Cellulose phenylcarbamate-derived hybrid bead-type chiral packing materials for efficient chiral recognition

Cellulose ◽  
2020 ◽  
Author(s):  
Geng Li ◽  
Xiao Dai ◽  
Yixuan Min ◽  
Chang Yu ◽  
Tomoyuki Ikai ◽  
...  
Keyword(s):  
Chiral Recognition ◽  
Packing Materials ◽  
Bead Type

Study of operating properties of aanticorrosion packing papers

2020 ◽  
Vol 76 (10) ◽  
pp. 1021-1027
Author(s):  
A. P. Ponomarev ◽  
L. G. Kolyada ◽  
E. V. Tarasyuk
Keyword(s):  
Steel Strip ◽  
Low Carbon Steel ◽  
Strength Characteristics ◽  
Low Carbon ◽  
Operating Characteristics ◽  
Packing Materials ◽  
Accelerated Corrosion ◽  
Operating Properties ◽  
Deformation And Strength Characteristics ◽  
Anticorrosion Properties

Metal products are subjected to atmospheric corrosion during transportation and storing. An important way to prevent this negative phenomenon is application of special packing materials, in particular materials, containing volatile inhibitors of corrosion, which protect metal against various corrosion agents. To protect metal effectively it is necessary to provide a definite level of operating characteristics of packing materials. The purpose of the work was the study of operating properties of inhibited crepe, inhibited and laminated polyethylene film, inhibited crepe and reinforced by polypropylene web papers, manufactured by OJSC “PP TechnoKhim”, Magnitogorsk, used for packing of metals. Structural and dimensional, sorption, deformation and strength characteristics, of the studied anticorrosion papers are presented, the characteristics being calculated based on the results of measurements. To determine their physical-mechanical and anticorrosion properties, standard methods and methodologies were used. To evaluate impact of moisture and transportation conditions, indices of water adsorption and wear of the studied papers were determined. Inhibitor content in these materials was determined by thermogravimetric analysis method. Their protective ability was studied on samples of low carbon steel strip. For accelerated corrosion tests the strip samples were degreased by alcohol, dried in air and packed in the studied anticorrosion papers, after that they were exposed under increased temperatures and moisture conditions. It was determined, that among the materials under the study, the inhibited crepe paper, reinforced by polypropylene web, hhas the best complex of physical-mechanical and anticorrosion properties. It provides a higher level of prevention corrosion of metal l and surpasses other materials in a number of deformation and strength characteristics. Recommendations were proposed to improve qquality of produced anticorrosion papers.

Enantioselective Recognition of Chiral Guests by the Water-Soluble Chiral Keplerate {Mo132} Spherical Capsule with 30 Inner Lactate Ligands

2019 ◽  
Author(s):  
Nancy Watfa ◽  
Weimin Xuan ◽  
Zoe Sinclair ◽  
Robert Pow ◽  
Yousef Abul-Haija ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Chiral Recognition ◽  
Association Constants ◽  
Water Soluble ◽  
Enantioselective Recognition ◽  
H Nmr ◽  
Dosy Nmr ◽  
Spherical Capsule ◽  
Surface Pores ◽  
Guest Chemistry

Investigations of chiral host guest chemistry are important to explore recognition in confined environments. Here, by synthesizing water-soluble chiral porous nanocapsule based on the inorganic metal-oxo Keplerate-type cluster, {Mo<sub>132</sub>} with chiral lactate ligands with the composition [Mo<sub>132</sub>O<sub>372</sub>(H<sub>2</sub>O)<sub>72</sub>(<i>x-</i>Lactate)<sub>30</sub>]<sup>42-</sup> (<i>x</i> = D or L), it was possible to study the interaction with a chiral guest, L/D-carnitine and (<i>R</i>/<i>S</i>)-2-butanol in aqueous solution. The enantioselective recognition was studied by quantitative <sup>1</sup>H NMR and <sup>1</sup>H DOSY NMR which highlighted that the chiral recognition is regulated by two distinct sites. Differences in the association constants (K) of L- and D-carnitine, which, due to their charge, are generally restricted from entering the interior of the host, are observed, indicating that their recognition predominantly occurs at the surface pores of the structure. Conversely, a larger difference in association constants (K<i><sub>S</sub></i>/K<i><sub>R</sub></i> = 3) is observed for recognition within the capsule interior of (<i>R</i>)- and (<i>S</i>)-2-butanol.

scholarly journals A Study on Liquid Leak Rates in Packing Seals

2021 ◽  
Vol 11 (4) ◽  
pp. 1936
Author(s):  
Abdel-Hakim Bouzid
Keyword(s):  
Environmental Protection ◽  
Liquid Flow ◽  
Environmental Protection Agency ◽  
Gas Flow ◽  
Outer Boundary ◽  
Health And Safety ◽  
Toxic Substances ◽  
Packing Materials ◽  
Thickness Change ◽  
Flow Through

