Quaternized Amphiphilic Block Copolymers as Antimicrobial Agents

In this study, a novel polystyrene-block-quaternized polyisoprene amphipathic block copolymer (PS-b-PIN) is derived from anionic polymerization. Quaternized polymers are prepared through post-quaternization on a functionalized polymer side chain. Moreover, the antibacterial activity of quaternized polymers without red blood cell (RBCs) hemolysis can be controlled by block composition, side chain length, and polymer morphology. The solvent environment is highly related to the polymer morphology, forming micelles or other structures. The polymersome formation would decrease the hemolysis and increase the electron density or quaternized groups density as previous research and our experiment revealed. Herein, the PS-b-PIN with N,N-dimethyldodecylamine as side chain would form a polymersome structure in the aqueous solution to display the best inhibiting bacterial growth efficiency without hemolytic effect. Therefore, the different single-chain quaternized groups play an important role in the antibacterial action, and act as a controllable factor.

TURKISH UNIVERSITY STUDENTS’ CAUSAL ATTRIBUTIONS TO THEIR PERCEIVED ACHIEVEMENTS AND FAILURES IN LEARNING ENGLISH

This study aimed to look into Turkish learners’ examples of success and failure, and attributions to their perceived achievements and failures in learning English as a foreign language. Data were collected from 41 students majoring in physics, metallurgy engineering and paramedics at a public university in Turkey. An open-ended questionnaire was translated into Turkish and delivered to the students to obtain data. Research findings firstly showed that one-third of the participants did not recount an example of success or failure, which might point out learners’ lack of self-awareness and self-assessment. Furthermore, their examples of success and failure mainly were grade-oriented. This finding might display the influence of the Turkish educational system focusing on academic achievement which is primarily evaluated by exam results. Secondly, students were found to attribute both their achievements and failures to effort as an internal and controllable factor. Another important factor was found to be motivation; hence the importance of motivating university students who claimed their own responsibility for success and failure arises.

Lessons from COVID-19 in South Africa: Keeping our environment clean should be the first law of health

In the wake of the coronavirus disease 2019 (COVID-19) pandemic, the links between poor hygiene, unclean environments and human health cannot be overemphasised, particularly in South Africa with its high incidence of infectious diseases and overburdened health system. One very controllable factor that is often overlooked is the poor disposal of litter and waste management and its adverse effects on public health. By wearing masks, regular handwashing and sanitising, as well as making sure that neighbourhoods and public spaces are clean and safe, the spread of COVID-19 and other diseases can be prevented.

Experimental study of concrete mixtures to produce UHPRC using sustainable brazilians materials

An experimental study is presented to produce Ultra High Performance Reinforced Concrete (UHPRC) with sustainable materials produced in Brazil. A complete factorial arrangement was defined and five controllable factors were selected based on the literature review. Cylindrical specimens were tested at 7, 14 and 28 days of curing, with and without heat treatment. The residual deviations of the results were determined and an analysis of variance using ANOVA was applied to know the contribution of each controllable factor on the compressive strength, which reached a maximum value of 138.12 MPa. Finally, a mix design is proposed to obtain UHPRC by applying a simple manufacturing procedure using commercial materials, with which a high performance concrete can be obtained, reaching at least 70% of its strength in seven days.

Cybernetics in Planning and Design

Cybernetics in landscape architecture planning and design are discussed in this paper. There are many differences and characteristic in the area of design products compared with other industrial products. The control stages or steps include: information collection in previous designs, information feedback in the planning and design, information feedback in a building construction or in a partly-finished building, information feedback in the use of a finished building. The article studies integrated ecology and design, integrated uses in urban and landscape areas, the method of interdisciplinary working. System theory is involved in this paper to discuss relevant problems. The paper also discusses the major controllable factor in the ecological strategies, and then examines effective planning and design. This article argues the problem of ecological strategies in the landscape design and planning, and the main contents of ecological strategies. It includes the strategy of landscape sustainable development, which is in conflict with rapid economies and historic preservation, ecological conservation.

Research on the Pedestrian Street System and its Ecological Strategies in the Urban Planning

This article argues the problems of ecological strategies in the planning of pedestrian street system, and the main contents of ecological strategies under the concept of low-carbon strategy. From a whole environmental ecosystem to an urban pedestrian ecosystem, some strategies of pedestrian zone are studied. The paper also discusses the contents of ecological strategies in the ecological design of pedestrian street system, the major controllable factor in the ecological strategies, the pedestrian street ecosystem and the urban spaces, the urban life etc. In addition to these, the article studies the composition of pedestrian street ecosystem, the relationship among the urban ecosystem and the pedestrian ecosystem, the planning and design integrated ecology, the method of interdisciplinary working. System theory is involved in this paper to discuss relevant questions.

Research on the Ecological Strategies in Landscape Design and Planning

This article argues the problem of ecological strategies in the landscape design and planning, and the main contents of ecological strategies. It includes the strategy of landscape sustainable development, which is in conflict with rapid economies and historic preservation, ecological conservation. The paper also discusses why people are the major controllable factor in the ecological strategies. In addition to these, the article studies the composition of landscape ecosystem, integrated ecology and design, integrated uses in landscape area, the method of interdisciplinary working. System theory is involved in this paper to discuss relevant questions.