882 resultados para International Association of Bridge, Structural and Ornamental Iron Workers
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This paper presents the results of a research project aimed at examining the capabilities and challenges of two distinct but not mutually exclusive approaches to in-service bridge assessment: visual inspection and installed monitoring systems. In this study, the intended functionality of both approaches was evaluated on its ability to identify potential structural damage and to provide decision-making support. Inspection and monitoring are compared in terms of their functional performance, cost, and barriers (real and perceived) to implementation. Both methods have strengths and weaknesses across the metrics analyzed, and it is likely that a hybrid evaluation technique that adopts both approaches will optimize efficiency of condition assessment and ultimately lead to better decision making.
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Background: High-resolution magnetic resonance (MR) imaging has been used for MR imaging-based structural stress analysis of atherosclerotic plaques. The biomechanical stress profile of stable plaques has been observed to differ from that of unstable plaques; however, the role that structural stresses play in determining plaque vulnerability remains speculative. Methods: A total of 61 patients with previous history of symptomatic carotid artery disease underwent carotid plaque MR imaging. Plaque components of the index artery such as fibrous tissue, lipid content and plaque haemorrhage (PH) were delineated and used for finite element analysis-based maximum structural stress (M-C Stress) quantification. These patients were followed up for 2 years. The clinical end point was occurrence of an ischaemic cerebrovascular event. The association of the time to the clinical end point with plaque morphology and M-C Stress was analysed. Results: During a median follow-up duration of 514 days, 20% of patients (n=12) experienced an ischaemic event in the territory of the index carotid artery. Cox regression analysis indicated that M-C Stress (hazard ratio (HR): 12.98 (95% confidence interval (CI): 1.32-26.67, pZ0.02), fibrous cap (FC) disruption (HR: 7.39 (95% CI: 1.61e33.82), p Z 0.009) and PH (HR: 5.85 (95% CI: 1.27e26.77), p Z 0.02) are associated with the development of subsequent cerebrovascular events. Plaques associated with future events had higher M-C Stress than those which had remained asymptomatic (median (interquartile range, IQR): 330 kPa (229e494) vs. 254 kPa (166-290), p Z0.04). Conclusions: High biomechanical structural stresses, in addition to FC rupture and PH, are associated with subsequent cerebrovascular events.
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Underground tunnels are vulnerable to terrorist attacks which can cause collapse of the tunnel structures or at least extensive damage, requiring lengthy repairs. This paper treats the blast impact on a reinforced concrete segmental tunnel buried in soil under a number of parametric conditions; soil properties, soil cover, distance of explosive from the tunnel centreline and explosive weight and analyses the possible failure patterns. A fully coupled Fluid Structure Interaction (FSI) technique incorporating the Arbitrary Lagrangian-Eulerian (ALE) method is used in this study. Results indicate that the tunnel in saturated soil is more vulnerable to severe damage than that buried in either partially saturated soil or dry soil. The tunnel is also more vulnerable to surface explosions which occur directly above the centre of the tunnel than those that occur at any equivalent distances in the ground away from the tunnel centre. The research findings provide useful information on modeling, analysis, overall tunnel response and failure patterns of segmented tunnels subjected to blast loads. This information will guide future development and application of research in this field.
Structural and kinetic studies of spin crossover in an Iron(II) complex with a novel tripodal ligand
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Configurational and ligand conformational influences on the kinetics of (1)A(1) reversible arrow T-5(2) spin crossover in the Fe(II) complex with the novel tripodal ligand, 1,1,1-tris((N-(2-pyridylmethyl)-N-methylamino)methyl)ethane (tptMetame), have been explored. Despite having six chelate rings and three chiral nitrogen atoms, only one enantiomeric pair of isomers, Delta, SSS, and Lambda, RRR, of the complex ion is observed. The conformation of the three rings forming the upper ''cap'' of the complex structure can be assigned delta or lambda with respect to the 3-fold molecular axis. X-ray data at 300 and 153 K, above and below the critical temperature for the spin transition, show that the conformation of the ligand ''cap'' is the same as the absolute configuration of the complex, with the same Lambda lambda(CAP)(or Delta delta(CAP)) combination prevailing for both the LS ((1)A(1)) and HS (T-5(2)) isomers. Molecular mechanics calculations further show that the ligand energy remains lowest for this Lambda lambda(CAP) (or Delta delta(CAP)) combination at all Fe-N distances over the range spanning the LS and HS isomers. Measurements of the spin crossover relaxation time have been carried out in solution over the temperature range 293-170 K. The observed monophasic relaxation traces are also consistent with the absolute configuration of the complex remaining unaltered during the spin crossover.
