Chemical Engineering Commons^™

Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar

SIUE Faculty Research, Scholarship, and Creative Activity

This article studies the strong stability of scalar difference equations of continuous time in which the delays are sums of a number of independent parameters tau_i, i = 1, 2, . . . ,K. The characteristic quasipolynomial of such an equation is a multilinear function of exp(-tau_i s). It is known that the characteristic quasipolynomial of any difference equation set in the form of one-delayper- scalar-channel (ODPSC) model is also in such a multilinear form. However, it is shown in this article that some multilinear forms of quasipolynomials are not characteristic quasipolynomials of any ODPSC difference equation set. The equivalence …

Strong Stability Of A Class Of Difference Equations Of Continuous Time And Structured Singular Value Problem, Qian Ma, Keqin Gu, Narges Choubedar

SIUE Faculty Research, Scholarship, and Creative Activity

This article studies the strong stability of scalar difference equations of continuous time in which the delays are sums of a number of independent parameters τi, i = 1, 2, . . . , K. The characteristic quasipolynomial of such an equation is a multilinear function of e−τis. It is known that the characteristic quasipolynomial of any difference equation set in the form of one-delay-per-scalar-channel (ODPSC) model is also in such a multilinear form. However, it is shown in this article that some multilinear forms of quasipolynomials are not characteristic quasipolynomials of any ODPSC difference equation set. The equivalence between …

Drawing And Twisting Of Graphene Fibers, Gregory T. Lane, Robert J. Sekerak, Isaias Diaz

Mechanical Engineering

The aim of this project was to develop a more automated process for drawing and twisting of graphene fibers than was currently in place. This was implemented by having two chemical baths with variable speed rollers at either end, and intermediate roller to spool fiber between stages, and a twisting cylinder with integral spool to twist the fiber as it is collected. The goal was to have this first iteration deliver a working prototype, however due to manufacturing delays and timing constraints, that will be missed. A second follow-on project would be able to continue the work presented here and …

Process Control Laboratory Skid Refurbishment, Danny Crowder

Williams Honors College, Honors Research Projects

This project evaluates a salvaged process control skid for potential refurbishment and educational re-use. In-lab work evaluated the existing skid. Several process control elements have been recommended for replacement, including the process tank (due to corrosion), the pressure transmitter (operability/corrosion), the flow meters (mechanical) and the control system (age). The control valves, temperature elements and transmitters, pump, holding tanks, and the electrical heat exchanger should be salvaged. An I/P converter and pressure relief valve should be added to the pneumatic feed. Enclosing of all electrical components should be prioritized. An electrical schematic for a new control system should be implemented. …

Use Of Natural Ores As Oxygen Carriers In Chemical Looping Combustion: A Review, Michael J. Matzen, Jessica Pinkerton, Xiaomeng Wang, Yaşar Demirel

Department of Chemical and Biomolecular Engineering: Faculty Publications

Chemical looping combustion (CLC) has gained considerable ground in energy production due to its inherent carbon capture with a minimal energy penalty. The choice of metal oxide used as an oxygen carrier (OC) in CLC has a substantial weight on the overall efficiency of energy production as well as the ultimate cost per MW. While much work has gone into manufacturing synthetic OCs with high fuel conversions, harsh operating conditions and process limitations cause some unavoidable loss of the oxygen carrier. With low production costs and minimal conditioning required, natural ores have grown in interest as cheap alternative oxygen carriers. …

Delay-Independent Stability Analysis Of Linear Time-Delay Systems Based On Frequency, Xianwei Li, Huijun Gao, Keqin Gu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper studies strong delay-independent stability of linear time-invariant systems. It is known that delay-independent stability of time-delay systems is equivalent to some frequency-dependent linear matrix inequalities. To reduce or eliminate conservatism of stability criteria, the frequency domain is discretized into several sub-intervals, and piecewise constant Lyapunov matrices are employed to analyze the frequency-dependent stability condition. Applying the generalized Kalman–Yakubovich–Popov lemma, new necessary and sufficient criteria are then obtained for strong delay-independent stability of systems with a single delay. The effectiveness of the proposed method is illustrated by a numerical example.

