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Carrying Capacity And Cracking Resistance At The Support Zone Of Halving Joints In Reinforced Concrete Beams, H. W. Chung

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Simulation Of Fluid Flow In Packed Beds Using A Simplified Model And Network Analysis Technique, Haggai W.K. Sarakikya

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Metabolic Activity Of Microorganisms Cultured On Inhibitory In Unsteady State, Cleophas L.C. Migiro

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Flowsheet Simulation Studies Of New Oilseed Extraction Processes, M. Khalfani

Tanzania Journal of Engineering and Technology (TJET)

Results are reported on the flowsheet simulation studies of new oilseed processes suitable for local conditions. A process model was developed and new design simulation methods using Computer Aided Design (CAD) approach were employed for the preliminary investigation of a number of alternative scenarios.

Results have shown that new processes should give considerable investment savings if separation of the crude product is not carried out by distillation. However, the economics of processes using alternative separation technology is highly dependent on operating conditions.

The use of spreadsheet programs for flowsheet evaluation studies offers opportunities for application of CAD techniques in local …

A Reiner-Rivlin Fluid Flow Through Entrance Region Of A Circular Pipe, V. G. Masanja

Tanzania Journal of Engineering and Technology (TJET)

The flow of a Reiner-Rivlin fluid with two viscosity coefficients through the entrance region of a circular pipe has been studied numerically. In particular the growth of the entrance length as a function of the Reynolds number and the non-Newtonian parameters has been examined. Where comparison could be made, the results have been compared with existing experimental -and numerical data as well as the limited theoretical work available.

Carrying Capacity And Cracking Resistance Of The Bracket, S. Mpinzire

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Behavior Of Ductile Materials Under Impulsive Loading, M. Y. Brunner

Tanzania Journal of Engineering and Technology (TJET)

Ductile materials under dynamic loading are known to be able to absorb energy and thereby delay or even prevent structural failure. This paper is concerned with such behaviour in the case of impulsive loads of short duration. It is shown that even when the feared, unstable, labile condition is attained, failure may not necessarily occur. This behaviour is particularly impressive for structures with large mass, because it is essentially the mass which slows down the attainment of the failure strains. If the impulsive load dies away quickly enough, the constant plastic resistance will be adequate to bring the increasing deformations …

Winery Waste Utilization-A Case Study Of Dowico, J. H.Y. Katima

Tanzania Journal of Engineering and Technology (TJET)

The Dodoma Winery Company (DOWICO), is presently processing about 1000 tonnes of grapes to produce different types of wines, with left overs of about 200 as wastes. These wastes are dumped outside the factory, obviously, a poor method of waste disposition as far as the environmental significance is concerned. Since the expansion programme, to enable the plant to handle up to 30000 tonnes of grapes per year is in the pipeline the best method of disposing the huge amount of waste (about 6000 tonnes) that will result, has to be sought.

This paper highlights the financial and sanitary advantage of …

Computation Of Frequency Characteristics Of Lumped-Element 3 Db Branch Line Directional Couplers, H. R. Mgombelo

Tanzania Journal of Engineering and Technology (TJET)

An analysis of the 3 dB lumped-element branchline directional coupler constructed using L-C and T networks is given. Matrices of lumped element capacitances and inductances in the form of low and high pass filters are equated to the matrices of the distributed element transmission lines at the centre frequency of operation, as a result of which design equations are derived. Using even and odd modes of excitation, frequency characteristics of the directional couplers are computed and compared to those of the coupler constructed using distributed element transmission lines.

Relationship Between Magnetic Ageing, Metallographic Evidence Of Ageing And Composition For Cold Rolled Si-Fe Electrical Sheets, J .V .Tesha

Tanzania Journal of Engineering and Technology (TJET)

The cold rolled Si-Fe sheets used for the production of the current cores for electricity meters suffer from ageing which causes an irreversible change in the magnetic properties. The ageing process is due to the precipitation of mixed iron silicon carbides in the microstructure. There exists already a thermal treatment and magnetic properties measurements method to detect the susceptibility to ageing. This requires a minimum of 1000 hours. In order to find the correlation between magnetic ageing, composition and metallographical evidence of ageing, different Si-Fe sheet compositions were investigated using the optical microscope to observe the time to appearance of …

Application Of Mechanical Vapour Recompression To Industrial Slides Drying, Allan Issangya

Tanzania Journal of Engineering and Technology (TJET)

A positive result of the oil crisis of the seventies is the realisation of energy’s value and the need to use it sparingly. Increasing attention has been focussed on all aspects of industry where fuel oil and gas had played a major role.

