Graduate and Professional Student Publications and Conference Presentations

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Smart Soft Actuation System
(Austin Publishing Group, 2015-06-06) Baghbani Kordmahale, Sina; Kameoka, Jun
We have demonstrated the fabrication of cantilever shaped soft material actuator, by integrating soft silicon material with Ti-Ni shape memory alloy (SMA) wires with the diameter of 250 micrometer. A 3D stereo-lithographic printer was used to pattern a polymeric solid mold that had metal notches to fix SMA wires which were integrated in Ecoflex 30 polymer that was dispensed into this mold to pattern cantilever structures. After curing process of Ecoflex 30, the entire soft actuator device was removed from the mold. SMA wires in soft cantilevers were electrically heated to reach their phase transition temperature that extends the length of SMA wires. Because of residual stress of silicone material and extension of SMA wires, and also remarkable SMA wire deflection because of the initial martensite phase, the Ecoflex 30 based cantilever was deflected. The angle of cantilever deflection as function of applied potential difference (or voltage) was investigated.
Causes and Policy Recommendations for Low Contraceptive use in Pakistan
(Humanities and Social Sciences Review, 2017-01) Raza, Fizza
According to Pakistan Demographic and Health Survey (2012-13), Pakistan is the sixth most populous country in the world with existing level of unmet demand for family planning services being as high as 20%; however, the Contraceptive Prevalence Rate (CPR) continues to remain lowest in the region of South Asia. This study is undertaken to analyse the factors that hinders the translation of fertility desires into real contraceptive behaviour. It will first examine the existing literature on the issue to analyse the trends in contraceptive use with respect to various background characteristics such as place of residence, level of education and provincial affiliation. The results of research indicate that contraceptive use differentials have reduced with respect to the variables named above, owing to the success of Lady Health Worker (LHW) programme. However, various other socio-economic and psychological factors such as opposition from husbands and mother in laws, fear of side effects and supply side difficulties as indicated by previous studies on same subject continues to hinder the use of contraceptives in the country.
Development of a Risk Based Inherent Safety Index Using an Integrated Approach
(American Institute of Chemical Engineers, 2018-04-25) Xu, Wei; Zhang, Bin; Sun, Yue; Escobar, Harold; Jain, Prerna; Zhu, Wen; Gopalaswami, Nirupama; Roy, Nitin; Mu, Shanjun; Mannan, M. Sam
The growing demand for petrochemical products and the implementation of new process technologies have made the petrochemical plants more complex; therefore, it becomes more challenging to manage the risk. Traditionally, additional layers of protection were added to prevent incidents, which further adds complexity to the existing process. Inherently safer design aims at managing the risk from the design stage of petrochemical plants, which eliminates the hazard in the process rather than control the risk during operation. When designing a new plant or modifying an existing plant, a safety index system will be helpful to assess the risk level of various options effectively. This can be achieved by considering the inherently safer design principles, i.e., elimination, substitution, moderation, and simplification. In this work, a novel safety index system was developed to cover the life cycle of a process design, which includes the research stage, process development stage, and engineering design stage. This safety index will be used to evaluate the risk level of petrochemical facilities by comparing toxic, flammable, explosive, runaway reaction, dust and physical explosion risks and identify the areas where inherently safer design principles can be used to improve the process. A case study on ethanol synthesis process will be presented for the validation of the index system developed.
Towards the Application of Uncertainty Analysis in Architectural Design Decision-Making
(CuminCAD, 2018-09) Shahsavari, Fatemeh; Koosha, Rasool; Vahid, Milad R.; Yan, Wei; Clayton, Mark J.
To this day, proper handling of uncertainties -including unknown variables in primary stages of a design, an actual climate data, occupants` behavior, and degradation of material properties over the time- remains as a primary challenge in an architectural design decision-making process. For many years, conventional methods based on the architects' intuition have been used as a standard approach dealing with uncertainties and estimating the resulting errors. However, with buildings reaching great complexity in both their design and material selections, conventional approaches come short to account for ever-existing but unpredictable uncertainties and prove incapable of meeting the growing demand for precise and reliable predictions. This study aims to develop a probability-based framework and associated prototypes to employ uncertainty analysis and sensitivity analysis in architectural design decision-making. The current research explores an advanced physical model for thermal energy exchange characteristics of a hypothetical building and uses it as a test case to demonstrate the proposed probability-based analysis framework. The proposed framework provides a means to employ uncertainty and sensitivity analysis to improve reliability and effectiveness in a buildings design decision-making process.
