Physical Sciences and Mathematics Commons^™

Singlemode-Multimode-Singlemode Fibre Structure For Phase Transition Monitoring In Phase Changing Materials, Rahul Kumar, Wei Han, Dejun Liu, Wai Pang Ng, Richard Binns, Krishna Busawon, Yong Qing Fu, Zabih Ghassemlooy, Christopher Underwood, Khamid Mahkmov, Jinhui Yuan, Chongxiu Yu, Huazhong Shu, Xing Ao Li, Tuan Guo, Gerald Farrell, Yuliya Semenova, Qiang Wu Prof.

Articles

Abstract. A platinum-coated singlemode-multimode structure is investigated in this paper as an optical fibre sensor (OFS) to monitor the phase transition of a phase change material (PCM). Paraffin wax has been used as an example to demonstrate the sensor’s performance and operation. Most materials have the same temperature but different thermal energy levels during the phase change process, therefore, sole dependency on temperature measurement may lead to an incorrect estimation of the stored energy in PCM. The output spectrum of the reflected light from the OFS is very sensitive to the bend introduced by the PCM where both liquid and …

Temperature-Related Mortality Impacts Under And Beyond Paris Agreement Climate Change Scenarios, Ana Maria Vicedo-Cabrera, Yuming Guo, Francesco Sera, Veronika Huber, Carl Friedrich Schleussner, Dann Mitchell, Shilu Tong, Micheline De Sousa Zanotti Stagliorio Coelho, Paulo Hilário Nascimento Nascimento Saldiva, Éric Lavigne, Patricia Matus Correa, Nicolas Valdes Ortega, Haidong Kan, Samuel Osorio, Jan Kyselý, Aleš Urban, Jouni J.K. Jaakkola, Niilo R.I. Ryti, Mathilde Pascal, Patrick J. Goodman, Ariana Zeka, Paola Michelozzi, Matteo Scortichini, Masahiro Hashizume, Yasushi Honda, Magali Hurtado-Díaz, Julio Gonzalez Cruz, Xerxes T. Seposo, Ho Kim, Aurelio Tobías, Carmen Iñiguez Fernández, Bertil Forsberg, Daniel Oudin Åström, Martina S. Ragettli, Martin Röösli, Yueleon Guo, Chang-Fu Wu, Antonella Zanobetti, Joel D. Schwartz, Michelle L. Bell, Tranngoc Ngoc Dang, Dung Do Van, C. Heaviside, Sotiris Vardoulakis, Shakoor Hajat, Andrew Haines, London School Of Hygiene & Tropical Medicine, London, United Kingdom London School Of Hygiene & Tropical Medicine, London, United Kingdom, Ben G. Armstrong, Kristie L. Ebi, Antonio Gasparrini

Articles

The Paris Agreement binds all nations to undertake ambitious efforts to combat climate change, with the commitment to Bhold warming well below 2 °C in global mean temperature (GMT), relative to pre-industrial levels, and to pursue efforts to limit warming to 1.5 °C^. The 1.5 °C limit constitutes an ambitious goal for which greater evidence on its benefits for health would help guide policy and potentially increase the motivation for action. Here we contribute to this gap with an assessment on the potential health benefits, in terms of reductions in temperature-related mortality, derived from the compliance to the agreed temperature …

Quantifying Excess Deaths Related To Heatwaves Under Climate Change Scenarios: A Multicountry Time Series Modelling Study, Yuming Guo, Antonio Gasparrini, Shanshan Li, Francesco Sera, Ana Maria Vicedo-Cabrera, Micheline De Sousa Zanotti Stagliorio Coêlho, Paulo Hilário Nascimento Nascimento Saldiva, Éric Lavigne, Benjawan Tawatsupa, Kornwipa Punnasiri, Ala Overcenco, Patricia Matus Correa, Nicolas Valdes Ortega, Haidong Kan, Samuel Osorio, Jouni J.K. Jaakkola, Niilo R.I. Ryti, Patrick J. Goodman, Ariana Zeka, Paola Michelozzi, Matteo Scortichini, Masahiro Hashizume, Honda, Yasushi Honda, Yasushi, Xerxes T. Seposo, Ho Young Kim, Aurelio Tobías, Carmen Iñiguez Fernández, Bertil Forsberg, Daniel Oudin Åström, Guo, Yue Leon Guo, Yue Leon, Bing Yu Chen, Antonella Zanobetti, Joel D. Schwartz, Tranngoc Ngoc Dang, Dung Do Van, Michelle L. Bell, Ben G. Armstrong, Ebi, Kristie L. Ebi, Kristie L., Shilu Tong

