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Process Control and Systems

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Articles 31 - 44 of 44

Full-Text Articles in Industrial Engineering

Optimization In The Application Of Varnishes Barrier On Cartonboard Packaging, Andre Ramalheiro De Andrade, Maria Isabel Rodrigues Phd, Eduardo Luiz Machado Phd Oct 2021

Optimization In The Application Of Varnishes Barrier On Cartonboard Packaging, Andre Ramalheiro De Andrade, Maria Isabel Rodrigues Phd, Eduardo Luiz Machado Phd

Journal of Applied Packaging Research

In this work adjustments in the rotogravure printing process are proposed to the varnish water vapor transmission rate (WVTR) aiming to obtain results smaller than 20g/m²/24h. One case study was used for the propositions for improvements, where focused on varnish application process in a gravure printer for an eight-printing unit cartonboard packaging, maximum printing speed of 175 m/min and a 285 g/m² weight cartonboard. The possible variables that influenced the WVTR result were selected from the technical expertise of the people involved in the project, the analysis in the printing process with the application of directed trials using experimental designs …


The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1 Dec 2019

The Potentials Of Faecal Sludge Treatment Using Local Conditioners In Tanzania: A Review, Doglas Benjamin1

Tanzania Journal of Engineering and Technology (TJET)

Worldwide, every day human beings generate millions of tons of Faecal Sludge (FS), which is rich in water, nutrients, energy, and organic compounds. Yet FS is not being managed in a way that permits us to derive value from its reuse, while at the same time, millions of farmers struggle with depleted soils and lack of water. In most of the developing countries, energy for cooking is mainly derived from cutting of trees, either as wood or charcoal. Resource recovery and reuse from FS can create livelihoods, enhance food security, support green economies, reduce waste and contribute to cost recovery …


On Accounting For Equipment-Control Interactions In Economic Model Predictive Control Via Process State Constraints, Helen Durand Feb 2019

On Accounting For Equipment-Control Interactions In Economic Model Predictive Control Via Process State Constraints, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Traditionally, chemical processes have been operated at steady-state; however, recent work on economic model predictive control (EMPC) has indicated that some processes may be operated in a more economically-optimal fashion under a time-varying operating policy. It is unclear how time-varying operating policies may impact process equipment, which must be investigated for safety and profit reasons. It has traditionally been considered that constraints on process states can be added to EMPC design to prevent the controller from computing control actions which create problematic operating conditions for process equipment. However, no rigorous investigation has yet been performed to analyze whether, when a …


Economic Model Predictive Control Design Via Nonlinear Model Identification, Laura Giuliani, Helen Durand Aug 2018

Economic Model Predictive Control Design Via Nonlinear Model Identification, Laura Giuliani, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Increasing pushes toward next-generation/smart manufacturing motivate the development of economic model predictive control (EMPC) designs which can be practically deployed. For EMPC, the constraints, objective function, and accuracy of the state predictions would benefit from process models that describe the process physics. However, obtaining first- principles models of chemical process systems can be time-consuming or challenging such that it is preferable to develop physics-based process models automatically from process operating data. In this work, we take initial steps in this direction by suggesting that because experiments that are used to characterize first-principles models often target specific types of data, an …


Data-Based Nonlinear Model Identification In Economic Model Predictive Control, Laura Giuliani, Helen Durand Jul 2018

Data-Based Nonlinear Model Identification In Economic Model Predictive Control, Laura Giuliani, Helen Durand

Chemical Engineering and Materials Science Faculty Research Publications

Many chemical/petrochemical processes in industry are not completely modeled from a first-principles perspective because of the complexity of the underlying physico-chemical phenomena and the cost of obtaining more accurate, physically relevant models. System identification methods have been utilized successfully for developing empirical, though not necessarily physical, models for advanced model-based control designs such as model predictive control (MPC) for decades. However, a fairly recent development in MPC is economic model predictive control (EMPC), which is an MPC formulated with an economics-based objective function that may operate a process in a dynamic (i.e., off steady-state) fashion, in which case the details …


Chemical Storage Of Wind Energy By Renewable Methanol Production: Feasibility Analysis Using A Multi-Criteria Decision Matrix, Michael J. Matzen, Mahdi H. Alhajji, Yaşar Demirel Jan 2015

Chemical Storage Of Wind Energy By Renewable Methanol Production: Feasibility Analysis Using A Multi-Criteria Decision Matrix, Michael J. Matzen, Mahdi H. Alhajji, Yaşar Demirel

Department of Chemical and Biomolecular Engineering: Faculty Publications

This study is for the technoeconomic analysis of an integral facility consisting of wind energy-based electrolytic hydrogen production, bioethanol-based carbon dioxide capture and compression, and direct methanol synthesis. ASPEN Plus was used to simulate the facility producing 97.01 mt (metric tons) methanol/day using 138.37 mt CO2/day and 18.56 mt H2/day. A discounted cash flow diagram for the integral facility is used for the economic analysis at various hydrogen production costs and methanol selling prices. The feasibility analysis is based on a multi-criteria decision matrix consisting of economic and sustainability indicators comparing renewable and non-renewable methanol productions. …


Low Volume Dispensing With High Speed Dispensers, Sunny Agarwal Aug 2013

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 …


A Systemic Framework For Implementation Of Tqm Programmes, Emanuel Mjema Dec 2009

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 …


Calibration Of Hdm-4 For Use In Pavement Management Systems (Pms), Nurdin Mushule Dec 2009

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 …


Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor Jun 2006

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 …


Degradation Of Waterfront Reinforced Concrete Structures At The Port Of Dar Es Salaam, I Sanga Jun 2005

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 Dec 2004

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 …


Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo Jun 2004

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.


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 Dec 1999

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 …