Industrial drying, one of the most widely applied unit operations in chemical and process engineering, is a highly energy intensive operation. Studies have identified a number of alternatives for lowering energy consumption in this process through various heat recovery techniques.

Due to the difference in their operating principles steam-heated dryers and air-heated dryers, in most aspects, require …

Optimal Allocation Of Water Among Industries In Dar Es Salaam City, Tanzania, J. I. Matondo

Tanzania Journal of Engineering and Technology (TJET)

Dar es Salaam is the city with the largest number of industries in Tanzania. However, the water demand for these industries is more than the supply. Therefore, there is a water use competing problem among the industries. Dynamic programming technique has been applied to optimally allocate the available water among the industries with the objective of maximizing the net benefits. Results reveal that, industries with the highest net return per unit of water will get the first priority of being allocated water.

Computer Model For Baker’S Yeast Production, A. K. Temu

Tanzania Journal of Engineering and Technology (TJET)

This paper concerns modelling of fermentation for bakers’ yeast (Saccharomyces Cerevisiae) production using sugar cane blackstrap molasses as a feed. The problem constitutes of expressing physical phenomena, mathematically, as function of operating conditions.

The program developed is easy to run and does not cost much in terms of preparations. With this program different operating conditions were tested and results show that available equations are not exhaustive. Thus more research is recommended.

Effect Of The Variations Of The Mobile Dislocation Density On The Thermally Activated Cyclic Deformation Behavior, J. S. Mshana

Tanzania Journal of Engineering and Technology (TJET)

The application of the transition state theory of rate processes to describe tension-tension, strain controlled cyclic deformation BEHAVIOUR was extended to describe the effect of the variations of the mobile dislocation density on the cyclic deformation BEHAVIOUR. It was shown from the derived constitutive relation that due to the net increase in the mobile dislocation density during strain controlled cyclic deformation the stress change per cycle (or in function of time) increases.

Development Of A Spray Drought Cooling Tower, O. K. Kaunde

Tanzania Journal of Engineering and Technology (TJET)

ABSTRACT A noval type direct contact cooling tower has been proposed in which the gas or air entering the tower is drawn by the ejector action of the sprays through which the feed water is admitted. The advantage offered by this type of tower is that it eliminates the usages of fan, thus saving the capital cost and power to drive it.

Entrainment of air by water was studied in a laboratory cooling tower and the result of the entire experiment indicate that the development of a spray drought tower is a feasible practice.

Production Of Blanking Circles And Dies - An Appropriate Method, V Bhandari

Tanzania Journal of Engineering and Technology (TJET)

A large important blanking die for production of multiwick stoves oil tanks was damaged beyond repair during normal maintenance. A replacement die could not be made available immediately. Initially an alternative blank production system based upon the adaptation of the inhouse and locally available tools was set up. Subsequently a temporary low cost and a permanent replacement blanking die was designed, developed and manufactured out of pad welding of mild steel plate. Recommendations have been drawn in light of the experiences gained in the deployment of these appropriate methods.

Towards The Development Of A Seed Minimum Tillage Planting, G Mutoizi

Tanzania Journal of Engineering and Technology (TJET)

Some advantages of minimum tillage compared to conventional tillage. systems are given. An evaluation of current minimum tillage planters is then made identifying two major problems namely the handling of trash. which detracts from making a continuous furrow of uniform depth, and unnecessary power Consumption When making this continuous furrow in spaced planting of seeds. Then the design, manufacture and development of a rig type of a seed injector for use in precision-drilling of a typical tropical geed is presented. It is to inject the Seed using rotary sleeve Valve in which is tractor drawn. Preliminary field testing of the …

The Design Of A Resonant Post Waveguide Filter, Ramjee Prasad

Tanzania Journal of Engineering and Technology (TJET)

A seven stage, quarter-wave coupled, single post, resonant cavity type waveguide filter has been studied. The posts are placed according to the Tchebyscheff distribution. The filter is designed and fabricated to meet the following specifications: Centre frequency: 9.31 GHz, Number of stages = 7, 3-dB bandwidth = 300 Mhz, Ripple tolerance in the passband = 0.5 dB. The frequency behaviour of this filter has been experimentally studied and is in close agreement with the specifications.

