901 resultados para Duluth, Missabe, and Iron Range Railway


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Future read heads in hard disc storage require high conformal coatings of metal magnetic layers over high aspect ratio profiles. This paper describes pioneering work on the use of MOCVD for the deposition of cobalt layers. While pure cobalt layers could be deposited at 400C their magnetic properties are poor. It was found that the magnetic properties of the layers could be significantly enhanced with an optimised rapid thermal anneal. This work was sponsored by Seagate Technology and led to a follow up PhD studentship on the co-deposition of cobalt and iron by MOCVD.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper reviews statistical models obtained from a composite factorial design study, which was carried out to determine the influence of three key parameters of mixture composition on filling ability and passing ability of self-consolidating concrete (SCC). This study was a part of the European project “Testing SCC”- GRD2-2000-30024. The parameters considered in this study were the dosages of water and high-range water-reducing admixture (HRWRA), and the volume of coarse aggregates. The responses of the derived statistical models were slump flow, T50 , T60, V-funnel flow time, Orimet flow time, and blocking ratio (L-box). The retention of these tests was also measured at 30 and 60 minutes after adding the first water. The models are valid for mixtures made with 188 to 208 L/m3 (317 to 350 lb/yd3) of water, 3.8 to 5.8 kg/m3 (570 to 970 mL/100 kg of binder) of HRWRA, and 220 to 360 L/m3 (5.97 to 9.76 ft3/yd3) of coarse aggregates. The utility of such models to optimize concrete mixtures and to achieve a good balance between filling ability and passing ability is discussed. Examples highlighting the usefulness of the models are presented using isoresponse surfaces to demonstrate single and coupled effects of mixture parameters on slump flow, T50 , T60 , V-funnel flow time, Orimet flow time, and blocking ratio. The paper also illustrates the various trade-offs between the mixture parameters on the derived responses that affected the filling and the passing ability.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A Holocene palaeoecological sequence from Villaverde, south-central Spain, is presented. The pollen stratigraphy is used to infer past vegetation changes within a catchment area that represents the boundary between semi-arid, plateau and mountain vegetation. From c. 9700–7530 cal. yr BP, Pinus is dominant, probably as a result of a combination of a relatively dry climate and natural fire disturbance. From c. 7530–5900 cal. yr BP, moderate invasion by Quercus appears to be a migrational response following increased moisture and temperature, but in part shaped by competitive adjustments. From c. 5900–5000 cal. yr BP, the pine forests are replaced by deciduous-Quercus forests with an important contribution from Corylus, Betula, Fraxinus and Alnus. Mediterranean-type forests spread from c. 5000 to 1920 cal. yr BP coincident with expansions of Artemisia, Juniperus and other xerophytes. From c. 1920–1160 cal. yr BP, Pinus becomes dominant after a disturbance- mediated invasion of the oak forests. Human impact upon the regional landscape was negligible during the Neolithic, and limited in the Bronze and Iron Ages. Local deforestation and the expansion of agro-pastoral activities occur after c. 1600 cal. yr BP.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: Psychological models of behaviour change are used to predict patients’ health behaviours but have rarely been used to explore healthcare professionals’ health-related behaviour. Aim: To explore the association between self-reported handwashing and a range of psychological variables in a sample of nurses in a large acute hospital. Results and discussion: Nurses in this study were more likely to wash their hands if they perceived it to be important and if they thought their workplace helped them in doing so. The best predictor of perceived importance was how strongly a nurse believed that poor handwashing practice contributes to spreading infection. Conclusion: In this study, psychological variables such as perception of importance, perception of workplace support, occupational stress and perception of risk were important predictors of handwashing behaviour.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Extraction of dibenzothiophene from dodecane using ionic liquids as the extracting phase has been investigated for a range of ionic liquids with varying cation classes (imidazolium, pyridinium, and pyrrolidinium) and a range of anion types using liquid-liquid partition studies and QSPR (quantitative structure-activity relationship) analysis. The partition ratio of dibenzothiophene to the ionic liquids showed a clear variation with cation class (dimethylpyridinium > methylpyridinium > pyridinium approximate to imidazolium approximate to pyrrolidinium), with much less significant variation with anion type. Polyaromatic quinolinium-based ionic liquids showed even greater extraction potential, but were compromised by higher melting points. For example, 1-butyl-6-methylquinolinium bis{(trifluoromethyl)sulfonyl} amide (mp 47 degrees C) extracted 90% of the available dibenzothiophene from dodecane at 60 degrees C.