Informal Sector Business Proliferation: Harnessing Potentials for Development in Ghana

The rapid and enormous growth of the informal sector, in spite of its erratic and muddling characterization, provides immeasurable backing for the nation’s economy. This implies that the development of the nation may leapfrog to a boastful height if available resources and opportunities are converged, organized, coordinated and regulated. This study focused on how potential skills within the sector could be harnessed toward the achievement of the first Millennium Development Goal (MDG) in Ghana. The paper was purely based on the review of literature, summarizing and giving a critical and evaluative account of existing knowledge related to the area of study. The trends of the informal sector is considered and seen from various studies to be growing and supportive of the economy. Unrelenting efforts to get organized and coordinate the activities of the sector are on-going. Concurrently, several other studies imply the need to revamp the sector (reinforcements, and changes in focus and strategies) in order to achieve the MDGs. The study reveals that development needs keep increasing, bringing along the need for augmented support. Challenges leading to failure in achieving success in the informal sector are slow employment-generating growth, absence of structural economic transformation, high demographic pressure, inappropriate education and training policies, failed labour regulations, no enabling environment for investment, economic choices motivated by politics, and brain drain. Recommendations made to extricate the confusion and guide policy-making for organized informal sector activities include lower-level collaborative partnership (LLCP), clustering and networking, just to mention a few. Key words: Informal sector; Informal sector employees; Lower-level collaborative partnership (LLCP

Component reliability test approaches for marine renewable energy

Philipp R Thies University of Exeter Cornwall Campus College of Engineering, Mathematics and Physical Science Penryn Cornwall TR10 9FE United KingdomArticleThis version is the author’s manuscript of the published article. Please cite the published version as: Thies PR, Johanning L, Karikari-Boateng KA, Ng C, McKeever P. (2015). Component reliability test approaches for marine renewable energy. Proc IMechE Part O: Journal of Risk and Reliability, Spec. Issue, Vol. 229 (5), pp. 403-416, DOI:10.1177/1748006X15580837.An increasing number of marine renewable energy (MRE) systems are reaching the stage where a working prototype must be demonstrated in operation in order to progress to the next stage of commercial projects. This stage is often referred to as ‘valley of death’ where device developers face the challenge of raising capital needed to demonstrate the prototype. The dilemma is that investors understandably demand a proven track record and demonstrated reliability in order to provide capital. One way to resolve this dilemma is specific component reliability testing that not only satisfies investor expectations but holds the potential to improve and de-risk components for MRE. This paper gives an overview to different component reliability test approaches in established industries and for MRE, covering both wave and tidal energy technologies. There has been notable activity in the research community to develop and implement dedicated component reliability test rigs that allow the investigation and demonstration of component reliability under controlled, yet representative conditions. Two case studies of physical test rigs will illustrate the possible test approaches. The Nautilus Powertrain test rig, a facility at the Offshore Renewable Energy (ORE) Catapult, focuses on the demonstration and testing of drive train components including gearboxes, generators, mechanical couplings and bearings. The Dynamic Marine Component test rig (DMaC) at the University of Exeter aims to replicate the forces and motions for floating offshore applications and their subsystems, including mooring lines and power cables. This paper highlights the relevance of component testing and qualification prior to large-scale commercial deployments and gives an insight to some of the test capabilities available in the sector. Several case studies illustrate the component test approach for tidal energy (Nautilus) and wave energy (DMaC) applications.European Union’s European Regional Development Fund (ERDF)Department of Energy and Climate Change (DECC)Peninsula Research Institute for Marine Renewable Energy (PRIMaRE)Engineering and Physical Sciences Research Council (EPSRC)Energy Technoliogy Istitute (ETI)Research Councils UK (RCUK) Energy programmeIndustrial Doctorate Centre in Offshore Renewable Energy (IDCORE

Accelerated testing of tidal turbine main bearing in a full scale Nacelle Test Rig

Tidal Energy is one of the growing renewable energy technologies that is aimed at tackling global energy challenges. The Horizontal Axis Tidal Turbine (HATT) is an in-stream Tidal Energy Converter (TEC) which extracts kinetic energy from tidal flows. These tidal turbines face many reliability challenges due to their complexity, harsh operating environment and low accessibility. One of the component contributing significantly to the reliability of a TEC is the bearing supporting the rotating shaft within the nacelle. The reliability assessment of this component is essential during the design process and before their eventual deployments. This work is describes shaft bearing reliability assessment procedures. In recent years, the Offshore Renewable Energy (ORE) Catapult’s National Renewable Energy Centre has developed a dedicated multi axis test facility for full scale testing of tidal turbine nacelles and components (i.e. Nautilus). This work presents a methodology for testing tidal turbine shaft bearings in a representative manner in the full scale nacelle test rig, Nautilus. Two aspects are considered, namely the damage assessment and the damage replication in an accelerated manner. The damage assessment process considers the global loading on the shaft bearing and a Rigid Dynamics (RD) model has been applied to identify the local bearing loads. Local loads are converted to stress enabling the identification of stress-life relationship and bearing damage. The damage replication process is aimed to evaluate the 20 year damage and the Acceleration by Phase-shift (AbP) method has been developed to accelerate the cumulative damage. The AbP method enables the assessment of performance characteristics of shaft bearings in a laboratory environment, reducing failure rates, validate performance in a cost effective manner by reduced testing times. Within this work, novel processes for shaft bearing reliability assessments and demonstration are suggested and it concludes with the presentation of a recommended test plan for carrying out accelerated tests on a full scale bearin

