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Benchmarking the Robustness of Cellular Up-Links in Automatic Weather Station Networks

Communications and Network 2018年第3期10卷 78-92页

作者： Emmanuel A. Kondela Amos Nungu Joseph W. Matiko Julianne S. Otim Bjorn Pehrson School of Computing and Information technology Makerere University Kampala Uganda Department of Computer Studies Dar es Salaam Institute of Technology Dar es Salaam Tanzania Telecommunication Systems Lab Royal Institute of Technology Kampala Sweden

We present a problem for benchmarking the robustness of cellular up-links, in an automatic weather station (AWS) testbed. Based on the problem, we conduct a small-scale measurement study of robustness, where the AWS is equipped with four (4) cellular modems for weather data delivery. The effectiveness of up-links is challenging because of overlapping spatial-temporal factors such as the presence of good reflectors that lead to multi-path effects, interference, network load or other reasons. We argue that, there is a strong need for independent assessments of their robustness, to perform end-to-end network measurement. However, it is yet difficult to go from a particular measurement to an assessment of the entire network. We extensively measure the variability of Radio Signal Strength (RSSI) as link metric on the cellular modems. The RSSI is one of the important link metrics that can determine the robustness of received RF signals, and explore how they differed from one another at a particular location and instant time. We also apply the statistical analysis that quantifies the level of stability by considering the robustness, referring short-term variation, and determines good up-link in comparison to weak one. The results show that the robustness of cellular up-links exists for an unpredictable period of time and lower than one could hope. More than 50% of up-links are intermittent. Therefore, we plan to extend our work by exploring RSSI thresholds, to develop a classification scheme supporting a decision whether a link is either intermittent or not. This will help in normalizing the level of stability, to design the RSSI estimation metric for the robust routing protocol in weather data networks.

关键词： Cellular Links Robustness Automatic Weather Station Terrestrial Wireless Links Intermittent Links

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Changing Trends of Natural Resources Degradation in Kagera Basin: Case Study of Kagera Sub-Basin, Uganda

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Natural Resources 2012年第3期3卷 95-106页

作者： Casim Umba Tolo Enock Amos Majule Joseph Perfect Department of Biology Mbarara University Mbarara Uganda institute of Resource Assessment (IRA) University of Dar Es Salaam Dar es Salaam Tanzania

In many respects, river basins are extremely convenient natural resources management units and hence calls for an integrated approach in case of transboundary nature. Environmental resources in Kagera basin are under great threat due to demographic factors leading to wide spread environmental degradation. Land degradation and biodiversity loss are central issues in the basin, but the extent and severity of the degradation pressures are not yet clearly illustrated and their implications largely unknown. To date, natural resource mapping in Kagera basin has been based on isolated case studies for specific purposes and not much has been done in mapping resources and classification of resources degradation by remote sensing applications considering the whole basin. In this study, basin-wide mapping approach was adopted and hot spot areas associated with natural resources use in the basin identified and trends over time established. However, this paper presents results from Kagera River sub-basin, Uganda. Mapping exercise was done by using landsat images and aerial photos of Kagera basin covering the years 1984-2002. Overall, bushland in Kagera sub-basin, Uganda increased by 78% and woodland cover showed mere 6% gain;but a 53% decrease in open woodland sub-type and 29% decrease in closed woodland. Significant shift occurred in cultivation with herbaceous crops (mainly banana) from year 1984-2002 moving from east to west of Kagera sub-basin, Uganda representing 167% increase. Area occupied by permanent swamp decreased 31%. Over the same period, land cover change detection matrix indicates main land cover changes include conversion to bushland (59.34%) followed by conversion to grassland (7.29%) and cultivated land (7.16%), with only 24.19% of the land cover remaining unchanged. It is concluded that the observed changes are, a result of human-induced factors and show unsustainable utilization of natural resources as most of the changes make the land susceptible to degradat

关键词： Natural Resources Degradation Mapping Kagera Basin Uganda

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Preliminary Report on Early Settlements and Archaeological Materials from Lindi Rural District, Lindi Region, Southeastern Tanzania

