Engineering Physics Commons^™

Electrical Characterization Of Crystalline Uo2, Tho2 And U0.71Th0.29O2, Christina L. Dugan

Theses and Dissertations

Uranium dioxide (UO₂), thorium dioxide (ThO₂), and U_xTh_1-xO₂ alloys are characterized for suitability in uranium-based neutron detectors. ThO₂ was studied for an envisioned UO₂/ThO₂ heterojunction. A U_0.71Th_0.29O₂ alloy was studied because of its resistance to oxidation and potential use in surface passivation. The U_0.71Th_0.29O₂ effective Debye temperature of 217± 24 K was measured using temperature-dependent x-ray photoemission spectroscopy (XPS). The specific heat capacity for the U_0.71Th_0.29O₂ alloy was calculated from the Debye …

Nonlinear Sliding Mode Observer Applied To Microalgae Growth, Rebecca J. Griffith

Doctoral Dissertations and Master's Theses

Modeling biological processes, such as algae growth, is an area of ongoing research. The ability to understand the multitude of parameters that influence this system provides a platform for better understanding the dynamics of microalgae growth. Empirical modeling efforts look to understand sources of driving nutrients that influence harmful algal blooms (HABs). These harmful algal blooms are dense aggregates that have an increasingly negative impact on local economics, marine and freshwater systems, and public health. They result from a high influx of nitrogen and nutrients that drive the algae biomass to exponentially grow. This growth blocks out the sun, potentially …

Quasi-Particle Band Structure And Excitonic Effects In One-Dimensional Atomic Chains, Eesha Sanjay Andharia

Graduate Theses and Dissertations

The high exciton binding energy in one dimensional (1D) nano-structures makes them prominent for optoelectronic device applications, making it relevant to theoretically investigate their electronic and optical properties. Many-body effects that are not captured by the conventional density functional theory (DFT) have a huge impact in such selenium and tellurium single helical atomic chains. This work goes one step beyond DFT to include the electron self-energy effects within the GW approximation to obtain a corrected quasi-particle electronic structure. Further, the Bethe-Salpeter equation was solved to obtain the absorption spectrum and to capture excitonic effects. Results were obtained using the Hyberstein-Louie …

Exfoliation, Synthesis, And Characterization Of Nanoscale Te, Takayuki Hironaka

Graduate Theses and Dissertations

Since the experimental discovery of graphene, two dimensional materials have enjoyed more attention and emphasis in academic research than nanowires, but the latter are an important area of study for creating 1D materials, or single atom chains, the next generation materials for advancing electronic devices. Atomically thin layers can be generated from 2D materials with weak bonds in one direction, and by applying this concept to one dimensional weakly bonded materials, we hypothesize that single atom chains with atomic-scale diameters may be produced. Tellurium (Te) and selenium (Se) have lattices consisting of spiral chains oriented along the c-axis, and each …

Fabrication And Characterization Of Electrochemical Glucose Sensors, Mohammed Marie

Graduate Theses and Dissertations

Electrochemical sensors based on the nanostructure of the semiconductor materials are of tremendous interest to be utilized for glucose monitoring. The sensors, based on the nanostructure of the semiconductor materials, are the third generations of the glucose sensors that are fast, sensitive, and cost-effect for glucose monitoring.

Glucose sensors based on pure zinc oxide nanorods (NRs) grown on different substrates, such ITO, FTO, and Si/SiO2/Au, were investigated in this research. Silicon nanowire (NW)- based glucose sensors were also studied. First, an enzyme-based glucose sensor was fabricated out of glass/ITO/ZnO NRs/BSA/GOx/nafion membrane. The sensor was tested amperometrically at different glucose concentrations. …

Improving Detection Of Dim Targets: Optimization Of A Moment-Based Detection Algorithm, Shannon R. Young

Theses and Dissertations

Wide area motion imagery (WAMI) sensor technology is advancing rapidly. Increases in frame rates and detector array sizes have led to a dramatic increase in the volume of data that can be acquired. Without a corresponding increase in analytical manpower, much of these data remain underutilized. This creates a need for fast, automated, and robust methods for detecting dim, moving signals of interest. Current approaches fall into two categories: detect-before-track (DBT) and track-before-detect (TBD) methods. The DBT methods use thresholding to reduce the quantity of data to be processed, making real time implementation practical but at the cost of the …

