36 research outputs found
Lexicographical polytopes
Within a fixed integer box of Rn, lexicographical polytopes are the convex hulls of the integer points that are lexicographically between two given integer points. We provide their descriptions by means of linear inequalities
Biomass (yard waste) Suspensions as Alternative Daily Cover Material for Landfills
Biomass makes up approximately 16% of the landfills (this number can vary significantly depending upon the geographical location and time of the year). A majority of the biomass disposed in landfills is comprised of yard waste including grass and leaf clippings. This is becoming a problem as most landfills are running out of space and it is expensive to build new landfills. Twenty-four states have prohibited the disposal of yard waste in landfills with more states likely to follow suit. To conserve landfill space it is important to identify processes and methods for effective utilization and disposal of yard waste. It has been shown in this research that conformal coating of a biomass suspension can be utilized as an alternative daily cover (ADC) for the landfills. The biomass is ground into fine particles (d ≤ 2 mm) and suspended in a surfactant solution. This approach can reduce the cost of daily operations for the landfill and provide a solution to the problem of yard waste disposal
Contextualizing students' alcohol use perceptions and practices within French culture: an analysis of gender and drinking among sport-science college students
Although research has examined alcohol consumption and sport in a variety of contexts, there is a paucity of research on gender and gender dynamics among French college students. The present study addresses this gap in the literature by examining alcohol use practices by men and women among a non-probability sample of French sport science students from five different universities in Northern France. We utilized both survey data (N = 534) and in-depth qualitative interviews (n = 16) to provide empirical and theoretical insight into a relatively ubiquitous health concern: the culture of intoxication. Qualitative data were based on students’ perceptions of their own alcohol use; analysis were framed by theoretical conceptions of gender. Survey results indicate gender differences in alcohol consumption wherein men reported a substantially higher frequency and quantity of alcohol use compared to their female peers. Qualitative findings confirm that male privilege and women’s concern for safety, masculine embodiment via alcohol use, gendering of alcohol type, and gender conformity pressures shape gender disparities in alcohol use behavior. Our findings also suggest that health education policy and educational programs focused on alcohol-related health risks need to be designed to take into account gender category and gender orientation
A História da Alimentação: balizas historiográficas
Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domÃnio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crÃtico da historiografia brasileira sobre o tema
Analysis of the effect of helmet shape and head position on performance during time-trial cycling
Polyhedral results and a branch-and-cut algorithm for the double traveling Salesman problem with multiple stacks
In the double TSP with multiple stacks, one performs a Hamiltonian circuit to pick up n items, storing them in a vehicle with s stacks of finite capacity q satisfying last in-first-out constraints, and then delivers every item by performing a Hamiltonian circuit. We introduce an integer linear programming formulation with arc and precedence variables. We show that the underlying polytope shares some polyhedral properties with the ATSP polytope, which let us characterize large number of facets of our polytope. We convert these theoretical results into a branch-and-cut algorithm for the double TSP with two stacks. Our algorithm outperforms the existing exact methods and solves instances that were previously unsolved