Articles

Background: Heatwaves are a critical public health problem. There will be an increase in the frequency and severity of heatwaves under changing climate. However, evidence about the impacts of climate change on heatwave-related mortality at a global scale is limited. Methods and findings: We collected historical daily time series of mean temperature and mortality for all causes or nonexternal causes, in periods ranging from January 1, 1984, to December 31, 2015, in 412 communities within 20 countries/regions. We estimated heatwave–mortality associations through a two-stage time series design. Current and future daily mean temperature series were projected under four scenarios of …

Development Of A Photopolymer Holographic Lens For Collimation Of Light From A Green Light-Emitting Diode, Sanjay Keshri, Kevin Murphy, Vincent Toal, Izabela Naydenova, Suzanne Martin

Articles

A holographic optical element (HOE) was developed to collimate a monochromatic light-emitting diode (LED). The fabrication was achieved by the interference of collimated and diverging beams from a 532 nm laser to produce the required photonic structure in a self-developing photopolymer material. The experimental values of diffraction efficiency and spatial period across the HOE were compared with their expected theoretical values. Good agreement was found for the spatial period; however, the diffraction efficiency varied significantly across the lens. In this paper, two approaches have been taken to address this variation: (1) modification of recording geometry and (2) optimization of recording …

Self-Processing Photopolymer Materials For Versatile Design And Fabrication Of Holographic Sensors And Interactive Holograms, Dervil Cody, Sabad-E Gul, Tatsiana Mikulchyk, Muhammad Irfan, Anastasia Kharchenko, Kamila Goldyn, Suzanne Martin, Svetlana Mintova, John Cassidy, Izabela Naydenova

Articles

The aim of this paper is to discuss the benefits as well as the limitations of utilizing photopolymer materials in the design of holograms that are responsive to changes in their environment, such as changes in the concentration of a specific substance, temperature, and pressure. Three different case studies are presented, including both surface and volume phase holograms, in order to demonstrate the flexibility in the approach of utilizing holographic photopolymers for the design of sensors and interactive optical devices. First, a functionalized surface relief hologram is demonstrated to operate as an optical sensor for the detection of metal ions …

Absorption Coefficient Dependent Non-Linear Properties Of Thin Film Luminescent Solar Concentrators, S. Chandra, M. Rafiee, John Doran, S. J. Mccormack

Articles

This research article studied absorption coefficient dependent losses and efficiency of thin film luminescent solar concentrator (LSC). The optimum absorption coefficient was determined by fabricating red dye doped thin film LSCs with varying absorption coefficients of 24–202 cm-1. The optical, electrical, and ray-trace model predicted results were compared to establish the optimum absorption coefficient for fabricated thin film LSCs. The optical and electrical efficiencies of thin film LSCs are a function of absorption coefficient; follow linearly at lower values, gradually becoming non- linear at higher values of absorption coefficient which restricts the overall efficiency. The multi layered ray–trace model predicted …

Some New And Generalized Distributions Via Exponentiation, Gamma And Marshall-Olkin Generators With Applications, Hameed Abiodun Jimoh

College of Graduate Studies: Theses & Dissertations

Three new generalized distributions developed via completing risk, gamma generator, Marshall-Olkin generator and exponentiation techniques are proposed and studied. Structural properties including quantile functions, hazard rate functions, moment, conditional moments, mean deviations, R\'enyi entropy, distribution of order statistics and maximum likelihood estimates are presented. Monte Carlo simulation is employed to examine the performance of the proposed distributions. Applications of the generalized distributions to real lifetime data are presented to illustrate the usefulness of the models.

