5,034 research outputs found
On the melting of the nanocrystalline vortex matter in high-temperature superconductors
Multilevel Monte Carlo simulations of the vortex matter in the
highly-anisotropic high-temperature superconductor BiSrCaCuO
were performed. We introduced low concentration of columnar defects satisfying
. Both the electromagnetic and Josephson interactions among
pancake vortices were included. The nanocrystalline, nanoliquid and homogeneous
liquid phases were identified in agreement with experiments. We observed the
two-step melting process and also noted an enhancement of the structure factor
just prior to the melting transition. A proposed theoretical model is in
agreement with our findings.Comment: 4 figure
Transition Metal-Ethylene Complexes as High-Capacity Hydrogen Storage Media
From first-principles calculations, we predict that a single ethylene
molecule can form a stable complex with two transition metals (TM) such as Ti.
The resulting TM-ethylene complex then absorbs up to ten hydrogen molecules,
reaching to gravimetric storage capacity of 14 wt%. Dimerization,
polymerizations and incorporation of the TM-ethylene complexes in nanoporous
carbon materials have been also discussed. Our results are quite remarkable and
open a new approach to high-capacity hydrogen storage materials discovery.Comment: 5 pages, 4 figures, additional content, Phys. Rev. Lett. in pres
Asylum blues: Staff attitudes towards psychiatric nursing in Sarawak, East Malaysia
This paper draws upon findings from an ethnographic study of psychiatric service users in a psychiatric institution in Sarawak, East Malaysia. Findings focus primarily on the accounts of nursing staff in relation to attitudes towards psychiatric work and patients. These indicate that despite a rhetoric of decentralized services, a custodial \u27asylum\u27 model continues to influence the care of patients at many levels. Negative professional attitudes towards patients lead to issues of both moral and physical containment. However, an associated attitude of stigma and prejudice towards mental illness impacts upon how attractive a career in psychiatric nursing is perceived to be by respondents, subject to gender differentials
Supporting ethnographic studies of ubiquitous computing in the wild
Ethnography has become a staple feature of IT research over the last twenty years, shaping our understanding of the social character of computing systems and informing their design in a wide variety of settings. The emergence of ubiquitous computing raises new challenges for ethnography however, distributing interaction across a burgeoning array of small, mobile devices and online environments which exploit invisible sensing systems. Understanding interaction requires ethnographers to reconcile interactions that are, for example, distributed across devices on the street with online interactions in order to assemble coherent understandings of the social character and purchase of ubiquitous computing systems. We draw upon four recent studies to show how ethnographers are replaying system recordings of interaction alongside existing resources such as video recordings to do this and identify key challenges that need to be met to support ethnographic study of ubiquitous computing in the wild
A PROFILE OF THE SPECIALTY FOOD RETAILING INDUSTRY IN THE EASTERN U.S.
This study investigated product introductions, marketing and distribution patterns among specialty food retailers in the eastern U. S. Based on 547 responses to a mailed survey, the results portray specialty food retailers as an extremely diverse group ranging from those who carry small specialty food sections within standard grocery or department stores to those who exclusively sell specialty foods. Respondents reported that new introductions account for about 22% of their total specialty food sales and that on average, they introduce about 23 products in a typical year. When evaluating new products, their most important considerations are quality followed by uniqueness.Agribusiness,
Solar energy conversion
If solar energy is to become a practical alternative to fossil fuels, we must have efficient ways to convert photons into electricity, fuel, and heat. The need for better conversion technologies is a driving force behind many recent developments in biology, materials, and especially nanoscience
Alleviation of Fuel Tax Evasion in Kentucky (Interim Report)
Motor fuel tax evasion is a problem of major significance nationwide. In Kentucky, evasion of motor fuel taxes could mean an annual loss of approximately $25 million. This study was initiated to provide Kentucky officials involved with fuel tax collection with the best available information on the problem of fuel tax evasion and the best uses of all resources to alleviate the problem.
This interim report concludes the first phase of the study and provides a qualitative look at motor fuel tax evasion in Kentucky. It discusses the fuel tax process in the Commonwealth, how evasion occurs, efforts to alleviate evasion, and preliminary findings and recommendations.
Findings include the tact that fuel tax evasion by dishonest dealers places honest dealers at a major competitive disadvantage, as well as contributing to the loss of funds tor highway construction end maintenance. Kentucky is combating evasion through a combination of state and cooperative regional and national efforts.
Future research will include examining three basic approaches to developing a quantitative estimate of the magnitude of fuel tax evasion in Kentucky end implementing the most promising of these approaches. Additional research could be conducted on experience gained by other states, average fuel burn rates tor various types of engines and furnaces, and a cost/benefit analysis tor Kentucky\u27s Motor Fuel Tax Audit program to justify additional funds for that program
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