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Search Results: 1 - 10 of 112605 matches for " Jared O. Odhiambo "
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Spatial-Temporal Characterization of Atmospheric Aerosols via Airborne Spectral Imaging and Growing Hierarchical Self-Organizing Maps  [PDF]
John W. Makokha, Jared O. Odhiambo
Journal of Geoscience and Environment Protection (GEP) , 2018, DOI: 10.4236/gep.2018.66008
Abstract: Neural network analysis based on Growing Hierarchical Self-Organizing Map (GHSOM) is used to examine Spatial-Temporal characteristics in Aerosol Optical Depth (AOD), Ångström Exponent (ÅE) and Precipitation Rate (PR) over selected East African sites from 2000 to 2014. The selected sites of study are Nairobi (1°S, 36°E), Mbita (0°S, 34°E), Mau Forest (0.0° - 0.6°S; 35.1°E - 35.7°E), Malindi (2°S, 40°E), Mount Kilimanjaro (3°S, 37°E) and Kampala (0°N, 32.1°E). GHSOM analysis reveals a marked spatial variability in AOD and ÅE that is associated to changing PR, urban heat islands, diffusion, direct emission, hygroscopic growth and their scavenging from the atmosphere specific to each site. Furthermore, spatial variability in AOD, ÅE and PR is distinct since each variable corresponds to a unique level of classification. On the other hand, GHSOM algorithm efficiently discriminated by means of clustering between AOD, ÅE and PR during Long and Short rain spells and dry spell over each variable emphasizing their temporal evolution. The utilization of GHSOM therefore confirms the fact that regional aerosol characteristics are highly variable be it spatially or temporally and as well modulated by PR received over each variable.
Trend Analysis of Aerosol Optical Depth and Ångström Exponent Anomaly over East Africa  [PDF]
John W. Makokha, Jared O. Odhiambo, Juma S. Godfrey
Atmospheric and Climate Sciences (ACS) , 2017, DOI: 10.4236/acs.2017.74043
Abstract: Trend analysis of atmospheric aerosols enhances confidence in the evaluation of both direct and indirect effects of aerosols on regional climate change. To comprehensively achieve this over East Africa, it’s important to understand aerosols temporal characteristics over well selected sites namely Nairobi (1°S, 36°E), Mbita (0°S, 34°E), Mau Forest (0.0°S - 0.6°S; 35.1°E - 35.7°E), Malindi (2°S, 40°E), Mount Kilimanjaro (3°S, 37°E) and Kampala (0°N, 32.1°E). In this context, trend analysis (annual (in Aerosol Optical Depth (AOD) at 550 nm and Ångström Exponent Anomaly (
Long Term Assessment of Aerosol Radiative Forcing over Selected Sites of East Africa  [PDF]
John W. Makokha, Jared O. Odhiambo, Juma Godfrey Shem
Journal of Geoscience and Environment Protection (GEP) , 2018, DOI: 10.4236/gep.2018.64002
Abstract: Atmospheric aerosols have contributed to radiative forcing through direct and indirect mechanisms. Aerosol effects are important in computing radiative forcing estimates for the past, current and future climate. In this study, a comprehensive assessment of regional aerosol radiative forcing, Optical Properties of Aerosol and Clouds (OPAC) model (wavelength range of 0.25 - 4.0 μm) over selected sites in East Africa was done. Aerosol optical properties constituted the inputs of a Radiative Transfer Model (RTM). Op-tical properties investigated included Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA) and Asymmetry Parameter (AP). Aerosol Radiative Forcing (ARF) during the study period at the surface (SFC), top of the atmosphere (TOA) and the atmosphere (ATM) was estimated to be -18.4 ± 1.4 W·m-2, +1.1 ± 0.3 W·m-2 and +19.5 ± 2.5 W·m-2, respectively. This corresponds to an increment in net atmospheric forcing at a heating rate of about 0.55 ± 0.05 K/day (0.41 ± 0.03 to 0.78 ± 0.03 K/day) in the lower troposphere. The study points out the significant role played by atmospheric aerosols in climate modification over the area of study. It is recommended that a further assessment be done in view of uncertainties that may impact on the findings and which were not within the scope of this research.
