90 research outputs found

    Drill and Blast Performance Evaluation at the Obra Pit of Chirano Gold Mines Ltd, Ghana

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    This paper investigates the causes of inefficient fragmentation and formation of toes in the Obra pit of Chirano Gold Mines Ltd and recommends best practices in order to produce optimum fragmentation to feed the crusher at a reduced cost and to provide good working pit floors. The methods employed included: drilling performance analysis using statistical methods; fragmentation analysis of blasting performance using Kuz-Ram Model and Wipfrag software; determination of the velocity of detonation of the bulk explosive using MREL Micro Trap VOD/Data Recorder; and estimation of the cost of secondary drilling and blasting using Mine Management Reporting Software. From the analyses, it was observed that the blast designed parameters and blasting practices were acceptable to produce good fragmentation but the actual drilling parameters deviated from the designed parameters by about 25%, 24% and 26% in hole depth, burden and spacing respectively. It was concluded that the cause of the ineffective fragmentation leading to high cost of secondary breakage and uneven pit floors was due to operational errors during drilling. It is therefore recommended that in order to reduce excessive deviations in the drilling parameters, periodic training of operators must be conducted, supervision of drilling and blasting operations must be enhanced, and inclinometers should be used during drilling activities to ensure the accuracy and precision of all blast holes. Keywords: Drilling, Blasting, Fragmentation, Kuz-Ram Model, Wipfrag Softwar

    Evaluation of Stakeholders’ Roles in the Management of Artisanal and Small-Scale Gold Mining in Anka, Zamfara State, Nigeria

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    This paper evaluates the roles of stakeholders in the management of Artisanal and Small-scale Gold Mining (ASGM) in Anka, a typical ASGM town in Zamfara State, North-western Nigeria, dominated by sporadic and mostly unlicenced ASGM activities. Conceptual, SWOT, PESTLE, MOTAP and SELOP analyses were used to evaluate stakeholders’ roles in the management of ASGM in the area. From the evaluation, weak legislation, poor policy implementation, stringent licencing procedures, centralised government functions and poor government attention were identified to be the major factors militating against the effective functioning of ASGM regulators. Lack of management skills by the ASGM operators in the area was identified as a major barrier to their economic prosperity. Child labour, poor environmental management and cultural practices contribute to the environmental, health and safety hazards ravaging the sporadic ASGM activities by the local miners. Community leaders are thus left to grapple with the control of ASGM activities in their domain. Relief agencies and international organisations were identified as the main anchors of intervention programmes, the success of which is linked to the support and cooperation of the community leaders. Decentralisation of government functions on ASGM and organisation of miners into cooperative groups and their full integration into the formal licenced mining sector are recommended for sustainable, effective and efficient ASGM in Anka. Keywords: Artisanal and small-scale gold mining, Management functions, Environmental degradation, Rural development, Regulators, Stakeholders, Community leaders

    Maintaining relevance in HIV systematic reviews: an evaluation of Cochrane reviews

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    Background Research turnover in the HIV field is rapid, and as a result, maintaining high-quality, up-to-date, and relevant systematic reviews is a challenge. One approach is to frequently update published reviews. Methods We evaluated the methods and relevance of all HIV systematic reviews and protocols published in the Cochrane Library over a 16-year period (2000–2016) to determine the need to update published reviews or complete of reviews in progress. Results Of 148 published reviews and protocols, 129 (87%) were identified as not for updating or progression to publication, mostly due to research questions which were either entirely outdated or addressed questions in an outdated manner (N = 89; 60%); this was anticipated for older reviews, but was found also to be the case for recent publications. Some research questions were also inadequately conceptualized, particularly when complex pragmatic trials or behavioral interventions were included. Conclusions We suggest that authors clearly characterize interventions and synthesis approaches in their review protocols. In research fields, such as HIV, where questions change frequently, systematic reviews and protocols should be regularly re-evaluated to ensure relevance to current questions. This process of re-evaluation should be incorporated into the methods of living systematic reviews