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International Journal of Geosciences 2016年第5期7卷 655-668页

作者： Charles Bernard Saanane Department of Archaeology and Heritage College of Humanities University of Dar Es Salaam Dar Es salaam Tanzania

This paper presents a preliminary report based on a reconnaissance survey so as to create the basis for further archaeological research works. The reconnaissance was conducted along areas in Mipingo ward north of Lindi town in Lindi Rural district, Lindi Region, Southeastern Tanzania. The reconnaissance work’s main objective was to pinpoint Iron Working, Neolithic and stone industrial techno-complexes (for example, Later Stone Age, Middle Stone Age and Sangoan-like traditions). Specifically, the reconnaissance works sought to identify cultural traditions such as Iron Working, Neolithic as well as Stone Age sequences/facies;to document other cultural heritage resources (movable and immovable, fauna or flora) in the areas;and later on, as a long-term goal after a fully-fledged research is done (after several years of works), to undertake community involvement for conservation as well as carry out presentation of the cultural heritage assets in form of a satellite museum/museums to be linked with the University of dares salaam Museum under the Department of Archaeology and Heritage. Normal archaeological survey strategies were employed in the area. The spotted materials were collected and GPS locations were noted. The area showed some potential archaeological remains that merit intensive archaeological research works. Such archaeological materials include ruins, tombs, stone tools and two pieces of pottery. In terms of cultural traditions, there is evidence pointing to Stone Age people from early Stone Age represented by Acheulian Industrial techno-complex followed by Middle Stone Age and Later Stone Age people. Furthermore, though two pieces of pottery were recovered, further intensive works may help to justify Iron Working people lived there. Moreover, remains of a house foundation reported to have been a store of slaves implying to the fact that slavery was not only practiced in Bagamoyo, Zanzibar and other places already reported in Tanzania, but also as far as Sou

关键词： Dinosaur Acheulian Industrial Techno-Complex Middle Stone Age Later Stone Age Sangoan Like Traditions Ruins Tombs Fauna and Flora

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Genetic Diversity and Structure of East African Tall Coconuts in Tanzania Using RAPD Markers

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Open Journal of Genetics 2014年第2期4卷 175-181页

作者： Linus I. Masumbuko Salama Sinje Alois Kullaya Mikocheni Agricultural Research institute Dar es Salaam Tanzania

RAPD markers were used to estimate levels of genetic diversity and structure among twelve East African Tall (EAT) coconut (Cocos nucifera L.) accessions that are maintained at Chambezi station. Ten primers were used in the analysis of 120 accessions. Cluster analysis was performed based on Jaccard’s coefficient and Nei genetic distances. Further analyses included principal coordinate analysis (PCA) and finally bootstrap analysis. The cluster analysis revealed two main clusters. One cluster contained provenances from Lindi and Mtwara regions (south) and those from Coast and dar es salaam regions (central);the second had provenances from Tanga region, which is the northern part of the coastal belt. A similar distribution of provenances was shown by the results of the principal coordinate analysis, whose first three coordinates explained 56% of the total variation. The results were able to discriminate between the different provenances and provide evidence of the different origins for the coconut palms in the northern and southern parts of coastal coconut-growing belt. The two major clusters concur well with the history and distribution of coconuts in the coastal belt of Tanzania.

关键词： Cocos nucifera L. RAPD Genetic Diversity Nei Genetic Distance

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Analysis of Climate Variability, Perceptions and Coping Strategies of Tanzanian Coastal Forest Dependent Communities

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American Journal of Climate Change 2014年第2期3卷 212-222页

作者： J. J. Kashaigili P. Levira E. Liwenga M. V. Mdemu Faculty of Forestry and Nature Conservation Sokoine University of Agriculture Morogoro Tanzania institute of Resource Assessment (IRA) University of Dar es Salaam Dar es Salaam Tanzania School of Urban and Regional Planning Ardhi University Dar es Salaam Tanzania Tanzania Meteorological Agency Dar es Salaam Tanzania

