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.

The influence of natural mineral coatings on feldspar weathering

Abstract: Quantification of the rate of weathering of feldspar, the most abundant mineral in the Earth's crust, is required to estimate accurately carbon dioxide fluxes over geological timescales and to model groundwater chemistry. Laboratory dissolution rates, however, are consistently found to be up to four orders of magnitude higher than the ‘natural' rates1,2 measured in the field. Although this discrepancy has been attributed to several factors2, previous research has tended to suggest that the underlying mechanism of feldspar dissolution under acidic pH may differ between the field and the laboratory3. Here we demonstrate that weathered albite surfaces, like laboratory-dissolved samples, are sodium- and aluminium-depleted, indicating that the dissolution mechanism in acidic soils is similar to that in acidic laboratory solutions. We find that microtopography images are consistent with dissolution occurring at specific surface sites — indicative of surface-controlled dissolution dominated by a non-stoichiometric layer. Elevated aluminium and silicon ratios reported previously3,4, and used to suggest a mechanism for field weathering different from laboratory dissolution3, can alternatively be explained by a thin, hydrous, patchy, natural coating of amorphous and crystalline aluminosilicate. This coating, which is largely undetected under scanning electron microscopy after cleaning, but visible under atomic force microscopy, alters surface chemistry measurements and may partially inhibit the field dissolution rate.

Predictors of Sexual Aggression among a National Sample of Male College Students

Abstract: An approximately representative national sample of 2,972 male students at 32 U.S. institutions of higher education was surveyed regarding their use of several degrees of verbal coercion and physical force to obtain sexual intimacy with women without consent. The most severe form of sexual aggression each man reported was used to classify him into one of five groups: sexually nonaggressive, sexual coercion, sexual contact, attempted rape, or rape. Respondents also provided data that was grouped into three blocks of variables: early experiences (family violence exposure, childhood sexual abuse, age of sexual initiation), psychological characteristics (MMPI Scale 4, Hostility Toward Women, rape supportive beliefs, gender role orientation), and current behavior (alcohol use, pornography use, male bonding, sexual values and activity, conflict tactics). Data were analysed via blockwise discriminant function analysis. Variables were entered following a suggested development sequence. Specifically, all early experience variables were entered first as a block. Then the entire set of psychological characteristics were entered stepwise followed by all the current behavior variables. Variables from all three blocks entered the model. The classification rates have been discussed and the implications of the analyses for future causal models of male sexual aggression considered. Language: en