scholarly journals Composition and Structure of Coal Organic Mass. Analytical Review

2009 ◽  
Vol 3 (4) ◽  
pp. 315-319
Author(s):  
Vadim Barsky ◽  
◽  
Vitaly Gulyaev ◽  
Andriy Rudnitsky ◽  
◽  
...  
Keyword(s):  
Molecular Structure ◽  
Chemical Structure ◽  
Chemical Potential ◽  
Solid Fuels ◽  
Organic Mass ◽  
Coal Structure ◽  
Critical Comparison ◽  
Composition And Structure ◽  
Analytical Review

The research works dedicated to the formation regularities of solid fuels chemical structure were analyzed. Modern conceptions of coals chemical structure, which are becoming deeper owing to tooling growth and facts accumulation, were examined by means of critical comparison of different hypothetical models of solid fuels “molecular” structure. The most general points of the respective theories were formulated, according to which “soft” influence on coal structure primary elements bonds system allows bringing its chemical potential to the maximum.

scholarly journals Composition and Structure of Coal Organic Mass. 3. Dinamics of Coal Chemical Structure During Metamorphism

2011 ◽  
Vol 5 (3) ◽  
pp. 285-290
Author(s):  
Vadim Barsky ◽  
◽  
Gennady Vlasov ◽  
Andriy Rudnitsky ◽  
◽  
...  
Keyword(s):  
Chemical Structure ◽  
Organic Mass ◽  
Composition And Structure

scholarly journals Demystifying and Unravelling the Factual Molecular Structure of the Biopolymer Sporopollenin

2019 ◽  
Author(s):  
Abanoub Mikhael ◽  
Kristina Jurcic ◽  
Celine Schneider ◽  
David carr ◽  
Gregory L. Fisher ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Nuclear Magnetic Resonance ◽  
Chemical Structure ◽  
Pollen Grains ◽  
Outer Wall ◽  
Mass Spectrometric ◽  
Chemical Degradation ◽  
Ionization Mass ◽  
Soft Ionization ◽  
Biochemical Pathways

<p></p><p>Sporopollenin is a natural, highly cross-linked biopolymer composed of carbon, hydrogen, and oxygen, which forms the outer wall of pollen grains. Sporopollenin is resilient to chemical degradation.<sup> </sup>Because of this stability, its exact chemical structure and the biochemical pathways involved in its biosynthesis remains a mystery and unresolved.<sup> </sup></p> <p>We have identified and characterized the molecular structure of the clean, intact sporopollenin using soft ionization mass spectrometric and nuclear magnetic resonance techniques. These analyses showed that sporopollenin contained a poly(hydroxyacid) dendrimer-like network, which accounted for the sporopollenin empirical formula. In addition, the identified hydroxy acid monomers contained a beta diketone moiety, which most probably accounts for the known antioxidant activity of sporopollenin. Moreover, our elucidation studies allowed us to identify a unique circular polyhydroxylated tetraketide polymer. This polymer acted as the rigid backbone on which the poly(hydroxyacid) network can be built, forming the scaffold of the spherical sporopollenin exine.</p><br><p></p>

scholarly journals Effect of chemical structure and linear density charge of sulfonate-containing aromatic polyamides on interaction with polycations in organic and water-organic media

2019 ◽  
Vol 60 (11) ◽  
pp. 40-47
Author(s):  
Natalya N. Smirnova ◽  
Keyword(s):  
Chemical Structure ◽  
Phase State ◽  
Linear Charge ◽  
Linear Charge Density ◽  
Sodium Sulfonate ◽  
Interpolyelectrolyte Complexes ◽  
Composition And Structure ◽  
Average Size ◽  
Organic Solutions ◽  
Acrylonitrile Copolymers

The interaction of sulfonate-containing aromatic poly- and copolyamides with acrylonitrile copolymers with N,N-dimethyl-N,N-diallylammonium chloride (DMDAAC) and N,N-diethylaminoethylmethacrylate (DEAEM) in organic and water-organic solutions was studied. It was shown that as a result of macromolecular reactions interpolyelectrolyte complexes (IPEC) forms. They are stabilized mainly by electrostatic forces. To characterize the interpolyelectrolyte complexes composition the φ parameter was used, that defines as the ratio of corresponding functional groups molar concentrations of interacting polyelectrolytes. The transformation degree in interpolymer reactions θ was calculated as the ratio of the salt bonds number between polyions to their maximum possible number. It was shown that the main factors determining the composition and structure of forming interpolyelectrolyte complexes are linear charge density of polyelectrolytes, the nature and composition of the solvent in which interpolymer reactions occurs. It is possible to obtain IPEC, the composition of which for the same polycation will vary from φ = 2.5 to φ = 1.0, changing these factors. It was found that at the complexation process is not accompanied by a change in the phase state of the interpolymer system, when the concentration of units with sulfonate groups in the macromolecular polyamide chain 5 mol.%. It was found that the introduction of polycation leads to the formation of IPEC structures in the form of particles with an average size of ~217.7 nm for poly-4,4'-(2-sodium sulfonate) – diphenylaminisophthalamide and ~248.1 nm in the case of poly-4,4'-(2-sodium sulfonate) -diphenylaminterephthalamide. It was shown that the decrease in the polymer content of units with sulfonate groups is accompanied by a decrease in the transformation degree from 0.65-0.66 to 0.18. It was found that the studied complexes can be transferred to the solution by increasing its ionic strength. The result obtained during this work can serve as a base for the development of for the manufacturing technology of film and membrane materials based on sulfonate-containing aromatic poly- and copolyamides.