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Recent thinking on open innovation and the knowledge-based economy have stressed the importance of external knowledge sources in stimulating innovation. Policy-makers have recognised this, establishing publicly funded Centres of R&D Excellence with the objective of stimulating industry–science links and localised innovation spillovers. Here, we examine the contrasting IP management practices of a group of 18 university- and company-based R&D centres supported by the same regional programme. Our analysis covers all but one of the Centres supported by the programme and suggests marked contrasts between the IP strategies of the university-based and company-based centres. This suggests the potential for very different types of knowledge spillovers from publicly funded R&D centres based in different types of organisations, and a range of alternative policy approaches to the future funding of R&D centres depending on policy-makers’ objectives.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The pathogenesis of diabetic retinopathy is multifactorial, and a range of hyperglycemia-linked pathways have been implicated in the initiation and progression of this condition. All cells in the retina are affected by the diabetic milieu, and in view of such disease and tissue complexity, it is unlikely that any single process is solely responsible for retinal pathophysiology. Nevertheless, establishing causal mechanisms remains an important research goal. This review concentrates on the formation of advanced glycation end products (AGEs) and the role they play in diabetic retinopathy. Perspective is provided on advanced glycation in the retina, the impact that this process has on retinal cell function, and how it relates to other pathogenic pathways. Emphasis is also placed the modulatory role of the receptor for AGEs (RAGE) and how its activation could evoke retinal inflammatory disease. Further research is needed to achieve a clear understanding of the cellular and molecular processes that underpin diabetic retinopathy's initiation and progression. Such advances in basic mechanisms may lead to effective treatments that can prevent progression of retinopathy from the point of the diagnosis of diabetes to sight-threatening proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

It is becoming increasingly evident that jellyfish (Cnidaria: Scyphozoa) play an important role within marine ecosystems, yet our knowledge of their seasonality and reproductive strategies is far from complete. Here, we explore a number of life history hypotheses for three common, yet poorly understood scyphozoan jellyfish (Rhizostoma octopus; Chrysaora hysoscella; Cyanea capillata) found throughout the Irish and Celtic Seas. Specifically, we tested whether (1) the bell diameter/wet weight of stranded medusae increased over time in a manner that suggested a single synchronised reproductive cohort; or (2) whether the range of sizes/weights remained broad throughout the stranding period suggesting the protracted release of ephyrae over many months. Stranding data were collected at five sites between 2003 and 2006 (n = 431 surveys; n = 2401 jellyfish). The relationship between bell diameter and wet weight was determined for each species (using fresh specimens collected at sea) so that estimates of wet weight could also be made for stranded individuals. For each species, the broad size and weight ranges of stranded jellyfish implied that the release of ephyrae may be protracted (albeit to different extents) in each species, with individuals of all sizes present in the water column during the summer months. For R. octopus, there was a general increase in both mean bell diameter and wet weight from January through to June which was driven by an increase in the variance and overall range of both variables during the summer. Lastly, we provide further evidence that rhizostome jellyfish may over-wintering as pelagic medusa which we hypothesise may enable them to capitalise on prey available earlier in the year.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Thioacetamide (TAA) administration is an established technique for generating rat models of liver fibrosis and cirrhosis. Oxidative stress is believed to be involved as TAA-induced liver fibrosis is initiated by thioacetamide S-oxide, which is derived from the biotransformation of TAA by the microsomal flavine-adenine dinucleotide (FAD)-containing monooxygense (FMO) and cytochrome P450 systems. A two-dimensional gel electrophoresis-mass spectrometry approach was applied to analyze the protein profiles of livers of rats administered with sublethal doses of TAA for 3, 6 and 10 weeks respectively. With this approach, 59 protein spots whose expression levels changed significantly upon TAA administration were identified, including three novel proteins. These proteins were then sorted according to their common biochemical properties and functions, so that pathways involved in the pathogenesis of rat liver fibrosis due to TAA-induced toxicity could be elucidated. As a result, it was found that TAA-administration down-regulated the enzymes of the primary metabolic pathways such as fatty acid beta-oxidation, branched chain amino acids and methionine breakdown. This phenomenon is suggestive of the depletion of succinyl-CoA which affects heme and iron metabolism. Up-regulated proteins, on the other hand, are related to oxidative stress and lipid peroxidation. Finally, these proteomics data and the data obtained from the scientific literature were integrated into an

