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Full-Text Articles in Risk Analysis

Noise Pollution In Maize Milling Smes, Erasto Elias Jun 2014

Noise Pollution In Maize Milling Smes, Erasto Elias

Tanzania Journal of Engineering and Technology (TJET)

Maize milling SMEs emit high levels of noise which can have adverse effects on human beings and therefore require controlling. This paper reports on a study that involved assessment and measurement of noise level in maize milling SMEs in DSM and Morogoro urban, gathering opinions of workers and the neighbouring population on noise problems, and suggesting solutions for noise control. Noise measurements in 41 SMEs were recorded from 89-103 dBA in DSM and 92-103 dBA in Morogoro near the milling machines. These values were higher than the safe level of 85 dBA for 8 hours working shift. Measurement also indicated …


Lemongrass And Cinnamon Essential Oils As Vitamin C Preservatives And Flavour Enhancers In Jam, Denice Byarushengo Jun 2014

Lemongrass And Cinnamon Essential Oils As Vitamin C Preservatives And Flavour Enhancers In Jam, Denice Byarushengo

Tanzania Journal of Engineering and Technology (TJET)

Lemongrass and cinnamon essential oils (LEO and CEO) are natural oils with high anti oxidation capacity, pleasant flavour, and various health benefits. Their ability to preserve vitamin C and flavour in jam have not been tested. In this study the performance of two essential oils (EOs) in preserving vitamin C and improving jam flavour were investigated. The EOs were produced by hydro-steam distillation of fresh lemongrasses and cinnamon leaves using a Clevenger apparatus. Jam samples were dosed with various concentrations of either single or mixed EOs and then stored at either room or refrigeration temperature. Samples were analysed for changes …


Accuracy Of Dem-Based Topographic Data In Flood Inundation Modelling: A Case Of Wami River, Tanzania, Preksedis Ndomba Jun 2014

Accuracy Of Dem-Based Topographic Data In Flood Inundation Modelling: A Case Of Wami River, Tanzania, Preksedis Ndomba

Tanzania Journal of Engineering and Technology (TJET)

Ihe objective of this Biper is to evaluate and further convnent on the accuracy of the DEW- based topographic data us input in flood mchdelling. Recent studies have indicated that hydraulic of the modified sections based on high resolution are geometrically and hydraulically similar to the measured ones, In the study hydraulic modelling intended to guide a developnent project whereby a protection embankment is contemplated. Therefore, accuracy in terns of positioning/alignment of natural features such as river banks and heights/elevarions was imperative m arrain. In order m achieve these, accuracy of various topographic data sources were qualitatively and/or quantitatively before …


Painted Rumble Stripes: Alternatives To Raised Pavement Markers (Rpms), Thomas M. Brennan Jr, Stuart R. Mikey, Darcy M. Bullock Jan 2014

Painted Rumble Stripes: Alternatives To Raised Pavement Markers (Rpms), Thomas M. Brennan Jr, Stuart R. Mikey, Darcy M. Bullock

JTRP Posters

This poster highlights research completed by the Joint Transportation Research Program (JTRP) led by Darcy Bullock, Lyles School of Civil Engineering, Purdue University, for JTRP Project SPR-3528, "Alternatives to Raised Pavement Markers (RPMs)." The poster includes photos taken at a construction site on State Road 25 located near Shadeland, Indiana. The top photo demonstrates how the center line corrected a driver when snow covered to avoid oncoming traffic. Photo was taken on US 231 near Country Road 800 in Tippecanoe County.