Terrestrial Lidar Raw Dataset For: Stemflow Dynamics In Relation To Individual Tree Canopy Structure, Neighborhood Conditions, And Meteorological Factors, Sandra A. Yankine, John T. Van Stan Ii, Jean-Francois Cote, Anke Hildebrandt, Dylan C. Mesta, Gustavo O. Maldonado, Jan Friesen

Datasets

These are raw 3-D (x,y,z) point files of a forest plot. Scans were collected at Herty Pines in Statesboro, Georgia, USA. Scans were collected using a Leica ScanStation C-10. Files were co-registered using Leica Cyclone II. Although file extension is ".pts" these are in ASCII format.

Temporal Changes In Submarine Groundwater Discharge In A Georgia Salt Marsh, Tanner C. Avery, Jacque L. Kelly

Earth, Environment & Sustainability: Faculty Presentations (1988-2022)

No abstract provided.

Ontologies And The Semantic Web For Digital Investigation Tool Selection, Hayden Wimmer, Lei Chen, Tom Narock

Computing: Faculty Publications

The nascent field of digital forensics is heavily influenced by practice. Much digital forensics research involves the use, evaluation, and categorization of the multitude of tools available to researchers and practitioners. As technology evolves at an increasingly rapid pace, the digital forensics field must constantly adapt by creating and evaluating new tools and techniques to perform forensic analysis on many disparate systems such as desktops, notebook computers, mobile devices, cloud, and personal wearable sensor devices, among many others. While researchers have attempted to use ontologies to classify the digital forensics domain on various dimensions, no ontology of digital forensic tools …

Mixed-Criticality Real-Time Task Scheduling With Graceful Degradation, Samsil Arefin

Masters Theses

”The mixed-criticality real-time systems implement functionalities of different degrees of importance (or criticalities) upon a shared platform. In traditional mixed-criticality systems, under a hi mode switch, no guaranteed service is provided to lo-criticality tasks. After a mode switch, only hi-criticality tasks are considered for execution while no guarantee is made to the lo-criticality tasks. However, with careful optimistic design, a certain degree of service guarantee can be provided to lo-criticality tasks upon a mode switch. This concept is broadly known as graceful degradation. Guaranteed graceful degradation provides a better quality of service as well as it utilizes the system resource …

Design Of A Multifunctional Sample Probe For Transport Measurements, Mustafa Öztürk, Numan Akdoğan

Turkish Journal of Physics

Herein, we describe a multifunctional sample probe equipped with a two-axis goniometer for transport measurements. The two-axis goniometer enables both computer-controlled 360$^{\circ}$ out-of-plane and manual 360$^{\circ}$ in-plane rotations. The multifunctional sample probe was successfully implemented to a host dewar and an electromagnet system. The developed probe is capable of performing transport measurements while fully controlling the parameters such as the magnetic and electrical fields, the angle, the temperature, and the current/voltage parameters in a wide range. The design of the multifunctional sample probe allows easy installation into different dewar and magnet systems and connection of a wide range of external …

Permanent Magnet Motion In A Copper Tube, Jaroslav Franek, Martin Soka

Turkish Journal of Physics

This paper deals with the investigation of braking forces induced by eddy currents, which have effects on the permanent magnet moving at a constant speed in the direction of the conductive tube axis. The analysis is based on calculation of an action of a force between the current density, representing the magnet, and the eddy currents. The chosen solution is based on classical electrodynamics and can serve as a guide for the calculation of other cases, where braking forces are created between the moving cell, which is a source of the magnetic field, and a close conductive subject. The obtained …

Control Of Laser-Induced Nonadiabatic Molecular Alignment In Dissipative Media, Gamze Kaya

Turkish Journal of Physics

Laser-induced nonadiabatic alignment in nitrogen and mixtures of nitrogen with Ar gas was investigated using the ultrafast optical Kerr effect in the collinear pump-probe setup. We find that dissipative media produce desired alignment characteristics in distinct manners to decoherence and to population relaxation. The results show that the intense laser alignment can be used as a control tool of molecular dynamics in dissipative environments.

