275 research outputs found

    Analysis of Risk Management Practices in the Oil and Gas Industry in Ghana. Case Study of Tema Oil Refinery (Tor)

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    Risk management refers to an interactive process consisting of steps, which when undertaken in sequence, enable continual improvement in decision making. The aim of risk management is to obtain understanding by all parties and agreement around what the risks really are and how they will be managed to improve performance, increase the value of firms and reduce financial distress .We used primary and secondary data in our analysis The study identified risks confronting Tema Oil Refinery (TOR) as instability in global oil prices, depreciation of the cedi against major currencies, health and safety, political interference, environmental pollution, brain drain, shortage of crude oil, huge debts as a result of subsidizing of petroleum products by government and default on the part of oil marketing companies to pay for products and  high operational risks .Other challenges as apathy on the part of staff to abide by safety rules was identified. TOR incorporates risk management in their strategic plan and have operations and Audit risk department but have been battling with effective implementation. Made recommendations to government and management of TOR on how to overcome the problems in implementing risk management in order to achieve the goals of the only refinery in Ghana. Keywords: Risk Management Practices, Management and industr

    Er3+ doped Silica-on-Silicon using fs-laser doping process for Integrated Waveguide Amplifier Platforms

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    Rare earth doped waveguide amplifier (EDWA) on silica-on-silicon (SOS) platform are area of great interest for silicon integrated photonics. We report the fabrication of erbium doped silica-on-silicon (SOS) wafer-scale platforms for integrated waveguide amplifier and laser application. We used a method named- ultrafast laser plasma doping (ULPD) process on silica- on-silicon substrates using erbium doped zinc-sodium tellurite glasses (TZN) as targets. The influence of laser energy on the doping process was studied in terms of the refractive index of the waveguides formed and their photoluminescence properties. Planar slab waveguides of refractive index1.64 at 633 nm and characteristic photoluminescence lifetimes of erbium at 1535 nm wavelength emission, varying from 13.38 ms to 10.52 ms were obtained. We used higher repetition rate (10 kHz) amplified Ti-Sapphire laser with pulse duration of 45 fs for faster and efficient growth of active waveguide layer in this research

    Sachet drinking water in accra: the potential threats of transmission of enteric pathogenic protozoan organisms

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    Background: The recent introduction of sachet water to consumers was to provide safe, hygienic and affordable instant drinking water to the public. Although this is a laudable idea current trends seem to suggest that sachet drinking water could be a route of transmission of enteric pathogens. Objective: To assess the safety of sachet drinkingwater. Materials and Methods: Twenty seven different brands of 500ml sachet water samples randomly selected and purchased from various vendors in Accra were subjected to microscopic examinations to determine the presence of parasitic protozoa. The study was carried out between January and May 2005. Results: Seventy-seven percent of the samples contained infective stages of pathogenic parasitic organisms. Common pathogens identified include, Microsporidia sp 14/27 (51.2%), Cryptosporidium parvum 17/27 (63.0%), Cyclospora cayetenensis16/27 (59.3%), Sarcocystis sp. 18/27 (66.7%). Rotifers 5/27 (18.5%), and Charcoat Leyden crystals 12/27 (44.4%). Ninety-three percent of the samples contained unidentified impurities/artifacts.29.6% of the samples contained at least one type of parasite, 14.8% contained at least 2 types of parasites, 25.9% contained at least three types of parasites, while 29.6% contained four types of parasites. Conclusion: The study indicated the presence of contaminants of feacal and zoonotic origin in some of the sachet water examined. This has grim public health implications as the organisms identified can cause water related diseases which have serious complications in children and adults particularly immunocompromised individuals. Sachet watershould be constantly monitored for its microbial quality

    Parasitic Load of Cattle Faecal Matter from Selected Farms in Kpong and its Health Implications