Electromagnetic Wave-Matter Interactions In Complex Opto-Electronic Materials And Devices, Raj Kumar Vinnakota

Doctoral Dissertations

This dissertation explores the fundamentals of light-matter interaction towards applications in the field of Opto-electronic and plasmonic devices. In its core, this dissertation attempts and succeeds in the the modeling of light-matter interactions, which is of high importance for better understanding the rich physics underlying the dynamics of electromagnetic field interactions with charged particles. Here, we have developed a self-consistent multi-physics model of electromagnetism, semiconductor physics and thermal effects which can be readily applied to the field of plasmotronics and Selective Laser Melting (SLM). Plasmotronics; a sub-field of photonics has experienced a renaissance in recent years by providing a large …

Cementitious Sensors Exhibiting Stopbands In Acoustic Transmission Spectra, Shreya Vemuganti

Shared Knowledge Conference

Ultrasonic monitoring in cementitious materials is challenging due to the high degree of attenuation. In wellbore environments, monitoring becomes more challenging due to inaccessibility. Meta materials, also known as acoustic bandgap materials, exhibit an interesting feature of forbidding the propagation of elastic/sound waves and isolate vibration in a certain frequency band. Traditionally, acoustic bandgap materials are developed with inclusions such as tin, aluminum, gold, steel in a polymer matrix. In this study, we present the development of three-dimensional cementitious sensors capable of exhibiting stopbands in the acoustic transmission spectra using carbon nanotubes. Relatively wide stopbands were engineered using Floquet-Bloch periodic …

Interplay Between Kitaev Interaction And Single Ion Anisotropy In Ferromagnetic Cri3 And Crgete3 Monolayers, Changsong Xu, Jungsheng Feng, Hongjun Xiang, Laurent Bellaiche

Physics Faculty Publications and Presentations

Magnetic anisotropy is crucially important for the stabilization of two-dimensional (2D) magnetism, which is rare in nature but highly desirable in spintronics and for advancing fundamental knowledge. Recent works on CrI3 and CrGeTe3 monolayers not only led to observations of the long-time-sought 2D ferromagnetism, but also revealed distinct magnetic anisotropy in the two systems, namely Ising behavior for CrI3 versus Heisenberg behavior for CrGeTe3. Such magnetic difference strongly contrasts with structural and electronic similarities of these two materials, and understanding it at a microscopic scale should be of large benefits. Here, first-principles calculations are performed and analyzed to develop a …

Probabilities Involving Standard Trirectangular Tetrahedral Dice Rolls, Rulon Olmstead, Doneliezer Baize

Rose-Hulman Undergraduate Mathematics Journal

The goal is to be able to calculate probabilities involving irregular shaped dice rolls. Here it is attempted to model the probabilities of rolling standard tri-rectangular tetrahedral dice on a hard surface, such as a table top. The vertices and edges of a tetrahedron were projected onto the surface of a sphere centered at the center of mass of the tetrahedron. By calculating the surface areas bounded by the resultant geodesics, baseline probabilities were achieved. Using a 3D printer, dice were constructed of uniform density and the results of rolling them were recorded. After calculating the corresponding confidence intervals, the …

Estimation Of Atmospheric Turbulence Using Differential Motion Of Extended Features In Time-Lapse Imagery, Santasri R. Bose-Pillai, Jack E. Mccrae, Christopher A. Rice, Ryan A. Wood, Conner E. Murphy, Steven T. Fiorino

Faculty Publications

We address the design, development, and testing of a pointer/tracker as a probe beam for the purpose of making high-speed, aero-optical measurements of the flow over a scaled beam director turret. The tracker uses retro-reflection of the probe beam off of a Reflexite annulus surrounding the turret. The constraints of the design required a near-total-commercial off the shelf system that could be quickly installed and removed in a rented aircraft. Baseline measurements of environmental vibrations are used to predict pointing performance; mitigation of line-of-sight jitter on the probe beam is achieved through passive isolation and the design of relay optics. …

Magnetoelectric Memory Cells With Domain-Wall-Mediated Switching, Kirill Belashchenko, Oleg Tchernyshyov, Alexey Kovalev, Dmitri Nikonov

