Materials Science and Engineering Commons^™

Study On Fracture Toughness Under Different Modes Through Continuum Damage Mechanics Based Fracture Locus, Yeting Sun

Graduate Studies Theses and Dissertations 2026

Traditional elastic-plastic fracture mechanics (EPFM) relies on crack-tip analysis, whereas continuum damage mechanics (CDM) is typically calibrated from uncracked bodies. This dissertation aims to bridge the gap between these two fundamental branches by explicitly linking fracture toughness with ductile damage models. Based on the assumptions regarding Mode I crack deformation, analytical solutions are derived to establish a novel relationship among Mode I fracture toughness, CDM-based ductile fracture strain, and material strain hardening capability. This theoretical framework is subsequently extended to encompass Mode II and Mode III loading conditions. To validate the proposed relationships, finite element (FE) models are developed in …

Advanced Ysz/Si(B)Cn And Bnnt/Si(B)Cn Ceramics Matrix Composites For Extreme Environments In Hydrogen Combustion, Yiting Wang

Graduate Studies Theses and Dissertations 2026

The growing demand for carbon-neutral energy conversion has accelerated the development of hydrogen-fueled gas turbine systems, which operate at significantly higher temperatures and more chemically aggressive environments than conventional natural gas turbines. To meet these stringent requirements, ceramic matrix composite (CMC) materials consisting of yttria-stabilized zirconia (YSZ) fiber reinforced Si(B)CN ceramic matrix were developed. To further enhance in-plane heat dissipation, thermal stability, thermal shock resistance, and thermal cycling performance, a Si(B)CN/Boron Nitride Nanotubes (BNNT) nanocomposite coating was incorporated onto the YSZ/Si(B)CN composites. Microstructural characterization confirmed the formation of a continuous Si(B)CN ceramic matrix reinforced with uniformly distributed BNNTs. The resulting …

Strontium Titanate For Capacitor And Energy Storage Applications At Cryogenic Temperatures, Hung Trinh

Doctoral Dissertations

This study investigates the dielectric properties of single crystal and ceramic strontium titanate (SrTiO₃) for cryogenic capacitor applications from room temperature to 4 K. Permittivity (k) and loss tangent are dependent on temperature, frequency, mechanical stress, and applied DC electric field. Accordingly, the dielectric constant and loss tangent were measured at various frequencies and DC bias levels. Loss tangent data are also presented as equivalent series resistance (ESR). For single crystal SrTiO₃, an impurity level of ≈500 ppm barium resulted in an increase of the maximum permittivity to approximately 50,000 at 6 K. This relatively high …

Regulation And Localization Of Urease In Sporosarcina Pasteurii: Implications For Coastal Protection, Amar Kosovac

UNF Graduate Theses and Dissertations

Coastal erosion is a persistent problem exacerbated by global warming. As the climate changes, the southeastern coast is likely to experience an increased frequency and intensity of storms, which can significantly damage the coastline. The coast is crucial as it serves as a habitat for numerous animals, supports tourism, and underpins infrastructure. Microbially induced calcite precipitation (MICP) is a novel method to enhance erosion resistance in sandy soils using the non-pathogenic bacterium Sporosarcina pasteurii. S. pasteurii produces urease to catalyze urea into bicarbonate, which drives the precipitation of calcium carbonate. Maximal expression of urease is a limiting factor for …

Mechanical Behavior Of Additively Manufactured Ti-6al-4v Eli Parts: Effects Of Laser Parameter Selection, Samuel Lopez

UNF Graduate Theses and Dissertations

Additive manufacturing (AM) of TI-6AL‑4V Extra‑Low Interstitial (ELI) enables complex geometries for fatigue‑critical medical device applications, yet fatigue performance remains sensitive to process‑induced defects. This work investigates the effect of laser process parameter selection on the microstructure, mechanical properties, and fatigue behavior of TI- 6AL‑4V ELI fabricated via laser powder bed fusion (L‑PBF) using a Renishaw RenAM system. The influence of laser parameters was isolated by holding powder chemistry, build orientation, scan strategy, sub‑transus annealing, and post‑processing constant between a non‑optimized baseline and an optimized parameter set selected based on tensile performance.

