Industrial Engineering Commons^™

Low Volume Dispensing With High Speed Dispensers, Sunny Agarwal

Graduate Dissertations and Theses

With the high pace of innovation in the semiconductor manufacturing industry, there has been an increasing demand for more energy efficient and environmental friendly products. This research relates to a complex process of fluid dispensing at low volumes on a printed circuit board. Currently, a more refined non-contact dispensing terminology named “Streaming” is widely used to stream out material at low volumes for various applications. The key solution is to frame a dispensing method that lends itself most closely to the requirements of a specific production process.

This study represents a detailed approach of dispensing low volumes of materials in …

S-Stem Scholars, A Second Generation: Support For At-Risk Upper Division And Transfer Students In Ceas, Andrew A. Kline, Betsy M. Aller

Academic Leadership Academy

Begun in 2010, the S-STEM Scholar Program increases opportunities for financially needy but academically talented students. These students:

•Are first-time, first year students •Demonstrate financial need through FAFSA applications

•Will enter a major in the College of Engineering and Applied Sciences

•Have a math ACT of 24 or above

Student awardees receive up to $3,000 per semester, and continue to receive this amount for up to eight semesters with continued academic success and progress to degree.

Calibration Of Hdm-4 For Use In Pavement Management Systems (Pms), Nurdin Mushule

Tanzania Journal of Engineering and Technology (TJET)

One of major problems of road management in developing countries is the lack of decision making tools for preparing road maintenance programmes. This results in poor resource allocation and poor utilisation of existing assets. Pavement management systems (PMS) have been developed around the world in order to assist with the pavement management process in a co-ordinated and systematic manner. Some developed countries have derived pavement performance models that are suited to local conditions by setting up long term pavement performance studies. Conversely, most developing countries do not have the resources required to set up similar large-scale field experiments. However, validation …

A Systemic Framework For Implementation Of Tqm Programmes, Emanuel Mjema

Tanzania Journal of Engineering and Technology (TJET)

The purpose of this paper is to present a systemic framework for implementation of TQM program in a manufacturing organisation that produces motor vehicle components in Port Elizabeth - South Africa. The approach used included conceptualisation of the systemic framework and then involvement of the stakeholders in adding scenarios to be considered in the design and implementing the framework in the real field. The findings obtained during the implementation of the systemic framework established that reduction of scrap rate, reduction of production costs, reduction of cycle time and employee motivation could be achieved through the implementation of a Systemic Framework …

The Effect Of Rotation And Temperature On The Inhibition Performance Of Cashew (Anacardium Occidentale L.) Nut Shell Liquid On Co2 Corrosion Of Carbon Steel, J Mutasingwa

Tanzania Journal of Engineering and Technology (TJET)

A natural extract of cashew nut shells, Cashew Nut Shell Liquid (CNSL) was investigated as a corrosion inhibitor for carbon steel in 3% NaCl solutions saturated with CO2 gas using electrochemical techniques (i.e. potentiodynamic polarization and ac-impedance). The investigation was performed at different temperatures under static and dynamic conditions using a Rotating Disk Electrode (RDE). It was found that CNSL reduces the electrochemical processes taking place on carbon steel undergoing corrosion. The percentage inhibitor efficiency increases with increase in CNSL concentration and decreases with rise in temperature. Better performance at low CNSL concentration was registered under dynamic conditions and room …

Investigation Of The Effect Of Particle Size On Groundnut-Oil Solvent Extraction, S Manyele

Tanzania Journal of Engineering and Technology (TJET)

An investigation of the effect of particle size on the performance of vegetable oil recovery by solvent extraction is reported. Experiments were conducted using soxhlet extractor, groundnuts and n-hexane. Samples were grouped into mean particle sizes of 0.25, 0.75, 1.3, 3.3, and 7.5 mm using standard sieves. The effect of particle size was studied for extraction time intervals of 1, 2, 3, 4, 5 and 8 hours. The oil yield, oil recovered per kg solvent used, kg solvent lost per unit time, and the rate of extraction (kg oil recovered per hour) decreased with increasing particle size. Meanwhile, the percent …

Geometric Programming As A General Method For Phase And Reaction Equilibrium Calculations, Godwill Mrema

Tanzania Journal of Engineering and Technology (TJET)

Geometric programming has been used to calculate a large mtmber ofdifferent ideal and non-ideal equilibria, including, for reaction and For non-ideal Systems the primal program is solved a number Of times With the nan-ideal terms fixed each time. After each primal solution, the nan-ideal terms are "'hdated using the corresponding dun! solution. This iteration generally converges. We have included one counter-example, where the failure is caused by the equation Of state, which Cannot giu• correct roots.