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    Cattle, one of the domesticated animals which are a potential source of parasitic contamination of land and water resources were studied to establish the parasitic load as a measure of quantifying the biological quality of land and water sources to determine the level of parasite load of the environment. A total of 180 faecal samples were collected from three farms in Kpong in the Lower Manya Krobo Municipality for the study. The samples were collected between 9 - 10 am when the animals released from kraal to be grazed and the faecal matter were collected as soon as it was dropped on the ground. The samples were collected with wide mouth plastic containers (about 500 ml) with lid. Samples were transported to the Water Research Institute Parasitology Laboratory for analysis. 10 g sample each was placed in a test tube and 10 ml of PBS was added to it. It was then processed and a drop was placed on a microscope slide and Lugol's iodine was added and observed under X 40 objective lens of the microscope. A total of 111 (61.67 %) out of the 180 faecal samples were found to contain the following parasites whilst 95 (85.59 %) had Ascaris sp., eight (7.20 %) had Strongyloides sp., one (0.90 %) had Trichuris erichiun and one (0.90 %) sample had Paragonimus sp. Five (4.50 %) samples had mix infections of Ascaris sp and Strongyloides sp. And 1 (0.90 %) sample had a mixture of Ascaris sp and T. berichiun. Infestation with Ascaris sp was found to be significantly higher (p > 0.001) than all the other parasites indicating that the animals are not often given worm expellants as expected and this can lead to zoonotic transmission of the parasite, as the cattle are reared on the same compound with the humans. This can affect the health of children as they played in the dung contaminated soils in their compound, thereby leading to absenteeism from school due to loss of blood from worm infestation leading to anaemia. The worm infestation can also lead to malnutrition and stunted growth in the children

    Prevalence of Giardia species in Cattle Faecal Matter in Selected Farms in Weija and Kpong Major Water Supply Heads to Accra, Ghana.

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    In developing countries including Ghana, giardiasis plays a major role in gastroenteritis in vertebrate. It poses health and socio-economic burden, and continues to be one of the causes of infant and calf mortality. Their infection continues to thrive in humans due to the zoonotic transmission of infected domesticated animals including cattle, dogs and cats, and their con­tinual presence in water bodies. The objective of this study was to establish their presence and evaluate the prevalence of Giardia sp. in cattle faecal matter in the environment in the Kpong and Weija communities. The Iron-haematoxylin staining techniques was used to analyze the faecal samples in order to identify Giardia sp. (Student t- test and Chi square were the statistical analyses) used for the studies. About five percent (5.3%) prevalence was obtained in both com­munities and this was significant (p> 0.05). The parasite was found to be most prevalent (9.4%) in calves less than 3 months old and this decreased with age of calf. It was also observed that Giardia plays an important role in the cause of diarrhoea in cattle. There is the need to educate people on the disease and its implication on the quality of water from the treatment plants. Keywords: Giardia sp, water, contamination, diarrhoea, infant mortality

    Phase changeable vanadium dioxide (VO₂) thin films grown from vanadium pentoxide (V₂O₅) using femtosecond pulsed laser deposition

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    There are significant challenges accompanied by fabricating a pure crystalline VO₂ (M1) thin film with an abrupt metal to insulator phase change properties. Most fabrication methods yield an amorphous VO₂ thin film that requires a post-annealing process to be converted into crystalline VO₂ (M1). Hence, the thickness of VO₂ (M1) films produced is very limited. In this work, we report the growth of pure VO₂ (M1) crystalline thin films onto a sapphire substrate in an oxygen atmosphere by the femtosecond pulsed laser deposition technique and using vanadium pentoxide (V₂O₅) as an ablation target. The thin films were deposited at substrate temperatures of 25 °C, 400 °C, and 600 °C, which reveal the crystallized structures of VO₂ (M1) without post-annealing. The thin film deposited at a substrate temperature of 600 °C exhibits a sharp and an abrupt metal-to-insulator transition (MIT) at a temperature of 66.0 ± 2.5 °C with nearly four orders of magnitude of the resistivity change (3.5 decades) and a narrow MIT hysteresis width of 3.9 °C. Furthermore, the influence of the substrate temperature, nanoparticle or grain size, and film thickness on the MIT parameters such as sharpness of the transition temperature, hysteresis width, and amplitude are discussed for potential applications of tunable antennas, terahertz planar antennas, and RF-microwave switches

    Detection of Human Genotype “B” Giardia lamblia in Ghanaian Cattle from Frafraha in Adentan Municipality of Ghana

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    Giardia duodenalis is a common intestinal parasite in humans, a wide range of domesticated and wild animals. There are human and animal specific, as well as zoonotic pathogenic gen­otypes. It is not clear whether livestock in close proximity to humans could be infected with human specific genotypes, and vice versa. In this study, Giardia-positive faecal samples were collected from both humans (n = 4) (from Maamobi Polyclinic in the Ayawaso Sub- Metro) and calves (n = 8) (from Animal Research Institute Farms, Adentan Municipality), in Ghana. Nested PCR amplification using Giardia-specific, Glutamate dehydrogenase (GDH) genes and Tri­osephosphate isomerase (TPI) gene primers for human and animal faecal samples respectively was carried out. Results showed that 100% of the calves carried the TPI-B genotype, which is a common pathogenic genotype in humans. This report is based on the unusual results obtained as Giardia duodenalis genotype B is known to occur in humans but is being observed in calves for the first time. This suggests that calves in close proximity to humans could be reservoirs and sources of human Giardia infections