Climate variability and change are among the biggest challenges of the 21st century. Like in many other areas globally, the coastal communities of Tanzania have always been facing climatic variability at various time scales. Using focus group discussion and a household survey, this study analyzes the perceptions of climate variability and change and the strategies for coping and adaptation by the selected coastal rural and peri-urban communities in Tanzania. The perception of climate variability and change is complemented with the time-series analysis of rainfall and temperature data from Julius Nyerere International Airport Met. station and Kisarawe using Instant Statistical Software. Results indicate that households are aware of climate variability and identify indicators of climate change and variability as being decreasing rainfall trends, increasing incidences of droughts, unpredictable rainfall patterns, disappearance of wetlands and failure to predict on-set of rainy season using traditional knowledge. Households primarily attribute reduced crop yields to changes in rainfall pattern and increasing incidences of drought leading to soil moisture stress. The implications are that the agriculture dependent households are now food insecure. As a way of coping to the observed changes, the coastal communities among others have shifted to production of high value horticultural crops and use of forest resources. Nevertheless, the increased use of forest resources is threatening the existence of coastal forests and contributes to the decline of forest resources and disappearance of wildlife in the forest reserves. It is concluded that the communities studied are aware of climate issues as revealed from perceived indicators of climate variability and changes. The results from statistical analysis of 30 years climatic data are consistent with community’s perception of climate variability and change. The study recommends examining the present coping strategies for the sus

关键词： Adaptation Climate Variability and Change Coping Strategies Coastal Communities Perception Tanzania

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A Comparative Study of Antioxidant Activities between Fresh and Dry Mushrooms in the Genera <i>Cantharellus</i>and <i>Afrocantharellus</i>from Tanzania

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Food and Nutrition Sciences 2014年第2期5卷 212-221页

作者： Donatha Damian Tibuhwa Department of Molecular Biology and Biotechnology (MBB) University of Dar es Salaam Dar es Salaam Tanzania.

Cantharellus and Afrocantharellus mushrooms are widely consumed in both fresh and dry forms. However, their antioxidant and whether their values changing with drying processes are not known. This study establishes their values and the effect of sun drying on their quality and quantity. Methanolic extracts of five Cantharellus and two Afrocantharellus species were investigated. The investigation used (1,1-diphenyl-2-picrylhydrazyl radical) DPPH as a substrate to determine radical scavenging abilities. Further quantitative analyses for carotenoids, flavonoid, total phenolic compounds and vitamin C content were done using spectrophotometric assay at 515 nm. Comparatively, fresh mushroom had higher vitamin C and Lycopene contents than their dry counterparts with β-carotene. Flavonoid and phenolic compounds were higher in dry forms than those in their fresh counterparts. Radical scavenging ability also varied with fresh forms depicting higher activity compared to dry forms. The variation was low in Afrocantharellus species (0.8% and 0.99%) while it was higher in Cantharellus species (24.12% and 7.52%). The highest ability was observed in fresh forms of Cantharellus pseudocibarius (EC50 50 = 0.4 mg/ml) was from dry form of Cantharellus rufopunctatus. This shows that studied mushrooms are rich in antioxidants and their quality and quantities are affected differently in both forms. Both dry and fresh mushrooms are potential sources of natural antioxidants. The portrayed high scavenging ability by these mushrooms envisages promoting them into potential nutraceutics.

关键词： Antioxidant Activity Fresh Mushrooms Sun-Dried Mushrooms Afrocantharellus Cantharellus 1 1-Diphenyl-2-picrylhydrazyl

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Diagnostic Analysis of Mechanical Conditions of Small-Scale Incinerators in the Healthcare Facilities in Tanzania

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Journal of Environmental Protection 2022年第11期13卷 895-912页

作者： Samwel Manyele Mahir Said Honest Anicetus Adolf Kiyunge Josephat Saria Michael Habtu Grace Saguti Department of Chemical and Mining Engineering University of Dar es Salaam Dar es Salaam Tanzania Ministry of Health Community Development Gender Elderly and Children Dodoma Tanzania Department of Environmental Studies The Open University of Tanzania Dar es Salaam Tanzania World Health Organization Dar es Salaam Country Office Dar es salaam Tanzania