Kirill Belashchenko Publications

A magnetoelectric memory cell with domain - wall - mediated switching is implemented using a split gate architecture . The split gate architecture allows a domain wall to be trapped within a magnetoelectric antiferromagnetic ( MEAF ) active layer . An extension of this architecture applies to multiple gate linear arrays that can offer advantages in memory density , programmability , and logic functionality . Applying a small anisotropic in - plane shear strain to the MEAF can block domain wall precession to improve reliability and speed of switching

A Dynamic Thermal Network Model Applied To Ventilated Attics, Johan Claesson, Petter Wallentén

International Building Physics Conference 2018

The need for tools to analyze heat and moisture behavior in wooden constructions is increasing with the increasing awareness of the moisture problems. An example of a construction with a history of mould problems is cold attics. Most heat models of attics use a lumped node technique for energy balance and ignore the variation in heat transfer coefficients. A model based on so called dynamic thermal networks has been developed that takes into account radiation between the interior surfaces and the different boundary conditions at the outside and inside surfaces. The first step is to develop analytical solutions for the …

A Holistic Decision Support Tool For Façade Design, Sinem Kultur, Nil Turkeri, Ulrich Knaack

International Building Physics Conference 2018

The aim of this paper is to present a tool which will support decision-makers of façade design process while giving decisions on façade parameters to consider their interactions with functional performance issues. The tool is believed to contribute the holistic design of facades which is lacking in existing literature. The functional performance aspects included in the tool are structural, fire, water related, air permeability related, thermal, moisture related, daylighting, and acoustic performances. Façade parameters that are taken as the main decision subjects within the tool are orientation, transparency ratio, façade type, window type, glazing, framing, solar control, wall configuration, finishing, …

On The Compliance Of Thermal Performance Requirements For Highly Insulated Building Units, Giovanni Murano, Ilaria Ballarini, Giovanna De Luca, Domenico Dirutigliano, Elisa Primo, Vincenzo Corrado

International Building Physics Conference 2018

The target of the nearly zero-energy building (nZEB), stated by the European Union, represents one of the most strenuous challenges to reduce energy consumptions and greenhouse gas emissions in the building sector. In Italy, the nZEB concept refers to a set of energy performance requirements, fixed at national level and establishing a maximum allowable mean thermal transmittance value of the building envelope, as a function of the heating degree-days and of the shape factor. The building envelope is becoming more and more thermally insulated; this determines the reduction of the energy need for heating, but on the other hand it …

The Effect Of Ambient Moisture Conditions On Heat Flux Time Shift And Decrement Factor Of Multi-Layered Walls, Nadja Bishara, Andrea Gasparella

International Building Physics Conference 2018

Thermal properties of the opaque building envelope components are crucial for limiting the energy needs of a building. In particular, dynamic thermal properties of envelope components can significantly contribute to the minimization of heat transfer through the envelope and to the appropriate utilization of the internal and solar gains. This is particularly important in the cooling operation, especially in hot climates. Previous experimental and numerical studies on the determination of dynamic thermal parameters of opaque building components neglected the influence of moisture conditions prevailing within the ambient climate. This paper utilizes a calibrated and validated dynamic heat and mass transfer …

Optimization Of Government Subsidization Strategies For Building Stock Energy Refurbishment, Alessandro Prada, Francesca Cappelletti, Andrea Gasparella

International Building Physics Conference 2018

The high initial investment required in existing building refurbishment can limit the initiative of the building owners and prevent the full exploitation of a huge energy saving potential. Public incentives can play an essential role in fostering the energy retrofitting of the existing buildings and in increasing the renovation rate of the building stock, effectively reducing the energy final uses, the dependence on the fossil fuels, and helping meet the national efficiency targets. Public subsidization are intended to enhance the economic performance in terms of global cost of the energy efficiency measures for the owner, in order to induce positive …

Evaluation Of Efficiency And Renewable Energy Measures Considering The Future Energy Mix, Fabian Ochs, Georgios Dermentzis

International Building Physics Conference 2018

Sustainable and responsible use of resources is required in order to mitigate climate change. Micro-economic goals usually consider the capitalized investment costs and/or the purchased energy but disregard environmental impacts. However, on macro-economic scale, the aim must be the reduction of the (non-renewable) primary energy (PE) use and of CO2-emissions. There is need for an appropriate evaluation method for comparing and ranking different passive and active building technologies, e.g. according to their impact on the PE consumption. National conversion factors for PE/CO2 differ significantly between different countries and are subject to change. Seasonal variations are not considered at all. The …

