Mechanical Engineering Commons^™

Numerical Comparative Study Of The Thermal Performance And Load-Bearing Capacity Of Hollow Clay Bricks Used In Construction In Libya, Osama Lawej, Mahmoud Ahmed, Ismael Ehtiwesh

Journal of Sustainable Construction Materials and Technologies

The optimization of structural and thermal performance in building components is a key challenge in sustainable construction, particularly in hot climate regions like Libya. Hollow clay bricks are widely used due to their local availability and affordability; however, their internal geometry is often not optimized for thermal resistance or mechanical integrity. This study addresses this gap by numerically investigating the effect of cavity geometry on the load-bearing capacity and thermal insulation performance of hollow clay bricks. Three configurations were analyzed, including two commercial designs from the Libyan market and a newly proposed arched cavity design. Finite Element Method (FEM) simulations …

Developing A Modular Circular Wall Over-Clad System For Facade Thermal Upgrade In Deep Energy Retrofit, Patrick Daly

Journal of Sustainable Construction Materials and Technologies

The EU has implemented several policy and legislative initiatives aimed at decarbonisation and circularity transition of the Built Environment including a strategy for large scale renovation of the building / housing stock. Modularised construction solutions are argued to be a potential acceleration pathway toward this objective. Yet there remains issues and challenges in implementing such strategies in a complex and heterogeneous stock and sector. This research investigates this decarbonisation pathway, examining the feasibility and potential of applying a modularised construction over-clad system, based on advanced circularity, in the deep energy retrofit of social housing. The research is based on a …

Influence Of Obesity On Knee Joint Mechanics: A Subject-Specific Musculoskeletal Modeling Approach, Ryan C. Knowles

Electronic Theses and Dissertations

Obesity has been consistently linked to knee osteoarthritis (KOA), a debilitating joint disease. While prior work has shown that obese individuals often walk with altered biomechanics compared to normal-weight (NW) individuals, which may accelerate KOA progression, less is known about how these mechanics affect load distribution between the medial and lateral tibiofemoral (TF) compartments, particularly during higher-demand activities. This study developed subject-specific musculoskeletal models of five obese and five NW individuals, incorporating CT-based bone measurements and individualized joint contact points. Simulations were driven by six degree-of-freedom (6DOF) kinematics obtained from high-speed stereo radiography (HSSR) to predict TF loading and associated …

Ceramic Waste As Sustainable Material In Self-Compacting Concrete: Experimental Study And Ann Predictive Modeling, Abderrezak Bouziane, Houssam Slimanou, Mohamed Amin Bouzidi, Nedjima Bouzidi

Journal of Sustainable Construction Materials and Technologies

Recycling of ceramic waste in the construction sector is a promising option for reducing the environmental impacts of the concrete industry. The main objective of this study is the elaboration of a solid predictive model for ceramic waste based self-compacting (SCC) concrete properties, using artificial neural networks (ANN). This further, reduces its environmental impact without compromising satisfactory performance. An experimental approach was adopted with different substitution ratios: 0 to 30 wt% and particle sizes ranging from 3-8 mm and 8-15 mm. Tested properties of modified SCC as compressive strength at 7 and 28 days (fc7, fc28), spread (L), sieve stability …

Comparative Study On The Performance Of Ggbs, Uggbs, And Rha-Incorporated Cement Mortar Mixes, Devansh Goel, Sudarshan D. Kore

Journal of Sustainable Construction Materials and Technologies

The environmental footprint of cement production has accelerated the pursuit of sustainable alternatives in the construction industry. Supplementary cementitious materials (SCMs), particularly those derived from industrial and agricultural waste, offer a promising approach to reducing cement consumption while maintaining performance. This study evaluates the fresh and mechanical behavior of binary, ternary, and quaternary cementitious mortar blends incorporating ground granulated blast-furnace slag (GGBS), ultrafine GGBS (UGGBS), and rice husk ash (RHA) as partial replacements for cement. A total of 32 mortar mixes were designed with water-to-binder (w/b) ratios ranging from 0.3 to 0.5 and varied replacement levels of RHA (0-20%), GGBS …

