photonics ◽  
2019 ◽  
Vol 6 (12) ◽  
pp. 3039-3056 ◽  
Author(s):  
Vanessa N. Peters ◽  
Srujana Prayakarao ◽  
Samantha R. Koutsares ◽  
Carl E. Bonner ◽  
Mikhail A. Noginov
Keyword(s):  
Chemical Processes ◽  
Physical And Chemical

scholarly journals Thermal decomposition of tris(O-ethyldithiocarbonato)-antimony(III)—a single-source precursor for antimony sulfide thin films

2021 ◽  
Author(s):  
Jako S. Eensalu ◽  
Kaia Tõnsuaadu ◽  
Jasper Adamson ◽  
Ilona Oja Acik ◽  
Malle Krunks
Keyword(s):  
Thin Films ◽  
Thermal Decomposition ◽  
Mass Loss ◽  
Solid Phase ◽  
Evolved Gas Analysis ◽  
Gas Analysis ◽  
Thermal Decomposition Mechanism ◽  
Product Analysis ◽  
Gaseous Species ◽  
Single Source Precursor

AbstractThermal decomposition of tris(O-ethyldithiocarbonato)-antimony(III) (1), a precursor for Sb2S3 thin films synthesized from an acidified aqueous solution of SbCl3 and KS2COCH2CH3, was monitored by simultaneous thermogravimetry, differential thermal analysis and evolved gas analysis via mass spectroscopy (TG/DTA-EGA-MS) measurements in dynamic Ar, and synthetic air atmospheres. 1 was identified by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) measurements, and quantified by NMR and elemental analysis. Solid intermediates and final decomposition products of 1 prepared in both atmospheres were determined by X-ray diffraction (XRD), Raman spectroscopy, and FTIR. 1 is a complex compound, where Sb is coordinated by three ethyldithiocarbonate ligands via the S atoms. The thermal degradation of 1 in Ar consists of three mass loss steps, and four mass loss steps in synthetic air. The total mass losses are 100% at 800 °C in Ar, and 66.8% at 600 °C in synthetic air, where the final product is Sb2O4. 1 melts at 85 °C, and decomposes at 90–170 °C into mainly Sb2S3, as confirmed by Raman, and an impurity phase consisting mostly of CSO 2 2− ligands. The solid-phase mineralizes fully at ≈240 °C, which permits Sb2S3 to crystallize at around 250 °C in both atmospheres. The gaseous species evolved include CS2, C2H5OH, CO, CO2, COS, H2O, SO2, and minor quantities of C2H5SH, (C2H5)2S, (C2H5)2O, and (S2COCH2CH3)2. The thermal decomposition mechanism of 1 is described with chemical reactions based on EGA-MS and solid intermediate decomposition product analysis.

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