Impact Of An Energy Efficiency Regulation In Northern Canada, Asok Thirunavukarasu, Hua Ge, Andreas Athienitis

International Building Physics Conference 2018

Extreme cold climates and Canada’s sparsely populated Northern regions have limited human and infrastructural capacity making it difficult to build energy-efficient homes. Despite such differences, homes are built based on codes and standards developed for Canada’s South. In 2008, a by-law was passed in Yellowknife, Canada requiring a minimum EnerGuide Housing (EGH) rating of 80 for all new single-family and two-family residential buildings. The EnerGuide’s Energy Rating Service (ERS) program is an energy assessment program for residential housing formerly known as the EnerGuide Rating for Houses (EGH). Homes are rated between 0 to 100; lower numbers represent homes that are …

Application Of C-Svm Classification Algorithm To The Lighting Visual Comfort Of University Classrooms, Rui Dang, Qingchen Wang, Yanhui Bu, Gang Liu

International Building Physics Conference 2018

Considering the quality of the classroom light-environment will directly affect students' eye health and learning efficiency, it is a problem to be solved that how to evaluate the visual comfort levels of the classroom light-environment and save lighting energy on the premise of necessary visual comfort. Aiming at these problems above, this study restored the classroom scene through adjustable full-size light-environment simulation laboratory, in which 135 subjects participated in the visual comfort evaluation experiment of the indoor light-environment. After features (illuminance and correlated color temperature) and labels (comfort levels) preprocessed ,we trained and visualized the visual comfort classification models of …

Generating Design-Sensitive Occupant-Related Schedules For Building Performance Simulations, Mohamed Ouf, William O'Brien, Burak Gunay

International Building Physics Conference 2018

Despite the benefits of occupant behavior (OB) models in simulating the effect of design factors on OB, there are challenges associated with their use in the building simulation industry due to extensive time and computational requirements. To this end, we present a novel method to incorporate these models in building performance simulations (BPS) as design-sensitive schedules. Over 2,900 design alternatives of an office were generated by varying orientation, window to wall ratio (WWR), the optical characteristics of windows and blinds, as well as indoor surfaces’ reflectance. By using daylight simulations and stochastic OB modeling, unique light use schedules were generated …

Visual Comfort Assessment Of Different Shading Strategies In A Commercial Office Building In The Southeastern Us, Armin Amirazar, Mona Azarbayjani, Ben Futrell, Amir Hosseinzadeh Zarrabi, Roshanak Ashrafi

International Building Physics Conference 2018

It is challenging to design buildings that simultaneously consider both the dynamic nature of daylight and specific occupant preferences. The authors have investigated this problem by studying the performance of four specific shading strategies using quantitative measurements of occupants visual comfort: discomfort glare and daylight availability. This paper specifically evaluates the performance of four shading strategies, two types of electrochromic (EC) glass, an automated fabric roller shade, and a venetian blind in a building located in the Southeastern United States. This paper examines how these technologies impact occupant visual comfort and it also examines how the buildings perform relative to …

An Experimental And Modelling Study On The Adsorption Characteristics Of Activated Carbon Under Different Challenge Concentration Levels, Chuan He, Jingjing Pei, Jensen Zhang

International Building Physics Conference 2018

Applying air cleaning devices is an effective approach to control targeted indoor gaseous pollutants. It is important to understand the adsorption characteristics of filter media (e.g, activated carbon) at typical indoor application conditions as well as standard test conditions. Tests per ASHRAE Standard 145.1 for filter media performance evaluation can provide a relative comparison among different media. However, as the tests are conducted at elevated gas concentrations (1~100 ppm), they do not represent the media performance under lower concentrations typical of indoor applications (

Field Experimental Investigation Of Temperature, Humidity And Solar Radiation Impacts On Formaldehyde Emission From Interior Furnishing Material (Particle Board): A Preliminary Study, Alula Yadete, Fitsum Tariku, Doug Horn

International Building Physics Conference 2018

Some part of indoor space components such as furniture and surfaces (like walls and floor carpet) contains contaminants and emit them over time. The emission is affected by different environmental factors like temperature, relative humidity, and solar radiation. As a result, three field experiments are conducted to assess the impact of these environmental factors on Formaldehyde emission. This study referred to previous literature on measuring volatile compound emission from wood stain using balance scale. Consequently, a similar test setup (balance scale) is adopted to investigate formaldehyde emission from test sample which is exposed to solar radiation in fully controlled test …