Optical Characterization of Atmospheric Aerosols via Airborne Spectral Imaging and Self-Organizing Map for Climate Change Diagnostics  [PDF]
John W. Makokha, Jared O. Odhiambo
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104698
Abstract:
Self-Organizing Map (SOM) analysis is used to perform optical characteri- zation of both Aerosol Optical Depth (AOD) and Angstrom Exponent (AE) retrieved from Moderate-resolution Imaging Spectroradiometer (MODIS) in relation to Precipitation Rate (PR) from Tropical Rainfall Measurement Mission (TRMM) over selected East African sites from 2000 to 2014 and further diagnose climate change over the region if any. SOM reveals a marked spatial variability in AOD and AE that is associated to changing aerosol transport, urban heat islands, diffusion, direct emission, hygroscopic growth and their scavenging from the atmosphere specific to each site. Temporally, all sites except Mbita and Kampala indicate two clusters in AOD that are associated to prevailing dry and wet seasons over East Africa. Moreover, all sites except Mbita and Mount Kilimanjaro show two clusters in AE that are related to aerosol mode of generation and composition over the region. The single cluster in AOD and ?E over Mbita indicate that aerosol characteristics over the site are influenced by biomass burning and local air circulation rather than the monsoon precipitation throughout the study period.
Seasonal Variability in Aerosol Microphysical Properties over Selected Rural, Urban and Maritime Sites in Kenya  [PDF]
Geoffrey W. Khamala, Jared O. Odhiambo, John W. Makokha
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104821
Abstract:
Atmospheric aerosols are posing a great threat to the already stressed climate with the effects being felt more on African continent. Their presence and interaction with the clouds contribute to the strongest uncertainty in aerosol characteristics and Earth’s energy budget hence; calling for a long term assessment to be done. The present study analyses long term spatiotemporal microphysical aerosol characteristics (namely: effective radius and surface-area concentration), using AErosolROboticNETwork (AERONET) framework over Kenyan urban atmosphere (Nairobi-1°S, 36°E), rural atmosphere (ICIPE-Mbita-0°S, 34°E) and maritime atmosphere (CRPSM-Malindi-2°S, 40°E). AERONET framework was used due to its availability over the selected sites; it is also located in sites that provided contrasting aerosols type, source and characteristics and due to its syner-gism with other frameworks. The findings indicated a spatial and temporal variability in microphysical properties over CRPSM-Malindi, Nairobi and ICIPE-Mbita. CRPSM-Malindi is dominated with coarse aerosols in all sea-sons while Nairobi with coarse mode in the DJF and MAM seasons. ICIPE-Mbita is on the other hand dominated with fine aerosols in all season. In terms of size distribution, the three AERONET sites displayed a bimodal distribution inflecting at 0.44 μm and fine mode radius of 0.15 μm while CRPSM-Malindi recorded a coarse mode of 3.86 μm and Nairobi and ICIPE-Mbita with 5.06 μm. The coarse aerosols have a higher concentration than the fine aerosols in all AERONET sites because of aerosol coagulation and dominance of certain type of aerosols that are coarse in nature.