Optical microscopy showed the optimized condition exhibited improved …

Development Of A Flexible In Vitro Model System For Studying Biomineralization In Humans And Marine Organisms, Reed J. Harper

UNF Graduate Theses and Dissertations

Biomineralization is a process where cells control the supersaturation of ions and spatiotemporal deposition of numerous proteins to guide biomineralization, resulting in hard mineralized tissues with complex structures and novel properties. The mechanisms of this process are not well understood but key components have been identified as critical for biomineralization to occur. The cellular expression of intrinsically disordered proteins (IDPs) and the subsequent post-translational modification (PTM) play a role in stabilization of mineral precursors, control of morphology and growth, phase/polymorph selection, and composition of mineral formed. Currently in vitro model systems use either synthetic polymers, native proteins extracted from mineralized …

Computational Design Of Nanoporous Materials For The Adsorption Of Per- And Polyfluoroalkyl Substances, Daniel D. Mottern

Dissertations

Per- and polyfluoroalkyl substances (PFAS) are a large family of chemicals that have seen wide usage due to their fluorinated carbon backbone. The presence of strong C-F bonds in the backbone lends PFAS molecules high thermal and chemical stability, as well as strong hydrophobicity and lipophobicity. This combination of properties has led to heavy use of PFAS as surfactants, non-stick coatings, and aqueous foam forming films and flame retardants. However, these properties bring their own consequences. The high chemical and thermal stability of PFAS renders them persistent, with the C-F bonds resisting naturally occurring forms of degradation. Existing forms of …

Data-Driven Analysis And Atomistic Simulations Of Next-Generation Materials For Energy Conversion And Storage, Yuliang Shi

Dissertations

Metal-organic frameworks (MOFs), with their modular architectures and tunable properties, represent an especially rich domain for accelerated material design and discovery for a range of diverse applications. Within this class of multifunctional materials, two-dimensional (2D) electrically conductive MOFs (EC MOFs) are of particular interest, as their 7r-stacked layered structures combine permanent porosity with electronic conductivity, enabling potential breakthroughs in energy storage, energy conversion, and quantum sensing. But the discovery and design of new EC MOFs based on expensive experimental screening is increasingly impractical due to the infinite chemical space. Furthermore, the practical implementation of EC MOFs for specific tasks depends …

Effect Of Local Steel Slag Incorporation On The Mechanical Properties Of Concrete, Ahmed Safaa Tariq Karmah, Wissam Khadum Alsaraj, Luma A. Zghair

Al-Esraa University College Journal for Engineering Sciences

The increasing interest in the production of concrete through the utilization of inexpensive materials has caused a rise in the number of studies concerning the use of materials with cementitious properties, such as Silica Fume, Slag, Fly Ash and other pozzolanic materials. Moreover, the increasing amounts of Steel Slag being produced from local factories that are being deposited without an available method of disposal provides an opportunity to harness the Slag in the production of an inexpensive, and possibly better concrete. Slag has been used as both an addition and substitution of the cement and fine aggregate. The mixtures included …

Decoding Climate Change: A Comprehensive Statistical Insight Into Temperature Anomalies In Iraq And Its Neighboring Countries, Jameel T. Al-Naffakha, Mohammed R. Al-Qassabanda, Israa Jafar

Al-Esraa University College Journal for Engineering Sciences

This study applies advanced statistical techniques, including the Mann-Kendall Trend Test and ARIMA forecasting, to validate and predict temperature anomalies across Iraq and its neighboring countries (2014–2024). Findings confirm a statistically significant warming trend (p < 0.00000005) across all nations, with Syria (1.02°C) and Turkey (0.97°C) experiencing the highest anomalies. GIS-based spatial analysis highlights regional disparities, identifying climate-vulnerable zones. The persistent rise in temperature anomalies correlates with worsening water scarcity, desertification, and extreme weather events, including prolonged droughts and heatwaves. Iraq’s peak anomaly (1.48°C) has exacerbated heat stress, agricultural decline, and reduced river inflows, while Kuwait and Saudi Arabia struggle to maintain critical infrastructure under record-breaking temperatures exceeding 50°C. These climate shifts pose severe risks to water availability, food security, and energy demand, necessitating urgent policy interventions. Key recommendations include enhanced water resource management, climate-adaptive agriculture, and renewable energy expansion. If left unaddressed, rising temperatures could destabilize the region, increasing socio-economic vulnerabilities and escalating resource conflicts. This study underscores the need for cross-border collaboration and sustainable adaptation policies to mitigate the long-term impacts of climate change in the Middle East.

