Engineering Commons^™

Research On Mppt Methods For Photovoltaic System Based On Microgrid, Jingchu Ji

Theses

This thesis introduces some basic concepts about a microgrid. Then it discusses the structure of photovoltaic system (PVS) which contains a solar panel and simplified PV models. Next, it discusses and compares different methods for Maximum Power Point Tracking (MPPT) with PVS. It presents three types of DC-DC converters -- Buck, Boost and Buck-Boost converter. This work proposes to apply a DC-DC converter of Buck-Boost type to make PVS controllable because this type of converter has the largest range for operational region so that it can get the best result on MPPT. Finally, this thesis presents a kind of new …

Engineering Spores To Display G Protein-Coupled Receptors For Directed Evolution, Alyssa Misoo Kim

Theses

All human cells are surrounded by a plasma membrane made from a phospholipid bilayer, which is responsible for maintaining a biologically active species, while stopping entry of deleterious substances from the outside. G protein-coupled receptors (GPCRs) are the membrane proteins, which transmit signals across the cell membrane. GPCRs are involved in almost every physiological process, and irregular control leads to pathological conditions. Therefore, they are major drug targets. Crystal structure determination is required to understand the molecular details of activation/deactivation. However, GPCRs are difficult to crystallize because of stability issues. An efficient protein engineering system needs to be developed. The …

Study Of Poly (L-Lactic Acid)/Poly (D-Lactic Acid) Stereocomplex As Nucleating Agent For Poly (L- Lactic Acid) Crystallization, Yuan Lao

Theses

Poly (lactic acid) (PLA) is a biodegradable polymer with good renewability and processability. However, it has some drawbacks. The Poly (lactic acid) (PLA) stereocomplex formed via the interaction between optical isomers Poly (L-lactic acid) (PLLA) and Poly (D-lactic acid) (PDLA), provides improvements on PLA thermomechanical properties. To investigate the nucleating effect brought by the PLA stereocomplex, samples of PLLA blended with different content of PDLA are prepared by the solution casting method. With different cooling rates (5, 15, 25 °C/min), DSC non-isothermal crystallization experiments are performed. The results suggest that in the presence of the stereocomplex, the PLLA crystallization temperatures …

Batch Foaming Of Hot Melt Extruded Excipient/Disintegrant/Api Pharmaceutical Formulations And The Study Of The Effects Of The Resulting Cellular Structures On Api Dissolution, Na Yao

Theses

This thesis focuses on the impact of a disintegrant included in a foamed immediate release system composed of a polymer excipient and an Active Pharmaceutical Ingredient (API). Indomethacin (INM) is used as model API; Eudragit® EPO (EPO) is used as polymer excipient; AcDiSol and Crospovidone (Cros) are used as two kinds of disintegrant. The main objectives are to gain an understanding of the resulting morphologies, as well as the impact of disintegrants on drug release from foamed polymeric matrices.

In the first part of this research, the Hot Melt Extrusion (HME) process is used to compound the following pharmaceutical formulations: …

Finite Element Modeling Of Temperature Elevation Due To Nir Exposure In Neural Tissue, Atabek Can Yucel

Theses

Near infrared (NIR) lasers have been used in various types of medical applications. Heating is one of the most important concerns in the neural tissue when illuminated with NIR light. Rodent models are frequently used to study laser-tissue interactions. As a part of ongoing research project in the neural interface laboratory, direct measurements of temperature in the rat brain cortex as a response to a pulsed sequence of NIR laser beam are available. In this thesis, finite element modeling approach is used to model and simulate the temperature elevation in neural tissue under the effect of NIR laser pulsing. Steady …

