Physics Commons^™

Commissioning Of The Uaeu Radio Array And Pilot Low-Frequency Radio Astronomy Studies, Aisha Ali Alnaqbi

Theses

As part of the UAEU Radio Astronomy Pathway Project, a 256-element Ground based Radio Array Facility was deployed at the UAEU. A comprehensive exploration of radio astronomy, and investigations on existing radio arrays, emphasizing low-frequency radio signals and the challenges faced at this range, are crucial for the commissioning phase of the array. A core aspect discussed is the vital role of coaxial cables in preserving the integrity of low-frequency radio signals. To address the electrical length differences between the coaxial cable pairs used to connect the array’s beamformers in the field to the beamformer controllers in the control room, …

Coastal Bathymetry Of The United Arab Emirates Using Satellite-Based Remote Sensing Data, Naser Salem Aldahmani

Theses

Bathymetry is the study of the bed under the water's surface, giving us the water's depth. The Thesis will be about studying the coastal area of the UAE by using satellite images that can help access large regions of the UAE Coast. Also, by using a history of 5 years of satellite visible bands and NIR images, we can see the change of depth near the coastal. The benefit of that study will help to build ship baths through shallow water and to go in and out of ports of UAE. Early warnings of the sea level increasing near the …

Estimating Mars Surface Wind Stress And Dust Lifting Using Reanalyses Based On Emm And Other Spacecraft Observations, Haneen Abouhaligah

Theses

Studying Mars offers insights into terrestrial planet evolution and informs future human expeditions. This thesis examines dust dynamics in Mars’ lower atmosphere, focusing on understanding its weather and climate. We investigate the role of Near-Surface Wind Stress (NSWS) in dust lifting, using six reanalysis datasets, respectively: MACDA, EMARS, OpenMARS, ACS–TIRVIM (ExoMars observations of the MY34 Global Dust storm), EMM1 and EMM2. Following the parameterization approach by Newman et al. (2002a), areas of agreement and discrepancy among datasets were identified. Time series analysis revealed consistent results where datasets overlap temporally. Some differences were expected and shown due to the different Global …

Cloud Tracking Winds On Mars Using Emm-Exi Imaging, Shaimaa Ahmed Alblooki

Theses

The Martian atmospheric wind structure is a major unknown in our understanding of Mars’ climate because it is difficult to measure wind remotely. The Emirates eXploration Imager (EXI) instrument on board the Emirates Mars Mission (EMM) takes visible and ultraviolet images of the whole hemisphere of the planet at a time, and can capture complete weather systems at once, along with their evolution over time. This project uses EXI 320 nm observations to measure winds on Mars using Correlation Imaging Velocimetry (CIV), a cloud tracking method based on software developed for laboratory fluid dynamics experiments, and with significant heritage in …

Design Modular Command And Data Handling Subsystem Hardware Architectures, Abdullah Alsalmani

Theses

Over the past few years, On-Board Computing Systems for satellites have been facing a limited level of modularity. Modularity is the ability to reuse and reconstruct the system from a set of predesigned units, with minimal additional engineering effort. CDHS hardware systems currently available have a limited ability to scale with mission needs. This thesis addresses the integration of smaller form factor CDHS modules used for nanosatellites with the larger counterparts that are used for larger missions. In particular, the thesis discusses the interfacing between Modular Computer Systems based on Open Standard commonly used in large spacecrafts and PC/104 used …

The Three-Dimensional Visualization Of Mars Dust Storms Based On Deriving Digital Elevation Maps From Satellite Imagery, Meirah Ali Alzeyoudi

Theses

This work focuses on generating a Three-Dimensional Visualization of Mars's local dust storms utilizing satellite images from publicly available archives. The work aimed to create a Three-Dimensional Visualization of two Local Dust storms, the first local dust storm occurred on May 20, 2020, in the Chryse Planitia Region of Mars, while the second one occurred on 8 June 2021, on the northern side of the Utopia Planitia Region of Mars. The visualization will assist in providing a better understanding of the dynamics of Dust Storms on Mars by indicating and analyzing the main features of dust storms on Mars. Also, …

