Effect of tilt angle on the performance of a thin-film photovoltaic system

Solar energy is among the cleanest and most sustainable ways to enhance electrical supply's resiliency and reliability for domestic and industrial use. A Photovoltaic (PV) system is the most effective way of capturing solar energy. Long-term warranty, low-cost maintenance, and vast resource availability, solar power generation has an advantage over other approaches. Thin-film technology PV cells are a new kind of solar cell that offers an efficient technique of generating electricity from sunlight. The thin-film PV technology (FFMAT-10, Renovagen, UK) used in this study can supply 0.9 to 1.6 kW of energy to the fast-fold energy hub. The hub’s system status and configuration display battery power input, battery’s state of charge, thin-film PV power and AC power output. Two fast-fold mats (with a surface area of 25.3 m2) were connected to the energy hub. Increasing energy demand coupled with frequent power outages, and inaccessibility of electricity in rural areas necessitates the usage of PV systems at their best performance level. The study objective, therefore, sought to assess the effect of tilt angle on the performance of the thin-film PV system. The study was conducted at Kimicha in Kirinyaga County Kenya, and Juja, Kenya at tilt angles between 0o to 30o. The results indicated that the mean peak PV power for Kimicha was 347.8±231.9 W at 5o and 517.7± 131.3 W at 15ofor Juja. The maximum solar radiation during the study period was 1086.4 ±211.4 W/m2 for Juja and 973.5±219.93 W/m2 for Kimicha. From the study, it was realized that an optimal tilt angle yields optimum solar radiation that translates to maximum power production. Even though the study was conducted in two different regions, it may be applied to any other geographical location. The outcome of the study aids in acquiring self-sustaining power in the most remote locations where electricity is scarce as well as improving energy security

Roadside air pollutants along elected roads in Nairobi City, Kenya

This paper presents a statistical analysis of air quality monitoring in Nairobi city, at three major roads and Industrial Area, a site closer to the main industrial activities. The study was carried out using different gas analyzers and samplers. From the statistical analysis it was found that, there were extremely high values of black carbon which went beyond the upper limit of the instruments (50,000 ŋg/m3) during the day on Ladhis road. Nakumatt Junction site recorded extreme values of Black carbon (14,008 ŋg/m3) in the evening hours, while at Pangani Roundabout site, the diurnal mean value was extreme (14,446.5 ŋg/m3) for the period. None of the four sites exceeded the WHO 24 h limit for both PM10 (50 μg/ m3) and PM2.5 (25 μg/m3). The 24 h mean values of PM10 in the three sites also did not exceed the ambient air quality tolerance Kenyan limit of 100 μg/Nm3 and 150 μg/Nm3 in industrial area. The diurnal mean of SO2 over the four sites was generally low with the highest amount of 1.08 ppb recorded at Pangani Roundabout. This amount is far much below the diurnal WHO and Kenyan limit of 10 ppb and 48 ppb respectively. The global background concentration of carbon monoxide ranges between 0.05-0.12 ppm. The mean 24 h amount of CO in all the sites was above the background concentration, with Pangani Roundabout recording the highest amount of 1.73 ppm. The eight h means for ozone in all the sites were below WHO limit of 51 ppb with the highest amount of 20.2 ppb recorded in industrial area

Visual analytics: tackling data related challenges in healthcare process mining

2018 Conference paper presented at Strathmore University. Thematic area(Health, Healthcare Management and Research Ethics)Data-science approaches such as Visual analytics tend to be process blind whereas process-science approaches such as process mining tend to be model-driven without considering the “evidence” hidden in the data. Use of either approach separately faces limitations in analysis of healthcare data. Visual analytics allows humans to exploit their perceptual and cognitive capabilities in processing data, while process mining represents the data in terms of activities and resources thereby giving a complete process picture. We use a literature survey of research that has deployed either or both Visual analytics and process mining in the healthcare environments to discover strengths that can help solve open problems and challenges in healthcare data when using process mining. We present a visual analytics (data science) approach in solving data challenges in healthcare process mining (process science). Historical data (event logs) obtained from organizational archives are used to generate accurate and evidence-based activity sequences that are manipulated and analysed to answer questions that could not be tackled by process mining. The approach can help hospital management and clinicians among others, audit their business processes in addition to providing important operational information. Other beneficiaries are those organizations interested in forensic information regarding individuals and groups of patients.1.Institute of Computing and Informatics, Technical University of Mombasa; 2.Faculty of information Technology, Strathmore University 3.School of Computing and Information technology, Muranga University of technology; 4.School of Computing and Informatics, Masinde Muliro University of Science and Technolog

