999 resultados para 378.014


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Bridge expansion joints, if not properly designed, constructed, and maintained, often lead to the deterioration of critical substructure elements. Strip seal expansion joints consisting of a steel extrusion and neoprene gland are one type of expansion joint and are commonly used by the Iowa Department of Transportation (DOT). Strip seal expansion joints are susceptible to tears and pull outs that allow water, chlorides, and debris to infiltrate the joint, and subsequently the bearings below. One area of the strip seal that is particularly problematic is where it terminates at the interface between the deck and the barrier rail. The Iowa DOT has noted that the initial construction quality of the current strip seal termination detail is not satisfactory, nor ideal, and a need exists for re-evaluation and possibly re-design of this detail. Desirable qualities of a strip seal termination detail provide a seal that is simple and fast to construct, facilitate quick gland removal and installation, and provide a reliable, durable barrier to prevent chloride-contaminated water from reaching the substructure. To meet the objectives of this research project, several strip seal termination details were evaluated in the laboratory. Alternate termination details may not only function better than the current Iowa DOT standard, but are also less complicated to construct, facilitating better quality control. However, uncertainties still exist regarding the long-term effects of using straight-through details, with or without the dogleg, that could not be answered in the laboratory in the short time frame of the research project.

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The current means and methods of verifying that high-strength bolts have been properly tightened are very laborious and time consuming. In some cases, the techniques require special equipment and, in other cases, the verification itself may be somewhat subjective. While some commercially available verification techniques do exist, these options still have some limitations and might be considered costly options. The main objectives of this project were to explore high-strength bolt-tightening and verification techniques and to investigate the feasibility of developing and implementing new alternatives. A literature search and a survey of state departments of transportation (DOTs) were conducted to collect information on various bolt-tightening techniques such that an understanding of available and under-development techniques could be obtained. During the literature review, the requirements for materials, inspection, and installation methods outlined in the Research Council on Structural Connections specification were also reviewed and summarized. To guide the search for finding new alternatives and technology development, a working group meeting was held at the Iowa State University Institute for Transportation October 12, 2015. During the meeting, topics central to the research were discussed with Iowa DOT engineers and other professionals who have relevant experiences.

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Aberrant crypt foci (ACF) are putative preneoplastic lesions that might represent the earliest morphological lesion visible in colonic carcinogenesis. However, findings concerning the growth and morphological features of these lesions in human studies suggest that ACF are highly heterogeneous in nature. In this study, we evaluated the morphological features of a large number of ACF in colon mucosa of 26 patients with colorectal carcinoma (CRC), four patients with adenoma as well as seven patients with nonneoplastic colonic diseases. By dissecting microscope, 508 ACF were identified, and of these, 378 were sampled for histological examination. The median ACF density (number of ACF/cm2) was significantly higher in the left colon than in the right colon (0.047 v 0.014 ACF/cm2). Unexpectedly, in our series, the overall ACF density was higher in the nonneoplastic colonic diseases than in CRC (0.13 v 0.032 ACF/cm2, P=.0087), cases of nonneoplastic diseases, however, being limited to 7 patients. ACF were significantly larger in colons with CRC or adenoma than in colons with nonneoplastic disease (P < .03). On histological examination, we observed 133 ACF with normal epithelium, 189 ACF with hyperplasia, 27 ACF with atypical hyperplasia, and 29 ACF with dysplasia. We noted a progressive increase of median ACF size from normal mucosa to hyperplasia, atypical hyperplasia, and dysplasia. Dysplastic ACF were more frequently observed in patients with CRC or adenoma and showed predominantly elongated crypt orifices (P < .0001). We conclude that ACF are histologically heterogeneous, encompass a spectrum of lesions of which only a subset are associated with dysplasia and then represent an early step in colorectal carcinogenesis. ACF with dysplasia are characterized by larger size, elongated crypt orifices, and an association with CRC.

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El estreno de la película Ágora de Alejandro Amenábar en octubre de 2009 puso nuevamente de moda la figura de la célebre filósofa y matemática Hipatia (a quien en rigor deberíamos llamar Hipacia) y generó la aparición de un gran número de monografías, novelas y artículos de todo tipo acerca de su figura. De entre toda esta producción destaca el libro de Clelia Martínez Maza, profesora titular de Historia Antigua de la Universidad de Málaga. Como pone de manifiesto su producción científica, la autora es una gran conocedora del fenómeno religioso y de los conflictos sociales vividos durante la Antigüedad tardía, algo que también puede observarse en la presente obra. Nos hallamos ante una monografía de divulgación culta, como manifiesta la abundante documentación que la autora maneja, aunque el libro carezca de notas tanto al final del volumen como a pie de página, algo normal en estos casos.

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La Cámara de Comercio de Bogotá inscribió el documento privado del accionista único mediante el cual constituyó la sociedad HOTEL GROUP S.A.S. Se solicitó la revocatoria del acto administrativo mediante el cual se registró la constitución de tal sociedad.