2,795 research outputs found
The computer simulation and prediction of rock fall
No full textThis thesis deals with the study of rock falls using a mathematical model, codified for computer use, entitled GeoFall. GeoFall, which was developed by the author, allows predictions to be made of rock fall trajectories, run out distances and kinetic energies for a rock of any arbitrary shape. Its main purpose is to assist in the design of remedial works. The mathematical model is based on rigid body mechanics, and analyses a fall in 2D space using a new theory of impact dynamics developed by Brach (1991). The main features and algorithms of the program are presented in this thesis. The performance of GeoFall was evaluated by comparing actual rock fall events described in several published papers with the output created by GeoFall. Also the output from GeoFall has been compared with the output from other rock fall simulation programs used to simulate the documented rockfalls. A new rock slope inventory system entitled the Rock Fall Risk Assessment System (RFRAS) has been developed by the author to determine the rock fall risk at specific rock fall sites. It consists of three phases of inspection, the slope survey, and the preliminary and detailed rating phases. The detailed rating phase uses 13 parameters that when assessed, evaluated and totalled, numerically differentiates slopes from the least to the most hazardous producing an overall rating in the range 21-1926. It not only allows the relative risk of rockfall between slopes to be assessed but it also categorises the rock fall risk and the potential number of future rockfalls. It has been tested on 18 slopes at ten locations in County Durham. The final part of the thesis details a new laboratory based procedure that can be used to determine the coefficients of restitution for any type of rock material. The normal coefficient of restitution has been determined for seven different types of rock, and the tangential coefficient of restitution has been determined for a local sandstone. Some tentative correlations between the normal coefficient of restitution and the rocks physical properties, such as its Unconfined Compressive Strength (UCS) have been presented
The rise and fall of the Labour league of youth
No full textThis thesis charts the rise and fall of the Labour Party’s first and most enduring youth organisation, the Labour League of Youth. The history of the League, from its birth in the early nineteen twenties to its demise in the late nineteen fifties, is placed in the context of the Labour Party’s subsequent fruitless attempts to establish and maintain a vibrant and functional youth organisation. A narrative is incorporated that illuminates the culture, organisation and political activism of the League and establishes it as a predominantly working class radical organisation. The reluctance on the part of the Labour Party to grant autonomy to its youth sections resulted in the history of the League of Youth being one of control, suppression and tension. This state of affairs ensured that subsequent youth groups, the Young Socialists and Young Labour, would be established in an atmosphere of reservation and scepticism.
The thesis places the prime responsibility for the failure of the party’s youth organisations with the party leadership but also considers the contributory factors of changing social and political circumstances. A number of themes are explored which include the impact of structure and agency factors, the power of the Parliamentary Labour Party, the political socialisation of leading figures within the party, the social context in which each of the groups emerged and the extent to which the youth groups were prey to intra-party factionalism.
The thesis redresses the balance of research where most accounts have focussed on the Young Socialists and traces the common characteristics that are prevalent in the way the party leadership has approached its relationship with its youth organisations. Use has been made of previously unpublished primary source material, the major source being the League of Youth members themselves whose recollections have helped to demonstrate the arguments put forward in this thesis
Turbocharger speed monitoring based on vibration measurements for diesel engine management
No full textThe density, construction and drag coefficient of electrostatic volcanic ash aggregates.
No full textRecent laboratory experiments have demonstrated that electrostatic charges generated during the fragmentation of volcanic pumice cause rapid aggregation of the silicate particles produced. Here, we present measurements of the mass and component particle size distribution of individual, electrostatically bound aggregates produced during these experiments. Particles produced by fracturing pumice aggregated as they fell ∼1.5 m within an enclosed fall chamber. Aggregate mass measurements indicate aggregate densities of ∼200 kg m−3 or less. The component particle size analysis demonstrates exponential-type cumulative distributions which are dominated (on a volume basis) by particles ∼10–40 μm in diameter and contain few particles >70 μm. By representing these particles as disks of 5 μm thickness the calculated aggregate densities are in agreement with those derived from the aggregate mass measurements and indicate a relatively constant aggregate density with size (in contrast with previous results from fall velocities). Combining the density measurements with fall velocity data allows the drag coefficient of aggregates to be determined. Empirical equations developed to describe the particle size distribution within aggregates are used to derive relative aggregation coefficients for the electrostatic aggregation process. Our results can be used within numerical models of volcanic plumes in order to improve their representation of electrostatic aggregation processes
Why infrastructure financing facilities often fall short of their objectives