Distributive Mixing Performance Of Rubber Internal Mixers, B Mutagahywa

Tanzania Journal of Engineering and Technology (TJET)

Results of experiments to study the distributive mixing performance of Internal mixers are reported in this paper. Distributive mixing was assessed by monitoring the uniformity of sulphur distribution throughout rubber mixes subjected to a range of rotor revolutions. The results indicate that distributive mixing in a well controlled Internal mixer is rapid and unlikely to be a source of mix variability.

Gain Margin And Phase Margin Interrelationships, M Luhanga

Tanzania Journal of Engineering and Technology (TJET)

The gain margin and the phase margin Of a control SY Stem are important parameters in the determination of the relative stability of control system. In this paper We derive general interrelationships between these parameters.

The Mean Return Time To A State For A Markov Chain Representing In Telephone Conversations, M Luhanga

Tanzania Journal of Engineering and Technology (TJET)

The mean return time to a state for a Markov chain representing N off-hook telephone conversations can be obtained by using ergodic flow rates [1] or renewal theory [2]. In this paper it is shown that the same result may be obtained by using no more knowledge of stochastic processes than the solution of time-homogeneous Chapman-Kolmogorov equations.

An Electro Hydrodynamic Study Of The Negative Corona Electric Wind, Henry Thadei Kadete

Tanzania Journal of Engineering and Technology (TJET)

The velocity of corona generated electric wind is measured. From the velocity profile mass movement and electrokinetic conversion efficiencies are deduced. High speed schlieren photographs illustrate the form of the velocity distribution function as well as its high degree of turbulence.

Simple Graphic Routines Ease Drawing Of Artwork For The Fabrication Of Microstrip Lines, H Mgombelo

Tanzania Journal of Engineering and Technology (TJET)

A method which uses simple graphic routines available to general computer users for drawing diagrams intended to be reproduced on printed circuit boards (PCB's) is presented. Experimental verifications for the created microchip lines are reported.

The Eccentric Disc Pitter Planter-A Soil Conservation Tillage Tool For Mechanized Farming., J Dumelow

Tanzania Journal of Engineering and Technology (TJET)

A planting technique which could enhance agricultural production is presented. The Edip planting technique which is discussed has low capital and operating costs. It also has reasonable and reliable yields as well as providing effective moisture and soil conservation.

Negative Corona Current Characteristics Of An Electric Wind System, Aviti Kadete

Tanzania Journal of Engineering and Technology (TJET)

The corona current characteristics of an electric wind system are investigated. First a brief summary of the negative point to plate corona mechanism and characteristics are presented. Then empirical equations for corona currents of an electric wind system are derived. Current waveform characteristics are also discussed. The effects of placing parallel rods in between a point-plate electrode gap to the corona currents are highlighted.

Engineer Education: Disciplinary Preferences In The Faculty Of Engineering University Of Dar Es Salaam, S Mosha

Tanzania Journal of Engineering and Technology (TJET)

Most practising engineers can hardly recall the days they had to make up their minds on whether engineering was their chosen career. This decision may have been approached with ignorance and very high expectations. Later after registering in a Faculty of Engineering the freshman was given a chance to choose a department; sometimes this had already been done for him by his sponsors so all he had to do was to walk into the preselected department.

A generation later, University entrants are faced with a similar predicament. This paper high-lights the procedures involved and proceeds to recommend the necessary fundamental …

Hydraulic Rams For Rural Water Supply Schemes In Selected Areas In Tanzania, T Mbwette

Tanzania Journal of Engineering and Technology (TJET)

This paper presents one of the many efforts made by the Faculty of Engineering and the Institute of Production Innovation of the University of Dar es Salaam towards the realization of the International Water Supply and Sanitation Decade. Special reference is made to the use of hydraulic rams along with some simple water treatment methods. Besides the account of theoretical and practical work done to-date in the field of water supply, a further evaluation of the theoretical model presented is recommended so as to enable a judgement of the present hydraulic ram designs to be done. Tests on a typical …

Some Aspects Of Dimensioning And Tolerancing Of Mechanical Engineering Drawings, B. Krayer

Tanzania Journal of Engineering and Technology (TJET)

Abstract

Materials Testing And Consultancy For The Tanzanian Industry, H. Fallenbach

Tanzania Journal of Engineering and Technology (TJET)

Abstract

The Psychic Responsibility Of Engineering, M Megji

Tanzania Journal of Engineering and Technology (TJET)

During the assessment of the manuscript, it was observed that the paper does not include an abstract. The document proceeds directry to the main content without providing a separate abstract that summarize the study's objectives, methodology, key findings and conclusions