Quantum Many-Body Interactions In The Presence Of Disordered Potentials, Riza Oğul

Turkish Journal of Physics

The time evolution of the quantum nonequilibrium states of many-body particles is described with a set of hierarchies of quantum kinetic equations with quantum wave functions. A collision term is obtained in terms of two-body interactions in the mean-field with a disordered potential, which is proposed for the first time. The implications and the limits of applicability of the resulting kinetic equations are discussed.

Thermodynamics Of Cosmological Models With Generalized $G$ And $\Lambda $, M Saratchandra Singh, Sanasam Surendra Singh

Turkish Journal of Physics

Here we investigate spatially flat Friedmann-Robertson-Walker space-time models of the universe to study the thermodynamic behaviors in light of variables $G$ and $\Lambda $. A particular method to find the solutions of Einstein's field equations and mathematical expressions for temperature and entropy of the perfect fluid cosmological models is introduced by using both the equation of state and the assumption $G=G_{0} \,a^{n}$. It is observed that the phantom field of ($\omega

Silicon Nitride As Antireflection Coating To Enhance The Conversion Efficiency Of Silicon Solar Cells, Rajinder Sharma

Turkish Journal of Physics

The aim of this work is to investigate the effect of single and double layer antireflection coating (ARC) on the performance of silicon solar cells. In this regard, various previous works on single and double layer ARCs have been consulted. Silicon nitride (Si3N4) has been used as ARC material because of its varying refractive index (1.8-3.0). Numerical calculations have been performed to obtain the reflectance for single and double layer Si3N4 using the transfer matrix method. Double layer antireflection coating (DLARC) of Si3N4 is found to have significant advantages over single layer antireflection coating (SLARC). Calculated reflectances have been further …

An Experimental Study On The Angular Dependence Of Coherent To Compton Scattering Differential Cross-Section Ratios Of Calcium, Tuba Akkuş

Turkish Journal of Physics

The coherent to Compton scattering cross-section ratio of calcium was measured experimentally for several polar scattering angles (90°, 100°, 110°, 120°, and 130°) and azimuthal scattering angles (30°, 20°, 10°, 0°, -10°, and -20°). A high purity germanium semiconductor detector with a resolution of 199.6 eV at 5.9 keV was used. The theoretical values of the coherent to Compton scattering differential cross-section of calcium were calculated on the basis of nonrelativistic form factors, relativistic form factors, and S-matrix theories. It was observed that the experimental results were most compatible with the nonrelativistic form factor theory.

Size Investigation Of Silicon Nanoclusters Deposited On Hopg Using Noncontact Atomic Force Microscopy, Mümi̇n Mehmet Koç

Turkish Journal of Physics

The sizes of silicon nanoparticles produced using two different novel methods are investigated in this report. The method of production used to generate silicon oxide nanoparticles was achieved via gas aggregation codeposition with water on a cold target, and also via a liquid jet method. The nanoparticles were drop-cast on a highly oriented pyrolytic graphite (HOPG) substrate and assessed using ultrahigh vacuum atomic force microscopy (AFM). Noncontact constant force mode was used in the AFM investigations. The silicon nanoparticles produced using the gas aggregation and water codeposition method were found to be smaller than 2 nm. A degree of deviation …

Miscible Gases Based Eor In Unconventional Liquids Rich Reservoirs: What We Can Learn, Dheiaa Alfarge, Mortadha Alsaba, Mingzhen Wei, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Over the last decade, Unconventional Liquids Rich Reservoirs (ULR) have become the main target for oil and gas investors as conventional formations started to deplete and diminish in numbers. These unconventional plays have a huge oil reserve; however, the primary oil recovery factor is predicted to be less than 10%. Unconventional Improved Oil Recovery (UIOR) techniques are still a new concept in the oil industry since there is no commercial project reported for any IOR technique yet. Miscible gas based EOR technique might be the most potential strategy to improve oil recovery in such complex plays. In this study, a …