Effect Of Packaging Material On Color Properties Of Catsup Tomato Sauce, Naser Kohan-Nia, Babak Pakbin, Razzagh Mahmoudi, Omid Fakhri

Journal of Applied Packaging Research

Catsup and tomato sauce products currently are one of the most popular and commercially available table sauces particularly consumed by young people and families around the world in recent decades. In this study colorimetric properties of catsup sauce samples including L*, a* and b* values in different packaging materials including PP, PE, PET, Glass and Sachet have been investigated during and after 180 days storage time at 22̊ C (environmental temperature). Hunter Lab system has been used to evaluate the color values of sauce samples. According to obtained results of experimental measurements and sensory evaluations, PP and PE packaging materials …

Pilot Scale Demonstration And Evaluation Of Innovative Non-Deslimed Non-Classified Gravity-Fed Hm Cyclone, Yumo Zhang

Theses and Dissertations--Mining Engineering

Coal preparation plants are required in some cases to produce a high-grade product using a low specific gravity cut-point. For these situations, a second higher gravity separation would be desirable to generate a mid-grade product that can be utilized for electricity generation thereby maximizing coal recovery. A study was conducted to evaluate the potential of achieving efficient separations at two different density cut-points in a single stage using a three-product dense medium cyclone. Variations in density cut-point and process efficiency values were quantified as a function of the feed medium density, feed medium-to-coal ratio, and feed pressure using a three-level …

Temperature Control Of An Emulsion Polymerization Process, Evan M. Arnold

Williams Honors College, Honors Research Projects

The project premise was to create a new temperature control scheme for an emulsion polymerization process at the pilot scale with intentions of implementing the system into a production facility in the near future. The data was collected using electronic instrumentation at a current emulsion polymerization pilot plant facility in real-time and saved in a Microsoft Excel format. The control scheme was based on three parameters: the rate of change, temperature dead band around the set point to determine heating or cooling, and a jacket fluid clamp temperature. After research and experimentation on actual emulsion polymerization batches it was determined …

The Synthesis Of Solid Supported Palladium Nanoparticles: Effective Catalysts For Batch And Continuous Cross Coupling Reactions, Kendra W. Brinkley

Theses and Dissertations

Catalysis is one of the pillars of the chemical industry. While the use of catalyst is typically recognized in the automobile industry, their impact is more widespread as; catalysts are used in the synthesis of 80% of the US commercial chemicals. Despite the improved selectivity provided by catalyst, process inefficiencies still threaten the sustainability of a number of synthesis methods, especially in the pharmaceutical industry. Recyclable solid supported catalysts offer a unique opportunity to address these inefficiencies. Such systems coupled with continuous synthesis techniques, have the potential to significantly reduce the waste to desired product ratio (E-factor) of the production …

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. …

Water System For Developing Countries / Disaster Relief Made With Local Materials, Shumon Hasan

Chemistry & Biochemistry Undergraduate Honors Theses

The objective of this project was to design a water purification system that can be constructed from easily available materials, common to the particular country, and is capable of the complete water purification process.

Formulation And Solution Of Contingency Constrained Acopf Problem With Pyomo, Stefanus D. Winarto, Jianfeng Liu, Carl D. Laird

The Summer Undergraduate Research Fellowship (SURF) Symposium

Power grids scattered around the world bring great importance to society as they are challenged to provide economically efficient and reliable power market. With consideration of possible system contingency, which refers to multi-scenario optimization where each scenario considers an individual transmission element failure, the determination of optimal generators’ set points in the transmission network is becoming even more essential and challenging. A problem formulation is developed to solve the optimal allocation and minimize the total operating cost for the nominal case while including a large number of contingency scenarios. To achieve that goal, traditional ACOPF (AC optimal power flow model) …

Orientation-Dependent Pseudomorphic Growth Of Inas For Use In Lattice-Mismatched Mid-Infrared Photonic Structures, Gregory Edward Triplett, Charles Meyer, Emily Cheng

Electrical and Computer Engineering Publications

In this study, InAs was deposited on GaAs (100) and GaAs (111)B 2 degrees towardssubstrates for the purpose of differentiating the InAs growth mode stemming from strain and then analyzed using in-situ reflection high energy electron diffraction, scanning electron microscopy, Raman spectroscopy, reflectance spectroscopy, and atomic force microscopy. The procession of InAs deposition throughout a range of deposition conditions results in assorted forms of strain relief revealing that, despite lattice mismatch for InAs on GaAs (approximately 7%), InAs does not necessarily result in typical quantum dot/wire formation on (111) surfaces, but instead proceeds two-dimensionally due primarily to the surface orientation.