Solar And Lighting Transmission In Complex Fenestration Systems With Perforated Solar Protection Systems, Waldo Bustamante, Daniel Uribe, Sergio Vera

International Building Physics Conference 2018

Santiago de Chile is a city with a semi-arid climate, with prolonged periods of high temperature and solar radiation. In recent years, in this city, office buildings have been built with high window to wall ratio (WWR) facades. 65% of the office buildings built in the period 2005-2014 have a WWR higher than 60%. Only 5% of these buildings showed an efficient glazed façade solar protection device. One of these systems corresponds to an exterior textile solar protection. This type of systems, together with the perforated screens, could be effective solutions for the solar protection of glazed facades, reducing the …

A Transparent Insulation Solar Façade Coupled With A Selective Absorber: An Experimentally Validated Building Energy Simulation Model, Miroslav Čekon, Jakub Čurpek

International Building Physics Conference 2018

The development of various advanced materials and their subsequent integration into innovative building envelope concepts has the potential to achieve energy savings. Additionally, their usability in practical applications can be enhanced via the use of building energy simulation (BES) methods. Experimental procedures in conjunction with numerical computations could enable the prediction of the future performance of solar thermal façade concepts. The presented study is focused on the thermal response of a transparent insulation material (TIM) incorporated in a façade structure. An experimental prototype of a solar façade element with both a selective and a nonselective absorber was developed for use …

Liquid Desiccant-Polymeric Membrane Dehumidification System For Improved Cooling Efficiency In Built Environments, Michael Bozlar, Eric Teitelbaum, Forrest Meggers

International Building Physics Conference 2018

We have recently demonstrated a new type of moisture absorber using a silicone-based liquid desiccant and a nonporous hydrophilic membrane. The setup consists of a core-shell structure where the desiccant flows inside the hydrophilic membrane (core) surrounded with humid air and confined inside a larger diameter tube (shell). In this work, we propose to extend the capabilities of this moisture absorber prototype by addressing two additional characteristics in order to fully validate its capabilities in the built environment. In the first section of this study, we developed a new setup to demonstrate the regeneration process of the liquid desiccant. The …

Study On The Design Method Of Integration Of Roof And Photovoltaic Based On Aesthetics, Technology And Energy-Saving Characteristic, Hongxin Feng, Juanli Guo, Gang Liu, Jiehui Wang

International Building Physics Conference 2018

The development and utilization of new energy has been concerned due to the traditional energy is increasingly scarce. In recent years, solar building has developed rapidly in the construction industry which is a major energy consuming component. As an organic part of the building, the combination of roof and solar energy has become the focus of attention because of its large size, less shielding and other characteristics. Based on the works of recent years’ Solar Decathlon, this paper analysed the design and implementation of the integration of solar building’s roof and photovoltaic. Meanwhile, taking an office building in Xinjiang, China …

Experimental Study On The Impact Of Passive Chilled Beam In A Room With Displacement Ventilation, Zhu Shi, Vishal Anand, Qingyan Chen

International Building Physics Conference 2018

Previous studies have demonstrated that displacement ventilation (DV) can provide better air quality than mixing ventilation (MV), and may save energy in buildings. However, since DV introduces supply air to the occupied zone directly, the temperature of supply air it provides is normally higher than in a MV system, so the ability to remove cooling load is limited with the same amount of air. On the other hand, passive chilled beam (PCB) systems have been shown to be able to remove a large cooling load while saving energy. Therefore, this research studied a coupled configuration that combined DV and PCB, …

Condensation-Free Radiant Cooling Using Infrared-Transparent Enclosures Of Chilled Panels, Eric Teitelbaum, Adam Rysanek, Jovan Pantelic, Dorit Aviv, Simon Obelz, Alexander Buff, Yongqiang Luo, Forrest Meggers

International Building Physics Conference 2018

Radiant cooling power in the humid climates is inherently limited by condensation. This research investigates a type of radiant cooling methodology whereby the cold temperature source is convectively and conductively isolated from the environment with a membrane transparent to visible radiation to allow supply temperatures to be decreased for radiant cooling systems in humid climates. We conduct an FTIR analysis on three candidate membrane materials and fabricate a prototype experimental test panel that allows for thermal performance evaluation at different panel orientation and depths. Our study shows that for a 5 °C chilled panel temperature, the exterior membrane surface temperature …