Optimal Power Flow Control In The Iraqi Power Grid Using Artificial Intelligence Algorithms For Carbon Emission Reduction, Mohammed Shakir Juber

Al-Esraa University College Journal for Engineering Sciences

Iraq’s power sector remains in a protracted and severe crisis characterized by a significant mismatch between supply and demand, high levels of losses during transmission and distribution, as well as an increasing challenge to the resources base being largely unfavourably. These inefficiencies impose heavy costs on the national economy in excess of 40 billion annually and they also reinforce greenhouse gas emissions, and exacerbate environmental issues. To deal with these problems, we proposed in this paper that a new hybrid AI tool should be developed for the solution of multi-objective optimization problem based on purpose Genetic Algorithm (GA) merger with …

Applying Machine Learning Techniques For Early Detection Of Cyber Attacks On Iot Devices, Noor Adnan Allamy

Al-Esraa University College Journal for Engineering Sciences

This research designs, implements, and evaluates a machine learning-based framework for the early detection of cyber attacks targeting Internet of Things (IoT) devices, with a specific focus on the context and challenges present in Iraq. The study conducts a comparative analysis of three supervised learning algorithms—Support Vector Machine (SVM), Random Forest (RF), and Deep Neural Networks (DNN)—using a combination of benchmark datasets (NSL-KDD, CIC-IDS-2017, Bot-IoT) and a synthesized dataset adapted to simulate the Iraqi threat landscape. Key performance metrics, including accuracy, precision, recall, and F1-score, were used for evaluation. The proposed Random Forest model demonstrated superior performance, achieving an accuracy …

Ai-Enhanced Heat Transfer Optimization In Magnetic Bio-Nanofluids, Hasan Attyah Shaboot

Al-Esraa University College Journal for Engineering Sciences

This study presents a hybrid Artificial Intelligence–Computational Fluid Dynamics (AI-CFD) framework for optimizing heat transfer in magnetic bio-nanofluids subjected to external magnetic fields. Magnetic bio-nanofluids, composed of biocompatible base fluids containing superparamagnetic nanoparticles, exhibit tunable thermal and flow behavior, making them promising for biomedical and micro-cooling applications. Conventional optimization methods based on experiments or brute-force CFD are computationally expensive and limited in exploring the full design space. To overcome these challenges, an Artificial Neural Network (ANN) surrogate model was developed to predict two key performance indicators, the Nusselt number and the friction factor, with high accuracy (R² > 0.997). The surrogate …

Hybrid Experimental–Computational Study On The Energy Absorption Of Graphene Nanoplatelet-Reinforced Sandwich Structures, Hamdan Yousif Hamdan

Al-Esraa University College Journal for Engineering Sciences

Background: Sandwich composites are widely used in aerospace, automotive, and marine applications because of their lightweight, stiffness, and strength, but they remain prone to out-of-plane impacts and barely visible impact damage (BVID). Graphene Nanoplatelets (GNPs) have shown strong potential to improve fracture toughness and impact resistance. However, hybrid experimental–computational studies applying such reinforcement are still lacking in developing contexts like Iraq, where practical and accessible solutions are essential. Aims: The study investigates the effect of GNP reinforcement on the low-velocity impact behavior and energy absorption of glass fiber/epoxy sandwich panels with PVC foam and balsa wood cores. Objectives include fabricating …

Effect Of Thick Closed Walls Of West And South Elevations Of Iraqi Middle And South Territory Housing Building On Reducing Energy Use, Abeer Qasim Jbur, Shaimaa M. Hamza, Mayyadah Lutfi Abdulwahhab

Al-Esraa University College Journal for Engineering Sciences

Thermal insulation is one of the most important factors in achieving sustainability, increasing efficiency, and reducing energy consumption, but modern insulation materials are expensive, in addition to their availability. Therefore, through our research, we resorted to investigating the issue of reducing thermal load in buildings through the use of thick-walled facades in the southern and western facades, where we studied a building with two windows with windows on the southern and western facades and another without these windows and with thick walls, for two locations, the first in central Iraq, which is the city of Baghdad, and the second in …

