Weatherability of hybrid organic–inorganic silica protective coatings on glass

Currently, there is a growing interest in the application of silicon-based technologies for the development of advanced hybrid organic–inorganic coatings with strong weatherability. In this study, the sol–gel process is used to prepare such coatings on glass and their resistance to weathering effects is assessed afterwards. Various sols were prepared by mixing a silica-based inorganic matrix (tetraethyl orthosilicate) with different quantities of silica alkoxides functionalised with various organic groups. Subsequently, the sols were dip-coated onto glass samples at low temperatures without any heat treatment. The coatings prepared were analysed before and after three model ageing tests simulating various weathering parameters. After ageing, the best performing coatings showed good overall homogeneity and transparency (optical microscopy, SEM), improved water repellency and adhesion to the glass substrate (static contact angle measurements, cross-cut tape tests) and no colour or chemical composition changes (UV–VIS, FTIR). Compared with commercial hybrid silica products, the alkyl- and methacryloxy-functionalised silica coatings particularly displayed improved homogeneity, elasticity and barrier properties. Thus, these low temperature coatings, easily applicable to thin films, appear to fulfil the main requirements for the protection of the glass exposed to weathering phenomena.     

Sexual self-presentation on social network sites: Who does it and how is it perceived?

The aims of this study were to investigate (a) the role of peer factors in adolescents’ sexual self-presentation on social network sites, and (b) how adolescents who present themselves sexually online are evaluated by others. 238 high school students (aged 12–18) evaluated either a sexual or non-sexual online presentation of same-sex and opposite-sex peers. Moreover, they filled in a questionnaire about their own self-presentation behavior. Findings showed that peer norms played a crucial role in whether adolescents posted sexual pictures of themselves online. Moreover, need for popularity was a strong predictor for posting such pictures. Girls who presented themselves in sexual ways were evaluated more negatively by other girls but more positively by boys. Similarly, boys who presented themselves in sexual ways were evaluated more positively by girls but not by boys.     

Negotiation based adaptive learning sequences: Combining adaptivity and adaptability

This study proposes a negotiation-based approach to combine the notion of adaptivity (system-controlled adaptation) and adaptability (user-controlled adaptation) for an adaptive learning system. The system suggests adaptations and the student also submits his/her adaptation preference. When the student preference opposes the system suggestion, the student then negotiates with the system to reach an agreement of adaptation. A negotiation-based adaptive learning system (NALS) is implemented to support the generation of personalized adaptive learning sequences by system negotiations with students regarding assessments of learning performance (i.e. negotiated open student model) of the current content and choices of the next learning content (i.e. negotiation of adaptation). Students require two metacognitions in deciding adaptive learning sequences: self-assessment for evaluating their understanding of the current content and regulation for choosing appropriate learning content. Negotiated open student model are used for assist student self-assessment and negotiation of adaptation are used for assist student regulation of content choices. An experiment was conducted to compare a system-controlled adaptive learning system (SALS, adaptivity), a user-controlled adaptive learning system (UALS, adaptability), and a NALS. The results revealed that NALS promoted better metacognitions in student calibration (i.e. self-assessment) accuracy and learning content choices (i.e. regulation). Preliminary evidences also showed that NALS promoted better student performance in a delay test. The results further suggested that students with poor calibration accuracy and inappropriate content choices were not suitable to use UALS and were suitable to use SALS. The NALS can also be used for training students to make appropriate adaptation for learning.     

Modeling Smart Grid neighborhoods with the ENERsip ontology

The electricity consumption in the buildings sector has been steadily increasing during the last decade, up to the point that energy efficiency in this sector has become a major problem for governments, utilities, customers, and the environment. The foreseen high penetration of distributed micro-generation facilities based on renewables can help to reduce the environmental footprint of buildings and households, although the complexity of managing effectively the electric grid increases dramatically under these conditions. The IEEE 2030 standard for interoperability in the Smart Grid remarks upon the importance of well-defined data models in such complex scenarios and puts emphasis on the benefits of ontologies and OWL (Web Ontology Language) for this purpose. This paper presents an OWL-based ontology that formally defines the vocabulary and taxonomy and captures the engineering and business semantics of this domain of knowledge (i.e., energy efficiency in the so-called nZEN – nearly Zero-Energy Neighborhoods). This ontology has been defined under the scope of the EU (European Union) research project ENERsip. The paper also highlights the main benefits the ontology brought to all the phases of the project life cycle, as well as how future work can make the most out of it.     