The effect of molecular structure on the anticancer drug release rate from prodrug nanoparticles

2015 ◽  
Vol 51 (64) ◽  
pp. 12835-12838 ◽  
Author(s):  
Yoshikazu Ikuta ◽  
Yoshitaka Koseki ◽  
Tsunenobu Onodera ◽  
Hidetoshi Oikawa ◽  
Hitoshi Kasai
Keyword(s):  
Molecular Structure ◽  
Controlled Release ◽  
Drug Release ◽  
Anticancer Drug ◽  
Release Rate ◽  
Chemical Structure ◽  
Anticancer Agent ◽  
Drug Release Rate ◽  
Drug Nanoparticles

The controlled release of an anticancer agent from drug nanoparticles could be successfully achieved by optimizing the chemical structure of dimeric compounds as prodrug.

scholarly journals Molecular Descriptors of Nanotube, Oxide, Silicate, and Triangulene Networks

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Wei Gao ◽  
Muhammad Kamran Siddiqui
Keyword(s):  
Molecular Structure ◽  
Carbon Nanotube ◽  
Interconnection Networks ◽  
Chemical Structure ◽  
Chemical Reactivity ◽  
Hexagonal Lattice ◽  
Zagreb Index ◽  
Chemical Graph Theory ◽  
Vertex Degrees ◽  
Carbon Nanotube Networks

A topological index is a real number associated with chemical constitution purporting for correlation of chemical structure with various physical properties, chemical reactivity, or biological activity. The concept of hyper Zagreb index, first multiple Zagreb index, second multiple Zagreb index, and Zagreb polynomials was established in chemical graph theory based on vertex degrees. It is reported that these indices are useful in the study of anti-inflammatory activities of certain chemical networks. In this paper, we study carbon nanotube networks which are motivated by molecular structure of regular hexagonal lattice and also studied interconnection networks which are motivated by molecular structure of a chemical compound SiO4. We determine hyper Zagreb index, first multiple Zagreb index, second multiple Zagreb index, and Zagreb polynomials for some important class of carbon nanotube networks, dominating oxide network, dominating silicate network, and regular triangulene oxide network.

scholarly journals Large, Rapid Swelling of High-cis Polydicyclopentadiene Aerogels Suitable for Solvent-Responsive Actuators

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1033 ◽  
Author(s):  
Despoina Chriti ◽  
Grigorios Raptopoulos ◽  
Benjamin Brandenburg ◽  
Patrina Paraskevopoulou
Keyword(s):  
Molecular Structure ◽  
Organic Solvents ◽  
Catalytic System ◽  
Chemical Sensors ◽  
Material Properties ◽  
Open Porosity ◽  
Ring Opening ◽  
Chemical Structure ◽  
Diffusion Distance ◽  
Metathesis Polymerization

High-cis polydicyclopentadiene (PDCPD) aerogels were synthesized using ring opening metathesis polymerization (ROMP) of dicyclopentadiene (DCPD) with a relatively air-stable ditungsten catalytic system, Na[W2(μ-Cl)3Cl4(THF)2]·(THF)3 (W2; (W3W)6+, a′2e′4), and norbornadiene (NBD)as a co-initiator. These aerogels are compared in terms of chemical structure and material properties with literature PDCPD aerogels obtained using well-established Ru-based alkylidenes as catalysts. The use of NBD as a co-initiator enhances the degree of crosslinking versus the more frequently used phenylacetylene (PA), yielding materials with a controlled molecular structure that would persist solvent swelling. Indeed, those PDCPD aerogels absorb selected organic solvents (e.g., chloroform, tetrahydrofuran) and swell rapidly, in some cases up to 4 times their original volume within 10 min, thus showing their potential for applications in chemical sensors and solvent-responsive actuators. The advantage of aerogels versus xerogels or dense polymers for these applications is their open porosity, which provides rapid access of the solvent to their interior, thus decreasing the diffusion distance inside the polymer itself, which in turn accelerates the response to the solvents of interest.

