Engineering Commons^™

The Training Of Marine Engineers : Present Methods And Future Directions In Developing Countries (Africa), Yassin Magongo Songoro

World Maritime University Dissertations

No abstract provided.

Fire Protection Onboard : Enhance Fire Safety By Design, Shangchun Zhang

World Maritime University Dissertations

No abstract provided.

An Investigation Into The Feasibility Of Introducing A Marine Engine Simulator Into The Algerian Met Maritime Education And Training System, Djelloul Bouras

World Maritime University Dissertations

No abstract provided.

Developing An Effective Mechanism Of Oil Pollution Management In The Niger Delta, Ja'afaru Labaran Daura

World Maritime University Dissertations

No abstract provided.

Modeling And Simulation Of The Dynamic Behavior Of Monoliths: Effects Of Pore Structure From Pore Network Model Analysis And Comparison With Columns Packed With Porous Spherical Particles, Athanasios I. Liapis, J. J. Meyers, Orrin K. Crosser

Chemical and Biochemical Engineering Faculty Research & Creative Works

A mathematical model is presented that could be used to describe the dynamic behavior, scale-up, and design of monoliths involving the adsorption of a solute of interest. The value of the pore diffusivity of the solute in the pores of the skeletons of the monolith is determined in an a priori manner by employing the pore network modeling theory of Meyers and Liapis [J. Chromatogr. A, 827 (1998) 197 and 852 (1999) 3]. The results clearly show that the pore diffusion coefficient, D(mp), of the solute depends on both the pore size distribution and the pore connectivity, n(T), of the …

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 …

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 …

Behavior Of Gamma Tial Subjected To Impact Damage And Elevated Temperature Fatigue, Trevor S. Harding, J. Wayne Jones

Materials Engineering

Gamma titanium aluminide has received significant attention in recent years as a candidate material for use in aerospace and industrial gas turbine engine applications. In particular, these materials offer significant weight reductions (densities are less than half that of nickel-based superalloys), high specific strength retention at elevated temperature and high specific stiffness which is particularly important in vibrating components such as blades. This combination of weight savings and good mechanical properties has led to the possibility that γ-TiAl may be a suitable replacement for nickel-based alloys, such as Inconel 718, in low pressure turbine blades without significant redesign of the …

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 …

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 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.

Mathematical Modelling Of Road Bumps, E. S. Massawe

Tanzania Journal of Engineering and Technology (TJET)

In this paper, a general mathematical model that may be used for construction of a road bump on an inclined road is developed. It is shown that if the parameters for the inclination are set to zero, the resulting model reflects the special case of a flat road. Existing experiences are briefly highlighted and a case study was done on different locations along the University Road to demonstrate the developed model.

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 …

Evaluation Of Soil Conservation Measures: A Case Study In Mbinga District, Ruvuma Region, Tanzania, S. Y. Thadei

Tanzania Journal of Engineering and Technology (TJET)

A study on soil conservation measures was conducted in two villages, Tukuzi and Mahenge, in Mbinga District, Ruvuma Region, Tanzania. The results showed that the ngoro farming system was effective in controlling soil erosion by water on both steep and gentle slopes. Sediments collected from ngoro had high concentrations of plant nutrients such as available phosphorus (P), total nitrogen (N), organic carbon (OC) and exchangeable bases. This was probably due to nutrients released from decomposed grass bundles buried in the soil. In preventing soil erosion, ngoro and bench terraces were equally effective, while contour ditches were as effective as ridges …

Production Of Fermentable Sugars From Waterhyacinth By High-Temperature Dilute-Acid Hydrolysis Method, J. H. Y. Katima

Tanzania Journal of Engineering and Technology (TJET)

A study on acid-catalyzed hydrolysis of Waterhyacinth (WH) biomass for production of monomeric sugars has been done. Waterhyacinth (Eichhornia Crassipes) plants were obtained from Lake Victoria. A yield of 18.5% w/w fermentable sugars was achieved during hydrolysis of oven-dried Waterhyacinth (ODWH) biomass at 220°C and 1.5% w/w H₂SO₄ acid. The waterhyacinth (WH) hydrolysates obtained from a high-temperature dilute-acid hydrolysis were rich in six-carbon (C₆) sugars (glucose) which could be fermented to ethanol. The production of fermentable sugars from waterhyacinth biomass is a promising new opportunity for its economic value which can in turn accelerate its rate of harvest and utilization.

