844 research outputs found

    Activation volume of selected liquid crystals in the density scaling regime

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    In this paper, we demonstrate and thoroughly analyze the activation volumetric properties of selected liquid crystals in the nematic and crystalline E phases in comparison with those reported for glass-forming liquids. In the analysis, we have employed and evaluated two entropic models (based on either total or configurational entropies) to describe the longitudinal relaxation times of the liquid crystals in the density scaling regime. In this study, we have also exploited two equations of state: volumetric and activation volumetric ones. As a result, we have established that the activation volumetric properties of the selected liquid crystals are quite opposite to such typical properties of glass-forming materials, i.e., the activation volume decreases and the isothermal bulk modulus increases when a liquid crystal is isothermally compressed. Using the model based on the configurational entropy, we suggest that the increasing pressure dependences of the activation volume in isothermal conditions and the negative curvature of the pressure dependences of isothermal longitudinal relaxation times can be related to the formation of antiparallel doublets in the examined liquid crystals. A similar pressure effect on relaxation dynamics may be also observed for other material groups in case of systems, the molecules of which form some supramolecular structures

    The role and awareness of sexual violence initiatives at Rowan University through undergraduate students\u27 perceptions

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    The purpose of this mixed methods study was to determine the overall role and awareness of Rowan University\u27s sexual violence programs through the perceptions of undergraduate students. An online survey was distributed to all enrolled Rowan University undergraduate students to determine their perceptions of the sexual violence initiatives. After the survey was closed, semi-structured virtual interviews were conducted to further investigate those perceptions. Out of the 16,874 surveys distributed, 301 complete responses were recorded, which was about a 1.8% response rate. Out of the 43 participants who signed up after the survey to complete an interview, eight of them followed through, which was about an 18.6% response rate. The findings show that there is an overall lack of awareness for the sexual violence initiatives and for sexual violence itself on Rowan\u27s campus. Nevertheless, data shows that there are also many benefits that the programs carry to help students and sexual violence victims/survivors, as well as helpful suggestions provided by the participants to improve them. It is hopeful that this research study promotes the urge for sexual violence prevention at Rowan University through the sexual violence initiatives and the perceptions from undergraduate students, as well as speak volumes of encouragement for other college campuses to do the same

    The Dramaturgy of Drag

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    Observation of highly decoupled conductivity in protic ionic conductors

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    YesIonic liquids (ILs) are key materials for the development of a wide range of emerging technologies. Protic ionic liquids, an important class of ILs, have long been envisioned as promising anhydrous electrolytes for fuel cells. It is well known that in comparison to all other cations, protons exhibit abnormally high conductivity in water. Such superprotonic dynamics was expected in protic ionic conductors as well. However, many years of extensive studies led to the disappointing conclusion that this is not the case and most protic ionic liquids display subionic behavior. Therefore, the relatively low conductivity seems to be the main obstacle for the application of protic ionic liquids in fuel cells. Using dielectric spectroscopy, herein we report the observation of highly decoupled conductivity in a newly synthesized protic ionic conductor. We show that its proton transport is strongly decoupled from the structural relaxation, in terms of both temperature dependence and characteristic rates. This finding offers a fresh look on the charge transport mechanism in PILs and also provides new ideas for design of anhydrous materials with exceptionally high proton conductivity.National Science Centre within the framework of the Opus project (Grant No. DEC 2011/03/B/ST3/02072). Financial assistance from FNP START. The LDRD Program of ORNL, managed by UT-Battelle, LLC, for the U.S. DOE. Support from the NSF under grant CHE-1213444

    Focal Adhesion-Independent Cell Migration.

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    Cell migration is central to a multitude of physiological processes, including embryonic development, immune surveillance, and wound healing, and deregulated migration is key to cancer dissemination. Decades of investigations have uncovered many of the molecular and physical mechanisms underlying cell migration. Together with protrusion extension and cell body retraction, adhesion to the substrate via specific focal adhesion points has long been considered an essential step in cell migration. Although this is true for cells moving on two-dimensional substrates, recent studies have demonstrated that focal adhesions are not required for cells moving in three dimensions, in which confinement is sufficient to maintain a cell in contact with its substrate. Here, we review the investigations that have led to challenging the requirement of specific adhesions for migration, discuss the physical mechanisms proposed for cell body translocation during focal adhesion-independent migration, and highlight the remaining open questions for the future

    As Borboletas (lepidoptera: Papilionoidea E Hesperioidea) Da Reserva Particular Do Patrimônio Natural Fazenda Lontra/saudade, Itanagra, Litoral Norte Da Bahia, Brasil

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    The Private Reserve of Natural Heritage Fazenda Lontra/Saudade (FLS), located in the Northern Coast of Bahia state, Brazil, is the largest (1,377.33 ha) preserved Atlantic Forest area between Paraguaçu and São Francisco rivers in Bahia and Sergipe, respectively. A list of 260 species belonging to six families of butterflies is presented herein, being recorded 4 species of Papilionidae, 16 of Pieridae, 29 of Lycaenidae, 41 of Riodinidae, 87 of Nymphalidae and 83 of Hesperiidae. The butterfly community was composed mainly by widespread species commonly found in open habitats. There were also many species typical of forested areas, as such Morpho telemachus richardusFruhstorfer, 1898 (Nymphalidae: Morphini), a new record to the Northeastern Brazil. © 2016, Universidade Estadual de Campinas UNICAMP. All rights reserved.16

    Elemol and amyris oil repel the ticks Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) in laboratory bioassays.

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    The essential oil from Amyris balsamifera (Rutaceae) and elemol, a principal constituent of the essential oil of Osage orange, Maclura pomifera (Moraceae) were evaluated in in vitro and in vivo laboratory bioassays for repellent activity against host-seeking nymphs of the blacklegged tick,Ixodes scapularis, and the lone star tick, Amblyomma americanum. Both bioassays took advantage of the tendency of these host-seeking ticks to climb slender vertical surfaces. In one bioassay, the central portion of a vertical strip of filter paper was treated with test solution and ticks placed or allowed to crawl onto the untreated lower portion. In the other bioassay, a strip of organdy cloth treated with test solution was doubly wrapped (treatment on outer layer) around the middle phalanx of a forefinger and ticks released on the fingertip. Both amyris oil and elemol were repellent to both species of ticks. Elemol did not differ significantly in effectiveness against A. americanum from the widely used repellent deet. At 2 and 4 h after application to filter paper, 827 μg amyris oil/cm2 paper repelled 80 and 55%, respectively, of A. americanum nymphs. Ixodes scapularis was repelled by lower concentrations of amyris oil and elemol than A. americanum
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