1000 resultados para assessment of damages


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This study investigates the use of computer modelled versus directly experimentally determined fire hazard data for assessing survivability within buildings using evacuation models incorporating Fractionally Effective Dose (FED) models. The objective is to establish a link between effluent toxicity, measured using a variety of small and large scale tests, and building evacuation. For the scenarios under consideration, fire simulation is typically used to determine the time non-survivable conditions develop within the enclosure, for example, when smoke or toxic effluent falls below a critical height which is deemed detrimental to evacuation or when the radiative fluxes reach a critical value leading to the onset of flashover. The evacuation calculation would the be used to determine whether people within the structure could evacuate before these critical conditions develop.

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Purpose. To examine the thermal transition(s) between different polymorphic forms of Nifedipine and to define experimental conditions that lead to the generation of polymorph IV. Methods. Experiments were performed using a DSC 823e (Mettler Toledo). Nifedipine exists in four polymorphic forms, as well as an amorphous state. Examination of Nifedipine was conducted using the following method(s): cycle 1: 25ºC to 190ºC, 190ºC to 25ºC (formation of amorphous Nifedipine); cycle 2: 25ºC to X (60,70,80...150ºC), X to 25ºC; cycle 3: 25ºC to 190ºC and holding isothermally for 5 min between cycles (heating/cooling rate of 10ºC/min). Results. The amorphous state Nifedipine can sustain heating up to 90ºC without significant changes in its composition. Cycle 2 of amorphous material heated up to 90ºC shows only the glass transition at ~44ºC. In cycle 3 of the same material, a glass transition has been recorded at ~44ºC, followed by two exotherms (~100 and ~115ºC (crystallisation of polymorph III and II, respectively) and an endotherm (169ºC (melting of polymorphs I/II)). Samples that have been heated to temperatures between 100ºC and 120ºC in the second cycle showed a glass transition at ~44ºC and an additional exotherm at ~95ºC (crystallisation of polymorph III) on cooling a exotherm was observed at ~40ºC (crystallisation of polymorph IV). The same material showed no glass transition in cycle 3 but an endotherm at around 62ºC (melting of polymorph IV) an exotherm (~98ºC) and an endotherm (169ºC) melting of polymorph I/II. Heating the sample to a temperatures greater than 130ºC in cycle two results in a glass transition at ~44ºC, and two exotherms at ~102 and 125ºC (crystallisation of polymorphs III and I, respectively). Conclusions. DSC data suggests that polymorph IV can only be produced from amorphous or polymorph III samples. The presence of polymorph I or II drives the conversion of the less stable polymorphic form IV into the most stable form, I. Although form IV of Nifedipine can easily be created, following defined experimental conditions, it may only coexist with amorphous or polymorph III states. When polymorphs I and II are present in the sample polymorph IV cannot be etected.

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Wild leafy vegetables play a vital role in the livelihoods of many communities in Africa. The focus of this study was to investigate the nutritional value of wild vegetables commonly consumed by the people of Buhera District in the Manicaland province of Zimbabwe. A variety of vegetables including Amaranthus hybridus, Cleome gynandra, Bidens pilosa, Corchorus tridens, and Adansonia digitata were collected during a survey in Buhera District. Samples were processed employing traditional methods of cooking and drying, then subjected to proximate and micronutrient analyses. The results indicate that these vegetables were particularly high in calcium, iron, and vitamin C. Compared with Brassica napus (rape), Amaranthus hybridus contained twice the amount of calcium, with other nutrients almost in the same range. Compared with Spinacia oleracea (spinach), Amaranthus hybridus contained three times more vitamin C (44 mg/100 g). Calcium levels were 530 mg/100 g. Amaranthus hybridus was also found to contain 7, 13, and 20 times more vitamin C, calcium, and iron respectively compared with Lactuca sativa (lettuce). Cleome gynandra contained 14 mg/100 g, 115 mg/100 g, 9 mg/100 g of vitamin C, calcium, and iron respectively. Bidens pilosa was found to be a valuable source of vitamin C (63 mg/100 g), iron (15 mg/100 g), and zinc (19 mg/100 g), compared with Brassica oleracea (cabbage). The leaves of Corchorus tridens were an excellent source of vitamin C (78 mg/100 g), calcium (380 mg/100 g), and iron (8 mg/100 g). The Adansonia digitata leaves were also rich in vitamin C (55 mg/100 g), iron (23 mg/ 100 g), and calcium (400 mg/100 g). Based on these nutrient contents, the above vegetables will have potential benefits as part of feeding programmes, as well as their promotion as part of composite diet for vulnerable groups.

