Detection of Internal Defects in Concrete Members Using Global Vibration Characteristics

Rock-pocket and honeycomb defects impair overall stiffness, accelerate aging, reduce service life, and cause structural problems in hardened concrete members. Traditional methods for detecting such deficient volumes involve visual observations or localized nondestructive methods, which are labor-intensive, time-consuming, highly sensitive to test conditions, and require knowledge of and accessibility to defect locations. The authors propose a vibration response-based nondestructive technique that combines experimental and numerical methodologies for use in identifying the location and severity of internal defects of concrete members. The experimental component entails collecting mode shape curvatures from laboratory beam specimens with size-controlled rock pocket and honeycomb defects, and the numerical component entails simulating beam vibration response through a finite element (FE) model parameterized with three defect-identifying variables indicating location (x, coordinate along the beam length) and severity of damage (alpha, stiffness reduction and beta, mass reduction). Defects are detected by comparing the FE model predictions to experimental measurements and inferring the low number of defect-identifying variables. This method is particularly well-suited for rapid and cost-effective quality assurance for precast concrete members and for inspecting concrete members with simple geometric forms.

A New Cryptically Dioecious Species of Bush Tomato (Solanum) From the Northern Territory, Australia

A new species of dioecious Solanum from the Australian “Dioicum Complex” of Solanum subgenus Leptostemonum is described. Solanum cowiei Martine sp. nov., is allied with other members of this problematic lineage, but differs in its slender leaves, limited armature and diminutive habit. The species was first segregated by botanists at the Northern Territory Herbarium as Solanum sp. Litchfield (I.D. Cowie 1428); and specimens representing this species have also been referred to by Symon as Solanum sp. Fitzmaurice River. Collections suggest that this is an endemic of the sub-arid tropical zone of the Northern Territory. SEM images support initial assumptions that the new species is cryptically dioecious via production of inaperturate pollen grains in morphologically hermaphrodite flowers.

Predictors of Attitudes toward Lesbians and Transgender Women in Relationships on a College Campus

The purpose of this study was to gain a better understanding of the attitudes which perpetuate intolerance toward LGBT individuals, and to recognize, in particular, the unique attitudes transpeople face as a minority in the nation and even in the LGBT community. This research contributes to the bodies of research concerning the interrelatedness of intrinsic religiosity, political conservatism, sexism, the rape myth, lack of effective legal protection, and the intolerance of gender non-conformists. I have identified distinctions between attitudes on the part of both women and men, as well as toward different gender non-conformists. I have also taken research as a whole further by assessing the predictors of attitudes toward specific members of the LGBT community in public relationships. The implications of these findings are potentially as far reaching as to have an impact on policies effecting healthcare, education, anti-discrimination and employer rights legislation, on both local and national levels.