ChemInform Abstract: K2 CO3 -Promoted Formation of Aryl Esters from Primary Aryl Amides by the Acyl-Acyl Exchange Process

ChemInform ◽  
2016 ◽  
Vol 47 (34) ◽  
Author(s):  
Yongjun Bian ◽  
Xingyu Qu
Keyword(s):  
Exchange Process ◽  
Acyl Exchange

K2CO3-promoted formation of aryl esters from primary aryl amides by the acyl–acyl exchange process

2016 ◽  
Vol 14 (16) ◽  
pp. 3869-3872 ◽  
Author(s):  
Yongjun Bian ◽  
Xingyu Qu
Keyword(s):  
Exchange Reaction ◽  
Exchange Process ◽  
Reaction Conditions ◽  
Acyl Exchange

A new acyl–acyl exchange reaction has been developed for the formation of aryl esters from primary aryl amides. The reaction could occur under mild reaction conditions with catalytic quantities of K2CO3, and could afford moderate to good yields of the desired products.

scholarly journals Evidence for the reversibility of the acyl-CoA:lysophosphatidylcholine acyltransferase in microsomal preparations from developing safflower (Carthamus tinctorius L.) cotyledons and rat liver

1984 ◽  
Vol 223 (2) ◽  
pp. 305-314 ◽  
Author(s):  
S Stymne ◽  
A K Stobart
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Rat Liver ◽  
Bovine Serum ◽  
Exchange Process ◽  
High Specificity ◽  
Carthamus Tinctorius ◽  
Back Reaction ◽  
Acyl Exchange ◽  
Rate Limiting Step

Acyl exchange between acyl-CoA and position 2 of sn-phosphatidylcholine occurs in the microsomal preparations of developing safflower cotyledons. Evidence is presented to show that the acyl exchange is catalysed by the combined back and forward reactions of an acyl-CoA:lysophosphatidylcholine acyltransferase (EC 2.3.1.23). The back reaction of the enzyme was demonstrated by the stimulation of the acyl exchange with free CoA and by the observation that the added CoA was acylated with acyl groups from position 2 of sn-phosphatidylcholine. Re-acylation of the, endogenously produced, lysophosphatidylcholine with added acyl-CoA occurred with the same specificity as that observed with added palmitoyl lysophosphatidylcholine. A similar acyl exchange, catalysed by an acyl-CoA:lysophosphatidylcholine acyltransferase, occurred in microsomal preparations of rat liver. The enzyme from safflower had a high specificity for oleate and linoleate, whereas arachidonate was the preferred acyl group in the rat liver microsomal preparations. The rate of the back reaction was 3-5% and 0.2-0.4% of the forward reaction in the microsomal preparations of safflower and rat liver respectively. Previous observations, that the acyl exchange in safflower microsomal preparations was stimulated by bovine serum albumin and sn-glycerol 3-phosphate, can now be explained by the lowered acyl-CoA concentrations in the incubation mixture with albumin and in the increase in free CoA in the presence of sn-glycerol 3-phosphate (by rapid acylation of sn-glycerol 3-phosphate with acyl groups from acyl-CoA to yield phosphatidic acid). Bovine serum albumin and sn-glycerol 3-phosphate, therefore, shift the equilibrium in acyl-CoA:lysophosphatidylcholine acyltransferase-catalysed reactions towards the rate-limiting step in the acyl exchange process, namely the removal of acyl groups from phosphatidylcholine. The possible role of the acyl exchange in the transfer of acyl groups between complex lipids is discussed.