Effect Of Scan Time On Resting State Parameters, Dhruti Patel

Theses

In the past decade the interest in studying the spontaneous low-frequency fluctuations (LFF) in a resting-state brain has steadily grown. By measuring LFF (< 0.08 Hz) in blood-oxygen-level-dependent (BOLD) signals, resting-state functional magnetic resonance imaging (rs-fMRI) has proven to be a powerful tool in exploring brain network connectivity and functionality. Rs-fMRI data can be used to organize the brain into resting state networks (RSNs). In this thesis, rs-fMRI data are used to determine the minimum data acquisition time necessary to detect local intrinsic brain activity as a function of both the amplitude of low frequency fluctuations (ALFF) and the fractional amplitude of low frequency fluctuations (fALFF) in BOLD signals in healthy subjects. The data are obtained from 22 healthy subjects to use as a baseline for future rs-fMRI analysis. Voxel-wise analysis is performed on the whole brain, gray matter volume, and two previously established RSNs: the default mode network (DMN) and the visual system network, for all the subjects in this study.

Pearson’s correlation coefficients (r-values) are calculated from each subject. The entire time series for one subject is divided into 31 subsections and the r-values are calculated between each consecutive subsection in a subject. In total, there are 30 r- values. To better understand what the results mean across subjects and within subjects Fisher transformations are applied to the 30 calculated r-values for each subject to get a normal z-distribution. The mean across 22 subjects’ z-values is …

Hydrodynamic Effects Of A Cannula In A Usp Dissolution Testing Apparatus 2, Qianqian Liu

Theses

Dissolution testing is routinely used in the pharmaceutical industry to provide in vitro drug release information for drug development and quality control purposes. The USP Testing Apparatus 2 is the most common dissolution testing system for solid dosage forms. Usually, sampling cannulas are used to take samples manually from the dissolution medium. However, the inserted cannula can alter the normal fluid flow within the vessel and produce different dissolution testing results.

The hydrodynamic effects introduced by a permanently inserted cannula in a USP Dissolution Testing Apparatus 2 were evaluated by two approaches. Firstly, the dissolution tests were conducted with two …

Detection Of Video Frame Insertion Based On Constraint Of Human Visual Perception, Lu Zheng

Theses

Recently, due to availability of inexpensive and easily-operable multimedia tools, digital multimedia technology has experienced drastic advancements. At the same time, video forgery becomes much easier and makes more difficult to validate the video content. Consequently, the origin and integrity of video can no longer be taken for granted. A methodology is developed that is capable of detecting the video frame insertion based on the constraint of human visual perception. The main idea is based on the so-called differential sensitivity. That is, that the variation of brightness of neighboring video frames has some constraint. First, the video sequence is partitioned …

Methane Partial Oxidation Over Phthalocyanine Catalyst, Yuan Zhu

Theses

The partial oxidation reaction of methane over a zeolite-supported ruthenium phthalocyanine catalyst is studied in a packed bed reactor. The investigation of such reaction is desirable because partial oxidation of methane yields a synthesis gas that can be upgraded to liquid chemicals and fuels.

Reactants of this study are He-diluted CH₄ and O₂. The effluent includes unreacted CH₄ and O₂, He, CO, CO₂, H₂, and H₂O vapor. Thermal conductivity gas chromatography is applied to identify the mole fractions of reactants and products. System pressure is maintained at 50 …

Production Of Stable Bcs Class Ii Drug Suspensions By Melt Emulsification And Subsequent Incorporation Into Polymer Strip Films, Emanuel Joseph Vizzotti

Theses

One of the ways to improve the dissolution rate of poorly water-soluble drugs is to produce fine drug particles with increased surface area. This increase will lead to bioavailability enhancement. However, smaller drug particles are thermodynamically unstable and tend to aggregate or grow. Therefore, proper formulation and process parameters must be chosen to keep the particles small. In this study, fine drug particles of two model drugs, fenofibrate and ibuprofen, are prepared by the melt emulsification technique. The influence of suspension formulation (i.e., the inclusion of polymers and surface-active agents) on particle stability is investigated. Moreover, different agitation techniques during …

