scholarly journals Biomass and biofuels

2018 ◽  
Vol 189 ◽  
pp. 00006
Author(s):  
Marco Fiala ◽  
Luca Nonini
Keyword(s):  
Chemical Structure ◽  
Fossil Fuels ◽  
Electric Energy ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Specific Production ◽  
Structure Of Molecules ◽  
Energy Processes ◽  
Physical And Chemical ◽  
And Chemical Properties

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.

scholarly journals Analysis of oxidation degree of graphite oxide and chemical structure of corresponding reduced graphite oxide by selecting different-sized original graphite

RSC Advances ◽  
2018 ◽  
Vol 8 (31) ◽  
pp. 17209-17217 ◽  
Author(s):  
Lu Shen ◽  
Lihua Zhang ◽  
Kui Wang ◽  
Lijing Miao ◽  
Qiaofeng Lan ◽  
...  
Keyword(s):  
Graphite Oxide ◽  
Chemical Structure ◽  
Chemical Properties ◽  
Thermal Reduction ◽  
Physical And Chemical Properties ◽  
Oxidation Degree ◽  
Reduced Graphite Oxide ◽  
Physical And Chemical ◽  
And Chemical Properties

The thermal reduction of GO is the most commonly used strategy for preparation of rGO, and the oxidation degree of GO would influence the chemical structure of prepared rGO, thereby affecting its physical and chemical properties.

scholarly journals Topological Aspects of Boron Nanotubes

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jia-Bao Liu ◽  
Hani Shaker ◽  
Imran Nadeem ◽  
Muhammad Hussain
Keyword(s):  
Thermal Stability ◽  
Electronic Properties ◽  
Chemical Structure ◽  
Chemical Properties ◽  
Topological Indices ◽  
The Other ◽  
Theoretical Studies ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

The degree-based topological indices are used to correlate the physical and chemical properties of a molecule with its chemical structure. Boron nanotubular structures are high-interest materials due to the presence of multicenter bonds and have novel electronic properties. These materials have some important issues in nanodevice applications like mechanical and thermal stability. Therefore, they require theoretical studies on the other properties. In this paper, we present certain degree-based topological indices such as ABC, the fourth ABC, GA, and the fifth GA indices for boron triangular and boron-α nanotubes.

scholarly journals The absorption spectra of the vapours of benzene and its homologues at different temperatures and pressures, and likewise of solutions of benzene

1908 ◽  
Vol 80 (537) ◽  
pp. 162-165 ◽  
Keyword(s):  
Absorption Spectra ◽  
Chemical Structure ◽  
Constant Pressure ◽  
Chemical Properties ◽  
Complete Agreement ◽  
Physical And Chemical Properties ◽  
Different Temperatures ◽  
Temperature And Pressure ◽  
Physical And Chemical ◽  
And Chemical Properties

The author having been engaged since the year 1877 in investigating and correlating the physical and chemical properties of aromatic substances in relation to their chemical structure or constitution, he has latterly found it desirable that several very definite compounds should be examined in a state of vapour, as well as in solution. The work of E. Pauer, W. Friederichs, and of L. Grebe is referred to in detail. The vapours of benzene and several of its derivatives have been examined (1) at different temperatures and constant pressure; and (2) at different pressures, the temperature being constant. The previous measurements of Pauer, Friederichs, and Grebe have been confirmed, and reconciled where they do not show complete agreement with each other. The records of temperature and pressure, and the shortening of the exposure of the photographic plates, constitute important differences between the work of the former investigators and that of the author.

scholarly journals Synthesis and structural features of 5-(4-(tert-butyl) phenyl)-4-((R)amino)-4H-1,2,4-triazole-3-thiols

2018 ◽  
pp. 60-65
Author(s):  
I. I. Aksyonova-Seliuk ◽  
O. I. Panasenko ◽  
E. G. Knysh
Keyword(s):  
Chemical Structure ◽  
Chemical Properties ◽  
Biologically Active ◽  
Physical And Chemical Properties ◽  
Tert Butyl ◽  
New Compounds ◽  
Physical And Chemical ◽  
Derivatives Of ◽  
Active Substances ◽  
And Chemical Properties