Performance Of Aerobic Bioreactors During Treatment Of Tanning Industry Wastewater, Samwel V. Manyele

Tanzania Journal of Engineering and Technology (TJET)

The performance of aerobic bioreactors loaded with novel biomass support (the KMT® support particles) during the treatment of tanning industry wastewater is presented in this paper. The wastewater samples were collected from TANWAT Company in Njombe, which extracts tannins from barks of the wattle tree. The wastewater generated from T ANWAT is very acidic with high loading of organic compounds, which are very complex and difficult to biodegrade using conventional methods. The paper introduces a new technology for treatment of heavily loaded industrial wastewater, like tannins, that is the Three-Phase Fluidized Bed Bioreactor (TPFBB) which utilizes the KM'f® support particles. …

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …

Effectiveness Of Hot Isostatic Pressing On Healing Oxide Film Defects In Cast Aluminium Alloys, C Nyahumwa

Tanzania Journal of Engineering and Technology (TJET)

Hot isostatic pressing (hipping) of cast aluminium alloys is recognized as a means of providing improved internal soundness and mechanical properties of the castings. However, little is known about the limitations and potential benefit of the hipping process to produce reliable aluminium alloy castings containing oxide film defects due to turbulently filling of moulds. In this study, oxide film defects and fatigue lives of turbule''Zt filled unfiltered AI-7Si-Mg alloy castings have been characterised in as-cast and hipped. conditions to quantify the effectiveness of hot isostatic pressing on healing oxide film defects in the castings. The average fatigue life and fatigue …

Gasification Kinetics Of Ultrafine Coal Char Oxidation In Flame Reactions, G John

Tanzania Journal of Engineering and Technology (TJET)

Pulverized coal combustion is exceedingly complex with a  vast number of variables. In order to avoid the complications associated with the burning of coal char, a controlled study has been made of the oxidation of fine graphite in laminar methane-air flame as a contribution to the understanding of the more complex phenomena of the gasification kinetics of the char. The burning of methane is equivalent to the burning of volatiles and graphite oxidation is similar to that of coal char. Aspects of this have been simulated in experimental and computational studies of 4pm diameter graphite particle burning in methane -air …

The Decomposition Kinetics Of Solids Thermodynamic Evidence For The Enthalpy Driven Cooling Of Reaction Environment Part 2, Akwilapo D

Tanzania Journal of Engineering and Technology (TJET)

The analysis of non-isothermal kinetic data for the decomposition of calcium carbonate, CaC03 (s) ~ CaO (s) + C02 (g) in flowing nitrogen, shows that the decomposition of solids is accompanied by self-cooling/heating of the reaction environment depending on the sample mass and heating rate. The correctness of the kinetic model is established by the calculation of the enthalpy change of the reaction. This is the thermodynamic evidence of endothermic enthalpy driven cooling of the reaction environment. The enthalpy change LJH = 179.33 kJmol-1 estimated from this work for the dissociation of CaC03 is in agreement with LJH = 179.17 …

Ceramic Properties Of Chimala Kaolin Clay, Leonard Akwilapo

Tanzania Journal of Engineering and Technology (TJET)

The physico-chemical properties of kaolinite clays occurring in abundance near Chimala were studied with a view of finding out their suitability in sanitary ware production. The viscosity of the clay was found to be within the range acceptable in industrial application (≤ 500 cp for 70% solids), enhancing its prospects for the manufacture of slip cast shapes with satisfactory properties. The chemical composition of the clay reveals a high content of Fe₂O₃, 1.48%, which is expected to affect the translucency and colour of the finished ware. However, such quantity would not have detrimental effects in the production of sanitary ware. …

Degradation Of Waterfront Reinforced Concrete Structures At The Port Of Dar Es Salaam, I Sanga

Tanzania Journal of Engineering and Technology (TJET)

The paper summarises the results of an investigation done on piers at the Dar es Salaam Port. The problem facing these structures and marine facilities is their exposure to aggressive environmental phenomena. The paper presents an investigation of the strength and corrosion of concrete seaport piers so as to determine degradation of the reinforced concrete waterfront structures in the port of Dar es Salaam. For instance the structures at a dhow quay terminal had been in use for about 100 years. The facility was in bad condition as the concrete had been badly damaged due to corrosion. Some of the …

Participatory Evaluation And Improvement Of Cassava Processing Machines For The Eastern Zone Of Tanzania, V Silayo

Tanzania Journal of Engineering and Technology (TJET)

Cassava processing machines previously introduced in Tanzania were chippers and graters of the International Institute Of Tropical Agriculture (IITA) design. Popularization of such machmes in Tanzania required thorough participatory testing with stakeholders. When tested with farmers in Muheza and Kibaha districts average throughputs were 11-18 kg/h, 752 kg/h and 270 kg/hfor the manual chipper, engine-powered chipper and the engine-powered grater, respectively. Despite their low throughputs the manual chipper and the grater were Veo difficult to operate, and therefore demanded improvement. Improvement on these machines included modifications on the design for increased throughput, ease of operation and safety. The improved machines …