Optimising The Performance Of Roundabouts In Dar Es Salaam City, David Mfinanga Dec 2013

Optimising The Performance Of Roundabouts In Dar Es Salaam City, David Mfinanga

Tanzania Journal of Engineering and Technology (TJET)

Intersections are one of the major bottlenecks that aggravate congestion in road networks; effective control of which is an important strategy in improving traffic flow. While developing countries have found it hard to adopt sophisticated means of intersection control, they have also not optimised the performance of roundabouts. This paper reviews the performance of roundabouts, which have become increasingly popular in recent years, as simple and low cost forms of intersection control. The performance of three major roundabouts in Dar es Salaam has been analysed and results show that roundabouts can accommodate high traffic volumes without causing excessive delays. The …


Isolation And Characterisation Of Micro-Organisms With Industrial Importance From Sisal Bole Rots, Consolatha Mhaiki Jun 2013

Isolation And Characterisation Of Micro-Organisms With Industrial Importance From Sisal Bole Rots, Consolatha Mhaiki

Tanzania Journal of Engineering and Technology (TJET)

Investigation of microorganisms naturally acclimatized to Agave hybrid H 11648 (sisal bole rot) was conducted, with the aim of isolating and characterizing Aspergillus niger strains for industrial use. Microorganism were identified morphologically and then confirmation made by polymerase chain reaction (PCR). Results showed the existence of four major groups, listed in order of abundances as follows; Aspergilli (36.0±0.8) %, Penicillin (28.0±0.1) %, Yeast (15.0±1.6) %and Fusarium (10.0±0.12) %. The main groups of Aspergilli strains were A. nidulans, A. tamari and A. niger in ratios (3:2:2), respectively. Several endo-spore forming non-enteric gram (-) rods and coccid bacteria identified by API 20 …


Problems And Prospects Of Hydraulic Modelling For Environmental Flows Assessment Studies In East Africa, Preksedis Ndomba Jun 2013

Problems And Prospects Of Hydraulic Modelling For Environmental Flows Assessment Studies In East Africa, Preksedis Ndomba

Tanzania Journal of Engineering and Technology (TJET)

The objective of this paper is to document the problems and prospects of hydraulic modelling for Environmental Flows Assessment (EFA) studies based on selected case studies. Most of studies in East Africa use Holistic methodologies. An ideal data set for defining river hydraulics for most of these methods would be six data points of stage measurements over a good distribution of discharges, the stage of zero discharge and some flood-related data. Besides, in East African region EFA studies suffer from data scarcity (i.e., poorly gauged sites) and limited expertise and funding. The hydraulics studies conducted by the authors entailed desktop …


Experimental Comparison Study Of The Response Of Polycarbonate And Laminated Glass Blast Resistant Glazing Systems To Blast Loading, Joshua Calnan Jan 2013

Experimental Comparison Study Of The Response Of Polycarbonate And Laminated Glass Blast Resistant Glazing Systems To Blast Loading, Joshua Calnan

Theses and Dissertations--Mining Engineering

This thesis recounts the experimental study of the dynamic response of polycarbonate blast resistant glazing systems to explosive loading through the use of triaxial load cells, pressure sensors, and a laser displacement gauge. This instrumentation captured the response of the glazing systems to blast loading over three phases of testing. The first phase of testing characterizes the load distribution around the perimeter and the second phase examines the repeatability of the results. The final phase of testing pushes the samples to failure. The results are then compared to HazL, a commonly used blast resistant glazing system analysis software tool. The …


A Financial Impact Assessment Of Ld 1725: Stream Crossings Presentation, New England Environmental Finance Center Jan 2011

A Financial Impact Assessment Of Ld 1725: Stream Crossings Presentation, New England Environmental Finance Center

Economics and Finance

This report looks at the potential financial impact of LD 1725 on the estimated 30,000 stream crossings in the State of Maine that would be affected by the law. Our research for this report included the analysis of nearly 2000 stream crossings and the data collection necessary for the development of extensive stream crossing replacement cost models. We found that the 1.2 bankfull requirements in LD 1725 would result in a 75% ‐ 250% increase in structure widths for stream crossing projects across the state. An upsize of this magnitude would increase the cost of replacing stream crossings statewide by …


Construction Cost Models, Barry Dikeman Aug 2010

Construction Cost Models, Barry Dikeman

Economics and Finance

The following are a series of cost estimate models similar in format to a typical engineer’s estimate that were developed in support of our financial impact assessment report for LD 1725. The models us current material costs, labor costs, and equipment costs for the region to provide a comparative cost analysis of seven culvert replacement scenarios. The models provide information about what the cost impact of LD 1725 would be for typical culvert replacements in Maine. However, due to the inherent restrictions of the cost modeling framework we were not able to include the abundance of variables that would be …