Quality of oxytocin available in low- and middle-income countries: a systematic review of the literature

BackgroundOxytocin is the drug of choice for preventing and treating postpartum haemorrhage, an important cause of maternal death. Oxytocin is widely available in low and middle-income countries (LMIC) but there are concerns about its quality. ObjectiveTo identify, critically appraise and synthesise the findings of studies on the quality of oxytocin available in LMIC. Search strategyWe searched seven electronic databases, without language restriction. Selection criteriaStudies reporting results of tests to assess quality of oxytocin samples from LMIC. Data collection and analysisStudy selection, data extraction and quality assessment were performed in duplicate. Results are presented descriptively. Main resultsThe search identified 2611 unique citationseight studies, assessing 559 samples from 15 different countries were included. Most samples were collected from facility level settings (n = 509) and from the private sector (n = 321). The median prevalence of oxytocin samples that failed quality tests was 45.6% (range 0-80%), mostly due to insufficient amounts of active pharmacological ingredient. Over one-third of the samples (n = 204) had low (<90%) oxytocin content indicating substandard medicinetwo samples had no active ingredient, suggesting possible counterfeit drugs. The proportion of low fails was higher in samples collected in Africa than in Asia or Latin America (57.5% versus 22.3% versus 0%, respectively, P < 0.0001), in private than in public sectors (34.0% versus 25.3%, P = 0.032) and in facilities than in central distributors (37.9% versus 22.0%, P = 0.030). ConclusionThere is a high prevalence of poor-quality oxytocin samples in LMIC countries, mainly due to inadequate amounts of active ingredient. Tweetable abstractSystematic review points to problems with quality of oxytocin samples from low- and middle-income countries. Tweetable abstract Systematic review points to problems with quality of oxytocin samples from low- and middle-income countries. This article includes Author Insights, a video abstract available atMerck Sharp and Dohme Corp.Merck and Co., Inc. (Kenilworth, NJ, USA)Univ Fed Sao Paulo, Dept Internal Med, Evidence Based Healthcare Postgrad Programme, Sao Paulo, BrazilWorld Hlth Org, Dept Essential Med & Hlth Prod, Geneva, SwitzerlandWorld Hlth Org, Dept Reprod Hlth & Res, Geneva, SwitzerlandEvidence Based Healthcare Post‐Graduate Programme, Department of Internal Medicine, Universidade Federal de São Paulo (UNIFESP), São Paulo, BrazilWeb of Scienc

Investigating the Effect of Curing Activators on the Cure Kinetics of Acrylonitrile–Butadiene Rubber Filled with Graphene Oxide and Reduced Graphene Oxides Nanocomposites

For the first time, acrylonitrile–butadiene rubber (NBR)–graphene oxide (GO) and reduced graphene oxide (rGO) composites were prepared without cure activators: zinc oxide/stearic acid (ZnO/SA) and studied. The vulcanization characteristics of the compounds were systematically studied at 160–190°C, with the aid of rheometer and differential scanning calorimetry (DSC) techniques. NBR revealed rapid curing time (t90) with greater cure rate index compared with NBR–GO/rGO composites for the rheometer measurement. This results were in correspondence with the activation energies Ea (kJ/mol) calculated by Ozawa and Kissinger models of vulcanization kinetics. NBR–rGO obtained reduced t90 and Ea (kJ/mol) than NBR–GO, perhaps due to lower oxygenated groups: epoxide (–C–O–C–), carboxyl (–O–C=O), and hydroxyl (–OH) present. Although, the composites delayed in curing, they significantly recorded high tensile properties with high reinforcing factors than NBR. The order of increasing mechanical properties: NBR < NBR–rGO < NBR–GO followed the same order of increasing crosslinking density. In terms of tensile strength, NBR–GO-1 obtained 62.5% and 18.2% increment than NBR and NBR–rGO-1, respectively. The findings from this study indicate that the absence of ZnO/SA in rubber compounds may slow down curing of rubber–GO/rGO composites and lower networks compared with those containing activators ZnO/SA. However, optimization of ZnO/SA and with desired functional groups on graphene and derivative graphene sheets (GDS) including other proposed factors may enhance the curing speed of rubber–GDS based systems, without compromising their mechanical integrity for advanced applications