Concurrent droplet charging and sorting by electrostatic actuation

This paper presents a droplet-based microfluidic device for concurrent droplet charging and sorting by electrostatic actuation. Water-in-oil droplets can be charged on generation by synchronized electrostatic actuation. Then, simultaneously, the precharged droplets can be electrostatically steered into any designated laminar streamline, thus they can be sorted into one of multiple sorting channels one by one in a controlled fashion. In this paper, we studied the size dependence of the water droplets under various relative flow rates of water and oil. We demonstrated the concurrent charging and sorting of up to 600 droplets∕s by synchronized electrostatic actuation. Finally, we investigated optimized voltages for stable droplet charging and sorting. This is an essential enabling technology for fast, robust, and multiplexed sorting of microdroplets, and for the droplet-based microfluidic systems.     

Open innovation in SMEs—An intermediated network model

In spite of increasing interest in open innovation, discussion about the concept and its potential application to the SME sector has been excluded from mainstream literature. However, given that the argument about the effect of firm size on the effectiveness of innovation is still ongoing, it is worth addressing the issue from an SME perspective. That is the focus of this article, which seeks, firstly, to place the concept of open innovation in the context of SMEs; secondly to suggest the input of an intermediary in facilitating innovation; and finally to report accounts of Korean SMEs’ success in working with an intermediary. The research results support the potential of open innovation for SMEs, and indicate networking as one effective way to facilitate open innovation among SMEs.     

Career patterns and competences of PhDs in science and engineering in the knowledge economy: The case of graduates from a UK research-based university

Based on data collected through a complex survey of science and engineering PhD graduates from a UK research-based university, this paper examines the different types of careers and to what extent different types of competences acquired from doctoral education are regarded as valuable in the different career types. The results show that employment outside the conventional technical occupations is the main destination for the survey respondents. This career type is not only successful at retaining its members, but is also the destination of the other career types. Moreover, different types of competences from doctoral education are regarded as relatively more valuable in different career types: knowledge directly tied to subject areas is regarded as more valuable in academia/public research; both knowledge directly tied to subject areas (but more general type of knowledge rather than specialist knowledge in PhD topics) and the more general and transferable skills are regarded as valuable in technical positions in manufacturing; and the general and transferable skills are regarded as more valuable in employment outside the conventional technical occupations. In absolute terms, general analytical skills and problem solving capability acquired from doctoral education are perceived as valuable in all three career types.     

Improved approaches to stability criteria for neural networks with time-varying delays

In this paper, the problem of stability analysis for neural networks with time-varying delays is considered. By the use of a newly augmented Lyapunov functional and some novel techniques, sufficient conditions to guarantee the asymptotic stability of the concerned networks are established in terms of linear matrix inequalities (LMIs). Three numerical examples are given to show the improved stability region of the proposed works.     

A microfluidic device for simultaneous measurement of viscosity and flow rate of blood in a complex fluidic network

Blood viscosity has been considered as one of important biophysical parameters for effectively monitoring variations in physiological and pathological conditions of circulatory disorders. Standard previous methods make it difficult to evaluate variations of blood viscosity under cardiopulmonary bypass procedures or hemodialysis. In this study, we proposed a unique microfluidic device for simultaneously measuring viscosity and flow rate of whole blood circulating in a complex fluidic network including a rat, a reservoir, a pinch valve, and a peristaltic pump. To demonstrate the proposed method, a twin-shaped microfluidic device, which is composed of two half-circular chambers, two side channels with multiple indicating channels, and one bridge channel, was carefully designed. Based on the microfluidic device, three sequential flow controls were applied to identify viscosity and flow rate of blood, with label-free and sensorless detection. The half-circular chamber was employed to achieve mechanical membrane compliance for flow stabilization in the microfluidic device. To quantify the effect of flow stabilization on flow fluctuations, a formula of pulsation index (PI) was analytically derived using a discrete fluidic circuit model. Using the PI formula, the time constant contributed by the half-circular chamber is estimated to be 8 s. Furthermore, flow fluctuations resulting from the peristaltic pumps are completely removed, especially under periodic flow conditions within short periods (T < 10 s). For performance demonstrations, the proposed method was applied to evaluate blood viscosity with respect to varying flow rate conditions [(a) known blood flow rate via a syringe pump, (b) unknown blood flow rate via a peristaltic pump]. As a result, the flow rate and viscosity of blood can be simultaneously measured with satisfactory accuracy. In addition, the proposed method was successfully applied to identify the viscosity of rat blood, which circulates in a complex fluidic network. These observations confirm that the proposed method can be used for simultaneous measurement of viscosity and flow rate of whole blood circulating in the complex fluid network, with sensorless and label-free detection. Furthermore, the proposed method will be used in evaluating variations in the viscosity of human blood during cardiopulmonary bypass procedures or hemodialysis.     