Chemistry of heterocyclic compounds is one of the most popular sector in organic chemistry. Scientists allocate among them a class of derivatives of 1,2,4-triazole. This class of compounds attracts attention his broad spectrum of biological activity. There are antiviral, anti-inflammatory, anti-tubercular, antimicrobial, antioxidant, actoprotective, anti-cancer and other activities. The derivatives of 1,2,4-triazole have one more important advantage. It is low toxicity. This properties do this class of derivatives promising for researches their chemical structure and biological activity and purposeful search of biologically active substances. The purpose of the work is synthesis of 5-(4-(tert-butyl)phenyl)-4-((R)amino)-4H-1,2,4-triazoles-3-thiols from appropriate ylidene derivatives of 4-amino-5-(4 (tert-butyl)phenyl)-4H-1,2,4-triazoles-3-thiol and research of their physical and chemical properties. The objects of research were 10 new compounds, derivatives of 4-amino-5-(4-(tert-butyl)phenyl)-4H-1,2,4-triazoles-3-thiol. These compounds are the crystal substances which are odorless, insoluble in water and soluble in organic solvents. Investigation of the physical and chemical properties of this compounds was carried out according to the methods listed in the State Pharmacopoeia of Ukraine. The melting temperature of synthesized compounds was determined by device OptiMelt Stanford Research Systems MPA100. The structure of the compound was confirmed by 1H-NMR spectroscopy (Mercury 400) and gas chromatography-mass spectrometry (Agilent 1260 Infinity HPLC). 10 new compounds, derivatives of 4-amino-5-(4-(tert-butyl)phenyl)-4H-1,2,4-triazoles-3-thiol, were synthesized in a study. The chemical structure of the new compounds was confirmed by modern instrumental methods of analysis. Results of the done work can be use in the future search of biologically active substances.

ChemInform Abstract: Quantitative Correlation of Physical and Chemical Properties with Chemical Structure: Utility for Prediction

ChemInform ◽  
2011 ◽  
Vol 42 (20) ◽  
pp. no-no ◽  
Author(s):  
Alan R. Katritzky ◽  
Minati Kuanar ◽  
Svetoslav Slavov ◽  
C. Dennis Hall ◽  
Mati Karelson ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Quantitative Correlation ◽  
Physical And Chemical ◽  
And Chemical Properties

scholarly journals M-Polynomials and Degree-Based Topological Indices of the Crystallographic Structure of Molecules

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 107 ◽  
Author(s):  
Wei Gao ◽  
Muhammad Younas ◽  
Adeel Farooq ◽  
Abid Mahboob ◽  
Waqas Nazeer
Keyword(s):  
Strain Energy ◽  
Chemical Properties ◽  
Quantitative Structure Activity Relationship ◽  
Topological Indices ◽  
Crystallographic Structure ◽  
Physical And Chemical Properties ◽  
Structure Of Molecules ◽  
Structure Activity ◽  
Physical And Chemical ◽  
And Chemical Properties

Topological indices are numerical parameters used to study the physical and chemical properties of compounds. In quantitative structure–activity relationship QSARs, topological indices correlate the biological activity of compounds with their physical properties like boiling point, stability, melting point, distortion, and strain energy etc. In this paper, we determined the M-polynomials of the crystallographic structure of the molecules Cu2O and TiF2 [p,q,r]. Then we derived closed formulas for some well-known topological indices using calculus. In the end, we used Maple 15 to plot surfaces associated with the topological indices of Cu2O and TiF2 [p,q,r].

Quantitative Correlation of Physical and Chemical Properties with Chemical Structure: Utility for Prediction

2010 ◽  
Vol 110 (10) ◽  
pp. 5714-5789 ◽  
Author(s):  
Alan R. Katritzky ◽  
Minati Kuanar ◽  
Svetoslav Slavov ◽  
C. Dennis Hall ◽  
Mati Karelson ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Quantitative Correlation ◽  
Physical And Chemical ◽  
And Chemical Properties

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 ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Oxidative Stability ◽  
Fossil Fuels ◽  
Chemical Properties ◽  
Esterification Reaction ◽  
Regression Equations ◽  
Physical And Chemical Properties ◽  
Dependent Variables ◽  
Physical And Chemical ◽  
And Chemical Properties

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.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

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.

Sign in / Sign up

Export Citation Format

Share Document