改进型冷却水管坝后预留槽设计与应用

冷却水管坝后预留槽施工关系到冷却水管连接、坝面外观和后期封堵等问题。采用传统的预留槽布置方案,需要进行预埋木盒的制作、安装以及拆除后的二期混凝土回填等工作,这些工作费工费时,且容易产生质量缺陷。介绍了一种改进型预留槽施工工艺,即在冷却水管外露端头绑扎土工布代替传统的预埋木盒。分析比较表明,该方法可有效减少施工成本和缩短工期,具有很强的推广价值。     

Crosstalk-aware multi-bit flip-flop generation for power optimization

Applying multi-bit flip-flops (MBFFs) for clock power reduction in modern nanometer ICs has been becoming a promising lower-power design technique. Many previous works tried to utilize as more MBFFs with larger number of bits as possible to gain more clock power saving. However, an MBFF with larger number of bits may lead to serious crosstalk due to the close interconnecting wires belonging to different signal nets which are connected to the same MBFF. This paper analyzes, evaluates, and compares the relationship between power consumption and crosstalk when applying MBFFs with different numbers of bits. To solve the addressed problem, a novel crosstalk-aware power optimization approach is further proposed to optimize power consumption while satisfying the crosstalk constraint. Experimental results show that the proposed approach is very effective in crosstalk avoidance when applying MBFFs for power optimization.     

PTA装置扩产氧化母液罐挖潜——搅拌器改造

上海石化0.4 Mt/a PTA装置扩产改造中,TJ-302氧化母液罐处理量不能满足需求,需要大幅度加快循环速度,在原有设备上增设搅拌器是最经济的选择。增设搅拌器后,又出现新问题,由于循环速度加快,设备中原有的固体含量增加,必须进行再改造。经充分的分析研究以及计算,增设了罐内轴滑动轴承,从而解决了上述问题。     

Waterborne acrylic–casein latexes as eco-friendly binders for coatings

The use of casein as renewable resource to produce eco-friendly hybrid latexes has an increasing importance in industrial applications especially for high performance waterborne coatings. This work describes the synthesis of hybrid acrylic–casein latexes by emulsion polymerization of acrylic monomers in presence of varied casein concentration, and in absence of emulsifier which is usually a challenge for preparing stable nanocomposite latexes. The production and microstructure characterization of the casein–acrylic nanoparticles, as well as the properties of the films obtained from the hybrid latexes are here reported. The synthesized acrylic–casein latexes are able to form films with promising properties for a potential application as waterborne bio-based coatings.     

Self-healing epoxy coatings loaded with inhibitor-containing polyelectrolyte nanocapsules

The self-healing polymer coatings containing organic corrosion inhibitors are intensively investigated as an alternative for highly toxic Cr(VI)-based systems. Protective self-healing coatings are realized by embedding “smart” containers, able to release a corrosion inhibitor under some specific conditions occurring when the corrosion process starts (e.g. on pH change) or upon a mechanical damage. In this study a system with the corrosion inhibitors (2-methylbenzothiazole (BT) and 2-mercaptobenzothiazole (MBT)) encapsulated inside the polyelectrolyte nanocapsules embedded in the water-based epoxy coatings is tested for its self-healing performance. The nanocontainers were prepared by the electrostatic adsorption of polyelectrolytes directly on the oil phase drops containing the inhibiting agent. The results for BT emulsion droplets and the mixture of BT and MBT encapsulated by docusate sodium salt/poly(diallyldimethylammonium chloride) (AOT/PDADMAC) and docusate sodium salt/poly(diallyldimethylammonium chloride)/poly(styrene sulfonate) (AOT/PDADMAC/PSS) surface complexes are presented.The X-ray Photoelectron Spectroscopy (XPS) was used to confirm the release of the inhibitor from the scratched coating. The influence of the nanocapsules on the barrier properties and self-healing performance of the epoxy coatings were tested by electrochemical impedance spectroscopy (EIS) in NaCl solution, the salt spray test (SST) according to ISO9227 and filiform corrosion test (FFT) according to EN ISO 3665. Potential blistering was rated according to EN ISO 4628-2.     

Putting yourself in someone else's shoes: The impact of a location-based,collaborative role-playing game on behaviour

The goal of this study was to probe the effectiveness of a mobile game-based learning approach in modifying behavioural outcomes and competence. The experiment was set against the background of low rates of laymen providing CPR during sudden cardiac arrests. A post-test control group design was used to contrast and evaluate the effects of the two different types of learning. Two hundred two students were randomly assigned to two conditions, a game-based variant simulating an emergency situation (experimental group), and an instruction-based approach (control group). After the intervention participants completed a questionnaire assessing self-prediction, self-efficacy, attitude, subjective norm, empathy and competence. The largest arguably significant difference between the two groups showed in self-prediction and capacity beliefs. Results further revealed a positive relationship between self-prediction and the variables attitude and self-efficacy. The type of scenario did not translate into the other concepts we assessed, though, and results were inconclusive regarding the effectiveness of the type of learning scenario and CPR knowledge. We explain the small effect size partly by the experimental procedure and the design of the game intervention, which is discussed in the course of this article.