Extraction,optimisation and characterisation of phenolics from Thymus vulgaris L.: phenolic content and profiles in relation to antioxidant,antidiabetic and antihypertensive properties

The objectives of this study were to examine varying extraction conditions of Thymus vulgaris L. as related to phenolic content and profiles of the extracts and their antioxidant, antihypertensive and antidiabetic properties. Phenolics were extracted under various conditions pertaining to free and bound phenolics, solvent type and combination of extraction time and temperature, and these extracts were evaluated in terms of their antioxidant activities and inhibitory activities of angiotensin‐converting enzyme (ACE), α‐glucosidase and α‐amylase. The acetone–water solvent mixture (1:1; v/v) produced the extract with the greatest phenolic content, antioxidant activity and inhibitory activities of ACE and α‐glucosidase. The optimal extraction temperature for maximum phenolic content and antioxidant activity associated with methanol extraction was 60 °C, whereas a lower temperature at 40 °C was required to maximise inhibitory activities for ACE, α‐glucosidase and α‐amylase. An inverse relationship was seen between antioxidant and glucosidase inhibitory activities vs. the ACE and α‐amylase inhibitory activities, which suggests the need for extractions to be directed to specific bioactivities of thyme extracts. Generally, the results indicate major differences in phenolic profiles among the tested extraction conditions with thymol as the predominant phenolic seen in most extractions, while gallic acid, rosmarinic acid or diosmin also predominated in other extracts. Extracts with the same predominant phenolic compound and similar phenolic content showed major disparities in their ACE, glucosidase and α‐amylase inhibitory activities, indicating that the major phenolic profiles of thyme extracts may not be necessarily related to the degree of inhibition of ACE, glucosidase and α‐amylase enzymes.     

Harnessing social dynamics through persuasive technology to promote healthier lifestyle

In light of current calls by medical professionals to confront the global issue of obesity and related illnesses, we developed a mobile application called STEP UP that monitors physical activity and provides data that can be easily shared within a social network. We then conducted an exploratory, theoretical study based on the theory of reasoned action (TRA) followed by an experimental trial and user study. The purpose of the studies was to explore the effect of persuasive technology on physical activity behavior and to investigate its effectiveness in motivating users to use the technology to be more physically active. The application was found to have a positive effect on the participants and their level of physical activity. They enjoyed using the application and were motivated to walk more, especially when enabled to share their step counts with their friends. The social component of the application clearly enhanced users’ walking experience, as the atmosphere of friendly competition motivated them to walk more. Based on user responses, we conclude that a further enhanced application that includes chat functionality may be even more successful in supporting increased physical activity and thus healthier lifestyle.     

Tritium Isotope Separation by Multiphoton Dissociation of CF3CTCIF

A conception of the advanced water chemistry diagnosis system for detection of anomalies and preventive maintenance of system components is proposed. Extension of anomaly diagnosis knowledge and more reliable water chemistry data are indispensable to the advanced system. Then, correlations between water chemistry (conductivity and pH) change in reactor water and anomaly occurrence in the components of the feed water line are analyzed theoretically. These correlations are verified as applicable to extension of the diagnosis knowledge for anomalies in the components of the feed water line, such as resin intrusion, sea water Leakage at the condenser, and a breakdown in ion exchange capacity of resin at the condensate demineralizer.     

A synthesis method for multicomponent distillation sequences with fewer columns

An easy‐to‐use matrix‐based method for the systematic synthesis of distillation configurations using less than n‐1 columns to separate any zeotropic n‐component feed into n product streams is described. The method is easily extended to obtain additional thermally coupled configurations. The only information needed to generate the configurations is the number of components in the feed, or equivalently, the number of distinct composition final product streams. We have successfully enumerated configurations for feeds containing up to eight components. This has resulted in a large number of hitherto unknown configurations even for four‐component separations. Some of the novel configurations generated using the method have substantially lower heat duty than the previously known fewer column configurations for a four‐component feed separation. Therefore, it is essential to include these novel configurations in the search space to find the optimal distillation configuration with fewer columns for a given application. © 2011 American Institute of Chemical Engineers AIChE J, 58: 2479–2494, 2012     

