complex chemical reactions
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2021 ◽  
Vol 2131 (2) ◽  
pp. 022007
Author(s):  
O V Dubinets ◽  
I M Gubaidullin ◽  
R M Uzyanbaev ◽  
M K Vovdenko ◽  
I G Lapshin

Abstract Annotation. One of the main problems in chemical kinetics is the establishment of the mechanisms of complex chemical reactions. The inverse problem of chemical kinetics is understood as the determination of the dependence of the concentration of the participating components on the basis of experimental data obtained from a laboratory installation for the oxidative regeneration of coked catalysts. One of the main methods used in inverse problems the genetic algorithm. The algorithms considered in the article make it possible to determine the values of the rate constants of the considered chemical stages.


Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7230
Author(s):  
Denis Constales ◽  
Gregory Yablonsky ◽  
Yiming Xi ◽  
Guy Marin

In this paper, two main ideas of chemical kinetics are distinguished, i.e., a hierarchy and commensuration. A new class of chemical kinetic models is proposed and defined, i.e., egalitarian kinetic models (EKM). Contrary to hierarchical kinetic models (HKM), for the models of the EKM class, all kinetic coefficients are equal. Analysis of EKM models for some complex chemical reactions is performed for sequences of irreversible reactions. Analytic expressions for acyclic and cyclic mechanisms of egalitarian kinetics are obtained. Perspectives on the application of egalitarian models for reversible reactions are discussed. All analytical results are illustrated by examples.


Heritage ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 3402-3420
Author(s):  
Francesca Caterina Izzo ◽  
Arja Källbom ◽  
Austin Nevin

The characteristics of commercially available refined and bodied linseed and tung oils, used as binders in the production of armour paints after historic recipes, are explored. Employed as anticorrosive paints mainly from the 1920s to 1960s, armour paints are greener alternatives that can be used for protection in industrial heritage conservation. Using a multi-analytical approach, chemical and physical properties of the fresh oils and solid films before and after accelerated ageing (ISO 16474-2:2013) were investigated to better understand which features are beneficial for the technical function of armour paints. Tests included measurements of density, the refractive index, insoluble impurities, alkaline impurities, the water content, the iodine value, the saponification value, the free fatty acid concentration, the acid value, the peroxide value and colour (Lovibond) and cold tests. The characterisation of the fresh oils using molecular analysis with FTIR and GC-MS revealed the complexity of the commercial formulations, for which additions of semi- and non-drying oils were detected. The results show that organic paint binders follow complex chemical reactions (such as oxidation and decrease of unsaturation being variable or swelling following water-immersion tests), with implications for their suitability for use in protection.


Author(s):  
Vasyl M. Trysnyuk ◽  
Viktor O. Shumeiko ◽  
Yuriy M. Holowan

The basic mechanisms of pollution of the surface atmosphere and upper soil layer emission car transport roadside strip. Road transport, together with heavy industry, is one of the main air pollutants. Exhaust gases, crankcase gases, smoke, soot lead to complex chemical reactions in the surface layer of the atmosphere. Presented a number of methods to assess the level of contamination, analyses their strengths and weaknesses. Considered methodology issuance previous forecast spread of contamination including disturbing factors and their impact on the concentration of contaminants, as well as mathematical tools to determine the quantitative characteristics of concentration levels pollutants substances. The developed methodology is one of the ways to issue a preliminary forecast of the spread of pollution, taking into account disturbing factors in the presence of a priori data. This methodology takes into account a set of factors influencing the level of pollution concentration and the empirically obtained functional dependences of the influence of each of the disturbing components on the level of pollution. The constructed model of interaction of the established factors in the form of the graph of interaction characterizes causal relations.


2021 ◽  
Author(s):  
Toshihiro Konishi ◽  
Ryosuke Miura

Abstract The current periodic table does not necessarily have a clear position for transition elements. Therefore, the purpose of this paper is to use the basic principle discovered by Mendeleev as it is and to create a periodic ta ble with consistency for transition elements. By setting some hypotheses, it was found that transition elements also have regular periodicity, so we succeeded in clarifying the energy level of electrons in each orbit. In addition, by utilizing its periodic ity, the electron configuration for each orbit was predicted for unknown elements. In this paper, we did not take the conventional idea of electron orbitals, that is, the idea of forming a hybrid orbital, but assumed a new orbital.Since the state in which electrons fit in orbits and stabilize is defined as an octet, this idea was used as the basic principle in this paper, but the hypothesis that "there are only three orbits in each shell" was established and verified.The calculatio n of the energy level of the electrons on the orbit became extremely easy, and the order of each orbit could be clarified. It was also found that the three dimensional structure of the molecule may be visualizedby paying attention to the valence electrons of the outermost shell of the element and the octet of the stability condition. Therefore, in this paper, by slightly expanding the structural formula of Kekulé, it became possible to easily determine whether or not the molecule synthesized by the became possible to easily determine whether or not the molecule synthesized by the bond bebond between elements is stable.tween elements is stable. In addition, it has become possible to predict the three In addition, it has become possible to predict the three--dimensional structure of the dimensional structure of the molecule as well.molecule as well. Furthermore, not only will it be easier for students studying chemistry to understand Furthermore, not only will it be easier for students studying chemistry to understand complex chemical reactions, but it will complex chemical reactions, but it will also be useful for researchers in the development also be useful for researchers in the development and research of new drugs.and research of new drugs.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2483
Author(s):  
Danutė Vaičiukynienė ◽  
Aras Kantautas ◽  
Simona Tučkutė ◽  
Fallon Manhanga ◽  
Eugenijus Janavičius ◽  
...  

