Composite Sorption-Active Materials Based on Zeolite and Ethylene Fluorine Derivatives Part II. Preparation of Composite Sorption-Active Materials, Investigation of Their Physicochemical Properties and Selection of Optimal Synthesis Conditions

2018 ◽  
pp. 058-068 ◽  
Author(s):  
N.V. Posternak ◽  
◽  
Yu.A. Ferapontov ◽  
L.L. Ferapontova ◽  
E.I. Akulinin ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Optimal Synthesis ◽  
Active Materials ◽  
Synthesis Conditions ◽  
Selection Of

Accelerating the optimization of enzyme-catalyzed synthesis conditions via machine learning and reactivity descriptors

2021 ◽  
Author(s):  
Zhongyu Wan ◽  
Quan-De Wang ◽  
Dongchang Liu ◽  
Jinhu Liang
Keyword(s):  
Machine Learning ◽  
Optimal Synthesis ◽  
Human Knowledge ◽  
Crucial Importance ◽  
Reactivity Descriptors ◽  
Synthesis Conditions ◽  
Wide Range ◽  
Synthesis Reactions ◽  
Selection Of

Enzyme-catalyzed synthesis reactions are of crucial importance for a wide range of applications. An accurate and rapid selection of optimal synthesis conditions is crucial and challenging for both human knowledge...

scholarly journals Preparation and characterization of thermally crosslinked films based on chitosan and poly(2-ethyl-2-oxasoline)

2019 ◽  
pp. 20-27
Author(s):  
G.K. Abilova ◽  
A.M. Abilkаrіm ◽  
G.S. Irmukhametova
Keyword(s):  
Ir Spectroscopy ◽  
Physicochemical Properties ◽  
Optimal Synthesis ◽  
Spectroscopy Data ◽  
Synthesis Conditions ◽  
Gel Fraction ◽  
Thermal Crosslinking ◽  
Amine Groups

Сrosslinked films based on chitosan (СHI) and poly(2-ethyl-2-oxazoline) (POZ) were prepared by thermal crosslinking. The optimal synthesis conditions and the composition of the film compositions were determined. The highest yield of the gel fraction was observed for CHI:POZ (80:20) films with a crosslinking time of 4 h at a temperature of 100°С. The main physicochemical properties of films based on pure CHI and CHI:POZ have been studied. The film swelling ability was reduced with the increase of poly(2-ethyl-2-oxazolin) content. The formation of crosslinks between N,N’-methylene-bis-acrylamide and functional amine groups of chitosan was proposed based on IR-spectroscopy data.

scholarly journals CHEMICAL INVESTIGATIONS ON THE ACTIVE PRINCIPLES OF THE PHENOMENON OF LOCAL SKIN REACTIVITY TO BACTERIAL FILTRATES

1938 ◽  
Vol 67 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Gregory Shwartzman ◽  
S. A. Morell
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Ammonium Sulfate ◽  
Culture Filtrate ◽  
Active Materials ◽  
Local Skin ◽  
Skin Reactivity ◽  
Average Porosity ◽  
Active Substances ◽  
Capillary Analysis

Several physicochemical properties of the active principles of the phenomenon of local skin reactivity to bacterial filtrates have been investigated. Ultrafiltration through Zsigmondy filters of graded porosities has shown that the active substances are retained by membranes finer than 100 to 120 seconds, whereas coarser ones readily permit their passage. The average porosity of this filtration end-point represents a particle size of about 50 to 100 mµ. When fractionally precipitated with ammonium sulfate, most of the activity of a culture filtrate was concentrated in the two-thirds saturated portion. Isoelectric properties were studied by means of capillary analysis and cataphoresis. At pH 3.0 and below, the substances suspended in the culture filtrates migrated to the cathode; activity in this chamber, however, could not be demonstrated. At pH 4.0 and above, reversal to the anode occurred, as the active materials became negatively charged and readily migrated to this chamber. The isoelectric point, therefore, was considered to be between pH 3.0 and 4.0. Preliminary experiments on adsorption, extraction, and pH stability have been described.

Optimal synthesis of refrigeration cycles and selection of refrigerants

AIChE Journal ◽  
1999 ◽  
Vol 45 (5) ◽  
pp. 997-1017 ◽  
Author(s):  
Shankar Vaidyaraman ◽  
Costas D. Maranas
Keyword(s):  
Optimal Synthesis ◽  
Selection Of

scholarly journals Optimal synthesis of a four-bar linkage by method of controlled deviation

2004 ◽  
Vol 31 (3-4) ◽  
pp. 265-280 ◽  
Author(s):  
Radovan Bulatovic ◽  
Stevan Djordjevic
Keyword(s):  
Objective Function ◽  
Optimal Synthesis ◽  
Straight Line ◽  
Individual Comparison ◽  
Four Bar Linkage ◽  
The Given ◽  
Initial Selection ◽  
Selection Of ◽  
Process Calculation ◽  
Made In

This paper considers optimal synthesis of a four-bar linkage by method of controlled deviations. The advantage of this approximate method is that it allows control of motion of the coupler in the four-bar linkage so that the path of the coupler is in the prescribed environment around the given path on the segment observed. The Hooke-Jeeves?s optimization algorithm has been used in the optimization process. Calculation expressions are not used as the method of direct searching, i.e. individual comparison of the calculated value of the objective function is made in each iteration and the moving is done in the direction of decreasing the value of the objective function. This algorithm does not depend on the initial selection of the projected variables. All this is illustrated on an example of synthesis of a four-bar linkage whose coupler point traces a straight line, i.e. passes through sixteen prescribed points lying on one straight line. .