Insights into Removal of Phenol from Aqueous Solutions by Low Cost Adsorbents: Clays Versus Algae

Abstract

Exchanged clays and cross-linked algae were compared based on their properties for the removal of phenol from aqueous solutions. Algae Lessonia nigrescens Bory (A1) and Macrocystis integrifolia Bory (A2) were cross-linked with CaCl₂ to enhance their physical and mechanical properties. The natural clays were chemically-exchanged with salts of tetramethyl ammonium (B1), hexadecyltrimethyl ammonium (B2), and bencyltriethyl ammonium (B3) ions to increase their affinity towards organic substrates. The effects of pH and adsorbent dose were evaluated. pH exhibited a strong effect mainly on the phenol aqueous chemistry. Sorption isotherm results were modelled on the Langmuir and Freundlich equations and complemented with EDX analysis, indicating that adsorption of phenol from water was mostly driven by hydrophobic forces, with the exchanged bentonites being the adsorbents that reported the maximum adsorption capacities. Conversely, a polar surface adsorption is suggested for algae mostly by means of hydrogen bonding formation. These results provide further insight into the adsorption mechanism of phenol and analogues and their use as powerful and cheap adsorbent for the treatment of phenol-containing real wastewater.     

项目管理“1+2”模式的创新与实践——以上海浦东国际机场二期航站区工程为例

以上海浦东国际机场二期航站区工程为案例,阐述了工程项目管理"1+2"模式(即以指挥部为管理核心,聘请管理总承包和工程监理共同组成项目管理的有机系统)及在项目管理方面的创新实践与优势,该实践为我国大型工程项目管理提供了一种新的且可以借鉴的思路。     

基于随机服务的机器维修应用研究

为了合理安排机械设备的维修人员数量和避免因设备维修时间过长而带来的经济损失,将随机服务模型应用到机器维修上。介绍了随机服务模型的3个组成部分,在此基础上讨论M/M/1模型中如何选择维修速度以及M/M/S模型中如何确定维修工数目,最后给出一个维修实例。结果为管理者提供了准确合理的维修建议,对进一步的决策具有很大的指导作用。     

新时期漳州广电网络1550nm传输设计方案

介绍了漳州广电网络1 550 nm传输设计方案,包括组网方式和直调1 550 nm光发射机的选型等,阐述了双重保护的概念。就怎样选择EDFA的输出光功率发表了自己的一些看法。     

Proof-of-concept study of chitosan-based carbon dioxide indicator for food packaging applications

A chitosan-based carbon dioxide (CO₂) indicator was developed to monitor freshness or quality of packaged foods during their storage, as elevated CO₂ levels inside a package is one of the prime indicators of microbial spoilage of food. The objective of this proof-of-concept study, therefore, was to develop a chitosan-based CO₂ indicator and to investigate its performance in different operating environments. For the enhancement of signal strength of indicator, 2-amino-2-methyl-1-propanol (AMP) was used as an additive to the chitosan solution. Aqueous chitosan–AMP suspensions were prepared by addition of chitosan (0.1%, 0.2% and 0.4%) and AMP (0%, 5%, 10% and 20%) to distilled water at pH 7.0. Thereafter, the aqueous chitosan suspensions were incubated under 100% and 20% CO₂ test atmospheres. The aqueous solubility of chitosan, which in turn impacts the degree of transparency of the suspension, was tested at different pHs and time intervals, spectrometrically. The transparency of 0.2% chitosan aqueous suspension increased dramatically below pH 6.5 under 20% or 100% CO₂ incubation. The addition of a 5% AMP concentration to the chitosan suspension was found optimal for maximum CO₂ absorption and this, therefore, increased transparency by more than 90%.     

酿酒专用粮食在多粮浓香型白酒生产中的应用

针对浓香型白酒企业对酿酒粮食的选用要求,以专用粮食和普通粮食为原料应用于酿酒过程,对酿酒发酵过程中的物质变化进行跟踪检测。结果表明,酿酒专用粮食窖内发酵过程淀粉和还原糖利用率均优于普通粮食,且后期利用酸类和乙醇合成呈香呈味物质能力更强,出酒率和优级率分别较普通粮食提高1.5%和6%,表明酿酒专用粮食对提高原酒酒质效果明显。