The Impact of Integration of Rapid Syphilis Testing during Routine Antenatal Services in Rural Kenya
Eleanor Fleming,Jared Oremo,Katherine O'Connor,Aloyce Odhiambo,Tun Ye,Simon Oswago,Clement Zeh,Robert Quick,Mary L. Kamb
Journal of Sexually Transmitted Diseases , 2013, DOI: 10.1155/2013/674584
Abstract: We evaluated the integration of rapid syphilis tests (RSTs) and penicillin treatment kits into routine antenatal clinic (ANC) services in two rural districts in Nyanza Province, Kenya. In February 2011, nurses from 25 clinics were trained in using RSTs and documenting test results and treatment. During March 2011–February 2012, free RSTs and treatment kits were provided to clinics for use during ANC visits. We analyzed ANC registry data from eight clinics during the 12-month periods before and during RST program implementation and compared syphilis testing, diagnosis, and treatment during the two periods. Syphilis testing at first ANC visit increased from 18% (279 of 1,586 attendees) before the intervention to 70% (1,123 of 1,614 attendees) during the intervention ( ); 35 women (3%) tested positive during the intervention period compared with 1 (<1%) before ( ). Syphilis treatment was not recorded according to training recommendations; seven clinics identified 28 RST-positive women and recorded 34 treatment kits as used. Individual-level data from three high-volume clinics supported that the intervention did not negatively affect HIV test uptake. Integrating RSTs into rural ANC services increased syphilis testing and detection. Record keeping on treatment of syphilis in RST-positive women remains challenging. 1. Introduction The World Health Organization (WHO) estimated that globally in 2008 1.4 million women had syphilis in pregnancy, causing approximately 520,000 adverse pregnancy outcomes including 305,000 perinatal deaths [1]. Untreated maternal syphilis currently equals or exceeds HIV, neonatal tetanus, or malaria as a cause of perinatal mortality [2]. Caused by the bacterium Treponema pallidum, syphilis is efficiently transmitted in utero to the fetus [3, 4]. When left untreated, adverse pregnancy outcomes can occur in up to 80% of affected pregnancies [4], with the most severe outcomes occurring in women with early (i.e., primary, secondary, or early latent) infections [3]. A recent meta-analysis adjusting for other causes of mortality estimated that, among asymptomatic women, untreated maternal syphilis caused stillbirth in 21% and neonatal death in 9% of affected pregnancies and led to low birth weight in 6% and congenital infection in 15% of surviving infants [5]. Infants born with syphilis may suffer disfigurement, delayed development, or other complications [3]. Early detection and adequate treatment (i.e., long-acting intramuscular penicillin) prevent poor outcomes due to mother-to-child transmission (MTCT) of syphilis [3, 4]. Nyanza
Thermodynamic Properties of Yttrium Based Cuprate Due to Electron-Cooper Pair Interaction Using BVT  [PDF]
Abel Wamalwa Mukubwa, Jared Oloo Odhiambo, John Wanjala Makokha
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104880
Abstract:
Since the discovery of high temperature superconductivity (HTSC), there have been varied results concerning the high pairing energy in the unconventional superconductivity. In an attempt to unearth the mechanism behind the high pairing energy, we study a model in which an excited electron interacts with a Cooper pair. The interaction was studied earlier on using second quantization which depended on a wave function. We now use Bogoliubov-Valatini trans-formation (BVT) that is independent of the wave function to study the thermodynamic properties due to the interaction between an electron and a Cooper pair in a Yttrium based cuprate. The interaction energy increases with temperature and at ; we record the interaction energy of 2.173 meV and the specific heat of 4.669 J·mol·1·K·1. The entropy of this system is found to be 5.11 mJ·g·1·K·1. The Sommerfeld’s coefficient is maximum at where . It has also been observed, for the first time, that the thermodynamic quantities of YBCO123 are constant when temperature varies between 0 K and 18 K. Above 18 K, the thermodynamic quantities rise sharply. This observation has been attributed to the pairing of electrons in the singlet-s and singlet-p states.
