Diffusive benefits of cylinders in front of a Schroeder diffuser

A numerical investigation is performed into the diffusive effects of cylinders positioned in front of a Schroeder diffuser. A regular line of cylinders is shown to offer notable improvements to diffusion from a periodic Schroeder device, provided lateral cylinder spacing is incommensurable with the Schroeder period width. Further investigation considers angular dependence and low frequency results in greater detail, as well as the effects on narrowband and modulated Schroeder devices. An optimization procedure is subsequently performed to investigate the effects of an irregular cylinder arrangement, which provides further diffusive benefits. (C) 2010 Acoustical Society of America

Volumetric diffusers : pseudorandom cylinder arrays on a periodic lattice

Most conventional diffusers take the form of a surface based treatment, and as a result can only operate in hemispherical space. Placing a diffuser in the volume of a room might provide greater efficiency by allowing scattering into the whole space. A periodic cylinder array (or sonic crystal) produces periodicity lobes and uneven scattering. Introducing defects into an array, by removing or varying the size of some of the cylinders, can enhance their diffusing abilities. This paper applies number theoretic concepts to create cylinder arrays that have more even scattering. Predictions using a Boundary Element Method are compared to measurements to verify the model, and suitable metrics are adopted to evaluate performance. Arrangements with good aperiodic autocorrelation properties tend to produce the best results. At low frequency power is controlled by object size and at high frequency diffusion is dominated by lattice spacing and structural similarity. Consequently the operational bandwidth is rather small. By using sparse arrays and varying cylinder sizes, a wider bandwidth can be achieved

The Development Of Test Protocols For Padded Clothing In Rugby Union Using Human Tissue Impact Surrogates

Padded clothing (shoulder padding) is worn in Rugby Union to allow players to protect themselves. A performance specification for padded clothing has been set out by World Rugby™, with the intention that padding only protects against Cuts and Abrasions [1]. This performance specification is set out in Regulation 12 (padded clothing) [2]. This limits its density (45 + 15 kg·m-3), thickness (10 + 2 mm) and impact attenuation performance (acceleration > 150 g for a 14.7 J impact). Regulation 12 was critiqued and areas for improvement were identified. A literature review was conducted, covering injury and protection in Rugby Union, injury modes, anatomy of the human shoulder, organic tissue properties and human tissue simulants. It was identified that padded clothing’s ability to prevent Cut and Abrasion injuries have yet to be quantitatively assessed. This was crucial in improving the Regulation 12 test protocols. To address this problem, a multi-faceted investigation was performed. To start with, assessments were made of rugby players’ external and internal shoulder anatomies using 3D and ultrasound scanning techniques. From this, geometries of rugby players’ shoulders were found. The material properties of organic tissues were also assessed, with the focus being on the tissue’s compressive response to load. The reason for this work was to aid the fabrication of a human shoulder surrogate. Both a simplified and anatomical human shoulder surrogate were fabricated using human tissue simulants, as well as 3D printing and moulding techniques. A bespoke muscle simulant was developed with similar compressive properties to organic muscle tissue. Both the simplified and anatomical surrogates were integrated into various impact testing procedures. Padded clothing was tested for its force attenuative properties, its ability to prevent blunt force Cut and Abrasion injuries, and its ability to prevent stud-induced injuries. The results from this have led to informed recommendations 3 being made for the improved assessment of padded clothing in Rugby Union and therefore an improved Regulation 12. The research conducted in this thesis was the first to quantitatively assess padded rugby clothing’s ability to protect from specific injuries. As well as fabricate a human shoulder surrogate for the assessment of sports padding. The testing protocols developed in this thesis can be easily adapted for the assessment of protection or padding in other collision sports or even in other industries like ballistics or automotive

Measuring Kruger visitors’ place attachment to specific camps

Tourists become emotionally, physically and socially attached to national parks as they become familiar with the park’s settings and endow it with value. Researchers have pointed out that place attachment leads to environmentally responsible behaviour and higher levels of visitor satisfaction. Therefore, increasing the level of attachment that visitors feel is vital for park and camp managers, and to do so a greater understanding of the various dimensions of it is needed. While attachment to parks has been evaluated previously, attachment to specific camps in parks has not been done. The main purpose of this research study was to measure the extent to which visitors to the Tamboti and Satara camps in the Kruger National Park feel attached to these camps. We also determined whether differences exist between visitors in terms of the level of attachment that they experience towards these camps. Finally, we established the variables that influence place attachment. A self-administered paper-based questionnaire was distributed to visitors to the Tamboti and Satara camps, with 201 questionnaires completed. The results show that visitors generally have a neutral feeling towards the camps. Furthermore, the differences in visitors’ levels of attachment could be attributed to their nationality, wild card membership and frequency of visits. Various managerial implications are drawn and recommendations made on how to increase place attachment to these camps. Conservation implications: This results indicate that visitors do not show particularly strong attachment towards Tamboti and Satara. Recommendations are given for camp managers to increase place attachment to the camps. If camp managers can succeed in fostering stronger levels of attachment to these camps, visitors are more likely to display environmentally responsible behaviour in the camps, with positive conservation implications

Understanding visitor expectations for responsible tourism in an iconic national park: Differences between local and international visitors

