Industrial Engineering Commons^™

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.

Measurement Of Dust Resistivity And The Effect Of Filter Operating Parameters On Its Value, S Issangya

Tanzania Journal of Engineering and Technology (TJET)

Methods of measuring electrical sensitivity of a dust layer have been outlined and the porous electrodes cell was used to measure the electrical resistivity of a dust layer and to determine the influence of various parameters. Dust layer thickness and applied voltage had no influence. Resistivity depended on particle size, packing density, temperature, and air relative humidity. Glass beads and limestone powders of different mean particle sizes were used. Temperature was varied from 20–100 °C and air moisture ranged from dry to near saturation. The results may help in understanding the performance of electrically enhanced fabric filters, which are influenced …

Evaluation Of The Influence Of The Magnetic System In Relays, D Chambega

Tanzania Journal of Engineering and Technology (TJET)

The paper evaluates the influence of different cores on the performance of relays. In particular two types ofc-cores, all made from IOW quality mag- netic steel, are considered. The two cores, one butt-constructed and the other interleaved, are mathematically modelled and the tesults are analyzed and obtained experimentally. Then the two sets of results are compared with those ofa c-shaped core of excellent magnetic material with the aim of qualifying the influence of the core material. It is observed that the method of constructing the core also influences the performance.

Power Shedding Experiences And Lessons In A Township, Alexander Kyaruzi

Tanzania Journal of Engineering and Technology (TJET)

This paper presents how power shedding by taking out one of the trans- former high voltage fuses causes phase imbalance. And for the same elec- nicc,l energy output generator fuel consuntption with unbalanced phases is 12.5% of The fuel consunwtion with balanced phases. Furthermore it is shown thal energy efficient lighting by use of energy efficient bulbs can reduce load shedding.

Polymer Supported Z-N Catalysts For C2h4-Polymerization,I: Development Catalyst Preparation Method, S Mteza

Tanzania Journal of Engineering and Technology (TJET)

Substantial improvement of low sensitivity pressure transducers aiming at obtaining a more realistic output signal is discussed. The output signal direct from these transducers has deficiencies of amplitude attenuation and phase lag, thus the measured values are not necessarily the true in- stantaneous values. In order to correct for such shortcomings the unit step response of these transducers is also studied experimentally. A math- ematical model is established based on the experimental results to build up a compensation circuit which is then included in the instrumentation setup to eliminate these deficiencies. The effectiveness of the compensated transducer is demonstrated by …

A Heuristic Procedure For Designing A Cellular Manufacturing System While Minimizing Makespan, Panduranga Badam

Masters Theses

This study is the first of its kind in Group Technology (GT) literature and successfully demonstrates the application of the simulation technique to analyze different alternatives for machine and part grouping problem.

This study considers several aspects such as processing time, sequence of operations, alternative routing, setup time and dynamic shop condition for machine-part grouping. The heuristic developed aims to reduce intercellular moves, setup time and makespan time of parts. It also enables the decision markers to evaluate performance measures and to choose the best alternative at every step of the machine grouping process. Two examples have been used to …

Building Oriented Surface Generation Through Iges Specification, Jujiang Bao

Theses

This thesis focuses the use of Initial Graphics Exchange Specification to generate automatically three dimensional surfaces. Currently, different CAD systems utilize their own data formats to generate graphic databases which are not compatible with one another. Besides, most of the existing CAD systems require an interactive data input process which is very much time consuming. In order to solve above problems, an efficient algorithm has been developed in this research to automatically generate portable graphic database following ICES specifications. This portable graphic database can be adopted by different commercial CAD/CAM systems. Using the proposed method, the current design process can …

Development Of A Knowledge-Based System For Wastewater Pipeline Rehabilitation, David Allen Reaves

Engineering Management & Systems Engineering Theses & Dissertations

The purpose of this thesis is to study and develop a knowledge-based system to make decisions for the rehabilitation of wastewater pipelines. Development includes justification for the use of an expert system, data acquisition from knowledge experts, program model development, model testing, implementation and future considerations including expansion. The model is developed and implemented using an expert system shell called XIPlus ®.

