Quasi-critical condition to balance the scaling and membrane lifespan tradeoff in hypersaline water concentration.

Mineral scaling is an inconvenient obstacle for membrane distillation in hypersaline wastewater concentration applications, compromising membrane lifespan to maintain high water recovery. Although various measures are devoted to alleviating mineral scaling, the uncertainty and complexity of scale characteristics make it difficult to accurately identify and effectively prevent. Herein, we systematically elucidate a practically applicable principle to balance the trade-off between mineral scaling and membrane lifespan. Through experimental demonstration and mechanism analysis, we find a consistent concentration phenomenon of hypersaline concentration in different situations. Based on the characteristics of the binding force between the primary scale crystal and the membrane, the quasi-critical concentration condition is sought to prevent the accumulation and intrusion of mineral scale. The quasi-critical condition achieves the maximum water flux on the premise of guaranteeing the membrane tolerance, and the membrane performance can be restored by undamaged physical cleaning. This report opens up an informative horizon for circumventing the inexplicable scaling explorations and develops a universal evaluation strategy to provide technical support for membrane desalination.

Armor-Structured Interconnected-Porous Membranes for Corrosion-Resistant and Highly Permeable Waste Ammonium Resource Recycling.

Ammonium recovery from wastewater by gas-permeable membranes is promising but suffers from the tradeoff between membrane stability and permeability under harsh operating conditions. Chemical-resistant membranes display modest permeability due to the poor solubility and processibility; chemically active membranes are easier to be endowed with better permeability however hinder by instability. To resolve such a problem, we cleverly design a novel membrane configuration via one-step solution-electrospinning, with the chemical-active component (low-strength fluorine polymer) as the inner skeleton to construct interconnected porous structures and the chemical-resistant component (high-strength fluorine polymer) as the outer armor to serve as a protective layer. Due to the significantly enhanced mass transfer coefficient, the interconnected-porous armor-structured membrane exhibited much higher permeability for NH4+-N recovery, which was 1.4 and 5 times that of the traditional PTFE membrane and PP membrane, respectively. Through long-term intermittent and consecutive experiments, the reusability and durability of the armor-structured nanofibrous membrane were verified. When treating actual hoggery wastewater with complicated water quality, the armor-structured nanofibrous membrane also displayed robust stable performance with excellent antiwettability. The mechanisms of membrane formation, corrosion resistance, and mass transfer were discussed in detail.

The potential of Second Life for university counseling: a comparative approach examining media features and counseling problems.

This study explored the potential of Second Life (SL), a popular multi-user virtual online environment, for university counseling. University students (n = 312) were asked to evaluate three counseling channels (i.e., traditional face-to-face, internet, and SL) based on a range of media features deemed relevant and important to counseling and to assess their relative preferability when faced with different counseling problems. For the purposes of this study, counseling rooms with different styles were built, virtual counselors with different genders, ages, and styles were created, and short video recordings of scripted counseling sessions were produced in SL. For the media feature comparisons, the collected data were analyzed by the multivariate analysis of variance, followed by the analysis of variance and post hoc comparisons when significant differences were found, whereas for counseling problem comparisons, repeated-measure analysis of variance and post hoc comparisons were used. The results for the media feature comparisons showed that SL counseling significantly out-rated traditional counseling in all of the examined media features, with the exception of the interactivity dimension. Additionally, while SL and internet counseling were both perceived as significantly better than traditional counseling in areas that are unique to computer-mediated communications, including anonymity, convenience, and flexibility with regard to time and space, as well as privacy of the counseling site, SL was perceived as distinctly superior to internet counseling in five areas due to its unique affordances, including the choice of appearance, choice of counselors, interactivity, diversity of counseling sites, and availability of counseling object dimensions. Furthermore, traditional counseling was regarded as better able to support more fluent and versatile interaction between the counselor and client than the other two computer-mediated channels. As for the results of counseling problem comparisons, SL was rated as least preferred for six out of the seven counseling problems (except for gender identity issues), despite its media affordances. Suggestions for practitioners and future research are provided based on the current findings.

The effects of an online student question-generation strategy on elementary school student English learning.

Recognizing the potential of online student question-generation to engage language learners in communicative activities and use the target language in a personally meaningful way for language and learning motivation development, an experimental study examining the English learning effects of this approach, in comparison to an online drill-and-practice strategy, was conducted. A quasi-experimental research design was adopted. Four sixth-grade classes (N = 106) participated in this study and were randomly assigned to different treatment groups. An online learning system supporting the various learning activities was adopted. The results of analysis of covariance (ANCOVAs) showed that students in the online student question-generation group performed significantly better in English assessments and exhibited higher learning motivation than those in the contrast group. The significance of this study and suggestions for instructional implementation and future works are also presented.

Experimental comparisons of face-to-face and anonymous real-time team competition in a networked gaming learning environment.

This study investigates the impact of anonymous, computerized, synchronized team competition on students' motivation, satisfaction, and interpersonal relationships. Sixty-eight fourth-graders participated in this study. A synchronous gaming learning system was developed to have dyads compete against each other in answering multiple-choice questions set in accordance with the school curriculum in two conditions (face-to-face and anonymous). The results showed that students who were exposed to the anonymous team competition condition responded significantly more positively than those in the face-to-face condition in terms of motivation and satisfaction at the 0.050 and 0.056 levels respectively. Although further studies regarding the effects of anonymous interaction in a networked gaming learning environment are imperative, the positive effects detected in this preliminary study indicate that anonymity is a viable feature for mitigating the negative effects that competition may inflict on motivation and satisfaction as reported in traditional face-to-face environments.