995 resultados para 269


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The construction industry accounts for a significant portion of the material consumption of our industrialised societies. That material consumption comes at an environmental cost, and when buildings and infrastructure projects are demolished and discarded, after their useful lifespan, that environmental cost remains largely unrecovered. The expected operational lifespan of modern buildings has become disturbingly short as buildings are replaced for reasons of changing cultural expectations, style, serviceability, locational obsolescence and economic viability. The same buildings however are not always physically or structurally obsolete; the materials and components within them are very often still completely serviceable. While there is some activity in the area of recycling of selected construction materials, such as steel and concrete, this is almost always in the form of down cycling or reprocessing. Very little of this material and component resource is reuse in a way that more effectively captures its potential. One significant impediment to such reuse is that buildings are not designed in a way that facilitates easy recovery of materials and components; they are designed and built for speed of construction and quick economic returns, with little or no consideration of the longer term consequences of their physical matter. This research project explores the potential for the recovery of materials and components if buildings were designed for such future recovery; a strategy of design for disassembly. This is not a new design philosophy; design for disassembly is well understood in product design and industrial design. There are also some architectural examples of design for disassembly; however these are specialist examples and there is no significant attempt to implement the strategy in the main stream construction industry. This paper presents research into the analysis of the embodied energy in buildings, highlighting its significance in comparison with operational energy. Analysis at material, component, and whole-of-building levels shows the potential benefits of strategically designing buildings for future disassembly to recover this embodied energy. Careful consideration at the early design stage can result in the deconstruction of significant portions of buildings and the recovery of their potential through higher order reuse and upcycling.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: More than half of all cerebral ischemic events are the result of rupture of extracranial plaques. The clinical determination of carotid plaque vulnerability is currently based solely on luminal stenosis; however, it has been increasingly suggested that plaque morphology and biomechanical stress should also be considered. We used finite element analysis based on in vivo magnetic resonance imaging (MRI) to simulate the stress distributions within plaques of asymptomatic and symptomatic individuals. Methods: Thirty nonconsecutive subjects (15 symptomatic and 15 asymptomatic) underwent high-resolution multisequence in vivo MRI of the carotid bifurcation. Stress analysis was performed based on the geometry derived from in vivo MRI of the carotid artery at the point of maximal stenosis. The finite element analysis model considered plaque components to be hyperelastic. The peak stresses within the plaques of symptomatic and asymptomatic individuals were compared. Results: High stress concentrations were found at the shoulder regions of symptomatic plaques, and the maximal stresses predicted in this group were significantly higher than those in the asymptomatic group (508.2 ± 193.1 vs 269.6 ± 107.9 kPa; P = .004). Conclusions: Maximal predicted plaque stresses in symptomatic patients were higher than those predicted in asymptomatic patients by finite element analysis, suggesting the possibility that plaques with higher stresses may be more prone to be symptomatic and rupture. If further validated by large-scale longitudinal studies, biomechanical stress analysis based on high resolution in vivo MRI could potentially act as a useful tool for risk assessment of carotid atheroma. It may help in the identification of patients with asymptomatic carotid atheroma at greatest risk of developing symptoms or mild-to-moderate symptomatic stenoses, which currently fall outside current clinical guidelines for intervention.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background The nitric oxide synthase 1 adaptor protein gene (NOS1AP) has previously been recognised as a schizophrenia susceptibility gene due to its role in glutamate neurotransmission. The gene is believed to inhibit nitric oxide (NO) production activated by the N-methyl-d-aspartate (NMDA) receptor and reduced NO levels have been observed in schizophrenia patients. However, association studies investigating NOS1AP and schizophrenia have produced inconsistent results, most likely because schizophrenia is a clinically heterogeneous disorder. This study aims to investigate the association between NOS1AP variants and defined depression phenotypes of schizophrenia. Methods Nine NOS1AP SNPs, rs1415259, rs1415263, rs1858232, rs386231, rs4531275, rs4656355, rs4657178, rs6683968 and rs6704393 were genotyped in 235 schizophrenia subjects screened for various phenotypes of depression. Result One NOS1AP SNP (rs1858232) was associated with the broad diagnosis of schizophrenia and eight SNPs were associated with depression related phenotypes within schizophrenia. The rs1415259 SNP showed strong association with sleep dysregulation phenotypes of depression. Conclusion Results suggest that NOS1AP variants are associated with various forms of depression in schizophrenia and are more prevalent in males. Limitation Schizophrenia is a clinically heterogeneous disease that can vary greatly between different ethnic and geographic populations so our observations should be viewed with caution until they are independently replicated, particularly in larger patient cohorts.