Flow visualization and PIV measurement of a water exchange process in a biosensor container

2004 ◽  
Vol 24 (Supplement1) ◽  
pp. 331-332
Author(s):  
Takashi MIKAMI ◽  
Masaru ISHIZUKA ◽  
Shinji NAKAGAWA ◽  
Koichiro KAWANO ◽  
Yoshio ISHIMORI ◽  
...  
Keyword(s):  
Flow Visualization ◽  
Water Exchange ◽  
Exchange Process ◽  
Piv Measurement

COMPUTER SIMULATION OF FLOW IN CORRUGATED CHANNEL OF PLATE HEAT EXCHANGER

2020 ◽  
pp. 51-58
Author(s):  
Л. А. Кущев ◽  
В. Н. Мелькумов ◽  
Н. Ю. Саввин
Keyword(s):  
Computer Simulation ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
High Speed ◽  
Exchange Process ◽  
Plate Heat Exchanger ◽  
System Stability ◽  
Plate Heat ◽  
Corrugated Channel ◽  
Heat Exchange Process

Постановка задачи. Рассматривается теплообменный процесс, протекающий в модифицированном гофрированном межпластинном канале интенсифицированного пластинчатого теплообменного аппарата с повышенной турбулизацией теплоносителя. Необходимо разработать компьютерную модель движения теплоносителя в диапазоне скоростей 0,1-1,5 м/с и определить коэффициент турбулизации пластинчатого теплообменника. Результаты. Приведены результаты компьютерного моделирования движения теплоносителя в межпластинном гофрированном канале оригинального пластинчатого теплообменного аппарата с помощью программного комплекса Аnsys . Определены критерии устойчивости системы. Выполнено 3 D -моделирование канала, образуемого гофрированными пластинами. При исследовании процесса турбулизации были рассмотрены несколько скоростных режимов движения теплоносителя. Определен коэффициент турбулизации Tu, %. Выводы. В результате компьютерного моделирования установлено увеличение коэффициента теплопередачи К, Вт/(м ℃ ) за счет повышенной турбулизации потока, что приводит к снижению металлоемкости и уменьшению стоимости теплообменного оборудования. Statement of the problem. The heat exchange process occurring in a modified corrugated interplate channel of an intensified plate heat exchanger with an increased turbulence of the heat carrier is discussed. A computer model of the coolant movement in the speed range of 0.1-1.5 m/s is developed and the turbulence coefficient of the plate heat exchanger is determined. Results. The article presents the results of computer modeling of the coolant movement in the interplate corrugated channel of the original plate heat exchanger using the Ansys software package. The criteria of system stability are defined. 3D modeling of the channel formed by corrugated plates is performed. In the study of the process of turbulence several high-speed modes of movement of the coolant were considered. The turbulence coefficient Tu, % is determined. Conclusions. As a result of computer simulation, an increase in the heat transfer coefficient K, W/(m ℃) was found due to an increased turbulization of the flow, which leads to a decrease in metal consumption and a decrease in the cost of heat exchange equipment.

INTEGRATED MEDICAL DATA MANAGEMENT SYSTEMS REVIEW

2019 ◽  
Author(s):  
Ihor Pysmennyi
Keyword(s):  
Health Informatics ◽  
Quality Care ◽  
Exchange Process ◽  
Knowledge Exchange ◽  
Clinical Information ◽  
Mobile Network ◽  
Developed Countries ◽  
Management Systems ◽  
Learning Techniques ◽  
Drastic Increase

In recent years we’ve seen breakthrough research success in medicine and computer science enabled by novel technology advancements, data analyses capabilities and learning techniques. Despite this, quality care doesn’t have full cove­ rage even in developed countries and access to care is recognised as one of the biggest challenges to the global healthcare system. Bound with population growth in remote areas in developing regions, which lack skilled professionals and medical resources, as well as aging in developed countries this caused a strong need for increasing healthcare effectiveness. Enabled by development of cloud technologies, quick expansion of mobile network coverage and internet access Clinical Information Management Systems integrated with decision support systems, Telemedicine (inclu­ ding distributed Virtual Healthcare Teams and medical imaging), Mobile Healthcare, medical Internet of Things (mIoT), Consumer Health Informatics with personal intelligent health assistants, Health Information Exchanges and deep learning techniques for diagnostics and knowledge extraction are among the state-of-the-art solutions which are more or less successfully used for coping with the problem mentioned above. This paper reviews current situation with implementing these novel informational systems, analyses their advantages, drawbacks, implementation impediments and outcome effectiveness suggesting platform for empowering their integration and maximizing output of each module. Such solution will have a synergy effect and result in a drastic increase of medical resource utilization effectiveness, service quality and providing bigger and fuller coverage with less spending at the same time empowering knowledge exchange process and laying foundation for future development and innovations in the whole healthcare domain.

