scholarly journals On the possibility of evaluative prediction of the extraction of organic substances of complex structure using the method of group increments

2020 ◽  
Vol 63 (6) ◽  
pp. 704-715
Author(s):  
M. F. Zayats ◽  
S. M. Leschev ◽  
A. U. Zaidzel
Keyword(s):  
Analytical Chemistry ◽  
Organophosphorus Compounds ◽  
Complex Structure ◽  
Polar Phase ◽  
Water Mixture ◽  
Organic Substances ◽  
Benzene Derivatives ◽  
Esters Of Carboxylic Acids ◽  
Distribution Constants ◽  
Experimental Values

The distribution of pesticides of different classes (amides, anilinopyrimidines, benzene derivatives, benzoylphenylureas, benzenesulfonates, hydrazides, dinitroanilines, carbamates, pyretroids, pyrimidines, tetrazines, triazoles, pheny lureas, organophosphorus compounds, esters of carboxylic acids) was studied at 20 ± 1 °C in the extraction systems of hexane–water, hexane–acetonitrile, hexane– acetonitrile and water mixture that are most often used in analytical chemistry of pesticides. The distribution constants P of pesticides and the increments of logarithms of the distribution constants If of their functional groups between the hydrocarbon and polar phases are calculated. Two main methods for evaluative prediction of lg P of pesticides are proposed and approved – substitutive method based on the calculation of lg P by replacing the substituents in the base molecule and the method of absolute addition of increments. The possibilities of the both methods are illustrated. The reasons for the deviations of the experimental values from the calculated ones are discussed. The influence of the nature and composition of the polar phase on the magnitudes of the observed deviations is estimated. In particular, they decrease dramatically with an increase in the acetonitrile content in the polar phase. Averaged values of correction to the calculated values of lg P are introduced. In most cases, they allow predicting lg P of pesticides with a deviation of not more than 0.5–1.0 from the calculated one.

scholarly journals Engineered Nanoparticles with Decoupled Photocatalysis and Wettability for Membrane-Based Desalination and Separation of Oil-Saline Water Mixtures

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1397
Author(s):  
Bishwash Shrestha ◽  
Mohammadamin Ezazi ◽  
Gibum Kwon
Keyword(s):  
Membrane Fouling ◽  
Municipal Wastewater ◽  
Uv Light ◽  
Saline Water ◽  
Membrane Surface ◽  
Sio2 Nanoparticles ◽  
Engineered Nanoparticles ◽  
Water Mixture ◽  
Organic Substances ◽  
Suspended Substances

Membrane-based separation technologies are the cornerstone of remediating unconventional water sources, including brackish and industrial or municipal wastewater, as they are relatively energy-efficient and versatile. However, membrane fouling by dissolved and suspended substances in the feed stream remains a primary challenge that currently prevents these membranes from being used in real practices. Thus, we directly address this challenge by applying a superhydrophilic and oleophobic coating to a commercial membrane surface which can be utilized to separate and desalinate an oil and saline water mixture, in addition to photocatalytically degrading the organic substances. We fabricated the photocatalytic membrane by coating a commercial membrane with an ultraviolet (UV) light-curable adhesive. Then, we sprayed it with a mixture of photocatalytic nitrogen-doped titania (N-TiO2) and perfluoro silane-grafted silica (F-SiO2) nanoparticles. The membrane was placed under a UV light, which resulted in a chemically heterogeneous surface with intercalating high and low surface energy regions (i.e., N-TiO2 and F-SiO2, respectively) that were securely bound to the commercial membrane surface. We demonstrated that the coated membrane could be utilized for continuous separation and desalination of an oil–saline water mixture and for simultaneous photocatalytic degradation of the organic substances adsorbed on the membrane surface upon visible light irradiation.

scholarly journals Neutralization of solvent vapors of brand 646 by the adsorption-catalytic method

2021 ◽  
pp. 130-136
Author(s):  
A. S. Panasyugin ◽  
N. P. Masherova ◽  
A. R. Tsyganov ◽  
N. D. Pavlovsky
Keyword(s):  
Mixed Solvent ◽  
Synthetic Zeolite ◽  
Hydroxyl Group ◽  
Methyl Groups ◽  
Organic Substances ◽  
Benzene Derivatives ◽  
Foam Material ◽  
Catalytic Method ◽  
Sorption Volume ◽  
Solvent Vapors

The aim of the paper is investigation of neutralization of solvent vapors of the brand 646 by an adsorption-catalytic method. The adsorption-catalytic method includes the following stages: adsorption of the solvent components by adsorbent, thermal desorption and periodic flameless catalytic oxidation of organic substances to carbon dioxide and water. Synthetic zeolite of the NaX brand was used as a sorbent, catalyst was porous Al2O3/SiO2 ceramic foam material with an active catalytic phase. Solvent contains aceton, toluene, butylacetate, ethanol, ethyl cellosolve, n-butanol. It is shown that the value of the sorption volume of zeolite for each class of compounds depends on the certain factors: the length and structure of the carbon skeleton, the position of the hydroxyl group (for alcohols and esters), number of methyl groups in the molecules (for benzene derivatives). The conversion of the mixed solvent components was 65.4–90.1 %.