Workplace Violence among Domestic Workers in Urban Households in Kenya: A Case of Nairobi City

This paper discusses findings of a study conducted in 2004/2005 on the prevalence and impact of domestic labour migration in Nairobi. Specifically, the paper examines the profile of domestic workers and extent of their vulnerability and exposure to different forms of abuse. The study integrated both qualitative and quantitative research techniques to attain its objectives. The qualitative approach included key informant survey and in-depth interviews. The quantitative approach on the other hand involved a cross-sectional household stratified sample survey in urban residential areas in Nairobi. The results reveal that overall, children account for a higher proportion of domestic workers, most of them girls from poor family backgrounds. Child domestic workers in Nairobi face many workplace social hazards that include injury, verbal harassment and sexual abuse. Based on these findings, the study makes appropriate policy recommendations. Eastern African Social Sciences Review Vol. 23 (1) 2007: pp. 37-6

E-Business Adoption Framework in the Hospitality Industry: The Case of Kenyan Coast

While the hospitality industry in the Kenyan Coast has adopted Information and Communication Technology (ICT), application of the same is limited to internal operations and control. The industry’s e-business adoption lags behind similar industries such as tours and travel. Earlier research in e-business adoption does not suggest intervention for improvement of Small and Medium Enterprises’ (SMEs) status and lacks focus on any specific industries. The aim of this chapter is to address this gap by analyzing the Kenya Association of Hotelkeepers & Caterers’ (KAHC) e-business readiness using a three-interrelated-level framework; namely, firm level, market and industry, and institutional and regulatory levels. This chapter presents results of an ongoing project that we are currently working on, related to one of the authors’ graduate degree research program that began in 2008. In this research, we adopt a survey approach that is supplemented by case studies of other countries’ implementations from literature. Findings show that the hospitality industry at the Kenyan coast is not ready for e-business adoption and we develop a framework to help facilitate readiness. The findings imply that as a competitive strategy, establishments which have been competitors need to become collaborators; and KAHC and its membership need to adopt e-business to not only remain competitive, but also to survive. The findings are beneficial to KAHC and the Kenyan government in evaluating the status of e-business readiness as well as adoption in similar industries. Other developing countries can also adopt the framework

A Framework for E-Learning Implementation in Developing Countries: A Students' Perspective

Institutions of higher learning in developing countries have lagged behind those in the developed world in e-learning (eL) adoption, mainly due to cost and poor Internet infrastructure. Introduction of eL in such institutions is often complex involving introduction of new technology, resistance by users and alignment issues. Most eL research in developed countries is on continuity, which is not the case in developing countries. The aim of this chapter is to address this gap by investigating whether Mombasa Polytechnic University College (MPUC) students, who had never had any eL experience, would accept it. The model used in this case is a Modified Unified Theory of Acceptance and Use of Technology (UTAUT). In this chapter, we adopt a survey approach supplemented by case studies. The findings are that majority of the students believe that their results will improve with eL and that a blended learning system or 'Click-nMortar institution with many courses online' is the best model for MPUC and similar institutions. The research proposes a framework for eL implementation. The findings are beneficial to institutions of higher learning in developing countries

Tackling Data Related Challenges in Healthcare Process Mining using Visual Analytics