This knowledge-based system is designed specifically for the Navy Public Works Center Utilities Department at Norfolk Naval Base in Norfolk, Virginia for making decisions for the rehabilitation of the 50-year-old wastewater collection system. Recent sewer collapses and a …

Analysis Of Efficiency Measures For Block Diagonal Machine-Component Charts, Hamid Seifoddini, Manocher Djassemi

Industrial Technology and Packaging

Group efficiency measures have been developed to evaluate machine-component charts for the formation of cellular manufacturing systems. In this paper the existing grouping efficiency measures will be evaluated by determining the relationship between the values of a grouping efficiency measure and the performance of the corresponding cellular manufacturing system.

Rear Seat Belt Usage And Comfort, Kuntal Thakurta

Masters Theses

Seat belts have been shown to be effective in reducing car crash fatalities and injuries. Despite consistent evidence that seat belts when worn can provide the greatest vehicle occupant protection of all currently available occupant restraint systems, seat belt use rates remain low. The rates of occupants wearing seat belts in rear seats is much lower than front seat occupants. One of the primary causes for occupants not using seat belts in rear seats has been lack of comfort. The purpose of this thesis was to study the relationship of comfort and seat belt use in rear seats. The current …

A Functional Architecture For Automated Highway Traffic Planning, H.-S. Jacob Tsao

Faculty Publications

In a fully automated Automated Highway System (AHS), the roadside control system and the vehicles themselves are responsible for moving the large number of vehicles safely and efficiently. Therefore, the task of operating an AHS is drastically different from and much more complex than its conventional counterpart. Resulting from a large number of design options, there exist many possible ways to operate an AHS. Each of these possible operating scenarios will support a different set of functions. A crucial task in AHS R&D is to evaluate and compare these potentially large number of different AHS operating scenarios with respect to …

Pulping Of Sisal Fibres: Effects Of Chemical Concentration, Na-Zs03/Na2c03 Ratio And Fibre To Chemical Ratio, J Katima

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on pulping of hard fibres extracted from the leaves Of agave sisalana using sodium sulphite buffered with sodium carbonate as pulping chemical. The cooking was carried Out at 1680Cfor a cooking period of 6 hours, with varying chemical concentration, sodium sulphite to sodium carbonate ratio and fibre to chemical ratio. The results show thar boll! the pulp yield and pulp viscosity decæase with increasing chemi- cal concentration, whereas Kappa number of pulp decreases to a limit of about 16.45. Brightness increases significantly with an increase in the ra- rio of Na2S03/Na2C03. The pulp yield obtained indicated the …

Electricity Consumption Patterns In Domestic House Holds, H Kadete

Tanzania Journal of Engineering and Technology (TJET)

Electricity tariff increases from 1988 to 1992 are presented. They are Compared with salaries paid to parastatal workers over the same period. Monthly expenditures on electricity are also presented. Electricity con- sumption profiles have been recorded. The typical end use electrical ap- pliances for each household category have been identified. About 69% of electricity is used for cooking in high demand households. In medium demand households electricity used for lighting dominates ar about 49%. Measurements indicate a 3 peak power consumption profile for domestic dwellings. Voltages of 180V were recorded instead of the expected 230V nominal. Power factor is nor …

Hazards Inherent In The Use Of Electricity, Alexanda Kyaruzi

Tanzania Journal of Engineering and Technology (TJET)

This paper describes hazards associated with thc use of electricity, empha- sis is given to hazards due to electric shocks. A survey carried Out by the author indicated that 68.5 % of all reported accidents and 55.3 % of all fatal accidents are due to people Coming into contact with normally non current carrying metallic parts. The necessary conditions which need to bc present in an electric system for electric shock to occur are described. How the human body responds to Various severity of electric shock is dis- cussed. Possible solutions, and how to prevent or minimise the effect Of …

Quality Problems Facing Tanzanian Industrial Firms, M Msafiri

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on the results of a study of quality problems facing Tanzanian industrial firms. The results show that Tanzanian firms do not set goals with respect to quality and quality management, thus their qual- ity performance is generally poor. A Ithough there are a number of opera- tional problems constraining the companies, the main problems lie with the internal management of the quality function. Extensive ideas and sug- gestions for improving the performance of the quality function are given.