Research on Hexahedral and Tetrahedral Mesh Applied to Strength Analysis of Bogie Frame

2013 ◽  
Vol 477-478 ◽  
pp. 150-154 ◽  
Author(s):  
Guang Jun Li ◽  
Wen Jing Wang ◽  
Li An ◽  
Ze Jin Zhang
Keyword(s):  
Structural Model ◽  
Complex Structure ◽  
Tetrahedral Mesh ◽  
Bench Test ◽  
Strength Analysis ◽  
Structure Model ◽  
Stress Distributions ◽  
Bogie Frame ◽  
Tetrahedral Elements ◽  
Experimental Values

The structure of bogie frame is meshed by hexahedral and tetrahedral elements respectively. FE analysis is taken based on the loads defined by JIS E 4207 standard and the stress distributions of two separate models are obtained. To clarify the accuracy of two kinds of finite element models, the bench test of the bogie frame is carried out. It shows that both the hexahedral and tetrahedral models are valid according to the comparison between FE results and experimental values when the structural model is regular. However, for complex structure model 10-node tetrahedral model takes precedence.

scholarly journals Hydraulic Jump: A Brief History and Research Challenges

Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1733
Author(s):  
Diana De Padova ◽  
Michele Mossa
Keyword(s):  
Hydraulic Jump ◽  
Complex Structure ◽  
Experimental Studies ◽  
Turbulence Models ◽  
Internal Flow ◽  
Leonardo Da Vinci ◽  
Hydraulic Jumps ◽  
Water Mixture ◽  
Specific Flow ◽  
Actual Configuration

This paper presents a brief history of the hydraulic jump and a literature review on hydraulic jumps’ experimental and numerical studies. Leonardo da Vinci noticed this phenomenon early on, but it was only later studied by Bidone in 1820. Since the beginning of the 20th century, the hydraulic jump has received a lot of attention following the development of energy dissipater designs and stilling basins. The late 1920s and early 1930s saw many experimental studies researching the surface roller profile and energy dissipation. The study of internal flow features started in the late 1950s. Starting in the 70s, it was believed that the flow of a jump must be analyzed in its actual configuration of air–water mixture, an aspect that cannot be overlooked. Several experimental studies in the late 1980s and 1990s highlighted the existence of oscillating phenomena under specific flow conditions and particularly, a cyclic variation of jump types over long-lasting experiments. The early 2000s saw many experimental studies researching the complex structure of the separated region in very large channels downstream of the lateral shockwaves. Whereas most of the experiments provide measurements at a point or on a plane, the complete flow field supplied by CFD simulations enables us to have a deeper understanding of the dynamics of coherent structures that are responsible for free-surface fluctuations and aeration in hydraulic jumps. Therefore, in recent years, the computational fluid dynamics (CFD) method, through turbulence models, has become a useful tool to study this complex environmental fluid mechanic problem.

scholarly journals On the ultimate analysis of vegetable and animal substances

1833 ◽  
Vol 2 ◽  
pp. 179-179
Keyword(s):  
Analytical Chemistry ◽  
Sulphuric Acid ◽  
Experimental Results ◽  
The Other ◽  
Organic Substances ◽  
Tabular Form ◽  
Atomic Theory ◽  
Ultimate Analysis ◽  
Organic Products ◽  
Considerable Length

Dr. Ure commences this paper by adverting to the fallacies to which the modes of analysing organic substances hitherto practised are subject; and in detailing the peculiar methods adopted in his own researches, he shows the means of obviating them, and of diminishing the various sources of inaccuracy to which these complicated processes of analytical chemistry are necessarily more or less liable. Where oxide of copper is used, its hygrometric quality has generally been overlooked, or not duly allowed for; and the animal and vegetable substances have not in general been exposed to any process of desiccation sufficiently exact or uniform; the author therefore always used the oxide of copper in some known or ascertained degree of humidity; and he dried the organic bodies in the air-pump vacuum, aided by the absorbent powers of a surface of sulphuric acid in the apparatus, and with precautions which he fully describes. He then details the best means of applying heat for the decomposition of organic substances, and describes a drawing representing the construction of his furnace, and other implements. Lastly, he points out the method of examining the results and products, and gives in detail the analysis of sulphuric ether, as illustrating the mode of computing the relations of the constituents, while the results of the other analyses are, for the sake of brevity, thrown into a tabular form. Dr. Ure concludes his paper with some general remarks on the analytical details. In respect to sugar, he observes, that on comparing pure crystalline sugar with diabetic sugar, the latter exhibits a notable excess of oxygen; and he considers weak sugars (as the refiners call them), in general, to exhibit the same peculiarity. In applying the atomic theory to his experimental results, the author enlarges on the different views which may be taken of the ultimate constitution of a variety of organic products, and enters at considerable length into details relating to the vegetable acids, with a view of determining with exactness their prime equivalents, and the relative proportions of combined water which they contain in their crystalline states.