This paper provides analytical diagnosis of mechanical conditions of medical waste incinerators used for healthcare waste (HCW) treatment in Tanzania. The main features assessed were types of incinerators, features of incinerators and incinerator house. The assessment was conducted in three levels of health care facilities (HCFs), that is, Regional, district hospitals and health centers, existed in 26 regions of Tanzania. Questionnaires, interview and checklists were used as tools for data collection. It was observed that High-Tech incinerators are mainly used in regional hospitals, while district hospital and health center use both High-Tech and De-Montfort incinerators. About 60% of the incinerators have defective doors. More than 55% of incinerators are corroded in regional and district hospitals. The chimney, top plates and grate which are good condition are 55.6% and 60% in regional hospitals and health centers, respectively. The situation is below 50% in district hospitals. The leakage of the roof and loose structures were observed in district hospitals and health center to be more than 50% of the incinerator houses. On other hand, the performance of burners and incinerator housing cleanliness are generally good. It was concluded that the incinerators in the HCFs are in bad conditions, necessitating maintenance.

关键词： Small-Scale Incinerators Healthcare Waste Mechanical Conditions Waste Generation Rate Operation and Maintenance Environmental Cleanliness

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Forecasts of cosmological constraints from HI intensity mapping with FAST,BINGO and SKA-I

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Research in Astronomy and Astrophysics 2019年第12期19卷 343-360页

作者： Elimboto Yohana Yi-Chao Li Yin-Zhe Ma Astrophysics and Cosmology Research Unit School of MathematicsStatistics&Computer ScienceUniversity of KwaZulu-NatalWestville CampusPrivate Bag X54001Durban4000South Africa dar es salaam University College of Education A Constituent College of the University of Dar Es SalaamP.O.Box 2329 Dar Es SalaamTanzania Astrophysics and Cosmology Research Unit School of Chemistry and PhysicsUniversity of KwaZulu-NatalWestville CampusPrivate Bag X54001Durban4000South Africa NAOC-UKZN Computational Astrophysics Centre(NUCAC) University of KwaZulu-NatalDurban4000South Africa

We forecast the cosmological constraints of the neutral hydrogen(HI) intensity mapping(IM)technique with radio telescopes by assuming 1-year of observational time. The current and future radio telescopes that we consider here are Five-hundred-meter Aperture Spherical radio Telescope(FAST), Baryon acoustic oscillations In Neutral Gas Observations(BINGO), and Square Kilometre Array phase Ⅰ(SKA-Ⅰ) single-dish experiments. We also forecast the combined constraints of the three radio telescopes with Planck. We find that the 1σ errors of(w0, wa) for BINGO, FAST and SKA-Ⅰ with respect to the fiducial values are respectively,(0.9293, 3.5792),(0.4083, 1.5878) and(0.3158, 0.4622). This is equivalent to(56.04%, 55.64%) and(66.02%, 87.09%) improvements in constraining(w0, wa) for FAST and SKA-Ⅰ respectively relative to BINGO. Simulations further show that SKA-Ⅰ will put more stringent constraints than both FAST and BINGO when each of the experiments is combined with Planck measurements. The 1σ errors for(w0, wa), BINGO + Planck, FAST + Planck and SKA-Ⅰ + Planck covariance matrices are respectively(0.0832, 0.3520),(0.0791, 0.3313) and(0.0678, 0.2679) implying there is an improvement in(w0, wa) constraints of(4.93%, 5.88%) for FAST + Planck relative to BINGO + Planck and an improvement of(18.51%, 23.89%) in constraining(w0, wa) for SKA-Ⅰ + Planck relative to BINGO + Planck. We also compared the performance of Planck data plus each single-dish experiment relative to Planck alone,and find that the reduction in(w0, wa) 1σ errors for each experiment plus Planck, respectively, imply the(w0, wa) constraints improvement of(22.96%, 8.45%),(26.76%, 13.84%) and(37.22%, 30.33%) for BINGO + Planck, FAST + Planck and SKA-Ⅰ + Planck relative to Planck alone. For the nine cosmological parameters in consideration, we find that there is a trade-off between SKA-Ⅰ and FAST in constraining cosmological parameters, with each experiment being more superior in constraining a particular set of parameter