Estimation Of Volatile Cloud Density For Single Coal Particles Using Microgravity Condition, H. Katalambula

Tanzania Journal of Engineering and Technology (TJET)

Single coal particle’s volatile cloud density has been estimated by employing a microgravity condition. The volatile yield was found to decrease with pressure while the density was found to increase, indicating that volatiles occupies less space when under pressure and hence causing some volatiles to be retained within the particle. The volatile cloud density was also found to increase with volatile yield suggesting volatile composition changes with yield. The effect of heating rate on volatile yield was found to be the same as reported by other investigators where the yield increased with heating rate.

Concrete Cracking In Coastal Areas, S. R. Mpinzire

Tanzania Journal of Engineering and Technology (TJET)

The paper discusses cracking and corrosion of reinforced concrete (RC) structures in coastal zones where aggressive action of salt burdened air is the primary cause of concrete deterioration. Case studies are presented, along with discussion of possible remedies including local demolition, reconstruction and epoxy injection as well as concrete treatment.

The Development Of Groundwater For Water Supply, C. F. Mhilu

Tanzania Journal of Engineering and Technology (TJET)

ABSTRACT This paper presents results of groundwater investigations carried out at Yombo Dovya Village, Temeke District in Dar es Salaam Region. The study has included hydrogeological and geoelectric resistivity sounding survey data obtained at the test site in Yombo village. The results of this investigation based on the application of vertical electrical sounding probe predictions have indicated the existence of reasonable amounts of groundwater resource for development. To verify these results borehole drilling tests were also conducted at the same site (Borehole No. DSM 79/99), and the results obtained by this method compares very well with those obtained earlier by …

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 …

An Assessment Of Building Energy Efficiency Options At Horn Island Ranger Station, Gulf Islands National Seashore, Florida Solar Energy Center, Stephen Barkaszi

FSEC Energy Research Center®

As requested by Joe Martin of the National Park Service (NPS), Southeast Support Office, researchers from the Florida Solar Energy Center (FSEC) conducted a building energy efficiency assessment for the ranger station on Horn Island, Mississippi. The assessment included audits and inspections of the energy systems, building thermal performance, appliances, and energy use patterns. FSEC researchers Stephen Barkaszi and John Harrison conducted the audits and on-site inspections June 29 and June 30, 1999. The purpose of the assessment was to evaluate the facility and to present recommendations for improving the energy efficiency of the building. This report summarizes the information …

Method And System For Gas Metal Arc Welding, Yuming Zhang, Liguo E

Electrical and Computer Engineering Faculty Patents

An improved method of gas metal arc welding (GMAW) is disclosed. The method includes utilizing a pulsed current having a variable waveform to ensure the detachment of one-droplet-per-pulse of current. During the welding process, the current is sufficient to produce a droplet at the end of a consumable electrode wire. After the droplet reaches a desired size, the current is lowered to induce an oscillation in the droplet. The current is then increased which, in combination with the momentum created by the oscillation, effects droplet detachment. The oscillation may be monitored by observing the arc voltage to determine a preferred …

Lead-Free Interconnection For Electronic Devices, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

An electronic device that is equipped with a plurality of bonding pads positioned on the device for making electrical interconnections and electrically conductive composite bumps adhered to the bonding pads wherein the bumps are formed of a composite material consisting of a thermoplastic polymer and at least about 30 volume percent of conductive metal particles based on the total volume of the metal particles and the thermoplastic polymer. The present invention is also directed to a method of making electrical interconnections to an electronic device by pressing a plurality of composite bumps of a polymeric based material against a substrate …