Network-based optimization techniques for wind farm location decisions
(Frontiers of Engineering Management, vol. 5, no. 4, p. 533, 2018, 2018-11-29) CISNEROS-SALDANA, Jorge Ignacio D.; BUTENKO, Sergiy; HOSSEINIAN, mohammadhossein
This study aims to find appropriate locations for wind farms that can maximize the overall energy output while controlling the effects of wind speed variability. High wind speeds are required to obtain the maximum possible power output of a wind farm. However, balancing the wind energy supplies over time by selecting diverse locations is necessary. These issues are addressed using network-based models. Hence, actual wind speed data are utilized to demonstrate the advantages of the proposed approach.
Network-based optimization techniques for wind farm location decisions
(Frontiers of Engineering Management, 2018-11-29) Cisneros-Saldana, Jorge Ignacio
This study aims to find appropriate locations for wind farms that can maximize the overall energy output while controlling the effects of wind speed variability. High wind speeds are required to obtain the maximum possible power output of a wind farm. However, balancing the wind energy supplies over time by selecting diverse locations is necessary. These issues are addressed using network-based models. Hence, actual wind speed data are utilized to demonstrate the advantages of the proposed approach.
Duplicate item. See http://hdl.handle.net/1969.1/172706
(2018-12-19) ;
False Analog Data Injection Attack Towards Topology Errors: Formulation and Feasibility Analysis
(IEEE, 2018-12-23) Cisneros-Saldana, Jorge Ignacio D.; Zhou, Yuqi; Xie, Le
In this paper, we propose a class of false analog data injection attack that can misguide the system as if topology errors had occurred. By utilizing the measurement redundancy with respect to the state variables, the adversary who knows the system configuration is shown to be capable of computing the corresponding measurement value with the intentionally misguided topology. The attack is designed such that the state as well as residue distribution after state estimation will converge to those in the system with a topology error. It is shown that the attack can be launched even if the attacker is constrained to some specific meters. The attack is detrimental to the system since manipulation of analog data will lead to a forged digital topology status, and the state after the error is identified and modified will be significantly biased with the intended wrong topology. The feasibility of the proposed attack is demonstrated with an IEEE 14-bus system.
Single-Phase PQ Inverter Model and Application to Unbalance Compensation in Islanded Microgrids (PSCAD Simulation)
(2019-01-21) Bassey, Ogbonnaya
This is a simulation study of islanded microgrids for black start purpose. The study focuses on the voltage unbalance that results from serving unbalanced loads in the distribution system and how this could be mitigated by the use of three-phase stacked single-phase PQ inverters. Simulation is performed in PSCAD/EMTDC software and the files have been freely made available. Full model and the voltage-controlled source model of the single-phase PQ inverters were developed and incorporated into the case studies.
On the Static Load Performance of a Large Size, Heavily Loaded Spring Supported Thrust Bearing
(Society of Tribologists and Lubrication Engineers, 2019-02-18) Koosha, Rasool; Luis, San Andres
This abstract describes a thermo-elasto-hydrodynamic (TEHD) analysis for prediction of the static load performance of a large size spring-supported thrust bearing (SSTB) operating at a mean surface speed of 20 m/s and 4 MPa specific load. The bearing pads include pockets for hydraulic lift and an internal cooling system with pipes laid out along the radial direction. Pressure induced deformations significantly enlarge the film thickness at the pads’ leading and trailing edges. Pad thermal deformations are lesser, except at the pad trailing edge where cooling lines do not reach. Bearing operation transitioning from a nominal rotor speed to a low rotor speed while the bearing pads remain hot simulates a quick shut-down process. With a hot pad the predictions produce a much lesser fluid film thickness than that arising during a slow shut-down process where the bearing pads cool at a steady rate. The gradient of minimum film thickness versus rotor speed is much higher during the fast shutdown process and which could produce a sudden bearing failure (seizure).
