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Properties Of Rice Husk Particle Boards Bonded By A Blend Of Tannin-Cnsl Resin, J. V. Tesha

Tanzania Journal of Engineering and Technology (TJET)

There are vast quantities of agricultural residues available in Tanzania. Rice husk being amongst those residues is reported to have low resistance to alkalis, high silica content, and have short fibres. These factors have made rice husks not attractive raw materials in panels’ production. However, it has been demonstrated that rice husks can be used to develop panel products of low cost and good performance if appropriate indigenous technologies and affordable binders that can bind siliceous materials are used.

This paper provides a summary on the study of the effectiveness of the binding characteristics of a blend of natural adhesive …

A Simple Method For Indexing Powder Diffraction Patterns Of Cubic Materials:(1) Using The Θ-Values Of Reference, Me Kamwaya

Tanzania Journal of Science

From the values of sin2θ taken from powder photographs of the cubic crystal system, a variable constant, K, which is a multiple of (h2 + k2 + l2) can be determined. The smallest value of sin2θ1 gives rise to a multiple of one, two, or three which corresponds to the smallest value of Σhl2 for the primitive, bcc and fcc crystals, respectively. The old assumption that when indexing, the occurrence of numbers of the form (h2 + k2 + l2) = 8n + 7, where n = 0.1.2.3… should cause each of (h2 + k2 + l2) to be multiplied …

Seat Belt Use Compliance In Kansas, Deogratias Eustace, Teresa M. C. Bartel

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Passenger vehicle occupant restraints are regarded as the easiest and the most effective way of reducing the number of highway fatalities. Strong vehicle occupant protection enforcement laws are regarded as the most effective way to increase seat belt use. The increase in restraint use in the United States and other countries has been largely attributed to mandatory seat belt use legislation. Many fatalities and injuries in motor vehicle crashes could be avoided if more passengers used their seat belts. Studies have shown that primary laws have been more effective in seat belt use compliance than secondary laws. Also, legislation has …

Nebraska Blueprint – Summer 2002

Nebraska Blueprint (Student Publication)

Table of Contents:

From the Editor

Engineers Help Improve Smiles – Multidisciplinary research project takes Biological Systems Engineering students to the Dental College.

Professor, Student, Take Team Approach – Last year, Katie Schmatz learned a lot about teamwork. The industrial and management systems engineering graduate (May, 2002) worked with Dr. Stephanie Adams, assistant professor, IMSE, to find out what exactly makes teams work.

Black Engineers' Contributions to the World – A look at history showcases Black engineers' many contributions to the world.

Student Profiles – "Student finds his place at UNL," "Ship to shore: Former sailor finds niche in EE," …

Analysis On Possible Solution To Decreasing The Effect Of Non-Uniform Air-Gaps Due To Rotor Eccentricity In Asynchronous Machines, Dominic Chambega

Tanzania Journal of Engineering and Technology (TJET)

Rotor eccentricity introduces non-uniformity of the airgap which in turn causes additional frictional torques and losses in addition to establishing a uni-directional pulling magnetic force which is disastrous to the machine. This paper analyses the extent of the damage to the machine due to non-uniformity of the air-gap and proposes increasing the number of poles as a possible solution to arrest the effect. It is found through the analysis that as the number of poles increases the effect of eccentricity decreases.

Comparison Of Repair Costs Of Two Wheel Drive Tractors Under Tanzania Conditions, S. M. Mpanduji

Tanzania Journal of Engineering and Technology (TJET)

The repair costs of 2WD tractors were investigated in order to provide important information, which lacks in the scope of agricultural mechanization in Tanzania. Previously repair cost functions established for tractors in developed countries were used for both theoretical and practical purposes. The findings of this study have revealed that repair costs of tractors vary substantially from one make to another. The prediction functions developed in this study indicated that the magnitudes of repair costs in Tanzania are higher than the repair costs established in Europe and North America. The reason for this could be either due to high cost …

Evaluation Of Water Levevaluation Of Water Levels In Relation To The Design Of Coastal Structures In Tanzaniaels In Relation To The Design Of Coastal Structures In Tanzania, Alfonse Dubi

Tanzania Journal of Engineering and Technology (TJET)

Water levels on the coastline of Tanzania vary under the influence of meteorological conditions (winds and barometric pressure) and the East African Coastal Current, whose strength varies with the monsoon winds. Available tidal information is not enough to warrant statistical analysis for evaluating extreme water levels. The highest mean water springs occur at Bagamoyo and Pangani (3.93 m) and the lowest are found at Lindi (2.96 m). The highest astronomical tide is 3.7 m for Dar es Salaam and 4.6 m for Zanzibar, both of which occur during March/April and November. Measured highest water levels approach 4.80 m for Dar …