scholarly journals Topological study of the para-line graphs of certain pentacene via topological indices

2018 ◽  
Vol 16 (1) ◽  
pp. 1200-1206 ◽  
Author(s):  
Zeeshan Saleem Mufti ◽  
Muhammad Faisal Nadeem ◽  
Wei Gao ◽  
Zaheer Ahmad
Keyword(s):  
Molecular Structure ◽  
Real Number ◽  
Chemical Structure ◽  
Topological Index ◽  
Line Graph ◽  
Chemical Properties ◽  
Topological Indices ◽  
Molecular Structures ◽  
Line Graphs ◽  
Graph Invariant

AbstractA topological index is a map from molecular structure to a real number. It is a graph invariant and also used to describe the physio-chemical properties of the molecular structures of certain compounds. In this paper, we have investigated a chemical structure of pentacene. Our paper reflects the work on the following indices:Rα, Mα, χα, ABC, GA, ABC4, GA5, PM1, PM2, M1(G, p)and M1(G, p) of the para-line graph of linear [n]-pentacene and multiple pentacene.

Fabrication of Thermochromatic Microencapsulated Phase Change Materials

2011 ◽  
Vol 332-334 ◽  
pp. 1856-1859
Author(s):  
Xiao Hua Liao ◽  
Hai Feng Shi ◽  
Nan Song ◽  
Xing Xiang Zhang
Keyword(s):  
Molecular Structure ◽  
Differential Scanning Calorimetry ◽  
Chemical Structure ◽  
Phase Change Materials ◽  
In Situ Polymerization ◽  
Melamine Formaldehyde ◽  
Scanning Calorimetry ◽  
Microencapsulated Phase Change Materials ◽  
Structure Properties

Microencapsulated n-octadecane (MicroC18) and doped with thermochromatic powders (TC-MicroC18) were prepared with melamine-formaldehyde (M-F) resin as the wall via in-situ polymerization. The chemical structure and thermal behavior of microcapsules were investigated using fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Experimental results show that 63 wt% n-C18 has been incorporated into microcapsules, and the obvious thermochromatic effect of TC-MicroC18 is displayed with temperature changing. The structure-properties of TC-MicroC18 also is discussed in detail from the aspect of molecular structure.

scholarly journals Energy technological complex based on the use of coal

2019 ◽  
Vol 124 ◽  
pp. 01027
Author(s):  
M. Savina ◽  
G. Mingaleeva ◽  
R. Cimbala
Keyword(s):  
Thermal Decomposition ◽  
Thermal Efficiency ◽  
Flow Chart ◽  
Solid Fuels ◽  
Energy Technology ◽  
Organic Mass ◽  
Technological Complex ◽  
Thermochemical Processing ◽  
Circuit Elements

The paper proposes a flow chart of an energy technology complex based on thermochemical processing of solid fuels with a consistent removal of separation products. The scheme is designed for the use of coal and other solid fuels, as a result of the developed methodology for modeling the processes occurring during the thermal decomposition of the organic mass. Calculations of the circuit elements show that the thermal efficiency is increased when implementing successive separation of exhaust coal products.

scholarly journals Intensification of humic acid extraction from lignites

2020 ◽  
Vol 192 ◽  
pp. 02024
Author(s):  
Tatiana Moskalenko ◽  
Valery Mikheev ◽  
Elena Vorsina
Keyword(s):  
Humic Substances ◽  
Chemical Process ◽  
Raw Materials ◽  
Chemical Exposure ◽  
Materials Processing ◽  
Solid Fuels ◽  
Acid Extraction ◽  
Organic Mass ◽  
Chemical Reagents ◽  
Technological Mode

One of the methods of initial properties of solid fuels changing by their organic mass oxidation is considered in the paper. Creation of innovative ways of intensification of existing solid fuels processing and their adoption by industry has always been and remains an actual task. Thus the chemical process is the most important stage of raw materials processing into target products. Chemical exposure allows to optimize the technological mode, expanding the scope of control of technological process parameters and, to a certain extent, modify the properties of the resulting products. The article presents the results of experimental research of influence of preliminary oxidation on the lignite organic mass from Kharanorsk and Kangalas deposits by different chemical reagents to determine a degree of this process impact on the efficiency of their processing into humic substances. Inorganic and organic oxidizers of different concentrations were used as reagents. The greatest effect for increasing the humic acids yield was observed when using 6-10 % hydrogen peroxide for oxidation, and 10 % hydrochloric acid. The results of experiments on the coal preoxidation effect can be used as a basis for the development of a new method of lignites processing into humic substances.

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