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Anisotropic gaussian beams are obtained as exact solutions to the parabolic wave equation. These beams have a quadratic phase front whose principal radii of curvature are non-degenerate everywhere. It is shown that, for the lowest order beams, there exists a plane normal to the beam axis where the intensity distribution is rotationally symmetric about the beam axis. A possible application of these beams as normal modes of laser cavities with astigmatic mirrors is noted.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A lattice-gas model of multilayer adsorption has been solved in the mean-field approximation by a different numerical method. Earlier workers obtained a single solution for all values of temperature and pressure. In the present work, multiple solutions have been obtained in certain regions of temperature and pressure which give rise to bysteresis in the adsorption isotherm. In addition, we have obtained a parameter which behaves like an order parameter for the transition. The potential-energy function shows a double minimum in the region of bysteresis and a single maximum elsewhere.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The study analyses the prevention or endorsing of the crime of infanticide in Finland 1702 1807, rather than the result. Also the impacts of the female body, biology of childbirth and experiences of pregnancy are examined, together with insights from modern medical research. Circumstances are reconstructed by a critical reading of judicial records on all levels of the judicial system. In all 269 cases of infanticide and 142 accessory crimes within the jurisdiction of the Turku court of appeal are studied, with particular focus on exceptionally well recorded cases of 83 accused women and 41 women and men accused of being party to the crime. Secondary sources are medical and jurisprudential writings, the public debate on infanticide, broadsheets and letters asking the King for pardon. Infanticide was considered murder by law. Unmarried women were predetermined as the main culprits. Nevertheless, deliberate infanticides were rare and committed mostly in accomplice. The majority of the infanticides studied were cases where inexperienced and unmarried women accidentally had given birth alone and usually to a dead child. Unaware that the pain they were experiencing was in fact a labour, the accused women instinctively sought solitude to push out the child. Some misunderstood the birth as an urgent need to defecate. The unexpected delivery ended in hiding the baby without remorse. This crime was promoted by several factors in Finnish rural culture, amongst others that also married women hid their pregnancy. The immediate household members did not necessarily know about the childbirth and failed to help the woman. This typical pattern in most cases of infanticide in 18th century Finland is also recorded in modern cases of unknown pregnancies. Fear of accountability prevented witnesses testifying to the actual course of events. The truth remained elusive. With only a few exceptions, the women were sentenced to death or imprisonment. The majority of those accused of accomplice were acquitted. However, too harsh sentences for accidents affected the reporting of the crime. Criminal politics failed to curtail infanticide as the crime was unsatisfactorily addressed by law, society and the judicial system.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The intent of this study was to design, document and implement a Quality Management System (QMS) into a laboratory that incorporated both research and development (R&D) and routine analytical activities. In addition, it was necessary for the QMS to be easily and efficiently maintained to: (a) provide documented evidence that would validate the system's compliance with a certifiable standard, (b) fit the purpose of the laboratory, (c) accommodate prevailing government policies and standards, and (d) promote positive outcomes for the laboratory through documentation and verification of the procedures and methodologies implemented. Initially, a matrix was developed that documented the standards' requirements and the necessary steps to be made to meet those requirements. The matrix provided a check mechanism on the progression of the system's development. In addition, it was later utilised in the Quality Manual as a reference tool for the location of full procedures documented elsewhere in the system. The necessary documentation to build and monitor the system consisted of a series of manuals along with forms that provided auditable evidence of the workings of the QMS. Quality Management (QM), in one form or another, has been in existence since the early 1900's. However, the question still remains: is it a good thing or just a bugbear? Many of the older style systems failed because they were designed by non-users, fiercely regulatory, restrictive and generally deemed to be an imposition. It is now considered important to foster a sense of ownership of the system by the people who use the system. The system's design must be tailored to best fit the purpose of the operations of the facility if maximum benefits to the organisation are to be gained.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Water adsorbs molecularly on a clean Zn(0001) surface; on a surface covered with atomic oxygen, however, hydroxyl species is produced due to proton abstraction by the surface oxygen atoms. Methanol, molecularly adsorbed on a clean surface at 80 K, transforms to methoxy species above 110 K. On an atomic oxygen-covered surface, adsorbed methanol gives rise to methoxy species and water, the latter arising from proton abstraction. HCHO adsorbs molecularly at 80 K on both clean as well as oxygen-covered surfaces and polymerizes at higher temperatures. Formic acid does not adsorb on a clean Zn surface, but on an oxygen-covered surface gives rise to formate and hydroxyl species.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The electrical and optical properties of the thermally induced quenched-in levels in p-silicon which have heen attributed to iron are studied. The two levels, HI and H2, are located at Ev + 0.42 eV and Ev + 0.52 eV, respectively, as determined by TSCAP, DLTS, and transient photocapacitance methods. The photoionization cross sections are well described by Lucovsky's model. The hole capture by H1 is temperature dependent; a barrier of 40 meV is measured. However, multiphonon emission mechanism cannot be invoked to explain this temperature dependence due to the inferred zero lattice relaxation. The source of iron contamination is found to be the ambient conditions, in particular the quartz tube. The conflicting reports regarding the stability and the variation in the reported capture cross section values suggests that the observed Ev + 0.4 eV level must be a complex centre. The inferred near zero lattice relaxation during the electron transition implies weak coupling to the host lattice.