Speech education ‐ ways and means of political education in Germany

This study of the utility of evidence differs from previous studies in its use of a respondent‐generated matrix of information and sources. This matrix comprised three dimensions (expertness × trustworthiness‐acquaintanceship x information type] and was used to produce Q‐statements which subjects sorted according to a most useful‐Jeast useful criterion in three hypothetical decision‐making situations. The Q‐analysis revealed several types of persons, including: types which found directive information most useful, types which preferred unknown but competent sources, and types which depended upon sources who were known and trusted regardless of the kind of information the source offered.     

EFFECTS OF TEACHER–STUDENT RELATIONSHIPS ON PEER HARASSMENT: A MULTILEVEL STUDY

Peer harassment is a major social problem affecting children and adolescents internationally. Much research has focused on student‐to‐student harassment from either an individual or a multilevel perspective. There is a paucity of multilevel research on students’ relationships with the classroom teacher. The purpose of this study was to use a socioecological perspective to examine the relationships between individual student‐level characteristics, problematic teacher–student relationships, and student‐reported peer harassment. A total of 1,864 children (50.7% female) aged 8 to 13 years (M = 9.82, SD = 1.24), nested in 27 schools (58.2% public) in Spain, participated in the study. Ninety‐four homeroom teachers reported on teacher–student relationships, and students completed self‐report measures related to peer harassment and teacher–student relationships. Multilevel models showed that relationships between students and teachers exerted a varying degree of influence on classroom levels of peer harassment. Specifically, student‐reported teacher support was associated with diminished student‐reported peer victimization, whereas direct and indirect student‐reported teacher‐to‐student aggression was associated with increased peer victimization. Additionally, student‐reported student‐to‐teacher aggression and teacher‐to‐student aggression were associated with increased student‐reported peer aggression. Teacher‐reported variables at the classroom level, however, contributed little to student‐reported outcomes. Results are discussed in the context of future research on relationships between teachers and students.     

Globalization and the freedom of knowledge

This article considers the transmission of knowledge in higher education. It takes the metaphor of the music industry that pre‐selects the music people can buy. The sales potential is the leading principle in the selection process. Often the small producer is excluded because his or her music is not of commercial interest. The end‐customer does not know what he or she is missing because he or she has never heard the music. It is to be feared that a similar market principle will also influence the selection of knowledge and affect the capacity of higher education institutions to freely generate and transmit new knowledge. The globalization of higher education risks homogenizing the cultural traditions of the non‐Western world through a process of Western cultural domination. On the other hand, the Internet, via open source software like LINUX, might serve to democratize higher education and allow greater grassroots input.     

Engaging ADHD students in tasks with hand gestures: a pedagogical possibility for teachers

This study examines the effects of teachers' speech and hand gestures on the task performances of students with Attention‐Deficit/Hyperactivity Disorder (ADHD). Forty‐five 7½‐year‐old students clinically diagnosed with ADHD participated in the study. The students were asked to solve three sets of puzzles. The teachers supported the students in the tasks by using three different scaffolding modalities: speech‐only, gesture‐only and speech in conjunction with gestures. The results indicate that when the teachers used the scaffolding that contained gesture components (either speech scaffolding in conjunction with gesture scaffolding or gesture‐only scaffolding), the ADHD students were more responsive, focused longer on the tasks and were more successful in completing the tasks. Moreover, teachers' representational and deictic gestures were found to be the most effective gestures in scaffolding. This study suggests that when teachers' hand gestures are used together with speech, they are a powerful pedagogical means to engage ADHD children in tasks.     

Organizing, Teaching, and Assessing for Student Success in Introductory College Physics

As part of a doctoral dissertation, Ben （2010） completed a study that extends to 462 pages. After a careful examination of this study and others that are in print, there seems to be a direct relationship between the decline in physics enrollment at the postsecondary level and the increase in the number of studies that have been carried out to determine why have we been off the mark in identifying the real problems that are contributing to the declining enrollment and the decreased student success in physics courses？ One problem is introductory physics books are generally written using a deductive approach, and because the teachers follow the organization of these books, they teach in a deductive, boring, and confusing way, and then, blame the students for being unprepared when they do not succeed. This approach distances the teachers--and physics--from the experience, knowledge, and initial interest of many beginning students. Another problem has been the absence of any alternative curriculum to the deductive one. In this paper, we describe a fully-developed alternative curriculum, really a detailed course design for Introductory College Physics I and II, each with its own text presented in the format of a three-ring binder, one for students and one for teachers which closely parallel one another. The course content is constructed to be both teacher and student friendly, so that a teacher can teach physics in an inductive, exciting, and clear manner. In addition, we describe and provide examples of the pedagogical and classroom management techniques that have proven extremely successful.