Evaluation Of Corrosion Inhibitor On Pre-Corroded Carbon Steel In Co2 Medium By Impedance Spectroscopy, Joseph Buchweishaija

Tanzania Journal of Engineering and Technology (TJET)

The effect of pre-corrosion of carbon steel on the performance of a commercial amine based fatty acid corrosion inhibitor, KI384, was investigated in formation water solutions saturated with CO₂ using electrochemical impedance spectroscopy (EIS) measurements. The investigation was performed at constant partial pressure of CO₂ using an autoclave system with Rotating Cylinder Electrodes (RCE). Carbon steel was pre-corroded for periods up to 7 days at 35 and 80 °C in the test solution prior to inhibitor injection. The results showed that when KI384 was applied on non-corroded carbon steel specimen, high inhibitor performance (99.8 %) was achieved independent of temperature. …

Investigation Of Forces Acting On Plain Discs, S. M. Mpanduji

Tanzania Journal of Engineering and Technology (TJET)

An investigation was carried out to study the mutually perpendicular forces generated by rotating and non-rotating plain discs similar to those used in disc ploughs. Experiments were conducted in a soil bin containing sand loam soil (Ryton sand) where forces were measured while changing disc rake and sweep angles. The results showed that draught forces were higher for non-rotating discs, while vertical and lateral forces were lower compared to rotating discs. Rotating discs were found to be suitable for counteracting high side forces because of less draught and higher lateral forces. The recommended optimum angles are between 8°–12° for disc …

Comparative Analysis Of H₂S Removal Ability Of Different Calcium-Based Absorbents Under Coal Gasification Conditions, Hassan Katalambula

Tanzania Journal of Engineering and Technology (TJET)

Calcium-based sorbents, such as limestone and dolomite are viable candidates for capturing pollutants in an in-situ coal gasification/desulphurisation process. Recently, scallop shell is also used as a Ca-based sorbent. However, the ability in capturing pollutants varies from one type to another and it also depends on the process involved. In this study, two types of limestone, scallop shell and dolomite were characterized and studied for H₂S absorption ability under the coal gasification conditions. The characterizations were done using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), Thermal analysis and Surface Area analysis. All of the samples showed a porous structure, and …

A Comparative Application Of Telecommunication Traffic Forecasting Methods To A Backbone Link In Tanzania, M. L. Luhanga

Tanzania Journal of Engineering and Technology (TJET)

In this paper various mathematical models to characterize and forecast telecommunication traffic time series traffic have been applied, and the ranges of validity of the models are determined by comparing them with measured traffic data using the measurement errors criteria method which resulted into the superior model. Based on this model the ARIMA (0,2,1) model for smoothed data, the traffic forecast findings show that by the year 2006, the traffic demand will exceed the current installed capacity of 140 Mbps in the Tanzania Telecommunications Company Limited (TTCL) network along the major link between the Dar es Salaam and Dodoma backbone …

Requirements Of A Sustainable Pavement Management System For Tanzania, N. K.M. Mushule

Tanzania Journal of Engineering and Technology (TJET)

Since the introduction of pavement management concepts in mid-1960s, more than three decades ago, a considerable number of Pavement Management Systems (PMS) have been developed and implemented widely in many parts of the world. These systems differ in scope and sophistication. However, in some cases, pavement management systems have fallen into marginal use, if not into complete disuse, because of a number of reasons. One of the major reasons leading to the marginalisation or abandonment of pavement management systems, is the failure of system developers to recognise specific and unique needs of the agency or authority responsible for road management. …

Intrinsic Biodegradation Potential Of Crude Oil In Salt Marshes, Julius Enock

LSU Master's Theses

Understanding the influence of different perturbations on the fate of spilled oil in marine ecosystems is useful in assessing the environmental impact and remedial investigation. The effect of flooding and spill recurrence on the fate of an experimental crude oil spill (2 L/m²) was investigated using salt marsh intact cores, incubated for about 3 months, by monitoring residual petroleum hydrocarbons, heterotrophic microbial activity (fluorescein diacetate assay) and soluble organic carbon (SOC). For the flooding study, biodegradation rate of crude oil (with half-lives varying between 16.50 and 49.51 days and turnover times between 23.81 and 71.43 days) and microbial …

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.