No full textTo encourage the private funding and provision of infrastructure services, governments have used specialized financing facilities to offer financial support to investors, often in the form of grants, soft loans, or guarantees. The authors present case studies of infrastructure financing facilities in various stages of development in Colombia, India, and Pakistan. They also present case studies of government-sponsored financing facilities (not of infrastructure) in Argentina, and Moldova. They find that these facilities have often fallen short of their objectives for two main reasons. First, the environment was not conducive to private participation in infrastructure because of poor sector policies, an unstable macroeconomic environment, and inadequate financial sector policies, among other reasons. Second, the facility was faulty in design - in terms of sectors targeted, pricing of instruments, and consistency of objectives, and instruments.Decentralization,Banks&Banking Reform,Payment Systems&Infrastructure,Public Sector Economics&Finance,Municipal Financial Management,Municipal Financial Management,Banks&Banking Reform,Housing Finance,Public Sector Economics&Finance,National Governance
ACCEPTED POSTER CONTRIBUTION - “Synchrotron Based Spectroscopic Investigations over the 4-hydroxycyanobenzene (4HCB) Molecule Supported by Theoretical DFT Methods” - PRESENTING AUTHOR
No full textAfrican horse sickness virus: history, transmission, and current status
No full textAfrican horse sickness virus (AHSV) is a lethal arbovirus of equids that is transmitted between hosts primarily by biting midges of the genus Culicoides (Diptera: Ceratopogonidae). AHSV affects draft, thoroughbred, and companion horses and donkeys in Africa, Asia, and Europe. In this review, we examine the impact of AHSV critically and discuss entomological studies that have been conducted to improve understanding of its epidemiology and control. The transmission of AHSV remains a major research focus and we critically review studies that have implicated both Culicoides and other blood-feeding arthropods in this process. We explore AHSV both as an epidemic pathogen and within its endemic range as a barrier to development, an area of interest that has been underrepresented in studies of the virus to date. By discussing AHSV transmission in the African republics of South Africa and Senegal, we provide a more balanced view of the virus as a threat to equids in a diverse range of settings, thus leading to a discussion of key areas in which our knowledge of transmission could be improved. The use of entomological data to detect, predict and control AHSV is also examined, including reference to existing studies carried out during unprecedented outbreaks of bluetongue virus in Europe, an arbovirus of wild and domestic ruminants also transmitted by Culicoides
Seasonal dynamics of Culicoides (Diptera: Ceratopogonidae) biting midges, potential vectors of African horse sickness and bluetongue viruses in the Niayes area of Senegal
No full textBackground The African horse sickness epizootic in Senegal in 2007 caused considerable mortality in the equine population and hence major economic losses. The vectors involved in the transmission of this arbovirus have never been studied specifically in Senegal. This first study of the spatial and temporal dynamics of the Culicoides (Diptera: Ceratopogonidae) species, potential vectors of African horse sickness in Senegal, was conducted at five sites (Mbao, Parc Hann, Niague, Pout and Thies) in the Niayes area, which was affected by the outbreak. Methods Two Onderstepoort light traps were used at each site for three nights of consecutive collection per month over one year to measure the apparent abundance of the Culicoides midges. Results In total, 224,665 specimens belonging to at least 24 different species (distributed among 11 groups of species) of the Culicoides genus were captured in 354 individual collections. Culicoides oxystoma, Culicoides kingi, Culicoides imicola, Culicoides enderleini and Culicoides nivosus were the most abundant and most frequent species at the collection sites. Peaks of abundance coincide with the rainy season in September and October. Conclusions In addition to C. imicola, considered a major vector for the African horse sickness virus, C. oxystoma may also be involved in the transmission of this virus in Senegal given its abundance in the vicinity of horses and its suspected competence for other arboviruses including bluetongue virus. This study depicted a site-dependent spatial variability in the dynamics of the populations of the five major species in relation to the eco-climatic conditions at each site
Assurance on XBRL-Related Documents: The Case of United Technologies Corporation
No full textThe eXtensible Business Reporting Language (XBRL) was developed to provide financial information users with a standardized method to prepare, publish, and exchange business information in digital format. XBRL is being used around the world for financial reporting and government e-filings. Although there has been growing awareness about assurance issues related to the use of XBRL, current audit practices and standards fall short of providing the needed guidance for the provision of assurance on XBRL-Related Documents. In this paper, we report on a mock assurance engagement that we conducted on the XBRL-Related Documents of United Technologies Corporation's 10-Q for the third quarter of 2005 and repeated on its 10-Q for the third quarter of 2008 to identify the issues that companies and auditors might encounter if they are requested to provide assurance on XBRL-Related Documents. We describe the assurance framework applied in the mock assurance engagement, present the findings from the examination process, and discuss future research opportunities associated with XBRL documents assurance.Peer reviewe
Stabilizing a previously centrally planned economy: Poland 1990
No full textWe examine the dynamics of the January 1990 stabilization programme in Poland, focusing on the substantial and sudden collapse in industrial output, and inflation persistence. We discuss three, non-mutually exclusive, explanations of these phenomena: excessive initial stocks of inventories, an exogenous fall in household demand and tight credit. We conjecture that tight credit was at centre stage: it helped to magnify the fall in output, and to coordinate such a fall across sectors. We base such a conjecture on the existence of substantial credit segmentation, and on the underdevelopment of private credit markets. This conjecture is further strengthened by the fact that wages increased, and even went beyond the programme's ceilings, as credit expanded during the year. We argue that the wage hike may be the reason why credit expansion did not result in a major output recovery, and inflation persisted during the year. There are discussions of this article by M. Burda and G. W. Kolodko, pp 209-212. -from Author
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