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Purpose. To study thermal stability of Aspirin and define thermal events that are associated with the thermal degradation of aspirin. Methods. Experiments were performed using a DSC 823e (Mettler Toledo, Swiss). Aspirin is prone to thermal degradation upon exposure to high temperatures. The melting point of aspirin is 140.1±0.4ºC (DSC). Aspirin has been examined by heating samples to 120ºC, 155ºC and 185ºC with subsequent cooling to -55ºC and a final heating to 155ºC. Although different heating and cooling ranges have been used, only results obtained at a rate of 10ºC/min will be presented. All runs where conducted in hermetically sealed pans. Results. Upon heating the sample to 120ºC no significant thermal event can be detected. After cooling the sample and reheating a glass transition can be observed at ~-8ºC, followed by the melting of aspirin at ~139ºC. By heating the sample to 155ºC melting of aspirin has been detected at ~139ºC. On cooling and subsequent heating a glass transition occurs at ~-32ºC, together with a broad crystallisation (onset at ~38ºC and peak maximum at ~57ºC) followed by a broad melting with an onset at 94ºC and peak maximum at ~112ºC. Finally, by heating the sample to 185ºC melting at ~ 139ºC was observed, and upon cooling and reheating a glass transition was detected at ~-26ºC and no further events could be recorded. Conclusions. This research demonstrates that the degradation steps of Aspirin depend on the thermal treatment. The main degradation products of different thermal treatments are currently unknown it is clear that acetic acid, which is one of the degradation products, acts as an antiplasticiser by lowering the glass transition temperature. In addition, due to the presence of the degradation products in liquid form (observed by hot stage microscopy), Aspirin is still present in the sample and recrystallises during the second heating step and melts at much lower temperatures.

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This paper describes a practical approach for the investigation, assessment and design of existing soakaways. This method can be utilised for measuring the performance and capacity of the systems and examining whether the systems are suitable for reuse when information about the design and installation of the systems is not available. The requirements for field observations and the procedure for a soil infiltration test for the installed system are suggested for successful assessment. The soil infiltration rate of the system is estimated from the field test data without requiring information on the design and construction details of the system. The system's working condition is measured by a performance indicator related to the time taken to empty the soakaway. This is then employed to evaluate the potential reuse of the system. The system's drain capacity is determined by the design principles of current practice and the effect of climate change on its drain capacity is considered. Contamination of soils around the systems after long-term use of discharge service and the water present in soakaway chambers are also investigated. A detailed case study for the reuse of four installed soakaways for a new housing development demonstrates how the proposed approach provides a straightforward process for the infiltration performance and drain capacity assessment of the existing systems. The effectiveness and applicability of the proposed approach are further demonstrated from the assessments for a number of installed systems over various sites

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This paper aims to explore and discuss the role of nostalgia (a concept that is inherently grounded within a psychological framework) in heritage interpretation from both provider and consumer perspectives. Whilst many cultural practitioners recognise the relationship between sentimentality and authenticity, particularly within a folk-heritage context, few have sought to examine the effect this has on the visitor experience. This paper questions visitors’ ability to objectively assess objects and experiences at heritage sites, and the role of practitioners in presenting often blurred views of social history that may sometimes negate historical fact. Drawing on case study research at two UK living museums, Blists Hill Victorian Town in Shropshire, England, and the Big Pit: National Coal Museum in Wales, notions of reminiscence, authenticity, myth and intangibility are considered within the framework of the interpretive experience. Findings suggest that the visitor experience is inherently subjective, highly individual and that the concept of intangibility is integral to an understanding of the nostalgia-authenticity debate.

