Engineered polysaccharides: α‐1,3‐glucan acetates showing upper critical solution temperature in organic solvents

Abstract Acetates of α‐1,3‐glucan dissolved in N , N ‐dimethyl acetamide/LiCl are prepared by converting the polysaccharide with acetyl chloride, acetic acid anhydride/pyridine, or with acetic acid/ N,N ′‐carbonyl diimidazole. Values of the degree of substitution for the acetyl groups (DS Ac ) of up to 2.6 are realized. NMR spectroscopic measurements reveal a preferred conversion of the primary hydroxyl group at position 6 followed by positions 2 and 4. Depending on the DS Ac , the samples may be soluble in solvents of different polarity at room temperature or at elevated temperatures showing upper critical solution temperature at DS of about 2.5. This process is found to be reversible

Мобильное приложение для онлайн продажи билетов на основе мессенджера Telegram

Объектом исследования является деятельность ООО "Меридиан" по онлайн продаже билетов в кинотеатры. Цель работы – проектирование мобильного приложения для онлайн продажи билетов на основе мессенджера Telegram. В процессе исследования была изучена специфика онлайн продаж с помощью мобильных приложений, был проведен теоретический анализ, обзор аналогов, проектирование и разработка мобильного приложения, анализ проявлений вредных и опасных факторов. В результате разработано мобильное приложение, реализующее основные функции: учет продажи билетов; информирование клиентов; анализ продаж и взаимосвязей с клиентами. Область применения: онлайн продажа билетов.The object of study is the activity of LLC "Meridian" in online sales of movie tickets. Purpose – to design mobile applications for online sale of tickets on the basis of the messenger Telegram. In the process of the study examined the specificity of online sales via mobile applications was the theoretical analysis, a review of analogues, the design and development of mobile applications, analysis of the manifestations of harmful and dangerous factors. The developed mobile application that implements the basic functions: accounting for the sale of tickets; informing customers; analysis of sales and relationship with customers. Scope: the online sale of tickets

Etude des coefficients de diffusion d'agents de surface et de la cinétique de micellisation d'un colorant. I. Mise au point d'une méthode expérimentale pour la détermination des coefficients de diffusion. II. Nettoyage des surfaces solides et cinétique de micellisation d'un colorant

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Well-Defined and Robust Rhodium Catalysts for the Hydroacylation of Terminal and Internal Alkenes

A Rh-catalyst system based on the asymmetric ligand tBu2PCH2P(o-C6H4OMe)2 is reported that allows for the hydroacylation of challenging internal alkenes with β-substituted aldehydes. Mechanistic studies point to the stabilizing role of both excess alkene and the OMe-group