Corrosion fatigue crack growth mechanisms in offshore monopile steel weldments

Offshore structures are generally fabricated of welded joints, which are considered as potential spots for crack initiation owing to the degree of stress concentrations imposed by the weld geometry and the effects of residual stresses introduced by welding processes. There are significant numbers of the current and anticipated offshore installations coupled with the use of newer materials and fabrication techniques. It is therefore important to understand the crack growth mechanisms in these structures accompanied with the effects of mean or residual stresses for a safe estimation of their service lives. In this paper, crack growth results of HAZ and weld materials similar to those used for offshore installations are presented. Tests were conducted in air and in simulated free-corrosion conditions at loading frequencies of 0.3 Hz in seawater, 5 Hz in air and at loading ratios of 0.1, 0.5 and 0.7. Results showed that crack growth rates were influenced by mean stresses, materials microstructure accompanied by welding procedure and environment. Crack growth results showed good agreement when compared with those obtained from other steels used for offshore structures

Threats to e-government implementation in the civil service: Nigeria as a case study

The rapid advancement in Information and Communication Technology (ICT) has undoubtedly influenced positive changes in carrying out administrative functions in government institutions. The ICT adoption rate in Africa is not impressive when compared to the more developed countries of the world. Nigeria, as a case study in this scenario, has also not implemented E-Government impressively, according to the required standards set up by the International Telecommunications Union (ITU). A comprehensive study conducted on the application and implementation of E-Government in Nigeria has provided some metrics that examine the stumbling blocks for realization of adequate and efficient E-Government implementation in the civil service. The research was carried out in the federal civil service in Nigeria in two phases namely, pre-IT implementation phase and post-IT implementation phase. Our findings reveal that ICT implementation will remain elusive in the civil service as long as the as threats explained below remain unaddressed. It has therefore been asserted that the need to overcome these threats is a precondition for realization of E-Government implementation in the federal civil service

Development of effective drying technology for quality enhancement of whitings fish (Merlangius merlangius)

A cost effective, affordable and environmental friendly solar tent dryer was developed for production of stockfish from Whitings fish (Merlangius merlangius) that is stable and free of contamination from air borne dust and insects. The dryer was constructed of locally available materials; basically steel and polythene. It was able to record an average differential temperature of 12 oC when compared with the ambient condition. The tent dried fresh samples of Whitings of 25 kg with average moisture content of 80.10% (wet basis) to a final weight of 5.42 kg with average moisture content of 10.13% (wet basis) in four days. Over 75 % overall acceptance was recorded when the stockfish was subjected to sensory analysis. The drying technology reduced the bacterial and fungal count of the fish sample used from initial value of 6.8 CFU/g x 102 and 3.6 CFU/g x 105 to 3.9 CFU/g x 102 and 2.7 CFU/g x 105 respectively. This is below the acceptable safe limit and what is obtainable in stockfish sold in the market. The output could be a good alternative to the imported stockfish in terms of food safety and sensory quality. Most importantly, it would reduce the huge amount of money being spent on importation of stockfish, and more job and wealth will be created for the teeming populace while the lovers of stockfish now have access to freshly processed products that would not endanger their life.Keywords : Stockfish, dryer, sensory, solar, qualit

Threats to E-Government Implementation in the Civil Service: Nigeria as a Case Study

The rapid advancement in Information and Communication Technology (ICT) has undoubtedly influenced positive changes in carrying out administrative functions in government institutions. The ICT adoption rate in Africa is not impressive when compared to the more developed countries of the world. Nigeria, as a case study in this scenario, has also not implemented E-Government impressively, according to the required standards set up by the International Telecommunications Union (ITU). A comprehensive study conducted on the application and implementation of E-Government in Nigeria has provided some metrics that examine the stumbling blocks for realization of adequate and efficient E-Government implementation in the civil service. The research was carried out in the federal civil service in Nigeria in two phases namely, pre-IT implementation phase and post-IT implementation phase. Our findings reveal that ICT implementation will remain elusive in the civil service as long as the as threats explained below remain unaddressed. It has therefore been asserted that the need to overcome these threats is a precondition for realization of E-Government implementation in the federal civil servic