关键词： surveys galaxies:statistics cosmology:observations large-scale structure of Universe galaxies:kinematics and dynamics

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Modeling Rift Valley Fever with Treatment and Trapping Control Strategies

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Applied Mathematics 2016年第6期7卷 556-568页

作者： Jonnes Lugoye Josephine Wairimu C. B. Alphonce Marilyn Ronoh Univeristy of dar es salaam Dar es Salaam Tanzania School of Mathematics University of Nairobi Nairobi Kenya

We consider a rift valley fever model with treatment in human and livestock populations and trapping in the vector (mosquito) population. The basic reproduction number R 0 is established and used to determine whether the disease dies out or is established in the three populations. When R 0 ≤ 1, the disease-free equilibrium is shown to be globally asymptotically stable and the disease does not spread and when R 0 > 1, a unique endemic equilibrium exists which is globally stable and the disease will spread. The mathematical model is analyzed analytically and numerically to obtain insight of the impact of intervention in reducing the burden of rift valley fever disease’s spread or epidemic and also to determine factors influencing the outcome of the epidemic. Sensitivity analysis for key parameters is also done.

关键词： Rift Valley Fever Mosquito Trapping Treatment Rift Valley Fever Control

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Assessment of Environmental Cleaning Practices and the Impacts on Infection Prevention and Control in Selected Hospitals in Tanzania

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Journal of Environmental Protection 2022年第10期13卷 698-715页

作者： Honest Anicetus Samwel Manyele Michael Habtu Adolf Kiyunge Josephat Saria Robert Njee Linda Thadei Khalid Massa Grace Elizabeth Saguti Zabulon Yoti Ministry of Health Community Development Gender Elderly and Children Dodoma Tanzania Department of Chemical and Mining Eng. University of Dar es Salaam Dar es Salaam Tanzania World Health Organization (WHO) Tanzania Dar es Salaam Tanzania Department of Environmental Studies The Open University of Tanzania Dar es Salaam Tanzani National institute of Medical Research Dar es Salaam Tanzania National Council for Technical Education Dar es Salaam Tanzania

To achieve Sustainable Development Goal (SDG) in healthcare facilities (HCFs,) the provision of water, sanitation, healthcare waste management, hand hygiene and environmental cleanliness services is crucial. Good WASH services in HCFs settings have the potential to reduce healthcare acquired infections (HAIs), increase trust and uptake of healthcare services, increase efficiency and improve staff morale. To address this, a National Assessment was carried out to ascertain environmental cleanliness condition of the healthcare facilities at all levels. The assessment of healthcare waste management in the facilities was conducted in all the 26 regions of Tanzania Mainland including districts and lower healthcare facilities. A standardized checklist and tools were used to assess and monitor various aspects related to healthcare waste management using open source software for data collection (ODK). Data were analyzed using SPSS computer software. It was observed that most of permanent staff (88%) in the Healthcare facilities had knowledge on hand hygiene, but the gap was observed to the waste handlers (12%) who were not equipped with the hand hygiene knowledge. About 89% of the hand washing stations were available at mortuary units, followed by 75% at main entrance and the lowest was 3% at waste zone areas of the healthcare facilities. Hand washing materials like soap were mainly found at theaters (64%) followed by mortuary (60%) and last at waste zones. The assessment concludes that handling of healthcare wastes is not practiced to the expectations, and there is a need to strengthen the situation. The findings provide evidence for those engaged in improving HCF conditions to develop evidence-based policies and efficient programs, enhance service delivery systems, and make better use of available resources.

关键词： Environmental Cleaning Infection Prevention Sanitation Hand Hygiene and Water Supplies

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