EDXRF Spectroscopic Elemental Analysis for Efficacy of Kibabii University Sewage Treatment System  [PDF]
Yonah Situma, Jared Oloo Odhiambo, John Wanjala Makokha
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104992
Abstract:
Elemental analysis of sewage effluents in Kibabii sewage treatment system was achieved via Energy-Dispersive X-Ray Fluorescence (EDXRF) spectroscopy with the aim of assessing the efficacy of the treatment system. Concentrations of lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As) were measured based on clay soil “standards” in concentration range for Pb, Hg and As as 12.7 ppm, 14.3 ppm and 8.83 ppm respectively for certification. Among other probable reference materials, clay soil “standards” were used for certification in this work because of similarity in matrix composition with the sediments. The concentration for Hg, Pb, and As in the sewage sediments were 10.65 ± 2.28 ppm, 8.86 ± 2.92 ppm and 3.41 ± 2.18 ppm respectively in lagoon A. In lagoon B the levels were 3.82 ± 0.56 ppm, 6.35 ± 1.50 ppm and 1.67 ± 0.53 ppm respectively. Lagoon C showed a reduction in the levels with 3.74 ± 1.39 ppm for Hg and 2.30 ± 0.27 ppm for Pb. As was not detected in lagoon C, on the other hand, Cd was not detected in all the lagoons. The efficacies in the treatment varied from 30.34% - 51.78%, 37.63% - 65.41% and 76.63% - 84.81% for lagoon A, B and C respectively. The study was successful in quantifying the heavy elements in the lagoons from which the efficacy in the treatment process was determined. The study provided awareness on the elemental concentration levels in the Kibabii University sewage treatment system, hence creating awareness on what is released into River Kibabii. With this information, the surrounding community and the University can partner in order to mitigate the effects of heavy metals in the effluents in future due to the growth of the University day by day.
NET-COMPUTER: Internet Computer Architecture and its Application in E-Commerce
M. O. Odhiambo,P. O. Umenne
Engineering, Technology & Applied Science Research , 2012,
Abstract: Research in Intelligent Agents has yielded interesting results, some of which have been translated into commer-cial ventures. Intelligent Agents are executable software components that represent the user, perform tasks on behalf of the user and when the task terminates, the Agents send the result to the user. Intelligent Agents are best suited for the Internet: a collection of computers connected together in a world-wide computer network. Swarm and HYDRA computer architectures for Agents’ execution were developed at the University of Surrey, UK in the 90s. The objective of the research was to develop a software-based computer architecture on which Agents execution could be explored. The combination of Intelligent Agents and HYDRA computer architecture gave rise to a new computer concept: the NET-Computer in which the comput-ing resources reside on the Internet. The Internet computers form the hardware and software resources, and the user is provided with a simple interface to access the Internet and run user tasks. The Agents autonomously roam the Internet (NET-Computer) executing the tasks. A growing segment of the Internet is E-Commerce for online shopping for products and services. The Internet computing resources provide a marketplace for product suppliers and consumers alike. Consumers are looking for suppliers selling products and services, while suppliers are looking for buyers. Searching the vast amount of information available on the Internet causes a great deal of problems for both consumers and suppliers. Intelligent Agents executing on the NET-Computer can surf through the Internet and select specific information of interest to the user. The simulation results show that Intelligent Agents executing HYDRA computer architecture could be applied in E-Commerce.
Local Polynomial Regression Estimator of the Finite Population Total under Stratified Random Sampling: A Model-Based Approach  [PDF]
Charles K. Syengo, Sarah Pyeye, George O. Orwa, Romanus O. Odhiambo
Open Journal of Statistics (OJS) , 2016, DOI: 10.4236/ojs.2016.66088
Abstract: In this paper, auxiliary information is used to determine an estimator of finite population total using nonparametric regression under stratified random sampling. To achieve this, a model-based approach is adopted by making use of the local polynomial regression estimation to predict the nonsampled values of the survey variable y. The performance of the proposed estimator is investigated against some design-based and model-based regression estimators. The simulation experiments show that the resulting estimator exhibits good properties. Generally, good confidence intervals are seen for the nonparametric regression estimators, and use of the proposed estimator leads to relatively smaller values of RE compared to other estimators.
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