Data-science approaches such as Visual analytics tend to be process blind whereas process-science approaches such as process mining tend to be model-driven without considering the "evidence" hidden in the data. Use of either approach separately faces limitations in analysis of healthcare data. Visual analytics allows humans to exploit their perceptual and cognitive capabilities in processing data, while process mining represents the data in terms of activities and resources thereby giving a complete process picture. We use a literature survey on both Visual analytics and process mining in the healthcare environments, to discover strengths that can help solve open problems in healthcare data when using process mining. We present a visual analytics approach in solving data challenges in healthcare process mining. Historical data (event logs) obtained from organizational archives are used to generate accurate and evidence based activity sequences that are manipulated and analyzed to answer questions that could not be tackled by process mining. The approach can help hospital management and clinicians among others, audit their business processes in addition to providing important operational information. Other beneficiaries include those organizations interested in forensic information regarding individuals and groups of patients

A SITUATIONAL METHOD FOR HEALTHCARE BUSINESS PROCESS IMPROVEMENT

Healthcare business processes are complex due to the many decisions and procedures captured, are highly dynamic, increasingly multidisciplinary and ad hoc which makes it difficult to achieve any meaningful improvement through control flow improvement. This study aims at developing and validating a method for healthcare business process improvement with extensions of process mining and visual analytics. Situational method engineering is used to develop a method for healthcare business process improvement and validated through simulations using synthetic event-logs. The results show that the throughput for all resource combinations gravitates to 1 hour after a simulation period of two hours in the original KPI. A new KPI with the lower upper bounds at 0.091 hours and medium upper bound 0.132 hours posts an average throughput of 0.94387hours (56.63 minutes) compared to the original 1.11hours (66.6 minutes) when two testers and one Solver (Complex) are added. This demonstrates the effectiveness of the method. It is also proven that deployment of resources on the most common trace has the highest impact on throughput reduction. Further testing of the method using real life or field data is to be carried out in future

PERFORMANCE EVALUATION OF AN EVAPORATIVE CHARCOAL COOLER UTILIZING THIN-FILM PHOTOVOLTAIC SYSTEM FOR PRESERVATION OF AVOCADO

Fruits are high moisture agricultural produce rendering them highly perishable hence the danger of postharvest losses is also lurking when there are inadequate storage facilities. The losses result from physical, chemical, and physiological changes that are triggered by the loss in moisture content. Preservation of fruits using available and affordable technologies (such as charcoal coolers) can benefit small-scale farmers in minimizing postharvest losses. An evaporative charcoal cooler 4 m long, 4 m wide, and 2.5 m high providing a 40 m3 storage capacity was utilized in the study. The cooler with a 150 mm wide cavity filled with charcoal had a perforated pipe connected to a 1000-litrecistern raised at 2.5 m above the ground and connected to a water pump (Pedrollo PKm 60, Italy) that kept the charcoal wet by a drip system. The pump and the three axial fans (REC-21725 A2 W, USA) rated 180 cubic feet per minute (CFM) and 2600 revolutions per minute (RPM) were powered by fast fold thin-film PV (FFMAT-10, Renovagen, UK) system connected to a 10-kWh rated energy hub (FFENERGYHUB-10, Renovagen, UK). Temperature, relative humidity and product quality parameters (weight loss, total soluble solids, vitamin C content and firmness were evaluated).The evaporative cooler temperatures reduced significantly (P<0.05) with an average 25.0±0.37 oC and 32.1±0.99 ºC outdoors temperatures. The cooler relative humidity increased significantly (P˂0.05) averaging 76.8±1.6% and 43±2.8% for ambient conditions. The average cooling efficiency in the charcoal cooler was 83.0%.The percentage weight loss of the avocado was 3.9% and 7.5% for the cooler and outdoors respectively. The percentage vitamin C loss was 39.0% for the cooler and 49.6% for those kept outside. The total soluble solids in the cooler rose from 0.5 to 1.6 oBrix and 0.5 to 2.6 oBrix in ambient conditions. Firmness decreased from an average 65.0 N to 10.7 N and 65.0 N to 8.0 N after 12 days for samples in the cooler and ambient conditions, respectively. In conclusion, the evaporative charcoal cooler incorporated with thin-film PV system preserved the postharvest quality and extended the shelf life of hass avocado