A survey on expectations for responsible tourism was administered to 201 visitors to the iconic Kruger National Park, comprising 55% South African nationals and 45% international tourists. Using Likert-scale questions, respondents were invited to indicate the level of importance they attached to 38 aspects of responsible tourism. Space was also provided for open comments. Conservation of biodiversity and geological features were rated very highly by both groups while aspects related to the local community, though considered important overall, were ranked lowest overall, with international tourists rating this category as more important than South Africans. Aspects related to traffic and access were rated to be more important by South Africans, probably because they mostly self-drive while international visitors rely more on organised game drives. Visual and aesthetic features of camps, as well as energy, water and waste management were all considered very important by all respondents, with members of both groups making further suggestions for improvement. This suggests that visitors are supportive of low environmental impact tourism in the Kruger National Park. In light of the strategic goal of South African National Parks to increase visitor numbers, it will be important that this goal is achieved without compromising sound environmental performance

The status of Habitats Directive Annex I saltmarsh habitats, transition zones and spartina species in England

On unmodified soft sediment coastlines, of which there are long lengths especially on the English east and south coasts, there should be a wide transitional zone between tidal areas and full terrestrial land. The conditions in this zone result in a rich and distinctive range of habitats. There are two saltmarsh habitats listed in Annex I of the Habitats Directive within this zone (H1420 Mediterranean and thermo-Atlantic halophilous scrubs and H1320 Spartina swards,Spartinion maritimae) reflecting its importance for nature conservation. At the time work for this project was started in 2012, the conservation status of these habitats was reported as ‘unfavourable, bad and deteriorating’. Due to construction of artificial sea defences, these zones are now much reduced in extent and distribution and are under threat from a range of factors. This project aims to provide an inventory and description of Annex I saltmarsh habitats and transitional vegetation in England. This will help to update future reporting on conservation status. The outcomes will also help improve understanding of the underpinning processes which can be used in design to improve the potential for recreating these elements of saltmarshes as part of intertidal restoration schemes. The project also provides an up to date assessment of Spartina alterniflora stands in the Solent SAC through review and field survey for 2012

In Vitro Assay Development and HTS of Small-Molecule Human ABAD/17β-HSD10 Inhibitors as Therapeutics in Alzheimer's Disease

This research was funded by the Scottish Universities Life Science Alliance (SULSA) assay development fund. This research was also kindly supported by The Rosetrees Trust and The Alzheimer’s Society, specifically The Barcopel Foundation, and partly funded by the MSD Scottish Life Sciences fund. As part of an ongoing contribution to Scottish life sciences, MSD Limited, a global health care leader, has given substantial monetary funding to the Scottish Funding Council for distribution via SULSA to develop and deliver a high-quality drug discovery research and training program.A major hallmark of Alzheimer’s disease (AD) is the formation of neurotoxic aggregates composed of the amyloid-β peptide (Aβ). Aβ has been recognized to interact with numerous proteins, resulting in pathological changes to the metabolism of patients with AD. One such mitochondrial metabolic enzyme is amyloid-binding alcohol dehydrogenase (ABAD), where altered enzyme function caused by the Aβ-ABAD interaction is known to cause mitochondrial distress and cytotoxic effects, providing a feasible therapeutic target for AD drug development. Here we have established a high-throughput screening platform for the identification of modulators to the ABAD enzyme. A pilot screen with a total of 6759 compounds from the NIH Clinical Collections (NCC) and SelleckChem libraries and a selection of compounds from the BioAscent diversity collection have allowed validation and robustness to be optimized. The pilot screen revealed 16 potential inhibitors in the low µM range against ABAD with favorable physicochemical properties for blood-brain barrier penetration.PostprintPeer reviewe

Measuring Kruger visitors’ place attachment to specific camps

Tourists become emotionally, physically and socially attached to national parks as they become familiar with the park’s settings and endow it with value. Researchers have pointed out that place attachment leads to environmentally responsible behaviour and higher levels of visitor satisfaction. Therefore, increasing the level of attachment that visitors feel is vital for park and camp managers, and to do so a greater understanding of the various dimensions of it is needed. While attachment to parks has been evaluated previously, attachment to specific camps in parks has not been done. The main purpose of this research study was to measure the extent to which visitors to the Tamboti and Satara camps in the Kruger National Park feel attached to these camps. We also determined whether differences exist between visitors in terms of the level of attachment that they experience towards these camps. Finally, we established the variables that influence place attachment. A self-administered paper-based questionnaire was distributed to visitors to the Tamboti and Satara camps, with 201 questionnaires completed. The results show that visitors generally have a neutral feeling towards the camps. Furthermore, the differences in visitors’ levels of attachment could be attributed to their nationality, wild card membership and frequency of visits. Various managerial implications are drawn and recommendations made on how to increase place attachment to these camps. CONSERVATION IMPLICATIONS : This results indicate that visitors do not show particularly strong attachment towards Tamboti and Satara. Recommendations are given for camp managers to increase place attachment to the camps. If camp managers can succeed in fostering stronger levels of attachment to these camps, visitors are more likely to display environmentally responsible behaviour in the camps, with positive conservation implications.The National Research Foundation of South Africa (Grant Number 114916).http://www.koedoe.co.zaam2020Tourism Managemen