Aeration Efficiency Of A Three-Phase Fluidized Bed Bioreactor During Food Industry Wastewater Treatment, S Manyele

Tanzania Journal of Engineering and Technology (TJET)

The implementation Of a three-phase fluidized bed bioreaclor (TPFBB) in food- processing wastewater (FPW'W) treatment is reported. This study includes the modification Of the air distributor (plate design and gas-liquid mixing) for the bioreactor and resting of its aeration efficiency under different liquids. The aeration efficiency for wastewater samples collected from a soft drink processing industry and tannin processing industry (TANWA T) and tap water were compared. The aeration efficiency parameters studied include bed expansion, air holdup. volumetric oxygen mass transfer coefficient, and alpha factors. The variation of these parameters With air flow rates were studied at different liquid heights, …

Comparative Study Of The Dynamics Of Circulating Fluidized Bed Riser And Downer Of Equal Diameters, Samwel V. Manyele

Tanzania Journal of Engineering and Technology (TJET)

The microscopic flow dynamics of the 100-mm internal diameter riser/downer circulating fluidized bed (CFB) unit were monitored using a solids concentration fiber optic probe. The comparison was conducted by comparing radial profiles Of the dynamic parameters derived from time-series analysis techniques (statistical and chaos analyses). The solids concentration signals used were recorded under similar operating conditions (gas velocity of 8.0 m/s and solids flux of 100 kg/m2s). Similar axial elevations were compared (entrance and fully developed sections of die reactors). A1 each loca!ion, the signals were sampled a! afrequency of 970 Hz for duration of 30 seconds. It was observed …

Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo

Tanzania Journal of Engineering and Technology (TJET)

No abstract provided.

Production Of Biogas From Water Hyacinth: Effect Of Substrate Loading In Semi-Batch & Batch Operations, J Katima

Tanzania Journal of Engineering and Technology (TJET)

A study was carried out to establish the effect of substrate loading rate on the production of biogas from water hyacinth. The experiments revealed that the maximum methane yield in a batch process was 0.166 normal litre (NLVg Of volatile solids (VS) added at substrate concentration of 25 g dry mass'litre after five days of incubation. The maximum methane yield in a semi-batch process was 0.153 NWg VS added at 1.30 g VS'litre day and retention time Of 15 days.

Recyclability Of Modified Ps-Aq Pulps At Around Kappa 30, Rwaichi Minja

Tanzania Journal of Engineering and Technology (TJET)

Bleachable grade pulps prepared from Nonvegian softwood spruce chips while simulating possible alternatives of improving pulp yield by application Of polysulphide (PS) and anthraquinone (AQ) have been used in this study. The tests for recyclability were performed on hydrogen form pulps. The pulps considered were Iso- Thermal cooking (ITC) kraft pulp which was used as a reference pulp, conventional PS-AQ pulp, soda PS-AQ pulp and kraft PS-AQ pulp. The loss Of swelling ability (homification) Of the pulps, was determined by measurement of water retention value (W R V). The results showed that, PS-AQ pulps had similar or slightly better swelling …

Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna

Tanzania Journal of Engineering and Technology (TJET)

Vibration is one of the techniques employed in the determination of dynamic properties of fruits and vegetables. It entails generation of a mechanical or acoustic vibrational signal which is propagated through the flesh of the agricultural material. A transducer is either attached or held close to the specimen to monitor the propagation of the signal through the specimen. The manner in which the signal is transmitted through the material is analyzed, and the dynamic properties of the specimen which relate to its firmness or its internal being are derived. The technique has been around for the past 30 years or …

Oxygen Transfer In A Three-Phase Fluidised Bed Bioreactor With Novel Biomass Support When Used In Industrial Wastewater Treatment, S Manyele,

Tanzania Journal of Engineering and Technology (TJET)

The effect of support mass and liquid height on the oxygen transfer in the three- phase fluidised bed were experi/nenta/ly investigated. Novel biomass support, rhe KMT*, with density of 850 kg/n/ and an equivalent size, dp 8.3 mm, has been used in this work. The oxygen transfer rate was expressed in terms of rhe volumetric oxygen transfer coefficient, kca. It has been found out that the* a values increased with increasing support mass up to a critical solids load of 4.0 kg, above which the kca decreased and that kca decreased with increasing liquid height. It has been recommended that …

New Technologies For Thermal Disposal Of Sewage Sludge, T Ogada

Tanzania Journal of Engineering and Technology (TJET)