    Examination of Combustion-Generated Smoke Particles from Biomass at Source: Relation to Atmospheric Light Absorption

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    The formation of carbonaceous aerosols from biomass combustion is associated with a high degree of uncertainty in global climate models. In this work, soot samples were generated from the combustion of pine wood, wheat straw and barley straw in a fixed bed stove; as well as from the combustion of biomass pyrolysis model compounds. Samples were collected on filters, which were used for the determination of Absorption Angstrom Exponent (AAE). In addition, the content and composition of elemental carbon (EC) and organic carbon (OC) were determined, and the interrelationships between these and the AAE were examined. It was found that the spectroscopic signature of samples with high ‘brown carbon’ emissions was comparable to that of many PAH and polyphenols, with AAE ranging from 1.0–1.2 for model compounds to 0.5–5.7 for biomass. In addition to the filter samples, particles were collected directly onto microscopy grids and analysed by transmission electron microscopy–electron energy loss spectroscopy (TEM-EELS) in order to determine structural characteristics. This was used to examine the impact of combustion conditions and flue gas dilution on particle structure. Smouldering phase and diluted particles were found to be less graphitic and twice as oxygenated as undiluted flaming phase particles. The results are interpreted to better understand the impact of combustion processes on soot formation from biomass combustion. Abbreviations: AAE: absorption angstrom exponent; ATN: light attenuation; AToFMS: aerosol time of flight mass spectrometer; BC: black carbon; BrC: brown carbon; C:O: carbon to oxygen ratio; CPD: cyclopentadienyl radical C5H5; DMS: differential mobility spectrometer; EC: elemental carbon; EELS: electron energy loss spectroscopy; HACA: hydrogen abstraction carbon addition; MCE: modified combustion efficiency; OA: organic aerosols; OC: organic carbon; PM: particulate matter; POM: primary (particulate)organic matter; Py-GC/MS: pyrolysis gas chromatography/mass spectrometry; sp2: amount of sp2 orbital hybridisation in atomic structure; SSA: single scattering albedo; TC: total carbon (BC+OC) or (EC+OC); TEM: transmission electron microscope; TGA: thermogravimetric analysis

    Fatty Acid Composition of Growing Kiko X Spanish Crossbred Intact Male Goats Fed Varying Levels of Peanut Skins

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    Abstract The objective was to evaluate the effects of feeding peanut skins (PS) on fatty acid profile of goat meat. The diets used contained 0, 10, 20, and 30% of PS. After 92 days, longissimus muscle (LM), mesenteric adipose (MA), and subcutaneous (SA) tissue samples were analyzed for fatty acid profile. Eighteen (18), 21, and 21 fatty acids were detected in LM, MS and SC adipose tissues, respectively. No changes were detected in the fatty acid profile, but C18:0 increased linearly in LM (p \u3c 0.05) with increasing level of PS whereas C18:1 decreased in the similar manner (p = 0.05). Total saturated fatty acid and monounsaturated fatty acid percentage increased linearly (p \u3c 0.05) in LM fat, but polyunsaturated fatty acids were not different (p \u3e 0.05) among treatments. The results showed that the fatty acid composition of goat carcass can be altered with the dietary addition of PS. Keywords: Meat Goats, Peanut Skins, Fatty Acid

    Femtosecond Laser Deposition of Germanium Selenide onto Silicon Platform at Different Substrate Temperatures

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    Germanium selenide (GeSe) thin films were fabricated by employing femtosecond pulsed-laser deposition (fs-PLD) on silicon (100) substrates at various substrate temperatures, ranging from 25 °C to 600 °C. The thin films’ surface morphology qualities and optical properties were studied by utilising transmission electron microscopy (TEM) and X-ray diffraction (XRD). The X-ray diffraction result signifies that the thin films deposited on the silicon at a substrate temperature below 400 °C were amorphous Ge-Se. In contrast, those grown at 400 °C and above exhibited crystallised peaks of Ge-Se orthorhombic and tetragonal structures. The deposition growth rate of the thin films was also found to decrease substantially with increasing substrate temperature. These results show that the fs-PLD process has great potential for fabricating good quality Ge-Se thin film. This technique could enable the manufacture of modern optoelectronic devices for applications in optical communication, sensing, and ovonic threshold switching for the high-density crossbar memory array
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