Advanced Ion Management To Improve Oil Recovery In Oil-Wet Carbonate-Sandstone Composite Reservoirs, Ali K. Alhuraishawy, Baojun Bai, Mingzhen Wei, Waleed H. Al-Bazzaz

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Waterflooding with different ionic composition called advanced ion management which play a role with ionic composition of injected water to enhance the oil production. In the last decade, many studies pointed out that the composition of injected water could changes rock wettability during waterflooding. The main purpose of this study is to evaluate the effects of SO4 and low salinity water on improving oil recovery in oil-wet carbonate reservoirs. Sulfate ion concentration, low salinity water, rock composition, porosity, and permeability were examined using a designed model. Typical seawater, increase SO₄, two and three times in the seawater, and …

New Insights Of Low Salinity Water Flooding In Low Permeability-Low Porosity Clay Rich Sandstone Reservoir, Ali K. Alhuraishawy, Baojun Bai, Mingzhen Wei, Waleed H. Al-Bazzaz

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

One of the EOR technologies is low-salinity water flooding (LSWF) is an EOR method that operates at a lower cost than other EOR methods, which makes it a preferred area of interest for oil industry economists, who continue to call for EOR costs to come down. The aim is to minimize the possible cost to recover as much oil as possible. The performance of low salinity waterflooding in decreasing residual oil saturation in low permeability-porosity clay-rich sandstone reservoir. Porosity test, core flooding test, XRD and scanning electron microscopy (SEM) tests were achieved in this study. Salinity effect on the porosity, …

Application Of Integrated Reservoir Geomechanics For Well Planning Of High-Angled Wells In A Mature Oil Field, Ahmed K. Abbas, Ralph E. Flori, Yousif M.B. Al-Asadi, Mortadha Alsaba, Nasser A. Al-Hamad

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Zubair oil reservoir has a significant potential to contribute to the petroleum supply in Iraq. Drilling highly deviated wells is a commonly used approach to enhance the production in mature fields. Drilling these wells in the Zubair Formation has been a challenge due to severe wellbore instability issues. This study presents how integrated reservoir geomechanics was used for efficient well planning and safe drilling of nearly horizontal wells (75° Inclination) through Zubair depleted sandstone oil reservoir. In this study, an integrated workflow was implemented mainly to build a geomechanical model using offset well data. The in-situ principal stresses and their …

Using Managed Pressure Drilling To Reduce Stuck Pipe Problem, Ethar H.K. Alkamil, Husam R. Abbood, Ralph E. Flori, George Medley, Sagar Nauduri, Mortadha Alsaba

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Differences between mud pressure in a wellbore and pore pressure in high permeability rocks can lead to differential sticking, particularly when drilling deviated wells and encountering mud losses. Several solutions, all challenging, can be used to address this problem, where the conventional mitigation method of managing the mud weight (MW) is often used. However, managed pressure drilling (MPD) offers a promising solution with a positive risk-adjusted cost and other benefits. Wells in the E oilfield in southern Iraq are typically drilled overbalanced and therefore often experience a high percentage of non-productive time (NPT) due to differential sticking. This study evaluates …

A Novel Ultra-Low Interfacial Tension Nanofluid For Enhanced Oil Recovery In Super-Low Permeability Reservoirs, Derong Xu, Baojun Bai, Ziyu Meng, Qiong Zhou, Zhe Li, Yao Lu, Hairong Wu, Jirui Hou, Wanli Kang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The exploration and development of super-low permeability reservoirs have become a global focus in recent years. However, conventional flooding systems commonly face problems of high injection pressure and poor displacement efficiency in super-low permeability reservoirs. Thus, it is imperative to find new flooding agents that tackle such problems. In this study, a novel ultra-low interfacial tension (IFT) nanofluid was formulated, consisting of surfactants to achieve ultra-low IFT and silica nanoparticles to reduce injection pressure. The compatibility test between the surfactants and silica nanoparticles in 10,000 mg/L NaCl solution at 90 °C was conducted to ensure their adaption to harsh reservoir …