Functional Biopolymers Applied To Sustainable Technologies In The Environment And Healthcare, Fengjie He

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biodegradable polymeric materials (biopolymers) are naturally derived materials known for their excellent biocompatibility, biodegradability, sustainability, and versatile chemical functionality. They have attracted increasing attention in various applications as alternative to synthetic materials ranging from food packaging to tissue engineering. Meanwhile, with intrinsic advantages, biopolymers have also emerged as promising materials in addressing contemporary challenges in both biomedical and environmental fields. Motivated by the significant potential of biopolymers and the growing need for sustainable materials, my research focuses on the design and engineering of biodegradable polymers with novel modification methods and application directions. In this work, two representative biopolymers are selected: …

Effect Of Moderate Decrease In Contractility On Epithelial Cell-Cell Contacts Under External Stretch, Saika Sharmin

Mechanical & Aerospace Engineering Theses & Dissertations

Epithelial tissues are characterized by extensive cell–cell contacts and often subject to stretch during normal function. Cell-cell contact adhesion strength maintains mechanical continuity from cell to cell. Mechanical forces exerted by cells via actomyosin contractility are known to strengthen cell-cell adhesions to a certain extent. While it is known that a large decrease in contractility causes cell-cell contact rupture due to weakened adhesions, it is unclear how a moderate reduction in contractility affects cell-cell junction stability. Here, we studied how a moderate inhibition of non-muscle myosin II (NMII) affects the integrity of epithelial cell-cell contacts, especially when subject to the …

Towards Improving Computational Modeling Of The Lumbar Spine - Impact Of Material Properties And Laminotomy On Spinal Biomechanics, Isaac K. Kumi

Mechanical & Aerospace Engineering Theses & Dissertations

Spinal ligaments play a crucial role in maintaining the mechanical stability of the lumbar spine. These dense, collagenous tissues not only resist excessive motion but also distribute loads between spinal components to protect neural structures. Traditionally, the mechanical response of ligaments has been modeled using linear elastic assumptions, which treat the tissue as having a constant stiffness regardless of loading history. While this simplifies analysis, it fails to capture the time-dependent behaviors, such as creep, stress relaxation, and hysteresis, that are characteristic of biological tissues.

Viscoelastic modeling may provide a more physiologically accurate representation by incorporating both elastic and viscous …

The Utilization Of Basic Oxygen Furnace Slag As Fine Aggregates In Concrete: Physical, Mechanical, And Durability Properties, Hakan Ozkan

Journal of Sustainable Construction Materials and Technologies

This study examines the feasibility of using basic oxygen furnace slag (BOFS) as an alternative to fine crushed limestone aggregate in concrete. BOFS is sourced from two steel production facilities in Türkiye, designated as I-BOFS and E-BOFS. The experimental results showed that as the E-BOFS aggregate replacement ratio increased, the water-to-cement (w/c) ratio increased to maintain the target workability. The concrete mixtures incorporating E-BOFS exhibited consistent reductions in the compressive strength with an increase in the BOFS ratio. At the same time, I-BOFS maintained higher compressive strength, with only minor losses up to 80% of the substitution ratio. Flexural strength …

Development Of A Self-Cured Alkali-Activated Mortar, Kübra Ekiz Barış

Journal of Sustainable Construction Materials and Technologies

Alkali-activated mortars (AAM) can be produced with self-curing (SC), which supplies internal moisture to accelerate alkaline-activation reactions. The aim of using SC is to make AAMs with an early-age strength without any additional curing energy consumption and higher CO2 emissions, and to obtain in-situ practical advantages that enable the large-scale application of AAMs. The previous study produced natural pozzolan-based AAMs by applying energy-intensive heat (HC), microwave (MWC), and hybrid (HC+MWC) curing. This study investigates alternative curing regimes that reduce production energy without compromising material properties. The impacts of air curing (AC), water curing (WC), and SC on the properties were …