scholarly journals VISCOSITY OF MONO-, DI- AND TRIETHYLENE GLYCOL AQUEOUS SOLUTIONS AT 298.15 K

2019 ◽  
Vol 62 (6) ◽  
pp. 41-46
Author(s):  
Valentin V. Loskutov
Keyword(s):  
Aqueous Solutions ◽  
Diethylene Glycol ◽  
Complex Structure ◽  
Molar Fraction ◽  
Triethylene Glycol ◽  
Water Mixture ◽  
Viscosity Deviation ◽  
Excess Viscosity ◽  
Wide Range ◽  
Monoethylene Glycol

The aim of this study was to analyze the change in the complex structure formed in water-glycols mixture under mixture composition. The dynamic viscosity for various glycol (mono-, di- and triethylene glycol) aqueous solutions have been measured over wide range of concentration at temperature 25 °C and atmospheric pressure. The new scale of viscosity concentration dependences of various glycols for common description in range of low glycol composition was suggested. From experimental data, the excess viscosity (deviation in viscosity) was calculated. Excess viscosity was negative for monoethylene glycol – water mixture over the entire range of composition. In the case diethylene glycol –water mixture excess viscosity values were found to be negative between 0 and 20 mol %, then became positive in the diethylene glycol rich region. In the case triethylene glycol – water mixture excess viscosity values were negative between 0 and 10 mol %. The Grunberg-Nissan parameter was calculated. By comparing the monoethylene glycol – water hydrogen bonding, reported in literature and Grunberg-Nissan parameter variation versus glycol molar fraction, a correspondence between Grunberg-Nissan parameter and the complex varieties was established. It was shown, that concentration dependence of the Grunberg-Nissan parameter separates the different concentration regions. The variation of the Grunberg-Nissan parameter with glycol molar fraction deals with the interaction variation between water and glycol molecules, the Grunberg-Nissan parameter slop varies.

scholarly journals An analysis of the dipole moments of some aromatic compounds

1934 ◽  
Vol 145 (854) ◽  
pp. 71-80 ◽  
Keyword(s):  
Dipole Moment ◽  
Aromatic Compounds ◽  
General Type ◽  
Dipole Moments ◽  
Aromatic Nucleus ◽  
Organic Substances ◽  
Benzene Derivatives ◽  
Electronic Theory ◽  
Disubstituted Benzene ◽  
Derivatives Of

The dipole moments of organic substances represent the resultants of a number of distinct moments within the molecule form which they must, as was pointed out by Sir J. J. Thomson, be obtainable by vector summation. This view was extended and further examined by Eucken and Meyer in 1929. It has been generally accepted and confirmed for a large variety of substances. The figures for para -disubstituted benzene derivatives of the type X. C 6 H 4 . Y are of particular importance for two reasons. First, it was anticipated by Ingold on the ground of the electronic theory of aromatic reactivity, that some deviation from the additive law might occur in this class of compound when Y was a group such as —NR 2 as a result of electronic displacements in the aromatic nucleus. When the necessary data became available by the measurements of Højendahl, a gross discrepancy of this kind appeared probable for p -nitraniline and p -nitroanisole, and this was specifically emphasized at that time. Secondly, a number of workers have recently made use of dipole moment data for aromatic ethers and sulphides of this same general type in order to compute the angle between the valencies of the characteristic atom (oxygen and sulphur) of the group Y.

A new method of complex structure analysis by electron microscopy

1978 ◽  
Vol 36 (1) ◽  
pp. 628-629
Author(s):  
V.V. Rybin ◽  
E.V. Voronina
Keyword(s):  
Complex Structure ◽  
Reciprocal Lattice ◽  
Stacking Faults ◽  
Plastic Strains ◽  
Base Position ◽  
Structural Regularity ◽  
Orientation Matrix ◽  
Computerized Processing ◽  
Fully Automatic ◽  
Diffraction Patterns

Recently, it has become essential to develop a helpful method of the complete crystallographic identification of fine fragmented crystals. This was maainly due to the investigation into structural regularity of large plastic strains. The method should be practicable for determining crystallographic orientation (CO) of elastically stressed micro areas of the order of several micron fractions in size and filled with λ>1010 cm-2 density dislocations or stacking faults. The method must provide the misorientation vectors of the adjacent fragments when the angle ω changes from 0 to 180° with the accuracy of 0,3°. The problem is that the actual electron diffraction patterns obtained from fine fragmented crystals are the superpositions of reflections from various fragments, though more than one or two reflections from a fragment are hardly possible. Finally, the method should afford fully automatic computerized processing of the experimental results.The proposed method meets all the above requirements. It implies the construction for a certain base position of the crystal the orientation matrix (0M) A, which gives a single intercorrelation between the coordinates of the unity vector in the reference coordinate system (RCS) and those of the same vector in the crystal reciprocal lattice base : .

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