The Impact Of Ethyl Levulinate Additive On Diesel Engine Performance And Emissions: An Experimental Study, Maha Ali Ghadbaan

Al-Esraa University College Journal for Engineering Sciences

This study explores the environmental and operational impact of adding Ethyl Levulinate—a biodegradable ester derived from biomass—to diesel fuel. A fuel blend known as B5El6 (comprising 5% biodiesel and 6% Ethyl Levulinate) was prepared and tested experimentally using a single-cylinder diesel engine operating at a constant speed of 1500 rpm under full load conditions. Performance metrics and emission data were recorded, and a Life Cycle Assessment (LCA) was conducted using the IMPACT2002+ methodology.

The results revealed that B5El6 significantly reduced greenhouse gas emissions (100 kg CO2 eq) and improved ecosystem quality. However, it presented challenges in terms of human health …

The Role Of The Scenario In Formulating The Contemporary Architectural Text, Rounaq Arif Mohsin, Abbas Ali Hamza, Bashar Shamil Alkhafaji

Al-Esraa University College Journal for Engineering Sciences

In order to create an integrated architectural text, which is a complicated art that blends beauty and practical elements, a rigorous design procedure is necessary. In this situation, the scenario’s role becomes crucial in developing the current architectural text and directing architectural approaches. In order to better understand how the scenario influences the design process and the interactions between various architectural aspects, this project intends to explore and analyze the impact of the scenario in developing and refining architectural text formulation approaches.

The study looks at the idea of a scenario and how it has been used in architecture, as …

Investigation Of Some Physical Properties Of Slurry Infiltrated Fibrous Concrete (Sifcon) Under Different Curing Times, Rand Kh. Mahmoud, Mohmmed Juad Khadhim, Fayq Hasan Jabbar

Al-Esraa University College Journal for Engineering Sciences

This research studied the effects of different types fibers (Basalt, Carbon and Basalt-Carbon hybrid mix) and curing ages (7, 14, 28 and 56 days) on some physical properties of - Slurry infiltrated fibrous concrete (SIFCON). Density, ultrasonic pulse velocity UPV, Poisson’s ratio and water absorption were measured for the experimental study with 30% cement replacement by Class F fly ash to increase sustainability. It was found that properties were significantly affected by the type and dosage of fiber admixture. The UPV was enhanced by basalt fibers and the absorption reduced up to an optimal range of 3–5% after which agglomeration …

Mechanical And Durability Properties Of Cement Panels Reinforced With Hybrid And Pva Fibers, Shukran H. Faraj, Mohammed J. Kadhim

Al-Esraa University College Journal for Engineering Sciences

This study examines the synergistic effects of hybrid fibers (HF) and polyvinyl alcohol (PVA) fibers on the structural and thermal properties of silica-fume cement panels. Scanning electron microscopy (SEM) was employed to examine mortar mixtures with varying fiber content to assess their enhancement of microstructure. We conducted several experiments on compressive, flexural, and splitting tensile strength, in addition to water absorption and thermal conductivity. The results indicate that 1% HF exhibits superior mechanical qualities, with a compressive strength of 46.89 MPa, a flexural strength of 8.56 MPa, and a reduced thermal conductivity of 0.83 W/m•K. PVA fibers at 2% enhance …

Experimental Analysis Of Droplet Deformation Dynamics In Combined Dc Electric And Shear Flow Fields Using Dpiv, Ayad Ibrahim Khlewee

Al-Esraa University College Journal for Engineering Sciences

This paper presented a systematic study of such droplet deformation at the intersection of uniform DC electric field and hydrodynamic shear flow, in which we focused on conductivity ratio (R) and permittivity ratio (S), describing their influence. The results demonstrate that droplet dynamics is extremely sensitive to the regime: under DC only, either elongation or compression depending on whether R > S or R S, similarly to classical EHD predictions. Under shear-only conditions, deformation was dictated by the balance of elongational stresses (EC) and rotational stresses (RC), with increasing capillary number (Ca) leading to progressive elongation and oscillatory orientation dynamics. When …