Generating Synthetic Satellite Images Of Mars Dust Storms Based On Radiative Transfer Models, As A Follow-On Application Of Marswrf Dust Cycle Simulations, Fatima Ali Alkaabi

Theses

Dust is a fundamental component of the Martian atmosphere; it plays a vital role in the planet's climate system and atmospheric variability. For these reasons, it is considered one of the essential keys to understanding the Martian atmosphere's behavior. The dust events on Mars range from local/regional dust storms that occur every Martian year to global dust storms that have only been observed, on average, once every 3-4 Martian years. The large regional and global dust storms have strong thermal and dynamic effects on the atmosphere. MarsWRF is a Mars version of the terrestrial numerical weather and climate model WRF …

Design And Assessment Of A Leo Gnss Miniconstellation For Positioning, Navigation, And Timing (Pnt), Mariya Abdulkhaleq Mohamad

Theses

Recently, there has been a resurgent demand in the United Arab Emirates for more accurate positioning, navigation, and timing signals, especially for some targeted applications such as autonomous vehicles and flying taxis. The existing Global Navigation Satellite Systems (GNSS) provide real-time positioning accuracy for up to several meters, while the targeted applications require fast convergence of centimeterlevel positioning accuracy. Recent studies have shown that transmitting GNSS signals from a Low Earth Orbit (LEO) instead of a Medium Earth Orbit (MEO) would enhance positioning accuracy. The main objective of this thesis is to design and simulate an optimum scenario of a …

First-Principles Calculations On The Electronic Structure, Mechanical, Vibrational, And Thermal Properties Of The Ca₃Bin Antiperovskite Alloy, Reem Maher Mohamad

Theses

Antiperovskites are the counterparts of perovskites. They have diverse properties that make them physically rich and technologically relevant. In the recent years, the alkaline earth based antiperovskites, especially the ones with small semiconductor bandgap, have captured tremendous attention due to their properties which make them efficient to be used in optoelectronic and thermoelectric applications. In this thesis, we are shading light on the alkaline antiperovskite 𝐶𝑎₃𝐵𝑖𝑁 due to its narrow bandgap. Thus, it can be considered as a promising candidate for thermoelectric and optoelectronic applications. Specifically, it is used to harvest waste thermal energy into electricity at low …

Orbit Propagation And Determination Algorithms For Satellite Ground Stations, Shamma Esmaeel Jamali

Theses

The satellite orbital parameters are essential for satellite operations. With these parameters, it is possible to estimate the satellite position in the recent past and near future, which is essential to effectively plan satellite operations and associate satellite telemetry with geographical locations.
However, for small or medium satellite operators who do not possess the infrastructure required to track their satellites, the problem of determining the satellite orbit is problematic. To access the orbit for their satellites, these organizations have to rely on third parties such as Celestrak. These entities provide the service free of charge but do not provide orbital …

Miniaturized Iii-V/ Si Hybrid Laser With An Integrated Modulator, Praveen Kumar Singaravelu

Theses

Light interaction with microscopic and nanoscopic structures enable manipulation of its characteristics which can be used to detect objects in 3D sensing, propel satellites to space using photonic propulsion and transmit data through optical communication. For optical communication, the basic components are lasers, modulators and photodetectors. The development of CMOS microfabrication foundries helps to manufacture silicon-based photonic devices with high yield that is directly co-integrated with electronics in a single chip. However, the lack of emission of photons efficiently in silicon propelled the necessity of hybrid photonic devices that inherits the combined advantage of different materials i.e. functionality and volume. …

Coupled Oscillators: Protein And Acoustics, Angelique N. Mcfarlane

Theses

This work encompassed three different vibrational energy transfer studies of coupled resonators (metal, topological, and microtubule comparison) inspired by the lattices of microtubules from regular and cancerous cells. COMSOL Multiphysics 5.4 was utilized to design the experiment. The simulation starts with an acoustic pressure study to examine the vibrational modes present in coupled cylinders, representing α-, β-tubulin heterodimers. The Metal Study consisted of 3 models (monomer, dimer, and trimer) to choose the correct height (40 mm) and mode (Mode 1) for study. The Topological Study was run to predict and understand how the lattice structure changes over a parametric sweep …