Thermo Hydrodynamic (THD) Computational Analysis For Tilting Pad Thrust Bearings (TPTBs)
(2019-03-27) San Andres, Luis; Koosha, Rasool
The report details a thermo-hydrodynamic (THD) analysis for the static and dynamic force performance of TPTBs. The goal is to deliver a modern predictive tool for TPTBs to be further integrated into the XLTRC2 software suite.The model couples a generalized Reynolds equation for the film pressure, including cross-film viscosity variation and turbulent flow effects, a 3D thermal energy transport equation for the film temperature, and a heat conduction equation for pad temperature. Numerical solution of the governing equations with approximate boundary conditions delivers pressure and temperature fields toward the calculation of a TPTB load capacity, shear drag power loss, and required flow rate. A small amplitude thrust collar motion (perturbation) analysis produces first-order pressure fields to calculate the bearing axial stiffness and damping (frequency reduced) coefficients. To check the accuracy of the model, predictions are benchmarked versus archival test data for a six-pad TPTB (228 mm OD) under specific load of 0.5 to 2.0 MPa and operating with rotor speed of 1.5 to 3.0 krpm (36 m/s). The predictions of the current THD model are in a good agreement with the test data with a maximum difference of 8% for pressure field, 17% for pad temperature, 20% for fluid film thickness, and 8% for power loss.
UNCERTAINTY AND SENSITIVITY ANALYSIS USING BUILDING INFORMATION MODELING (An Energy Analysis Test Case)
(the Association for Computer-Aided Architectural Design Research in Asia (CAADRIA), Hong Kong, 2019-04-15) Shahsavari, Fatemeh; Koosha, Rasool; Yan, Wei
Building design decision-making is associated with uncertainties due to variations over time and unpredictable parameters. There is a growing demand for probabilistic methods, i.e., uncertainty and sensitivity analyses to handle the uncertainties in building design. This research intends to encourage the application of Building Information Modeling (BIM) for addressing design uncertainties affecting building energy performance. The mapping between BIM (Revit and Dynamo) and a customized model-based energy analysis tool in Excel is investigated to translate architectural models to energy models and conduct the probabilistic analyses. The application of this method is demonstrated with a test case of a hypothetical residential unit in College Station, Texas, USA. Input variables in this example are the thermal properties of building elements, and the two simulation outputs are annual heating and cooling energy consumption, and deviation from comfort temperature. The results indicate the probability distribution of simulation outputs and the importance factor of each design input. This method deals with uncertainties and provides a more reliable and robust basis for design decision-making.
A Thermo-Elasto-Hydrodynamic (TEHD) Computational Analysis of Tilting Pad Thrust Bearings: Analytical and FE Pad Structure Models
(2019-05-08) Koosha, Rasool; San Andres, Luis
Work in 2018 extends an earlier (2017) single-pad, laminar flow thermohydrodynamic (THD) model, into a multiple-pad, turbulent flow thermoelastohydrodynamic (TEHD) model for the prediction of the static and dynamic force performance of tilting pad thrust bearings (TPTBs). The updated XLTHRUSTBEARINGR software offers three ways, simple to complex, to account for mechanical and thermal pad deformations in the analysis. The first way relies on an approximate solution, based on a generalization of the EulerBernoulli beam theory, and outputs the axial deformation field on a pad top surface. The second method is an in-house three dimensional (3D) Finite Element (FE) model that accounts for all modes of elastic deformations, both pressure and temperature induced, and delivers a complete 3D pad deformation field. The third method, specific for pads with a complex geometry, provides a user with the option to model the pad in a commercial FE software and to import the (reduced) stiffness matrix into the code. This method only accounts for pad mechanical deformations and produces axial deformations of the pad top surface.