The Imaginary In Architecture: The Conceptual Structure Of The Imaginary And Its Manifestations In Architectural Text, Noora Ghadir Hlail, Abbas Ali Hamza Al Greiza

Al-Esraa University College Journal for Engineering Sciences

This study explores the concept of the imaginary as a collective cognitive and cultural structure that shapes symbolic reality through images, myths, and deeply rooted symbols in collective memory. The research applies this concept within the field of architecture, aiming to understand how the imaginary is embodied in architectural texts as symbolic carriers of identity and cultural meaning. Adopting a descriptive-analytical methodology, the study develops a theoretical framework comprising key components—preconditions, mechanisms, and traits of the imaginary—and applies it to two selected case studies: the General Secretariat of the Iraqi Council of Ministers and the Louvre Abu Dhabi Museum. The …

Generative Ai For Method Development In Analytical Chemistry: A New Paradigm In Experimental Design And Optimization, Yasir Fathi Mahmood

Al-Esraa University College Journal for Engineering Sciences

The fast development of artificial intelligence (AI), especially generative AI models, is changing the environment of analytical chemistry. As classical method generation in analytical methods relies on manual trial-and-error methodology as well as statistical methods, generative AI is a new paradigm with automated generation of experimental methodology and optimization. In this paper, the authors discuss the use of generative AI-based technologies, including large language models (LLMs) and neural network-based generators, to create new, efficient, and customized methods of analysis. The paper examines existing applications, technology frameworks, and issues and offers a roadmap with regards to the future incorporation of generative …

Numerical Modeling And Experimental Validation Of A High-Temperature Latent Heat Thermal Energy Storage System Using Metallic Phase Change Materials For Concentrated Solar Power Applications, Fouad Hashim Sharhan

Al-Esraa University College Journal for Engineering Sciences

To ensure reliable performance for the power-block of CSP plants, high power density and near-isothermal discharge must be achieved. A robust means of achieving this is through thermal energy storage (TES). High temperature latent heat storage (LHS) with phase change materials (PCMs) can serve these purposes, however the conventional salts used in PCMs typically suffer from low thermal conductivity that limits power density and increases energy storage charging/discharging times. This manuscript investigates ways to address these limitations using high temperature metallic phase change materials (MPCMs) while also developing a validated numerical framework to aid in their design. To this end, …

Thermal Performance Evaluation Of Solar Cooling Systems For Educational Facilities In Baghdad, Yasser Alawi Mohammed Attia Al-Jubouri

Al-Esraa University College Journal for Engineering Sciences

Schools in Baghdad also suffer from poor thermal comfort, which is a common problem in high-temperature and low-humidity arid climates such as that of the city, where using cooling devices leads to a large energy demand and overloads on the national power grid. Such study offers a thorough assessment of the thermal performance of solar-based cooling systems in an efficient manner to be suitable for educational buildings in Baghdad. The analysis is centred on a solar thermal cooling system with absorption as the heat interaction medium, and an experimental characterisation and mathematical simulation itself are performed. A pilot installation, consisting …

Aerodynamics And Heat Transfer In Polymer Blown Film Processing: Experimental And Numerical Investigation, Mohammad Luqman Zulbakri, Nur Atiqah Mat. Rautin, Raa Khimi Shuib, Ku Marsilla Ku Ishak, Auratus Zuratul Ain Abdul Hamid, Mohamad Danial Shafiq, Mohamad Yusof Idroas, Muhammad Khalil Abdullah

Makara Journal of Technology

The effects of airflow dynamics, heat transfer, and mechanical properties on the HDPE blown film extrusion process were examined using a single-lip air ring with a fixed compressed-air valve opening angle of 10°. Reynolds numbers ranging from 9175 to 25911 were analyzed to understand their impact on cooling efficiency, bubble morphology, and film properties. Numerical simulations employing the Standard k−ω turbulence model in ANSYS FLUENT v2023, with mesh refinement achieving y+ ≈ 1, captured detailed flow and heat transfer behavior. Results showed that higher Reynolds numbers significantly enhanced the heat transfer coefficient, with values increasing from 1096 W/m²·K at Reynold …

Bio-Papcz: Corn Starch-Based Composite Bioplastic Reinforced With Pineapple Leaf Fiber (Palf), Zinc Oxide (Zno), And Polyvinyl Alcohol (Pva), Marvin C. Caya, Shervin Austin C. Huang, Jovar Khalel J. Maghari, Ruel M. Levida

