3,851 research outputs found
Poverty and Disability: The Endless Loop
[Excerpt] Disability is a critical dimension of poverty in developing countries because poverty contributes to disability and disability leads to poverty. Poverty alleviation measures are unlikely to help poor disabled people who are insulated from information and isolated from opportunities and services by a de facto apartheid enforced by informational, physical and social obstacles. To be fully effective, poverty programs must take disability explicitly into account. The World Bank has noted that without paying attention to the rights and needs of people with disabilities (PWDs), Millennium Development Goals are unlikely to be achieved
Henri Temianka Correspondence; (mermelstein)
https://digitalcommons.chapman.edu/temianka_correspondence/2490/thumbnail.jp
Cohesive Traction-Separation Laws for Tearing of Ductile Metal Plates
The failure process ahead of a mode I crack advancing in a ductile thin metal plate or sheet produces plastic dissipation through a sequence of deformation steps that include necking well ahead of the crack tip and shear localization followed by a slant fracture in the necked region somewhat closer to the tip. The objective of this paper is to analyze this sequential process to characterize the traction–separation behavior and the associated effective cohesive fracture energy of the entire failure process. The emphasis is on what is often described as plane stress behavior taking place after the crack tip has advanced a distance of one or two plate thicknesses. Traction–separation laws are an essential component of finite element methods currently under development for analyzing fracture of large scale plate or shell structures. The present study resolves the sequence of failure details using the Gurson constitutive law based on the micromechanics of the ductile fracture process, including a recent extension that accounts for damage growth in shear. The fracture process in front of an advancing crack, subject to overall mode I loading, is approximated by a 2D plane strain finite element model, which allows for an intensive study of the parameters influencing local necking, shear localization and the final slant failure. The deformation history relevant to a cohesive zone for a large scale model is identified and the traction–separation relation is determined, including the dissipated energy. For ductile structural materials, the dissipation generated during necking prior to the onset of shear localization is the dominant contribution; it scales with the plate thickness and is mesh-independent in the present numerical model. The energy associated with the shear localization and fracture is secondary; it scales with the width of the shear band, and inherits the finite element mesh dependency of the Gurson model. The cohesive traction–separation laws have been characterized for various material conditions.Engineering and Applied Science
Triggering social interactions:chimpanzees respond to imitation by a humanoid robot and request responses from it
Even the most rudimentary social cues may evoke affiliative responses in humans and promote socialcommunication and cohesion. The present work tested whether such cues of an agent may also promotecommunicative interactions in a nonhuman primate species, by examining interaction-promoting behavioursin chimpanzees. Here, chimpanzees were tested during interactions with an interactive humanoid robot, whichshowed simple bodily movements and sent out calls. The results revealed that chimpanzees exhibited twotypes of interaction-promoting behaviours during relaxed or playful contexts. First, the chimpanzees showedprolonged active interest when they were imitated by the robot. Second, the subjects requested ‘social’responses from the robot, i.e. by showing play invitations and offering toys or other objects. This study thusprovides evidence that even rudimentary cues of a robotic agent may promote social interactions inchimpanzees, like in humans. Such simple and frequent social interactions most likely provided a foundationfor sophisticated forms of affiliative communication to emerge
Finite temperature theory of the trapped two dimensional Bose gas
We present a Hartree-Fock-Bogoliubov (HFB) theoretical treatment of the
two-dimensional trapped Bose gas and indicate how semiclassical approximations
to this and other formalisms have lead to confusion. We numerically obtain
results for the fully quantum mechanical HFB theory within the Popov
approximation and show that the presence of the trap stabilizes the condensate
against long wavelength fluctuations. These results are used to show where
phase fluctuations lead to the formation of a quasicondensate.Comment: 4 pages, 3 figure
Rolling at small scales
The rolling process is widely used in the metal forming industry and has been so for many years. However, the process has attracted renewed interest as it recently has been adapted to very small scales where conventional plasticity theory cannot accurately predict the material response. It is well-established that gradient effects play a role at the micron scale, and the objective of this study is to demonstrate how strain gradient hardening affects the rolling process. Specifically, the paper addresses how the applied roll torque, roll forces, and the contact conditions are modified by strain gradient plasticity. Metals are known to be stronger when large strain gradients appear over a few microns; hence, the forces involved in the rolling process are expected to increase relatively at these smaller scales. In the present numerical analysis, a steady-state modeling technique that enables convergence without dealing with the transient response period is employed. This allows for a comprehensive parameter study. Coulomb friction, including a stick–slip condition, is used as a first approximation. It is found that length scale effects increase both the forces applied to the roll, the roll torque, and thus the power input to the process. The contact traction is also affected, particularly for sheet thicknesses on the order of 10 μm and below. The influences of the length parameter and the friction coefficient are emphasized, and the results are presented for multiple sheet reductions and roll sizes.</jats:p
Three-dimensional anatomy of the ostrich (Struthio camelus) knee joint