Power Dissipation And Mixing Time In A Partially Filled Pharmaceutical Reactor Equipped With A Retreat-Blade Impeller At Different Fill Ratios, Aniruddha Banerjee

Theses

Glass-lined, stirred reactors and tanks are of significant industrial importance, especially in the pharmaceutical and fine chemical industries. These reactors are manufactured with a “glass-lining,” i.e., a glass layer applied to the agitator, the inside of the reactor/tank and to any of the surfaces in contact with its contents in order to maximize corrosion resistance, facilitate reactor cleaning, and minimize product contamination. Because of glass-lining fabrication issues, a retreat blade impeller with a low impeller clearance off the tank bottom is commonly used in glass-lined reactors. In addition, since wall baffles cannot be easily mounted on the wall of glass-lining …

Model Predictive Control For Building Temperature Regulation, Weiqiang Dong

Theses

With the rapid increase in human consumption of energy, global warming is becoming an urgent problem. According to the past research, a significant part of greenhouse gas release and electricity consumption has been connected to buildings. Heating systems are the major contributor to high energy consumption of buildings. Better methods for decreasing energy consumption of buildings should be proposed and applied.

Model predictive control is widely used in building temperature regulation. Each model predictive control has its advantage. Through the comparison of several methods, this thesis discusses their respective features. The combination of a Matlab-based modeling system CVX and model …

Hollow Fiber Membrane-Based Air Gap Membrane Distillation, Xuan Wang

Theses

Membrane Distillation (MD) is a thermally-driven separation process. In this research, desalination of 1 % NaCl solution is achieved by one type of MD namely, Air Gap Membrane Distillation (AGMD). The characteristics of AGMD are evaluated by using a hollow-fiber-set-based compact device. Hot brine solution and cold water are passed through two different fiber sets separately: porous hydrophobic polyvinylidene fluoride hollow fibers of the E type (PVDF E) and solid polypropylene (PP) hollow fibers. Vapor from the hot brine crosses the membrane pores of the PVDF fibers and the air gap, and finally condenses over the surface of solid hollow …

Measurement Of Gas Flow Through Porous Structures Using Thz Spectroscopy, Yihui Wang

Theses

Comparing THz transmission through a sample with the transmission through free-space allows one to calculate the THz absorbance of a sample. Previous studies have focused on using THz absorbance to measure the diffusion of liquid through materials. In this study, the ability of THz spectroscopy to measure the flow of gas in a porous material, packaging foam, is investigated. Specifically, Terahertz spectroscopy from 0.5 to 0.7 THz is used to measure the THz absorption of 1, 1 -difluoroethane. Several experiments are performed to test the ability of THz spectroscopy to measure the flow of gas in a porous material: (1) …

Qsar Modeling Of Chemical Penetration Enhancers Using Novel Replacement Algorithms, Hui Qiu

Theses

The applications of transdermal delivery are limited because of the resistance of the skin to drug diffusion. Only potent drugs, with molecular weight less than 500 Da, are suitable to cross the skin barrier. Chemical Penetration Enhancers (CPEs) are used to promote the absorption of solutes across the dermal layers. In this investigation, a Quantitative Structure-Activity Relationship (QSAR) model is applied to relate chemical penetration enhancer structures with the flux enhancement ratio through a statistical approach.

A database, consisting of 61 non-polar CPEs, is selected for the study. Each compound is represented by 777 QSAR descriptors, which encode the physical …

Dissolution Of Different Commercial Aspirin Tablets Using A Novel Off-Center Paddle Impeller (Opi) Dissolution Testing System, Yang Qu

Theses

Dissolution testing is routinely conducted in the pharmaceutical industry to provide in vitro drug release information for quality control purposes. The most common dissolution testing system for solid dosage forms is the United States Pharmacopeia (USP) Dissolution Testing Apparatus 2. In this work, a modified Apparatus 2, termed "OPI" System for "off-center paddle impeller," in which the impeller is placed 8 mm off center in the vessel is tested to determine its sensitivity to differentiate between the dissolution profiles of differently formulated and manufactured tablets. Dissolution tests are conducted with both the OPI System and the Standard System using three …