The traditional methods for the disposal of sewage sludge are landfilling, recycling as fertilisers in agricultural lands, dumping into sea and incineration. In thc recent past, Sludge incineration has been rapidly gaining ground duc to environmental constraints facing the Other methods. However, the cost of pollution control during sewage sludge incineration is currently very high due to the expensive flue gas treatment facility required. Futhermore, large quantity Of ash is produced which is highly contaminated with heavy metals and must be disposed off in special landfilling sites in order to avoid ground water pollution. To reduce the cost Of pollution …

Experimental Study Of Domestic Charcoal Stoves, Simbo Kimario

Tanzania Journal of Engineering and Technology (TJET)

The demand of fuelwood for domestic cooking especially the charcoal fuel is increasing in the urban settlements due to the increase in population of low income class earners who are the main consumers Of this type of fuel. This paper is presenting rhe results Of experiments conducted on the popularly used domestic charcoal stoves in Tanzania. The results revealed some significant differences on stoves performances. The type of insulation materials and some design features incorporated into the combustion chambers of the stoves had positive impacts in relative charcoal fuel saving. About two tons of charcoal fuel could be saved by …

The Significance And Effects Of Oil Injection On The Performance Of Sliding Vane Compressors., M Mkumbwa

Tanzania Journal of Engineering and Technology (TJET)

A computer model of a sliding vane air compressor was used to predict the behaviour of machines having different geometries operating at different conditions. The performance parameters which were calculated by the model were the free air delivery, power input and specific capacity which is defined as the free air delivery per unit of power input.The model also included the study of the effects of Oil injection on these mentioned compressor performance parameters. The paper describes the simulation model developed incorporating an analysis Of the effects of the oil injected into the compressor on lhe thermodynamic processes taking place in …

A Study On Ring Pack Lubrication In Internal Combustion Engine, I Mshoro

Tanzania Journal of Engineering and Technology (TJET)

Most efthe lubricating oil from Internal Combustion Engine (ICE) is lost through piston rings. Hence, in order to optimally reduce ICE oil consumption, a better insight into tribology of the ring pack is required. This can only be achieved by an inwroved characterization of the lubricant behaviour within the opelating environment of the engine. In The present ieork, an optical tcchnique using laser- induced fluorescence was employed to measure oil film thickness within the ring pack. The experiment was conducted on a Phaser 1000 Series engine, whereby optical access to the ring pack was achieved by a fused silica-window positioned …

Design Considerations For A Three-Phase Fluidized-Bed Bioreactor, S Manyele

Tanzania Journal of Engineering and Technology (TJET)

The design Of a three-phase fluidized bed bioreactor using novel biomass support for industrial wastewater treatment is reported in this paper. A column of 0.20 m diameter with variable height up to 6.60 m equipped with a foam breaker tank was designed, commissioned and operated. A novel biomass support, KMTR support, has been used Separate gas and liquid feeding systems were designed to facilitate proper bioreactor operation. A flat distriburor plate with 4 mm holes- diameter was desined A study on the hydrodynamic properties of the three-phase fluidized bed bioreactor revealed high values of bed expansion and air hold-ups. Purification …

Design Approach For Small Scale Continuous, Steady State Plants, O Kaunde

Tanzania Journal of Engineering and Technology (TJET)

One of the major steps in the design of a process plant is development of an appiopriate flowsheet. At this step, the technical solutions may be con- sidered in relation to the social and economic factors. In this paper, guide- lines for developing a flowsheet for continuous, steady State process in a developing country environment have been proposed. To illustrate the pro- posed guidelines, a case study involving design of an ethanol distillation plant has been used.

Experimental Investigation On The Use Of Native Biomass As Biosorbents For Metal Pollutant Removal, R Litto

Tanzania Journal of Engineering and Technology (TJET)

Waste water treatment is a perrnunent task. Many novel techniques have emerge in recent years and one of them is using biomass in removing heavy- metals. In this research screening and preliminary optimization experi- ments have identified different types of abundant biomass which can accu- mulate heavy metals such as Fe3*, C03•, Cu2+ and ftvm effluent. Cystoseira Myrica has a high uptake ofCr3+ while Sargassum Polycystum has been found to have a high uptake 0fFe3+. Observed biosorption kinet- ics shows rapid initial stage, followed by slower second stage and the amount of material adsorbed increases linearly as its concentration in …

Improved Heat Transfer By Means Of Steam Injection In A Shell & Tube Heat Exchanger, O Kaunde

Tanzania Journal of Engineering and Technology (TJET)

When designing a heat exchanger; one aims at attaining high heat transfer rates SO as to minimise heat transfer area and therefore the overall cost. This paper presents a method of improving the overall heat travsfer coef- ficient of a conventional shell and tube heal exchanger. The method in- volves injecting steam into the process fluid as it enters the heat exchanger thus effecting mixing of fluid as it travels along the exchanger Tests car- • ried out using this technique showed a significant increase in the overall heat transfer coefficient values.