Concrete plants accumulate large amounts of concrete wash water. This water, which pH is highly alkaline, has a negative impact on the environment. Its reuse in fresh concrete slightly reduces its mechanical properties. The combination of concrete wash water and zeolitic by-product led to an increase of 4.6% in the compressive strength at 7 days hydration and up to 30% at 28 days hydration. The same combination led to the denser microstructure compared to the samples made with concrete wash water. This could be explained by the pozzolanic reaction of the zeolitic by-product. The complex chemical reactions of cement, zeolitic by-product, and fines presented in the concrete wash water occurred. Therefore, it was suggested the reusing method of concrete wash water together with zeolitic by-product in the fresh concrete mixtures by substituting some amount of tap water with concrete wash water. In this way, the consumption of tap water is possible to reduce in cement systems.


Metabolites ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 184
Author(s):  
Takoua Jendoubi

Metabolomics deals with multiple and complex chemical reactions within living organisms and how these are influenced by external or internal perturbations. It lies at the heart of omics profiling technologies not only as the underlying biochemical layer that reflects information expressed by the genome, the transcriptome and the proteome, but also as the closest layer to the phenome. The combination of metabolomics data with the information available from genomics, transcriptomics, and proteomics offers unprecedented possibilities to enhance current understanding of biological functions, elucidate their underlying mechanisms and uncover hidden associations between omics variables. As a result, a vast array of computational tools have been developed to assist with integrative analysis of metabolomics data with different omics. Here, we review and propose five criteria—hypothesis, data types, strategies, study design and study focus— to classify statistical multi-omics data integration approaches into state-of-the-art classes under which all existing statistical methods fall. The purpose of this review is to look at various aspects that lead the choice of the statistical integrative analysis pipeline in terms of the different classes. We will draw particular attention to metabolomics and genomics data to assist those new to this field in the choice of the integrative analysis pipeline.


Author(s):  
Takoua Jendoubi

Metabolomics deals with multiple and complex chemical reactions within living organisms and how these are influenced by external or internal perturbations. It lies at the heart of omics profiling technologies not only as the underlying biochemical layer that reflects information expressed by the genome, the transcriptome and the proteome, but also as the closest layer to the phenome. The combination of metabolomics data with the information available from genomics, transcriptomics, and proteomics offers unprecedented possibilities to enhance current understanding of biological functions, elucidate their underlying mechanisms and uncover hidden associations between omics variables. As a result, a vast array of computational tools have been developed to assist with integrative analysis of metabolomics data with different omics. Here, we review and propose five criteria – hypothesis, data types, strategies, study design and study focus – to classify statistical multi-omics data integration approaches into state-of-the-art classes under which all existing statistical methods fall. The purpose of this review is to look at various aspects that lead the choice of the statistical integrative analysis pipeline in terms of the different classes. We will draw a particular attention to metabolomics and genomics data to assist those new to this field in the choice of the integrative analysis pipeline.


Author(s):  
Varsha N, Malavika B Vyshnavi V Rao and ShamsiyaRizwana

Human body coordinates through chemical signals released by the brain. Chemical signals play a major role in bio-regulatory reactions responsible for emotions. Emotions are complex chemical reactions in nervous systemcharacterized by neurophysiologic changes associated with thoughts and behavioral responses. On pinching, one can cry, skin becomes hot, heart beat increases and our brain desires to shout out loud or hit something in return. We experience a sudden influx of physical and mental stimuli underlying a basic emotion. A person experiences diverse emotions throughout the day that are helpful in learning, reasoning and creativity. Emotions are one the most central and pervasive aspects of human experience. Emotions motivate empathic and moral behavior and play a role in an individual’s sense of self. While emotions enrich human experience they can also cause dramatic disruptions of judgment and performance. Since ancient days psychiatrists have been cracking the brain process responsible for emotions. Greeks were the first to find the link between the physical body and human emotional responses. Human brain is a complex network that transmit information every second via neurons through chemicals called neurotransmitters such as dopamine, serotonin etc. These chemicals essentially let the organs communicate with each other and express the emotions such as anger and happiness. Analysis of hormones and their effects on human behavior is a major contribution of biochemistry to the understanding of emotions and related behavior. In this article we are trying to provide an in-depth knowledge about chemistry of emotion which we experience every day.


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