New and updated convex shape models of asteroids based on optical data from a large collaboration network

Context. Asteroid modeling efforts in the last decade resulted in a comprehensive dataset of almost 400 convex shape models and their rotation states. These efforts already provided deep insight into physical properties of main-belt asteroids or large collisional families. Going into finer detail (e.g., smaller collisional families, asteroids with sizes 20 km) requires knowledge of physical parameters of more objects. Aims. We aim to increase the number of asteroid shape models and rotation states. Such results provide important input for further studies, such as analysis of asteroid physical properties in different populations, including smaller collisional families, thermophysical modeling, and scaling shape models by disk-resolved images, or stellar occultation data. This provides bulk density estimates in combination with known masses, but also constrains theoretical collisional and evolutional models of the solar system. Methods. We use all available disk-integrated optical data (i.e., classical dense-in-time photometry obtained from public databases and through a large collaboration network as well as sparse-in-time individual measurements from a few sky surveys) as input for the convex inversion method, and derive 3D shape models of asteroids together with their rotation periods and orientations of rotation axes. The key ingredient is the support of more that 100 observers who submit their optical data to publicly available databases. Results. We present updated shape models for 36 asteroids, for which mass estimates are currently available in the literature, or for which masses will most likely be determined from their gravitational influence on smaller bodies whose orbital deflections will be observed by the ESA Gaia astrometric mission. Moreover, we also present new shape model determinations for 250 asteroids, including 13 Hungarias and three near-Earth asteroids. The shape model revisions and determinations were enabled by using additional optical data from recent apparitions for shape optimization. © 2016 ESO.J.H. greatly appreciates the CNES post-doctoral fellowship program. J.H. and M.D. were supported by the project under the contract 11-BS56-008 (SHOCKS) of the French Agence National de la Recherche (ANR), JD by grant GACR 15-04816S of the Czech Science Foundation, DO by the grant NCN 2012/S/ST9/00022 of Polish National Science Center, and A. Marciniak by grant 2014/13/D/ST9/01818 of Polish National Science Center.Peer Reviewe

SAG-FW Welding of C90 Riser Steel Connectors

Weld simulations have been conducted on a C90 quenched tempered steel used in offshore riser systems, in order to investigate the possibility of introducing an effective solid state weld procedure. As a secondary objective, the microstructure of the HAZ of a TIG welding is to be evaluated. The C90 is as steel of high hardenability and its base microstructure consists of tempered martensite with a Vickers hardness of 239 HV10. The main focus in this work has been to sufficiently soften the weld as well as obtaining impact toughness properties within requirements, by implying a post weld heat treatment procedure. Hardness values cannot exceed 270 HV10 and impact toughness energy must exhibit an average value above 40 J. Steel samples have been heated to a peak temperature of 1150 ˚C, followed by controlled cooling at 10 and 60 ˚C/s, prior to post weld heat treatment. Tempering at temperatures of 680 and 720 ˚C has been conducted on the post quenched structure for up to three hours and has been performed in an air circulating furnace and in a Smitweld Thermal Cycle apparatus. Low tempering times (up to 1200 s) have been performed in the Smitweld apparatus. Weld hardness and impact toughness requirements was met after three hours of post weld heat treatment at 720 ˚C in an air circulating furnace, producing a hardness value of 253 HV10 and a Charpy-V energy of 66 J for the parallel quenched at 10 ˚C/s. After some tempering of the structure, the two cooling rates used did not affect hardness values significantly. Tempering at 680 ˚C did not soften the structure sufficiently to meet the criteria, with the lowest measured hardness of 315 HV10 after three hours. The hardness of the intercrictial zone of the weld was reduced to 246 HV10 after tempering for three hours at 720 ˚C. Tempering in the Smitweld apparatus softened the structure more efficiently than what was observed in the furnace, producing hardness values of 271 HV10 after only twenty minutes of tempering at 720 ˚C. It has been suggested that due to substantially higher heating rates obtained by the Smitweld apparatus, low temperature tempering mechanisms may be inhibited or delayed, resulting in a post tempered structure consisting of coarse carbides with large inter particle spacing, contributing little to precipitation hardening. Heating rates obtained by Smitweld is in the same range as those obtainable by the SAG-FW procedure, and the two methods are therefore considered comparable. FMC Technologies uses a TIG weld procedure followed by a six hour post weld heat treatment to obtain satisfactory mechanical properties on the C90 steel quality. It is suggested, that by applying a solid state weld procedure, the total tempering time can be reduced with at least 50 %

The Effects of Toluene on the Ontogenetic Development of the Fish, Oryzias latipes, the Japanese Medaka