Naoh Molarity Effect On Mechanical And Hydrochloric Acid Resistance Of Geopolymer Mortar Based On Slag, Mahmoud Ziada, Zahraa Mohammed Kamil Al-Mayali

Journal of Sustainable Construction Materials and Technologies

The present research investigates the influence of different sodium hydroxide (NaOH) molarities on the mechanical characteristics and hydrochloric acid (HCl) resistance of geopolymer grouts manufactured from ground granulated blast-furnace slag (GGBS). Geopolymer mortars have attracted interest as sustainable substitutes for traditional cementitious materials due to their advantageous environmental effects and enhanced durability features. This study involved the fabrication of geopolymer mortar specimens by altering the NaOH molarity (M) from 6 M to 14 M. The mechanical and physical qualities were assessed using compressive strength, capillary water absorption, flexural strength, slump flow, and ultrasonic pulse velocity (UPV) tests. Subsequently, the geopolymer …

Effect Of Expanded Perlite And Exfoliated Vermiculite Aggregate Additives On Water Vapor Permeability Performance Of Cement-Based Lightweight Mortars, Lütfullah Gündüz, Şevket Onur Kalkan

Journal of Sustainable Construction Materials and Technologies

Vapor diffusion is the movement of water vapor molecules through porous materials such as wood, insulation products, and lightweight wall elements due to differences in vapor pressure. Vapor retarders are used to control vapor diffusion through wall sections and surfaces. All building materials provide some resistance to vapor diffusion, and the amount of resistance varies depending on the material's properties. These properties can vary with relative humidity and moisture content, age, temperature, and other factors. Vapor resistance is usually expressed using the inverse term of ``vapor permeability,'' which is the relative ease of vapor diffusion through a material. Water vapor …

Rubber-Modified Self-Compacting Mortar: Evaluating Setting Time And Strength Development, Navvar Makansi, Süleyman Ipek, Erhan Güneyisi

Journal of Sustainable Construction Materials and Technologies

The influence of using crumb rubber (CR) obtained from the second scraping of used tires as fine aggregate in manufacturing self-compacting mortar (SCM) was investigated experimentally in this study. To explore this, natural fine aggregate in SCM mixes was partially replaced with CR at levels ranging from 5% to 25% by total fine aggregate volume. Two mix series, one with a total binder of 500 kg/m3 and the other with a 540 kg/m3 binder, were designed at water-to-binder ratios of 0.40 and 0.33. Ordinary Portland cement (80% by weight) and fly ash (20% by weight) were used to manufacture mortars. …

Smart Traffic Management At Intersections, Gezim Hoxha, Piotr Gorzelanczyk, Rame Likaj, Shaban Thaqi, Flori Cikaqi

Journal of Sustainable Construction Materials and Technologies

Effective traffic control methods, whether at intersections or other nodes within the road network, play a critical role in ensuring traffic quality and safety. An inappropriate choice of traffic control techniques or poorly optimized light signal programming at intersections often leads to unsatisfactory service levels. This study specifically addresses the issues related to intersections controlled by traffic lights. It aims to identify the key factors influencing the regulation and programming of traffic lights, with a focus on using different microcontrollers, particularly the Raspberry Pi. The primary objective of this research is to develop a methodology and an adapted programming approach …

Identification Of Barriers And Drivers In The Adoption Of Sustainable Construction Practices In The Turkish Construction Industry: Exploratory Factor Analysis, Tülay Çivici, Mustafa Serhan Ünlütürk