Improving The Design Of Low Volume Sealed Roads In Tanzania, Mfinanga A Dec 2008

Improving The Design Of Low Volume Sealed Roads In Tanzania, Mfinanga A

Tanzania Journal of Engineering and Technology (TJET)

The main objective of the study was to identify appropriate road designs for Low Volume Sealed Roads (LVSRs) with the aim of improving the design of such roads in Tanzania. The study was conducted in Dar es Salaam and Morogoro regions in Tanzania where data for LVSRs were collected from primary and secondary sources in the two regions. The study found that by using an improved pavement design method specifically meant for LVSRs results in cost savings for LVSRs of up to 51% compared with the conventional method of pavement design in Tanzania. The study recommends that the pavement design …


Integrated Remote Sensing And Gis Techniques For Groundwater Exploration In Semi-Arid Region: A Case Of Karamoja Region – Uganda, Lubang Nobert Dec 2008

Integrated Remote Sensing And Gis Techniques For Groundwater Exploration In Semi-Arid Region: A Case Of Karamoja Region – Uganda, Lubang Nobert

Tanzania Journal of Engineering and Technology (TJET)

Groundwater is a precious resource that covers wide geographical extent. Proper evaluation is required in order to ensure prudent use of groundwater resources. The current groundwater assessment in Karamoja region, as in many parts of the world, uses Apparent Resistivity and Vertical Electrical Sounding, which has limited coverage to some localized usually predetermined areas. Comprehensive groundwater development program needs a wide area coverage and large volume of multidisciplinary data. In the present study, an integrated remote sensing and GIS based methodology is developed and tested for the evaluation of groundwater resources of Karamoja Sub Region, Northeastern Uganda. The components of …


Potential Use Of Waterguard As A Disinfectant For Domestic Water Use, Yohana L Dec 2008

Potential Use Of Waterguard As A Disinfectant For Domestic Water Use, Yohana L

Tanzania Journal of Engineering and Technology (TJET)

been identified as an alternative method for treatment of domestic drinking water. The aim of this study was to investigate the effectiveness of Water Guard in disinfecting drinking water from different sources drawn from Kinondoni district, Dar es Salaam as well as to establish appropriate dosage that can be used during the treatment. Results showed that, a dose of 4.0mL per 20 litrer of water guard is sufficient for disinfection of urban water sources. The above prescribed doses provide 100% disinfection efficiency with residue chlorine of less than 0.3mg/l. Water with turbidity values of 30-35 NTU, chlorine dosage of 8mL/20 …


An Equation For Estimating The (R) Usle Slope Steepness Factors, Mathew Mulemgera Dec 2008

An Equation For Estimating The (R) Usle Slope Steepness Factors, Mathew Mulemgera

Tanzania Journal of Engineering and Technology (TJET)

Abstract Currently three equations are used for calculating slope steepness factor for the Revised Universal Soil Loss Equation (RUSLE); one for slopes less than nine percent, the second for slopes equal or greater than nine percent, and the third equation that has been proposed for use in China for slopes equal or greater than 17 %. The three equations have linear relationships between slope steepness factor, S and the sine of the slope angle, θ. The three equations under predict the factor, S when used on slope steepness beyond the data sets used to develop them. In addressing this problem …


The Limnogeology Of The Lakes Sagara And Nyamagoma, Hudson Nkotagu Jun 2008

The Limnogeology Of The Lakes Sagara And Nyamagoma, Hudson Nkotagu

Tanzania Journal of Engineering and Technology (TJET)

The present study focuses on the limnogeological aspects of the lakes Sagara and Nyamagoma within the Malagarasi Wetland Ecosystem. Abiotic parameters from water and sediment samples were determined during the dry and wet seasons using appropriate gears and methods. The data show variation of the abiotic parameters in both lakes from the water surface to the bottom. Lake Nyamagoma is less turbid (0.7-24 NTU) than Lake Sagara (25 to 65 NTU). The water transparency was also high at Lake Nyamagoma (0.75-1.5 m) thus supporting the observed turbidity trend. The physical chemical changes may be attributed to processes such as cooling, …