scholarly journals Synthesis conditions influencing formation of MAPbBr3 perovskite nanoparticles prepared by the ligand-assisted precipitation method

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anna Jancik Prochazkova ◽  
Markus Clark Scharber ◽  
Cigdem Yumusak ◽  
Ján Jančík ◽  
Jiří Másilko ◽  
...  
Keyword(s):  
Optical Properties ◽  
Colloidal Stability ◽  
Precursor Solution ◽  
Solvent System ◽  
Precipitation Method ◽  
Colloidal Solutions ◽  
Capping Agents ◽  
Synthesis Conditions ◽  
Perovskite Nanoparticles ◽  
Selection Of

Abstract This work reports on an optimized procedure to synthesize methylammonium bromide perovskite nanoparticles. The ligand-assisted precipitation synthetic pathway for preparing nanoparticles is a cost-effective and promising method due to its ease of scalability, affordable equipment requirements and convenient operational temperatures. Nevertheless, there are several parameters that influence the resulting optical properties of the final nanomaterials. Here, the influence of the choice of solvent system, capping agents, temperature during precipitation and ratios of precursor chemicals is described, among other factors. Moreover, the colloidal stability and stability of the precursor solution is studied. All of the above-mentioned parameters were observed to strongly affect the resulting optical properties of the colloidal solutions. Various solvents, dispersion media, and selection of capping agents affected the formation of the perovskite structure, and thus qualitative and quantitative optimization of the synthetic procedure conditions resulted in nanoparticles of different dimensions and optical properties. The emission maxima of the nanoparticles were in the 508–519 nm range due to quantum confinement, as confirmed by transmission electron microscopy. This detailed study allows the selection of the best optimal conditions when using the ligand-assisted precipitation method as a powerful tool to fine-tune nanostructured perovskite features targeted for specific applications.

scholarly journals Dynamic covalent chemistry in polymer networks: a mechanistic perspective

2019 ◽  
Vol 10 (45) ◽  
pp. 6091-6108 ◽  
Author(s):  
Johan M. Winne ◽  
Ludwik Leibler ◽  
Filip E. Du Prez
Keyword(s):  
Physicochemical Properties ◽  
Reaction Mechanisms ◽  
Polymer Networks ◽  
Molecular Network ◽  
Polymer Materials ◽  
Dynamic Covalent Chemistry ◽  
Selection Of

A selection of dynamic chemistries is highlighted, with a focus on the reaction mechanisms of molecular network rearrangements, and on how mechanistic profiles can be related to the mechanical and physicochemical properties of polymer materials.

Composition and Spectral Investigation for Tetranitro Iron Phthalocyanine

2016 ◽  
Vol 859 ◽  
pp. 175-178 ◽  
Author(s):  
Shu Ying Li ◽  
Zhao Yang Zeng ◽  
Shan Shan Du
Keyword(s):  
Optimal Synthesis ◽  
Microwave Assisted Synthesis ◽  
Iron Phthalocyanine ◽  
Single Variable ◽  
Green Color ◽  
Synthesis Conditions ◽  
Microwave Assisted ◽  
Green Vegetation ◽  
Dark Green ◽  
Green Paint

Because of the dark green color similar to vegetation, tetranitro iron phthalocyanine has great potentiality in military camouflage application. Tetranitro iron phthalocyanine was synthesized in the method of improved microwave-assisted synthesis. By single-variable controlling principle, the optimal synthesis conditions in laboratory for tetranitro iron phthalocyanine composing was determined. The spectra difference under different conditions between tetranitro iron phthalocyanine and green vegetation was analyzed. The possibility for using tetranitro iron phthalocyanine as green paint in camouflage was discussed

scholarly journals The use of bioceramic root canal sealers for obturation of the root canal system: A review

2021 ◽  
Vol 2 (1) ◽  
pp. 14-25
Author(s):  
Musliana Mustaffa
Keyword(s):  
Physicochemical Properties ◽  
Root Canal ◽  
Scientific Evidence ◽  
Filling Material ◽  
Flow Properties ◽  
Filling Materials ◽  
System A ◽  
Root Canal System ◽  
Root Canal Sealers ◽  
Selection Of

The use of bioceramic root canal sealers in endodontics is a promising approach because of the advantages such as improved flow properties, biocompatible and could promote the formation of hard tissue. Due to the recent technology and limited scientific evidence, the effectiveness of bioceramic root canal sealers remains unclear. This article focuses on the physicochemical properties, biocompatibility, biomineralisation, retreatability, 3D obturation and current practice of using bioceramic root canal sealers. The relevant articles for this review were searched manually from Google Scholar and PubMed using keywords ‘bioceramic root filling material AND endodontics’, ‘bioceramic root canal sealers AND endodontics’, ‘cytotoxicity AND bioceramic root canal sealers’, ‘bioceramic root canal sealers AND physicochemical properties’, ‘biomineralisation AND bioceramic root canal sealers’ and ‘retreatment efficacy AND bioceramic root filling materials’. Since the clinical data concerning the obturation with bioceramic root canal sealers is lacking, the selection of materials should be made based on the available scientific evidence, individual cases, material availability and operator’s preference.

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