Determinants of effective control of accidents in the port of Mombasa, Kenya.

Mombasa port plays a pivotal role in the economic development of East and Central African countries where goods of varying hazards transit the port. The risk of serious accidents is inevitable due dangerous operations involving cranes and handling of hazardous materials. Ports are potential sources of accidents such as spills, explosions, fires, toxic fumes The goal of this study was to evaluate determinants of effective control of accidents in the port of Mombasa. The study employed a descriptive survey research design where structured questionnaires were used to collect data. Random sampling was used to identify 248 study participants from a population of 650 workers. Data was analyzed using SPSS version 20 at 95% confidence interval. Data was subjected to descriptive tests to determine proportions as well as chi square test and presented using graphs and tables. The rates of occupational accidents in Mombasa port were significantly high with 99.5% of the port workers reporting to have witnessed occurrence of accidents. Accidents reported by port workers include crane failure, chemical spillage, fire accidents and explosions. The main container terminal had recorded the highest number of occupational accidents compared to other terminals. There was a significant association between training on accident hazards and improvement on understanding of accident prevention (X2 = 0.029 P= 0.05 DF = 1). study reveal that training on accident would help reduce occurrence. The determinants of effective control of accidents in the port of Mombasa that were studied included: Safe sytems of work, risk assessment, cargo handling equipment and training

Hybrid Power Systems for Commercial Application in Kenya

The cost, availability and stability of power are parameters that greatly define the quality of energy supplied by a generating system. A hybrid power system with different sources of energy must be properly designed in order to capitalize on the positive features of the deployed resources. Hybrid power system optimization is a process that allows for deliberate attainment of desired output from a power system. In this paper, a learning institution, East African School of Aviation (EASA) was selected as a case study for investigating the outcome of harnessing local energy resources to serve a commercial consumer in Kenya. A cost competitive hybrid power system was obtained through Simulation and optimization processes

Health effects of lead exposure among Jua Kali (informal sector) workers in Mombasa, Kenya: A case study of the "Express" Jua Kali workers

The objective of this study is to analyze the effects of lead exposure among the Jua Kali workers. Correlation study: relationship between lead exposure and its effects on blood lead levels (BLL), kidney function and haemoglobin levels between the lead-exposed versus the lead un-exposed workers. 162 adult Jua Kali workers participated. Out of 119 exposed workers, 8 (6.72%) were aware of lead while only 3 of them (2.5%) used protective equipment. The highest BLL in the test group was 32 μg/dl with 16 of them (13.45%) having BLL above 10 μg/dl. The mean BLL in this group was 6.76 ± 5.96. In the control group, the highest BLL was 9 μg/dl with none having BLL above10 μg/dl. The mean BLL was 2.58 ± 1.69. The spearman's correlation coefficient was 0.272 significant at 0.05 level. 14 out of 119 (13.45%) exposed workers had impaired glomerular filtration rates (GFR). The mean GFR in the exposed workers was 104.85 ± 16.485. In the un-exposed workers, 1 out of 43 (2.4%) had impaired GFR. The mean GFR was 109.98 ± 15.408. The spearman's correlation coefficient was -0.113, not statistically significant. 21 out of 119 (17.6%) lead-exposed workers had haemoglobin (HB) less than 13 g/dl with mean HB of 14.12 ± 1.600. 1 out 43 (2.3%) in the control group had an HB of less than 13 g/dl with the mean HB of 14.37 ± 1.34. Spearman's correlation coefficient of negative 0.321 (P<0.05) implying significant inverse relationship. Recommendations: education on lead and its effects, provision of protective equipments, medical facilities to diagnose and manage lead and other heavy metal toxicity

Evaluation of scatter suppression algorithm for X-ray exposure of soft tissue equivalent phantoms over nominal energy range using FLUKA code

Soft tissue imaging is heavily impaired by streaks and cupping effects associated with X-ray scatter. Quality of images from projection imaging may be improved by the use of enhanced anti-scatter grids’ designs with potency to reject significant scatter. However, optimization of grid characteristics requires investigation to improve diagnostic image quality. Transmitted scatter spatially distributed degrades images engendering need for effective scatter correction protocols. This study investigated the pre-scan scatter suppression algorithm for X-ray exposure of soft tissue equivalent phantoms over nominal energy range. Adipose tissue and polymethyl methacrylate phantoms of cross-sectional area (30 x 30) cm2 and of varying thickness from 2 to 8 cm in 1 cm increments were successively exposed using energy ranging between 20–50 kVp. Monte Carlo simulation based on FLUKA code and flair interface was used to generate an input file for execution. The source simulated five cycles of ten million photons each of annular X-ray photon beam of radius, r = 0.5 cm at fixed field of view (FOV) through anti-scatter grid on to gadolinium oxysulfide detector. The transmitted total, scatter and primary estimates were evaluated with and without grids over varying phantom thicknesses, energy and grid design features. The simulated and experimental results obtained were comparable and in agreement with previous literature. Pearson’s correlation coefficients for scatter fraction and scatter to primary ratio were 0.983 and 0.981, respectively. The strong correlation between simulation and experiment results indicated correctness in methodology and protocol. The algorithms and protocols in the simulation would be appropriate for designing grids with enhanced scatter rejection capabilities. Keywords: FLUKA code, Monte Carlo simulation, Scatter suppression algorithm, Scatter correction, X-ray imaging systems. &nbsp