The three-dimensional anatomy of the ostrich (Struthio camelus) knee (femorotibial, femorofibular, and femoropatellar) joint has scarcely been studied, and could elucidate certain mechanobiological properties of sesamoid bones. The adult ostrich is unique in that it has double patellae, while another similar ratite bird, the emu, has none. Understanding why these patellae form and what purpose they may serve is dually important for future studies on ratites as well as for understanding the mechanobiological characteristics of sesamoid bone development. For this purpose, we present a three-dimensional anatomical study of the ostrich knee joint, detailing osteology, ligaments and menisci, and myology. We have identified seven muscles which connect to the two patellae and compare our findings to past descriptions. These descriptions can be used to further study the biomechanical loading and implications of the double patella in the ostrich
Relative Sea-Level Change in the Northern Strait of Georgia, British Columbia
Twenty-four new radiocarbon dates from isolation basin cores, excavations and natural exposures, and an archeological site, constrain relative sea-level change since the last glaciation in the northern Strait of Georgia, British Columbia. Relative sea level fell rapidly from about 150 m elevation to 45 m elevation from 11 750 to 11 000 BP (13 750 to 13 000 cal BP), then its rate of fall slowed. The initial rapid emergence began soon after the transition from proximal to distal glaciomarine sedimentation, when the glacial front retreated from the Strait of Georgia and the Earth’s surface was unloaded. A sea-level lowstand a few metres below present-day sea level may have occurred in the early Holocene, but sea level was near its present level by 2000 BP. Sea-level change in the northern Strait of Georgia lagged the mid Strait of Georgia, 80 km to the south, by a few hundred years during initial emergence. The lowstand in the northern strait was later and probably shallower than in the mid strait. Isostatic depression inferred from the sea-level observations can be fit with two decaying exponential terms with characteristic decay times of 500 and 2600 years. The faster decay time corresponds to a shallow mantle viscosity of about 1019 Pa s, consistent with previous glacio-isostatic modelling. The present-day crustal uplift rate from the residual isostatic effects of the Cordilleran Ice Sheet is about 0.25 mm/a. Crustal uplift is not expected to significantly ameliorate projected sea-level rise in the mid and northern Strait of Georgia because present-day vertical crustal movements are inferred to be small.Vingt-quatre nouvelles dates au 14C provenant de carottes sédimentaires de bassins isolés, d’excavations, de coupes naturellement exposées et archéologiques permettent de cerner les changements du niveau marin relatif depuis la dernière glaciation dans la partie nord du détroit de Géorgie, en Colombie-Britannique. Le niveau marin relatif a rapidement passé de 150 m à 45 m d’altitude entre 11 750 et 11 000 ans BP (13 750-13 000 cal. BP), le taux d’abaissement ayant ralenti par la suite. L’émersion initiale rapide correspond à la fin de la sédimentation glaciomarine distale qui accompagnait le retrait du front glaciaire. Un bas niveau de quelques mètres sous le niveau actuel a pu s’instaurer durant l’Holocène inférieur, jusqu’en 2000 ans BP. Au début, le soulèvement isostatique a accusé un retard de quelques siècle sur celui de la zone du détroit à 80 km plus au sud. Le bas niveau de la partie nord du détroit est survenu plus tard et fut moins prononcé. Les données indiquent un enfoncement isostatique de type exponentiel avec des constantes de désintégration de 500 et de 2600 ans 14C. Le taux le plus rapide correspond à une viscosité du manteau terrestre d’environ 1019 Pa s, ce qui concorde avec les résultats de la modélisation glacio-isostatique. Le taux de soulèvement glacio-isostatique actuel résultant de l’inlandsis de la Cordillère s’établit à environ 0,25 mm/a. Ce taux ne peut contrer les effets du rehaussement du niveau marin prévu pour cette région en raison des faibles mouvements de la croûte terrestre qui y sont envisagés
Response: The Relationship between Lung Function and Metabolic Syndrome in Obese and Non-Obese Korean Adult Males (Korean Diabetes J 2010;34:253-60)
A Cross National Study of Golf Tourists’ Satisfaction
The purpose of this study was two-fold: firstly, it was to examine the determinants satisfaction levels of golf tourists and secondly to investigate if these vary across golf tourists’ country of residence. Using data collected through a survey of golf tourists visiting Lisbon (Portugal), attributes directly related to playing golf as well as more generic destination attributes were examined as potential determinants of golf tourists’ satisfaction. The data was analysed in two stages by the means of logistic regression. In stage one, the analysis was based on a representative sample of golf tourists to the region. In the second stage, two separate analyses were undertaken, one examining the satisfaction of Nordic golf tourists and another of British golf tourists (the two main markets for Lisbon). The results indicate that the satisfaction level of golf tourists is influenced by several factors, including those related to perceived quality and value. In addition, the results suggest that satisfaction is influenced by cross-cultural differences. While some determinants were important influences for both the British and the Nordic golfers, other determinants were specific to each country of origin. lytoinvestigateifthesevaryacrossgolftourists’countryofresidence.Using data collectedthroughasurveyofgolftouristsvisitingLisbon(Portugal),attributesdirectlyrelatedto playinggolfaswellasmoregenericdestinationattributeswereexaminedaspotentialdeterminantsof golf tourists’satisfaction.Thedatawasanalysedintwostagesbythemeansoflogisticregression.In stage one,theanalysiswasbasedonarepresentativesampleofgolftouriststotheregion.Inthesecond stage, twoseparateanalyseswereundertaken,oneexaminingthesatisfactionofNordicgolftourists and anotherofBritishgolftourists(thetwomainmarketsforLisbon).Theresultsindicatethatthe satisfactionlevelofgolftouristsisinfluencedbyseveralfactors,includingthoserelatedtoperceived qualityandvalue.Inaddition,theresultssuggestthatsatisfactionisinfluencedbycross-cultural differences.WhilesomedeterminantswereimportantinfluencesforboththeBritishandtheNordic golfers,otherdeterminantswerespecifictoeachcountryoforigin
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