Baseflow Separation Based On Storage-Outflow Modelling Of Streamflow Recessions, With Application To Semi- Arid Catchments In Tanzania, S Mwakalila

Tanzania Journal of Engineering and Technology (TJET)

Discharge in many rivers is Often fed by baseflow provided by drainage of the saturated zone in the shallow permeable soils. It is becoming clear that the outflow from this saturated zone is not linear proportional to storage as is commonly assumed in many algorithms. The objectives Of this study theretore, are first to explore the extent to which the assumption of linearity in storage-outflow relationships is valid and secondly to introduce an alternative approach to baseflow separation algorithms for estimating direct mnoff time series. Numerical analysis Of streamflow recessions from the semi-arid catchments of the Great Ruaha basin in …

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 …

Some Aspects Of Erosive Waves At Kunduchi Beach, Dar Es Salaam, Tanzania, Alfonse Dubi

Tanzania Journal of Engineering and Technology (TJET)

The area north of the Dar es Salaam City is endowed with beautiful sandy beaches and high concentration or tourist beach hotels that are threatened by coastal erosion. In order to protect the buildings and land, coastal erosion must be controlled by mitigation options that are based on scientific data, wave and current climate along the East African region are generally controlled by the seasonal monsoon winds. During the north-east monsoon period when Winds blow from the Northeast, the wind-generated waves approach the coast from the northerly direction and produce long-shore Currents With a southerly component. During the southerly monsoon …

Efeci's In Reinforced Concrete Due To Environmental Conditions, And Concrete Treatment: A Case Study At The University Of Dar Es Salaam, I Rubaratuka

Tanzania Journal of Engineering and Technology (TJET)

Concrete is produced by mixing together cement, water and aggregates (i. e. sand and coarse aggregates) in specified proportions, It can do well with compressive forces but it is very weak under tensile forces. TO Overcome this problem, steel reinforcement are normally added to produce reinforced concrete which can also withstand tensile forces Experience shows that environmental conditions may have a negative impact On the durability of reinforced concrete structures resulting in development of defects if not properly assessed and appropriate measures adopted to arrest the same at the design and construction stages. The severity of damages for the investigated …

Stress Conditions In The Kilombero Rift, Central Tanzania, A Mruma

Tanzania Journal of Engineering and Technology (TJET)

The ancient and current Stress conditions at the northwestern flank of the Kilombero Rift are assessed in this paper. Neoproterozoic Stresses in the area were associated With 3200/200 trending principal axis of straining in the rocks. Ihis deformation imparted Precambrian ductile gneissic and concordant mineral foliation with attitude Of 0200/3$WNW, 3200/200 trending b•minerai lineation and isoclinal folds With axes trending parallel to the mineral lineation.phanerozoie deformations are mainly of pennvrriasic and Cenozoic periods. Both Of the two episodes Of deformation had constant orientation of princi axes of stresses with trending 0600/020, 02 trending 1600/800 and trending 33 1100. Stress conditions …

Electrokinetic Cha Raci'erisation Of Colloidal A-Alumina, J Ntalikwa

Tanzania Journal of Engineering and Technology (TJET)

Electrophoretic mobility (uD is an important rneasurable parameter in studying the electrokinetic properties of a colloid dispersion. This parameter is Often convened into zeta potential (C) Which piays a great role in thc description Of the stability towards aggregation Of dispersed particles. In this paper, measurements of Of colloidal a-alumina dispersed in various concentrations of electrolyte arc reported. It was observed that, the isoelectric points (the pH at which us = O) occurred at 7.52 ± 0.32, 8.05 ± 0.11 and 7,95 ± 0.18 in Naci, KCI and NaNOs respectively. The isoelectric point was observed to be a function Of …

Comparative Analysis Of Rng K-E And 'Standard' K-C Models For Fluid Flow Around A Cylinder, A Temu

Tanzania Journal of Engineering and Technology (TJET)

A two-dimensional computational scheme for simulating fluid flow around a cylinder was investigated. RNG (Re-NOrmalisation Group) and 'standard' turbulent closure models were used. simulation was implemented with assistance OfFLOW-3D computational fluid dynamics (CFD) code. The governing equation Of fluid motion, in Eulerian form, included body forces as well as surface forces. The computational model predictions for fluid velocity showed good agreement between the two models. Comparison Of the viscosities showed a large deviation from the two models, with RNG k-E model giving a better approximation. Comparison Of the velocity around the cylinder, as obtained from RNG k-c model, with approximation …

A Study Into Lack Of Product Innovation And Business Techniques At The Tricycle Workshop And Rrs Lessons To Small Companies, E Elias

Tanzania Journal of Engineering and Technology (TJET)

A study was carried out at the Tricycle Workshop (TW) which was facing the problem of !ack of orders and therefore stagnation Of business. The objective of the study was to find out reasons for this situation and to propose possible remedial solutions. The study was conducted using the principles of the Product Innovation process where internal and external issues related to the business Of the company were investigated for information. Analysis Of information obtained indicated that the bad situation of the TW had mainly been caused by the nature of the tricycles-supply system whereby users (disabled persons) are unable …

Defects In Reinforced Concrete Due To Environmental Conditions And Concrete Treatment: A Case Study At The University Of Dar Es Salaam, A. Rubaratuka

Tanzania Journal of Engineering and Technology (TJET)

Concrete is produced by mixing together cement, water and aggregates (i. e. sand and coarse aggregates) in specified proportions. It can do well with compressive forces but it is very weak under tensile forces. To overcome this problem, steel reinforcement are normally added to produce reinforced concrete which can also withstand tensile forces. Experience shows that environmental conditions may have a negative impact on the durability of reinforced concrete structures resulting in development of defects if not properly assessed and appropriate measures adopted to arrest the same at the design and construction stages.