The effects of toluene to the ontogenetic development of the Cyprinodontid fish, Oryzias latipes, the Japanese Medaka was established. By the use of static bioassays, the median tolerance limits (TL 50 values) were calculated with their respective 95% confidence limits for different stages of embryonic development exposed to the chemical for periods of 24-hrs, 48-hrs, and 96-hrs. The TL 50 values were also obtained for embryos at the time of hatching of the eggs and at the time of the absorption of the yolk’s oil droplet, one week after hatching. The mortality effects of toluene to newly hatched fry were determined. Again TL50 values were obtained at 24-hrs, 48-hrs, 96-hrs, and 168-hrs exposure to toluene solutions. The effects of the chemical to the hatchability of the eggs was noted. The induction of gross anatomical deformities was examined. The results indicated that newly hatched fry, the earlier stages of development (before the hardendening of the chorion), and the later stages of development (prior to hatching) were t he more sensitive periods to the action of the toluene. The 96-hr TL50 values of these groups ranged from 20-30 mg/l toluene. Factors influencing mortalities were: (1) the stage of embryonic development at which the embryo was initially introduced to the toluene solutions, (2) the concentration of toluene in which the embryo was introduced, and (3) the duration of exposure to which the embryo was subjected. The induction of embryonic deformities was influenced by: (1) the degree of cellular organization at the time the embryo was initially introduced to the toluene, and (2) the concentration of toluene to which the embryo was treated. Deformities were restricted to those embryos treated with toluene before stage 28 (74 hrs). The more predominant deformities were: (1) disruptions of the cleaving blastomeres, (2) malformation of the heart and vitelline circulatory systems, (3) deformation of the eyes, (4) malformation of the tail musculature as indicated by a bending of the tail, and (5) a failure of some of the visceral organs to develop properly. Tissue of a mesodermal origin in whole or in part appeared to be most sensitive to the teratogenic action of toluene. The differential susceptibility of the embryos and fry was discussed in relation to the extent of cellular organization present at the time when first introduced in to the toluene solutions. The use of fish embryos in bioassays was discussed. Fish embryos appear to be well suited for screening tests in the determination of the toxic effects of aquatic pollutants

The Effects of Toluene on the Ontogenetic Development of the Fish, Oryzias latipes, the Japanese Medaka

The effects of toluene to the ontogenetic development of the Cyprinodontid fish, Oryzias latipes, the Japanese Medaka was established. By the use of static bioassays, the median tolerance limits (TL 50 values) were calculated with their respective 95% confidence limits for different stages of embryonic development exposed to the chemical for periods of 24-hrs, 48-hrs, and 96-hrs. The TL 50 values were also obtained for embryos at the time of hatching of the eggs and at the time of the absorption of the yolk’s oil droplet, one week after hatching. The mortality effects of toluene to newly hatched fry were determined. Again TL50 values were obtained at 24-hrs, 48-hrs, 96-hrs, and 168-hrs exposure to toluene solutions. The effects of the chemical to the hatchability of the eggs was noted. The induction of gross anatomical deformities was examined. The results indicated that newly hatched fry, the earlier stages of development (before the hardendening of the chorion), and the later stages of development (prior to hatching) were t he more sensitive periods to the action of the toluene. The 96-hr TL50 values of these groups ranged from 20-30 mg/l toluene. Factors influencing mortalities were: (1) the stage of embryonic development at which the embryo was initially introduced to the toluene solutions, (2) the concentration of toluene in which the embryo was introduced, and (3) the duration of exposure to which the embryo was subjected. The induction of embryonic deformities was influenced by: (1) the degree of cellular organization at the time the embryo was initially introduced to the toluene, and (2) the concentration of toluene to which the embryo was treated. Deformities were restricted to those embryos treated with toluene before stage 28 (74 hrs). The more predominant deformities were: (1) disruptions of the cleaving blastomeres, (2) malformation of the heart and vitelline circulatory systems, (3) deformation of the eyes, (4) malformation of the tail musculature as indicated by a bending of the tail, and (5) a failure of some of the visceral organs to develop properly. Tissue of a mesodermal origin in whole or in part appeared to be most sensitive to the teratogenic action of toluene. The differential susceptibility of the embryos and fry was discussed in relation to the extent of cellular organization present at the time when first introduced in to the toluene solutions. The use of fish embryos in bioassays was discussed. Fish embryos appear to be well suited for screening tests in the determination of the toxic effects of aquatic pollutants.SUNY BrockportBiological SciencesMaster of Science (MS)Environmental Science and Ecology These

Effect of inbreeding on mortality and growth in rainbow trout

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Belastungen und Stress in der ambulanten Pflege

„Belastungen und Stress in der ambulanten Pflege: Ein Vergleich Stadt – Land unter Verwendung des Belastungsscreening TAA – Ambulante Pflege“ Durch den demographischen Wandel, die immer kleiner werdenden Haushalte und Familien wird das Gesundheitssystem vor eine große Herausforderung gestellt. Immer weniger Frauen und Männer können die Versorgung ihrer pflegebedürftigen Verwandten und Familienangehörigen selbst übernehmen und übergeben diese Aufgabe einem ambulanten Pflegedienst. Im Bericht der Statistik Austria zur Bevölkerungs-Prognose ist zu lesen, dass der Anteil der über 75-Jährigen sich in den nächsten Jahren am stärksten verändern wird. Durch die ständig steigende Anzahl der zu Pflegenden stehen die Pflege-Organisationen unter teilweise hohem Leistungsdruck. Bei dieser wissenschaftlichen Arbeit ging es darum festzustellen ob es am Land oder in der Stadt zu unterschiedlich starken Belastungen und Stress in der ambulanten Pflege kommt. Anhand des „Belastungsscreening TAA-Ambulante Pflege“ wurden in der Stadt und am Land je 58 Pflegpersonen befragt. Die Ergebnisse der Auswertungen zeigen, dass der kritische Wert einige male erreicht oder überschritten wird, es jedoch nur geringe Unterschiede bei den einzelnen Skalen im städtischen Bereich und am Land gibt