Structure Of The Picornavirus Replication Platform: A Potential Drug Target For Inhibiting Virus Replication, Meghan Suzanne Warden

Chemistry & Biochemistry Theses & Dissertations

Picornaviruses are small, positive-stranded RNA viruses, divided into twelve different genera. Members of the Picornaviridae family cause a wide range of human and animal diseases including the common cold, poliomyelitis, foot and mouth disease, and dilated cardiomyopathy. The picornavirus genome is replicated via a highly conserved mechanism involving a presumed cloverleaf structure located at the 5’ noncoding region of the virus genome. The 5’ cloverleaf consists of three stem loops (B, C, and D) and one stem (A), which interact with a variety of virus and host cell proteins during replication. In this dissertation, human rhinovirus serotype 14 (HRV-14) SLB …

Development Of A 300 Kv Dc High Voltage Photogun And Beam Based Studies Of Alkali Antimonide Photocathodes, Yan Wang

Physics Theses & Dissertations

To advance magnetized gun research in the United States, a compact DC high voltage photogun with inverted-insulator geometry was designed, built, and operated reliably at - 300 kV bias voltage using alkali-antimonide photocathodes. This photogun will provide a magnetized electron beam for the future Jefferson Lab Electron-Ion Collider (JLEIC) cooler. This research describes key electrostatic design features of the photogun and evaluates the performance of the in-house fabricated photocathodes and the quality of the electron beams. The thermal emittance of the electron beam was measured with various conditions: different gun bias voltages, different laser spot sizes, and photocathodes with different …

Adaptive Methods For Point Cloud And Mesh Processing, Zinat Afrose

Computational Modeling & Simulation Engineering Theses & Dissertations

Point clouds and 3D meshes are widely used in numerous applications ranging from games to virtual reality to autonomous vehicles. This dissertation proposes several approaches for noise removal and calibration of noisy point cloud data and 3D mesh sharpening methods. Order statistic filters have been proven to be very successful in image processing and other domains as well. Different variations of order statistics filters originally proposed for image processing are extended to point cloud filtering in this dissertation. A brand-new adaptive vector median is proposed in this dissertation for removing noise and outliers from noisy point cloud data.

The major …

Genotypic Responses Of Brachiaria Grass (Brachiaria Spp.) Accessions To Drought Stress, Duncan Cheruiyot, Charles Aura Odhiambo Midega, Johnnie Van Den Berg, John Anthony Pickett, Zeyaur Rahman Khan

All Peer-Reviewed Publications

Background and Objective: Brachiaria, a warm season C4 grass, is rapidly gaining popularity as fodder crop in Africa where it is also used as a component of a habitat management strategy for maize stem borers. However, increasing drought limits productivity of this grass species. The aim of this study was to evaluate and select high yielding brachiaria genotypes under simulated drought conditions. Materials and Methods: The morphological and physiological performance of 18 apomictic accessions of brachiaria in simulated drought conditions in a screen house were evaluated. Plants were exposed to different watering regimes. Well-watered (control) plants were watered every 48 …

First Test Results Of Superconducting Twin Axis Cavity For Erl Applications, Hyekyoung Park, Subashini De Silva, Jean R. Delayen, Andrew Hutton, Frank Marhauser

Physics Faculty Publications

RF superconducting (SRF) cavities with two beam pipes have been proposed in the past for energy recovery linac applications. The relatively complex geometry of those cavities presented a serious challenge for fabrication and surface processing. The main concerns have now been overcome with the fabrication and successful RF testing of a new elliptical twin-axis cavity proposed by Jefferson Lab (JLab) and optimized by the Center for Accelerator Science (CAS) at Old Dominion University (ODU) in the framework of a DoE accelerator stewardship program. The cavity design provides uniform accelerating or decelerating fields for both beams. This paper describes the cavity …