Journal of Sustainable Construction Materials and Technologies

Although the importance of sustainability in the construction industry has been emphasised by many researchers and endorsed by many authorities, it is clear that the practices in the industry still need to be improved. The primary issue for adopting sustainable practices in the construction industry is identifying the barriers and drivers. For this reason, the study analysed the literature to identify the critical barriers and incentives for adopting sustainable practices in the construction industry. In light of the information from the literature, the necessary barriers and motivators in adopting sustainable practices in the construction industry were determined, and a questionnaire …

Synergistic Effect Of Alccofine As Partial Replacement Of Cement And M-Sand As Sand Substitution In Concrete For The Assessment Of Mechanical And Microstructural Properties, Yellinedi Madhavi, R.S. Ravichandran, J. Saravanan, N. Venkatasairam Kumar

Journal of Sustainable Construction Materials and Technologies

Using supplementary cementitious materials (SCMs) and traditional binder mass has revolutionized concrete production technology in the building industry. This study examines how Alcofine-1203 affects the microstructure and mechanical characteristics of concrete. The mechanical qualities of the mixtures were evaluated using six different mixes prepared for each M25 and M40 Grade. In the proposed mixes, cement is substituted with alccofine at 0 to 25% and M-Sand as fine aggregate. The Compressive strength and ultrasonic pulse velocity were assessed after 3, 7, 14, 28, 56, and 90 days of curing, and split tensile strength and flexure strength were evaluated after 28 and …

Sustainable Modification Of Stone Column Technique With Polyethylene Terephthalate (Pet) Plastic For Strengthening The Expansive Clay, Ng Jun Shen, Muzamir Hasan

Journal of Sustainable Construction Materials and Technologies

This research investigated the modification of stone column application by the association of PET plastic as a coarse aggregate material for sustainable material replacement. Clay soil improvement with a granular material fabricated column substantially affected its soil-bearing capacity. Subsequently, it avoided severe problems such as soil settlement and structural instability. Previous studies have mentioned the function and alteration of stone columns using materials like bottom ash and fly ash. Still, no attention has been paid to the utilization of PET plastic for this area. This study examined the feasibility and reliability of materials, PET plastic, and kaolin clay S300 before …

Effect Of Reinforcement Thickness And Content On The Properties Of Compressed Earth Blocks, Salah Eddine Mokeddem, Abdelmadjid Hamouine, Rabia Abdeldjebar, Atef Hamaidi

Journal of Sustainable Construction Materials and Technologies

This study explores the mechanical, hygroscopic, and thermal behavior of stabilized and unstabilized compressed earth blocks (CEB) by incorporating date palm wood chips (DPWC) as a natural fiber additive. The investigation covers a range of DPWC thicknesses (1 mm, 2 mm, 3 mm) and content variations (0% to 1% by weight), focusing on the interaction between the bio-based reinforcement and the stabilized soil matrix, which is stabilized with 10% white Portland cement. The mixtures were compressed at a pressure of 5 MPa using a hydraulic press, providing a detailed examination of how these parameters impact the structural integrity and functional …

Hands-Free Balance Protocol And Development Of An Iphone App For Self-Assessment, Jacob Matties

Master's Theses

For many clinical populations, the measurement of balance is a critical task. Previous studies have agreed that smartphone IMUs provide a valid measure of balance that can be significantly correlated with force plate measurements and is sensitive enough to distinguish between various balance poses, but many balance assessment protocols require uncommon equipment or the use of hands during assessment. These limit accessibility of balance assessment. To eliminate the need for hands or any additional equipment, this study assessed the use of a smartphone recording the root mean square of 3D acceleration magnitude. The goal of the study was to determine …

Deciphering And Translating Bioinspired Structures For Engineering Materials Design Via Computational Modeling And Machine Learning, Zhangke Yang

All Dissertations

Nature has evolved extraordinary structural materials—such as nacre, bone, and the mantis shrimp’s dactyl club—that achieve remarkable combinations of strength, toughness, and impact resistance. These properties arise from sophisticated synergies between structure and composition. Inspired by these biological systems, this dissertation presents a comprehensive investigation into bioinspired materials, uncovering fundamental mechanisms and providing guidance on designing materials with superior mechanical properties.

