The dynamics and stability of lubricating oil films during droplet transport by electrowetting in microfluidic devices

The operation of digital microfluidic devices with water droplets manipulated by electrowetting is critically dependent on the static and dynamic stability and lubrication properties of the oil films that separate the droplets from the solid surfaces. The factors determining the stability of the films and preventing surface fouling in such systems are not yet thoroughly understood and were experimentally investigated in this study. The experiments were performed using a standard digital microfluidic cartridge in which water droplets enclosed in a thin, oil-filled gap were transported over an array of electrodes. Stable, continuous oil films separated the droplets from the surfaces when the droplets were stationary. During droplet transport, capillary waves formed in the films on the electrode surfaces as the oil menisci receded. The waves evolved into dome-shaped oil lenses. Droplet deformation and oil displacement caused the films at the surface opposite the electrode array to transform into dimples of oil trapped over the centers of the droplets. Lower actuation voltages were associated with slower film thinning and formation of fewer, but larger, oil lenses. Lower ac frequencies induced oscillations in the droplets that caused the films to rupture. Films were also destabilized by addition of surfactants to the oil or droplet phases. Such a comprehensive understanding of the oil film behavior will enable more robust electrowetting-actuated lab-on-a-chip devices through prevention of loss of species from droplets and contamination of surfaces at points where films may break.     

Filipino Arts Among Elders in Institutionalized Care Settings

The use of traditional art in recreational therapies is unexplored. This paper, thus, attempts to surface the unique power of traditional Filipino arts (TFA) as synergizing lens in capturing the individual and the collective experiences of a select group of Filipino elderly in an institutionalized care setting relative to their feelings of depression and self-esteem. Three Filipino elderly housed in an institutionalized care setting were chosen for this phenomenological study, a robotfoto and a series of semistructured interviews constitute the main data gathering tool. Field texts were subjected to phenomenological reduction via the repertory grid analysis. Emerged themes were subjected to a series of member checking procedures to ensure the trustworthiness of the reported data. Depression and self-esteem were interpreted via two emerged themes. The themes were Me, Myself, and Melancholy and Will Not Let My Worth Wither. Through recreational therapies in the form of traditional Filipino arts, participants found novel psychological crutches that overcame the challenges of depression and give them hope toward more positive views of themselves and life.     

On Determining Three Dimensional Regions of Significance

How educational goals are conceptualized as a construct has implications for developing and evaluating educational programs and activities. The author used EQS 3.0 to test the factorial validity of 4 models of conceptualization of educational goals by conducting confirmatory factor analysis on empirical data collected from 1,134 education faculty members. The 4-factor model espoused by Goodlad fit the data best, and the participants wanted academic, vocational, personal, and social goals to be in relative harmony. Implications for educational theory, practice, and research are discussed.     

LibStatCAT: a library statistical collection assessment tool for individual libraries & cooperative collection development

The following presentation to the Acquisitions Institute at Timberline Lodge focuses on LibStatCAT, a prototype collection assessment tool under development at Portland State University. Our presentation explores the current uses of LibStatCAT, as well as future developments of LibStatCAT as a regional library data farm for comprehensive assessment of library collections and services for individual libraries and cooperative collection development. We share a variety of other collection assessment tools in use at Portland State University Library.     

Expression of self-concept and adjustment against repeated aggressions: the case of a longitudinal study on school bullying

Bullying between students in the school setting is an increasing problem. Bullying can be defined as any form of repeated mental or physical violence carried out by one or several individuals on a person who is not capable of defending himself (Roland and Idsoe, Aggress Behav 27:446–462, 2001). The aim of this paper is to observe the expression of self-concept and adjustment strategies developed by children subject to this kind of violence. Five hundred twenty-four students between the ages of 8 and 12 (m = 9.44) participated in the longitudinal study. Two measurements were made during the same school year at an interval of 6 months. The results show that the student victims of bullying present weaker self-conceptions than the control group. Recourse to avoidance strategies would be dominant among student victims of bullying. Moreover, recourse to “avoidance” type strategies would lead to an increase in the frequency of bullying while recourse to “approach”-type strategies would lead to a reduction in it. Furthermore, it would seem that recourse to avoidance strategies at T1 lowers the student’s self-concepts at T2. The opposite effect is observed with the approach strategies. These different results emphasize the necessity to establish prevention programs which allow an intervention simultaneously on the level of the school, the family, and the student.