The severity of damages for the investigated …

Production Innovation Through Design Methodology: Development Of A Fuel Pump For Motorists, E. Elias

Tanzania Journal of Engineering and Technology (TJET)

Design Methodology is a discipline of scientific engineering design for provision of solutions to user needs. It is composed of design models (showing the path/procedural steps of design) and design tactics (i.e. techniques, technologies and methods aiding the designer). When rigorously applied, design methodology leads to innovation of products and businesses.

The present paper describes how design methodology was applied to the development of a siphon device (Apump@) for motorists when in need to refill fuel in their vehicles away from petrol stations. The need for the device was realised through the method of Alooking around & deep thinking@ and …

The Behaviour Of Reinforced Block-Work Walls In Axial Tension, Laurent Shirima

Tanzania Journal of Engineering and Technology (TJET)

Reinforced blockwork with horizontally laid reinforcing bars is used for walls in liquid retaining structures in developing countries. This is the case where, the level of technology in terms of skills and equipment is not in a position to allow successful construction of reinforced concrete walls. Blockwork walls are very sensitive to cracking which cannot be prevented by reinforcement. The major problem for designers is the behaviour of such walls in tension caused by hydrostatic pressure of the stored liquid. This paper reports results of a research work to study the behaviour of reinforced blockwork walls in tension. It was …

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 …

Measurement Of Markstein Lengths In Laminar Spherical Explosion Flames, E .M.J Mushi

Tanzania Journal of Engineering and Technology (TJET)

Schlieren photography was used to record the development of spherical flames in a combustion bomb. Flame speed and flame stretch were evaluated from the data and used to evaluate Markstein lengths and numbers. The results indicate a strong influence of both the spark discharge energy and equivalence ratio. Low spark discharge energy is observed to give rise to more unstable flames compared to high energy sparks. It is observed that for the range of energy tested, 80 and 400 mJ gave the best stability for the flames. For equivalence ratio less or equal to 1.225 an 80 mJ discharge results …

Evaluation Of Extreme Wind Speeds In Relation To The Design Of Coastal Structures In Tanzania, Alfonse Dubi

Tanzania Journal of Engineering and Technology (TJET)

Five distribution functions, FT-I and Weibull with the exponent k = 0.75, 1.0, 1.4 and 2.0 respectively, have been applied to 25-year wind data collected between 1972 and 1996 at Tanga, Dar Es Salaam, Zanzibar and Mtwara Meteorological stations. One maximum value for every year from the full data record was drawn to constitute the annual maxima series for each station. For each of the stations, 2-, 50- and 100-year return wind speeds with corresponding 90% confidence intervals were computed. The distribution functions were fitted to the data by the Least Squares Method. Results from the study show that FT-I …

Strategic Transformation Of Public Enterprises In Tanzania: Action Research Oriented Methodology, M A.M Victor

Tanzania Journal of Engineering and Technology (TJET)

Naturally, enterprises are dynamic in the sense that they can either grow or shrink. Growth is the wish of all owners and particularly of fast growth. We talk of growth here as both increasing the speed of circulation of the working capital profitably and increasing the size or expansion of the fixed assets through retained earnings. Proper management will in most cases assure a gradual growth. However, in some situations, gradual growth may not be sustainable due to global competition and/or some other political changes such as elimination of monopoly. In these situations, enterprises will need a strategic transformation, not …

The Effect Of System And Oxygen Partial Pressure On Single Coal Particle Heterogeneous Ignition Temperature Under Conditions Of Negligible Convection; Experimental Observation, H. Katalambula

Tanzania Journal of Engineering and Technology (TJET)

Abstract Under conditions of high volatile concentrations, the influence of oxygen concentration on single coal particle ignition becomes more significant. The high volatile concentration conditions have been simulated by employing a microgravity environment. Results show that under these conditions, the heterogeneous ignition temperature decreases faster with increasing oxygen concentration than under normal conditions. The ignition temperature also decreases with increasing system and oxygen partial pressure under both conditions. Generally, the system and oxygen partial pressure show similar and complimenting effects on ignition temperature.