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The objective of this study was to identify, through a consensus process, the essential practices in primary palliative care. A three-phase study was designed. Phase 1 methods included development of a working group; a literature review; development of a baseline list of practices; and identification of levels of intervention. In Phase 2, physicians, nurses, and nurse aides (n = 425) from 63 countries were asked in three Delphi rounds to rate the baseline practices as essential or nonessential and select the appropriate levels of intervention for each. In Phase 3, representatives of 45 palliative care organizations were asked to select and rank the 10 most important practices resulting from Phase 2. Scores (1-10) were assigned to each, based on the selected level of importance. Results of Phase 1 were a baseline list of 140 practices. Three levels of intervention were identified: Identification/Evaluation; Diagnosis; and Treatment/Solution measures. In Phase 2, the response rates (RR) for the Delphi rounds were 96.5%, 73.6%, and 71.8%, respectively. A consensus point (=80% agreement) was applied, resulting in 62 practices. In Phase 3, RR was 100%. Forty-nine practices were selected and ranked. "Evaluation, Diagnosis and Treatment of Pain" scored the highest (352 points). The working group (WG) arranged the resulting practices in four categories: Physical care needs, Psychological/Emotional/Spiritual care needs, Care Planning and Coordination, and Communication. The IAHPC List of Essential Practices in Palliative care may help define appropriate primary palliative care and improve the quality of care delivered globally. Further studies are needed to evaluate their uptake and impact.
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Dissertação para a obtenção de grau de doutor em Bioquímica pelo Instituto de Tecnologia Química e Biológica. Universidade Nova de Lisboa
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The Proceedings of the Ninth Annual Conference of the British Association for Biological Anthropology and Osteoarchaeology (BABAO) held at the University of Reading in 2007. Contents: 1) A life course perspective of growing up in medieval London: evidence of sub-adult health from St Mary Spital (London) (Rebecca Redfern and Don Walker); 2) Preservation of non-adult long bones from an almshouse cemetery in the United States dating to the late nineteenth to the early twentieth centuries (Colleen Milligan, Jessica Zotcavage and Norman Sullivan); 3) Childhood oral health: dental palaeopathology of Kellis 2, Dakhleh, Egypt. A preliminary investigation (Stephanie Shukrum and JE Molto); 4) Skeletal manifestation of non-adult scurvy from early medieval Northumbria: the Black Gate cemetery, Newcastle-upon-Tyne (Diana Mahoney-Swales and Pia Nystrom); 5) Infantile cortical hyperostosis: cases, causes and contradictions (Mary Lewis and Rebecca Gowland); 6) Biological Anthropology Tuberculosis of the hip in the Victorian Britain (Benjamin Clarke and Piers Mitchell); 7) The re-analysis of Iron Age human skeletal material from Winnall Down (Justine Tracey); 8) Can we estimate post-mortem interval from an individual body part? A field study using sus scrofa (Branka Franicevec and Robert Pastor); 9) The expression of asymmetry in hand bones from the medieval cemetery at Écija, Spain (Lisa Cashmore and Sonia Zakrezewski); 10) Returning remains: a curator’s view (Quinton Carroll); 11) Authority and decision making over British human remains: issues and challenges (Piotr Bienkowski and Malcolm Chapman); 12) Ethical dimensions of reburial, retention and repatriation of archaeological human remains: a British perspective (Simon Mays and Martin Smith); 13) The problem of provenace: inaccuracies, changes and misconceptions (Margaret Clegg); 14) Native American human remains in UK collections: implications of NAGPRA to consultation, repatriation, and policy development (Myra J Giesen); 15) Repatriation – a view from the receiving end: New Zealand (Nancy Tayles).