Results Using An Alternative Approach To Channel Equalization Using A Pattern Classification Strategy, Frank M. Caimi, Gamal A. Hassan

Electrical Engineering and Computer Science Faculty Publications

In underwater acoustic communication, (ACOMMs), ocean surface and bottom conditions create multi path propagation's for the transmitted signal that result in Inter symbol Interference (ISI) at the receiver. Generally, Equalization, Diversity IBeam forming, and Channel Coding are three independent techniques that are used to improve received signal quality. Equalization compensates for ISI created by a band-limited, time-dispersive channel through implementation of specialized filtering schemes within the receiver. The coefficients of the equalizer need to be continuously adjusted to compensate for the variability in the channel. Since the number of states required by the equalizer (or beam former) is finite, and …

Near-Band-Gap Cupt-Order-Induced Birefringence In Al0.48Ga0.52Inp2, Mathias Schubert, Tino Hofmann, Bernd Rheinlander, Ines Pietzonka, Torsten Sass, Volker Gottschalch, John A. Woollam

Department of Electrical and Computer Engineering: Faculty Publications

The order-induced birefringence in the near-band-gap spectral range (0.75 to 2.5 eV), and its dependence on the degree of ordering η is reported for Al_0.48Ga_0.52InP₂. Transmission and reflection generalized variable angle spectroscopic ellipsometry, dark-field spectroscopy, and cross-polarized reflectance difference spectroscopy (CRDS) are used to determine precisely the room-temperature dielectric functions for polarization parallel and perpendicular to the ordering direction of a series of spontaneously CuPt-ordered samples grown by metalorganic vapor-phase epitaxy. The CRDS technique is introduced as an approach to sense extremely weak anisotropy at oblique angles of incidence. The observed order birefringence is …

Method For Testing Field Programmable Gate Arrays, Charles E. Stroud, Miron Abramovici

Electrical and Computer Engineering Faculty Patents

A method of testing field programmable gate arrays (FPGAs) includes the step of configuring programmable logic blocks of the FPGAs for completing a built-in self-test. This is followed by the steps of initiating the built-in self-test, generating test patterns with the programmable logic blocks and analyzing a resulting response to produce a pass/fail indication with the programmable logic blocks. More specifically, the configuring step includes establishing a first group of programmable logic blocks as test pattern generators and output response analyzers and a second group of programmable logic blocks as blocks under test. The blocks under test are then repeatedly …

United States Patent: Method And System For Estimating The Tenderness Of A Meat Product, Maria Victoria Spadaro, Rosana Moreira, Jimmy Keeton, D. H. Allen

Department of Engineering Mechanics: Faculty Publications

A method for estimating the tenderness of a meat product is provided. The method includes determining the stress relaxation coefficient of a meat sample. One or more physical parameters of the meat sample are then determined from the stress relaxation coefficient. Diagnostic sensory characterization data, such as a numerical estimation of the meat's overall tenderness, is then determined for the meat sample. The physical parameters are then correlated to the diagnostic sensory characterization data, to allow the diagnostic sensory characterization data to be estimated solely from the measured physical parameters.

Method For Providing Discharge Protection Or Shielding, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

Electrostatic discharge protection or electromagnetic interference shielding is provided by applying a composition comprising a thermoset or thermoplastic polymeric matrix, and a conductive filler component, where said filler component comprises electrically conductive particles and at least one conducting polymer to a dielectric substrate.

Aviation Disaster Primer: Psychologies Of Error, Ibpp Editor

International Bulletin of Political Psychology

This article describes common psychological phenomena that often mitigate against accurate induction and deduction of the causes of aviation disasters.

Trends. The Egyptair 990 Crash: A Misconception About Psychological Screening, Ibpp Editor

International Bulletin of Political Psychology

The article discusses the common, publicly promulgated misconception about psychological screening of pilots and other aircrew members in the aftermath of the EgyptAir 990 crash.