Removal of Toxic Dyestuffs from Aqueous Solution by Amphoteric Bioadsorbent

2020 ◽  
Vol 16 ◽  
Author(s):  
Reda M. El-Shishtawy ◽  
Abdullah M. Asiri ◽  
Nahed S. E. Ahmed
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Dye Removal ◽  
Exchange Process ◽  
Cationic Dyes ◽  
Carboxyl Groups ◽  
Maximum Adsorption Capacity ◽  
Equilibrium Isotherm ◽  
Ion Exchange Process ◽  
Dyes And Pigments

Background: Color effluents generated from the production industry of dyes and pigments and their use in different applications such as textile, paper, leather tanning, and food industries, are high in color and contaminants that damage the aquatic life. It is estimated that about 105 of various commercial dyes and pigments amounted to 7×105 tons are produced annually worldwide. Ultimately, about 10–15% is wasted into the effluents of the textile industry. Chitin is abundant in nature, and it is a linear biopolymer containing acetamido and hydroxyl groups amenable to render it atmospheric by introducing amino and carboxyl groups, hence able to remove different classes of toxic organic dyes from colored effluents. Methods: Chitin was chemically modified to render it amphoteric via the introduction of carboxyl and amino groups. The amphoteric chitin has been fully characterized by FTIR, TGA-DTG, elemental analysis, SEM, and point of zero charge. Adsorption optimization for both anionic and cationic dyes was made by batch adsorption method, and the conditions obtained were used for studying the kinetics and thermodynamics of adsorption. Results: The results of dye removal proved that the adsorbent was proven effective in removing both anionic and cationic dyes (Acid Red 1 and methylene blue (MB)), at their respective optimum pHs (2 for acid and 8 for cationic dye). The equilibrium isotherm at room temperature fitted the Freundlich model for MB, and the maximum adsorption capacity was 98.2 mg/g using 50 mg/l of MB, whereas the equilibrium isotherm fitted the Freundlich and Langmuir model for AR1 and the maximum adsorption capacity was 128.2 mg/g. Kinetic results indicate that the adsorption is a two-step diffusion process for both dyes as indicated by the values of the initial adsorption factor (Ri) and follows the pseudo-second-order kinetics. Also, thermodynamic calculations suggest that the adsorption of AR1 on the amphoteric chitin is an endothermic process from 294 to 303 K. The result indicated that the mechanism of adsorption is chemisorption via an ion-exchange process. Also, recycling of the adsorbent was easy, and its reuse for dye removal was effective. Conclusion: New amphoteric chitin has been successfully synthesized and characterized. This resin material, which contains amino and carboxyl groups, is novel as such chemical modification of chitin hasn’t been reported. The amphoteric chitin has proven effective in decolorizing aqueous solution from anionic and cationic dyes. The adsorption behavior of amphoteric chitin is believed to follow chemical adsorption with an ion-exchange process. The recycling process for few cycles indicated that the loaded adsorbent could be regenerated by simple treatment and retested for removing anionic and cationic dyes without any loss in the adsorbability. Therefore, the study introduces a new and easy approach for the development of amphoteric adsorbent for application in the removal of different dyes from aqueous solutions.

Information Exchange Process for AR based Smart Facility Maintenance System Using BIM Model

2019 ◽  
Author(s):  
Suwan Chung ◽  
Soonwook Kwon ◽  
Daeyoon Moon ◽  
K.H. Lee ◽  
J.H. Shin
Keyword(s):  
Information Exchange ◽  
Exchange Process ◽  
Maintenance System ◽  
Facility Maintenance
Sign in / Sign up

Export Citation Format

Share Document