Physics Commons^™

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 …

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 …

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, …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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, …

Exact Localized Solutions Of The Nonlinear Dirac Equation, Yaser Hasan Sabbah

Theses

The nonlinear Dirac equation is a relativistic classical field theory that describes the behavior of a system of self-interacting spinor fields. According to this theory, the interactions among spinor fields are represented by additional Kerr-nonlinearity added to the Dirac equation, which justifies and models the noticed solitonic behavior of the systems. There are various models of the nonlinear Dirac equation which differ from each other in the factors taken into account in the modelling, especially the mode of the coupling among the spinor fields as well as the nature of the system represented by the model. In this present thesis, …

Optimization Of A Combined Carbon/Oxygen And Neutron Porosity Oil Well Logging Tool, Entisar Ali Al Muraikhi

Theses

Well logging technique is used to determine the physical and chemical properties of borehole formation, by using neutron porosity oil well logging tools. The present study simplifies logging tool design in order to reduce the time spent on obtaining well logging. We have combined both carbon/oxygen (C/O) tool and thermal neutron porosity tool. This has been done by adding boron lining on the detectors in C/O tool, where the boron lining acts as a thermal neutron porosity tool while maintaining C/O functions simultaneously. The Monte Carlo N-Particle (MCNP) Transport Code, which was originally developed in Los Alamos National Laboratory, is …

Unwrapping Mri Phase By Using Multi-Echo Technique, Shamma Ali Rashed Ali Al Hassani

Theses

Phase unwrapping is a classic signal processing problem and an unavoidable procedure that can be faced with in a variety of applications which are interested in the phase, such as synthetic aperture radar (SAR), field mapping in magnetic resonance imaging (MRI), wavefront distortion measurement of adaptive optics, interferometry, and surface shape measurement. Although phase unwrapping is one of the most challenging tasks in signal processing because of the presence of residues, noise in the data, discontinuities or other phase particularities, there are many successful phase unwrapping techniques and algorithms that have been developed in the last decades. In this thesis, …

Fabrication And Characterization Of Graphite Oxide Based Field Effect Transistors For Non­ Enzymatic Glucose-Sensor Application, Khadija Said Rahman

Theses

Graphite-oxide based metal–oxide–semiconductor field-effect transistors (MOSFETs) were fabricated and used as glucose sensor. Herein, graphite-oxide was assembled between two planer electrical electrodes. The sensitivity of the sensor has been enhanced by adding copper (Cu) or silver (Ag) nanoparticles. The nanoparticles were produced by sputtering and inert gas condensation inside an ultra-high vacuum compatible system, and they were self-assembled on the graphite-oxide. The sensitivity of the sensor was increased by an order of magnitude when the silver nanoparticles were added. The sensitivity of each MOSFET was studied at different concentrations of non-enzymatic glucose for potential use in medical and industrial applications.

Achievable Accuracy Of Radiation Dose Measurement For Linear Accelerators Using Different Protocols, Mariam Hamad Al Darmaki

Theses

The aim of radiotherapy treatment is to deliver a specified radiation dose throughout a definite target volume within predetermined levels of accuracy and homogeneity; at the same time ensuring adequate dose sparing of surrounding normal tissue. Radiotherapy is a complex process involving a number of steps and the accuracy of each stage has a direct impact on the treatment outcome. At each stage, comprehensive quality assurance procedures are required to ensure safe and accurate delivery of the prescribed dose.

This project will aim to determine the currently achievable accuracy and reproducibility of radiotherapy dosimetry and assess the current recommendations for …

Control Of Radiation Exposure To Paediatric Patients At Conventional Radiology And Cardiac Centers At Dubai Hospital, Najlaa Khalfan Saeed Almazrouei

Theses

In view of increasing the number of x-ray examinations over the years, paediatric radiation safety is considered as one of the critical subjects in the modern medical imaging. Paediatric patients are at higher risk from ionizing radiation than adults if they receive same amount of dose. This project was conducted to evaluate paediatric patient radiation dose levels in digital radiology (both fixed and mobile x-ray units) and interventional cardiology at Dubai Hospital. The results of this study are expected to contribute in establishing local and national diagnostic reference levels in United Arab Emirates (UAE). A combination of phantom studies and …