scholarly journals PREDICTIVE MODEL FOR DETERMINING THE MASS OF BHA AND BHT TO BE ADDED IN COMMERCIAL BIODIESEL

Química Nova ◽  
2021 ◽  
Author(s):  
Felipe Savada ◽  
Hagata Silva ◽  
Ana Mantovani ◽  
Letícia Chendynskic ◽  
Karina Angilelli ◽  
...  

Biodiesel is a biofuel produced by the esterification reaction. It is an option to replace fossil fuels, mainly diesel, due to its similar physical and chemical properties. In this research, a mathematical modeling was performed to predict the antioxidant mass to be added in a commercial biodiesel to achieve the minimum oxidative stability provided by the legislation. An equation for each additive was proposed, with the mass of these antioxidants considered as dependent variables and the conformity parameters as independent ones, obtaining multiple regression equations without intercept. The BHA and BHT antioxidants were used. The equations provided were lower at the 5% level and presented determination coefficients (R²) equal to 0.9790 and 0.9770 for the BHA and BHT, respectively, proving their predictability ability and also showing that they can be used to estimate the antioxidant mass to be added in a biodiesel to reach the current regulations.

2021 ◽  
pp. 50-56
Author(s):  
А. В. Хільковець

Nitrogen-containing heterocyclic compounds are widely represented in modern organic chemistry. A special place among the huge number of substances presented is occupied by derivatives of 1,2,4-triazole due to their uniqueness and prospects. In recent years, these derivatives have remained the object of close attention of both synthetic chemists and researchers engaged in the search for new biologically active substances of a wide spectrum of action, the synthesis of optical materials, dyes, corrosion inhibitors, veterinary drugs, etc. It is known from the literature that the combination of the aromatic heterocycle of thiophene and 1,2,4-triazole is a promising area for research. The result of such combinations is a number of compounds obtained with fairly high yields and a wide range of activities. Thus, further chemical modification of 1,2,4-triazole derivatives by additional administration of a typical thiophene pharmacophore is an urgent task. The aim of the study is to obtain new compounds in a number of S-substituted 5-thiophene-(3-ylmethyl)-4R-1,2,4-triazole-3-thiols and study their physico-chemical properties using complex analysis methods. The study of the physical and chemical properties of the compounds obtained was carried out according to methods that meet the standards of the state pharmacopoeia of Ukraine. The synthesis of new compounds was carried out according to generally accepted methods. The previously obtained 5-thiophene-(3-ylmethyl)-4h-1,2,4-triazole-3-thiol and 5-thiophene-(3-ylmethyl)-4-phenyl-1,2,4-triazole-3-thiol were used as starting compounds. Preparation of thioethanones was performed in an alkaline medium in the presence of methanol. The acids were obtained in an alcohol-alkaline medium with the addition of monochloroacetic acid. To obtain esters, two conventional methods were used. The first method is based on the alkylation in an alkaline-alcohol medium of the starting thiols with isopropyl ester of monochloroacetic acid. The second method is the classical esterification reaction. To confirm the structure and study of the physical and chemical properties, all the resulting compounds were crystallized. As a result, some new compounds that were not previously described were obtained, namely: thioethanones, thioacetamides, thioacetic acids, thioacetates, and a number of other thiopo-derivatives of these initial compounds. The structure and individuality of the obtained molecules were confirmed by elemental analysis (CHNS), IR and 1H NMR spectra. A number of new S-derivatives of 5-thiophene-(3-ylmethyl)-4R-1,2,4-triazole-3-thiols have been obtained. The physical and chemical properties of the obtained compounds are determined and their structure is confirmed using modern analysis methods. Some compounds will be transferred for further research.


Author(s):  
T.C. Tso ◽  
D. Hoffmann ◽  
G Rathkamp

AbstractSimple correlation and multiple regressions among 160 variables of leaf characteristics and smoke constituents were calculated, based on experimental cigarettes made from 4 cultivars of bright-type tobacco, each from 8 stalk positions. Smoke composition is a function of the botanical, physical, and chemical properties of leaf tobacco used to make the cigarette. Detailed simple correlation data, multiple-regression equations, and expressions of variety and stalk position as factors of TPM and BaP formation are presented.


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 11
Author(s):  
Dmitry Alexandrovich Korolchenko ◽  
Tatiana Yurievna Eremina

Mathematical and experimental research plays an active role in fire protection investigation. The choice of optimal conditions for the experimental program is the main methodological part of this research. The peculiarities of new fire-protective compositions were investigated. Many experiments in this work are aimed at the investigation of the physical and chemical properties of the materials.


2018 ◽  
Vol 189 ◽  
pp. 00006
Author(s):  
Marco Fiala ◽  
Luca Nonini

Biomass includes all materials that contain organic carbon bound in the chemical structure of molecules, resulting from the chlorophylline photosynthesis, carried out by autotrophies organisms. Lots of biomass from agricultural, agri-food and forestry sectors can be used for energy purposes, representing an essential renewable energy source that, if appropriately managed, can help to reduce the negative environmental impacts arising from the exploitation of fossil fuels. The possibility of using biomass for a specific production process mainly depends on its physical and chemical properties. This paper is organized in two sections: in the first one, the most important biomass used worldwide for energy generation (thermal energy and/or electric energy), as well as its properties, are described. In the second one, the main biomass-to-energy processes (thermochemical and biochemical conversions) are shortly explained. Finally, some emerging techniques (such as bio-methane and bio-hydrogen production) are discussed in more detail.


1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.


2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.


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