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This paper describes the condition of a reinforced concrete balustrade consisting of some 1000 individual beam elements all exposed similarly to the hostile marine environment of the North Sea at Arbroath, Scotland since 1943. A comparison is made of the condition of the original construction with the condition of repairs carried out in 1968 and in 1993. It is shown that the 1943 construction shows very little corrosion-induced cracking and little rust staining even though it does not appear to be of high construction quality. Only a very low percentage of the balustrade beams have been replaced. In contrast the beam installed in 1968 and later in 1993 show very considerable and large concrete cracks directly attributable to the corrosion of the longitudinal reinforcement, even though the concrete is of a higher quality and density. A detailed condition survey and statistics of crack sizes are presented in the paper. It is found that the higher corrosion resistance of the 1943 concrete is generally consistent with the concrete electrical resistivity measurements but the degree of corrosion of the reinforcing bars is inconsistent with chloride penetration measurements. The results are compared with the very few observations available in the literature for ageing concrete structures in marine environments. The results cast doubt on the conventional wisdom that chloride content at the reinforcement correlates well with reinforcement corrosion.

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The rationale behind the use of analyses of estuarine organisms to assess levels of heavy-metal contamination is described and compared with alternative methods such as the analysis of waters or sediments. Based on field observations in United Kingdom estuaries and on evidence from the literature, an assessment is made of the suitability of 17 species as the indicators of metals and metalloids including Ag, As, Cd, Co, Cr, Cu, Hg, Ni, Se, Sn, Pb and Zn.

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The relatively new recreational pursuit of coasteering, which has developed in the St David's area of Pembrokeshire, appears to be expanding rapidly. The majority of local commercial recreation providers (outdoor pursuit centers etc.) now appear to offer this pursuit. The majority of the rocky coastlines where it takes place lie within Pembrokeshire Marine Special Area of Conservation (SAC), and are also Sites of Special Scientific Interest (SSSI). No assessment has yet been undertaken of coasteering's potential impact on the intertidal habitats. Therefore the Countryside Council for Wales (CCW) commissioned the Marine Life Information Network (MarLIN) to undertake a desk study of the likely environmental effects of coasteering on rocky intertidal habitats within the Pembrokeshire marine SAC. The desk study was based on a review of the available literature, and in particular the effects of trampling on rocky intertidal communities. Communities (as biotopes) within the Pembrokeshire marine SAC likely to be exposed to coasteering activities were identified from Phase I biotope data for the area, provided by CCW. Where possible, existing research by MarLIN into the intolerance, recoverability and sensitivity of the biotopes identified, was used to identify their potential vulnerability to trampling. The literature review revealed that: - foliose canopy forming algae (e.g. fucoids) were particularly intolerant and sensitive to trampling impacts; - trampling damaged erect coralline turfs, barnacles, and resulted in an increase in bare space; in some cases paths across the shore were visible; - on brown algae dominated shores, understorey algae could suffer due to increased desiccation but algal turf species, opportunists and gastropod grazers (e.g. limpets) could increase in abundance as an indirect effect of trampling, and that - trampling impacts resulted from physical contact and wear and were dependant on the intensity, duration, and frequency of trampling, and even the type of footwear used. A total of 19 intolerant rocky intertidal biotopes were identified as potentially vulnerable to trampling and hence coasteering within the Pembrokeshire marine SAC, of which six are of Welsh importance and eight are nationally rare or scarce. Trampling is a highly localized impact and it was not possible to identify biotopes, and hence communities, actually impacted by coasteering activities in the Pembrokeshire marine SAC. In addition, the majority of the literature addresses the impacts of trampling on wave sheltered or moderately exposed brown algal dominated shores, while coasteering occurs on more wave exposed, steeply inclined shores. Therefore, direct survey of the routes used by coasteering groups within the Pembrokeshire marine SAC is required to identify the intensity, duration and frequency of trampling impact, together with the communities impacted. Given the paucity of data concerning trampling effects in the rocky intertidal in the UK, a survey of the impacts of coasteering would provide an opportunity to examine the effects of trampling and visitor use in steep rocky, wave exposed shores. The report recognizes the potential to engage coasteerers in contributing to the development of strategies for minimizing adverse impacts, recording impacts and collecting information of use in identifying climate change and the occurrence of non-native species.