It has often been observed anecdotally and implied through experimentation that acrylic emulsion paintings accumulate and entrain soils over time due to the inherent mechanical softness in artist's acrylic paint films, through the presence of hydrophilic film components, and by virtue of the ubiquitous presence of surfactant moieties on these film surfaces once they dry. In the present study, it has been this last effect that we have sought to describe more fully in terms of surfactant responsiveness to both temperature and relative humidity (RH). Surfactant hydration and dehydration under varying temperature and RH conditions affects the ultimate partitioning of the surfactant at the paint–air interface, as well as the inherent size, aggregation tendencies, and solubility of surfactant in the bulk paint materials which contain components that are highly responsive to changes in temperature and RH (e.g. polyacrylic or polymaleic anhydride-type dispersal materials). In this work, analytical techniques including three-dimensional microscopy and quartz crystal microbalance with dissipation were used to add to and reinforce current understanding of the physical and mechanical changes to acrylic paint films with temperature and RH. The migration of surfactant at the film surface was studied using desorption electrospray ionization-mass spectrometry and attenuated total reflectance Fourier transform infrared microscopy. 相似文献
The increasing availability of high quality digital texts and usage data about them provides opportunities to identify new uses for collections, alternative ways to present and explore content, and expanded audiences for the materials. Using this information and a rapid development model called a “flash build,” JSTOR is creating and partnering with other organizations to build new tools that add value to library investments in digital collections. Two examples are discussed: “Classroom Readings,” a tool designed to help educators find articles on JSTOR that are good candidates for teaching, and “Understanding Shakespeare,” a resource created in collaboration with the Folger Shakespeare Library that enables scholars to follow links in lines from Shakespeare plays to articles on JSTOR that reference them. The rapid development model used for these projects is easily reproducible and effective, and could be applied to many library-driven efforts. 相似文献
This study explores the associative influence of pretrial publicity on (a) an individual’s perceptions of a criminal offender as malicious and (b) an individual’s judgment of the criminal offender’s punishment for the crime. Expanding on the uses of agenda-setting and framing theories, this research indicates that attention to pretrial news media about a specific criminal is significantly associated with negative judgments of a criminal offender. The criminal offender in the Colorado theater shooting case, James Holmes, was the criminal offender used in this study. Results from a national survey (N = 236) indicated that pretrial publicity significantly influenced participants’ perceptions of James Holmes as malicious and resulted in increased retributivist support (i.e., views of the offender deserving a harsher punishment). Mediation scenarios were also detected, whereas pretrial publicity exposure mediated the relationship between case interest and judgments of James Holmes as malicious and deserving retributivist punishment. 相似文献
AbstractWinthrop University is a public comprehensive university of about 6000 students, 5000 of whom are undergraduates. The Department of Mathematics offers a baccalaureate degree in mathematics, but has no graduate degree programs. As late as 2009, there was essentially no undergraduate research in the department. At this time, faculty made efforts to cultivate a research program that would motivate faculty to pursue more scholarly opportunities and include undergraduates in their scholarship. These efforts began with in-house-sponsored summer programs that lasted a few weeks and grew over the subsequent 5 year period to several externally funded undergraduate research programs, including a National Science Foundation-sponsored Research Experience for Undergraduates program. In this paper, we discuss some lessons we learned in developing a culture of undergraduate research. We focus on the advantages and challenges of undergraduate research at primarily undergraduate universities, offer advice for starting or growing a research program, and provide resources for funding undergraduate research. 相似文献
Peer relationships provide an important context for the young child's social development. Teachers can influence children's
developing social competence in a variety of ways. This article describes how teachers can support children's peer relationships
by intentionally shaping the classroom's physical and emotional context. With these basic supports in place, teachers can
effectively use planned activities and on-the-spot guidance to help children learn to interact competently and form satisfying
relationships. 相似文献
Courses: Communication Criticism, Rhetorical Criticism, Family and Communication, Gender and Communication, Popular Communication, and theory-based courses
Objectives: This activity engages students in dynamic, supportive, social discussion groups; helps them to identify and review the central ideas from the reading; and creates a record of their ideas that they can draw upon in later discussions. By the end of the activity, students should be able to (1) provide their own examples for difficult communication concepts, (2) work effectively with their peers, (3) understand a given case-study from a variety of perspectives, and (4) be prepared to contribute to a whole class discussion regarding sensitive, complex, and/or theoretical communication topics. Speed-Discussion is not a graded activity but rather a fun, low-risk, discussion activity that primes the pump for a dynamic, discussion-based class experience. 相似文献
Courses: Research Methods (undergraduate or graduate level)
Objective: The aim of this exercise is to optimize the ability for students to integrate an understanding of various methodologies across research paradigms within a 15-week semester, including a review of procedural steps and experiential learning activities to practice each method, a criteria for understanding how to consume primary research, and a recognition of how the methodological techniques can be used in the classroom and in professional settings. 相似文献