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Uniform metal iron ellipsoidal particles of around 200 nm in length were obtained by reduction and passivation of alumina-coated alpha-Fe2O3 (hematite) particles under different conditions of temperature and hydrogen flow rate. The monodispersed hematite particles were prepared by the controlled hydrolysis of ferric sulfate and further coated with a homogeneous thin layer of Al2O3 by careful selection of the experimental conditions, mainly pH and aluminum salt concentration. The reduction mechanism of alpha-Fe2O3 into alpha-Fe was followed by x-ray and electron diffraction, and also by the measurements of the irreversible magnetic susceptibility. The transformation was found to be topotactic with the [001] direction of hematite particles, which lies along the long axis of the particles, becoming the [111] direction of magnetite and finally the [111] direction of metal iron. Temperature and hydrogen flow rate during the reduction have been found to be important parameters, which determine not only the degree of reduction but also the crystallite size of the final particles. Magnetic characterization of the samples shows that the only parameters affected by the crystallite size are the saturation magnetization and magnetic time-dependence effect, i.e., activation volume. (C) 2002 American Institute of Physics.
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Using inert gas condensation techniques the properties of sputtered neodymium-iron-born clusters were investigated. A D.C. magnetron sputtering source created vaporous Nd-Fe-B which was then condensed into clusters and deposited onto silicon substrates. A composite target of Nd-Fe-B discs on an iron plate and a composite target of Nd-(Fe-Co)-B were utilized to create clusters. The clusters were coated with a carbon layer through R.F. sputtering to prevent oxidation. Samples were investigated in the TEM and showed a size distribution with an average particle diameter of 8.11 nm. The clusters, upon deposition, were amorphous as indicated by diffuse diffraction patterns obtained through SAD. The EDS showed compositionally a direct correlation in the ratio of rare-earth to transition metals between the target and deposited samples. The magnetic properties of the as-deposited clusters showed superparamagnetic properties at high temperatures and ferromagnetic properties at low temperatures; these properties are indicative of rare-earth transition metal amorphous clusters. Annealing of samples showed an initial increase in the coercivity. Samples were annealed in an inert gas atmosphere at 600o C for increasing amounts of time. The samples showed an initial increase in coercivity, but showed no additional increases with additional annealing time. SAD of annealed cluster samples showed the presence of Nd2Fe17 and a bcc-Nd phase. The bcc-Nd is the result of oxidation at high temperatures created during annealing and surface interface energy. The magnetic properties of the annealed samples showed weak coercivity and a saturation magnetization equivalent to that of Nd2Fe17. The annealed clusters showed a slight increase in coercivity at low temperatures. These results indicate a loss of boron during the sputtering process.
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Objective: We sought to determine whether a reported history of childhood adversity is associated with components of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP-III)-defined metabolic syndrome in adults with mood disorders. Method: This was a cross-sectional analysis of adult outpatients (N = 373; n = 230 female, n = 143 male; mean age [SD] = 42.86 [14.43]) from the International Mood Disorders Collaborative Project (University of Toronto and Cleveland Clinic) with DSM-IV-defined major depressive disorder and bipolar I/II disorder. Childhood adversity was measured with the Klein Trauma & Abuse-Neglect self-report scale. The groups with and without childhood adversity were compared to determine possible differences in the rates of metabolic syndrome and its components. Logistic and linear regressions adjusted for age, sex, education, employment status, and smoking were used to evaluate the association between childhood adversity and components of metabolic syndrome. Results: For the full sample, 83 subjects (22.25%) met criteria for metabolic syndrome. Individuals reporting a history of any childhood adversity had higher systolic and diastolic blood pressure (systolic: p = 0.040; diastolic: p = 0.038). Among subjects with a history of sexual abuse, a significant proportion met criteria for obesity (45.28% vs. 32.88%; p = 0.010); a trend toward overweight was found for subjects with a history of physical abuse (76.32% vs. 63.33%; p = 0.074), although this relationship did not remain significant after adjusting for potential confounders. There was no statistically significant difference in the overall rate of dyslipidemia and/or metabolic syndrome between subjects with and without childhood adversity. Conclusion: The results herein provide preliminary evidence suggesting that childhood adversity is associated with metabolic syndrome components in individuals with mood disorders. Int'l. J. Psychiatry in Medicine 2012;43:165-177)