This dissertation begins by examining the "brick-and-mortar" structure of nacre, which informs the design of layered polymer-graphene nanocomposite films. Using coarse-grained molecular dynamics simulations, I elucidate mechanisms of dynamic wave propagation and energy dissipation in these systems, providing critical …

Cruising On The Beach (Cob), Juan Diego Molina Ii, Ashley Kianna Burga

Biomedical Engineering

This report details the design and development process of Cruising on the Beach (COB), a modular motorized wheelchair intended to improve beach accessibility for high school students with mobility impairments. The project aimed to create an affordable, portable, and sand-capable device using balloon wheels, an adjustable control panel, and a customizable base. Extensive background research, market analysis, design modeling, and test plans were completed. However, final fabrication was not achieved due to financial constraints and limited access to industrial machining tools needed for custom metal components. Despite these setbacks, the project delivered a robust conceptual design and a fully …

Dust Analyses In Ventilation Ducts, Karolina Vyhlidalova, Petr Vlček, Olga Rubinová, Jiří Bernard

Journal of Sustainable Construction Materials and Technologies

The paper describes the importance of monitoring the dust in the atmosphere of human life. It deals with the issue of dust in air ducts, approaching the methods that can be used to detect the amount of dust. For conditions for buildings in the Czech Republic there is created the methodology of quantitative and qualitative evaluation of dust sediment for the needs of HVAC and other building surfaces. The scale for visual evaluation was created and it has been elaborated the assessment of kind of particles contained in dust.

Assessment Of Long Time Approximation Equation To Determine Thermal Conductivity Of High Porous Materials With Nss Probe, Hussein Humaish, Bastien Ruet, Laurent Marmoret, Hassen Beji

Journal of Sustainable Construction Materials and Technologies

Recent economic changes have increased the focus on energy conservation in buildings. Improve insulation represents one of the biggest challenge to save energy. The TP02 Huksefux® Non Steady State Probe (NSSP) has been used to determine the thermal conductivity of the building insulation materials. Usually, the long term approximation equation (linear form) is applied to determine the thermal conductivity when using hot wire techniques. Long term approximation has been successfully used to characterize glycerol: a fluid which doesn’t present contact resistance and porosity. But, an S-shaped appears for more porous materials. So to generalize the possibility of using this method, …

Development Of 6d Electromagnetic Actuation For Micro/Nanorobots In High Viscosity Fluids For Drug Delivery, Mostafa Abdelaziz, Maki Habib

Mechanical Engineering

This research focuses on the development, design, implementation, and testing (with complete hardware and software integration) of a 6D Electromagnetic Actuation (EMA) system for the precise control and navigation of micro/nanorobots (MNRs) in high-viscosity fluids, addressing critical challenges in targeted drug delivery within complex biological environments, such as blood vessels. The primary objective is to overcome limitations in the actuation efficiency, trajectory stability, and accurate path-tracking of MNRs. The EMA system utilizes three controllable orthogonal pairs of Helmholtz coils to generate uniform magnetic fields, which magnetize and steer MNRs in 3D for orientation. Another three controllable orthogonal pairs of Helmholtz …

Optimizing A Perfusion-Compression Bioreactor Via Python Integration, Umamah Amer

Honors Theses

Bioreactors are widely used in tissue engineering to support cell and tissue growth under controlled conditions. Perfusion-compression bioreactors, like the one developed in our lab, can be used to replicate the physiological loading of bone on 3D-printed scaffolds. When seeded with osteogenic cells and subjected to mechanical loading, these scaffolds serve as a model to study osteogenesis. To simulate physiological conditions, the bioreactor must apply 1000 compression cycles at forces up to 200 N, three times daily over 14 days. Upon implementation, validation testing and experimental studies exposed several limitations in the bioreactor’s control code. The system was initially programmed …