Sinaya: A Philippine Journal for Senior High School Teachers and Students

Plastic pollution poses a serious global threat, as petroleum-based plastics persist for centuries, and their surging production of over 450 million tons overwhelms ecosystems (Ritchie et al., 2023). Using a quantitative experimental research design, the study examined the effects of varying concentrations of cornstarch-based bioplastic reinforced with pineapple leaf fiber (PALF), polyvinyl alcohol (PVA), and zinc oxide (ZnO) on the bioplastic’s tensile strength and soil degradability. Sample C2 (ZnO 3.0 %w/w; PVA 9.0 %w/w) demonstrated the optimal tensile properties with a tensile strength of 0.76 MPa and an elongation at break of 6.40%, which was attributed to the addition of …

Effects Of Foam Type And Thickness On Impact Resistance, Thermal Insulation, And Cost-Effectiveness Of Medical Containers For Drone Delivery, Josh Henry C. Soriano, Eriel V. Fonte, Lambertsus S. Novera, Nicolai Paolo B. Villarin, Joel B. Jalon, Jr.

Sinaya: A Philippine Journal for Senior High School Teachers and Students

Accessible healthcare remains a challenge for rural communities lacking reliable infrastructure for medical supply delivery. Delivery drones have recently emerged as a viable alternative, dropping medical containers during flight. However, the effectiveness of different foam types and thicknesses combined with corrugated cardboard as shock-absorbing materials in a medical container for delivery drones has yet to be tested. Thus, this study designed cost-effective containers using corrugated cardboard and multiple foam types and thicknesses, aiming to preserve the integrity of the contents, withstand impact, and control temperatures. Four foam types—polystyrene, polyurethane, polyethylene, and expanded polystyrene (EPS) —were tested at 1 cm, 2 …

Curing Duration Optimization To Reduce Shrinkage Cracking In One-Part Alkali-Activated Slag Concrete, A. Sadrmomtazi, H. Zanganeh

Journal of Sustainable Construction Materials and Technologies

The consequences of inadequate curing on one-part alkali-activated slag concrete (O-AAS) performance relative to ordinary Portland cement concrete (OPCC) have been investigated in this research. Prior to exposure to unsaturated conditions, samples underwent initial moist curing for durations ranging from 24 hours to one year. The testing program included compressive strength evaluation, chloride ion transport analysis, and measurement of free and restrained shrinkage. In addition, cylindrical cores were extracted from concrete columns to assess internal strength and chloride penetration resistance. Under unsaturated exposure, O-AAS exhibited a strength-aging phenomenon, with up to a 37% decrease in compressive strength over 360 days, …

Laboratory Investigation And Numerical Modelling Effect Of Carbon Nanotubes On Hot Mix Asphalt Permanent Displacement, Sepehr Saedi, Auwal Usman Nadada

Journal of Sustainable Construction Materials and Technologies

One of the primary causes of asphalt pavement deterioration is rutting; in contrast, one of the most effective methods to address this type of damage is the use of additives and quality evaluation during the design stages. In this research, laboratory testing and modeling using Abaqus software were employed to validate the laboratory results and predict and assess the potential for rutting. Carbon nanotubes (CNTs) were selected as an additive due to their exceptional mechanical properties and molecular interactions with bitumen. These nanotubes were used to modify the bitumen for the preparation of laboratory samples. The laboratory results from the …

Influence Of Early Microwave Curing On Performance Of Slag-Based Geopolymer Mortars, Ahmet Taşdemı̇R, Abdulkadir Çevı̇K

Journal of Sustainable Construction Materials and Technologies

In this article, an experimental study was conducted to examine the effect of curing time and microwave power on the compressive strength of early microwave-cured slag based geopolymers. Geopolymers have the potential to serve as an environmentally friendly substitute for cement-based building materials, and the use of microwave curing to geopolymers holds the promise of substantial strength improvement. Different microwave curing energies (300 - 800 Watts) were utilized at varying durations (10 - 60 minutes) on demoulded mortar specimens after one day. After that, compressive strength tests were conducted on both the cured and uncured specimens at three different ages: …