Mos Compatible Deposited Materials For Optical Interconnects, Simone Iadanza

Theses

The recent years' exponential growth of data transmission in datacom and telecom technology (such as in Wavelength Division Multiplexing - WDM) has highlighted the energy consumption challenges of electronics, shifting research and industry interest towards optical interconnects. Novel and more efficient integrated photonics is being given the objective to face the ever-increasing demand for speed and bandwidth. This has initiated, in both industrial and academic environments, a quest for low-power, compact and cost-effective optical interconnects that can be integrated on electronic boards of Datacentres and transceivers all over the world. In this thesis, different types of WDM compatible Hybrid External …

Fabrication And Characterization Of Nanostructured Hybrid Materials For Gas Sensing Applications, Husam H.D Altakroori

Theses

The rapid increase in environmental pollution has become a major concern, and its monitoring has evolved into a priority for human health. This fact has directed the researchers to make more efforts to find new techniques for the detection of gases hazardous to the environment and human health. With the tremendous advances in technology, gas-sensing devices have become popularly used in environmental applications to detect various toxic gases at very low concentrations.

This work aims at developing high-performance gas sensors with enhanced sensitivity, selectivity, low response time, and low operating temperature. The proposed sensors are fabricated based on the integration …

Asssembly And Deployment Of The Uaeu 256-Element Radio Array For Space Science, Ibrahim J.M. Alghoul

Theses

The scope of this project, a 256-element Radio Interferometer Array was assembled and deployed as part of the “UAEU Radio Astronomy Pathway Project”, which is jointly supported by the College of Science and the National Space Science & Technology Centre (NSSTC) at the UAE University. This antenna array was deployed at the NSSTC site, and it will serve as the central part of the ground-based radio observations facility to be utilized for multi-disciplinary space science research at the UAEU. The facility is capable of making low-frequency radio observations of astronomical sources and events, measurements for spacecraft tracking, atmospheric studies, planetary …

The Interactive Simulation Of Mars Dust Storms With The Mars General Circulation Model Marswrf At The Resolution Of 7.5°×9° (Latitude By Longitude), Khulood Hasan Alshehhi

Theses

The Mars dust cycle, including dust storms, has a great impact on the temperature, and the climate in general, on Mars. Dust particles in the atmosphere have a great capacity for absorbing/emitting infrared radiation resulting in large changes in the Martian climate. Local and regional dust storms occur in any Martian Year (MY), but global dust storm events (GDEs), which can cover the whole planet, occur, on average, once every 3-4 MYs. MarsWRF is a Mars version of the terrestrial numerical weather and climate model WRF (Weather Research and Forecasting Model) and part of the Planet WRF models for planetary …

Molecular Cloud Properties In High-Mass Star Forming Regions, Mohammed Essa Abdulla Ali Ahli

Theses

Using high spatial resolution observation of ¹²CO (2−1) and ¹³CO (2−1) emissions, I present the molecular cloud properties of N42 in the Small Magellanic Cloud. The observations were taken using the Atacama Large Millimeter Array observations. I conducted a thorough analysis of molecular gas properties to understand how the cloud properties of N42 differ from those of Galactic clouds. My analysis shows that, in N42, the majority of CO emission appears clumpy, while molecular cores with YSOs exhibit greater linewidths and masses. Massive clump cores are associated with YSOs. Virial analysis of the ¹²CO and ¹³CO …

The Correlation Between The Effects Of Strain And Stochiometric Coefficient On The Magnetic Properties Of Srsno₃ And Sr₃Sno, Amal Sameh Kashcoul

Theses

Perovskites (ABX₃) are one of the most prominent families of crystalline alloys have received excellent research attention globally because of their diverse multi-functionalities and the interesting physics underpinning them. On the other hand, antiperovskites (X₃BA) are electronically inverted perovskite derivates, yet they are not an insignificant class of functional materials. Antiperovskites, inheriting the flexible structural characteristics of perovskites and rich in cations at X sites, display unusual chemical and physical properties. The SrSnO₃ is a distinctive perovskite oxide in that it possesses a higher electron conductivity despite its sizeable optical band gap. This dissertation has …