Nir Light Transmission Through Skin And Muscle, Deniz Ozgulbas

Theses

Light has been used extensively in the medical field for both therapeutic and diagnostic applications. Tissue optical window or therapeutic window defines the range of wavelengths where the light has the maximum transmittance through tissue. In this range, absorption and scattering effects are relatively lower when compared to the visible or middle infrared wavelengths. Knowledge of the transmittance through tissue can help determine the effective light intensities in medical applications.

The objective of this thesis is to determine the NIR light transmission through different thicknesses of animal tissue and its spatial spread due to the scattering effect. Primarily pork skin …

Brain Computer Interface Based Neurorehabilitation Technique Using A Commercially Available Eeg Headset, Abhineet Mishra

Theses

Neurorehabilitation has recently been augmented with the use of virtual reality and rehabilitation robotics. In many systems, some known volitional control must exist in order to synchronize the user intended movement with the therapeutic virtual or robotic movement. Brain Computer Interface (BCI) aims to open up a new rehabilitation option for clinical population having no residual movement due to disease or injury to the central or peripheral nervous system. Brain activity contains a wide variety of electrical signals which can be acquired using many invasive and non-invasive acquisition techniques and holds the potential to be used as an input to …

Current Measurements In Electrospinning, Clinton K. Lien

Theses

Electrospinning provides an economical method of producing nanofibers. The current carried by the main spinning jet is found to be one of the factors in determining the diameter of the fiber product. However, current sources such as the corona discharge and secondary jets will lead to a systematic overestimation of the actual current value.

In this research, experiments with different configurations are set up to investigate the influence of various parameters on the measured current. It is noticed that the measured current is nearly independent on the flow rate of the solution and the external cover. A large amount of …

Effects Of Api Particle Size On The Dissolution Rate In Molten Polymer Excipient Matrices During Hot Melt Extrusion, Conducted In A Co-Rotating Twin-Screw Extruder, Meng Li

Theses

The effect of the Active Pharmaceutical Ingredient (API) particle size on the dissolution rate in the polymer excipient during hot melt extrusion is investigated using a co-rotating twin-screw extruder with three different screw configurations. Acetaminophen (APAP) and amphiphilic polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (PVCap-PVAc-PEG) (Soluplus) are chosen as the model API and water- soluble polymer excipient, respectively. APAP is milled using a fluid energy mill (FEM) into two different particle sizes. The thermal properties of processed samples are characterized by TGA and DSC. SEM and optical microscopy are also used in the morphological studies. Under quiescent conditions, API particles …

Admittance Control Of The Intelligent Assist Robot Manipulator For People With Duchenne Muscular Dystrophy, Madeline Corrigan

Theses

Duchenne muscular dystrophy (DMD), a neuromuscular disease with a prevalence of 1 in 3500 male births, results in characteristic muscle weakness which is progressive with age and leads to loss of independence. And, in this population, maintaining optimal quality of life depends on the preservation of self-sufficiency. Despite the loss of function, non-ambulant people with DMD retain some muscle strength, just not sufficient strength to overcome the force of gravity. There are a number of upper-limb passive and active orthotic devices that attempt to augment the loss of upper limb function in people with DMD by taking advantage of this …

Role Of Materials & Design On Performance Of Baseball Bats, Kim Benson-Worth

Theses

Baseball bat safety has become an increasing area of interest with more than 19 million people in the United States alone participating in this sport. An increase in injuries resulting from bat injuries has brought the performance of the bats into question. A review of several studies focusing on the effects of the material properties of various baseball bats designs were examined. From this review it is evident that player and spectator safety greatly rely on proper baseball bat design. There was a 30% reduction in the Multi-Piece Failures (MPF) of wooden bats once the requirement of a Slope of …