Developing Process Control Experiments For Undergraduate Chemical Engineering Laboratories, Chase M. Swaffar

Graduate Theses and Dissertations

It is the intent of this work to develop a process control apparatus and series of experiments that will help students visualize the PID (Proportional-Integral-Derivative) control of a process and enhance their understanding of the subject. The apparatus is a computer-controlled PID mixing system that responds quickly to set point changes and process disturbances which are directly observable. The system can easily be simulated with a transfer function model in Matlab's Simulink, so that the controller can be optimized for the desired system response. Four experiments can be conducted with this system including: exploration of system modeling and controller optimization …

Tin Sensitization For Electroless Plating, Xingfei Wei

Graduate Theses and Dissertations

The tin sensitization process has been used in electroless plating since 1940s Brenner and Riddell developed the electroless plating for surface metallization method. It was found to be an interesting topic to study tin sensitization for chemically controlling metal deposition on different substrates, because the tin sensitization process had critical effects on the electroless plated metal thin films. Nowadays electroless plating metal deposition is still an important method for depositing metals. It has a few advantages over the vapor deposition and electrodeposition method, such as work in an ambient condition, on nonconductive substrates, and without extra power input. Applying electroless …

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 …

Development Of A High Precision Quantum Dot Synthysis Method Utilizing A Microfluidic Reactor And In-Line Fluorescence Cell, Harry Lafferty, Jonny Hoadley

Materials Engineering

Quantum dots show great potential for use as spectral converters in solar cells, lighting applications and biological imaging. These applications require precise control of quantum dot size to maximize performance. The fluorescence profile of quantum dots in solution correlates directly with particle size. An alternative, high precision process was developed for the synthesis of cadmium-selenide quantum dots using a microfluidic reactor and fluorescence flow through cell. The process required creating separate cadmium and selenium precursors that were then mixed in a nitrogen environment at 17± 1°C. Using an NE-300^® syringe pump, the solution was pumped through a microfluidic reactor …

Energy Audit In Wastewater Aeration System, Dinesh R. Kandel, Jacimaria R. Batista, Sajjad Ahmad

College of Engineering: Graduate Celebration Programs

To evaluate the energy consumption air to aeration basins in wastewater treatment aeration system and to compare the standard computations of oxygen demand and blower power requirements with the actual plant data.

Froth Flotation Performance Enhancement By Feed Cavitation And Magnetic Plastic Particle Addition, Mehmet Saracoglu

Theses and Dissertations--Mining Engineering

Froth flotation is the most commonly used process to recover and upgrade the portion of the coal preparation plant feed that has a particle size smaller than 150 microns. Problems that occur when employing froth flotation in the coal industry include i) coal surfaces that are weakly-to-moderately hydrophobic, and ii) flotation systems that are overloaded and limited by insufficient retention time.

Research was performed to evaluate techniques that could be implemented to improve flotation performance under the aforementioned scenarios. Pre-aeration of flotation feed using a cavitation system was extensively evaluated in laboratory and full-scale test programs. The benefits of adding …

Modeling, Fabrication And Characterization Of Scalable Electroless Gold Plated Nanostructures For Enhanced Surface Plasmon Resonance, Gyoung Gug Jang

Graduate Theses and Dissertations

The scientific and industrial demand for controllable thin gold (Au) film and Au nanostructures is increasing in many fields including opto-electronics, photovoltaics, MEMS devices, diagnostics, bio-molecular sensors, spectro-/microscopic surfaces and probes. In this study, a novel continuous flow electroless (CF-EL) Au plating method is developed to fabricate uniform Au thin films in ambient condition. The enhanced local mass transfer rate and continuous deposition resulting from CF-EL plating improved physical uniformity of deposited Au films and thermally transformed nanoparticles (NPs). Au films and NPs exhibited improved optical photoluminescence (PL) and surface plasmon resonance (SPR), respectively, relative to batch immersion EL (BI-EL) …

New Approaches In Automation, Allen Lam

Hong Kong Innovative Users Group Meetings

No abstract provided.