Measurement Of Dust Resistivity And The Effect Of Filter Operating Parameters On Its Value, Allan Issangya

Tanzania Journal of Engineering and Technology (TJET)

Methods sed to measure the electrical resistivity of a dust layer and to determine the influence of various parameters. Dust layer thickness and applied voltage were found to have no influence. Resistivity depends on particle size, packing density, temperature, and air relative humidity. Glass beads and limestone powders of different mean particle sizes were used. Temperature was varied from 20–100 °C and air moisture ranged from dry to near saturation. The findings may help in understanding electrically enhanced fabric filters, whose performance is influenced by the resistivity of the collected dust layer.

Optimal Capacity Allocation Truck Industry In Tanzania:A Case Of National Transport Corporations(Ntc), R Mgaya

Tanzania Journal of Engineering and Technology (TJET)

This paper tries to examine truck transportation service in Tanzania, particularly, in National Transport Corporation’s subsidiary companies - Regional Transport Companies. It provides an analysis based on operations research approach on resource allocation, specifically, truck allocation, with an aim of trying to minimize running costs and hence improve profits. It is established that there had been higher running costs and hence decline of profits in some Regional Transport Companies due to misallocation of capacity. However, this problem had been compounded by some other factors as discussed in the paper. It is recommended that these Regional Transport Companies and other transport …

Dual Versus Single Spark Plug: A Critique, I Mshoro

Tanzania Journal of Engineering and Technology (TJET)

Dual spark plugs are occasionally employed on certain modern Spark lg- nited (S') engines, viz lean burn engines. Their benefit has generally been noticed in the operating conditions whenfuel-air mixture is very lean, or when a larger proportion of EGR has been employed, or during the part load conditions and so on. An extensive literature survey has indi- cared an interesting spectrum of reasons for gains due to the dual spark plug. A consistent explanation is found to be missing which can describe the behaviour of the engines with single versus dual spark plugs There are quite "few researchers who …

Suitability Of The Present Strategic Information Technology Planning (Sitp) Methodologies To The Developing Countries, A Victor

Tanzania Journal of Engineering and Technology (TJET)

The needfor strategy formulation, or in general terms strategic planning, for IT is considered as one of the most important aspects of IT manage- ment. To this end, there are a number of IT strategy formulation method- ologies world-wide. These methodologies were developed over a span of time, starting from mid 1960's when IT use started to become a serious issue in the developed countries, and continued with the trends in IT de- velopment and use, as was applicable in those countries. Morc recent of the methodologies were developed through improvements on earlier ones, and based on the new challenges …

A Preliminary Model For Lot Sizing In Semiconductor Manufacturing, Tali F. Carmon, Steven Nahmias

Industrial and Manufacturing Engineering

No abstract provided.

An Empirical Investigation Of Total Quality Management (Tqm) Effectiveness In Healthcare Organizations, Lokesh S. Basappa

Masters Theses

American hospitals are implementing quality programs to offer higher quality service at reduced cost. However, the results of these programs in many hospitals have often not met expectations.

This research analyzed the effectiveness of Total Quality Management (TQM). The objective of the study was to better understand how TQM strategies can best be applied by hospitals. An empirical survey was distributed to Michigan hospitals and an analysis was performed to meet this objective.

The survey results show that hospitals involved indirectly with quality programs haven't realized that they are implementing TQM strategies. On the other hand some hospitals say that …

An Ergonomics Approach To Evaluate The Use Of Two Different Fixtures For Upholstering, Maria Luisa Roa

Masters Theses

A furniture company in West Michigan proposed an evaluation of a new fixture that will be used in a repetitive manual stapling operation.

Numerous studies reveal that activities involving repetitive wrist motions cause inflammation in the median nerve that runs through the structure of the carpal wrist, causing a cumulative disorder known as Carpal Tunnel Syndrome (CTS). This syndrome is one of the most prevalent in industrial settings and service companies.