Heterogeneous Combustion Of Condensed Particles In Transition Regime, Deniz Yildiz

Theses

A steady-state model of heterogeneous combustion for a spherical particle is developed accounting for the transition regime of heat and mass transfer. The model assumes formation of condensed products and reaction rate controlled by the transport of oxidizer to the particle surface. The model is based on the Fuchs’ limiting sphere approach. Calculations are performed for combustion of zirconium particles of different sizes. Temperature and oxygen concentration profiles are calculated and compared to those predicted by the continuous medium transfer model. It is shown that for particles in the range from 100 nm up to 30 gm heat and mass …

Effect Of Tablet Compression On The Dissolution Of Aspirin Tablets Using A Novel Off-Center Paddle Impeller (Opi) Dissolution Testing System, Chuan Sun

Theses

In the pharmaceutical industry, dissolution testing is routinely carried out to determine the dissolution rate of oral solid dosage forms. Among several testing devices, the USP Dissolution Apparatus 2 is the device most commonly used. However, despite its widespread use, this apparatus has been shown to produce test failures and to be very sensitive to a number of small geometry changes.

The objective of this study was to determine whether a novel dissolution system termed “OPI” for “off-center paddle impeller” was sensitive enough to determine differences in tablet dissolution profiles caused by different compression pressure during the tablet manufacturing process. …

Safety Performance Comparison Between Light Rail Transit And Subway, Nehemie Jasmin

Theses

Along with the expansion and addition of guide way transit systems, such as light rail and subway, there came the need to compare the safety performance of each mode. The multimodal transportation systems with many different technologies, operating characteristics and diversified environments made it more difficult to compare their safety.

In order to evaluate the potential for intermodal comparison of safety performance measures, the thesis has focused on the subway and Light Rail Transit (LRT) modes at the national level. Starting with clear definitions of each safety category, the analysis utilizes mostly the National Transit Database (NTD) from recent years …

Fuzzy Logic For Task Space Telemanipulation Of A Five Fingered Robotic Hand, Raaghavann Srinivasan

Theses

This work presents a fuzzy logic based HandyMan (Hand gesture commands for grasping and manipulation) system to recognize the operator's hand gestures during task space telemanipulation. A combination of joint positions may be shared between at least two manipulation gestures. To avoid misinterpretation of gestures by the gesture recognition system, six new manipulation gestures were introduced. The gestures are produced by the user wearing a CyberGlove™.

This system replaces the previous HandyMan gesture recognition method. The output of the fuzzy system drives the state machines to implement the gestures with the robot hand.

The experimental results show that the proposed …

Quantification Of Human Motion On Roller Coaster Rides, Chirag Burman

Theses

Case reports have been published of people experiencing symptoms of traumatic brain injury (TBI) and/or ailments of the vascular tissue around the head. These reports pointed towards G-forces, a scalar measure without a specified direction, which represent the measure of the acceleration of an object divided by acceleration caused by gravity (9.81 m/s²), as a cause of said injuries. Research has been conducted on quantifying the G-forces experienced while on roller coasters, as well as the change in heart rate. However these studies have not been able to show a link between roller-coasters and symptoms.

This thesis aims …

Diffuse Axonal Injury Effect On Myelinating Cells And Axons, Jennifer Alison Zalk

Theses

There is no supporting evidence whether myelin degeneration in diffuse axonal injury (DAI) of the white matter is due to death of myelinating oligodendrocytes or secondary axotomy. Cortical neurons are not able to remain healthy in culture to have their axons myelinated. Dorsal root ganglion (DRG) neurons have been shown to be myelinated by cortical oligodendrocytes in culture. An in vitro stretch injury model was used to analyze the DRG axon pathology during and after injury. DRG myelinating Schwann cells are analyzed to demonstrate what is expected from injury to oligodendrocytes. DRG axons demonstrated a high tolerance to stretch …