A Review Of Some Subtleties Of Practical Relevance, Keqin Gu

SIUE Faculty Research, Scholarship, and Creative Activity

This paper reviews some subtleties in time-delay systems of neutral type that are believed to be of particular relevance in practice. Both traditional formulation and the coupled differential-difference equation formulation are used. The discontinuity of the spectrum as a function of delays is discussed. Conditions to guarantee stability under small parameter variations are given. A number of subjects that have been discussed in the literature, often using different methods, are reviewed to illustrate some fundamental concepts. These include systems with small delays, the sensitivity of Smith predictor to small delay mismatch, and the discrete implementation of distributed-delay feedback control. The …

A Direct Sampling Particle Filter From Approximate Conditional Density Function Supported On Constrained State Space, Sridhar Ungarala

Chemical & Biomedical Engineering Faculty Publications

Constraints on the state vector must be taken into account in the state estimation problem. Recently, acceptance/rejection and projection methods are proposed in the particle filter framework for constraining the particles. A weighted least squares formulation is used for constraining samples in unscented and ensemble Kalman filters. In this paper, direct sampling from an approximate conditional probability density function (pdf) is proposed. It is obtained by approximating the a priori pdf as a Gaussian. The support of the conditional density is a subset of the intersection of two supports, the 3-sigma bounds of the priori Gaussian and the constrained state …

Applied Control Strategies At A Cogeneration Plant, Joseph William Burns

Master's Theses

The purpose of this paper is to demonstrate the effectiveness of “classical strategies for dynamic control” on authentic cogeneration processes. These strategies are applied to several processes at the University of Connecticut’s cogeneration plant. Case studies of their applications are presented in this paper. Strategies that are applied include the following:

1) The classical SISO feedback structure

2) The First Order Plus Dead Time (FOPDT) process model

3) The Internal Model Control (IMC) correlations for PI controller tuning

4) Static feed forward with feedback trim

5) Cascade Control

Running Head: Analysis Of The Just In Time Inventory System At Uhs Wilson Medical Center, Kyle P. Roeber

MPA Capstone Projects 2006 - 2015

In November 2007, United Health Services Materials Management implemented a Just in Time Inventory system to have a tighter control of their supply chain. This project examines the accuracy of the par levels currently employed by the United Health Services and the financial impact of operating a Just in Time inventory system using inaccurate inventory and par levels. In addition, the project researches other hospitals using JIT inventory management systems to compare implementation and management practices of JIT process.

Retrofit Of Distillation Columns In Biodiesel Production Plants, Nghi Nguyen, Yaşar Demirel

Yaşar Demirel Publications

Column grand composite curves and the exergy loss profiles produced by the Column-Targeting Tool of the Aspen Plus simulator are used to assess the performance of the existing distillation columns, and reduce the costs of operation by appropriate retrofits in a biodiesel production plant. Effectiveness of the retrofits is assessed by means of thermodynamics and economic improvements. We have considered a biodiesel plant utilizing three distillation columns to purify biodiesel (fatty acid methyl ester) and byproduct glycerol as well as reduce the waste. The assessments of the base case simulation have indicated the need for modifications for the distillation columns. …

Electrodeposition Of Tin Using Tin (Ii) Methanesulfonate From Mixture Of Ionic Liquid And Methane Sulfonic Acid., Yang Kok Kee

Student Works (2010-2019)

The electrodeposition of tin from Tin(II) Methane Sulfonate (MSA) with varying concentration in air and water stable 1-butyl-1-methyl-pyrrolidinium trifluoromethanesulfonate, (BMPOTF) ionic liquid at room temperature was studied. Cyclic Voltammetry served to characterize the electrochemical behavior of tin reduction and oxidation. The diffusion coefficient of stannous ions in the mixture of BMPOTF ionic liquid and MSA based electrolyte obtained via Randles-Sevcik and Cottrell equation was 2 × 10-7 cm2/s. Electroplating on copper panel was conducted under different current densities to determine BMPOTF based tin plating solution current efficiency. Mixture of BMPOTF and MSA based tin plating solution gave current efficiency as …

Optimization Of Inductively Coupled Plasma Dry Etching For Planar Waveguide Fabrication., Lim Weng Hong

Student Works (2010-2019)

Optimization of the Inductively Coupled Plasma (ICP) dry etching process parameters has been carried out. Seven main etching characteristics were considered in order to produce good etching quality. These characteristics are glass etching rates, selectivity of chromium to glass etching rate, channel side wall roughness, channel side wall vertical profile, channel cleanliness, critical dimension and resolution. Several ICP parameters that are affecting the etching characteristic were optimized in this work. These optimised ICP parameters obtained from this work are ICP power (880 W), bias power (45 W), operating chamber pressure (10 mtorr), reactant gas composition, reactant gas flow rate (35sccm …

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 …