Non-Adiabatic Perturbations And Non-Gaussianity During Inflation: Affine Gravity Approach, Isaac Bamwidhi

Theses

This thesis is concerned with providing a complete study of non-Gaussianity and entropy perturbations that are sourced by multiple fields nonminimally coupled to gravity. The study will be performed in the framework of the two important formulations of gravity, namely: purely metric (general relativity) and purely affine formulation – where the metrical structure results from the dynamics of the spacetime affine connection. We shall employ a covariant formalism in our framework and demonstrate that it leads to a curved field space which can produce a conspicuous departure from the purely metric gravity. This work is expected, not only to derive …

Assembly And Detection Of 3-D Qr Codes Through Additive Manufacturing And Terahertz Imaging, Patrick Dunn

Theses

Automatic identification and data capture, or AIDC, plays a substantial role in contemporary business, advertising, and military needs. The purpose of this study is to generate a potential alternative to current AIDC approaches by constructing three-dimensional plastic tags (or ‘3D QR codes’) using additive manufacturing techniques and interrogate them using Terahertz radiation. 3D Quick Response (QR) codes are designed in 3D computer-aided design software. The QR codes are 3D structures embedded in the printed plastic in which an air gap in the plastic (or an air gap filled in with another type of plastic) indicates a bit of information. Information …

Wavelength Swept Photonic Crystal Laser, Sharon Marie Butler

Theses

Photonics has become integral to society, based on its ability to sense the environment, to manipulate materials and to transport information. The dominance of silicon electronics has made silicon photonics a compelling vision, but difficulties with light emission have caused delays in implementation and an enduring role for III-V materials. The research conducted in this Ph.D. thesis involves study and utilisation of a combination of the optical gain of Indium Phosphide with the precision and energy of silicon nanophotonics in a novel family of lasers. A continuously tunable akinetic reflective filter is exploited to obtain a wavelength swept laser. The …

Photoluminescence Properties Of Novel Iii-V Semiconductor Systems, Shumithira Gandan

Theses

Perturbation of the inherent radiation equilibrium in solids by an external energy could engender an emission of the superfluous energy as electromagnetic radiation, or luminescence. Photoluminescence methods precipitate this disintegration of radiation equilibrium often by supplying the external energy as photons with energies higher than the bandgap energy of the solid. Since the excitation energy momentarily transforms the medium before luminescence is emitted, photoluminescence experiments are able to produce diverse and intricate spectroscopic data detailing the optical properties of the solid as a measure of this transformation. The pliability of allowed electron states in semiconductors have instigated bourgeoning research in …

Dynamics Of A Swept Source Laser Under External Injection, Uday Bangavadi Munivenkatappa

Theses

Swept Sources are lasers with a periodically modulated frequency, over a wide scanning range. They are widely used in Optical Coherence Tomography (OCT) for medical imaging and metrology. The narrow instantaneous linewidth of a swept source is required for longer OCT imaging depths. The goal of the project is to investigate the mechanism that deteriorates the coherence of a swept-source laser by analyzing its properties under external injection and investigate the possibilities for a phase-locked laser operation, in order to control the coherence properties. The laser under study was a semiconductor ring fiber-based cavity laser, incorporating a tunable narrow transmission …

Treated Hfo2 Based Rram Devices With Ru, Tan, Tin As Top Electrode For In-Memory Computing Hardware, Yuvraj Dineshkumar Patel

Theses

The scalability and power efficiency of the conventional CMOS technology is steadily coming to a halt due to increasing problems and challenges in fabrication technology. Many non-volatile memory devices have emerged recently to meet the scaling challenges. Memory devices such as RRAMs or ReRAM (Resistive Random-Access Memory) have proved to be a promising candidate for analog in memory computing applications related to inference and learning in artificial intelligence. A RRAM cell has a MIM (Metal insulator metal) structure that exhibits reversible resistive switching on application of positive or negative voltage. But detailed studies on the power consumption, repeatability and retention …