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The purpose of this article is to critically examine the literature to provide a rationale for including systemic family therapy (SFT) in the psycho-social treatment of people suffering the impact of post-traumatic stress (PTS). Attention is drawn to the relatively underdeveloped academic literature on PTS and the family. The impact of PTS is conceptualized within a psycho-social framework and the current evidence base for psycho-social interventions for PTS responses is described, highlighting the opportunity and need to undergird this area of daily practice. The impact of PTS on the family at multiple levels is identified, emphasizing its recursive nature. The case for SFT is articulated and a range of models of family intervention for PTS briefly reviewed, concluding with an emphasis on Walsh's key processes in family resilience as a framework for practice.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Despite the much vaunted triumph of human rights, amnesties continue to be a frequently used technique of post-conflict transitional justice. For many critics, they are synonymous with unaccountability and injustice. This article argues that despite the rhetoric, there is no universal duty to prosecute under international law and that issues of selectivity and proportionality present serious challenges to the retributive rationale for punishment in international justice. It contends that many of the assumptions concerning the deterrent effect in the field are also oversold and poorly theorized. It also suggests that appropriately designed restorative amnesties can be both lawful and effective as routes to truth recovery, reconciliation, and a range of other peacemaking goals. Rather than mere instruments of impunity, amnesties should instead be seen as important institutions in the governance of mercy, the reassertion of state sovereignty and, if properly constituted, the return of law to a previously lawless domain.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The study explored the relationship between student wellbeing and academic achievement among 7–11 years old students and whether the relationship was moderated by gender and deprivation. 1081 students in Northern Ireland participated in a crosssectional survey that captured data on academic achievement and a range of wellbeing indicators. Findings suggested the existence of an underlying wellbeing factor, which was positively related to achievement. The relationship was not moderated by gender and/or deprivation. Findings were explored using a model of ‘academic buoyancy’. There was no evidence that suggested efforts to improve achievement that focus on wellbeing should be targeted speci?cally at students in economically deprived areas or be modi?ed in terms of gender.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Rice has been demonstrated to be one of the major contributors to arsenic (As) in human diets in addition to drinking water, but little is known about rice products as an additional source of As exposure. Rice products were analyzed for total As and a subset of samples were measured for arsenic speciation using high performance liquid chromatography interfaced with inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). A wide range of rice products had total and inorganic arsenic levels that typified those found in rice grain including, crisped rice, puffed rice, rice crackers, rice noodles and a range of Japanese rice condiments as well as rice products targeted at the macrobiotic, vegan, lactose intolerant and gluten intolerance food market. Most As in rice products are inorganic As (75.2-90.1%). This study provides a wider appreciation of how inorganic arsenic derived from rice products enters the human diet. (C) 2008 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

We report the simultaneous measurement of temperature and humidity by analysing square wave voltammetric responses of two ferrocene derivatives, decamethylferrocene (DmFc) and 1,2-diferrocenylethylene (bisferrocene, BisFc) in 1-(2-methoxyethyl)-1-methyl-pyrrolidinium tris(pentafluoroethyl) trifluorophosphate ([Moepyrr][FAP]). These two molecules produce three peaks in square wave voltammetry. Through study of the peak potentials of BisFc/BisFc(+) (vs. DmFc/DmFc(+)) and BisFc(+)/BisFc(2+) (vs. DmFc/DmFc(+)) over a temperature range of 298 K to 318 K and humidity range of 1% to 50% using square wave voltammetry, the temperature and humidity dependences of the relative peak potentials were investigated. A reliable method to calculate the humidity and temperature based on the voltammetric experiment is characterised and demonstrated.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper focuses on the mismatch between income and deprivation measures of poverty. Using the first two waves of the European Community Household Panel Survey, a measure of relative deprivation is constructed and the overlap between the relative income poor and relatively deprived is examined, There is very limited overlap with the lowest relative income threshold. The overlap increases as the income threshold is raised, but it remains true that less than half those below the 60 percent relative income line are among the most deprived. Relative deprivation is shown to be related to the persistence of income poverty, but also to a range of other resource and need factors. Income and deprivation measures each contain information that can profitably be employed to enhance our understanding of poverty and a range of other social phenomena. This is illustrated by the manner in which both income poverty and relative deprivation are associated with self-reported difficulty making ends meet.