Application Of Non-Destructive Testing In Evaluating Reinforced Concrete Structural Elements In Buildings, I Rubaratuka Jun 2008

Application Of Non-Destructive Testing In Evaluating Reinforced Concrete Structural Elements In Buildings, I Rubaratuka

Tanzania Journal of Engineering and Technology (TJET)

Of recent a large number of existing reinforced concrete buildings have required reconstruction, renovation and improvement. This tendency poses a number of problems that have to be solved, the main one being to determine the actual strength condition of the structural components/elements of the building. It includes determination of the quality of materials used, specification of the types and description of apparent faults and damages and extent of wear of the building. To undertake this evaluation, non – destructive testing methods are used. In this paper, applications of non – destructive testing methods to determine the strength state of reinforced …


Assessment Of Integrated Water Resources Management Practice In Yatta Canal, Machakos District, Kenya, Lawrence Simitu Jun 2008

Assessment Of Integrated Water Resources Management Practice In Yatta Canal, Machakos District, Kenya, Lawrence Simitu

Tanzania Journal of Engineering and Technology (TJET)

Yatta Canal is situated in Yatta division, Machakos district about 100 km from Nairobi along Thika- Garissa road. It is about 60 Km long and supplies water for domestic, livestock and irrigation use. Over the years, the water supply has been unreliable especially during dry season leading to conflicts between upstream and downstream consumers. Sometimes the Government has been forced to intervene to restore order. The study aimed at assessing the use of Yatta canal, based on the principles of Integrated Water Resources Management (IWRM) which stipulates efficient use of water and involvement of all stakeholders in decision making for …


Sediment Yield Prediction In Tanzania: Case Study Of Dodoma District Catchments, Mathew Mulemgera Jun 2008

Sediment Yield Prediction In Tanzania: Case Study Of Dodoma District Catchments, Mathew Mulemgera

Tanzania Journal of Engineering and Technology (TJET)

Soil erosion and sedimentation is serious and is resulting in rapid sedimentation of streams and reservoirs in Tanzania. This makes sediment yield modeling important before undertaking water resources development projects, although it has so far not been done in the country. At present sediment yield prediction can be done using physically based models, empirical soil erosion and sediment yield models, and sediment rating curves. The physically based models contain numerous parameters that are difficult to measure or estimate, making them inappropriate in developing countries like Tanzania. The rating curves give rough estimates while the empirical sediment yield models need runoff …


Quality Control In The Construction Of Reinforced Concrete Buildings In Dar Es Salaam, I Rubaratuka Jun 2008

Quality Control In The Construction Of Reinforced Concrete Buildings In Dar Es Salaam, I Rubaratuka

Tanzania Journal of Engineering and Technology (TJET)

Quality Control in the construction industry is very important to ensure that what is being done conforms to the applicable standards or good practice and the contract documents. In this article, results of investigations conducted at different construction sites for reinforced concrete buildings in Dar es Salaam to check if quality control measures are being implemented are discussed. It has been established that generally quality control is not properly carried out. Finally, measures to enhance quality control on sites are outlined.


Sedimentation Status Of Lake Victoria: Loading From River Mouth And In-Lake Sedimentation, F Mwanuzi1 Jun 2008

Sedimentation Status Of Lake Victoria: Loading From River Mouth And In-Lake Sedimentation, F Mwanuzi1

Tanzania Journal of Engineering and Technology (TJET)

Lake sediments consist of the input of suspended solids by river discharges, the autochthonous produced particulate matter in the water column and the settled material on the lake bottom. The loading, transport, formation and decay of the sediments entering the Lake Victoria from Tanzanian side was monitored for the period 2000 to 2005. The sedimentation study focused on; quantification of settling fluxes of particulate nutrients and organic carbon at the off shore(Pelagic) and near-shore(Littoral) monitoring stations. Monitored data on sedimentation rate and settling velocities has been sampled and analysed in the period November 2000 to March 2005. The mean sedimentation …