The accurate prediction of liquid leak rates in packing seals is an important step in the design of stuffing boxes, in order to comply with environmental protection laws and health and safety regulations regarding the release of toxic substances or fugitive emissions, such as those implemented by the Environmental Protection Agency (EPA) and the Technische Anleitung zur Reinhaltung der Luft (TA Luft). Most recent studies conducted on seals have concentrated on the prediction of gas flow, with little to no effort put toward predicting liquid flow. As a result, there is a need to simulate liquid flow through sealing materials in order to predict leakage into the outer boundary. Modelling of liquid flow through porous packing materials was addressed in this work. Characterization of their porous structure was determined to be a key parameter in the prediction of liquid flow through packing materials; the relationship between gland stress and leak rate was also acknowledged. The proposed methodology started by conducting experimental leak measurements with helium gas to characterize the number and size of capillaries. Liquid leak tests with water and kerosene were then conducted in order to validate the predictions. This study showed that liquid leak rates in packed stuffing boxes could be predicted with reasonable accuracy for low gland stresses. It was found that internal pressure and compression stress had an effect on leakage, as did the thickness change and the type of fluid. The measured leak rates were in the range of 0.062 to 5.7 mg/s for gases and 0.0013 and 5.5 mg/s for liquids.

A Self‐Assembled Cage for Wide‐Scope Chiral Recognition in Water

2021 ◽  
Author(s):  
Guangcheng Wu ◽  
Yixin Chen ◽  
Shuai Fang ◽  
Lu Tong ◽  
Libo Shen ◽  
...  
Keyword(s):  
Chiral Recognition ◽  
Wide Scope ◽  
Self Assembled

ChemInform Abstract: Molecular Chiral Recognition in Supercritical Solvents.

ChemInform ◽  
2010 ◽  
Vol 25 (18) ◽  
pp. no-no
Author(s):  
E. FOGASSY ◽  
M. ACS ◽  
T. SZILI ◽  
B. SIMANDI ◽  
J. SAWINSKY
Keyword(s):  
Chiral Recognition ◽  
Supercritical Solvents

Separation of tetrahydrozoline enantiomers in capillary electrophoresis with cyclodextrin-type chiral selectors and investigation of chiral recognition mechanisms

2021 ◽  
Vol 1643 ◽  
pp. 462084
Author(s):  
Ann Gogolashvili ◽  
Ketevan Lomsadze ◽  
Lali Chankvetadze ◽  
Nino Takaishvili ◽  
Paola Peluso ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Chiral Recognition ◽  
Chiral Selectors

scholarly journals Evaluation of Tomato-Based Packing Material for Retention of Ammonia, Nitrous Oxide, Carbon Dioxide and Methane in Gas Phase Biofilters: A Laboratory Study

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 360
Author(s):  
José L. S. Pereira ◽  
Adelaide Perdigão ◽  
Francisco Marques ◽  
Catarina Coelho ◽  
Mariana Mota ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Laboratory Study ◽  
Packing Material ◽  
Control Treatment ◽  
Airflow Rate ◽  
Pig Slurry ◽  
Air Pollution Control ◽  
Gaseous Emissions ◽  
Packing Materials ◽  
Tomato Waste

Biofilters are an effective air pollution control technology to break down gaseous contaminants and produce innocuous end products. This laboratory study aimed to evaluate a biofilter media, mainly composed by tomato waste, as packing material to reduce NH3, N2O, CO2 and CH4 losses from stored pig slurry. Three mixtures of packing materials, with and without oxalic acid, were arranged in treatments, namely: mixture of tomato waste, pine bark and agricultural compost; mixture of tomato waste and rice husk; tomato waste only. A control treatment (no biofilter) was also included. The experiments were conducted using a system of laboratory scale biofilters connected to jars filled with pig slurry and under a constant airflow rate. The gas concentrations were measured for 14 days and the physicochemical of the packing materials were assessed. Results showed that biofilter media mixtures had a potential for NH3 retention ranging from 51 to 77% and the addition of oxalic acid to these biofilters increased NH3 retention to 72–79%. Additionally, the biofilter media mixtures with and without oxalic acid showed a potential retention for CH4 (29–69%) but not for N2O, yet with no impact on the global warming potential. It can be concluded that tomato based biofilters had the potential to reduce gaseous emissions from slurry.

scholarly journals Catalytic enantioselective synthesis of macrodiolides and their application in chiral recognition

2021 ◽  
Author(s):  
Wanlong Xiao ◽  
Yuhao Mo ◽  
Jing Guo ◽  
Zhishan Su ◽  
Shunxi Dong ◽  
...  
Keyword(s):  
Chiral Recognition ◽  
Enantioselective Synthesis ◽  
Quinone Methides ◽  
New Type

A new type of C2-symmetric chiral macrodiolides are readily obtained via chiral N,Nʹ-dioxide-scandium(III) complex-promoted asymmetric tandem Friedel-Crafts alkylation/intermolecular macrolactonization of ortho-quinone methides with C3-substituted indoles. This protocol provides an array...

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