Kent State University

About: Kent State University is a education organization based out in Kent, Ohio, United States. It is known for research contribution in the topics: Liquid crystal & Population. The organization has 10897 authors who have published 24607 publications receiving 720309 citations. The organization is also known as: Kent State & KSU.

Letters of Gratitude: Further Evidence for Author Benefits

Abstract: This study examined the effects of writing letters of gratitude on three primary qualities of well-being; happiness (positive affect), life-satisfaction (cognitive evaluation), and depression (negative affect). Gratitude was also assessed. Participants included 219 men and women who wrote three letters of gratitude over a 3 week period. A two-way mixed method ANOVA with a between factor (writers vs. non-writers) and within subject factor (time of testing) analysis was conducted. Results indicated that writing letters of gratitude increased participants’ happiness and life satisfaction, while decreasing depressive symptoms. The implications of this approach for intervention are discussed.

Students' Spatial Structuring of 2D Arrays of Squares

Abstract: We define spatial structuring as the mental operation of constructing an organization or form for an object or set of objects. It is an essential mental process underlying students' quantitative dealings with spatial situations. In this article, we examine in detail students' structuring and enumeration of 2-dimensional (2D) rectangular arrays of squares. Our research indicates that many students do not "see" the row-by-column structure we assume in such arrays. We describe the various levels of sophistication in students' structuring of these arrays and elaborate the nature of the mental process of structuring.

Ionic-Liquid-Assisted Synthesis of Uniform Fluorinated B/C-Codoped TiO2 Nanocrystals and Their Enhanced Visible-Light Photocatalytic Activity

Abstract: Exploiting advanced photocatalysts under visible light is of primary significance for the development of environmentally relevant photocatalytic decontamination processes. In this study, the ionic liquid (IL), 1-butyl-3-methylimidazolium tetrafluoroborate, was employed for the first time as both a structure-directing agent and a dopant for the synthesis of novel fluorinated B/C-codoped anatase TiO(2) nanocrystals (T(IL)) through hydrothermal hydrolysis of tetrabutyl titanate. These T(IL) nanocrystals feature uniform crystallite and pore sizes and are stable with respect to phase transitions, crystal ripening, and pore collapse upon calcination treatment. More significantly, these nanocrystals possess abundant localized states and strong visible-light absorption in a wide range of wavelengths. Because of synergic interactions between titania and codopants, the calcined T(IL) samples exhibited high visible-light photocatalytic activity in the presence of oxidizing Rhodamine B (RhB). In particular, 300 °C-calcined T(IL) was most photocatalytically active; its activity was much higher than that of TiO(1.98)N(0.02) and reference samples (T(W)) obtained under identical conditions in the absence of ionic liquid. Furthermore, the possible photocatalytic oxidation mechanism and the active species involved in the RhB degradation photocatalyzed by the T(IL) samples were primarily investigated experimentally by using different scavengers. It was found that both holes and electrons, as well as their derived active species, such as (·)OH, contributed to the RhB degradation occurring on the fluorinated B/C-codoped TiO(2) photocatalyst, in terms of both the photocatalytic reaction dynamics and the reaction pathway. The synthesis of the aforementioned novel photocatalyst and the identification of specific active species involved in the photodegradation of dyes could shed new light on the design and synthesis of semiconductor materials with enhanced photocatalytic activity towards organic pollutants.

Sedimentary deposits of the 26 December 2004 tsunami on the northwest coast of Aceh, Indonesia

Abstract: The 2004 Sumatra-Andaman tsunami flooded coastal northern Sumatra to a depth of over 20 m, deposited a discontinuous sheet of sand up to 80 cm thick, and left mud up to 5 km inland. In most places the sand sheet is normally graded, and in some it contains complex internal stratigraphy. Structures within the sand sheet may record the passage of up to 3 individual waves. We studied the 2004 tsunami deposits in detail along a flow-parallel transect about 400 m long, 16 km southwest of Banda Aceh. Near the shore along this transect, the deposit is thin or absent. Between 50 and 400 m inland it ranges in thickness from 5 to 20 cm. The main trend in thickness is a tendency to thicken by filling low spots, most dramatically at pre-existing stream channels. Deposition generally attended inundation—along the transect, the tsunami deposited sand to within about 40 m of the inundation limit. Although the tsunami deposit contains primarily material indistinguishable from material found on the beach one month after the event, it also contains grain sizes and compositions unavailable on the current beach. Along the transect we studied, these grains become increasingly dominant both landward and upward in the deposit; possibly some landward source of sediment was exposed and exploited by the passage of the waves. The deposit also contains the unabraded shells of subtidal marine organisms, suggesting that at least part of the deposit came from offshore. Grain sizes within the deposit tend to fine upward and landward, although individual units within the deposit appear massive, or show reverse grading. Sorting becomes better landward, although the most landward sites generally become poorly sorted from the inclusion of soil clasts. These sites commonly show interlayering of sandy units and soil clast units. Deposits from the 2004 tsunami in Sumatra demonstrate the complex nature of the deposits of large tsunamis. Unlike the deposits of smaller tsunamis, internal stratigraphy is complex, and will require some effort to understand. The Sumatra deposits also show the contribution of multiple sediment sources, each of which has its own composition and grain size. Such complexity may allow more accurate modeling of flow depth and flow velocity for paleotsunamis, if an understanding of how tsunami hydraulics affect sedimentation can be established.