Strategies For Promoting The Use Of Concrete Pavements In Tanzania: Technical And Institutional Considerations, Mfinanga A Jun 2008

Strategies For Promoting The Use Of Concrete Pavements In Tanzania: Technical And Institutional Considerations, Mfinanga A

Tanzania Journal of Engineering and Technology (TJET)

High-type roads in Tanzania have been predominantly of asphaltic concrete construction. This ever enlarging and ageing asphaltic road network represents increasing resource requirements on the road agency in the form of maintenance. Limited resources coupled with the ever sky-rocketing costs of petroleum products and the competing demands of social economic developments, presupposes the need to look for alternative road construction technology that is more cost-effective and resource optimising. Experience gained from developed and some developing countries where concrete pavements have been widely used suggests the potential of this type of pavement in many developing countries. This paper discusses the technical …


Trends Of Rainfall And Maize Productivity In Malawi, T Kimaro Jun 2008

Trends Of Rainfall And Maize Productivity In Malawi, T Kimaro

Tanzania Journal of Engineering and Technology (TJET)

Daily rainfall data between 1966 and 2005 across all Agricultural Development Areas (ADDs) in Malawi was investigated to determine changes in selected rainfall characteristics and their impact on Maize productivity. Rainfall indices analyzed included rainfall amounts (annual and seasonal), onset, cessation, dry spells and length of rainy season. Man Kendal’s trend test was applied to the time series of these indices to detect any trends in the time series. Water Requirement Satisfaction Index (WRSI) for maize crop was used to study the spatial-temporal variation of maize productivity and thus its linkage to rainfall. Definition of onset and cessation adopted from …


Sustainable Portland: Implementation Series 1, New England Environmental Finance Center Apr 2008

Sustainable Portland: Implementation Series 1, New England Environmental Finance Center

Climate Change

When the Sustainable Portland Task Force Report was released in November 2007, under the leadership of Mayor Jim Cohen, Portland Councilor Kevin Donoghue had the idea that students at the Muskie School of Public Service might be able to help implement recommendations from the report. It may have helped that Kevin was himself a graduate of the Community Planning and Development Master’s program at the Muskie School, but it was a good idea nevertheless. He approached Professor Sam Merrill in the CPD program, who spoke with the new Mayor Ed Suslovic about a possible partnership between the City and the …


Characterization Of On-Road Petrol Vehicle Emissions Patterns In Dar Es Salaam City (Tanzania), Geoffrey John Dec 2006

Characterization Of On-Road Petrol Vehicle Emissions Patterns In Dar Es Salaam City (Tanzania), Geoffrey John

Tanzania Journal of Engineering and Technology (TJET)

Motor vehicle emissions have been identified to be the major source of air pollution in most urban cities. It has serious impact on urban air quality and public health. The Governments of many countries need to adopt stringent vehicle emissions regulations to protect the air quality, the undertaking of which can only be implemented once the problem at hand is known. In the present study, the characteristics of on road vehicle emissions from the selected local ar~as at the city of Dar es Salaam in a developing country for in-use petrol vehicles for urban driving conditions ranging from idling, lOkm/h …


Determination Of Wind Loads Causing Flutter Effects, Ladislaus Lwambuka Dec 2006

Determination Of Wind Loads Causing Flutter Effects, Ladislaus Lwambuka

Tanzania Journal of Engineering and Technology (TJET)

A new method on the determination Of wind forces by experimental means in a wind tunnel is discussed. The method reported herein is based on the identification methodology Of model parameters under time response (i.e. time domain identification). As a test model, a thin plate Of Cypress wood, elasticully suspended in three degrees Of freedom to represent the idealized form of a classical airfoil, for Which theoretical wind load parameters exist, has been employed. Wind load parameters, experimentally obtained on the test model under the new method, are compared With the theoretical values of classical airfoils. Advantages of the new …


Investigation On Distribution Of Cast Properties On Aluminum Plates Poured By Side Gating Technique, Joseph Runyoro Dec 2006