The Negative Impact of Solar Reflections Caused by Reflective Buildings’ Facades: Case Study of the Nasher Museum in Texas
(The 2019 Sustainable Built Environment Conference Proceedings, 2019-05-22) Abdelwahab, Sahar; Elhussainy, Mariam; Labib, Rania
Large reflective facades in buildings can cause severe visual discomfort due to the reflection of sunlight falling on buildings' surfaces. These intense reflections can cause a intolerable glare and contribute to overheating the interior of surrounding buildings. An example of reflective building materials causing glare is experienced in Dallas, Texas, where a residential tower, which was fitted with a fully glazed façade, has caused intense specular reflections into the Nasher sculpture museum. The problem has caused glare and overheating of the interior spaces in the museum, thus leading to the damage and deterioration of the sculptures on display. In order to examine the negative impact of the Museum Tower's reflective façade on the visual comfort inside the Nasher museum, glare simulations are carried out at different times of the year. Additionally, to examine a possible solution to the glare problem, a proposed solution of using a less reflective material on the tower's facade is examined via glare simulations. The initial set of simulations confirmed that tower skin contributed to blinding glare particularly at 12:00 and 15:00 on the summer and winter solstice, and the spring equinox. Use of less reflective material on the tower façade concluded that the tower façade still contributed to glare and that is due to its convex geometry.
PSCAD Implementation of IEEE 123 Node Test Feeder
(2019-05-22) Bassey, Ogbonnaya; Chen, Bo; Butler-Purry, Karen L.; Chen, Chen
The accompanying file is a PSCAD setup of the IEEE 123 node test feeder. In the PSCAD model, the substation transformer has been omitted. The switches default states have been set according to their default setting in the IEEE 123 node test feeder documents. All voltage regulators’ tap settings have been fixed to those obtained in the IEEE results though an option is provided to set each regulator to vary its tap settings with changing primary voltage. The loads are modeled as ZIP loads with values set to be the same with the IEEE test system. The results from the PSCAD simulation closely matches the published result in the original test system. This PSCAD model could potentially be used in such applications as restoration, reconfiguration, distributed generator interconnection and transient simulation studies.
A case study for sensitivity-based building energy optimization
(ARCC Conference Repository, 2019-05-26) shahsavari, Fatemeh; Yan, Wei; Koosha, Rasool
Building design optimization process is associated with uncertainties due to climate change, unpredictable occupant behavior, and physical degradation of building material over time. The inherent uncertainties in the design process reduce the reliability and robustness of the optimal design solution(s) and affect design decision-making results. This research studies the capabilities of parametric design tools in adopting probabilistic methods to handle uncertainties in building performance optimization. Variance-based methods, e.g., Monte Carlo sensitivity analyses are implemented to identify the most critical parameters in design optimization problems and improve the efficiency of design optimization. The optimal solutions achieved with variance-based methods are satisfying the design objectives more efficiently, also remain robust to changes and uncertainties.
Appendices - Parent-Coaching in a Multimodal Communication Intervention for Children with Autism
(2019-05-28) Liao, Ching-Yi; Ganz, Jennifer; Wattanawongwan, Sanikan; Haas, April; Ura, Sarah; Vannest, Kimberly; Morin, Kristi
Appendices - Effects of a Parent-Mediated Multimodal Communication Intervention on Children with Autism Spectrum Disorder
(2019-05-28) Liao, Ching-Yi; Ganz, Jennifer; Wattanawongwan, Sanikan; Haas, April; Ura, Sarah; Vannest, Kimberly; Morin, Kristi
Operational Behavioral Definitions
(2019-06-23) Liao, Ching-Yi; Ganz, Jennifer; Wattanawongwan, Sanikan; Haas, April; Ura, Sarah; Vannest, Kimberly; Morin, Kristi
Finite element formulation of variable thickness plates
(2019-08-11) Ravaji, Babak
The intense competition between companies especially in automotive industries, pushes the engineers and designers to safer and cheaper products every day. Multi-variable and multi-strength blanks known as Tailor Welded Blanks (TWB’s) are one of the breakthrough improvements in designing and manufacturing of the automotive bodies in the past decade. Mass producing TWB is possible thanks to the advent of fast and reliable laser welding for steel alloys and friction and stir welding for aluminum alloys. Tailor welded blanks are made from individual sheets of steel of different thickness, strength and coating which are joined together by laser welding. This process allows for right properties in the right place. In this report the governing equations of the first-order shear deformation theory for plates and its application via finite element method in addition to the capability of modeling variable thickness plate is studied.

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