    A systematic review of the relationship between rumination and suicidality

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    Rumination has been persistently implicated in the etiology of hopelessness and depression: proximal predictors of suicidality. As a result, research has started to examine the role of rumination in suicidality. This systematic review aims to: (i) provide a concise synopsis of the current progress in examining the relationship between rumination and suicidality; and (ii) highlight areas for future research. To this end, a search of the international literature was conducted using the three main psychological and medical databases (Psych Info [1887-October 2007], Medline [1966-October 2007] and Web of Knowledge [1981-October 2007]). Eleven studies were identified providing evidence, with one exception, of a relationship between rumination and suicidality. This systematic review has highlighted a considerable dearth of studies, specifically of case-control and prospective, clinical studies, in the worldwide literature. Key areas for future research are discussed

    Building a Small Cinema: Resisting Neoliberal Colonization in Liverpool

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    In its stated aim of “creating cinemas not supermarkets,” the Small Cinema project voiced its alterity to the recent redevelopment of Liverpool’s city center and those of other former industrial cities throughout the Midlands and the north of the UK. These regeneration projects addressed the problem of a shrinking manufacturing base by replacing them with service industries, a move which has entailed the privatization of vast tracts of public space. Conversely, the building, functioning, and general praxis of the Small Cinema project suggests a mode of practice that more accurately fits within the paradigm of a collaborative commons than a capitalist marketplace. The project’s exemption from market criteria grants it the freedom to pursue public over private goods, thereby constituting a point of resistance to the ongoing neoliberalization of the city and changes to government policy that make it increasingly difficult for non-profit projects to exist. Historically speaking, cinemas have been accessible to the working class in a way that other artistic media have not. However, while the history of film as a tool for political subversion is well documented, less attention has been paid to the physical construction of independent cinematic space, its programming/running, and its potential as a node of resistance to neoliberal colonization. This paper uses the case study of the Small Cinema project in Liverpool as a means by which to understand how cinematic spaces can counteract the effects of policies that continue to have such a detrimental impact on the arts and education, as well as social health and well-being

    Sonic diaspora, vibrations and rhythm: thinking through the sounding of the Jamaican dancehall session

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    The propagation of vibrations may provide a better way of understanding diasporic spread than the conventional focus on the circulation of products (Hall 1980, Appadurai 1986, 1996, Gilroy 1993a, Brah 1996). Jamaican sound systems operate as a broadcast medium and a source of CDs, DVDs and other commercial products (Henriques 2007a). But the dancehall sound system session also propagates a broad spectrum of frequencies diffused through a range of media and activities - described as “sounding” (following Small’s 1998 concept of “musicking”). These include the material vibrations of the signature low-pitched auditory frequencies of Reggae as a bass culture (Johnson 1980), at the loudness of “sonic dominance” (Henriques 2003). Secondly a session propagates the corporeal vibrations of rituals, dance routines and bass-line “riddims” (Veal 2007). Thirdly it propagates the ethereal vibrations (Henriques 2007b), “vibes” or atmosphere of the sexually charged popular subculture by which the crowd (audience) appreciate each dancehall session as part of the Dancehall scene (Cooper 2004). The paper concludes that thinking though vibrating frequencies makes it easier to appreciate how audiences with no direct or inherited connection with a particular music genre can be energetically infected and affected - to form a sonic diaspora

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Time series model of occupational injuries analysis in Ghanaian mines. A case study

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    Abstract: This study has modeled occupational injuries at Gold Fields Ghana Limited (GFGL), Tarkwa Mine using time series analysis. Data was collected from the Safety and Environment Department from January 2007 to December 2010. Testing for stationarity condition using line graph from Statistical Package for Social Sciences (SPSS) 17.0 edition failed, hence the use of Box-Jenkins method of differencing which tested positive after the first difference. ARIMA (1,1,1) model was then applied in modeling the stationary data and model diagnostic was done to ensure its appropriateness. The model was further used to forecast the occurrence of injuries at GFGL for two year period spanning from January 2011 to December 2012. The results show that occupational injuries for GFGL are going to have a slight upward and downward movement fro
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