Bilateral Gait Trainer For Transtibial Amputees, Desmond Greer, Odinachi Anene, Andrew Wallace, Noah Hill

Bioengineering Senior Theses

Lower limb amputation affects over 2.3 million individuals in the U.S., with peripheral vascular disease and diabetes as leading causes. Prosthetic rehabilitation is critical for restoring mobility, yet barriers like therapist shortages, cost, and inconsistent at-home training limit patient outcomes. This thesis presents the design, development, and testing of a bilateral gait training device that addresses these challenges by providing real-time haptic feedback and quantitative gait metrics for at-home rehabilitation. The device integrates force-sensitive resistors embedded in insoles to monitor plantar pressure distribution, haptic actuators (eccentric rotating mass motors) mounted on thigh straps to deliver corrective feedback, and an Arduino-based …

Advancing Tka Biomechanics: From Joint Simulator To Boundary Condition Development, Yashar Ali Behnam

Electronic Theses and Dissertations

This dissertation addresses four specific aims that collectively attempted to advance the experimental and computational analysis of total knee arthroplasty (TKA) components. The first study focused on the development of a novel whole knee joint simulator capable of simultaneous tibiofemoral and patellofemoral knee loading. This simulator employs custom fixturing to facilitate dynamic, unconstrained, muscle-driven PF articulation alongside controlled TF contact mechanics. Validation against experimental measurements showed strong agreement, demonstrating the simulator's potential as a valuable tool for future TKA design and surgical technique investigations.

The second study verified implant-specific physiological boundary conditions which accurately simulate activities of daily living using …

Determinants Of Knee Motion In Health, Disease, And Repair, Sean Edward Higinbotham

Electronic Theses and Dissertations

The human knee joint is a complex and intricate structure, enabling a wide range of motions and facilitating various dynamic activities throughout a person's lifetime. The combination of the knee's complexity and its role as a primary load-bearing joint has made it susceptible to regular wear and tear, leading to pain and the development of Osteoarthritis (OA), to which, the only treatment currently is total knee arthroplasty (TKA). Despite TKA being a mature procedure, 20% of patients receiving a TKA are dissatisfied with their “new” knee. To reduce that 20% dissatisfaction and improve surgical outcomes, orthopedic companies are developing advanced …

Investigating Spatial Mapping Of Lipid And Protein Alterations Within Cells And Tissues Using Raman Microspectroscopy, Elnaz Sheikh

LSU Doctoral Dissertations

The progression of various diseases is associated with alterations in the microenvironment of cells, consisting of a variety of metabolites like lipids and proteins. It is well known that lipids and proteins are potential biomarkers for indicating alterations within the cell microenvironment induced by disease, and various methods are frequently used for their examination. To understand the chemical composition and spatial distribution of constituents in tissues and cells, confocal Raman spectroscopy and microscopy, as non-destructive tools, have shown potential for monitoring abnormalities at the cellular level with high resolution and can facilitate detection through targeting multiple biomarkers. The application of …

Emg-Based Intraoperative Neuromonitoring Using Advanced Machine Learning Approaches, Abdalla Nabil Elsharkawy, Nourhan Zayed

Mechanical Engineering

Intraoperative neuromonitoring (IONM) plays a critical role in minimizing nerve damage during surgeries by providing real-time feedback on neural integrity. This study evaluated models associated with deep learning and machine learning models for electromyography classification of signal during intraoperative neuromonitoring (IONM). The CNNLSTM model achieved the highest accuracy (85.2%), outperforming traditional models like KNN (53%), RF (62%), and CNN (76%). This demonstrates the degree to which the CNN-LSTM model can gain insight into temporal and spatial dependencies throughout the EMG signals, which makes it optimal for real-time classification in IONM applications. This implies that deep learning techniques can improve surgical …