Acting rehearsal in collaborative multimodal mixed reality environments

This paper presents the use of our multimodal mixed reality telecommunication system to support remote acting rehearsal. The rehearsals involved two actors, located in London and Barcelona, and a director in another location in London. This triadic audiovisual telecommunication was performed in a spatial and multimodal collaborative mixed reality environment based on the 'destination-visitor' paradigm, which we define and put into use. We detail our heterogeneous system architecture, which spans the three distributed and technologically asymmetric sites, and features a range of capture, display, and transmission technologies. The actors' and director's experience of rehearsing a scene via the system are then discussed, exploring successes and failures of this heterogeneous form of telecollaboration. Overall, the common spatial frame of reference presented by the system to all parties was highly conducive to theatrical acting and directing, allowing blocking, gross gesture, and unambiguous instruction to be issued. The relative inexpressivity of the actors' embodiments was identified as the central limitation of the telecommunication, meaning that moments relying on performing and reacting to consequential facial expression and subtle gesture were less successful

Nurturing lifelong learning in communities through the National University of Lesotho: prospects and challenges

This paper analyses one aspect of a pan-African action research project called ITMUA (Implementing the Third Mission of Universities in Africa). This particular paper draws on the data from that project to explore the National University of Lesotho’s contribution to lifelong learning in its communities. It provides background information on the ITMUA initiative and analyses interview and focus group responses to two case studies in terms of their contribution to lifelong learning. It uses, as its analytical framework, a modified version of Mbigi’s African perspective on the four De Lors’ ‘pillars’, by adding a fifth pillar, courtesy of Torres. The paper argues that community engagement is a two-way process between universities and their wider constituencies with opportunities for mutual lifelong learning. But there are also challenges of understanding and process which must be addressed if the full range of these lifelong learning pillars is to be accommodated within African contexts. The paper provides an introduction to the history of community engagement in Africa as a university mission, followed by a brief discussion of lifelong learning within African perspectives. After describing the particular context of Lesotho, the concept of community service and community engagement in contemporary African contexts introduces the action research project and the case studies. The final part of the paper presents and discusses the research findings

Prevalence and factors associated with hypertension among rural community dwellers in a local government area, South West Nigeria

Background: Many African countries including Nigeria are said to be at various stages of an epidemiological transition from communicable to non-communicable diseases (NCD). Objective: This study determined the current pattern and correlates of hypertension among adults in some rural communities in South West Nigeria. Methods: It was a descriptive cross-sectional study of 1012 individuals across 16 rural communities. The respondents\u2019 blood pressure, weight, height and waist circumference were measured. Bivariate and multivariate analyses were done. Results: Among the participants, 461 (45.6%) had hypertension out of whom 217 (47.1%) and 244 (52.9%) had stage 1 and stage 2 hypertension respectively. The systolic, diastolic and mean arterial blood pressures increased with age. The significant predictors of hypertension were; increasing age (p<0.001), higher waist circumference (p = 0.01) and overweight / obesity (p = 0.03). While systolic blood pressure (SBP) had the strongest correlation with age, waist circumference (WC) was the strongest correlate of diastolic blood pressure (DBP). Conclusion: Despite being a rural population, there was a high prevalence of hypertension in the study area

Outdoor host seeking behaviour of Anopheles gambiae mosquitoes following initiation of malaria vector control on Bioko Island, Equatorial Guinea