Radio Observations Of The Neutron Star X-Ray Binary Circinus X-1: Clues On The Onset Of Radio Emission And Jet Formation, Batool Ahmad Essa Saleh Ilyasi

Theses

Circinus X-1 is a Neutron-Star X-ray Binary System which features strong and variable radio emission. This emission is triggered as a result of the interaction between neutron star and its companion as they approach periastron. Radio observations of Circinus X-1 have not been carried out over the past 7 years. Here are the results of the radio observation and monitoring campaign on Circinus X-1 with the Australia Telescope Compact Array (ATCA) – Australia, at centimeter wavelengths (5.5 and 9 GHz). The radio behavior of Circinus X-1 has been monitored over two of its orbits (16.6 days each) to probe its …

The Primary Volatile Composition Of Comet C/2015 Er61 (Panstarrs), Aaron Butler

Theses

In the outer edges of the solar system exist two regions: the Kuiper belt and Oort cloud. These two regions have a high amount of icy bodies (comets) orbiting the Sun. Comets located within the Oort cloud and Kuiper belt contain an ancient codex to the solar systems contents, before the formation of our solar system. Presented are near-infrared, high-resolution (λ/Δλ ~40000) data obtained from the immersion-grating echelle spectrograph iSHELL at the 3m NASA Infrared Telescope Facility (IRTF) in Maunakea, Hawaii of the Oort cloud comet C/2015 ER61 (PANSTARRS). Observations took place on April 15 and 17 in 2017 while …

Hybrid Frequency Modulated Silicon Photonic Crystal Laser, Andrei Bakoz

Theses

Silicon photonics takes advantage of the mature complementary metal-oxide semiconductor (CMOS) infrastructure and processes, and is actively pursued for the implementation of complex optical components and photonic integrated circuits (PICs) at low cost and high volumes. Despite a constant refinement of silicon photonics technology to meet the evolving requirements for applications, the poor light emission ability of silicon remains a constraint. As a result, the most essential building block of an optical system, an efficient light emitter, remains absent in PICs based on silicon. This thesis is focused on study of the potential of an external cavity (EC) hybrid III-V …

Fabrication Of Organic-Inorganic Hybrid Nanocomposite-Based Sensor For H2s Gas Detection, Fajr Ibrahim Musa Ali

Theses

Low power consumption, low limits of detection, and low cost are the compelling demands in the world of gas sensors development that motivate the search for new materials. Recently, gas sensors based on organic-inorganic nanocomposite materials have attracted much attention due to their high performance and low working temperatures in comparison with the commercial sensors for Hydrogen sulfide (H_₃S) gas. The development of H_₂S gas sensors is vital because H_₂S is one of the major air pollutants produced in large quantities in petroleum/natural gas drilling and refining. H_₂S gas is extremely toxic, …

Development Of Uv Led Based Lamps With Modular Optical Heads, Ciara O'Hara

Theses

This project was centred around the development of the optical components, and the optimisation of the optical performance, of ProPhotonix Ltd’s Cobra Cure FX series of products. These are high irradiance, high dose, UVA (primarily 395 nm and 365 nm) Light Emitting Diode (LED) lamps designed for curing applications. An initial prototype developed by ProPhotonix, the smallest in the series, the FX1, underwent significant redesign throughout the project, and the two larger lamps, the FX2 and the FX3 were developed during the course of the project. This work primarily consisted in characterising, accurately modelling, and thereby refining, the optical reflector …

Dynamics Of Swept Source Lasers, Ben O'Shaughnessy

Theses

The aim of this thesis is to investigate the dynamics of two kinds of swept source lasers for optical coherence tomography. A mathematical model consisting of a pair of coupled delay differential equations was adapted to study Fourier Domain Mode-Locked (FDML) lasers and short cavity swept source lasers, and to explain experimental observations of these lasers.

The short cavity laser is experimentally observed to produce pulses during the frequency sweep. This ‘sliding frequency mode-locking’ behaviour is reproduced by simulation, which is then used to establish simple relationships between the key parameters of sweep speed, linewidth and output power.

The FDML …