Hybrid Power System Sizing and Design for Commercial Application in Kenya

Hybrid power system sizing involves determination of local load and energy resources’ conditions as well as availability of generating system components. Each component of the system is preliminarily sized individually using prevailing load, resource and conversion system’s conditions. The Net Present Cost (NPC), Cost of Energy (COE) may be included in determining the configuration of the most optimal system that can meet all the desired power system’s goals. In order to refine the sizing and design process, a simulation software is used to select and size system components that can serve the load effectively. In this study, a Solar PV, Wind and Grid hybrid power system was systematically sized to meet the demand of a commercial consumer, East African School of Aviation (EASA). HOMER software was used to simulate the operation of the proposed HPS. The most suitable HPS was found to consist of Wind generation of an installed capacity of 200 kW, solar PV of 120 kW and the Grid. This system had an NPC of KSh 77,684,050 and a COE of KSh 8.34/kWh

Development and evaluation of a Loop Mediated Isothermal Amplification (LAMP) technique for the detection of hookworm (Necator americanus) infection in fecal samples

Abstract Background Hookworm infection is a major concern in sub-Saharan Africa, particularly in children and pregnant women. Necator americanus and Ancylostoma duodenale are responsible for this condition. Hookworm disease is one of the Neglected tropical diseases (NTDs) that are targeted for elimination through global mass chemotherapy. To support this there is a need for reliable diagnostic tools. The conventional diagnostic test, Kato-Katz that is based on microscopic detection of parasite ova in faecal samples, is not effective due to its low sensitivity that is brought about mainly by non-random distribution of eggs in stool and day to day variation in egg output. It is tedious, cumbersome to perform and requires experience for correct diagnosis. LAMP-based tests are simple, relatively cheap, offer greater sensitivity, specificity than existing tests, have high throughput capability, and are ideal for use at the point of care. Methods We have developed a LAMP diagnostic test for detection of hookworm infection in faecal samples. LAMP relies on auto cycling strand displacement DNA synthesis performed at isothermal temperature by Bst polymerase and a set of 4 specific primers. The primers used in the LAMP assay were based on the second Internal Transcribed Spacer (ITS-2) region and designed using Primer Explorer version 4 Software. The ITS-2 region of the ribosomal gene (rDNA) was identified as a suitable target due to its low mutation rates and substantial differences between species. DNA was extracted directly from human faecal samples, followed by LAMP amplification at isothermal temperature of 63 °C for 1 h. Amplicons were visualized using gel electrophoresis and SYBR green dye. Both specificity and sensitivity of the assay were determined. Results The LAMP based technique developed was able to detect N. americanus DNA in faecal samples. The assay showed 100 % specificity and no cross-reaction was observed with other helminth parasites (S. mansoni, A. lumbricoides or T. trichiura). The developed LAMP assay was 97 % sensitive and DNA at concentrations as low as 0.4 fg were amplified. Conclusion The LAMP assay developed is an appropriate diagnostic method for the detection of N. americanus DNA in human stool samples because of its simplicity, low cost, sensitivity, and specificity. It holds great promise as a useful diagnostic tool for use in disease control where infection intensities have been significantly reduced

Piecewise disassembly of a large-herbivore community across a rainfall gradient: the UHURU experiment.

Large mammalian herbivores (LMH) strongly influence plant communities, and these effects can propagate indirectly throughout food webs. Most existing large-scale manipulations of LMH presence/absence consist of a single exclusion treatment, and few are replicated across environmental gradients. Thus, important questions remain about the functional roles of different LMH, and how these roles depend on abiotic context. In September 2008, we constructed a series of 1-ha herbivore-exclusion plots across a 20-km rainfall gradient in central Kenya. Dubbed "UHURU" (Ungulate Herbivory Under Rainfall Uncertainty), this experiment aims to illuminate the ecological effects of three size classes of LMH, and how rainfall regimes shape the direction and magnitude of these effects. UHURU consists of four treatments: total-exclusion (all ungulate herbivores), mesoherbivore-exclusion (LMH >120-cm tall), megaherbivore-exclusion (elephants and giraffes), and unfenced open plots. Each treatment is replicated three times at three locations ("sites") along the rainfall gradient: low (440 mm/year), intermediate (580 mm/year), and high (640 mm/year). There was limited variation across sites in soil attributes and LMH activity levels. Understory-plant cover was greater in plots without mesoherbivores, but did not respond strongly to the exclusion of megaherbivores, or to the additional exclusion of dik-dik and warthog. Eleven of the thirteen understory plant species that responded significantly to exclusion treatment were more common in exclusion plots than open ones. Significant interactions between site and treatment on plant communities, although uncommon, suggested that differences between treatments may be greater at sites with lower rainfall. Browsers reduced densities of several common overstory species, along with growth rates of the three dominant Acacia species. Small-mammal densities were 2-3 times greater in total-exclusion than in open plots at all sites. Although we expect patterns to become clearer with time, results from 2008-2012 show that the effects of excluding successively smaller-bodied subsets of the LMH community are generally non-additive for a given response variable, and inconsistent across response variables, indicating that the different LMH size classes are not functionally redundant. Several response variables showed significant treatment-by-site interactions, suggesting that the nature of plant-herbivore interactions can vary across restricted spatial scales