<p>Abstract</p> <p>Background</p> <p>Indoor-based anti-vector interventions remain the preferred means of reducing risk of malaria transmission in malaria endemic areas around the world. Despite demonstrated success in reducing human-mosquito interactions, these methods are effective solely against endophilic vectors. It may be that outdoor locations serve as an important venue of host seeking by <it>Anopheles gambiae </it>sensu lato (s.l.) mosquitoes where indoor vector suppression measures are employed. This paper describes the host seeking activity of anopheline mosquito vectors in the Punta Europa region of Bioko Island, Equatorial Guinea. In this area, <it>An. gambiae </it>sensu stricto (s.s.) is the primary malaria vector. The goal of the paper is to evaluate the importance of <it>An gambiae </it>s.l. outdoor host seeking behaviour and discuss its implications for anti-vector interventions.</p> <p>Methods</p> <p>The venue and temporal characteristics of host seeking by anopheline vectors in a hyperendemic setting was evaluated using human landing collections conducted inside and outside homes in three villages during both the wet and dry seasons in 2007 and 2008. Additionally, five bi-monthly human landing collections were conducted throughout 2009. Collections were segregated hourly to provide a time distribution of host-seeking behaviour.</p> <p>Results</p> <p>Surprisingly high levels of outdoor biting by <it>An. gambiae </it>senso stricto and <it>An. melas </it>vectors were observed throughout the night, including during the early evening and morning hours when human hosts are often outdoors. As reported previously, <it>An. gambiae </it>s.s. is the primary malaria vector in the Punta Europa region, where it seeks hosts outdoors at least as much as it does indoors. Further, approximately 40% of <it>An. gambiae </it>s.l. are feeding at times when people are often outdoors, where they are not protected by IRS or LLINs. Repeated sampling over two consecutive dry-wet season cycles indicates that this result is independent of seasonality.</p> <p>Conclusions</p> <p><it>An. gambiae </it>s.l. mosquitoes currently seek hosts in outdoor venues as much as indoors in the Punta Europa region of Bioko Island. This contrasts with an earlier pre-intervention observation of exclusive endophagy of <it>An. gambiae </it>in this region. In light of this finding, it is proposed that the long term indoor application of insecticides may have resulted in an adaptive shift toward outdoor host seeking in <it>An. gambiae </it>s.s. on Bioko Island.</p

The multiplicity of malaria transmission: a review of entomological inoculation rate measurements and methods across sub-Saharan Africa

Plasmodium falciparum malaria is a serious tropical disease that causes more than one million deaths each year, most of them in Africa. It is transmitted by a range of Anopheles mosquitoes and the risk of disease varies greatly across the continent. The "entomological inoculation rate" is the commonly-used measure of the intensity of malaria transmission, yet the methods used are currently not standardized, nor do they take the ecological, demographic, and socioeconomic differences across populations into account. To better understand the multiplicity of malaria transmission, this study examines the distribution of transmission intensity across sub-Saharan Africa, reviews the range of methods used, and explores ecological parameters in selected locations. It builds on an extensive geo-referenced database and uses geographical information systems to highlight transmission patterns, knowledge gaps, trends and changes in methodologies over time, and key differences between land use, population density, climate, and the main mosquito species. The aim is to improve the methods of measuring malaria transmission, to help develop the way forward so that we can better assess the impact of the large-scale intervention programmes, and rapid demographic and environmental change taking place across Africa

The influence of mosquito resting behaviour and associated microclimate for malaria risk

<p>Abstract</p> <p>Background</p> <p>The majority of the mosquito and parasite life-history traits that combine to determine malaria transmission intensity are temperature sensitive. In most cases, the process-based models used to estimate malaria risk and inform control and prevention strategies utilize measures of mean outdoor temperature. Evidence suggests, however, that certain malaria vectors can spend large parts of their adult life resting indoors.</p> <p>Presentation of hypothesis</p> <p>If significant proportions of mosquitoes are resting indoors and indoor conditions differ markedly from ambient conditions, simple use of outdoor temperatures will not provide reliable estimates of malaria transmission intensity. To date, few studies have quantified the differential effects of indoor <it>vs </it>outdoor temperatures explicitly, reflecting a lack of proper understanding of mosquito resting behaviour and associated microclimate.</p> <p>Testing the hypothesis</p> <p>Published records from 8 village sites in East Africa revealed temperatures to be warmer indoors than outdoors and to generally show less daily variation. Exploring the effects of these temperatures on malaria parasite development rate suggested indoor-resting mosquitoes could transmit malaria between 0.3 and 22.5 days earlier than outdoor-resting mosquitoes. These differences translate to increases in transmission risk ranging from 5 to approaching 3,000%, relative to predictions based on outdoor temperatures. The pattern appears robust for low- and highland areas, with differences increasing with altitude.</p> <p>Implications of the hypothesis</p> <p>Differences in indoor <it>vs </it>outdoor environments lead to large differences in the limits and the intensity of malaria transmission. This finding highlights a need to better understand mosquito resting behaviour and the associated microclimate, and to broaden assessments of transmission ecology and risk to consider the potentially important role of endophily.</p