This study investigated if the use of a new design of a fixture had an impact on operators' performances. Three-dimensional comparative analysis was used to observe operators' wrist angular …

A Finite Capacity Queue With Markovian Arrivals And Two Servers With Group Services, Srinivas Chakravarthy, Attahiru S. Alfa

Industrial & Manufacturing Engineering Publications

In this paper we consider a finite capacity queuing system in which arrivals are governed by a Markovian arrival process. The system is attended by two exponential servers, who offer services in groups of varying sizes. The service rates may depend on the number of customers in service. Using Markov theory, we study this finite capacity queuing model in detail by obtaining numerically stable expressions for (a) the steady-state queue length densities at arrivals and at arbitrary time points; (b) the Laplace-Stieltjes transform of the stationary waiting time distribution of an admitted customer at points of arrivals. The stationary waiting …

Capacity Of Automated Highway Systems: Effect Of Platooning And Barriers, H.-S. Jacob Tsao, Randolph Hall, Bruce Hongola

Faculty Publications

The concept of Automated Highway Systems (AHS) is based on the belief that an appropriate integration of control and communication technologies placed on the vehicle and on the highway can lead to a large improvement in capacity and safety without requiring a significant amount of additional highway right-of-way. Stemming from this belief are various conceptual scenarios for vehicle/highway automation.An AHS consists of two major components: vehicle/highway automation technology and highway operating strategy. In this paper, we study the capacity of key AHS operating scenarios.

A Probabilistic Model For Avcs Longitudinal Collision/Safety Analysis, Jacob Tsao, Randolph Hall

Faculty Publications

This paper develops a probabilistic model for analyzing longitudinal collision/safety between an abruptly decelerating vehicle and its immediate follower. The input parameters are the length of the gap between the two vehicles, their common speed prior to the failure, the reaction delay of the following vehicle and a bivariate distribution for the two deceleration rates. The output includes the probability of a collision and the probability distribution of the relative speed at collision time We use this model to compare the safety consequences associated with the platooning and “free-agent” longitudinal-separation rules. We also demonstrate that the free-agent rule implemented with …

Constraints On Initial Ahs Deployment And The Concept Definition Of A Shuttle Service For Ahs Debut, Jacob Tsao

Faculty Publications

Highway automation and its evolution involve a multitude of systems issues. Particularly important and difficult in defining a deployment sequence is the very first step, i.e. the first user service involving fully automated freeway driving. However, this importance and the difficulty imply that many factors may severely constrain the initial deployment. After discussing the paramount importance of initial AHS deployment, this paper points out major high-level issues and constraints. Any realistic deployment strategy must take into consideration gradual technology maturation, introduction of new driver role and diminishing conventional driver role for automated driving, high cost of early-generation automation-equipped vehicles, gradual …

Error Recovery In Intelligent Robotic Workcells, R. D. Borchelt, Sema E. Alptekin

Industrial and Manufacturing Engineering

This paper focuses on the requirements for achieving automated diagnosis and error recovery in a robotic assembly cell. Untended robust operation is the goal which is discussed, and the use of a knowledge-base oriented diagnostic/control system to support on-line error recovery is advocated. It is proposed that error recovery attempts should be made, not only based on information gathered by system sensors, but also by using additional cell-specific knowledge pertaining to recovery strategies. Recovery attempts are to be made even in the absence of complete diagnosis, in order to gather additional information. A control structure developed to implement this approach …

The Importance Of Considering Size Effect Along The Cutting Edge In Predicting The Effective Lead Angle For Turning, William J. Endres, Daniel Waldorf

Industrial and Manufacturing Engineering

The concept of an effective orthogonal cutting edge in turning is considered. The orientation of this edge in the radial-longitudinal plane, as commonly modeled through an effective lead angle, is studied. The methods of effective lead angle prediction used in numerous previously developed force models are plagued with large errors over ranges of process inputs, in particular feed rate and depth of cut. Four previously developed methods of effective lead angle prediction are reviewed and compared to a new method presented here. This new method accounts for the size effect as introduced through the variation in chip thickness along the …