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Aecidium sp. (Pucciniaceae) on Marsdenia sp. is reported for the first time from Australia.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The paper describes a Simultaneous Implicit (SI) approach for transient stability simulations based on an iterative technique using traingularised admittance matrix [1]. The reduced saliency of generator in the subtransient state is taken advantage of to speed up the algorithm. Accordingly, generator differential equations, except rotor swing, contain voltage proportional to fluxes in the main field, dampers and a hypothetical winding representing deep flowing eddy currents, as state variables. The simulation results are validated by comparison with two independent methods viz. Runge-Kutta simulation for a simplified system and a method based on modelling damper windings using conventional induction motor theory.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

[Excerpt] It is not easy for a speaker to prepare documents and presentations especially when speaking to diverse audiences, i.e. when people have different languages, different backgrounds, different level of knowledge or include people with intellectual disabilities. Sometimes, speakers do not know how they can transmit information to people with intellectual disability.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A simulation model that combines biological, search and economic components is applied to the eradication of a Miconia calvescens infestation at El Arish in tropical Queensland, Australia. Information on the year M. calvescens was introduced to the site, the number of plants controlled and the timing of control, is used to show that currently there could be M. calvescens plants remaining undetected at the site, including some mature plants. Modelling results indicate that the eradication programme has had a significant impact on the population of M. calvescens, as shown by simulated results for uncontrolled and controlled populations. The model was also used to investigate the effect of changing search effort on the cost of and time to eradication. Control costs were found to be negligible over all levels of search effort tested. Importantly, results suggest eradication may be achieved within several decades, if resources are increased slightly from their current levels and if there is a long-term commitment to funding the eradication programme.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The study is part of a research project of 269 psychiatric patients with major depression, Vantaa Depression Study, in the Department of Mental Health and Alcohol Research of the National Public Health Institute and the Department of Psychiatry of the Peijas Medical Care District. The aim was to study at the onset of MDE psychosocial differences in subgroups of patients and clustering of events into time before depression and its prodromal phase, to study whether more severe life events and less social support predict poorer outcome in all patients, but most among those currently in partial remission, whether social support declines as a consequence of time spent in MDE, is sensitive to improvement, and whether social support is influenced by neuroticism and extraversion. After screening, a semistructured interview (SCAN, version 2.0) was used for the presence of DSM-IV MDE, and other psychiatric diagnoses. Life events and social support were studied with semistructured methods (IRLE, Paykel 1983; IMSR, Brugha et al. 1987), perceived social support and neuroticism/extraversion with questionnaires (PSSS-R, Blumenthal et al. 1987; EPI, Eysenck and Eysenck 1964) at baseline, 6 and 18 months. At the onset of depression life events were common. No major differences between subgroups of patients were found; the younger had more events, whereas those with comorbid alcoholism and personality disorders perceived less support. Although events were distributed evenly between the time before depression, the prodromal phase and the index MDE, two thirds of the patients attributed their depression to some life event. Adversities and poor perceived support influenced the outcome of all psychiatric patients, most in the subgroup of full remission. In the partial remission group, the impact of severe events and in the MDE, perceived support was important. Low objective and subjective support were predicted by longer time spent in MDE. Along with improvement subjective support improved. Neuroticism and extraversion were associated with the size of social network and perceived support and predicted change of perceived support. In conclusion, adversities were common in all phases of depression. They may thus have many roles; before depression they may precipitate it, in the prodromal phase worsen symptoms, and during the MDE, the outcome of depression. Patients often attributed their depression to a life event. Psychosocial subgroup differences were quite small. Perceived support predicted the outcome of depression, and time spent in MDE objective and subjective support. Neuroticism and extraversion may modify the level and change particularly in perceived support, thereby indirectly effecting vulnerability to depression.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Crystal structures of six isopropylidene nucleoside derivatives are described. The results show that, under external cyclic constraints, the ribose assumes a variety of unusual conformations. In those compounds which possess a base-to-sugar cyclization through the C(4′) atom, the furanose pucker is predominantly C(4′)-endo, O(4′)-exo. The possible relevance of the sulphur geometry in two of the compounds to certain structural aspects of the action of the enzyme thymidylate synthetase is also pointed out.