Investigation On Distribution Of Cast Properties On Aluminum Plates Poured By Side Gating Technique, Joseph Runyoro

Tanzania Journal of Engineering and Technology (TJET)

Casting technologies wllich improve casting yield and intenzal sOllndness of thin wall cast components are of particular interest to industry especially for critical applications. The main aim of fOll1ldries is to achieve castings free from defects at low cost. It hils been thought that pouring casting by side ingate technique improve directional solidification as the metal stays hot for long time in the feeder cum ingate. Experiments were carried alit IIsing a side gating technique to cast a number of 300 mm x 300 mm LMO and LM 25 plates in furall and pepset sand moulds. The thickness used was …


Geophysical Exploration For Groundwater Resources Potential Over Basement Formations At Kwandolwa And Mwisho Wa Shamba Villages, Korogwe District, Tanzania, Cuthbert Mhilu Dec 2006

Geophysical Exploration For Groundwater Resources Potential Over Basement Formations At Kwandolwa And Mwisho Wa Shamba Villages, Korogwe District, Tanzania, Cuthbert Mhilu

Tanzania Journal of Engineering and Technology (TJET)

In this paper results of geophysical exploration studies to identify potential areas with groundwater resources at Kwamndolwa and Mwisho wa Shamba Villages in Korogwe District have been presented. The resistivity curves of eight sites at the two study areas were obtained using field data measurements made based on the application of a vertical electrical sounding (VES) method. The resisivity values obtained for sites VES-K3 and VES-M2 were found to be 10.9 and 24.0 ohm-m respectively. The interpretation of the resisivity values made for the two sites gave also an indication of the presence of sedimentary rocks composed of sandstone materials …


Sampling Procedure For Pavement Condition Evaluation Of Local Collectors And Access Roads, David Mfinanga Dec 2006

Sampling Procedure For Pavement Condition Evaluation Of Local Collectors And Access Roads, David Mfinanga

Tanzania Journal of Engineering and Technology (TJET)

Road surface condition evaluation involves the collection Of a lof Of data on different types of distresses. •lie exercise consumes a lot Of resources if the whole road section length is sureeyed and may be prone to errors as a result Of surveyors' fatigue. It is therefore important Io develop n reprevntative sample to be used When road condition manually. This study aimed nt determining sample size for condition evaluation of local collector access roads in urban areas in Tanzania. Two such roads namely l.ufungira and Kilimahewn roads respectively were selected for the study. It is recommended that a section …


Suitability Of Crusher-Dust As Masonry Construction Material, John Makunza Jun 2006

Suitability Of Crusher-Dust As Masonry Construction Material, John Makunza

Tanzania Journal of Engineering and Technology (TJET)

Crusher dust generated at Kunduchi quarries in Dar es Salaam during aggregate crushing is counted as a waste material, and some times it .is disposed away or sold at a cheap price of not more than a quarter of that of sand. A study on the use of the crusher dust as a building material has been carried out in which samples were collected and analyzed for grading (sieve analysis). In additional to that, other samples were stabilized with a small amount of cement, from which bricks were produced and tested for compressive strength. Other bricks were bonded together using …


Comparison Of Two Different Transport Models To Predict Sediment Transport: Simiyu River, Tanzania, Case Study, F Mwanuzi1 Jun 2006

Comparison Of Two Different Transport Models To Predict Sediment Transport: Simiyu River, Tanzania, Case Study, F Mwanuzi1

Tanzania Journal of Engineering and Technology (TJET)

This paper presents the results of a study which focused at the spatial and temporal characteristics of sediment transport and deposition in the main river channels and floodplains. Two different numerical models were used to simulate stream flow and to analyze sediment transport and deposition in the river channels: (1) the SMS modules RMA2 and SED2D and (2) the SCALDIS model developed at the Free University of Brussels. Both numerical models contain a two-dimensional hydrodynamic module and a sediment transport module, allowing simulation of stream flow and sediment transport processes in river channels. However, they differ in the following aspects: …